I1: Microenvironments and Nanoparticles to Quantify and Target Cancer
Chair: Nicole Moore
Chair: Shelly Peyton
- Monday AM, December 2, 2013
- Sheraton, 2nd Floor, Back Bay B
9:00 AM - I1.02
Bioderived, Self-Loading, Aptamer-Virus-Porphyrin Nanoconstructs for Targeted Photodynamic Therapy
Over the last two decades, the use of bioderived nanomaterials have gained much traction where in this field, viruses represent a unique, self-assembling multifunctional platform. Viruses have, for instance been used as biological templates, delivery vessels, and nanoscale catalysts for chemical reactions or materials synthesis. In this work we use of a virus-like particle as a multivalent platform to demonstrate vitro targeted photodynamic therapy (PDT) experiments toward breast cancer. PDT is an effective treatment for many cancer types, yet the current class of photosensitizers suffers from lack of tissue specificity, often leading to unwanted side effects. By loading photosensitizers into a targeted nanodelivery vessel, potential side effects resulting from systemic photosensitizer accumulation could be avoided. Additionally, delivering a relatively high concentration of photosensitizers in a confined nanoscale volume can increase the amount of localized singlet oxygen concentration, leading to increased PDT efficacy. In this work, nanoscale drug delivery vessels are formed via nucleotide-driven packaging of cationic porphyrins inside MS2 bacteriophage capsids, followed by attachment of G-quadruplex DNA aptamers to the capsid exterior via chemical conjugation. Prior work has demonstrated that approximately 250 porphyrins can be loaded into each capsid, and capsid-loaded porphyrins retain their capability to generate singlet oxygen upon photoexcitation with 632 nm light. The G-quadruplex DNA aptamer targets nucleolin, which is often overexpressed on the surface of many cancer cells. We show that approximately 80 DNA aptamers were conjugated to the surface of each capsid, previously loaded with the cationic porphyrin TMAP. Cell viability was assayed with the MTT assay and Live/Dead staining where targeted PDT experiments showed that MCF-7 human mammary adenocarcinoma cells were selectively killed, whereas normal human mammary epithelial MCF-10A cells remain unaffected.
9:15 AM - I1.03
Combination Delivery of Chemotherapy Drugs and RNAi Using Layer-by-Layer Nanoparticles for Cancer Treatments
Our recent studies have proposed that layer-by-layer (LbL) assembly of polyelectrolytes on nanoparticles provides a promising drug delivery system. These studies have investigated the impact of different film architectures on the nanoparticle surface, elucidating key control variables necessary to generate a serum-stable particle as well as the effect of terminal layers on the pharmacokinetics of the nanocarriers. The current work is aimed to incorporate siRNA into nanoparticles through layer-by-layer assembly. In combination with liposomal doxorubicin, this work presents a combinatorial delivery design for more efficacious treatment of cancer.
We first screened a library of both natural and synthetic polycations for optimal loading of siRNA/polycation LbL films on the nanoparticles. The physicochemical properties of these LbL nanoparticles were carefully examined, which included the size, surface charge, polydispersity, siRNA loading, film stability and N-to-P ratio. We demonstrated that incorporation of polycation-siRNA layers on nanoparticles were colloidally stable and resulted in uniform coatings, as indicated by an approximately 5 nm increase per layer in hydrodynamic size. In GFP-expressing breast cancer MDA-MB-468 cells, a dose-dependent gene silencing was seen for the candidate LbL nanoparticle. The candidates yielding minimal cytotoxicity and ideal release behavior were selected to demonstrate the systemic delivery of siRNA for TNBC targeting. In these studies, a single dose of the siRNA-loaded LbL nanoparticles that target a luciferase protein were intravenously injected into the nude mice with luciferase-expressing MDA-MB-468 cell xenografts. Five days post-injection, the treatments significantly decreased the target gene expression in the animal tumors, compared to the control of a sequence-scrambled siRNA treatment. The half life of the LbL nanoparticles was found to be 27 hours in the blood and a significant tumor accumulation effect was seen. These nanoparticles did not elicit any escalated level of inflammatory cytokines in the serum. To further assess the combination delivery, we incorporated the siRNA LbL films onto liposomes loaded with chemotherapy drugs, such as doxorubicin or cisplatin. A staggered release profile was seen for the two components in physiological buffer. A co-delivery of doxorubicin with siRNA that targets a resistance reverse gene was tested both in vitro and in vivo (subcutaneous and orthotopic xenograft) human triple negative breast cancer models. The combinatory delivery demonstrated an improved efficacy of the chemotherapy drug, compared to the single component treatment.
This work presented a novel delivery platform for combinatory therapeutics using LbL nanoparticles. This platform is easy-to-fabricate, modular and controlled for improved biostability and delivery of RNAi and chemotherapeutics. The study here also presents a potential new treatment for treat triple negative breast cancer.
9:30 AM - *I1.04
Bone Microenvironment Tissue Surrogates Engineered for Multiscale Reporting of Metastasized Breast Cancer Osteolytic Activity
Poor experimental models that recapitulate the bone metastatic environment have led to poor options for breast cancer patients with bone metastatic lesions that are usually incurable. There is also a clinical problem of patient-to-patient variability in rates of disease progression and metastasis due to differences in the cancer cells, but also in the osteoclasts recruited in the metastatic niche to assist local proteolytic remodeling necessary for osteolytic lesion establishment, primarily through secretion of cathepsin K, the most powerful human collagenase. The relative contributions of each and synergism between the two in altering the biochemical and biomechanical properties of the colonized bone are difficult to parse with animal models.
To quantify the relative contributions of breast cancer cells and osteoclasts in bone resorption, we have been developing engineered bone microenvironment tissue surrogates by adapting a poly(ester urethane) urea system embedded with microbone particles. When seeded with breast cancer cells and/or osteoclasts isolated from human subjects or cell lines, this can provide temporal, multiscale reporters of bone resorption that can be measured non-destructively: 1) collagen degradation measured by C-terminal collagen fragment release, 2) mineral dissolution by measuring calcium released with the calcium arsenazo assay, and 3) fluorogenic reporters of cathepsin activity with BODIPY-labeled extracellular matrix substrates. Additionally, osteoclast production of cathepsin K varies from patient to patient, which may be correlated with progression to metastatic disease.
This study will report differences in bone resorption by osteoclasts isolated from different patients co-cultured with and without breast cancer cells quantified using these novel multiscale biomaterials as a model system to investigate synergism between metastasized breast cancer cells and recruited osteoclasts to osteolytic lesion formation.
10:00 AM -
10:30 AM - I1.05
Detection and Treatment of Specific Cancer Cells Using Smart Nanoparticles
Developing high-performance, multifunctional nanodevices for cancer (“theranostics”) is a major direction in nanomedicine. Magnetic-plasmonic nanoparticles (NPs) have high potential for medical applications. High surface enhanced Raman scattering (SERS) signals due to suitably shaped plasmonic Au NPs can be used for biological sensing and medical imaging. On the other hand, magnetic Fe3O4 NPs can generate heat under an alternating magnetic field, enabling hyperthermia therapy. Furthermore, a thermo-sensitive material such as poly(N-isopropylacrylamide) (pNIPAm) can be used for drug delivery. Combining Au, a Raman reporter, Fe3O4, pNIPAm, drug and an antibody could form novel nanodevices with both diagnostic and therapeutic functions. HER2-positive breast cancer is a cancer that tests positive for a protein called human epidermal growth factor receptor 2 (HER2), which promotes cancer cell growth. In this investigation, drug-loaded, thermo-sensitive and magnetic-plasmonic Fe3O4@Au@pNIPAm hybrid NPs with HER2 targeting ability were developed (NP diameter: ~50 nm). HER-2/c-erbB-2/neu rabbit polyclonal antibody was conjugated to hybrid NPs for cancer cell targeting. Sensing of HER2-positive cancer cells was provided by high SERS signals that were enabled by hybrid NPs which acted as a SERS-active tag. These hybrid NPs could only be internalized by human breast cancer cells with HER2 (e.g., SK-BR-3 cells), but not by human breast cancer cells without HER2 (e.g., MCF-7 cells). Under a NIR laser or an alternating magnetic field, hyperthermia would occur, causing cancer cell death. Firstly, core-shell structured Fe3O4@Au NPs were made. A pNIPAm coating, which was incorporated with 4-MBA (a Raman reporter) and 5-Fluoroaracil (5-FU, an anti-cancer drug), was produced on Fe3O4@Au. pNIPAm had a lower critical solution temperature (LCST) of 32.3°C. In in vitro release tests, below LCST, only a small amount of 5-FU was released from hybrid NPs. At 42°C, 5-FU was released quickly from hybrid NPs. The viability of SK-BR-3 cells and MCF-7 cells after 48 hrs incubation with hybrid NPs (at various concentrations: 0 to 100 µg/mL) was examined using MTT assay. The hybrid NPs exhibited good biocompatibility even at the NP concentration of 100 µg/mL. Antibody-conjugated hybrid NPs as a stable SERS-active tag for HER2-positive cancer cells were demonstrated. SK-BR-3 cells were detected via strong SERS signals, whereas MCF-7 cells showed little SERS signals. NPs in the right size range accumulated preferentially at SK-BR-3 cells. TEM and LSCM analyses showed that hybrid NPs were successfully internalized by SK-BR-3 cells. In contrast, no cellular uptake of hybrid NPs was observed in MCF-7 cells which are HER2-negtive cells. The hybrid NPs also offered hyperthermia therapy for cancer.
10:45 AM - I1.06
Preparation and Evaluation of 5-Fluorouracil Drug Delivery System with Calcium Carbonate Nanoparticles
Targeted delivery of a cytotoxic drug is beneficial to maximize the efficacy of the drug and reduce side effects associated with its delivery. Nanoparticulate-based drug delivery systems are being developed to control the release of drugs in the body, to protect the drugs from enzymatic or chemical degradation, and to attain organ- or tissue-targeted delivery. Studies have shown that biological sources of calcium carbonate (CaCO3) nanoparticles are highly porous, biocompatible, biodegradable, and have pH-sensitive properties. Such desirable properties make CaCO3 nanoparticles one of the best candidates for biological drug delivery systems. In this research, the CaCO3 nanoparticles were derived from egg shells using sonochemical and mechanochemical methods. 5-Fluorouracil (5-FU) is a well-known anti-cancer drug, which is commonly used for several cancer therapies. 5-FU is administered subcutaneously or intravenously to patients, which results in low patient compliance. CaCO3 nanoparticles encapsulated with 5-FU were combined with other excipients to create a tablet for colonic drug delivery. To protect the tablet from premature degradation within the gastrointestinal (GI) tract, it was coated with Eudragit S100. We hypothesize that the combination of Eudragit S100 and 5-FU loaded CaCO3 nanoparticles will give the tablet a sustained release, after it reaches a pH above 7.2 in the GI tract. Dissolution studies for the tablet were tested in conditions mimicking the body, first placed into 0.1 M of HCl for two hours and then into phosphate buffered saline (PBS) for five hours at 37°C at 141 rpm. The transit time was monitored in vivo within Sprague Dawley rats and found to be radiologically undetectable after 4 hours. Results show a sustained release for 5 hours in vitro, but due to the sphincter within the rat’s stomach, the tablet was mechanically opened while trying to exit the stomach.
11:00 AM - I1.07
Double-Targeted Theranostic Nanocarriers for PDT Therapy in Brain Tumors
Therapeutic drug delivery across the blood-brain barrier (BBB) is not only inefficient but also nonspecific, thereby posing a major shortcoming in effective treatment of brain cancer. Photodynamic therapy (PDT) is a localized treatment modality, relying on both a photosensitizer and drug activation using a specific wavelength. The widespread use of PDT in brain tumor therapy has been partially hampered by non-targeted phototoxicity towards healthy tissue. The development of nanoparticles selectively targeted to cell surface receptors that can act as drug delivery vehicles is critical for improving the treatment and therapeutic responsiveness in inaccessible tumors, such as glioblastomas. Gold nanoparticles (Au NPs) provide an excellent platform with a surface that can be tailored to attach biomolecules for targeted drug delivery and biocompatible coatings that can efficiently encapsulate the hydrophobic photosensitizer drug, Pc 4, thereby reducing off-site cytotoxicity. In this study, we demonstrate a novel double targeted, noncovalent Au NP drug delivery agent, which selectively delivers drugs to brain tumors for PDT. These double-targeted Au NPs loaded with Pc 4 have been compared with previously studied single targeted Au NPs. Hydrophobic Au NPs have been cap exchanged with mono- and bi-functional PEG linkers. Specific targeting of the PEGylated Au NPs to glioma cells is achieved by coupling receptor-binding peptides to the carboxyl moiety of the bi-functional PEG linker. Subsequently, hydrophobic Pc 4 is adsorbed in the PEG corona (mono-functional linker) to form Pc 4 loaded and targeted Au NPs. Packaging of Pc 4 within the PEG core impedes leaching of the drug into the extracellular environment and improves circulation in vivo. UV-Vis absorption measurements indicate encapsulation of Pc 4 within the PEGylated Au NPs. Hydrodynamic diameter of these agents lies well within the limits needed to cross the BBB as determined by dynamic light scattering. In vitro cell uptake studies in glioma cell lines, LN229 and U87, which express differential patterns of the epidermal growth factor (EGF) and transferrin (Tf) receptor targets, show a significant increase in cellular uptake and intracellular localization for double targeted conjugates as compared to either single targeted Au NPs. Titration studies have been carried out in cells to optimize delivery; the optimal concentration for double targeted Au NPs is 500 nM, half of the current clinical standard observed for single targeted Au NPs over the same period of incubation. In vivo imaging utilizing real time, longitudinal fluorescence in mice shows notable accumulation of these agents in the tumor. Co-localization of the targeted Au NPs in regions overexpressing EGF and Tf receptors has been validated by immunohistochemistry. Future experiments involve activation of Pc 4 by PDT after delivery by the double-targeted Au NPs and monitoring tumor cell death.
11:15 AM - I1.08
Imaging Of Genetically-Engineered Primary Human T-Cells with Multi-Modal Contrast Nanoparticles
Primary human immune T cells isolated and frozen at an early healthier stage can be restored, genetically modified for specificity, selectively expanded, and administered to the patient at a later morbid stage to exert the anti-tumor response. The response to this therapy during the clinical trials, Adoptive T Cell Therapy, remains inconsistent at best. In order to improve the reliability, efficacy and safety of the clinical trials it is important to image the biodistribution of these genetically modified T cells. This can determine if the T cells are homing to their tumor targets and can be used to modulate the T-cell-based drug load. Current methods to assess biodistribution of infused T cells include serial sampling from various tissues followed by quantitative PCR (Q-PCR) or flow cytometry; which is invasive, painful, and does not provide whole-body distribution. Magnetic Resonance Imaging (MRI) has been used to image cells in vivo, it requires the approximate location of cells to be already known. We hypothesized that if T cells can be labeled with PET-MRI imaging agents, this initial positioning of cells can be provided by Positron Emission Tomography (PET) at high-sensitivity. MRI can then be used to scan these areas and report on anatomically correlated biodistribution of adoptively transferred T cells at high-resolution.
Previously frozen peripheral blood mononuclear cells were thawed and genetically modified with Sleeping Beauty transposon/transposase system to express CD19-specific chimeric antigen receptor (CAR) and firefly luciferase (ffLuc) enzyme. CD19-specific-CAR+ffLuc+ T cells were selectively expanded on artificial antigen presenting cells and labeled with super paramagnetic iron oxide nanoparticles conjugated to fluorescent probe and positron emitter (SPION-FL-64Cu). SPION retention in T cells was studied using flow cytometry and the internalization into the cytoplasm was verified using confocal microscopy. Iron content in a single T cell was determined by inductively coupled plasma mass spectrometer. Effect of SPION and 64Cu on cell viability was assessed by the ffLuc enzymatic activity. MRI signal was obtained from the series of diluted and homogenously suspended T cell phantoms. Chromium release assay and live-cell time-lapse imaging was used to assess the in vitro tumor targeting capability of CD19-specific-CAR+ffLuc+SPION+ T cells.
Our approach builds upon ongoing clinical trials for CD19+ B-cell malignancies and uses an approach that can be readily undertaken in compliance with current good manufacturing practice for Phase I/II trials.
I2: Quantitative Understanding and Treatment of Cancer
Chair: Jess Snedeker
Chair: Courtney Williams
- Monday PM, December 2, 2013
- Sheraton, 2nd Floor, Back Bay B
1:30 PM - I2.01
Simultaneous Delivery of siRNA and Anticancer Drug Using Polymeric Nanoparticles
Pridgen, Ga Young
Cisplatin and other DNA-damaging chemotherapeutics are widely used to treat a broad spectrum of malignancies. However, their application is limited by the emergence of tumor chemoresistance. Most mutations that result from DNA damage are the consequence of error-prone translesion DNA synthesis (TLS), which could thus be responsible for the acquired resistance against DNA-damaging agents. Recent studies have shown that the suppression of crucial gene products (e.g. REV1, REV3L) involved in the error-prone TLS pathway reduces the frequency of acquired drug resistance of relapsed tumors so that they remain susceptible to subsequent chemotherapy. In this context, combining conventional DNA-damaging chemotherapy with small interfering RNA (siRNA)-based therapeutics represents a promising strategy for treating patients with malignances. Towards this end, we have developed a versatile nanoparticle (NP) platform to simultaneously deliver a cisplatin prodrug and REV1/REV3L specific siRNAs to the same tumor cells. NPs are formulated through self-assembly of a biodegradable poly(lactide-co-glycolide)-b-poly(ethylene glycol) (PLGA-b-PEG) diblock copolymer and a self-synthesized cationic lipid. We demonstrated the potency of the siRNA-containing NPs to efficiently knockdown target genes both in vitro and in vivo. The therapeutic efficacy of NPs containing both cisplatin prodrug and REV1/REV3L specific siRNAs was further investigated in vitro and in vivo. qRT-PCR results showed that the NPs exhibited a significant and sustained suppression of both genes in tumors for up to 3 days after a single dose. Administering these NPs revealed a synergistic effect on tumor inhibition in an LNCaP xenograft mouse model that was strikingly more effective than platinum monotherapy.
1:45 PM - I2.02
Layer-by-Layer Functionalized Nanomedicine
Introduction: Layer-by-Layer (LbL) assembly is a highly tunable, modular approach to surface-limited functionalization of materials with nanoscale precision over the composition and properties of the film components. This high level of control affords the capability to design systems that are multi-functional in nature, with temporal and spatial control over the release of a diverse range of materials and therapeutics of interest. Application of this approach to nanomedicine has been successful in designing hydrated, protein-resistive long-circulating nanoparticles, as well as systems that shed a hydrated shell used for enhanced persistence in the bloodstream and EPR-based accumulation in the hypoxic tumor microenvironment, whereby exposure of a positively-charged material facilitates rapid uptake by tumor cells. This has driven much interest in further characterizing these systems as drug carriers, with the means to sustain drug in complex biological settings, such as the bloodstream.
Materials and Methods: Solid nanoparticles (PLGA, quantum dots) provide the foundation for LbL assembly, which is conducted via incubation of particle systems in excess polyelectrolyte materials (synthetic polypeptides, such as poly(L-lysine); glycosoaminoglycans, such as hyaluronic acid, alginate) at physiologic pH for iterative adsorption of materials on the basis of electrostatics. Encapsulating a model drug, near-IR emitting cardiogreen, in a complementary near-IR labeled LbL nanoparticle, real-time dual-tracking capabilities in vivo provided exquisite temporal and spatial resolution over the biological performance of systems generated. Multiple readouts were generated to evaluate these systems on the basis of fluorescence recovery (biodistribution, blood circulation, feces drug recovery). This approach is also being adapted to systems investigating molecular targeting in vivo, as well as multi-drug loaded nanoparticles for synergistic treatment of cancer.
Results and Discussion: Using a two-color imaging approach and IVIS whole-animal fluorescence imaging, multiple readouts regarding the stability and drug-retention capabilities of a series of LbL nanoparticles were generated. Variation on number of film bilayers and terminal layer properties were evaluated as a means of understanding the biological performance of these systems. It was found that highly hydrated, protein-resistive anionic terminal coatings, such as hyaluronic acid and alginate, significantly improve the pharmacokinetics of the drug and particle core system being used as a template for LbL. This has facilitated on-going work evaluating LbL as a means to molecularly engage cell receptors in vivo for targeted delivery, as well as programmable release of film components for staged delivery of synergistic combinations of drugs for treatment of invasive cancer types, such as triple negative breast cancer, where timing has been shown to enhance drug combination efficacy.
2:00 PM - I2.03
Orientation-Specific Attachment of Polymeric Microtubes on Cell Surfaces
The interaction of living cells with micro or nanoparticles has become more important as particles are increasingly used for drug delivery and other biomedical applications. Shape, surface chemistry and size characteristics can be designed to increase drug delivery efficiency by controlling the targeting and clearance of the synthetic particles. In particular, it has been found that the local shape of an anisotropic particle in contact with the cell determines the internalization rate of the particle. This insight drives the desire to design anisotropic particles that orient themselves on the cell surface to either promote or resist internalization depending on the desired purpose. One can imagine using the controlled interactions of anisotropic particles to form stable cell-biomaterial hybrids for drug delivery. Inspired by the use of chemically non-uniform Janus or patchy particles to control the local orientation of synthetic particles in colloid systems, we designed a tube-shaped, chemically non-uniform microparticle with the capability to control its orientation on cell surfaces.
These anisotropic microtubes were fabricated using a sacrificial membrane template method and were designed to present cell-adhesive ligands on the ends of the tubes and a cell-resistant surface on the sides. In this work the cell-adhesive region incorporated hyaluronic acid to interact with the CD44 receptor on the surface of lymphocyte B-cells and a highly swollen polyelectrolyte multilayer was chosen to resist cell adhesion. Our results show that by altering the presentation of polymer on the end versus the side we can alter the proportion of cells connecting to the end of tubes versus the side of tubes. This simple method to make anisotropic and chemically non-uniform particles is generalizable and could incorporate a wide variety of materials for potential applications in stimuli responsive presentation of cell-adhesive regions or drug release. Recent literature also has shown that the conjugation of material to the cell surface is useful for cell-mediated drug delivery and by controlling the orientation of the material on the cell surface we can better design the cellular response to the synthetic materials. This advancement opens the possibility to design new cell-biomaterial hybrids for a variety of biomedical applications.
2:15 PM - I2.04
Optimized Protocol for the Use of Thermo-Sensitive Liposome in Tumor Therapeutics
Park, Sun Min
Park, Hyun Ryoung
With concerns existing in conventional chemotherapeutic regimens such as low drug efficacy and severe systemic toxicity, the development of novel drug delivery systems (DDS) has been highly required. Nanotechnology has been employed to address the current challenges while formulating drug delivery carriers with an improvement of therapeutic efficiency by an increase of delivered drug as well as reduction of dose-limiting toxicity. Liposome is one of the nano-sized drug carriers that have been approved in clinical use. There are liposomal DDS products that have been already commercialized in tumor therapeutics, which mainly rely on the ability of passive tumor targeting via enhanced permeability and retention (EPR) effect resulting from the leaky tumor vasculature. However, a slow sustained release of drug from cumulated liposomes has not led to an impressive increase of anti-tumor efficacy. Thermo-sensitive liposomes (TSLs) have shown the ability to trigger encapsulated drugs by locally treated thermal stimuli within the region of tumor, resulting in an abrupt exposure of highly concentrated drugs to tumor tissues while TSLs pass through tumor vessels. Celsion, one of the leading groups developing TSLs for tumor therapeutics, had entered phase III of clinical trials with lysolipid-containing thermo-sensitive liposome (LTSL); however, they have ended up not meeting the primary endpoint in the clinical study. Some other studies claimed that a limitation of LTSL is possibly from a short half life and premature leakage of drugs from liposomes that led to low accumulation of bioavailable drugs. In contrast, TSL with improved stability in plasma resulted in enhanced anti-tumor efficacy. As interests upon TSL have increased along with ongoing clinical trials, there are few protocols setup for the use of TSL to treat tumors that have been established through the process optimization with a desirable heat source.
We have previously developed short chain elastin-like polypeptide incorporating thermo-sensitive liposome (STL) that has 4-times better stability than that of LTSL with high sensitivity upon thermal stimulation at the range of mild hyperthermia (42°C). In this study, we examined various approaches for the use of STL in tumor therapy. First, we optimized the protocols to obtain the largest amount of drug accumulation; namely, conditions for mild hyperthermia treatment to enhance the EPR effect, and time course analysis with lag-time after injecting STL to be accumulated in tumor tissues during systemic circulation. Second, we examined the timings of heat stimuli at tumor sites for drug-bursting while or after STLs are accumulated in tumor tissues. We also compared the efficiency of two different heat sources, a warm water bath (42°C) and high intensity focused ultrasound (HIFU) in the use of STL.
2:30 PM - I2.05
pH-Responsive Expansile Nanoparticle Mediated Delivery of Paclitaxel to Peritoneal Carcinomatosis of Pancreatic Origin
Despite recent improvements in cancer therapy, intraperitoneal (IP) carcinomatosis of pancreatic ductal adenocarcinoma origin remains a significant and unresolved therapeutic challenge with 5 year survival rates of ~5%. Treatment failure is attributed, in part, to the inability to detect and remove microscopic disease. To address this problem, hyperthermic IP chemotherapy (e.g. paclitaxel (Pax)) has been used and shown to provide a modest benefit in some peritoneal cancers (e.g. ovarian). However, toxicity of the carrier, a 50/50 mixture of Cremophor/ethanol (C/E), and rapid clearance of IP administered Pax has prevented this treatment from being curative, with patients ultimately relapsing due to residual disease. In particular, 50% of the injected Pax is cleared within 3 hours even as systemic side effects persist. Since Pax only acts during cell replication and, at any given time, only 10-15% of tumor cells are expected to be in mitosis, tumoral response to Pax is reduced due to short exposure times. In order to prolong the delivery of Pax to tumor tissues, we have designed a polymeric nanoparticle drug delivery system. Nanoparticles are frequently leveraged as drug delivery systems for their ability to encapsulate high concentrations of insoluble or readily degraded chemotherapeutic agents directly to tumor sites while minimizing systemic toxicity and adverse side effects. We have developed polymeric pH-responsive expansile nanoparticles (eNPs) that achieve intracellular delivery of hydrophobic drugs (e.g. Pax) via pH-triggered swelling in the late endosome. Acetal-protecting groups within the polymer are cleaved at mildly acidic pH resulting in a compositional change within the eNP from hydrophobic to hydrophilic resulting in infiltration of water into the nanoparticle. Hydration of eNPs, and subsequent swelling, allows Pax to diffuse out leading to intracellular delivery/accumulation of Pax and, consequently, cell death. To investigate the efficacy of Pax-loaded eNPs (Pax-eNPs), we used a human pancreatic cancer line (Panc-1) to develop cancer stem-like cells (CSCs), which more accurately mimic the increased tumorigenesis, chemotherapy- and anoikis-resistance seen clinically. Results demonstrate rapid internalization (characterized via confocal microscopy and flow cytometry) of fluorescent-rhodamine-labeled eNPs (Rho-eNPs) within a Panc-1-CSCs as well as dose-dependent cytotoxicity of Pax-eNPs against this same line. Furthermore, in vivo results demonstrate that Rho-eNPs administered intraperitoneally localize to both micro- and macroscopic tumors without the need for targeting ligands. These results suggest that eNPs may provide a useful means of delivering high doses of Pax to peritoneal carcinomatoses of pancreatic ductal carcinoma origin, thereby improving patient outcomes.
2:45 PM -
3:15 PM - *I2.06
Gradient Hydrogel Platforms to Analyze Glioma Malignancy
Pedron Haba, Eftalda
Human glioblastoma multiforme (hGBM) is a common and aggressive form of brain tumor. Biomaterials able to replicate elements of the native tumor microenvironment are a critical topic in the field of cancer research. Such a system could serve as a diagnostic platform for clinical assessment of therapeutic strategies. We have developed an adaptable hydrogel system based on methacrylated gelatin (GelMA) backbone which allows for systematic alteration of the adhesive and biophysical environment. Using this tool we have begun to explore the impact of the local matrix microenvironment on glioma malignancy using the U87MG glioma cell line. Critically, grafting brain-mimetic hyaluronic acid (HA) into the hydrogel network was found to induce significant, dose-dependent alterations of markers of glioma malignancy versus non-grafted 3D gelatin or PEG hydrogels. Clustering of glioma cells was observed exclusively in HA containing gels and expression profiles of malignancy-associated genes were found to vary biphasically with incorporated HA content. We also found HA-induced expression of MMP-2 was blocked by +EGFR signaling (a common mutation found in highly-malignant GBM tumors), suggesting a connection between CD44 and EGFR in glioma malignancy. We have now combined the GelMA hydrogel system with a microfluidic mixer to create overlapping mixtures of the multiple hydrogel precursor suspensions prior to UV-mediated photopolymerization. Using this approach we create single hydrogels containing coincident patterns of glioma-inspired cell, matrix, and biomolecular cues. We can subsequently image individual cells or cell masses via confocal microscopy as well as remove discrete regions for subsequent genomic and bioactivity analyses. Using this tool we have examined the impact of transitions across gradient hydrogels that mimic those seen across the heterogeneous glioma tumor mass (e.g., glioma core vs. periphery). Notably, gradients in matrix crosslinking density and HA incorporation induced changes in U87MG cell morphology, gene expression, and malignant phenotype as seen in disparate monolithic hydrogels. Moving forwards, we are using this tool as a brain tumor biochip to examine the impact of increasingly heterogeneous environments (incorporating additional cellular and biomolecular cues) on glioma cell malignancy with the goal of identifying linkages between biophysical environments and therapeutic efficacies.
3:45 PM - I2.07
Gold-Iron Oxide Nanoparticles for Photothermal Cancer Treatment
Hybrid plasmonic-superparamagnetic agglomerates [1,2] (less than 100 nm in diameter) consisting of multiple SiO2 -coated Au and Fe2O3 nanoparticles (~30 nm in diameter each) are made reproducibly by scalable gas-phase flame aerosol technology. By finely tuning the Au interparticle distance by the SiO2 film thickness  (or content), the plasmonic coupling of gold nanoagglomerates is closely controlled along with the optical absorption to the near-IR spectral region. The SiO2 shell facilitates dispersion and prevents the reshaping or coalescence of Au particles during laser irradiation facilitating their use multiple treatments. The effectiveness of such plasmonic nanostructures as photothermal agents is demonstrated on human breast cancer cells by near-IR laser irradiation at low power (4.9 W/cm2) and 785 nm for 4 minutes.
 Sotiriou G. A., Hirt A. M., Lozach P. Y., Teleki A., Krumeich F. and Pratsinis S. E. Hybrid, silica-coated, Janus-like plasmonic-magnetic nanoparticles. Chem. Mater. 23, 1985-1992 (2011).
 G.A. Sotiriou, Biomedical Applications of Multifunctional Plasmonic Nanoparticles. WIREs Nanomed. Nanobiotechnol. 5, 19-30 (2013).
 Sotiriou G. A., Sannomiya T., Teleki A., Krumeich F., Vörös J. and Pratsinis S. E. Non-toxic dry-coated nanosilver for plasmonic biosensors. Adv. Funct. Mater. 20, 4250-4257 (2010).
4:00 PM - I2.08
Nano Graphene Oxide - Hyaluronate Conjugate for Photo-Ablation Therapy of Melanoma Skin Cancer Using NIR Laser
Hahn, Ho Sang
Jung, Won Ho
Graphene oxide (GO) has been widely investigated for biomedical applications due to its unique physical, mechanical and optical properties. In particular, GO and reduced GO have a high photothermal effect under NIR irradiation due to their effective light-to-heat conversion compared to other carbon allotropes. Here, we report transdermal nano-sized GO (NGO) - hyaluronate (HA) conjugates for photo-ablation therapy of melanoma skin cancer using NIR laser. Melanoma is less common, but it is one of the most dangerous skin cancers and the main cause of skin cancer related death. Melanoma can infiltrate and spread deeply into the skin. To our knowledge, this is the first report to deliver NGO through transdermal pathway and treat skin cancer with NIR irradiation. The NGO-HA appeared to be transdermally delivered to the skin cancer in mice with highly expressed HA receptors and a relatively leaky structure rendering the enhanced permeation of nanoparticles. After bioimaging for the transdermal delivery of NGO-HA labeled with NIR fluorescent Hilyte 647 dye, we successfully demonstrated the photo-ablation therapy of melanoma skin cancer in mice. The anti-tumor photo-ablation effect was confirmed by ELISA for caspase-3 activity, histological analysis and immuno-histochemical TUNEL assay. Minimizing the possible side effect of NGO in the body, this system is likely to be much safer than systemic delivery systems, because NGO-HA is directly and locally accumulated in tumor tissues by the transdermal pathway. In combination with drug loading to NGO-HA by - stacking, this system can be applied for transdermal chemo- and photothermal therapy of various skin cancers.
4:15 PM - I2.09
Magnetic Nanotubes for Cellular Signal Interrogation via Nanospearing
Extraction of intracellular signal molecules is essential for interrogation of cellular pathways and characteristics. However, the extraction in live cells still remains as a significant challenge. Here our experimental results show that nanospearing could serve as a promising technique for cell interrogation. The basic idea is to conduct external magnetic field-assisted driving of magnetic nanotubes (MNTs) to penetrate cell body and carry out the molecules. The MNTs are synthesized through poly-carbonate template-assisted electrochemical deposition. Electropolymerization of a protective layer of biomaterials was used to render the surface of MNTs to be biocompatible. Under magnetic field-driving, MNTs penetrated through the cells without causing cell death. Green fluorescent protein (GFP) expressed from GFP-plasmid was used to visualize the process. During the progress of penetration, some GFP molecules entrapped in the tubes were forced out of the cells by external magnetic field. Furthermore, real-time polymerase chain reaction analysis detected β-actin mRNA and DNA in the penetrated-MNTs. These results implicate that nanospearing can extract cellular signal molecules from live cells. It could lay out a novel approach to investigate cellular pathways of pathogenesis and help to explore novel diagnosis and therapeutics of diseases.
I3: Poster Session I: Cancer I
Chair: Shelly Peyton
Chair: Nicole Moore
Chair: Courtney Williams
Chair: Jess Snedeker
- Monday PM, December 2, 2013
- Hynes, Level 1, Hall B
8:00 PM - I3.01
A Microfluidic Study of Nanoparticles in Simulated Blood Flows: Understanding the Effect of Margination
There has been a growing interest in using nanoparticles as drug delivery vehicles, especially for cancer treatment [1, 2]. Nanoparticles of different sizes and shapes have been produced from a variety of materials and the surface chemistry of these nanoparticles can be further tailored to evade the immune system and/or facilitate their selective attachment at the targeted sites. However, little is known about the flow dynamics, or rheology, of nanoparticles in blood flow, which must be understood if the nanoparticles are to be administered intravenously. Further, Decuzzi et al.  proposed theoretically that the interactions between the blood vessel walls and nanoparticles can lead to a “margination” phenomenon wherein the nanoparticles trend toward the periphery of blood vessels. The implication is a higher chance for the nanoparticles to diffuse into the tumor through the leaky vasculature typically found near tumor sites. To advance our fundamental understanding of margination, we have constructed microfluidic devices that mimic blood vessel bifurcation. Fluorescently tagged polystyrene nanoparticles of varying size and shape have been used as a model system. The trajectory of these nanoparticles has been characterized to explore the effects of flow geometry, particle size and shape, and suspending medium rheology on the margination propensity. The findings may have far-reaching implications on the rational design of nanoparticles to allow more specific delivery of anticancer drug into tumors. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1247393 and by the National Science Foundation under Grant No. 1250661. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation. This research is also supported by the Department of Defense Mentor-Predoctoral Fellow Research Award program under award number W81XWH-10-1-0434. Views and opinions of, and endorsements by the author(s) do not reflect those of the US Army or the Department of Defense.
1. Ferrari, M., Cancer nanotechnology: opportunities and challenges. Nat. Rev. Cancer, 5(3): 161-171 (2005).
2. Davis, M.E., Fighting cancer with nanoparticle medicines - The nanoscale matters. MRS Bulletin, 37: 828-835 (2012).
3. Decuzzi, P., Lee. S., Bushan, B., Ferrari, M., A theoretical model for the margination of particles within blood vessels. Annals Biomed. Eng., 33(2): 179-190 (2005).
8:00 PM - I3.02
Biocompatible Shaped Particles from Dried Multilayer Polymer Capsules
The use of particles as delivery vehicles is considered a powerful tool in the fields of biomedical imaging and drug delivery. Recently, particle shape has been recognized as an important factor in biological processes affecting particle cellular uptake and vascular dynamics. We demonstrate a simple approach to fabricate biocompatible monodisperse hollow microparticles of controlled geometry. The robust hemispherical, spherical and cubical particles are obtained by drying multilayer capsules of hydrogen-bonded poly(N-vinylpyrrolidone)/tannic acid, (PVPON/TA)n. Drying spherical capsules results in hemispherical particles if 15
8:00 PM - I3.03
Carborane-Kojic Acid Conjugate for Melanoma-Targeting Boron Neutron Capture Therapy
Metastatic and malignant melanoma remains highly lethal cancer. BNCT (boron neutron capture therapy) is single cell-selective radiation therapy for cancer. So, BNCT has been attracted great deal of attention as a potent modality for malignant melanoma. The success of BNCT depends on the boron delivery system to accumulate effectively and deeply inside the tumor cells. Clinically, Boronophenylalanine (BPA) and Sodium borocaptate (BSH) are currently used for BNCT as boron carriers. However, these compounds have some disadvantages on accumulation, water-solubility, or selectivity toward tumor tissue. On the other hand, it has been well known that kojic acid possesses a whitening ability to melanocytes by a strong tyrosinase inhibition. This fact suggests that kojic acid could work as effective ligand for melanoma-targeting. In order to construct a novel boron delivery system for melanoma-targeting BNCT, we used carborane-kojic acid conjugate (CKA). Because CKA shows little water-solubility, various cyclodexitrins were used as a solubilizer. As the inclusion complex of hydroxypropyl-β-cyclodextrin (HP-β-CD) provides the highest concentration of CKA solution, herein, the CKA/ HP-β-CD complex was estimated as boron carrier for melanoma-targeting BNCT.
Water-soluble CKA complexes were effectively prepared with HP-β-CD by using mixing with vortex-mixer. After addition of CKA/HP-β-CD to culture medium of B16BL6 (murine melanoma) and colon26 (murine colorectal cancer), relative cell viability was estimated in 24 hours. CKA/HP-β-CD shows little toxicity under 40 ppmB. Therefore, Cellular uptake and cellular distribution of CKA/HP-β-CD were evaluated within 10 ppmB. CKA/HP-β-CD was taken up more efficiently by B16BL6 than colon26. Uptake by B16BL6 was inhibited with excess kojic acid/HP-β-CD complex. These results indicate CKA/HP-β-CD possesses melanoma affinity and selectivity. Moreover, CKA/HP-β-CD was localized at nucleus in 1 hour after treatment. Therefore, CKA/HP-β-CD might perform BNCT effectively by its nuclear accumulation.
The therapeutic and antitumor efficiency of CKA/HP-β-CD were evaluated by using tumor-bearing mice implanted with B16BL6 cells. CKA/HP-β-CD and L-BPA fructose complex were injected by i.p before 1 hr of irradiation. Neutron irradiation was carried out at Kyoto University Research Reactor (5 MW, 18 min, 5.0×1012 neutron/cm2). By irradiation, proliferation and antitumor efficiency of BNCT were improved within concentration-dependent and neutron fluence-dependent. Moreover, CKA/HP-β-CD shows similar or superior tumor suppression effect to L-BPA.
In summary, CKA/HP-β-CD can deliver toward melanoma selectively and effectively. Therefore, CKA/HP-β-CD can improve the survival of the tumor-bearing mice as effective as L-BPA. This boron carrier is promising for melanoma BNCT.
8:00 PM - I3.05
Bioreducible Block Copolymers as the Carrier of Doxorubicin for Cancer Therapy
Um, Jae Hyung
Stimuli-sensitive polymeric nanoparticles have emerged as a promising carrier for triggered release of hydrophobic anticancer drugs. In this study, we synthesized a bioreducible amphiphilic diblock copolymer, composed of poly(ethyleneglycol) (PEG) and poly(γ-benzyl L-glutamate) (PBLG), bearing disulfide bond (PEG-SS-PBLG) as the potential carrier of doxorubicin (DOX). Owing to its amphiphilic nature, the amphiphilic copolymers formed nano-sized micelles (137nm in diameter) in aqueous conditions. The micelles were stable in the physiological condition (pH 7.4), whereas they were rapidly disassembled in the presence of glutathione (GSH), a thiol-containing tripeptide capable of reducing the disulfide bond. Doxorubicin (DOX), chosen as the model anticancer drug, was effectively encapsulated into the hydrophobic core of the micelle. At 10 mM GSH, DOX was completely released in 18 h from the micelles, whereas only 34% of DOX was released at 2μM GSH. Since GSH is abundant at the intracellular level, DOX-loaded PEG-SS-PBLG micelles exhibited higher toxicity to SCC7 cells than DOX-loaded PEG-b-PBLG micelles without the disulfide bond. These results suggest that the diblock copolymer bearing the bioreducible linker have potential as the carrier for the triggered intracellular drug delivery.
8:00 PM - I3.06
Leukemia Cells Detection Using Au-Nnoparticles/Jacalin Conjugates
The development of biomolecules-nanoparticles conjugates is a topic of intense and growing interest for extending the applications of nanomaterials in biomedicine. Despite the recent advances, the biomedical applications of these materials are still limited, among other factors, by the low efficiency of functionalization, low stability and high toxicity. Overcoming these obstacles requires a complete understanding of the interactions between nanomaterials and biomolecules. Here, we present the development of jacalin-conjugated gold nanoparticles (AuNPs/jacalin) for leukemia cells detection with focus on the understanding and characterization of the nanoconjugates. Jacalin is a lectin that may specifically recognize a tumor-associated disaccharide that is overexpressed in most types of human cancers. AuNPs were synthesized in presence of poly(amido amine) generation 4 (PAMAM G4) and conjugated with a jacalin targeted with the fluorescein isothiocyanate (FITC). The AuNPs/jacalin formation is driven by an entropic process with good affinity, as revealed by isothermal titration calorimetry and quenching fluorescence measurements. Moreover, in vitro tests revealed that the AuNPs/jacalin-FITC complexes presented higher affinity against leukemia cells compared to normal ones. The nanoconjugates were successfully immobilized on specific electrodes for impedimetric detection of leukemia cells. Our findings are relevant for extending the understanding of the interactions between nanomaterials and biomolecules besides of their applications in biomedicine, especially for cancer cells detection.
8:00 PM - I3.08
Gold Protruding Magnetic Nanoclusters for Magnetic Resonance Imaging Guided Photothermal Therapy
Kang, Eun Bi
Recent advances in nanomedicine have introduced a novel concept, theragnosis, to serve as a simultaneous therapeutic and diagnostic tool with the use of well-tailored nanoplatforms. This relatively new concept enables efficient delivery of therapeutic agent co-currently with real time monitoring of tumor region. Herein, we synthesized a novel gold protruding magnetic nanocomposite (GP-MNC) with the water soluble magnetic core as a magnetic resonance imaging agent and the gold protruded outer shell having optical resonance situated in near infrared (NIR) region for photothermal therapy. First, the carboxylate terminated MNCs with high saturation of magnetization were synthesized and used as a template for the seed mediated growth of gold spikes with the assistance of cetyltrimethylammonium bromide (CTAB). Increasing volumes of growth solution (2-20ml) were used for the formation of protrusions for tuning the surface plasmon resonance (SPR) in the NIR region for effective hyperthermia. CTAB layer was then replaced with monofunctional polyethylene glycol (CH3-PEG-SH) for in vivo stability of GP-MNCs. The morphology of the particles was studied by using High Resolution Transmission Electron Microscopy and the crystal structure was confirmed by X-ray diffraction. Surface chemical analysis of GP-MNCs was further evaluated by X-ray photoelectron spectroscopy. Biocompatiblity of the particles was affirmed by performing MTT assay for various GP-MNCs concentrations. To assess the potential of the as-synthesized particles for MRI guided photothermal therapy, Magnetic Resonance Imaging and in vitro/in vivo heat generation by laser irradiation against human gastric cancer cells (MKN-45 cells) were investigated. Accordingly, this study demonstrated that GP-MNCs are highly efficient MRI agents guiding effective hyperthermia effect in tumor cells, thus finding applications in clinical cancer therapies.
8:00 PM - I3.09
In Vitro and In Vivo Delivery of Anticancer Therapeutics by Protein-Coated, pH-Responsive Mesoporous Silica Nanoparticles
We have previously shown two different approaches for improving therapeutic delivery with mesoporous silica nanoparticles (MSNP): mechanized pore control and employing targeting ligands on the MSNPs. Pore control is achieved by functionalizing the silica surface with pH-sensitive nanovalves that utilize supramolecular chemistries to form host-guest complexes to block the pores. These nanovalves remain closed at physiological pH (7.4), protecting and trapping the cargo. When the MSNPs are endocytosed by cells and enter the lysosome (pH < 6), the pH-sensitive nanovalve will be activated— opening and releasing its contents to provide a stimulus-responsive and autonomous release of therapeutics. Alternatively, derivitizing the MSNP surface with biologically active molecules (e.g. folate, RGD, proteins, transferrin) causes increased cellular uptake. By integrating these two functions, a delivery system is fabricated that delivers therapeutics in a selective and controlled manner. In this work, the design and fabrication of an integrated, multifunctional mesoporous silica nanoparticle system, able to simultaneously image, target, and autonomously deliver therapeutics in vitro and in vivo is presented. The integrated, multimodal system is composed of targeting and fluorescent imaging modes, as well as pH-sensitive nanovalves that can autonomously activate and deliver cargo when exposed to pH lower than 6. Abiotic studies show the nanovalves’ ability to function under the bulky protein and release cargo. In vitro studies demonstrated the improved delivery of doxorubicin into human pancreatic cancer cells (MiaPaCa-2) due to the efficacy of the targeting agent. Finally, the operation of this system in xenografts on SCID mice was demonstrated, proving that the system is capable of functioning in an in vivo model.
8:00 PM - I3.10
NIR SERS Dots with Plasmonic Au/Ag Hollow-Shell Assemblies for In Vivo Multiplex Detection
Lee, Dae Hong
For the effective application of surface-enhanced Raman scattering (SERS) nanoprobes for in vivo targeting, the tissue transparency of the probe signals should be as high as it can be in order to increase detection sensitivity and signal reproducibility. Herein, we demonstrate near-infrared (NIR)-sensitive SERS nanoprobes (NIR SERS dots) for in vivo multiplex detection. NIR SERS dots consist of plasmonic Au/Ag hollow-shell (HS) assemblies on silica nanospheres and Raman labels. We modulate the optical properties of the HS assemblies by adjusting the HS nanostructures, which results in the red-shift of their extinction bands from 480 nm to 825 nm. The red-shifted plasmonic extinction of NIR SERS dots enables them to produce more enhanced SERS signals at NIR excitation window. Owing to the enhanced sensitivity of SERS in the NIR window, a single NIR SERS dot can produce very intense SERS signals with an average SERS enhancement factor value of 2.8×10^5. In addition, the NIR SERS dots exhibit very narrow distributions of SERS intensity with high reproducibility, which is very important for the quantitative detection of target molecules. The increased sensitivity of NIR SERS dot enables us to easily obtain SERS signals from deep tissues of up to 8-mm depth. Finally, the NIR SERS dots were successfully applied for in vivo multiplex detection by injecting them into the tissues of a live animal.
8:00 PM - I3.11
Bioreducibly Crosslinked Hyaluronic Acid/siRNA Nanocomplexes for Systemic siRNA Delivery in Tumor Treatment
Heo, Hong Yeol
Kim, Ick Chan
Kwon, Jae Hyung
The siRNA delivery systems for cancer therapy have been primarily prepared by simple, ionic complexation between negatively charged siRNA and positively charged polymers. However, their poor stability and lack of targetability have been major hurdles for successful clinical translation. To overcome these limitations, we developed the hyaluronic acid-graft-poly(dimethylaminoethyl methacrylate) (HPD) conjugate which can form biostable complexes with siRNA via disulfide crosslinking. The in vitro gel-retardation images demonstrated that the disulfide-crosslinked HPD/siRNA complexes (C-siRNA-HPD) showed higher stability than that of uncrosslinked HPD/siRNA complexes (U-siRNA-HPD) in the presence of 50 % rat serum. Both of U-siRNA-HPD and C-siRNA-HPD were efficiently taken up by the cancer cells (B16F10) over-expressing CD44 via receptor-mediated endocytosis, whereas they were not significantly internalized by normal fibroblast cells (NIH3T3). When the RFP-expressing B16F10 cells were treated with C-siRNA-HPD, U-siRNA-HPD, and free siRNA, the highest gene-silencing effect was found for C-siRNA-HPD. From the non-invasive animal imaging results, it was found that C-siRNA-HPD complexes were significantly accumulated at the tumor site after systemic administration, resulting in remarkable decrease in RFP expression in vivo. Overall, these results suggested that the HPD conjugates are promising carriers of siRNA for tumor-targeted gene therapy.
8:00 PM - I3.12
Naphthalocyanine Based Near-Infrared Photosensitizers for Photodynamic Therapy of Cancer
Photodynamic therapy (PDT) is an emerging modality for the diagnosis and treatment of various cancers and metastases.1 Recently, research efforts have been devoted to the development of near-infrared photosensitizers for the treatment of deep-seated tumors.2,3 In this work, novel hydrophilic naphthalocyanines (Nc) were synthesized by metal-templated cyclization of substituted 2, 3-dicyanonaphthalene. These Ncs have strong absorbance at long wavelengths ( 770∼780 nm); the light penetration through tissues in this region is approximately twice that of clinical used porphyrin-mediated PDT (630 nm). In addition, these Ncs can also efficiently generate singlet oxygen in DMF upon illumination with NIR light (λ= 750 ± 10 nm) with the ΦΔ value as high as 0.66, which is the best singlet oxygen quantum yield that was reported for Nc so far, indicating these Ncs are superior NIR singlet oxygen generators. The in vitro photodynamic activities were investigated against Hela cells. In the absence of light, all these compounds were not cytotoxic. Upon irradiation with red light ( ∼1J/cm2), these Ncs were highly photocytotoxic with IC50 as low as 3.7 µM. Due to their complicated synthetic procedures and poor solubility in common organic solvents, few Ncs have been reported in the biomedical area so far despite their great potential in PDT. In particular, hydrophilic Ncs remain extremely rare. Our results indicate that these novel hydrophilic Ncs have efficient photodynamic activities in NIR region, and are therefore highly promising NIR photosensitizers for PDT of cancer.
1. Chem. Rev. 1999, 99, 2379.
2. J. Am. Chem. Soc. 2008, 130, 15782.
3. J. Am. Chem. Soc. 2010, 132, 7844.
8:00 PM - I3.13
Expansile Nanoparticle-Mediated Delivery Improves the Potency of Temozolomide against Glioblastoma Cells
Glioblastoma multiforme (GBM) is a high grade astrocytoma that exhibits extreme resistance to conventional therapies and commonly recurs following resection, leading to a dismal 12-month median survival post-diagnosis. However, most GBM tumors recur within 2 cm of the original tumor site, while extracranial metastasis is extremely rare. Therefore, a highly specific and efficacious treatment that can be administered locally after tumor resection could drastically improve patient outcomes by destroying remaining tumor cells, and thereby reducing GBM recurrence. Temozolomide (TMZ) is an alkylating agent that has been shown to demonstrate efficacy as a single agent for the treatment of recurrent GBM tumors. However, TMZ undergoes rapid hydrolysis under neutral and alkaline conditions and has a half-life of only 1.24 hours. Thus there is a need for a drug delivery system that can protect and deliver high local concentrations of pharmacologically active TMZ following tumor resection. We have engineered a nanoparticle (NP) drug delivery system to meet these criteria. NPs are a unique class of therapeutics that have gained momentum in recent years. Polymeric NPs have been especially used for the delivery of anti-cancer agents due to their ability to provide controlled and sustained drug release, as well as their ability to protect encapsulated agents from degradation while simultaneously minimizing systemic toxicity. We have engineered a novel, controlled, and pH-responsive expansile nanoparticle (eNP) system which can be used for the localized delivery of TMZ to GBM tumors. eNPs undergo a conformational change under mildly acidic conditions, such as those found in the endosome and lysosome, causing the particles to swell and release their payload intracellularly. Additionally, eNPs protect TMZ from degradation, and therefore demonstrate superior potency against a standard GBM cell line (U87), with an IC50 of ~200 ng/mL—a three order of magnitude improvement over free TMZ (IC50 of ~20,000 ng/mL). We herein demonstrate the internalization of rhodamine-labeled eNPs in both GBM cancer stem cells (CSCs) and “standard” tumor cells via flow cytometric analysis and confocal microscopy. We also show that TMZ-loaded eNPs demonstrate improved, dose-dependent cytotoxicity against both cell lines in vitro.
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I3.14 TRANSFERRED TO I6.18Show Abstract
8:00 PM - I3.15
LPEI-Coated Calcium Phosphate Nanoparticles for Long Chain microRNA Delivery
Jung, Sung Young
Calcium phosphate nanoparticles (CaPNs) have received increasing attention for biomedical applications due to its excellent biocompatibility and biodegradability. However, preparation of homogeneous and nano-sized CaPNs is still challenging due to irregular particle growth at the nano-level. In this study, linear polyethylenimne (LPEI) was coated onto the CaPNs for producing the well-controlled CaPNs, which was employed as a biocompatible and efficient carrier for the delivery of therapeutic microRNA, microRNA34a (miR34a). A miR34a, which acts as a tumor suppressor in many types of solid tumors, was chemically crosslinked to produce long chain miR34a (lc-miR34a). Naked miR34a and lc-miR34a were incorporated into the LPEI-CaPNs, respectively. The particle size of LPEI-CaPNs incorporating lc-miR34a was much smaller than that of LPEI-CaPNs incorporating naked miR34a. The LPEI-CaPNs incorporating lc-miR34a were successfully internalized into cytoplasm and suppressed the cell migration and proliferation for human prostate cancer cell, PC3, in contrast to the LPEI-CaPNs incorporating naked miR34a. The LPEI-CaPNs did not show any cytotoxicity. In conclusion, it was demonstrated that the LPEI-CaPNs with long chain microRNA might be an efficient carrier systems for microRNA delivery as well as potential therapeutic effects for cancer cells.
8:00 PM - I3.16
Detection of Melanoma Cells through Gold Nano-Needles
Melanoma is one of the most threatening skin cancers which when undetected leads to fatal results. There were 76,690 new cases and 9,480 deaths in U.S. alone. Early detection of melanoma is very crucial for treatment, as well as for the prevention of the metastatic cancer. The objective of the present study was to design a novel, easy-to-use, melanoma detection method. Here, Melan-A was chosen as the biomarker for melanoma cells. Because of its unique optical-electronics properties and bio-compatibility, gold nanoparticles are used for diagnosis and delivery of drugs. In this study, we created gold nano-needles and coated them with a specific monoclonal antibody to Melan-A to detect the melanoma cells. The conjugated golden nano-needles will bind to the protein, Melan-A, on the surface of the melanoma cells, and with its optical and colorimetric properties, the conjugated golden nano needles will change color for an optical positive reading visible to the naked eye.
8:00 PM - I3.17
Multifunctional Plasmonic Nanorattles for Spectrum-Guided Locoregional Therapy
Nanotechnology holds great promise to achieve revolutionary advances in virtually all aspects of medicine including in vitro diagnostics, bioimaging, targeted and externally-triggered therapy, image-guided surgery, and regenerative medicine. Multifunctional nanostructures that enable targeted and externally-triggered delivery of therapeutic agents along with non-invasive tracking and monitoring of the therapy process are a holy grail in nanomedicne. Here we report a novel multifunctional plasmonic nanorattle that enables externally-triggered and highly localized combination therapy and non-invasive tracking of therapy process using surface enhanced Raman scattering (SERS). Nanorattles are comprised of ultrabright SERS probes with two Raman reporters, precisely engineered to track the therapy process non-invasively. We demonstrate that a combination of photothermal ablation of the plasmonic nanorattles and triggered release of chemotherapeutic drug from the nanorattles can induce locoregional death of cancer cells in vitro. The completion of therapy process is indicated as a “Raman signal flip” between the two reporters of the SERS probe. Simple yet powerful approach to non-invasively monitor the therapy process serves as a new tool for precise control over the therapy process using plasmonic nanostructures.
8:00 PM - I3.18
Hybrid Lipid-Polymer Nanoparticles for Delivery of Hydrophobic Drugs to Brain Tumors
Nanotechnology holds a great promise to overcome the current challenges in treatment of diseases such as cancer and neurological disorders by providing highly specific and efficient delivery vehicles. To date, many polymeric and lipid-based delivery systems have been developed and examined for delivery of drugs, proteins, and genes. Recently, hybrid lipid-coated polymer nanoparticles (LCPNs) that combine the advantages of biomimetic lipid membranes and solid polymeric nanoparticles have attracted a lot of attention since these vehicles offer excellent loading capacities, tunable and sustained release profiles, highly specific delivery, and outstanding serum stabilities. These LCPNs have, therefore, been explored for delivery of a number of therapeutics and vaccines to different sites of the body. In this study, we aim to develop LCPNs that enable efficient delivery of therapeutics to the brain to ultimately target brain tumors.
Many of therapeutic compounds currently used for treatment of brain cancer or neurological disorders are hydrophobic and hence, require appropriate delivery systems to effectively reach their target site. Here, we investigate the potential of LCNPs for encapsulation and release of a hydrophobic cargo, curcumin that has been applied for treatment of diseases such as cancer and Alzheimer’s disease (AD). Curcumin is a member of the ginger family and a traditional medicine in countries such as India and China. This natural compound is known to have anti-oxidant, anti-inflammation, anti-amyloid, and anti-tau hyperphosphorylation properties that make it an appealing candidate to tackle cancer and amyloidogenic diseases such as AD. The application of this compound has, however, remained limited due to its poor solubility in aqueous solutions, which in turn limits its bioavailability. In this work, we applied FDA-approved biodegradable polymer, poly (lactide-co-glycolide) acid (PLGA), to encapsulate curcumin and coated these particles with lipid membranes that would carry specific targeting ligands for efficient delivery to the brain tumors. We used nanoprecipitation technique to fabricate curcumin-loaded PLGA nanoparticles and investigated the effect of different parameters such as polymer and drug concentration on particle properties. Resultant drug-loaded nanoparticles were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We then encapsulated these nanoparticles within a lipid membrane coating, and evaluated their properties such as size and zeta potential compared to bare PLGA nanoparticles. Finally, we examined and compared the encapsulation efficacy and release profile of curcumin in PLGA and lipid-enveloped PLGA nanoparticles. These LCNPs will next be decorated with tumor-specific ligands for targeted delivery to the brain tumors. Long-term goal of this work is to employ these LCPNs for delivery of anti-cancer agents to brain tumors in vivo.