Shelly Peyton, University of Massachusetts
Nicole Moore, National Cancer Institute
Jess Snedeker, University and ETH Zurich
Courtney Williams, Regeneron Pharmaceuticals
Symposium Support NCI
Regeneron Pharmaceuticals Inc.
Royal Society of Chemistry
I2: Quantitative Understanding and Treatment of Cancer
Monday PM, December 02, 2013
Sheraton, 2nd Floor, Back Bay B
2:30 AM - I2.01
Simultaneous Delivery of siRNA and Anticancer Drug Using Polymeric Nanoparticles
Xiaoyang Xu 1 2 Kun Xie 2 Xueqing Zhang 1 2 Eric Pridgen 2 Ga Young Park 2 Stephen Lippard 2 Robert Langer 2 Graham Walker 2 Omid Farokhzad 1
1Harvard Medical School Boston USA2Massachusetts Institute of Technology Boston USAShow Abstract
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.
2:45 AM - I2.02
Layer-by-Layer Functionalized Nanomedicine
Stephen Morton 1 2 Zhiyong Poon 2 Zhou Deng 2 Nisarg Shah 1 2 Michael Lee 2 3 Erik Dreaden 2 Mohiuddin Quadir 2 Kevin Shopsowitz 2 Michael Yaffe 2 3 Paula Hammond 1 2
1Massachusetts Institute of Technology Cambridge USA2Massachusetts Institute of Technology Cambridge USA3Massachusetts Institute of Technology Cambridge USAShow Abstract
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.
3:00 AM - I2.03
Orientation-Specific Attachment of Polymeric Microtubes on Cell Surfaces
Jonathan B Gilbert 1 Janice S O'Brien 2 Harini S Suresh 2 Robert E Cohen 1 Michael F Rubner 2
1Massachusetts Institute of Technology Cambridge USA2Massachusetts Institute of Technology Cambridge USAShow Abstract
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.
3:15 AM - I2.04
Optimized Protocol for the Use of Thermo-Sensitive Liposome in Tumor Therapeutics
Jae Min Cha 1 Eun-Jung Choi 1 Sang-Jun Park 1 Sun Min Park 1 Eun-Sung Park 1 Hyun Ryoung Kim 1
1Samsung Advanced Institute of Technology Yongin-Si, Gyeonggi-Do Republic of KoreaShow Abstract
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.
3:30 AM - I2.05
pH-Responsive Expansile Nanoparticle Mediated Delivery of Paclitaxel to Peritoneal Carcinomatosis of Pancreatic Origin
Aaron Colby 1 Nelson Ruiz-Opazo 2 Glaiza A. Tan 2 Victoria Herrera 2 Mark W. Grinstaff 1
1Boston University Boston USA2Boston University School of Medicine Boston USAShow Abstract
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.
4:15 AM - *I2.06
Gradient Hydrogel Platforms to Analyze Glioma Malignancy
Sara Pedron Haba 1 Eftalda Becka 2 Brendan Harley 1 2
1University of Illinois at Urbana-Champaign Urbana USA2University of Illinois at Urbana-Champaign Urbana USAShow Abstract
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.
4:45 AM - I2.07
Gold-Iron Oxide Nanoparticles for Photothermal Cancer Treatment
Georgios Sotiriou 1 2 Fabian Starsich 2 Sotiris E. Pratsinis 2
1Harvard University Boston USA2ETH Zurich Zurich SwitzerlandShow Abstract
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).
5:00 AM - I2.08
Nano Graphene Oxide - Hyaluronate Conjugate for Photo-Ablation Therapy of Melanoma Skin Cancer Using NIR Laser
Sei Kwang Hahn 1 Ho Sang Jung 1 Won Ho Kong 1 Min-Young Lee 1
1Pohang University of Science and Technology (POSTECH) Pohang Republic of KoreaShow Abstract
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.
5:15 AM - I2.09
Magnetic Nanotubes for Cellular Signal Interrogation via Nanospearing
Zhen Yang 1 2 Dong Cai 1 Zhonghong Gao 2 Zhifeng Ren 1
1University of Houston Houston USA2Huazhong University of Science and Technology Wuhan ChinaShow Abstract
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
Monday PM, December 02, 2013
Hynes, Level 1, Hall B
9:00 AM - I3.01
A Microfluidic Study of Nanoparticles in Simulated Blood Flows: Understanding the Effect of Margination
Erik Carboni 1 Grant Bouchillon 2 Leslie Shor 1 3 Suzy Torti 4 Anson Ma 5
1University of Connecticut Storrs USA2University of Connecticut Storrs USA3University of Connecticut Storrs USA4University of Connecticut Farmington USA5University of Connecticut Storrs USAShow Abstract
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).
9:00 AM - I3.02
Biocompatible Shaped Particles from Dried Multilayer Polymer Capsules
Veronika Kozlovskaya 1 Jun Chen 1 Mohammad Saeed 2 Eugenia Kharlampieva 1
1University of Alabama at Birmingham Birmingham USA2Southern Research Institute Birmingham USAShow Abstract
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
9:00 AM - I3.03
Carborane-Kojic Acid Conjugate for Melanoma-Targeting Boron Neutron Capture Therapy
Riku Kawasaki 1 Koji Ono 2 Shin-ichiro Masunaga 2 Yosinori Sakurai 2 Mitsunori Kirihata 3 Takeshi Nagasaki 1
1Osaka City University Osaka Japan2Kyoto University Kumatori Japan3Osaka Prefecture University Sakai JapanShow Abstract
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.
9:00 AM - I3.05
Bioreducible Block Copolymers as the Carrier of Doxorubicin for Cancer Therapy
Hyewon Ko 1 Thavasyappan Thambi 2 Wooram Um 2 Jae Hyung Park 1 2
1Sungkyunkwan University Suwon Republic of Korea2Sungkyunkwan University Suwon Republic of KoreaShow Abstract
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 2mu;M 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.
9:00 AM - I3.06
Leukemia Cells Detection Using Au-Nnoparticles/Jacalin Conjugates
Valeria Spolon Marangoni 1 Juliana Cancino 1 Valtencir Zucolotto 1
1University of Sao Paulo Samp;#227;o Carlos BrazilShow Abstract
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.
9:00 AM - I3.08
Gold Protruding Magnetic Nanoclusters for Magnetic Resonance Imaging Guided Photothermal Therapy
Aastha Kukreja 1 Eun-Kyung Lim 2 Jihye Choi 1 Eunji Jang 1 Hyun-Ouk Kim 1 Byunghoon Kang 1 Eun Bi Choi 1 Yong-Min Huh 2 Seungjoo Haam 1
1Yonsei University Seoul Republic of Korea2Yonsei University Seoul Republic of KoreaShow Abstract
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.
9:00 AM - I3.09
In Vitro and In Vivo Delivery of Anticancer Therapeutics by Protein-Coated, pH-Responsive Mesoporous Silica Nanoparticles
Angela Hwang 1 Jie Lu 2 Fuyuhiko Tamanoi 2 Jeffrey Zink 1
1UCLA Los Angeles USA2UCLA Los Angeles USAShow Abstract
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.
9:00 AM - I3.10
NIR SERS Dots with Plasmonic Au/Ag Hollow-Shell Assemblies for In Vivo Multiplex Detection
Homan Kang 1 Sinyoung Jeong 2 Joonhyuk Yim 3 San Kyeong 3 Jin-Kyoung Yang 3 Jong-Ho Kim 5 Ho-Young Lee 4 Dae Hong Jeong 2 1 Yoon-Sik Lee 3 1
1Seoul National University Seoul Republic of Korea2Seoul National University Seoul Republic of Korea3Seoul National University Seoul Republic of Korea4Seoul National University Bundang Hospital Seongnam Republic of Korea5Hanyang University Ansan Republic of KoreaShow Abstract
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.
9:00 AM - I3.11
Bioreducibly Crosslinked Hyaluronic Acid/siRNA Nanocomplexes for Systemic siRNA Delivery in Tumor Treatment
Roun Heo 1 Hong Yeol Yoon 2 3 Wooram Um 3 Kwangmeyung Kim 2 Ick Chan Kwon 2 Jae Hyung Park 1 3
1Sungkyunkwan University Suwon Republic of Korea2Korea Institute of Science and Technology Seoul Republic of Korea3Sungkyunkwan University Suwon Republic of KoreaShow Abstract
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 t