Light-Responsive Unique Plasmonic Nanomaterials Conjugated with Bioorthogonal Catalysts for Theragnostics

Any chemical reaction which occurs inside the living system without interference from the biochemical reaction, so-called a bioorthogonal reaction, can be a new powerful strategy to manipulate the biological system.¹ To achieve the bioorthogonal reaction, the selection of bioorthogonal catalyst is important, which provide a platform for the changing of substrates to activated species, such as drug, photosensitizers, and fluorescent.¹ Especially, palladium (Pd) is the highly efficient catalyst for the bioorthogonal reaction of prodrugs and pro-fluorophores, however, the intrinsically insufficient catalytic activities have restricted their biological <i>in vivo</i> application.² Herein, we introduced the unique light-responsive plasmonic nanomaterials conjugated with the palladium as bioorthogonal nanocatalysts for combinatorial photothermal and photodynamic cancer treatment along with tumor imaging. The light can modulate the catalytic performance of these bioorthogonal nanocatalysts in terms of LSPR induced hot carrier generation, local field enhancement, and heat, which in return, would enhance the bioorthogonal nanocatalysts activities for cleavage reaction, and generate more activated photosensitizer from pro-photosensitizer at the given condition. The pro-photosensitizer conversion experiments with our hybrid bioorthogonal nanocatalysts under light illumination showcased the significant enhancement of conversion efficiency, confirming the enhancement of bioorthogonal reaction efficiency by using plasmonic features. In addition, the photothermal effect was incorporated to achieve synergistic photothermal and photodynamic therapy. Taken together, our bioorthogonal nanocatalysts open up a new paradigm to achieve an efficient bioorthogonal reaction to treat cancer.<br/><b>References</b><br/>[1] E. Latocheski; G.M. D. Forno; T. M. Ferreira; B. L. Oliveira; G. J. L. Bernardes and J. B. Domingos, <i>Chem. Soc. Rev.</i>, <b>2020</b>, <i>49</i>, 7710-7729.<br/>[2] M. A. Miller; B. Askevold; H. Mikula; R. H. Kohler; D. Pirovich and R.Weissleder, <i>Nat. Commun.</i>, <b>2017</b>, <i>8</i>, 15906.<br/> <b>KEYWORDS: </b>bioorthogonal catalyst, deallylation, plasmonic effect, photodynamic therapy, photothermal therapy