Engineered Bioorthogonal Nanocatalysts For Eradicated Biofilms

This work describes the Master’s Thesis project carried out at the University of Massachusetts, Amherst. The goal of this project is to create selective and effective bioorthogonal nanocatalysts for the treatment of biofilm-associated infections. The antimicrobial activity through the activation of a pro-drug using polymeric nanoparticles encapsulating hydrophobic transmission metal catalysts (TMCs) is analysed. Bioorthogonal chemistry has emerged as a promising strategy for modulating bioprocesses through reactions that cannot be achieved by natural enzymes and TMC-mediated bioorthogonal catalysis has not been previously demonstrated for the eradication of biofilms. Based on a previous work [1], the quaternary ammonium polymer (PONI-C11-TMA) is used to synthesize polymeric nanoparticles (PNPs) encapsulating iron-porphyrin [Fe(TPP)]Cl and the characterization of dimension and catalytic behaviour, performed by the in vitro activation of a resorufin-based pro-fluorophore, are carried out. Having characterized the activity of the polyzyme, the bioorthogonal catalysis in GFP-(Green Fluorescent Protein) expressing E. Coli biofilms is subsequently probed by confocal microscopy images. The ability of the polyzyme to catalyze chemical reactions in a biological environment is then exploited to activate the non-toxic pro-Moxifloxacin analysing the viability of E.Coli (CD-2) biofilms after the treatment. These preliminary studies states that these TMC-loaded polymeric nanoparticles can penetrate biofilms and perform pro-drug activation efficiently to eradicate infections. Polymer-based nano-catalysts or polyzymes feature significant innovations in structure, function and therapeutic applications. The expectation is that engineering the surface of polyzymes will provide selectivity toward biofilms compared to healthy mammalian cells, reducing side-effects. Furthermore, the ability to perform multi-drug activation will provide enhanced therapeutic efficacy. The polyzyme platform provides a modular toolkit to perform bioorthogonal reactions with precise control while maintaining high efficiency and a potentially powerful tool to combat bacterial biofilm-associated infections.