Smart light-responsive polymers with antimicrobial and antibiofilm properties

Abstract

It is recognized that the development of multidrug-resistant bacteria is one of the great challenges in Modern Medicine and has brought the discussion of a post-antibiotic era. In the form of biofilm, bacteria represent an additional concern as they are the causes of chronic and recalcitrant infections. In this vein, it is necessary to develop new treatments capable of eliminating resistant bacteria mainly in the form of biofilms and preventing the possibility of a new proliferation. This project aims to develop synthetic antimicrobial polymers (PSAm) combining different polymeric segments recognized for exhibiting antimicrobial activity through different mechanisms. The new PSAms will potentially (i) prevent biofilm formation; (ii) disrupt the cytoplasmic membrane; and (iii) act as biocide via a photodynamic mechanism. For this, the antibiofilm effects of the poly(2-lactobionamidoethyl methacrylate) will be combined with the capability of the poly(2- (dimethylamino) ethyl methacrylate) to induce interactions and cause damage to the cytoplasmic bacterial membrane and with the effects of the poly(curcumin diacrylate) which will impair the light-responsive properties and promote photodynamic inactivation of the bacteria. The polymers will be obtained via chain transfer polymerization by Reversible Addition-Fragmentation (RAFT), following the arm-first methodology that allows to obtain highly star-like (co)polymers, which exhibit higher antimicrobial activity than the linear analogs. The antimicrobial effects will be evaluated against Escherichia coli and Staphylococus aureus, pathogens which represent the biggest dilemmas for the discovery of new therapies. (AU)