Photodynamic antibacthrial activity 0f natural photosensitizhrs in Combination with nanomaterials Against multidrug reisistant Organisms isolated from chronic Wounds

Abstract

The major hurdle of wound management and therapy are bacterial and fungal infection. Untreated infection leads to delayed healing and sepsis, which in worst case may lead to mortality. Prophylactic use of antibiotics in an inappropriate manner has led to the emergence of resistance among pathogens and this is anticipated to have adverse impact on human kind which might face premature deaths of 300 million people by 2050. Conventional antimicrobials are ineffective against fast growing planktonic cells and adhered biofilm. Antimicrobial photodynamic therapy (PDT) using natural photosensitizer (PS) is a potential alternative method to antibiotics for treating microbial infections and eliminating bacterial biofilms. PDT aims at eradication of the infectious organisms by employing a light source to illuminate a PS and further initiate generation of reactive oxygen species (ROS) by the excited PS which helps to kill the infectious organisms. So far the efficacy of various synthetic PS has been broadly investigated by various researchers. Commercial synthetic PS such as photofrin, visudyne and LS11 can cause allergic response and hence cannot be used in children and pregnant women. In present study, a new approach was adopted to deliver natural PS viz such as curcumin and phycocyanin in the form of encapsulated chitosan nanoparticles (CNPs) that were tested against planktonic cells and biofilm forming multi drug resistant organisms. Several previous reports have studied strains of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) that have shown resistance to antibiotics. These two strains of bacteria were isolated from patients with chronic wounds using standard procedure. The antibiotic susceptibility profiles of bacteria were assessed using different classes of antibiotics. Our study used CNPs encapsulated with curcumin and phycocyanin towards wound healing process that were synthesized by ionic gelation method. CNPs encapsulated with PS were characterized by SEM, TEM, UV-Visible analysis, FT-IR, XRD and TGA newline newline newline