Antimicrobial photodynamic and wound healing activity of curcumin encapsulated in silica nanoparticles

The multidrug resistance of pathogenic bacteria has become a serious problem to public health. Therefore finding novel approaches to combat multidrug resistant bacteria have therefore become increasingly important. One promising approach is antimicrobial photodynamic therapy (aPDT) which involves the use of photosensitizer (nontoxic dyes) that are excited by visible light and produce oxygen free radicals in the presence of oxygen. In this study, we investigated the antimicrobial photodynamic effect of free curcumin and curcumin silica nanoparticle as photosensitizer on planktonic and biofilm forms of Pseudomonas aeruginosa, Staphylococcus aureus. After performing MTT assay (to evaluate curcumin nano complex toxicity on human fibroblast cells), the effect of aPDT at 465 nm on bacteria in the planktonic and biofilm forms were investigated. The results showed that by using curcumin in the form of curcumin-silica nanoparticle as photosensitizer, there is a reduction in the number of bacteria in planktonic condition and bacterial biofilm production. Curcumin-silica nanoparticle not only did not show any significant cytotoxic effect against human normal fibroblast but also showed wound healing properties as confirmed with in vitro scratch assay. Therefore, aPDT based curcumin-silica nanoparticle could be suggested as novel approach in the treatment of multi drug resistant bacteria in chronic wound infection condition.