Probing the effects of chitosan-based membranes with different molecular weights on their biocompatibility and antimicrobial activity

Chitosan is a polysaccharide widely used in biomedical applications due to its bioactivity, which can be modulated by its structural characteristics. Among these, molecular weight is one of those that most influences its action. In this context, this study aimed to evaluate the bioactivity of membranes formed by high (HMWChi) and low (LMWChi) molecular weight chitosans and associated with turmeric (HMWChi/Tur and LMWChi/Tur), produced by the casting technique. The membranes were characterized physicochemically and morphologically. Its bioactivity was evaluated through the inhibition halo formed on bacterial strains and verifying its biocompatibility in fibroblast cell lines (L929), performed by alamarBlue® (Metabolic activity/viability) and PicoGreen assays (DNA proliferation). Self-supporting and homogeneous membranes were obtained. FTIR spectra show the main vibrational bands for the chemical groups of chitosan and contact angle results show that turmeric-containing membranes are more hydrophilic than pure chitosan. The presence of the inhibition halo was observed in both bacterial cultures for all membranes, with LMWChi and LMWChi/Tur showing a greater inhibitory effect. The membranes produced did not present a cytotoxic effect, as they induced an increase in cell proliferation. In general, LMWChi/Tur provided greater cell proliferation, suggesting that low molecular weight chitosan is the most promising material for application as dressings.