Biocompatibility and antimicrobial evaluation of montmorillonite/chitosan nanocomposites

Delaminated montmorillonite particles (DMtP) are novel two-dimensional nanomaterials. Chitosan (CS) is a biodegradable polysaccharide with good biocompatibility. New nanocomposites of CS and 10−104 ppm of DMtP were prepared. The good dispersion of DMtP in the CS matrix was probably a result of the charge interaction between the two components. The nanocomposites demonstrated better dynamic mechanical moduli. DMtP were found to be enriched on the surface of the nanocomposites when the amount of DMtP was > 103 ppm. This was accompanied by a decrease of the contact angle. The proliferation of fibroblasts on DMtP/CS 103 ppm was significantly greater than on other materials. The antimicrobial activity was enhanced markedly with the increased amount of DMtP in DMtP/CS. The inflammatory responses of DMtP in vitro and in subcutaneous rats were not obvious until the concentration of DMtP was > 103 ppm. The biocompatibility of DMtP/CS at 103 ppm was even better than that of CS. The biodegradation rate of CS of the DMtP/CS nanocomposite was much faster than that of the pure CS polymer. These results suggested potential antimicrobial applications for DMtP/CS nanocomposites, especially for those containing 103 ppm (0.1%) of DMtP.

► Nanocomposites from delaminated montmorillonite particles (DMtP) and chitosan (CS).
► DMtP were exposed on the surface when the amount of DMtP was > 103 ppm.
► The antimicrobial activity was enhanced markedly with the increased DMtP content.
► The biodegradation rate of the nanocomposites was much faster than that of CS.
► CS controlled the release of DMtP within the safety limit for a long term.