Bacterial Nanocellulose Membranes for Codelivery of Carvacrol and Thymol: Physico-chemical Characterization and In vitro Studies.

INTRODUCTION: Skin wounds represent a worldwide problem. Biopolymers have been attracting interest in healthcare products for wound dressing. Among these, bacterial nanocellulose membranes (BNC) are attractive for their unique structure, but they lack antimicrobial activity. Thus, the incorporation of the monoterpenes Carvacrol (Car) and Thymol (Thy) - which present antimicrobial and healing properties - toward the improvement of skin wound healing, consists of an appealing approach. This research aimed to produce and characterize nanocellulose membranes containing carvacrol and/or thymol, and investigate their release behavior, cytotoxicity, and antimicrobial properties. METHOD: BNC/Car, BNC/Thy, and BNC/Car-Thy membranes were produced at doses of 0.1 and 1.0 mg/cm2. RESULTS: The natural components incorporation into the nanocellulose did not interfere with the ultra-structure or its physical characteristics. Pilot studies showed that membranes with 1.0 mg/cm² of monoterpenes were toxic to fibroblasts. Therefore, all further studies used the lower dose of 0.1 mg/cm². Release experiments showed a burst release between 2-4 h with sustained release till 24 h, reaching around 80% of the initial amount of the incorporated monoterpenes. Studies with fibroblast and keratinocytes indicated no cytotoxicity and that cells could proliferate over the BNC/Car- Thy membranes. Microbiological studies suggested some antimicrobial potential of the BNC doped with Car and Thy. DISCUSSION: BNC membranes incorporated with Car and Thy were successfully produced and the monoterpenes incorporation into the BNC did not interfere with either ultra-structure or with its physico- chemical characteristics. Natural products incorporation induced cell proliferation and presented antimicrobial properties, besides increasing the solubility and stability of these natural compounds. CONCLUSION: This innovative biomaterial has the potential for healthcare products.