(217cc) Effect Of The Incorporation Of Polyhexamethylenebiguanide (PHMB) On The Properties Of Chitosan-Alginate FILMS

The treatment of infected wounds is one of the great challenges in medicine. Therefore, the development of modern wound dressings with antimicrobial and healing activity, easy of applicability and especially low cost is still a necessity in the medical field.

PHMB (polyhexamethylenebiguanide) is considered one of the most relevant antiseptics available nowadays due to its safety and efficacy against a broad antimicrobial spectrum, including Gram-positive and Gram-negative bacteria. This germicide is used in a variety of applications, such as to prevent microbial contamination in skin wounds, contact lenses, wipes and surgical instruments.

In this work, chitosan and alginate, two natural polysaccharides, were employed to produce porous biodegradable membranes in the presence of the surfactant Pluronic F68 at 2% (m/m). PHMB was added to these membranes at 1% (m/m) to confer antimicrobial activity. The obtained membranes, containing or not PHMB, were characterized regarding its physical and chemical characteristics and release behavior of PHMB.

The results obtained indicate that PHMB can be incorporated to chitosan-alginate porous membranes without altering the membranes aspect, morphology, thickness, vapor sorption capacity, tensile strength and thermal behavior. However, vapor permeability and absorption of different aqueous solutions were increased, what was considered as a positive result in the treatment of highly exuding wounds. Negative impacts of the incorporation of PHMB were the reduction of elongation at break and of membranes stability in aqueous solutions. FTIR-ATR and FTIR-KBr analysis were not sensitive enough to indicate the presence of PHMB incorporated in the membranes, and the evaluation of PHMB release kinetics indicated that this antiseptic has a very high affinity to the chitosan and alginate matrix, due to its hydrophilic character and high electrical charge density. Based on the results of the reduced PHMB release rates to aqueous media, it can be concluded that the devices obtained can be successfully used as barriers to microbial contaminants.

The authors thank the Foundation for Science and Technology from Portugal and the São Paulo Research Foundation (FAPESP), the Coordination of Enhancement of Higher Education Personnel (CAPES) and the National Council for Scientific and Technological Development (CNPq) from Brazil for the support.