Development and analysis of the properties of chitosan and alginate membranes containing polyhexamethylene biguanide for the treatment of skin lesions

Author(s)

Cecília Zorzi Bueno

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2015-02-24

Examining board members

Angela Maria Moraes; Ana Paula Rodrigues; Ana Silvia Prata; Lucimara Gaziola de la Torre; Rossana Mara da Silva Moreira Thiré

• Advisor: Angela Maria Moraes; Mara Elga Medeiros Braga

Abstract

Skin lesions represent a great challenge for health professionals, since most of the existing modern wound dressings are imported and expensive. Therefore, there is a need to create more accessible products to the public, made from renewable raw materials and processed through simple and low cost technologies. Chitosan and alginate are biocompatible biopolymers that have healing properties and are abundant in nature, which are attractive characteristics to the production of wound dressings. The incorporation of antimicrobial agents, such as polyhexamethylene biguanide (PHMB), to these dressings can lead to a better performance. In this work, dense and porous chitosan-alginate membranes were obtained in the presence of different proportions of the surfactant Pluronic F68. It was noticed that inclusion of up to 10% (w/w) Pluronic F68 caused an increase in porosity (from 0.46 to 0.84), thickness (from 0.08 to 0.50 mm), roughness (from 1.27 to 21.20 µm), fluids absorption capacity (from 14.22 to 21.27 g/g for 0.9% NaCl) and water vapor absorption capacity (from 15.5 to 36.5%) and a decrease in tensile strength (from 31.1 to 1.1 MPa) and elongation at break (from 4.0 to 2.0%) of the membranes. The obtained materials were not toxic to mouse fibroblasts. The antimicrobial agent PHMB was incorporated to the membranes through three different methods: addition to the polymeric mixture, adsorption in aqueous solution and via supercritical fluid. The addition to the polymeric mixture was considered the most promising incorporation method, since it had high yields (between 72 and 86 %) and did not cause changes in the membranes aspect and morphology. Release kinetic studies in PBS showed that most of the PHMB loaded remained in the membranes, indicating high affinity between PHMB and the polymeric matrix. The obtained membranes showed adequate antimicrobial activity, having potential applicability as barriers against microorganims commonly found in skin wounds, such as Staphylococcus aureus and Pseudomonas aeruginosa (AU)

• FAPESP's process: 09/17755-9 - Porous chitosan-alginate membranes containing polyhexamethylene biguanide as a novel wound dressing
• Grantee: Cecilia Zorzi Bueno
• Support Opportunities: Scholarships in Brazil - Doctorate