Development of a novel wound management dressing based on the combination of collagen and Manuka honey

Abstract

Wound care, is an extremely challenging field, particularly in the management of chronic hard-to-heal wounds. Nowadays a number of patients are affected by this kind of injuries, which are often associated with other common pathologies, especially diabetes or vascular issues. Chronic wounds are characterised by recurring infections, prolonged inflammation phase and high levels of proteolytic enzymes impairing the normal process of healing. A dressing that actively promotes healing and prevent infection in these difficult wounds is still required; to address this problem a novel formulation based on collagen combined with honey is presented in this work. Collagen is characterised by weak antigenicity and biodegradability. It is naturally involved in the physiological healing process and has shown some potential in the termination of the chronic state of a wound [1]. Manuka honey’s unique anti-inflammatory and anti-bacterial properties are confirmed by a very long clinical history [2]. For these reasons, their combination in the form of film dressings seems suitable for addressing chronic superficial wounds. In addition, the fabrication of collagen–fibronectin films has also been studied. Fibronectin is involved in wound repair in vivo and is also known for stabilising the fibrillary structure of collagen. A process for the production of collagen-based films has been developed. Samples were obtained by swelling and homogenisation of Bovine Type I Collagen with fibronectin or with varying amounts of Manuka honey. The resulting suspensions were dried in hydrophobic glass moulds in a convection oven at 37°C to produce the two types of film dressings (collagen-honey and collagen-fibronectin). The thermal stability, chemical composition, homogeneity, microstructure and mechanical behaviour (stiffness, strength, elongation at break, fracture energy and viscoelasticity) of the films has been extensively investigated and related to their suitability as wound dressings. The swelling behaviour and the degradation rate have been assessed using buffers at different pH values in order to simulate wounds of different depth. The degradation kinetics has also been tested in a simulated wound bed developed in this project in order to mimic more accurately the final application environment. Also, the moisture vapour transmission has been tested. In vitro studies suggest that the collagen-honey films provide good cell viability and proliferation of human skin fibroblasts and keratinocytes while inhibiting bacteria growth for Staphylococcus aureus and epidermidis. The results obtained from the characterisation of the collagen-based films suggest that they are remarkably promising for wound healing application.