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

摘要

Wound management represents a challenging area, both in research and product development and in clinic, where patients present with an array of wound types. The global wound care market in 2015 has been estimated at over $14 billion, with antimicrobial dressings and bioengineered skin and skin substitutes accounting for over 10% and 3% of this total respectively. Infection is a common problem in wound healing, which can result in reduced healing rates, prolonged hospitalisation time and increased care costs. There is a need for active dressings able to promote healing while preventing infection in a variety of wound types. The focus of this study lies in the development of a novel collagen-honey dressing for such applications. Collagen exhibits strong biocompatibility, weak antigenicity, is biodegradable and can terminate the chronic state of a wound. Honey has been utilised for centuries as a topical ointment for wounds, and exhibits anti-inflammatory and anti-bacterial properties. Herein the combination of collagen and honey is investigated for the design of a novel bioactive wound dressing film able to actively promote healing. The films are intended to adhere and conform to the wound site and to degrade in contact with wound exudate. The fabrication process can be categorised into two stages, suspension preparation and drying. The suspension is prepared by swelling of Bovine Type Ⅰ Collagen (Sigma Aldrich) in acidic environment, followed by 1 hours homogenisation, during which Manuka Honey (Haddrell's of Cambridge) is added in different collagen/honey (C/H) weight ratios: C:H=5:1; C:H=5:2 and C:H=1:1. The resulting suspensions are poured into hydrophobic glass moulds (15cm × 7.8cm) and dried in a convection oven at 37°C to create thin films with thicknesses of approximately 15μm. The materials are characterised for degradation and swelling rate, mechanical properties and the cellular response of human skin fibroblast (BJ-ATCC CRL-2522) using AlamarBlue and colorimetric viability assays. Degradation studies performed at 37°C in saline buffers at pH levels ranging from 7.3 to 9.0 reveal that the films may have similar characteristics in different chronic wound environments. Honey accelerates degradation but all films retain their integrity for up to 7 days. The standard water absorption ranges between 4.83 and 1.88, similar to values measured for woven cotton gauze and fabric of viscose, currently used for low exudating wounds. The ultimate tensile strength of dry films is up to 10 times higher than that of wet films. However, the wet samples elongate 8 times more than the dry ones before fracture. Initial cellular work suggests that the present combinations of collagen with honey provide good cell adhesion, viability and proliferation rate compared with the control culture well. In particular, adhesion is significantly enhanced by around 100%.