Investigation into the development of a gelatin-based biocomposite for wound-management

Abstract

The application of wound dressings is the most common method of wound management. In the past two decades, a novel type of wound dressing has been introduced that functions according to tissue engineering principles and provides an implantable platform for wound regeneration. The focus of this thesis was to develop such a wound dressing with multi-layer architecture that would be capable of absorbing wound exudates, be flexible with adequate contact with the wound bed, and have desirable porosity to allow cell migration. This thesis concludes with the development of a wound dressing which is comprised of three separate layers bonded together. The first layer, which would be directly in contact with the wound bed, was a gelatin scaffold of uniform porosity produced through an optimised gas foaming method. In this part of the research, in addition to optimising the gas foaming process parameters, a comprehensive comparison between applying four different crosslinking agents (glutaraldehyde, hexamethylene diisocyante, poly ether epoxide, and genipin) was carried out. The scaffolds, although showing a uniform porosity, had the tensile strength (240 kPa) lower than the reported value for natural skin (850 kPa). To strengthen the porous scaffold, a middle layer was applied and bonded to it. The middle layer with a thickness of 120m was adhered to the gelatin scaffold, functioning as a mechanical support and exudate absorbent. This layer comprised of a chitosan-gelatin composite which exhibited a tensile strength of 26 MPa. The chitosangelatin membrane bonded to the gelatin scaffold had a combined tensile strength of 644 kPa, approaching natural skin tensile properties. The wound dressing assembly was completed by applying a plasticised gelatin membrane as the third and final layer above the chitosan-gelatin composite. This membrane with a thickness of 130m, was plasticised using glycerol. It was designed with the primary function of covering the wound against debris, bacteria, and excessive manipulation, but also safeguarding the chitosan-gelatin membrane from disintegration once the wound exudate had been absorbed. The presented multi-layer design architecture provides a combination of a conventional wound dressing occlusive functionality with a modern tissue engineering approach in one product. Application of gas foaming resulted in a pore system that had an optimised porosity in comparison with commercially available wound dressings, by providing a more spherical pore system with pore size distribution closer to desirable values for skin tissue engineering (125m). It is anticipated that the design of the biomaterial would result in accelerated wound healing and reducing long term care in a cost-effective manner.

Date of Award	2015
Original language	English
Awarding Institution	University of Northampton
Supervisor	Alex Lehner (Supervisor) & Paula Antunes (Supervisor)