Physical and Biological Characterisation of Collagen-Based Wound Dressings to Promote Chronic Wound Healing

Abstract

Chronic wounds pose a significant global problem, causing patient morbidity and a substantial financial burden on healthcare systems worldwide. As the prevalence of chronic wounds continues to rise, there is an urgent need for the development of therapies that can alleviate the economic and societal burden on both patients and healthcare systems. Collagen-based dressings are a large class of dressings that offer several beneficial properties for the treatment of recalcitrant wounds. Although commercially available collagen-based wound dressings vary in composition, they all have similar claims. Unfortunately, there is a lack of comparative data to differentiate between these dressings and to understand their modes of action. In collaboration with 3M Global marketing team, a comparative study including KerraMax Care outer layer as a control non-woven dressing, 3M™ Promogran™ Protease Modulating Matrix and 3M™ Promogran Prisma™ Wound Balancing Matrix (3M, Saint Paul, MN, US), and both US competitors Puracol® (Medline Industries Inc., Northfield, IL, US), ColActive® Plus (Covalon Technologies Ltd., Mississauga, Ontario, Canada), and EU synthetic competitor UrgoStart® (UrgoMedical, Chenôve, France), a dressing with similar claims to collagen-based dressings, was performed. These dressings were characterised physically and chemically using a variety of techniques such as SEM, FTIR and tensile test; and biologically via in vitro assays such as XTT and scratch assay and in a db/db mouse model, where six mice with two dorsal excisional wounds were used for each treatment group. The wounds collected from the murine model were used for histological, immunohistological analysis and gene expression via qRT-PCR. From a structural point of view, the dressings with the highest porosity induced the highest granulation tissue formation, which resulted in also high re-epithelialisation. Overall, when it comes to the induction of expression of pro-resolving mediators or the deregulation of pro-inflammatory mediators, no statistical differences linking the structural properties presented here and the in vitro and in vivo results could be seen. This underlines the need for further testing into the dressings' abilities to modulate neutrophil interactions and macrophage polarisation, deemed both essential factors when looking at the chronicity of wounds.

Date of Award	1 Aug 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Elizabeth Mann (Supervisor), Kimberly Mace (Supervisor) & Sarah Cartmell (Supervisor)