Characterization of a Micronized Native Collagen Wound Matrix And Its Effectiveness In a Swine Full-Thickness Wound Healing Model

Introduction: Collagen-based wound dressings are widely used in both chronic and acute wound treatments. Micronized formulations of wound matrix materials are particularly valuable for treatment of exudating, irregularly shaped, or tunneling wounds. Collagen Wound Matrix-Micronized* (CWM-MZ) is a micronized purified native collagen matrix consisting of a single layer of porcine intestinal collagen that has been recently developed. In this study, CWM- MZ has been characterized to evaluate the structure and components in addition to evaluating CWM-MZ in a porcine wound healing model compared to a market leading porcine derived extracellular matrix† (CPM). Methods In vitro studies were performed to characterize CWM-MZ including particle size, DNA quantification, and histological staining. Particle size was analyzed using a Laser Light Scattering Particle Sizing Analysis (LLSPSA). DNA quantification was assessed using the Quanti-iT™ PicoGreen® assay. Structurally, the CWM-MZ micro- and nano- structure was assessed using SEM. A porcine full-thickness wound model was completed where wounds were either treated (n=36 wounds each) with CWM-MZ, CPM, or left open and covered with a secondary dressing. Local response and effects on wound healing were assessed on Days 10, 20, and 35 using clinical observations, wound measurements, and histo-pathological analysis. Results: CWM-MZ is composed of particles less than 1000 μm with a graphical average of 286 and 334 mm for wet and dry analysis, respectively. Assessments of DNA confirmed the robust decellularization process resulting in ≤ 0.016 μg/mg residual DNA. The micronization process retained native collagen structure with identifiable individual collagen fibers as well as characteristic collagen banding. In a porcine full-thickness wound healing model, there were no statistical differences observed in the surface area of the wound or the percentage healed between CWM-MZ and CPM-treated wounds. Additionally, microscopic evaluation of the wounds on days 10, 20, and 35 found no differences between treatments via histological grading. Discussion: Herein, we have described characterization of a micronized native collagen wound matrix specifically the particle size, the robust decellularization process, and the maintenance of native collagen structure. Additionally, using a porcine full-thickness wound healing model, we found that CWM-MZ performance was comparable to CPM.