The Combination of Minced Autologous Tissue and Micronized Collagen-Chondroitin-Sulfate Accelerates Skin Wound Healing in a Porcine Model

Background - The growing demand for cell and tissue-based products, rich in growth factors, multiple cell types, and extracellular matrix, stems from their ability to accelerate the wound healing process. An autologous source of tissue contains regenerative properties for patients without the risk of immunogenicity. However, limitations reside in the quantity of harvestable tissue and donor site morbidities.

This study investigates the use of micronized collagen-chondroitin-sulfate (MCCS) matrix reconstituted with saline as an extender to minced skin graft in the treatment of full-thickness skin defects.

Methods - Sixteen 2cm diameter full-thickness skin wounds were created in a Yorkshire pig. Full-thickness autologous skin was harvested from the flank and roughly minced with sterile scissors. Approximately 15% of the weight of the excised wound was replaced with one of the following treatments: (a) minced full-thickness skin grafts (b) minced full-thickness skin grafts + MCCS (c) MCCS alone (N=4/group) or (d) untreated.  Dressing changes and wound images were captured every 3-4 days, and tissues were harvested at 10 days for histological analysis.

Results - At Day 10, the granulation bed in the untreated group was composed of a continuous layer of maturing dense collagen consistent with contractile tissue. Semi-quantitative scoring reveals the two groups containing minced full-thickness skin grafts yielded the highest quality dermal tissue and a 2x faster reepithelialization than the untreated group while also breaking up and interrupting contractile tissue formation. The MCCS alone group also had high-quality dermal tissue formation due to the interruption of contractile tissue formation, but reepithelialization and epidermal thickness were limited when compared to the groups treated with minced full-thickness skin grafts. Groups containing MCCS and/or minced full-thickness skin grafts maintained a 3-fold improvement in dermal tissue quality over the untreated control.

Conclusions - Results suggest that MCCS can be successfully used to supplement autologous tissue to allow for the reduction in donor site harvest area and the disruption of contractile tissue formation. This study suggests that the combination of autologous minced tissue with MCCS provides a synergistic effect in the regeneration of high-quality skin tissue and faster reepithelialization while minimizing donor site morbidities.