A Head-to-Head Comparison of Topical Collagen Powder to Primary Closure for Acute Full-Thickness Punch Biopsy-Induced Human Wounds: An Internally Controlled Pilot Study

Background: Collagen-based products have been implemented in wound healing due to collagen's hemostatic properties, low antigenicity, and poor culture ability. Objective: To compare the rate and quality of full-thickness wound healing for topical collagen powder and primary closure. Methods: Eight volunteers received one 4 mm punch biopsy on each thigh. One wound was managed with primary closure while the other received daily collagen powder. Wounds were biopsied at four weeks for histopathological analysis. Subjects rated itch, pain, and treatment preferences at weeks 1, 2, 4, 6, and 12. Results: Six out of eight collagen-treated wounds were completely healed 4 weeks after initial wounding. Histologic analysis of the wounds revealed epidermal re-epithelization in both groups. More organized granulation tissue was noted in collagen-treated wounds and confirmed using Masson trichrome and CD31 staining for collagen and neoangiogenesis, respectively. Subjects reported similar itch and pain metrics between wounds. Both subjects and blinded dermatologists preferred the early cosmetic appearance of collagen-treated wounds over primarily closed wounds. Limitations: Small sample size, absence of negative control. Conclusion: These data suggest that collagen powder is non-inferior to primary closure at the macro- and microscopic levels, while possibly leading to superior early cosmetic outcomes and accelerated histologic wound maturation. Ethics/Clinical Trials Registration: Study was approved by the George Washington University Institutional Review Board (IRB protocol #121745). ClinicalTrials.gov: NCT03481907. J Drugs Dermatol. 2019;18(7):667-673.

Cannabinoids: Potential Role in Inflammatory and Neoplastic Skin Diseases.

The endocannabinoid system is a complex and nearly ubiquitous network of endogenous ligands, enzymes, and receptors that can also be stimulated by exogenous compounds such as those derived from the marijuana plant, Cannabis sativa. Recent data have shown that the endocannabinoid system is fully functional in the skin and is responsible for maintaining many aspects of skin homeostasis, such as proliferation, differentiation, and release of inflammatory mediators. Because of its role in regulating these key processes, the endocannabinoid system has been studied for its modulating effects on both inflammatory disorders of the skin and skin cancer. Although legal restrictions on marijuana as a Schedule I drug in the USA have made studying cannabinoid compounds unfavorable, an increasing number of studies and clinical trials have focused on the therapeutic uses of cannabinoids. This review seeks to summarize the current, and rapidly expanding field of research on the broad potential uses of cannabinoids in inflammatory and neoplastic diseases of the skin.