A novel use for the biodegradable temporizing matrix

Analysis of the Radial Forearm Phalloplasty Donor Site: Do Dermal Matrices Improve Donor Site Morbidity?

Background

The radial forearm free flap is frequently chosen for phalloplasty; however, flap size required for phalloplasty is associated with a large scar burden and functional concerns. We sought to investigate donor site functionality, aesthetics, and volume deficits in a cohort of individuals who underwent radial forearm phalloplasty (RFP) with donor site skin grafting alone or dermal substitute and subsequent skin grafting.

Methods

Donor site functionality was assessed using the quick Disabilities of Arm, Shoulder, and Hand (qDASH). Patient- and clinician-reported aesthetics were assessed using the Patient and Observer Scar Assessment Scale (POSAS). An Artec Leo three-dimensional scanner was used to measure volumetric differences from the donor site forearm and contralateral forearm.

Results

Fifteen patients who underwent RFP agreed to participate. No statistically significant differences were identified between different donor site closure methods regarding qDASH, patient-reported POSAS, or total volumetric deficits. A blinded clinician reported that POSAS approached significance at 4.7 for biodegradable temporizing matrix (BTM), 4.2 for Integra, and 3.0 for split-thickness skin graft (P = 0.05). No statistically significant differences were identified regarding distal, middle, or proximal volume deficits; however, a trend was observed regarding total volumetric deficits with BTM experiencing the lowest deficit (10.3 cm3) and skin graft experiencing the highest deficit (21.5 cm3, P = 0.82).

Conclusions

The addition of dermal matrix (BTM or Integra) to the treatment algorithm for RFP did not show statistically significant improvement in donor site volume deficits, patient-reported scar appearance (POSAS), or functionality (qDASH).

A potential bilayer skin substitute based on electrospun silk-elastin-like protein nanofiber membrane covered with bacterial cellulose

Skin substitutes are designed to promote wound healing by replacing extracellular matrix. Silk-elastin-like protein is a renewable extracellular matrix-like material that integrated the advantages of silk and elastin-like protein. In this study, electrospun silk-elastin-like protein (SELP) nanofiber membrane covered with bacterial cellulose (BC) was created as a potential skin substitute to mimic gradient structure of epidermis and dermis of skin. The two layers were glued together using adhesive SELP containing 3,4-dihydroxyphenylalanine (DOPA) converted from tyrosine by tyrosinase. Skin topical drugs commonly used in clinical practice can penetrate through the SELP/BC barrier, and the rate of penetration is proportional to drug concentration. BC with dense fibrous structure can act as a barrier to preserve the inner SELP layer and prevent bacterial invasion, with a blocking permeation efficiency over 99% against four species of bacteria. Cell experiments demonstrated that the reticular fibers of SELP could provide an appropriate growth environment for skin cells proliferation and adhesion, which is considered to promote tissue repair and regeneration. The promising results support this strategy to fabricate a silk-elastin-like protein-based biomaterial for skin substitutes in the clinical treatment of full skin injuries and ulcers.

Engineering edgeless human skin with enhanced biomechanical properties

Despite the advancements in skin bioengineering, 3D skin constructs are still produced as flat tissues with open edges, disregarding the fully enclosed geometry of human skin. Therefore, they do not effectively cover anatomically complex body sites, e.g., hands. Here, we challenge the prevailing paradigm by engineering the skin as a fully enclosed 3D tissue that can be shaped after a body part and seamlessly transplanted as a biological clothing. Our wearable edgeless skin constructs (WESCs) show enhanced dermal extracellular matrix (ECM) deposition and mechanical properties compared to conventional constructs. WESCs display region-specific cell/ECM alignment, as well as physiologic anisotropic mechanical properties. WESCs replace the skin in full-thickness wounds of challenging body sites (e.g., mouse hindlimbs) with minimal suturing and shorter surgery time. This study provides a compelling technology that may substantially improve wound care and suggests that the recapitulation of the tissue macroanatomy can lead to enhanced biological function.

Treatment of Complex Wounds with NovoSorb® Biodegradable Temporising Matrix (BTM)-A Retrospective Analysis of Clinical Outcomes

Complex and chronic wounds represent a highly prevalent condition worldwide that requires a multimodal and interdisciplinary treatment approach to achieve good functional and aesthetic outcomes. Due to increasing costs of health care, an aging population and an increase in difficult-to-treat microbial colonization of wounds, complex wounds will become a substantial clinical, social and economic challenge in the upcoming years. In plastic reconstructive surgery, a variety of dermal skin substitutes have been established for clinical use. Since its approval as a dermal skin substitute in Germany, NovoSorb^® Biodegradable Temporising Matrix (BTM) has become a valuable therapeutic option for the treatment of full-thickness wound defects. The clinical data published to date are limited to case reports and small-scale case series with the main focus on single wounds. The aim of this single-center study was a retrospective analysis of our own patient collective that has received treatment with BTM for complex wounds. Overall, BTM showed to be a reliable and versatile reconstructive option, especially for patients with multiple co-morbidities and microbiologically colonized wounds. Although the preliminary findings have produced promising results, further investigation and research are warranted regarding long-term outcomes and additional clinical applications.