Efficacy and safety of external tissue expansion technique in the treatment of soft tissue defects: a systematic review and meta-analysis of outcomes and complication rates

Mechanical force regulates the paracrine functions of ADSCs to assist skin expansion in rats

BACKGROUND

In the repair of massive tissue defects using expanded large skin flaps, the incidence of complications increases with the size of the expanded area. Currently, stem cell therapy has limitations to solve this problem. We hypothesized that conditioned medium of adipose-derived stem cells (ADSC-CM) collected following mechanical pretreatment can assist skin expansion.

METHODS

Rat aortic endothelial cells and fibroblasts were cultured with ADSC-CM collected under 0%, 10%, 12%, and 15% stretching force. Ten-milliliter cylindrical soft tissue expanders were subcutaneously implanted into the backs of 36 Sprague-Dawley rats. The 0% and 10% stretch groups were injected with ADSC-CM collected under 0% and 10% stretching force, respectively, while the control group was not injected. After 3, 7, 14, and 30 days of expansion, expanded skin tissue was harvested for staining and qPCR analyses.

RESULTS

Endothelial cells had the best lumen formation and highest migration rate, and fibroblasts secreted the most collagen upon culture with ADSC-CM collected under 10% stretching force. The skin expansion rate was significantly increased in the 10% stretch group. After 7 days of expansion, the number of blood vessels in the expanded area, expression of the angiogenesis-associated proteins vascular endothelial growth factor, basic fibroblast growth factor, and hepatocyte growth factor, and collagen deposition were significantly increased in the 10% stretch group.

CONCLUSIONS

The optimal mechanical force upregulates specific paracrine proteins in ADSCs to increase angiogenesis and collagen secretion, and thereby promote skin regeneration and expansion. This study provides a new auxiliary method to expand large skin flaps.

A comprehensive review of the application of 3D-bioprinting in chronic wound management

INTRODUCTION

Chronic wounds require more sophisticated care than standard wound care because they are becoming more severe as a result of diseases like diabetes. By resolving shortcomings in existing methods, 3D-bioprinting offers a viable path toward personalized, mechanically strong, and cell-stimulating wound dressings.

AREAS COVERED

This review highlights the drawbacks of traditional approaches while navigating the difficulties of managing chronic wounds. The conversation revolves around employing natural biomaterials for customized dressings, with a particular emphasis on 3D-bioprinting. A thorough understanding of the uses of 3D-printed dressings in a range of chronic wound scenarios is provided by insights into recent research and patents.

EXPERT OPINION

The expert view recognizes wounds as a historical human ailment and emphasizes the growing difficulties and expenses related to wound treatment. The expert acknowledges that 3D printing is revolutionary, but also points out that it is still in its infancy and has the potential to enhance mass production rather than replace it. The review highlights the benefits of 3D printing for wound dressings by providing instances of smart materials that improve treatment results by stimulating angiogenesis, reducing pain, and targeting particular enzymes. The expert advises taking action to convert the technology's prospective advantages into real benefits for patients, even in the face of resistance to change in the healthcare industry. It is believed that the increasing evidence from in-vivo studies is promising and represents a positive change in the treatment of chronic wounds toward sophisticated 3D-printed dressings.

Continuous External Tissue Expansion for Closure of Forehead Flap Donor Site

Continuous external tissue expansion has been shown to be effective in the management of craniofacial wounds resulting from tumor resection, trauma, and wound dehiscence. Forehead flap donor sites are typically managed with secondary intention healing. However, this can create esthetic problems in pigmented skin because of the tendency to form thick scars. Here, the authors describe the use of continuous external tissue expansion for the management of a paramedian forehead flap donor site. A Dermaclose device was used at the time of forehead flap elevation and removed at the pedicle division and inset. Sufficient skin expansion was achieved for primary closure. The final scar was esthetically pleasing. External tissue expansion is ideal for forehead flap donor sites as the second stage of the operation provides an opportunity for expander removal and wound closure.

Platelet-rich gel versus external tissue expansion technique in treating scalp defects: A retrospective study

Reconstruction of scalp defects is a complicated and challenging procedure for reconstructive surgeons. This retrospective observational study assessed the effectiveness of using platelet-rich gel (PRG) versus the external tissue expansion technique (TET) in reconstructing scalp defects. The clinical data of 24 patients with scalp defects treated with PRG or external TET were collected from September 2018 to March 2022. Data on the wound characteristics, wound healing time, cost of treatment, visual analog scale, and observed wound healing status were collected. The mean wound healing times in the PRG and TET groups were 25.00 ± 5.77 and 13.58 ± 9.68 days, respectively (P < .05). The PRG group was significantly more cost-effective than the TET group (P < .05). TET treatment significantly increased patients' postoperative pain, which decreased over time (P < .05), while PRG treatment caused no significant change in pain (P > .05). The 2 groups showed no tissue depression or color change after wound healing at follow-up, but the hair growth in the TET group was significantly better than that in the PRG group (P < .05). Compared with TET treatment of scalp defects, PRG is not only simple and painless but also has a low treatment cost and, more importantly, does not involve the risk of surgery and anesthesia. However, using TET to treat scalp defects requires the careful selection of appropriate cases.

Theta-Gel-Reinforced Hydrogel Composites for Potential Tensile Load-Bearing Soft Tissue Repair Applications

Engineering synthetic hydrogels for the repair and augmentation of load-bearing soft tissues with simultaneously high-water content and mechanical strength is a long-standing challenge. Prior formulations to enhance the strength have involved using chemical crosslinkers where residues remain a risk for implantation or complex processes such as freeze-casting and self-assembly, requiring specialised equipment and technical expertise to manufacture reliably. In this study, we report for the first time that the tensile strength of high-water content (>60 wt.%), biocompatible polyvinyl alcohol hydrogels can exceed 1.0 MPa through a combination of facile manufacturing strategies via physical crosslinking, mechanical drawing, post-fabrication freeze drying, and deliberate hierarchical design. It is anticipated that the findings in this paper can also be used in conjunction with other strategies to enhance the mechanical properties of hydrogel platforms in the design and construction of synthetic grafts for load-bearing soft tissues.