Case Report: Wound Closure Acceleration in a Patient With Toxic Epidermal Necrolysis Using a Lyophilised Amniotic Membrane

Snowflake Amniotic Membrane in Scalp Reconstruction for Pitbull Bite

Amniotic membrane, derived from the innermost placenta, is widely employed in surgery to help regenerate soft tissue and promote re-epithelialization. The authors detail a case report of a 59-year-old female who presented with a large, full-thickness scalp avulsion injury (13 × 10 cm) after being attacked by her pet pitbull. Innovative application of "snowflake" or fragmented amniotic membrane to her wound bed was used during both stages of scalp reconstruction: irrigation and debridement with Integra biological membrane placement and later split-thickness skin grafting. The patient had an uncomplicated recovery with a satisfactory cosmetic outcome. The authors believe that the "snowflake" application of amniotic membrane played an important role in forming healthy granulation tissue and optimizing the wound bed for definitive coverage. "Snowflake" amniotic membrane may help maximize its mechanical and biological benefits and holds promise to be an important adjunctive treatment for surgical wound healing.

An individual patient data meta-analysis of wound care in patients with toxic epidermal necrolysis

Toxic epidermal necrolysis (TEN) involves extensive mucocutaneous loss, and care is supportive. The approach to wound care includes surgical debridement or using dressings while leaving the epidermis intact. Robust evidence for either approach is lacking. We compared surgical debridement to the use of dressings while leaving the epidermis in situ (referred to hereon as dressings) in adult patients with TEN. The primary outcome assessed was mortality. The secondary outcome was time to re-epithelialisation. The impact of medications was evaluated. An individual patient data (IPD) systematic review and meta-analysis was undertaken. A random effects meta-analysis and survival analysis for IPD data examined mortality, re-epithelisation time and the effect of systemic medications. The quality of evidence was rated per the Grading of Recommendations Assessment, Development and Evaluation (GRADE). PROSPERO: CRD42021266611 Fifty-four studies involving 227 patients were included in the systematic review and meta-analysis, with a GRADE from very low to moderate. There was no difference in survival in patients who had surgical debridement or dressings (univariate: p = 0.91, multivariate: p = 0.31). Patients who received dressings re-epithelialised faster than patients who underwent debridement (multivariate HR: 1.96 [1.09-3.51], p = 0.023). Intravenous immunoglobulin (univariate HR: 0.21 [0.09-0.45], p < 0.001; multivariate HR: 0.22 [0.09-0.53], p < 0.001) and cyclosporin significantly reduced mortality (univariate HR: 0.09 [0.01-0.96], p = 0.046; multivariate HR: 0.06 [0.01-0.73], p = 0.028) irrespective of the wound care. This study supports the expert consensus of the dermatology hospitalists, that wound care in patients with TEN should be supportive with the epidermis left intact and supported with dressings, which leads to faster re-epithelialisation.

Amnion-derived hydrogels as a versatile platform for regenerative therapy: from lab to market

In recent years, the amnion (AM) has emerged as a versatile tool for stimulating tissue regeneration and has been of immense interest for clinical applications. AM is an abundant and cost-effective tissue source that does not face strict ethical issues for biomedical applications. The outstanding biological attributes of AM, including side-dependent angiogenesis, low immunogenicity, anti-inflammatory, anti-fibrotic, and antibacterial properties facilitate its usage for tissue engineering and regenerative medicine. However, the clinical usage of thin AM sheets is accompanied by some limitations, such as handling without folding or tearing and the necessity for sutures to keep the material over the wound, which requires additional considerations. Therefore, processing the decellularized AM (dAM) tissue into a temperature-sensitive hydrogel has expanded its processability and applicability as an injectable hydrogel for minimally invasive therapies and a source of bioink for the fabrication of biomimetic tissue constructs by recapitulating desired biochemical cues or pre-defined architectural design. This article reviews the multi-functionality of dAM hydrogels for various biomedical applications, including skin repair, heart treatment, cartilage regeneration, endometrium regeneration, vascular graft, dental pulp regeneration, and cell culture/carrier platform. Not only recent and cutting-edge research is reviewed but also available commercial products are introduced and their main features and shortcomings are elaborated. Besides the great potential of AM-derived hydrogels for regenerative therapy, intensive interdisciplinary studies are still required to modify their mechanical and biological properties in order to broaden their therapeutic benefits and biomedical applications. Employing additive manufacturing techniques (e.g., bioprinting), nanotechnology approaches (e.g., inclusion of various bioactive nanoparticles), and biochemical alterations (e.g., modification of dAM matrix with photo-sensitive molecules) are of particular interest. This review article aims to discuss the current function of dAM hydrogels for the repair of target tissues and identifies innovative methods for broadening their potential applications for nanomedicine and healthcare.

Biological importance of human amniotic membrane in tissue engineering and regenerative medicine

The human amniotic membrane (hAM) is the innermost layer of the placenta. Its distinctive structure and the biological and physical characteristics make it a highly biocompatible material in a variety of regenerative medicine applications. It also acts as a supply of bioactive factors and cells, which indicate the advantages over other tissues. In this review, we firstly discussed the biological properties of hAM-derived cells in vivo or in vitro, along with their stemness of markers, pointing out a promising source of stem cells for regenerative medicine. Then, we systematically summarized current knowledge on the collection, preparation, preservation, and decellularization of hAM, as well as their characteristics helping to improve the understanding of applications in tissue engineering. Finally, we highlighted the recent advances in which hAM has undergone additional modifications to achieve an adequate perspective of regenerative medicine applications. More investigations are required in utilizing appropriate modifications to enhance the therapeutic effectiveness of hAM in the future.

Biological properties and surgical applications of the human amniotic membrane

The amniotic membrane (AM) is the inner part of the placenta. It has been used therapeutically for the last century. The biological proprieties of AM include immunomodulatory, anti-scarring, anti-microbial, pro or anti-angiogenic (surface dependent), and tissue growth promotion. Because of these, AM is a functional tissue for the treatment of different pathologies. The AM is today part of the treatment for various conditions such as wounds, ulcers, burns, adhesions, and skin injury, among others, with surgical resolution. This review focuses on the current surgical areas, including gynecology, plastic surgery, gastrointestinal, traumatology, neurosurgery, and ophthalmology, among others, that use AM as a therapeutic option to increase the success rate of surgical procedures. Currently there are articles describing the mechanisms of action of AM, some therapeutic implications and the use in surgeries of specific surgical areas, this prevents knowing the therapeutic response of AM when used in surgeries of different organs or tissues. Therefore, we described the use of AM in various surgical specialties along with the mechanisms of action, helping to improve the understanding of the therapeutic targets and achieving an adequate perspective of the surgical utility of AM with a particular emphasis on regenerative medicine.

Application of Perinatal Derivatives on Oncological Preclinical Models: A Review of Animal Studies

The increasing cancer incidence has certified oncological management as one of the most critical challenges for the coming decades. New anticancer strategies are still needed, despite the significant advances brought to the forefront in the last decades. The most recent, promising therapeutic approaches have benefitted from the application of human perinatal derivatives (PnD), biological mediators with proven benefits in several fields beyond oncology. To elucidate preclinical results and clinic outcomes achieved in the oncological field, we present a narrative review of the studies resorting to animal models to assess specific outcomes of PnD products. Recent preclinical evidence points to promising anticancer effects offered by PnD mediators isolated from the placenta, amniotic membrane, amniotic fluid, and umbilical cord. Described effects include tumorigenesis prevention, uncontrolled growth or regrowth inhibition, tumor homing ability, and adequate cell-based delivery capacity. Furthermore, PnD treatments have been described as supportive of chemotherapy and radiological therapies, particularly when resistance has been reported. However, opposite effects of PnD products have also been observed, offering support and trophic effect to malignant cells. Such paradoxical and dichotomous roles need to be intensively investigated. Current hypotheses identify as explanatory some critical factors, such as the type of the PnD biological products used or the manufacturing procedure to prepare the tissue/cellular treatment, the experimental design (including human-relevant animal models), and intrinsic pathophysiological characteristics. The effective and safe translation of PnD treatments to clinical practice relies on the collaborative efforts of all researchers working with human-relevant oncological preclinical models. However, it requires proper guidelines and consensus compiled by experts and health workers who accurately describe the methodology of tissue collection, PnD isolation, manufacturing, preservation, and delivery to the final user.

A rapid-triggered approach towards antibacterial hydrogel wound dressing with synergic photothermal and sterilization profiles

Developing non-antibiotic-dependent antibacterial hydrogels for repairing infected skin defect remains largely unexplored. Herein, a synergic photothermal and synergic antibacterial hydrogel was designed via one-pot approach to cope with full-thickness skin wound infection. In this work, the mixture of silver‑sodium lignin sulfonate nanoparticles (Ag-SLS NPs) and polypyrrole-polydopamine nanoparticles (PPy-PDA NPs) for the first time as synergic photothermal agent was introduced into poly (ethylene glycol) diacrylate (PEGDA) to form Ag-SLS/PPy-PDA@PEGDA hydrogel. Thanks to the near-infrared light into heat conversion capacity of both Ag and PPy-PDA NPs, the formed hydrogel shows ultrahigh photothermal activity, and outstanding antibacterial activity to both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria in vitro. Additionally, in vivo assay indicates that the hydrogel has outstanding long-term antibacterial effect due to the photothermal sterilization along with Ag ions release. Overall, the dual-synergic photothermal and antibacterial effects of the Ag-SLS/PPy-PDA@PEGDA hydrogel could highly accelerate infection wound healing, and thus has great potential to be used for tissue engineering.