Assembly of skin substitute by cross-linking natural biomaterials on synthetic biodegradable porous mat for critical-size full-thickness burn wound regeneration

Effect of electrospun poly (L-lactide-co-caprolactone) and formulated porcine fibrinogen for diabetic foot ulcers

Diabetic foot ulcers were a significant complication of diabetes and were accompanied by delayed wound healing. To compare the effect of topical application electrospun poly (L-lactide-co-caprolactone) and formulated porcine fibrinogen (PLCL/Fg) dressing with alginate dressing when treating diabetic foot ulcers (DFUs). A single-center, prospective, randomized, patient-blinded clinical trial was conducted from July 1, 2023, to December 26, 2023. The clinical trial registration was completed on August 28, 2023 (ClinicalTrials.gov Identifier: NCT06014437). The eligible patients with DFUs of 1-20 cm2 present for at least 1 month and with Wagner grade 1 or 2. They were randomized 1:1 to receive PLCL/Fg or alginate dressing. Participants received PLCL/Fg dressing 1-3 times per week or alginate dressing 3 times per week for 12 weeks. A total of 52 patients (33 men [63.5 %]; mean [SD] age, 63.1 [11.9] years; mean [SD] diabetes time, 8.3 [4.6] years) with DFUs were assessed for this study. The DFUs classified as Wagner grade 1 or 2 (mean [SD] ulcer area, 3.8 [3.2] cm2) were randomized to receive either the PLCL/Fg dressing (n = 26) or the alginate dressing (n = 26) for as long as 12 weeks. In this study, the incidence of complete healing included 22 patients (91.7 %) in the PLCL/Fg group and 14 (63.6 %) in the alginate group during the 12-week treatment period (P = 0.003). The treatment-related adverse events that occurred were 5 (20.8 %) in the PLCL/Fg group and 4 (18.1 %) in the comparator group. In this randomized clinical trial, PLCL/Fg dressing showed beneficial effects in DFUs treatment of wound surface reduction and regulating the wound microenvironment.

Preclinical animal study of electrospun poly (l-lactide-co-caprolactone) and formulated porcine fibrinogen for full-thickness diabetic wound regeneration

Diabetic foot ulcer is one of the most serious chronic complications of diabetes mellitus. It may lead to amputation of the lower extremities for diabetics. Our study was to evaluate the effect of electrospun poly (L-lactide-co-caprolactone) and formulated porcine fibrinogen (PLCL/Fg) wound dressing on animal wound model. A blend ratio of PLCL/Fg scaffold was 4 (PLCL):1 (Fg). The scanning electron microscopy findings showed that the fibers' diameter was 122.5 ± 80.3 nm, and the tensile strength was 9.2 ± 0.2 MPa. In-vivo study of the hog normal model demonstrated that PLCL/Fg dressing had better biocompatibility, degradability, and ability to restore the skin's normal structure. We evaluated the wound healing processes in the rat diabetic model by macroscopic observation and histological observation at 1, 2, and 3 post-operation weeks. In our study, the PLCL/Fg group performed better 3 weeks after surgery, in terms of macroscopic healing and scarring. After surgery, the PLCL/Fg group showed better fibroblast accumulation, tissue granulation, and collagen expression than the control group. Topical treatment with PLCL/Fg dressing effectively enhanced wound healing in both normal and hyperglycemic conditions, suggesting that it may possess wound-healing potential.

Formulation and Characterization of Gelatin Methacrylamide – Hydroxypropyl Methacrylate Based Bioink for Bioprinting Applications

Three-dimensional (3D) bioprinting has emerged as a revolutionary technology for constructing functional tissue equivalents/scaffolds for tissue engineering applications. Bioink design is a crucial element in 3D bioprinting, which typically comprises a mixture of biomaterials, biological molecules or cells followed by its printing and tissue maturation. An ideal bioink should possess suitable physicochemical, mechanical, rheological, and biological features of the target tissue. However, mimicking multifaceted compositions similar to native extracellular matrix (ECM) with bioactive milieu of soluble and non-soluble factors is challenging. Herein, we report the formulation and characterization of a bioink system, comprising methacrylamide modified gelatin (GelMA) and 2-hydroxylpropyl methacrylate (HPMA) with a cost-effective redox initiators based cross-linking. GelMA was synthesized by reacting gelatin with methacrylic anhydride (MA) and subsequently, copolymerized with HPMA at room temperature by redox mechanism. Various hydrogel formulations by varying GelMA: HPMA w/v% ratios (G:HP) were studied as 10:0 (G100HP0), 9.5:0.5 (G95HP05), 9:1 (G90HP10), 8:2 (G80HP20), and 6:4 (G60HP40), to identify the best bioink composition. The formulations were characterized for its opacity, chemical, rheological, mechanical, porosity and swelling properties and cytocompatibility as per ISO-10993 standards. Cell encapsulation studies using live/dead assay analyzed cell viability inside the handprinted and 3D printed constructs. The preliminary results indicate successful formulation of cytocompatible bioink for potential 3D bioprinting and biofabrication applications.

Silk Fibroin-Based Bioengineered Scaffold for Enabling Hemostasis and Skin Regeneration of Critical-Size Full-Thickness Heat-Induced Burn Wounds

Millions of people around the globe are affected by full-thickness skin injuries. A delay in the healing of such injuries can lead to the formation of chronic wounds, posing several clinical and economic challenges. Current strategies for wound care aim for skin regeneration and not merely skin repair or faster wound closure. The present study aimed to develop a bioactive wound-healing matrix comprising natural biomaterial silk fibroin (SF), clinical-grade human fibrin (FIB), and human hyaluronic acid (HA), resulting in SFFIBHA for regeneration of full-thickness burn wounds. A porous, hemostatic, self-adhesive, moisture-retentive, and biomimetic scaffold that promotes healing was the expected outcome. The study validated a terminal sterilization method, suggesting the stability and translational potential of the novel scaffold. Also, the study demonstrated the regenerative abilities of scaffolds using in vitro cell culture experiments and in vivo full-thickness burn wounds of critical size (4 cm × 4 cm) in a rabbit model. Under in vitro conditions, the scaffold enhanced primary dermal fibroblast adhesion and cell proliferation with regulated extracellular matrix (ECM) synthesis. In vivo, the scaffolds promoted healing with mature epithelium coverage involving intact basal cells, superficial keratinocytes, multilayers of keratohyalin, dermal regeneration with angiogenesis, and deposition of remodeled ECM in 28 days. The relative gene expression of the IL6 marker indicated transitions from inflammation to proliferation stage. In addition, we observed skin appendages and rete peg development in the SFFIBHA-treated wound tissues. Although wound closure was observed, neither negative (untreated/sham) nor positive (commercially available product; NeuSkin) control wounds developed skin appendages/rete pegs or native skin architecture. After 56 days, healing with organized ECM production enabled the recovery of mechanical properties of skin with higher tissue maturity in SFFIBHA-treated wounds. Thus, in a single application, the SFFIBHA scaffold proved to be an efficient biomimetic matrix that can guide burn wound regeneration. The developed matrix is a suture-less, hemostatic, off-the-shelf product for potential wound regenerative applications.