Microorganism-derived biological macromolecules for tissue engineering

Sargassum glaucescens Extract/Marine-Derived Collagen Blend Sponge and Their Properties for Wound Healing

Burn wounds are challenging to treat due to considerable tissue damage and fluid loss. Creating wound dressings from natural and biological materials makes it possible to treat wounds and promote rapid epithelialization to speed healing and restore skin function. As a result, the ability of a collagen scaffold (Col) made from rainbow trout (Oncorhynchus mykiss) and putative bioactive phytochemical components from a Sargassum glaucescens (S. glaucescens) extract (SGE) to promote burn wound healing was assessed in this work. Synthesized collagen (40 mg/ml)/SGE (1-3 mg/ml) samples were then characterized physiochemically and physiologically. The physicochemical examination validated the bioactive component of SGE, the type of collagen (type I, α1, and α2), the successful incorporation of SGE into collagen scaffolds (Col/SGE), the thermal stability, and excellent hydrophilicity and water absorption capacity of produced scaffolds. Moreover, biological experiments approved the excellent antioxidant and antibacterial activity of SGE, structural stability improvement against degradation, and cell proliferation enhancement without cell toxicity. The results showed the Col/SGE 3 mg/ml sample also had the highest level of cell activity, according to the antibacterial and cell viability assays. Additionally, using Col/SGE in vivo on burn wounds in rat models demonstrated a quicker rate of wound healing with stronger re-epithelialization and dermal remodeling, fewer inflammatory cells, more fibroblast cells, and great collagen buildup. Therefore, since the collagen/SGE scaffold is structurally stable and can potentially promote cell proliferation without causing cell toxicity, the acquired results suggested that it may significantly impact wound healing.

Study of chondrogenesis of umbilical cord mesenchymal stem cells in curdlan- poly(vinyl alcohol) composite hydrogels and its mechanical properties of freezing-thawing treatments

The curdlan gel is a natural material produced by bacteria. It utilizes chemical cross-linking reactions to form a 3D porous composite hydrogel, increasing its porosity and water content, and improving its mechanical properties. It can be used in tissue repair and regenerative medicine. Curdlan-Poly(vinyl alcohol) (PVA) composite hydrogel can rapidly swell within 1 min due to its porous structure. Compression tests confirmed that it still maintains its original mechanical strength, even after five repeated freeze-thaw (FT) processes, making it suitable for long-term cryopreservation. The purpose of this study is to transplant umbilical cord mesenchymal stem cells (UC-MSCs) on Curdlan-PVA composite hydrogel and observe the chondrocytes on the material. The results of using 4',6-diamidino-2-phenylindole (DAPI), hematoxylin and eosin (H&E), calcein-acetoxymethyl ester (calcein AM), and Collagen type II-Fluorescein isothiocyanate (FITC) staining, confirmed that UC-MSCs can attach and differentiate into chondrocytes on 3D Curdlan-PVA composite hydrogel.

Fabrication and characterization of bilayer scaffolds made of decellularized dermis/nanofibrous collagen for healing of full-thickness wounds

Skin tissue engineering has progressed from simple wound dressings to biocompatible materials with desired physico-chemical properties that can deliver regenerative biomolecules. This study describes using a novel biomimetic hybrid scaffold of decellularized dermis/collagen fibers that can continuously deliver stromal cell-derived factor-1 alpha (SDF-1α) for skin regeneration. In diabetic rat models, the idea that sustained SDF-1α infusion could increase the recruitment of CXCR4-positive cells at the injury site and improve wound regeneration was investigated. The morphology of the scaffold, its biocompatibility, and the kinetics of SDF-1 release were all assessed. SDF-1α was successfully incorporated into collagen nanofibers, resulting in a 200-h continuous release profile. The microscopic observations exhibited that cells are attached and proliferated on proposed scaffolds. As evaluated by in vivo study and histological examination, fabricated scaffold with SDF-1α release capacity exhibited a remarkably more robust ability to accelerate wound regeneration than the control group. Besides, the SDF-1α-loaded scaffold demonstrated functional effects on the proliferation and recruitment of CD31 and CXCR4-positive cells in the wound bed. Additionally, no adverse effects such as hyperplasia or scarring were found during the treatment period. It may be concluded that the fabricated hybrid scaffold based on natural polymer opens up a new option for topical administration of bioactive molecules. We believe the SDF-1α-loaded hybrid scaffold has promise for skin tissue engineering.