An adhesive gelatin-coated small intestinal submucosa composite hydrogel dressing aids wound healing

The application of small intestinal submucosa in tissue regeneration

The distinctive three-dimensional architecture, biological functionality, minimal immunogenicity, and inherent biodegradability of small intestinal submucosa extracellular matrix materials have attracted considerable interest and found wide-ranging applications in the domain of tissue regeneration engineering. This article presents a comprehensive examination of the structure and role of small intestinal submucosa, delving into diverse preparation techniques and classifications. Additionally, it proposes approaches for evaluating and modifying SIS scaffolds. Moreover, the advancements of SIS in the regeneration of skin, bone, heart valves, blood vessels, bladder, uterus, and urethra are thoroughly explored, accompanied by their respective future prospects. Consequently, this review enhances our understanding of the applications of SIS in tissue and organ repair and keeps researchers up-to-date with the latest research advancements in this area.

Preparation of nano-silver containing black phosphorus based on quaternized chitosan hydrogel and evaluating its effect on skin wound healing

Hydrogels with favorable biocompatibility and antibacterial properties are essential in postoperative wound hemorrhage care, facilitating rapid wound healing. The present investigation employed electrostatic adsorption of black phosphorus nanosheets (BPNPs) and nano‑silver (AgNPs) to cross-link the protonated amino group NH3+ of quaternized chitosan (QCS) with the hydroxyl group of hyaluronic acid (HA). The electrostatic interaction between the two groups resulted in the formation of a three-dimensional gel network structure. Additionally, the hydrogel containing AgNPs deposited onto BPNPs was assessed for its antibacterial properties and effects on wound healing. Hydrogel demonstrated an outstanding drug-loading capacity and could be employed for wound closure. AgNPs loaded on the BPNPs released silver ions and exhibited potent antibacterial properties when exposed to 808 nm near-infrared (NIR) radiation. The ability of the hydrogel to promote wound healing in an acute wound model was further evaluated. The BPNPs were combined with HA and QCS in the aforementioned hydrogel system to improve adhesion, combine the photothermal and antibacterial properties of the BPNPs, and promote wound healing. Therefore, the reported hydrogels displayed excellent biocompatibility and hold significant potential for application in the field of tissue engineering for skin wound treatment.

A Janus adhesive hydrogel sheet for preventing postoperative tissue adhesion of intestinal injuries

Although adhesive hydrogels represent an alternative to surgical sutures for non-invasive tissue wound sealing, those with indiscriminate adhesion fail to hold wounds while inhibiting postoperative tissue adhesion, thus limiting their application in intestinal repair. In this study, an asymmetric adhesive hydrogel sheet composed mainly of polyacrylic acid (PAA) and gelatin (GA) that can be wet-adhered to the surface of intestinal tissue was developed. One side of the GA-PAA hydrogel sheet was complexed with polyvinyl alcohol (PVA), which shielded the excess adhesion based on a physical barrier. Both sides of the PVA/GA-PAA hydrogel showed distinct adhesive and antiadhesive properties. Intriguingly, the anti-adhesive side showed significant anti-adhesion toward specific proteins. The results of animal experiments showed that the PVA/GA-PAA hydrogel could firmly adhere to the intestine to stop leakage and prevent post-operative tissue adhesion two weeks after surgery. The hematoxylin and eosin (H&E) staining results showed that the damaged intestinal serosa was repaired without tissue adhesion. It is believed that the controllable adhesion of the adhesive hydrogel offers better prospects for intestinal repair.

Recent advances in fabrication of dECM-based composite materials for skin tissue engineering

Chronic wound management is an intractable medical and social problem, affecting the health of millions worldwide. Decellularized extracellular matrix (dECM)-based materials possess remarkable biological properties for tissue regeneration, which have been used as commercial products for skin regeneration in clinics. However, the complex external environment and the longer chronic wound-healing process hinder the application of pure dECM materials. dECM-based composite materials are constructed to promote the healing process of different wounds, showing noteworthy functions, such as anti-microbial activity and suitable degradability. Moreover, fabrication technologies for designing wound dressings with various forms have expanded the application of dECM-based composite materials. This review provides a summary of the recent fabrication technologies for building dECM-based composite materials, highlighting advances in dECM-based molded hydrogels, electrospun fibers, and bio-printed scaffolds in managing wounds. The associated challenges and prospects in the clinical application of dECM-based composite materials for wound healing are finally discussed.

Asymmetric adhesive SIS-based wound dressings for therapeutically targeting wound repair

Severe tissue injuries pose a significant risk to human health. Conventional wound dressings fall short in achieving effective tissue regeneration, resulting in suboptimal postoperative healing outcomes. In this study, an asymmetric adhesive wound dressing (marked as SIS/PAA/LAP) was developed, originating from acrylate acid (AA) solution with laponite (LAP) nanoparticles polymerization and photo-crosslinked on the decellularized extracellular matrix small intestinal submucosa (SIS) patch. Extensive studies demonstrated that the SIS/PAA/LAP exhibited higher tissue adhesion strength (~ 33 kPa) and burst strength (~ 22 kPa) compared to conventional wound dressings like Tegaderm and tissue adhesive products. Importantly, it maintained favorable cell viability and demonstrated robust angiogenic capacity. In animal models of full-thickness skin injuries in rats and skin injuries in Bama miniature pigs, the SIS/PAA/LAP could be precisely applied to wound sites. By accelerating the formation of tissue vascularization, it displayed superior tissue repair outcomes. This asymmetrically adhesive SIS-based patch would hold promising applications in the field of wound dressings.

A multi-functional double cross-linked chitosan hydrogel with tunable mechanical and antibacterial properties for skin wound dressing

Chitosan hydrogels with essential antibacterial properties and biocompatibility have great potential in tissue engineering and regeneration medicine. However, pure chitosan hydrogel could be limited by insufficient mechanical properties. In this work, we designed a multi-functional chitosan hydrogel based on the combination of chitosan methacrylate (CTSMA) and sulfhydrated chitosan (CTSSH), which is cross-linked simultaneously by free-radical polymerization reaction and Thiol-ene reaction. The CTSMA/CTSSH (CMS) hydrogels displayed superior tissue adhesive and mechanical properties when compared to pure CTSMA hydrogel. Additionally, the resulting hydrogels exhibited potent antimicrobial effects against both E. coli and S. aureus. Besides, the CMS hydrogels exhibited good biocompatibility as demonstrated by cytotoxicity and cell proliferation experiments using fibroblasts cells (L929) and adipose-derived stem cells (ADSCs). In vivo experiment, the repairing effect of hydrogels on full-thickness skin defect model in rats was studied. Histological and immunohistochemical staining results showed that CMS hydrogels promoted angiogenesis, dermal repair and epidermal regeneration. Overall, the study highlights the potential of the CMS hydrogels as a promising biomaterial in wound healing applications.

Fabrication of an Adhesive Small Intestinal Submucosa Acellular Matrix Hydrogel for Accelerating Diabetic Wound Healing

The treatment of diabetic skin defects comes with enormous challenges in the clinic due to the disordered metabolic microenvironment. In this study, we therefore designed a novel composite hydrogel (SISAM@HN) with bioactive factors and tissue adhesive properties for accelerating chronic diabetic wound healing. Hyaluronic acid (HA) modified by N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrosophenoxy) butanamide (NB) held the phototriggering tissue adhesive capacity. Decellularized small intestinal submucosa (SIS) was degreased and digested to form the acellular matrix, which facilitated bioactive factor release. The results of the burst pressure test demonstrated that the in situ formed hydrogel possessed a tissue adhesive property. In vitro experiments, based on bone marrow stromal cells, revealed that the SIS acellular matrix-containing hydrogel contributed to promoting cell proliferation. In vivo, a diabetic mouse model was created and used to evaluate the tissue regeneration function of the obtained hydrogel, and our results showed that the synthesized hydrogel could assist collagen deposition, attenuate inflammation, and foster vascular growth during the wound healing process. Overall, the SIS acellular matrix-containing HA hydrogel was able to adhere to the wound sites, promote cell proliferation, and facilitate angiogenesis, which would be a promising biomaterial for wound dressing in clinical therapy of diabetic skin defects.

Decellularized extracellular matrix-based composite scaffolds for tissue engineering and regenerative medicine

Despite the considerable advancements in fabricating polymeric-based scaffolds for tissue engineering, the clinical transformation of these scaffolds remained a big challenge because of the difficulty of simulating native organs/tissues' microenvironment. As a kind of natural tissue-derived biomaterials, decellularized extracellular matrix (dECM)-based scaffolds have gained attention due to their unique biomimetic properties, providing a specific microenvironment suitable for promoting cell proliferation, migration, attachment and regulating differentiation. The medical applications of dECM-based scaffolds have addressed critical challenges, including poor mechanical strength and insufficient stability. For promoting the reconstruction of damaged tissues or organs, different types of dECM-based composite platforms have been designed to mimic tissue microenvironment, including by integrating with natural polymer or/and syntenic polymer or adding bioactive factors. In this review, we summarized the research progress of dECM-based composite scaffolds in regenerative medicine, highlighting the critical challenges and future perspectives related to the medical application of these composite materials.