Preparation of Super Absorbent and Highly Active Fish Collagen Sponge and its Hemostatic Effect in vivo and in vitro

Neutrophil extracellular traps-inspired DNA hydrogel for wound hemostatic adjuvant

Severe traumatic bleeding may lead to extremely high mortality rates, and early intervention to stop bleeding plays as a critical role in saving lives. However, rapid hemostasis in deep non-compressible trauma using a highly water-absorbent hydrogel, combined with strong tissue adhesion and bionic procoagulant mechanism, remains a challenge. In this study, a DNA hydrogel (DNAgel) network composed of natural nucleic acids with rapid water absorption, high swelling and instant tissue adhesion is reported, like a band-aid to physically stop bleeding. The excellent swelling behavior and robust mechanical performance, meanwhile, enable the DNAgel band-aid to fill the defect cavity and exert pressure on the bleeding vessels, thereby achieving compression hemostasis for deep tissue bleeding sites. The neutrophil extracellular traps (NETs)-inspired DNAgel network also acts as an artificial DNA scaffold for erythrocytes to adhere and aggregate, and activates platelets, promoting coagulation cascade in a bionic way. The DNAgel achieves lower blood loss than commercial gelatin sponge (GS) in male rat trauma models. In vivo evaluation in a full-thickness skin incision model also demonstrates the ability of DNAgel for promoting wound healing. Overall, the DNAgel band-aid with great hemostatic capacity is a promising candidate for rapid hemostasis and wound healing.

Collagen-Based Medical Devices for Regenerative Medicine and Tissue Engineering

Assisted reproductive technologies are key to solving the problems of aging and organ defects. Collagen is compatible with living tissues and has many different chemical properties; it has great potential for use in reproductive medicine and the engineering of reproductive tissues. It is a natural substance that has been used a lot in science and medicine. Collagen is a substance that can be obtained from many different animals. It can be made naturally or created using scientific methods. Using pure collagen has some drawbacks regarding its physical and chemical characteristics. Because of this, when collagen is processed in various ways, it can better meet the specific needs as a material for repairing tissues. In simpler terms, collagen can be used to help regenerate bones, cartilage, and skin. It can also be used in cardiovascular repair and other areas. There are different ways to process collagen, such as cross-linking it, making it more structured, adding minerals to it, or using it as a carrier for other substances. All of these methods help advance the field of tissue engineering. This review summarizes and discusses the current progress of collagen-based materials for reproductive medicine.

Physico chemical characterisation of pectin incorporated gelatin sponge and its functional evaluation in modulating contact activation haemostasis

Even though it is a common occurrence in practice, maintaining haemostasis can sometimes become a challenging issue in case of trauma, perioperative period, coagulation disorders, cancers, etc. Hemostatic materials are extensively used to assist in the cessation of bleeding. However, the definition of efficiency of haemostasis varies between intended procedures. This paper explores the feasibility of incorporating agents to increase the efficiency of local haemostasis. Pectin or β -D galacto hexopyranuronic acid/β Gal A, a structural polysaccharide widely present in terrestrial plants having an intrinsic hemostatic potential, is blended with gelatin and is explored in modulating passive haemostasis. The sponges are physico chemically characterized, and their hemostatic efficiency is evaluated in vitro using various assays. Biocompatibility evaluation is done by in vitro cytotoxicity assay. The results suggest that this biopolymer combination is a promising candidate for hemostatic control.

Preventive effect of tilapia skin collagen hydrolysates on ulcerative colitis mice based on metabonomic and 16 S rRNA gene sequencing

BACKGROUND

Tilapia skin collagen hydrolysates (TSCHs) are the product of enzymatic hydrolysis of collagen, which is mainly extracted from tilapia skin. The components of TSCHs have recently been reported to play a preventive role in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). However, it has not been illustrated whether TSCHs can prevent against DSS-induced UC via the gut microbiota and its derived metabolites.

RESULTS

TSCHs are mainly composed of amino acids, which have similar characteristics to collagen, with most having a molecular weight below 5 kDa. In a mouse model of UC, TSCHs had no toxic effect at a dose of 60 g kg^-1 and could reduce body weight changes, colon length, histopathological changes and score, and the level of the serum inflammatory cytokine interleukin (IL)-6. Concurrently, 16 S rRNA sequencing showed that TSCHs significantly reduced the abundance of Bacteroidetes and Proteobacteria at the phylum level and norank_f__Muribaculaceae and Escherichia-Shigella at the genus level, while they increased the abundance of Firmicutes at the phylum level and Lachnoclostridium, Allobaculum, Enterorhabdus, and unclassified__f__Ruminococcaceae at the genus level. Target metabolomic analysis showed that TSCHs elevated the concentration of total acid, acetic acid, propanoic acid, and butanoic acid, but reduced isovaleric acid concentrations. Moreover, Pearson correlation analysis revealed that Allobaculum, unclassified_Ruminococcaceae, and Enterorhabdus were positively correlated with acetic acid and butyric acid, but not Escherichia-Shigella.

CONCLUSION

These findings suggest that TSCHs can prevent UC by modulating gut microbial and microbiota-derived metabolites. © 2023 Society of Chemical Industry.

Design, Manufacturing and Functions of Pore-Structured Materials: From Biomimetics to Artificial

Porous structures with light weight and high mechanical performance exist widely in the tissues of animals and plants. Biomimetic materials with those porous structures have been well-developed, and their highly specific surfaces can be further used in functional integration. However, most porous structures in those tissues can hardly be entirely duplicated, and their complex structure-performance relationship may still be not fully understood. The key challenges in promoting the applications of biomimetic porous materials are to figure out the essential factors in hierarchical porous structures and to develop matched preparation methods to control those factors precisely. Hence, this article reviews the existing methods to prepare biomimetic porous structures. Then, the well-proved effects of micropores, mesopores, and macropores on their various properties are introduced, including mechanical, electric, magnetic, thermotics, acoustic, and chemical properties. The advantages and disadvantages of hierarchical porous structures and their preparation methods are deeply evaluated. Focusing on those disadvantages and aiming to improve the performance and functions, we summarize several modification strategies and discuss the possibility of replacing biomimetic porous structures with meta-structures.

Preparation of fish decalcified bone matrix and its bone repair effect in rats

Decalcified bone matrix has great potential and application prospects in the repair of bone defects due to its good biocompatibility and osteogenic activity. In order to verify whether fish decalcified bone matrix (FDBM) has similar structure and efficacy, this study used the principle of HCl decalcification to prepare the FDBM by using fresh halibut bone as the raw material, and then degreasing, decalcifying, dehydrating and freeze-drying it. Its physicochemical properties were analyzed by scanning electron microscopy and other methods, and then its biocompatibility was tested by in vitro and in vivo experiments. At the same time, an animal model of femoral defect in rats was established, and commercially available bovine decalcified bone matrix (BDBM) was used as the control group, and the area of femoral defect in rats was filled with the two materials respectively. The changes in the implant material and the repair of the defect area were observed by various aspects such as imaging and histology, and its osteoinductive repair capacity and degradation properties were studied. The experiments showed that the FDBM is a form of biomaterial with high bone repair capacity and lower economic cost than other related materials such as bovine decalcified bone matrix. FDBM is simpler to extract and the raw materials are more abundant, which can greatly improve the utilization of marine resources. Our results show that FDBM not only has a good repair effect on bone defects, but also has good physicochemical properties, biosafety and cell adhesion, and is a promising medical biomaterial for the treatment of bone defects, which can basically meet the clinical requirements for bone tissue repair engineering materials.

Characterization and Analysis of Chitosan-Gelatin Composite-Based Biomaterial Effectivity as Local Hemostatic Agent: A Systematic Review

Chitosan and gelatin were the most widely used natural materials in pharmaceutical and medical fields, especially as local hemostatic agents, independently or as a composite material with the addition of other active substances. Chitosan and gelatin have excellent properties in biocompatibility, biodegradability, non-toxicity and water absorption capacity. The objective of this review was to analyze the characteristics of chitosan-gelatin (CG) composite-based biomaterial and its effectivity as a local hemostatic agent. We used PRISMA guidelines and the PICO framework to compile this review. The findings demonstrated that the CG composite-based biomaterial had excellent physical, chemical, mechanical properties and local hemostatic agent activity by adding other active substances such as oxidized fibers (OF), silica nanoparticles (SiNPs), calcium (Ca) and biphasic calcium phosphate (BCP) or by setting the CG composite proportion ratio.

Effects and metabolism of fish collagen sponge in repairing acute wounds of rat skin

Objective: Study the repair effect of tilapia collagen on acute wounds, and the effect on the expression level of related genes and its metabolic direction in the repair process. Materials and methods: After the full-thickness skin defect model was constructed in standard deviation rats, the wound healing effect was observed and evaluated by means of characterization, histology, and immunohistochemistry. RT-PCR, fluorescence tracer, frozen section and other techniques were used to observe the effect of fish collagen on the expression of related genes and its metabolic direction in the process of wound repair. Results: After implantation, there was no immune rejection reaction, fish collagen fused with new collagen fibers in the early stage of wound repair, and was gradually degraded and replaced by new collagen in the later stage. It has excellent performance in inducing vascular growth, promoting collagen deposition and maturation, and re-epithelialization. The results of fluorescent tracer showed that fish collagen was decomposed, and the decomposition products were involved in the wound repair process and remained at the wound site as a part of the new tissue. RT-PCR results showed that, without affecting collagen deposition, the expression level of collagen-related genes was down-regulated due to the implantation of fish collagen. Conclusion: Fish collagen has good biocompatibility and wound repair ability. It is decomposed and utilized in the process of wound repair to form new tissues.

A Biodegradable Flexible Micro/Nano-Structured Porous Hemostatic Dental Sponge

A biodegradable micro/nano-structured porous hemostatic gelatin-based sponge as a dentistry surgery foam was prepared using a freeze-drying method. In vitro function evaluation tests were performed to ensure its hemostatic effect. Biocompatibility tests were also performed to show the compatibility of the sponge on human fetal foreskin fibroblasts (HFFF2) cells and red blood cells (RBCs). Then, 10 patients who required the extraction of two teeth were selected, and after teeth extraction, for dressing, the produced sponge was placed in one of the extracavities while a commercial sponge was placed in the cavity in the other tooth as a control. The total weight of the absorbed blood in each group was compared. The results showed a porous structure with micrometric and nanometric pores, flexibility, a two-week range for degradation, and an ability to absorb blood 35 times its weight in vitro. The prepared sponge showed lower blood clotting times (BCTs) (243.33 ± 2.35 s) and a lower blood clotting index (BCI) (10.67 ± 0.004%) compared to two commercial sponges that displayed its ability for faster coagulation and good hemostatic function. It also had no toxic effects on the HFFF2 cells and RBCs. The clinical assessment showed a better ability of blood absorption for the produced sponge (p-value = 0.0015). The sponge is recommended for use in dental surgeries because of its outstanding abilities.