Bacteriosynthetic Degradable Tranexamic Acid-Functionalized Short Fibers for Inhibiting Invisible Hemorrhage

Exudate Management, Facile Detachment, and Immunometabolism Regulation for Wound Healing Using Breathable Dressings

Developing breathable dressings with multifunctional properties (such as exudate management, easy removal, and immunometabolism regulation) presents significant challenges in wound healing. This study employs the Hofmeister effect to prepare a sodium citrate-cross-linked cryogel (CA-CS) with versatile functions, including porous and loose structures, rapid shape recovery ability, superior fatigue resistance behavior, and outstanding biocompatibility capabilities. The CA-CS cryogels demonstrated strong anti-inflammatory properties by reversing the lipopolysaccharides-induced M1 macrophages and increasing M2 macrophage percentages in vitro. Additionally, these breathable CA-CS cryogels exhibited superior hemostatic activity in vivo. The easily detachable CA-CS cryogels enhanced nutrient exchange, promoted exudate absorption, regulated immune response, and induced metabolic reprogramming, thereby supporting skin regeneration and hair follicle formation in a full-thickness skin defect mouse model. We expect that these CA-CS cryogels will drive the development of next-generation dressings for effective wound regeneration in clinical practice.

Potential of novel antibacterial bio-adhesive for the treatment of periodontitis

Periodontitis seriously affects people's daily health, and the development of a non-antibiotic bio-adhesive with antimicrobial and periodontitis regeneration for periodontal pockets will effectively promote the treatment of periodontitis. In this study, we constructed a hybrid hydrogel (GelMA-BC-PL) by introducing aldehyde bacterial cellulose (BC) short nanofibers into the photosensitive hydrogel gelatin methacryloyl (GelMA), which binds to periodontal tissues to play an adhesive role through the Schiff base reaction, and further introducing ϵ-polylysine (PL), which could achieve the adhesive, antibacterial, and regenerative effect. Pigskin adhesion experiments showed that the adhesion of GelMA hydrogel to pigskin was only 0.39 N, while that of GelMA-BC-PL reached 1.42 N. The adhesion performance of the hydrogel was significantly improved by adding aldehyde BC nanofibers. Due to the introduction of PL, the antimicrobial properties of the hybrid hydrogel against two typical periodontitis bacteria (porphyromanas gingivalis and fusobacterium nucleatum), were significantly improved. Experiments with human periodontal membrane fibroblasts showed that the hybrid hydrogel had excellent cell spreading and proliferation promotion properties. The hybrid hydrogel simultaneously achieves adhesion, antimicrobial properties and promotes periodontal regeneration, which has great potential for application in the treatment of periodontitis diseases.

Preparation of an antibacterial, injectable, thermosensitive, and physically cross-linked hemostatic hydrogel based on quaternized linetype poly(N-isopropylacrylamide)

Bleeding and wound infection are two significant potential risks to life and health. While antibacterial hemostatic hydrogels can meet the requirements for hemostasis and the prevention of wound infections, the inclusion of antibacterial agents inevitably complicates the regulation of interactions between components, making it difficult to synergistically control the mechanical and antibacterial properties of the hydrogels, which limits the overall hydrogel performance. In this study, we propose the use of linear poly(N-isopropylacrylamide) (L-P-(C6H15N+)) with an antibacterial quaternary ammonium end-group for preparing hydrogels, rather than conventionally adding antibacterial agents. An injectable, highly antibacterial and wet-adhesive double-network hemostatic hydrogel was constructed using L-P-(C6H15N+), gelatin (G), and hyaluronic acid (HA). The comprehensive properties of the hydrogel could be adjusted through changing the molecular weight of the L-P-(C6H15N+) and the end-group effects. The G/HA/L-P-(C6H15N+) hydrogel demonstrated a gel time of 12.2-14 s, an adhesion strength of 26.9 ± 2.0 kPa and a burst pressure of 264 ± 20 mmHg. It also exhibited strong antibacterial activity against E. coli (93 ± 2.7%) and S. aureus (97 ± 3.2%), with satisfactory biocompatibility. Additionally, the hydrogel demonstrated good blood clotting ability in vitro and achieved rapid hemostasis (<15 s) in vivo. This work offers a simple and efficient strategy to fabricate high-performance smart antibacterial hemostatic hydrogels.

Fructose-Modified Chitosan/Gelatin 3D Composite Sponge for Enhanced Rapid Hemostasis

Managing uncontrolled and noncompressible bleeding presents a major challenge in emergency trauma care. Methods to halt bleeding quickly and efficiently, without applying direct pressure on the wound, have become a key focus of research. Herein, a novel fructose-modified chitosan/gelatin composite sponge has been developed, exhibiting high elasticity, low rebound pressure, and excellent cell compatibility. This material can rapidly return to its original form in around 1.5 s after being compressed by 80% upon contact with water. Additionally, experimental results from a rat liver wound model demonstrated that it exhibited a clear hemostatic effect. The hemostatic time was shortened from 204 ± 15.35 s to 53.3 ± 6.54 s, and the blood loss was reduced from 867 ± 153.15 mg to 187 ± 61.06 mg. Moreover, it can promote tissue healing by inhibiting the production of inflammatory factors including TNF-α, MCP-1, and IL-6. This material offers an effective solution for noncompressible tissue injuries.

A tranexamic acid-functionalized acellular dermal matrix sponge co-loaded with magnesium ions: Enhancing hemostasis, vascular regeneration, and re-epithelialization for comprehensive diabetic wound healing

Excessive inflammation, accumulation of wound exudate, and blood seepage are common in diabetic wounds, hindering cell proliferation and disrupting tissue remodeling, leading to delayed healing. This study presents a multifunctional sponge scaffold (P5T3@Mg) created by combining an acellular dermal matrix with tranexamic acid and MgO nanoparticles, designed for hemostatic and anti-inflammatory effects. The P5T3@Mg scaffold effectively absorbs wound fluid while promoting healing. In vivo and in vitro hemostasis experiments demonstrate that the P5T3@Mg sponge exhibits excellent hydrophilicity, enhancing blood absorption at the wound site, inhibiting fibrinolysis, and expediting hemostasis. Additionally, the sustained release of Mg2+ from the P5T3@Mg sponge promotes collagen deposition and angiogenesis in diabetic rat wounds, suppressing chronic inflammation and accelerating tissue remodeling and repair.

In Situ Self-Assembled Naringin/ZIF-8 Nanoparticle-Embedded Bacterial Cellulose Sponges for Infected Diabetic Wound Healing

The treatment of diabetic foot ulcers (DFUs) represents a significant challenge due to the complexity of the wound microenvironment. Several factors, including infection, inflammation, and impaired angiogenesis, can complicate the healing process and reduce the effectiveness of current clinical treatments. To address these challenges, this work develops a multifunctional sponge containing a zeolitic imidazolate framework-8/bacterial cellulose (ZIF-8/BC) matrix loaded with the antioxidant naringin (Nar). This sponge is fabricated using a straightforward method that involves in situ synthesis followed by lyophilization. The as-prepared Nar/ZIF-8/BC sponge exhibits excellent mechanical properties (e.g., tensile strength reaching 2.28 MPa), high exudate management performance (water absorption approximately 70 times), and excellent antimicrobial activity (100%). Additionally, the pH-responsive properties of ZIF-8 enable the composite sponge to release naringin in response to the DFU microenvironment. The released drug promotes angiogenesis, resulting in antioxidant and anti-inflammatory effects, which further encourage the healing of infected wounds in diabetic rats. Overall, the Nar/ZIF-8/BC sponge is a promising multifunctional dressing for DFU healing, providing an efficient solution for intractable wounds by regulating the microenvironment, which meets complex clinical demands.

Protonated-chitosan sponge with procoagulation activity for hemostasis in coagulopathy

Hemostatic materials are essential for managing acute bleeding in medical settings. Chitosan (CS) shows promise in hemostasis but its underlying mechanism remains incompletely understood. We unexpectedly discovered that certain protonated-chitosan (PCS) rapidly assembled plasma proteins to form protein membrane (PM) upon contact with platelet-poor plasma (PPP). We hypothesized that the novel observation was intricately related to the procoagulant effect of chitosan. Herein, the study aimed to elucidate the conditions necessary and mechanism for PM formation, identify the proteins within the PM and PCS's procoagulant action at the molecule levels. We confirmed that the amount of -NH3 + groups (>4.9 mmol/g) on PCS molecules played a crucial role in promoting coagulation. The -NH3 + group interacted with blood's multiple active components to exert hemostatic effects: assembling plasma proteins including coagulation factors such as FII, FV, FX, activating blood cells and promoting the secretion of coagulation-related substances (FV, ADP, etc) by platelets. Notably, the hemostatic mechanism can be extended to protonated-chitosan derivatives like quaternized, alkylated, and catechol-chitosan. In the blood clotting index (BCI) experiment, compared to other groups, PCS95 achieved the lowest BCI value (∼6 %) within 30 s. Protonated-chitosan exhibited excellent biocompatibility and antibacterial properties, with PCS95 demonstrating inhibition effectiveness of over 95 % against Escherichia coli (E.coil) and Staphylococcus aureus (S. aureus). Moreover, PCS performed enhanced hemostatic effectiveness over chitosan-based commercially agents (Celox™ and ChitoGauze®XR) in diverse bleeding models. In particular, PCS95 reduced bleeding time by 70 % in rabbit models of coagulopathy. Overall, this study investigated the coagulation mechanism of materials at the molecular level, paving the way for innovative approaches in designing new hemostatic materials.

Elastic and recoverable sponges based on collagen/yeast β-glucan for quick hemostasis

In this investigation, we aimed to engineer sponges with exceptional mechanical and hemostatic capabilities for effective wound healing. By combining collagen, a stiff fibril protein in ECM, with β-glucan, an elastic and triple-helical polysaccharide from yeast cell wall, we prepared a series of composite sponges, designated as CY sponges. This material exhibited a uniform pore structure, displaying enhanced elasticity and shape recovery ability compared to pure collagen sponges. Also, the incorporation of Yeast β-glucan (YG) significantly improved the fluid absorption ability and stability of the sponges. In vitro hemostasis tests demonstrated that the CY sponges exhibited a notably lower in vitro coagulation index (19.21 %) compared to the collagen control (64.84 %), accompanied by superior erythrocyte (64.64 %) and platelet (64.95 %) adhesion properties. Animal studies further substantiated the sponge's hemostatic efficacy, as CY40 led to a reduction in average bleeding volume by 25.26 % and 28.97 %, and a shorter hemostatic time by 31.70 % and 30.77 % compared to collagen, indicating accelerated wound healing. These findings suggest that the addition of yeast β-glucan into collagen sponges can improve their elasticity, shape recovery ability, hemostatic performance and wound repair ability.

3D Printing of Naturally Derived Adhesive Hemostatic Sponge

Hydrogel hemostatic sponges have been recognized for its effectiveness in wound treatment due to its excellent biocompatibility, degradability, as well as multi-facet functionalities. Current research focuses on optimizing the composition and structure of the sponge to enhance its therapeutic effectiveness. Here, we propose an adhesive hydrogel made from purely natural substances extracted from okra and Panax notoginseng. We utilize 3-dimensional (3D) printing technology to fabricate the hemostatic hydrogel scaffold, incorporating gelatin into the hydrogel and refining the mixing ratio. The interaction between gelatin and okra polyphenols contributes to successful injectability as well as stability of the printed scaffold. The okra in the scaffold exhibits favorable adhesion and hemostatic effects, and the total saponins of Panax notoginseng facilitate angiogenesis. Through in vitro experiments, we have substantiated the scaffold's excellent stability, adhesion, biocompatibility, and angiogenesis-promoting ability. Furthermore, in vivo experiments have demonstrated its dual functionality in rapid hemostasis and wound repair. These features suggest that the 3D-printed, natural substance-derived hydrogel scaffolds have valuable potential in wound healing and related applications.

Fabricating the multibranch carboxyl-modified cellulose for hemorrhage control

Excessive bleeding is associated with a high mortality risk. In this study, citric acid and ascorbic acid were sequentially modified on the surface of microcrystalline cellulose (MCAA) to increase its carboxyl content, and their potential as hemostatic materials was investigated. The MCAA exhibited a carboxylic group content of 9.52 %, higher than that of citric acid grafted microcrystalline cellulose (MCA) at 4.6 %. Carboxyl functionalization of microcrystalline cellulose surfaces not only plays a fundamental role in the structure of composite materials but also aids in the absorption of plasma and stimulation of platelets. Fourier -transform infrared (FT-IR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) spectra confirmed that carboxyl groups were successfully introduced onto the cellulose surface. Physical properties tests indicated that the MCAA possessed higher thermal stability (Tmax = 472.2 °C) compared to microcrystalline cellulose (MCC). Additionally, in vitro hemocompatibility, cytotoxicity and hemostatic property results demonstrated that MCAA displayed good biocompatibility (hemolysis ratio <1 %), optimal cell compatibility (cell viability exceeded 100 % after 72 h incubation), and impressive hemostatic effect (BCIMCAA = 31.3 %). Based on these findings, the hemostatic effect of covering a wound with MCAA was assessed, revealing enhanced hemostatic properties using MCAA in tail-amputation and liver-injury hemorrhage models. Furthermore, exploration into hemostatic mechanisms revealed that MCAA can significantly accelerate coagulation through rapid platelet aggregation and activation of the clotting cascade. Notably, MCAA showed remarkable biocompatibility and induced minimal skin irritation. In conclusion, the results affirmed that MCAA is a safe and potentially effective hemostatic agent for hemorrhage control.