A new hemostatic agent composed of Zn2+-enriched Ca2+ alginate activates vascular endothelial cells in vitro and promotes tissue repair in vivo

Haemostatic potency of sodium alginate/aloe vera/sericin composite scaffolds - preparation, characterisation, and evaluation

Fabrication of haemostatic materials with excellent antimicrobial, biocompatible and biodegradable properties remains as a major challenge in the field of medicine. Haemostatic agents play vital role in protecting patients and military individuals during emergency situations. Natural polymers serve as promising materials for fabricating haemostatic compounds due to their efficacy in promoting hemostasis and wound healing. In the present work, sodium alginate/aloe vera/sericin (SA/AV/S) scaffold has been fabricated using a simple cost-effective casting method. The prepared SA/AV/S scaffolds were characterised for their physicochemical properties such as scanning electron microscope, UV-visible spectroscopy and Fourier transform infra-red spectroscopy. SA/AV/S scaffold showed good mechanical strength, swelling behaviour and antibacterial activity. In vitro experiments using erythrocytes proved the hemocompatible and biocompatible features of SA/AV/S scaffold. In vitro blood clotting assay performed using human blood demonstrated the haemostatic and blood absorption properties of SA/AV/S scaffold. Scratch wound assay was performed to study the wound healing efficacy of prepared scaffolds. Chick embryo chorioallantoic membrane assay carried out using fertilised embryos proved the angiogenic property of SA/AV/S scaffold. Thus, SA/AV/S scaffold could serve as a potential haemostatic healthcare product due to its outstanding haemostatic, antimicrobial, hemocompatible, biocompatible and angiogenic properties.

In vitro effects of wound-dressings on key wound healing properties of dermal fibroblasts

Healing of complex wounds requires dressings that must, at least, not hinder and should ideally promote the activity of key healing cells, in particular fibroblasts. This in vitro study assessed the effects of three wound-dressings (a pure Ca2+ alginate: Algostéril®, a Ca2+ alginate + carboxymethylcellulose: Biatain alginate® and a polyacrylate impregnated with lipido-colloid matrix: UrgoClean®) on dermal fibroblast activity. The results showed the pure calcium alginate to be non-cytotoxic, whereas the other wound-dressings showed moderate to strong cytotoxicity. The two alginates stimulated fibroblast migration and proliferation, whereas the polyacrylate altered migration and had no effect on proliferation. The pure Ca2+ alginate significantly increased the TGF-β-induced fibroblast activation, which is essential to healing. This activation was confirmed by a significant increase in Vascular endothelial growth factor (VEGF) secretion and a higher collagen production. The other dressings reduced these fibroblast activities. The pure Ca2+ alginate was also able to counteract the inhibitory effect of NK cell supernatants on fibroblast migration. These in vitro results demonstrate that tested wound-dressings are not equivalent for fibroblast activation. Only Algostéril was found to promote all the fibroblast activities tested, which could contribute to its healing efficacy demonstrated in the clinic.

Recent Advances in Topical Hemostatic Materials

Untimely or improper treatment of traumatic bleeding may cause secondary injuries and even death. The traditional hemostatic modes can no longer meet requirements of coping with complicated bleeding emergencies. With scientific and technological advancements, a variety of topical hemostatic materials have been investigated involving inorganic, biological, polysaccharide, and carbon-based hemostatic materials. These materials have their respective merits and defects. In this work, the application and mechanism of the major hemostatic materials, especially some hemostatic nanomaterials with excellent adhesion, good biocompatibility, low toxicity, and high adsorption capacity, are summarized. In the future, it is the prospect to develop multifunctional hemostatic materials with hemostasis and antibacterial and anti-inflammatory properties for promoting wound healing.

Granular Hemostatic Composite of Alginate, Calcium, and Zinc for Rapid and Effective Management of Post-Traumatic Hemorrhage

Post-traumatic hemorrhage, which can result from accidents or battlefield injuries, is a significant global concern due to the high prehospital mortality rate. Substantial efforts have been made to develop hemostatic agents that can effectively reduce hemorrhage in the immediate aftermath of a traumatic event. The present study investigated the potential efficacy of Ca2+ and Zn2+ supplemented sodium alginate-based dry hemostatic particles (SA-CZ DHP) to manage excessive blood loss or post-traumatic hemorrhage. SA-CZ DHP were developed, followed by their physical and biochemical characterization, cytocompatibility and hemocompatibility testing, and critical evaluation of the hemostatic potential in vitro and in vivo. The safe SA-CZ DHP showed high absorption and accelerated blood clotting kinetics with reduced coagulation time (≈70%, p < 0.0001) in whole human blood, observed with insignificant hemolysis and uninterrupted RBC morphology. SA-CZ DHP significantly reduced the mean blood loss (≈90% in SD rats tail incision), and bleeding time (≈60% in BALB/c mice tail incision) was at par with commercially available Celox hemostatic granules. In conclusion, the biocompatible SA-CZ DHP exhibited rapid and effective management of excessive blood loss. It is also pertinent to note that the developed formulation could be a cost-effective alternative to its commercial counterparts.

Fabricating Oxidized Cellulose Sponge for Hemorrhage Control and Wound Healing

Uncontrolled hemorrhage and infection are the main reasons for many trauma-related deaths in both clinic and battlefield. However, most hemostatic materials have various defects and side effects, such as low hemostatic efficiency, poor biocompatibility, weak degradation ability, and lack of antimicrobial properties. Herein, an oxidized cellulose (OC) sponge with antibacterial properties and biosafety was fabricated for hemorrhage control and wound healing. The as-prepared OC sponges were prone to water triggered expansion and superabsorbent capacity, which could facilitate blood component concentration effectively. Importantly, they had significant biodegradability with little irritation to the skin. This hemostat could also reduce the plasma clotting time to 53.54% in vitro and demonstrated less blood loss than commercially available hemostatic agents (GS) in a mouse model of bleeding from liver defects. Furthermore, the biocompatibility antimicrobial properties and possible hemostatic mechanism of the OC sponge were also systematically evaluated. Importantly, the potential wound healing applications have also been demonstrated. Therefore, the materials have broad clinical application prospects.

Gelatin Sponges with a Uniform Interoperable Pore Structure and Biodegradability for Liver Injury Hemostasis and Tissue Regeneration

Developing a hemostatic sponge that can effectively control bleeding from visceral injuries while guiding in situ tissue regeneration in incompressible wounds remains a challenge. Most of the existing hemostatic sponges degrade slowly, are relatively single-functioning, and cannot cope with complex environments. Herein, a biodegradable rapidly hemostatic sponge (GPZ) was created by dual-dynamic-bond cross-linking among Zn2+, protocatechualdehyde (PA)-containing catechol and aldehyde groups, and gelatin. GPZ had a uniformly distributed interconnected pore structure with excellent fluid absorption. It could effectively absorb the oozing blood and increase the blood concentration while stimulating platelet activation and accelerating blood coagulation. Compared to commercial hemostats, GPZ treatment significantly accelerated hemostasis in the rat liver defect model (∼0.33 min, ≥50% reduction in the hemostatic time) and in the rabbit liver defect model (∼1.02 min, ≥60% reduction in the hemostatic time). Additionally, GPZ had excellent antibacterial and antioxidant properties that effectively protected the wound from infection and excessive inflammation. In the liver regeneration model, GPZ significantly increased the rate of hepatic tissue repair and promoted rapid functional recovery without complications and adverse reactions. Overall, we designed a simple and effective biodegradable rapid hemostatic sponge with good clinical translational potential for treating lethal incompressible bleeding and promoting wound healing.

Preparation and evaluation of a novel alginate-arginine-zinc ion hydrogel film for skin wound healing

In this paper, the mixed solution of sodium alginate (SA) and arginine (Arg) was dried into a film and then crosslinked with zinc ion to form sodium alginate-arginine-zinc ion (SA-Arg-Zn²⁺) hydrogel for skin wound dressings. SA-Arg-Zn²⁺ hydrogel had higher swelling ability, which was beneficial to absorbing wound exudate. Moreover, it exhibited antioxidant activity and strong inhibition against E. coli and S. aureus, and had no obvious cytotoxicity to NIH 3T3 fibroblasts. Compared with other dressings utilized in rat skin wound, SA-Arg-Zn²⁺ hydrogel showed better wound healing efficacy and the wound closure ratio reached to 100 % on the 14th day. The result of Elisa test indicated that SA-Arg-Zn²⁺ hydrogel down-regulated the expression of inflammatory factors (TNF-α and IL-6) and promoted the growth factor levels (VEGF and TGF-β₁). Furthermore, H&E staining results confirmed that SA-Arg-Zn²⁺ hydrogel could reduce wound inflammation and accelerate re-epithelialization, angiogenesis and wound healing. Therefore, SA-Arg-Zn²⁺ hydrogel is an effective and innovative wound dressing, moreover, the preparation technique is simple and feasible for industrial application.

Chitosan-Based Biomaterials for Hemostatic Applications: A Review of Recent Advances

Hemorrhage is a detrimental event present in traumatic injury, surgery, and disorders of bleeding that can become life-threatening if not properly managed. Moreover, uncontrolled bleeding can complicate surgical interventions, altering the outcome of surgical procedures. Therefore, to reduce the risk of complications and decrease the risk of morbidity and mortality associated with hemorrhage, it is necessary to use an effective hemostatic agent that ensures the immediate control of bleeding. In recent years, there have been increasingly rapid advances in developing a novel generation of biomaterials with hemostatic properties. Nowadays, a wide array of topical hemostatic agents is available, including chitosan-based biomaterials that have shown outstanding properties such as antibacterial, antifungal, hemostatic, and analgesic activity in addition to their biocompatibility, biodegradability, and wound-healing effects. This review provides an analysis of chitosan-based hemostatic biomaterials and discusses the progress made in their performance, mechanism of action, efficacy, cost, and safety in recent years.

A calcium and zinc composite alginate hydrogel for pre-hospital hemostasis and wound care

We developed, characterized, and examined the hemostatic potential of sodium alginate-based Ca²⁺ and Zn²⁺ composite hydrogel (SA-CZ). SA-CZ hydrogel showed substantial in-vitro efficacy, as observed by the significant reduction in coagulation time with better blood coagulation index (BCI) and no evident hemolysis in human blood. SA-CZ significantly reduced bleeding time (≈60 %) and mean blood loss (≈65 %) in the tail bleeding and liver incision in the mice hemorrhage model (p ≤ 0.001). SA-CZ also showed enhanced cellular migration (1.58-fold) in-vitro and improved wound closure (≈70 %) as compared with betadine (≈38 %) and saline (≈34 %) at the 7th-day post-wound creation in-vivo (p < 0.005). Subcutaneous implantation and intra-venous gamma-scintigraphy of hydrogel revealed ample body clearance and non-considerable accumulation in any vital organ, proving its non-thromboembolic nature. Overall, SA-CZ showed good biocompatibility along with efficient hemostasis and wound healing qualities, making it suitable as a safe and effective aid for bleeding wounds.