Advances in the development and optimization strategies of the hemostatic biomaterials

Insight into hemostatic performance and mechanism of natural mixed-dimensional Attapulgite clay

Clay minerals have attracted wide attention as biomedical materials due to the unique crystal structure, abundant morphology and good biocompatibility. However, the relevant studies on the abundant natural mixed clay deposits were scarcely reported. Herein, the hemostatic performance of natural mixed-dimensional attapulgite clay (MDAPT) composed of one-dimensional attapulgite and multiple two-dimensional clay were systematically investigated based on the structural evolution using oxalic acid for different time. The results of hemostatic evaluation showed that MDAPT leached by oxalic acid with 1 h presented the shortest clotting time (134 ± 12.17 s), a 15.09 % and 41.74 % reduction of relative hemoglobin absorbance at 180 s and 120 s when compared with the control group, respectively, and an increase of 19.45 % of the blood clotting index in vitro, as well as MDAPT obtained the shortest bleeding time (158.5 ± 6.9 s), nearly 66 % and 31 % reduction blood loss as compared to the blank group and the YNBY group in vivo. This improvement was primarily ascribed to the synergistic effect of lamellar non-expandable illite, and nano rod-like attapulgite. Furthermore, the rapid hemostasis of MDAPT was also due to the joint effect of superhydrophobic property toward blood, minimizing blood loss, surface negative charge, metal ions from MDAPT structural skeleton, promoting an average increase of 21 % for platelet activation. The results suggested that MDAPT could be served as a promising efficient inorganic hemostatic materials, which provided a feasible strategy to realize the high-valued utilization of natural mixed clay resources.

Alginate based hemostatic materials for bleeding management: A review

Severe bleeding has caused significant financial losses as well as a major risk to the lives and health of military and civilian populations. Under some situations, the natural coagulation mechanism of the body is unable to achieve fast hemostasis without the use of hemostatic drugs. Thus, the development of hemostatic materials and techniques is essential. Improving the quality of life and survival rate of patients and minimizing bodily damage requires fast, efficient hemostasis and prevention of bleeding. Alginate is regarded as an outstanding hemostatic polymer because of its non-immunogenicity, biodegradability, good biocompatibility, simple gelation, non-toxicity, and easy availability. This review summarizes the basics of hemostasis and emphasizes the recent developments regarding alginate-based hemostatic systems. Structural modifications and mixing with other materials have widely been used for the improvement of hemostatic characteristics of alginate and for making multifunctional medical devices that not only prevent uncontrolled bleeding but also have antibacterial characteristics, drug delivery abilities, and curing effects. This review is hoped to prepare critical insights into alginate modifications for better hemostatic properties.

Process optimization and character evaluation of Bletilla striata polysaccharide (BSP) and chitosan (CS) composite hemostatic sponge (BSP-CS)

Bletilla striata polysaccharide (BSP) and chitosan (CS) were chemically cross-linked using oxalyl chloride to prepare a composite hemostatic sponge (BSP-CS), and the process parameters were optimized using the Box-Behnken design (BBD) with response surface methodology. To optimize the performance of the hemostatic sponge, we adjusted the ratio of independent variables, the amount of oxalyl chloride added, and the freeze-dried volume. A series of evaluations were conducted on the hemostatic applicability of BSP-CS. The characterization results revealed that BSP-CS had a stable bacteriostatic effect on Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa within 72 h, and the bacteriostatic rate was above 30%. The CCK-8 cytotoxicity test demonstrated that BSP-CS had a certain effect on promoting cell proliferation of L929 cells. In the mouse tail-cutting experiment, the hemostasis time of BSP-CS was 463.0±38.16 s, shortened by 91.3 s on average compared with 554.3±34.67 s of the gauze group. The blood loss of the BSP-CS group was 28.47±3.74 mg, which was 34.7% lower than that of the control gauze group (43.6±3.83 mg). In the in vitro coagulation experiment, the in vitro coagulation index of the BSP-CS group was 97.29%±1.8%, which was reduced to 8.6% of the control group. The CT value of the BSP-CS group was 240±15 s, which was 155 s lower than that of the gauze group (355±31.22 s). All characterization results indicate that BSP-CS is an excellent hemostatic material.

Multifunctional chitosan-based gel sponge with efficient antibacterial, hemostasis and strong adhesion

Developing wound dressings with solid adhesive properties that enable efficient, painless hemostasis and prevent wound infection remain a huge challenge. Herein, the tris(hydroxymethyl) methyl glycine-modified chitosan derivative (CTMG) was prepared and freeze-dried after simply adjusting the concentration of CTMG to obtain the chitosan-based gel sponge with desired multi-hollow structure, special antibacterial and biocompatibility. The adhesion strength on porcine skin was impressive up to 113 KPa, much higher than fibrin glue. It can withstand the pressure that far exceeds blood pressure. CTMG exhibits bacteriostatic abilities as demonstrated in a bacteriostatic assay, and alongside biocompatibility, as shown in cytotoxicity and hemolytic assays. Moreover, CTMG gel sponge showed hemostatic properties in both in vivo and in vitro hemostasis experiments. During an experiment on liver hemorrhage in rats, CTMG gel sponge proved to be more effective in controlling bleeding than other hemostatic sponges available on the market, indicating its promising hemostatic properties. CTMG gel sponge possesses the potential to function as a wound dressing and hemostatic material, making it suitable for various clinical applications.

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.

The hierarchical porous structures of diatom biosilica-based hemostat: From selective adsorption to rapid hemostasis

Here, we developed a Ca2+ modified diatom biosilica-based hemostat (DBp-Ca2+) with a full scale hierarchical porous structure (pore sizes range from micrometers to nanometers). The unique porous size in stepped arrangement of DBp-Ca2+give it selective adsorption capacity during coagulation process, resulted in rapid hemorrhage control. Based on in vitro and in vivo studies, it was confirmed that the primary micropores of DBp-Ca2+gave it high porosity to hold water (water absorption: 78.46 ± 1.12 %) and protein (protein absorption: 83.7 ± 1.33 mg/g). Its secondary mesopores to macropores could reduce of water diffusion length to accelerate blood exchange (complete within 300 ms). The tertiary stacking pores of DBp-Ca2+ could absorb platelets and erythrocytes to reduce more than 50 % of thrombosis time, and provided enough contact between Ca active site and coagulation factors for triggering clotting cascade reaction. This work not only developed a novel DBs based hemostat with efficient hemorrhage control, but also provided new insights to study procoagulant mechanism of inorganic hemostat with hierarchical porous structure from selective adsorption to rapid hemostasis.

An ex vivo rat trachea model reveals abnormal airway physiology and a gland secretion defect in cystic fibrosis

Cystic fibrosis (CF) is a genetic disease hallmarked by aberrant ion transport that results in delayed mucus clearance, chronic infection, and progressive lung function decline. Several animal models have been developed to study the airway anatomy and mucus physiology in CF, but they are costly and difficult to maintain, making them less accessible for many applications. A more available CFTR-/- rat model has been developed and characterized to develop CF airway abnormalities, but consistent dosing of pharmacologic agents and longitudinal evaluation remain a challenge. In this study, we report the development and characterization of a novel ex vivo trachea model that utilizes both wild type (WT) and CFTR-/- rat tracheae cultured on a porcine gelatin matrix. Here we show that the ex vivo tracheae remain viable for weeks, maintain a CF disease phenotype that can be readily quantified, and respond to stimulation of mucus and fluid secretion by cholinergic stimulation. Furthermore, we show that ex vivo tracheae may be used for well-controlled pharmacological treatments, which are difficult to perform on freshly excised trachea or in vivo models with this degree of scrutiny. With improved interrogation possible with a durable trachea, we also established firm evidence of a gland secretion defect in CFTR-/- rat tracheae compared to WT controls. Finally, we demonstrate that the ex vivo tracheae can be used to generate high mucus protein yields for subsequent studies, which are currently limited by in vivo mucus collection techniques. Overall, this study suggests that the ex vivo trachea model is an effective, easy to set up culture model to study airway and mucus physiology.

The effect of different hemostatic agents following dental extraction in patients under oral antithrombotic therapy: a network meta-analysis

This network meta-analysis was done to thoroughly evaluate the available literature on the use of different hemostatic agents for dental extraction in patients under oral antithrombotic therapy, aiming to identify the agent with the best/worst performance in bleeding control. Considering that such patients have a higher risk of bleeding, choosing the right hemostatic is essential. Twenty-three randomized clinical trials articles were included after completing the literature search. Cyanoacrylate tissue adhesive showed a reduction in the odds of postoperative bleeding events compared with conventional methods (i.e., gauze/cotton pressure, sutures), with a tendency toward a statistical significance (OR 0.03, P = 0.051). Tranexamic acid was the only agent that demonstrated a significantly lower risk of developing postoperative bleeding events (OR 0.27, P = 0.007). Interestingly, chitosan dental dressing and collagen plug had the shortest time to reach hemostasis. However, they ranked last among all hemostatic agents, regarding bleeding events, revealing higher odds than conventional measures. Therefore, it is concluded that the use of cyanoacrylate tissue adhesive and tranexamic acid gives favorable results in reducing postoperative bleeding events following dental extractions. Although chitosan dental dressing and collagen exhibited a faster time to reach hemostasis, they led to a higher occurrence of bleeding events.

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.

Portable Handheld "SkinPen" Loaded with Biomaterial Ink for In Situ Wound Healing

In situ bioprinting has emerged as an attractive tool for directly depositing therapy ink at the defective area to adapt to the irregular wound shape. However, traditional bioprinting exhibits an obvious limitation in terms of an unsatisfactory bioadhesive effect. Here, a portable handheld bioprinter loaded with biomaterial ink is designed and named "SkinPen". Gelatin methacrylate (GelMA) and Cu-containing bioactive glass nanoparticles (Cu-BGn) serve as the main components to form the hydrogel ink, which displays excellent biocompatibility and antibacterial and angiogenic properties. More importantly, by introducing ultrasound and ultraviolet in a sequential programmed manner, the SkinPen achieves in situ instant gelation and amplified (more than threefold) bioadhesive shear strength. It is suggested that ultrasound-induced cavitation and the resulting topological entanglement contribute to the enhanced bioadhesive performance together. Combining the ultrasound-enhanced bioadhesion with the curative role of the hydrogel, the SkinPen shows a satisfactory wound-healing effect in diabetic rats. Given the detachable property of the SkinPen, the whole device can be put in a first-aid kit. Therefore, the application scenarios can be expanded to many kinds of accidents. Overall, this work presents a portable handheld SkinPen that might provide a facile but effective approach for clinical wound management.