Blood Cell Adhesion Research Articles

Inflammation-responsive PCL/gelatin microfiber scaffold with sustained nitric oxide generation and heparin release for blood-contacting implants

Delayed endothelialization, the excessive proliferation of smooth muscle cells (SMCs), and persistent inflammation are the main reasons for the implantation failure of blood-contacting materials. To overcome this problem, an inflammation-responsive, core-shell structured microfiber scaffold is developed using polycaprolactone (PCL), selenocystamine-modified gelatin (Gel-Se), L-ascorbyl 6-palmitate (AP), and dexamethasone as the fiber shell, with poly (l-lysine) (PLL) and heparin incorporated in the fiber core. Superhydrophilic microfiber scaffolds exhibit antifouling properties that inhibit protein adsorption and blood cell adhesion, thereby effectively mitigating the risk of acute thrombosis. The continuous release of heparin and sustained generation of nitric oxide (NO) through the catalytic decomposition of S-nitrosothiols by selenocystamine lead to a biomimetic endothelial function for the enhancement of blood compatibility. The inflammation-responsive compound AP can detoxify excess reactive oxygen species (ROS) while controlling the release of dexamethasone to reduce chronic inflammation. We demonstrate the ability of microfiber scaffolds to reduce thrombotic and inflammatory complications, inhibit SMC proliferation, and promote rapid endothelialization both in vitro and ex vivo. Hence, microfiber scaffolds are robust and promising for blood-contacting implants with enhanced antithrombogenicity and anti-inflammatory capabilities.

Developing a multifunctional chitosan composite sponge for managing traumatic injuries

Developing porous hemostatic sponges that are both biosafe and multifunctional remains a complex challenge. Conventional hemostatic techniques often fall short in managing bleeding effectively, leading to severe critical cases such as suboptimal hemostasis, increased infection risk, and complications arising from profuse bleeding. To address these deficits, our study introduces a novel multifunctional nanocomposite sponge that synergistically incorporates chitosan (CS), cellulose (Cel), graphene oxide (GO), and silver (Ag) nanoparticles. The resulting CS/Cel/GO/Ag developed demonstrates a swelling rate exceeding 3000 %, an absorption rate of over 2100 %, and the lowest stress surpassing 20 kPa at an initial 80 % strain. In vitro analyses reveal that the CS/Cel/GO/Ag sponge has excellent cytocompatibility, non-hemolytic nature, and competence in blood cell adherence and bacterial inhibition. In vivo evaluations further demonstrate that compared to conventional hemostatic methods, the sponge substantially enhances hemostatic efficacy, as evidenced by the marked reductions in clotting times and diminished blood loss compared to conventional hemostatic methods. Specifically, the test results of the CS/Cel/GO/Ag sponge across three different models are as follows: for the rat tail amputation model, the clotting time was 99 s, while blood loss was 222 mg; for the rat liver injury model, the clotting time was 129 s. while blood loss was 812 mg; for the rat femoral artery laceration model, the clotting time was 96 s, while blood loss was 758 mg. The compelling attributes of the CS/Cel/GO/Ag sponges position them as a promising solution for the acute management of bleeding. Their excellent performance indicates they have potential role to play in trauma care.

Swelling-assisted surface grafting strategy for multichannel antifouling membranes: Reconstruction of surface pore structure and applications in microalgae harvesting and blood purification

Membrane fouling remains a major challenge in membrane separation. The modification of hydrophilic membrane surfaces can mitigate irreversible fouling deposition, thereby improving antifouling properties. Effective surface modification strategies are essential techniques for developing highly efficient antifouling membranes. In this work, a swelling-assisted surface grafting strategy was proposed for multichannel antifouling membranes, where various lengths of polyvinylpyrrolidone (PVP) brushes were grafted on the surface of polysulfone membrane using reversible addition-fragmentation chain transfer polymerization. The successful grafting of PVP polymer brushes was confirmed using Fourier transform infrared spectrometer and X-ray Photoelectron Spectroscopy. Changes in membrane morphology and pore structure were observed via scanning electron microscope and atomic force microscope. During the grafting process, the amphiphilic macromolecules formed through grafting were selectively swelled by graft solvent, leading to the formation of mesopores in both the surface layer and sublayer of the membrane, which formed additional water transport channels. The introduction of hydrophilic polymer brushes and the change of pore structure significantly boosted the hydrophilicity and permeability of the membranes. As a result, the water contact angle decreased from 85° to 42°, accompanied by an approximate 3.24-fold increase in pure water flux (PWF). Due to superior hydrophilicity, modified membranes demonstrated exemplary performance in microalgae harvesting, boasting a microalgae retention rate nearing 100 % and low fouling resistance (2.12 × 1012 m−1). In algal filtration experiments, a confocal laser scanning microscope was employed to assess the activity of filtered algae on the membrane surface. The prepared membranes effectively maintained the bioactivity of algae while also achieving a high flux recovery rate (90.7 %) following filtration and cleaning. Furthermore, in blood cell compatibility tests, the modified membranes exhibited resistance to blood cell adhesion and sustained a low hemolysis rate (0.06 %). Overall, this strategy offers unique insights into the fabrication of antifouling surfaces and shows considerable promise for large-scale applications in microalgae harvesting and blood purification.

Lysine-Mediated Yttrium Oxide Nanoparticle-Incorporated Nanofibrous Scaffolds with Tunable Cell Adhesion, Proliferation, and Antimicrobial Potency for In Vitro Wound-Healing Applications.

The intricate healing mechanism of chronic wounds and their multitude of healing-related obstacles, such as infections, compromised cellular processes, and impediments to the healing process, pose a significant healthcare problem. Exploration of metal oxide nanoparticles, such as yttrium oxide (Y2O3) nanoparticles, can lead to innovative discoveries in the field of chronic wound healing by offering cues that promote cell proliferation in the scaffolds. To achieve this, Y2O3 nanoparticles were synthesized and incorporated within poly(vinyl alcohol) (PVA) nanofibrous scaffolds. Moreover, lysine was infused in the nanofibrous scaffolds to tune its cell adhesion and antimicrobial property. The structure and morphology of the synthesized nanofibers were confirmed through various physicochemical characterizations. Notably, all the fabricated scaffolds have remarkably tuned WVTR values within the range of 2000-2500 g/m2/day, favorable for removing the wound exudate, which facilitate the healing process. The scaffolds exhibited substantial antimicrobial property of approximately 68% and 72.2% against both E. coli and S. aureus at optimized Y2O3 loading. They further prevented the formation of biofilm by 68.6% for S. aureus and 51.2% for P. aeruginosa, suggesting the inhibition of recurrent wound infection. The scaffolds illustrated good blood biocompatibility, cytocompatibility, and cell adhesion capabilities. In vitro ROS inhibition study also corroborated the antioxidant property of the scaffold. Similarly, the wound scratching experiment showed high proliferative capability of a yttria-loaded PVA/lysine (S3) sample through the development of an extracellular matrix support. Molecular insight of wound healing was also validated through flow cytometry analysis and immunocytochemistry imaging studies. The findings revealed increased collagen I (Col-I) expression of approximately 19.48% in cultured fibrocytes. The findings are validated from immunocytochemistry imaging. In summary, the results furnish a captivating paradigm for the use of these scaffolds as a therapeutic biomaterial and to foster their potential efficacy toward wound care management.

The effect of mesoporous bioglass on hemostatic, antibacterial and biocompatible properties of composite sponge

AbstractHemostatic materials used in penetrating injuries or incompressible wounds must possess exceptional efficacy in preventing bleeding. In this study, mesoporous bioglass (MBG) was synthesized using a two‐step acid‐catalyzed self‐assembly method, and a novel hemostatic sponge (MBG/CH/GEL) was prepared by combining chitosan (CH), gelatin (GEL), and MBG using a freeze‐drying method. The characteristics and hemostatic effects of the MBG/CH/GEL composite hemostatic sponge were analyzed and evaluated. Research has shown that the high specific surface area of MBG (730 m2/g) provides more blood cell adhesion sites during hemostasis, resulting in a low hemolysis rate, favorable swelling rate, and porosity of the hemostatic sponge. Additionally, MBG can release Si4+ and Ca2+ ions during hemostasis, giving the composite hemostatic sponge excellent cell compatibility and promoting cell growth. Compared with commercially available gelatin hemostatic sponges, it cannot only quickly stop bleeding but also has a greater compressive strength (212.07 kPa) and adhesion strength (11.54 ± 0.16 kPa), making it suitable for use in hemostasis of incompressible wounds. Furthermore, the composite hemostatic sponge exhibited significant antibacterial effects against Staphylococcus aureus and Escherichia coli. These results indicate that the MBG/CH/GEL composite hemostatic sponge, which is a hemostatic material, has promising applications.

Coagulopathy-independent injectable catechol-functionalized chitosan shape-memory material to treat non-compressible hemorrhage

Uncontrolled non-compressible hemorrhage, which is often accompanied by coagulopathy, is a major cause of mortality following traumatic injuries in civilian and military populations. In this study, coagulopathy-independent injectable catechol-modified chitosan (CS-HCA) hemostatic materials featuring rapid shape recovery were fabricated by combining controlled sodium tripolyphosphate-crosslinking with hydrocaffeic acid (HCA) grafting. CS-HCA exhibited robust mechanical strength and rapid blood-triggered shape recovery. Furthermore, CS-HCA demonstrated superior blood-clotting ability, enhanced blood cell adhesion and activation, and greater protein adsorption than commercial hemostatic gauze and Celox. CS-HCA showed enhanced procoagulant and hemostatic capacities in a lethal liver-perforation wound model in rabbits, particularly in heparinized rabbits. CS-HCA is suitable for mass manufacturing and shows promise as a clinically translatable hemostat.

Calcium Ion-Coupled Polyphosphates with Different Degrees of Polymerization for Bleeding Control.

The development of efficient hemostatic materials is crucial for achieving rapid hemorrhage control and effective wound healing. Inorganic polyphosphate (polyP) is recognized as an effective modulator of the blood coagulation process. However, the specific effect of polyP chain length on coagulation is not yet fully understood. Furthermore, calcium ions (Ca2+) are essential for the coagulation process, promoting multiple enzyme-catalyzed reactions within the coagulation cascade. Hence, calcium ion-coupled polyphosphate powders with three different degrees of polymerization (CaPP-n, n = 20, 50, and 1500) are synthesized by an ion-exchange reaction. CaPP exhibits a crystalline phase at a low polymerization degree and transitions to an amorphous phase as the polymerization degree increases. Notably, the addition of Ca2+ enhances the wettability of polyP, and CaPP promotes hemostasis, with varying degrees of effectiveness related to chain length. CaPP-50 exhibits the most promising hemostatic performance, with the lowest blood clotting index (BCI, 12.1 ± 0.7%) and the shortest clotting time (302.0 ± 10.5 s). By combining Ca2+ with polyP of medium-chain length, CaPP-50 demonstrates an enhanced ability to accelerate the adhesion and activation of blood cells, initiate the intrinsic coagulation cascade, and form a stable blood clot, outperforming both CaPP-20 and CaPP-1500. The hemostatic efficacy of CaPP-50 is further validated using rat liver bleeding and femoral artery puncture models. CaPP-50 is proven to possess hemostatic properties comparable to those of commercial calcium-based zeolite hemostatic powder and superior to kaolin. In addition, CaPP-50 exhibits excellent biocompatibility and long-term storage stability. These results suggest that CaPP-50 has significant clinical and commercial potential as an active inorganic hemostatic agent for rapid control of bleeding.

Phenotypic and genomic analysis of the hypervirulent methicillin-resistant Staphylococcus aureus ST630 clone in China.

Methicillin-resistant Staphylococcus aureus (MRSA) sequence type 630 (ST630) is a rarely reported lineage worldwide. This study aimed to trace the dissemination of the emerging MRSA ST630 clones in China and investigate their virulence potential. We collected 22 ST630-MRSA isolates from across China and performed whole-genome sequencing analysis and virulence characterization on these isolates. Epidemiological results showed that MRSA ST630 isolates were primarily isolated from pus/wound secretions, mainly originating from Jiangxi province, and carried diverse virulence and drug resistance genes. Staphylococcal cassette chromosome mec type V (SCCmec V) predominated (11/22, 50.0%) among the MRSA ST630 isolates. Interestingly, nearly half (45.5%) of the 22 ST630-MRSA isolates tested lacked intact SCCmec elements. Phylogenetic analysis demonstrated that ST630-MRSA could be divided into two distinct clades, with widespread dissemination mainly in Chinese regions. Five representative isolates were selected for phenotypic assays, including hemolysin activity, real-time fluorescence quantitative PCR, western blot analysis, hydrogen peroxide killing assay, blood killing assay, cell adhesion and invasion assay, and mouse skin abscess model. The results showed that, compared to the USA300-LAC strain, ST630 isolates exhibited particularly strong invasiveness and virulence in the aforementioned phenotypic assays. This study described the emergence of a highly virulent ST630-MRSA lineage and improved our insight into the molecular epidemiology of ST630 clones in China.IMPORTANCEMethicillin-resistant Staphylococcus aureus (MRSA) sequence type 630 (ST630) is an emerging clone with an increasing isolation rate in China. This study raises awareness of the hypervirulent MRSA ST630 clones in China and alerts people to their widespread dissemination. ST630-staphylococcal cassette chromosome mec V is a noteworthy clone in China, and we present the first comprehensive genetic and phenotypic analysis of this lineage. Our findings provide valuable insights for the prevention and control of infections caused by this emerging MRSA clone.

Biodegradable quaternized silk fibroin sponge with highly uniform pore structure for traumatic hemostasis and anti-infection

Developing a biodegradable sponge with rapid shape recovery and potent antibacterial and coagulation properties for traumatic hemostasis and anti-infection remains challenging. Herein, we fabricated quaternized silk fibroin (SF) sponges by freeze-drying under a constant cooling rate and modification with quaternary ammonium groups. We found the constant cooling rate enabled the sponges with a highly uniform pore structure, which provided excellent self-elasticity and shape recovery. Decoration with quaternary ammonium groups enhanced blood cells adhesion, aggregation, and activation, as well as resistance to infections from Staphylococcus aureus and Escherichia coli. The SF sponge had superior hemostatic capacity to gauze and commercial gelatin sponge in different hemorrhage models. The SF sponge exhibited favorable biodegradability and biocompatibility. Moreover, The SF sponge also promoted host cell infiltration, capillary formation, and tissue ingrowth, suggesting its potential for guiding tissue regeneration. The developed SF sponge holds great application prospects for traumatic hemostasis, anti-infection, and guiding tissue regeneration.

Additive-free Absorbable Keratin Sponge With Procoagulant Activity for Noncompressible Hemostasis.

The development of a natural, additive-free, absorbable sponge with procoagulant activity for noncompressible hemostasis remains a challenging task. In this study, we extracted high molecular weight keratin (HK) from human hair and transformed it into a hemostatic sponge with a well-interconnected pore structure using a foaming technique, freeze-drying, and oxidation cross-linking. By controlling the cross-linking degree, the resulting sponge demonstrated excellent liquid absorption ability, shape recovery characteristics, and robust mechanical properties. The HK10 sponge exhibited rapid liquid absorption, expanding up to 600% within 5 s. Moreover, the HK sponge showed superior platelet activation and blood cell adhesion capabilities. In SD rat liver defect models, the sponges demonstrated excellent hemostatic performance by sealing the wound and expediting coagulation, reducing the hemostatic time from 825 to 297 s. Furthermore, HK sponges have excellent biosafety, positioning them as a promising absorbable sponge with the potential for the treatment of noncompressible hemostasis.

Hemostatic Dressing Immobilized with ε-poly-L-lysine and Alginate Coated Mesoporous Bioactive Glass Prevents Blood Permeation by Pseudo-Dewetting Behavior.

The integration of hemostats with cotton fabrics is recognized as an effective approach to improve the hemostatic performance of dressings. However, concerns regarding the uncontrollable absorption of blood by hydrophilic dressings and the risk of distal thrombosis from shed hemostatic agents are increasingly scrutinized. To address these issues, this work develops an advanced dressing (AQG) with immobilized nano-scale mesoporous bioactive glass (MBG) to safely and durably augment hemostasis. The doubly immobilized MBGs, pre-coated with ε-poly-L-lysine and alginate, demonstrate less than 1% detachment after ultrasonic washing. Notably, this MBG layer significantly promotes the adhesion, aggregation, and activation of red blood cells and platelets, adhered five times more red blood cells and 29 times more platelets than raw dressing, respectively. Specially, with the rapid formation of protein corona and amplification of thrombin, dense fibrin network is built on MBG layer and then blocked blood permeation transversely and longitudinally, showing an autophobic pseudo-dewetting behavior and allowing AQG to concentrate blood in situ and culminate in faster hemostasis with lower blood loss. Furthermore, the potent antibacterial properties of AQG extend its potential for broader application in daily care and clinical setting.

The hemostatic performance and mechanism of palygorskite with structural regulate by oxalic acid gradient leaching

Palygorskite (Pal) is a naturally available one-dimensional clay mineral, featuring rod-shaped morphology, nanoporous structure, permanent negative charges as well as abundant surface hydroxyl groups, exhibiting promising potential as a natural hemostatic material. In this study, the hemostatic performance and mechanisms of Pal were systematically investigated based on the structural regulate induced by oxalic acid (OA) gradient leaching from perspectives of structure, surface attributes and ion release. In vitro and in vivo hemostasis evaluation showed that Pal with OA leaching for 1 h exhibited a superior blood procoagulant effect compared with the raw Pal as well as the others leached for prolonging time. This phenomenon might be ascribed to the synergistic effect of the intact nanorod-like morphology, the increase in the surface negative charge, the release of metal ions (Fe3+ and Mg2+), and the improved blood affinity, which promoted the intrinsic coagulation pathway, the fibrinogenesis and the adhesion of blood cells, thereby accelerating the formation of robust blood clots. This work is expected to provide experimental and theoretical basis for the construction of hemostatic biomaterials based on clay minerals.

Injectable and rapidly expandable thrombin-decorated cryogels achieve rapid hemostasis and high survival rates in a swine model of lethal junctional hemorrhage

Effective therapies are urgently needed to stabilize patients with marginally compressible junctional hemorrhage long enough to get them to the hospital alive. Herein, we report injectable and rapidly expandable cryogels consisting of polyacrylamide and thrombin (AT cryogels) created by cryo-polymerization for the efficient management of lethal junctional hemorrhage in swine. The produced cryogels have small pore sizes and highly interconnected porous architecture with robust mechanical strength. The cryogels exhibit rapid shape memory properties and prove to be resilient against fatigue. These cryogels also show high water/blood absorption capacity, fast blood clotting effect, and enhanced adhesion of red blood cells and platelets in vitro. Further, in vivo, hemostatic efficacy tests in a lethal swine junctional hemorrhage model suggest that treatment with AT cryogels, especially AT-2 cryogels, achieves the least blood loss and the highest survival rate (100 %) compared to currently employed products such as XStat® and combat gauze. The high hemostatic performance of the cryogels may be attributed to highly interconnected porous architecture with small pore size and the use of thrombin as a pro-coagulant agent. Collectively, injectable and rapidly expandable thrombin-decorated polyacrylamide-based cryogels show significant promise as hemostatic material, offering effective management of marginally compressible junctional hemorrhages in prehospital settings.

Self-restoring cryogels used for the repair of hemorrhagic bone defects by modulating blood clots

Bleeding from severe traumatic bone defects poses a significant threat to patient survival, and conventional hemostatic agents prove inadequate for addressing bone defects when pressure application is not feasible. Therefore, the development of a bio-multifunctional material with outstanding hemostatic and osteogenic performances is highly desirable. In this study, chitosan/hydroxyapatite nanowires cryogels (CSHAn) were fabricated via schiff base reaction and electrostatic interaction. These CSHAn cryogels demonstrate an impressive absorption capacity, reaching up to 5387 %, and possess considerable mechanical strength, quantified at 167.92 kPa, along with significant compressive recovery capabilities. CSHAn cryogels demonstrate superior blood-clotting ability, enhanced blood cell and platelet adhesion, and activation compared to gelatin sponges. Moreover, in vitro cellular assessments indicate that the developed CSHAn2 exhibits favorable cytocompatibility and significantly promote osteogenesis by upregulating the formation of alkaline phosphatase and calcium nodules. Taken together, this multi-functional cryogels is potentially valuable for clinical applications towards hemorrhagic bone defect repair.

In vitro evaluation of the platelet adhesion and interferon-γ production capacity of mononuclear cells coming in contact with a hydrophilic polymer-embedded polysulfone dialyzer

BackgroundA polysulfone dialysis membrane containing both polyvinylpyrrolidone (PVP) and the novel hydrophilic polymer (NV polymer) has been developed in an attempt to modify the blood contact surface of the membrane. In the present study, we performed an in vitro evaluation of the NV polymer-embedded membrane (NV membrane), focusing on the adhesion of blood cells to the membrane and the interferon (IFN)-γ production capacity of peripheral blood mononuclear cells coming in contact with the membrane.MethodsTwo membranes, the NV membrane and the conventional membrane embedded with PVP alone (CX), were evaluated simultaneously by dividing the porcine blood obtained from the same animal into two portions. The blood cell adhesion to the membranes was evaluated by measuring the hemoglobin concentrations and lactate dehydrogenase (LDH) activities in the eluates extracted from the membranes. The IFN-γ production capacity in response to phytohemagglutinin stimulation of mononuclear cells coming in contact with either membrane was evaluated.ResultsBoth the hemoglobin concentration and LDH activity, corrected by excluding erythrocytes from the eluate, were about 25% lower in the eluate from the NV membrane than in the eluate from the CX membrane. The IFN-γ production capacity of the mononuclear cells coming in contact with dialysis membrane remained unchanged for the case of the NV membrane, while it decreased for the case of the CX membrane.ConclusionsA lower degree of adhesion of blood cells to the membrane and a lower degree of reduction in the IFN-γ production capacity of mononuclear cells coming in contact with the membrane were observed for the NV membrane, as compared with the PVP membrane, which may suggest improved biocompatibility of the NV membrane.

A super hydrophilic and high strength chitosan hemostatic sponge prepared by freeze-drying and alkali treatment for rapid hemostasis

Excessive blood loss caused by natural accidents or major surgical procedures can be life-threatening and requires rapid hemorrhage management. Developing hemostatic materials with high water absorption capacity and high strength properties is still challenging. Super hydrophilic/high-strength chitosan hemostatic sponges (SHHS-CHS) were prepared by freeze-drying and alkali treatment. The freeze-drying technology formed a porous three-dimensional structure of sponges, and alkali treatment increased the hydrophilicity of sponges and the rigidity of the chitosan molecular chain, improving the hydrophilicity and mechanical properties of chitosan sponges. Characterization experiments revealed that SHHS-CHS had high water absorption capacity, rich pore structure, and excellent mechanical properties. The cytotoxicity and hemolysis experiments showed that SHHS-CHS had good biocompatibility. Compared to the commercial hemostatic gelatin sponges and chitosan hemostatic material, SHHS-CHS had better blood coagulation and red blood cell and platelet adhesion ability. Moreover, SHHS-CHS showed better hemostatic ability than gelatin sponges in rat-liver injury and rat leg vein rupture models, significantly reducing the hemostasis time and bleeding volume. In conclusion, SHHS-CHS has broad prospects for clinical application as a hemostatic material.

Study on PTFE superhydrophobic coating modified by IC@dMSNs and its enhanced antibacterial effect

IntroductionVascular catheter-related infections and thrombosis are common and may lead to serious complications after catheterization. Reducing the incidence of such infections has become a significant challenge. ObjectivesThis study aims to develop a super hydrophobic nanocomposite drug-loaded vascular catheter that can effectively resist bacterial infections and blood coagulation. MethodsIn this study, a SiO2 nanocoated PTFE (Polytetrafluoroethylene) catheter (PTFE-SiO2) was prepared and further optimized to prepare a SiO2 nanocoated PTFE catheter loaded with imipenem/cilastatin sodium (PTFE-IC@dMSNs). The catheters were characterized for performance, cell compatibility, anticoagulant performance, in vitro and in vivo antibacterial effect and biological safety. ResultsPTFE-IC@dMSNs catheter has efficient drug loading performance and drug release rate and has good cell compatibility and anticoagulant effect in vitro. Compared with the PTFE-SiO2 catheter, the inhibition ring of the PTFE-IC@dMSNs catheter against Escherichia coli increased from 3.98 mm2 to 4.56 mm2, and the antibacterial rate increased from about 50.8 % to 56.9 %, with a significant difference (p < 0.05). The antibacterial zone against Staphylococcus aureus increased from 8.63 mm2 to 11.74 mm2, and the antibacterial rate increased from approximately 83.5 % to 89.3 %, showing a significant difference (p < 0.05). PTFE-IC@dMSNs catheter also has good biocompatibility in vivo. Furthermore, the PTFE-IC@dMSNs catheter can reduce the adhesion of blood cells and have excellent anticoagulant properties, and even maintain these properties even with the addition of imipenem/cilastatin sodium. ConclusionCompared with PTFE, PTFE-SiO2 and PTFE-IC@dMSNs catheters have good characterization performance, cell compatibility, and anticoagulant properties. PTFE SiO2 and PTFE-IC@dMSNs catheters have good antibacterial performance and tissue safety against E. coli and S. aureus. Relatively, PTFE-SiO2 and PTFE-IC@dMSNs catheter has better antibacterial properties and histocompatibility and has potential application prospects in anti-bacterial catheter development and anticoagulation.

A self-elastic chitosan sponge integrating active and passive hemostatic mechanisms for effectively managing uncontrolled coagulopathic hemorrhage

Developing a self-elastic sponge integrating active and passive hemostatic mechanisms for the effective management of uncontrolled coagulopathic hemorrhage remains a challenge. We here developed a chitosan-based sponge by integrating freeze-drying, chemical decoration of alkyl chains and phosphate groups, and physical loading of thrombin. The sponge exhibited high mechanical strength, self-elasticity, and rapid shape recovery. The sponge facilitated blood cell adhesion, aggregation, and activation through hydrophobic and electrostatic interactions, as well as accelerated blood clotting. The sponge exhibited higher efficacy than commercial gauze and gelatin sponge in managing uncontrolled hemorrhage from heparinized rat tail amputation, liver superficial injury, and liver perforating wound models. In addition, the sponge exhibited favorable biodegradability and biocompatibility. These findings revealed that the developed sponge holds great potential as a novel hemostat for effectively managing uncontrolled coagulopathic hemorrhage from superficial and perforating wounds.

Instant mucus dressing of PEO reinforced by chitosan nanofiber scaffold for open wound healing

Dressings seamlessly attached to the open wound bed are necessary for fully unleashing the dressing healing ability, as leaving the voids beneath the dressing poses infection hazards. The present study prepared an instant mucus dressing (IMD) of polyethylene oxide (PEO) reinforced by chitosan (CS) nanofiber scaffold, which formed by immersing PEO/CS nanofiber mat in water. The PEO/CS nanofiber mat were fabricated by the solution blow spinning (SBS) method using PEO and CS mixed solutions. Attenuated total reflection Fourier transform infrared spectroscopy (FTIR-ATR), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and differential scan calorimetry (DSC) analyses indicate that PEO macromolecules formed the most of nanofiber shell due to their lower surface tension while CS macromolecules stayed mainly inside the fiber as the core. When such a PEO/CS nanofiber mat was immersed in water, PEO swelled to form mucus dressing reinforced by CS inside the nanofiber, which was fluidic and able to fully fill the voids on the wound. In vivo rat experiment verified that the dressing significantly accelerated the open wound healing through seamlessly attaching of mucus to the open wound and providing moist environment. The dressings exhibit good platelets and whole blood cells adhesion properties, excellent hemostasis function and no cytotoxicity. This instant mucus dressing provided a new perspective for manufacturing high performance open wound dressings.

Multifunctional polyvinyl alcohol/gallic acid functionalized chitosan hydrogels prepared by freeze-thaw method for potential application as wound dressings

The design of multifunctional hydrogel dressings to effectively promote wound healing is highly desirable in clinical trauma and surgery. Inspired by excellent mechanical properties of polyvinyl alcohol (PVA) and strong adhesion of polyphenols, gallic acid was grafted onto chitosan molecular chain (CS-GA) by free radical polymerization in this study, and PVA/CS-GA hydrogels were successfully prepared by repeated freeze-thaw method, without introducing toxic crosslinking agents. The prepared PVA/CS-GA hydrogels could adhere to various substrates, which confirmed excellent universal adhesion properties. The red blood cells adhesion ratio was 67.1%, indicating its potential for promoting wound coagulation. Meanwhile, the mechanical strength of PVA/CS-GA hydrogel was significantly enhanced, exhibiting approximately twice tensile strength and failure stretch compared with PVA hydrogel. Furthermore, attributing to GA molecule, PVA/CS-GA hydrogels not only showed favorable antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), but also could scavenge free radicals, showing effective antioxidant activity. The hydrogels also had good biocompatibility, met the basic requirements of biomedical materials and may promote wound repair. It should be noted that the content of GA had significant impact on cytotoxicity. Therefore, multifunctional PVA/CS-GA hydrogels with excellent mechanical, adhesion, antioxidant, antibacterial and biocompatible properties show promising potential applications in the biomedicine field, especially as functional wound dressings.