The hemocompatibility of the modified polysulfone membrane with 4-(chloromethyl)benzoic acid and sulfonated hydroxypropyl chitosan

Improving Hemocompatibility of Polysulfone Membrane by UV-Assisted Grafting of Sulfonated Chitosan

The most prevalent type of hemodialysis membrane is polysulfone (PSf). However, due to inadequate biocompatibility, it significantly compromises the safety of dialysis for patients. In this study, we modify the surface of the PSf membrane with 2,4-dihydroxybenzophenone (DBPh) groups to serve as anchoring sites during UV irradiation. Subsequently, a tailored sulfonated dihydroxy propyl chitosan (SDHPCS) is grafted onto the modified PSf membrane to compensate for the deficiencies in hydrophilic additives. The modified PSf membrane exhibits outstanding hydrophilicity and stability, as demonstrated by its characterization and evaluation. This paper focuses on investigating the interaction between platelet membrane formation, protein adsorption, and anticoagulant activity. The results show that the modified PSf membrane exhibits remarkable enhancement in surface hydrophilicity, leading to a significant reduction in protein and platelet adsorption as well as adhesion.

The Surface of a PMP Hollow Fiber Membrane Was Modified with a Diamond-like Carbon Film to Enhance the Blood Compatibility of an Artificial Lung Membrane

The contact between the blood and the surface of medical materials causes a series of rejection reactions. In this process, the plasma protein is adsorbed to the surface of materials within seconds and binds to glycoprotein receptors on platelets, causing platelet activation, coagulation cascade, and complement activation to form thrombus, which greatly limits the application of medical materials. In our work, the surface of poly(4-methyl-1-pentene) hollow fiber membranes (PMP HFMs) was coated with a diamond-like carbon (DLC) film by the ion plating method. The blood compatibility of the DLC coating was evaluated by protein adsorption, platelet adhesion, clotting time, red blood cell (RBCs) hemolysis, dynamic coagulation, and extracorporeal blood circulation tests. Compared with the unmodified PMP membrane, the DLC film could effectively reduce protein adsorption and platelet adhesion and prolong the coagulation time. The DLC coating showed BSA adsorption of as low as 0.53 μg/cm2 as well as a long activated partial thromboplastin time (APTT) value of 71.84 s. Furthermore, the PMP membrane modified with the DLC coating was used for extracorporeal blood circulation without thrombosis forming within 28 days. The DLC coating is one of the most promising medical coatings as an artificial lung membrane in extracorporeal membrane oxygenation (ECMO) equipment.

Construction of an Antithrombotic and Anti-Inflammatory Polyethersulfone Membrane

In addition to being the core factor in thrombosis, thrombin is involved in various inflammatory disease responses, but few studies have examined whether and how it is involved in membrane-related inflammation. In this study, the thrombin inhibitor dabigatran is used to modify a polyethersulfone dialysis membrane. The modified membrane shows good hydrophilic properties and dialysis performance. It reduces the thrombin level in a targeted manner, thereby significantly inhibiting coagulation factor activation (based on the prothrombin time, international normalized ratio, activated partial thromboplastin time and thrombin time) and reducing the fibrinogen level and platelet adhesion. On thromboelastography, it shows excellent dynamic antithrombotic capacity. The modified membrane inhibited membrane-related inflammation by inhibiting the production of the inflammatory mediators C-reactive protein (CRP), interleukin-6 (IL-6), and interleukin-1β (IL-1β) via the thrombin/complement C5a pathway. Moreover, it is found to be safe in an in vivo study. Thus, the dabigatran-modified polyethersulfone membrane may reduce dialysis-related complications through its dual antithrombotic and anti-inflammatory effects.

Synthesis and Anticancer Activity of Bagasse Xylan/Resveratrol Graft-Esterified Composite Nanoderivative

Biomass materials are high-quality raw materials for the preparation of natural, green and highly active functional materials due to their rich active groups, wide sources and low toxicity. Bagasse xylan (BX) and resveratrol (Res) were used as raw materials to introduce ethylene glycol dimethacrylate (EGDMA) via grafting reaction to obtain the intermediate product BX/Res-g-EGDMA. The intermediate was esterified with 3-carboxyphenylboronic acid (3-CBA) to obtain the target product 3-CBA-BX/Res-g-EGDMA. The BX/Res-composite-modified nanoderivative with antitumor activity was synthesized with the nanoprecipitation method. The effects of the reaction conditions on the grafting rate (G) of BX/Res-g-EGDMA and the degree of substitution (DS) of 3-CBA-BX/Res-g-EGDMA were investigated using single-factor experiments. The results showed that under the optimized process conditions, G and DS reached 142.44% and 0.485, respectively. The product was characterized with FTIR, XRD, TG-FTC, ¹H NMR and SEM, and its anticancer activity was simulated and tested. The results showed that 3-CBA-BX/Res-g-EGDMA had a spherical structure with an average particle size of about 100 nm and that its crystalline structure and thermal stability were different from those of the raw materials. In addition, 3-CBA-BX/Res-g-EGDMA showed the best docking activity with 2HE7 with a binding free energy of −6.3 kJ/mol. The inhibition rate of 3-CBA-BX/Res-g-EGDMA on MGC80-3 (gastric cancer cells) reached 36.71 ± 4.93%, which was 18 times higher than that of BX. Therefore, this material could be a potential candidate for biomedical applications.

Functionalized Hemodialysis Polysulfone Membranes with Improved Hemocompatibility

The field of membrane materials is one of the most dynamic due to the continuously changing requirements regarding the selectivity and the upgradation of the materials developed with the constantly changing needs. Two membrane processes are essential at present, not for development, but for everyday life—desalination and hemodialysis. Hemodialysis has preserved life and increased life expectancy over the past 60–70 years for tens of millions of people with chronic kidney dysfunction. In addition to the challenges related to the efficiency and separative properties of the membranes, the biggest challenge remained and still remains the assurance of hemocompatibility—not affecting the blood during its recirculation outside the body for 4 h once every two days. This review presents the latest research carried out in the field of functionalization of polysulfone membranes (the most used polymer in the preparation of membranes for hemodialysis) with the purpose of increasing the hemocompatibility and efficiency of the separation process itself with a decreasing impact on the body.

Enhanced hydrophilicity and anticoagulation of polysulfone materials modified via dihydroxypropyl, sulfonic groups and chitosan

A novel modified polysulfone (PSF) is successfully prepared for hemodialysis by grafting with a well-defined heparin-like polymer, sulfonated dihydroxypropyl chitosan (SDHPCS), which is obtained in proper sequence via alkalization of chitosan, etherification and sulfonation. PSF is modified via chloroacetyl chloride, and then, the chloroacylated polysulfone (CAPSF) with pristine PSF is transformed into CAPSF/PSF blend membrane via the phase inversion, followed introducing amino group into CAPSF on the surface and taking glutaraldehyde as bridge between modified PSF membrane and SDHPCS. The result of ¹H NMR spectrum of prepared CAPSF indicates that the degree of the substitution of chloroacetyl group. The SEM, EDS mapping, FTIR and XPS show that SDHPCS-g-PSF membranes are successfully prepared. The hydrophilicity of the membrane modified by SDHPCS is improved obviously, and the contact angle remarkably reduced from 87 ° to below 45°, exhibiting much better hydrophilicity. The hemocompatibility characterizations including BSA adsorption, Plasma recalcification time (PRT), hemolysis ratio (HR), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) also certificates that SDHPCS-g-PSF possesses lower BSA adsorption and enhanced blood compatibility.

Preparation, characterization, and antibiofilm activity of cinnamic acid conjugated hydroxypropyl chitosan derivatives

In this study, cinnamic acid (CA) conjugated hydroxypropyl chitosan (HPCS) derivatives (HPCS-CA) with different degrees of substitution (DS) were successfully synthesized. The reaction was divided into two steps: the first step was to modify chitosan (CS) to HPCS, and the second step was to graft CA onto HPCS. Structural characterization and properties were carried out employing elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, nuclear magnetic resonance (NMR) spectra, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The solubility test revealed the better water solubility of derivatives than CS. In addition, in vitro antibacterial and antibiofilm tests were performed. As expected, HPCS-CA derivatives exhibited good antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The MIC and MBC of HPCS-CA derivatives could reach 256 μg/mL and 512 μg/mL, respectively. Confocal laser scanning microscopy (CLSM) analysis proved the inhibitory effect of HPCS-CA derivatives on S. aureus and E. coli biofilms by disrupting the formation of biofilms, reducing the thickness of biofilms, and the number of live bacteria. These results suggest the potential applicability of HPCS-CA derivatives in the treatment of biofilm-associated infections and provide a practical strategy for the design of novel CS-based antibacterial materials.

Improved hemocompatibility by modifying acellular blood vessels with bivalirudin and its biocompatibility evaluation

The incidence rate of cardiovascular diseases is increasing year by year. The demand for coronary artery bypass grafting has been very large. Acellular blood vessels have potential clinical application because of their natural vascular basis, but their biocompatibility and anticoagulant energy need to be improved. We decellularized the abdominal aorta of SD rats, and then modified with bivalirudin via polydopamine. The mechanical properties, blood compatibility, cytocompatibility, immune response, and anticoagulant properties were evaluated, and then the bivalirudin-modified acellular blood vessels were implanted into rats for remodeling evaluation in vivo. The results we got show that the bivalirudin-modified acellular blood vessels showed good cytocompatibility and blood compatibility, and its anti-inflammatory trend was dominant in the immune response. After 3 months of transplantation, the bivalirudin-modified acellular blood vessels did not easily form thrombus. It was not easy to form calcification and could make the host cells grow better. Through vascular stimulation and immunofluorescence test, we found that vascular smooth muscle cells and endothelial cells proliferated well in the bivalirudin group. Bivalirudin-modified acellular blood vessels provided new idea for small diameter tissue engineering blood vessels, and may become a potential clinical substitute for small-diameter vascular grafts.

Preparation of modified polysulfone material decorated by sulfonated citric chitosan for haemodialysis and its haemocompatibility

Polysulfone (PSF) works potentially in haemodialysis due to its great mechanical and chemical stability, but performs poorly in haemocompatibility. For promoting the unpleasant haemocompatibility, sulfonated citric chitosan (SCACS) with the structure and groups similar to heparin was primarily synthesized by acylation and sulfonation. Furthermore, the chloroacylated PSF was pretreated by electrophilic chloroacetyl chloride to achieve more active sites for further reaction; the following membranes underwent the amination and were named amination polysulfone (AMPSF) membranes. Moreover, SCACS with abundant carboxyl and sulfonic groups was covalently grafted at the surface of pretreated PSF membranes, called PSF-SCACS membranes. The PSF-SCACS membranes were successfully synthesized and characterized by 1H NMR, ATR-FTIR and XPS. In addition, the water contact angle of PSF-SCACS membranes decreased by 47° and the morphologies of the membranes changed little compared with the unmodified PSF membranes. The haemocompatible testing results, including protein adsorption, platelet adhesion, haemolysis rate, plasma recalcification time, activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT), demonstrated that the PSF-SCACS membranes possessed excellent haemocompatible performances, and SCACS played an important role in the modification.

Self-assembled phospholipid-based mixed micelles for improving the solubility, bioavailability and anticancer activity of lenvatinib

The clinical efficacy of lenvatinib (LFT) is limited by its poor aqueous solubility and low bioavailability. In this work, LFT-loaded soy phospholipid and sodium glycocholate mixed micelles (LFT-MMs) were prepared through classical co-precipitation. And it was served as an oral administration to address these shortcomings. The preparation conditions were optimized by single-factor experiments. The mass ratio of PC, SGC and LFT, and the species of dispersing media were proved to be decisive factors in controlling the properties of LFT-MMs. The optimal LFT-MMs presented prominent enhancement (500-fold) in LFT solubility, high encapsulation efficiency (87.6 %) as well as suitable stability (>1 month at 4 °C). The biocompatibility of LFT-MMs was estimated by in vitro serum stability measurement and hemolysis test. It showed that serum proteins hardly adhered to the surface of LFT-MMs, and insignificant hemolytic rate (<0.5 %) was observed at the micelles concentration below 1 mg/mL. Cytotoxicity test (MTT assay) was carried out to judge the in vitro antitumor activity. LFT-MMs showed an enhanced inhibitory activity against two main kinds of differentiated thyroid cancer cells over LFT and LFT Mesylate. To estimate the in vivo oral bioavailability of LFT-MMs, SD rats were used as animal model. Notably, the relative bioavailability of LFT-MMs compared with the original form of LFT was 176.7 %. These superior characteristics indicated that the mixed micelles are promising water-soluble formulations suitable for LFT oral delivery.

A novel anticoagulant affinity membrane for enhanced hemocompatibility and bilirubin removal

Affinity membrane is widely employed to promote specific adsorption of toxins and reduce the blood purification therapeutic time. However, it suffers from insufficient toxin binding and low hemocompatibility. Herein, a novel anticoagulant affinity membrane (AAM) was developed to clear bilirubin from human blood in a pore-flow-through way. Firstly, a nylon net membrane with a regularly arranged pore as the matrix was coated with poly(pyrrole-3-carboxylic acid) via chemical vapor deposition (CVD) method. Then, poly(L-arginine) (PLA) as a highly specific ligand of bilirubin, was immobilized onto the surface of the composited membrane after the modification of heparin. Owing to the 3-dimensional molecular architecture of PLA, up to 86.1 % of bilirubin was efficiently cleared. Besides, the AAM exhibited effective anticoagulant activity in the measurement of clotting time, with suppressed thrombus formation, low hemolysis ratio, minimized platelet and leukocyte adhesion, and excellent biosafety. Therefore, the AAM has enormous potential in blood purification therapy for enhancing hemocompatibility and bilirubin removal.

A zwitterionic hydrogel coated titanium surface with high-efficiency endothelial cell selectivity for rapid re-endothelialization

Coronary stent implantation is an effective procedure for percutaneous coronary intervention treatment. However, its long-term safety and efficacy are still hindered by the in-stent restenosis and late thrombus formation. Herein, an anti-biofouling and endothelial cell selective zwitterionic hydrogel coating was developed to simultaneously enhance the nonspecific resistance and rapid re-endothelialization of the titanium surface. An endothelial cell selective peptide, REDV, could be simply conjugated on the zwitterionic carboxybetaine (CB) hydrogel to prepare the REDV/CB coating. It was found that the REDV/CB hydrogel layer maintained antifouling properties, which could inhibit the protein adsorption, bacterial adhesion, platelet activation and aggregation, and smooth muscle cell proliferation. More importantly, the co-culture study confirmed that the conjugated REVD peptide could specifically capture endothelial cells and promote their migration and proliferation, and simultaneously decrease the adhesion and proliferation of smooth muscle cells. Therefore, the antifouling and endothelial cell selective coating proposed in this work provides a promising strategy to develop an intravascular stent for promoted re-endothelialization and inhibited neointimal hyperplasia in clinical applications.