Evaluation Of Blood Compatibility Research Articles

Development of dietary fibers moringa-sterculia gum hydrogel for drug delivery applications

IntroductionKeeping in view the role of polysaccharide gums in pharmaceutical applications. Herein this research, Moringa gum (MOG) and Sterculia gum (SG) polysaccharides have been explored to design the network structure in the form of hydrogels which can act as a wound dressing for better wound healing. Both gums are hydrophilic stem exudate and their anti-fungal and antioxidant activities have been reported for wound healing which can help the increase in wound healing potential of the antibiotic drug encapsulated hydrogel dressings. ObjectivesTo design the moringa gum, sterculia gum and polyacrylic acid based hydrogel wound dressings by graft copolymerization method impregnated with antibiotic drug levofloxacin for better wound care. MethodologyThe co-polymers were prepared by grafting and crosslinking of the polyacrylic acid onto MOG and SG. The copolymers were characterized by cryo-SEM, AFM, FTIR, 13C NMR and swelling studies along with the evaluation of blood compatibility, wound fluid absorption, antioxidant activity, permeability (O2, H2O and, microbial), mucoadhesion, mechanical and in vitro release dynamics of antibiotic drug levofloxacin. Results and conclusionThe Cryo-SEM and AFM images of the hydrogels showed the porous nature and rough surface morphology of the hydrogels. The porosity in the hydrogel controlled the wound fluid absorption and drug diffusion from dressing. The release of the levofloxacin from MOG-cl-SG-co-poly(AAc) hydrogel occurred by the non-Fickian diffusion mechanism and release profile was best fitted in the Korsmeyer-Peppas kinetic model of drug release in the simulated wound fluid . The gum-based dressings were found permeable and antioxidant in nature. Overall, these hydrogels could be proposed as suitable materials for biomedical applications including drug delivery and wound dressing for better wound care.

Synthesis and Characterization of Psyllium Polysaccharide–Poly(2-hydroxypropyl methacrylate)−Poly(acrylamide) Hydrogels for Use in Sustained Drug Delivery Applications

Psyllium has been explored for various food and pharmaceutical applications. Recently, its therapeutic action against cancer has been reported. Hence, herein in this research it has been modified to develop hydrogels through graft copolymerization reaction for use as sustained drug delivery carriers for anti-cancer drug “5-fluorouracil” (FU) to enhance the therapeutic potential. Synthesis of hydrogels was carried out by grafting of poly(2-hydroxypropyl methacrylate) and poly(acrylamide) onto psyllium in the presence of crosslinker. Polymers were characterized by cryo-SEM, AFM, XRD, 13C-NMR, and TGA techniques, beside evaluation of swelling, drug release, blood compatibility, mucoadhesion, antioxidant properties and gel strength of the hydrogels. The porous network structure with rough surface was observed in cryo-SEM and AFM images of the samples. Release of FU from psy-cl-poly(HPMA-co-AAm) polymer occurred with non-Fickian diffusion in sustained manner. These hydrogels were mucoadhesive (work of adhesion = 8.45 ± 0.32 N mm), non-haemolytic (haemolytic index = 1.05 ± 0.07%), and antioxidant (with 19.12 ± 0.14% inhibition in DPPH assay) in nature, therefore they could be used as slow drug delivery carriers for ailments associated GIT system.

Development and blood compatibility evaluation of novel fibrous textile scaffold based on polyurethane amalgamated with Alternanthera sessilis oil for the bone tissue engineering

In the recent decade, the growth of medical textiles is enormous and it paves the sustained development in the quality of life. In this research, an electrospun textile scaffold comprising polyurethane impregnated with Alternanthera sessilis oil was developed for the bone tissue engineering. Morphology analysis showed that the addition of Alternanthera sessilis oil in the polyurethane membrane resulted in reduced fiber diameter (821 ± 140.87 nm) compared to the pristine PU (890 ± 119.11 nm). The presence of Alternanthera sessilis oil in polyurethane membrane was confirmed through hydrogen bond formation as revealed in the infrared analysis. Further, the polyurethane blended with Alternanthera sessilis oil showed hydrophobic (113.7° ± 3.215) and improved surface roughness (329 nm) than the pristine polyurethane (contact angle – 100° ± 0.5774 and Ra – 313 nm). Moreover, the blood compatibility assessments revealed that the developed biocomponent polyurethane/ Alternanthera sessilis oil membrane possesses enhanced anticoagulant nature compared to the pristine polyurethane. Finally, the newly developed biocomponent polyurethane/ Alternanthera sessilis oil membrane with reduced fiber diameter, hydrophobic behavior, improved surface roughness, and enhanced blood compatibility enabled them as a potential candidate for bone tissue regeneration.

Immobilization of Fibronectin-Loaded Polyelectrolyte Nanoparticles on Cardiovascular Material Surface to Improve the Biocompatibility

Vascular stent interventional therapy is the main method for clinical treatment of coronary artery diseases. However, due to the insufficient biocompatibility of cardiovascular materials, the implantation of stents often leads to serious adverse cardiac events. Surface biofunctional modification to improve the biocompatibility of vascular stents has been the focus of current research. In this study, based on the structure and function of extracellular matrix on vascular injury healing, a novel fibronectin-loaded poly-l-lysine/heparin nanoparticles was constructed for stent surface modification. In vitro blood compatibility evaluation results showed that the nanoparticles-modified surface could effectively reduce platelet adhesion and activation. In vitro cellular compatibility evaluation results indicated that the nanocoating may provide adequate efficacy in promoting the adhesion and proliferation of endothelial cells and thereby accelerate endothelialization. This study provides a new approach for the surface biological function modification of vascular stents.

Evaluation of a simple off-the-shelf bi-layered vascular scaffold based on poly(L-lactide-co-ε-caprolactone)/silk fibroin in vitro and in vivo.

Purpose: In the field of small-caliber vascular scaffold research, excellent vascular remodeling is the key to ensuring anticoagulant function. We prepared an off-the-shelf bi-layered vascular scaffold with a dense inner layer and a loose outer layer and evaluated its remodeling capabilities by in vivo transplantation.Materials and Methods: Based on poly(L-lactide-co-ε-caprolactone) (PLCL), silk fibroin(SF), and heparin (Hep), PLCL/SF/Hep bi-layered scaffolds and PLCL/Hep bi-layered scaffolds were prepared by electrospinning. The inner layer was a PLCL/SF/Hep or PLCL/Hep nanofiber membrane, and the outer layer was PLCL/SF nano yarn. The in vitro tests included a hydrophilicity test, mechanical properties test, and blood and cell compatibility evaluation. The in vivo evaluation was conducted via single rabbit carotid artery replacement and subsequent examinations, including ultrasound imaging, immunoglobulin assays, and tissue section staining.Results: Compared to the PLCL/Hep nanofiber membrane, the hydrophilicity of the PLCL/SF/Hep nanofiber membrane was significantly improved. The mechanical strength met application requirements. Both the blood and cell compatibility were optimal. Most importantly, the PLCL/SF/Hep scaffolds maintained lumen patency for 3 months after carotid artery transplantation in live rabbits. At the same time, CD31 and α-SMA immunofluorescence staining confirmed bionic endothelial and smooth muscle layers remodeling.Conclusion: Using this hybrid strategy, PLCL and SF were combined to manufacture bi-layered small-caliber vascular scaffolds; these PLCL/SF/Hep scaffolds showed satisfactory vascular remodeling.

Production, blood compatibility and cytotoxicity evaluation of a single stage non-woven multicomponent electrospun scaffold mixed with sesame oil, honey and propolis for skin tissue engineering

Scaffolds used in skin tissue engineering must mimic the native function of the extracellular matrix (ECM) and facilitate the fibroblast cell response for new tissue growth. In this study, a novel dressing scaffold based on polyurethane (PU) with sesame oil, honey, and propolis was fabricated by electrospinning. Scanning electron microscopy (SEM) images showed that the diameter of the electrospun scaffolds decreased by blending sesame oil (784 ± 125.46 nm) and sesame oil/honey/propolis (576 ± 133.72 nm) into the PU matrix (890 ± 116.911 nm). Fourier infrared (FT-IR) and thermogravimetric (TGA) analysis demonstrated the formation of hydrogen bonds and interaction between PU and sesame oil, honey, and propolis. Contact-angle measurement indicated reduced wettability of PU/sesame oil scaffold (114 ± 1.732) and improved wettability (54.33 ± 1.528) in the PU/sesame oil/honey/propolis scaffold. Further, tensile tests and atomic force microscopy (AFM) analysis indicated that the fabricated composite membrane exhibited enhanced mechanical strength and reduced surface roughness compared to the pristine PU. The developed composite displayed less toxicity to the red blood cells (RBC’s) compared to the pristine PU. Cytotoxicity assay showed enhanced cell viability of HDF in electrospun scaffolds than pristine PU after 72 h culture. These enhanced properties of the developed scaffolds suggest the potential of utilizing them in skin tissue engineering.

Analysis of the safety evaluation for premarketing clinical trials of hemodialyzer and of postmarketing safety reports of hemodialyzer in Japan and the US: insights into the construction of a sophisticated premarketing evaluation.

Our aim was to conduct a scoping review of the regulations for hemodialyzers in the safety evaluation in Japan and the United States, and to evaluate the criteria for premarketing clinical trials and postmarketing safety reports to inform the development of a sophisticated premarketing evaluation in Japan. Regulations for approval of hemodialyzers were identified from the databases of the Ministry of Health, Labor and Welfare in Japan and the Federal Drug Agency (FDA) in the United States (US). The criteria for premarket clinical trials and postmarketing safety reports were evaluated for both countries. Standards in Japan required evaluation of blood compatibility and reporting of acute adverse effects by a premarketing clinical trial in 6 of 86 applications with semipermeable membrane materials deemed to be different to those of previously approved devices from 1983 to 31 August 2015. By comparison, the clinical trial was required in one of 545 approvals in the US from 1976 to 29 January 2016, but blood compatibility was not the point. All postmarketing adverse effects identified in Japan were included in the set of 'warnings'. The more stringent requirements for evaluation of blood compatibility and acute adverse effects in Japan seemed to be related to differences in the history of quality management systems for medical devices between the two countries. This study revealed that there were differences between Japan and the US in requiring the premarketing clinical trials for the hemodialyzers. Our findings could be useful for constructing sophisticated premarketing safety evaluation.

Click Grafting of Chitosan onto PVC Surfaces for Biomedical Applications

ABSTRACTIn this study, polyvinyl chloride (PVC) has been modified through click grafting of chitosan onto its surface. This goal has been achieved using three consecutive steps involving amination, activation, and grafting. Both the amination and chitosan grafting steps were confirmed based on the determination of nitrogen content. The chemical structure of the modified PVC membranes was confirmed by FTIR spectroscopy and thermal analysis, and the morphological changes were monitored by scanning electron microscopy. In addition, the induced physicochemical characteristics were investigated by analyzing the water uptake, mechanical properties, surface roughness, and contact angle. Finally, an evaluation of blood compatibility and protein adsorption characteristics for the chitosan‐g‐PVC membranes is presented.

In vitro blood compatibility evaluation of silk fibroin by chemical crosslinking

Poly(ethylene glycol) diglycidyl ether (PEG-DE) has been used as a crosslinker to construct artificial blood vessels of silk fibroin, endowing materials suitable compliance. As a biomaterial directly contacting with blood, it requires excellent anticoagulant property. In this article, hemolysis, platelet adhesion, platelet activity and plasma recalcification time of PEG-DE crosslinked silk fibroin were investigated using absorption spectrometry, scanning electron microscopy, methyl thiazolyl tetrazolium analysis and the time counting method. The hemolysis at ratios of PEG-DE crosslinked silk fibroin materials was < 0·5%, although it increased with increasing PEG-DE content. The platelet adhesion ratio and aggregation activity of PEG-DE crosslinked silk fibroin were higher than those of ethanol treated silk fibroin and increased with increasing PEG-DE content. However, the plasma recalcification time of PEG-DE crosslinked silk fibroin was longer than that of the ethanol treated silk fibroin and increased slightly with the increase of PEG-DE content. Based on these, PEG-DE used to crosslink silk fibroin showed different anticoagulant characteristics in different coagulation pathways.

Novel heparin-mimicking polymer brush grafted carbon nanotube/PES composite membranes for safe and efficient blood purification

Nowadays, polymeric membrane based hemodialysis is considered to be the most practical approach for the treatment of kidney failure. To develop advanced hemodialysis membrane integrated with favorable blood and cell compatibilities and efficient blood purification ability, novel biocompatible composite membranes consisting of heparin-mimicking polymer brush functionalized carbon nanotubes (f-CNTs) and polyethersulfone (PES) are designed. Firstly, surface initiated atom transfer polymerization (SI-ATRP) is applied to synthesize heparin-mimicking polymer brush (contained the sodium styrene sulfonate (SS) and methyl ether methacrylate (EGMA) units) grafted CNT. Then, the f-CNT/PES composite membranes are prepared by a liquid–liquid phase separation technique. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) results indicated that the f-CNT would not cause severe damage on the membrane morphologies. Systemic protein ultrafiltration experiment indicated that the heparin-mimicking composite membranes owned satisfied antifouling property and protein rejection ratio. Further blood compatibility evaluation revealed that the composite membranes had decreased protein adsorption, prolonged clotting time, and suppressed platelet adhesion compared to pristine PES membrane. The results of human embryonic hepatocytes (LO-2) culture revealed that the cyto-compatibility of the modified membrane was enhanced by the blending of heparin mimicking polymer functionalized CNT. Furthermore, with the addition of f-CNT, the composite membranes showed remarkably increased removal efficiency of uremic toxin. In general, the fabricated heparin-mimicking f-CNT/PES composite membranes exhibited anti-fouling ability in ultrafiltration, excellent blood and cell compatibility and efficient toxic molecules removal ratio, thus present great potential for various applications, such as hemodialysis and bio-artificial liver support. Furthermore, the proposed method might forward the fabrication of advanced hemodialysis membrane by integrating functional nanomaterials and bioactive polymers.

Preparation and characterization of poly(vinyl alcohol) cryogel-silver nanocomposites and evaluation of blood compatibility, cytotoxicity, and antimicrobial behaviors

In this investigation, cryogels composed of poly(vinyl alcohol) (PVA) were prepared by repeated freeze-thaw method. The prepared cryogels served as templates for producing highly stable and uniformly distributed silver nanoparticles via in situ reduction of silver nitrate (AgNO3) using alkaline formaldehyde solution as reducing agent. The structure of the PVA/Ag cryogel nanocomposites was characterized by a Fourier transform infrared and Raman spectroscopy. The morphologies of pure PVA cryogels and PVA/Ag nanocomposites were observed by a scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The SEM analysis suggested that cryogels show a well defined porous morphology whereas TEM micrographs revealed the presence of nearly spherical and well separated Ag nanoparticles with diameter about 100 nm. XRD results showed all relevant Bragg's reflections for crystal structure of silver nanoparticles. The amount of silver in cryogel nanocomposites and thermal stability were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and thermogravimetric analysis measurements. Mechanical properties of nanocomposites were observed in terms of tensile strength. The antibacterial studies of the synthesized nanosilver containing cryogels showed good antibacterial activity against both gram-negative and gram-positive bacteria. The prepared PVA/Ag nanocomposites were also investigated for swelling and deswelling behaviors. The results reveal that both the swelling and deswelling process depends on the chemical composition of the cryogel silver nanocomposites, number of freeze-Thaw cycles and pH and temperature of the swelling medium. The biocompatibility of the prepared nanocomposites was judged by in vitro methods of percent hemolysis and protein (BSA) adsorption. POLYM. COMPOS., 2014. © 2014 Society of Plastics Engineers

In Vitro Study on Mg–Sn–Mn Alloy as Biodegradable Metals

The mechanical properties, chemical properties and biocompatibility of Mg–3Sn–0.5Mn alloy were tested. A series of in vitro evaluations such as tensile test, static and dynamic immersion test, hemocompatibility test as well as cytotoxicity test were presented, with commercial magnesium alloy WE43 as the control. Mg–3Sn–0.5Mn alloy possesses suitable strength and superior ductility compared with WE43 and AZ31. Static immersion and dynamic degradation tests showed more uniform degradation with a more moderate rate for Mg–3Sn–0.5Mn alloy (0.34 mm/y in static condition and 0.25 mm/y in dynamic condition) compared with WE43 alloy (0.42 mm/y in static condition and 0.33 mm/y in dynamic condition) in Hank's solution. Blood compatibility evaluation suggested that Mg–3Sn–0.5Mn alloy had no destructive effect on erythrocyte and showed excellent anti-thrombogenicity to blood system. Besides, Mg–3Sn–0.5Mn alloy showed no inhibition effect to L929 metabolic activity and mild toxicity to vascular smooth muscle cell (VSMC) in preliminary cell viability assessment. By considering its excellent mechanical strength, corrosion resistance, low ion release rate and good biocompatibility, Mg–3Sn–0.5Mn alloy may be a promising economical candidate as biomedical implant material for load-bearing clinical applications in the future.

Evaluation of drug release property and blood compatibility of aspirin-loaded electrospun PLA/RSF composite nanofibers

In this paper, PLA/RSF with different mass ratios and aspirin-loaded PLA/RSF composite nanofiber membranes were prepared via electrospinning. Polylactic acid (PLA) and regenerated silk fibroin (RSF) were dissolved in trifluoroacetic acid and dichloromethane at a volume ratio of 70/30. The structure analysis made by Fourier transform infrared spectroscopy (FTIR) suggested that PLA and RSF blended very well in the composite membranes. In addition, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the average diameters of composite nanofibers were between 80 and 210 nm. Furthermore, the composite nanofibers had better uniformity in the range of the experiment, and the average diameter of composite nanofibers decreased with the increase of aspirin content. Wettability performance was investigated via contact water angle meter; the hydrophilic property of composite membranes had been improved with the existence of SF. Drug release property was tested by detecting the absorbency of drug in PBS solution via UV–visible spectroscopy, and the results showed that drug release rate reached the maximum when the mass ratio of PLA/RSF was 8/3. With the raise of aspirin content, the drug release rate increased. The in vitro anticoagulation behavior was studied by static platelet adhesion test. The results revealed that the anticoagulation property of composite membranes was superior to that of pure PLA nanofiber membranes. The anticoagulation property significantly improved in the presence of aspirin.

Influence of a layer‐by‐layer‐assembled multilayer of anti‐CD34 antibody, vascular endothelial growth factor, and heparin on the endothelialization and anticoagulation of titanium surface

The endothelialization of the metal surface of vascular stents came into focus as a new method for improving the biocompatibility of intravascular stents. This article has its focus on building a biofunctional layer on the activated titanium surface with anti-CD34 antibody, vascular endothelial growth factor (VEGF), and heparin by a layer-by-layer (LBL) self-assembly technique, to promote the endothelialization of the surface. When compared with titanium surface, the number of adhered endothelial progenitor cells (EPCs) on LBLs increased 47.1% after 5 days culture, meanwhile the proliferation rate of EPCs on LBLs during 5 days culture also exhibit significantly improvement. The results of blood compatibility evaluation clearly show that the LBLs reduce the number of adhered and activated blood platelets (adhered: Ti 83% vs. LBL <20% and activated: Ti 57% vs. LBL 19%), and the activated partial thromboplastin time of the LBL surface prolonged about 20 s in compared with platelet-poor plasma. The assembled LBL thus improves the thromboresistance of the titanium surface. The presented biofunctional multilayer of anti-CD34, VEGF, and heparin on titanium can significantly improve the blood compatibility and the endothelialization of a medical device. The biofunctional layer supports generation of a new endothelium onto titanium surface by capturing EPCs and oriented differentiation.

Fabrication of Interpenetrating Networks of Poly (vinyl alcohol-g-acrylamide) and Chitosan-g-polyacrylamide Chains and Evaluation of Water Sorption, Blood Compatibility and Cytotoxicity Behaviors

In the present study an interpenetrating polymer network (IPN) of poly (vinyl alcohol-g-acrylamide) and chitosan-g-polyacrylamide chains were prepared by the redox polymerization method. The prepared network was characterized by FTIR, DSC and ESEM techniques. The hydrogels were evaluated for their water intake potential and influence of various factors such as chemical composition of the hydrogels, pH and temperature of the swelling bath; various simulated biological fluids were investigated on the water sorption capacity of the IPNs. The in-vitro blood compatibility of the prepared IPN was judged by blood-clot formation, percent haemolysis, protein (BSA) adsorption, and cytotoxicity methods.

Characterization and bioactivity evaluation of (starch/N‐vinylpyrrolidone)—hydroxyapatite nanocomposite hydrogels for bone tissue regeneration

AbstractHydrogel series composed of starch/N‐vinylpyrrolidone (starch/NVP) have been synthesized by means of γ‐radiation‐induced graft copolymerization and crosslinking process. Optimization of the preparation conditions was achieved to ensure the highest gelation degree. The produced hydrogels were characterized using fourier transform spectroscopy, as well as by studying their swelling behavior. In situdeposition of hydroxyapatite (HAp) was achieved via alternate soaking technique. The developed nanocomposites nHAp‐(starch/NVP) were characterized using energy dispersive X‐ray spectroscopy, thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy. Mechanical study revealed that the compressive strength of the composites increased initially after the first cycle of deposition, then it decreased gradually by increasing the number of the deposition cycles. In vitro bioactivity and blood compatibility evaluation of the obtained nanocomposites indicated that these nanocomposites were both bioactive and biocompatible. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Immobilization of Heparin on the Surface of Polypropylene Non-Woven Fabric for Improvement of the Hydrophilicity and Blood Compatibility

A polypropylene non-woven fabric (PPNWF) was exposed to oxygen plasma to produce peroxides on its surface. These peroxides were used to initiate graft polymerization of acrylic acid (AA) on the surface of PPNWF. Direct heparinization was accomplished via a reaction between heparin and PP-PAA (AA grafted PPNWF) which was activated by EDC (N-ethyl-N’-[3-(dimethylamino)propyl] carbodiimide). Indirect heparinized PPNWF was prepared by grafting poly(ethylene oxide) (PEO) on a PP-PAA surface to form PP-PAA-PEO, followed by reaction with heparin which was activated by EDC before use. The surface modified PPNWFs were characterized by attenuated total reflection Fourier transform infrared (ATR–FT-IR) spectroscopy, electron spectroscopy for chemical analysis (ESCA) and contact angle goniometry. It was found that hydrophilicity was greatly improved, as indicated by the decrease of the water contact angle from 142 to 33°. In vitro blood compatibility evaluation of modified PPNWFs, including hemolysis rate, platelet adhesion, plasma protein adsorption and activated partial thromboplastin time (APTT) was investigated. The results suggested that both heparinized PPNWFs showed lower hemolysis rates and better platelet anti-adhesion than non-heparinized controls. Furthermore, PPNWF obtained via indirect immobilization of heparin showed better hydrophilicity and blood compatibility than direct heparinization of PPNWF.

Surface Phosphorylation for Polyelectrolyte Complex of Chitosan and Its Sulfonated Derivative: Surface Analysis, Blood Compatibility and Adipose Derived Stem Cell Contact Properties

Many studies have tried to look for the application of chitosan in tissue engineering since its structure is similar to glycoaminoglycans, the main components of the extracellular matrix. Previous studies had indicated that the incorporation of sulfonic or phosphonic functionalities would be beneficial to the growth of certain cells. However, no study has explored the effect of incorporation of both above-mentioned anionic functionalities onto the chitosan structure. In this study, we have surface-phosphorylated the polyelectrolyte film formed by chitosan and water-soluble sulfonated chitosan with the aim to incorporate phosphonic and sulfonic functionalities onto the film surface. Surface analyses by ESCA and ATR–FT-IR have shown that these two functional groups have been successfully grafted onto the surface, and that the ratio of P/S was dependent upon the weight ratio of phosphorylation agents added. Blood compatibility evaluation indicated that phosphorylated polyelectrolyte complexes extended the plasma recalcification time as compared to non-treated chitosan and direct-phosphorylated chitosan film. In addition, these phosphorylated polyelectrolyte complexes showed similar or slightly less platelet reactivity than the non-phosphorylated counterpart. In contrast, significant platelet activation and adhesion were noted on the direct-phosphorylated chitosan. This implicated the incorporation of sulfonic acid onto the phosphorylated surface can increase the platelet compatibility. An adipose-derived stem cell incubation study has demonstrated that the incorporation of both phosphonic and sulfonic acid functionalities onto the chitosan surface can enhance the stem cell growth. Therefore, the phosphorylated polyelectrolyte complexes were not only blood compatible but also stem cell compatible, and could be a novel biomaterial in tissue-engineering applications.

In Vitro Haemocompatibility Evaluation of PET Surfaces Using the Quartz Crystal Microbalance Technique

Owing to the complex influences of several experimental conditions on the in vitro alteration of blood, there is still a lack of viable in vitro tests and methods for blood compatibility evaluation of biomaterials. The aim of this research was to study a new approach for the haemocompatibility assessment of differently modified PET surfaces using the quartz crystal microbalance with dissipation unit (QCM-D) technique and measure the mass increase caused by clot formation under physiological conditions. For this purpose some of the most frequently applied in vitro methods for haemocompatibility determination, i.e., clotting time measurement and observation of red blood cells' mobility, were applied and their accuracy and sensitivity compared to the new QCM-D approach. Haemocompatibility was evaluated for non-modified poly(ethylene terephthalate) (PET) surfaces and PET surfaces coated with dextran sulphate and heparin. The basic anti-coagulant properties of heparin and dextran sulphate were analysed by means of their activated partial thromboplastine time (APTT). PET, as well as different polysaccharides coatings were chosen for this study due to their promising biocompatible properties and numerous possibilities for biomedical applications. The results showed that the new QCM-D technique to study clot formation in contact with PET surfaces under physiological environment was the most informative and accurate for in vitro haemocompatibility assessment. Although the results achieved with the other two methods were in good correlation, they did not provide such a high level of sensitivity.

Gold nanoparticles generated and stabilized by water soluble curcumin–polymer conjugate: Blood compatibility evaluation and targeted drug delivery onto cancer cells

Curcumin (Cur) shows low anticancer activity in vivo due to its reduced systemic bioavailability stemmed from its poor aqueous solubility and instability. Suitably functionalized nanocarriers designed to empty the drug specifically at tumor sites can potentially enhance the antitumor activity of Cur. We devised a simple method for the fabrication of water soluble Cur conjugated gold nanoparticles to target various cancer cell lines. Cur was conjugated to hyaluronic acid (HA) to get a water soluble conjugate (HA–Cur). We generated gold nanoparticles (AuNPs) by reducing chloroauric acid using HA–Cur, which played the dual role of a reducing and stabilizing agent and subsequently anchored folate conjugated PEG. These entities were probed using different analytical techniques, assayed the blood compatibility and cytotoxicity. Their interaction with cancer cell lines (HeLa cells, glyoma cells and Caco 2 cells) was followed by flow cytometry and confocal microscopy. Blood–materials interactions studies showed that the nanoparticles are highly hemocompatible. Flow cytometry and confocal microscopy results showed significant cellular uptake and internalization of the particles by cells. HA–Cur@AuNPs exhibited more cytotoxicity comparing to free Cur. The strategy, we adopted here, resulted the formation blood compatible Cur conjugated AuNPs with enhanced targeting and improved efficacy.