scholarly journals A Biofouling Resistant Zwitterionic Polysulfone Membrane Prepared by a Dual-Bath Procedure

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Irish Valerie B. Maggay ◽  
Hana Nur Aini ◽  
Mary Madelaine G. Lagman ◽  
Shuo-Hsi Tang ◽  
Ruth R. Aquino ◽  
...  
Keyword(s):  
Blood Cell ◽  
Biomedical Applications ◽  
Cell Attachment ◽  
Solution Viscosity ◽  
Recovery Ratio ◽  
Polysulfone Membrane ◽  
Casting Solution ◽  
Random Polymer ◽  
Ft Ir

This study introduces a zwitterionic material to modify polysulfone (PSf) membranes formed by a dual bath procedure, in view of reducing their fouling propensity. The zwitterionic copolymer, derived from a random polymer of styrene and 4-vinylpyrridine and referred to as zP(S-r-4VP), was incorporated to the PSf solution without any supplementary pore-forming additive to study the effect of the sole copolymer on membrane-structuring, chemical, and arising properties. XPS and mapping FT-IR provided evidence of the modification. Macrovoids appeared and then disappeared as the copolymer content increased in the range 1–4 wt%. The copolymer has hydrophilic units and its addition increases the casting solution viscosity. Both effects play an opposite role on transfers, and so on the growth of macrovoids. Biofouling tests demonstrated the efficiency of the copolymer to mitigate biofouling with a reduction in bacterial and blood cell attachment by more than 85%. Filtration tests revealed that the permeability increased by a twofold factor, the flux recovery ratio was augmented from 40% to 63% after water/BSA cycles, and irreversible fouling was reduced by 1/3. Although improvements are needed, these zwitterionic PSf membranes could be used in biomedical applications where resistance to biofouling by cells is a requirement.

Nano-Sized [60]Fullerene-Cyclodextrin Molecules

2001 ◽  
Vol 675 ◽  
Author(s):  
Jeong-Seo Park ◽  
Han-Chang Kang ◽  
Kurt E. Geckeler
Keyword(s):  
Biomedical Applications ◽  
Addition Reaction ◽  
Water Soluble ◽  
Separation And Purification ◽  
Subsequent Reaction ◽  
Fullerene Derivatives ◽  
Covalently Bonded ◽  
Scattering Measurements ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

ABSTRACTAs [60]fullerene is a very hydrophobic macromolecule, there have been a number of attempts to make it more hydrophilic for biomedical applications. By attaching hydrophilic moieties such as poly(oxyethylene)(POE) chains and cyclodextrin molecules to [60]fullerene, novel water-soluble and biocompatible materials have been successfully prepared [1,2].The synthesis of novel macrocyclic fullerene conjugates which are water-soluble is reported. The telechelic fullerene derivatives have been prepared via addition reaction of POE-based arms with covalently bonded β-cyclodextrin (CD) to [60]fullerene. To this end, a mono-tosylated CD derivative has been prepared in pyridine and then reacted with an amino-functional POE in the presence of triethylamine. The subsequent reaction of [60]fullerene with the hydrophilic POE-conjugated CD-derivative yielded the macrofullerene after separation and purification procedures.The macrocyclic [60]fullerene derivatives obtained were soluble in water and characterized by UV-VIS and FT-IR spectroscopy as well as light scattering measurements and thermogravimetric analysis.

Mechanical and Superelastic Properties of Au-51Ti-18Co Biomedical Shape Memory Alloy Heat-Treated at 1173 K to 1373 K

2016 ◽  
Vol 97 ◽  
pp. 141-146 ◽  
Author(s):  
Taywin Buasri ◽  
Hyunbo Shim ◽  
Masaki Tahara ◽  
Tomonari Inamura ◽  
Kenji Goto ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Critical Stress ◽  
Biomedical Applications ◽  
Shape Recovery ◽  
Treatment Temperature ◽  
Recovery Ratio ◽  
Recovery Strain ◽  
Heat Treated ◽  
Alloy Heat

The effect of heat treatment temperature from 1173 K to 1373 K for 3.6 ks on mechanical and superelastic properties of an Ni-free Au-51Ti-18Co alloy (mol%) was investigated. The stress for inducing martensitic transformation (SIMT) and the critical stress for slip deformation (CSS) slightly decrease with increasing the heat–treatment temperature. Regardless of heat–treatment temperature, good superelasticity was definitely recognized with the maximum shape recovery ratio up to 95 % and 4 % superelastic shape recovery strain. As the mentioned reasons, the Au-51Ti-18Co alloy is promising for practical biomedical applications.

P0542EVALUATION OF BLOOD CELL ADHESION AND SOLUTE REMOVAL PERFORMANCE BY AN EX VIVO EXPERIMENT OF A POLYSULFONE HEMOFILTER USING AN NV POLYMER MEMBRANE FOR CONTINUOUS RENAL REPLACEMENT THERAPY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yoshitaka Kurihara ◽  
Shunichi Ueki ◽  
Kozue Kobayashi ◽  
Kokubo Kenichi ◽  
Hirosuke Kobayashi ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Pressure Drop ◽  
Blood Cell ◽  
Ex Vivo ◽  
Polysulfone Membrane ◽  
Molecular Weights ◽  
Performance Change ◽  
Molecular Weight Cutoff ◽  
Blood Clots ◽  
Before And After

Abstract Background and Aims Since hemofilters used for continuous renal replacement therapy (CRRT) come in prolonged contact with blood during treatment, clotting and cell adhesion induced by contact of blood with the membrane often occur, increasing the risk to the patient and burden on the staff. Suppressed platelet adhesion and better biocompatibility have been reported with the use of a dialysis membrane whose surface has been modified with an NV polymer in patients on maintenance hemodialysis. Therefore, it may be advantageous to use the NV membrane as a hemofilter for CRRT. In the present study, we evaluated the solute removal performance change and blood cell adhesion on the NV membrane after it comes in contact with blood, to clarify the characteristics of the NV membrane for long-time use. Methods A new polysulfone membrane containing the NV polymer (SNV) and a conventional polysulfone membrane (SHG) were used for the ex vivo blood filtration experiment. To compare the solute removal performance change and blood cell adhesion after blood comes in contact with the membranes, porcine blood collected from a single animal was divided into two portions, and a 24-hour of continuous hemofiltration (CHF) experiment was performed. The circulation conditions were as follows; blood flow rate, 100 mL/min; filtrate flow rate, 20 mL/min; heparin dose adjusted as appropriate to maintain the activated clotting time from 300 to 400 sec during the experiment. We evaluated the time-courses of the transmembrane pressure (TMP) and pressure drop at the hemofilter and the change in the sieving coefficients of dextran of different molecular weights (molecular weight cutoff curve) before and after the experiment, and blood cell adhesion. The amount of blood cell adhesion was evaluated based on the hemoglobin content and lactate dehydrogenase (LDH) activity in the eluate from the residual blood clots on the hemofilter 24 hours after the CHF experiment. Results The changes in the TMP and the pressure drop were significantly lower with the use of SNV as compared to SHG (n = 9, p < 0.01). From the molecular weight cutoff curves before and after the experiment, the molecular weights when the sieving coefficient was 0.1 to 0.4, which reflect the pore size of the pores through which relatively small molecules can pass, decreased to a lower extent after blood contact with SNV as compared to SHG (n = 3, SC = 0.1-0.3, p < 0.05; SC = 0.4, p < 0.01).The hemoglobin content and LDH activity in the blood clots adhering to the membrane after the experiment were significantly lower in SNV as compared to SHG (n = 9; Hb, p < 0.01; LDH, p < 0.05), indicating that blood cell adhesion on SNV was less pronounced than that on SHG. Conclusion SNV suppressed the increase in the TMP and also the pressure drop, allowed a high rate of solute removal performance to be maintained, and suppresses blood cell adhesion to a greater extent as compared to the conventional polysulfone membrane.

scholarly journals STARCH MEDIATED SYNTHESIS OF HYDROXYAPATITE NANOPARTICLE FOR BIOMEDICAL APPLICATIONS

2015 ◽  
Vol 2 (1) ◽  
pp. 15-17
Author(s):  
Indira J
Keyword(s):  
Biomedical Applications ◽  
Soluble Starch ◽  
Morphological Properties ◽  
Spherical Nanoparticles ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Average Size ◽  
Controllable Size

Hydroxyapatite (HAP) nanoparticles with uniform morphologies and controllable size have been synthesized by template directed method. The environment and eco-friendly polysaccharide soluble starch is used as a template to regulate size and shape of the nanoparticles synthesized. Structural and morphological properties of as-synthesized hydroxyapatite nanoparticles have been examined through the techniques like Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD) and Scanning Electron Microscopy(SEM), respectively. The results indicate that the obtained particles are uniform discrete spherical nanoparticles. The average size of the hydroxyapatite nanoparticles were ranged from 45 to 60 nm.

scholarly journals Synthesis and characterizations of nano-silica for biomedical applications

2021 ◽  
Vol 10 (2) ◽  
pp. 114-118
Author(s):  
Huyen Nguyen Thi ◽  
Tam Lai Thi Thanh ◽  
Yudy Paola Monreno Gonzalez ◽  
Thinh Nguyen Ngoc ◽  
Mai Nguyen Thi Tuyet ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Biomedical Applications ◽  
Cetyltrimethylammonium Bromide ◽  
Average Length ◽  
Biological Applications ◽  
Nano Silica ◽  
Facile Synthesis ◽  
Structure Morphology ◽  
Ft Ir

This paper presents a facile synthesis of nano-silica by hydrothermal treatment assisted by cetyltrimethylammonium bromide (CTAB). The effect of CTAB on the morphology of the material was also investigated. Structure, morphology, and composition of the material were studied byvarious methods such as XRD, SEM, FT-IR, and EDX.The results showed that a sample of nanosilica with amount of 1,0 g CTAB at pH 10-11 reached the most appropriate size, with the average length and width are 231,34±48,98 nm và 113,05±16,45 nm, respectively. In addition, the results indicated that the nanoparticles are completely pure, with many silanol groups on the surface, suitable for applications in bone tissue engineering and other biological applications.

Synthesis of Biocompatible Magnetic Iron Oxide (γ-Fe2O3 and Fe3O4) Nanoparticles by a Modified Polyol Process for Biomedical Applications

2010 ◽  
Vol 1256 ◽  
Author(s):  
Georgia Basina ◽  
Ioannis Panagiotopoulos ◽  
Eamonn Devlin ◽  
George Hadjipanayis ◽  
Levent Colak ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Magnetic Particles ◽  
Polyol Process ◽  
X Rays ◽  
Colloidal Solutions ◽  
Heating Rates ◽  
Fast Heating ◽  
Ft Ir ◽  
Magnetite Phase ◽  
Ft Ir Spectroscopy

AbstractHighly crystalline superparamagnetic Fe3O4 nanoparticles coated by poly-vinylpyrrolidone (PVP) were prepared by simultaneous thermal decomposition of ferrous and ferric inorganic salts in polyethylene glycol (PEG) with molecular weight 200. The magnetic particles have a diameter in the range of 8-15 nm, and after exchange with citric acid diammonium salt, they transform into very stable super hydrophilic colloidal solutions. The presence of magnetite phase was confirmed using powder X-rays diffraction (XRD) and Mössbauer spectroscopy, while thermogravimetric analysis and FT-IR spectroscopy confirmed the presence of PVP or citrate anions on the nanoparticles surface. The magnetic properties revealed superparamagnetic behavior, with the composite material showing a saturation magnetization up to 57 emu/g. The Fe3O4 nanoparticles prepared by this modified polyol process are suitable for biomedical applications because of the biocompatibility of citrate anions. Magnetic hyperthermia experiments in neutral water solutions shows that the particles induce fast heating rates with specific absorption rate (SAR) values which reached 57.53 W/gFe, when the concentration of iron is 11.2 mgFe/ml.

scholarly journals Development of 3D Bioactive Nanocomposite Scaffolds Made from Gelatin and Nano Bioactive Glass for Biomedical Applications

2010 ◽  
Vol 19 (2) ◽  
pp. 096369351001900 ◽  
Author(s):  
M. Mozafari ◽  
F. Moztarzadeh ◽  
M. Rabiee ◽  
M. Azami ◽  
N. Nezafati ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bioactive Glass ◽  
Biomedical Applications ◽  
Cell Attachment ◽  
Tissue Engineering Scaffolds ◽  
Study Results ◽  
Nanocomposite Scaffold ◽  
Nanocomposite Scaffolds ◽  
First Time

In this research, macroporous, mechanically competent and bioactive nanocomposite scaffolds have been fabricated from cross-linked gelatine (Gel) and nano bioactive glass (nBG) through layer solvent casting combined with freeze-drying and lamination techniques. This study has developed a new composition to produce a new bioactive nanocomposite which is porous with interconnected microstructure, pore sizes are 200-500 μm, porosity are 72%-86%. Also, we have reported formation of chemical bonds between nBG and Gel for the first time. Finally, the in vitro cytocompatability of the scaffolds was assessed using MTT assay and cell attachment study. Results indicated no sign of toxicity and cells found to be attached to the pore walls offered by the scaffolds. These results suggested that the developed nanocomposite scaffold possess the prerequisites for bone tissue engineering scaffolds and it can be used for tissue engineering applications.

Cleavage of human 7-domain VCAM-1 (CD106) by thrombin

2006 ◽  
Vol 95 (05) ◽  
pp. 873-880 ◽  
Author(s):  
Steven Barthel ◽  
Mats Johansson ◽  
Douglas Annis ◽  
Deane Mosher
Keyword(s):  
Cell Adhesion ◽  
Blood Cell ◽  
White Blood Cell ◽  
Cell Attachment ◽  
Chinese Hamster ◽  
Full Length ◽  
Type I ◽  
Thrombin Cleavage ◽  
Alternatively Spliced ◽  
Splice Forms

SummaryVascular cell adhesion molecule 1 (VCAM-1,CD106) is expressed as a type I transmembrane integrin counter-receptor on activated endothelium and mediates white blood cell attachment. The alternatively spliced 7-domain (7d) form of VCAM-1 contains a potential thrombin cleavage site. Thrombin proteolysis of 7d-VCAM-1 may help regulate adhesive activity of VCAM-1. We determined whether 7d-VCAM-1 is proteolyzed and rendered inactive by thrombin. Recombinant extracellular domain of 7d-VCAM-1 was cleaved by thrombin to generate 33- and 44-kDa products. Cleavage was in the sequence PGPR/IAAQIG near the N-terminal border of the alternatively spliced fourth immunoglobulin (Ig)-like module. There was no cleavage of 6d-VCAM-1 lacking the fourth module. Expression of full-length 7d-VCAM-1 presented on Chinese hamster ovary (CHO) monolayers, as detected by flow cytometry with an antibody directed to Ig-like modules 1–3, was reduced by thrombin treatment whereas there was no reduction in the expression of fulllength 6d-VCAM-1. Adhesion of blood eosinophils to full-length 7d-VCAM-1 was reduced after treatment of CHO cells with thrombin, whereas adhesion to full-length 6d-VCAM-1 was not affected. We conclude that cleavage of 7d-VCAM-1 by thrombin is a potential mechanism for differential regulation of VCAM-1 splice forms in white blood cell adhesion and trafficking.

scholarly journals Fabrication of a Novel Antifouling Polysulfone Membrane with in Situ Embedment of Mxene Nanosheets

2019 ◽  
Vol 16 (23) ◽  
pp. 4659 ◽  
Author(s):  
Zhen Shen ◽  
Wei Chen ◽  
Hang Xu ◽  
Wen Yang ◽  
Qing Kong ◽  
...  
Keyword(s):  
Contact Angle ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Water Contact Angle ◽  
Bovine Serum ◽  
Composite Membranes ◽  
Recovery Ratio ◽  
Water Contact ◽  
Polysulfone Membrane

Membrane fouling is still a critical issue for the application of ultrafiltration, which has been widely used in water treatment due to its efficiency and simplicity. In order to improve the antifouling property, a new 2D material MXene was used to fabricate composite ultrafiltration membrane with the approach of in situ embedment during the phase inversion process in this study. Scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), water contact angle, bovine serum albumin rejection and porosity measurements were utilized to characterize the prepared membranes. Due to the hydrophilicity of the MXene, the composite membranes obtained higher hydrophilicity, confirmed by the decreased water contact angle. All the modified membranes had a high bovine serum albumin rejection above 90% while that of the pristine polysulfone membrane was 77.48%. The flux recovery ratio and the reversible fouling ratio of the membranes were also improved along with the increasing content of the MXene. Furthermore, the highest flux recovery ratio could also reach 76.1%. These indicated the good antifouling properties of MXene composite membranes. The enhanced water permeability and protein rejection and excellent antifouling properties make MXene a promising material for antifouling membrane modification.

scholarly journals Strategies for Using Polydopamine to Induce Biomineralization of Hydroxyapatite on Implant Materials for Bone Tissue Engineering

2020 ◽  
Vol 21 (18) ◽  
pp. 6544 ◽  
Author(s):  
Neha Kaushik ◽  
Linh Nhat Nguyen ◽  
June Hyun Kim ◽  
Eun Ha Choi ◽  
Nagendra Kumar Kaushik
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Cell Attachment ◽  
Cell Types ◽  
Bioactive Molecules ◽  
Cellular Interaction ◽  
Biomimetic Mineralization ◽  
Adhesive Properties ◽  
Implant Materials ◽  
Defect Repair

In the field of tissue engineering, there are several issues to consider when designing biomaterials for implants, including cellular interaction, good biocompatibility, and biochemical activity. Biomimetic mineralization has gained considerable attention as an emerging approach for the synthesis of biocompatible materials with complex shapes, categorized organization, controlled shape, and size in aqueous environments. Understanding biomineralization strategies could enhance opportunities for novel biomimetic mineralization approaches. In this regard, mussel-inspired biomaterials have recently attracted many researchers due to appealing features, such as strong adhesive properties on moist surfaces, improved cell adhesion, and immobilization of bioactive molecules via catechol chemistry. This molecular designed approach has been a key point in combining new functionalities into accessible biomaterials for biomedical applications. Polydopamine (PDA) has emerged as a promising material for biomaterial functionalization, considering its simple molecular structure, independence of target materials, cell interactions for adhesion, and robust reactivity for resulting functionalization. In this review, we highlight the strategies for using PDA to induce the biomineralization of hydroxyapatite (HA) on the surface of various implant materials with good mechanical strength and corrosion resistance. We also discuss the interactions between the PDA-HA coating, and several cell types that are intricate in many biomedical applications, involving bone defect repair, bone regeneration, cell attachment, and antibacterial activity.

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