Membrane creates the functions of protection, supporting, dispersion and separation. More functions can be designed by modifying membrane surface and grafting/loading selective ligands or catalysts on the membrane, thus membrane technology has been widely applied in biological detection, and its application approaches becomes diverse. Rational design of functional membranes can meet the demands in different steps of biological detection process, including sample pretreatment, preparation, response and sensing. This review summarized the functionalization methods of filtration membranes, applications of membrane technology in sample preparation and detection process, as well as the research on the integration of functional membranes. By revisiting the research progress on functional membrane design, preparation and applications for biological detection, it is expected to take better advantage of membrane materials structure and performance for constructing efficient and stable detection platform, which is more "adapted" to the detection environment.
Membranes, Artificial

OBJECTIVETo use a new kind of fixing material, i.e. Sol-Gel organic-inorganic hybridized material to immobilize bacterium to detect Biochemical oxygen demand quickly.

METHODSThe biosensor was fabricated using a thin film in which Hansenula anomala was immobilized by sol-gel and an oxygen electrode. The optimum measurement for biochemical oxygen demand was at pH 7.0; 28 degrees C; response time 3 - 12 min. Pure organic compound, sewage and rate of recovery were detected with the biosensor.

RESULTSIt shows that the BOD biosensor can be used to detect many organic compounds such as amino acid, glucide. It is suitable to monitor sewage and industrial waste water which has low level alcohols and phenols. The microbial membrane can work 3 months and remain its 70% activity. It is measured that the rate of recovery of BOD is between 90% to 105% in sewage.

CONCLUSIONThe study confirmed the effectiveness and usefulness of BOD sensor, which is quick, convenient, low cost and reliable with little interference.

Bacteria ; Biosensing Techniques ; instrumentation ; Cells, Immobilized ; Gels ; Membranes, Artificial ; Nylons ; Oxygen ; analysis ; Sewage ; analysis ; microbiology

Chromatography, Micellar Electrokinetic Capillary ; methods ; Liposomes ; Membranes, Artificial ; Pharmaceutical Preparations ; chemistry

BACKGROUNDS/AIMS: Stem cell therapies for liver disease are being studied by many researchers worldwide, but scientific evidence to demonstrate the endocrinologic effects of implanted cells is insufficient, and it is unknown whether implanted cells can function as liver cells. Achieving angiogenesis, arguably the most important characteristic of the liver, is known to be quite difficult, and no practical attempts have been made to achieve this outcome. We carried out this study to observe the possibility of angiogenesis of implanted bio-artificial liver using scaffolds. METHODS: This study used adipose tissue-derived stem cells that were collected from adult patients with liver diseases with conditions similar to the liver parenchyma. Specifically, microfilaments were used to create an artificial membrane and maintain the structure of an artificial organ. After scratching the stomach surface of severe combined immunocompromised (SCID) mice (n=4), artificial scaffolds with adipose tissue-derived stem cells and type I collagen were implanted. Expression levels of angiogenesis markers including vascular endothelial growth factor (VEGF), CD34, and CD105 were immunohistochemically assessed after 30 days. RESULTS: Grossly, the artificial scaffolds showed adhesion to the stomach and surrounding organs; however, there was no evidence of angiogenesis within the scaffolds; and VEGF, CD34, and CD105 expressions were not detected after 30 days. CONCLUSIONS: Although implantation of cells into artificial scaffolds did not facilitate angiogenesis, the artificial scaffolds made with type I collagen helped maintain implanted cells, and surrounding tissue reactions were rare. Our findings indicate that type I collagen artificial scaffolds can be considered as a possible implantable biomaterial.
Actin Cytoskeleton ; Adult ; Animals ; Artificial Organs ; Biocompatible Materials ; Collagen Type I* ; Humans ; Liver Diseases ; Liver* ; Membranes, Artificial ; Mice ; Stem Cells* ; Stomach ; Tissue Scaffolds ; Vascular Endothelial Growth Factor A

OBJECTIVETo found new interface of human hepatocyte/poly propylene with good cytocompatibility for made polypropylene hollow fibers bioreactor of bioartificial liver in future.

METHODSUsing the macromolecular hydroperoxide groups on the polypropylene membrane surface as initiators, acrylamides were polymerized on the polypropylene membranes, under induction by both UV irradiation and Fe2+ reduction. Growth characteristics of human hepatocyte L-02 were detected when it was cultured on polystyrene, polypropylene and modified polypropylene membrane surface.

RESULTSWater contact angle measurement of the polypropylene and the modified polypropylene membranes decreased from (72 +/- 5) degrees to (30 +/- 4) degrees , which indicated that the hydrophilicity of the membrane was improved obviously after the grafting modification. Human hepatocyte L-02 could not adhere and spread on modified polypropylene membrane surface, and grown in spheroidal aggregate with higher density and higher proliferation ratio measured by MTT method.

CONCLUSIONSAcrylamide polymerized on the polypropylene membranes is a good method which not only improved human hepatocytes cytocompatibility but also found a new simple culture method with spheroidal aggregate culture of human hepatocyte.

Cell Culture Techniques ; methods ; Cell Division ; Cells, Cultured ; Hepatocytes ; cytology ; Humans ; Liver, Artificial ; Membranes, Artificial ; Polypropylenes ; chemistry ; Surface Properties ; Tissue Engineering ; methods

Membrane separation technology is a major branch in modern separation technology, which is widely applied in chemical, pharmaceutical and other industries. The purpose of this paper is to introduce principle and the application example of the membrane separation technology in medical devices, to analyse the problems existing in the current application, and to discuss the future development direction.
Equipment and Supplies ; Membranes, Artificial ; Technology

Compound membranes of chitosan/hydroxyapatite were prepared by blending. The physical performance showed that the air-water contact angles decreased from chitosan's 103 degrees to chitosan/hydroxyapatite's 57 and the water adsorption rate increased slightly. When immersed into culture medium, the materials adsorbed Ca2+, and low crystalline hydroxyapatite deposited on the surface of the membranes. Chitosan/hydroxyapatite compound membranes could enhance the attachment and proliferation of mescenchymal stem cells (MSCs). After 12 days' induction on the materials, the alkaline phosphatase (ALP) activity value of MSCs on the compound membrane was 10.1, being much higher than 1.6 on chitosan membrane (P<0.01). All these results indicate that chitosan does not have very good affinity for MSCs, but the biocompatibility of chitosan can be apparently enhanced after mixing with hydroxyapatite. The compound membrane stimulates MSCs to differentiate into osteoblasts and it may be a good potential material for bone substitution.
Alkaline Phosphatase ; metabolism ; Animals ; Bone Substitutes ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Chitosan ; chemical synthesis ; pharmacology ; Durapatite ; chemical synthesis ; pharmacology ; Membranes, Artificial ; Mesenchymal Stromal Cells ; cytology ; Rats

In this study, porous polymer (PLA/PCL) membrane was first treated with ethanol to become hydrophilic, and then immersed into DMEM with 50% fetal bovine serum to enhance the affinity to cells. MSCs cultured in osteogenic medium were loaded into the membrane at density of 5 x 10(6)/cm2 for 7 days, and scanning electrical microscope was used to observe the growth of the MSCs. The growth of MSCs inside the constructs was functionally well, and the cells proliferated with the time of culture. We concluded from current study that the membrane had satisfactory biocompatibility and the constructs could be used to guided bone regeneration.
Animals ; Biocompatible Materials ; Bone Marrow Cells ; cytology ; Bone Regeneration ; Bone Substitutes ; Cell Differentiation ; Cell Division ; Cells, Cultured ; Extracellular Matrix ; Female ; Guided Tissue Regeneration ; Lactic Acid ; Membranes ; Membranes, Artificial ; Mesenchymal Stromal Cells ; cytology ; Polyesters ; Polymers ; Tissue Engineering

Nano-scale particles of silk fibroin peptide (SFP) were prepared from discarded materials of cocoon or filature by dissolving and enzymolysis. Polyvinyl Alcohol films inlaid with silk fibroin peptide nano-scale particles (SFP in PVA) were prepared by blending nano-SFP and PVA in water according to different blending ratios. The films' characteristics and their promoting cell growth functions were investigated. Silk fibroin fiber was dissolved in 60% NaSCN solution, and was decomposed with alpha-Chymotrypsin, Trypsin and Neutral, respectively. The uniformity of size of SFP nano-particles prepared by Neutral was better and appeared about 80-150 nm. (SFP in PVA) films were characterized by infrared spectroscopy (IR) measurement which demonstrated the combination of SFP and PVA. Scanning electron microscopy revealed the PVA films already inlaid with SFP micro-segment. The surface and form stability in water of the (SFP in PVA) films with blending ratios of 10/90, 20/80, 30/70 and 40/60 were observed. And the results showed that SFP/PVA film with the blending ratio of 30/70 has smoother surface and better stability in water. The Chinese hamster ovary (CHO) cells were cultured, and the promoting cell growth function of (SFP in PVA) films was assessed by MTT colorimetric assay. These findings indicate that SFP/PVA (30/70) film has excellent function of promoting cell growth.
Animals ; CHO Cells ; cytology ; Cell Proliferation ; drug effects ; Cricetinae ; Cricetulus ; Fibroins ; chemistry ; Membranes, Artificial ; Nanoparticles ; chemistry ; Peptides ; chemistry ; Polyvinyl Alcohol ; chemistry

Some different membranes were prepared by Chitosan with the degree of deacetylation (DD) of 63.7%, 73.7%, 83% and 97% respectively. To study the biocompatibility of Chitosan membrane toward corneal stromal cells, the rabbit cells were cultured on the surface of different DD chitosan membranes. The morphological characteristics, the cell-adhesion, the cell proliferation and the activity of LDH in the medium were investigated. The results of experiment shows that the DD of Chitosan has very significant effect on the biocompatibility of Chitosan membrane toward corneal stromal cells. The more DD of Chitosan, the less injury was made to corneal stromal cells by the chitosan membrane, which is favor of the growing and adhesion of corneal stromal cells. The biocompatibility of the membrane made with low DD Chitosan with corneal stromal cells became worse.
Acetylation ; Animals ; Biocompatible Materials ; chemistry ; pharmacology ; Cell Adhesion ; drug effects ; Cell Division ; drug effects ; Chitosan ; chemistry ; pharmacology ; Cornea ; cytology ; Materials Testing ; Membranes, Artificial ; Rabbits ; Stromal Cells ; drug effects