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

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

The key materials for bioartificial liver (BAL) construction include biomaterials and scaffolding materials. The former mainly refers to hepatocytes, nonparenchymal cells, etc. The latter mainly refers to films and other scaffolding materials, the properties of which correlate directly with hepatocyte growth and functions, and thus are related to the support effects of BAL. Several kinds of scaffolding materials frequently used for BAL construction in recent years are reviewed in this article.
Biocompatible Materials ; Liver, Artificial ; Membranes, Artificial ; Polyurethanes ; Polyvinyls ; Tissue Engineering

In recent studies there have been various attempts at replacing a damaged retina with an artificial one. This paper outlines the assembly of an artificial retina membrane by incorporating a photorective protein bacteriorhodopsin into an electrochemically syntheszed conducting polymer polypyrrole. An electrophysiologic test was conducted to evaluate the photoresponsiveness of the bacteriorhodopsin and rabbit eyes were used to examine the biocompatibility of the artificial retina. The electrophysiologic test analyzed both wave forms and amplitudes obtained by photostimulating the artificial retina membrane with various light intensites(0.2, 2, 20J). In the biocompatibility test, the artificial membrane was inserted into the anterior chambers(4 eyes) and vitreous cavities(8 eyes) of rabbits. The condition of the eyes was then observed for one month. At the end of the first moonth, the eyes were enucleated and a histological examination was carried out. The electrophysiologic study displayed negative reflection waves, which are characteristic in rhodpsin, and their amplitudes showed a correspondign increase with stronger light intensities. The results of the biocompatibility test demonstrated that inflammatory reactions were not prominent in either the anterior chambers or the vitreous cavities during the first month and the histological examinations revealed no specific findings. In conclusion, a membrane assembled utilizing an electroactive polymer and a phocial retina.
Anterior Chamber ; Bacteriorhodopsins ; Membranes ; Membranes, Artificial ; Polymers ; Rabbits ; Retina*

Guided bone regeneration (GBR) is an important technique to solve bone defect problems. In this technique, GBR barrier membranes play an irreplaceable role. GBR membranes can act as a barrier protecting fibroblasts from bone defects and promote osteoblast adhesion and proliferation, leading to bone regeneration. GBR barrier membranes should be enhanced because of the disadvantages of collagen membranes, which are extensively applied to the field of GBR. Therefore, various efforts have been devoted to modifying the antibacterial and osteogenic properties of GBR barrier membranes and developing novel materials. This article reviews the research advancements on the modification of GBR barrier membranes and discover future directions for the development of GBR barrier membranes to provide a reference for bone tissue engi-neering and repair.
Bone Regeneration ; Collagen ; Membranes, Artificial ; Osteoblasts ; Osteogenesis

OBJECTIVEThe UF process of model systerm of Huanglian Jiedu decoction is researched in the study to lay a foundation for the exploring of the substance foudation of membrane fouling, and for the the optimal design of membrane technology in the production of Chinese drugs preparation.

METHODUsing the membrane flux, fouling degree of membrane, preserving degree and adsorption capacity of effective materials as guide line, trying to find out the influence of macromolecule materials on small molecules in Huanglian Jiedu decoction.

RESULTThe two small molecules berberine and gardenoside in Huanglian Jiedu decoction have high permeation rate. But for the reasons of interaction of macromolecule, the permeation rate of small molecules reduced greatly, membrane fouling and membrane flux declined intensify.

CONCLUSIONStarch and pectin are the two main macromolecule materials in Huanglian Jiedu decoction which cause membrane fouling and flux falling.

OBJECTIVETo prepare novel electrospun porphyrinated polyimide nanofibrous membrane for rapid detection of trace amount of methanol vapor.

METHODSPorphyrin chromophore was copolymerized into polyimide backbones and the porphyrinated polyimide nanofibrous membrane was prepared by electrospinning technique. By optimizing the processing parameters, such as solution concentration and electrospinning voltage, nanofibrous membrane with three dimensional and large surface-to-area ratio structure was fabricated for trace amount of methanol vapor sensing applications.

RESULTSThe obtained nanofibrous membrane preserved typical photophysical properties of porphyrin chromophores with uniformly fine and smooth fiber diameter. When exposed to methanol vapor, a red-shift of the absorption spectra and decrease in the emission intensities was observed, while no significant changes were seen when the membrane contacting with other common alcohols. After five times of 150 ppm methanol vapor quenching and nitrogen gas regeneration, the fluorescence of the membrane remained unchanged, indicating a good reversibility.

CONCLUSIONCombining the specific optical properties of porphyrin with large surface-area-to-volume ratio of nanofibrous membranes, a porphyrinated polyimide nanofibrous membrane has been facilely fabricated for trace methanol vapor detection. The sensing membrane exhibits good sensitivity, selectivity and reproducibility.

The aim of the present study was to detect the transmission rate of ultrasonic low intensity pulsed ultrasound (LIPUS) through polytetrafluoroethylene (PTFE) membrane (Thickness: 0.01 mm) and Bio-Gide collagen membrane, and to provide the basis for the barrier membrane selection on the study of LIPUS combined with guided tissue regeneration (GTR). The ultrasonic (LIPUS, frequency 1.5 MHz, pulse width 200 micros, repetition rate 1.0 kHz) transmission coefficient of the two kinds of barrier membrane were detected respectively through setting ten groups from 10 to 100mW/cm2 every other 10 mW/cm2. We found in the study that the ultrasonic transmission coefficient through 0.01 mm PTFE membrane was 78.1% to 92.%, and the ultrasonic transmission coefficient through Bio-Gide collagen membrane was 43.9% to 55.8%. The ultrasonic transmission coefficient through PTFE membrane was obviously higher than that through Bio-Gide collagen membrane. The transmission coefficient of the same barrier membrane of the ultrasonic ion was statistically different under different powers (P < 0.05). The results showed that the ultrasonic transmittance rates through both the 0.01 mm PTFE membrane and Bio-Gide collagen membrane were relatively high. We should select barrier membranes based on different experimental needs, and exercise ultrasonic transmission coefficient experiments to ensure effective power.
Biocompatible Materials ; Collagen ; chemistry ; Membranes, Artificial ; Permeability ; Polytetrafluoroethylene ; chemistry ; Ultrasonics

AIMTo investigate the interaction between drugs and ordered phospholipid membrane using immobilized artificial membrane chromatography (IAMC).

METHODSIAMC was used to determine the interaction drugs with phospholipid membrane, expressed as membrane affinity (lg kIAM). An n-octanol/buffer system was also employed as the reference hydrophobicity (lg Do/w,7.4).

RESULTSWithin the range of used acetonitrile percentages (phi) 0-30% in mobile phase, retention index (lg kIAM) showed excellent correlation with phi. Intercepts of fitted straight lines between lg kIAM and phi were comparable but slopes were much different for the three organic modifiers (acetonitrile, ethanol and methanol). Effects by adding CH2 substituent on lipophilicity difference (delta lg kIAM and delta lg Do/w,7.4) were similar for p-hydroxyl benzoic methyl ester to butyl ester, whereas different for p-hydroxylbenzoic acid to methyl ester.

CONCLUSIONIAMC system is a convenient, efficient and rapid tool for determining membrane interaction.

Recently, porous titanium granules (PTGs) have been indicated for the preservation of the dimensions of post-extraction sockets, as a filler in sinus lift procedures and for the treatment of peri-implant and periodontal defects, based on the osteoconductivity and dimensional stability of the titanium granules. However, there is a lack of information regarding the use of this material in larger defects and in conjunction with membranes. The objective of this study is to test the behavior of PTGs used to fill critical size defects in rabbit tibiae, with and without membranes. Critical defects were created in both tibiae of rabbits, divided randomly into three groups: Group A (defect filled with PTG), Group B (defect filled with PTG+collagen membrane) and a control group (empty defect). After six weeks, histomorphometric analysis was performed. The results showed more defect closures at the cortical area (87.37%±2.2%) and more bone formation at the marrow area (57.6%±1.3%) in Group B, in comparison with the other groups (P<0.05); the use of membranes improved the material stability expressed as more percentages of the original material when membranes were used (P<0.05). Finally, inflammatory reactions were observed when the granules were not protected by membranes. In spite of the limitations of this animal study, it may be concluded that PTG particles are osteoconductive and allow bone growth. The PTG particles must be covered by a membrane, especially when grafting larger defects, in order to control particle migration, promote clot stabilization and separate the PTG graft from undesired soft tissue cells.
Animals ; Male ; Membranes, Artificial ; Rabbits ; Tibia ; abnormalities ; Titanium ; chemistry