Effects of microporous membranes with different pore sizes on the filtration of tumor cells / 临床检验杂志

Objective To investigate the filtration roles of microporous membranes with different pore sizes in the tumor cells with different diameters,and effects on the filtered cells.Methods Three kinds of tumor cells with different cell diameters and same concentrations,including Jurkat,K562 and A549,were filtered by the polycarbonate microporous membranes with different pore sizes such as 1,3,5,8 and 10 μm,respectively,and their filtration rates were determined.The diameters of three kinds of tumor cells before and after filtration,and the fixed K562 cells with formaldehyde,were measured by an optical microscope.The activity of the filtered K562 cells were detected by the trypan blue staining.After the filtered K562 cells were re-cultured,their proliferation activity was analyzed by the growth curve.Results Jurkat,K562 and A549 cells couldn't pass the filter membrane with 1 μm of pore size.The filtration rates of three kinds of tumor cells passing the fliter membranes with 3 μm,5 μm,8 μm and 10 μm of pore sizes increased in turn.The survival rate of K562 cells filtered by 3 μm of pore size of membrane was 92.0％,and the proliferation acticity of re-cultured K562 cells was still strong.The filtration rate of the fixed K562 cells with formaldehyde was significantly decreased,and the average diameter of the filtered cells had no obvious change.Conclusion The living cells are able to pass the membranes with the pore sizes less than their diameters.The living cells passed the filter membranes may still maintain their growth and proliferation activity.However,the fixation of formaldehyde may significantly reduce the number of cells passed the membrane.

Influence of Poly-L-Lactic Acid Scaffold's Pore Size on the Proliferation and Differentiation of Dental Pulp Stem Cells

The aim of this study was to evaluate the influence of the poly-L-lactic acid (PLLA)-based scaffold's pore size on the proliferation and differentiation of dental pulp stem cells (DPSCs). The scaffolds were prepared in pulp chambers of 1-mm-thick tooth slices from third molars using salt crystals (150-250 µm or 251-450 µm) as porogen. DPSC (1x105 cells) were seeded in the scaffolds with different pore sizes, and cultured in 24-well plates. The cell proliferation was evaluated using the WST-1 assay after 3-21 days. Furthermore, RT-PCR was used to assess the differentiation of the DPSCs into odontoblasts, using markers of odontoblastic differentiation (DSPP, DSP-1 and MEPE). RNA from human odontoblasts was used as control. Cell proliferation rate was similar in both scaffolds except at the 14th day period, in which the cells seeded in the scaffolds with larger pores showed higher proliferation (p<0.05). After 21 days DPSCs seeded in both evaluated scaffolds were able of expressing odontoblastic markers DMP-1, DSPP and MEPE. In summary, both scaffolds tested in this study allowed the proliferation and differentiation of DPSCs into odontoblast-like cells.

O objetivo desse estudo foi avaliar a influência do tamanho dos poros de um scaffold à base de poli ácido láctico (PLLA) sobre a proliferação e diferenciação de células tronco da polpa dental (dental pulp stem cells - DPSC). Os scaffolds foram preparados dentro da câmara pulpar de discos de terceiros molares (1 mm), utilizando sal como porógeno (150-250 µm ou 251-450 µm). DPSC (1x105 células) foram semeadas nos scaffolds com diferentes tamanhos de poros e cultivadas em placas de 24 poços. A proliferação celular foi avaliada utilizando WST-1 após 3-21 dias. Além disso, RT-PCR foi utilizado para avaliar a diferenciação odontoblástica das DPSC utilizando marcadores da diferenciação odontoblástica (DSPP, DMP-1 e MEPE). RNA obtido de odontoblastos humanos foi utilizado como controle. A taxa de proliferação celular foi semelhante nos dois scaffolds avaliados, exceto no 14° dia, no qual as células cultivadas nos scaffolds com os maiores poros apresentaram uma maior taxa de proliferação (p<0,05). Após 21 dias, as DSPC cultivadas em ambos scaffolds avaliados foram capazes de expressar os marcadores odontoblásticos DMP-1, DSPP e MEPE. Em resumo, ambos scaffolds avaliados nesse estudo permitiram a proliferação e diferenciação odontoblástica das DPSC. .

The factors influencing the transfer of porcine endogenous retroviruses across the membrane in bioartificial livers / 中华肝胆外科杂志

ObjectiveTo identify the factors influencing the transfer of porcine endogenous retroviruses across the membrane of a new bioartificial liver (BAL),which is a necessary caution to consider for BALs carrying porcine hepatocytes.MethodsA novel porcine BAL composed of two circuits was constructed using a plasma filter with membrane pore size of 500 nm and a plasma component separator with membrane pore sizes 10 nm,20 nm,30 nm,and 35 nm.Co-cultured cells of porcine hepatocytes and mesenchymal stem cells or single porcine hepatocytes were incubated in the bioreactors.The BAL was continuously worked for 72 hours during which the supernatant was collected from the internal and external circuits every 12 hours.PERV RNA,reverse transcriptase (RT) activity,and in vitro infectivity from the supernatant were detected.ResultsIn the plasma filter group,the PERV RNAlevels were the same in both circuits,suggesting little to no effect of the plasma filter on the PERV RNA's crossing.With plasma component separators,PERV RNA was found in the external circuits at different times without positive RT activity and HEK293 cell infection,but its level was reduced significantly.The larger the membrane pore size was,the earlier and the more RNA was detected.ConclusionsThe membrane pore size,the treatment time and the viral level in the internal circuit are contributing factors influencing the transfer of PERV RNA across the membrane in a BAL.

Propriedades físicas do solo, influenciadas pela distribuição de poros, de seis classes de solos da região de Lavras-MG / Soil physical properties, influenced by pores distribution, of six soil classes in the region of Lavras-MG

A distribuição de poros dos solos condiciona seu comportamento físico-hídrico. Assim, influencia os processos dinâmicos do ar e da solução do solo, bem como a potencialidade agrícola dos mesmos. Desta forma, com o presente trabalho, objetivou-se avaliar a influência da distribuição de poros sobre as propriedades físicas de seis classes de solos, sob vegetação natural, localizados na região de Lavras (MG). Coletaram-se amostras deformadas e indeformadas da camada superficial (0-20 cm) para a caracterização física e a determinação da curva de distribuição de poros dos solos. Os resultados indicaram que as propriedades físicas dos solos não foram influenciadas pelos poros com diâmetro entre 0,03 e 0,0375 mm. Verificou-se, também, que os valores de macroporosidade foram diretamente proporcionais aos valores de condutividade hidráulica saturada dos solos estudados.

The soil pores distribution conditions its physical-hydraulic behavior. Therefore, it influences the dynamic processes of air and solution of the soil, and also its agricultural potentiality. This work aimed at evaluating the influence of pores distribution on physical properties of six classes of soil, under natural vegetation, located in the region of Lavras (MG). Disturbed and undisturbed samples were collected from superficial layer (0-20 cm) for physical characterization and determination of pores distribution curves. The results indicated that soil physical properties were not influenced by the pores with diameter between 0,03 and 0,0375 mm. It was also verified that macroporosity values were directly proportional to the hydraulic conductivity values of saturated soils.

Surface characteristics of anodic oxidized titanium according to the pore size / 대한치과보철학회지

Statement of problem. The success of osseointegration can be enhanced with an implant that has improved surface characteristics. Anodic oxidation is one of the surface modifying method to achieve osseointegration. Voltage of anodic oxidation can change surface characteristics and cell activity. Purpose. This study was performed to evaluate MG63 cell responses such as affinity, proliferation and to compare surface characteristics of anodic oxidized titanium in various voltage. Material and method. The disks for cell culture were fabricated from grade 3 commercially pure titanium, 1 mm in thickness and 12 mm in diameter. Surfaces of 4 different roughness were prepared. Group 1 had a machined surface, used as control. Group 2 was anodized under 220 V, group 3 was anodized under 300 V and group 4 was anodized under 320 V. The microtopography of specimens was observed by scanning electron microscope (JSM-840A, JEOL, Japan) and atomic force microscope(Autoprobe CP, Park Scientific Instrument, USA). The surface roughness was measured by confocal laser scanning microscope(Pascal, LSM5, Zeiss, Germany). The crystal structure of the titanium surface was analyzed with x-ray diffractometer(D8 advanced, Bruker, Germany). MG63 osteoblast-like cells were cultured on these specimens. The cell morpholgy was observed by field emission electron microscope(Hitachi S-4700, Japan). The cell metabolic and proliferative activity was evaluated by MTT assay. Results and conclusion. With in limitations of this in vitro study, the following conclusions were drawn. 1. In anodizing titanium surface, we could see pores which did not show in contol group. In higher anodizing voltage, pore size was increased. 2. In anodizing titanium surface, we could see anatase. In higher anodizing voltage, thicker oxide layer increased crystallinity(anatase, anatase and rutile mixed). 3. MG63 cells showed more irregular, polarized and polygonal shape and developed more lamellipodi in anodizing group as voltage increased. 4. The activity of cells in MTT assay increased significantly in group 3 and 4 in comparison with group 1 and 2. However, there was no difference between group 3 and 4 at P<0.05. Proliferation of MG63 cells increased significantly in pore size(3-5.5 micrometer) of group 3 and 4 in comparison with in pore size(0.2-1 micrometer) of group 2.

Histological Changes of Rabbit Cornea Implanted with Seoul Type Keratoprosthesis

Keratoprosthesis implantation is the only alternative method to restore vision in patients who might invariably fail allograft coneal transplantation. Seoul type keratoprosthesis adapted 20 micrometer pore sized expanded polytetrafluoroethyl-ene[PTFE, Gore-Tex]as a skirt material in this study. To evaluate compatibility of this material as a skirt we performed in vitro cell culture experiment and animal experiment. For in vitro experiment, expanded PTFE membrane was cultured with rabbit keratocytes in 24-well culture plate for a week.For animal experiment Seoul type keratoprosthesis was implanted in the rabbit cornea. Two months after the operation specimens for pathologic examination were retrieved. In culture experiment no keratocyte invaded pores. In animal experiment no keratocyte but only many inflammatory cells mainly polymorphonuclear leukocytes infiltrated pores of skirt and surrounding cornea. In conclusion, 20 micrometer pore sized expanded PTFE is not good as a skirt material of keratoprosthesis.

Exploration of Application of Large Pore Size Ultrafiltration Membrane in Chinese Medicine Production / 中成药

Objective: In order to improve the technology of Chinese medicine extraction, experiments were made with large pore size ultrafiltration (LPS UF) membranes in the process of Chinese medicine production, and the feasibility of replacing traditional alcohol sedimentation with LPS UF method in the production of compound Chinese medicine was also explored. Methods: The water extraction liquid of Shenbao Mixture with alcohol percolation extract was ultrafiltered. Icariin as index component was determined. Results: Component of Icariin was reserved as 90%, this technology was similar to alcohol extraction. Conclusion: The experiments on the extraction of “Shengbao” mixture show that the LPS UF membranes with MWCO above 100,000 were more effective in retaining the effective ingredients and removing the precipitates.