AIM: To study the therapeutic effect of three tubeguides with electrical conductivity associated to mesenchymal stem cells(MSCs) on neuro-muscular regeneration after neurotmesis.METHODS: Rats with 10-mm gap nerve inju...AIM: To study the therapeutic effect of three tubeguides with electrical conductivity associated to mesenchymal stem cells(MSCs) on neuro-muscular regeneration after neurotmesis.METHODS: Rats with 10-mm gap nerve injury were tested using polyvinyl alcohol(PVA), PVA-carbon nanotubes(CNTs) and MSCs, and PVA-polypyrrole(PPy). The regenerated nerves and tibialis anterior muscles were processed for stereological studies after 20 wk. The functional recovery was assessed serially for gait biomechanical analysis, by extensor postural thrust, sciatic functional index and static sciatic functionalindex(SSI), and by withdrawal reflex latency(WRL). In vitro studies included cytocompatibility, flow cytometry, reverse transcriptase polymerase chain reaction and karyotype analysis of the MSCs. Histopathology of lung, liver, kidneys, and regional lymph nodes ensured the biomaterials biocompatibility. RESULTS: SSI remained negative throughout and independently from treatment. Differences between treted groups in the severity of changes in WRL existed, showing a faster regeneration for PVA-CNTs-MSCs(P < 0.05). At toe-off, less acute ankle joint angles were seen for PVA-CNTs-MSCs group(P = 0.051) suggesting improved ankle muscles function during the push off phase of the gait cycle. In PVA-PPy and PVA-CNTs groups, there was a 25% and 42% increase of average fiber area and a 13% and 21% increase of the "minimal Feret's diameter" respectively. Stereological analysis disclosed a significantly(P < 0.05) increased myelin thickness(M), ratio myelin thickness/axon diameter(M/d) and ratio axon diameter/fiber diameter(d/D; g-ratio) in PVA-CNT-MSCs group(P < 0.05). CONCLUSION: Results revealed that treatment with MSCs and PVA-CNTs tube-guides induced better nerve fiber regeneration. Functional and kinematics analysis revealed positive synergistic effects brought by MSCs and PVA-CNTs. The PVA-CNTs and PVA-PPy are promising scaffolds with electric conductive properties, bio- and cytocompatible that might prevent the secondary neurogenic muscular atrophy by improving the reestablishment of the neuro-muscular junction.展开更多
Superovulation is used to stimulate the production and release of large amounts of oocytes in mice by using two hormones that mimic FSH (PMSG) and LH (hCG) effects. Since superovulation can have a negative impact on o...Superovulation is used to stimulate the production and release of large amounts of oocytes in mice by using two hormones that mimic FSH (PMSG) and LH (hCG) effects. Since superovulation can have a negative impact on oocyte and embryo development, this investigation aimed to compare two alternatives for 2-cells embryo collection in order to reduce the number of females and to benefit from the superovulation process. Data from mouse embryo collection from our facility was analyzed to compare the number of 2-cells embryos collected at 1.5 dpc and the number of 2-cells embryos obtained after overnight incubation of 1-cell embryos, collected at 0.5 dpc. Genetically modified mouse strains with a similar background (C57BL/6J, B6*129 and FVB/NJ) were analyzed and for strains at a C57BL/6J and B6*129 background, the number of 2-cells embryos obtained after incubation was significantly higher when compared to the number of 2-cells embryos collected at 1.5 dpc (1.4-fold and 1.7-fold, respectively). C57BL/6J wild type mice had similar results with a higher number of 2-cells embryos when collection was performed at 0.5 dpc followed by incubation (1.4-fold). These results can help the planning of 2-cells embryo harvesting by reducing the number of females needed for this procedure.展开更多
基金Supported by System of Incentives for Research and Technological development of QREN in the scope of project n°38853/2013-DEXGELERATION:"Solucoes avancadas de regeneracao ossea com base em hidrogeis de dextrin"the European Community FEDER fund through ON2-O Novo Norte-North Portugal Regional Operational Program 2007-2013+4 种基金Project n°34128-BEPIM II:"Microdispositivos biomédicos com capacidade osteointegrativa porμPIM"funded by Ad Ithe program COMPETE-Programa Operacional Factores de Competitividade,projects Pest-OE/AGR/UI0211/2011PTDC/CVT/103081/2008CDRsp’s Strategic Project-UI-4044-2011-2012(Pest-OE/EME/UI4044/2011)funding from FCT
文摘AIM: To study the therapeutic effect of three tubeguides with electrical conductivity associated to mesenchymal stem cells(MSCs) on neuro-muscular regeneration after neurotmesis.METHODS: Rats with 10-mm gap nerve injury were tested using polyvinyl alcohol(PVA), PVA-carbon nanotubes(CNTs) and MSCs, and PVA-polypyrrole(PPy). The regenerated nerves and tibialis anterior muscles were processed for stereological studies after 20 wk. The functional recovery was assessed serially for gait biomechanical analysis, by extensor postural thrust, sciatic functional index and static sciatic functionalindex(SSI), and by withdrawal reflex latency(WRL). In vitro studies included cytocompatibility, flow cytometry, reverse transcriptase polymerase chain reaction and karyotype analysis of the MSCs. Histopathology of lung, liver, kidneys, and regional lymph nodes ensured the biomaterials biocompatibility. RESULTS: SSI remained negative throughout and independently from treatment. Differences between treted groups in the severity of changes in WRL existed, showing a faster regeneration for PVA-CNTs-MSCs(P < 0.05). At toe-off, less acute ankle joint angles were seen for PVA-CNTs-MSCs group(P = 0.051) suggesting improved ankle muscles function during the push off phase of the gait cycle. In PVA-PPy and PVA-CNTs groups, there was a 25% and 42% increase of average fiber area and a 13% and 21% increase of the "minimal Feret's diameter" respectively. Stereological analysis disclosed a significantly(P < 0.05) increased myelin thickness(M), ratio myelin thickness/axon diameter(M/d) and ratio axon diameter/fiber diameter(d/D; g-ratio) in PVA-CNT-MSCs group(P < 0.05). CONCLUSION: Results revealed that treatment with MSCs and PVA-CNTs tube-guides induced better nerve fiber regeneration. Functional and kinematics analysis revealed positive synergistic effects brought by MSCs and PVA-CNTs. The PVA-CNTs and PVA-PPy are promising scaffolds with electric conductive properties, bio- and cytocompatible that might prevent the secondary neurogenic muscular atrophy by improving the reestablishment of the neuro-muscular junction.
文摘Superovulation is used to stimulate the production and release of large amounts of oocytes in mice by using two hormones that mimic FSH (PMSG) and LH (hCG) effects. Since superovulation can have a negative impact on oocyte and embryo development, this investigation aimed to compare two alternatives for 2-cells embryo collection in order to reduce the number of females and to benefit from the superovulation process. Data from mouse embryo collection from our facility was analyzed to compare the number of 2-cells embryos collected at 1.5 dpc and the number of 2-cells embryos obtained after overnight incubation of 1-cell embryos, collected at 0.5 dpc. Genetically modified mouse strains with a similar background (C57BL/6J, B6*129 and FVB/NJ) were analyzed and for strains at a C57BL/6J and B6*129 background, the number of 2-cells embryos obtained after incubation was significantly higher when compared to the number of 2-cells embryos collected at 1.5 dpc (1.4-fold and 1.7-fold, respectively). C57BL/6J wild type mice had similar results with a higher number of 2-cells embryos when collection was performed at 0.5 dpc followed by incubation (1.4-fold). These results can help the planning of 2-cells embryo harvesting by reducing the number of females needed for this procedure.
