Study On Bioactivity Of Polycaprolactone Encapsulated Mesenchymal Stem Cells

Objective To separate and culture rat bone mesenchymal stem cells as study object, establish retrieve method for encapsulated cells and develop cell bioactivity determination methods,investigate the impact of polycaprolactone(PCL) semipermeable membrane tube encapsulation on bioactivity of cells and explore its mechanism,it is expected to offer better help for related research and application.Method Bone mesenchymal stem cells isolated,purified and cultured from SD rat,third generation cells prepared for experiments.Cell suspension implanted into PCL semipermeable membrane tube and encapsulated at 70 centigrade,cell activity and retrieving rate were measured in varies time of 0.25%trypsin digestion.Impact of PCL capsulation on the mesenchymal stem cells activity studied in vitro studied,one plate culture with complete culture medium for control group and three encapsulated culture for experimental groups installed.Experimental group 1:complete culture medium for cell suspended before package and for culture,in which small molecule nutrients can be maintained through infiltration;experimental group 2:complete culture medium for cell suspended before package and serum free basic culture medium for culture,in which small molecule nutrients can not be supplemented through infiltration;experimental group 3: basic culture medium for cell suspended before package and complete culture medium for culture,in which small molecule nutrients can be supplemented through infiltration without serum macromolecules nutrition included.Retrieving capsulated cells for cell counting, MTT assay,CCK-8 assay daily for 8days to determine cell activity,and analysis growth curve.Impact of PCL capsulation on the mesenchymal stem cell activity studied in vivo, one plate culture with complete culture medium for control group with and two encapsulated transplantation for experimental groups(complete culture medium or basic culture medium for cell suspended) installed,after package and transplantation,retrieving capsulated cells for cell count,MTT assay,CCK-8 assay Daily for 8days to determine cell activity,and analysis growth curve.Result Typical rat bone marrow-derived mesenchymal stem cells isolated and cultured, 70℃packaging and three minutes 0.25%trypsin digestion retrieve no less than 97%cells in which more than 95%of living cells without obvious injury.Mesenchymal stem cells in experimental group 1 survived well,cell proliferation rate reach to 150%,activity of mesenchymal stem cells in experimental group 2 decreased rapidly and all died within one week,bioactivity of mesenchymal stem cells in experimental group 3 gradually increased after a decline,but cell proliferation rate less than 10%,all three experimental groups have significant differences compare with control group in which proliferation rate is 210%.For in vivo experiment,mesenchymal stem cells in experimental group 1 survived well,cell proliferation rate reach to 140%;bioactivity of mesenchymal stem cells in experimental group 2 gradually increase after a decline,but cell proliferation rate less than 10%,.two experimental groups have significant differences compare with control group in which proliferation rate is 200%Convludion Retrieve method for encapsulated cells established and cell bioactivity determination methods developed based on cell retrieve,encapsulation in some degree decreased cell activity in vitro and in vivo.We confirmed small molecular substances in serum is of great significance,and is the key to cell survival and growth,macromolecules in serum play a role in proliferation of the cells,lack of serum hinder cell proliferation, intracapsular macromolecules depletion may be one of the reasons for the decline of cells for long-term transplantation.Low molecular weight substances permeability provide a certain time of cell activity,semipermeable membrane immunoisolation technology can be potential method for allograft rejection...