| Interventional therapy has been a very important treatment for the coronary stenosis due to arteriosclerosis. But restenosis complicating interventional therapy has limited the therapeutic effect and its further development. Biodegradable stent provide an effective method for the prevention, control and treatment to restenosis, which has been a research hot spot. We investigate the cytocompatibility of PLGA and PLGA-PEG combined with vascular muscle cell by culturing rabbit vascular smooth muscle cell(VSMC) on PLGA and PLGA-PEG. So we can provide lab data for the application of biodegradable polymer in interventional therapy. Objective: To investigate the cytocopatibility of PLGA and PLGA-PEG combined with vascular muscle cell so as to provide lab data in vessel tissue engineering.Method: rabbit vascular smooth muscle cell (VSMC) were cultured in vitro and identified with immune histologic assessment.The morphological characters were observed with phase contrast microscope. Compared with control ,VSMC were cultured with PLGA and PLGA-PEG, then the morphological characters were observed with phase contrast microscope. The total number of the cell were taken account everyday, and the morphological characters were represented on a graph. VSMC were culture on 96-hole board at a dose of 1.0*105/L,cell viability were detected with MTT assay on 1st ,3rd ,5st and 7st day. VSMC were culture on 6-hole board at a dose of 3.0*105/L,and cell cycle were detected with flow cytometer(FCM) seven days later.Result: VSMC grew well with PLGA and PLGA-PEG. From the fist day to the seventh day the number of the cell is respectively (control: 1.00±0.00, 5.60±0.48, 6.64±0.20, 7.21±0.15, 7.40±0.36, 8.99±0.39, 9.59±0.3;PLGA group: 1.00±0.00,5.32±0.23,6.52±0.35,7.04±0.32,7.25±0.12,8.72±0.39,9.24±0.31；PLGA-PEG group:1.00±0.00,5.44±0.21,6.31±0.45,7.01±0.31,7.14±0.22,8.62±0.32,9.14±0.82).Compared with control one, the number of the three group had not obvious difference (P>0.05) though the number of PLGA group and PLGA-PEG group were less. Cell proliferation of PLGA group and PLGA-PEG group was good as control one. Flow cytometer show that the content of DNA and the distributing of cell cycle were similar .The T test and x2 test were applied when appropriate. Differences were considered significant when P<0.05.Discuss: Percutaneous transluminal coronary angioplasty(PTCA) has been accepted as a treatment for coronary disease,but late restenosis that coccurs in 30%-40%of patient .The stent implantation in the human coronary arteries reduced the rate of the restenosis ,but restenosis within 6 months(10-30%) remains a significant problem Biodegradable stent has deal with many fatal shortcomings of metal stent. For example, the surfaces of most metal are electropositively charged and therefore are thrombogenic because blood elements are negatively charged. Moreover, the stent becocomes a permanent foreign body due to the type of metal,electrostatic charges and possible physical irritation from individual filaments leading to atrophy of the medium layer, formation of aneurysm and restenosis. Biodegradable stent have the potential to remain in situ for a predicted period of time keeping the vessel wall patent and then degrading to non-toxic substance. Therefore, after complication of their functions and resorption of the stent ,the vessel wall can preserve its normal function .The release profiles of drugs from a biodegradable stent can also be adjusted by the degradation behaviour. If the problems of thrombosis and restenosis could be overcome by biodegradable stent this new method would gain more attention. The biodegradable polymers in our experiment are PLLA,PLGA and the combination with PEG at high molecular weight. The dregradation rate of the stent can be controlled by the degree of p...
|
PDF Full Text Request