ObjectiveTo observe the protective effect of etomidate (ET) on cultured retinal ganglion cells (RGC) with mechanical injury in vitro. MethodsNew Sprague-Dawley rat RGC was cultured in vitro and identified by double immunofluorescent labeling of Thy1.1 and microtubule associated protein 2. The cultured primary cells were randomly divided into control group, RGC scratch group, ET low dose group (1 μmol/L), ET medium dose group (5 μmol/L) and ET high dose group (10 μmol/L). The RGC mechanical injury model was established by using iris knife to culture cells in RGC scratch group and ET group with different concentration. Seven days after modeling, the RGC survival rate of each group was detected by cell count Kit 8 proliferation assay. The apoptosis rate of RGC was detected by Annexin Ⅴ/propyl iodide double staining. Single factor analysis of variance was used to compare the groups. The pairwise comparison between groups was tested by the least significant difference method. ResultsThe survival rates of RGC in RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (72.60±2.97)%, (73.73±1.14)%, (79.19±1.79)% and (83.88±0.94)%, respectively. The RGC apoptosis rates of control group, RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (5.08±0.17)%, (18.67±1.24)%, (17.96±0.74)%, (15.11± 0.56)% and (11.67±1.32)%, respectively. Comparison of RGC survival rate between groups: compared with RGC scratch group, the cell survival rate of ET low-dose group, ET medium-dose group and ET high-dose group was increased, and the difference between RGC scratch group and ET low-dose group was not statistically significant (P=0.728); the differences between RGC scratch group, ET medium dose group and ET high dose group were statistically significant (P＜0.001); the difference between ET medium dose group and ET high dose group was statistically significant (P=0.002). Comparison of apoptosis rate of RGC among groups: the apoptosis rate of RGC scratch group was significantly higher than that of control group, the difference was statistically significant (P＜0.001). Compared with RGC scratch group, the apoptosis rate of ET low-dose group, ET medium-dose group and ET high-dose group was decreased, and there was no statistical significance between RGC scratch group and ET low-dose group (P=0.869). The differences of apoptosis rate between RGC scratch group, ET medium dose group and ET high dose group were statistically significant (P＜0.05). The difference of apoptosis rate between ET medium dose group and ET high dose group was statistically significant (P=0.007). ConclusionET has neuroprotective effect on RGC cultured in vitro with mechanical injury, and the protective effect increases with the increase of ET dose in a certain range.
The osteogenc potential of bone marrow has been proved by experiment. To investigate more in details, bone marrow was obtained from the trochanteric region of femur of NewZealand rabbit in 4 to 8 weeks old. After being cultured in vitro for one week, the hematopoietic component of the bone marrow had disappeared, thus the stromal cells were obtained. Then the stromal cells were subcultured in cultural fluid containing dexamethasone (10-8 mol/L) and natrium glycerophosphate (10mmol/L). Under the phasecontrast microscope, it was found that being cultured for 15 days. The stromal cells were lined up in one layer and late the secretion activity was increased and gradually transformed into multilayer structure and was congregated into diffused opaque clusters in twenty days. During culture, the cells were examined by tetracycline fluorescence label, histochemistry stains, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray microanalysis. The results showed that the morphological and biological characteristics of the cultured stromal cells derived from the bone marrow were similiar to those of osteoblasts and could synthesized mineralized new bone tissue in vitro.
Objective
To observe the effect of ciliary neurotrophic factor (CNTF) with different concentrations on the growth and survival of ratsrsquo; retinal ganglion cells (RGC) in vitro.
Methods
The retinae of 15 Wistar rats which were 2 or 3 days after birth were dissociated into cell suspension with 0.05% trypsin digestion. After 3 days, cultured RGC were identified with immunohistochemistry method using anti-rat Thy-1.1 monoclonal antibody. Cultured RGC were divided into the 10, 20, 40 ng/ml CNTF group （Ⅰ,Ⅱ, and Ⅲgroup） and the control group respectively. The duration of living RGC was recorded. After 3, 5 and 7 days, the A value of living cells was tested by methylthio-tetrazole colorimetric microassay.
Results
The result of immunohistochemical examination showed that 90% of living cells cultured for 3 days were RGC. No protuberance or volume increase of RGC were observed in CNTF groups and the control group. The duration of the living RGC was prolonged 3 to 4 days in CNTF groups compared with the control group. The A values of living RGC at the 5th and 7th days in the CNTF groups and the control group were: 0.0758plusmn;0.0139 and 0.0693plusmn;0.0113 in I group, 0.0902plusmn;0.0114 and 0.0825plusmn;0.0125 in Ⅱ group, 0.0792plusmn;0.0133 and 0.0653plusmn;0.0086 in Ⅲ group, and 0.0620plusmn;0.0071 and 0.0513plusmn;0.0068 in the control group, respectively. The differences between the simultaneous CNTF and control group were significant (between Ⅱ group and the control group: P＜0.01; between Ⅰ and Ⅲ group, and the control group: P＜0.05).
Conclusion
CNTF with some certain concentrations could facilitate survival of RGC in vitro. CNTF has no effect on the conformation of RGC.
(Chin J Ocul Fundus Dis, 2002, 18: 283-285)
Objective To prepare the silk fibroin microcarrier loaded with clematis total saponins (CTS) (CTS-silk fibroin microcarrier), and to investigate the effect of microcarrier combined with chondrocytes on promoting rabbit knee articular cartilage defects repair. Methods CTS-silk fibroin microcarrier was prepared by high voltage electrostatic combined with freeze drying method using the mixture of 5% silk fibroin solution, 10 mg/mL CTS solution, and glycerin. The samples were characterized by scanning electron microscope and the cumulative release amount of CTS was detected. Meanwhile, unloaded silk fibroin microcarrier was also prepared. Chondrocytes were isolated from knee cartilage of 4-week-old New Zealand rabbits and cultured. The 3rd generation of chondrocytes were co-cultured with the two microcarriers respectively for 7 days in microgravity environment. During this period, the adhesion of chondrocytes to microcarriers was observed by inverted phase contrast microscope and scanning electron microscope, and the proliferation activity of cells was detected by cell counting kit 8 (CCK-8), and compared with normal cells. Thirty 3-month-old New Zealand rabbits were selected to make bilateral knee cartilage defects models and randomly divided into 3 groups (n=20). Knee cartilage defects in group A were not treated, and in groups B and C were filled with the unloaded silk fibroin microcarrier-chondrocyte complexes and CTS-silk fibroin microcarrier-chondrocyte complexes, respectively. At 12 weeks after operation, the levels of matrix metalloproteinase 9 (MMP-9), MMP-13, and tissue inhibitor of MMP 1 (TIMP-1) in articular fluid were detected by ELISA. The cartilage defects were collected for gross observation and histological observation (HE staining and toluidine blue staining). Western blot was used to detect the expressions of collagen type Ⅱ and proteoglycan. The inflammatory of joint synovium was observed by histological staining and inducible nitric oxide synthase (iNOS) immunohistochemical staining. Results The CTS-silk fibroin microcarrier was spherical, with a diameter between 300 and 500 μm, a porous surface, and a porosity of 35.63%±3.51%. CTS could be released slowly in microcarrier for a long time. Under microgravity, the chondrocytes attached to the surface of the two microcarriers increased gradually with the extension of culture time, and the proliferation activity of chondrocytes at 24 hours after co-culture was significantly higher than that of normal chondrocytes (P<0.05). There was no significant difference in proliferation activity of chondrocytes between the two microcarriers (P>0.05). In vivo experiment in animals showed that the levels of MMP-9 and MMP-13 in group C were significantly lower than those in groups A and B (P<0.05), and the level of TIMP-1 in group C was significantly higher (P<0.05). Compared with group A, the cartilage defects in groups B and C were filled with repaired tissue, and the repaired surface of group C was more complete and better combined with the surrounding cartilage. Histological observation and Western blot analysis showed that the International Cartilage Repair Scoring (ICRS) and the relative expression levels of collagen type Ⅱ and proteoglycan in groups B and C were significantly better than those in group A, and group C was significantly better than group B (P<0.05). The histological observation showed that the infiltration of synovial inflammatory cells and hyperplasia of small vessels significantly reduced in group C compared with groups A and B. iNOS immunohistochemical staining showed that the expression of iNOS in group C was significantly lower than that in groups A and B (P<0.05).Conclusion CTS-silk fibroin microcarrier has good CTS sustained release effect and biocompatibility, and can promote the repair of rabbit cartilage defect by carrying chondrocyte proliferation in microgravity environment.
Objective To make a comparative study on the effects of whole bone marrow culture method and density gradient centrifugation method in isolating hBMSCs. Methods hBMSCs were obtained from healthy adult volunteers and isolated by whole bone marrow culture method and density gradient centrifugation method. Primary cell morphology was observed using inverted phase contrast microscope and the cells in the 2nd passage were stained with HE after being cultured for 7 days. And then, the generation time of the primary, 2nd and 3rd passage hBMSCs was comparedbetween two methods and the surface markers were detected by flow cytometer. In addition, the ALP expression inosteoinductive hBMSCs were evaluated by ALP activity kit at 3, 6 and 9 days and ALP staining was used for osteoinductivehBMSCs with Kaplow method at 9 days. Results Primary cells isolated with whole bone marrow culture method showedaggregation growth while cells isolated with density gradient centrifugation method showed diffusion growth. HE stainingshowed no significant difference in the morphology of the 2nd passage cells between these two methods. The generationtime of primary cells isolated by whole bone marrow culture method (15.36 ± 1.67) days was significantly shorter than that of cells isolated by density gradient centrifugation method [(18.57 ± 1.05) days] (P lt; 0.01), while the generation time of the 2nd and 3rd passage cells showed no statistically significant differences between these methods (P gt; 0.05). The concent of positive surface markers (CD29, CD44, CD71, CD105, CD166) and negative surface marker CD34 in the 2nd cells showed no significant difference between these two isolation methods (P gt; 0.05); however, negative markers CD14 and CD45 showed significant difference (P lt; 0.01). The ALP expression in osteoinductive cells showed no statistical significant (P gt; 0.05) at 3, 6 and 9 days; and the ALP staining positive cell ratio of whole bone marrow culture method was basically in accordance with that of density gradient centrifugation method at 9 days. Conclusion hBMSCs could be isolated by whole bone marrow culture method, and the cell isolation effects of whole bone marrow culture method are equivalent with density gradient centrifugation method.
Objective To investigate the effect of nidus vespae on lymphocyte blastisation in mixed culture system of lymphocyte and pancreatic islet. Methods Solution of nidus vespae was extracted with ethanol from its herb. Rat lymphocyte and pig pancreatic islet were isolated and then were mixed together and cultured in incubators of 37 ℃ (concentration in volume: 5%CO2). Three different concentrations of extracted solution of nidus vespae （experimental group Ⅰ: 4.0 g/ml, group Ⅱ: 0.4 g/ml, group Ⅲ: 0.2 g/ml） were added to the mixed culture system of lymphocyte, respectively. Radioactive nuclide counts per minute were measured by 3H-thymdine test in order to examine the role of nidus vespae in inhibiting blatisation of lymphocyte, and the results were also compared with control group and CsA group, respectively. Results The counts were all reduced significantly (P＜0.001) in 3 experimental groups compared with control group (group Ⅰ 45.3%, group Ⅱ 29.6%and group Ⅲ 9.2%). It also showed that the inhibitory effect became ber in higher concentration but still weaker than that in CsA group (80.7%). Conclusion Nidus vespae could inhibit the blastisation of lymphocyte in mixed culture system of lymphocyte and pancreatic islet, and the effect increased as the the concentration increased, which may suggest that nidus vespae could suppress the rejection induced by T cells.
Objective To discuss the applycation possibility of themicroscopic stripping technique used in the primary culture of human embryonicesophagus squamous epithelial cells, and of the methodds for the isolation, depuration and subculture of the esophagus epithelial cells in vitro. Methods The squamous epithelial cells wereobtained from the esophagus mucous membrane of the 20-week abortion fetus through the microscopic stripping technique, and were digested with trypsin. Then, the morphological, immunohistochemical observation and the growth curve of the isolated cells were studied. Results The isolated cells were spherical in the cell suspension and spherical-like or polygon-like after attachment to the culture flask.The squamous epithelial specialized cytokeratin staining was bly positive. And the morphological studies by the transmission electron microscopy indicated that the cultured cells were squamous epithelial cells. The squamous epithelial cells reached the peak level 3-4 days after the transfer of the culture. The absorbanceat 3 and 4 days was significantly higher than that at 1,2,5 and 6 days (P＜0.05). Conclusion A large mumber of squamous epithelial cells can be available with the microscopic stripping technique and the digestion method. Thecultured squamous epithelial cells can be proliferated quickly, and fit for the tissue engineering study.
In order to investigate the compatibility and growth between the tendon cell or fibroblast of rabbit and artificial materials, the combined-culture of the two cells with the carbon fiber, terylene and chitin was observed respectively. Results showed as following: in vitro, the compatibility of carbon fiber with these two cells was well, cell-adhesion ability was good as well. Few cells grew on terylene. Chitin inhibited the growth of either cells. No matter the tendon cell or the fibroblast, the amount of cells adhering on the carbon fiber was far more than that on terylene or chitin. When the three materials were interlaced together, the collagen fibers produced by the cells were arranged in direction parallel to the carbon fibers. As the time elapsed, the cells on the carbon fiber distributed evenly and enveloped the material in network-like fashion, this suggested that carbon fiber was a good material for producing living artificial tendon and ligament.
Objective To explore the biocompatibility of poly(lacticacid/glycolic acid/asparagic acid-co-polyethylene glycol) biomaterials (PLGA-ASP-PEG) and biological behaviors of cultured marrow stroml stem cells (MSCs) combined with this new type of scaffold in tissue engineering. Methods The PLGA-ASP-PEG tri-block copolymers were obtained through bulk ringopening copolymerization method.MSCs were isolated from the bone marrow of 4 week old New Zealand rabbits. The 3rdgeneration MSCs were cultured combining with PLGA-ASP-PEG in vitro, while cells cultured in PLGA as control group. The cell adhesion rate and the adhesivepower were examined by conventional precipitation method and micropipette aspiration technique respectively. The morphological features were studied by scanning electron microscope. The proliferation behavior of the cells was analyzed by MTT assay. The cell cycle, proliferation index, DNA index and apoptosis of the cells were detected by flow cytometry. The synthesis of protein and collagen were examined by Coomassie Brilliant Blue dyes and 3H-Proline incorporation test. Results The MSCs adhered and grew well on the surface of the biomaterial PLGA-ASP-PEG. The powers of cell adhesion, proliferation and protein and collagen synthesis of the cells were all significantly higher than those of PLGA group (P＜0.05), but the apoptosis rate was significantly lower than that of PLGA group (P＜0.05). The DNA indexes showed the cells of both PLGA-ASP-PEG group and PLGAgroup were normal diploid cells. Conclusion PLGA-ASP-PEG showedgood biocompatibilityand the biological properties improved greatly compared with the PLGA scaffold materials. These results demonstrated that the promise of PLGAASPPEG canbe used as an ideal scaffold material for construction of tissue engineered bone to restore bone defects in bone tissue engineering．
