The Effect Of IGF-1 On Proliferation Of Cultured Adult Rabbit Articular Chondrocytes In Vitro

ObjectiveArticular cartilage injury caused by trauma or disease is common clinically. Most of patients are adult and old people, especially in orthopaedis' sufferers. Then there are not blood vessels and nerves in the cartilage tissues, so self -repaired of the injury is not easy. Discriminating with those studies' animals are always the fetal rabbits or immature rabbits'articular cartigate in previous, whose prolifeation are more fast than the adult rabbits'. we used the adult rabbits articular chondrocytes as the object of study. Under the effect of IGF - 1 alone to promote chondrocytes proliferation by drawing cell growth curve and detecting the survival number of the chondrocytes by MTT test, We can provide theortical-ly basis of culture and proliferation in vitro of adult people articular chondrocytes.Materials and Methods1. Isolation and Culture of adult rabbits chondrocytes: under the sterile condition , slice the articular cartigate of one Japanese big ear rabbit with the age of 22 months, the cartigate slices was cut into small cubes(1.0mm × 1.0mm × 1. 0mm or so) , digested, centrifuged. The collected cells were then resupended in DMEM culture medium ( containing 20% fetal bovine serum, penicillin 100u/ ml, streptomycin 100μg/ml) , adjust the number of cells to 4 × 10⁵ and cultivated in culture flask at 37℃ ,containing 5% of CO₂. First change the liquid at the day after tomorrow, later, change the liquid every 2 days, till cartilage cell together with 85%.2. Observe the form and growth condition of the cells under the invert microscope.3. Observing the cells climbing to the carry sheet glass , which are stained with HE.4. Detect with MTT test to comprehend the survival numbers of the chondro-cytes .5. Cell counting and draw growth curve to observe the proliferation state of the chondrocytes under the effect of IGF - 16. Statistics with analysis of t testDiscussion1. Using the invert microscope:Chondrocytes began to sticking to the wall of the dish at 6 hours after inoculated and after 72 hours almost all the cells are sticking to the wall. Their phase changed spherical to polygon and some is fusiformis. With the increase of the quantity and volue, cells phase because to be unanimous. The chondrocytes of the test group which be added with IGF - 1 are polygon mostly and have more division cells and blend to be monolayer as " flagstone". the cells of the control group growth slowly and have a few division cells, the proportion of the fusiformis cells increased.2. Observing the cells climbing to the carry sheet glass , which are stained with HE:Under. The light microscope, the shapes of chondrocytes may be seen more clearly, being small mostly, in the shapes of fusiform, roundlet and polygon, etc. and karyokinesis may be seen.3. MTT colorimetric test:Determination of the survival numbers of the cells:0. D. (optical density) value determined by MTT and the survival numbers of the cells are in directra-tio. According to the histogram with various concentrations of IGF -1, analyzed statistically, the cell nonmember is more super than the control group remarka-blely. So we determined that IGF -1 has the strongest effect of stimulating chon-drocyte proliferation and has the best stimulating concentration.4. Cell counting and draw growth curve:Chondrocytes appeared incubation after cell seeding firstly. 4 days later, Proliferation of cells of the test group were enhanced and the multiplication time in the logarithm period is 120 hours. Meanwhile, the control group appeared cell proliferation slowly and has no obvious logarithm period. At 16 days, the cell number of test group was 3 times that of control group and has outstanding pronounced. This was in accordanced with the MTT test result. Which showed that IGF -1 can advanced cell proliferation of the adult rabbits articular chondrocytes.Results;Under tissue engineering techniques get large number autogenous chondrocytes to repair articular cartilage defect has made significant progress, Even though early hyaline cartilage has been observed in some of these studies, complete and consistent, long - term reheneration of articular cartilage in an adult animal has not yet been achieved. In previous studies, the donors of chondrocytes almost were immature articular cartilage, it is not apply to adult or order patients who want to repair articular defect with autogenous chondrocytes. At present study, we cultured adult rabbits articular chondrocytes in vitro which similar with the adult or older people. We found that the adult rabbits articular chondrocytes were survived in no growth factor condition, but they growed slowly, keep phenotypic bad and excretion weaken. This illustrate the most chondrocytes of adult articular cartilage is in tranquillization state that their dirrerentia-tion and proliferation is ceased, but part of them still has the capability to proliferation in order to complement the reduce of cells because of the damaging and cell ageing. Yet, want to get large nonmember functional cells in tissue engineering various complicated factors must be regulated and controlled.With the developing of cell biology and the study is deeping on expression of special gene of chondrocytes cultured in vitro. By drawing cell growth curve and detecting the survival number of the chondrocytes by MTT test, it proved...