Objective To study the effect of serum rich in growth factors (SRGF) derived from plateletrich plasma (PRP) on the biological function of human and rat osteoblast.Methods PRP and platelet-poor plasma (PPP) obtained from healthy human and SD rat were activated by thrombin toget SRGF and serum poor in growth factors (SPGF). The level of TGFβ1 and PDGF-AB in human-SRGF and SPGF were assayed by enzyme-linked immunoassay(ELISA). Rat and human osteoblast were cultured and identified. Rat osteoblasts were treated with 5% rat-SRGF, 5% rat-SPGF and serumfree F12 medium, respectively. And human osteoblast were treated with 5% human-SRGF, 5% human-SPGF and serumfree DMEM. Cellular mitogenic activity was evaluated by thiazoly blue (MTT) colorimetric assay at 24, 48, 72 and 96hours.Results The level of TGF-β1 in human-SRGF was 307.67±35.57 ng/ml, and that of PDGF-AB was 52.76±7.89 ng/ml. The proliferation of rat and human osteoblast were promoted after treated with rat-SRGFand human-SRGF, respectively. In rat osteoblast groups, there were significant differences in absorbency between ratSPGF group and rat-SRGF group at 48 and 96 hours(Plt;0.05). In human osteoblast groups, the differences between human-SPGF group and human-SRGF group were significant at 48, 72 and 96 hours(Plt;0.05). The proliferation of these two kinds of osteoblasts almost stopped in serum-free medium, and the differences in absorbency , compared with othergroups，were significant (Plt;0.05). Conclusion High quality of PRP can be achieved by the improved method and SRGF is capable of up-regulating the proliferation of rat osteoblast and human osteoblast.
Objective To investigate the ability of plateletrich plasma(PRP) combined with cells and artificial bone in accelerating the repair of bone defect. Methods The marrow stromal stem cells (MSCs) of rabbit were cultured and induced into the osteoblast-like cells in vitro. PRP was produced with low-density twice centrifugations. Forty-eight New Zealand rabbits were made 1.2 cm bilateral radius defect models and divided into 4 groups averagely at random: group A(left:PRP／MSCs／β-tricalcium phosphate(β-TCP), right: MSCs／β-TCP), group B (left:autoradius, right: PRP／MSCs／β-TCP)； group C (left:autoradius,right: MSCs／β-TCP), and group D(left:PRP／β-TCP; right:β-TCP). At 2, 6 and 12 weeks after operation， the repair of bone defect was evaluated by the generalobservation, histology, biomechanics and histomorphology. Results There was a stable platelet concentration in PRP and it was about 5.45±0.23 times of whole blood. In the aspect of bone bridge and conture of the defects, at 2 and 6 weeks, PRP／MSCs／β-TCP and MSCs／β-TCP displayed asimilar outcome and were less than auto in general sample and X-ray;at12 weeks，PRP／MSCs／β-TCP was similar to autoradius and better than MSCs／β-TCP.in the aspect of quantity and quality of bone formation，histology showed that PRP／MSCs／β-TCP and autoradius were better than MSCs／β-TCP（P＜0.05），and there was nosignificantdifference between PRP／MSCs／β-TCP and autoradius（P＞0.05）. At 2 and 6 weeks，there was no significant difference between PRP／β-TCP and β-TCP（P＞0.05）。At 12 weeks，PRP／β-TCP was better than β-TCP（P＜0.05）. In the aspect of intensity f bone formation，at 6 and 12 weeks，PRP／MSCs／β-TCP and autoradiuswere better than MSCs／β-TCP（P＜0.05）. At 6 weeks，autoradius was better than PRP／MSCs／β-TCP（P＜0.05）. At 12 weeks，there was no significant difference between PRP／MSCs／β-TCP and auto（P＞0.05）. PRP／TCP and β-TCP had no significant difference at 12 weeks（P＞0.05）. Conclusion PRP／MSCs／β-TCP demonstrated excellent ability of forming bone in experiment. PRP was most likely to accelerate the repair of bone defect through increasing the activity of proliferation and differentiationof MSCs and osteoblasts.
Objective To examine an effect of the locally-used platelet derived growth factor-BB (PDGF-BB) on the healing of the medial collateral ligament (MCL) in the knee joints of rats. Methods Forty-eight rats were equally randomly divided into 2 groups: the experimental group (group A) and the control group(group B). MCL of all the rats were ruptured to establish the wound models. In group A, 5 μg of PDGF-BB was locally injected in the wound of each rat and then the wound was sutured; but in group B, the wound was only sutured. After 2 weeks, histological evaluations were performed to determine whether PDGF-BB could promote the healing of MCL. Results There were significantly more fibroblasts formed during the ligament healing process in group A than in group B (213.44±15.32 vs. 180.42±12.78, Plt;0.01). The fibroblasts were more mature andmore regularlyarranged in group A than in group B. The type, content, and crosslink of the collagen were improved to a greater extent in group A than in group B (Plt;0.01). Conclusion PDGF can promote the healing of the injured ligament.
Objective To investigate the effects of platelet-derived growth factor(PDGF) on the expression of α-smooth muscle actin(α-SMA) of cultured human retinal pigment epithelium cells(RPE). Methods Cultured human RPE cells of the 4-6 th passages were divided into two groups: Delbecco′s modified Eagle′s medium (DMEM) and 2%DMEM (20 g/L foeta calf serum+DMEM). PDGF (0,1,50 ng/ml) was added to medium.The expression of α-SMA was detected and quantitatively analyzed by image process of immunofluorescence.Results PDGF stimulated the expression of α-SMA of human RPE cells.In group of DMEM, The rate of RPE of α-SMA expression was 40%-50% and the intension of fluorescence was 8.08 without PDGF. After stimulated by PDGF(1 ng/ml,50 ng/ml), the rates were 80% and 90% respectively, and the intension of fluorescence were 12.35 and 17.23. In 2%DMEM group, The rates of RPE of α-SMA expression were 85% without PDGF, and 95% ,100% respectively treated with PDGF (1 ng/ml,50 ng/ml). The intension of fluorescence was 14.79 without PDGF, and after stimulated by PDGF, they were 16.28 at 1 ng/ml and 21.36 at 50 ng/ml，which was 2 .7 times ber than that in DMEM group without PDGF. Conclusion PDGF could stimulate RPE cells to express α-SMA. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To investigate the factors that affect platelet-rich plasma (PRP) in promoting bone regeneration and repairing. Methods Recent l iterature was reviewed, concerning the preparations of PRP, physiological mechanism and the latest appl ications in orthopedic field. Results PRP, the concentrated body of autologous platelet, was rich in platelets and was the source of autologous growth factors. Many studies had shown that PRP played an important role in promoting bone regeneration and repairing. However, a few experimental results contradicted this point. The reason might be that the biological properties of PRP were influenced by various factors, such as workmanship, vector, activation schemes, working concentration, individual difference. Conclusion The concentration and qual ity of platelet and other related factorsof PRP affect the rel iabil ity of the results and conclusions. So an efficient and stable production method of PRP should beestabl ished.
Objective To investigate the expression and clinical significance of T lymphocyte subsets, natural killer (NK) cells and CD19+ B cells in the elderly with primary immune thrombocytopenia (ITP) before and after treatment. Methods The elderly ITP patients diagnosed and treated in the Songjiang Hospital Affiliated to Shanghai Jiaotong University School of Medicine (preparatory stage) between January 2014 and June 2019 were retrospectively selected as the observation group. The healthy elderly in the same period were selected as the control group. According to the treatment, the observation group was divided into effective group and ineffective group. The expression levels of T lymphocyte subsets (CD3+, CD4+, CD8+ and CD4+/CD8+), NK cells and CD19+ B cells were observed and analyzed. Results A total of 75 subjects were included, including 35 in the observation group and 40 in the control group. The total effective rate was 85.71% (30/35). Before treatment, the expression levels of T lymphocyte subsets (CD3+, CD4+ and CD4+/CD8+) in the observation group were lower than those in the control group (P<0.05). There was no significant difference in other indexes between the two groups (P>0.05). After treatment, except for CD8+, the expression levels of T lymphocyte subsets (CD3+, CD4+ and CD4+/CD8+) in the observation group were higher than those before treatment (P<0.05). The expression levels of NK cells and CD19+ B cells were lower than those before treatment (P<0.05). The expression levels of T lymphocyte subsets (CD3+, CD4+ and CD4+/CD8+) in the effective group were higher than those before treatment (P<0.05), while the expression level of CD19+ B cells was lower than that before treatment (P<0.05). There was no significant difference in other indexes before and after treatment (P>0.05). There was no significant difference in the expression levels of T lymphocyte subsets (CD3+, CD4+, CD8+ and CD4+/CD8+), NK cells and CD19+ B cells in the ineffective group before and after treatment (P>0.05). Conclusions T lymphocyte subsets are abnormal in elderly ITP patients. The immune abnormality of T lymphocyte may be one of the reasons for elderly patients with ITP. With the improvement of therapeutic effect, immune cell subsets have also been improved.
Cardiopulmonary bypass(CPB) is associated with thrombocytopenia and platelet dysfunction. The primary cause of acquired platelet defect is thought to be activation and release of alpha granules during CPB. Before CPB, platelet-rich plasma (PRP) was prepared by obtaining the required amount of patient’s whole blood by autologous plateletpheresis. PRP could be reinfused after operation in order to protect the function and quantities of the platelets. On the other hand, PRP could be made into autologous platelet gel (APG). APG contains supraphysiologic amounts of growth factors, and has adequate tensile strength and adhesive ability. Therefore, it can be used for hemostasis in operation, sealing wound and enhancing incision or dehiscent sternal wounds healing.