Objective To find a feasible method that can reconstruct the composite tissue-engineered skin fast in vitro and can provide enoughskin as soon as possible for covering the surface of the large-area burn. Methods The foreskin was taken during the posthectomy. The epidermal cells and fibroblasts were isolated, identified and cultured. The cytokeratin 19 (K19) flow cytometry and the fluorescein isothiocyanate (FITC)immunofluorescence for K19 and the FITCimmunofluorescence for PAN-cytokeratin of the epidermal cells and the FITCimmunofluorescence for vimentin of the fibroblasts were performed to identify the epidermal cells and the fibroblasts. Then, the epidermal cells were seeded onto the papillary surface of an acellular dermal matrix (ADM) and were submerged into the condition culture medium added with 25 ng/ml of the keratinocyte growth factor (KGF). However, in the control group, no KGFwas added. After 24 hours, the ADM was moved up to the airfluid surface, and the culture was continued. After 6 days, the fibroblasts were seeded onto the other surface of the ADM. After a 24 hour culture, the ADM was harvested and fixed in formalin, and the hematoxylin-eosin staining was conducted. Then, the structure of the reconstructed skin was observed under the microscope and the cell count in the epidermal layer was also conducted. Results All the cultured and expanded epidermal cells stained by the immunofluorescence demonstrated a positive reaction for PANFITC, and a partially positive for K19-FITC, and 17% of the cells demonstrated a positive reaction for K19 identified by the flow cytometry. The fibroblasts could be expanded by more than 100 times after a 7day culture in vitro, and they could demonstrate a positive reaction for vimentin-FITC. After a 7day culture, a composite tissue-engineered skin could be attained. The hematoxylineosin staining of the reconstructed skin showed that there was one continuous layer of the epidermis on the papillary surface of the ADM and there were fibroblasts in the superficial layer of the other one, but the epidermal layer did not stick tightly to the ADM. The cell count demonstrated that KGF promoted the epidermal cells to proliferate better（Plt;0.01）and to form more significantly continuous layers of the epidermis in the experimental group than in the control group（Plt;0.01）. Conclusion Through the seed-cell separation by the digestion of collagenase and trypsin combined with the use of the KGF-added condition ulture medium, a composite tissueengineered skin can be reconstructed within 7 days.
ObjectiveTo interpret the mechanisms of vascular repair disorders in steroid-induced avascular necrosis of the femoral head (SANFH) via detection of the changes of proliferation, migration, and macrophage migration inhibitory factor (MIF)/vascular endothelial growth factor (VEGF) expressions of endothelial cells (ECs) under hypoxia/glucocorticoid. MethodsAccording to culture conditions, human umbilical vein ECs (HUVECs) at passage 3 were divided into group A (normal), group B (1.0×10-6 mol/L dexamethasone), group C (hypoxia), and group D (hypoxia+1.0×10-6 mol/L dexamethasone). The cell activity was detected by AlamarBlue; the number of viable cells was detected in live/dead cell staining; the cell morphology was observed after cytoskeleton staining; cell migration ability was compared by scratch test; and the levels of MIF and VEGF expressions were detected by ELISA. ResultsAt 24 hours after culture, the cell activity and the number of living cells in group C were significantly higher than those in the other 3 groups, showing significant difference between groups (P < 0.05), and group D had the worst cell activity and least living cells. Cytoskeleton staining showed that cells had normal morphology in groups A and B; cells had rich cytoskeleton and secretion granules in group C; cytoskeleton form disorder and nucleus pyknosis were observed in group D. Scratch test showed that the cell migration ability of group C was strongest while cell migration ability of group D was weakest. Accumulated concentration of MIF and VEGF in 4 groups significantly increased with time extending. Accumulated concentration of MIF in group C were significantly higher than that in other 3 groups at each time point (P < 0.05). Within 24 hours after intervention, stage concentration of MIF during 1-8 hours was significantly lower than that during 0-1 hour and 8-24 hours in every group (P < 0.05). Stage concentration of MIF in group C was significantly higher than other groups during 0-1 hour and 8-24 hours (P < 0.05). Within 2 hours after intervention, stage concentration of MIF in 4 groups during 0.5-1 hour was significantly higher than that during other stages (P < 0.05). Accumulated concentration of VEGF in group C was significantly higher than that in other groups at 8 and 24 hours (P < 0.05). The stage concentration of VEGF in groups C and D during 8-24 hours was significantly higher than that during 0-1 hour and 1-8 hours (P < 0.05). There was no significant difference in the stage concentration of VEGF within and among group A, B, C, and D at every stage within 2 hours after intervention (P > 0.05). ConclusionIn hypoxia environment, the proliferation and migration of ECs is enhanced, and the secretion of VEGF and MIF is increased. High concentration of dexamethasone will suppress the process above, which induces vascular repair disorders and aggravating SANFH.
Objective To investigate the effects of different temperatures on the system of in vitro physiological environment fostering limbs. Methods Twenty-four limbs were harvested from 6 adult Bama mini pigs and were randomly divided into 4 groups (n=6) according to different temperatures: limbs were placed in in vitro physiological environment foster-ing limbs at 26℃ (group A), 4℃ (group B), 10℃ (group C), and 18℃(group D). After 12 hours of perfusion, the morphology observation was done for the structure and ultrastructure changes of the skeletal muscle by light microscope and transmission electron microscope. The mRNA levels of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were detected by real-time fluorescent quantitative PCR (RT-qPCR). Results Histological results showed that the skeletal muscle exhibited mild edema, integrity of the sarcolemma, and occasional perivascular inflammatory cell infiltration in groups B, C, and D, meanwhile, the cells of group C had normal morphology; however, muscle fibers degenerated, muscle cells were seriously damaged, a great number of inflammatory cells infiltrated in the fractured muscle fibers in group A. Transmission electron microscope results showed as follows: the muscle fibers arranged in disorder, and many focal solubility necrosis occurred in group A; the muscle fibers arranged in order relatively and sarcolemma was still intact, with mild swelling and flocculent degenerative mitochondria in group B; a large number of muscle fibers arranged in order and regularity with clear sarcomere in group C; and the muscle fibers arranged in disorder and irregularity and partly dissolved in group D. RT-qPCR results showed that the expressions of inflammatory factor TNF-α and IL-1β mRNA in group A were significantly higher than those in groups B, C, and D (P lt; 0.05); the expressions were significantly lower in groups B and C than in group D, and in group C than in group B (P lt; 0.05). Conclusion In the system of in vitro physiological environment fostering limbs, temperature plays an important role in the preservation of amputated limbs. It is suggested that 10℃ can significantly attenuate the reperfusion-induced skeletal muscle cell injuries in this system.
Objective To analyze published literature about the clinical studies on elective single versus double embryo transfer using meta-analysis, so as to provide more convincing evidence for the clinical application of elective single embryo transfer. Methods We electronically searched foreign and domestic biomedical databases including PubMed, Ovid, EMbase, MEDLINE and CENTRAL, to collect randomized controlled trials (RCTs) on elective single versus double embryo transfer. According to Cochrane systematic review method, two reviewers independently screened studies according to inclusion and exclusion criteria, extracted data, and assessed methodological quality of the included studies. Then, meta-analysis was performed using RevMan 5.1 software. Results A total of 9 RCTs involving 2 784 cases were included, of which, 1 452 were in the trial group while the other 1 332 were in the control group. The results of meta-analysis indicated that, compared with elective double embryo transfer, during each transfer period elective single embryo transfer reduced the live birth rate (RR=0.66, 95%CI 0.59 to 0.73, Plt;0.000 01), multiple pregnancy rate (RR=0.05 95%CI 0.02 to 0.11, Plt;0.000 01), preterm birth rate (RR=0.39, 95%CI 0.26 to 0.60, Plt;0.000 1), and low birth weight rate (RR=0.25, 95%CI 0.15 to 0.44, Plt;0.000 01). However, it had no effect on the ectopic pregnancy rate (RR=0.55, 95%CI 0.11 to 2.77, P=0.47), miscarriage rate (RR=1.33, 95%CI 0.92 to 1.91, P=0.13), and neonatal mortality rate (RR=0.31, 95%CI 0.03 to 2.76, P=0.29). Conclusion Compared with elective double embryo transfer, during each transfer period elective single embryo transfer reduces the live birth rate, multiple pregnancy rate, preterm birth rate, and low birth weight rate. No significant difference was found between the two groups in the other indicators.
Objective To investigate the influence of the exogenouscollagen on the function of cells in construction of artificial biotendon.Methods Three materials including human hair, carbon fiber(CF) and polyglycolic acid (PGA) were combined with exogenous collagen and co-cultured with standard transferred human embryonic tenocytes at a concentration of 3×106/mm3 in vitro. The cell number and morphology were observed under inverted microscope and scanning electron microscope after 2 hours, 3 days and 5 days.Results In the artificial biotendon combined with collagen, the cells concentrated around the materials and the cells adhering to the materials turned into round after 2 hours. After 3 days, the adhering cells increased. After 5 days, the shape of the cells changed from round to spindle.ConclusionExogenous collagen will facilitate the cells to adhere onto materials and proliferate.
Objective To establish a rapid, simple, and economic method to prepare osteoporosis (OP) in vitro model. Methods Eighty pairs of fresh goat femur were collected from 18-month-old female goats and were randomly divided into 4 groups (20 pairs in each group). The femur was immersed decalcifying solution (18% EDTA) for 1-5 days (group B), 6-10 days (group C), and 11-15 days (group D), while group A had no treatment as control. Four pairs of femur were taken out every day. Quantitative computed tomography was used to scan the medial and lateral femoral condyles, and the bone mineral density (BMD) was calculated. Electronic universal testing machine was used to do three-point bending test and compress and tensile ultimate strenght test, and the mechanical parameters for femur were calculated. Results With demineralized time passing, BMD of the medial and lateral femoral condyles were downtrend in groups A, B, C, and D, showing significant differences among 4 groups (P lt; 0.05); BMD of the lateral femoral condyle was significantly higher than that of the medial femoral condyle in each group (P lt; 0.05). The three-point bending test showed that broken load, ultimate strength, and elastic modulus of groups A and B were significantly higher than those of groups C and D (P lt; 0.05); but no significant difference was found between groups A and B, and between groups C and D (P gt; 0.05). Compress and tensile ultimate strength test showed that the compress and tensile ultimate strengths were significantly higher in group A than in groups C and D (P lt; 0.05), and in group B than in group D (P lt; 0.05), but no significant difference was found between groups A and B, between groups B and C, and between groups C and D (P gt; 0.05). Conclusion The 18% EDTA immersing for 6-15 days is a fast, simple, economical method to prepare an OP in vitro model of goat femur.
Objective Titania and Ag containing nano-hydroxyapatite/polyamide 66 (TiO2-Ag-nHA/PA66) composite bone fill ing material has good biocompatibil ity and biological safety. To investigate the antibacterial effect and Ag+ release characteristics of TiO2-Ag-nHA/PA66 composite bone fill ing material containing different concentrations of Ag+ in vitro. Methods The n-HA/PA66 composite bone fill ing material A1 (material A1) was prepared by co-polymerization method, and TiO2-Ag-nHA/PA66 composite bone fill ing materials A2 and A3 (materials A2 and A3) were prepared by thesame way containing Ag+ of 0.22wt% and 0.64wt%, respectively, and the TiO2 content was 2.35wt%. The materials A2 and A3 were respectively immersed in 50 mL simulated body fluid (SBF), and Ag+ concentration was measured by atomic absorption spectrometry at 1, 3, 7, 14, 21, and 49 days. The inhibition ring test and colony count method were used to evaluate antibiotic effect against Staphylococcus aureus and Escherichia coli, the anti-adhesion capacity of Staphylococcus aureus and Escherichia coli was observed by scanning electron microscope (SEM). Results There was no significant difference in the Ag+ concentration between materials A2 and A3 at 1 day and 3 days (P gt; 0.05); and there were significant differences in the Ag+ concentration between materials A2 and A3 after 7 days (P lt; 0.05). The inhibition ring diameters of materials A2 and A3 to Staphylococcus aureus and Escherichia coli reached the maximum at 1 day, which were (13.40 ± 2.88), (9.40 ± 1.14) mm and (23.60 ± 1.14), (18.80 ± 0.84) mm, showing significant difference (P lt; 0.05) between materials A2 and A3 respectively; and then, the diameter of inhibition ring reduced with the time. The antibacterial effect of materials A2 and A3 against Staphylococcus aureus and Escherichia coli lasted 15, 33 days and 9, 24 days, respectively. No inhibition ring was observed around material A1 all the time. And the inhibitory rates of materials A2 and A3 were 89.74% ± 3.62%, 94.18% ± 2.05% and 78.65% ± 5.64%, 85.96% ± 2.50%; showing significant differences (P lt; 0.05) among materials A1, A2, and A3. SEM showed that bacterial adhesion of materials A2 and A3 was obviously fewer than that of material A1. Conclusion TiO2-Ag-nHA/PA66 composite bone fill ing material has antibacterial property against Staphylococcus aureus and Escherichia coli, and it has a good release effect in SBF.
Human SW480 colonic cancer cell line was evaluated for its growth response to pentagastrin, gastrin receptor antagonist proglumide (PGL) in vitro by MTT assay and flow cytometry. The results showed that gastrin possessed a proliferative effect on SW480 cell, PGL alone had no obvious effect on SW480 cell, but it inhibited gastrin-induced growth of SW480 cell with dosage dependent when it was used with gastrin, its inhibitive effect did not steadly increase at a dose＞32μg/ml. This suggests that effect of gastrin is achieved via gastrin receptor. Gastrin promoted the sythesis of DNA, protein and triggered the cancer cell shifting from phase G0/G1 to phase S, G2M. PLG inhibited the effect of gastrin, it suggests that gastrin possessed a proliferation on SW480 cell at post receptor is achieved by the effect of gastrin on cell cycle.
ObjectiveTo systematically review the clinical effects of short-term and conventional fertilization for vitro fertilization-embryo transfer (IVF-ET). MethodsRandomized controlled trials (RCTs) about the clinical effects of short-term fertilization versus conventional fertilization for IVF-ET were searched in PubMed, The Cochrane Library (Issue 8, 2014), CBM, CNKI, WanFang Data and VIP from inception to August 2014. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed methodological quality of included studies. Then meta-analysis was performed using RevMan 5.2 software. ResultsA total of six RCTs involving 1 373 patients were finally included. The results of meta-analysis indicated that:short-term fertilization was superior to conventional fertilization in increasing high quality embryo rates (OR=1.42, 95%CI 1.18 to 1.70, P=0.000 2) as well as clinical pregnancy rates (OR=1.67, 95%CI 1.33 to 2.09, P < 0.000 01). However, the two groups were alike in fertilization rates, polyspermy rates, and miscarriage rates. ConclusionCurrent evidence indicates that short-term fertilization is superior to conventional fertilization in increasing high quality embryo rates as well as clinical pregnancy rates. Due to limited quality and quantity of the included studies, the above conclusion should be verified by conducting more large-scale, high quality RCTs with long-term follow-up.
Objective To observe the morphology and growing status of mesenchymal stem cells(MSCs) of human bone marrow in vitro, in order to confirm that MSCs of human bone marrow are ideal seed cells and provide basic theory for further MSCs research. Methods The methods of density gradient centrifugation with lymphocyte separation medium for human and adherent filtration were used to isolate and purify MSCs of human bone marrow. We observed the cellular growth status and morphology of the primary MSCs and the surface antigens of second passage MSCs were tested. Results The primary culture cells fused into monolayer after 14-16 d. The passage cells kept the same morphological characteristics of primary culture cells. Ultrastructure of the second passage MSCs showed that the shape of nuclei was irregular, there were multiple nucleoli in some of the nuclei, and morphological differentiation of intracytoplasm organelles was immature. The growth curve of the first, fifth and tenth passage cells showed a logarithmic growth at day 3, a peak growth at day 5, and no clones occurred after tenth passage. Cloning efficiency of first passage, fifth passage and tenth passage was respectively 25.83%±2.93%, 14.67%±1.63% and 4.67%±0.52%. Test of MSCs phenotypic characteristics showed a high homogeneity among the cells and surface antigen profiles were positive for CD29, CD44 and negative for CD34, CD45. Conclusion The methods of density gradient centrifugation with lymphocyte separation medium for human and adherent filtration are simple, economic and efficient to isolate and purify MSCs from human bone marrow. With a high proliferating ability in vitro, MSCs from human bone marrow are ideal seed cells for tissue engineers.