Objective To investigate the effect of homograft of marrow mesenchymal stem cells (MSCs) seeded onto poly-L-lactic acid (PLLA)/gelatin on repair of articular cartilage defects. Methods The MSCs derived from36 Qingzilan rabbits, aging 4 to 6 months and weighed 2.5-3.5 kg were cultured in vitroand seeded onto PLLA/gelatin. The MSCs/ PLLA/gelatin composite was cultured and transplanted into full thickness defects on intercondylar fossa. Thirty-six healthy Qingzilan rabbits were made models of cartilage defects in the intercondylar fossa. These rabbits were divided into 3 groups according to the repair materials with 12 in each group: group A, MSCs and PLLA/gelatin complex(MSCs/ PLLA/gelatin); group B, only PLLA/gelatin; and group C, nothing. At 4,8 and 12 weeks after operation, the gross, histological and immunohistochemical observations were made, and grading scales were evaluated. Results At 12 weeks after transplantation, defect was repaired and the structures of the cartilage surface and normal cartilage was in integrity. The defects in group A were repaired by the hylinelike tissue and defects in groups B and C were repaired by the fibrous tissues. Immunohistochemical staining showed that cells in the zones of repaired tissues were larger in size, arranged columnedly, riched in collagen Ⅱ matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in group A at 12 weeks postoperatively. In gross score, group A(2.75±0.89) was significantly better than group B (4.88±1.25) and group C (7.38±1.18) 12 weeks afteroperation, showing significant differences (P＜0.05); in histological score, group A (3.88±1.36) was better than group B (8.38±1.06) and group C (13.13±1.96), and group B was better than group C, showing significant differences (P＜0.05). Conclusion Transplantation of mesenchymal stem cells seeded onto PLLA/gelatin is a promising way for the treatment of cartilage defects.
OBJECTIVE To confirm membrane-guided tissue regeneration in the healing course of segmental bone defects and study the mechanism. METHODS Segmental, 1 cm osteoperiosteal defects were produced in both radii of 12 rabbits. One side was covered with hydroxyapatite/polylactic acid(HA/PLA) membrane encapsulated as a tube. The contralateral side served as an untreated control. Healing courses were detected by radiographic and histologic examinations. RESULTS All control sides showed nonunion, whereas there were consistent healing pattern in test sides. CONCLUSION Membrane technique can promote bone regeneration.
Objective To prepare a self-made compound, hemostatic jelly with polylactic acid(PLA), which has the hemostatic and absorbable effect on injured cancellous bone. Methods Two bone defects of 5 mm in diameter and 4 mm in depth were subjected on 20 health rabbits by drilling through their either outside plate of the iliac, and were filled with hemostatic jelly(group A), bone wax(group B) and blank(group C) respectively. Hemostasis were observed and recorded after 1 and 10 minutes. Five specimens were harvested at 2, 4, 8 and 12 weeks postoperatively for histological observation. Results ① Hemostatic effect: Bleeding of injured spongy bone stopped within 10 minutes after the treatment of hemostatic jelly and bone wax, but bleeding of balnk did not stop. Hemostatic jelly and bone wax adhered to bone defects firmly within 10 minutes was after the treatment. ② Absorbable effect: Hemostatic jelly and bone defects have not changed visibly in the first 2 weeks. With histological observation 4 to 8 weeks after the operation, hemastatic jelly was absorbed gradually and replaced by osteogenous tissue. It was absorbed completely after 8 to 12 weeks. Bone wax was not absorbed after 12 weeks, no new bone tissue was observed at bone wax area. The blank was replaced by connective tissue and osteogenous tissue partially after 12 weeks. Conclusion The compound hemostatic jelly manifests both hemostatic and absorbable effects on injured cancellous bone and may substitute for bone wax in clinical application.
Objective To analyze the effectiveness and effect on pregnant outcome about living preparation of lactobacillus versus metronidazole in the treatment of bacterial vaginosis in pregnancy. Methods We searched PubMed, The Cochrane Library, VIP, CNKI, Wangfang, CBM, FMJS, and FEBMT to identify randomized controlled trials (RCT) of living preparation of lactobacillus versus metronidazole for bacterial vaginosis in pregnancy. The quality of the included trials was assessed. RevMan 5.0.24 software was used for meta-analysis. Results Eight trials involving 1 687 patients were included. The results of meta-analysis showed: no significant difference was found in the effectiveness between the two groups (RR=1.04, 95%CI 1.00 to 1.08, P=0.08); living preparation of lactobacillus had lower recurrence rate and lower premature delivery rate compared with metronidazole (RR=0.16, 95%CI 0.06 to 0.43, P=0.0004; RR=0.56, 95%CI 0.33 to 0.94, P=0.03); no significant differences were found in premature rupture of membrane, puerperal infection, infant of low-birth weight, infant infection, and infant jaundice between the two groups. Conclusion The effectiveness about living preparation of lactobacillus versus metronidazole for bacterial vaginosis in pregnancy is similar, but living preparation of lactobacillus has lower recurrence rate and lower premature delivery rate, the others of effect on pregnant outcome are similar.
Objective To observe the degradation of the polyactic glycolate acid (PLGA) microparticles with releasing-slowly vascular endothelial growth factor(VEGF) synthesized by the method of emulsification-diffusion. Methods The method of emulsification-diffusion is to incorporate VEGF into microparticles composed of biodegradable PLGA. The controlled release of microparticles are acquired. The content of the VEGF released slowly from PLGA microparticles in vitro was detected with ELISA at different time. Results We synthesized 100 releasing-slowly VEGF PLGA microparticles with the size of 0.20-0.33 μm by 5 times. The contents were 62±11 ng/L, 89±14 ng/L, and 127±19 ng/L in the 1st, the 2nd and the 3rd months after degradation, respectively. Conclusion The PLGAmicroparticles with releasing-slowly VEGF can be synthesized by the method of emulsification-diffusion.
摘要:目的:研究生物降解聚DL乳酸(PDLLA)自锁式捆绑带固定骨折的生物力学性能。方法:80只新西兰大白兔随机分为两组,建立股骨干非负重骨折动物模型,应用生物降解自锁式捆绑带固定骨折为实验组,钢丝固定骨折为对照组,分别于术后1、4、8、12周行生物力学检查进行比较。结果:捆绑带组在术后4、8、12周均比钢丝组的弯曲强度高,但4周、12周时Pgt;005,无统计学差异,8周时Plt;005,提示有统计学差异。离体同种固定物不同时间段抗拉强度自身比较:钢丝固定术后4阶段抗拉强度比较Pgt;005,任何两两比较都没有统计学差异,抗拉强度未随术后时间延长发生明显下降。捆绑带固定术后4周与术后1周比较Pgt;005,抗拉强度无明显降低,但术后8周和术后12周时Plt;005,抗拉强度明显下降。结论:生物降解自锁式捆绑带在非负重骨折治疗中可发挥良好的固定作用。生物降解自锁式捆绑带降解时,应力传导促进了骨折的愈合。Abstract: Objective: To study the biomechanics function of selflocking cerclage band made of biodegradable material polyDLlactic acid (PDLLA) in the fixation of fractures. Methods: Eighty rabbits were divided into two groups. Femur fracture models were made. Fractures were fixed using biodegradable selflocking cerclage band in experimental group and metal fixation material in control group. The biomechanics was analyzed and compared after 1, 4, 8 and 12 weeks respectively． Results: The bending strength of experimental group is more ber than that of control group after 4, 8 and 12 weeks, but it was not statistically significant at 4 and 12 weeks (Pgt;005). It was statistically significant at 8 weeks (Plt;005). The tensile strength of the same cerclage instrument was compared at different stage in vitro, and the result of the control group was not statistically significant at the four stage (〖WTBX〗P〖WTBZ〗gt;005). Regarding the changes of tensile strength of the cerclage instrument at different stage, the result of the experimental group was not statistically significant after 1 and 4 weeks (Pgt;005). However, the decrease of tensile strength was statistically significant after 8 and 12 weeks (Plt;005). Conculsion: Biodegradable selflocking cerclage band could be used in thetreatment of nonweightbearing fractures. The stress force conducting promotes healing of fracture when the selflocking biodegradable cerclage band degrades.
Objective To make a histological evaluation of poly(dextrogyr-levogyr)lactide acide-triiodothy-ronine (PDLLA-T3) in sciatic nerve defect of rat. Methods Ninety SD rats were evenly divided into 3 groups (autograft group A, PDLLA-T3 group B and PDLLA group C). Group D was control group. The left sciatic nerves were cut off by operation and 1 cm-nerve-defect was set up. The specimens were collected 2 weeks,1 month and 2 months after the operation respectively, simultaneously the right sciatic nerves were collected as normal control group D. HE stainning, electron microscope, S100 immunohistochemistry, and Bielschowsky staining were done in all the specimens, the quantity and quality of the regenerated nerves were observed, and all the results were processed by image analyzer.Results Two weeks after the operation,histological observation indicated that the materials in groups B and C were not completely degraded. Transmission electron microscopic observationshowed that the myelin sheath was not thick and it was about 0.5 μm in thickness. There was no significant difference among the 3 groups. One month after theoperation, histological observation indicated that in group A the regenerated nerves passed through the scaffold and in the new nerves there were regenerated blood vessels. The materials in groups B and C were not completely degraded. S-100 immunohistochemical observation and Bielschowsky staining showed that in groupB PDLLA-T3 repaired the defect successfully and the regenerated nerve myelinsheath was 1.81±0.19 μm in thickness. The effect in group B was better thanthat of groups A and C (P＞0.05). Two months after the operation, the materials in groups B and C were completely degraded. The quantity of the regeneratednerves in group B confirmed by S-100 immunohistochemical observation and Bielschowslcy staining was more than that in group C(P＜0.05) and close to that in group A. The regenerated nerve myelin sheath in group B was 2.15±0.27 μm in the thickness and was thicker than that in group C (P＜0.05)， but thinner than that in groups A and D (P＜0.05). Conclusion PDLLA-T3 can repair the defect of rat sciatic nerve with satisfactory quantity andquality of regenerated nerves.
In order to find an ideal biological material to prevent peridural adhesion following laminectomy, 30 rabbits were used as animal model, in each of which 2 defects with a size of 1 cm x 0.5 cm were made following laminectomy of L3, L5 spine. One of the defects was covered extradurally with chitosan, gelatin foam or PLA membrane respectively, while the other defect was exposed as control. All of these animals were sacrificed on the 2nd, 4th, 6th, 8th and 10th week after operation, and the extradural fibrosis and adhesion of every animal were evaluated by gross observation and histological examinations. It was revealed that in the chitosan and PLA membrane groups, the extradural tissue was smooth without thickening and there was no fibrous proliferation or adhesion in the epidural cavity, and that in the chitosan group, the growth of fibroblast was restrained but the growth of the epithelial cells was promoted significantly, thus, wound healing was rapid. In the control group and gelatin foam group, obvious extradural fibrosis and adhesion were observed and the extradural space had almost disappeared. Therefore, it was concluded that the biodegradable PLA membrane and chitosan were both an ideal material in the prevention of postoperative epidural adhesion.
【Abstract】 Objective To investigate the manufacture and biocompatibil ity of a bioabsorbable poly-D,L-lactic acid(PDLLA) plate containing rhBMP-2. Methods rhBMP-2 was composited with PDLLA (0.05 mg/plate) through vacuum to repare PDLLA plate containing rhBMP-2. Thirty-two New Zealand rabbits (male or female) weighted (3.0 ± 0.5) kg were used in he study. A 2.5 mm middle ulna osteotomy was made bilaterally. The bones as well as periosteum were removed. The right side of all the animals was experimental side (n=32), was fixed internally by PDLLA plate containing rhBMP-2.The left side of all the animals was control side (n=32), was fixed by common PDLLA plate. After a follow-up of 2, 4, 8 and 12 weeks, the ulnas were examined visually, radiographically, histologically, and by computer graph analysis to compare the biocompatibil ity. Re sults Po rosity of PDLLA plate containing rhBMP-2 was 90%, aperture was 150 μm, tensile strength was higher than 50 MPa, three point flexural strength was higher than 90 MPa and intrinsic viscosity was 1.6 dL/g (chloroform solvent). All animals had a good heal ing 1 or 2 weeks after operation. All the animal’s diet and movement were normal. All the fractures were stable. The plates in the experimental group degraded faster than those in the control group. Relative values of callus density evaluated by X-ray at 2, 4, 8 and 12 weeks after operation in the experimental group were 39.22 ± 2.48, 48.79 ± 1.26, 63.78 ± 1.78 and 78.60 ± 1.25 respectively. Those in the control defects were 33.83 ± 1.13, 41.28 ± 1.25, 55.23 ± 0.68 and 66.54 ± 1.33. At each time point, the experimental side produced better and more trabeculae than the control side did (P ＜ 0.01). Histological examination showed that the newbone formation in the experimental side at 2, 4, 8 and 12 weeks after operation was 0.106% ± 0.015%, 0.292% ± 0.019%, 0.457% ± 0.048% and 0.601% ± 0.037%, while those in the control side was 0, 0.193% ± 0.019%, 0.339% ± 0.029% and 0.574% ± 0.047%respectively. At each time point, the experimental side produced better new bone formation than the control side did (P lt; 0.05). The experimental side showed better compatibil ity between plates and surrounding tissue, faster bone formation, more bone regeneration mass and better medullary canal structure than the control side. Conclusion PDLLA plate containing rhBMP-2 has good biocompatibil ity and osteoinducibil ity to enhance fracture heal ing.
Objective To determine the incidence of vitamin B1 deficiency in critically ill patients, to compare vitamin B1 levels between septic and non-septic patients, and to explore the relationship between vitamin B1 levels and lactate levels. Methods Using a retrospective study method, critically ill patients admitted to the Department of Intensive Care of Nanjing Drum Tower Hospital from February 2022 to November 2022 were included in the study, and the patients were divided into sepsis and non-sepsis groups according to the admission diagnosis, and the differences in the vitamin B1 levels of the patients between the two groups were analyzed, as well as the correlation between the vitamin B1 levels and the lactic acid levels. Results There was a significant difference in serum vitamin B1 levels between the sepsis patients and the non-sepsis patients [(1.6±0.3)ng/mL vs. (2.1±0.2)ng/mL, P=0. 009]. For all patients, there was no correlation between vitamin B1 levels and lactate levels. But when the patient was in a hyperlactate state (lactate level ≥2 mmol/L), vitamin B1 levels were significantly negatively correlated with lactate levels (r=–0. 229, P=0. 004). Conclusions Vitamin B1 deficiency is prevalent in critically ill patients and is strongly correlated with whether or not the patient is septic. Vitamin B1 levels are significantly and negatively correlated with lactate levels when the patient's lactate level is ≥2 mmol/L.