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.
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 fabricate a novel porous bioactivecomposite biomaterial consisting of poly lactic acid (PLA)bone matrix gelatin(BMG) by using the supercritical carbon dioxide fluid technique (SC-CO2) and to evaluate its osteoinductive activity. Methods The cortical bones selected from healthy adult donors were processed into BMG by the defatting, demineralizing, and deproteinizing processes. PLA and BMG were mixed at a volume radio of 3∶1; then, the PLA-BMG mixed material and the pure PLA material were respectively placed in the supercritical carbon dioxide reaction kettles, and were respectively added by the NaCl particles 100200 μm in diameter for theporosity of the materials so that the porous PLA-BMG composite material and the porous PLA composite material could be formed. The mouse osteoblastlike MC3T3-E1 cells were cultured in the dulbecco’s modified eagle medium (DMEM) supplemented with 10% fetal bovine serum. Then, 20 μl of the MC3T3E1 cell suspensions containing 2 ×106 cells /ml were delivered into the culturing plate (24 wells/plate) made of the different materials, which were co-cultured for 2 weeks. In the PLA-BMG group, 100 μg of the crushed PLA-BMG material was contained in each well; in the PLA group, 100 μg of the crushed PLA material was containedin each well; and in the DMEM group, only DMEM was contained, which served as the control group. There were 6 wells in each group. The quantitative analysis onthe calcification area was performed by the staining of the alizarin red S. Theco-cultured cells were harvested and lysated in 1 ml of 0.2% Nonidet P-40 by the ultrasonic lysating technique. Then, the ALP activity and the Ca content were measured according to the illuminations of the reagent kits. Results The porous PLABMG composite material showed a good homological porosity with a pore diameter of 50-150 μm and a good connectivity between the pores. The ALP activity, the Ca content, and the calcification area were significantly greater in the PLABMG group than in the PLA group and the control group (325.59±70.40 U/gprot, 3.51±1.64 mmol/gprot, 42.98±4.44% vs. 63.62±30.01 U/gprot, 1.04±0.21 mmol/gprot, 9.55±1.94%, and 2.40±1.47 U/gprot, 0.70±0.24 mmol/gprot, 0.86±0.41%; Plt;0.05). Meanwhile, there was a statistically significant difference between the PLA group and the control group in the ALP activity and the calcification area (Plt;0.05). Conclusion The porous PLABMG composite material prepared by the use of SC-CO2 has a good steoinductive activity and can be used as a promising bone biomaterial and a bone tissue engineered scaffold.
ObjectiveTo evaluate the biocompatibility of poly lactic acid/bone matrix gelatin (PLA/BMG) composite biomaterial so as to lay a foundation for bone defect repair. MethodsRats'MC3T3-E1 cells were cultured with leaching solution of PLA/BMG and PLA material respectively for 7 days. The cell proliferation rate was tested by MTT and cell toxicity grading was carried out everyday. The PLA/BMG and MC3T3-E1 cells were co-cultured, the cell shape and proliferation were observed by inverted phase contrast microscope at 1, 3, and 5 days and cell adhesion by scanning electron microscope at 5 days. The PLA and PLA/BMG were implanted subcutaneously in 15 Wistar rats. The histological observation was done, and the thickness of fibrous membrane, the number of inflammatory cells, and the vascularization area were measured at postoperative 2nd, 4th, and 8th week. ResultsThe tests for cytotoxicity in vitro showed that the cell proliferation rates were over 100% and the cell cytotoxic grades were grade 0 at 1-7 days in PLA/BMG group. While in PLA group, the cell proliferation rates were less than 100% and the cell cytotoxic grades were grade 1 at 2, 4, and 7 days. After co-culture of PLA/BMG and MC3T3-E1 cells, cells grew on the surface and in the pores of PLA/BMG, and the cellular morphology was triangle or polygon with abundant microvillus on the surface. After subcutaneous implantation, the rats survived to the end of experiment, and incision healed well. PLA was wrapped by connective tissue where there were a lot of lymphocytes and neutrophilic granulocytes. The cells and tissue grew slowly in PLA. The PLA/BMG materials were wrapped by little connective tissue where there were a few inflammatory cells. The connective tissue ingrowth was observed in the center of PLA/BMG. There was no significant difference in the thickness of fibrous membrane between 2 groups at each time point (P>0.05). The number of inflammatory cells of PLA/BMG group were significantly less than those in PLA group at 2, 4, and 8 weeks (P<0.05); the vascularization area was significantly larger than that in PLA group (P<0.05). ConclusionPLA/BMG composite biomaterials prepared by super critical-CO2 technique are good in cell and tissue biocompatibilty.
Objective To investigate the clinical effect of polylactic acid membrane in prevention of epidural scar and adhesion. Methods From July 1998 to April 2000, 62 patients with lumbar disc herniation were randomly assigned into two groups. All were treated surgically with discectomy by fenestration or laminectomy.One group were placed with a thin of polylactic acid membrane covering the interlaminar space(n=32). The thickness of the film was 0.1mm. The other group was blank control(n=30). After 2 weeks of operation, we observed the local and systemic reactions. After 6 months clinical symptoms were revaluated and the degrees of epidural scar and adhesion were determined by CT scans. Results After 2 weeks, we found no adverse systemic reactions in all patients. Wound healing was excellent. No abnormalities of hepatic and renal functions as well as blood for routine were found. Temperature after operation was normal. After 6 months, the curative effects were as follows in experimental group and in control group: excellent in 27 patients and in 24 patients, good in 4 patients and in 4 patients, fair in 1 patient and in 1 patient, and poor in 0 patient and in 1 patient, respectively. There are no significant difference between two groups. The CT scans showed no adhesion between the epidural scar and the dural sac in all patients of experimental group. There existed various extents of adhesion in control group. Conclusion The results demonstrate that the polylactic acidmembrane can effectively prevent the epidural scar adhesion with a good biocompatibility and no toxity. Its clinical application was promising.
Objective To study the result of using nerve conduit coated with chitin and filled with a guide-fiber to repair peripheral nerve defect. Methods Twenty-four female adult SD rats were made the model of 14 mm-gap on bilateral sciatic nerve under sterile condition. The rats were randomly divided into 4 groups(n=6),group A: polymer polyglycolic-lactic acid(PGLA) nerve conduit coated with chitin and filled with a guide-fiber as experimental group to repair 14 mm gap of rat sciatic nerve；group B: PGLA nerve conduit coated with chitin； group C: PGLA nerve conduit； group D: autograft (control group). The repair result was evaluated by normal observation, EMG testing and S-100 histological immunostaining analysis 4 and 12 weeks after operation.Results Four weeks after the operation，there were new regenerated immature fibers in groups A,B and C, 12 weeks after the operation, the regenerated nerve fibers were seen to have bridged the gap. There were myelinated fibers equably distributed and rarely newgenerated nerve fibers in distal parts of group D. The repair result of PGLA nerve conduit coated with a chitin and filled with guide-fiber was better than that of groups B and C（Plt;0.05）. There was significant difference of nerve fiber diameter，thickness of myelin sheath and fiber density in group D from those in groups A, B and C（Plt;0.05），but there were degenerative changes such as vacuoles insheaths and myelin separation in proximal and few new regenerated nerve fibers in distal parts of group D. Conclusion PGLA nerve conduit coated with chitin and filled with a guide-fiber offers a possible substitute for the repair of peripheral nerve defect.
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．
ObjectiveTo explore the effect of silk fibroin/poly(L-lactic acid-co-e-caprolactone) [SF/P(LLA-CL)] nanofibrous scaffold on tendon-bone healing of rabbits.MethodsSF/P(LLA-CL) nanofibrous scaffold was fabricated by electrospinning methods. The morphology of the scaffold was observed by scanning electron microscope (SEM). Pre-osteoblasts MC3T3-E1 cells were seeded on the scaffold and cultured for 1, 3, and 5 days. Cell adhesion and proliferation were also observed by SEM. Meanwhile, twenty-four New Zealand white rabbits were randomly divided into the autogenous tendon group (control group) and the autogenous tendon wrapped with SF/P(LLA-CL) scaffold group (experimental group), with twelve rabbits in each group. An extra-articular model was established, the effect was evaluated by histological examination and mechanical testing.ResultsThe morphology of SF/P(LLA-CL) nanofibrous scaffold was random, with a diameter of (219.4±66.5) nm. SEM showed that the MC3T3-E1 cells seeded on the scaffold were in the normal shape, growing well, and proliferating with time course. The results of histological examination showed that inflammatory cells infltrated into the graft-host bone interface at 6 weeks after operation in both groups. Besides, the width of interface showed no significant difference between groups. At 12 weeks after operation, protruding new bone tissue could be observed at the interface in the experimental group, while scar tissue but no new bone tissue could be seen at the interface in the control group. Mechanical testing showed that there was no significant difference in the failure load and the stiffness between groups at 6 weeks after operation (P>0.05). The failure load and the stiffness in the experimental group were significantly higher than those in the control group at 12 weeks after operation (P<0.05).ConclusionThe SF/P(LLA-CL) nanofibrous scaffold has good cell biocompatibility and can effectively promote tendon-bone healing, thus providing new method for modifying graft for ACL reconstruction in the clinical practice.
ObjectiveTo investigate the preparation and osteogenic properties of poly (L-lactic acid)(PLLA)/lecithin porous scaffolds with open pore structure.MethodsPLLA/lecithin porous scaffolds with different lecithin contents (0, 5%, 10%, 20%, 30%, 40%, 50%) were prepared by thermally induced phase separation (groups A, B, C, D, E, F, and G, respectively). Scanning electron microscopy (SEM) was used to observe the surface morphology of the scaffolds. Wide-angle X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to detect the crystallinity of the scaffolds. The water uptake ability of the scaffolds was measured. The cell growth and viability of bone marrow mesenchymal stem cells (BMSCs) of mouse on each scaffold was assessed by cell counting kit 8 (CCK-8) method. The osteogenic differentiation ability of BMSCs on each scaffold was evaluated by alkaline phosphatase (ALP) activity. Finally, a critical-size rat calvarial bone defect model was used to evaluate the osteogenesis of the scaffolds in vivo. Micro-CT was used to reconstruct the three-dimensional model of the defect area, and the bone volume and bone mineral density were quantitatively analyzed.ResultsSEM results showed that the lecithin could slightly reduce the pore size; when lecithin content was 50%, platelet-like structure could be observed on the scaffolds. Wide angle XRD and DSC showed that the crystallinity of scaffolds gradually decreased with the increase of lecithin content. The water uptake ability test showed that the hydrophilicity of scaffolds increased with the increase of lecithin content. CCK-8 assay showed that cell activity gradually increased with the increase of culture time. After 7 days of culture, the absorbance (A) value of groups C, D, E, and F were significantly higher than that of groups A, B, and G (P<0.05), but no significant difference was found among groups C, D, E, and F (P>0.05). After 14 days of osteogenic induction, with the increase of lecithin content, there was a significant difference in ALP activity of each group. The ALP activity in groups D, E, F, and G were significantly higher than that in groups A, B, and C (P<0.05).In vivo, the results of Micro-CT examination and bone volume and bone mineral density showed that the scaffolds with 30% lecithin had the best repairing effect.ConclusionPrepared by thermally induced phase separation, the cytocompatibility, osteogenic differentiation, and bone repair ability of the PLLA/lecithin porous scaffold is obviously better than that of pure PLLA scaffold. PLLA/lecithin porous scaffold with suitable lecithin content is a promising scaffold material for bone tissue engineering.
【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.