Objective To const ruct art ificial derm is on co llagen2chondront in sulfate (CS) scaffo ld. Methods Co llagen w as compounded from CS and 1-ethyl-3-(13-dimethyl am inop ropyl) carbodiim ide (EDC) used as a cro sslinker. Physical and chem ical p ropert ies of the scaffo ld w ere characterized by elect ron spect ro scopy fo r chem ical analysis (ESCA ) , scanning elect ron m icrograph (SEM ) , HE staining, and mechanical p roperty test. Derm is fibroblasts w ere iso lated from human embryo and w ere cultured on the scaffo lds. Th rough h isto logical test ing, immunoh istochem ical test ing and biochem ical p roperty test ing, the p roperty of co llagen-CS art ificial derm is w as compared w ith that of colla gen spongy art ificial derm is. Results Co llagen-CS had th ree2dimension st ructure w ith po rous. Compared w ith co llagen scaffo ld, themechanical p roperty of co llagen2CS scaffo ld imp roved. There w eremo re po lar group s on the surface of co llagen-CS scaffo ld. The fibroblasts on the co llagen-CS scaffo ld grew w ell, and art ificial derm is w as const ructed. Conclus ion Co llagen-CS art ificial derm is has mo re excellent bio logical and mechanical p ropert ies. F ibroblasts at tach and p ro liferate bet ter on co llagen2CS scaffo ld than on co llagen scaffo lds.
Objective To investigate the synergetic effect and possibil ity of repairing spinal cord injury (SCI) by transplantation of olfactory ensheathing cells (OECs) and chondroitinase ABC (ChABC) in adult rats. Methods Three adult male SD rats were used to isolated olfactory bulb and primarily cultured OECs. In the 8th or 9th day, OECs were transplanted, the concentration of cells was modulated to 1 × 105/μL. Fifty-four SD rats were made the models of T8 spinal cord crush injury and divided into 4 groups. In group A (control, n=36), injured site was not treated; in groups B, C and D (n=6), OECs, ChABC and OECs+ChABC were injected into injured site, respectively. At 1, 2, 3, 7 and 14 days after injury, the BBB score system was used to evaluate the motion function. At 0, 1, 2, 3, 7, 14 days in group A and at 14 days in groups B, C, D after injury, the maximal transverse diameter and gross area of necrosis were evaluated on HE stained sections. The immunofluorescence double label ing staining for gl ial-fibrillary acidic protein (GFAP)/CS56, GFAP/growth associated protein 43(GAP-43) and GFAP/neurofilament 160(NF160) was carried out to evaluate the regeneration of nerve fiber. Results At 14 days after injury, there were significant difference in the BBB scores between group A and groups B, C, D (P lt; 0.05), and between groups B, C and group D (P lt; 0.05), HE staining showed that the formation of cavity was observed in each group at 14 days after injury. There were significant difference in the maximal transverse diameter and gross area of necrosis between groups B, C, D and group A (P lt; 0.01), and between groups B, C and group D (P lt; 0.01). The immunofluorescence staining indicated that expression of GFAP were more intense in group A than in other groups, and the cavity of the lesion site was apparent, but it was moderate in groups B and C. The expression of GAP-43 was more intense in group D than in groups B and C. The expression of NF160 was more intense in group D. Conclusion Transplantation strategy of OECs combined with ChABC was effective in the repair of SCI in some extent.
Objective Bioactive borate glass (BG) has good biocompatibil ity and biodegradation. To investigate the feasibilty of bioactive borate glass as a carrier of the antibiotic controlled-releasing by implanting vancomycin-loaded BG (VBG)into the focus of tibia chronic osteomyel itis after debridement. Methods VBG and vancomycin-loaded calcium sulfate (VCS) were prepared with a vancomycin content of 80 mg/g. Sixty-five New Zealand white rabbits, weighing 2.12-3.91 kg (mean, 2.65 kg), were used. The tibia chronic osteomyel itis rabbit models were establ ished by injecting methicill in-resistant Staphylococcus aureus (MRSA, 0.1 mL, 1 × 109 cfu/mL) into the right tibia of 65 rabbits. After 3 weeks of injection, 54 rabbits of successful models were randomly divided into groups A (n=11), B (n=11), C (n=16), and D (n=16). Simple debridement was performed in group A; BG, VCS, and VBG were implanted into the infection sites of groups B, C, and D respectively after thorough debridement. A sample of the debrided tissues was harvested for bacterial examination. The vancomycin serum levels were determined in groups C and D at 1, 2, 4, 10, 24, and 48 hours after operation. The boron serum levels were determined in groups B and D at 10, 24, 48, 72, and 120 hours after operation. After 8 weeks, the effectiveness was assessed radiographically, bacteriologically, and histopathol ogically. Results Ten rabbits died after operation. No vancomycin was detected in group C; the vancomycin level increased gradually, reached the highest level at 4 hours after operation, and then decreased rapidly in group D. No boron was detected in group B; the boron reached the highest serum level at 10 hours after operation, and then decreased gradually in group D. At 8 weeks, calcium sulfate degraded in group C; BG degraded partially in group D; and no obvious degradation was observedin group B. The repair effect was better in group D than in group C. There was no significant difference in radiograph scoring between groups A, B, C and D (P gt; 0.05) before operation, but there was significant difference between group D and groups A, B, C (P lt; 0.05) at 8 weeks after operation. The bacterial culture showed that all the MRSA results were positive in 4 groups. At 8 weeks, the negative rates of MRSA examination were 36.36%, 18.18%, 73.33%, and 81.25% respectively in groups A, B, C, and D, showing significant differences between group D and groups A, B (P lt; 0.05). The histopathological observation showed that a large number of new bones formed and no foreign body reaction occurred in group D. The histopathologic scores of groups A, B, C, and D were 6.45 ± 3.62, 7.55 ± 3.36, 4.27 ± 2.91, and 3.81 ± 3.04 respectively, showing significant differences between group D and groups A, B, and between group C and group B (P lt; 0.05). Conclusion VBG can improve the repair of bone defect in the treatment of chronic osteomyel itis.
Objective To discuss the role of heparan sulfate (HS) in bone formation and bone remodeling and summarize the research progress in the osteogenic mechanism of HS. Methods The domestic and abroad related literature about HS acting on osteoblast cell line in vitro, HS and HS composite scaffold materials acting on the ani-mal bone defect models, and the effect of HS proteoglycans on bone development were summarized and analyzed. Results Many growth factors involved in fracture healing especially heparin-binding growth factors, such as fibroblast growth factors, bone morphogenetic protein, and transforming growth factor β, are connected noncovalently with long HS chains. HS proteoglycans protect these proteins from protease degradation and are directly involved in the regulation of growth factors signaling and bone cell function. HS can promote the differentiation of stem cells into osteoblasts and enhance the differentiation of osteoblasts. In bone matrix, HS plays a significant role in promoting the formation, maintaining the stability, and accelerating the mineralization. Conclusion The osteogenesis of HS is pronounced. HS is likely to become the clinical treatment measures of fracture nonunion or delayed union, and is expected to provide more choices for bone tissue engineering with identification of its long-term safety.
Objective To systematically evaluate the effects of magnesium sulfate on postoperative pain and complications after general anesthesia. Methods A literature search was conducted in following databases as The Cochrane Library, EMbase, PubMed, EBSCO, Springer, Ovid, CNKI and CBM from the date of establishment to September 2011 to identify randomized controlled trials (RCTs) about intravenous infusion of magnesium sulfate during general anesthesia. All included RCTs were assessed and the data were extracted according to the standard of Cochrane systematic review. The homogenous studies were pooled using RevMan 5.1 software. Results A total of 11 RCTs involving 905 patients were included. The results of meta-analyses showed that compared with the control group, intravenous infusion of magnesium sulfate during general anesthesia significantly reduced the visual analog scale (VAS) scores at the time-points of 2, 4, 6, 8, 16, and 24 hours, respectively, after surgery, the postoperative 24 hours morphine requirements, and the incidents of postoperative nausea and vomiting (RR=0.61, 95%CI 0.40 to 0.91, P=0.02) and chilling (RR=0.29, 95%CI 0.14 to 0.59, P=0.000 7). Although the incidents of bradycardia (RR=1.93, 95%CI 1.05 to 3.53, P=0.03) increased, there were no adverse events or significant differences in the incidents of hypotension and serum concentration changes of magnesium. Conclusion Intravenous infusion of magnesium sulfate during general anesthesia may obviously decrease the pain intensity, and the incidents of nausea and vomiting and chilling after surgery, without increasing cardiovascular adverse events and risk of hypermagnesemia. The results still need to be confirmed by more high-quality and large-sample RCTs.
ObjectiveTo observe the ability of osteogenesis in vivo using the injected absorbable polyamine acid/calcium sulfate (PAA/CS) composites and assess their ability to repair bone defects. MethodWe selected 48 New Zealand white rabbits, and half of them were male with a weight between 2.0 and 2.5 kg. Bone defect models were made at the rabbit femoral condyle using electric drill, and the rabbits were divided into two groups. One group accepted implantation of the material at the defect, while nothing was done for the control group. After four, eight, twelve and sixteen weeks, the animals were killed. The line X-ray and hard tissue slices histological examination (HE, MASSON staining) were observed to assess the situation of degradation, absorption and bone formation of the material. ResultsFour weeks after operation, bone defect of the experimental group had no obvious callus growth on X-ray imaging. Histology showed that the material began to degrade and new immature trabecular bone grew. The bone defect of the experimental group had a small amount of callus growth on X-ray imaging after eight weeks. And histology showed that the material continued to degrade and new immature trabecular bone grew continually. There was an obvious callus growth after twelve weeks, and the bone defect area had smaller residual low-density shadow on X-ray imaging. Histology showed that most of the materials degraded and parts of woven bone grew into lamellar bone. After sixteen weeks, the composites were absorbed completely, replaced by new bone tissues, and the new bone was gradually changed from woven bone into mature plate of bone. There was no significant change in bone defect in the control group within twelve weeks, and part of bone defect hole became smaller, and partial edge repair could be detected. ConclusionsThe PAA/CS composites can be completely degraded and absorbed, with a certain activity of bone formation, expected to be used as bone repair materials.
ObjectiveTo evaluate the ectopic osteogenesis of recombinant human bone morphogenetic protein 2 (rhBMP-2) loaded chitosan (CS)/dextran sulfate (DS) by micro-CT. MethodsrhBMP-2/CS/DS microspheres were prepared by the ionic crosslinking and its shape was observed under the scanning electron microscope. The release of rhBMP-2 was determined from resultant microspheres by ELISA assay. Forty-eight Sprague Dawley male rats were randomly divided into 4 groups (n=12), quadriceps muscle bag model was made, gelatin sponge (group A), CS/DS microspheres (group B), rhBMP-2 (group C), and CS/DS/rhBMP-2 microspheres (group D) were implanted into the bags respectively. The tissue samples with heterotopic ossification were harvested for micro-CT scanning at 4, 8, 12, and 16 weeks. The tissue mineral density (TMD), bone volume fraction (BVF), trabecular thickness (Tb.Th), trabecular number (Tb.N), bone mineral density (BMD), and tissue mineral content (TMC) were measured. ResultsThe prepared rhBMP-2/CS/DS microspheres with smooth surfaces were spherical and evenly disperses without obvious agglomeration. At 2 hours, microsphere started a sudden release period in vitro; the release reached a peak at 2 days; and the release cycle lasted about 20 days. The rats survived to the end of the experiment. At each time point after operation, no radiation developed and no osteogenesis was observed by three dimensional reconstruction in groups A and B. However, radioactive strength and reconstructed bone tissue gradually increased in groups C and D, and group D had more radioautography and more bone tissues than group C. At each time point, TMD, BVF, Tb.Th, Tb.N, BMD, and TMC of groups A and B were zero. Ectopic bone formed with time, the other parameters showed an increasing trend except Tb.N in groups C and D, showing significant difference when compared with groups A and B at each time point (P < 0.05). There was no significant difference between groups C and D at 4 weeks (P>0.05); the parameters of group D were significantly higher than those of group C at 8-16 weeks (P < 0.05). ConclusionrhBMP-2/CS/DS microspheres have stronger ability of ectopic bone formation than single rhBMP-2.
Objective To investigate the clinical effect of medical grade calcium sulfate(Osteoset) as a bone graft substitute. Methods From December 2004 to May 2005, 9 cases of bone defect(limb group)were repaired with Osteoset pellets; bone defect was caused by benign tumor inlimbs, including 3 cases of fibroma xanthomas in humerus(1 case) and acetabulum (2 cases), 2 cases of bone cysts in humerus(1) and radius(1), 1 case of nonossifying fibroma, 1 case of ossifying fibroma and 2 cases of osteofibrous dysplasia in femurs. Five cases of lumbar posterolateral fusion (spine group) were treated with Osteoset pellets as autograft volume expander, including 2 cases of lumbar spinal stenosis, 2 cases of lumbar spondylolisthesis and 1 case of lumbar spondylolysis. Radiological method was used to evaluate the repair effect of Osteoset pellets. Results The mean follow-up time was 6.2 months (3to 9 months). Osteoset pellets began to be absorbed after 1 to 3 months of operation, and were totally absorbed and replaced by osseous tissue after 4 to 6months. No local recurrence was detected in limb group and the function of limbs was normal. At 6 months after operation, all patients in spine group got bony fusion. Conclusion Medical grade calcium sulfate (Osteoset) isan ideal bone graft substitute with excellent bone repair effect.
ObjectiveTo study the preparation and properties of the hyaluronic acid (HA)/α-calcium sulfate hemihydrate (α-CSH)/β-tricalcium phosphate (β-TCP) material (hereinafter referred to as composite material). Methods Firstly, the α-CSH was prepared from calcium sulfate dihydrate by hydrothermal method, and the β-TCP was prepared by wet reaction of soluble calcium salt and phosphate. Secondly, the α-CSH and β-TCP were mixed in different proportions (10∶0, 9∶1, 8∶2, 7∶3, 5∶5, and 3∶7), and then mixed with HA solutions with concentrations of 0.1%, 0.25%, 0.5%, 1.0%, and 2.0%, respectively, at a liquid-solid ratio of 0.30 and 0.35 respectively to prepare HA/α-CSH/ β-TCP composite material. The α-CSH/β-TCP composite material prepared with α-CSH, β-TCP, and deionized water was used as the control. The composite material was analyzed by scanning electron microscope, X-ray diffraction analysis, initial/final setting time, degradation, compressive strength, dispersion, injectability, and cytotoxicity. ResultsThe HA/α-CSH/β-TCP composite material was prepared successfully. The composite material has rough surface, densely packed irregular block particles and strip particles, and microporous structures, with the pore size mainly between 5 and 15 μm. When the content of β-TCP increased, the initial/final setting time of composite material increased, the degradation rate decreased, and the compressive strength showed a trend of first increasing and then weakening; there were significant differences between the composite materials with different α-CSH/β-TCP proportion (P<0.05). Adding HA improved the injectable property of the composite material, and it showed an increasing trend with the increase of concentration (P<0.05), but it has no obvious effect on the setting time of composite material (P>0.05). The cytotoxicity level of HA/α-CSH/β-TCP composite material ranged from 0 to 1, without cytotoxicity. Conclusion The HA/α-CSH/β-TCP composite materials have good biocompatibility. Theoretically, it can meet the clinical needs of bone defect repairing, and may be a new artificial bone material with potential clinical application prospect.
Objective To evaluate the tissue response induced by three kinds of bone transplantation materials implanted in rat so as to provide proper evidence for their cl inical appl ication. Methods Thirty-six healthy mature Sprague- Dawly mice, weighing from 229 g to 358 g, were randomly assigned to groups A and B (n=18). Three kinds of materials wereimplanted into muscles of rats. Calcium sulfate (CS) granular preparations and allogeneic demineral ized bone matrix (DBM) were transplanted into the left (group A1) and right (group A2) thigh muscle pouches of group A. Respectively, whereas xenogenic DBM were transplanted into the left (group B1) thigh muscle pouches of group B and the right (group B2) sites were taken as control without implant. The samples (n=6) were collected to make the observation of gross and histology and to analyze histological score after 2, 4, and 6 weeks. Results The gross observation: implanted materials were gradually absorbed at late stage in group A1. No obvious degradation and absorption, but fibrosis of tissues were observed in group A2 and B1. The inflammatory reactions were more severe in groups A2 and B1. In group B2, only the changes of scar were seen at operative site. The histological observation: no obvious inflammatory reactions were seen in group A1, CS were gradually absorbed and completely absorbed at 6 weeks, while fibrosis of tissues increased at late stage. Inflammatory reactions in group A2 and group B1 were alleviated gradually, no obvious absorption and degradation were observed. The different two DBM could induce granulation tissues and bone formation at different sites and secondary fibrosis with no obvious immune response was observed. In group B2, there was an increase in collagen fiber density and angiogenesis at late stage. The scores of inflammatory infiltration were significantly higher in groups A2, B1 than in groups A1, B2 (P lt; 0.05), and the scores of fibrosis was larger in groups A1, A2 and B1 than in group B2 (P lt; 0.05). Conclusion CS has rapid dissolution and good biocompatibil ity. It is a good replaceable packing materials of bone defects in some upper l imb’s or acute bone fracture. Both of two DBM have biocompatibil ity and osteoinductive potential, which dissolution are very slow. Due to these capacity, they can be served as an ideal materials in treatment of lower l imb’s bone defect and nonunion.