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.
ObjectiveTo investigate the mechanism of magnesium sulfate in protecting rabbit cartilage by initiating autophagy.MethodsTwenty-four adult female New Zealand rabbits were used to prepare post-traumatic osteoarthritis (PTOA) models by anterior cruciate ligament transection. Then, the PTOA models were randomly divided into PTOA group, distilled water group, and magnesium sulfate group, with 8 rabbits in each group. Immediately after operation, the distilled water group and the magnesium sulfate group were injected with 0.5 mL distilled water and 20 mmol/L magnesium sulfate solution in the joint cavity 3 times a week for 4 weeks, respectively. The PTOA group was not treated. The general condition of the animals was observed after operation. After 4 weeks, the expressions of tumor necrosis factor α (TNF-α) and collagen typeⅡ in the joint fluid and the expression of collagen type Ⅱ in venous blood were detected by ELISA assay. The protein expressions of transient receptor potential channel vanilloid 5 (TRPV5) and microtubule associated protein 1 light chain 3 (LC3; LC3-Ⅱ/LC3-Ⅰ) in femoral cartilage were detected by Western blot. The mRNA expressions of interleukin 1β (IL-1β), TNF-α, matrix metalloproteinases 3 (MMP-3) in synovial tissue and collagen type Ⅱ, Aggrecan (AGN), SOX9 in cartilage tissue were detected by real-time fluorescence quantitative PCR. Cartilage tissue sections were stained with HE staining, Masson staining, and Alcian blue staining and scored according to the modified histological osteoarthritis (OA) score.ResultsAll animals survived until the experiment was completed. Compared with the other two groups, the expression of TNF-α in joint effusion and collagen type Ⅱ in joint effusion and venous blood were decreased in magnesium sulfate group; the protein expression of TRPV5 decreased, and the ratio of LC3-Ⅱ/LC3-Ⅰ increased significantly; the mRNA expressions of IL-1β, TNF-α, and MMP-3 in synovial tissue were decreased, and the mRNA expressions of collagen type Ⅱ, AGN, and SOX9 in cartilage tissue were increased; OA scores also decreased significantly. All differences were statistically significant (P<0.05). There was no significant difference in the above indicators between the PTOA group and the distilled water group (P>0.05).ConclusionIntra-articular injection of magnesium sulfate can reduce intra-articular inflammation, reduce the loss of collagen type Ⅱ and AGN, and is beneficial to cartilage regeneration in rabbits. The mechanism may be related to the initiation of chondroautophagy by inhibiting the calcium channel TRPV5.
Objective To investigate the effect of chondroitinase ABC (ChABC) on the expression of growth associated protein 43 (GAP-43) and gl ial fibrillary acidic protein (GFAP) after spinal cord injury (SCI) in rats. Methods A total of 150 adult female SD rats, weighing 250-300 g, were randomly divided into ChABC treatment group (group A), sal ine treatment group (group B), and sham operation group (group C) with 50 rats in each group. In groups A and B, the rats were made the SCI models and were treated by subarachnoid injection of ChABC and sal ine; in group C, the rats were not treated as a control. At 1, 3, 7, 14, and 21 days after operation, the Basso, Beattie, and Bresnahan (BBB) score system was used toevaluate the motion function, and immunofluorescent histochemical staining was used to observe the expressions of GAP-43 and GFAP. Results At different time points, the BBB scores of groups A and B were significantly lower than those of group C (P lt; 0.05); there was no significant difference in BBB score between groups A and B after 1, 3, and 7 days of operation (P gt; 0.05), but the BBB score of group A was significantly higher than that of group B after 14 and 21 days of operation (P lt; 0.01). At different time points, the GAP-43 and GFAP positive neurons of groups A and B were significantly higher than those of group C (P lt; 0.05). After 14 and 21 days of operation, the GAP-43 positive neurons of group A were more than those of group B (P lt; 0.01). After 7, 14, and 21 days of operation, the GFAP positive neurons of group A were significantly less than those of group B (P lt; 0.01). Conclusion ChABC can degrade gl ial scar, improve the microenvironment of the injured region and enhance the expression of GAP-43, which promotes axonal growth and extension.
With silk fibroin and vancomycin (VCM) as carrier and drug model, respectively, we prepared silk fibroin microspheres (SFM) with different concentration using the water-in-oil emulsion solvent diffusion method. We further developed VCM loaded calcium sulfate hemihydrates (CSH)/SFM artificial bone composites. In this study, surface morphology of the materials was observed using scanning electron microscope (SEM). Structure of the materials was studied with Fourier transform infrared spectroscopy (FTIR). Antibacterial activity of the materials was validated with the inhibition zone test. Drug release property of materials was evaluated using ultraviolet/visible spectrophotometry. Mechanical property of the materials was tested using computer-controlled electronic universal testing machine. The results showed that silk fibroin concentration had no significant effect on molecular conformation and antibacterial property of the SFM. The average diameter of SFM increased and the release rate decreased gradually as the silk fibroin concentration increased. The release rate decreased and the compressive fracture work increased as the silk fibroin concentration increased when adding SFM to CSH. This composite had partly corrected the disadvantages of CSH including the high brittleness and initial burst release. The research would have a good application foreground in the clinical treatment of infectious bone defect.
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.
ObjectiveTo fabricate an injectable composite bone substitute with hyaluronic acid (HA) and calcium sulfate and to evaluate the biocompatibility and effect of the composite on cell proliferation, osteogenic differentiation in vitro and osteogenic capability in vivo. MethodsCalcium sulfate powder was mixed with HA solution, cross-linked HA solution, and phosphate buffer solution (PBS) in a ratio of 2∶1 (W/V) to get composites of CA+HA, CA+HAC, and CA. The standard extracts from above 3 materials were prepared according to ISO10993-5, and were used to culture mouse MC3T3-E1 cells. The composite biocompatibility and cell proliferation in different concentrations of extract were tested with cell counting kit-8 (CCK-8). The cells were cultured with standard medium as a control. The optimal concentration was selected for osteogenic differentiation test, and ELISA Kit was used to determine the alkaline phosphatase (ALP), collagen type I (COL-I), and osteocalcin (OCN). The femoral condylar bone defect was made on New Zealand white rabbits and repaired with CA+HA, CA+HAC, and CA. Micro-CT was done to evaluate new bone formation with bone volume/tissue volume (BV/TV) ratio at 6 and 12 weeks. HE staining was used to observe bone formation. ResultsCA+HA and CA+HAC were better in injectability and stability in PBS than CA. The biocompatibility test showed that absorbance (A) value of CA group was significantly lower than that of control group (P<0.05) at 6, 12, and 24 hours after culture, but no significant difference was found inA values between CA+HA group or CA+HAC group and control group (P>0.05). The proliferation test showed 25% and 50% extract of all 3 materials had significantly higherA value than control group (P<0.05). For 75% and 100% extract, only CA+HA group had significantly higherA value than control group (P<0.05). And 50% extract was selected for osteogenic differentiation test. At 14 and 21 days, ALP, COL-I and OCN concentrations of CA+HA group and CA+HAC group were significantly higher than those of CA group and control group (P<0.05). Micro-CT results showed higher BV/TV in CA+HA group and CA+HAC group than CA group at 6 and 12 weeks (P<0.05), but no significant difference was found between CA+HA group and CA+HAC group (P>0.05). HE staining revealed that a little bone tissue was seen in CA+HA group and CA+HAC group, but there was no bone formation in CA group at 6 weeks; more streak bone tissue in CA+HA group and CA+HAC group than CA group at 12 weeks. ConclusionComposites prepared with calcium sulfate and HA or with cross-linked HA are stable, injectable, and biocompatible. The materials have excellent effect on proliferation and differentiation of mouse MC3T3-E1 cells. They also show good osteogenic capability in vivo. So it is a potential bone substitutes for bone defective diseases.
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.
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 investigate the short-term effectiveness of balloon vertebroplasty combined with short-segment pedicle screw instrumentation for the treatment of thoracolumbar burst fractures. MethodsBetween June 2011 and December 2013, 22 patients with thoracolumbar burst fractures were included. There were 14 males and 8 females, aged 20-60 years (mean, 42.5 years). The fracture segments included T11 in 1 case, T12 in 4 cases, L1 in 10 cases, L2 in 6 cases, and L3 in 1 case. According to AO classification system, there were 13 cases of type A and 9 cases of type B. Spinal cord injury was classified as grade C in 2 cases, grade D in 3 cases, and grade E in 17 cases according to Frankel scale. The time from injury to operation was 3-10 days (mean, 5.5 days). All patients underwent posterior reduction and fixation via the injured vertebra, transpedicular balloon reduction of the endplate and calcium sulfate cement (CSC) injection. The ratio of anterior vertebral height, the ratio of central vertebral height, the sagittal Cobb angle, the restoration of nervous function, and internal fixation failure were analyzed. ResultsPrimary healing of incision was obtained in the others except 2 cases of poor healing, which was cured after dressing change or debridement. All the patients were followed up 9-40 months (mean, 15 months). CSC leakage occurred in 2 cases. Absorption of CSC was observed at 8 weeks after operation with complete absorption time of 12-16 weeks (mean, 13.2 weeks). The mean fracture healing time was 18.5 weeks (range, 16-20 weeks). The ratio of anterior vertebral height, ratio of central vertebral height, and sagittal Cobb angle were significantly improved at 1 week and 3 months after operation and last follow-up when compared with preoperative values (P<0.01), but no significant difference was found among 3 time points after operation (P>0.01). There was no internal fixation failure or Cobb angle loss more than 10°. Frankel scale was improved with no deterioration of neurologic function injury. ConclusionBalloon vertebroplasty combined with short-segment pedicle screw instrumentation is simple and safe for the treatment of thoracolumbar burst fractures, and it can improve the quality of reduction, restore vertebral mechanical performance effectively, and prevent the loss of correction and internal fixation failure.
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.