Objective Rapid and effective vascularization of scaffolds used for bone tissue engineering is critical to bony repair. To study the cooperative and promotion effects of enhanced bioactive glass/collagen composite scaffold on vascularization for searching for a kind of el igible vascularized scaffold to repair bone defect. Methods The human umbil ical vein endothel ial cells (HUVECs) were collected from human umbil ical core, and identified through von Willebrandfactor (vWF) and CD34 immunofluorescence. The 1st passage of HUVECs were suspensed and seeded into the scaffold. The attachment and prol iferation of HUVECs on the scaffold were observed through scanning electron microscope (SEM). HUVECs were seeded on the scaffold as the experimental group, and on 96-well plate as the control group. The growth rate of HUVECs was detected through alarmarBlue at 1, 3, 5, 7, 9, and 11 days. Meanwhile, the mRNA expression levels of VEGF, fms-related tyrosine kinase 1 (Flt-1), and kinase insert domain receptor (Kdr) were detected through real-time fluorescence quantitative PCR. Twelve scaffolds were embedded subcutaneouly into 6 Sprague-Dawley rats. The enhanced scaffolds were used and the arteria and vein saphena bundle were embedded straightly through the central slot of scaffold in experimental group, and the common scaffolds were used in control group. Frozen section and HE staining of scaffolds were performed at 5 days and 10 days to observe the vascularization of embedded scaffold. Results HUVECs were identified through morphology, vWF and CD34 immunofluorescence. SEM results showed HUVECs could attach to the scaffold tightly and viably. HUVECs prol iferated actively on the scaffold in experimental group; the growth rate in experimental group was higher than that in control group at 3-11 days, showing significant differences within 5-11 days (P lt; 0.05). The real-time fluorescence quantitative PCR results showed thatthe mRNA expression levels of VEGF, Flt-1, and Kdr in experimental group were higher than those in control group at 3 days, showing significant differences (P lt; 0.05). Frozen section and HE staining of the scaffolds in experimental group showed that the embedded vessel bundle were still patency at 5 days and 10 days, that many new vessels were observed around the embedded vessel bundle and increased with time, host vessels infiltrated in the surrounding area of scaffold and fewer neo-vessels at the distant area. But there was only some fibrous tissue appeared in control group, and at 10 days, the common scaffold degradated, so few normal tissue appeared at the embedded area. Conclusion Enhanced bioactive glass/collagen composite scaffold can promote vascularization in vitro and in vivo, and may be used in bone tissue engineering.
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 investigate the cl inical appl ication of self-setting CPC loading rhBMP-2 for repair of bone defects and to evaluate the cl inical effect and safety. Methods From June 2006 to September 2007, 112 bone defects patients were treated by CPC loading rhBMP-2 (rhBMP-2/CPC group) or CPC (control group). The range of bone defect was from1 cm × 1 cm × 1 cm to 4 cm × 3 cm × 3 cm. In the control group, 63 patients included 31 males and 32 females, aging from 17 to 70 years with an average of 47.4 years. The bone defects were located as follows: calcaneus in 19 patients, tibial plateau in 20 patients, proximal humerus in 8 patients, distal radius in 9 patients and thoracolumbar vertebrae in 7 patients. In the rhBMP-2/CPC group, 49 patients included 31 males and 18 females, aging from 16 to 68 years with an average of 45.6 years. The bone defects were located as follows: calcaneus in 11 patients, tibial plateau in 16 patients, proximal humerus in 7 patients, distal radius in 2 patients, distal tibia in 2 patients and thoracolumbar vertebrae in 11 patients. All defects were repaired with rhBMP-2/CPC (2-5 g) and CPC (2-50 g) in the rhBMP-2/CPC group and the control group, respectively. Results A total of 108 patients got primary heal ing after operation. Incisions oozing l ight yellow fluids were found in 4 patients (control group in 1, rhBMP-2/CPC group in 3), and then healed through dressing changes and taking glucocorticoid. There were no allergic or toxic reaction, no rush or high fever, no fluctuation of hepatic and renal function, blood routine, CRP and urine routine. All patients were followed up for 12 to 24 months (mean 13.2 months). The X-ray examination showed that the implanted material was firmly bonded to the bone at the interface and the anatomic contour of the bone at the sites of defects was successfully restored, and no ablation occurred. All patients got bone union after 3 months of operation. The movement and function of flexion and extension of affected l imbs recovered to the normal level. Conclusion Repairing bone defects with rhBMP-2/CPC is safe and effective. Using rhBMP-2/CPC is a promising therapy to deal with bone defects.
Objective To investigate the osteogenic potential of four kinds of new bioactive ceramics combined with bovine bone morphogenetic proteins (BMP) and to explore the feasibility of using compounds as bone substitute material.Methods Ninety-six rats were divided into 4 groups(24 in each group). BMP was combined with hydroxyapatite(HA), tricalcium phosphate(TCP), fluoridated-HA(FHA), and collagen-HA(CHA) respectively. The left thighs of the rats implanted with HA/BMP, TCP/BMP, FHA/BMP,and CHA/BMP were usedas experimental groups. The right thighs of the rats implanted with HA, TCP, CHA, and decalcified dentin matrix(DDM) were used as control groups. The rats weresacrificed 1, 3, 5 and 7 weeks after implantation and bone induction was estimated by alkaline phosphatase(ALP),phosphorus(P), and total protein(TP)measurement. The histological observation and electronic microscope scanning ofthe implants were also made. Results The cartilage growth in the 4 experimental groups and the control group implanted with DDM was observed1 week after operation and fibrous connective tissues were observed in the other 3 control groups. 3 weeks after implantation, lamellar bone with bone marrow and positive reaction in ALP stain were observed in the 4 experimental groups. No bone formation or positive reaction in ALP stain were observed in the control groups. The amount of ALP activity, P value, and new bone formation in the experimental groups were higher than those in the control group(Plt;0.05). The amount of ALP activity, P value, and new bone formation in TCP/BMP group were higher than those in HA/BMP, CHA/BMP and FHA/BMP groups(Plt;0.05). There was no significant difference in TP between the BMP treatment group and the control groups. From 5th to 7th week, new bone formation, histochemistry evaluation, and the level of ALP、P、TP value were as high as those in the 3rd week. Conclusion New composite artificial bone of TCP/BMP, HA/BMP, CHA/BMP, and FHA/BMP all prove to be effective, but TCP/BMP is the most effective so that it is the most suitable biomaterial replacement of tissue.
Abstract A new type of artificial material could possibly be produced by combination of osteoblast with bioactive material in culture, and thus, make the material "alive" . To study the behavior of osteoblast cultured with bioactive materials, the osteoblasts were isolated from the periosteum of Newzeland Rabbits tibia, and cultured in RPMI1640 medium. After 13 subcultures, the cells were identified as osteoblast in vitro by electron microscope, AKP activity and detection of mineral deposition ability. The osteoblasts were subcultured with three bioactive materials: bioactive glass ceramics (BGC), hydroxyapatite (HA), and double phase hydroxyapatite (HA/TCP). After incubationfor 48 hours, scan electron microscope, 3H-TDR, XRD, RS and EDXAwere performed. The results showed that the osteoblasts grew on the HA/TCR had a higher proliferation rate and better osteoblastoid shape than those grew on BCG and HA. Themechanism of the growth of osteoblasts on bioactive materials was discussed, and the factors influencing the growth of osteoblast were analyzed.
ObjectiveTo review the mechanisms of bioactive substances of mesenchymal stem cells-derived exosomes (MEX) in tissue repair and analyze the therapeutic values of MEX. MethodRecent relevant literature about MEX for tissue repair was extensively reviewed and analyzed. ResultsThe diameter of exosomes ranges from 30 to 100 nm which contain an abundance of bioactive substances, such as mRNA, microRNA, and protein. The majority of the exact bioactive substances in MEX, which are therapeutically beneficial to a wide range of diseases, are still unclear. ConclusionsBioactive substances contained in the MEX have repairing effect in tissue injury, which could provide a new insight for the clinical treatment of tissue damage. However, further studies are required to investigate the individual differences of MEX and the possible risk of accelerating cancer progression of MEX.
Objective To compare the healing process and clinical results of bioactive glass and allogenic bone in the repair of bone defects after benign bone tumor curettage. Methods Between November 2011 and December 2012, 20 patients with benign bone tumor received bioactive glass and allogenic bone for repair of bone defects after benign bone tumor curettage. There were 17 males and 3 females, aged 9-68 years (median, 18.5 years). The mean course of disease was 3.3 months (range, 1-9 months). Pathological examination revealed that there were 7 cases of chondroblastoma, 5 cases of bone cyst, 2 cases of non-ossifying fibroma, 2 cases of enchondroma, 1 case of vascular tumor of bone, 1 case of lipoma of bone, 1 case of osteoid osteoma, and 1 case of chondromyxoid fibroma. The lesion located at the femur in 5 cases, at the tibia in 11 cases, at the humerus in 1 case, at the calcaneus in 2 cases, and at the talus in 1 case. The bioactive glass and allogenic cancellous bone were implanted in the cavity at the same time. The Musculoskeletal Tumor Society (MSTS) function evaluation score was used for evaluation of postoperative limb function. According to the imaging and clinical benefit, the healing processes of two kinds of implants were evaluated. The healing rate and healing time were compared. The distribution of the bioactive glass was divided into two layers: the layer close to host bone and the layer close to allogenic bone. The bone ingrowth time and bone resorption time in different layers were evaluated and compared. Results All cases were followed up 12-42 months (mean, 34.5 months). All incisions healed by first intention. There were no complications of wound infection or deep infection, rejection, nonunion of bone, fracture at bone graft site, and collapsing of articular surface. There was no tumor recurrence during follow-up. The mean MSTS functional score was 29.5 (range, 28-30) at last follow-up. Complete healing was observed in 11 cases and healing in 9 cases. The healing rates of two kinds of implants were both 100%. The healing time of bioactive glass and allogenic bone was (4.7±1.3) months and (5.2±1.6) months, respectively, showing no significant difference (t=-1.240, P=0.244). The bone ingrowth time and the bone absorption time were (3.6±0.9) months and (3.7±1.0) months in the layer close to host bone and were (4.2±1.3) months and (4.2±1.3) months in the layer close to allogenic bone, all showing no significant difference (t=1.785, P=0.097; t=1.476, P=0.172). Conclusion For the repair of bone defects after benign bone tumor curettage, bioactive glass can achieve satisfactory healing result and has good safety.
Objective To review the research and application progress of bioactive glass in bone repair. Methods The recently published literature concerning bioactive glass in bone repair was reviewed and summarized. Results Bioactive glass can classified different types, such as bioactive glass particulate, bioactive glass scaffold, bioactive glass coating, injectable bioactive glass cement, and bioactive glass delivery system. Bioactive glass has been well studied in the field of bone repair due to its excellent biological properties. Also, the remarkable progress has been made in various aspects. Conclusion Bioactive glass is a reliable material of bone repair and will play an even more important role in the future.
ObjectiveTo summarize the clinical application and research status of bioactive glass (BAG) in bone repair.MethodsThe recently published literature concerning BAG in bone repair at home and abroad was reviewed and summarized.ResultsBAG has been widely used in clinical bone repair with a favorable effectiveness. In the experimental aspect, to meet different clinical application needs, BAG has been prepared in different forms, such as particles, prosthetic coating, drug and biological factor delivery system, bone cement, and scaffold. And the significant progress has been made.ConclusionBAG has been well studied in the field of bone repair due to its excellent bone repair performance, and it is expected to become a new generation of bone repair material.
Bioactive glass (BG) has been widely used in the preparation of artificial bone scaffolds due to its excellent biological properties and non-cytotoxicity, which can promote bone and soft tissue regeneration. However, due to the brittleness, poor mechanical strength, easy agglomeration and uncontrollable structure of glass material, its application in various fields is limited. In this regard, most current researches mainly focus on mixing BG with organic or inorganic materials by freeze-drying method, sol-gel method, etc., to improve its mechanical properties and brittleness, so as to increase its clinical application and expand its application field. This review introduces the combination of BG with natural organic materials, metallic materials and non-metallic materials, and demonstrates the latest technology and future prospects of BG composite materials through the development of scaffolds, injectable fillers, membranes, hydrogels and coatings. The previous studies show that the addition of BG improves the mechanical properties, biological activity and regeneration potential of the composites, and broadens the application of BG in the field of bone tissue engineering. By reviewing the recent BG researches on bone regeneration, the research potential of new materials is demonstrated, in order to provide a reference for future related research.