Objective To review the research progress in the treament of bone defect or osteomyel itis with drug-carried bionic nano-bone so as to offer some theoretic supports and experimental references for those relative researchers. Methods The related l iterature was reviewed. The research progress in the treatment of bone defect or osteomyel itis with drug-carried bionic nano-bone was analyzed, which included the designing and preparing of drug-carried nano composites, the way of making infected bone defect animal models, and the general steps, test indexes and results. ResultsTraumatic osteomyel itis and bone defect were two kinds of disease to difficultly cure in nowadays cl inical orthopaedics. The osteomyel itis, especially chronic one was quite troublesome during the treatments. Many researchers made artifical bone with nano-materials and added drugs into them by various ways for the purpose of controlling infection and repairing bone defection simultaneously. But these researches were still at the laboratory phase, lacking the criterions of making relative animal models, and needed to be improved in the way of drug slow-releasing and nano-scaffold producing. Conclusion The drug-carried bionic nano-bone as a kind of newly emerging replacement material has splendid effects in the treatments of traumatic large area bone defect or osteomyelitis and will have a brill iant future.
OBJECTIVE: To explore the possibility of repair long segmental bone defects and preventing infection with cefazolin loaded bone matrix gelatin (C-BMG). METHODS: C-BMG was made from putting cefazolin into BMG by vacuum adsorption and freeze-drying techniques. The sustaining period of effective drug concentration in vitro and in vivo was detected by inhabition bacteria, and the drug concentration in local tissues (bone and muscle) and plasma after implantation of C-BMG was examined by high performance liquid chromatography(HPLC). RESULTS: The effective inhibition time to staphylococcus aureus of C-BMG was 22 days in vitro, while 14 days in vivo. The drug concentration in local tissues(bone and muscle) were higher than that of plasma, and the drug concentration in local tissues was higher in early stage, later it kept stable low drug release. It suggested that C-BMG had excellent ability to repair segmental long bone defects. CONCLUSION: C-BMG can gradually release cefazolin with effective drug concentration and has excellent ability to repair segmental long bone defects. It may be a novel method to repair segmental long bone defects and prevent infection after the operation.
Objective To investigate the research progress of drug-loaded antibacterial coating of orthopedic metal implants in recent years. Methods The recent literature on the drug-loaded antibacterial coating of orthopedic metal implants were reviewed. The research status, classification, and development trend of drug-loaded antibacterial coating were summarized. Results The drug-loaded antibacterial coating of orthopedic metal implants can be divided into passive release type and active release type according to the mode of drug release. Passive drug release coating can release the drug continuously regardless of whether the presence of bacteria around the implants. Active drug release coating do not release the drug unless the presence of bacteria around the implants. Conclusion The sustained and stable release of drugs is a key problem to be solved in various antibacterial coatings research. The intelligent antibacterial coating which release antibiotics only in the presence of bacteria is the future direction of development.
Objective To observe effect of self-designed drug-loaded nanofilm in preventing postoperative peritoneal cavity adhesion during cholecystectomy in New Zealand white rabbit. Methods The 40 New Zealand white rabbits were randomly divided into blank control group, chitosan group, nanofilm group, and drug-loaded nanofilm group using random number table, the peritoneal cavity adhesions after cholecystectomy at different time (on day 7, 14, 21, and 28) were observed among these 4 groups. Results The adhesion of gallbladder forssa was serious in the blank control group and the adhesion situation had obviously improved among the other three groups, furthermore, the adhesion of the drug-loaded nanofilm group was the slightest. The adhesion score was significantly decreased in the chitosan group, the nanofilm group, or the drug-loaded nanofilm group as compared with the blank control group (P<0.05), which in the drug-loaded nanofilm group was significantly decreased as compared with the chitosan group (P<0.05) or the nanofilm group (P<0.05), which had no significant difference between the chitosan group and the nanofilm group (P>0.05). The nanofilm was degraded on day 14 after surgery and basically completely degraded on day 28 after surgery. The nanofilm degradation points had no significant differences between the nanofilm group and the drug-loaded nanofilm group at different time (P>0.05). Conclusions Drug-loaded nanofilm could prevent postoperative peritoneal cavity adhesion from physical barrier and drug therapy. It provides a new idea for prevention of peritoneal cavity adhesion after general surgery and research and development of new material to prevent peritoneal cavity adhesion in future.
A multiple-stimuli-responsive drug-conjugated cross-linked micelles was prepared by radical copolymerization. The chemical structure, morphology, and size of the cross-linked micelles were characterized, and the drug loading of the micelle was calculated. The experimental results indicated that the hydrodynamic size of the drug-loaded micelles were about 100 nm, and the as prepared micelles could be degraded and swelled in presence of reducing glutathione (GSH). The low critical solution temperature (LCST) of the micelle was around 39.4℃. According to the experimental results, the micelles will shrink at temperature above the LCST. Subsequently, the accumulative drug release rate was up to 91.78% under acidic (pH 5.0), reductive (GSH 10 mmol/L) and high temperature (42.0℃) conditions mimicking the tumor microenvironment, while a relatively low release rate of 1.12% was observed without stimulation. The drug-conjugated cross-linked micelles showed a strong cell uptake behavior. In the cytotoxicity assay, the micelles exhibited effective anti-cancer activity and excellent biocompatibility. In brief, the experimental results show that the as-prepared drug-conjugated cross-linked micelle exhibits multiple stimuli-responsiveness, which holds great promise for anti-cancer drug delivery.
Curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres (Cur-HP-β-CD-PiBCA) were prepared by one-step emulsification with α-isobutyl cyanoacrylate as materials, poloxamer 188 as emulsifier, and curcumin complex with hydroxypropyl-β-cyclodextrin (Cur-HP-β-CD) as drug prepared by kneading method. Effects of emulsifier and drug concentration on microspheres size and distribution, drug loading and encapsulation efficiency were investigated in detail. And the curcumin release of drug-loaded microspheres was also studied. Results showed that as the emulsifier concentration increased from 0.01% to 0.07%, particle size of the drug-loaded microspheres decreased while particle size distribution, drug loading and entrapment efficiency increased. The optimized concentration of surfactant was 0.05%. With increasing the concentration of drug from 0.03% to 0.07%, drug loading of Cur-HP-β-CD-PiBCA increased, but encapsulation efficiency decreased. Additionally, the results of drug release experiments revealed that the higher drug loading of Cur-HP-β-CD-PiBCA was, the lower cumulative release percentage was. Drug-loading of cumulative inclusions in HP-β-CD by PiBCA can improve its wettability, and increase the degree of dissolution and bioavailability.
ObjectiveTo summarize the research progress of four mainstream drug-eluting beads (DEB) in transcathete arterial chemoembolization (TACE) for hepatocellular carcinoma in recent years.MethodThrough retrieving relevant literatures at home and abroad, the physicochemical properties, pharmacokinetics, effectiveness, and safety of four mainstream DEBs were reviewed.ResultsThe current mainstream DEBs on the market had the characteristics of high drug loading rate and sustained release of drugs, which could reduce the adverse reactions after the embolization to a certain extent. The safety and tolerance of patients receiving DEB-TACE were slightly higher than those receiving traditional TACE (c-TACE). There were no serious complications after the DEB-TACE, but the short-term and long-term efficacies between the two methods were not significantly different.ConclusionsAt present, most studies believe that the safety and tolerance of DEB are slightly higher than that of c-TACE, but whether the former is more effective than the latter is still controversial at home and abroad, and more high-quality multicenter randomized controlled trials are needed to confirm it.