| Bone and joint infections are painful for patients and frustrating for both them and their doctors. The high success rates of antimicrobial therapy in most infectious diseases have not yet been achieved in bone and joint infections owing to the physiological and anatomical characteristics of bone. Despite the great improvement in research of the surgical techniques and antibiotics, the orthopaedic infection is still a big puzzle. The main goal of the treatment of kinds of bone infection is to lower the level of bacteria in the infectious area, so that the bone healing can happen. Debridement, irrigation and use antibiotcs systematicly are the common way to treat the bone and joint infection, while systematic antibiotics is very difficult to be taken into the local infection site, there will be only a very small part of them can get to the target, especially for those who have ischemic problems after big debridement. Repeatedly operation and enlength the usage of antibiotics are of no use at that time. Thus it is a critical thing to prevent the infection in the orthopaedic clinics. It must be very popular, if there is a antibiotics delivery system that can be degradable and can deliver high concentrations of antibiotics to local site and can help bone healing as well.Objectives:To design and fabricate a series of inorganic/organic composites that can load on vancomycin with different delivery mechanism. The effective delivery lasts from several days to several weeks so that they can meet with the need of different length of antibiotic treatment to different infection conditions.Materials and Methods:Sodium alginate(SA) and chitosans(CS) were dissolved and blended with vancomycin and TCP. Put SA dropwise into calcium ion solution to form small spheres of calcium algiante/TCP/vancomycin and thus freeze dried those spheres, then we got the spherens of calcium alginate/TCP/vancomycin. Then polycaprolactone (PCL) solutions were used to coat these spheres ang characteristics such as SEM and TGA were assessed as well as their drug delivery. And CS/TCP/vancomycin porous scaffold were made with freeze drying. The characteristics such as SEM,TGA and their drug delivery were also observed. Then we coate these porous scaffold with PCL again and those characteristics and drug delivery characteritcs were assesed again. In the end, silk fibroin (SF) was poured into the mould and lyophilized to be a tube like porous capsule. TCP and vancomycin were packed into this kind of capsule to be a simple delivery system, the drug delivery of which was tested in vitro and the bone induction of which was tested in vivo.Result:There were5materials tested in this thesis. AG/TCP/vancomycin could deliver vancomycin effectively for3days in vitro, and could be increased to5days(1.25%PCL) and8days(2.5%PCL); CS/TCP/vancomycin composites with the pore of196.4μm～205.2μm, could deliver vancomycin effectively for12days, and could be increase to maximum42days after coated with2.5%PCL solutions. As to the SF capsule packed with TCP and vancomycin could help heal the radius bone defect well and can effectively prevent the infection postoperatively. This kind of capsule can deliver antibiotics for5days in vitro.Conclusions:The several polymer/inorganic composites loaded with antibiotics were developed and tested, and the conclusions were that these delivery systems can deliver antibiotics for several days (3d) to several weeks (6w). It must be vey popular and can fit the need of the clinics from the prophylaxis of bone and joint infection to the treatment of chronic osteomyelitis if some procedures can be improved. |
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