The Study Of The Properties Of Calcium Phosphate Cement-fibrin Glue Composite For Bone Regeneration

The material researchers and the doctors in clinic focused on the research to find theideal biomaterial for the bone defects. The ideal material should include:(1) the goodbiocompatibility;(2) degradable and absorbable;(3) the good biomechanical properties;(4)preparation on the room temperature;(5) optimal pore size. Nowadays, CPC is the goodosteoinductive and osteoconductive material known by material scientists and is widelyused in bone tissue engineering. However, poor mechanical property of CPC has limitedits application into the non-load bearing condition. In order to improve the mechanicalproperties of CPC, other injectable materials such as chitosan, gelatin and collagen havebeen introduced into this material. Fibrin Glue (FG) is a kind of elastomeric,biocompatible material with sufficient adhesive strength, which has been approved by theChinese State Food and Drug Administration. It is unclear that the CPC/FG compositewhether could stimulate the bone regeneration. And it is also unclear that whether different ratio of CPC and FG has different properties for the bone reconstruction.1、The mechanical and biological properties of an injectable calcium phosphatecement-fibrin glue composite for bone regeneration in vitroCalcium phosphate cement (CPC) that can be injected to form a scaffold in situ haspromise for the repair of bone defects. However, its low-strength limits the CPC to nonstress-bearing repairs. Fibrin glue (FG) with good sticking property and biocompatibilityis possible used to reinforce the CPC. The objective of this study was to investigate theeffects of FG on the mechanical and biological properties of CPC in an injectable CPC/FGcomposite. The initial setting time of this CPC/FG was delayed compared with the CPCcontrol at different powder/liquid (P/L) mass ratio (p>0.05). At a P/L of5, the strengthwas (38.4±4.32) MPa for the CPC/FG, much higher than (27.42±2.85) MPa for the CPCalone (p <0.05). Osteoblast cell adhesion and proliferation were examined by MTTmethod and alkaline phosphatase (ALP) was assessed using test kits. The data allsupported that CPC/FG at any ratio could stimulate the activity of the osteoblast cell. Theresults demonstrate that this stronger CPC/FG scaffold may be useful for osteoblastcelll-based bone regeneration in moderate load-bearing orthopedic applications.2、The Mechanical and Biological Studies of Calcium Phosphate Cement-Fibrin Gluefor Bone Reconstruction of Rabbit femoral defectsIn order to improve the mechanical and biological properties of calcium phosphatecement (CPC, nanometer-biomaterial) for bone reconstruction in the rabbit femoral defectmodel, fibrin glue (FG, the natural product, purified from the blood) was introduced atthree different ratios. The CPC powder and the FG solution were mixed respectively at thepower/liquid (P/L) ratios (g/ml) of1:1,3:1and5:1(g/ml), and pure CPC was used ascontrol. After being implanted into the femoral defect in rabbit, the healing process wasevaluated by micro-CT scan, biomechanical testing and histological examination. Bymicro-CT analysis the P/L ratio of1:1(g/ml) group indicated largest quantity of new boneformation at4w,8w, and12w after implantation respectively. BV/TV of1:1group was highest in the four groups, which was1.45±0.42%,7.35±1.45%, and29.10±1.67%at4w,8w, and12w after the operation respectively. In the biomechanical tests, thecompressive strength and the elastic modulus of three CPC/FG groups were much higherthan those of the pure CPC group at the determined time point (p<0.05). The histologicalevaluation also showed the best osseointegration in the1:1group at4w,8w, and12w afterthe operation respectively. In1:1group, the bone grew into the pore of cement in thelaminar arrangement and connected with the cement tightly at the12thweek after theoperation. This present study indicated that CPC/FG composite at the P/L ratio of1:1(g/ml)stimulated bone regeneration better than any other designed group, which suggested thatCPC/FG at the P/L ratio of1:1has significant potential as the bioactive material for thetreatment of bone defects.3、The Comparison between the remolded CPC/FG and the injectable CPC/FG forthe Reconstruction of femoral defects in a rabbit modelThe aim of this study was to compare the remolded CPC/FG composite with theinjectable CPC/FG composite at the P/L ratio of1:1(g/ml) for new bone formation.Calcium phosphate cement (CPC) is a family of injectable biomaterial made of calciumphosphate, and FG is the natural product purified from human blood. In this study, theremolded CPC/FG composite at the P/L ratio of1:1(g/ml) was defined as Group A, andthe injectable one was defined as Group B. After being implanted into the cavity defect offemur in rabbits, the healing process was evaluated by micro-CT scan, biomechanicaltesting and histological examination at6w and12w after the operation. In micro-CTanalysis, Group B indicated larger quantity of new bone formation at6week and12weekafter the operation. The compressive strength of Group B was lower than that of Group Aat12week (p<0.05), and the elastic modules of Group B was more stable after theoperation compared with Group A. The histological analysis showed the similar imagingas micro-CT analysis. This present study indicated that the injectable CPC/FG compositeat the P/L ratio of1:1(g/ml) stimulated bone regeneration better than the remolded one.The study showed that the CPC/FG could stimulate the bone regeneration, and the injectabla CPC/FG at the P/L ratio of1:1(ml/g) has the best activity for new boneformation.