Preparation And Biological Evaluation Of Magnesium Potassium Phosphate Cement

Biomaterials have a significant effect on the repairing of the artificial bones.The traditional bone repair biomaterials PMMA and calcium phosphate materials have been unable to meet the demands of clinical treatment,and the new bone repair biomaterial magnesium phosphate materials have gradually been appearing.The magnesium oxide activity,acid-base ratio,etc.in magnesium phosphate materials have significant effects on its biocompatibility and physicochemical properties.In this study,potassium dihydrogen phosphate is applied to replace ammonium dihydrogen phosphate in conventional magnesium phosphate materials.At the same time,reasonable active magnesium oxide is selected and a small amount of hydroxyapatite is added to develop a new style material called magnesium potassium phosphate cement(MKPC)based on the standard of minimum in vitro cytotoxicity.The prepared MKPC is subjected to XRD analysis,SEM scanning,compressive strength testing,and in vitro degradation testing to evaluate its physicochemical properties.The results illustrate that MKPC has a laminated structure similar to conventional magnesium phosphate materials,which can provide good mechanical support,however,its compressive strength are 19 MPa and lower than the traditional material PMMA,which can not be used for the repair of heavy bones.It needs modification to improve the mechanical properties to adapt to clinical practice.Thus,modification is needed for improving its mechanical properties to meet the demands clinical treatment.The degradation rate of MKPC in vitro simulated solution reached more than 80% in the third week,which indicated that MKPC had excellent degradation performance and provided the possibility for avoiding the second operation after bone repair.The prepared MKPC is subjected to an animal skin irritation test and pyrogen test.At the same time,the extract liquid of MKPC is injected into mice by intraperitoneal injection to detect acute systemic toxicity.Select the femoral condyle in white rabbits from New Zealand as the defect modeling,implant the MKPC and commercial calcium phosphate cement(CPC)into the bone defects respectively,and conduct fluorescent marks for histological analysis.There was no edema erythema on the epidermis of experiment rabbit,which indicated that MKPC did not irritate the skin of animals.There was normal weight growth of mouse without adverse physiological symptoms,which indicated that MKPC did not carry potential pyrogens and had no toxic effect on animals.The femoral condyle defects in white rabbits rabbit are partly repaired,but MKPC filler materials’ degradation rate is higher than that of the commercial CPC fillers.The rate of regenerated bone growth at the bone defects from the MKPC filler is faster than that of the commercially available CPC-filled bone defect.Overall,MKPC has excellent bone compatibility,good degradation performance,outstanding bone conduction ability and osteoinductivity,which can provide certain mechanical supports and induce new bones generation.MKPC has tremendous prospects in clinical application.