Preparation And Properties Of Degradable PMMA Bone Cement Incorporated With N-Acetyl Cysteine

Objective: Prepare degradable PMMA bone cement incorporated with N-acetyl cysteine and search for its compressive strength,operability,surface appearance,NAC-release,degradationproperty,biocompatibility and osteogenic capacity.Methods: 1.Prepare traditional PMMA bone cement and degradable PMMA bone cement incorporated with NAC. 2.Test compressive strength and choose appropriate MDO concentration for further study. 3.Record the time of drawing stage and dough stage. 4.Observe surface appearance with SEM. 5.Samples were immerged into PBS and concentration of NAC at each time point was recorded to calculatethe release rate of NAC. 6.test the number-average molecular weight of bone cement that was soaked in glacial acetic acid for 1,5 days and observe their appearance. 7.The extracts of the bone cements cultured with MC3T3-E1, The biocompatibility of bone cements in vitro was assessed by CCK8. Observe the morphology of cell after stainedwitheosin-hematoxylin.SEM was used to observe the cell morphology on bone cement. 8.Alizarin red was used to evaluate the osteogenic capacity of bone cement.Result:1.Compressive strength decreased by the increasing MDO concentration, and NAC/5%MDO bone cement was used for further study. 2.none of the drawing stage time and dough stage time of the C-PMMA and NAC/5%MDO bone cement showed significant difference. 3.Surface appearance of the C-PMMA and NAC/5%MDO bone cement was same. 4.NAC/5%MDO bone cement can release NAC slowly and continuously. 5.Nnumber-average molecular of NAC/5%MDO bone cement decreased to 49.6% after 1 day in glacial acetic acid while C-PMMA didn’t decrease significantly. 6.There is no cytotoxicity of C-PMMA and NAC/5%MDO bone cement according to CCK8.Cells stainedwitheosin-hematoxylin looks well-spread.The cells seeded on the NAC/5%MDO bone cement were well-spread with good morphology. 7.NAC/5%MDO bone cement owed deeper color than C-PMMA after stainedwith alizarin red.Conclusion:NAC and MDO do not harm the compressive strength and operability of PMMA bone cement.degradable PMMA bone cement incorporated with NAC can release NAC slowly and continuously.Besides,it was biodegradable,nontoxic,and can promote osteogenesis.