Synthesis And Characterization Of An Injectable And Multifunctional Poly(Methyl Methacrylate) Bone Cement

Part ? Evaluation of an injectable and smart polymethylmethacrylate cement functionalized with chitosan-glycerophosphate thermo-sensitive hydrogel,nano-sized hydroxyapatite and gentamicinObjective:To develop novel and versatile PMMA based cements and investigate their clinic-related properties,e.g.handling property,mechanical performance,biomineralization capacity and infection-resist ability.Materials and Methods:Osteoconductive nano-sized hydroxyapatite(Nano-HA)and gentamicin(GM)were initially loaded into chitosan-glycerophosphate(CS-GP)thermo-sensitive hydrogel.Then the extracellular matrix(ECM)-like hydrogel was mixed with PMMA acting as a pore-forming agent to optimize the final bulk behaviors of the PMMA cement.Finally,the performance changes under simulated physiological conditions of the cements were tested by a type K thermocouple,scanning electron microscopy(SEM),X-ray diffraction(XRD),micro-computed tomography(m-CT),calcium ion test kit and mechanical compression tests.Results:It is shown that CS-GP thermo-sensitive hydrogel effectively decreased the Tmax,prolonged the working time,created irregular pores,enhanced the antibacterial activity and led to appropriate mechanical properties of the cements.Furthermore,the incorporated nano-HA particles sufficiently increase the mineralization capacity of the cement without compromising its mechanical properties and the incorporated GM remarkably enhances the anti-bacterial activity of the cement.Conclusion:The injectable and multi-functional p-PMMA/CS-GP/nano-HA/GM cement will hold strong promise for future bone reconstruction applications with easy handling property,proper mechanical performance,favorable biomineralization capacity and effective infection-resist ability.Part ? Evaluation of an injectable and smart polymethylmethacrylate cement functionalized with chitosan-poly(vinyl alcohol)thermo-sensitive hydrogel,nano-sized hydroxyapatite and silver ionsObjective:Based on the previous model,we want to develop another type of versatile PMMA based cements to overcome the antibiotic-resistant bacteria and investigate their clinic-related properties.Materials and Methods:Osteoconductive nano-sized hydroxyapatite(Nano-HA)and silver ions(Ag+)were initially loaded into chitosan-poly(vinyl alcohol)(CS-PVA)thermo-sensitive hydrogel.Then the extracellular matrix(ECM)-like hydrogel was mixed with PMMA acting as a pore-forming agent to optimize the final bulk behaviors of the PMMA cement.Finally,the performance changes under simulated physiological conditions of the cements were tested by a type K thermocouple,scanning electron microscopy(SEM),X-ray diffraction(XRD),micro-computed tomography(m-CT),calcium ion test kit and mechanical compression tests.Results:It is shown that CS-PVA thermo-sensitive hydrogel effectively decreased the Tmax,prolonged the working time,created irregular pores,enhanced the antibacterial activity and led to appropriate mechanical properties of the cements.Furthermore,the incorporated nano-HA particles sufficiently increase the mineralization capacity of the cement without compromising its mechanical properties and the incorporated Ag+ remarkably enhances the anti-bacterial activity of the cement.Conclusion:The injectable and multi-functional p-PMMA/CS-PVA/nano-HA/Ag+cement has easy handling property,proper mechanical performance,favorable biomineralization capacity and effective infection-resist ability.Part ? A versatile and injectable poly(methyl methacrylate)cement functionalized with quaternized chitosan-glycerophosphate/nano-sized hydroxyapatite hydrogelObjective:To improve the complicated system and overcome the drawbacks of antibacterial agents,we want to develop another type of versatile PMMA based cements and investigate their clinic-related properties.Materials and Methods:Osteoconductive nano-sized hydroxyapatite(Nano-HA)was initially loaded into quaternized chitosan-glycerophosphate(HTCC-GP)thermo-sensitive hydrogel.Then the extracellular matrix(ECM)-like hydrogel was mixed with PMMA acting as a pore-forming agent to optimize the final bulk behaviors of the PMMA cement.Finally,the performance changes under simulated physiological conditions of the cements were tested by a type K thermocouple,scanning electron microscopy(SEM),X-ray diffraction(XRD),micro-computed tomography(m-CT),calcium ion test kit and mechanical compression tests.Results:It is shown that HTCC-GP thermo-sensitive hydrogel effectively decreased the Tmax,prolonged the working time,created irregular pores,enhanced the antibacterial activity and led to appropriate mechanical properties of the cements.Furthermore,the incorporated nano-HA particles sufficiently increase the mineralization capacity of the cement without compromising its mechanical properties.Conclusion:The injectable and multi-functional p-PMMA/HTCC-GP/Nano-HA cement simplified the system,overcome the drawbacks of antibacterial agents and hold easy handling property,proper mechanical performance,favorable biomineralization capacity and effective infection-resist ability.