Mechanical Behaviour of Composite Bioactive Bone Cements Consisting of Two Different Types of Surface Treated Hydroxyapatite as Filler

Bioactive bone cements based on a paste-paste system for orthopaedic applications were developed consisting of hydroxyapatite （ HA ） filler panicles in a methacrylate matrix comprising urethane dimethacrylate （ UDMA ） and triethylene glycol dimethacrylate （ TEGDMA ）. To improve the interface between inorganic filler and organic matrix the HA panicles were subjected to two different surface treatment methods, using polyacrylic acid （PAA） and γ-methacryloxy propyl trimethoxy silane （γMPS）. The aim of the present study was to determine the influence of surface treatment and the inclusion of multifunctional methacrylates on the mechanical properties, namely 3-point flexural strength （FS） and fracture toughness of the cements and the effect of ageing in simulated body fluid. Comparing the mechanical properties of the two cements, the γMPS- HA cement showed that the fracture toughness of the experimental bone cements were significantly greater （ p 〈 0.001） compared to that of the PMMA cement, whereas PAA-HA containing cement had strength vollues around 20% lower. Interestingly, PAA was found to be more effective in improving the interface as the PAA treated HA cement （ UTHAPPA ） maintained its strength on immersion in SBF, suggesting that PAA provided a coupling, which was less sensitive to moisture, a similar trend was also observed with the inclusion of the carboxyl containing multifunctional methacrylates.

Development and clinical trial of a novel bioactive bone cement

Strontium(Sr)and related compounds have become more attractive in the prevention and treatment of osteoporosis.Previously,we developed a novel bioactive bone cement which is mainly composed of strontium-con-taining hydroxyapatite(Sr-HA)filler and bisphenol A diglycidylether dimethacrylate(Bis-GMA)resin.This bone cement is superior to conventional polymethylmethacrylate(PMMA)bone cement in bioactivity,biocompatibility,and osseointegration.It also has shown sufficient mechanical strength properties for its use in percutaneous vertebro-plasty(PVP)and total hip replacement(THR).In this paper,we review the in vitro,in vivo and clinical evidence for the effectiveness of this bioactive bone cement.

Development of methods for detecting the fate of mesenchymal stem cells regulated by bone bioactive materials

The fate of mesenchymal stem cells(MSCs)is regulated by biological,physical and chemical signals.Developments in biotechnology and materials science promoted the occurrence of bioactive materials which can provide physical and chemical signals for MSCs to regulate their fate.In order to design and synthesize materials that can precisely regulate the fate of MSCs,the relationship between the properties of materials and the fate of mesenchymal stem cells need to be clarified,in which the detection of the fate of mesenchymal stem cells plays an important role.In the past 30 years,a series of detection technologies have been developed to detect the fate of MSCs regulated by bioactive materials,among which high-throughput technology has shown great advantages due to its ability to detect large amounts of data at one time.In this review,the latest research progresses of detecting the fate of MSCs regulated by bone bioactive materials(BBMs)are systematically reviewed from traditional technology to high-throughput technology which is emphasized especially.Moreover,current problems and the future development direction of detection technologies of the MSCs fate regulated by BBMs are prospected.The aim of this review is to provide a detection technical framework for researchers to establish the relationship between the properties of BMMs and the fate of MSCs,so as to help researchers to design and synthesize BBMs better which can precisely regulate the fate of MSCs.