title: Preparation and in vitro evaluation of strontium-doped calcium silicate/gypsum bioactive bone cement.
abstract: The combination of two or more bioactive components with different biodegradability could cooperatively improve the physicochemical and biological performances of the biomaterials. Here we explore the use of α-calcium sulfate hemihydrate (α-CSH) and calcium silicate with and without strontium doping (Sr-CSi, CSi) to fabricate new bioactive cements with appropriate biodegradability as bone implants. The cements were fabricated by adding different amounts (0-35 wt%) of Sr-CSi (or CSi) into the α-CSH-based pastes at a liquid-to-solid ratio of 0.4. The addition of Sr-CSi into α-CSH cements not only led to a pH rise in the immersion medium, but also changed the surface reactivity of cements, making them more bioactive and therefore promoting apatite mineralization in simulated body fluid (SBF). The impact of additives on long-term in vitro degradation was evaluated by soaking the cements in Tris buffer, SBF, and α-minimal essential medium (α-MEM) for a period of five weeks. An addition of 20% Sr-CSi to α-CSH cement retarded the weight loss of the samples to 36% (in Tris buffer), 43% (in SBF) and 54% (in α-MEM) as compared with the pure α-CSH cement. However, the addition of CSi resulted in a slightly faster degradation in comparison with Sr-CSi in these media. Finally, the in vitro cell-ion dissolution products interaction study using human fetal osteoblast cells demonstrated that the addition of Sr-CSi improved cell viability and proliferation. These results indicate that tailorable bioactivity and biodegradation behavior can be achieved in gypsum cement by adding Sr-CSi, and such biocements will be of benefit for enhancing bone defect repair.
authors.affiliation: Department of Orthopedics, Rui'an People's Hospital & the 3rd Hospital Affiliated to Wenzhou Medical University, Rui'an 325200, People's Republic of China.
authors.forename: Juncheng
authors.initials: J
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Sun
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Chen
authors.forename: Kailuo
authors.initials: K
authors.lastname: Xie
authors.forename: Mian
authors.initials: M
authors.lastname: Lin
authors.forename: Guojing
authors.initials: G
authors.lastname: Yang
authors.forename: Sanzhong
authors.initials: S
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.forename: Zhongru
authors.initials: Z
authors.lastname: Gou
mesh_terms: D020341:Absorbable Implants; D001031:Apatites / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D001843:Bone Cements / Q000737:chemistry*; D002021:Buffers; D017610:Calcium Compounds / Q000737:chemistry*; D002133:Calcium Sulfate / Q000737:chemistry*; D049109:Cell Proliferation; D002470:Cell Survival; D003470:Culture Media; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology; D011208:Powders; D017640:Silicates / Q000737:chemistry*; D013314:Stress, Mechanical; D013324:Strontium / Q000737:chemistry*; D013499:Surface Properties; D013778:Tetrazolium Salts / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D001843:Bone Cements; D002021:Buffers; D017610:Calcium Compounds; D003470:Culture Media; D007477:Ions; D011208:Powders; D017640:Silicates; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue; C031293:calcium silicate; D002133:Calcium Sulfate; D013324:Strontium