Controllable Preparation, Drug Delivery And Antitumor Properties Of Nanometer Hydrotalcite

As chemotherapy drug methotrexate(MTX) can not maintain efficient drug concentration in vivo, the treatment effect of bone tumor is remarkable decreased. One effective way to solve the question above is to build a drug-delivery system, which can locally, persistently and slowly deliver anti-tumor drug. Hydrotalcite-like compounds(LDHs) possess good biocompatibility, non-toxic and drug delivery performance, and have been largely used as drug loader. So loading MTX via LDHs may be a feasible way to treat osteosarcoma.In this paper, LDHs intercalated with carbonate(LDHs-C) was synthesized through coprecipitation, and LDHs intercalated with nitrate, silicate and phosphate(LDHs-N, LDHs-Si and LDHs-P) were obtained via calcined-recovery separately. Their surface appearance and structure were observed by SEM, TEM, XRD, FTIR, BET and ICP. The four kinds of LDHs own layered structure, lear hexagonal nanosheets appearance, larger specific surface area(LDHs-C 107.407 m2/g,LDHs-N 205.22m2/g 、 LDH-Si 153.538 m2/g and LDH-P 34.634 m2/g), and mesoporous channel due to the accumulation of flake particles. The differences of anions lead to the differences of stability: LDH-Si>LDH-P>LDH-C>LDH-N. So the solubility is also different. They can release Mg2+ and corresponding anions in deionized water.The biocompatibility and osteoinductivity of the specimens were also studied by using human bone marrow stromal cells(h BMSCs) as cell models; the drug loading and release performance were obtained through detecting the concentration variation of MTX solution; the antitumor property of the specimens was studied by using human osteosarcoma cells Saos-2 seeding on LDHs loading with MTX of different concentration. LDHs-C, LDHs-N, LDHs-Si and LDHs-P are safe biomaterials and express good biocompatibility. Also, they presented better MTX loading and releasing effect and osteosarcoma resistance performance compared with Hap. LDHs-Si shows better osteoinductivity and can facilitate the expression of osteoblastic genes.For further studying the clinical possibility, the LDHs/chitosan/carbon fibers(LDHs/CS/CFs) porous scaffold was built. Its surface appearance and structure were observed by SEM, TEM, XRD, FTIR, XPS and TG-DTA. The perfect p H value of preparing LDHs/CS/CFs is 10, where it expresses better morphology. LDHs/CS can load on the CFs uniformly, and LDHs can stand on the CFs vertically. SBF immersion test has been employed to evaluate the in vitro apatite-forming ability of the porous scaffold; the result proved the LDHs/CS/CFs own better apatite-forming ability in vitro. The biocompatibility of the porous scaffold was also studied by using human bone marrow stromal cells(h BMSCs) as cell models. Proliferation and morphology of h BMSCs showed that LDHs/CS/CFs owned better biocompatibility.