Synthesis and characterization of gelatin-CaO-SiO2-TiO2 bioactive hybrid applied in bone repairing

Hairong YIN; Lihua WU; Jigen DING; Gaoyang ZHAO; Guanghua ZHANG

ABSTRACT

BACKGROUND:

It has been reported that bioactivity is found to be favored by the co-operative behavior of silanol (Si-OH)or Ti-OH etc. groups on the material surface and the involved calcium ions. To confirm the hypothesis that a new family of organic-inorganic hybrid materials, which incorporate gelatin chains covalently into Si-O-Ti network, is synthesized through sol-gel procedure.

OBJECTIVE:

To synthesize a hybrid of gelatin and CaO-SiO2-TiO2 system which is used for bone repairing, and observe its structure and bioactivity.

DESIGN:

Randomized control observation.SETTING; the laboratory, School of Material Science and Engineering, Shaanxi University of Science and Technology. MATERIALS Gelatin (Sinopharm Chemical Reagent Co., Ltd), titanic acid isopropyl ester (Gu'an Hengye Fine Chemicals Co., Ltd), γ-glycidoxy propyl trimethoxy silane (Jingzhou Jianghan Fine Chemicals Co., Ltd), calcium nitrate (Tianjin Bodi Chemicals Co., Ltd)

METHODS:

The experiment was carried out in the laboratory, School of Materials Sciences and Engineering, Shaanxi University of Science and Technology between April and August in 2006. A new type of bioactive organic-inorganic hybrid was synthesized through sol-gel processing starting from gelatin, γ-(2,3-glycidoxypropyl)trimethoxysilane (GPSM),Tetraisopropyltitanate (TiPT) and calcium nitrate. ①Structure of the hybrid The structures of the products were investigated with Fourier transformed infrared (FT-IR) diffusive reflection spectroscope, X-ray diffraction (XRD) instrument and scanning electron microscope (SEM) respectively.②Bioactivity The products Ti15Ca0 and Ti15Ca20 were soaked in a stimulated body fluid (SBF) to evaluate the morphology of the surfaces by SEM and thin-film XRD. MAIN OUTCOME

MEASURES:

The structure and bioactivity of the hybrid.

RESULTS:

①The hybrid was completely amorphous and its surface was almost homogenous, which implied the covalent bonding between the organic component and inorganic component. FT-IR spectra result verified the occurrence of Si-OH group and Si-O-Ti bond, as well as the addition of TiPT supplied Si-O-Ti bond. ②There were lots of apatite crystallines formed on the surface of hybrid Ti15Ca20 after soaked in SBF for 7 days, which confirmed their in vitro bioactivity. These apatite particles were similar to the bioglass and other bioactive materials in the patterns.

CONCLUSION:

A new type of organic-inorganic hybrid material, which incorporates gelatin chains covalently into Si-O-Ti network, is synthesized through sol-gel procedure. There are lots of apatite and brushite crystals formed on the surface of the product Ti15Ca2O after soaking in SBF for 7 days, which obviously proves the bioactivity of the hybrid.