Papers by Author: Jiang Chang

Abstract: Poly(butylenes succinate) (PBSU) had good biocompatibility and biodegradability, but it is left unexplored for the possible application of PBSU in tissue engineering. The aim of this study was to compare PBSU and poly (lactide-co-glycolide) (PLGA) scaffolds prepared by electrospinning technique as vascular tissue engineering materials. Both scaffolds were characterized by fiber morphology, pore structure and mechanical properties. Smooth muscle cells (SMCs) and endothelial cells (ECs) were seeded on the electrospun PBSU and PLGA scaffolds and cultured for different time periods. Cell adhesion and proliferation on the scaffolds were measured by MTT assay, while SEM was used for observing cell morphology on the scaffolds. The results showed that fiber diameter of the electrospun scaffolds ranged from 300nm to 800nm and their porosities were higher than 90%. The electrospun PBSU scaffolds showed a high tensile strength of 2.06±0.11MPa, whereas the ultimate tensile strength of the electrospun PLGA scaffolds reached 14.31±5.24MPa. Cell adhesion efficacy had no significant difference between PBSU and PLGA scaffolds, but cell proliferation rate on PLGA scaffolds was significantly higher than that on PBSU scaffolds after 7 days of culture. Cell morphology was similar on both scaffolds with the polygonal shape for ECs and spindle-like shape for SMCs. From these results, the present in vitro study revealed that as compared to PLGA scaffolds, the electrospun PBSU scaffolds showed lower tensile strength and slower proliferation rate, but as regards the biocompatibility and pore structure, the electrospun PBSU scaffolds had a potential application in vascular tissue engineering.

Abstract: Calcium is generally determined by EDTA titration after separation of phosphate radicals, and the phosphorus is determined by weigh method. This traditional analytical process is time consuming and unfavourable for quality controlling. In contrast, the ICP-AES is simple and fast, and can simultaneously determine multielements. In this paper, the ICP-AES method was used to simultaneously determine calcium and phosphorous in calcium phosphate based bioceramics, and wavelengths of 317.933 nm and 213.618 nm were selected for the measuring of the calcium and phosphorus, respectively. The results obtained by ICP-AES are well consistent with the results determined by the traditional EDTA titration and weigh method, and suggest that the ICP-AES analysis is a simple, fast and accurate method for simultaneous determination of calcium and phosphorous in calcium phosphate based bioceramics.

Abstract: In the present study, Ca2P2O7-doped β-Ca3(PO4)2 bioceramics were fabricated by pressureless sintering process. The effect of Ca2P2O7 on the sintering ability, mechanical strength and degradability of the ceramics were investigated. The results showed that the Ca2P2O7 could apparently decrease the sintering ability and mechanical properties of β-Ca3(PO4)2. Moreover, the relative density and mechanical strength of the sintered samples decreased gradually with the increase of the Ca2P2O7 additive amount. However, the dissolution rate of the samples increased with the increase of the Ca2P2O7 additive amount.

Abstract: Attempt to increase the mechanical properties of porous bioceramics, a dense/porous structured β-TCP bioceramics that mimic the characteristics of nature bone were fabricated. Experimental results show that the dense/porous structured β-TCP bioceramics demonstrated excellent mechanical properties with compressive strength up to 74 MPa and elastic modulus up to 960 MPa, which could be tailored by the dense/porous cross-sectional area ratio obeying the rule of exponential growth. The interface between the dense and porous bioceramics is connected compactly and tightly with some micropores distributed in the matrix of both porous and dense counterparts. The dense/porous structure of β-TCP bioceramics may provide an effective way to increase the mechanical properties of porous bioceramics for bone regeneration at weight bearing sites.

Abstract: In this study, CaSiO3 (CS)/Ca3(PO4)2 (TCP) composites with 50% CS and 50% TCP sintered at different temperatures (1100oC, 1200oC and 1300oC) were prepared. The formation of bone-like apatite on CS-TCP composites was investigated by soaking the ceramics in simulated body fluid (SBF), and the presence of bone-like apatite layer on the composite surface after soaking in SBF was determined by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The results showed that the bone-like apatite was formed on all the CS-TCP composites sintered at different temperatures after 7 days of immersion. In addition, the degradation of CS-TCP composites prepared at different temperatures was evaluated by measurement of weight loss of the ceramics in Tris-HCl buffer solution at 37oC, and the results showed that there was no difference in degradation rate between the samples. In vitro cell experiments indicated that the osteoblasts proliferated faster on the CS-TCP ceramics sintered at higher temperature, and cells on the CS-TCP ceramics sintered at 1300oC showed highest proliferation rate. These results provide valuable information for designing CS-TCP composite bioceramics for bone regeneration applications.

Abstract: fabricated by pressureless sintering process. The effect of BG on the sintering ability and mechanical strength of the ceramics, and the adhesion and proliferation of osteoblasts were investigated. The results showed that the optimum amount of BG was 20wt.% and the samples sintered at 1100oC for 5h revealed a bending strength of 172 MPa, which was approximately 2-times higher than that of the pure CaSiO3 ceramics. The cell experiments showed that BG reinforced CaSiO3 ceramics supported osteoblast adhesion and possessed higher proliferation than that of the pure CaSiO3 ceramics, which indicated excellent biocompatibility. Our results suggested that BG reinforced CaSiO3 ceramics could be potential candidates as bioactive bone implant materials.