Zuo Yi

A study on nano-composite of hydroxyapatite and polyamide

A new kind of nano-composite of nano-hydroxyapatite (n-HA) and polyamide8063 (PA) was prepared directly using nano-hydroxyapatite slurry and co-solution method under normal atmospheric pressure. The results show that the n-HA content in the composite can reach 65 wt%, similar to the apatite content in natural bone. Interface chemical bonding forms between n-HA and polyamide, the n-HA keeps the original morphological structure with a crystal size of 10–30 nm in diameter by 50–90 nm in length with an aspect ratio of 2.5, and distributes uniformly in the composite. The synthetic nano-composite could be one of the best bioactive materials for load-bearing bone repair or substitution.

Synthesis and properties of a copolymer of poly(l,4-phenylene sulfide)–poly(2,4-phenylene sulfide acid) and its nano-apatite reinforced composite

Abstract A new kind of copolymer of poly(1,4-phenylene sulfide)–poly(2,4-phenylene sulfide acid) (PPS–PPSA) and its nano-apatite (NA) composite have been obtained by polycondensation in l-methly-2-pyrrolidone (NMP). The NA content in the composite can reach 60 wt.%. The structures and properties of copolymer and its NA composite were studied though infrared spectroscopy. X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy. The copolymer has high molecular weight and excellent thermal properties. There is a stable interface formed between NA and PPS–PPSA copolymer in the composite. NA keeps the original morphological structure and crystal behavior in the composite. The composites have good homogeneity and outstanding thermal stability. NA particles are uniformly distributed in the composite. The diameter of apatite in the composite is about 40–60 nm. The PPSA in the copolymer can increase the affinity to apatite and does not decrease the melting point and thermal stability of copolymer.

Development of Nanohydroxyapatite/Polycarbonate Composite for Bone Repair:

In this study, nano-hydroxyapatite (n-HA) combined polycarbonate was synthesized by a novel method. The physical and chemical property of the composite was tested. The results indicated the n-HA a crystal has the similar grain size, phase composition and crystal structure as. TEM photos results show the n-HA crystals were uniformly distributed in the polymer matrix. Then, the chemical bond between inorganic n-HA and polycarbonate was investigated and discussed. Proliferation of MSCs/composite cultured for up to 11 days the adhesion were tested by MTT and SEM. The in vitro test confirmed that the n-HA/PC composite was biocompatible and no negative effect on MSCs has found. The composite is proved to be osteoconductive, and can stimulate the growth of new bone. These results indicated that the composite meet the basic requirement of bone substitute material, and be potentially applied for clinic.In this study, nano-hydroxyapatite (n-HA) combined polycarbonate was synthesized by a novel method. The physical and chemical property of the composite was tested. The results indicated the n-HA a crystal has the similar grain size, phase composition and crystal structure as. TEM photos results show the n-HA crystals were uniformly distributed in the polymer matrix. Then, the chemical bond between inorganic n-HA and polycarbonate was investigated and discussed. Proliferation of MSCs/composite cultured for up to 11 days the adhesion were tested by MTT and SEM. The in vitro test confirmed that the n-HA/PC composite was biocompatible and no negative effect on MSCs has found. The composite is proved to be osteoconductive, and can stimulate the growth of new bone. These results indicated that the composite meet the basic requirement of bone substitute material, and be potentially applied for clinic.

In vitro and in vivo evaluation on the bioactivity of ZnO containing nano-hydroxyapatite/chitosan cement.

A ZnO containing nano-hydroxyapatite/chitosan (n-HA/CS) cement was developed and its bone formation ability was investigated in vitro and in vivo. The physico-chemical properties of the cement were determined in terms of pH variation during and after setting, injectability and wettability. The results indicated that, the pH varied from 7.04 to 7.12 throughout the soaking of the cement in distilled water. The injectability was excellent during the first 4 min, but the cement became less injectable or even not injectable at all after 7 min setting. The static contact angle of the cement against water was 53.5 +/- 2.7 degrees . The results of immersion tests in simulated body fluid (SBF) indicated that the cement exhibited excellent bone-like apatite forming ability. In vivo studies, involving the installation of the cement of tibial-bone defects in rabbit tibia revealed an inflammatory response around the cement at 3 days of implantation. After 4 weeks, the inflammation began to disappear and the cement had bound to the surrounding host bone. Radiological examination also confirmed that the ZnO containing n-HA/CS cement significantly induced new bone formation. These results suggest that the ZnO containing n-HA/CS cement may be beneficial to enhance bone regeneration in osseous defect sites.