Application of polyvinyl alcohol in biomedical engineering / 生物医学工程学杂志

This paper explicated the present application of poly- vinyl alcohol (PVA) in the field of biomedical engineering, such as artificial cartilage, drug delivery systems, microorganism enwrapping, cell micro-capsulation, anti-thrombin materials, and biomedical sponges. And a preliminary study of the good dispersion of PVA as a surfactant on nano-particles of hydroxyapatite was presented.

Microencapsulation of immortalized mandibular condylar chondrocytes / 生物医学工程学杂志

To explore the possibility of microencapsulation of chondrocytes in cartilage tissue engineering, immortalized manibular condylar chondrocytes (IMCCs) were microencapsuled by Alginate-polylysine-alginate (APA) method, according to air pressure shearing model. Phase contrast microscopy, trypan blue staining exclusion, cell number counting, HE staining and immunohistochemistry method were used to observe the morphology of the microencapsules, the growth character of cells, cartilage characteristics, and so on. The results showed that IMCC could survive and grow in microencapsule, and the viability rate of cells is more than 80 per cent. The diameter of microcapsule is 779 microns in average. The number of cell increased with time, and cells went into platform in about 20 days. Cells grew in clusters and cartilage specific proteoglycans and type II collagen were highly expressed. It was concluded that IMCC could form cartilage-like tissue within microencapsulation, implying that microencapsule technique might be applicable to cartilage tissue engineering.

Sintering character of nanocrystal calcium-deficient apatite / 实用口腔医学杂志

Objective:To study the sintering character of calcium-deficient apatite.Methods:Calcium-deficient apatite synthesised by wet chemical method was sintered at different temperature and then its chemical composition, phase structure and morphology were examined by FT-IR spectroscopy, X-ray diffraction (XRD) and field emission scanning microscopy (FESEM) respectively.Results:When the heating temperature is below 500 ℃, apatite crystal kept a stable size with a diameter of 12-26 nm and a length of 30-66 nm. After sintered at 600 ℃ for 2 h, apatite crystal were with a diameter of 25-40 nm and a length of 75-100 nm. Around 800 ℃ for 2 h, apatite was decomposed into Ca_3(PO_4)_2.The crystal size of the Ca_3(PO_4)_2 surpassed 200 nm in diameter and length. NH_4+ ion could be removed at temperature beyond 300 ℃.Conclusion: Calcium-deficient apatite has it's specific sintering character.