Biomimetic mineralization synthesis of hydroxyapatite bacterial cellulose nanocomposites

Hydroxyapatite (HAp)/bacterial cellulose (BC) nanocomposites were prepared by an optimal biomimet ic mineralization synthesis approach for bone tissue engineering application. BC wi th ultrafine three dimensional network was negatively charged by the adsorption of polyvinylpyrrolidone (PVP) to initiate the nucl eation of HAp. The HAp was grown in vitro along the nanofiber network of BC via dynamic simulated body fluid (SBF) treatment. It was found that rod-like HAp particles in the nano-scale (100 ? 200 nm) homogeneously deposited on the surface of PVP-BC. AT R-Fourier Transform Infrared Spectroscopy (ATR-FTIR) results showed that carbonate-containing HAp crystals resembling natural bones were fo rmed by biomimetic mineralization method. Moreover, the amount of HAp observed increased with increasing mineralization time. And the Ca/P overall ratio ranged from 1.37 to 1.59. The results from Inductively Coupl ed Plasma Atomic Emission Spectroscopy (ICP-AES) indicated that PVP treatment enhanced the apatite nucleation ability of BC with higher HAp deposit amount.     

无创血氧饱和度传感系统的研究

分析了光通过人体组织的传输特性,提出了无创在体监测血氧饱和度的原理和方法.基于这种方法,研制了无创血氧饱和度传感系统.临床使用表明,本传感系统与传统的血气分析仪有很好的一致性,相关系数达到0.984.