早期生物矿化过程中紫外吸收动力学曲线上的负峰现象

近年来, Jens等1]利用紫外光度法测定生物矿化溶液的吸光度(即混浊度)的变化, 实时地记录生物矿物形成过程的信息, 从而研究其矿化规律. 实验发现, 胶原/羟基磷灰石矿化的紫外吸收动力学曲线并不是胶原和磷酸钙沉淀混浊度的简单迭加, 而是一条平滑的阶梯形曲线, 它反映了有机相和无机相相互作用的过程特征. 在采用紫外光度法研究生物矿化过程中首次发现, 阶梯形矿化曲线上还有更精细的变化: 在一定条件下, 矿化曲线起峰时出现一个负峰. 本文还研究了磷酸钙浓度、胶原浓度及入射光波长对该负峰峰位和峰值的影响. 研究该负峰与系统参数的相关性, 对于了解早期生物矿化的机理和优化新型骨及牙齿等组织工程框架材料的制备工艺2]都具有重要的意义.

A Phenomenon of Negative Peak Appeared in Kinetic Ultraviolet Absorb Curve of Initial Biomineralization

The ultraviolet photometry is an effective method to investigate the kinetic process of biomineralization because it can be used to monitor the reaction in real time without disturbance. This paper reports an interesting phenomenon in experiment on collagen mineralization. An abnormal negative peak was found in kinetic ultraviolet absorb curve of collagen/calcium phosphate biomineralization system in Tris-HCl buffer(pH=7.4). Influence of several experiment conditions on the negative peak was studied. SEM observation of the sample before and after the negative peak revealed that the crystals morphology and the aggregation of the mineralized collagen fibers are different. It indicated that the negative peak in the kinetic curve is an optical phenomenon related to the compositional and structural change of the mineral, which are the important elements in biomineralization mechanism study.