人体仿生消化道在生物可利用性微量金属体外测量样品前处理中应用

体外测量生物可利用性微量金属是经口摄入环境样品危险性和食品药品有效性评价关键共性难题。.项目据“消化酶、有机无机成分、酸度、体温、节律性蠕动、肠道微生物代谢”等要素设计人体消化器官(口腔、胃、小肠、大肠)“消化、转运、代谢”功能，将样品中金属转为生物可给性金属；据“消化道细胞膜、光催化剂、金属吸附剂、磁载体”等功能设计，按“磷酸基链式键合+范德华力亲合吸附成膜+冻融”法合成Fe3O4@SiO2@TiO2@双层脂质体，创新性实现：(1)双层脂质体萃取、透过，与纳米TiO2吸附协同，同时模拟金属被动和主动跨膜转运,建立最接近消化道主要吸收模式的新模型,(2)脂质膜隔离、磁分离集聚、光催化降解有机物(含金属配体和脂质体)协同处理样品，消除干扰,(3)光催化转化生物可利用性金属为易洗脱和易检测的金属离子。.项目可提供全器官全功能全模拟的人体仿生消化道和生物可利用性金属体外测量样品前处理技术。

The bioavailability of trace metals in food, drug or environmental samples via intentional and unintentional oral intake is the key and common technical challenge..A biomimetic gastrointestinal tract, including oral, stomach, small intestine, and colon, will be designed on the basis of human physiology, i.e., digestive enzymes, organic and inorganic components, acidity, body temperature, rhythmic peristalsis, digestion time and gut microbiomes. After in vitro digestion and gut microbial metabolism, the sample will be transformed into the chyme and then the bioaccessible metals will released from the samples into gastrointestinal tract..A multifunctional nanocomposite, Fe3O4@SiO2@TiO2@liposomes bilayer membrane, will be prepared by nucleophilic bond between phosphoryl and hydroxyl groups from liposomes and TiO2, film formation via affinity adsorption of hydrocarbon chains from liposomes, and then will be proposed as a absorption model of cell membrane from digestive tract, magnetic carrier, photocatalyst, and metal adsorbent. Metal absorption via both passive and active transmembrane transport will be simulated simultaneously by extraction and permeation with liposomes bilayer membrane, adsorption with TiO2. After the segregation with liposomes bilayer membrane, magnetic separation, and photodegradation of organic compounds (including metal organic ligands, liposomes and so on), the interference will be eliminated, and the metal complexes will be transformed into metal ions which can be eluted and detected easily. The metal bioavailability can be measured by metal transmembrane transport and subsequent selective metal detection..A new sample pretreatment method for in vitro measurement of metal bioavailability, using biomimetic gastrointestinal tract organs and functions, and TiO2-based multifunctional nanocomposites, will be offered by our project.