肿瘤标记物亲和肽库的微流控-质谱联用筛选及原位鉴定分析

Peptide drugs and probes have important application values in cancer diagnosis and treatment. Screening out peptides with high specificity and high affinity towards tumor markers has become a key point in biomedical research field. Traditional target peptide screening techniques are always multi-step, long-period, low-efficiency and difficult to realize on-line characterization. According to the above mentioned problems, a novel microfluidic system, which integrates on-line sorting and in-situ identification, is to be constructed in order to screen target peptide against tumor markers from the high-throughput combinatorial libraries. Continuous flow microfluidic chip is going to be designed and fabricated in order to sort "one bead one compound" peptide libraries and separate the target beads automatically. Furthermore, a microarray chip with microcavities is to be series connected for continuous beads trapping, on-line cleavage and single bead detection by combining with matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Based on the optimized microfluidic system, combinatorial peptide libraries towards a tumor marker epithelial cell adhesion molecule (EpCAM) are to be designed and synthesized. High-efficiency and high-throughput peptide screening against EpCAM and in-situ identification will be performed in the microfluidic system. The method proposed in this project provide new ideas for lead compound screening on cancer diagnosis and treatment. What's more important is that this universal method is suitable for peptide screening towards almost any receptor proteins. It is also expected to become an effective tool for high-throughput screening of various drugs and probes.

多肽药物和探针在肿瘤治疗、癌症诊断等方面具有重要应用价值。寻找针对肿瘤标记物高特异、高亲和的活性多肽已成为生物医药研究的关键问题。为改进传统肽库筛选方法步骤多、周期长、效率低、难于在线鉴定等瓶颈问题,本项目创新地建立了具有在线分选与原位鉴定功能的微流控芯片系统，用于从组合化学肽库中高通量筛选可识别肿瘤标记物的靶向多肽。设计连续流动微流控芯片，通过标记磁珠对高通量"一珠一物"肽库进行分选，实现阳性肽珠的自动化富集；进一步集成微点阵芯片并与基质辅助激光解吸电离-飞行时间质谱联用，可对阳性肽珠进行连续捕获、单珠容纳、在线裂解与原位鉴定。针对肿瘤标记物EpCAM蛋白胞外结构域设计并合成组合化学肽库，进行靶向多肽的高效、高通量筛选与鉴定。本项目提出的方法为用于癌症治疗及诊断的多肽筛选提供新的思路。该方法的普适性可用于几乎任意受体蛋白对靶向多肽的筛选，使得其有望成为药物、探针高通量筛选的有效工具。

小分子多肽探针在肿瘤治疗、癌症诊断等方面具有重要应用价值。寻找针对肿瘤标记物高特异、高亲和的活性多肽已成为生物医药研究的关键问题。为改进传统肽库筛选方法步骤多、周期长、效率低、难于在线鉴定等瓶颈问题,本项目创新地建立了具有在线分选与原位鉴定功能的微流控芯片系统，用于从组合化学肽库中高通量筛选可识别肿瘤标记物的靶向多肽。设计连续流动微流控芯片，通过标记磁珠对高通量"一珠一物"肽库进行分选，实现阳性肽珠的自动化富集；进一步集成微点阵芯片并与基质辅助激光解吸电离-飞行时间质谱联用，可对阳性肽珠进行连续捕获、单珠容纳、在线裂解与原位鉴定。针对一系列肿瘤标记物如HER2、APN、EpCAM及VEGFR2等蛋白，设计合成组合化学肽库，实现靶向多肽的高效、高通量筛选与鉴定，获得了一系列具有高亲和力的肿瘤靶向多肽探针。利用这些多肽探针对纳米材料进行功能化，成功实现了活体内的靶向成像、载药以及示踪研究。