Bioorthogonal Strategies for Targeted PET Imaging Probe Development

描述（由申请人提供）：本提案的总体目标是开发新的方法来实现用PET示踪剂对肽和肽拟物进行位点选择性标记。新的策略将基于结合生物正交标记的非天然氨基酸通过固相肽合成方案。由此产生的放射性标记肽将被并行评估，并在动物成像实验中进一步测试候选物。候选人Thomas Reiner在定量科学，特别是合成有机金属和有机化学方面拥有丰富的经验。他以前研究过生物正交策略。他将把他的技能应用到这种转化方法中，这是有机合成，生物学和生物医学成像的接口。技术和方案的成功发展使得生物正交标记能够选择性地结合到多肽中，并对其相应的放射性标记版本进行并行评估，这将是生物医学成像研究的重要一步，极大地促进了诊断性放射性标记探针的设计、评估和最终的临床转化。候选人的长期目标是开发新颖和更有效的方法，允许PET标记显像剂与靶向生物分子的偶联。这项工作将在纪念斯隆-凯特琳癌症中心放射科进行，由Jason Lewis博士指导。Hedvig Hricak博士和Wolfgang Weber博士都是临床前和临床影像研究方面的专家，他们将担任共同导师。咨询委员会的成员完全致力于指导候选人的研究培训，使他能够发展成为一名独立的生物医学研究人员，并取得成功。本提案的具体目的是首先合成四氮和反式环烯氨基酸，然后将它们掺入生长抑素类似物中，生成生物正交标记肽库。然后，利用平行生物正交组装和纯化技术将这些肽转化为相应的18F， 89Zr和64Cu标记版本。高亲和力和选择性肽将随后在癌症动物模型中进行测试。在这里，四氮和反式环烯氨基酸不仅可以快速和选择性地合成，而且可以快速地纯化放射性标记肽，促进多重平行合成放射性标记肽库。被击中的候选人将根据他们的表现进行评估

DESCRIPTION (provided by applicant): The broad goal of this proposal is to develop novel methodologies to achieve site-selective labeling of peptides and peptidomimetics with PET tracers. The novel strategies will be based on the incorporation of bioorthogonally labeled unnatural amino acids via solid phase peptide synthesis protocols. The resulting radiolabeled peptides will be evaluated in parallel, and hit candidates further tested in animal imaging experiments. The candidate, Thomas Reiner, has extensive experience in the quantitative sciences, specifically synthetic organometallic and organic chemistry. He has worked on bioorthogonal strategies before. He will apply his skillset to this translational approach, which i at the interface of organic synthesis, biology and biomedical imaging. The successful development of techniques and protocols which allow site-selective incorporation of bioorthogonal labels into peptides, as well as the parallelized evaluation of their corresponding radiolabeled versions will represent a major step in biomedical imaging research, greatly facilitating design, evaluation, and ultimately clinical translation of diagnosic radiolabeled probes. The long term goal of the candidate is to develop novel and more efficient methodologies which allow conjugation of PET labeled imaging agents to targeted biomolecules. This work will be performed at the Department of Radiology of Memorial Sloan-Kettering Cancer Center under the mentorship of Dr. Jason Lewis. Both Dr. Hedvig Hricak and Dr. Wolfgang Weber, who are experts in preclinical and clinical imaging research, will serve as co-mentors. The members of the advisory committee are fully committed to the mentored research training of the candidate, allowing him to develop a strong and successful career as an independent biomedical researcher. The specific aims of this proposal are to first synthesize tetrazine and trans-cyclooctene amino acids, followed by their incorporation into somatostatin-analogs, generating a library of bioorthogonally labeled peptides. Then, these peptides will be converted into their corresponding 18F, 89Zr and 64Cu labeled versions by utilizing parallel bioorthogonal assembly and purification techniques. High affinity and selectivity peptides will subsequently be tested in animal models of cancer. Here, tetrazine and trans-cyclooctene amino acids will not only allow the fast and selective synthesis, but also the rapid chromatography free purification of radiolabeled peptides, facilitating multiplexed parallel synthesis of radiolabeled peptide libraries. Hit candidates will be evaluated for their performance as targeted probes in animal models of cancer. If successful, these new technologies will allow the rational and high-throughput evaluation of targeted peptidic PET probes, streamlining their development and increasing the chances of successful outcomes. The design of radiolabeled targeted peptides via tetrazines/trans-cyclooctenes could become a standard technique for preclinical biomedical imaging and ultimately clinical research.