Long-Lasting Bioluminescence Imaging of the Fibroblast Activation Protein by an Amphiphilic Block Copolymer-Based Probe
Long-Lasting Bioluminescence Imaging of the Fibroblast Activation Protein by an Amphiphilic Block Copolymer-Based Probe
复制标题
通过基于两亲性嵌段共聚物的探针对成纤维细胞激活蛋白进行持久生物发光成像
DOI：
10.1021/acs.analchem.0c03638
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发表时间：
2021-02-18
影响因子：
7.4
通讯作者：
Yang，Ronghua
中科院分区：
文献类型：
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作者：
Zhou，Yibo;Yin，Keyi;Yang，Ronghua
成纤维细胞激活蛋白(FAP)的长期特异性示踪非常重要，因为它在多种疾病的间质成纤维细胞中大量表达，而且与FAP相关的几种疾病是慢性的。生物发光成像检测FAP具有不需要外界激发的优点，但目前的生物发光探针是通过共价掩蔽萤火虫荧光素酶底物而构建的，很容易从动物体内分泌出来，从而导致FAP的瞬时生物发光成像。为了解决这一问题，开发了一种基于多肽连接的两亲性嵌段共聚聚合物探针(PABC)，并将其应用于FAP在体内的长时间BL图像。为此，制备了一种含有FAP响应肽的两亲性嵌段共聚物，以自组装成胶束，胶束作为一个储存库来负载大量的d-荧光素，以构建BL探针。当与FAP反应时，胶束将被破坏，通过荧光素酶催化的反应释放内含的d-荧光素以发射蓝光。利用胶束的高负载性，FAP的检测范围为0.50~10 ng/m L，检出限为0.105 ng/m L，高灵敏度使其具有区分癌细胞和正常细胞的能力。重要的是，与游离荧光素相比，PABC可用于在活细胞和体内持续成像FAP。这种对FAP的持久特异性示踪的特点使我们可以预见，这种BL探针将来可以用于FAP抑制剂的筛选和各种FAP相关疾病的诊断。
Long-term specific tracing of the fibroblast activation protein (FAP) has been of great importance because it is heavily expressed by stromal fibroblasts of multiple diseases, and several disorders associated with FAP are chronical. Bioluminescence (BL) imaging has its advantages to detect FAPin vivosince no external excitation is required, but the current FAP-responsive BL probe was constructed by covalently masking the firefly luciferase substrate and easily secreted out from the animal, resulting in transient BL imaging of FAP. To circumvent this problem, a peptide-linked amphiphilic block copolymer-based probe (PABC) was developed and applied to the long-lasting BL image of FAPin vivo. For this purpose, an amphiphilic block copolymer containing an FAP-responsive peptide was fabricated to self-assemble into micelles, which act as a depot to load amounts ofd-luciferin for constructing the BL probe. Upon reaction with FAP, the micelle would be destroyed to release the internald-luciferin for BL emission by a luciferase-catalyzed reaction. By virtue of the high loading capability of micelles, the FAP was determined from 0.5 to 10 ng/mL with a detection limit of 0.105 ng/mL, and the high sensitivity makes the PABC capable of distinguishing cancer cells from normal ones. Importantly, compared with freed-luciferin, PABC can be used to persistently image the FAP in living cells andin vivo. This characteristic of long-lasting specific tracing of the FAP makes us envision that this BL probe could be used for screening of FAP inhibitors and diagnosing various FAP-related diseases in future.