Highly Specific and Highly Sensitive Aptamer-Gold Nanoparticle Based NIR Contrast

说明（由申请人提供）：荧光团是光学成像不可或缺的信号介质。如果这种荧光造影剂对靶分子具有特异性并且具有更高的灵敏度，则它可以更有效。金纳米颗粒（GNP）上的表面电磁（等离子体）场可以通过允许人工猝灭/增强荧光而有助于该造影剂具有这些性质。对于分子靶向特定的生物分子，发现适体与单克隆抗体（传统的靶向剂）一样好。适体还具有额外的有益特性，例如更容易和更便宜的生产，更小的尺寸，免疫原性小，等。通过结合荧光团，GNP和适体的有益特性，我们建议开发一种分子信标样纳米实体，用于早期和准确检测侵袭性乳腺癌，具有高灵敏度和特异性;并且还用于同时监测治疗方案的疗效。 待开发的纳米荧光剂是表达MMP-14的乳腺癌类型，MMP-14被认为是具有侵袭性的乳腺癌的标志物。该实体的组成部分包括具有两个胸苷核苷酸序列的乳腺癌靶向适体AS 1411。序列的一端与GNP结合，另一个序列的一端与Cypate（ICG的类似物）（FDA批准的近红外荧光团）缀合。链的长度约为GNP产生Cypate最大荧光的距离的一半。这些链通过MMP-14的底物连接，MMP-14很小，因此使GNP和Cypate非常接近，迫使完全淬灭。最初，该实体发射很少的荧光，因为GNP的强等离子体激元场淬灭荧光。当将其应用于具有侵袭性的乳腺癌患者时，其通过AS 1411受体的靶向位点特异性地递送至乳腺癌。然后 将暴露于肿瘤细胞壁上/中的MMP-14。当基质被MMP-14切割时，Cypate从GNP移动到由链长指定的距离，这导致在激发光应用时高度增强的荧光发射。 我们将这种实体命名为AptaPET（适体-纳米颗粒等离子体能量转移），它允许癌症检测并提供有关癌症性质的信息，对于我们的系统，癌症的侵袭性。通过选择具有治疗特性的特殊适体AS 1411，该实体也可用于检测和治疗。此外，无需进一步修改，AptaPET可以成为X射线/CT的良好造影剂。同样的概念可以用于其他疾病以及其他类型癌症的检测、诊断和预后。

DESCRIPTION (provided by applicant): Fluorophores have been indispensable signal mediators for optical imaging. This fluorescent contrast agent can be more effective if it is specific for the target molecule and with higher sensitivity. The surface electro-magnetic (plasmon) field on the gold nanoparticles (GNPs) can be helpful for this contrast agent to have these properties by allowing artificial quenching/enhancing fluorescence. For molecular targeting particular biomolecules, aptamers are found to be as good as monoclonal antibodies, the traditional targeting agent. Aptamers also have additional beneficial properties, such as easier and cheaper production, smaller size, little immunogenicity, etc. By combining beneficial properties of fluorophores, GNPs, and aptamers, we propose to develop a molecular beacon-like nano-entity for early and accurate detection of aggressive breast cancer, with high sensitivity and specificity; and also for concurrently monitoring the efficacy of the therapeutic regimen. The nano-fluorescent agent to be developed is a breast cancer type expressing MMP-14, which is known as a marker for the breast cancer with aggressive nature. The components of this entity include a breast cancer targeting aptamer AS1411 with two Tymidine nucleotide sequences. One end of a sequence is bound to a GNP and one end of the other sequence is conjugated to Cypate, analogue of ICG (FDA approved near infrared fluorophore). The length of the chain is to be approximately a half of the distance producing the maximum fluorescence of Cypate by a GNP. The chains are connected via the substrate of MMP-14, which is small and, therefore, places the GNP and Cypate very close, forcing complete quenching. Initially, this entity emits little fluorescence because the strong plasmon field of GNP quenches the fluorescence. When it is applied to human body with breast cancer with aggressive nature, it is delivered to the breast cancer specifically via the targeting site of the AS1411 receptor. Then, it will be exposed to the MMP-14 on/in the tumor cell wall. As the substrate gets cleaved by the MMP-14, Cypate moves away from the GNP to the distance specified by the chain length, which results in highly enhanced fluorescence emission upon excitation light application. We have named this entity AptaPET (Aptamer-nanoparticle Plasmon Energy Transfer) and It allows both cancer detection and provides the information on nature of the cancer, for our system, the aggressiveness of the cancer. By selecting a special aptamer AS1411 with therapeutic properties, this entity can also be used both for detection and treatment. In addition, with no further modification, the AptaPET can be a good contrast agent for X-ray/CT. The same concept can be used for detection, diagnosis, and prognosis of other diseases as well as of other types of cancer.