实体瘤患者中癌症的局部复发是目前治疗策略失败的最常见原因。这一事实表明,目前的肿瘤切除方法只能治愈50%的患者。肿瘤切除失败的主要原因是脱靶药物的细胞毒性和肿瘤检测方法缺乏敏感性。随着靶向治疗和诊断的发展,这些缺点得到了解决。显着帮助治疗策略。靶向诊断利用显示肿瘤生物标志物显著上调的肿瘤细胞的特性。这些生物标志物由连接到荧光团的归巢配体靶向,用于在手术期间进行视觉检查。然而,这些方法有缺点,如来自背景组织的高自发荧光,组织吸收,和散射,导致图像灵敏度和分辨率下降。使用近红外(NIR)荧光团来克服这些缺点引起了研究人员前所未有的兴趣。NIR窗口位于650至1,700nm的范围内,这导致组织的吸收和散射减少,从而提供更深的组织渗透和减少的自发荧光。NIR荧光团可以被设计为靶向肿瘤生物标志物,例如在癌症组织上发现过表达的前列腺特异性膜抗原(PSMA)或叶酸盐受体。这些靶向荧光团由与NIR染料缀合的小分子配体组成,所述NIR染料以高特异性结合PSMA和叶酸受体。在这个协议中,我们已经广泛描述了PSMA(DUPA-NIR生物缀合物)和叶酸(叶酸-NIR生物缀合物)的靶向NIR试剂的合成方法,以及临床前评估的详细步骤。描述了计算体外对癌细胞的结合亲和力的程序。以及体内不同小鼠模型中的摄取和生物分布。©2022Wiley期刊有限责任公司。基本方案1:通过SPPS策略合成和纯化DUPA和叶酸肽接头基本方案2:缀合,净化,用于深层组织成像应用的具有NIR探针的靶向生物缀合物和表征基本方案3:使用分光光度计体外评估靶向DUPA-NIR和叶酸-NIR生物缀合物的结合亲和力基本方案4:在小鼠中诱导肿瘤以开发CDX或转移性肿瘤模型基本方案5:在小鼠CDX或转移性肿瘤模型中静脉施用靶向DUPA-NIR和叶酸-NIR生物缀合物用于深层组织成像。
Local re-occurrence of cancer in patients with solid tumors is currently the most common reason for failure of treatment strategies. This fact indicates that prevailing approaches for tumor resection can cure only 50% of patients. A major cause of failure in tumor resection is off-target drug cytotoxicity and lack of sensitivity in tumor detection methods. These disadvantages are addressed with the development of targeted therapy and diagnostics, which significantly aid treatment strategies. Targeted diagnostics exploit properties of tumor cells that show significant up-regulation of tumor biomarkers. These biomarkers are targeted by a homing ligand attached to a fluorophore for visual inspection during surgery. However, these approaches suffer from disadvantages like high autofluorescence from background tissues, tissue absorption, and scattering, resulting in decreased image sensitivity and resolution. The use of near-infrared (NIR) fluorophores to overcome these drawbacks has generated unprecedented interest among researchers. The NIR window lies within the range of 650 to 1,700 nm, which results in reduced absorption and scattering by the tissues, thereby providing deeper tissue penetration and reduced autofluorescence. NIR fluorophores can be designed to target tumor biomarkers such as prostate specific membrane antigen (PSMA) or folate receptors found over-expressed on cancer tissues. These targeted fluorophores consist of small-molecule ligands conjugated with NIR dyes that bind with high specificity to PSMA and folic acid receptors. In this protocol, we have extensively described the methodology for the synthesis of targeted NIR agents for PSMA (DUPA-NIR bioconjugate) and folic acid (folate-NIR bioconjugate), along with detailed steps for preclinical evaluation. Procedures to calculate the binding affinity to cancer cells in vitro are described, along with uptake and biodistribution in different mice models in vivo. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Synthesis and purification of DUPA and folate-peptide linkers via a SPPS strategy Basic Protocol 2: Conjugation, purification, and characterization of targeted bioconjugates with NIR probe for deep-tissue imaging applications Basic Protocol 3: In vitro evaluation of binding affinity of targeted DUPA-NIR and folate-NIR bioconjugates using a spectrophotometer Basic Protocol 4: Induction of tumor in mice to develop CDX or metastatic tumor models Basic Protocol 5: Intravenous administration of targeted DUPA-NIR and folate-NIR bioconjugates in mouse CDX or metastatic tumor models for deep-tissue NIR imaging and tumor resection.