肿瘤归巢-穿膜肽介导靶向载药相变纳米粒用于肿瘤超声分子成像与治疗研究

Based on our previous research, we found that homemade targeted ultrasound microbubble contrast agent (UMCA) carring gene and cell-penetrating peptide can realize ultrasound molecular imaging and targeted therapy to some extent. However, because of intravascular targeted defect - UMCA can't achieve real level of whole cell molecular imaging and targeted therapy, it restricts severely ultrasound molecular imaging quality and the improvement of targeted therapy. Therefore, to solve the key problem of ultrasound molecular imaging and targeted therapy, this project will prepare a new targeted drug-loaded phase-shift nanoparticles mediated by tumor homing-penetrating peptide with the characteristic of extracellular accumulation and intracellular penetration (ultrasonic molecular probe). Nanoparticles penetrate tumor cells mediated by tumor targeting and penetrating property of tumor homing-penetrating peptide, combined with low intensity focused ultrasound (LIFU) to realize phase-shift and ultrasound-targeted microbubble destruction (UTMD) technology to realize targeted drug delivery in tumor cells, which achieve high quality ultrasound molecular imaging and efficient drug delivery. It is expected that targeted drug-loaded phase-shift nanoparticles mediated by tumor homing-penetrating peptide is prepared successfully, evaluated qualitatively and quantitatively the effect of ultrasound molecular imaging and targeted therapy in vivo and in vitro experiments, which provides a new strategy and method for ultrasound molecular imaging diagnosis and tumor treatment mediated by UTMD drug delivery system.

基于申请者前期研究发现，自制靶向载基因及穿膜肽超声微泡造影剂能在一定程度上实现超声分子成像与靶向治疗，但由于血管内靶向缺陷-不能实现真正全细胞水平分子成像与靶向治疗，严重制约超声分子成像质量与靶向治疗水平的提高。因此，申请者设想研制一种新型的肿瘤归巢-穿膜肽介导同时具有细胞外积聚和细胞内渗透作用的靶向载药液-气相变型液态氟碳纳米粒即超声分子探针，利用肿瘤归巢-穿膜肽的肿瘤靶向及穿膜特性引导纳米粒深入靶向肿瘤细胞，并联合低强度聚焦超声使其相变成含气微泡、超声靶向破裂微泡技术（UTMD）介导肿瘤细胞靶向药物投递，实现高质量超声分子成像及安全高效的药物投递，以解决目前超声分子成像与靶向治疗中的核心问题。预期成功研制肿瘤归巢-穿膜肽介导的靶向载药液-气相变纳米粒，通过体内外实验定性定量评价该纳米粒的超声分子成像及靶向治疗效果，为超声分子成像诊断及UTMD介导药物递送治疗肿瘤提供一种新策略和新手段。

肿瘤是严重威胁人类健康的重要疾病，化疗是治疗肿瘤的一个重要策略。然而，较差的肿瘤靶向和化疗药物的全身分布影响化疗的临床疗效。为了实现精确的肿瘤靶向、增加肿瘤靶点积聚及提高肿瘤治疗水平，肿瘤靶向药物递送系统成为目前研究热点。肿瘤归巢穿膜肽为肿瘤靶向药物递送系统能够到达深部肿瘤组织提供新思路。超声分子影像学是分子影像学的重要分支，尤其是与超声靶向破坏微泡技术（UTMD ）联合可实现药物/基因定位递送的独特优势，使其成为一种极具临床应用潜力的新型诊疗一体化技术。该项目成功合成具有细胞穿膜特性的肿瘤归巢肽即肿瘤归巢-穿膜肽；成功制备一种肿瘤归巢-穿膜肽介导的靶向载药液-气相变纳米粒（tLyP-1-10-HCPT-PFP NPs）作为新型的超声分子探针和药物递送载体；优化体内外相变条件，实现对其相变过程及药物释放的安全可控，为其应用于超声分子成像与治疗奠定基础；实现tLyP-1-10-HCPT-PFP NPs对肿瘤细胞模型的体外寻靶能力、细胞穿膜性及可控药物释放的靶向治疗；实现tLyP-1-10-HCPT-PFP NPs对肿瘤动物模型的体内超声分子成像及靶向治疗。该项目研制的肽功能化靶向载药液-气相变纳米粒，同时具有穿透双层肿瘤组织屏障、细胞外积聚和细胞内渗透作用，在粒径优势下，纳米粒能够穿过肿瘤血管内皮细胞间隙；在肿瘤归巢穿膜肽的介导下，纳米粒能够靶向肿瘤细胞，并可穿入到深层肿瘤组织细胞，实现细胞水平精准定位；联合LIFU聚焦辐照后，纳米粒所包裹的液态PFP相变成气体，纳米粒从而变成微泡增强超声成像效果，实现超声分子成像； 联合UTMD导致的“爆炸效应”、定点释放药物，实现物理化学协同治疗肿瘤作用。该纳米粒可用于肿瘤的诊疗一体化，为实现真正分子水平的肿瘤精准诊疗提供一种新策略和新方法。该项目申请国家发明专利1项，发表SCI 3篇（单篇最高12.712）及CSCD 11篇。