School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, China.
Biomater Sci. 2018 Feb 27;6(3):604-613. doi: 10.1039/c7bm01182b.
Peptide nanodrugs have been developed as promising antitumor chemotherapeutics because they partially overcome the drawbacks of free peptide drugs, but insufficient tumor penetration and interference of peptide function limit their further application. In this work, we have developed multifunctional peptide conjugated dendrimers for improving tumor penetration, cancer cell-specific peptide delivery and anticancer ability. The cytotoxic peptide KLAK, cell-penetrating peptide TAT and matrix metalloproteinase 2 (MMP2)-sensitive peptide-poly(ethylene glycol) (PEG) were conjugated onto dendrimers by one-pot synthesis to gain PKT-S-PEG. The enzyme-sensitive properties and incubation stability of the dendrimers were investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Moreover, the cell viability, internalization pathway, mitochondria-regulated apoptosis and tumor penetration ability were measured by CCK-8 assay, lysosome colocalization, JC-1 assay and multicellular spheroid (MCS) experiments, respectively, in human primary glioblastoma (U87) cells. PKT-S-PEG showed significantly enhanced intracellular delivery performance, antitumor efficacy and deep tumor penetration capacity compared to a control non-MMP2 sensitive dendrimer PKT-C-PEG. The MMP2-overexpressing tumor microenvironment caused deprotection by removal of PEG, resulting in the decrease of particle size and exposure of KLAK and TAT, which enhanced tumor penetration, the entry of bioactive peptides into cells and subsequently the effective disruption of mitochondria. We believe that the peptide-dendrimer conjugate has potential for specific and effective delivery of peptide-based therapeutics into tumors.
肽纳米药物已被开发为有前途的抗肿瘤化疗药物，因为它们部分克服了游离肽药物的缺点，但肽的肿瘤穿透能力不足和功能干扰限制了它们的进一步应用。在这项工作中，我们开发了多功能肽偶联树状聚合物，以提高肿瘤穿透性、癌细胞特异性肽递药和抗癌能力。细胞毒性肽 KLAK、穿膜肽 TAT 和基质金属蛋白酶 2（MMP2）敏感肽-聚乙二醇（PEG）通过一锅合成偶联到树状聚合物上，得到 PKT-S-PEG。通过动态光散射（DLS）和透射电子显微镜（TEM）研究了树枝状聚合物的酶敏感性质和孵育稳定性。此外，通过 CCK-8 测定、溶酶体共定位、JC-1 测定和多细胞球体（MCS）实验分别测量了细胞活力、内化途径、线粒体调节的细胞凋亡和肿瘤穿透能力在人原发性脑胶质瘤（U87）细胞中。与非 MMP2 敏感的树枝状聚合物 PKT-C-PEG 相比，PKT-S-PEG 表现出显著增强的细胞内递药性能、抗肿瘤功效和深肿瘤穿透能力。MMP2 过表达的肿瘤微环境通过去除 PEG 引起脱保护作用，导致粒径减小，KLAK 和 TAT 暴露，从而增强肿瘤穿透性、生物活性肽进入细胞的能力，并随后有效破坏线粒体。我们相信，肽-树状聚合物缀合物具有将基于肽的治疗剂特异性和有效地递送到肿瘤中的潜力。
