Bioconjug Chem. 2018 Jun 20;29(6):1973-2000. doi: 10.1021/acs.bioconjchem.8b00208. Epub 2018 May 30.
Polymer-drug conjugation is an attractive approach for target delivering insoluble and highly toxic drugs to tumor sites to overcome the side-effects caused by cancer chemotherapy. In this study we designed and synthesized novel polymer-drug-peptide conjugates for improved specificity on targeting cancer cells. Chemically modified polysaccharide, carboxymethylcellulose (CMC), was conjugated with doxorubicin (DOX) anticancer drug by amide bonds and dually biofunctionalized with integrin-target receptor tripeptide (RGD) and l-arginine (R) as cell-penetrating amino acid for synergistic targeting and enhancing internalization by cancer cells. These bioconjugates were tested as prodrugs against bone, breast, and brain cancer cell lines (SAOS, MCF7, and U87) and a normal cell line (HEK 293T, reference). The physicochemical characterization showed the formation of amide bonds between carboxylates (-RCOO) from CMC biopolymer and amino groups (-NH) from DOX and peptides (RGD or R). Moreover, these polymer-drug-peptide bioconjugates formed nanoparticulate colloidal structures and behaved as "smart" drug delivery systems (DDS) promoting remarkable reduction of the cytotoxicity toward normal cells (HEK 293T) while retaining high killing activity against cancer cells. Based on cell viability bioassays, DNA-staining, and confocal laser microscopy, this effect was assigned to the association of physicochemical aspects with the difference of the endocytic pathways and the drug release rates in live cells caused by the biofunctionalization of the macromolecule-drug systems with RGD and l-arginine. In addition, chick chorioallantoic membrane (CAM) assay was performed as an in vivo xenograft model test, which endorsed the in vitro results of anticancer activities of these polymer-drug systems. Thus, prodrug nanocarriers based on CMC-DOX-peptide bioconjugates were developed for simultaneously integrin-targeting and high killing efficacy against cancer cells, while preserving healthy cells with promising perspectives in cancer chemotherapy.
聚合物-药物偶联物是一种有吸引力的方法，可将难溶性和高毒性药物递送至肿瘤部位，以克服癌症化疗引起的副作用。在这项研究中，我们设计并合成了新型聚合物-药物-肽缀合物，以提高针对癌细胞的靶向特异性。通过酰胺键将化学修饰的多糖羧甲基纤维素（CMC）与阿霉素（DOX）抗癌药物偶联，并通过整合素靶向受体三肽（RGD）和精氨酸（R）双重生物功能化，作为细胞穿透氨基酸，以协同靶向并增强癌细胞的内化作用。这些生物缀合物被用作前药，用于针对骨癌、乳腺癌和脑癌细胞系（SAOS、MCF7 和 U87）和正常细胞系（HEK 293T，参考）进行测试。物理化学特性表明，在 CMC 生物聚合物的羧酸根（-RCOO）和 DOX 及肽（RGD 或 R）的氨基（-NH）之间形成了酰胺键。此外，这些聚合物-药物-肽生物缀合物形成了纳米颗粒胶体结构，并表现为“智能”药物递送系统（DDS），可显著降低对正常细胞（HEK 293T）的细胞毒性，同时保持对癌细胞的高杀伤活性。基于细胞活力生物测定、DNA 染色和共聚焦激光显微镜，这种效果归因于物理化学方面的关联以及通过 RGD 和精氨酸对大分子-药物系统进行生物功能化引起的活细胞中内吞途径和药物释放率的差异。此外，鸡胚绒毛尿囊膜（CAM）试验作为体内异种移植模型试验进行，该试验支持了这些聚合物-药物系统抗癌活性的体外结果。因此，基于 CMC-DOX-肽生物缀合物的前药纳米载体被开发用于同时针对整合素和对癌细胞的高杀伤效力，同时保护健康细胞，在癌症化疗中具有广阔的前景。
