Kashyap Smita, Singh Nitesh, Surnar Bapurao, Jayakannan Manickam
Department of Chemistry, Indian Institute of Science Education and Research Pune , Dr. Homo Bhabha Road, Pune 410008, Maharashtra, INDIA.
Biomacromolecules. 2016 Jan 11;17(1):384-98. doi: 10.1021/acs.biomac.5b01545. Epub 2015 Dec 22.
Dual responsive polymer nanoscaffolds for administering anticancer drugs both at the tumor site and intracellular compartments are made for improving treatment in cancers. The present work reports the design and development of new thermo- and enzyme-responsive amphiphilic copolymer core-shell nanoparticles for doxorubicin delivery at extracellular and intracellular compartments, respectively. A hydrophobic acrylate monomer was tailor-made from 3-pentadecylphenol (PDP, a natural resource) and copolymerized with oligoethylene glycol acrylate (as a hydrophilic monomer) to make new classes of thermo and enzyme dual responsive polymeric amphiphiles. Both radical and reversible addition-fragmentation chain transfer (RAFT) methodologies were adapted for making the amphiphilic copolymers. These amphiphilic copolymers were self-assembled to produce spherical core-shell nanoparticles in water. Upon heating, the core-shell nanoparticles underwent segregation to produce larger sized aggregates above the lower critical solution temperature (LCST). The dual responsive polymer scaffold was found to be capable of loading water insoluble drug, such as doxorubicin (DOX), and fluorescent probe-like Nile Red. The drug release kinetics revealed that DOX was preserved in the core-shell assemblies at normal body temperature (below LCST, ≤ 37 °C). At closer to cancer tissue temperature (above LCST, ∼43 °C), the polymeric scaffold underwent burst release to deliver 90% of loaded drugs within 2 h. At the intracellular environment (pH 7.4, 37 °C) in the presence of esterase enzyme, the amphiphilic copolymer ruptured in a slow and controlled manner to release >95% of the drugs in 12 h. Thus, both burst release of cargo at the tumor microenvironment and control delivery at intracellular compartments were accomplished in a single polymer scaffold. Cytotoxicity assays of the nascent and DOX-loaded polymer were carried out in breast cancer (MCF-7) and cervical cancer (HeLa) cells. Among the two cell lines, the DOX-loaded polymers showed enhanced killing in breast cancer cells. Furthermore, the cellular uptake of the DOX was studied by confocal and fluorescence microscopes. The present investigation opens a new enzyme and thermal-responsive polymer scaffold approach for DOX delivery in cancer cells.
用于在肿瘤部位和细胞内区室给药抗癌药物的双响应聚合物纳米支架被制备出来以改善癌症治疗。目前的工作报道了分别用于在细胞外和细胞内区室递送阿霉素的新型热响应和酶响应两亲共聚物核壳纳米颗粒的设计与开发。一种疏水性丙烯酸酯单体由3-十五烷基苯酚(PDP,一种自然资源)特制而成,并与低聚乙二醇丙烯酸酯(作为亲水性单体)共聚,以制备新型的热和酶双响应聚合物两亲物。自由基聚合和可逆加成-断裂链转移(RAFT)方法都被用于制备两亲共聚物。这些两亲共聚物在水中自组装形成球形核壳纳米颗粒。加热时,核壳纳米颗粒发生相分离,在低临界溶液温度(LCST)以上产生更大尺寸的聚集体。发现双响应聚合物支架能够负载水不溶性药物,如阿霉素(DOX)和荧光探针尼罗红。药物释放动力学表明,DOX在正常体温(低于LCST,≤37°C)下保存在核壳组装体中。在接近癌组织温度(高于LCST,约43°C)时,聚合物支架发生突发释放,在2小时内释放90%的负载药物。在细胞内环境(pH 7.4,37°C)中,在酯酶存在的情况下,两亲共聚物以缓慢且可控的方式破裂,在12小时内释放>95%的药物。因此,在单个聚合物支架中实现了在肿瘤微环境中货物的突发释放和在细胞内区室的控制递送。对新生的和负载DOX的聚合物进行了乳腺癌(MCF-7)和宫颈癌(HeLa)细胞的细胞毒性测定。在这两种细胞系中,负载DOX的聚合物在乳腺癌细胞中显示出增强的杀伤作用。此外,通过共聚焦和荧光显微镜研究了DOX的细胞摄取。本研究为在癌细胞中递送DOX开辟了一种新的酶和热响应聚合物支架方法。