Dually Stabilized Triblock Copolymer Micelles with Hydrophilic Shell and Hydrophobic Interlayer for Systemic Antisense Oligonucleotide Delivery to Solid Tumor
Dually Stabilized Triblock Copolymer Micelles with Hydrophilic Shell and Hydrophobic Interlayer for Systemic Antisense Oligonucleotide Delivery to Solid Tumor
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DOI：
10.1021/acsbiomaterials.9b00384
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发表时间：
2019-11-01
影响因子：
5.8
通讯作者：
Miyata, Kanjiro
中科院分区：
文献类型：
--
作者：
Kim, Beob Soo;Kim, Hyun Jin;Miyata, Kanjiro
为了将反义寡核苷酸（ASO）静脉内递送至实体瘤，由聚（2-乙基-2-恶唑啉）（PEtOx）、聚（2-正丙基1-2-恶唑啉）（PnPrOx）和聚（L-赖氨酸）（PLL）片段合成了三嵌段共聚物。三嵌段共聚物 PEtOx-PnPrOx-PLL 用于制造分段聚合物胶束，该胶束具有亲水性 PEtOx 壳、热响应性 PnPrOx 中间层和 ASO/PLL 聚离子复合物 (PIC) 核。在此配方中，PnPrOx 衍生的中间层在较低的临界溶解温度 (LCST) 下经历了从亲水伸长状态到疏水塌陷状态的相变，以增强胶束稳定性。比较了包含不同长度 PEtOx 链段（2k、7k 和 12 kDa）的三种三嵌段共聚物，以研究亲水链长度对胶束性质的影响。三嵌段共聚物胶束 (TCM) 采用两步方式制备：将三嵌段共聚物和 ASO 在 4 ℃ 的缓冲溶液中混合，然后将溶液温度升高至 37 ℃。该方案对于制造具有较小尺寸和较窄尺寸分布的 TCM 至关重要，这可能是由于在胶束结构中形成了分隔良好的疏水性夹层。与对照二嵌段共聚物胶束 (DCM) 相比，PnPrOx 片段的存在显着增强了中药在含血清培养基中的稳定性，并引发细胞更有效地摄取 ASO 有效负载，从而在培养的前列腺癌 (PC-3) 细胞中产生更高的基因沉默效率。随着 PEtOx 片段长度的增加，中药的血液循环特性延长，从而允许 ASO 有效负载在皮下 PC-3 肿瘤模型中有效积累。最终，中药全身递送靶向长非编码RNA（lncRNA）的ASO，以序列特异性方式显着降低了皮下PC-3肿瘤中lncRNA的表达水平。这些结果证明了配备亲水外壳和疏水夹层的中药相对于癌症靶向全身 ASO 递送的优越性。
For intravenous delivery of antisense oligonucleotides (ASOs) to solid tumors, a triblock copolymer was synthesized from poly(2-ethyl-2-oxazoline) (PEtOx), poly(2-n-propy1-2-oxazoline) (PnPrOx), and poly(L-lysine) (PLL) segments. The triblock copolymer, PEtOx-PnPrOx-PLL, was utilized to fabricate a compartmentalized polymeric micelle featuring a hydrophilic PEtOx shell, thermoresponsive PnPrOx interlayer, and ASO/PLL polyion complex (PIC) core. In this formulation, the PnPrOx-derived interlayer underwent the phase transition from hydrophilic elongated state to hydrophobic collapsed state at a lower critical solution temperature (LCST) to enhance the micelle stability. Three triblock copolymers comprising varying lengths of PEtOx segment (2k, 7k, and 12 kDa) were compared to investigate the effect of hydrophilic chain length on the micelle properties. The triblock copolymer micelles (TCMs) were prepared in a two-step manner: mixing between triblock copolymer and ASO in a buffer solution at 4 degrees C and then increasing the temperature of the solution up to 37 degrees C. This protocol was crucial for the fabrication of TCMs with both smaller size and narrower size distribution, probably due to the formation of the well-compartmentalized hydrophobic interlayer in the micelle structure. The presence of the PnPrOx segment dramatically enhanced the stability of TCMs in serum-containing media and elicited more efficient cellular uptake of ASO payloads, resulting in higher gene silencing efficiency in cultured prostate cancer (PC-3) cells, compared with a control diblock copolymer micelle (DCM). The blood circulation property of TCMs was prolonged with an increase in the length of PEtOx segment, permitting the efficient accumulation of ASO payloads in a subcutaneous PC-3 tumor model. Ultimately, the systemic delivery of ASO targeting a long noncoding RNA (lncRNA) by the TCMs significantly reduced the expression level of lncRNA in the subcutaneous PC-3 tumor in a sequence-specific manner. These results demonstrate the superiority of TCMs equipped with the hydrophilic shell and hydrophobic interlayer to the cancer-targeted systemic ASO delivery.