Data_Sheet_1_Optimizing the Pharmacological Properties of Discoidal Polymeric Nanoconstructs Against Triple-Negative Breast Cancer Cells.pdf

Fine-tuning loading and release of therapeutic and imaging agents associated with polymeric matrices is a fundamental step in the preclinical development of novel nanomedicines. Here, 1,000 × 400 nm Discoidal Polymeric Nanoconstructs (DPNs) were realized via a top-down, template-based fabrication approach, mixing together poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol)-diacrylate (PEG-DA) chains in a single polymer paste. Two different loading strategies were tested, namely the “direct loading” and the “absorption loading.” In the first case, the agent was directly mixed with the polymeric paste to realize DPNs whereas, in the second case, DPNs were first lyophilized and then rehydrated upon exposure to a concentrated aqueous solution of the agent. Under these two loading conditions, the encapsulation efficiencies and release profiles of different agents were systematically assessed. Specifically, six agents were realized by conjugating lipid chains (DSPE) or polymeric chains (PEG) to the near-infrared imaging molecule Cy5 (DSPE-Cy5 A and DSPE-Cy5 B); the chemotherapeutic molecules methotrexate (DSPE-MTX and PEG-MTX) and doxorubicin (LA-DOX and DSPE-DOX). Moderately hydrophobic compounds with low molecular weights (MW) returned encapsulation efficiencies as high as 80% for the absorption loading. In general, direct loading was associated with encapsulation efficiencies lower than 1%. The agent hydrophobicity and MW were shown to be critical also in tailoring the release profiles from DPNs. On triple-negative breast cancer cells (MDA-MB-231), absorption loaded DOX-DPNs showed cytotoxic activities comparable to free DOX but slightly delayed in time. Preliminary in vivo studies demonstrated the high stability of Cy5-DPNs. Collectively, these results demonstrate that the pharmacological properties of DPNs can be finely optimized by changing the loading strategies (direct vs. absorption) and compound attributes (hydrophobicity and molecular weight).

针对聚合物基质中治疗剂和成像剂的加载与释放进行微调，是新型纳米药物临床前开发的基础步骤。本研究中，通过自上而下的模板化制造方法，实现了1,000 × 400 nm的圆盘状聚合物纳米结构（DPN）。该结构通过将聚乳酸-羟基乙酸共聚物（PLGA）和聚乙二醇二丙烯酸酯（PEG-DA）链混合在单一聚合物糊状物中制成。测试了两种不同的加载策略，即“直接加载”和“吸收加载”。在第一种情况下，治疗剂直接与聚合物糊状物混合以制备DPN；而在第二种情况下，DPN首先进行冷冻干燥，然后在暴露于治疗剂浓缩水溶液时进行复水。在这两种加载条件下，不同治疗剂的包封效率和释放特性被系统性地评估。具体而言，通过将脂链（DSPE）或聚合物链（PEG）与近红外成像分子Cy5偶联，制备了六种不同的治疗剂（DSPE-Cy5 A和DSPE-Cy5 B）；化疗分子甲氨蝶呤（DSPE-MTX和PEG-MTX）和柔红霉素（LA-DOX和DSPE-DOX）。具有低分子量（MW）和适度疏水性的化合物在吸收加载条件下表现出高达80%的包封效率。总的来说，直接加载的包封效率低于1%。研究表明，治疗剂的疏水性和分子量对于调节DPN的释放特性也至关重要。在Triple-negative乳腺癌细胞（MDA-MB-231）上，吸收加载的DOX-DPN显示出与游离DOX相当的细胞毒性，但作用时间略有延迟。初步的体内研究表明，Cy5-DPN具有很高的稳定性。综上所述，这些结果证实，通过改变加载策略（直接与吸收）和化合物属性（疏水性和分子量），可以精细优化DPN的药理特性。