Ferreira Miguel, Rizzuti Ilaria Francesca, Palange Anna Lisa, Barbato Maria Grazia, Di Francesco Valentina, Di Francesco Martina, Decuzzi Paolo
Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy.
Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, Italy.
Front Bioeng Biotechnol. 2020 Feb 19;8:5. doi: 10.3389/fbioe.2020.00005. eCollection 2020.
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 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).
对与聚合物基质相关的治疗剂和成像剂的加载和释放进行微调是新型纳米药物临床前开发的基本步骤。在此，通过自上而下的基于模板的制造方法，将聚（乳酸-共-乙醇酸）（PLGA）和聚（乙二醇）-二丙烯酸酯（PEG-DA）链在单一聚合物糊剂中混合，实现了1000×400nm的盘状聚合物纳米结构（DPN）。测试了两种不同的加载策略，即“直接加载”和“吸附加载”。在第一种情况下，将试剂直接与聚合物糊剂混合以实现DPN，而在第二种情况下，DPN首先被冻干，然后在暴露于试剂的浓水溶液时再水化。在这两种加载条件下，系统地评估了不同试剂的包封效率和释放曲线。具体而言，通过将脂质链（DSPE）或聚合物链（PEG）与近红外成像分子Cy5（DSPE-Cy5 A和DSPE-Cy5 B）共轭，实现了六种试剂；化疗分子甲氨蝶呤（DSPE-MTX和PEG-MTX）和阿霉素（LA-DOX和DSPE-DOX）。对于吸附加载，低分子量（MW）的中等疏水性化合物的包封效率高达80%。一般来说，直接加载的包封效率低于1%。试剂的疏水性和MW在定制DPN的释放曲线方面也被证明是至关重要的。在三阴性乳腺癌细胞（MDA-MB-231）上，吸附加载的DOX-DPN显示出与游离DOX相当的细胞毒性活性，但时间上略有延迟。初步研究证明了Cy5-DPN的高稳定性。总的来说，这些结果表明，通过改变加载策略（直接与吸附）和化合物属性（疏水性和分子量），可以精细地优化DPN的药理性质。
