Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Bioconjug Chem. 2022 Nov 16;33(11):2065-2075. doi: 10.1021/acs.bioconjchem.2c00412. Epub 2022 Oct 25.
Nanoparticle (NP) drug carriers have revolutionized medicine and increased patient quality of life. Clinically approved formulations typically succeed because of reduced off-target toxicity of the cargo. However, increasing carrier accumulation at disease sites through precise targeting remains one of the biggest challenges in the field. Novel multivalent ligand presentations and self-assembled constructs can enhance cell association, but an inability to draw direct comparisons across formulations has hindered progress. Furthermore, how nanoparticle structure influences function often is unclear. In this report, we leverage the well-characterized hyaluronic acid (HA)-CD44 binding pair to investigate how the surface architecture of modified NPs impacts their association with ovarian cancer cells that overexpress CD44. We functionalized anionic liposomes with 5 kDa HA by either covalent conjugation via surface coupling or electrostatic self-assembly using the layer-by-layer (LbL) adsorption method. Comparing these two methods, we observed a consistent enhancement of NP-cell association with the self-assembly LbL technique, particularly with higher molecular weight (≥10 kDa) HA. To further optimize association, we increased the surface-available HA. We synthesized a bottlebrush glycopolymer composed of a polynorbornene backbone and pendant 5 kDa HA and layered this macromolecule onto NPs. Flow cytometry revealed that the LbL HA bottlebrush NP outperformed the LbL linear display of HA. Cellular visualization by deconvolution optical microscopy corroborated results from all three constructs. Using exogenous HA to block NP-CD44 interactions, we found the LbL HA bottlebrush NP had a 4-fold higher binding avidity than the best-performing LbL linear HA NP. We further observed that decreasing the density of HA bottlebrush side chains to 75% had minimal impact on LbL NP stability or cell association, though we did see a reduction in binding avidity with this side-chain-modified NP. Our studies indicate that LbL surfaces are highly effective for multivalent displays, and the mode in which they present a targeting ligand can be optimized for NP cell targeting.
纳米颗粒 (NP) 药物载体彻底改变了医学并提高了患者的生活质量。临床批准的制剂通常会成功，因为货物的脱靶毒性降低了。然而，通过精确靶向增加疾病部位的载体积累仍然是该领域最大的挑战之一。新型多价配体呈现和自组装构建体可以增强细胞关联，但制剂之间无法进行直接比较阻碍了进展。此外，纳米颗粒结构如何影响功能往往不清楚。在本报告中，我们利用经过充分研究的透明质酸 (HA)-CD44 结合对来研究修饰后的 NP 的表面结构如何影响它们与过度表达 CD44 的卵巢癌细胞的关联。我们通过表面偶联共价连接或使用层层 (LbL) 吸附方法的静电自组装将 5 kDa HA 功能化到阴离子脂质体上。通过比较这两种方法，我们观察到自组装 LbL 技术与 NP-细胞的关联得到了一致增强，特别是对于更高分子量（≥10 kDa）的 HA。为了进一步优化关联，我们增加了表面可用的 HA。我们合成了一种由多环硼烷骨架和侧挂 5 kDa HA 组成的刷状糖聚合物，并将这种大分子层压到 NP 上。流式细胞术显示，LbL HA 刷状 NP 的性能优于 LbL 线性显示的 HA。通过离焦光学显微镜对细胞进行可视化，证实了所有三种结构的结果。使用外源性 HA 阻断 NP-CD44 相互作用，我们发现 LbL HA 刷状 NP 的结合亲和力比表现最佳的 LbL 线性 HA NP 高 4 倍。我们还观察到，将 HA 刷状侧链的密度降低到 75%对 LbL NP 的稳定性或细胞关联几乎没有影响，尽管我们确实看到了具有这种侧链修饰的 NP 的结合亲和力降低。我们的研究表明，LbL 表面非常适合多价显示，并且它们呈现靶向配体的方式可以针对 NP 细胞靶向进行优化。
