Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, United States.
Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, United States.
J Colloid Interface Sci. 2024 Jun 15;664:1042-1055. doi: 10.1016/j.jcis.2024.03.055. Epub 2024 Mar 11.
Conjugating biomolecules, such as antibodies, to bioconjugate moieties on lipid surfaces is a powerful tool for engineering the surface of diverse biomaterials, including cells and nanoparticles. We developed supported lipid bilayers (SLBs) presenting well-defined spatial distributions of functional moieties as models for precisely engineered functional biomolecular-lipid surfaces. We used quartz crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM) to determine how vesicles containing a mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[azido(polyethylene glycol)-2000] (DSPE-PEG-N) form SLBs as a function of the lipid phase transition temperature (T). Above the DPPC T, DPPC/DSPE-PEG-N vesicles form SLBs with functional azide moieties on SiO substrates via vesicle fusion. Below this T, DPPC/DSPE-PEG-N vesicles attach to SiO intact. Intact DPPC/DSPE-PEG-N vesicles on the SiO surfaces fuse and rupture to form SLBs when temperature is brought above the DPPC T. AFM studies show uniform and complete DPPC/DSPE-PEG-N SLB coverage of SiO surfaces for different DSPE-PEG-N concentrations. As the DSPE-PEG-N concentration increases from 0.01 to 6 mol%, the intermolecular spacing of DSPE-PEG-N in the SLBs decreases from 4.6 to 1.0 nm. The PEG moiety undergoes a mushroom to brush transition as DSPE-PEG-N concentration varies from 0.1 to 2.0 mol%. Via copper-free click reaction, IgG was conjugated to SLB surfaces with 4.6 nm or 1.3 nm inter-DSPE-PEG-N spacing. QCM-D and AFM data show; 1) uniform and complete IgG layers of similar mass and thickness on the two types of SLB; 2) a higher-viscosity/less rigid IgG layer on the SLB with 4.6 nm inter-DSPE-PEG-N spacing. Our studies provide a blueprint for SLBs modeling spatial control of functional macromolecules on lipid surfaces, including surfaces of lipid nanoparticles and cells.
将生物分子（如抗体）与脂质表面上的生物缀合部分连接，是工程化各种生物材料（包括细胞和纳米颗粒）表面的有力工具。我们开发了具有明确功能部分空间分布的支撑脂质双层（SLB）作为精确工程化功能生物分子-脂质表面的模型。我们使用石英晶体微天平（QCM-D）和原子力显微镜（AFM）来确定包含 1,2-二棕榈酰基-sn-甘油-3-磷酸胆碱（DPPC）和 1,2-二硬脂酰基-sn-甘油-3-磷酸乙醇胺-N-[叠氮（聚乙二醇）-2000]（DSPE-PEG-N）混合物的囊泡如何形成 SLB，其功能是作为脂质相转变温度（T）的函数。在 DPPC T 以上，DPPC/DSPE-PEG-N 囊泡通过囊泡融合在 SiO 基底上形成具有功能叠氮部分的 SLB。在这个温度以下，DPPC/DSPE-PEG-N 囊泡完整地附着在 SiO 上。当温度升高到 DPPC T 以上时，SiO 表面上完整的 DPPC/DSPE-PEG-N 囊泡融合并破裂形成 SLB。AFM 研究表明，对于不同的 DSPE-PEG-N 浓度，SiO 表面上 DPPC/DSPE-PEG-N SLB 的覆盖率均匀且完整。随着 DSPE-PEG-N 浓度从 0.01 增加到 6 mol%，SLB 中 DSPE-PEG-N 的分子间间距从 4.6 减小到 1.0 nm。当 DSPE-PEG-N 浓度从 0.1 增加到 2.0 mol%时，PEG 部分经历从蘑菇到刷的转变。通过无铜点击反应，将 IgG 连接到具有 4.6nm 或 1.3nm 间隔的 DSPE-PEG-N 的 SLB 表面。QCM-D 和 AFM 数据表明：1）在两种类型的 SLB 上具有相似质量和厚度的均匀和完整的 IgG 层；2）在具有 4.6nm 间隔的 DSPE-PEG-N 的 SLB 上具有更高粘度/更刚性的 IgG 层。我们的研究为 SLB 提供了蓝图，用于模拟脂质表面上功能大分子的空间控制，包括脂质纳米颗粒和细胞的表面。
