Chemical and Biological Engineering, University of New Mexico , 210 University Blvd NE, Albuquerque, New Mexico 87131-0001, United States.
Center for Micro-Engineered Materials, Advanced Materials Laboratory, University of New Mexico , MSC04 2790, 1001 University Blvd SE, Suite 103, Albuquerque, New Mexico 87106, United States.
ACS Nano. 2016 Sep 27;10(9):8325-45. doi: 10.1021/acsnano.6b02819. Epub 2016 Jul 25.
Many nanocarrier cancer therapeutics currently under development, as well as those used in the clinical setting, rely upon the enhanced permeability and retention (EPR) effect to passively accumulate in the tumor microenvironment and kill cancer cells. In leukemia, where leukemogenic stem cells and their progeny circulate within the peripheral blood or bone marrow, the EPR effect may not be operative. Thus, for leukemia therapeutics, it is essential to target and bind individual circulating cells. Here, we investigate mesoporous silica nanoparticle (MSN)-supported lipid bilayers (protocells), an emerging class of nanocarriers, and establish the synthesis conditions and lipid bilayer composition needed to achieve highly monodisperse protocells that remain stable in complex media as assessed in vitro by dynamic light scattering and cryo-electron microscopy and ex ovo by direct imaging within a chick chorioallantoic membrane (CAM) model. We show that for vesicle fusion conditions where the lipid surface area exceeds the external surface area of the MSN and the ionic strength exceeds 20 mM, we form monosized protocells (polydispersity index <0.1) on MSN cores with varying size, shape, and pore size, whose conformal zwitterionic supported lipid bilayer confers excellent stability as judged by circulation in the CAM and minimal opsonization in vivo in a mouse model. Having established protocell formulations that are stable colloids, we further modified them with anti-EGFR antibodies as targeting agents and reverified their monodispersity and stability. Then, using intravital imaging in the CAM, we directly observed in real time the progression of selective targeting of individual leukemia cells (using the established REH leukemia cell line transduced with EGFR) and delivery of a model cargo. Overall, we have established the effectiveness of the protocell platform for individual cell targeting and delivery needed for leukemia and other disseminated disease.
许多目前正在开发的纳米载体癌症治疗药物，以及那些在临床环境中使用的药物，都依赖于增强的通透性和保留（EPR）效应，以被动地在肿瘤微环境中积累并杀死癌细胞。在白血病中，白血病发生的干细胞及其后代在周围血液或骨髓中循环，EPR 效应可能不起作用。因此，对于白血病治疗药物，靶向和结合单个循环细胞至关重要。在这里，我们研究了介孔硅纳米颗粒（MSN）支撑的脂质双层（原细胞），这是一类新兴的纳米载体，并建立了合成条件和脂质双层组成，以实现高度单分散的原细胞，这些原细胞在复杂介质中保持稳定，这通过动态光散射和冷冻电子显微镜在体外进行评估，并通过在鸡胚绒毛尿囊膜（CAM）模型中直接成像在鸡胚中进行评估。我们表明，对于囊泡融合条件，其中脂质表面积超过 MSN 的外部表面积，并且离子强度超过 20 mM，我们在具有不同尺寸、形状和孔径的 MSN 核上形成单尺寸的原细胞（多分散指数<0.1），其保形两性离子支持的脂质双层赋予其优异的稳定性，这可以通过在 CAM 中循环和在体内小鼠模型中最小的调理作用来判断。在建立了稳定胶体的原细胞配方后，我们进一步用抗 EGFR 抗体对其进行修饰作为靶向剂，并重新验证了它们的单分散性和稳定性。然后，使用 CAM 中的活体成像，我们直接实时观察到个体白血病细胞（使用转导 EGFR 的已建立的 REH 白血病细胞系）的选择性靶向和模型货物的递呈的进展。总的来说，我们已经建立了原细胞平台对于白血病和其他播散性疾病所需的个体细胞靶向和递呈的有效性。
