We report self-assembled polymeric nanovesicles composed of 1,4-bis4′-[N,N-bis(6′′-trimethylammoniumhexyl)amino]styryl}benzene tetrabromide (C1), poly[(ethylene oxide)-block-(sodium 2-acrylamido-2-methyl-1-propane sulfonate)] (Em-An), and hexadecyltrimethylammonium bromide (C16). Transmission electron microscopy (TEM) micrographs confirm the vesicular bilayer structures and atomic force microscopy (AFM) images show that the C1/Em-An/C16 complexes form spherical nanostructures with a particle size ranging from 40 to 80 nm. The encapsulation of C1 inside the nanovesicles enhances ∼2-fold the fluorescence quantum yield (η) and two-photon action cross-section (ηδ, where δ is the two-photon absorption cross-section), and allows internalization into the cells, as revealed by the bright two-photon microscopy (TPM) images of human cervical epithelioid carcinoma (HeLa) cells labeled with the nanovesicles. Moreover, nanovesicles containing a chemotherapeutic drug and a neutral molecule can also be prepared. Furthermore, the C1/vesicular complex is disassembled under acidic conditions, highlighting its potential as a pH-responsive smart nanocarrier for the intracellular drug delivery. These results suggest a new possibility of using nanovesicles as efficient two-photon probes for TPM imaging and possibly as nanocarriers for intracellular drug delivery.
我们报告了由 1,4-双4′-[N,N-双(6′′-三甲基
己基铵)
氨基]
苯乙烯基}四
溴化苯(C1)、聚[(
环氧乙烷)-block-(2-
丙烯酰胺基-2-甲基-1-
丙烷磺酸钠)](Em-An)和
十六烷基三甲基溴化铵(C16)组成的自组装聚合物纳米微粒。透射电子显微镜(
TEM)显微照片证实了囊状双层结构,原子力显微镜(A
FM)图像显示,C1/Em-An/C16 复合物形成了粒径为 40 至 80 纳米的球形纳米结构。正如用纳米微粒标记的人宫颈上皮样癌(HeLa)细胞的明亮双光子显微镜(TPM)图像所显示的那样,纳米微粒内包裹的 C1 可使荧光量子产率(η)和双光子作用截面(ηδ,其中 δ 为双光子吸收截面)提高 2 倍,并可内化到细胞中。此外,还可以制备含有化疗药物和中性分子的纳米颗粒。此外,C1/囊泡复合物在酸性条件下会被分解,这突显了它作为一种 pH 响应型智能纳米载体用于细胞内药物递送的潜力。这些结果表明,纳米囊泡有可能成为用于 TPM 成像的高效双光子探针,也有可能成为细胞内给药的纳米载体。