Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8414473 | European Journal of Pharmaceutics and Biopharmaceutics | 2013 | 10 Pages |
Abstract
Polymeric nanoparticles have tremendous potential either as carriers or markers in treatment for diseases or as diagnostics in biomedical applications. Finding the optimal conditions for effective intracellular delivery of the payload to the location of interest is still a big challenge. The particles have to overcome the barrier of the cell membrane. Here, we investigated the uptake in HeLa cells of fluorescent polystyrene particles with different size and surface charge. Particles stabilized with the nonionic surfactant Lutensol AT50® (132Â nm, 180Â nm, 242Â nm, 816Â nm, 846Â nm diameter) were synthesized via dispersion polymerization. Cationic particles (120Â nm, 208Â nm, 267Â nm, 603Â nm diameter) were obtained by a combination of miniemulsion and seed dispersion polymerization using cationic surfactant (cetyltrimethylammonium chloride (CTMA-Cl). The particle uptake into HeLa cells was studied by confocal laser scanning microscopy and flow cytometry. Nonionic particles were - independent of their size - taken up by cells only at a barely detectable level, thus aggravating a quantitative comparison. The uptake of positively charged particles was substantially higher and therefore enabling further investigation keeping constant one of these parameters: either material amount or particles number or total interaction surface area. It was found that the uptake rather depends on the total amount of polymeric material present in the media than on the number of particles. The total particle's surface area does not correlate linearly with the uptake, thus indicating that there is no direct dependency between the total surface area and the cellular endocytotic process to overcome the biobarrier “cell membrane.” A potentially novel uptake mechanism is found which can be described as an excavator shovel like mechanism. It is a kind of macropinocytosis dependent on actin filaments as well as dynamin, but is clathrin-independent.
Keywords
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biotechnology
Authors
Simone Lerch, Martin Dass, Anna Musyanovych, Katharina Landfester, Volker Mailänder,