The influence of the size and aspect ratio of anisotropic, porous CaCO3 particles on their uptake by cells

Abstract

BackgroundRecent reports highlighting the role of particle geometry have suggested that anisotropy can affect the rate and the pathway of particle uptake by cells. Therefore, we investigate the internalization by cells of porous calcium carbonate particles with different shapes and anisotropies.ResultsWe report here on a new method of the synthesis of polyelectrolyte coated calcium carbonate particles whose geometry was controlled by varying the mixing speed and time, pH value of the reaction solution, and ratio of the interacting salts used for particle formation. Uptake of spherical, cuboidal, ellipsoidal (with two different sizes) polyelectrolyte coated calcium carbonate particles was studied in cervical carcinoma cells. Quantitative data were obtained from the analysis of confocal laser scanning microscopy images.ConclusionsOur results indicate that the number of internalized calcium carbonate particles depends on the aspect ratio of the particle, whereby elongated particles (higher aspect ratio) are internalized with a higher frequency than more spherical particles (lower aspect ratio). The total volume of internalized particles scales with the volume of the individual particles, in case equal amount of particles were added per cell.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-015-0111-7) contains supplementary material, which is available to authorized users.

Quantitative uptake of colloidal particles by cell cultures

“…This is demonstrated in Fig. 4 (Parakhonskiy et al, 2015). In this study, colloids with different aspect ratio were investigated.…”

“…First, upon immunostaining of endosomes/lysosomes, co-localization analysis provides information whether colloids are inside these intracellular vesicles and have been therefore internalized (Kastl et al, 2013;Parakhonskiy et al, 2015), cf. Fig.…”

“…The number of internalized capsules per cell N caps(in) was determined and displayed as a) cumulative distribution function p(N caps(in) ), or b) as cumulative distribution function p(V tot,caps(in) ), with V tot,caps(in) = N caps(in) ·V. The image has been adopted from Parakhonskiy et al (2015). Uptake of colloids was quantified in terms of time-dependent fluorescence intensity I(t) on cells.…”

Release from Polyelectrolyte Multilayer Capsules in Solution and on Polymeric Surfaces

“…[21] Recent findings have revealed that the geometry of the templates could affect their uptake into cells by phagocytosis. [22] Attachment of particles to the specific site of cells can be tuned not only via surface chemistry but also by changing the geometry of the particles even at the nanoscale. [23], [24], [25] Thus, future trends in particle assisted drug delivery are seen towards novel methods of synthesis and elaboration of anisotropic particles which in some cases may even resemble such natural entities as bacteria.…”

Decoupling the shape parameter to assess gold nanorod uptake by mammalian cells

“…10,11 One of the earliest studies was by Chithrani et al on cetyltrimethylammonium bromide (CTAB) coated gold nanorods where a negative correlation between aspect ratio and cellular uptake was found. 12,13 However, recent research has highlighted the significance of multiple convoluted variables such as ligand cytotoxicity, 14 particokinetics, 15,16 colloidal stability 17 and nanoparticle volume, 18 among others. An appropriate example of this is the study of Qiu et al who found a similar result as Chithrani et al except that upon passivating the surface with polyelectrolytes the apparent shape-dependent uptake was diminished.…”