Beeinflussung der Aufnahme und lysosomalen Azidifizierung durch die Steifigkeit kolloidaler Partikel in vitro

Stiffness-Transformable Nanoplatforms Responsive to the Tumor Microenvironment for Enhanced Tumor Therapeutic Efficacy

Herein, we report, for the first time, a unique stiffness-transformable manganese oxide hybridized mesoporous organosilica nanoplatform (MMON) for enhancing tumor therapeutic efficacy. The prepared MMONs had a quasi-spherical morphology and were completely transformed into soft bowl-like nanocapsules in the simulated tumor microenvironment through the breakage of Mn-O bonds, which decreased their Young's modulus from 165.7 to 84.5 MPa. Due to their unique stiffness transformation properties, the MMONs had reduced macrophage internalization, improved tumor cell uptake, and enhanced penetration of multicellular spheroids. In addition, in vivo experiments showed that the MMONs displayed a 3.79- and 2.90-fold decrease in non-specific liver distribution and a 2.87- and 1.83-fold increase in tumor accumulation compared to their soft and stiff counterparts, respectively. Furthermore, chlorin e6 (Ce6) modified MMONs had significantly improved photodynamic therapeutic effect.

Quantitative Particle Uptake by Cells as Analyzed by Different Methods

There is a large number of two-dimensional static in vitro studies about the uptake of colloidal nano- and microparticles, which has been published in the last decade. In this Minireview, different methods used for such studies are summarized and critically discussed. Supplementary experimental data allow for a direct comparison of the different techniques. Emphasis is given on how quantitative parameters can be extracted from studies in which different experimental techniques have been used, with the goal of allowing better comparison.

Cubical Shape Enhances the Interaction of Layer-by-Layer Polymeric Particles with Breast Cancer Cells

Blood-borne objects display a nonspherical shape with in-flow dimensions much larger than the vascular endothelial fenestrations, yet, at the diseased state, are able to traverse through these fenestrations owing to their elasticity. The role of physical parameters including shape and elasticity in the behavior of objects found in the tumor microenvironment needs to be understood to ultimately enhance chemotherapy and minimize its side effects. In this study, sphere- and cube-shaped biocompatible elastic microparticles (EM) made via layer-by-layer assembly of hydrogen-bonded tannic acid/poly(N-vinylpyrrolidone) (TA/PVPON) as hollow polymer shells and their rigid core-shell precursors (RM) are explored. In contrast to rigid five-bilayer (TA/PVPON) core shells, hollow elastic shells are unrecognized by J774A.1 macrophages, yet interact with endothelial and breast cancer cells. Internalization of cubical shells is fivefold more efficient by HMVEC (human microvascular endothelial cells) and sixfold and 2.5-fold more efficient by MDA-MB-231 and by SUM159 (breast cancer cells), respectively, compared to spherical shells. The interaction of cubical (TA/PVPON)5 shells with endothelial cells is similar under 10 s(-1) (characteristic of tumor vasculature) and 100 s(-1) shear rate (normal vasculature) while it is decreased at 100 s(-1) shear rate for the spherical shells. Our data suggest that cubical geometry promotes interaction of particles with breast cancer cells, while elasticity prevents engulfment by phagocytic cells in the tumor microenvironment.