pH effect on cellular uptake of Sn(IV) chlorine e6 dichloride trisodium salt by cancer cells in vitro

Silk Nanocarrier Size Optimization for Enhanced Tumor Cell Penetration and Cytotoxicity In Vitro

Silk nanofibers are versatile carriers for hydrophobic and hydrophilic drugs, but fall short in terms of effective delivery to cells, which is essential for therapeutic benefits. Here, the size of silk nanofibers was tuned by ultrasonic treatment to improve the cell penetration features without impacting the structural features. The gradual decrease in silk nanofiber length from 1700 to 40 nm resulted in improved cell uptake. The internalized silk nanofiber carriers evaded lysosomes, which facilitated retention in cancer cells in vitro. The smaller sizes also facilitated enhanced penetration of tumor spheroids for improved delivery in vitro. The cytotoxicity of paclitaxel (PTX)-laden nanocarriers increased when the length of the silk nanocarriers decreased. Both the drug loading capacity and delivery of silk nanocarriers with optimized sizes suggest potential utility in cell treatments.

Micro Versus Macro - The Effect of Environmental Confinement on Cellular Nanoparticle Uptake

While the microenvironment is known to alter the cellular behavior in terms of metabolism, growth and the degree of endoplasmic reticulum stress, its influence on the nanoparticle uptake is not yet investigated. Specifically, it is not clear if the cells cultured in a microenvironment ingest different amounts of nanoparticles than cells cultured in a macroenvironment (for example a petri dish). To answer this question, here we used J774 murine macrophages and fluorescent nanodiamonds (FND) as a model system to systematically compare the uptake efficiency of cells cultured in a petri dish and in a microfluidic channel. Specifically, equal numbers of cells were cultured in two devices followed by the FND incubation. Then cells were fixed, stained and imaged to quantify the FND uptake. We show that the FND uptake in the cells cultured in petri dishes is significantly higher than the uptake in a microfluidic chip where the alteration in CO2 environment, the cell culture medium pH and the surface area to volume ratio seem to be the underlying causes leading to this observed difference.