Colloidal Clusters and Networks Formed by Oppositely Charged Nanoparticles with Varying Stiffnesses.

Colloidal clusters and gels are ubiquitous in science and technology. Particle softness has a strong effect on interparticle interactions; however, our understanding of the role of this factor in the formation of colloidal clusters and gels is only beginning to evolve. Here, we report the results of experimental and simulation studies of the impact of particle softness on the assembly of clusters and networks from mixtures of oppositely charged polymer nanoparticles (NPs).

Microfluidic arrays of dermal spheroids: a screening platform for active ingredients of skincare products.

Organotypic micrometre-size 3D aggregates of skin cells (multicellular spheroids) have emerged as a promising model that can be utilized as an alternative of animal models to test active ingredients (AIs) of skincare products; however, a reliable dermal spheroid-based microfluidic (MF) model with a goal of AI screening is yet to be developed. Here, we report a MF platform for the growth of massive arrays of dermal fibroblast spheroids (DFSs) in a biomimetic hydrogel under close-to-physiological flow conditions and with the capability of screening AIs for skincare products. The DFSs formed after two days of on-chip culture and, in a case study, were used in a time-efficient manner for screening the effect of vitamin C on the synthesis of collagen type I and fibronectin.

Matrix Stiffness-Regulated Growth of Breast Tumor Spheroids and Their Response to Chemotherapy.

Interactions between tumor cells and the extracellular matrix (ECM) are an important factor contributing to therapy failure in cancer patients. Current in vitro breast cancer spheroid models examining the role of mechanical properties on spheroid response to chemotherapy are limited by the use of two-dimensional cell culture, as well as simultaneous variation in hydrogel matrix stiffness and other properties, e.g.

Compound droplets derived from a cholesteric suspension of cellulose nanocrystals.

This study reports microfluidic generation of Janus droplets that consist of a liquid crystal component (a cholesteric aqueous suspension of cellulose nanocrystals, Ch-CNC) and a mineral oil (MO) component. The composition of the droplets was controlled by varying the relative flow rates of MO and Ch-CNC suspension. The shape of the Ch-CNC component of the droplets was changed from a truncated sphere to a hemisphere to a crescent moon.

Supramolecular Nanofibrillar Thermoreversible Hydrogel for Growth and Release of Cancer Spheroids.

Growth of three-dimensional cancer spheroids (CSs) in man-made hydrogels mimicking natural extracellular matrix is an important and challenging task. Herein, we report on a supramolecular temperature-responsive hydrogel designed for the growth and subsequent release of CSs. A filamentous hydrogel was formed at 37 °C from an aqueous suspension of cellulose nanocrystals surface-functionalized with temperature-responsive polymer molecules.