Morphological Diversity, Protein Adsorption, and Cellular Uptake of Polydopamine-Coated Gold Nanoparticles.

Polydopamine (PDA)-coated nanoparticles are adhesive bionanomaterials widely utilized in intracellular applications, yet how their adhesiveness affects their colloidal stability and their interactions with serum proteins and mammalian cells remain unclear. In this work, we systematically investigate the combined effects of dopamine (DA) concentration and polymerization time (both reaction parameters spanning 2 orders of magnitude) on the morphological diversity of PDA-coated nanoparticles by coating PDA onto gold nanoparticle cores. Independent of the DA concentration, Au@PDA NPs remain largely aggregated upon several hours of limited polymerization; interestingly, extended polymerization for 2 days or longer yield randomly aggregated NPs, nearly monodisperse NPs, or worm-like NP chains in the ascending order of DA concentration.

Effect of Alkylation on the Cellular Uptake of Polyethylene Glycol-Coated Gold Nanoparticles.

Alkyl groups (CH) are prevalent in engineered bionanomaterials used for many intracellular applications, yet how alkyl groups dictate the interactions between nanoparticles and mammalian cells remains incomprehensively investigated. In this work, we report the effect of alkylation on the cellular uptake of densely polyethylene glycol-coated nanoparticles, which are characterized by their limited entry into mammalian cells. Specifically, we prepare densely PEGylated gold nanoparticles that bear alkyl chains of varying carbon chain lengths (n) and loading densities (termed "alkyl-PEG-AuNPs"), followed by investigating their uptake by Kera-308 keratinocytes.

In Vitro Modeling of Emulsification of Silicone Oil as Intraocular Tamponade Using Microengineered Eye-on-a-Chip.

Purpose: There is a lack of a standardized methodology or a physiologically realistic in vitro model to investigate silicone oil (SO) emulsification. In this study, we replicated the SO-aqueous interface within a microfluidic chip to study the formation of SO emulsion droplets in the eye cavity.

Methods: A chip made of poly(methylmethacrylate) was used to represent a cross-section of the posterior eye chamber.