Hollow polydimethylsiloxane beads with a porous structure for cell encapsulation.

Based on a water-in-oil-in-water emulsion system, porous and hollow polydimethylsiloxane (PDMS) beads containing cells using a simple fluidic device with three flow channels are fabricated. Poly(ethylene glycol) (PEG) in the PDMS oil phase is served as a porogen for pore development. The feasibility of the porous PDMS beads prepared with different PEG concentrations (10, 20, and 30 wt%) for cell encapsulation in terms of pore size, protein diffusion, and cell proliferation inside the PDMS beads is evaluated. The PDMS beads prepared with PEG 30 wt% are exhibited a highly porous structure and facilitated fast diffusion of protein from the core domain to the outer phase, eventually leading to enhanced cell proliferation. The results clearly indicate that hollow PDMS beads with a porous structure could provide a favorable microenvironment for cell survival due to the large porous structure.

Fabrication of dihydroxyflavone-conjugated hyaluronic acid nanogels for targeted antitumoral effect.

We prepared hyaluronic acid (HA)-based nanogels conjugated with dihydroxyflavone (DHF) and evaluated their cellular uptake and antitumoral efficiency. 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) was used as a conjugation agent for esterification between DHF and HA as well as crosslinking among HA. The conjugations were confirmed by nuclear magnetic resonance spectroscopy, UV/vis spectroscopy, and high-performance liquid chromatography. The size and Zeta-potential of the DHF/HA nanogels were reduced with an increase in the concentration of DMTMM due to the involvement of more HA molecules for the conjugation reactions. The DHF/HA nanogel with a smaller size was greatly taken up by two kinds of tumor cells (HeLa and HepG2), compared to NIH3T3. The cell viabilities were reduced to approximately 60% for HeLa and HepG2 cells after 48 h post treatment with DHF/HA nanogels.