The pH and NaCl induced swelling response and drug and protein loading of poly(methacrylic acid-co-acrylic acid) microgels (4-10 μm diameter) were measured as a function of cross-link density. The swelling ratio (Q) of the microgels increased linearly from 2 to 12 when the mole fraction of crosslinking monomer decreased from 0.25 to 0.10 (at pH’s > 5.3). In the presence of 5 M NaCl (at pH’s > 5...

The organization of cells within a well-defined microenvironment is important in generating the resulting tissue function. However, the cellular organization within biodegradable scaffolds often does not resemble those of native tissues. In this study, we present directed assembly of microgels to organize cells for building porous 3D tissue constructs. Cell-laden microgels were generated by mol...

A new process technology modified from conventional coaxial electrospinning process has been developed to prepare polymer fibers from a high concentration solution. This process involves a pure solvent concentrically surrounding polymer fluid in the spinneret. The concentric spinneret was constructed simply by inserting a metal needle through a high elastic silica gel tube. Two syringe pumps we...

Alginate microgels are widely used as delivery systems in food, cosmetics, and pharmaceutical industries for encapsulation and sustained release of hydrophilic compounds and cells. However, the encapsulation of lipophilic molecules inside these microgels remains a great challenge because of the complex oil-core matrix required. The present study describes an original two-step approach allowing ...

Droplet microfluidic technology is applied for the high-throughput synthesis via Michael-type addition of reactive, micrometer-sized poly(ethylene glycol) (PEG) hydrogels ("microgels") with precisely controlled dimension and physicochemical properties. A versatile chemical scheme is used to modify the reactive PEG microgels with tethered biomolecules to tune their bioactive properties for the b...

The catalytic activity of Au nanoparticles in phenylboronic acid-containing polymer microgels can be tuned through the swelling-deswelling transition of the microgels in response to changes in glucose concentration. Upon adding glucose, the model catalytic reduction of hydrophilic 4-nitrophenol is accelerated, while the reduction of relatively more hydrophobic nitrobenzene slows down.

Electrospinning is a simple and versatile technique that relies on the electrostatic repulsion between surface charges to continuously draw nanofibers from a viscoelastic fluid. Electrospinning can generate nanofibers with a number of secondary structures. Surface and/or interior of nanofibers can be functionalized with molecular species or nanoparticles during or after an electrospinning proce...

The fabrication of the Guided Tissue Regeneration (GTR) membrane materials have become the key technique of the tissue engineering scaffold study. The cells adhere well on the fibers whose dimension is below their own so that the porous three dimension scaffold material can mimic the strueture of the natural extracellular matrix better and have the potential to be an ideal GTR membrane material...

Ionic PNIPAm microgels were synthesized by free-radical precipitation polymerization using 2-acrylamido-2-methyl-1-propanesulfonic acid as an ionic co-monomer (references 7 and 9 of the paper), and fluorescently labelled with the covalently linked dye methacryloxyethyl thiocarbamoyl rhodamine B. N, N-methylene-bis-acrylamide was used as a cross-linker (with a 2.74 mol% cross-link density) and p...