We have developed collagenase-sensitive hydrogels by incorporating a collagenase-sensitive fluorogenic substrate (CS-FS) within the backbone of a polyethylene glycol (PEG) copolymer to visualize collagenase activity during three-dimensional cell migration. CS-FS was synthesized by conjugating Bodipy dyes to a peptide with collagenase-sensitive sequence, Leu-Gly-Pro-Ala (LGPA), and the products ...

Glucose-sensitive hydrogels were prepared by the copolymerization of diethylaminoethyl methacrylate (DEAEM), poly(ethylene glycol) monomethacrylate (PEGMA) and functionalized glucose oxidase (GOD) and catalase in solution. Tetra(ethylene glycol) dimethacrylate (TEGDMA) was used as the crosslinking agent. The equilibrium and dynamic swelling properties were studied to investigate the pHsensitive...

Controlled and sustained drug delivery has become the standard in modern pharmaceutical design and an intensive research work is going on in obtaining better drug product effectiveness, reliability and safety. In this regard, many polymers are very useful with majority of hydrogels, which undergo reversible volume and/or sol-gel phase transitions in response to physiological or other external s...

PURPOSE Diabetic retinopathy (DR) is a leading cause of blindness in diabetic patients that involves early-onset retinal cell loss. Here, we report our recent work using subconjunctivally implantable hydrogels for sustained insulin release to the retina to prevent retinal degeneration. METHODS The hydrogels are synthesized by UV photopolymerization of N-isopropylacrylamide and a dextran macro...

Injectable hydrogels as an important biomaterial class have been widely used in regenerative medicine. A series of injectable poly(L-glutamic acid)/chitosan (PLGA/CS) hydrogels were fabricated by selfcrosslinking aldehyde-modified PLGA (PLGA–CHO) and lactic acid-modified chitosan (CS–LA). The oxidation degree of PLGA–CHO and degree of substitution (DS) of CS–LA could be adjusted by the amount o...

Hydrogel actuators were prepared by combining ionoprinting technique with reversible metal ion coordination chemistry found in mussel adhesive proteins. Hydrogels were formulated with biomimetic dopamine moiety, which contains a catechol side chain that is capable of forming mono-, bis-, and tris-complexes with ferric (Fe 3+ ) ions with increasing pH. CatecholFe 3+ complexation increased local ...

To study the release of liposome-associated drugs into hydrogels, we designed and synthesized two pH-sensitive rhodamine derivatives to use as model compounds of different lipophilicities. The dyes were fluorescent when in the free form released from liposomes into the chitosan hydrogel, but not when incorporated within liposomes. The effect of liposomal composition, surface charge and vesicle ...

Hydrogels composed of N-quaternized chitosan (NQC) and poly(vinyl alcohol) (PVA) in different weight ratios (1:3), (1:1) and (3:1) chemically crosslinked by glutaraldehyde in different weight ratios – 1.0 and 5.0% – have been prepared. The prepared hydrogels were characterized via several analysis tools such as: Fourier transform IR (FTIR), X-ray diffraction (XRD), scanning electron microscope ...