Sustained delivery of doxorubicin using biodegradable pH/temperature-sensitive poly(ethylene glycol)-poly(β-amino ester urethane) multiblock copolymer hydrogels

Polyurethane foam containing rhEGF as a dressing material for healing diabetic wounds: Synthesis, characterization, in vitro and in vivo studies

“…For PUFs, an -NCO peak was not observed around 2,265 cm -1 . This result is consistent with previous reports that exhibit isocyanate group disappearance [48]. The disappearance of the -NCO peak after reaction with -OH groups in glycerol and water indicated that the urethane and urea linkages are well-formed, without unreacted -NCO group.…”

“…Based on this observation, it is expected that rhEGF/PUFs are relatively suitable as a dressing material in terms of their WVTR. are caused by amine groups (-NH stretching and bending vibrations) existing in the urethane and urea linkages [48]. A peak around 1,700 cm -1 is caused by a carbonyl group (-C=O stretching) existing in the PU polymer [49].…”

Injectable polymeric hydrogels for the delivery of therapeutic agents: A review

“…The addition of urea bonding enhanced the mechanical strength as well as prolonged the degradation time, which was promising for long-term applications [110]. In contrast, ester bonding in the multiblock and triblock poly(b-amino ester urethane) served as the hydrolytically degradable factor, which enhanced the degradation rate of the hydrogels [111,112]. Using 4-arm polyethylene glycol to build the star-shaped copolymer led to gelation even with low molecular weight polymers [113].…”

“…Aqueous solutions of these short chain gelators have exhibited a pH-and temperature-responsive sol-gel transition, with the gel windows occurring under physiological conditions. For therapeutic applications, these polymers and oligomers may be potential carriers for the delivery of various types of drugs or proteins such as doxorubicin [111,118], human growth hormone [112], lidocaine [115], chlorambucil [109,113], FITC-BSA [110], paclitaxel [108], and insulin [117].…”

Sulfamethazine-based pH-sensitive hydrogels with potential application for transcatheter arterial chemoembolization therapy

“…At a predetermined time, 1.5 mL of the release medium was sampled and stored at -21 o C, and 1.5 mL of fresh medium was added to the vials to maintain a constant volume of release medium. The DOX concentrations in the release and standard samples were analyzed by UV-Vis spectroscopy at 485 nm [61]. The absorbance values were used to calculate the DOX concentration and cumulative release profile.…”