Thiol/Acrylate-Modified PEO-PPO-PEO Triblocks Used as Reactive and Thermosensitive Copolymers

Abstract

The reactive thermal-sensitive hydrogels, which combined the reversible thermosensitive and mild reactive property, were designed based on thiol-ene reaction in physiological conditions between thiol and acrylate capped thermosensitive Poloxamer 188. The modified P188A, P188SH, and their reactivity were characterized by (1)H NMR, FT-IR, GPC, DSC, Ellman method, and Rheometer. It was found that the thiol-ene reaction was pH and thermal-sensitive. There was 77.7% SH involved into the reaction at 37.0 degrees C and pH 7.4 within the first 30 min. The most of molecules reacted as CC/SH mol ratio was 1.5. The exothermic thiol-ene reaction was mild, with about DeltaH = -91.18 J/g changes. The multiblocks or network structure limited the dissolution of hydrogel, correspondingly the gel's duration and the release time of methylene blue were prolonged to 124 h. The experimental results indicated the reactive thermal-sensitive hydrogel's potential applications in drug delivery, tissue engineering, and cell encapsulation.

Sustained-release of FGF-2 from a hybrid hydrogel of heparin-poloxamer and decellular matrix promotes the neuroprotective effects of proteins after spinal injury

“…The solution-gel transition temperature of FGF2-dscECM-HP solution at which the immobility of the meniscus in each vial was first noted was recorded. 21 Meanwhile, the apparent viscosity of the FGF2-dscECM-HP solution was also tested in a coaxial cylinder rheometer (DV-III; Brookfield, Middleborough, MA, USA) with an SC4-14 rotor and a small sample adapter. Curves of apparent viscosity at different temperatures were obtained.…”

Three-dimensional structure micelles of heparin-poloxamer improve the therapeutic effect of 17β-estradiol on endometrial regeneration for intrauterine adhesions in a rat model

“…Their surface morphology was observed using an SEM. 19 In vitro release of drug E 2 solution and E 2 -HP hydrogel were prepared as previously described. In vitro release of E 2 was prepared according to the literature, with some modifications.…”

Chemically crosslinkable thermosensitive polyphosphazene gels as injectable materials for biomedical applications

“…In the present study, the kinetics of chemical cross-linking between the thiol functionalized polymer and cross-linkers were evaluated, and previously only a few research groups [40,46] have studied the kinetics of chemical cross-linking of thiol-based polymers.…”