Polyurethane-based thiomers: A new multifunctional copolymer platform for biomedical applications

Plasma Treatment of Polymer Powder as an Effective Tool to Functionalize Polymers: Case Study Application on an Amphiphilic Polyurethane

“…On the other hand, the formation of urethane linkages was proved by the appearance of characteristic bands at: 1720 and 1630 cm −1 , attributed to the stretching vibration of free and H-bonded carbonyl groups, respectively; 1540 cm −1 , ascribed to the bending N-H vibration and the stretching of the C-N bonds and 3350 cm −1 , assigned to the stretching vibration of N-H bonds. However, the peak at 1630 cm −1 may be also generated by the presence of urea bonds, which could be formed as byproduct of the first step, according to the work recently published by Laurano et al [17] and Qin, Jiang et al [26]. Nevertheless, the possible presence of a small amount of urea bonds is not expected to affect the successful synthesis of a high molecular weight poly(ether urethane).…”

“…We have previously reported that [15][16][17] aqueous solutions of the here-studied amphiphilic PEU, containing Poloxamer® 407 as building block, undergo temperature driven sol-to-gel transition by micelle self-assembly. In this work, the effect of plasma treatment on PEU thermosensitivity was studied, by estimating the critical micellar temperature of aqueous solutions of the modified polymer.…”

“…Each step consisted of sample incubation at the set temperature for 5 min followed by UV/Vis spectroscopy (Lambda 25, PerkinElmer, Waltham, MA, USA) within the spectral range 330-400 nm (resolution 1 nm). Finally, CMT was estimated by considering the first inflection of the sigmoidal curve obtained by plotting the measured absorbance at 356 nm vs. temperature [15,17].…”

Hybrid Injectable Sol-Gel Systems Based on Thermo-Sensitive Polyurethane Hydrogels Carrying pH-Sensitive Mesoporous Silica Nanoparticles for the Controlled and Triggered Release of Therapeutic Agents

“…Primary amines exposed along polymer backbone upon Bocremoval were quantified according to the method recently published by Laurano et al (2020) that adapted to water-soluble polymers the protocol usually used to quantify amino groups exposed on polymer surfaces (Noel et al, 2011). Briefly, the polymer was dissolved (0.04% w/v) in an Orange II Sodium Salt (Sigma Aldrich, Italy) aqueous solution (0.175 mg/ml in double distilled water, ddH 2 O) previously adjusted at pH 3 and then the resulting solutions were incubated for 18 h at RT, in the dark.…”

“…The effects of Boc-deprotection reaction on the integrity of PEU backbone were investigated by ATR-FTIR and SEC analyses, meanwhile the effective Boc group removal was assessed by Proton Nuclear Magnetic Resonance spectroscopy. Finally, exposed -NH 2 groups were colorimetrically quantified according to Laurano et al (2020).…”