Effect of surface functionalization on the physicomechanical properties of a novel biofunctional copolymer

Abstract

The physicomechanical properties of functionally active poly(hydroxyethyl methacrylate-co-methyl methacrylate) [poly(HEMA-co-MMA)] are evaluated. It has been reported that the surface phosphorylated poly(HEMAco-MMA) is capable of eliciting direct bone bonding when implanted in vivo. Hence, it is important to examine the physicomechanical property of the copolymer as a function of surface modification. The properties assessed are differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), equilibrium swelling, compressive strength, and dynamic mechanical analysis. According to the DSC data, the glass transition temperature, T g of poly(HEMA -co-MMA) is not significantly altered by surface phosphorylation. The TGA results demonstrated that unmodified and surface phosphorylated copolymers have similar degrada-tion profile. The differential thermal analysis further supports the data. The equilibrium swelling of functionalized poly(HEMA-co-MMA) in phosphate buffer saline ascertained that surface phosphorylation significantly increased the hydrophilicity of the copolymer. The study further illustrated that the percentage of equilibrium swelling appreciably increases with increase in HEMA content in the copolymer and reached a plateau after 100 h. Both compressive strength and compressive modulus of poly (HEMAco-MMA) decreased due to surface phosphorylation while dynamic storage modulus value was not altered.

Hierarchically Porous Osteoinductive Poly(hydroxyethyl methacrylate-co-methyl methacrylate) Scaffold with Sustained Doxorubicin Delivery for Consolidated Osteosarcoma Treatment and Bone Defect Repair

“…Altogether, a synergistic effect of higher degree of phosphorylation (evidenced from XPS analysis) and hydroxyl groups has led to greater extent of swelling for P-PHM scaffolds of the 90:10 group. 24 The porous scaffolds have displayed water contact angle values <90 o (Figure 5C) offering corroborative evidences to the hydrophilic nature of the scaffolds. 53 However, there were no statistically significant changes in hydrophilicity noticed following surface phosphorylation.…”

“…22 Our previous reports testify that 2-hydroxy ethyl methacrylate (HEMA) can be effectively used to impart functionalization to the methyl methacrylate solid polymer [methyl methacrylate (MMA) and HEMA molar ratio is 0.90:0.07], where the −OH groups of HEMA in the copolymer led to surface phosphorylation and promoted bone bonding in vivo. 23,24 Inspired from our previous findings, here, we present porous bifunctional poly(HEMA-co-MMA) therapeutic scaffolds synthesized with reverse composition of HEMA and MMA at two different millimolar ratios (HEMA/MMA 90:10 and 80:20). The therapeutic copolymer scaffold with a customized biodegradation profile and hierarchical porosity was synthesized by free radical copolymerization employing biocompatible porogens (H 2 O/NaCl), followed by surface phosphorylation and impregnation of doxorubicin (DOX).…”

Infection-Triggered, Self-Cleaning Surfaces with On-Demand Cleavage of Surface-Localized Surfactant Moieties

“…As shown in Figure , copolymerization with the TX conjugate did not significantly affect the time to reach the equilibrium swollen state, with the degree of swelling of the copolymers and the p­(HEMA) homopolymer increasing until 28 h of immersion in both pH 7 and pH 10 universal buffers, after which no further increase in weight was reported. The copolymers displayed significantly higher EWCs than the p­(HEMA) homopolymer at pH 7 and pH 10 as anticipated because of the influence of the surfactant conjugate on the hydrophilic character and the corresponding polymer swelling capacity . Furthermore, no significant differences in EWCs were observed between the polymers in buffers of different pH values because of the absence of ionizable pendant groups …”

“…The copolymers displayed significantly higher EWCs than the p(HEMA) homopolymer at pH 7 and pH 10 as anticipated because of the influence of the surfactant conjugate on the hydrophilic character and the corresponding polymer swelling capacity. 28 Furthermore, no significant differences in EWCs were observed between the polymers in buffers of different pH values because of the absence of ionizable pendant groups. 29 In Vitro pH-Mediated Surfactant Release Kinetics.…”

Anti-Adherent Biomaterials for Prevention of Catheter Biofouling

“…Plots of drug release with time into 1% w/v benzalkonium solutions are shown in (Hoffman 2002;Luo, et al 2009;Sailaja, et al 2011). As expected, the behavior observed herein, namely the significantly faster rates of hydrophobic drug release from the 5% and 10% p(MMP-co-HEMA) copolymers and the NMP-loaded p(HEMA) in contrast to the more sustained release from p(HEMA), 1% p(MMP-co-HEMA) and their p(DMP-co-HEMA) counterparts was analogous to that observed in the equilibrium swelling study, where the former three polymers displayed EWCs >100% and the latter polymers displayed EWCs <100%.…”