Structural characterization, mechanical properties, and in vitro cytocompatibility evaluation of fibrous polycarbonate urethane membranes for biomedical applications

Abstract

This paper reports the electrospinning of a series of oxidatively stable polycarbonate urethanes (PCU) [carbothane (ECT), bionate (EBN), and chronoflex (ECF)] using N,N-dimethyl formamide and tetrahydrofuran as the mixed solvent. The nonwoven membranes were characterized for their structure, performance, and compatibility with cells. Scanning electron microscope was utilized to study the structural morphology and fiber diameter. Microcomputed tomography (micro-CT) was used to characterize the 3D architecture, pore size distribution, and percentage porosity. All the membranes displayed a porous architecture with average fiber diameter in the range of 1.5-2 μm. Static mechanical tests on the membranes revealed that the tensile strength was greater than 7 MPa and the dynamic mechanical tests showed that the average storage modulus (E(i) ) is 2 MPa at 37°C. PCU membranes were subjected to accelerated in vitro degradation for 90 days in 20% hydrogen peroxide/0.1M cobalt chloride solution. Mechanical characterization of the membranes postdegradation confirmed a 64% reduction in tensile strength for EBN at the end of 90 days where as ECF and ECT did not show any significant mechanical property deterioration in the oxidative medium. Cytotoxicity of the membranes was evaluated using L929 fibroblast cells and the results indicated that all the PCU membranes were cytocompatible and showed good adherence to L929 cells. Accordingly, these results highlight the potential of these fibrous PCU membranes for biomedical applications but further in vivo correlation studies are required for better understanding of the biodegradation and biological efficacy.

Fabrication of Sealed Nanostraw Microdevices for Oral Drug Delivery

“…47–49 Thus, these devices are not likely to degrade before excretion from the GI tract, as they are composed of materials that degrade on the order of months or longer. 50–53 Furthermore, these devices could be tuned to release the majority of their drug payload within an hour (Supporting Information Figure S6), during which time the majority of devices remain bound to GI tissue in ex vivo studies, indicating that these devices could efficiently release their drug payload before passing through the GI tract. Together, the in vitro and ex vivo adhesion assays demonstrated that the nanostraws enhanced adhesion of the drug-releasing device surface to the intestinal epithelium while exposed to fluid flow, indicating that the nanostraws will facilitate prolonged and unidirectional drug release directly toward GI tissue.…”

Biocompatibility and biomechanical analysis of elastic TPU threads as new suture material

“…In this study, we evaluated the potential of filamentous TPU as a novel elastic biomaterial. PUs have been used in medicine in various fields as an implantable material because of its excellent biocompatibility and mechanical characteristics . The positive experiences with various PUs in vascular and orthopedic surgery led to the assumption that filaments of the relatively stable polycarbonate urethane could also prove effective as basis for a suture material with possibly superior mechanical characteristics .…”

“…PUs have been used in medicine in various fields as an implantable material because of its excellent biocompatibility and mechanical characteristics. 8,20,21 The positive experiences with various PUs in vascular and orthopedic surgery led to the assumption that filaments of the relatively stable polycarbonate urethane could also prove effective as basis for a suture material with possibly superior mechanical characteristics. 21,22 In a previous study, Lambertz et al 23 already showed that laparotomy closure using elastic sutures is feasible, without increasing the risk of burst abdomen.…”

One-Step Synthesis of Highly Efficient Oligo(phenylphosphonic Dihydroxypropyl Silicone Oil) Flame Retardant for Polycarbonate

“…Polycarbonate (PC) has become the fastest growing general engineering plastic among the five engineering plastics due to its good physical and chemical properties, including excellent transparency, high mechanical strength, good thermal stability, and high heat distortion temperature [1][2][3]. Moreover, PC exhibits more superior flame retardancy than ordinary plastics owing to its relatively high limiting oxygen index (22%-25%) and flame-retardant grade (UL-94 V-2) [4,5].…”