Polyurethane with tethered copper(II)–cyclen complex: Preparation, characterization and catalytic generation of nitric oxide from S-nitrosothiols

Abstract

The preparation and characterization of a commercial biomedical grade polyurethane (Tecophilic, SP-93A-100) material possessing covalently linked copper(II)-cyclen moieties as a nitric oxide (NO) generating polymer are described. Chemiluminescence NO measurements demonstrate that the prepared polymer can decompose endogenous S-nitrosothiols (RSNOs) such as S-nitrosoglutathione and S-nitrosocysteine to NO in the presence of thiol reducing agents (RSHs; e.g., glutathione and cysteine) at physiological pH. Since such RSNO and RSH already exist in blood, the proposed polymer is capable of spontaneously generating NO when in contact with fresh blood. This is demonstrated by utilizing the polymer as an outer coating at the distal end of an amperometric NO sensor to create a device that generates response toward the RSNO species in the blood. This polymer possesses the combined benefits of a commercial biomedical grade polyurethane with the ability to generate biologically active NO when on contact with blood, and thus may serve as a useful coating to improve the hemocompatibility of various medical devices.

Immobilized ruthenium complexes and aspects of their reactivity

“…(14) and (15), the ruthenium cyclam complex in SiO 2 matrix is reacted with NO (g) resulting in SiO 2 /trans-[Ru(NO)Cl(cyclam)](PF 6 ) 2 Eqs. (16) and (17) …”

“…A wide range of materials can be used as matrices, including inorganic and organic polymers such as silica [1][2][3][4][5]7,20,[29][30][31], xerogels [21,[32][33][34], organic inorganic hybrid materials [34,35], silicone rubbers [36], polyurethane (PU) [16,36], poly(vinyl chloride) (PVC) [37], poly(vinyl alcohol) (PVA) [36,[38][39][40][41][42], poly(lactic-co-glycolic) acid (PLGA) [14], poly(methylmethacrylate) (PMA) [43] and dendrimers [6,44]. In addition, most of these materials can be made and/or modified, thereby resulting in different forms and shapes like powders, thin films, monoliths, nano or microparticles, and fibers [14,33,36,41,[45][46][47], which can serve as a platform for the immobilization of metal coordination compounds.…”

Nitric oxide based strategies for applications of biomedical devices

“…Meyerhoff and co-workers prepared polymers containing copper within the polymer network [143,151]. Tecophilic hydrophilic PU and polymethacrylate polymers with covalently linked Cu II -cyclen complexes have been shown to generate NO spontaneously from fresh sheep blood.…”

Evaluation of experimental methods for nitric oxide release from cardiovascular implants; bypass grafts as an exemplar

“…Before the SNAP solution was introduced to the reaction flasks, aqueous solutions of CuSO 4 and ascorbic acid were utilized to initiate NO release. A major mechanism of RSNO decomposition is mediated through catalytic breakdown using Cu 2+ , which involves the reduction of Cu 2+ to Cu + through reducing agents such as ascorbic acid or trace thiolate anion present in the solution [Frost and Meyerhoff, 2005;Hwang and Meyerhoff, 2008;Wang et al 2002].…”