Non-enzymatic nitric oxide release from biodegradable S-nitrosothiol bound polymer: synthesis, characterization, and antibacterial effect

Nitric oxide (NO) delivery is an effective method for the development of NO-mediated therapy under the physiological conditions for biological applications. S-nitrosothiol is the most widely used NO donor for therapeutics which is capable of spontaneously releasing NO under physiological conditions and acts as a potential stable source of NO and as an S-nitrosating agent. In this present work, the preparation of a biodegradable and biocompatible polymer poly(acrylic acid) (PAA–CANO) cross linked with the S-nitrosothiol,cysteamine (CANO) is reported. Thus, prepared polymer showed a controlled maximum release of NO up to 6 days and it provided a potential defense against pathogenic bacteria. The prepared PAA–CANO was characterized by various techniques such as Fourier transform infrared spectroscopy, ultraviolet–visible spectrophotometry, nuclear magnetic resonance spectroscopy, and thermogravimetric analysis. In addition, loading of PAA–CANO into spongy scaffolds consisting of chitosan and alginate in 1:2 ratio resulting in a new antibacterial active compound suitable for providing infection-free environment on surgical covers, devices, and apparel is also reported. This polymeric scaffold showed a controlled NO release of 2.43 × 10⁻¹⁰ M/s/cm². The morphology of the scaffolds is a micro-fibrous structure with a porosity of 57% and it was characterized by scanning electron microscopy.

Covalent tethering of nitric-oxide-releasing compound S-nitrosocysteamine to poly(acrylic acid) improves its stability and leads to controlled release of nitric oxide useful for the antibacterial activity.