H2S-Releasing Composite: a Gasotransmitter Platform for Potential Biomedical Applications

This is the authors' abstract. We don't add key points for this paper.

Hydrogen sulfide (H 2 S) is an endogenous gasotransmitter in the human body involved in various physiological functions including cytoprotection, maintaining homeostasis, and regulation of organ development. Therefore, H 2 S-releasing polymers that can imitate endogenous H 2 S release can offer great therapeutic potential. Despite decades of research, the use of H 2 S donors in medical device applications is mostly unexplored largely due to the challenge of the steady H 2 S release from a suitable polymeric platform that does not compromise the normal cellular functions of the host. In this work, an exogenous H 2 S release system was developed by integrating sodium sulfide (Na 2 S), a common H 2 S donor, into a medical-grade thermoplastic silicone-polycarbonate-urethane polymer, Carbosil 20 80A (hereon as Carbosil), via a facile solvent evaporation technique. The spatial distribution and nature of Na 2 S in Carbosil were characterized through X-ray diffraction (XRD) spectroscopy and field emission scanning electron microscopy (FESEM) with energy-dispersive spectroscopy (EDS), indicating an amorphous phase shift upon incorporating Na 2 S in Carbosil. The composite, Na 2 S–Carbosil, is responsive in physiological conditions, resulting in sustained H 2 S release measured for 3 h. In vitro cellular responses of 3T3 mouse fibroblasts, human lung epithelial (HLE), and primary human umbilical vein endothelial cells (HUVEC) were investigated. Fibroblast cells showed cell proliferation in 24 h and complete cell migration in 42 h in vitro . The Na 2 S–Carbosil composites were cytocompatible toward HUVEC and HLE cells. This study provided important in vitro proof of concept that warrants potential use of these H 2 S-releasing platforms in engineering biomedical devices, tissue engineering, and drug delivery applications.