Abstract
Nitric oxide (NO) is involved in physiological processes, including vasodilatation, wound healing and antibacterial activities. As NO is a free radical, designing drugs to generate therapeutic amounts of NO in controlled spatial and time manners is still a challenge. In this study, the NO donor S-nitrosoglutathione (GSNO) was incorporated into the thermoresponsive Pluronic F-127 (PL)-chitosan (CS) hydrogel, with an easy and economically feasible methodology. CS is a polysaccharide with known antimicrobial properties. Scanning electron microscopy, rheology and differential scanning calorimetry techniques were used for hydrogel characterization. The results demonstrated that the hydrogel has a smooth surface, thermoresponsive behavior and good mechanical stability. The kinetics of NO release and GSNO diffusion from GSNO-containing PL/CS hydrogel demonstrated a sustained NO/GSNO release, in concentrations suitable for biomedical applications. The GSNO-PL/CS hydrogel demonstrated a concentration-dependent toxicity to Vero cells, and antimicrobial activity to Pseudomonas aeruginosa (minimum inhibitory concentration and minimum bactericidal concentration values of 0.5 µg·mL−1 of hydrogel, which corresponds to 1 mmol·L−1 of GSNO). Interestingly, the concentration range in which the NO-releasing hydrogel demonstrated an antibacterial effect was not found to be toxic to the Vero mammalian cell. Thus, the GSNO-PL/CS hydrogel is a suitable biomaterial for topical NO delivery applications.
Highlights
Nitric oxide (NO) is an endogenous molecule involved in several biological signaling pathways.At low concentrations, NO has regulatory functions, such as the promotion of vasodilation, wound healing, cell proliferation, inhibition of platelet adhesion and aggregation [1,2,3].At higher concentrations, NO has antitumor and antimicrobial effects [2,3,4].NO is considered a promising alternative to conventional antimicrobials
The diffusion of GSNO from aqueous GSNO reached a value of 50% of the total GSNO content after 4.5 h of monitoring, whereas in the case of GSNO-Pluronic F-127 (PL)/CS hydrogel the amount of GSNO that diffused was 20%, at the same time frame (Figure 5)
Can be observed, a typical characteristic of cytotoxicity (Figure 7B,D). These results demonstrated a concentration-dependent cytotoxicity of the GSNO-PL/CS
Summary
Nitric oxide (NO) is an endogenous molecule involved in several biological signaling pathways.At low concentrations (pico- to nanomolar), NO has regulatory functions, such as the promotion of vasodilation, wound healing, cell proliferation, inhibition of platelet adhesion and aggregation [1,2,3].At higher concentrations (micro- to millimolar), NO has antitumor and antimicrobial effects [2,3,4].NO is considered a promising alternative to conventional antimicrobials. Polymers 2018, 10, x FOR PEER REVIEW deliver a precise NO concentration directly to the target site of application, in sustained and convenient to deliver precise. NO concentration directly to the target site of application, in sustained and manners andawith minimal side effects [1]. NO is a free radical (half-life one to fiveeffects seconds), NO is awith free biomolecules radical (half-life oneastohemoglobin), five seconds), andlimiting can be inactivated upon reaction To biological overcomesystems this issue, upon NO-releasing reaction with biomolecules (such been as hemoglobin), limiting its effects. To overcome this of several biomaterials have prepared tothus carry and deliver therapeutic amounts issue, several
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
