12 research outputs found
Improvement of hyaluronic acid enzymatic stability by the grafting of amino-acids
Injection of hyaluronic acid (HA)-based hydrogels has proven to provide many therapeutic benefits. To
increase the stability of HA-based products against enzymatic digestion, we modified hyaluronic acid by
grafting various amino acids on its carboxylic group and then evaluated the enzymatic stability of the
various conjugates in presence of a hyaluronidase. Our results showed that all amino acid-modified HA
polymers were more resistant to degradation compared to the native HA albeit with variation according
to the amino acids. Amino acids with carboxylate groups such as aspartic acid or with hydroxyl functions
(threonine, serine or tyrosine) conferred a particularly strong resistance to HA towards enzymatic
digestion. The HA-amino acid products were then cross-linked with butanediol diglycidyl ether (BDDE).
The swelling properties of the formed hydrogels appeared close to native HA whereas the increased
resistance towards hyaluronidase digestion remained. These results suggest that amino acid-modified
HA derivatives can become promising material for viscosupplementation or drug delivery
Beneficial Effect of Covalently Grafted alpha-MSH on Endothelial Release of Inflammatory Mediators for Applications in Implantable Devices
Intravascular devices for continuous glucose monitoring are promising tools for the follow up and treatment of diabetic patients. Limiting the inflammatory response to the implanted devices in order to achieve better biocompatibility is a critical challenge. Herein we report on the production and the characterization of gold surfaces covalently derivatized with the peptide alpha-alpha-melanocyte stimulating hormone (alpha-MSH), with a quantifiable surface density. In vitro study demonstrated that the tethered alpha-MSH is able to decrease the expression of an inflammatory cytokine produced by endothelial cells