Alginate-Chitosan Hydrogels Provide a Sustained Gradient of Sphingosine-1-Phosphate for Therapeutic Angiogenesis

• Published in: Annals of biomedical engineering 2017-04, Vol.45 (4), p.1003-1014
• Main Authors: Williams, Priscilla A., Campbell, Kevin T., Gharaviram, Hessam, Madrigal, Justin L., Silva, Eduardo A.
• Format: Article
• Language: English
• Subjects: Alginates; Alginates - chemistry; Alginates - pharmacokinetics; Alginates - pharmacology; Biochemistry; Biological and Medical Physics; Biomaterials; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Cells, Cultured; Chitosan; Chitosan - chemistry; Chitosan - pharmacokinetics; Chitosan - pharmacology; Classical Mechanics; Controlled release; Delayed-Action Preparations - chemistry; Delayed-Action Preparations - pharmacokinetics; Delayed-Action Preparations - pharmacology; Gels; Glucuronic Acid - chemistry; Glucuronic Acid - pharmacokinetics; Glucuronic Acid - pharmacology; Hexuronic Acids - chemistry; Hexuronic Acids - pharmacokinetics; Hexuronic Acids - pharmacology; Human Umbilical Vein Endothelial Cells - metabolism; Humans; Hydrogels; Hydrogels - chemistry; Hydrogels - pharmacokinetics; Hydrogels - pharmacology; Hypoxia; Lipids; Lysophospholipids - chemistry; Lysophospholipids - pharmacokinetics; Lysophospholipids - pharmacology; Medical services; Neovascularization, Physiologic - drug effects; Sphingosine - analogs & derivatives; Sphingosine - chemistry; Sphingosine - pharmacokinetics; Sphingosine - pharmacology; Surgical implants; Vascular diseases
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1007/s10439-016-1768-2

Sphingosine-1-phosphate (S1P), a bioactive lipid, is a potent candidate for treatment of ischemic vascular disease. However, designing biomaterial systems for the controlled release of S1P to achieve therapeutic angiogenesis presents both biological and engineering challenges. Thus, the objective of this study was to design a hydrogel system that provides controlled and sustained release of S1P to establish local concentration gradients that promote neovascularization. Alginate hydrogels have been extensively studied and characterized for delivery of proangiogenic factors. We sought to explore if chitosan (0, 0.1, 0.5, or 1%) incorporation could be used as a means to control S1P release from alginate hydrogels. With increasing chitosan incorporation, hydrogels exhibited significantly denser pore structure and stiffer material properties. While 0.1 and 0.5% chitosan gels demonstrated slower respective release of S1P, release from 1% chitosan gels was similar to alginate gels alone. Furthermore, 0.5% chitosan gels induced greater sprouting and directed migration of outgrowth endothelial cells (OECs) in response to released S1P under hypoxia in vitro . Overall, this report presents a platform for a novel alginate-chitosan hydrogel of controlled composition and in situ gelation properties that can be used to control lipid release for therapeutic applications.