title: Sodium Deoxycholate Hydrogels: Effects of Modifications on Gelation, Drug Release, and Nanotemplating.
abstract: In the present study, sodium deoxycholate (NaDC) was used to produce gelation of tris(hydroxymethyl)amino-methane (TRIS) solutions above, below, and near the pKa of NaDC, respectively, which yielded a neutral gelator, a charged gelator, and a mixture of each. Impacts of ionic interactions on gel formation were studied in detail and showed that pH can be used to modify many hydrogel properties including sol-gel temperature, crystallinity, and mechanical strength. Several formulations yielded a unique rheological finding of two stable regions of elastic modulus. The release of a small molecule has been investigated under different hydrogel conditions and at variable shear rate, suggesting utility as a drug-delivery vehicle. It was also observed that pH modification of the hydrogels affected nanoparticle formation. Nanoparticles derived from a Group of Uniform Materials Based on Organic Salts (nanoGUMBOS), specifically cyanine-based NIR dyes, were templated within the hydrogel network for potential applications in tissue imaging. These nanoGUMBOS were found to be size-tunable, although material-dependent. Further understanding of NaDC/TRIS gelation has broadened the tunability and multidimensional applications of these tailored hydrogel systems.
authors.affiliation: †Department of Chemistry, Louisiana State University, 434 Choppin Hall, Baton Rouge, Louisiana 70803, United States.
authors.forename: Kelsey E
authors.initials: KE
authors.lastname: McNeel
authors.affiliation: †Department of Chemistry, Louisiana State University, 434 Choppin Hall, Baton Rouge, Louisiana 70803, United States.
authors.forename: Susmita
authors.initials: S
authors.lastname: Das
authors.affiliation: †Department of Chemistry, Louisiana State University, 434 Choppin Hall, Baton Rouge, Louisiana 70803, United States.
authors.forename: Noureen
authors.initials: N
authors.lastname: Siraj
authors.affiliation: †Department of Chemistry, Louisiana State University, 434 Choppin Hall, Baton Rouge, Louisiana 70803, United States.|‡Louisiana State University AgCenter, 304 Thomas Boyd Hall, Baton Rouge, Louisiana 70803, United States.
authors.forename: Ioan I
authors.initials: II
authors.lastname: Negulescu
authors.affiliation: †Department of Chemistry, Louisiana State University, 434 Choppin Hall, Baton Rouge, Louisiana 70803, United States.
authors.forename: Isiah M
authors.initials: IM
authors.lastname: Warner
mesh_terms: D016880:Anisotropy; D003840:Deoxycholic Acid / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000295:instrumentation; D065546:Drug Liberation; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007477:Ions / Q000737:chemistry; D008422:Materials Testing; D055595:Mechanical Phenomena; D046529:Microscopy, Electron, Transmission; D008859:Microscopy, Polarization; D053758:Nanoparticles / Q000737:chemistry; D012212:Rheology; D044366:Transition Temperature; D014325:Tromethamine / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D020100:Hydrogels; D007477:Ions; D003840:Deoxycholic Acid; D014325:Tromethamine