Supramolecular gels based on a gemini imidazolium amphiphile as molecular material for drug delivery

Abstract

A novel physical gel was obtained using a gemini imidazolium-based amphiphilic molecule dissolved in ethanol-water mixtures. The structure of the gel is comprised of intertwining nanofibres with widths of approximately 80 nm. The ethanol/water ratio has an important influence on the gelation process: the gelator is sparingly soluble in water and soluble in ethanol. The gelator is capable of incorporating anionic drugs in its fibrillar network easily; sodium ibuprofenate, indomethacin and the sodium salt of methotrexate were used as model drugs that were incorporated into the quickly forming gels. The characterization of these composite xerogels was made by different microscopy techniques as well as X-ray powder diffraction. The ability of the amphiphile to form a gel is largely maintained in the presence of the different model drugs and the overall morphology of the gels (that present a fibre like structure in all cases with intertwined ribbons) is very similar. Furthermore the in vitro release of the drugs from the gel and the in vivo anti-inflammatory efficacy was studied. The overall results show better release profiles and anti-inflammatory efficacy for indomethacin, and prove the promise of this molecular gel in controlled drug release, in the present case dermatological application.

Developing a self-healing supramolecular nucleoside hydrogel

“…Whilst these acyl cytidine derivatives are suitable for drug delivery in cancer i.e. intratumoural drug delivery and topical drug delivery, 19 the requirement for ethanol in establishing a mechanically stable gel, made them unsuitable for broader drug delivery applications such as sub-cutaneous or ocular delivery. Indeed, there was an opportunity to create a hydrogelator, without the requirement of ethanol for gelation, based on cytidine and extending the applications of this drug delivery platform.…”

Self-assembled sorbitol-derived supramolecular hydrogels for the controlled encapsulation and release of active pharmaceutical ingredients

“…LMWGs based on different building blocks, including G-quartets, 13 imidazolium amphiphiles 14 and fatty-acid-modified disaccharides, 15 have been tested for drug delivery. In attempts to control API release, Kim and co-workers demonstrated controlled release of AZT from a biotinylated amino acid, with streptavidin modifying release rate, 16 while Yang and co-workers used a fatty-acid-modified amino acid hydrogel with the pH of the receiving medium having a small impact on salicylic acid release.…”

In situ template synthesis of gold nanoparticles using a bis-imidazolium amphiphile-based hydrogel

“…Furthermore, the bis-imidazolium gelator used is an ionophore [26,27] meaning that, compared with other examples in the literature, the synthesized GNPs can incorporate anions without further modification. We describe the formation of GNPs using a recently reported hydrogel [28] of 1,3-bis[(3-octadecyl-1-imidazolio) methyl]benzene dibromide (1Á2Br) (Fig. 1) as a matrix.…”