Drug Doping Drug Release Of Supramolecular Complex Nature Of The Gel And Biomolecular Response

The self-assembling of small functional molecules into supramolecular structures is a powerful approach toward the development of new biomedical materials and nanoscale devices. As a novel class of self-assembled materials, organogels have received considerable attention in recent years because they can organize into regular supramolecular structures through specific noncovalent interactions including hydrogen bonds,π-πinteractions, van der Waals forces and hydrophobic interactions. In this thesis, three functional organogels were designed and synthesized. Their functionalities, morphology in the gel state were studied in details. Furthermore, the small amount of the compounds can entrap large quantities of water-soluble drug tetracycline hydrochloride (TH) into a stable gel in ethanol/water system. Release experiments were carried out under solutions of bovine serum albumin (BSA) and three amino acids (L-isoleucine, L-phenylalanine and L-tryptophan) with various concentrations. The whole paper contains two parts as following:1. Inclusion of drug molecule into supramolecular gel and Its functionalities research1) We synthesized 3,4,5-trihydroxybenzoic derivatives with different linker length(1a, 1b and 1c) and found that the small amount of low weight molecules can entrap large quantities of water-soluble drug tetracycline hydrochloride up to 96.12% into a stable gel in ethanol/water system.2) The FT-IR and absorption spectral study indicate the formation of strong intermolecular hydrogen bond between 1c and TH. This intermolecular interaction thus increase the aqueous solubility of the composite and can gel a quantity of water. To obtain better insight into the molecular organization in the gel specimens, the morphology of the composite xerogels were investigated by scanning electron microscopy (SEM).2. Controlled release response to varieties of biomolecule from composite gels entrapped drug molecule1) We have studied the different release profiles of four composite gels (1b+THmin, 1b+THmax, 1c+THmin, 1c+THmax) at various concentrations of BSA and amino acids. The result indicate dramatic enhancement in the release rate of TH at BSA solution (10 mg/mL) in the initial time and the retention of the gel structure after the release.2) The release dynamics of composite gels at various concentrations of BSA and three amino acids solutions was further studied. The result shows that the mechanism of TH release response to amino acids solutions is a diffusion mechanism, while BSA is mainly due to the intermolecular interactions over the given initial 1.75 h.