Characterization And Biocompatibility Of In-situ-forming Organogels Based On Carboxylic Acid Derivatives

The stable gagregates are formed by molecular self-assembly through non covalent bond,which can form supramolecular gagregates containing a veriety of different shapes and structures.Supramolecular gel is a kind of important compounds by use of the traditional chemicial synthesis technology and supramolecular assembly technology,which is a three-dimensional network structure material through the weak π-π stacking,van der waals interaction,hydrogen bonding,hydrophilic/hydrophobic effect and other interactions.Supramolecular gel structurally similar to solid,but morphology is liquid.The structure of supramolecular gel makes the gel have many potential applications in tissue engineering,drug slow release,recycling and remove pollutants and so on.In this paper,we designed and synthesized a series of amphiphiles containing carboxylic acid group and detected their gelation behavior in many solvent and explored aggregate morphologies,self-assembly method and formation mechanism and so on.Meanwhile,we studied the properties of the drug release and the application in the biological activity.(1)We designed and synthesized the carboxylic acid derivatives,which can not gel any organic solvents.Interestingly,it can form gel quickly as soon as water was adding into the organic solution containing carboxylic acid derivatives.FT-IR,XRD,SEM and 1H-NMR is used to study the aggregation morphology and formation mechanism for gel.The results showed that the dimer of carboxylic acid group and van der waals interaction is the main driving force for the formation of gel.(2)The octadecyl malonic acid(C18ma)can form very stable gel in pH=7.0,which can be used as drug carriers and drugs release.We explored the effects of concentration of the drug,the amount of gel agent,pH of buffer solution on the drug release rate by using the drugs of salicylic acid and 2-hydroxyquinoline,The results show that the release rate decreased gradually with the increase of gelling agent concentration,,but the concentration of the drug have little effect on the rate of drug and the alkaline environment can destroy the structure of gel.(3)The gel preparation can be injected into mice because the amphiphile containing Carboxylic acid group can from gel quickly in the water,The results show that it can form in situ gel in mice subcutaneous injection site.The weight of mice showed that it is normal after a month,which suggests that gel injection agent has good biological compatibility.(4)We designed and synthesized carboxylic-acid-derived molecule containing Azobenzene group,which can form a one-component ultrasound organic gel under alkaline condition.FT-IR,SEM and XRD is used to study the aggregation morphology and formation mechanism for gel.The results showed that the dimer of carboxylic acid group and π-π stacking is the main driving force for the formation of gel.