Biocompatibility Amphiphilic Molecular Structure And Performance Study Of Lyotropic Liquid Crystal

Biocompatibility refers to a kind of property that when any foreign substancesenter into the biology or biological organization and coexist with noumenon, thebiology allows such substances exist in the body organisms and interact with thebiology. The biocompatible amphiphilic molecules is the surfactant has goodcompatibility with the biology. Chitosan, alkyl polyglucoside, glucose amide, sucroseester and cyclodextrins or its derivatives such representative biocompatibilityamphiphilic molecules are known as a new generation of world-class greenamphiphilic molecules and have the security non-toxic and mild to human body andeasily biodegradable properties. The superiority of biocompatibility mainly performsin several ways: （1） Biocompatibility amphiphilic molecules are almost non-toxic,have no stimulation to the eyes and skin. （2） Biocompatibility amphiphilic moleculesare more biodegradable than the kind of polyoxyethylene surfactants. （3）Biocompatibility amphiphilic molecules have a good effcet when it blends with othersurfactants. （4） Part of the biocompatibility amphiphilic molecules have a goodmedicinal value. Choose the green, easily degradable, no stimulus effect to humanskin biocompatibility amphiphilic molecules and study the aggregate properties ofsuch surfactants, then use it in the targeting release and slow-release of fundamentaldrugs, provide certain theoretical guidance for the actual drug production andapplication.In this paper, the sucrose ester and water-soluble chitosans are the main researchobjects, through mixing surfactants and blending surfactants with biocompatible oilphase to explore the influences of environmental temperature, surfactantconcentrations and interaction on the construction and performance of the liquidcrystal.1. Assembly of water-soluble chitosan used for VC carrierTwo kinds of ordered assemblies were found to be formed in the aqueoussolutions of a water-soluble chitosan, with changes in the concentration of the chitosan and temperature. （1） Steady rheological properties and dynamic rheologicalproperties of the two assemblies have been studied in different temperatures. Basedon this, choose two kinds of assemblies for release experiment of Vitamin C. （2）Steady rheological curves indicated that the two assemblies have strong fake plasticproperty. Dynamic measurements showed that the assemblyⅠmeets the Maxwellmodel in the low-frequencies, while it performs as an elastomer at the higherfrequencies. In the investigated frequency range, the loss modulus is always lowerthan the storage modulus for the assemblyⅡ. （3） Two kinds of assemblies have agood stability and release effect.2. Surfactant and oil effects on the liquid crystal formation ofS1570/Brij98 mixed systemsSurfactant and oil effects on the formation and the rheological properties oflyotropic liquid crystals formed by sucrose stearate were investigated by means ofphase diagrams, rheological techniques. （1） It shows that sucrose stearate can formliquid crystal phase at much lower concentration and lower temperature by addingoleyl polyoxyethylene （20） surfactant. After Inducing isopropyl myristate, the liquidcrystal phase formed by Brij98/S1570 system transformed from hexagonal liquidcrystal to lamellar liquid crystal. （2） The rheological experiments indicate that all theliquid crystal samples have strong fake plastic property and follow a shear-thinningbehavior. Dynamic measurements show that the hexagonal liquid crystal meets thegeneral Maxwell model, exhibiting viscoelastic behavior. In the investigatedfrequency range, the loss modulus of lamellar liquid crystal is always lower than thestorage modulus, performing as an elastomer. （3） In addition, when the mass ratio ofBrij98/S1570 is 5/5, shear stress and platform modulus of the lamellar liquid crystalincrease as the IPM concentration increases. Whereas at the 3/7 mass ratio ofBrij98/S1570, these values of lamellar liquid crystal decrease with this changes.3. Surfactant and oil effects on the liquid crystal formation ofS1570/Brij97 mixed systems In the S1570/Brij97 mixed systems, through mixing surfactants and blendingsurfactant with biocompatible oil phase to study the influences of environmentaltemperature, surfactant concentrations and interaction on the construction andperformance of the liquid crystal. （1） The sucrose ester is synthesized through theDMF method, its CMC is 1.902×10^-4mol/L and theγcmcis 37.32 mN/m. （2） Raisingtemperature or increasing the concentration of Brij97 help to form liquid crystal in theS1570/Brij97/H₂O mixed system. Steady rheological curves indicated that fourlamellar liquid crystal samples BS1^BS4 have strong fake plastic property. （3） In theS1570/Brij97/Oleic Acid/water systems at 37℃with the mass ratio of S1570/ Brij97is 7/3 and 5/5 respectively, polarizing texture of samples changes from oil texture intothe cross pattern texture and then changes to incomplete texture along with theincrease of the content of oleic acid. The storage modulus and loss modulus ofsamples reduce gradually as the oleic acid content increases, explaining that the layerstructure changes into micelle solution. （4） From the small Angle X-ray spectrumdiagram, we can find that Oil phase of oleic acid has much more influence on thestructure in the S1570/Brij97/Oleic Acid/water systems at 37℃with the mass ratio ofS1570/ Brij97 is 7/3. However, Oil phase of oleic acid has weak influence on thestructure in the S1570/Brij97/Oleic Acid/water systems at 37℃with the mass ratio ofS1570/ Brij97 is 5/5. When the content of Brij97 is higher, liquid crystal structure ismore stable in the mixed systems.