Preparation Of Self-assembled Octenyl Succinic Anhydride Modified Short Glucan Chains And Study On Loading Curcumin

In this paper,short glucan chain were prepared by enzymatic hydrolysis and then octenyl succinic anhydride was hydrophobically modified to obtain octenyl succinic short glucan chain polymer,which was self-assembled into a core-shell structure by direct dissolution method.The nanomicelles were finally embedded in curcumin with the parent octenyl succinic short glucan chain nanoparticle as a carrier to obtain a curcumin nanoparticle transport carrier.The structure of the amphiphilic starch polymer and its degree of substitution were determined by FTIR and 1HNMR.FTIR results showed that the octenyl succinic group successfully introduced into starch molecules;and nuclear magnetic resonance（¹H NMR）technique was used to determine the DS of OSA-SGC.X-ray diffraction（XRD）,thermogravimetry（TGA）,differential scanning calorimetry（DSC）,transmission electron microscopy（TEM）,dynamic light scattering（DLS）,fluorescence spectrophotometer,and other techniques were used to study short octenyl succinic acid glucan chain nanomicelle configuration,thermal stability,glass transition,melting,morphology,particle size,critical micelle concentration（CMC）and other properties.The results showed that when the degree of substitution was relatively low,the degree of crystallinity did not change and was consistent with short dextran chain,and the crystal form was B+V type;when the degree of substitution was increased,the structure of the particles showed a V-shaped structure,and the molecular structure changes from double helix to a single helix;after the esterification reaction,the thermodynamic stability of the SGC decreases,the reason may be that the modification of the OSA destroys the partial crystalline structure of the SGC;the T₀,Tp and Tc of octenyl succinic short dextran chain nanoparticles are lower than those of natural waxy maize starch.This characteristic is more obvious with the increase of the DS of the substitution,which may be due to the destruction of the crystalline structure of the short-chain dextran after OSA modification;In addition,gelatinization enthalpy△H decreased with the increase of DS of substitution;TEM showed that the self-assembled starch nanomicelles were spherical particles;DLS data showed that octenylsuccinic acid short chain glucan increased as the degree of substitution increased.The particle size of nanospheres decreased significantly.The octenylsuccinic acid short glucan chain nanomicelles have good dispersibility in the range of 110-190 nm,and the fluorescence spectrophotometer determines the CMC of the octenyl succinic acid short glucan chain polymer.As the degree of substitution increases,the CMC gradually decreases.The polydispersity coefficient was kept below 0.2,indicating that the prepared octenylsuccinic acid short glucan chain nanospheres have better dispersibility.The solubility of octenyl succinate-degraded short glucan chain was significantly improved,and it dissolved well in deionized water.The solution was clear and transparent.Using octenyl succinic anhydride modified short glucan chain nanomicelles as carrier and hydrophobic drug curcumin as a model,a core-shell nano-transport system loaded with curcumin was prepared.The results showed that the embedding rate reached more than 60%,and the efficient loading of curcumin was achieved,and the solubility of curcumin was greatly improved.In the simulated gastrointestinal fluid digestion test,the digestion and absorption rate of curcumin nanoparticles（12.6%）is four times that of curcumin and octenylsuccinic acid short dextran chain mixture（3.2%）,the effect of digestion and absorption was significantly increased,and the bioavailability of curcumin was improved.The results of in vitro release showed that OSA-SGC-CUR nanoparticles have a phased burst-relieved release-controlled release behavior in the intestinal environment,enabling curcumin to rapidly reach an effective concentration in the blood and prolonging the action time of curcumin in the blood.With intestinal slow release control function.The release of OSA-SGC-CUR nanoparticles from the simulated intestinal fluid environment is more complete and has a good targeted intestinal drug release.