Oleoyl Sodium Alginate Synthesis Optimization Along With The Nanoparticle Preparation And Characterization

Sodium alginate and its derivatives are popular research objects in the field of cellimmobilization, tissue engineering, drug delivery, controlled release, microorganismsimmobilization technology and food industry. It has been confirmed so many timesthat chemical modification can introduce great new features to natural seeweedpolysaccharides, and for that, amidation modification is carried out in this paper. Andultrasound-assisted self-assembly oleoyl-sodium alginate nanoparticles are preparedand investigated for many properties such like morphology and stabilitycharacteristics, and followed by the analysing the nanoparticle adsorption behavior ofbovine serum albumin (BSA).Firstly, we graft oleoyl group on to the carboxyl group of alginate in water-phasewith the aid of1-Ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride(EDC) and N-Hydroxysulfosuccinimide sodium salt (NHS). Formation of Amidebond Is confirmed by FT-IR and the degree of substitution(DS) is calculated byN-element content using energy dispersive spectrometer. Then we use Responsesurface methodology (RSM) to optimize the process and find the optimum synthesisconditions: sodium alginate volumn of100ml, mass ratio of8.70between oleamideand sodium alginate, rection time of24h and pH value of3.5. Under these conditions,the particle size and yield of OA are observed to be318.2nm and81.77%, which arein accordance with the predicted results.Then we chose samples of different DS and prepare the ultrasound-assistedself-assembled nanoparticals in aqueous media. With help from fluorescencespectroscopy, dynamic light scattering (DLS) and transmission electron microscopy,et al,it is proved successfully to achieve complete nanospheres in approximatespherical shape. While in its own water solution, the nanoparticles seem to dispersewell, have negative zeta potential,and presnet good storage and dilution stability.Associated with the degree of substitution results,it has been found that with the increaseing amidation modification, DS of the materials has increased from12.7%to13.79%,the self-assembled nano-particle size has decreased from485.20nm to284.74nm,and the CAC value has decreased from0.0103mg/ml to0.0043mg/ml.The BSA adsorption behavior of OA nanoparticles includes a incubation inducedadsorption process and a dilute KOH induced desorption process. We conclude fromthe kinetics study results that the protein adsorpted amounts of all nanoparticles haveaccumulated with time increasing, and reached a adsorption balance obtaining themaximum value at12hours, and is inversely proportional to the nano particle sizeunder the same incubation time. After constructing the adsorption isotherms, we findout that the equilibrium adsorption amount is proportional to the initial proteinconcentration and pH value，and inversely proportional to the particle size. Afterchanging the research objects to nanoparticles with different DS and same size, wefind out that the adsorpted amout is proportional to DS. Then we can demonstrate thatthe maximum adsorpted amount is inversely proportional to the particle size whichinfluence the adsorption behavior greatly, and proportional to the degree ofsubstitution which functions as a supporting role.DSC results show clearly that theadsorption process cause almost no change to the protein thermal stability, andSDS-PAGE gel electrophoresis has detected no protein molecule size or volumechange.