| Sodium hyaluronate,as a kind of human endogenous substance,has a high level of security,excellent water retention and viscoelasticity,and various physiological functions such as reducing inflammatory response and promoting wound healing.2021,sodium hyaluronate was listed as a new food ingredient,which has a broad application prospect in the food field.As sodium hyaluronate is susceptible to intermolecular depolymerization and molecular weight change under the influence of reducing and acidic substances,which affects its biological activity.In order to maintain the stability of sodium hyaluronate and its biological activity after feeding,this paper adopts sodium alginate as a sphere-forming matrix to prepare sodium hyaluronate into microspheres,optimize its preparation process,and determine its particle size,water content,swelling rate and other characteristics;and investigate the intestinal release effect of microspheres and their anti-inflammatory activity before and after digestion to provide a theoretical basis for the development of functional foods with sodium hyaluronate.1.Optimization of preparation process conditions for sodium hyaluronate/sodium alginate microspheresSodium alginate was used as the sphere-forming matrix,and sodium hyaluronate was encapsulated by extrusion method.The effects of sodium alginate concentration,calcium chloride concentration,curing time and sodium hyaluronate/sodium alginate mass ratio on the encapsulation rate of microspheres were investigated by single-factor test and response surface test to optimize the microsphere preparation process using encapsulation rate as an index.The results showed that the optimal process for the preparation of microspheres was 1.26%sodium alginate concentration,1.52%calcium chloride concentration,1:8.82 sodium hyaluronate:sodium alginate mass ratio,and 15 min curing time,and the encapsulation rate of sodium hyaluronate was 52.43%under this condition.2.Characterization of sodium hyaluronate/sodium alginate microspheres and their release effect studyThe particle size,water content,swelling rate,hardness,reversibility and elasticity of microspheres were determined by scanning electron microscopy and mass spectrometer,and the release of microspheres in the gastrointestinal tract was investigated by simulating the digestion of gastrointestinal fluid in vitro.The results showed that the average particle size of sodium hyaluronate/sodium alginate microspheres was 2.39±0.94 mm,water content was at 96%±0.52%,swelling rate was 2.60%±0.04%,hardness was 160.88±11.86,adhesion was-1.15±0.48,reversibility was 21.83±0.88,cohesiveness was 0.60±0.006,elasticity was 90.97±8.52,adhesive property 96.97±6.70,and masticatory property 87.84±5.88;the release rate of sodium hyaluronate/sodium alginate microspheres was 8.54%±1.87%in in vitro simulated gastric fluid digestion and 84.41%±13.18%in in vitro simulated intestinal fluid digestion,and the intestinal release of sodium hyaluronate/sodium alginate microspheres was better.3.Study of anti-inflammatory activity of sodium hyaluronate/sodium alginate microspheresThe MTS assay revealed that 0-200 μg/mL sodium hyaluronate had no toxic effect on RAW264.7 cells.RT-qPCR results showed that microsphere endolysate without in vitro mock digestion decreased the expression of LPS-induced inflammatory factors IL-6,IL-1β,TNF-α,and COX-2 mRNA in RAW264.7 cells by 25.55%,22.8%,23.66%,and 19.84%,respectively,and microsphere release by in vitro mock digestion decreased the expression of cellular inflammatory factors IL-6,IL-1β,TNF-α,and COX-2 mRNA by 27%,20.47%,22.14%,and 20.63%,respectively.western bloting assay showed that microsphere release without in vitro mock digestion The microsphere endolysate without in vitro mock digestion decreased the expression of LPS-induced inflammatory factors IL-6,IL-1β,TNF-α,and COX-2 protein in RAW264.7 cells by 18.94%,15%,30.66%,and 31.25%,respectively,and the microsphere release by in vitro mock digestion decreased the expression of the inflammatory factors IL-6,IL-1β,TNF-α,and COX-2 protein expression by 28.03%,30.8%,33.58%,and 30.56%,respectively.The microspheres inhibited cellular inflammatory factors before and after digestion,and the effects were not significantly different(p>0.05). |
