Study On The Structure And Property Of Sodium Alginate/Gelatin/Chitosan Complex Hydrogel Microsphere

The hydrogel,made of sodium alginate which is one of the natural polymer as the main material,can shrink in the acid circumstances,while swell and degrade in the alkalinity circumstances.Therefore it's suitable for Intest targeted delivery of drugs,with a satisfactory prospect in the application and development.In this study,we prepared the sodium alginate/gelatin/chitosan blend beads (SA/GT/CS) and investigated the framework and properties.It was prepared by the methods of blending and coacervation-phase separation,the appearance framework was determined by the electronmicroscope,the chemical constitution was analyzed by the fourier transform infrared spectroscopy(FTIR),the property of swelling was determined by the volumetric method,and the property of degradation was determined by the weighting method.Then we took the bovine serum albumin (BSA)as the model drug,and observed the properties of the sodium alginate/gelatin/chitosan/bovine serum albumin blend beads(SA/GT/CS/BSA) in vitro by the spectrophotometric method;What's more,we researched in the differences of frameworks and properties among calcium alginate(CA),sodium alginate/chitosan(SA/CS),sodium alginate/gelatin(SA/GT)and sodium alginate/gelatin/chitosan blend beads(SA/GT/CS).Main results were as follows:1.The research in the framework and properties of SA/GT/CS indicated that,the best compounding would be SA/GT=5/1,CS=0.8%,CaCl₂=3%;while the optimal gelation time was 30 minutes;the water ratio was very high,the volume might become ten percent after been dried;the blend beads showed satisfactorily pH-sensitive and Temp-sensitive;and we saw the bonding between the molecule chains by FTIR.2.We synthesised the SA/GT/CS/BSA,and found that the more dosage,the higher loading drug ratio(DL),and the lower embedding ratio(ER),we determined the optimal dosage was 30mg/mL,at this time,the DL was 23.90%,the ER was 77.33%.Because the SA/GT/CS/BSA could degrade with the drug released in the alkalinity circumstances,we assessed that the SA/GT/CS/BSA belonged to the corrosion poly-agent system,the degradation is obvious in the alkaline environment,while in the acid environmentis not.Therefore,it was profit for the protein drugs' orient-release in the simulated intestinal solution.3.Comparing with the CA,SA/GT,SA/CS,SA/GT/CS,we concluded that blending the sodium alginate,gelatin and chitosan simultaneously could improve the hydrogel tenacity and obtain a better mechanical ability;the effect of the diversity of the material composition is very low;otherwise,the swellings and degradations could be described as SA/GT＞CA＞SA/GT/CS＞SA/CS;the figure of SEM also identified that the SA/GT/CS/BSA could have the highest DL and ER.The toxic substances such as the cross-linking agents were not inlet in the preparation,which could maintain the biocompatibility of natural polymer.What's more,blending the sodium alginate,gelatin and chitosan simultaneously may be a new idea for reshaping the medicinal carriers.SA/GT/CS has a better pH-sensitive and degradation,a large loading and imbedding,thus it will be a ideal pharmaceutical grade protein carrier for the oral administration,there will be significant for improving the bioavailability and therapeutic effect.