Dissertation > Excellent graduate degree dissertation topics show

Preparation and Properties of Chitosan-based Thermosensitive Composite Hydrogel

Author: YuTao
Tutor: LiHePing
School: Changsha University of Science and Technology
Course: Organic Chemistry
Keywords: Chitosan Carboxyethyl Folic acid Temperature -sensitive hydrogel pH sensitivity of Drug carrier Sustained-release
CLC: R943
Type: Master's thesis
Year: 2011
Downloads: 15
Quote: 0
Read: Download Dissertation

Abstract


Some new type chitosan-based thermosensitive hydrogels were designed and synthesized with folic acid or N-carboxyethyl modified,we used 5-fluorouracil as model drug and constructed the drug sustained releasing systems, then studied their releasing behavior. The main contents of this thesis as following:(1) Two series of novel chitosan-based thermosensitive hydrogel drug carriers were designed and synthesized. They were: N-carboxyethyl modified chitosan- based thermosensitive hydrogel, including ACS/FuH which loaded drug by hydrogel-entrapping, ACSFuH which loaded drug by chemical-bonding, and ACSCH prepared by both chemical-bonding and hydrogel-entrapping; folic acid modified chitosan-based thermosensitive hydrogel, including FACS/FuH prepared by folic acid modified chitosan, CS/FAFuH and ACS/FAFuH synthesized by folic acid modified 5- fluorouracil. A total of six new hydrogels were obtained, and their structures were characterized by IR, UV-Vis or LC/MS.(2) Discussed the best optimum conditions of N-carboxyethyl chitosan and its hydrogel. When the feeding of acrylic acid and chitosan ratio was 2.0 ml/0.1 g and the reaction temperature is 60℃, ACS could easily obtained by microwave heating only for 1 h in a grafting yield of 52.97%, which was proved to be a faster and more efficient way than the ordinary methods. The experiment also confirmed that the reactive amino in hydrogel, pH and temperature of solution could affect the change of sol-gel, N-carboxyethyl chitosan-based hydrogel could changed into gel at 37℃for 25 min when the pH of solution was 7.(3) The drug loading and releasing properties in vitro of drug sustained releasing systems of series N-carboxyethyl were determined with UV-Vis. ACS/FuH had highest drug loading in series N-carboxyethyl, the drug loading was 50% and encapsulation efficiency was 100%. But it effect of releasing was bad, the cumulative release rate of ACS/FuH was 64.68% in the first 3 h with a slight burst releasing, and reached 78.80% at 8h, the complete releasing happened in 15 h, showing a relatively fast releasing. ACSFuH had the best releasing effect, the cumulative release rate was 43.52% in the first 8 h, and 94.76% in 7 d, and however its drug loading was only 17.26%. ACSCH had both excellent releasing effect and high drug loading, its drug loading was 29.44% and encapsulation efficiency was 33.84%. The cumulative release rate of ACSCH was 48.25% in the first 3 h and 60.16% in 8 h without apparent burst releasing, in addition the drug loading and release effect of ACSCH could be adjusted according to the actual situation.(4) In series folic acid modified, FACS/FuH had the highest drug loading, the maximum of the amount of contained 5-Fu only be determined via its solubility in the solution. Although CS/FAFuH and ACS/FAFuH were loaded drug by hydrogel-entrapping, but as the solubility of 5-Fu-FA was very poor, we couldn’t obtained the products which had high drug loading, the drug loading of them were 10.73%. We found that the diffusion rate would be slower when 5-fluorouracil was modified by folic acid, and ACS/FAFuH had pH sensitivity, it could Swelling in the PBS buffer which pH was 7.4, in this environment its cumulative release rate was 73.2% in 8h and more suitable as a drug carrier.

Related Dissertations

  1. Studies on Chitosan and Its Derivatives Adsorption for Paralytic Shellfish Poisoning in Ostrea Rivularis Could,TS254.4
  2. Thermal Stability of Complexes of Chitosan Quaternary Ammonium Salt and Metal Ion,O634
  3. Polyethylenimine Conjugated Stearic Acid-g-chitosan Oligosaccharide Micelles for Antitumor Gene Therapy,R450
  4. Preparation and Characterization of the OCS/PLLA Composite Film for Biomedical Materials,R318.08
  5. Study on the Accumulation and Remove of Cadmium and Lead in Oysters,X174
  6. Fire Retardancy Performance of Poly (Ethylene Terephthalate) Containing Melamine Cyanurate,TB383.1
  7. Study on the Synthesis and Adsorption Behaviour of Chitosan Derivative,TS254.9
  8. Improvement of Preparation Technology for Chitin and Chitosan from By-product of Litopenaeus Vannamei,TS254.9
  9. Biological Control of Meloidogyne Spp. in Cucumber (Cucumis Sativus L.) and Development of the Ecological and Environment-friendly Fertilizer with Pesticides,S436.421
  10. Acid solution on the structure and properties of chitosan / hydroxyapatite composite,R318.08
  11. Study on Chitosan-Based Composiate Nano-Coating Dope and Its Effect of Fresh-Keeping for Coated Egg,TS253.2
  12. The Experimental Study of Semiconductor Laser Radiation and 5-FU Sustained Release Repressed Oral Malignant Tumor Cell,R739.8
  13. Studies on the Dissolution of Chitosan in Ionic Liquids,O636.1
  14. Application Adipose-devired Stem Cells and Silk Fibroin and Chitosan Scaffold Materials Building Common Cells-stents Complex Experiments,R329
  15. Bovine serum albumin and protamine from NOCC / alginate hydrogels release : the isoelectric point of two different biological molecules controlled trial,R943
  16. Alginate - chitosan membrane in guided bone regeneration in applied research,R318.08
  17. Chitosan Supported Metal Complexes and Their Catalytic Oxidation Resistance,O634
  18. Chitosan / tricalcium phosphate scaffold for tissue engineering Preparation and Properties,R318.08
  19. The Marrlid Reaction of Chitosan Oligsccarids and the Antioxidant Activity of It’s Derivatives,R285
  20. Chemical Modification and Application of Ginseng Organic Complex Fertilizer,S567.51

CLC: > Medicine, health > Pharmacy > Pharmacy > Pharmaceutics
© 2012 www.DissertationTopic.Net  Mobile