Synthesis And Characterization Of Cellulose-based Drug-loading Functional Materials

The drug delivery system which has slow-release property and target ability has attracted much attention.It was found that drug delivery system could decrease the toxicity and improve the therapeutic effect.Cellulose is an important class of natural polymers with good biocompatibility,biodegradability and low toxicity.As a result,it is widely used to prepare drug delivery systems.This dissertation focuses on the preparation of three functional hydrogels based on cellulose,The application of cellulosic hydrogel as drug carrier were explored.?1?A novel magnetic drug carrier based on cellulose,guar g?m,and Fe₃O₄ hydrogel microspheres was synthesized by chemical crosslinking.The magnetic hydrogel microspheres were characterized via an optical microscope,Fourier transform infrared spectroscopy,vibrating sample magnetometer and so on.The results showed that with the increase of guar g?m content in the mixed solution,the particle size decreased significantly and the swelling property increased remarkably.Applications of thus hydrogels in drug delivery were further evaluated,from which 5-fluorouracil?5-Fu?were chosen as model drugs.The results showed that with the increase of guar gum content,the drug loading increased first and then decreased.When cellulose:guar gum=5:1,the drug embedding rate was 89.1%.And,as the increase of the Fe₃O₄ content,the drug loading and the maxim?m c?mulative release has decreased remarkably.?2?In this work,with methyl cellulose as raw material,NaCl and sodium alginate as additives.Effects of NaCl and sodium alginate on rheological behavior of methyl cellulose aqueous solution were studied.The results showed that the phase transition temperature of methyl cellulose solution decreased with the increase of NaCl mass fraction due to"salting out".And,sodium alginate promotes the dissolution of methyl cellulose.Therefore,with the increase of sodium alginate content,the gelation temperature of the mixed solution increases,the gel strength decreases,the apparent viscosity increases,and the drug release rate increases from 24 h to 84 h.?3?A novel Indomethaein conjugated Methylcellulose prodrugs?MC-IND?were synthesized at home temperature by an amidation reaction between hydroxyl group on MC and carboxyl group on IND.The amphiphilic prodrug which still has properties of water solubility will undergo a completely reversibly sol-gel phase transition upon heating.The poperties of prodrug and hydrogel were characterized by H NMR Spectroscopy?¹H NMR?,scanning electron microscope?SEM?,rheology and so on.The results showed that increasing the loading of precursor molecules can effectively reduce the gelation temperature and increase the apparent viscosity of the hydrogel.In vitro release experiments showed that the release time of 5-fluorouracil in the gel was about 48h,and the time of methylcellulose-indomethacin was about 84 h,realizing the drug release in stages and synergistic treatment.