The Reaserch Of Hydroxybutylchitosan Sensitivehydrogel As A Blood Vessel Embolismcarrier

Recently, much attention has been paid on injectable hydrogels in the felds ofbiomaterials and polymer science. These materials are fowable aqueous solutionsbefore administration, but gel rapidly under the physiological condition. Hydrogelsthat are hydrophilic three-dimensional polymeric networks capable of absorbing largequantities of water have been widely used in biomedical feld as wound dressing, drugdelivery systems and tissue engineering scaffolds.Chitosan, generally derived from naturally abundant chitin, is a non-toxic,biocompatible, and biodegradable material. However, due to the existence of strongintramolecular and intermolecular hydrogen bonding interactions of chitosan andstable crystallization, chitosan have poor dissolving property. Chitosan can only bedissolved in a dilute acid solution, e.g. dilute sulfuric acid, dilute hydrochloric acidand acetic acid, etc., which greatly limits its application. Thus enhancement of thedissolving properties of chitosan, especially the water solubility, is an importantresearch direction in the study of modified chitosan. In this paper, we used1,2-butylene oxide as the etherifying agent and introduced hydroxybutyl to the chitosanunder alkaline conditions to obtain water-soluble hydroxybutyl chitosan (HBC).Furthermore, reagent dosage, reaction temperature, reaction time were researched andthe best preparation conditions of hydroxybutyl chitosan were preliminarydetermined.In this paper, we prepared different concentrations of HBC solutions, andconcentrated HBC aqueous solution could transform into hydrogel within30s afterinjection under physiological temperature in non-chemical fashion. The properties ofthe HBC gels including chemical structure, surface morphology and rheologicalproperties were studied. Gelation temperature and gelation time of HBC could beadjusted by HBC concentrations. The gel erosion rate in vivo was faster thansolubilization rate in vitro. The mild infammatory response caused by implantation of the hydrogel was acceptable. The DOX·HCl (1mg/ml) loaded HBC gels displayedslow release rates that were independent of the HBC concentration, and signifcantlyreduced viability of4T-1cells compared with the HBC gels after1day incubation.These results indicate thermosensitive HBC hydrogel have promising potential as aninjectable drug carrier for pharmaceutical applications.In this paper, HBC gel is used to study biology behavior as embolizationmaterials. The in vivo performance to auricular arteries in rabbit results present hereindicated that HBC hydrogel could cause the arterial blood interruption, and theembolized tissue died. In conclusion, HBC hydrogel acquired good embolizationeffects and is an excellent alternative to superselective embolization materials.