Studies On Hybrid Thermosensitive Hydrogel Of Cyclic Ether Modificated Amphiphilic Copolymer/Hyaluronic Acid

As a kind of drug delivery carrier, thermosensitive injectable in situ hydrogel isone of the most important forms. On the basis of the study of PCL-PEG-PCL, a newpolymer, poly(3-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone)-poly(ethyleneglycol)-poly(3-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) triblockcopolymers,(PECT), was developed by modifying the segment of PCL with pendentcycle ethers. PECT has advantages in storage, dissolving in water, temperaturesensing, gelation behavior and biocompatibility. However, the hydrogel used forreleasing drugs must have proper mechanical properties so that it should not collapseuntimely with the extrusion of surrounding tissue. PECT hydrogel has a shortage inthe mechanical strength and this limits the application of PECT hydrogel in the fieldof biomedicine. In this article, hyaluronic acid (HA) was introduced into PECThydrogel systems to form PECT/HA hybrid thermosensitive injectable hydrogel withthe methods of physical blending and chemical crosslinking.The gelation behavior was researched with the variation of HA’s molecularweight, content in the hydrogel, and the pattern of crosslinking. Besides, therheological properties, in vitro degradation, and drug release behavior were also tested.In addition, the cytotoxicity of PECT/HA hydrogel was tested on NIH3T3.Experimental results indicate that with the participation of HA, the rheologicalproperties of PECT hydrogel was improved. Furthermore, the strength of hydrogel,the in vitro degradation speed, and the rate of ASA release behavior can be adjusted insome degree by changing the molecular weight, content and the pattern ofcrosslinking. Moreover, the PECT/HA hydrogel also presented good biocompatibility.Therefore, the introducing of HA is a workable solution to strengthen the PECThydrogel. At the same time, it provided a method to adjust of the properties ofhydrogel.