Modification On Hydrophobic Segment Of Poly(Ethyleneglycol)-poly(ε-caprolactone) And Its Properties As Nanocarriers For Drug Delivery

In this study, hydroxyl groups, cinnamoyloxy groups and poly (methacrylic acid)brush were introduced to PCL segment to prepare novol copolymers. Firstly, thecopolymers was well characterized by1HNMR, FT-IR, GPC, DSC, XRD and etal.Secondly, the properties of NPs were investigatd. Lastly, the toxicity of blank anddrug loaded nanoparticels were evaluated.The introduction of hydroxyl groups onto the core-forming block could decreasethe hydrophobicity of copolymers thus improving the storage stability of NPs inaqueous solution. Moreover, higher loading capacity of DOX was observed, whichwas due to the hydrogen-bonding formation between DOX and hydroxyl groups.Meanwhile, the MTT assay demonstrated that the blank NPs were biocompatible toHepG2cells while free DOX and DOX-loaded NPs showed significant cytotoxicityagainst the cells.The introduction of cinnamoyloxy groups onto the core-forming block coulddecrease the crystallinity of the copolymers and imprpve the drug loading efficiency.The stability of NPs has been largely improved and PTX release was significantlyinhibited by crosslinking via UV irradiation at λ=254nm. MTT assays demonstratedthat both blank non-crosslinked and crosslinked NPs showed low cytotoxicity toNCL-H460cells while PTX-loaded non-crosslinked and crosslinked NPs exhibitedobvious cytotoxicity against NCL-H460cells, and the cytotoxicity was bothdose-dependent and time-dependent.The introduction of poly (methacrylic acid) brush groups onto the core-formingblock endowed the NPs pH sensitivity. The diameters and zeta potentials of NPsprepared from mPEG-b-(PCL-g-PMAA) were pH dependent. The in vitro release ofIBU from the NPs accelerated with pH increasing. The MTT assay indicated thatblank NPs prepared from mPEG-b-(PCL-g-PMAA) did not show significant toxicityagainst NCL-H460cells.The properties of NPs could be modified through the introduction of functionalgroups to the core-forming block, which could provided some basis for the design ofpolymer NPs.