Design, Synthesis And Characterization Of Dendron-Like Poly (ε-Caprolactone) Based Biomaterials

Using dendron-like biodegradable Dm-PCL as precursor, we obtaineda series of dendron-like/linear/dendron-like biodegradable block copolymersand dendron-like PCL with cell-targeted group and photosensitive group.(1) Synthesis and Characterization of Dendron-like/Linear/Dendron-like Dm-PCL-b-PEG-b-Dm-PCL Copolymers via the ClickChemistryA new class of dendron-like/linear/dendron-like PCL-b-PEG-b-PCLtriblock copolymers was synthesized via controlled ring-openingpolymerization (ROP) of ε-caprolactone (CL) followed by a clickconjugation with bifunctional azide-terminated poly (ethylene glycol)(N3-PEG-N3). Their molecular structures and physical properties were indetail characterized by FT-IR, NMR, MALLS-GPC, DSC, and WAXD.Moreover, the biodegradable micelles and vesicles with different sizes (lessthan50nm) were easily fabricated from these triblock copolymers inaqueous solution, and both the morphology and the average size of thenanoparticles were investigated by the techniques of TEM and DLS. Thecopolymer composition and the dendritic topology of hydrophobic core hadno apparent influence on the morphology of nanoparticles. The loadeddoxorubicin drug hardly affected on the final morphology of nanoparticles.Moreover, the doxorubicin-loaded nanoparticles fabricated from thedumbbell copolymer showed a higher drug loading efficiency and a longerdrug-release time than the linear counterpart. (2) Synthesis and Characterization of Bifunctional Photosensitiveand Targeted Dendron-like Dm-PCLA bifunctional dendron-like PCL with photosensitive2-Diazo-1,2-naphthoquinones (DNQ) and targeted glycosyl residues (Glu-/Lac-) wassynthesized via sulfonylation followed by a click conjugation withazide-terminated glycosyl (Glu-N3/Lac-N3). Their molecular structures andphysical properties were in detail characterized by FT-IR, and NMR. Themorphology, the average size, as well as the photosensitive properties of theself-assembled nanoparticles were investigated by means of TEM, DLS, andUV-vis. The controlled drug-release behavior, especially the photosensitivedurg-release properties were in detail investigated. Moreover, the recognitionproperties were characterized by DLS and UV, and theGlu-PCL-DNQ/Lac-PCL-DNQ had specific recognition with ConA/RCA120lectin, respectively.