Supramolecular Polypseudorotaxanes composed of star-shaped porphyrin-cored poly(epsilon-caprolactone) and alpha-cyclodextrin.
Star-shaped porphyrin-cored poly(epsilon-caprolactone) (SPPCL) was synthesized using a tetrahydroxyethyl-terminated porphyrin as a core initiator and stannous octoate as a catalyst in bulk at 120 degrees C. The molecular weight of as-synthesized polymer could be adjusted linearly by controlling the molar ratio of epsilon-caprolactone to porphyrin core initiator, and the molecular weight distribution was reasonably narrow. Supramolecular polypseudorotaxanes were prepared by inclusion complexation of SPPCL with alpha-cyclodextrin (alpha-CD) and thoroughly characterized by means of FT-IR, 1H NMR, 13C CP/MAS NMR, DSC, TGA, and WAXD. The results demonstrated that the porphyrin-cored polypseudorotaxanes formed through alpha-CD molecules threading onto the branch chains of star-shaped SPPCL polymers, and they had a channel-type crystalline structure. Meanwhile, the original crystallization of SPPCL polymers within the polypseudorotaxanes was completely suppressed in the alpha-CD cavities. Moreover, inclusion complexation between SPPCL and alpha-CD enhanced the thermal stability of both the guest SPPCL polymers and the host alpha-CD. Furthermore, both the SPPCL polymers and the polypseudorotaxanes showed similar fluorescent and UV-vis spectra compared with porphyrin core initiator. Consequently, this will not only provide potentially porphyrin-cored poly(epsilon-caprolactone) and its polypseudorotaxanes for photodynamic therapy but also improve the compatibility between poly(epsilon-caprolactone) and peptide drugs for drug delivery.
Dai
Xiao-Hui
XH
Department of Polymer Science & Engineering, School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Dong
Chang-Ming
CM
Fa
Huan-Bao
HB
Yan
Deyue
D
Wei
Yen
Y
D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011091:Polyesters / Q000737:chemistry*; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry*; D043862:Rotaxanes / Q000138:chemical synthesis / Q000737:chemistry*; D013816:Thermodynamics; D047391:alpha-Cyclodextrins / Q000737:chemistry*
D011091:Polyesters; D011166:Porphyrins; D043862:Rotaxanes; D047391:alpha-Cyclodextrins; C016240:polycaprolactone; C032613:alpha-cyclodextrin