Formation and characterization of pseudo-polyrotaxanes based on poly(p-dioxanone) and cyclodextrins

• Poly(p-dioxanone) (PPDO) can form pseudo-polyrotaxanes (PPRs) with cyclodextrin (CD).
• The formation of CD-PPRs was demonstrated using WAXD, 2DNMR, POM and FTIR analyses.
• Both thermal stability and hydrophilicity of PPDO were improved via CD imprisoning.
• The degradation behavior of PPDO can be controlled by the types and amounts of CDs.

Novel pseudo-polyrotaxanes (PPRs) consisting of poly(p-dioxanone) (PPDO) and cyclodextrins (CDs) were obtained via heat-cool (H-C) cycles. The optimum preparation condition for achieving the highest yield was investigated, which was selected as follow: 3 times H-C cycles in 72 h of PPDO and CDs dissolved in DMF at 60 °C. The PPRs were further characterized by using wide-angle X-ray diffraction (WAXD), NMR, FT-IR, and thermogravimetric analysis (TGA). It was found that PPDO could be wrapped by CDs units. Compare to the single PPDO chain, the PPRs have better thermal stability. Moreover, the hydrophilicity of PPRs is also enhanced significantly determined by the water static contact angle tests. In addition, hydrolytic degradation experiments showed that the PPRs had unique degradation behaviors. The construction of the PPRs based on the PPDO and CDs would further expand the application of PPDO as biomaterials.