Synthesis and characterization of thermosensitive hydrogel based on PEG-PCL-PEG block copolymers / 生物医学工程学杂志

In this paper, a series of low-molecular-weight PEG-PCL-PEG triblock copolymers were successfully synthesized by ring-opening polymerization method, and were characterized using 1H-NMR and FTIR. The aqueous solution displayed specific thermosensitive gel-sol transition when the concentration was above corresponding critical gel concentration (CGC). The gel-sol phase diagram was recorded using test tube-inverting method, which was depended on the hydrophilic/hydrophobic balance in macromolecular structure, as well as heating history. As a result, the gel-sol transition temperature range could be altered, which might be very useful for its application as injectable drug delivery system.

A novel nano-hydroxyapatite/aliphatic polyesteramide composite / 生物医学工程学杂志

Hydrothermally synthesized nano-hydroxyapatite (n-HA) varying in weight from 10% to 30% was used as filler to make nanocomposites with novel aliphatic polyesteramide (PEA) in our laboratory. The structure and properties of PEA and its n-HA composites were investigated through transmission electron microscopy, infrared spectrometry, X-ray diffractioin, scanning electron microscopy and energy spectrometry. The shape and size of the n-HA crystals are similar to those of the apatite crystals in natural bone. Molecule interactions are present between the n-HA and PEA in the composite, which allows the uniform dispersion of n-HA in PEA matrix. This contributes enhanced mechanical property and bioactivity to the composite. The cytocompatibility of the composites has been investigated by culturing osteoblasts on the membranes. Good cell attachment and proliferation manner were observed on the membranes after 1 week. These results suggest that the PEA/n-HA composites prepared in this study may serve as potential candidate scaffold for tissue engineering.