Thermo-responsive release of diclofenac sodium from poly (?-caprolactone)/glyceryl trilaurate co-continuous composite prepared by heat treatment

Nowadays, it is still a tough challenge to prepare thermo-responsive drug delivery system without the use of poly (N-isopropylacrylamide) (PNIAPAM) and its derivatives. Herein, we attempted to fabricate a novel co-continuous composite with thermo-responsive drug release behavior induced by the phase transition of dispersed phase. Poly (epsilon-caprolactone) (PCL) scaffold with connected porous structure was prepared first, followed by the introduce and impregnating of diclofenac sodium/glyceryl trilaurate (DS/C12) hot melt mixture. After solidification at 25 degrees C, PCL/C12 composites with co-continuous structure were obtained. The connected porous structure of PCL scaffold and morphology of PCL/C12 composites were confirmed by scanning electron microscope. The thermoresponsive drug release mechanism of PCL/C12 composites was investigated by differential scanning calorimeter and two-dimensional infrared correlation spectroscopy. The results indicated that the temperature of onset melting and melting point of C12 was about 41.5 degrees C and 47.5 degrees C, respectively. When the temperature was switched from 37 degrees C to 45 degrees C, C12 underwent a melt transition, and the regular aggregation of C12 molecular chain was disrupted, accelerating the release of DS. The in vitro release results presented that PCL/C12 composites could achieve on-off controlled release of DS under alternative temperature of 45 degrees C and 37 degrees C. According to the comprehensive test results, this PCL/C12 composites should have promising application in bone tissue engineering.

Automated summary

A novel thermo-responsive drug release material was fabricated in this study, achieving controlled release of drugs by changing temperature. The experimental results showed that this material can accelerate drug release at specific temperatures, indicating its potential application in bone tissue engineering.