Preparation and drug release behavior of temperature-responsive mesoporous carbons

A temperature-responsive composite based on poly (N-isopropylacrylamide) (PNIPAAm) and ordered mesoporous carbons (OMCs) has been successfully prepared by a simple wetness impregnation technique. The structures and properties of the composite were characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 sorption, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The results showed that the inclusion of PNIPAAm had not greatly changed the basic ordered pore structure of the OMCs. Ibuprofen (IBU) was selected as model drug, and in vitro test of IBU release exhibited a temperature-responsive controlled release delivery.

The bands located at 1650 and 1549 cm−1 could be assigned to CO stretching and N–H bending vibrations for polymer PNIPAAm (a). The bands at 1388 and 1369 cm−1 were due to isopropyl group, and the band at 1459 cm−1 was related to the bending vibration of C−H (a). For the PNIPAAm/OMCs composite, the characteristic bands of polymer were still observed besides those for carbon materials and the bands at around 1585 cm−1 and a broad band at about 1100 cm−1 were characteristics for the carbon materials(c). In addition, little shifts of CO and N−H bands compared to the pure PNIPAAm were also observed (b), indicating a weak interaction between the polymer and carbon material. These results could be a proof that the PNIPAAm has been incorporated into the carbon material.Figure optionsDownload as PowerPoint slideHighlights
► A temperature-responsive PNIPAAm/OMCs composite was successfully synthesized by a simple wetness impregnation technique for the first time.
► The inclusion of PNIPAAm had not greatly changed the basic ordered pore structure of the OMCs.
► In vitro test of IBU release exhibited a temperature-responsive controlled release delivery.