Facile synthesis of nanofibrous and hollow titania microspheres as drug-laden cell carriers

Microspheres are one type of promising cell-supporting matrices. However, the synthesis of nanofibrous and hollow microspheres as drug-laden cell carriers is still a great challenge. Here, the nanofibrous and hollow titania nanowire (NH-TiNW) microspheres were synthesized by in situ alkali hydrothermal treatment of hollow titania (H-Ti) microspheres, and their microstructure, biocompatibility, and drug delivery property were evaluated. By controlling hydrothermal temperature from 80 to 120 degrees C and hydrothermal time from 1 to 4 h, the surface of H-Ti microspheres was controllably tailored with nanoparticles and NWs. The results showed that NH-TiNW microspheres were spherical in morphology with a diameter of 100-200 mu m, hierarchically assembled by numerous TiNWs with the diameter of 10-20 nm, and possessed a nanofibrous and hollow structure. In vitro biocompatibility evaluation showed that NH-TiNW microspheres presented an enhanced cell attachment and proliferation compared with H-Ti microspheres due to the presence of the nanofibrous surface. Drug delivery evaluation showed that NH-TiNW microspheres strongly adsorbed tetracycline hydrochloride (one type of antibiotic, model drug) with a loading efficiency of 81.5% +/- 1% due to the presence of the nanofibrous and hollow structure and also effectively maintained the biological efficiency of the loaded drugs to inhibit the growth of bacteria.