Paclitaxel-loaded hydroxyapatite/collagen hybrid gels as drug delivery systems for metastatic cancer cells.

Hydroxyapatite (HA) is a biocompatible and porous inorganic material that can behave as an effective drug carrier. In this study, HA nanoparticles were prepared according to the hydrothermal method and used as a drug carrier for a water-insoluble anticancer drug, paclitaxel (Tax). The absorption of Tax onto the HA was dependent on the solvent composition. The Tax-loaded HA (Tax/HA) exhibited a lower level of activity than the free Tax because the HA material was not stably dispersed in aqueous media. The Tax/HA was therefore embedded in a collagen gel to give the Tax/HA-embedded collagen gel (Tax/HA/Col), which exhibited a higher level of activity than the Tax-containing collagen gel (Tax/Col). Interestingly, the highly metastatic MDA-MB-231 cells were more sensitive to the Tax/HA/Col than the poorly metastatic MCF-7 cells. Tax/HA/Col is therefore useful for the drug delivery into metastatic cancer cells.