Synthesis and characterization of porous CaCO3 microspheres templated by yeast cells and the application as pH value-sensitive anticancer drug carrier

Using yeast as organic template and PDDA/PSS with opposite charge as polyelectrolyte, CaCO 3 was deposited on yeast cells by Layer-by-Layer self-assembly method, and then porous calcium carbonate hybrid microspheres (CaCO 3 -HMPs) were prepared by calcination. The CaCO 3 -HMPs were characterized by FT-IR, XRD, SEM and TG. It was found that the prepared CaCO 3 -HMPs were nearly spherical, with visible pores on the surface, small particle size uniformity (d = 3 μ m) and good dispersion. Doxorubicin hydrochloride (DOX) was used as the model drug to study drug loading and release properties of CaCO 3 -HMPs. Then, the drug loading, DOX release under different pH conditions, and the degradation of CaCO 3 -HMPs under different pH conditions were investigated. The drug release test results showed that the DOX-loaded microspheres released more drugs (99 %) at pH = 4.8 than pH = 7. It indicated that the CaCO 3 -HMPs were pH sensitive. The cytotoxicity of DOX-loaded microspheres was also studied. It was found that CaCO 3 -HMPs had good biocompatibility. In addition, compared with DOX group, cytotoxicity test results showed that the DOX-loaded microspheres had the same efficacy but sustained drug release for up to 120 h. Therefore, the CaCO 3 -HMP microspheres have good application prospects as anticancer drug carriers.