Preparation and Properties of Calcium Peroxide/Poly(ethylene glycol)@Silica Nanoparticles with Controlled Oxygen-Generating Behaviors.

The hypoxic microenvironment is the main challenge for the repair of damaged tissue, and oxygen supply is an effective means of alleviating hypoxia. In this study, a series of core-shell-structured calcium peroxide/poly(ethylene glycol)@silica (CPO@SiO) nanoparticles are prepared to generate oxygen steadily. The size of the CPO@SiO nanoparticles ranges from 205 to 302 nm, with a narrow polydispersity index (PDI). In this system, the nano CPO core acts as the oxygen source to improve hypoxia, while the SiO shell layer serves as the physical barrier to control the oxygen-generating rate and improve biocompatibility. The results suggest that the thickness of the SiO shell layer can be modulated by adjusting the amount of tetraethyl orthosilicate (TEOS). The prepared CPO@SiO nanoparticles show a controlled oxygen-generating rate. Moreover, compared with CPO, the CPO@SiO nanoparticles have good biocompatibility. To assess the modulating effects for the hypoxic microenvironment, L929 cells are co-cultured with CPO@ SiO nanoparticles under hypoxia. The results suggest that the CPO@ SiO nanoparticles can support the cell survival under hypoxia. Moreover, they can effectively decrease oxidative stress damage and reduce the levels of expression of hypoxia-induced superoxide dismutase (SOD) and malondialdehyde (MDA). Therefore, the prepared CPO@ SiO nanoparticles with controlled oxygen-generating properties could be a promising candidate for repairing damaged tissue.