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@SiO₂) nanoparticles are prepared to generate oxygen steadily. The size of the CPO@SiO₂ 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 SiO₂ shell layer serves as the physical barrier to control the oxygen-generating rate and improve biocompatibility. The results suggest that the thickness of the SiO₂ shell layer can be modulated by adjusting the amount of tetraethyl orthosilicate (TEOS). The prepared CPO@SiO₂ nanoparticles show a controlled oxygen-generating rate. Moreover, compared with CPO, the CPO@SiO₂ nanoparticles have good biocompatibility. To assess the modulating effects for the hypoxic microenvironment, L929 cells are co-cultured with CPO@ SiO₂ nanoparticles under hypoxia. The results suggest that the CPO@ SiO₂ 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@ SiO₂ nanoparticles with controlled oxygen-generating properties could be a promising candidate for repairing damaged tissue.