An enhanced chemotherapeutic effect facilitated by sonication of MSN

Sonodynamic therapy (SDT) is a non-invasive therapeutic modality for cancer treatment. Finding new effective sonosensitizers has attracted great attention in the field of SDT. Mesoporous silica nanoparticles (MSN) have been extensively explored as a drug delivery system because of their good biocompatibility and satisfactory drug loading ability. However, there are relatively few studies devoted to using MSN as an efficient sonosensitizer. In this paper, we found that MSN could be used as an efficient sonosensitizer to induce cell apoptosis after ultrasound (US) treatment. To make the full use of MSN and increase its activity for cancer treatment, a chemotherapeutic drug was encapsulated inside MSN to achieve a chemotherapy-SDT synergistic function. Furthermore, photoinitiated polymerization cross-linked methacrylated hyaluronic acid (m-HA) gel was covered on the surface of DOX@MSN to improve its tumour targeting ability. In vitro and in vivo research studies indicated that the degradation of the m-HA shell by hyaluronidase (HAase) that is concentrated in the tumour environment results in the release of DOX@MSN. Importantly, subsequent US treatment could not only trigger SDT of MSN but also promote DOX release from MSN to show chemotherapeutic activity.