Manganese silicate nanospheres-incorporated hydrogels：starvation therapy and tissue regeneration

To prevent postoperative skin tumor recurrence and repair skin wound, a glucose oxidase (GOx)-loaded manganese silicate hollow nanospheres (MS HNSs)-incorporated alginate hydrogel (G/MS-SA) was constructed for starvation-photothermal therapy and skin tissue regeneration. The MS HNSs showed a photothermal conversion efficiency of 38.5%, and endowed composite hydrogels with satisfactory photothermal effect. Taking advantage of the catalytic activity of Mn ions, the composite hydrogels could decompose hydrogen peroxide (H₂O₂) into oxygen (O₂), which can alleviate the problem of tumor hypoxia microenvironment and endow GOx with an ability to consume glucose in the presence of O₂ for tumor starvation. Meanwhile, hyperthermia triggered by near infrared (NIR) irradiation could not only accelerate the reaction rate of H₂O₂ decomposition by MS HNSs and glucose consumption by GOx, but also ablate tumor cells. The anti-tumor results showed that synergistic effect of starvation-photothermal therapy led to the highest death rate of tumor cells among all groups, and its anti-tumor effect was obviously improved as compared with that of single photothermal treatment or starvation treatment. Interestingly, the introduction of MS HNSs into hydrogels could distinctly promote the epithelialization of the wound beds by releasing Mn ions as compared with the hydrogels without MS HNSs. It is expected that such a multifunctional platform with starvation-photothermal therapy will be promising for treating tumor-caused skin defects in combination of its regeneration bioactivity in the future.