Mesoporous bioactive glasses equipped with stimuli-responsive molecular gates for the controlled delivery of levofloxacin against bacteria

Abstract

Increase of bone diseases incidence has boosted the study of ceramic biomaterials as a potential osteo-inductive scaffolds. Particularly, mesoporous bioactive glasses have demonstrated to possess a broad application in the bone regeneration field, due their osteo-regenerative capability and their ability to release drugs from its mesoporous structure. These special features have been studied as an option to fight against bone infection, which is one of the most common problems regarding bone regeneration therapies. In this work, we develop a mesoporous bioglass functionalized with polyamines and capped with ATP as molecular gate for the controlled release of the antibiotic levofloxacin. Phosphate bonds of the ATP are hydrolyzed in the presence of acid phosphatase (APase), which significantly increases its concentration in bone infection due to the activation of bone resorption processes. The solid has been characterized and tested successfully against bacteria. The final gated solid only induces bacterial death in the presence of acid phosphatase. Additionally, it has also been demonstrated that the solid is not toxic for human cells. The double function of the prepared nanodevice as drug delivery system and bone regeneration enhancer, confirms the possible development of a new approach in tissue engineering field, where controlled release of therapeutic agents can be finely tuned at the same time that osteoinduction is favored.