Multifunctional pH sensitive 3D scaffolds for treatment and prevention of bone infection

TL;DR

This study presents pH-sensitive 3D scaffolds that combine antibacterial activity against S. aureus with bone regeneration capabilities, using a novel nanocomposite design for controlled drug release.

Contribution

The paper introduces a new hierarchical MGHA nanocomposite scaffold with pH-responsive drug release and dual functionality for infection treatment and bone regeneration.

Findings

Effective inhibition of S. aureus biofilm formation.

Controlled levofloxacin release at different pH levels.

No cytotoxic effects on human osteoblasts.

Abstract

Multifunctional-therapeutic 3D scaffolds have been prepared. These biomaterials are able to destroy the S. aureus bacteria biofilm and to allow bone regeneration at the same time. The present study is focused on the design of pH sensitive 3D hierarchical meso-macroporous scaffolds based on MGHA nanocomposite formed by a mesostructured glassy network with embedded hydroxyapatite nanoparticles, whose mesopores have been loaded with levofloxacin as antibacterial agent. These 3D platforms exhibit controlled and pH-dependent levofloxacin release, sustained over time at physiological pH (7.4) and notably increased at infection pH (6.7 and 5.5), which is due to the different interaction rate between diverse levofloxacin species and the silica matrix. These 3D systems are able to inhibit the S. aureus growth and to destroy the bacterial biofilm without cytotoxic effects on human osteoblasts and allowing an adequate colonization and differentiation of preosteoblastic cells on their surface. These findings suggest promising applications of these hierarchical MGHA nanocomposite scaffolds for the treatment and prevention of bone infection.