Controlling release kinetics of gentamicin from silica nano-carriers

Antibiotic release from a carrier can be employed to reduce the frequency of administration or prolong efficacy. In this work, we prepared silica nanoparticles loaded with gentamicin through different synthetis routes (entrapment, adsorption, covalent bonding and Layer-by-Layer (LbL)). The nanocarriers physical-chemical properties were characterised and antibiotic release from the nanocarriers was monitored. The nanoparticles prepared entrapping gentamicin gave the highest drug load but completed the release over a period of 4 h. No significant differences in antibiotic load were noticed between absorption or binding of gentamicin onto the silica nanoparticles surface; moreover the release of the drug occurred over 2 days in both cases. The nanoparticles coated with gentamicin through LbL technique released the antibiotic for 3 weeks. This work demonstrates that silica nanoparticles can be employed as antibiotic carriers providing a continuous release of antibiotic over a period that can be tuned through the choice of preparation method.