Gentamicin-Releasing Mesoporous ZnO Structures

Abstract

Among metal oxides, zinc oxide (ZnO) is one of the most attractive materials thanks to its biocompatible and biodegradable properties along with the existence of various morphologies featuring piezoelectric, semiconducting and photocatalytic activities. All of these structures were successfully prepared and tested for numerous applications, including optoelectronics, sensors and biomedical ones. In the last case, biocompatible ZnO nanomaterials positively influenced cells growth and tissue regeneration as well, promoting wound healing and new bone formation. Despite showing high surface areas, ZnO morphologies generally lack an intrinsic mesoporous structure, strongly limiting the investigation of the corresponding drug loading and release properties. Within this scope, this study focuses on the adsorption and release properties of high surface area, mesoporous ZnO structures using gentamicin sulfate (GS), a well known antibiotic against bacterial infections especially in orthopedics. The particular ZnO morphology was achieved starting from sputtered porous zinc layers, finally converted into ZnO by thermal oxidation. By taking advantage of this mesoporous framework, GS was successfully adsorbed within the ZnO matrix and the kinetic release profile evaluated for up to seven days. The adsorption of GS was successfully demonstrated, with a maximum amount of 263 mg effectively loaded per gram of active material. Then, fast kinetic release was obtained in vitro by simple diffusion mechanism, thus opening further possibilities of smart pore and surface engineering to improve the controlled delivery.

Zinc Oxide Nanocrystals and High-Energy Shock Waves: A New Synergy for the Treatment of Cancer Cells

“…Such nanotools indeed could be intrinsically toxic (Bisht and Rayamajhi, 2016), e.g., through the release of metal ions, or could be remotely activated to achieve cell death, as in the photothermal and photodynamic therapies (Lim et al, 2015). Zinc Oxide (ZnO) in particular has raised researchers' interest thanks to its biocompatibility and peculiar piezoelectric and semiconductive properties (Jiang et al, 2018;Racca et al, 2018) useful for its exploitation for imaging (Jiang et al, 2011), biosensing (Sanginario et al, 2016;Shanmugam et al, 2017;Stassi et al, 2017), tissue engineering (Laurenti and Cauda, 2017) and drug delivery (Laurenti and Cauda, 2018;Martínez-Carmona et al, 2018) purposes. Remarkably, ZnO nanoparticles are also studied for their intrinsic anticancer properties thanks to their selective toxicity toward cancer cells (Bisht and Rayamajhi, 2016).…”

A Microwave-Assisted Synthesis of Zinc Oxide Nanocrystals Finely Tuned for Biological Applications

“…As an example, the wide bandgap typical of ZnO (about 3.37 eV at room temperature, RT) entails a fluorescence excitation situated in the ultraviolet (UV) region [4], which allows ZnO to be successfully employed for optical cell imaging. More in general, it has been demonstrated how ZnO could be a promising material for therapeutic and diagnostic applications [2], showing high levels of drugs loading and a quite easy control over the following release [5,6]. In this context, the optical, targeting and drug delivery properties of ZnO can be more specifically addressed by the combination of various synthetic procedures (sol-gel, sputtering, hydro-solvothermal, etc.)…”

Supercritical Solvent Impregnation of Different Drugs in Mesoporous Nanostructured ZnO

“…Zinc oxide (ZnO) is a material that is widely used in pharmaceutical topical formulations thanks to its biocompatibility and its intrinsic anti-inflammatory, antimicrobial, and antifungal activity [11,12]. In recent years, ZnO nanostructures have been exploited as anti-cancer, anti-diabetic, or antibiotic drug carriers by many research groups [11,13]. However, the recent review by Gurikov and Smirnova [4] does not include this material among those that can be used to achieve drug amorphization by SSI, and our research group appears to be the only one that has attempted its investigation [14,15].…”