Aminofunctionalized LAPONITE® as a versatile hybrid material for chlorhexidine digluconate incorporation: Cytotoxicity and antimicrobial activities

Aminofunctionalized LAPONITE® RD was employed for efficient chlorhexidine digluconate (CHX-DG) incorporation. The structure and properties of the unloaded (Lap-APTES) and loaded (Lap-APTES:CHX-DG) hybrids were investigated by powder X-ray diffraction (PXRD), thermal analysis, small angle X-ray scattering (SAXS), and infrared absorption spectroscopy (FTIR). A typical adsorption experiment was conducted to evaluate how the parameters contact time and concentration affected CHX-DG incorporation into the clay and showed that this compound had high affinity for Lap-APTES, adsorption equilibrium was reached at 90 min, with CHX-DG incorporation of 1402.7 mg/g. FTIR analysis confirm the interaction by hydrogen bonds between the CHX-DG and APTES amine groups and the laponite OH groups, resulting in materials with potential antibacterial properties for controlled drug release. Even at low concentrations (0.042 mg/g), Lap-APTES:CHX-DG was effective against S. pyogenes. The Lap, Lap-APTES, and Lap-APTES:CHX-DG cytotoxicity to GM07492A cells (human fibroblasts) was investigated by the XTT colorimetric assay, which revealed that CHX-DG incorporation into Lap-APTES reduced drug cytotoxicity. Drug release experiments demonstrated that a maximum of 10% (m/m) CHX-DG was released within 24 h and confirmed the higher affinity between Lap-APTES and CHX-DG. [Display omitted] •LAPONITE®RD with amine groups are loaded with chlorhexidine by adsorption•The interaction on surface and interlayer space of solid occurs via hydrogen bonds.•In vitro drug delivery reveal that 10% of chlorhexidine were released after 24h•Incorporation of chlorhexidine into Lap-APTES reduced drug cytotoxicity•Antibacterial results shown Lap-APTES:CHX-DG was effective against S. pyogenes