Adsorption/desorption study of antibiotic and anti-inflammatory drugs onto bioactive hydroxyapatite nano-rods.

The use of high doses of antibacterial and anti-inflammatory drugs for patients with bone diseases, associated to implants or bone filling, can develop adverse effects; and consequently, it promotes to think new strategies to avoid this problem. In this work, it has been described the adsorption/release (or desorption) behavior of two drugs, ciprofloxacin (CIP) and ibuprofen (IBU), onto hydroxyapatite (nano-HA) at 37 °C. Through Ultraviolet-Visible (UV-Vis) spectroscopy, the concentrations of both drugs in adsorption, kinetic and desorption processes were obtained. The Fourier Transformed-Infrared (FT-IR) spectroscopy, Zeta-potential (ζ-potential), High-Resolution Transmission Electron Microscopy (H-TEM) and x-Ray Diffraction (xRD) were also used to characterize bared nanoparticles and those with adsorbed drugs. Five adsorption models (Langmuir, Freundlich, Sips, Temkin and Dubinin-Radushkevich) were used for describing the behavior of both active compounds. The adsorption processes (CIP/nano-HA and IBU/nano-HA) were better predicted by the Sips model than by the others. The kinetic adsorption data were processed, for both active agents, by application of Avrami's model. Desorption/release process (of both drugs) was evaluated though Korsmeyer-Peppas (K-P) model. Owing to the predictability of these systems, we propose the use of these active ceramics as potential bone filler for improving the treatment against bacterial bone infections and to avoid its associated inflammatory process.

Benedini L ，Placente D ，Ruso J ，Messina P ... -  《-》

Antibacterial alginate/nano-hydroxyapatite composites for bone tissue engineering: Assessment of their bioactivity, biocompatibility, and antibacterial activity.

Bone substitute materials based on bioceramics and polymers have evolved shifting from a passive role where they are merely accepted by the body; to an active role, where they respond to particular environmental conditions or to different types of cues generating suitable integration (osseointegration for this case) inside the host tissue. In this work, two types of composite materials based on a bioceramic (synthetic nano-hydroxyapatite, HA) and a biopolymer (sodium alginate, ALG) have been designed and assessed for promoting the bone regeneration. These materials were loaded with ciprofloxacin (CIP) for obtaining, not only a suitable material for a filling but with antibacterial properties. Therefore, their main features were studied through Fourier transformed-infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ultraviolet-Visible (UV-Vis) spectroscopy was used for obtaining the released concentrations of CIP and Zeta-potential (ζ-potential) was used for characterizing the adsorption of CIP onto nanoparticles. The release profile of this drug has been fit with the Ritger-Peppas model, used for studying the release kinetics of hydrogel-based systems. The bioactivity of these composites was also evaluated after 30 days of incubation in a simulated body fluid solution (SBF). Then, the assessment of antibacterial capability against the three main strains cause osteomyelitis was performed. Finally, the cell viability study and the cellular morphology assay were also carried out. These last assays have shown encouraging results and, gathered with their other properties, such as their bioactivity and antibacterial properties; they could lead to propose these materials as new bone filler antibiotic devices.

Benedini L ，Laiuppa J ，Santillán G ，Baldini M ，Messina P ... -  《-》

Multi-drug delivery system based on lipid membrane mimetic coated nano-hydroxyapatite formulations.

Local delivery systems from an osteoconductive biomaterial are suggested as a promising strategy to avoid simultaneously peri-implant traumas and to induce tissue regeneration. In this work, it is detailed the design and construction of a multi-drug delivery formulation based on lipid membrane mimetic coated nano-hydroxyapatite, LMm/nano-HA, as a bone-specific drug delivery approach. The optimal LMm/nano-HA formulation was selected after analysing the lipid/nano-HA interaction by dynamic light scattering (DLS), ζ-potential, transmission electron microscopy (TEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC) and UV-vis spectroscopy. After the initial screening, Ciprofloxacin and Ibuprofen simultaneous -load and -release efficiency from selected LMm/nano-HA was assessed. pH-responsive kinetic profiles of local drug distribution were characterized and compared with currently applied systemic doses. Finally, the systems' biocompatibility and drug released activity were positively validated. The obtained results demonstrated that LMm/nano-HA formulations can represent a valuable multi-modal platform in bone tissue therapies.

Placente D ，Benedini LA ，Baldini M ，Laiuppa JA ，Santillán GE ，Messina PV ... -  《-》

Hydroxyapatite-ciprofloxacin delivery system: Synthesis, characterisation and antibacterial activity.

Ciocilteu MV ，Mocanu AG ，Mocanu A ，Ducu C ，Nicolaescu OE ，Manda VC ，Turcu-Stiolica A ，Nicolicescu C ，Melinte R ，Balasoiu M ，Croitoru O ，Neamtu J ... -  《-》

Modified Fe3O4/HAp Magnetically Nanoparticles as the Carrier for Ibuprofen: Adsorption and Release Study.

The adsorption capacity and release attributes of magnetic Fe3O4@hydroxyapatite (Fe3O4/HAp) nanoparticles for drug molecules can be improved by modified their surfaces with logical chosen organic groups. The internal surface of nanoparticles was functionalized with (3-aminopropyl) trimethoxysilane (APTS). Comparative studies of their adsorption and release properties for various model drug molecules (such as pure hydroxyapatite, Fe3O4@hydroxyapatite and functionalized Fe3O4@hydroxyapatite) were then conducted. The characteristic of the obtained materials was performed with X-ray-diffraction (XRD), energy dispersive X-ray microanalysis (EDS), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), UV-Vis analysis, vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). Results show that functionalized magnetic Fe3O4@hydroxyapatite nanoparticles leads than a substantial decrease of the drug delivery rate in pH=6.8 after investigated drug release in intestine environment. In addition, the results demonstrate that high adsorption capacity for drug and slower drug release rate was obtained after functionalized nanoparticles than Fe3O4@hydroxyapatite and pure hydroxyapatite.

Mohammadi-Aghdam S ，Valinezhad-Saghezi B ，Mortazavi Y ，Qhoreishi SM ... -  《-》