Abstract
Luminescent nanoparticles are innovative tools for medicine, allowing the imaging of cells and tissues, and, at the same time, carrying and releasing different types of molecules. We explored and compared the loading/release ability of diclofenac (COX-2 antagonist), in both undoped- and luminescent Terbium3+ (Tb3+)-doped citrate-coated carbonated apatite nanoparticles at different temperatures (25, 37, 40 °C) and pHs (7.4, 5.2). The cytocompatibility was evaluated on two osteosarcoma cell lines and primary human osteoblasts. Biological effects of diclofenac-loaded-nanoparticles were monitored in an in vitro osteoblast’s cytokine–induced inflammation model by evaluating COX-2 mRNA expression and production of PGE2. Adsorption isotherms fitted the multilayer Langmuir-Freundlich model. The maximum adsorbed amounts at 37 °C were higher than at 25 °C, and particularly when using the Tb3+ -doped particles. Diclofenac-release efficiencies were higher at pH 5.2, a condition simulating a local inflammation. The luminescence properties of diclofenac-loaded Tb3+ -doped particles were affected by pH, being the relative luminescence intensity higher at pH 5.2 and the luminescence lifetime higher at pH 7.4, but not influenced either by the temperature or by the diclofenac-loaded amount. Both undoped and Tb3+-doped nanoparticles were cytocompatible. In addition, diclofenac release increased COX-2 mRNA expression and decreased PGE2 production in an in vitro inflammation model. These findings evidence the potential of these nanoparticles for osteo-localized delivery of anti-inflammatory drugs and the possibility to localize the inflammation, characterized by a decrease in pH, by changes in luminescence.
Highlights
Nanotechnology is finding increasing applications in medicine; in particular nanoparticles (NPs) can be used as vehicles to transport and deliver different classes of biologically active molecules, including chemotherapeutics, antibiotics, antiinflammatory drugs, hormones, fluorophores, targeting agents [1,2,3,4,5,6,7], depending on the pathology considered, acting both in diagnosis and therapy
The luminescence results of the CO3 -Ap (cAp)-Tb-DF conjugated nanoparticles show that R.L.I. is higher at pH 5.2 than at pH 7.4, and the luminescence lifetime higher at pH 7.4 than at 5.2, and that neither the concentration of DF nor the temperature affect the R.L.I. and the luminescence lifetime significantly
The significant reduction in the PG22 release that we observed after the treatment of the inflamed cells with DF loaded cAp-Tb could be attributed to the ability of cAp-Tb to release DF. These results show the potential of cAp nanoparticles as nanocarriers for loading and controlled release of DF, and of cAp-Tb nanoparticles as luminescent nanoprobes with diagnostic, as well as therapeutic applications in pathological conditions
Summary
Nanotechnology is finding increasing applications in medicine; in particular nanoparticles (NPs) can be used as vehicles to transport and deliver different classes of biologically active molecules (so-called nanocarriers), including chemotherapeutics, antibiotics, antiinflammatory drugs, hormones, fluorophores, targeting agents [1,2,3,4,5,6,7], depending on the pathology considered, acting both in diagnosis and therapy Their main advantage is linked to their nanoscale dimensions, enabling them to carry high amounts of molecules to chosen body sites, in the meantime protecting the drugs from rapid degradation or clearance. For all these pathologies the available therapeutic strategies are still unsatisfactory, namely because of the associated side effects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
