Preparation and Characterization of Self-Assembled Poly(l-Lactide) on the Surface of β-Tricalcium Diphosphate(V) for Bone Tissue Theranostics

This work was aimed to obtain and characterize the well-defined biocomposites based on β-tricalcium diphosphate(V) (β-TCP) co-doped with Ce3+ and Pr3+ ions modified by poly(l-lactide) (PLLA) with precise tailored chain length and different phosphate to polymer ratio. The composites as well as β-tricalcium diphosphate(V) were spectroscopically characterized using emission spectroscopy and luminescence kinetics. Morphological and structural properties were studied using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The self-assembled poly(l-lactide) in a shape of rose flower has been successfully polymerized on the surface of the β-tricalcium diphosphate(V) nanocrystals. The studied materials were evaluated in vitro including cytotoxicity (MTT assay) and hemolysis tests. The obtained results suggested that the studied materials may find potential application in tissue engineering.

Enhancing IR to NIR upconversion emission in Er3+-sensitized phosphors by adding Yb3+ as a highly efficient NIR-emitting center for photovoltaic applications

The IR to NIR upconversion emission is enhanced through codoping Yb3+ and the upconversion luminescence kinetics involved is investigated.

Disorder-enhanced luminescence kinetics in volcanic feldspars

A granitic feldspar is well-ordered and has a stable thermoluminescence signal enabling its dating with high reliability. In contrast, a volcanic feldspar (sanidine) exhibits a slight cristallographic disorder and an anomalously fast fading of the thermoluminescence signal (Visocekas et al. 2014). It is shown here how disorder changes the decay of the signal and enhances the kinetics, while the increase in the microscopic complexity plays no role.

Investigation of Pyrophosphates KYP2O7Co-Doped with Lanthanide Ions Useful for Theranostics

Diphosphate compounds (KYP2O7) co-doped with Yb3+ and Er3+ ions were obtained by one step urea assisted combustion synthesis. The experimental parameters of synthesis were optimized using an experimental design approach related to co-dopants concentration and heattreatment as well as annealing time. The obtained materials were studied with theinitial requirements showing appropriate morphological (X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM)) and spectroscopic properties (emission, luminescence kinetics). Moreover, the effect of Er3+ and Yb3+ ions doped KYP2O7 on morphology, proliferative and metabolic activity and apoptosis in MC3T3-E1 osteoblast cell line and 4B12osteoclasts cell line was investigated. Furthermore, the expression of the common pro-osteogenic markers in MC3T3-E1 osteoblast as well as osteoclastogenesis related markers in 4B12 osteoclasts was evaluated. The extensive in vitro studies showed that KYP2O7 doped with 1 mol% Er3+ and 20 mol% Yb3+ ions positively affected the MC3T3-E1 and 4B12 cells activity without triggering their apoptosis. Moreover, it was shown that an activation of mTOR and Pi3k signaling pathways with 1 mol% Er3+, 20 mol% Yb3+: KYP2O7 can promote the MC3T3-E1 cells expression of late osteogenic markers including RUNX and BMP-2. The obtained data shed a promising light for KYP2O7 doped with Er3+ and Yb3+ ions as a potential factors improving bone fracture healing as well as in bioimaging (so-called in theranostics).