Nanomedicine and nano delivery systems are a relatively new but rapidly developing science where materials in the nanoscale range are employed to serve as means of diagnostic tools or to deliver therapeutic agents to specific targeted sites in a controlled manner. Nanotechnology offers multiple benefits in treating chronic human diseases by site-specific, and target-oriented delivery of precise medicines. Recently, there are a number of outstanding applications of the nanomedicine (chemotherapeutic agents, biological agents, immunotherapeutic agents etc.) in the treatment of various diseases. The current review, presents an updated summary of recent advances in the field of nanomedicines and nano based drug delivery systems through comprehensive scrutiny of the discovery and application of nanomaterials in improving both the efficacy of novel and old drugs (e.g., natural products) and selective diagnosis through disease marker molecules. The opportunities and challenges of nanomedicines in drug delivery from synthetic/natural sources to their clinical applications are also discussed. In addition, we have included information regarding the trends and perspectives in nanomedicine area.

The structural and luminescence properties of erbium doped zirconium oxide prepared by the sol-gel processes were analyzed. The annealed powders presented a concentration dependent crystallite sizes and crystalline phase, ranging from 28 to 46 nm and from 40 to 96% for the monoclinic phase, respectively. Green (545 nm) and red (680 nm) emissions bands were observed with 489 and 962 nm excitation. Experimental results showed that the emission bands can be tuned by controlling the ${\mathrm{Er}}^{\text{3+}}$ concentration and that the red band is almost quenched with 489 nm whereas it is enhanced with 962 nm excitation. The nature of this behavior is discussed taking into account the nonradiative energy transfer and cross-relaxation process.

The photoluminescence and crystalline structure characterization of undoped and several samarium doped ${\mathrm{ZrO}}_2$ samples are reported. Strong fluorescence emission produced by the transitions ${}^4{G}_{\text{5/2}}{\to }^6{H}_{\text{5/2,7/2,9/2}}$ of ${\mathrm{Sm}}^{\text{3+}}$ was obtained by the excitation of the host at 320 nm. The energy transfer process from the host to the samarium ion was confirmed by the analysis of the ${\mathrm{ZrO}}_2$ fluorescence decay curve. It is shown that the content of the active ions stabilizes the tetragonal structure of ${\mathrm{ZrO}}_2$ at 1000 °C, being 73% for $\text{2\hspace{0.05em}}\mathrm{mol}\mathrm{ \% }{\mathrm{Sm}}_2{\mathrm{O}}_3$ doped and 3% for undoped samples. The dependence between the fluorescence emission and the crystalline structure is discussed.