The purpose of the work was to emphasize the main differences and similarities in the degradation mechanisms in the case of polymeric coatings compared with the bulk ones. Combined with the current background, this work reviews the properties of commonly utilized degradable polymers in drug delivery, the factors affecting degradation mechanism, testing methods while offering a retrospective on the evolution of the controlled release of biodegradable polymeric coatings. A literature survey on stability and degradation of different polymeric coatings, which were thoroughly evaluated by different techniques, e.g., polymer mass loss measurements, surface, structural and chemical analysis, was completed. Moreover, we analyzed some shortcomings of the degradation behavior of biopolymers in form of coatings and briefly proposed some solving directions to the main existing problems (e.g., improving measuring techniques resolution, elucidation of complete mathematical analysis of the different degradation mechanisms). Deep studies are still necessary on the dynamic changes which occur to biodegradable polymeric coatings which can help to envisage the future performance of synthesized films designed to be used as medical devices with application in drug delivery.

Spherical metallic nanoparticles have been formed in ${\mathrm{SiO}}_2$ layers by 160-keV implantation of Co ions at a fluence of ${10}^{17}$ ions ${\mathrm{cm}}^{-2}.$ The implanted samples were next irradiated with $200-\mathrm{MeV}{}^{127}\mathrm{I}$ at fluences ranging from ${10}^{11}$ to ${10}^{14}$ ions ${\mathrm{cm}}^{-2}$ at room temperature. Modifications of nanoparticle size and shape were observed by transmission-electron microscopy and have been characterized by magnetic measurements at 295 and 5 K. For ${}^{127}\mathrm{I}$ fluences below ${10}^{12}$ ions ${\mathrm{cm}}^{-2},$ the nanoparticles grow in size but remain spherical. For higher fluences an anisotropic growth occurs, with elongation and the preferential easy axis seen along the incident-beam direction. The nanoparticle’s growth and deformations are attributed to thermal spike effects.

Yb-doped ZnO thin films were prepared on glass substrates by spray pyrolysis technique in order to investigate the insertion of Yb ions in the ZnO matrix and the related optical properties of the films. The molar ratio of Yb in the spray solution was varied in the range of $0–5\text{at}\text{.}\mathrm{\%}$ . X-ray diffraction patterns showed that the undoped and Yb-doped ZnO films exhibit the hexagonal wurtzite crystal structure with a preferential orientation along [002] direction. No secondary phase is observed in Yb-doped ZnO films. All films exhibit a transmittance between 75 and 90% in the visible range with a sharp absorption onset about 375 nm corresponding to the fundamental absorption edge at 3.3 eV. The photoluminescence measurements show a clear luminescence band at 980 nm that is characteristic of ${\text{Yb}}^{3+}$ transition between the electronic levels ${{}^2\text{F}}_{5/2}$ and ${{}^2\text{F}}_{7/2}$ . This is an experimental evidence for an efficient energy transfer from ZnO matrix to ${\text{Yb}}^{3+}$ . Hall effect measurements showed low resistivities and high carrier mobilities which makes these films of interest to photovoltaic devices.