Gabriela Kratošová

Even though the biodegradability of polycaprolactone (PCL) and its nanocomposites is lower compared to other biodegradable polyesters, this property and good biocompatibility are used for development of materials for drug delivery with a long‐term effect. We prepared novel PCL/clay nanocomposite films with antimicrobials chlorhexidine (CH) or octenidine (OCT) combined with ZnO anchored on vermiculite (VER). The intercalation of CH and OCT into the interlayer of VER/ZnOVER was confirmed by XRD, FTIR and SEM. The organically modified nanofillers compared to VER (−46.0 mV) or ZnOVER (−34.9 mV) showed a positive ζ‐potential (+30.7 mV (VER_CH), +21.9 mV (VER_OCT), +24.6 mV (ZnOVER_CH)) indicating a relatively stable materials, except ZnOVER_OCT (+8.6 mV), which strongly agglomerated. Thin PCL/clay films were prepared by solvent casting method and the effect of used nanofillers on structural, thermal, mechanical and antimicrobial properties followed by degradation under hydrolytic conditions was studied. The results showed that presence of ZnO significantly decreases thermal and mechanical stability. The nanofillers with the higher hydrophilic character are responsible for the fastest degradation of PCL matrix. Films possessed high antimicrobial efficiency in long time intervals, hence these nanocomposites open new avenues for the possible application of such materials for the drug delivery with a long‐term effect. Highlights Antimicrobial active PCL/clay nanocomposites were prepared. Nanofillers influenced the structure and properties of prepared thin PCL films. ZnO caused lower thermal stability and worse mechanical properties of PCL films. PCL/clay nanocomposite films degraded slowly by a hydrolytic mechanism. High potential as medical materials with long‐lasting antimicrobial efficacy.

On a daily basis, a wide range of materials including inorganic nanoparticles (NPs) inadvertently find their way into the environment. Meanwhile, intentionally used NPs, such as the new generation of nanofertilizers (NFs) are designed to enhance agronomic production. However, their physicochemical properties and not-so-well understood effects raise potential risks to the plant reproductive cycle, specifically pollen development, a subject largely absent in academic research. Even slight contamination, deformation, or aberration of pollen could have enormous impacts on the ecosystem. Thus, our objective was to evaluate the influence of various metal-based NPs on sunflower pollen morphology and its yield. Nano-formulations were applied during the 2019–2021 agronomic seasons on two sunflower hybrids, Neostar and Edison, in Dolná Malanta, near Nitra, Slovak Republic. Pollen morphology findings indicated that conventional ZnSO4 had the most positive impact on the size of pollen grains compared to ZnO-NPs, Fe3O4-NPs, and the NP-free control. Gold-NPs on SiO2 mesoporous silica (AuSi-NPs) showed a statistically insignificant impact, while the use of TiO2-NPs in agriculture remained a topic of debate. Surprisingly, pollen characteristics did not fully correspond to crop yields. Despite causing a reduction in pollen grain size, the TiO2-NPs consistently showed the highest yield compared to other variants. Employing low concentrations of NFs did not notably alter pollen morphology, reinforcing our commitment to eco-friendly, precise, and sustainable agriculture.