In the current study, nanocomposites were prepared by combining $k$-carrageenan, polyvinyl alcohol (PVA), and doped nanoparticles (Magnesium oxide) MgO, (Magnesium Zinc oxide) MgZnO 1%, MgZnO 3%, and MgZnO 5%. The nanoparticles were synthesized by a sol–gel method and mixed with a mixture of $k$-carrageenan/PVA (Ca/PVA) in various ratios. The structure of the composites was analyzed using thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The Ca/PVA mixture was then mixed with nanoparticles and loaded with active ingredient, catechin. Scanning electron microscope (SEM) and texture analysis were performed to analyze the nanocomposites. Entrapment efficiency (EE%) and drug release studies confirmed that $k$-carrageenan/PVA/MgZnO 5% had the highest EE% at 81.58% and a drug release of 75.21% $\pm$ 0.94. The EE% of $k$-carrageenan/PVA/MgO was 55.21% and its drug release was 45%. This indicates that ZnO plays an effective role in the structure and performance of Ca/PVA composites. The SEM images of MgO composites show smoother surfaces compared to MgZnO composites. This may be one of the reasons for the increased EE% and drug release of MgZnO composites. The addition of ZnO to the composite structure can lead to the appearance of pores on the surface of the composite, increasing entrapment and drug release.

Currently, the role of the nanoparticles in the structure of the composites and their benefits for the health of the body is valuable. In this study, the effects of the doping on the structural and morphological properties of the hydrogels using a Mg co-doped ZnO hydrogel, which has been fabricated by the sol–gel process, have been investigated. Then, a hydrogel containing nanoparticle and a hydrogel without any nanoparticles was produced as a control. The hydrogels were loaded with catechin and the related characterization was evolved based on the new structure of the matrices. The Mg_0.99Zn_0.01O nanoparticles were synthesized using a green synthesis method. To investigate the properties of the nanoparticles, zeta potential and XRD were studied. The field emission scanning electron microscopy (FESEM), FTIR, TGA, swelling Ratio, and compression tests were investigated for the hydrogels. Based on the results, FESEM showed a more compressed structure for hydrogels including nanoparticles rather than the hydrogels without a nanoparticle. The TGA showed a higher decomposition temperature in the hydrogels including nanoparticles. The swelling ratio of hydrogels containing a nanoparticle was higher than the control hydrogel. κ-Carrageenan/ Mg_0.99Zn_0.01O/NaCMC/Catechin had the highest swelling ratio (44.15%) rather than the κ-Carrageenan/NaCMC (33.22%). Mg_0.99Zn_0.01O nanoparticles presented a stronger structure of hydrogels in the compression test. It is concluded that the role of the synthesized nanoparticle is critical in the structure of the hydrogel.

Melissa officinalis is a medicinal plant belong to lamiacea family. This plant has been cultivated in many parts of the world due to its therapeutic effects. This study was conducted to improve antioxidant activities of proliferated shoots from tissue culture. The seeds of plant were cultured in MS hormone free medium ...

The present study aimed to develop a protocol for hairy root induction from Dracocephalum moldavica leaf explants and evaluate the effects of iron nanoparticles (Fe NPs) (0, 250, 500 and 1000 ppm), copper nanoparticles (Cu NPs) (0, 25, 50 and 100 ppm) and the combination of both (Fe/Cu NPs) on antioxidant capacity, phenolic, flavonoids and rosmarinic acid content of hairy roots. Hairy root induction in D. moldavica was significantly (P ≤ 0.01) influenced by Agrobacterium rhizogenes strains, culture media and sucrose concentration. The highest hairy root induction (86/6%) was related to ATCC15834 strain on Murashige and Skoog culture medium supplemented with 30 g l^− 1 sucrose. The individual and combined effect of Fe and Cu NPs on the measured traits was highly significant (P ≤ 0.01). The highest amount of rosmarinic acid (26.38 mg/g DW) was obtained in Cu NPs (100 ppm) with Fe NPs (1000 ppm) treatment that was 6.6-fold higher compared to control. The highest amount of flavonoids, malondialdehyde (MDA), phenolic compounds, hydrogen peroxide (H₂O₂), proline, and anthocyanin production was obtained in Cu NPs (100 ppm) + Fe NPs (1000 ppm) treatment that was 1.86, 1.56, 1.76, 2.07, 1.62 and 1.65-fold higher compared to respective control. Correlation and principal component analysis revealed a clear separation between treatments groups and control also a positive correlation among rosmarinic acid production and other traits. The findings of this study indicated the best results were obtained with the combined effect of Cu NPs (100 ppm) with Fe NPs (1000 ppm) treatment.