Green Synthesis of Silver Nanoparticles and Preparation of Ag/Dioxidine/Gelatin Composite Systems via Cryoforming

One of the rapidly developing directions in modern nanotechnologies is green synthesis of metal and metal oxide nanoparticles, including silver nanoparticles, offering pronounced antibacterial activity. The advantages of this approach are environmental safety, low cost, and biocompatibility of the resulting materials. In this paper, we report the synthesis of silver nanoparticles with the use of an aqueous Quercus robur bark extract. Their average size is 60 ± 5 nm according to transmission electron microscopy (TEM) images. The composition and size of the nanoparticles have been confirmed using X-ray diffraction, UV/visible spectroscopy, TEM, and dynamic light scattering measurements. The antibacterial agent dioxidine and silver nanoparticles prepared using both the Quercus robur extract and a previously reported technique with the use of Matricaria chamomilla and Calendula officinalis flower extracts have been incorporated into macroporous gelatin-based biopolymer matrices via cryochemical modification. The composition and morphology of the hybrid systems have been studied using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). We have assessed the kinetics of drug release and the antibacterial activity of the systems for Escherichia coli and Staphylococcus aureus. Combining the plant extracts with silver nanoparticles has been found to ensure synergistic effects in enhancing the antibacterial activity of the systems.