IN THIS study, silver nanoparticles (AgNPs) were synthesized using biological and chemical methods. Trisodium citrate (TSC) was used as a reducing and stabilizing agent in the chemical method. While three seaweed aqueous extracts from Enteromorpha intestinalis, Sargassum vulgare, and Asparagopsis taxiformis and two cyanobacteria filtrates from Spirulina platensis, and Oscillatoria acuminata were utilized in the biological method. The production of the synthesized AgNPs was verified through UV-Vis spectroscopy analysis. Both of the synthesized AgNPs exhibited remarkable antibacterial activity against multidrug-resistant pathogenic bacterial isolates of Staphylococcus aureus (S1), Escherichia coli (E1), Klebsiella pneumoniae (K1), Staphylococcus epidermidis (S5), and Pseudomonas auroginosa (P1) when compared with sulfamethoxazole as the control. AgNPs biologically synthesized using S. vulgare aqueous extract exhibited the maximum antibacterial activity and were further characterized by X-ray diffraction (XRD) diffraction, Fourier transform infrared spectroscopy analysis (FTIR), and transmission electron microscopy (TEM). XRD revealed crystalline shape of AgNPs with a mean size of 28.93 and 29.31 nm for the chemically and biologically synthesized AgNPs, respectively; and Zeta potential was recorded at −50.3±10.4 and −52.1±10.8 mV, respectively. Moreover, the AgNPs (100 μg/mL) were safe for human fibroblast normal cell lines at 24h. Both types of AgNPs were loaded onto polylactic acid/ polyethylene glycol (PLA/PEG) films, and a significant antibacterial activity was observed against S1 and E1 after 3 and 6h of treatment. Thus, these results demonstrate the potential use of biologically synthesized AgNPs from seaweeds for wound infection treatments and therapeutic applications as a safe and economic alternative to chemical agents.