Green synthesis of broad spectrum microbicidal silver nanoparticles and griseofulvin loaded casein/hydroxypropyl methylcellulose nanocomposite

Microbial secondary infections are violent that cause different varieties of microorganisms. The broad-spectrum antimicrobial agents are the key solution for such infections which can be killed: Gram-positive and Gram-negative bacteria and sometimes supported with antifungal activity as well. Biopolymer-based nanocomposites are globally enhancing the efficiency of loaded materials, especially drugs. Currently, a new formulation of nanocomposite (NCO) based on casein (CN) and hydroxypropyl methylcellulose (HPMC) was used as capping and stabilizing agents for in situ synthesis of silver nanoparticles (AgNPs) and was incorporated with griseofulvin (Gf), an antifungal drug. The prepared NCO was investigated using several techniques such as physiochemical analysis; UV–visible spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Additionally, the topography and the size were investigated using a scanning electron microscope (SEM) and transmission electron microscope (TEM), which emphasized the successfully prepared NCO with particle size around 80 nm and the size of AgNPs around 30 nm. The dynamic light scattering (DLS) results affirmed these findings where the particle size distribution was recorded at two peaks at 30 and 80 nm as well as average zeta potential was recorded as − 54.2 mV. The prepared NCO was subjected to a release study that reflected a sustained controlled release of Gf for 48 h at different pHs, 1.5 and 7.2, and at pH 8 for 2 h. The NCO exhibited excellent cytocompatibility as well as synergetic antimicrobial activity against Gram-positive and Gram-negative bacteria as well as unicellular and filamentous fungi with MIC 50 about 27 µg/mL. Moreover, the time required for the killing was calculated for bacteria and unicellular and filamentous fungi as 16, 18, and 72 h, respectively. Based on that promising data, the prepared NCO was formulated in a green eco-friendly method aboard antimicrobial activity.