Synthesis and characterization of plant extracts loaded PVA/PVP blend films and evaluate their biological activities

Background: antibacterial agent based on herbal extracts is considered an attractive area for developing countries. Nevertheless, herbal aqueous extracts usually show drawbacks, such as long-term volatility, poor bioavailability and rapid burst release. Methodology: In this study, polymer films were prepared from poly (vinyl alcohol) (PVA) blended with poly (vinylpyrrolidone) (PVP)and cross-linked with glutaraldehyde (GA), then post-loaded with T. indica, C. pepo, H. sabdriffol, and L. nobilis hot water extracts. The effects of two polymers (PVA, PVP) and of the incorporated extracts were studied concerning the physical and in vitro bacterial growth inhibition properties of films; additionally, the antioxidant activity of each extracts was investigated. Results: The results showed improved swelling behaviour and mechanical properties (tensile strength, tensile modulus, and % elongation at break) of the cross-linked PVA/PVP films (CPP) compared to pure PVA (PV) films. Plant extracts conferred significant antibacterial effects to (CPP) films toward E. coli (ATCC 25922) and S. aureus (ATCC 25923). Also, both T. indica and H. sabdriffol extracts showed strong antioxidant against DPPH in vitro. Conclusion: The prepared films showed significant antibacterial activities, specifically in films loaded with the T.indica extract against E. Coli and in films loaded with C.pepo and L.nobilis against S.aureus.