Physicochemical and antimicrobial properties of in situ crosslinked alginate/hydroxypropyl methylcellulose/ε-polylysine films

In the present study, in situ crosslinked films were easily prepared by the spray deposition of Phase A, composed by sodium alginate (Alg), hydroxypropyl methylcellulose (HPMC), epsilon-polylysine (epsilon-PL), and plasticizers, followed by the spray deposition of Phase B (Ca2+ ions) on polystyrene dishes. The effect of the amount of plasticizer, HPMC, and epsilon-PL in Phase A on the films properties was explored in a set of 12 systems. Fourier transform infrared vibrational spectroscopy in the attenuated total reflectance mode revealed that plasticizers compete with Ca2+ ions for complexation with Alg. Films with high HPMC content and low content of plasticizer and epsilon-PL presented the best mechanical properties. The best system presented Young modulus of 0.76 +/- 0.10 GPa, water vapor transmission of 5.35 +/- 0.28 mg cm(-2) h(-1), swelling ratio of 1374 +/- 97%, 99.99% reduction against Gram-negative Escherichia coli bacteria, and 99.9% reduction against Gram-positive Staphylococcus aureus bacteria. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48832.