Resumen: Severe bacterial and fungal infections have become a major clinical and public health concern. Nowadays, additional efforts are needed to develop effective antimicrobial materials that are not harmful to human cells. This work describes the synthesis and characterization of chitosan-ascorbic acid-silver nanocomposites as films exhibiting high antimicrobial activity and non-cytotoxicity towards human cells. The reductive and stabilizing activity of both the biocompatible polymer chitosan and ascorbic acid were used in the synthesis of silver nanoparticles (AgNPs). Herein, we propose an improved composite synthesis based on medium average molecular weight chitosan with a high deacetylation degree, that together with ascorbic acid gave films with a uniform distribution of small AgNPs (<10 nm) exhibiting high antimicrobial activity against biofilm forming bacterial and fungal strains of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. At the same time, the resulting solid nanocomposites showed, at the same doses, reduced or totally excluded cytotoxicity on mammalian somatic and tumoral cells. Data obtained in the present study suggest that adequately designed chitosan-silver nanocomposites are powerful and promising materials for reducing pathogenic microorganism-associated infections without harmful effects towards mammalian cells. Idioma: Inglés DOI: 10.1039/c7ra08359a Año: 2017 Publicado en: RSC Advances 7, 83 (2017), 52398-52413 ISSN: 2046-2069 Factor impacto JCR: 2.936 (2017) Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 71 / 171 = 0.415 (2017) - Q2 - T2 Factor impacto SCIMAGO: 0.863 - Chemistry (miscellaneous) (Q1) - Chemical Engineering (miscellaneous) (Q1)