Piotr Orlowski, Magdalena Zmigrodzka, Emilia Tomaszewska, Katarzyna Ranoszek-Soliwoda, Monika Czupryn, Malgorzata Antos-Bielska, Janusz Szemraj, Grzegorz Celichowski, Jaroslaw Grobelny, Malgorzata Krzyzowska

Silver nanoparticles (AgNPs) have been shown to promote wound healing and to exhibit antimicrobial properties against a broad range of bacteria. In our previous study, we prepared tannic acid (TA)-modified AgNPs showing a good toxicological profile and immunomodulatory properties useful for potential dermal applications. In this study, in vitro scratch assay, antimicrobial tests, modified lymph node assay as well as a mouse splint wound model were used to access the wound healing potential of TA-modified and unmodified AgNPs. TA-modified but not unmodified AgNPs exhibited effective antibacterial activity againstPseudomonas aeruginosa,Staphylococcus aureusandEscherichia coliand stimulated migration of keratinocytes in vitro. The tests using the mouse splint wound model showed that TA-modified 33 and 46 nm AgNPs promoted better wound closure, epithelialization, angiogenesis and formation of the granulation tissue. Additionally, AgNPs elicited expression of VEGF-α, PDGF-β and TGF-β1 cytokines involved in wound healing more efficiently in comparison to control and TA-treated wounds. However, both the lymph node assay and the wound model showed that TA-modified AgNPs sized 13 nm can elicit strong inflammatory response not only during wound healing but also when applied to the damaged skin. TA-modified AgNPs sized >26 nm promote wound healing better than TA-modified or unmodified AgNPs. These findings suggest that TA-modified AgNPs sized >26 nm may have a promising application in wound management.