An Effective Antimicrobial Cationic Nanoparticle Matrix Without Cytotoxicity Found with Zinc or Silver

Introduction: While Silver is widely regarded as an effective antimicrobial agent it can be cytotoxic to fibroblast and keratinocytes, and the reported antibacterial effects of silver are based on in-vitro studies rather than the more complex in-vivo environment. We herein introduce a novel cationic nanoparticle (NP) matrix* as a new alternative to topical silver antimicrobials. Having demonstrated broad antimicrobial efficacy against common pathogens, we sought to compare the cytotoxicity of the test product (NP*) with both Zinc and Silver on Human Fibroblasts and Keratinocytes.Methods:Human foreskin fibroblasts (HFF) and human epidermal keratinocytes (HEK) were cultured in standard growth mediums. Test Compounds (NP*, Zn, and Ag) were added in triplicate wells to the cells. We used TC50 as a measure to determine toxicity to certain types of cells. Typically, highly cytotoxic compounds have TC50 concentrations below .10 mg/mL.Results: For HFF, the TC50 for NP* was measured at 1.58, whereas both Zinc and Silver were found to be highly cytotoxic with TC50 of .037 and .0055, respectively. For HEK , the TC50 for NP* was 0.17, whereas both Zinc and Silver were found to be highly cytotoxic with TC50 of .037 and .0055, respectively.Discussion: These results demonstrate that in addition to its highly effective antibacterial activity, this unique iron containing cationic NP matrix* was far more safe to human cells than the commonly used zinc and silver containing products.References:1.Macgregor L, Luis J. International Consensus. Appropriate Use of Silver Dressings in Wounds. An Expert Working Group Consensus. Wounds Int. 2012. www.woundsinternational.com. 2.Khansa I, Schoenbrunner AR, Kraft CT, Janis JE. Silver in Wound Care - Friend or Foe?: A Comprehensive Review. Plast Reconstr Surg - Glob Open. 2019;7(8). doi:10.1097/GOX.0000000000002390 3.Sambale F, Wagner S, Stahl F, Khaydarov RR, Scheper T, Bahnemann D. Investigations of the toxic effect of silver nanoparticles on mammalian cell lines. J Nanomater. 2015;2015. doi:10.1155/2015/136765 4.Poon VKM, Burd A. In vitro cytotoxity of silver: Implication for clinical wound care. Burns. 2004;30(2):140-147. doi:10.1016/j.burns.2003.09.030 5.Hartman TL, ImQuest BioSciences. Final Technical Report: Cytotoxicity Evaluation of Rectorite in Human Foreskin Fibroblasts and Epidermal Keratinocytes. 2021;(Project #: 642-02-02).