Antimicrobial peptide P60.4Ac-containing creams and gel for eradication of methicillin-resistant Staphylococcus aureus from cultured skin and airway epithelial surface
Authors
Elisabeth M. Haisma, Anikó Göblyös, Bep Ravensbergen, Alwin E. Adriaans, Robert A. Cordfunke, Jasmijn Schrumpf, Ronald W.A.L. Limpens, Kirsten J.M. Schimmel, Jan den Hartigh, Pieter S. Hiemstra, Jan Wouter Drijfhout, Abdoelwaheb El Ghalbzouri,and Peter H. Nibbering
Institution
Leiden University Medical Center
Country
Netherlands
Year
0000
Abstract
Previously we found the LL-37-derived peptide P60.4Ac to be effective against
MRSA on human epidermal models (EMs). The goal of this study was to identify the
preferred carrier for this peptide for topical application on skin and mucosal surfaces.
We prepared P60.4Ac in three formulations, i.e. a water-in-oil cream with softisan-
649, an oil-in-water cream with cetomacrogol, and a hypromellose-4000 gel. We
tested in these formulations peptide’s antimicrobial efficacy against mupirocin
resistant and -sensitive MRSA on EMs and bronchial epithelial models (BEMs).
Cytotoxic effects of formulated P60.4Ac on these models were determined using
histology and MTT and LDH assays. Moreover, we assessed peptide stability in these
formulations up to 3 months of storage.
Killing of MRSA by P60.4Ac in the two creams was less effective than in
hypromellose. In agreement, P60.4Ac in hypromellose was highly effective in
eradicating the two MRSA strains from EMs. We found that already 0.1% (wt/wt)
P60.4Ac in hypromellose gel killed >99% of the viable planktonic bacteria and >85%
of biofilm-associated-bacteria on EMs. Hypromellose gels containing 0.1% and 0.5%
(wt/wt) P60.4Ac effectively reduced the numbers of viable MRSA by >90% from
BEMs. No cytotoxic effects of P60.4Ac in hypromellose up to 2% on keratinocytes in
EMs and up to 0.5% (wt/wt) on epithelial cells in BEMs were observed. HPLC
analysis showed that P60.4Ac was stable in softisan cream and hypromellose gel, but
not in cetomacrogol cream.
We conclude that P60.4Ac formulated in hypromellose gel is both stable and highly
effective in eradicating MRSA from colonized EMs and BEMs.