Human foreskin fibroblasts hff 1

The 300-PEO-PEOT/PBT 55/45 was acquired from PolyVation™ (Groningen, The Netherlands) in the form of pellets and processed without prior purification. Chloroform 99%, anhydrous (CHCl₃) was purchased from Sigma Aldrich (St. Louis, MO, USA). Glass cover slips (Ø = 12 and 25 mm) were ordered from VWR (Radnor, PA, USA) and cleaned with ethanol prior to use. Ar, He, N₂ and dry air (Alphagaz 1) were ordered from Air Liquide (Paris, France).
Human foreskin fibroblasts (HFF-1) were acquired from ATCC (Manassas, VA, USA). DMEM glutamax, penicillin (10 U/mL), streptomycin (10 mg/mL), fetal bovine serum (FBS) and sodium pyruvate were ordered from Gibco Invitrogen (Waltham, MA, USA). Calcein AM (1 mg/mL) was purchased from Anaspec (Fremont, CA, USA) and propidium iodine was ordered from Sigma Aldrich (St. Louis, MO, USA). Yellow tetrazolium dye 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was acquired from Merck Promega (Darmstadt, Germany).

All chemicals were from Sigma-Aldrich (Buchs, Switzerland), Sigma Chemical Co. (St. Louis, MI, USA) and Merck KGaA (Darmstadt, Germany). Sodium phosphate monobasic was from Fluka Analytical (Darmstadt, Germany). The cell reagents were provided by Life Technologies, S.A. (Madrid, Spain) and Biowest (Nuaillé, France). Human foreskin fibroblasts (HFF-1) were obtained from ATCC (Manassas, VI, USA). Human immortalized nontumorigenic keratinocytes cell line (HaCaT) was acquired from CLS Cell Lines Service (Eppelheim, Germany). Elastatinal inhibitor and human neutrophil elastase were from Enzo Life Sciences (Farmingdale, NY, USA).