Design and biophysical characterization of 5-fluorouracil-loaded nanosystem for topical skin cancer therapy: in vitro, ex vivo and in vivo studies

CALIENNI, NATALIA; PRIETO, JIMENA; ALONSO, SILVIA DEL VALLE; MONTANARI, JORGE

Tucuman

Congreso; III Latin American Federation of Biophysical Societies (LAFeBS) ? IX IberoAmerican Congress of Biophysics ? XLV Reunión Anual SAB; 2016

Sociedad Argentina de Biofisica

Ultradeformable  liposomes  (UL)  are  a  drug  delivery  nanosystem  with  an  elastic  modulus lower than conventional liposomes. UL are capable to penetrate the stratum corneum (SC) of the skin and release their content into the viable epidermis, where neoplastic events occur in skin  cancer.  5-Fluorouracil  (5FU)  is  an  antineoplastic  drug,  administered  parenterally,  with severe side effects. Therefore,  the  incorporation of 5FU  in UL  improves specific-site delivery and aims to reduce side effects. UL  were  prepared  by  resuspension  with  a  5FU  solution  of  a  thin  lipid  film  (soy phosphatidylcholine  and  sodium  cholate  as  border  activator),  formed  by  vacuum  rotary evaporation. Vesicles were sonicated to reduce in size and lamellarity. Non-encapsulated 5FU was removed by molecular exclusion chromatography.  Size was determined by DLS and NTA and  the stability by ζ potential. The  interaction drug-lipid was assessed by DSC, using Laurdan and MC540 probes. Drug-lipid ratio, encapsulation efficiency  and  release  in  the  time  were  determined.  Size  and  lamellarity  were  also corroborated  by  AFM  and  TEM.  In  order  to  study  the  elastic  properties,  force  distance measurements  by AFM  and  a  deformability  test  in  an  automated  extruder were  performed. Free radical scavenging activity was evaluated using DPPH free radical. In  vitro  cytotoxicity  studies were  carried  out  in HaCaT  and  SK-Mel-28  human  cell-lines  by MTT,  Crystal  Violet  and  Neutral  Red.  Cellular  uptake  at  4º  and  37ºC  was  assessed  by fluorescent microscopy.  Ex vivo penetration studies were performed on a Saarbrücken Penetration Model device with human  skin  explants.  Intact  skin  and  transversal  sections  were  studied  by  confocal microscopy and penetration profile was quantified in the SC after tape stripping. Finally, in vivo nanotoxicological and teratogenic studies were carried out in the animal model zebrafish (Danio rerio).