Protein-chitosan mass ratio determination for Insulin nanoencapsulation

MARTÍNEZ, KARINA DAFNE; PRUDKIN SILVA C; PÉREZ OE; COLUCCIO LESKOW F,

Buenos Aires

Congreso; Frontiers in physical sciences Symposium.Lugar y fecha: 14 al 18 de noviembre de 2016, en el Polo CyT, UNSAM y la Facultad de Economía (UBA) en la Ciudad Autónoma de Buenos Aires.; 2016

Nanocapsules   acting   as   drug   carrier   systems   are  widely   used   in   the   farmaceuticalindustry.  When   administered   through   nasal  mucosa,   they  may   protect   the   drug   fromenzymatic degradation,   increase  the drug dissolution rate, and act  as a controlled releasesystem resulting in prolonged blood concentrations. The   encapsulating  material   of   choice  was   chitosan   (CS),  which   is   a   biodegradable,biocompatible   and   non-toxic   amino   polysaccharide   derived   from   chitin.   It   has   beenextensively   employed   for   developing   drug   delivery   systems   because   of   its   excellentmucoadhesive properties. Insulin (I) is one of the most used peptides worldwide, for insulin-dependent patients treatments.The aim of   this contribution was   to  find  the CS´s  concentration  to enable  the properencapsulation of insulin, under the molecular "self-assembly? concept.Insulin solution, 0.2 %, w/w, was kindly donated by Denver Farma Laboratories, BuenosAires, Argentina. Chitosan was kindly donated by the Microbiology Laboratory of INTI Mar delPlata, Argentina. Particle size distribution and ζ-potential measurements were registered bydynamic   light   scattering   (Zetasizer  Nano-Zs,  Malvern   Instruments,  Worcestershire,  UK).Measurements were made at  pH of  6  to  favor  electrostatic  interactions between  the  twospecies.  Variations   in   the  ζ  -potential   values   of   I-CS mixtures  were   observed   upon   increasingconcentrations of CS. The CS mass needed for insulin charge titration was 10-3 % w/w; thisresult  would  indicate  the biopolymers mass  ratio  for  core-shell  nanocapsules generation.Thus,  mixed systems particle size distribution was obtained  for several CS concentrationsand exhibited a noticeable shift from free insulin size distribution.  Chitosan   apparently   induced  molecular   changes   in   protein   structure   as   determined   byfluorescence spectroscopy at pH of 6.The nanocapsules´s structure and topography were characterized by SEM.