Protein-chitosan mass ratio determination for insulin nanoencapsulation

KARINA D. MARTINEZ; CECILIA PRUDKIN SILVA; PEREZ, OSCAR E; FEDERICO COLUCCIO LESKOW

Buenos Aires

Simposio; ICAS Frontiers in Physical Sciences; 2016

p { margin-bottom: 0cm; direction: ltr; color: rgb(0, 0, 0); text-align: center; }p.western { font-family: "Arial",sans-serif; font-size: 12pt; font-weight: bold; }p.cjk { font-family: "Times New Roman",serif; font-size: 12pt; font-weight: bold; }p.ctl { font-family: "Arial",sans-serif; font-size: 10pt; }a:link { color: rgb(0, 0, 255); }Nanocapsulesacting as drug carrier systems are widely used in the farmaceuticalindustry. When administered through the nasalmucosa,they may protect the drug from enzymatic degradation, increase thedrug dissolution rate and act as a controlled release systemresulting in prolonged blood concentrations. In thiswork, the encapsulating material of choice was chitosan (CS), whichis a biodegradable,biocompatible and non-toxic amino polysaccharide derived from chitin.It has been extensively employed for developing drug delivery systemsdue to its excellent mucoadhesive properties. Insulinis one of the most used peptide drugs worldwide, forinsulin-dependent patients treatments. The aim of our work was todetermine the most efficient conditions to enable thenanoencapsulation ofInsulin, under themolecular "self-assembly? concept. Insulinsolution, 0.2 %, w/w, was kindly donated by Denver FarmaLaboratories, Buenos Aires, Argentina. Chitosan was kindly donated bythe Microbiology Laboratory of INTI Mar del Plata, Argentina.Particle size distribution and ζ-potentialmeasurements were registered by dynamic light scattering (ZetasizerNano-Zs, Malvern Instruments, Worcestershire, UK).Measurements were made at pHof 6 to favor electrostatic interactions between the two species.Variationsin the ζ-potentialvalues of Insulin-CS mixtures were observed upon increasingconcentrations of CS. The CS mass needed for insulin charge titrationwas 10-3%w/w; this result would indicate the appropriate biopolymers massratio to ensure generation of core-shell nanocapsules. Thus,Insulin-CSmixtures particlesize distribution was obtainedfor several CS concentrations, exhibiting a noticeable shift fromfree insulin size distribution. Additionally, CS may induce molecularchanges in protein structure as determined by fluorescencespectroscopy atpH of 6.Finally, the nanocapsules´sstructure and topography were characterized by SEM.