چکیده (انگلیسی):

The purpose of this study was to examine the effect of charge
ratio on the formation and properties of the chitosan (CS)–
dextran sulfate (DS) nanoparticles developed for the delivery
of water-soluble small and large molecules, including proteins.
Rhodamine 6G (R6G) and bovine serum albumin (BSA)
were chosen as model molecules. CS-DS nanoparticles were
formulated by a complex coacervation process under mild
conditions. The influence of formulation and process variables,
including the charge ratio of the 2 ionic polymers, on
particle size, zeta potential, and nanoparticle entrapment of
R6G and BSA was studied. The in vitro release of R6G and
BSA was also evaluated, and the integrity of BSA in the
release fraction was assessed using sodium dodecyl sulfate–
polyacrylamide gel electrophoresis. Depending on the concentration
and charge ratio of DS and CS, nanoparticles with
varied size (≥244 nm) and zeta potential (–47.1-60 mV) were
obtained. High entrapment efficiency (98%) was achieved
for both R6G and BSA when the charge ratio of the 2 ionic
polymers was greater than 1.12. The release of both R6G and
BSA from nanoparticles was based on the ion-exchange mechanism.
BSA showed much slower continuous release for up
to 7 days while still maintaining its integrity for an extended
period. The CS-DS nanoparticles developed based on the modulation
of charge ratio show promise as a system for controlled
delivery of both small and large molecules, including proteins.