The
poly (lactide-co-glycolide) (PLGA)-based nanoparticles, coated by the
heparin- or
chitosan-
Pluronic conjugate, were used to improve a relatively low
tumor-targeting efficiency of the bare PLGA nanoparticles. The prepared nanoparticles were in the size range of 100-150nm, and the surface exposure of the functional moiety (
heparin or
chitosan) was confirmed by negatively or positively increased zeta potential values, respectively. The viability tests for both normal and
tumor cells displayed minimal cytotoxicity of the nanoparticles. The stable surface coating, which was evident from no change in the size distribution profiles in spite of the surface charge changes in serum environment, effectively provided the desired functionalized surface that clearly enhanced the in vitro cellular uptake of the nanoparticles for both
heparin and
chitosan functionalization. The in vivo
tumor model study, which was carried out in SCC7
tumor-bearing athymic mice, demonstrated that there was a limited, but positive effect of surface functionalization, more effective for
chitosan functionalization. The accumulation of
chitosan-functionalized PLGA nanoparticles in
tumor was 2.4 folds higher than that of the control, PLGA nanoparticles coated with bare
Pluronic, and the accumulation in liver was lower than the control. In the case of
heparin functionalization, the mean value was 2.2 folds higher than that of the control, but the accumulation in liver was similar to that of the control. Therefore, the surface-functionalization by the
chitosan- or
heparin-conjugated
Pluronic may be an effective approach for the hydrophobic nanoparticle systems aiming for the enhanced
tumor imaging and
therapy.