TY - JOUR
T1 - Caproic acid grafted chitosan cationic nanocomplexes for enhanced gene delivery
T2 - Effect of degree of substitution
AU - Layek, Buddhadev
AU - Singh, Jagdish
N1 - Funding Information:
The authors greatly acknowledge the financial support from the Fraternal Order of Eagles and EPSCoR .
PY - 2013/4/15
Y1 - 2013/4/15
N2 - This work was designed to investigate the effect of the degree of substitutions of caproic acid on plasmid DNA (pDNA) binding, cellular uptake, biocompatibility, and transfection efficiency of caproic acid grafted chitosan (CGC). The CGC with three substitution degrees (CGC-5, CGC-15, and CGC-25) were synthesized by coupling caproic acid with chitosan. Chemical characterization of graft polymers was performed using FTIR, NMR, and elemental analysis. The CGC polymers showed good pDNA condensing capacity and efficient protection of pDNA from DNase I. The nanosized CGC/pDNA polyplexes exhibited well-defined spherical shapes and stability in serum. Isothermal titration calorimetry demonstrated reduction in CGC-pDNA binding constant with increase in the degree of caproic acid substitution. Caproic acid substitution resulted in 2-7-fold higher cellular uptake in HEK 293 cells mainly via the clathrin-mediated pathway without affecting biocompatibility. In vitro transfection study suggested a dependence of transfection efficiency on the variability of caproic acid substitution. The CGC-15 polymer exhibited 31-fold and 1.33-fold higher gene expression compared to chitosan and the marketed non-viral vector FuGENE ®HD, respectively. These finding suggests that the CGC-15 graft polymer is a promising non-viral gene delivery vector due to its superior transfection efficiency and biocompatibility.
AB - This work was designed to investigate the effect of the degree of substitutions of caproic acid on plasmid DNA (pDNA) binding, cellular uptake, biocompatibility, and transfection efficiency of caproic acid grafted chitosan (CGC). The CGC with three substitution degrees (CGC-5, CGC-15, and CGC-25) were synthesized by coupling caproic acid with chitosan. Chemical characterization of graft polymers was performed using FTIR, NMR, and elemental analysis. The CGC polymers showed good pDNA condensing capacity and efficient protection of pDNA from DNase I. The nanosized CGC/pDNA polyplexes exhibited well-defined spherical shapes and stability in serum. Isothermal titration calorimetry demonstrated reduction in CGC-pDNA binding constant with increase in the degree of caproic acid substitution. Caproic acid substitution resulted in 2-7-fold higher cellular uptake in HEK 293 cells mainly via the clathrin-mediated pathway without affecting biocompatibility. In vitro transfection study suggested a dependence of transfection efficiency on the variability of caproic acid substitution. The CGC-15 polymer exhibited 31-fold and 1.33-fold higher gene expression compared to chitosan and the marketed non-viral vector FuGENE ®HD, respectively. These finding suggests that the CGC-15 graft polymer is a promising non-viral gene delivery vector due to its superior transfection efficiency and biocompatibility.
KW - Caproic acid
KW - Chitosan
KW - Gene delivery
KW - Polyplex
KW - Transfection
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U2 - 10.1016/j.ijpharm.2013.02.052
DO - 10.1016/j.ijpharm.2013.02.052
M3 - Article
C2 - 23467080
AN - SCOPUS:84875070321
SN - 0378-5173
VL - 447
SP - 182
EP - 191
JO - International journal of pharmaceutics
JF - International journal of pharmaceutics
IS - 1-2
ER -