Evaluation of pharmacokinetics of bioreducible gene delivery vectors by real-time PCR.
OBJECTIVE
To investigate pharmacokinetics of reversibly stabilized DNA nanoparticles (rSDN) using a single-step lysis RT-PCR.


METHODS
rSDN were prepared by coating bioreducible polycation/DNA polyplexes with multivalent N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers. Targeted polyplexes were formulated by linking cyclic RGD ligand (c(RGDyK)) to the HPMA surface layer of rSDN. The pharmacokinetic parameters in tumor-bearing mice were analyzed by PKAnalyst.


RESULTS
The pharmacokinetics of naked plasmid DNA, simple DNA polyplexes, rSDN, and RGD-targeted rSDN exhibited two-compartment model characteristics with area under the blood concentration-time curve (AUC) increasing from 1,102 ng x ml(-1) x min(-1) for DNA to 3,501 ng x ml(-1) x min(-1) for rSDN. Non-compartment model analysis revealed increase in mean retention time (MRT) from 4.5 min for naked DNA to 22.9 min for rSDN.


CONCLUSIONS
RT-PCR is a sensitive and convenient method suitable for analyzing pharmacokinetics and biodistribution of DNA polyplexes. Surface stabilization of DNA polyplexes can significantly extend their MRT and AUC compared to naked DNA. DNA degradation in rSDN in blood circulation, due to a combined effect of disulfide reduction and competitive reactions with charged molecules in the blood, contributes to DNA elimination.
Zhou
Qing-Hui
QH
Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48202, USA.
Wu
Chao
C
Manickam
Devika Soundara
DS
Oupický
David
D
D000178:Acrylamides / Q000737:chemistry; D000818:Animals; D004247:DNA / Q000008:administration & dosage* / Q000032:analysis / Q000378:metabolism / Q000493:pharmacokinetics*; D004220:Disulfides / Q000378:metabolism; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D008297:Male; D008546:Melanoma, Experimental / Q000628:therapy; D008689:Methacrylates / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry; D010084:Oxidation-Reduction; D011073:Polyamines / Q000737:chemistry; D000071228:Polyelectrolytes; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000191:economics / Q000379:methods*; D012680:Sensitivity and Specificity
D000178:Acrylamides; D004247:DNA; D004220:Disulfides; D008689:Methacrylates; D009842:Oligopeptides; D011073:Polyamines; D000071228:Polyelectrolytes; C047981:arginyl-glycyl-aspartic acid; C032976:N-(2-hydroxypropyl)methacrylamide; C032802:hydroxypropyl methacrylate