Biodistribution and Toxicity Assessment of Superparamagnetic Iron Oxide Nanoparticles In Vitro and In Vivo

Abstract

Biodistribution and toxicity assessment are critical for safe clinical use of newly developed medicines. Superparamagnetic iron oxide nanoparticles (SPION) are effective carriers for targeted drug delivery. This study aimed to examine the toxicity and biodistribution of SPION coated with polyethylenimine (PEI) (SPION-PEI) designed for small interfering RNA (siRNA) delivery both in vitro and in vivo. SPION-PEI/siRNA complexes were prepared at different weight ratios. Cytotoxic effects of SPION-PEI/siRNA on HSC-T6 cell viability were determined by using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). Rats were divided into three groups: a control group, a normal-saline group and a SPION-PEI/siRNA group. After a single intravenous injection, in vivo nanoparticle biodistribution and accumulation were evaluated by Prussian blue staining in the heart, liver, spleen, lung and kidney 8 h, 24 h, and 7 days after the injection. Their distribution was histologically studied at the three time points by measuring ironpositive areas (μm²) in organ sections stained with Prussian blue. The same organs were analyzed by H&E staining for any possible histopathological changes. Furthermore, biochemical indexes such as alanine amino transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN) and creatinine (CREA) were also assessed at all experimental time points. Electrophoresis exhibited that the SPION-PEI could retard siRNA altogether at weight ratios above 4. MTT assay showed that SPION-PEI loaded with siRNA had low cytotoxicity. In vivo study revealed that the liver and spleen were the major sites of SPION-PEI/siRNA deposition. The iron content was significantly increased in the liver and spleen, peaking 24 h after intravenous injection and then declining gradually. No evidence was found of irreversible histopathological damage to any of the organs tested. These results suggested that most SPION-PEI/siRNA complexes were distributed in the liver and spleen, which might be the target organs of SPION-PEI/siRNA complexes. SPIONPEI/siRNA may serve as in vivo carrier for biomedical medicines.

Keywords

superparamagnetic iron oxide nanoparticles / toxicity / biodistribution / Prussian blue staining

References

[1] DavidsonBL, McCrayPB. Current prospects for RNA interference-based therapies. Nat Rev Genet, 2011, 12(5): 329-340

[2] UngureanuBS, TeodorescuCM, SăfoiuA. Magnetic nanoparticles for hepatocellular carcinoma diagnosis and therapy. J Gastrointestin Liver Dis, 2016, 25(3): 375-383

[3] PecotCV, CalinGA, ColemanRL, et al.. RNA interference in the clinic: challenges and future directions. Nat Rev Cancer, 2011, 11(1): 59-67

[4] BarretoJA, MalleyWO, KubeilM, et al.. Nanomaterials: applications in cancer imaging and therapy. Adv Mater, 2011, 23(12): H18-H40

[5] HamidiM, AzadiA, RafieiP. Hydrogel nanoparticles in drug delivery. Adv Drug Deliv Rev, 2008, 60(15): 1638-1649

[6] KumariA, YadavSK, YadavSC. Biodegradable polymeric nanoparticles based drug delivery systems. Colloids Surf B-Biointerfaces, 2010, 75(1): 1-18

[7] EstelrichJ, Sanchez-MartinMJ, BusquetsMA. Nanoparticles in magnetic resonance imaging: From simple to dual contrast agents. Int J Nanomed, 2015, 10: 1727-1741

[8] EstelrichJ, EscribanoE, QueraltJ, et al.. Iron oxide nanoparticles for magnetically-guided and magnetically-responsive drug delivery. Int J Mol Sci, 2015, 16(4): 8070-8101

[9] SawdonA, WeydemeyerE, PengCA. Antitumor therapy using nanomaterial-mediated thermolysis. J Biomed Nanotechnol, 2014, 10(9): 1894-1917

[10] LiuG, XieJ, ZhangF, et al.. N-Alkyl-PEI-Functionalized iron oxide nanoclusters for efficient siRNA delivery. Small, 2011, 7(19): 2742-2749

[11] KievitFM, VeisehO, FangC, et al.. Chlorotoxin labeled magnetic nanovectors for targeted gene delivery to glioma. ACS Nano, 2010, 4(8): 4587-4594

[12] MokH, VeisehO, FangC, et al.. pH-Sensitive siRNA nanovector for targeted gene silencing and cytotoxic effect in cancer cells. Mol Pharm, 2010, 7(6): 1930-1939

[13] KievitFM, ZhangM. Surface engineering of iron oxide nanoparticles for targeted cancer therapy. Acc Chem Res, 2011, 44(10): 853-862

[14] ChoulyC, PouliquenD, LucetI, et al.. Development of superparamagnetic nanoparticles for MRI: effect of particle size, charge and surface nature on biodistribution. J Microencapsul, 1996, 13(3): 245-255

[15] GuL, FangRH, SailorMJ, et al.. In vivo clearance and toxicity of monodisperse iron oxide nanocrystals. ACS Nano, 2012, 6(6): 4947-4954

[16] VeisehO, KievitFM, LiuV, et al.. In vivo safety evaluation of polyarginine coated magnetic nanovectors. Mol Pharm, 2013, 10(11): 4099-4106

[17] BellusciM, BarberaAL, PadellaF, et al.. Biodistribution and acute toxicity of a nanofluid containing manganese iron oxide nanoparticles produced by a mechanochemical process. Int J Nanomedicine, 2014, 9(1): 1919-1929

[18] Wahajuddin. Superparamagnetic iron oxide nanoparticles: magnetic nanoplatforms as drug carriers. Int J Nanomedicine, 2012, 7: 3445-3471

[19] ChenJ, ZhuS, TongLQ, et al.. Superparamagnetic iron oxide nanoparticles mediated 131I-hVEGF siRNA inhibits hepatocellular carcinoma tumor growth in nude mice. BMC Cancer, 2014, 14(1): 114

[20] SouthernEM. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol, 1975, 98: 503-517

[21] NeuM, FischerD, KisselT. Recent advances in rational gene transfer vector design based on poly(ethyleneimine) and its derivatives. J Gene Med, 2005, 7(8): 992-1009

[22] DeJongWH, BormPJ. Drug delivery and nanoparticles: applications and hazards. Int J Nanomed, 2008, 3(2): 133

[23] LongmireM, ChoykePL, KobayashiH. Clearance properties of nano-sized particles and molecules as imaging agents: considerations and caveats. Nanomedicine, 2008, 3(5): 703-717

[24] TsuchiyaK, NittaN, SonodaA, et al.. Histological study of the biodynamics of iron oxide nanoparticles with different diameters. Int J Nanomedicine, 2011, 6: 1587-1594

[25] VeisehO, GunnJW, ZhangM. Design and fabrication of magnetic nanoparticles for targeted drug delivery and imaging. Adv Drug Deliv Rev, 2010, 62(3): 284-304

[26] JainRK. Transport of molecules, particles, and cells in solid tumors. Annu Rev Biomed Eng, 1999, 1(1): 241-263

[27] TapanKJ, MoralesMA, Leslie-PeleckyDL, et al.. Biodistribution, clearance, and biocompatibility of iron oxide magnetic nanoparticles in rats. Mol Pharm, 2007, 5(2): 316-327

[28] JainRK. Delivery of molecular medicine to solid tumors: lessons from in vivo imaging of gene expression and function. J Control Release, 2001, 74(1-3): 7-25