Guohua Xia

Pharmacokinetic parameters and tissue distribution of magnetic Fe(3)O(4) nanoparticles in mice.

Background This study explored the pharmacokinetic parameters and tissue distribution of magnetic iron oxide nanoparticles (Fe3O4 MNPs) in imprinting control region (ICR) mice. Methods The Fe3O4 MNPs were synthesized by chemical coprecipitation, and their morphology and appearance were observed by transmission electron microscopy. ICR mice were divided into a control group and a Fe3O4 MNP-treated group. Probable target organs in ICR mice were observed, and the pharmacokinetic parameters and biodistribution of Fe3O4 MNPs in tissues were identified using atomic absorption spectrophotometry. Results Fe3O4 MNPs were spherical with a well distributed particle diameter, and were distributed widely in various target organs and tissues including the heart, liver, spleen, lungs, kidneys, brain, stomach, small intestine, and bone marrow. The majority of Fe3O4 MNPs were distributed to the liver and the spleen. Fe3O4 MNP levels in brain tissue were higher in the Fe3O4 MNP-treated group than in the control group, indicating that Fe3O4 MNPs can penetrate the blood–brain barrier. Conclusion These results suggest that the distribution of Fe3O4 MNPs was mostly in the liver and spleen, so the curative effect of these compounds could be more pronounced for liver tumors. Furthermore, Fe3O4 MNPs might be used as drug carriers to overcome physiologic barriers.

Multifunctional magnetic Fe3O4 nanoparticles combined with chemotherapy and hyperthermia to overcome multidrug resistance

Background Multidrug resistance in cancer is a major obstacle for clinical therapeutics, and is the reason for 90% of treatment failures. This study investigated the efficiency of novel multifunctional Fe3O4 magnetic nanoparticles (Fe3O4-MNP) combined with chemotherapy and hyperthermia for overcoming multidrug resistance in an in vivo model of leukemia. Methods Nude mice with tumor xenografts were randomly divided into a control group, and the treatment groups were allocated to receive daunorubicin, 5-bromotetrandrine (5-BrTet) and daunorubicin, Fe3O4-MNP, and Fe3O4-MNP coloaded with daunorubicin and 5-bromotetrandrine (Fe3O4-MNP-DNR-5-BrTet), with hyperthermia in an alternating magnetic field. We investigated tumor volume and pathology, as well as P-glycoprotein, Bcl-2, Bax, and caspase-3 protein expression to elucidate the effect of multimodal treatment on overcoming multidrug resistance. Results Fe3O4-MNP played a role in increasing tumor temperature during hyperthermia. Tumors became significantly smaller, and apoptosis of cells was observed in both the Fe3O4-MNP and Fe3O4-MNP-DNR-5-BrTet groups, especially in the Fe3O4-MNP-DNR-5-BrTet group, while tumor volumes in the other groups had increased after treatment for 12 days. Furthermore, Fe3O4-MNP-DNR-5-BrTet with hyperthermia noticeably decreased P-glycoprotein and Bcl-2 expression, and markedly increased Bax and caspase-3 expression. Conclusion Fe3O4-MNP-DNR-5-BrTet with hyperthermia may be a potential approach for reversal of multidrug resistance in the treatment of leukemia.

Biocompatibility of Fe3O4/DNR magnetic nanoparticles in the treatment of hematologic malignancies.

Purpose The objectives of this research were to assess the biocompatibility of self-assembled Fe3O4 magnetic nanoparticles (MNPs) loaded with daunorubicin (DNR), ie, (Fe3O4-MNPs/DNR), and to explore their potential application in the treatment of hematologic malignancies. Methods A hemolysis test was carried out to estimate the hematologic toxicity of Fe3O4- MNPs/DNR and a micronucleus assay was undertaken to identify its genotoxicity. Fe3O4-MNPs/ DNR were injected intraperitoneally into mice to calculate the median lethal dose (LD50). The general condition of the mice was recorded, along with testing for acute toxicity to the liver and kidneys. Results Hemolysis rates were 2.908%, 2.530%, and 2.415% after treatment with different concentrations of Fe3O4-MNPs/DNR. In the micronucleus assay, there was no significant difference in micronucleus formation rate between the experimental Fe3O4-MNPs/DNR groups and negative controls (P > 0.05), but there was a significant difference between the experimental groups and the positive controls (P < 0.05). The LD50 of the Fe3O4-MNPs/DNR was 1009.71 mg/kg and the 95% confidence interval (CI) was 769.11–1262.40 mg/kg, while that of the DNR groups was 8.51 mg/kg (95% CI: 6.48–10.37 mg/kg), suggesting that these nanoparticles have a wide safety margin. Acute toxicity testing showed no significant difference in body weight between the treatment groups at 24, 48, and 72 hours after intraperitoneal injection. The mice were all in good condition, with normal consumption of water and food, and their stools were formed and yellowish-brown. Interestingly, no toxic reactions, including instability of gait, convulsion, paralysis, and respiratory depression, were observed. Furthermore, alanine transaminase, blood urea nitrogen, and creatinine clearance in the experimental Fe3O4-MNPs/ DNR groups were 66.0 ± 28.55 U/L, 9.06 ± 1.05 mmol/L, and 18.03 ± 1.84 μmol/L, respectively, which was not significantly different compared with the control and isodose DNR groups. Conclusion Self-assembled Fe3O4-MNPs/DNR appear to be highly biocompatible and safe nanoparticles, and may be suitable for further application in the treatment of hematologic malignancies.

The effect of magnetic nanoparticles of Fe(3)O(4) on immune function in normal ICR mice.

We investigated the effect of magnetic nanoparticles of Fe3O4 (Fe3O4-MNPs) on the mice immune system. Imprinting control region (ICR) mice were assigned randomly into four groups and treated with normal saline or low, medium, or high doses of Fe3O4-MNPs, respectively. After intravenous administration of Fe3O4-MNPs for 72 hours, the peripheral T cells and the induction of primary immune responses in mice were investigated by flow cytometry and determined using enzyme-linked immunosorbent assay, respectively. The results showed that the ratio of spleen to body weight was not different between the experimental groups and control group (P > 0.05). The lymphocyte transformation rates in the suspension of spleen were higher in low-dose group than those in the control group (P < 0.05), while the proliferation of splenocytes was low in the medium and high groups when compared to the control group (P < 0.05). In peripheral blood, both the proportions of subset CD4+ and CD8+ T lymphocytes in the low-dose group were higher than those in the control group, whereas there was no difference in the number of CD4+ T cells between the medium- and low-dose groups. Interestingly, the Fe3O4-MNPs enhanced the production of interleukin-2 (IL-2), interferon-γ, and IL-10 but did not affect the production of IL-4 in peripheral blood. It is concluded that Fe3O4-MNPs could influence immune functions of normal ICR mice in a dose-dependent manner.

Daunorubicin-loaded magnetic nanoparticles of Fe3O4 overcome multidrug resistance and induce apoptosis of K562-n/VCR cells in vivo.

Multidrug resistance (MDR) is a major obstacle to cancer chemotherapy. We evaluated the effect of daunorubicin (DNR)-loaded magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4) on K562-n/VCR cells in vivo. K562-n and its MDR counterpart K562-n/VCR cell were inoculated into nude mice subcutaneously. The mice were randomly divided into four groups: group A received normal saline, group B received DNR, group C received MNPs-Fe3O4, and group D received DNR-loaded MNPs-Fe3O4. For K562-n/VCR tumor, the weight was markedly lower in group D than that in groups A, B, and C. The transcriptions of Mdr-1 and Bcl-2 gene were significantly lower in group D than those in groups A, B, and C. The expression of Bcl-2 was lower in group D than those in groups A, B, and C, but there was no difference in the expression of P-glycoprotein. The transcriptions and expressions of Bax and caspase-3 in group D were increased significantly when compared with groups A, B, and C. In conclusion, DNR-loaded MNPs-Fe3O4 can overcome MDR in vivo.

Synthesis and antitumor efficacy of daunorubicin-loaded magnetic nanoparticles.

Background A promising approach to optimize the disposition of daunorubicin-loaded magnetic nanoparticles (DNR-MNPs) was developed to minimize serious side effects of systematic chemotherapy for cancer. Methods The physical properties of DNR-MNPs were investigated and their effect on leukemia cells in vitro was evaluated by a standard WST-1 cell proliferation assay. Furthermore, cell apoptosis and intracellular accumulation of DNR were determined by FACSCalibur flow cytometry. Results Our results showed that the majority of MNPs were spherical and their sizes were from 10 to 20 nm. The average hydrodynamic diameter of DNR-MNPs in water was 94 nm. The in vitro release data showed that the DNR-MNPs have excellent sustained release property. Proliferation of K562 cells was inhibited in a dose-dependent manner by DNR in solution (DNR-Sol) or by DNR-MNPs. The IC50 for DNR-MNPs was slightly higher than that for DNR-Sol. DNR-MNPs also induced less apoptosis in K562 cells than did DNR-Sol. Detection of fluorescence intensity of intracellular DNR demonstrated that DNR-MNPs could be taken up by K562 cells and persistently released DNR in cells. Conclusion Our study suggests that optimized DNR-MNPs formulation possesses sustained drug-release and favorable antitumor properties, which may be used as a conventional dosage form for antitumor therapy.

Reversal of multidrug resistance by cisplatin-loaded magnetic Fe3O4 nanoparticles in A549/DDP lung cancer cells in vitro and in vivo

The purpose of this study was to explore whether magnetic Fe3O4 nanoparticles (Fe3O4-MNP) loaded with cisplatin (Fe3O4-MNP-DDP) can reverse DDP resistance in lung cancer cells and to investigate mechanisms of multidrug resistance in vitro and in vivo. MTT assay showed that DDP inhibited both A549 cells and DDP-resistant A549 cells in a time-dependent and dose-dependent manner, and that this inhibition was enhanced by Fe3O4-MNP. An increased rate of apoptosis was detected in the Fe3O4-MNP-DDP group compared with a control group and the Fe3O4-MNP group by flow cytometry, and typical morphologic features of apoptosis were confirmed by confocal microscopy. Accumulation of intracellular DDP in the Fe3O4-MNP-DDP group was greater than that in the DDP group by inductively coupled plasma mass spectrometry. Further, lower levels of multidrug resistance-associated protein-1, lung resistance-related protein, Akt, and Bad, and higher levels of caspase-3 genes and proteins, were demonstrated by reverse transcriptase polymerase chain reaction and Western blotting in the presence of Fe3O4-MNP-DDP. We also demonstrated that Fe3O4-MNP enhanced the effect of DDP on tumor growth in BALB/c nude mice bearing DDP-resistant human A549 xenografts by decreasing localization of lung resistance-related protein and Ki-67 immunoreactivity in cells. There were no apparent signs of toxicity in the animals. Overall, these findings suggest potential clinical application of Fe3O4-MNP-DDP to increase cytotoxicity in lung tumor xenografts.

The reversal effect of magnetic Fe3O4 nanoparticles loaded with cisplatin on SKOV3/DDP ovarian carcinoma cells.

To explore whether the magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4) loaded with cisplatin can reverse the diaminedichloro platinum (DDP) resistance to multidrug resistance of ovarian carcinoma cells and to investigate its mechanisms. The SKOV3/DDP cells were divided into DDP treatment (DDP group), MNPs-Fe3O4 treatment (MNPs-Fe3O4 group), DDP + MNPs-Fe3O4 treatment (DDP + MNPs-Fe3O4 group), and control group. After incubation with those conjugates for 48 h, the cytotoxic effects were measured by MTT assay. Apoptosis and the intracellular DDP concentration were investigated by flow cytometry and inductively coupled plasma atomic emission spectroscopy, respectively. The expression of apoptosis associated gene Bcl-2 mRNA was detected by reverse transcription polymerase chain reaction and the expressions of MDR1, lung resistance-related protein (LRP), and P-glycoprotein (P-gp) genes were studied by Western blot. Our results indicated that the 50% inhibition concentration (IC50) of the MNPs-Fe3O4 loaded with DDP was 17.4 μmol/l, while the IC50 was 39.31 μmol/l in DDP groups (p < 0.05); Apoptosis rates of SKOV3/DDP cells increased more than those of DDP groups. Accumulation of intracellular cisplatin in DDP + MNPs-Fe3O4 groups was higher than those in DDP groups (p < 0.05). Moreover, the expression of Bcl-2 mRNA and the protein expressions of MDR1, LRP, and P-gp were decreased when compared with those of DDP groups, respectively. Our results suggest that MNPs-Fe3O4 can reverse the DDP resistance to the ovarian carcinoma cell. The effects may be associated with over-expression of MDR1, LRP, P-gp, and Bcl-2, which can increase the intracellular platinum accumulation and induce the cell apoptosis.

Effect of magnetic nanoparticles on apoptosis and cell cycle induced by wogonin in Raji cells

Traditional Chinese medicine is gradually becoming a new source of anticancer drugs. One such example is wogonin, which is cytotoxic to various cancer cell lines in vitro. However, due to its low water solubility, wogonin is restricted to clinical administration. Recently, the application of drug-coated magnetic nanoparticles (MNPs) to increase water solubility of the drug and to enhance its chemotherapeutic efficiency has attracted much attention. In this study, wogonin was conjugated with the drug delivery system of MNPs by mechanical absorption polymerization to fabricate wogonin-loaded MNPs. It was demonstrated that MNPs could strengthen wogonin-induced cell inhibition, apoptosis, and cell cycle arrest in Raji cells by methylthiazol tetrazolium assay, flow cytometer assay, and nuclear 4′,6-diamidino-2-phenylindole staining. Furthermore, the molecular mechanisms of these phenomena were explored by western blot, in which the protein levels of caspase 8 and caspase 3 were increased significantly while those of survivin and cyclin E were decreased significantly in wogonin-MNPs group. These findings suggest that the combination of wogonin and MNPs provides a promising strategy for lymphoma therapy.

Reversal of multidrug resistance by magnetic Fe3O4 nanoparticle copolymerizating daunorubicin and MDR1 shRNA expression vector in leukemia cells

In many instances, multidrug resistance (MDR) is mediated by increasing the expression at the cell surface of the MDR1 gene product, P-glycoprotein (P-gp), a 170-kD energy-dependent efflux pump. The aim of this study was to investigate the potential benefit of combination therapy with magnetic Fe3O4 nanoparticle [MNP (Fe3O4)] and MDR1 shRNA expression vector in K562/A02 cells. For stable reversal of “classical” MDR by short hairpin RNA (shRNA) aiming directly at the target sequence (3491–3509, 1539–1557, and 3103–3121 nucleotide) of MDR1 mRNA. PGC silencer-U6-neo-GFP-shRNA/MDR1 called PGY1–1, PGY1–2, and PGY1–3 were constructed and transfected into K562/A02 cells by lipofectamine 2000. After transfected and incubated with or without MNP (Fe3O4) for 48 hours, the transcription of MDR1 mRNA and the expression of P-gp were detected by quantitative real-time PCR and Western-blot assay respectively. Meanwhile intracellular concentration of DNR in K562/A02 cells was detected by flow cytometry (FCM). PGC silencer-U6-neo-GFP-shRNA/MDR1 was successfully constructed, which was confirmed by sequencing and PGY1–2 had the greatest MDR1 gene inhibitory ratio. Analysis of the reversal ratio of MDR, the concentration of daunorubicin (DNR) and the transcription of MDR1 gene and expression of P-gp in K562/A02 showed that combination of DNR with either MNP (Fe3O4) or PGY1–2 exerted a potent cytotoxic effect on K562/A02 cells, while combination of MNP (Fe3O4) and PGY1–2 could synergistically reverse multidrug resistance. Thus our in vitro data strongly suggested that a combination of MNP (Fe3O4) and shRNA expression vector might be a more sufficient and less toxic anti-MDR method on leukemia.