Magnetic nanoparticles based cancer therapy: current status and applications.

Nanotechnology holds a promising potential for developing biomedical nanoplatforms in cancer therapy. The magnetic nanoparticles, which integrate uniquely appealing features of magnetic manipulation, nanoscale heat generator, localized magnetic field and enzyme-mimics, prompt the development and application of magnetic nanoparticles-based cancer medicine. Considerable success has been achieved in improving the magnetic resonance imaging (MRI) sensitivity, and the therapeutic function of the magnetic nanoparticles should be given adequate attention. This work reviews the current status and applications of magnetic nanoparticles based cancer therapy. The advantages of magnetic nanoparticles that may contribute to improved therapeutics efficacy of clinic cancer treatment are highlighted here.

Ultrasmall Ferrite Nanoparticles Synthesized via Dynamic Simultaneous Thermal Decomposition for High-Performance and Multifunctional T1 Magnetic Resonance Imaging Contrast Agent.

Large-scale synthesis of monodisperse ultrasmall metal ferrite nanoparticles as well as understanding the correlations between chemical composition and MR signal enhancement is critical for developing next-generation, ultrasensitive T1 magnetic resonance imaging (MRI) nanoprobes. Herein, taking ultrasmall MnFe2O4 nanoparticles (UMFNPs) as a model system, we report a general dynamic simultaneous thermal decomposition (DSTD) strategy for controllable synthesis of monodisperse ultrasmall metal ferrite nanoparticles with sizes smaller than 4 nm. The comparison study revealed that the DSTD using the iron-eruciate paired with a metal-oleate precursor enabled a nucleation-doping process, which is crucial for particle size and distribution control of ultrasmall metal ferrite nanoparticles. The principle of DSTD synthesis has been further confirmed by synthesizing NiFe2O4 and CoFe2O4 nanoparticles with well-controlled sizes of ∼3 nm. More significantly, the success in DSTD synthesis allows us to tune both MR and biochemical properties of magnetic iron oxide nanoprobes by adjusting their chemical composition. Beneficial from the Mn2+ dopant, the synthesized UMFNPs exhibited the highest r1 relaxivity (up to 8.43 mM-1 s-1) among the ferrite nanoparticles with similar sizes reported so far and demonstrated a multifunctional T1 MR nanoprobe for in vivo high-resolution blood pool and liver-specific MRI simultaneously. Our study provides a general strategy to synthesize ultrasmall multicomponent magnetic nanoparticles, which offers possibilities for the chemical design of a highly sensitive ultrasmall magnetic nanoparticle based T1 MRI probe for various clinical diagnosis applications.

Molecular magnetic resonance probe targeting VEGF165: preparation and in vitro and in vivo evaluation.

A new method for imaging the tumor human vascular endothelial growth factor 165 (VEGF 165) is presented. A magnetic resonance imaging (MRI) probe was prepared by crosslinking ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles to the aptamer for tumor vascular endothelial growth factor 165 (VEGF165-aptamer). The molecular probe was evaluated for its in vitro and in vivo activities toward VEGF165. Enzyme-linked immunosorbent assay showed that the VEGF165-aptamer-USPIO nanoparticles conjugate specifically binds to VEGF165 in vitro. A cell proliferation test showed that VEGF165-aptamer-USPIO seems to block the proliferation of human umbilical vein endothelial cells induced by free VEGF165, suggesting that VEGF165 is an effective target of this molecular probe. In xenograft mice carrying liver cancer that expresses VEGF165, T2-weighted imaging of the tumor displayed marked negative enhancement 3 h after the intravenous administration of VEGF165-aptamer-USPIO. The enhancement disappeared 6 h after administration of the probe. These results suggest the targeted imaging effect of VEGF165-aptamer-USPIO probe in vivo for VEGF165-expressing tumors. This is the first report of a targeted MRI molecular probe based on USPIO and VEGF165-aptamer.

[Recent advances in curcumin and its derivatives for treatment of liver diseases].

Curcumin is a principal polyphenolic curcuminoid extracted from turmeric rhizome, which has been used for treating inflammation of joints, ulcers, jaundice and other disorders in Asian traditional medicine. In recent years, many studies have indicated that curcumin plays important roles in treatment of liver diseases. Curcumin attenuates liver injury and non-alcoholic fatty liver disease by lowering the release of inflammation cytokines, minimizing oxidative stress, enhancing the sensitivity of insulin and altering lipid metabolism. Curcumin shows potent anti-fibrosis activity, contributing to inhibit the activation of hepatic stellate cells and reduce the deposition of extracellular matrix by its regulation of PPAR-γ, NF-ΚB and TGF-ß signaling pathways. Moreover, curcumin exhibits anti-cancer effect by inducing G2/M phase cell cycle arrest and apoptosis in several hepatoma cell lines. However, poor water solubility and low bioavailability of curcumin limit its clinical applications. To overcome its limited systemic bioavailability, many new approaches have been explored to deliver curcumin effectively. This article focuses on advances in the effects of curcumin and its derivatives for treatment of liver injury, non-alcoholic fatty liver disease, liver fibrosis and hepatocarcinoma.

Enhanced immunity against hepatoma induced by dendritic cells pulsed with Hsp70-H22 peptide complexes and CD40L.

PURPOSE: Dendritic cell (DC)-based cancer vaccines have become an attractive antitumour therapeutic approach. However, clinical application of current DC-based cancer vaccines has been limited by their ineffectiveness. Heat shock protein 70 from Mycobacterium tuberculosis (TBhsp70) is known to have a potent adjuvant capability to induce maturation of DCs and thus acts as an alternative ligand to the CD40 ligand (CD40L) on T cells to induce a T-cell response. The aim of this study is to investigate whether the combination of TBhsp70-H22 tumour-peptide complexes and CD40L might improve the antitumour efficacy for development of therapeutic DC-based vaccines against hepatoma. METHODS: The CD40, CD80, CD86 and HLA-DR expression on DCs pulsed with TBhsp70-H22 tumour-peptide complexes and soluble CD40L was studied by flow cytometric analysis, and T-helper type 1 cytokine secretion, such as IL-12p70 secretion, was tested by ELISA. The H22-specific cytotoxic T-lymphocytes (CTLs) were detected by a (51)Cr-release assay, and the in vivo antitumour immunity against hepatoma was measured by utilising H22-tumour-bearing mice after therapeutic administration. RESULTS: Up-regulation of CD40, CD80, CD86 and HLA-DR expression on DCs pulsed with TBhsp70-H22 tumour-peptide complexes and CD40L was found, which stimulated a high level of T-helper type 1 cytokine secretion, such as IL-12p70, and resulted in the induction of H22-specific CTLs. The therapeutic administration of DCs pulsed in vitro with TBhsp70-H22 tumour-peptide complexes and CD40L significantly reduced the progression of H22 tumours in mice compared with DC-Hsp70-H22 peptide complexes or DC-CD40L alone. CONCLUSIONS: Our findings demonstrate that DCs pulsed with Hsp70-H22-peptide complexes and CD40L enhance the antitumour immunity against hepatoma, which provides a novel immunotherapeutic approach against cancer.

[The effects of curcumin derivative on experimental steatohepatitis].

OBJECTIVE: To observe the effects of curcumin derivative on non-alcoholic steatohepatitis (NASH). METHODS: 60 SD male rats were randomly divided into 5 groups. The NASH model was induced by high fat diet combined with carbon tetrachloride. These rats were then treated with curcumin and curcumin derivative, saline treating group as control. The serum biochemical parameters and liver histological examinations were observed. The TNF alpha, NF-kappa B and HMG-CoA reductase mRNA transcriptions of liver tissue were detected with RT-PCR. The protein expressions of TNF alpha and NF-kappa B were detected by western blot. RESULTS: Compared with the saline group, A remarkable reduction was observed in serum ALT (U/L), AST (U/L) and TC (mmol/L) in rats treated with curcumin derivatives [(69.20 +/- 27.58) vs (102.43 +/- 47.29), (158.00 +/- 39.15) vs (229.50 +/- 105.20) and (2.08 +/- 0.30) vs (2.58 +/- 1.02), P < 0.05]. The degrees of fibrosis were significantly alleviated; Compared with curcumin group, liver index and serum ALT, AST of curcumin derivative group were also significantly decreased [(4.88 +/- 0.62) vs (5.16 +/- 0.61); (69.20 +/- 27.58) vs (82.5 +/- 33.23); (158.00 +/- 39.15) vs (211.75 +/- 106.30), P < 0.05]; The liver steatosis and inflammation grade were also significantly improved .The gene transcriptions of TNF alpha, NF-kappa B and HMG-CoA reductase in curcumin derivative group were significantly lower than those in curcumin and saline group (P < 0.05). CONCLUSION: These results indicate that the water-soluble curcumin derivative displays superior bioavailability to the parent curcumin, which can effectively improve the lipid metabolism and delay the progression of hepatic fibrosis in rats with steatohepatitis.

A novel approach for transferring oleic acid capped iron oxide nanoparticles to water phase.

A novel and simple method was described to transfer oleic acid stabilized iron oxide nanoparticles from organic solutions to water. The oxidation of OA by sodium periodate in mixed solvents formed a carboxyl group or vicinal diol to make the hydrophobic groups to hydrophilic groups on the surface of the nanoparticles. The characterization of nanoparticles indicated that the phase transfer based on the oxidation of OA was successful performed without change in the size and shape of the iron oxide nanoparticles. The hydrophilic groups on the iron oxide surface stabilized the nanoparticles in aqueous solution and the oxidized nanoparticles can be applied to bimolecular immobilization.

Cytotoxicity of Fe3O4/Au composite nanoparticles loaded with doxorubicin combined with magnetic field.

GoldMag (Fe3O4/Au) nanoparticles have the advantages of both magnetic response in an external magnetic field and the immobilization of molecules on their surface in a single step. The cytotoxicities of GoldMag nanoparticles and GoldMag nanoparticles loaded with doxorubicin (Dox-GoldMag) combined with an external magnetic field were tested in vitro on HepG2 malignant tumor cells. The results showed that cell viability remained above 92% when using GoldMag nanoparticles at a concentration as high as 2.0 mg/ml, suggesting the biocompatibility of the nanoparticles. The IC50 (0.731 microg/ml) of the Dox-GoldMag group was higher than that (0.522 microg/ml) of the Dox group (P < 0. 05). However, the Dox-GoldMag group combined with a magnetic field had an obviously increased inhibition rate for the HepG2 cell line and the IC50 was lower than that of the Dox group (0.421 microg/ml). These results indicated that GoldMag nanoparticles loaded with doxorubicin combined with a permanent magnetic field are more cytotoxic and could be a potential targeted drug delivery system.

[Advance in the study of poly(lactide-co-glycolide) nano/microparticles as gene vector].

Biodegradable nano/microparticles of poly(D, L-lactide-co-glycolide) (PLGA) is a novel non-viral gene vector, which has many advantages, such as safety, non-immunogenicity, easy of large-scale preparation and well load-capability. Therefore, more and more attentions and researches have been paid on its application. Especially, PLGA has shown enormous potential application value and space in the field of plasmid DNA (pDNA) delivery system. On the basis of the current situation of PLGA nano/microparticles for pDNA delivery, this paper focused on summarizing the current preparation approaches and surface modified methods of PLGA particle, furthermore showing its application in gene therapy and genetic vaccine delivery. These showed that PLGA nano/microparticles have extensive prospect in the development of controlled gene delivery system.

Silica- and polymer-supported platinum(II) polypyridyl complexes: synthesis and application in photosensitized oxidation of alkenes.

Square-planar polypyridine platinum(II) complexes have been introduced into a silica/polymer matrix by covalent ligand modification. The photophysical properties of the supported matrices are well retained as their model complexes, and the quantum yields for singlet oxygen ((1)O(2)) generation are comparable with that of TPP (tetraphenylporphyrin) under similar conditions. A preliminary application in photosensitized oxidation indicates the silica/polymer-supported matrices are promising, which can be reused without loss of reactivity by a simple filtration. Moreover, the polymer-supported matrix exhibits excellent compatibility in various solvents.

Facile preparation of 3,4-diarylpyrroles and hydrogen by a platinum(II) terpyridyl complex.

With visible-light irradiation of the platinum(II) terpyridyl complex 1 (lambda > 450 nm), an effective photocatalytic conversion from readily available 3,4-diaryl-2,5-dihydropyrroles (2a-2e) to 3,4-diarylpyrroles (3a-3e) and hydrogen (H(2)) is achieved with high efficiency and large catalytic turnover in a homogeneous solution.

Expression of interleukins-23 and 27 leads to successful gene therapy of hepatocellular carcinoma.

IL-23 and IL-27 are two novel IL-12 cytokine family members who are quite similar to, but yet clearly distinct from IL-12 in their structures and T-cell stimulatory mechanisms. Here, we demonstrated that either IL-27 or IL-23 has potent antitumor activity in murine models of MM45T.Li hepatocellular carcinoma (HCC). These potent antitumor effects were induced primarily by CD8(+)T cells, secreting IFN-gamma while CD4(+)T cells were also involved as a help of antitumor immunity. However, the antitumor response induced by IL-27 was observed from an early stage of tumor growth whereas that of IL-23 was only evident in the late stage of tumor cell proliferation. IL-23 could induce mice to develop a long-term systemic immunologic memory response against parental MM45T.Li tumors cells, an effect IL-27 was not able to accomplish. CTLs specific for MM45T.Li cells were significantly induced by IL-23, whereas antitumor efficacy mediated by IL-27 and IL-12 involved NK cells, which IL-23 failed to activate. Furthermore, we demonstrated that CD40 expression also plays an important role in the induction of antitumor activities by IL-27, IL-23 or IL-12. Together our data suggest that IL-27 and IL-23 may be two novel and attractive candidate agents to apply to cancer immunotherapy.

Molecular cloning, expression and characterization of an interleukin 27 p28 homolog in pig (Sus scrofa).

IL-27 is the newest member of the IL-12 cytokine family and plays an important role in the immune regulation. It is composed of two subunits, p28 and EBV-induced gene 3(EBI3). Although human and mouse IL-27 p28 genes have been cloned, pig IL-27 p28 gene has not ever been reported. In the present study, we have cloned and characterized the full-length cDNA of IL-27 p28 from pig. The open reading frame of pig IL-27 p28 gene is 720 bp, which encodes a protein of 239 amino acids with a predicted molecular mass of 26.6 kDa. The deduced amino acid sequence of pig IL-27 p28 showed a high degree of homology to human (63%) and mouse (58%). It was a 4-helix cytokine and belonged to 4-helix cytokine superfamily. Pig IL-27 p28 has one transmembrane region, one signal peptide, and one N-glycosylation site, two Protein kinase C phosphorylation sites, three Casein kinase II phosphorylation sites and one N-myristoylation site. For the expression of pig IL-27 p28 protein in a eukaryotic expression system the recombinant plasmid was constructed. The expression of pig IL-27 p28 in mammalian cells were confirmed by flow cytometry analysis, immunofluorescence and Western blot. The analysis also confirmed a cross reactivity with anti-mouse IL-27 p28 antibody. This is the first report of cloning and characterization of IL-27 p28 in pig.

[Establishing a L02 cell model with whole HBV gene transfection and analyzing its expressions of HLA-A, B, C and MICA/B].

OBJECTIVE: To establish a cell model with HBV secretion by plasmid transfection with whole HBV genes into hepatic L02 cells, and to analyze the effect of HBV on the expression of HLA-A, B, C and MICA/B in L02 cells. METHODS: The mock control plasmid was built by digesting pEcob6 plasmid with EcoR I at the HBV DNA site and ligating the fragment without HBV DNA. The L02 cells were transfected with pEcob6 or mock plasmid and pcDNA3 1-neo by liposome. The expressions of HBsAg, HBcAg/HBeAg and HBV DNA were detected by immunofluorescence assay, Abbott enzymoimmunoassay, or FQ-PCR. The expressions of HLA-A, B, C and MICA/B were determined by FACS and the differences in the two molecules were analyzed. RESULTS: After the transfected cells were selected by G418, the HBsAg and HBeAg in the supernatant of L02-HBV cells were 24.78(S/N) and 4.117(S/N). The quantity of HBV DNA was 9.67 x 10(4) copies/ml, but in L02-mock and in L02 cells they were all negative. Under a confocal microscope HBsAg was brightly shown in the cytoplasm while HBcAg showed dimly in the cytoplasm or in the nuclei. By using FACS, the L02 and L02-mock cells showed some low expressions of HLA-A, B, C and a little expression of MICA/B, while the expression of the two molecules was higher in L02-HBV and the differences were significant (P < 0.05). CONCLUSION: A cell model with the expression of HBV antigens and the secretion of HBV DNA was established by pEcob6 transfection into L02 cells, the transcription or replication of HBV gene might induce stronger expressions of HLA-A, B, C and MICA/B on hepatic cells. They might be related to the immune injuries of hepatic cells.

[Immune response to HSP70-HBcAg(18-27) complex in HBV transgenic mice].

OBJECTIVES: To study the cellular immune response to HSP70-HBcAg(18-27) complex in HBV transgenic mice. METHOD: HSP70-HBcAg(18-27) complex was reconstituted in vitro, then it was injected into HBV transgenic mice to observe the cellular immune response. At the same time, we investigated whether HSP70-HBcAg(18-27) complex could generate antigen specific cytotoxic T lymphocyte responses in spleen cells. RESULTS: Our results demonstrated that HSP70-HBcAg(18-27) complex increased levels of CD4+ and CD8+ T cells in the spleens and peripheral blood of HBV transgenic mice, and the complex also activated dendritic and natural killer cells. CONCLUSION: HSP70-HBcAg(18-27) complex has an immunological antigenicity in raising the immunoresponse to chronic HBV infection in HBV transgenic mice. HSP70-HBcAg(18-27) complex might be considered as a candidate for further studies on its role as a therapeutic vaccine against chronic HBV infection in humans.

A DNA vaccine against chimeric AFP enhanced by HSP70 suppresses growth of hepatocellular carcinoma.

Alpha-fetoprotein (AFP) is produced principally in fetal liver, gastrointestinal tract and the yolk sac which is temporarily present during embryonic development. AFP is overexpressed in the majority of hepatocellular carcinoma (HCC) and thus offers an attractive target for immunotherapy against this neoplasm. Here, we report that anti-HCC effects were achieved in a therapeutic setting with a DNA vaccine encoding mouse AFP and co-expressing heat shock protein 70 (HSP70) gene. We also demonstrated that this vaccine elicited a marked and highly effective AFP specific CTL response against AFP-positive target cells. This vaccine also induced the prolongation of life span in mice bearing the tumor and the eradication of HCC. It is anticipated that vaccine strategies such as this may contribute to the effective future treatment of hepatocellular carcinoma.

Photooxidation of olefins under oxygen in platinum(II) complex-loaded mesoporous molecular sieves.

Cyclometalated platinum(II) complex has been successfully incorporated into the (3-aminopropyl) triethoxysilane-modified channels of ordered mesoporous silica SBA-15 that has large pore hexagonal channels. Studies on the (1)O(2) generation conclusively demonstrates that the olefins in the nano-channels of SBA-15 can be enriched 8 times higher than those in the homogeneous solution as the diffusion quantum yield of singlet oxygen ((1)O(2)) is assumed to be unit. The platinum(II) complex loaded in the channel of SBA-15 is stable, and the photosensitized oxidation occurs efficiently. No obvious degradation and leaching of photosensitizers is observed even after 10 runs. Only a simple filtration is needed for the recycled use of the expensive noble metal catalysts. This versatile system is a good example of photochemical reactions occurring in the mesoporous silica molecular sieve. SBA-15 not only provides a support for the photosensitizer, but also acts as a nano-reactor to facilitate the photooxidation.

Switch between charge transfer and local excited states in 4-aminophenyl-substituted Hantzsch 1,4-dihydropyridine induced by pH change and transition metal ions.

The absorption and fluorescence spectra of a Hantzsch 1,4-dihydropyridine derivative bearing a N,N-dimethylaminophenyl group at 4-position (H(2)Py-PhN(CH(3))(2)) in aprotic solvents have been examined and compared to model compounds 4-phenyl- and 4-methyl-substituted Hantzsch 1,4-dihydropyridines (H(2)Py-Ph and H(2)Py-Me). While H(2)Py-Ph and H(2)Py-Me show fluorescence around 420 nm from the local excited state of the dihydropyridine chromophore, H(2)Py-PhN(CH(3))(2) exhibits fluorescence around 520 nm from the intramolecular charge transfer (ICT) state involving the aniline and dihydropyridine groups as donor and acceptor, respectively. Upon addition of an acid to the solution of H(2)Py-PhN(CH(3))(2), the amino group in the aniline is protonated. Thus, the photoinduced intramolecular charge transfer is prevented, and only the fluorescence from the local excited state of the dihydropyridine chromophore can be detected. These changes in the fluorescence behavior are fully reversible: subsequent addition of a base to the acidic solution leads to the recovery of the ICT fluorescence and the quenching of the local fluorescence. Transition metal ions also can switch the fluorescence of H(2)Py-PhN(CH(3))(2). Evidence for the interaction between transition metal ions and the amino group in the dimethylaniline have been provided by absorption and emission spectrum as well as NMR studies.

[Immune adjuvant effect of TB.HSP70 to its accompanying cytotoxic T lymphocytes epitope elicits HBV specific immune response].

OBJECTIVE: To investigate whether Mycobacterium tuberculosis heat shock protein 70 (TB.HSP70) can be used as an adjuvant carrier to stimulate immune response to an accompanying cytotoxic T lymphocytes (CTL) epitope peptide from hepatitis B virus (HBV) core antigen. METHODS: In vitro, peripheral blood mononuclear cells (PBMCs) from chronic hepatitis B volunteers were stimulated with TB.HSP70-CTL fusion protein and TB.HSP70/CTL complex, and then HBV specific CTL activity was assessed. In vivo, the CD4+ T, CD8+ T and natural killer cells (NKs) in the peripheral blood and in spleens of the immunized mice were measured by flow cytometry and the protective HBV specific immune responses of the mice were also evaluated. RESULTS: The results revealed that both of them could induce HBV specific CTL response in human PBMCs and in the immunized mice. In the mice they activated CD4+ T, CD8+ T and NKs. Furthermore, the immunocompetence of the TB.HSP70-CTL fusion protein was stronger than that of TB.HSP70/CTL complex. The HBV specific killing rate was 28.9%, the CD8+ T cell population was 43.9% and the NKs was 13.6% in splenocytes of immunized mice with TB.HSP70-CTL fusion protein. The CTL peptide alone was capable of generating weak CTL lysis. The TB.HSP70 showed almost no target cell killing. CONCLUSION: The results demonstrate that TB.HSP70 may be used as a new adjuvant carrier to improve the immunogenicity of short CTL epitope and produce effective CTL response.

[The primary study on the anti-HBV effect of whole recombinant yeast].

OBJECTIVES: Based on the immunologic character of Pichia pastoris yeast, a new therapeutic vaccine, whole recombinant yeast, was used to explore a new way to activate cell-mediated anti-viral immunity. METHODS: The recombinant plasmids, pPIC9K/S and PIC9K/hsp(1-370)-S, were constructed by inserting the gene encoding HBsAg, HSP70 (1-370) -HBsAg into vector pPIC9K and then the recombinants were transfected into Pichia pastoris yeast,GS115, respectively. Then that recombinant yeast immunized BALB/C mice were detected for humoral and cellular immunity to HBsAg. RESULTS: Recombinant yeast successfully activated the humoral immunity to HBsAg in mice, but failed to activate the cellular immunity. CONCLUSION: The whole recombinant yeast can be used as vaccine, but need further study for optimal way of immunization.