Magnetoliposomes Containing Multicore Nanoparticles and a New Antitumor Thienopyridine Compound with Potential Application in Chemo/Thermotherapy.

Multicore magnetic nanoparticles of manganese ferrite were prepared using carboxymethyl dextran as an agglutinating compound or by an innovative method using melamine as a cross-coupling agent. The nanoparticles prepared using melamine exhibited a flower-shape structure, a saturation magnetization of 6.16 emu/g and good capabilities for magnetic hyperthermia, with a specific absorption rate (SAR) of 0.14 W/g. Magnetoliposome-like structures containing the multicore nanoparticles were prepared, and their bilayer structure was confirmed by FRET (Förster Resonance Energy Transfer) assays. The nanosystems exhibited sizes in the range of 250-400 nm and a low polydispersity index. A new antitumor thienopyridine derivative, 7-[4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl]thieno[3,2-b]pyridine, active against HeLa (cervical carcinoma), MCF-7 (breast adenocarcinoma), NCI-H460 (non-small-cell lung carcinoma) and HepG2 (hepatocellular carcinoma) cell lines, was loaded in these nanocarriers, obtaining a high encapsulation efficiency of 98 ± 2.6%. The results indicate that the new magnetoliposomes can be suitable for dual cancer therapy (combined magnetic hyperthermia and chemotherapy).

Development of Thermo- and pH-Sensitive Liposomal Magnetic Carriers for New Potential Antitumor Thienopyridine Derivatives.

The development of stimuli-sensitive drug delivery systems is a very attractive area of current research in cancer therapy. The deep knowledge on the microenvironment of tumors has supported the progress of nanosystems' ability for controlled and local fusion as well as drug release. Temperature and pH are two of the most promising triggers in the development of sensitive formulations to improve the efficacy of anticancer agents. Herein, magnetic liposomes with fusogenic sensitivity to pH and temperature were developed aiming at dual cancer therapy (by chemotherapy and magnetic hyperthermia). Magnetic nanoparticles of mixed calcium/manganese ferrite were synthesized by co-precipitation with citrate and by sol-gel method, and characterized by X-ray diffraction (XRD), scanning electron microscopy in transmission mode (STEM), and superconducting quantum interference device (SQUID). The citrate-stabilized nanoparticles showed a small-sized population (around 8 nm, determined by XRD) and suitable magnetic properties, with a low coercivity and high saturation magnetization (~54 emu/g). The nanoparticles were incorporated into liposomes of dipalmitoylphosphatidylcholine/cholesteryl hemisuccinate (DPPC:CHEMS) and of the same components with a PEGylated lipid (DPPC:CHEMS:DSPE-PEG), resulting in magnetoliposomes with sizes around 100 nm. Dynamic light scattering (DLS) and electrophoretic light scattering (ELS) measurements were performed to investigate the pH-sensitivity of the magnetoliposomes' fusogenic ability. Two new antitumor thienopyridine derivatives were efficiently encapsulated in the magnetic liposomes and the drug delivery capability of the loaded nanosystems was evaluated, under different pH and temperature conditions.

Magnetoliposomes Based on Magnetic/Plasmonic Nanoparticles Loaded with Tricyclic Lactones for Combined Cancer Therapy.

Liposome-like nanoarchitectures containing manganese ferrite nanoparticles covered or decorated with gold were developed for application in dual cancer therapy, combining chemotherapy and photothermia. The magnetic/plasmonic nanoparticles were characterized using XRD, UV/Visible absorption, HR-TEM, and SQUID, exhibiting superparamagnetic behavior at room temperature. The average size of the gold-decorated nanoparticles was 26.7 nm for MnFe2O4 with 5-7 nm gold nanospheres. The average size of the core/shell nanoparticles was 28.8 nm for the magnetic core and around 4 nm for the gold shell. Two new potential antitumor fluorescent drugs, tricyclic lactones derivatives of thienopyridine, were loaded in these nanosystems with very high encapsulation efficiencies (higher than 98%). Assays in human tumor cell lines demonstrate that the nanocarriers do not release the antitumor compounds in the absence of irradiation. Moreover, the nanosystems do not cause any effect on the growth of primary (non-tumor) cells (with or without irradiation). The drug-loaded systems containing the core/shell magnetic/plasmonic nanoparticles efficiently inhibit the growth of tumor cells when irradiated with red light, making them suitable for a triggered release promoted by irradiation.

Magnetoliposomes Based on Shape Anisotropic Calcium/Magnesium Ferrite Nanoparticles as Nanocarriers for Doxorubicin.

Multifunctional lipid nanocarriers are a promising therapeutic approach for controlled drug release in cancer therapy. Combining the widely used liposome structure with magnetic nanoparticles in magnetoliposomes allies, the advantages of using liposomes include the possibility to magnetically guide, selectively accumulate, and magnetically control the release of drugs on target. The effectiveness of these nanosystems is intrinsically related to the individual characteristics of the two main components-lipid formulation and magnetic nanoparticles-and their physicochemical combination. Herein, shape-anisotropic calcium-substituted magnesium ferrite nanoparticles (Ca0.25Mg0.75Fe2O4) were prepared for the first time, improving the magnetic properties of spherical counterparts. The nanoparticles revealed a superparamagnetic behavior, high saturation magnetization (50.07 emu/g at 300 K), and a large heating capacity. Furthermore, a new method for the synthesis of solid magnetoliposomes (SMLs) was developed to enhance their magnetic response. The manufacturing technicalities were optimized with different lipid compositions (DPPC, DPPC/Ch, and DPPC/DSPE-PEG) originating nanosystems with optimal sizes for biomedical applications (around or below 150 nm) and low polydispersity index. The high encapsulation efficiency of doxorubicin in these magnetoliposomes was proven, as well as the ability of the drug-loaded nanosystems to interact with cell membrane models and release DOX by fusion. SMLs revealed to reduce doxorubicin interaction with human serum albumin, contributing to a prolonged bioavailability of the drug upon systemic administration. Finally, the drug release kinetic assays revealed a preferable DOX release at hyperthermia temperatures (42 °C) and acidic conditions (pH = 5.5), indicating them as promising controlled release nanocarriers by either internal (pH) and external (alternate magnetic field) stimuli in cancer therapy.

Photodeposition of Silver on Zinc/Calcium Ferrite Nanoparticles: A Contribution to Efficient Effluent Remediation and Catalyst Reutilization.

The efficient photodegradation of textile dyes is still a challenge, especially considering resistant azo dyes. In this work, zinc/calcium mixed ferrite nanoparticles prepared by the sol-gel method were coupled with silver by a photodeposition method to enhance the photocatalytic potency. The obtained zinc/calcium ferrites are mainly cubic-shaped nanoparticles sized 15 ± 2 nm determined from TEM and XRD and an optical bandgap of 1.6 eV. Magnetic measurements indicate a superparamagnetic behavior with saturation magnetizations of 44.22 emu/g and 27.97 emu/g, respectively, for Zn/Ca ferrite and Zn/Ca ferrite with photodeposited silver. The zinc/calcium ferrite nanoparticles with photodeposited silver showed efficient photodegradation of the textile azo dyes C.I. Reactive Blue 250 and C.I. Reactive Yellow 145. Subsequent cycles of the use of the photocatalyst indicate the possibility of magnetic recovery and reutilization without a significant loss of efficiency.

Stealth Magnetoliposomes Based on Calcium-Substituted Magnesium Ferrite Nanoparticles for Curcumin Transport and Release.

Despite the promising pharmacological properties of curcumin, the transport and effective release of curcumin is still a challenge. The advances in functionalized nanocarriers for curcumin have also been motivated by the anticancer activity of this natural compound, aiming at targeted therapies. Here, stealth (aqueous and solid) magnetoliposomes containing calcium-substituted magnesium ferrite nanoparticles, CaxMg1-xFe2O4 (with x = 0.25, 0.50, 0.75) were developed as nanocarriers for curcumin. The magnetic nanoparticles exhibit superparamagnetic properties and crystalline structure, with sizes below 10 nm. The magnetoliposomes based on these nanoparticles have hydrodynamic diameters around or below 150 nm and a low polydispersity. The influence of an alternating magnetic field (AMF) on drug release over time was evaluated and compared with curcumin release by diffusion. The results suggest the potential of drug-loaded magnetoliposomes as nanocarriers that can be magnetically guided to the tumor sites and act as agents for a synergistic effect combining magnetic hyperthermia and controlled drug release.

Development of Novel Magnetoliposomes Containing Nickel Ferrite Nanoparticles Covered with Gold for Applications in Thermotherapy.

Multifunctional nanosystems combining magnetic and plasmonic properties are a promising approach for cancer therapy, allowing magnetic guidance and a local temperature increase. This capability can provide a triggered drug release and synergistic cytotoxic effect in cancer cells. In this work, nickel ferrite/gold nanoparticles were developed, including nickel ferrite magnetic nanoparticles decorated with plasmonic gold nanoparticles and core/shell nanostructures (with a nickel ferrite core and a gold shell). These nanoparticles were covered with a surfactant/lipid bilayer, originating liposome-like structures with diameters below 160 nm. The heating capacity of these systems, upon excitation with light above 600 nm wavelength, was assessed through the emission quenching of rhodamine B located in the lipid layer. The developed nanosystems show promising results for future applications in thermotherapy.

Magnetic Nanoparticles of Zinc/Calcium Ferrite Decorated with Silver for Photodegradation of Dyes.

Magnetic nanoparticles of zinc/calcium ferrite and decorated with silver were prepared by coprecipitation method. The obtained nanoparticles were characterized by UV/Visible absorption, XRD, TEM and SQUID. The mixed zinc/calcium ferrites exhibit an optical band gap of 1.78 eV. HR-TEM imaging showed rectangular nanoplate shapes with sizes of 10 ± 3 nm and aspect ratio mainly between 1 and 1.5. Magnetic measurements indicated a superparamagnetic behavior. XRD diffractograms allowed a size estimation of 4 nm, which was associated with the nanoplate thickness. The silver-decorated zinc/calcium ferrite nanoparticles were successfully employed in the photodegradation of a model dye (Rhodamine B) and industrial textile dyes (CI Reactive Red 195, CI Reactive Blue 250 and CI Reactive Yellow 145). The nanosystems developed exhibited promising results for industrial application in effluent photoremediation using visible light, with the possibility of magnetic recovery.

Magnetoliposomes Containing Calcium Ferrite Nanoparticles for Applications in Breast Cancer Therapy.

Magnetoliposomes containing calcium ferrite (CaFe2O4) nanoparticles were developed and characterized for the first time. CaFe2O4 nanoparticles were covered by a lipid bilayer or entrapped in liposomes forming, respectively, solid or aqueous magnetoliposomes as nanocarriers for new antitumor drugs. The magnetic nanoparticles were characterized by UV/Visible absorption, XRD, HR-TEM, and SQUID, exhibiting sizes of 5.2 ± 1.2 nm (from TEM) and a superparamagnetic behavior. The magnetoliposomes were characterized by DLS and TEM. The incorporation of two new potential antitumor drugs (thienopyridine derivatives) specifically active against breast cancer in these nanosystems was investigated by fluorescence emission and anisotropy. Aqueous magnetoliposomes, with hydrodynamic diameters around 130 nm, and solid magnetoliposomes with sizes of ca. 170 nm, interact with biomembranes by fusion and are able to transport the antitumor drugs with generally high encapsulation efficiencies (70%). These fully biocompatible drug-loaded magnetoliposomes can be promising as therapeutic agents in future applications of combined breast cancer therapy.

Development of Inhalable Superparamagnetic Iron Oxide Nanoparticles (SPIONs) in Microparticulate System for Antituberculosis Drug Delivery.

Tuberculosis (TB) is an infectious disease which affects millions of people worldwide. Inhalable polymeric dry powders are promising alternatives as anti-TB drug carriers to the alveoli milieu and infected macrophages, with potential to significantly improve the therapeutics efficiency. Here, the development of a magnetically responsive microparticulate system for pulmonary delivery of an anti-TB drug candidate (P3) is reported. Microparticles (MPs) are developed based on a cast method using calcium carbonate sacrificial templates and incorporate superparamagnetic iron oxide nanoparticles to concentrate MPs in alveoli and enable drug on demand release upon actuation of an external alternate magnetic field (AMF). The MPs are shown to be suitable for P3 delivery to the lower airways and for alveolar macrophage phagocytosis. The developed MPs reveal unique and promising features to be used as an inhalable dry powder allowing the AMF control over dosage and frequency of drug delivery anticipating improved TB treatments.

Development of Multifunctional Liposomes Containing Magnetic/Plasmonic MnFe2O4/Au Core/Shell Nanoparticles.

Multifunctional liposomes containing manganese ferrite/gold core/shell nanoparticles were developed. These magnetic/plasmonic nanoparticles were covered by a lipid bilayer or entrapped in liposomes, which form solid or aqueous magnetoliposomes as nanocarriers for simultaneous chemotherapy and phototherapy. The core/shell nanoparticles were characterized by UV/Visible absorption, X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Superconducting Quantum Interference Device (SQUID). The magnetoliposomes were characterized by Dynamic Light Scattering (DLS) and TEM. Fluorescence-based techniques (FRET, steady-state emission, and anisotropy) investigated the incorporation of a potential anti-tumor drug (a thienopyridine derivative) in these nanosystems. The core/shell nanoparticles exhibit sizes of 25 ± 2 nm (from TEM), a plasmonic absorption band (λmax = 550 nm), and keep magnetic character. XRD measurements allowed for the estimation of 13.3 nm diameter for manganese ferrite core and 11.7 nm due to the gold shell. Aqueous magnetoliposomes, with hydrodynamic diameters of 152 ± 18 nm, interact with model membranes by fusion and are able to transport the anti-tumor compound in the lipid membrane, with a high encapsulation efficiency (EE (%) = 98.4 ± 0.8). Solid magnetoliposomes exhibit hydrodynamic diameters around 140 nm and also carry successfully the anticancer drug (with EE (%) = 91.2 ± 5.2), while also being promising as agents for phototherapy. The developed multifunctional liposomes can be promising as therapeutic agents for combined chemo/phototherapy.

Solid and aqueous magnetoliposomes as nanocarriers for a new potential drug active against breast cancer.

Iron oxide nanoparticles, with diameters around 12nm, were synthesized by coprecipitation method. The magnetic properties indicate a superparamagnetic behavior with a coercive field of 9.7Oe and a blocking temperature of 118K. Both aqueous and solid magnetoliposomes containing magnetite nanoparticles have sizes below 150nm, suitable for biomedical applications. Interaction between both types of magnetoliposomes and models of biological membranes was proven. A new antitumor compound, a diarylurea derivative of thienopyridine, active against breast cancer, was incorporated in both aqueous and solid magnetoliposomes, being mainly located in the lipid membrane. A promising application of these magnetoliposomes in oncology is anticipated, allowing a combined therapeutic approach, using both chemotherapy and magnetic hyperthermia.

Magnetic liposomes based on nickel ferrite nanoparticles for biomedical applications.

Nickel ferrite nanoparticles with superparamagnetic behavior at room temperature were synthesized using a coprecipitation method. These magnetic nanoparticles were either covered with a lipid bilayer, forming dry magnetic liposomes (DMLs), or entrapped in liposomes, originating aqueous magnetoliposomes (AMLs). A new and promising method for the synthesis of DMLs is described. The presence of the lipid bilayer in DMLs was confirmed by FRET (Förster Resonance Energy Transfer) measurements between the fluorescent-labeled lipids NBD-C12-HPC (NBD acting as a donor) included in the second lipid layer and rhodamine B-DOPE (acceptor) in the first lipid layer. An average donor-acceptor distance of 3 nm was estimated. Assays of the non-specific interactions of magnetoliposomes with biological membranes (modeled using giant unilamellar vesicles, GUVs) were performed. Membrane fusion between both aqueous and dry magnetoliposomes and GUVs was confirmed by FRET, which is an important result regarding applications of these systems both as hyperthermia agents and antitumor drug nanocarriers.

Intratumoral lymphatic vessel density in vulvar squamous cell carcinomas: a possible association with favorable prognosis.

Lymphatic vessels serve as major routes for regional dissemination, and therefore, lymph node status is a key indicator of prognosis. To predict lymph node metastasis, tumor lymphatic density and lymphangiogenesis-related molecules have been studied in various tumor types. To our knowledge, no previous studies have evaluated the role of intratumoral lymphatic vessel density (LVD) in the behavior of vulvar carcinomas. The aim of this study was to analyze intratumoral LVD in relation to patient survival and well-characterized prognostic factors for cancer. Thirty-five patients with vulvar squamous cell carcinoma underwent vulvectomy and dissection of regional lymph nodes. Clinical records were reviewed, in addition to histological grade, peritumoral lymphatic invasion, and depth of infiltration for each case. Tissue microarray paraffin blocks were created, and lymphatic vessels were detected using immunohistochemical staining of podoplanin (D2-40 antibody). Intratumoral LVD was quantified by counting the number of stained vessels. Higher values for intratumoral LVD were associated with low-grade and low-stage tumors, and with tumors without lymphatic invasion and reduced stromal infiltration. In a univariate analysis, high intratumoral LVD was associated with a higher rate of overall survival and a lower rate of lymph node metastasis. Our results suggest that increased intratumoral LVD is associated with favorable prognosis in vulvar squamous carcinomas.

Oriented single-crystal-like molecular arrangement of optically nonlinear 2-methyl-4-nitroaniline in electrospun nanofibers.

In-plane aligned nanofibers of organic 2-methyl-4-nitroaniline (MNA) were produced by the electrospinning technique using a 1:1 weight ratio with poly(l-lactic acid). The fibers are capable of enormous efficient optical second harmonic generation as strong as pure MNA crystals in powder form. Structural, spectroscopic, and second harmonic generation polarimetry studies show that the MNA crystallizes within the fibers in an orientation in which the aromatic rings of MNA are predominantly orientated edge-on with respect to the plane of the fiber array and with their dipole moments aligned with the fiber axis. The results show that the electrospinning technique is an effective method to fabricate all-organic molecular functional devices based on polymer nanofibers with guest molecules possessing strong nonlinear optical and/or polar properties.

Intratumoral lymphatic vessel density and clinicopathologic features of patients with early-stage cervical cancer after radical hysterectomy.

INTRODUCTION: Lymphangiogenesis plays a key role in tumor growth, progression, and metastasis, yet few studies have investigated lymphatic vessel density (LVD) in cases of cervical cancer. The aim of this retrospective study was to evaluate intratumoral LVD, in addition to other histologic variables, in relation to lymph node metastases and survival of patients with stage IB to IIA cervical cancer after radical hysterectomy. METHODS: Between 2000 and 2008, 144 patients had a diagnosis of cervical uterine cancer and underwent radical hysterectomy. Tumor stages for these patients were identified according to the criteria of the International Federation of Gynecology and Obstetrics and included 84 stage IB1, 44 stage IB2, and 16 stage IIA cases. With an antibody directed against human podoplanin (D2-40), immunohistochemical staining was used to measure LVD. The correlation between LVD and clinicopathologic features of the resected tumors was analyzed. RESULTS: Lymphatic vessel density was significantly higher in tumors less than 2 cm in diameter (P = 0.001) and in tumors with 1.0-cm-or-less depth of invasion (P = 0.007), with early stage (P = 0.001), and with negative lymph nodes (P = 0.05). After multivariate analysis, the predictive factors associated with lymph node metastases were depth of infiltration (P = 0.027), lymphovascular space invasion (P < 0.001), and parametrial involvement (P = 0.01). For patient death, the predictive factors were International Federation of Gynecology and Obstetrics stage (P = 0.017), histologic type (P = 0.010), lymph node status (P = 0.031), and histologic grade (P = 0.041). Lymphatic vessel density was not a predictive variable for lymph node metastasis or death. CONCLUSIONS: Intratumoral LVD was greater in early cervical cancer (ie, smaller tumors, early clinical stage, and negative lymph nodes), and no relationship between LVD and lymph node metastases or survival was observed.

Prognostic value of podoplanin expression in intratumoral stroma and neoplastic cells of uterine cervical carcinomas.

OBJECTIVE: To investigate the clinicopathological significance of podoplanin expression in the intratumoral stroma and neoplastic cells of early stage uterine cervical cancer. MATERIALS AND METHODS: A total of 143 patients with clinical stage I and IIA uterine cervical carcinomas underwent surgery between 2000 and 2007. Clinicopathological data and slides associated with these cases were retrospectively reviewed. Immunodetection of podoplanin expression in histologic sections of tissue microarray blocks was performed using the monoclonal antibody D2-40. RESULTS: Expression of podoplanin was detected in neoplastic cells in 31/143 (21.6%) cases, with 29/31 (93.5%) of these cases diagnosed as squamous carcinoma. For all of the cases examined, the strongest signal for podoplanin expression was observed at the proliferating edge of the tumor nests. The rate of positive podoplanin expression for node-positive cases was lower than that of node-negative (18.9% vs. 22.6%, respectively). Furthermore, the rate of positive podoplanin expression in fatal cases was 10.5% vs. 21.6%, respectively. In 27/143 (18.8%) cases, podoplanin expression was detected in fibroblasts of the intratumoral stroma, and this expression did not correlate with patient age, clinical stage, tumor size, histologic type, depth of infiltration, or vascular involvement. Moreover, expression of podoplanin in intratumoral stroma fibroblasts was only negatively associated with nodal metastasis. A greater number of fatal cases was observed among negative intratumoral stroma fibroblasts (15.5% vs. 3.7%, respectively), although this difference was not significant. CONCLUSIONS: These preliminary results suggest that podoplanin may have a role in host-tumor interactions and, as a result, may represent a favorable prognostic factor for squamous cervical carcinomas.

Prognostic value of podoplanin expression in intratumoral stroma and neoplastic cells of uterine cervical carcinomas

OBJECTIVE: To investigate the clinicopathological significance of podoplanin expression in the intratumoral stroma and neoplastic cells of early stage uterine cervical cancer. MATERIALS AND METHODS: A total of 143 patients with clinical stage I and IIA uterine cervical carcinomas underwent surgery between 2000 and 2007. Clinicopathological data and slides associated with these cases were retrospectively reviewed. Immunodetection of podoplanin expression in histologic sections of tissue microarray blocks was performed using the monoclonal antibody D2-40. RESULTS: Expression of podoplanin was detected in neoplastic cells in 31/143 (21.6 percent) cases, with 29/31 (93.5 percent) of these cases diagnosed as squamous carcinoma. For all of the cases examined, the strongest signal for podoplanin expression was observed at the proliferating edge of the tumor nests. The rate of positive podoplanin expression for node-positive cases was lower than that of node-negative (18.9 percent vs. 22.6 percent, respectively). Furthermore, the rate of positive podoplanin expression in fatal cases was 10.5 percent vs. 21.6 percent, respectively. In 27/143 (18.8 percent) cases, podoplanin expression was detected in fibroblasts of the intratumoral stroma, and this expression did not correlate with patient age, clinical stage, tumor size, histologic type, depth of infiltration, or vascular involvement. Moreover, expression of podoplanin in intratumoral stroma fibroblasts was only negatively associated with nodal metastasis. A greater number of fatal cases was observed among negative intratumoral stroma fibroblasts (15.5 percent vs. 3.7 percent, respectively), although this difference was not significant. CONCLUSIONS: These preliminary results suggest that podoplanin may have a role in host-tumor interactions and, as a result, may represent a favorable prognostic factor for squamous cervical carcinomas.