The Centrosomes of Haploid and Diploid Cells Have an Equal Number of Centrioles in the Parasitoid Wasp Anisopteromalus Calandrae.

BACKGROUND: The centrosome is the main center of the organization of microtubules (MT) in the cell, the origin for the formation of flagella and cilia, as well as the site of many regulatory intracellular processes. In diploid cells, the centrosome includes two centrioles connected to some additional structures and surrounded by pericentriolar material. METHODS: The ultrastructure of the cells was studied using transmission electron microscopy on serial ultrathin sections. RESULTS: Here, using transmission electron microscopy on a complete series of ultrathin sections of the centrosome region, we studied the relation between the number of centrioles and ploidy in diploid cells of female wasps and haploid cells of male in the parasitoid wasp Anisopteromalus calandrae (Hymenoptera). It showed that the haploid cells of the male insect have the same number of centrioles as the diploid cells of the female. CONCLUSIONS: It can be concluded that there is no strict correlation between the number of chromosome sets (ploidy) and the number of centrioles in haplodiploid insects.

Electrochemical Nanopipette Sensor for In Vitro/In Vivo Detection of Cu2+ Ions.

In vitro/in vivo detection of copper ions is a challenging task but one which is important in the development of new approaches to the diagnosis and treatment of cancer and hereditary diseases such as Alzheimer's, Wilson's, etc. In this paper, we present a nanopipette sensor capable of measuring Cu2+ ions with a linear range from 0.1 to 10 µM in vitro and in vivo. Using the gold-modified nanopipette sensor with a copper chelating ligand, we evaluated the accumulation ability of the liposomal form of an anticancer Cu-containing complex at three levels of biological organization. First, we detected Cu2+ ions in a single cell model of human breast adenocarcinoma MCF-7 and in murine melanoma B16 cells. The insertion of the nanoelectrode did not result in leakage of the cell membrane. We then evaluated the distribution of the Cu-complex in MCF-7 tumor spheroids and found that the diffusion-limited accumulation was a function of the depth, typical for 3D culture. Finally, we demonstrated the use of the sensor for Cu2+ ion detection in the brain of an APP/PS1 transgenic mouse model of Alzheimer's disease and tumor-bearing mice in response to injection (2 mg kg-1) of the liposomal form of the anticancer Cu-containing complex. Enhanced stability and selectivity, as well as distinct copper oxidation peaks, confirmed that the developed sensor is a promising tool for testing various types of biological systems. In summary, this research has demonstrated a minimally invasive electrochemical technique with high temporal resolution that can be used for the study of metabolism of copper or copper-based drugs in vitro and in vivo.

Neutrophil as a Carrier for Cancer Nanotherapeutics: A Comparative Study of Liposome, PLGA, and Magnetic Nanoparticles Delivery to Tumors.

Insufficient drug accumulation in tumors is still a major concern for using cancer nanotherapeutics. Here, the neutrophil-based delivery of three nanoparticle types-liposomes, PLGA, and magnetite nanoparticles-was assessed both in vitro and in vivo. Confocal microscopy and a flow cytometry analysis demonstrated that all the studied nanoparticles interacted with neutrophils from the peripheral blood of mice with 4T1 mammary adenocarcinoma without a significant impact on neutrophil viability or activation state. Intravital microscopy of the tumor microenvironment showed that the neutrophils did not engulf the liposomes after intravenous administration, but facilitated nanoparticle extravasation in tumors through micro- and macroleakages. PLGA accumulated along the vessel walls in the form of local clusters. Later, PLGA nanoparticle-loaded neutrophils were found to cross the vascular barrier and migrate towards the tumor core. The magnetite nanoparticles extravasated in tumors both via spontaneous macroleakages and on neutrophils. Overall, the specific type of nanoparticles largely determined their behavior in blood vessels and their neutrophil-mediated delivery to the tumor. Since neutrophils are the first to migrate to the site of inflammation, they can increase nanodrug delivery effectiveness for nanomedicine application.

Synthesis of Prostate-Specific Membrane Antigen-Targeted Bimodal Conjugates of Cytotoxic Agents and Antiandrogens and Their Comparative Assessment with Monoconjugates.

Prostate cancer is the second most common cancer among men. We designed and synthesized new ligands targeting prostate-specific membrane antigen and suitable for bimodal conjugates with diagnostic and therapeutic agents. In vitro studies of the affinity of the synthesized compounds to the protein target have been carried out. Based on these ligands, a series of bimodal conjugates with a combination of different mitosis inhibitors and antiandrogenic drugs were synthesized. The cytotoxicity of the compounds obtained in vitro was investigated on three different cell lines. The efficacy of the two obtained conjugates was evaluated in vivo in xenograft models of prostate cancer. These compounds have been shown to be highly effective in inhibiting the growth of PSMA-expressing tumors.

Investigation of the Antifungal and Anticancer Effects of the Novel Synthesized Thiazolidinedione by Ion-Conductance Microscopy.

In connection with the emergence of new pathogenic strains of Candida, the search for more effective antifungal drugs becomes a challenge. Part of the preclinical trials of such drugs can be carried out using the innovative ion-conductance microscopy (ICM) method, whose unique characteristics make it possible to study the biophysical characteristics of biological objects with high accuracy and low invasiveness. We conducted a study of a novel synthesized thiazolidinedione's antimicrobial (for Candida spp.) and anticancer properties (on samples of the human prostate cell line PC3), and its drug toxicity (on a sample of the human kidney cell line HEK293). We used a scanning ion-conductance microscope (SICM) to obtain the topography and mechanical properties of cells and an amperometric method using Pt-nanoelectrodes to register reactive oxygen species (ROS) expression. All data and results are obtained and presented for the first time.

Pt(IV) Prodrugs with Non-Steroidal Anti-inflammatory Drugs in the Axial Position.

We report herein the design, synthesis, and biological investigation of a series of novel Pt(IV) prodrugs with non-steroidal anti-inflammatory drugs naproxen, diclofenac, and flurbiprofen, as well as these with stearic acid in the axial position. Six Pt(IV) prodrugs 5-10 were designed, which showed superior antiproliferative activity compared to cisplatin as well as an ability to overcome tumor cell line resistance to cisplatin. By tuning the drug lipophilicity via variation of the axial ligands, the most potent Pt(IV) prodrug 7 was obtained, with an enhanced cellular accumulation of up to 153-fold that of cisplatin and nanomolar cytotoxicity both in 2D and 3D cell cultures. Pt2+ species were detected at different depths of MCF-7 spheroids after incubation with Pt(IV) prodrugs using a Pt-coated carbon nanoelectrode. Cisplatin accumulation in vivo in the murine mammary EMT6 tumor tissue of BALB/c mice after Pt(IV) prodrug injection was proved electrochemically as well. The drug tolerance study on BALB/c mice showed good tolerance of 7 in doses up to 8 mg/kg.

In Vitro/In Vivo Electrochemical Detection of Pt(II) Species.

The biodistribution of chemotherapy compounds within tumor tissue is one of the main challenges in the development of antineoplastic drugs, and techniques for simple, inexpensive, sensitive, and selective detection of various analytes in tumors are of great importance. In this paper we propose the use of platinized carbon nanoelectrodes (PtNEs) for the electrochemical detection of platinum-based drugs in various biological models, including single cells and tumor spheroids in vitro and inside solid tumors in vivo. We have demonstrated the quantitative direct detection of Pt(II) in breast adenocarcinoma MCF-7 cells treated with cisplatin and a cisplatin-based DNP prodrug. To realize the potential of this technique in advanced tumor models, we measured Pt(II) in 3D tumor spheroids in vitro and in tumor-bearing mice in vivo. The concentration gradient of Pt(II) species correlated with the distance from the sample surface in MCF-7 tumor spheroids. We then performed the detection of Pt(II) species in tumor-bearing mice treated intravenously with cisplatin and DNP. We found that there was deeper penetration of DNP in comparison to cisplatin. This research demonstrates a minimally invasive, real-time electrochemical technique for the study of platinum-based drugs.

Room temperature synthesized solid solution AuFe nanoparticles and their transformation into Au/Fe Janus nanocrystals.

Solid solution AuFe nanoparticles were synthesized for the first time under ambient conditions by an adapted method previously established for the Fe3O4-Au core-shell morphology. These AuFe particles preserved the fcc structure of Au incorporated with paramagnetic Fe atoms. The metastable AuFe can be segregated by transformation into Janus Au/Fe particles with bcc Fe and fcc Au upon annealing. The ferromagnetic Fe was epitaxially grown on low index fcc Au planes. This preparation route delivers new perspective materials for magnetoplasmonics and biomedical applications and suggests the reconsideration of existing protocols for magnetite-gold core-shell synthesis.

Synthesis and Biological Evaluation of PSMA Ligands with Aromatic Residues and Fluorescent Conjugates Based on Them.

Prostate-specific membrane antigen (PSMA), also known as glutamate carboxypeptidase II (GCPII), is a suitable target for specific delivery of antitumor drugs and diagnostic agents due to its overexpression in prostate cancer cells. In the current work, we describe the design, synthesis, and biological evaluation of novel low-molecular PSMA ligands and conjugates with fluorescent dyes FAM-5, SulfoCy5, and SulfoCy7. In vitro evaluation of synthesized PSMA ligands on the activity of PSMA shows that the addition of aromatic amino acids into a linker structure leads to a significant increase in inhibition. The conjugates of the most potent ligand with FAM-5 as well as SulfoCy5 demonstrated high affinities to PSMA-expressing tumor cells in vitro. In vivo biodistribution in 22Rv1 xenografts in Balb/c nude mice of PSMA-SulfoCy5 and PSMA-SulfoCy7 conjugates with a novel PSMA ligand demonstrated good visualization of PSMA-expressing tumors. Also, the conjugate PSMA-SulfoCy7 demonstrated the absence of any explicit toxicity up to 87.9 mg/kg.

Neutrophil and Nanoparticles Delivery to Tumor: Is It Going to Carry That Weight?

The application of cell carriers for transporting nanodrugs to the tumor draws much attention as the alternative to the passive drug delivery. In this concept, the neutrophil (NΦ) is of special interest as this cell is able to uptake nanoparticles (NPs) and cross the vascular barrier in response to tumor signaling. There is a growing body of literature describing NP-NΦ interactions in vitro and in vivo that demonstrates the opportunity of using these cells to improve the efficacy of cancer therapy. However, a number of conceptual and technical issues need to be resolved for translating the technology into clinics. The current review summarizes the recent advances and challenges associated with NP-NΦ interactions, with the special focus on the complex interplay between the NP internalization pathways and the modulation of NΦ activity, and its potential consequences for nanodrug delivery.

Cobalt Ferrite Nanoparticles for Tumor Therapy: Effective Heating versus Possible Toxicity.

Magnetic nanoparticles (MNPs) are widely considered for cancer treatment, in particular for magnetic hyperthermia (MHT). Thereby, MNPs are still being optimized for lowest possible toxicity on organisms while the magnetic properties are matched for best heating capabilities. In this study, the biocompatibility of 12 nm cobalt ferrite MNPs, functionalized with citrate ions, in different dosages on mice and rats of both sexes was investigated for 30 days after intraperitoneal injection. The animals' weight, behavior, and blood cells changes, as well as blood biochemical parameters are correlated to histological examination of organs revealing that cobalt ferrite MNPs do not have toxic effects at concentrations close to those used previously for efficient MHT. Moreover, these MNPs demonstrated high specific loss power (SLP) of about 400 W g-1. Importantly the MNPs retained their magnetic properties inside tumor tissue after intratumoral administration for several MHT cycles within three days. Thus, cobalt ferrite MNPs represent a perspective platform for tumor therapy by MHT due to their ability to provide effective heating without exerting a toxic effect on the organism. This opens up new avenues for smaller MNPs sizes while their heating efficiency is maintained.

Intravital imaging of liposome behavior upon repeated administration: A step towards the development of liposomal companion diagnostic for cancer nanotherapy.

Accumulation of liposomal drugs into human tumors has substantial variability influencing the probability of positive response to the therapy. Therefore, it becomes very important to identify the eligibility of patients for various treatment options. The existing strategies of tumor stratification using companion diagnostics are based on the assumption that the initial and subsequent doses of nanoparticles (NP) behave in a sufficiently similar manner to enable a valuable prognosis. Here, we use a combination of in vivo imaging techniques to validate the applicability of magnetic liposomes (ML) as a reliable tool to predict whether or not the tumor would respond to nanomedicine therapy. The results demonstrated that liposome biodistribution, interactions with immune cells, and extravasation behavior in tumors were not affected by the pretreatment with liposomes 24 h prior to the repeat dosing. Co-administration of liposomal doxorubicin (DXR) and liposomes loaded with maghemite NP resulted in a high colocalization rate between two nanomedicines in tumors suggesting that neither contrast agent, nor chemotherapeutics altered biodistribution of liposomes. Based on magnetic resonance imaging of 4T1 tumors performed before and 6 h after ML treatment, animals were classified into high and low accumulation subgroups. Higher ML deposition in tumors was associated with a reduction in lesion size and enhanced survival in animals treated with liposomal DXR, but not with DXR alone. Given that liposomes are the most numerous class of clinically approved nanomedicines the development of safe and cost-effective liposomal companion diagnostic suitable for non-invasive imaging is of paramount importance for improving the efficacy of cancer therapy.

Multifunctional Fe3O4-Au Nanoparticles for the MRI Diagnosis and Potential Treatment of Liver Cancer.

Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe3O4-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe3O4-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r2 relaxivity (166.5 mM-1·s-1 and 99.5 mM-1·s-1 in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T2 contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/gFe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing.

In Vitro and In Vivo Electrochemical Measurement of Reactive Oxygen Species After Treatment with Anticancer Drugs.

In vivo monitoring of reactive oxygen species (ROS) in tumors during treatment with anticancer therapy is important for understanding the mechanism of action and in the design of new anticancer drugs. In this work, a platinized nanoelectrode is placed into a single cell for detection of the ROS signal, and drug-induced ROS production is then recorded. The main advantages of this method are the short incubation time with the drug and its high sensitivity which allows the detection of low intracellular ROS concentrations. We have shown that our new method can measure the ROS response to chemotherapy in tumor-bearing mice in real-time. ROS levels were measured in vivo inside the tumor at different depths in response to doxorubicin. This work provides an effective new approach for the measurement of intracellular ROS by platinized nanoelectrodes.

Synthesis and Evaluation of New Trivalent Ligands for Hepatocyte Targeting via the Asialoglycoprotein Receptor.

Since the asialoglycoprotein receptor (also known as the "Ashwell-Morell receptor" or ASGPR) was discovered as the first cellular mammalian lectin, numerous drug delivery systems have been developed and several gene delivery systems associated with multivalent ligands for liver disease targeting are undergoing clinical trials. The success of these systems has facilitated the further study of new ligands with comparable or higher affinity and less synthetic complexity. Herein, we designed two novel trivalent ligands based on the esterification of tris(hydroxymethyl) aminomethane (TRIS) followed by the azide-alkyne Huisgen cycloaddition with azido N-acetyl-d-galactosamine. The presented triazolyl glycoconjugates exhibited good binding to ASGPR, which was predicted using in silico molecular docking and assessed by a surface plasmon resonance (SPR) technique. Moreover, we demonstrated the low level of in vitro cytotoxicity, as well as the optimal spatial geometry and the required amphiphilic balance, for new, easily accessible ligands. The conjugate of a new ligand with Cy5 dye exhibited selective penetration into HepG2 cells in contrast to the ASGPR-negative PC3 cell line.

Temperature-controlled magnetic nanoparticles hyperthermia inhibits primary tumor growth and metastases dissemination.

Magnetic hyperthermia (MHT) is a promising approach for cancer therapy. However, a systematic MHT characterization as function of temperature on the therapeutic efficiency is barely analyzed. Here, we first perform comparative temperature-dependent analysis of the cobalt ferrite nanoparticles-mediated MHT effectiveness in two murine tumors models - breast (4T1) and colon (CT26) cancer in vitro and in vivo. The overall MHT killing capacity in vitro increased with the temperature and CT26 cells were more sensitive than 4T1 when heated to 43 °C. Well in line with the in vitro data, such heating cured non-metastatic CT26 tumors in vivo, while only inhibiting metastatic 4T1 tumor growth without improving the overall survival. High-temperature MHT (>47 °C) resulted in complete 4T1 primary tumor clearance, 25-40% long-term survival rates, and, importantly, more effective prevention of metastasis comparing to surgical extraction. Thus, the specific MHT temperature must be defined for each tumor individually to ensure a successful antitumor therapy.

Neutrophil-mediated transport is crucial for delivery of short-circulating magnetic nanoparticles to tumors.

Recently neutrophil-based nanoparticles (NPs) drug delivery systems have gained considerable attention in cancer therapy. Numerous studies have been conducted to identify optimal NPs parameters for passive tumor targeting, while there is a fundamental dearth of knowledge about the factors governing cell-mediated delivery. Here, by using intravital microscopy and magnetic resonance imaging, we describe accumulation dynamics of 140 nm magnetic cubes and clusters in murine breast cancer (4T1) and colon cancer (CT26) models. Notwithstanding rapid clearance from the blood flow, NPs readily accumulated in tumors at later time points. Both NPs types were captured mostly by intravascular neutrophils immediately after injection, and transmigration of NPs-bound neutrophils through the vessel wall was first shown in real-time. A dramatic drop in NPs accumulation upon Ly6G and Gr1 depletion further confirmed the role of neutrophils as a biocarrier for targeting tumors. Of note, for shorter circulating NPs, a cell-dependent delivery route was more impactful, while the accumulation of longer circulating counterpart was less compromised by neutrophil depletion. Neutrophil-mediated transport was also shown to depend on tumor type, with more efficiency noted in neutrophil-rich tumors. Revealing NPs characteristics and host factors influencing the neutrophil-based tumor targeting will help to rationally design drug delivery systems for improved cancer treatment. STATEMENT OF SIGNIFICANCE: Utilizing host cells as trojan horses for delivery nanodrugs to tumor site is a promising approach for cancer therapy. However, it is not clear yet how nanoparticles characteristics and tumor properties affect the efficiency of cell-based nanoparticles transport. Here, we compare neutrophil-based delivery of different-shaped magnetic nanoparticles (cubes and clusters) in two tumor models. The results suggest that neutrophil-mediated route is more impactful for rapidly cleared cubes, than for longer circulating clusters. The efficiency of cell-based accumulation also correlated with the level of neutrophils recruitment to different tumor types. These finding are important for rationale design of nanocarriers and predicting the efficiency of neutrophil-mediated drug delivery between patients and tumor types.

Extravasating Neutrophils Open Vascular Barrier and Improve Liposomes Delivery to Tumors.

Liposomes are the most extensively used nanocarriers in cancer therapy. Despite the advantages these vehicles provide over free drugs, there are still limitations with regards to the efficiency of liposomes delivery to tumors and off-target accumulation. A better understanding of nanodrugs extravasation mechanisms in different tumor types and normal vessels is needed to improve their antitumor activity. We used intravital microscopy to track for fluorescent liposomes behavior in xenograft tumor models (murine breast cancer 4T1 and melanoma B16, human prostate cancer 22Rv1) and normal skin and identified two distinct extravasation patterns. Microleakage, a local perivascular nanoparticle deposition, was found both in malignant and healthy tissues. This type of liposomes leakage does not provide access to tumor cells and is presumably responsible for drug deposition in normal tissues. In contrast, macroleakage penetrated deep into tissues and localized predominantly on the tumor-host interface. Although neutrophils did not uptake liposomes, their extravasation appeared to initiate both micro- and macroleakages. Based on neutrophils and liposomes extravasation dynamics, we hypothesized that microleakage and macroleakage are subsequent steps of the extravasation process corresponding to liposomes transport through endothelial and subendothelial barriers. Of note, extravasation spots were detected more often in the proximity of neutrophils, and across studied tumor types, neutrophils counts correlated with leakage frequencies. Reduced liposomes accumulation in 4T1 tumors upon Ly6G depletion further corroborated neutrophils role in nanoparticles delivery. Elucidating liposomes extravasation routes has a potential to help improve existing strategies and develop effective nanodrugs for cancer therapy.

Intravital microscopy reveals a novel mechanism of nanoparticles excretion in kidney.

Developing nanocarriers that accumulate in targeted organs and are harmlessly eliminated still remains a big challenge. Nanoparticles (NP) biodistribution is governed by their size, composition, surface charge and coverage. The current thinking in bionanotechnology is that renal clearance is limited by glomerular basement membrane pore size (≈6 nm), although there is a growing evidence that NP exceeding the threshold can also be excreted with urine. Here we compare biodistribution of PEGylated 140 nm iron oxide cubes and clusters with a special focus on renal accumulation and excretion. Atomic emission spectroscopy, fluorescent microscopy and magnetic resonance imaging revealed rapid and transient accumulation of magnetic NP in kidney. Using intravital microscopy we tracked in real time NP translocation from peritubular capillaries to basal compartment of tubular cells and subsequent excretion to the lumen within 60 min after systemic administration. Transmission electron microscopy revealed persistence of intact full-sized NP in urine 2 h post injection. The results suggest that translocation through peritubular endothelium to tubular epithelial cells is an alternative mechanism of renal clearance enabling excretion of NP above glomerular cut-off size.

Long-term live cells observation of internalized fluorescent Fe@C nanoparticles in constant magnetic field.

BACKGROUND: Theranostics application of superparamagnetic nanoparticles based on magnetite and maghemite is impeded by their toxicity. The use of additional protective shells significantly reduced the magnetic properties of the nanoparticles. Therefore, iron carbides and pure iron nanoparticles coated with multiple layers of onion-like carbon sheath seem to be optimal for biomedicine. Fluorescent markers associated with magnetic nanoparticles provide reliable means for their multimodal visualization. Here, biocompatibility of iron nanoparticles coated with graphite-like shell and labeled with Alexa 647 fluorescent marker has been investigated. METHODS: Iron core nanoparticles with intact carbon shells were purified by magnetoseparation after hydrochloric acid treatment. The structure of the NPs (nanoparticles) was examined with a high resolution electron microscopy. The surface of the NPs was alkylcarboxylated and further aminated for covalent linking with Alexa Fluor 647 fluorochrome to produce modified fluorescent magnetic nanoparticles (MFMNPs). Live fluorescent imaging and correlative light-electron microscopy were used to study the NPs intracellular distribution and the effects of constant magnetic field on internalized NPs in the cell culture were analyzed. Cell viability was assayed by measuring a proliferative pool with Click-IT labeling. RESULTS: The microstructure and magnetic properties of superparamagnetic Fe@C core-shell NPs as well as their endocytosis by living tumor cells, and behavior inside the cells in constant magnetic field (150 mT) were studied. Correlative light-electron microscopy demonstrated that NPs retained their microstructure after internalization by the living cells. Application of constant magnetic field caused orientation of internalized NPs along power lines thus demonstrating their magnetocontrollability. Carbon onion-like shells make these NPs biocompatible and enable long-term observation with confocal microscope. It was found that iron core of NPs shows no toxic effect on the cell physiology, does not inhibit the cell proliferation and also does not induce apoptosis. CONCLUSIONS: Non-toxic, biologically compatible superparamagnetic fluorescent MFMNPs can be further used for biological application such as delivery of biologically active compounds both inside the cell and inside the whole organism, magnetic separation, and magnetic resonance imaging (MRI) diagnostics.