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1.
Int J Mol Sci ; 25(4)2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38396747

ABSTRACT

Nanoencapsulation has become a recent advancement in drug delivery, enhancing stability, bioavailability, and enabling controlled, targeted substance delivery to specific cells or tissues. However, traditional nanoparticle delivery faces challenges such as a short circulation time and immune recognition. To tackle these issues, cell membrane-coated nanoparticles have been suggested as a practical alternative. The production process involves three main stages: cell lysis and membrane fragmentation, membrane isolation, and nanoparticle coating. Cell membranes are typically fragmented using hypotonic lysis with homogenization or sonication. Subsequent membrane fragments are isolated through multiple centrifugation steps. Coating nanoparticles can be achieved through extrusion, sonication, or a combination of both methods. Notably, this analysis reveals the absence of a universally applicable method for nanoparticle coating, as the three stages differ significantly in their procedures. This review explores current developments and approaches to cell membrane-coated nanoparticles, highlighting their potential as an effective alternative for targeted drug delivery and various therapeutic applications.


Subject(s)
Nanoparticles , Precision Medicine , Cell Membrane/metabolism , Drug Delivery Systems
2.
Bioact Mater ; 34: 237-247, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38223536

ABSTRACT

Despite notable progress in cancer therapy, metastatic diseases continue to be the primary cause of cancer-related mortality. Multi-walled carbon nanotubes (MWCNTs) can enter tissues and cells and interfere with the dynamics of the cytoskeletal nanofilaments biomimetically. This endows them with intrinsic anti-tumoral effects comparable to those of microtubule-binding chemotherapies such as Taxol®. In this study, our focus was on exploring the potential of oxidized MWCNTs in selectively targeting the vascular endothelial growth factor receptor (VEGFR). Our objective was to evaluate their effectiveness in inhibiting metastatic growth by inducing anti-proliferative, anti-migratory, and cytotoxic effects on both cancer and tumor microenvironment cells. Our findings demonstrated a significant reduction of over 80 % in malignant melanoma lung metastases and a substantial enhancement in overall animal welfare following intravenous administration of the targeted biodegradable MWCNTs. Furthermore, the combination of these nanomaterials with the conventional chemotherapy agent Taxol® yielded a remarkable 90 % increase in the antimetastatic effect. These results highlight the promising potential of this combined therapeutic approach against metastatic disease and are of paramount importance as metastasis is responsible for nearly 60,000 deaths each year.

3.
Int J Mol Sci ; 24(12)2023 Jun 16.
Article in English | MEDLINE | ID: mdl-37373381

ABSTRACT

The coronavirus SARS-CoV-2 has highlighted the criticality of an accurate and rapid diagnosis in order to contain the spread of the virus. Knowledge of the viral structure and its genome is essential for diagnosis development. The virus is still quickly evolving and the global scenario could easily change. Thus, a greater range of diagnostic options is essential to face this threat to public health. In response to the global demand, there has been a rapid advancement in the understanding of current diagnostic methods. In fact, innovative approaches have emerged, leveraging the benefits of nanomedicine and microfluidic technologies. Although this development has been incredibly fast, several key areas require further investigation and optimization, such as sample collection and preparation, assay optimization and sensitivity, cost effectiveness, scalability device miniaturization, and portability and integration with smartphones. Addressing these gaps in the knowledge and these technological challenges will contribute to the development of reliable, sensitive, and user-friendly NAAT-based POCTs for the diagnosis of SARS-CoV-2 and other infectious diseases, facilitating rapid and effective patient management. This review aims to provide an overview of current SARS-CoV-2 detection methods based on nucleic acid detection tests (NAATs). Additionally, it explores promising approaches that combine nanomedicine and microfluidic devices with high sensitivity and relatively fast 'time to answer' for integration into point-of-care testing (POCT).


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , COVID-19 Testing , Clinical Laboratory Techniques/methods , Nanomedicine , Point-of-Care Testing , Nucleic Acid Amplification Techniques/methods , Lab-On-A-Chip Devices , Sensitivity and Specificity , Point-of-Care Systems
4.
Int J Nanomedicine ; 17: 5747-5760, 2022.
Article in English | MEDLINE | ID: mdl-36466783

ABSTRACT

Introduction: A great challenge in nanomedicine, and more specifically in theranostics, is to improve the specificity, selectivity, and targeting of nanomaterials towards target tissues or cells. The topical use of nanomedicines as adjuvants to systemic chemotherapy can significantly improve the survival of patients affected by localized carcinomas, reducing the side effects of traditional drugs and preventing local recurrences. Methods: Here, we have used the Shiga toxin, to design a safe, high-affinity protein-ligand (ShTxB) to bind the globotriaosylceramide receptor (GB3) that is overexpressed on the surfaces of preneoplastic and malignant cancer cells in the head and neck tumors. Results: We find that ShTxB functionalized gold nanorods are efficiently retrotranslocated to the GB3-positive cell cytoplasms. After 3 minutes of laser radiation with a wavelength resonant with the AuNR longitudinal localized surface plasmon, the death of the targeted cancer cells is activated. Both preclinical murine models and patient biopsy cells show the non-cytotoxic nature of these functionalized nanoparticles before light activation and their treatment selectivity. Discussion: These results show how the use of nanomedicines directed by natural ligands can represent an effective treatment for aggressive localized cancers, such as squamous cell carcinoma of the oral cavity.


Subject(s)
Carcinoma, Squamous Cell , Mouth Neoplasms , Nanotubes , Humans , Animals , Mice , Gold , Shiga Toxin , Mouth Neoplasms/drug therapy
5.
Biomedicines ; 10(4)2022 Mar 22.
Article in English | MEDLINE | ID: mdl-35453483

ABSTRACT

Head and neck squamous cell carcinoma is the sixth leading cancer in the world. This cancer is difficult to treat and is characterized by recurrences that are often fatal. This cancer is generally removed surgically, but it often regrows from the edges of the lesion from where most recurrences reappear. In this study, we have investigated if the expression of GB3 in human cell lines, tissues from patient biopsies, and a murine animal model could be used as an early and determinant marker of HNC. We found that in all the investigated systems, this marker appears in neoplastic cells from the very early stages of their malignant transformation. Our conclusions support the hypothesis that GB3 is a reliable and independent target for HNC identification and selective delivery of treatments. Furthermore, we show that the level of expression of this marker correlates with the degree of malignancy of the tumor. These studies suggest that GB3 may provide the basis for the early identification and new targeted therapies for head and neck cancer.

6.
Bioact Mater ; 8: 153-164, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34541393

ABSTRACT

Nowadays, a number of promising strategies are being developed that aim at combining diagnostic and therapeutic capabilities into clinically effective formulations. Thus, the combination of a modified release provided by an organic encapsulation and the intrinsic physico-chemical properties from an inorganic counterpart opens new perspectives in biomedical applications. Herein, a biocompatible magnetic lipid nanocomposite vehicle was developed through an efficient, green and simple method to simultaneously incorporate magnetic nanoparticles and an anticancer drug (doxorubicin) into a natural nano-matrix. The theranostic performance of the final magnetic formulation was validated in vitro and in vivo, in melanoma tumors. The systemic administration of the proposed magnetic hybrid nanocomposite carrier enhanced anti-tumoral activity through a synergistic combination of magnetic hyperthermia effects and antimitotic therapy, together with MRI reporting capability. The application of an alternating magnetic field was found to play a dual role, (i) acting as an extra layer of control (remote, on-demand) over the chemotherapy release and (ii) inducing a local thermal ablation of tumor cells. This combination of chemotherapy with thermotherapy establishes a synergistic platform for the treatment of solid malignant tumors under lower drug dosing schemes, which may realize the dual goal of reduced systemic toxicity and enhanced anti-tumoral efficacy.

7.
Cancers (Basel) ; 13(19)2021 Sep 30.
Article in English | MEDLINE | ID: mdl-34638405

ABSTRACT

Head and Neck Cancer (HNC) is the seventh most common cancer worldwide with a 5-year survival from diagnosis of 50%. Currently, HNC is diagnosed by a physical examination followed by an histological biopsy, with surgery being the primary treatment. Here, we propose the use of targeted nanotechnology in support of existing diagnostic and therapeutic tools to prevent recurrences of tumors with poorly defined or surgically inaccessible margins. We have designed an innocuous ligand-protein, based on the receptor-binding domain of the Shiga toxin (ShTxB), that specifically drives nanoparticles to HNC cells bearing the globotriaosylceramide receptor on their surfaces. Microscopy images show how, upon binding to the receptor, the ShTxB-coated nanoparticles cause the clustering of the globotriaosylceramide receptors, the protrusion of filopodia, and rippling of the membrane, ultimately allowing the penetration of the ShTxB nanoparticles directly into the cell cytoplasm, thus triggering a biomimetic cellular response indistinguishable from that triggered by the full-length Shiga toxin. This functionalization strategy is a clear example of how some toxin fragments can be used as natural biosensors for the detection of some localized cancers and to target nanomedicines to HNC lesions.

8.
J Nanobiotechnology ; 19(1): 129, 2021 May 05.
Article in English | MEDLINE | ID: mdl-33952241

ABSTRACT

BACKGROUND: The intrinsic physicochemical properties of carbon nanotubes (CNTs) make them unique tools in nanotechnology. Their elemental composition, resilience, thermal properties, and surface reactivity make CNTs also of undisputed interest in biotechnology. In particular, their extraordinary ability to capture biomolecules on their surface makes them essential in this field. The proteins adsorbed on the CNTs create a biological coating that endows them the ability to interact with some cell receptors, penetrate membranes or interfere with cell biomechanics, thus behaving as an active bio-camouflage. But some of these proteins unfold, triggering an immune response that unpredictably changes the biological activity of CNTs. For this reason, the control of the biocorona is fundamental in the nanobiotechnology of CNTs. RESULTS: Using TEM and AFM here we demonstrate a significant increase in CNTs diameter after protein functionalization. A quantitative analysis using TGA revealed that between 20 and 60% of the mass of functionalized nanotubes corresponds to protein, with single-walled CNTs capturing the highest amounts. To qualitatively/quantitatively characterize these biocoatings, we studied the biochemical "landscape" of the proteins captured by the different nanotubes after functionalization under various conditions. This study revealed a significant variability of the proteins in the corona as a function of the type of nanotube, the functionalization temperature, or the time after exposure to serum. Remarkably, the functionalization of a single type of CNT with sera from various human donors also resulted in different protein landscapes. Given the unpredictable assortment of proteins captured by the corona and the biological implications of this biocoating, we finally designed a method to genetically engineer and produce proteins to functionalize nanotubes in a controlled and customizable way. CONCLUSIONS: We demonstrate the high unpredictability of the spontaneous protein corona on CNTs and propose a versatile functionalization technique that prevents the binding of nonspecific proteins to the nanotube to improve the use of CNTs in biomedical applications.


Subject(s)
Biofouling/prevention & control , Blood Proteins , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Adsorption , Blood Proteins/genetics , Blood Proteins/metabolism , Humans , Protein Corona , Serum/chemistry
9.
Pharmaceutics ; 13(1)2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33451053

ABSTRACT

Solid lipid particles (SLPs) can sustainably encapsulate and release therapeutic agents over long periods, modifying their biodistribution, toxicity, and side effects. To date, no studies have been reported using SLPs loaded with doxorubicin chemotherapy for the treatment of metastatic cancer. This study characterizes the effect of doxorubicin-loaded carnauba wax particles in the treatment of lung metastatic malignant melanoma in vivo. Compared with the free drug, intravenously administrated doxorubicin-loaded SLPs significantly reduce the number of pulmonary metastatic foci in mice. In vitro kinetic studies show two distinctive drug release profiles. A first chemotherapy burst-release wave occurs during the first 5 h, which accounts for approximately 30% of the entrapped drug rapidly providing therapeutic concentrations. The second wave occurs after the arrival of the particles to the final destination in the lung. This release is sustained for long periods (>40 days), providing constant levels of chemotherapy in situ that trigger the inhibition of metastatic growth. Our findings suggest that the use of chemotherapy with loaded SLPs could substantially improve the effectiveness of the drug locally, reducing side effects while improving overall survival.

10.
Int J Mol Sci ; 21(24)2020 Dec 16.
Article in English | MEDLINE | ID: mdl-33339139

ABSTRACT

There are many nanoencapsulation systems available today. Among all these, mesoporous silica particles (MSPs) have received great attention in the last few years. Their large surface-to-volume ratio, biocompatibility, and versatility allow the encapsulation of a wide variety of drugs inside their pores. However, their chemical instability in biological fluids is a handicap to program the precise release of the therapeutic compounds. Taking advantage of the dissolving capacity of silica, in this study, we generate hollow capsules using MSPs as transitory sacrificial templates. We show how, upon MSP coating with different polyelectrolytes or proteins, fully customized hollow shells can be produced. These capsules are biocompatible, flexible, and biodegradable, and can be decorated with nanoparticles or carbon nanotubes to endow the systems with supplementary intrinsic properties. We also fill the capsules with a fluorescent dye to demonstrate intracellular compound release. Finally, we document how fluorescent polymeric capsules are engulfed by cells, releasing their encapsulated agent during the first 96 h. In summary, here, we describe how to assemble a highly versatile encapsulation structure based on silica mesoporous cores that are completely removed from the final polymeric capsule system. These drug encapsulation systems are highly customizable and have great versatility as they can be made using silica cores of different sizes and multiple coatings. This provides capsules with unique programmable attributes that are fully customizable according to the specific needs of each disease or target tissue for the development of nanocarriers in personalized medicine.


Subject(s)
Nanocapsules/chemistry , Silicon Dioxide/chemistry , Drug Liberation , Fluorescent Dyes/administration & dosage , HeLa Cells , Humans , Polyelectrolytes/chemistry
11.
Nanoscale ; 12(42): 21647-21656, 2020 Nov 05.
Article in English | MEDLINE | ID: mdl-32766635

ABSTRACT

Temperature is a key parameter for optimal cellular function and growth. Temperature perturbation may directly lead to cell death. This can be used in cancer therapies to kill cells in tumors, a therapeutic approach called hyperthermia. To avoid overheating of tumors that may damage healthy tissues, a knowledge of the intracellular temperature reached during the hyperthermia treatment of cancer cells is relevant. Recently, several luminescent intracellular nanothermometers have been proposed; however an application to sense temperature during a hyperthermia treatment is lacking. Here we present a technique to measure intracellular temperature changes in in vitro cancer cell models. For this purpose, we study for the first time the temperature dependence of the green fluorescent protein (GFP)'s fluorescence lifetime parameter. We find the fluorescence lifetime of GFP can be used for nanothermosensing. We use GFP in a bound form to actin filaments as an intracellular thermal reporter. Furthermore, we assess intracellular temperature during in vitro magnetothermal therapy on live HeLa cells incubated with polyacrylic acid-coated iron oxide nanoparticles. Compared to other thermosensitive materials and formulations reported so far, the GFP nanothermosensor is easily expressed via transfection and various GFP variants are commercially available. We foresee that the nanothermometer developed might find widespread applications in cancer therapy research and development.


Subject(s)
Hyperthermia, Induced , Neoplasms , Fluorescence , HeLa Cells , Humans , Hyperthermia , Neoplasms/therapy , Temperature
12.
Pharmaceutics ; 12(7)2020 Jul 07.
Article in English | MEDLINE | ID: mdl-32645938

ABSTRACT

The development of nanotechnology-based solutions for cancer at a preclinical level advances at an astounding pace. So far, clinical translation of these new developments has not been able to keep the pace due to a range of different reasons. One of them is the mismatch between in vitro and in vivo results coming from the expected difference in complexity. To overcome this problem, extensive characterisation using advanced in vitro models can lead to stronger preliminary data to face in vivo tests. Here, a comprehensive in vitro validation of a combinatorial therapy nanoformulation against solid tumours is presented. The information extracted from the different in vitro models highlights the importance of advanced 3D models to fully understand the potential of this type of complex drugs.

13.
Chemistry ; 26(20): 4531-4538, 2020 Apr 06.
Article in English | MEDLINE | ID: mdl-31867807

ABSTRACT

To fight against cancer, smarter drugs and drug delivery systems are required both to boost the efficiency of current treatments while reducing deleterious side effects, and combine diagnosis/monitoring with therapy (theranosis) in the search for the final goal of personalized medicine. This work presents the design, preparation, and proof-of-principle validation of a novel hybrid organic-inorganic nanocomposite joining together non-invasive imaging capabilities through magnetic resonance imaging and externally actuated therapeutic properties through a combination of chemo- and thermotherapy. The lipidic matrix of the nanocomposite was composed of carnauba wax, which was simultaneously dual loaded with magnetite nanoparticles and the anticancer drug Oncocalyxone A. Obtained formulations were fully characterized and showed outstanding performances as T2 -contrast agents in magnetic resonance imaging (r2 >800 mm-1 s-1 ), heat generating sources in magnetic hyperthermia (specific absorption rate, SAR>200 W g-1 Fe ), and magnetically responsive drug delivery vehicles. The potential of the designed formulations as theranostic agents was validated in vitro and results indicated a synergistic thermo/chemotherapeutic effect derived from heat generation and controlled drug delivery to cancer growth. Thereby, this external control over the drug delivery profile and the integrated imaging capability open the door to personalized cancer medicine and real-time monitoring of tumor progression.


Subject(s)
Antineoplastic Agents/therapeutic use , Doxorubicin/pharmacology , Hyperthermia, Induced/methods , Magnetic Resonance Imaging/methods , Theranostic Nanomedicine/methods , Antineoplastic Agents/administration & dosage , Cell Line, Tumor , Contrast Media , Doxorubicin/therapeutic use , Drug Compounding , Drug Delivery Systems/methods , Humans , Magnetics , Magnetite Nanoparticles , Nanocomposites
14.
Int J Nanomedicine ; 14: 9077-9088, 2019.
Article in English | MEDLINE | ID: mdl-31819420

ABSTRACT

BACKGROUND: Oral administration remains the most common mode of drug delivery. However, orally administered bioactive compounds must first survive digestion and then be absorbed at the intestine in order to reach other tissues or organs. The efficiency of both processes can be improved by encapsulation or conjugation with polymeric nanoparticles. Here we report the synthesis of amphiphilic hyaluronic acid (HyA) nanogels as nanocarriers for drug delivery. METHODS: HyA nanogels were prepared by self-assembly from amphiphilic HyA conjugates produced by grafting hydrophobic alkyl chains to the HyA backbone. The dye Cy5.5 was covalently bonded and used for tracking. The nanogels were characterised according to their structure, size and zeta potential, as well as biocompatibility towards an intestinal epithelial cell line. The uptake and intestinal permeability of the nanogels were assessed using in vitro models, which physiological relevance was verified regarding the morphology of the epithelium, the production of mucus, the expression of occludin and the transepithelial electrical resistance. RESULTS: The covalent binding of Cy5.5 did not affect significantly the size and surface charge of the nanogels at 125.1 ± 3.2 nm and -57.6 ± 6.2 mV respectively after labelling. Studies of biocompatibility showed that the nanogels were non-toxic to Caco-2 cells up to the concentration of 0.1 mg∙mL-1. The presence of mucus affected the nanogel uptake and highlighted the importance of considering mucus-producing cells in in vitro intestinal models. The uptake or adsorption to a Caco-2/HT29-MTX co-culture (8.1%) was higher than with single Caco-2 cell cultures (4.3%). Interestingly, both models led to minute (<0.5%) permeation of the nanogels across the intestinal barrier. CONCLUSION: The HyA nanogels demonstrated to be mucoadhesive and effectively uptaken by intestinal cells. Both are determinant features for sustained release, but if systemic delivery is envisaged further modification with targeting moieties could be important to improve the nanogel permeability.


Subject(s)
Fluorescent Dyes/chemistry , Hyaluronic Acid/chemistry , Intestines/physiology , Nanogels/chemistry , Caco-2 Cells , Electric Impedance , Humans , Intestinal Mucosa/metabolism , Mucus/metabolism , Nanoparticles/chemistry , Permeability , Tight Junctions/metabolism
15.
Chemistry ; 25(2): 431-441, 2019 Jan 07.
Article in English | MEDLINE | ID: mdl-29999200

ABSTRACT

Manganese-based nanostructured contrast agents (CAs) entered the field of medical diagnosis through magnetic resonance imaging (MRI) some years ago. Although some of these Mn-based CAs behave as classic T1 contrast enhancers in the same way as clinical Gd-based molecules do, a new type of Mn nanomaterials have been developed to improve MRI sensitivity and potentially gather new functional information from tissues by using traditional T1 contrast enhanced MRI. These nanomaterials have been designed to respond to biological environments, mainly to pH and redox potential variations. In many cases, the differences in signal generation in these responsive Mn-based nanostructures come from intrinsic changes in the magnetic properties of Mn cations depending on their oxidation state. In other cases, no changes in the nature of Mn take place, but rather the nanomaterial as a whole responds to the change in the environment through different mechanisms, including changes in integrity and hydration state. This review focusses on the chemistry and MR performance of these responsive Mn-based nanomaterials.

16.
Mater Sci Eng C Mater Biol Appl ; 93: 206-217, 2018 Dec 01.
Article in English | MEDLINE | ID: mdl-30274052

ABSTRACT

The synthesis of hydrophilic graphene-based yolk-shell magnetic nanoparticles functionalized with copolymer pluronic F-127 (GYSMNP@PF127) is herein reported to achieve an efficient multifunctional biomedical system for mild hyperthermia and stimuli-responsive drug delivery. In vitro tests revealed the extraordinary ability of GYSMNP@PF127 to act as smart stimuli-responsive multifunctional nanomedicine platform for cancer therapy, exhibiting (i) an outstanding loading capacity of 91% (w/w, representing 910 µg mg-1) of the chemotherapeutic drug doxorubicin, (ii) a high heating efficiency under an alternating (AC) magnetic field (intrinsic power loss ranging from 2.1-2.7 nHm2 kg-1), and (iii) a dual pH and thermal stimuli-responsive drug controlled release (46% at acidic tumour pH vs 7% at physiological pH) under AC magnetic field, in just 30 min. Additionally, GYSMNP@PF127 presents optimal hydrodynamic diameter (DH = 180 nm) with negative surface charge, high haemocompatibility for blood stream applications and tumour cellular uptake of drug nanocarriers. Due to its physicochemical, magnetic and biocompatibility properties, the developed graphene-based magnetic nanocarrier shows high promise as dual exogenous (AC field)/endogenous (pH) stimuli-responsive actuators for targeted thermo-chemotherapy, combining magnetic hyperthermia and controlled drug release triggered by the abnormal tumour environment. The presented strategy and findings can represent a new way to design and develop highly stable added-value graphene-based nanostructures for the combined treatment of cancer.


Subject(s)
Doxorubicin , Drug Delivery Systems/methods , Graphite , Hyperthermia, Induced , Magnetic Fields , Nanoparticles , Neoplasms/therapy , Doxorubicin/chemistry , Doxorubicin/pharmacokinetics , Doxorubicin/pharmacology , Graphite/chemistry , Graphite/pharmacokinetics , Graphite/pharmacology , Hep G2 Cells , Humans , Nanoparticles/chemistry , Nanoparticles/therapeutic use , Neoplasms/metabolism , Neoplasms/pathology , Poloxamer/chemistry , Poloxamer/pharmacokinetics , Poloxamer/pharmacology
17.
Chemistry ; 24(34): 8624-8631, 2018 Jun 18.
Article in English | MEDLINE | ID: mdl-29645299

ABSTRACT

A versatile iron oxide nanoparticle platform is reported that can be orthogonally functionalized to obtain highly derivatized nanomaterials required for a wide variety of applications, such as drug delivery, targeted therapy, or imaging. Facile functionalization of the nanoparticles with two ligands containing isocyanate moieties allows for high coverage of the surface with maleimide and alkyne groups. As a proof-of-principle, the nanoparticles were subsequently functionalized with a fluorophore as a drug model and with biotin as a targeting ligand towards tumor cells through Diels-Alder and azide-alkyne cycloaddition reactions, respectively. The thermoreversibility of the Diels-Alder product was exploited to induce the on-demand release of the loaded molecules by magnetic hyperthermia. Additionally, the nanoparticles were shown to target cancer cells through in vitro experiments, as analyzed by magnetic resonance imaging.

18.
Chemistry ; 24(6): 1295-1303, 2018 Jan 26.
Article in English | MEDLINE | ID: mdl-29178467

ABSTRACT

The development of responsive magnetic resonance imaging contrast agents opens the door to a highly sensitive and specific diagnosis of altered physiological conditions. In this field, manganese dioxide (MnO2 ) is starting to be a leading contributor due to its susceptibility to conditions relevant to human diseased states, such as cancer. So far, the preclinical application of MnO2 has mainly been in the form of nanosheets, with enhancements of magnetic resonance imaging signals up to 50-fold upon activation. Herein, we thoroughly investigate, through a simple reaction, a series of Mnx Oy samples and correlate their phase composition and structure/morphology to the performance as classic/responsive MRI contrast agents in response to redox changes. Signal enhancements as high as 140-fold were obtained from MnO2 nano-urchins, and their capability as responsive magnetic resonance imaging contrast agents was demonstrated in vitro.


Subject(s)
Contrast Media/chemistry , Magnetic Resonance Imaging/methods , Manganese Compounds/chemistry , Nanostructures/chemistry , Oxides/chemistry , A549 Cells , Cell Survival , Humans , Kinetics , Oxidation-Reduction
19.
Int J Nanomedicine ; 12: 6317-6328, 2017.
Article in English | MEDLINE | ID: mdl-28919736

ABSTRACT

Carbon nanotubes (CNTs) are likely to transform the therapeutic and diagnostic fields in biomedicine during the coming years. However, the fragmented vision of their side effects and toxicity in humans has proscribed their use as nanomedicines. Most studies agree that biocompatibility depends on the state of aggregation/dispersion of CNTs under physiological conditions, but conclusions are confusing so far. This study designs an experimental setup to investigate the cytotoxic effect of individualized multiwalled CNTs compared to that of identical nanotubes assembled on submicrometric structures. Our results demonstrate how CNT cytotoxicity is directly dependent on the nanotube dispersion at a given dosage. When CNTs are gathered onto silica templates, they do not interfere with cell proliferation or survival becoming highly compatible. These results support the hypothesis that CNT cytotoxicity is due to the biomimetics of these nanomaterials with the intracellular nanofilaments. These findings provide major clues for the development of innocuous CNT-containing nanodevices and nanomedicines.


Subject(s)
Cytoskeleton/drug effects , Nanotubes, Carbon/chemistry , Nanotubes, Carbon/toxicity , Silicon Dioxide/chemistry , Biomimetics , Cytoskeleton/metabolism , HeLa Cells , Humans , Tubulin/metabolism
20.
Nanoscale ; 8(21): 10963-73, 2016 Jun 07.
Article in English | MEDLINE | ID: mdl-27228212

ABSTRACT

Zinc is a crucial element in biology that plays chief catalytic, structural and protein regulatory roles. Excess cytoplasmic zinc is toxic to cells so there are cell-entry and intracellular buffering mechanisms that control intracellular zinc availability. Tubulin and actin are two zinc-scavenging proteins that are essential components of the cellular cytoskeleton implicated in cell division, migration and cellular architecture maintenance. Here we demonstrate how exposure to different ZnO nanostructures, namely ZnO commercial nanoparticles and custom-made ZnO nanowires, produce acute cytotoxic effects in human keratinocytes (HaCat) and epithelial cells (HeLa) triggering a dose-dependent cell retraction and collapse. We show how engulfed ZnO nanoparticles dissolve intracellularly, triggering actin filament bundling and structural changes in microtubules, transforming these highly dynamic 25 nm diameter polymers into rigid macrotubes of tubulin, severely affecting cell proliferation and survival. Our results demonstrate that nano-ZnO causes acute cytoskeletal collapse that triggers necrosis, followed by a late reactive oxygen species (ROS)-dependent apoptotic process.


Subject(s)
Actins/chemistry , Cytoskeleton/chemistry , Keratinocytes/cytology , Metal Nanoparticles , Necrosis , Tubulin/chemistry , Zinc Oxide , Apoptosis , Cell Survival , HeLa Cells , Humans , Reactive Oxygen Species/metabolism
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