Nanotechnology-Based Strategies to Evaluate and Counteract Cancer Metastasis and Neoangiogenesis

Cancer metastasis is the major cause of cancer-related morbidity and mortality. It represents one of the greatest challenges in cancer therapy, both because of the ability of metastatic cells to spread into different organs, and because of the consequent heterogeneity that characterizes primary and metastatic tumors. Nanomaterials can potentially be used as targeting or detection agents owing to unique chemical and physical features that allow tailored and tunable theranostic functions. This review highlights nanomaterial-based approaches in the detection and treatment of cancer metastasis, with a special focus on the evaluation of nanostructure effects on cell migration, invasion, and angiogenesis in the tumor microenvironment

Biomolecular Corona Associated with Nanostructures: The Potentially Disruptive Role of Raman Microscopy

When nanostructures and other materials are exposed to biological fluids, they are immediately covered by a layer of biological molecules, which is typically referred to as a “biomolecular corona” (BC). This represents the first component of a material that interacts with biological systems, so characterizing the composition and the dynamic evolution of BC is essential for predicting the interactions of materials and living organisms. This review provides an analysis of current BC characterization techniques, with particular attention to nanostructures involved in biomedical applications. The influence on cell–nanostructure interactions is assessed and the advantages and limitations of each technique are discussed and compared. An in-depth analysis of Raman microscopy, a relatively unexploited tool with great potential in the characterization of BC, is then conducted. Raman microscopy can be used to analyze a vast amount of specimens without the need for staining, and can provide analysis on a spatial scale of hundreds of nanometers: it may thus represent a potentially disruptive tool for the characterization of BC, as it overcomes many of the limitations posed by current techniques

Superparamagnetic iron oxide nanoparticles for magnetic hyperthermia: recent advancements, molecular effects, and future directions in the omics era

Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted attention in the biomedical field thanks to their ability to prompt hyperthermia in response to an alternated magnetic field. Hyperthermia is well known for inducing cell death, in particular in tumour cells, which seem to have a higher sensitivity to temperature increases. For this reason, hyperthermia has been recommended as a therapeutic tool against cancer. Despite the potentialities of this approach, little is still known about the effects provoked by magnetic hyperthermia at the molecular level, and about the particular cell death mechanisms that are activated. Nevertheless, in-depth knowledge of this aspect would allow improvement of therapeutic outcomes and favour clinical translation. Moreover, in the last few decades, a lot of effort has been put into finding an effective delivery strategy that could improve SPION biodistribution and localisation at the action site. The aim of this review is to provide a general outline of magnetic hyperthermia, focusing on iron oxide nanoparticles and their interactions with magnetic fields, as well as on new strategies to efficiently deliver them to the target site, and on recent in vitro and in vivo studies proposing possible cell death pathways activated by the treatment. We will also cover their current clinical status, and discuss the contributions of omics in understanding molecular interactions between iron oxide nanoparticles and the biological environment

Probing the Ultrastructure of Spheroids and Their Uptake of Magnetic Nanoparticles by FIB–SEM

Spheroids are 3D cellular systems largely adopted as model for high-throughput screening of molecules and diagnostics tools. Furthermore, those cellular platforms also represent a model for testing new delivery carries for selective targeting. The coupling between the 3D cell environment and the nanovectors can be explored at the macroscale by optical microscopy. However, the nanomaterial-cell interplay finds major action at the single cell and extracellular matrix level with nanoscale interactions. Electron microscopy offers the resolution to investigate those interactions; however, the specimen preparation finds major drawbacks in its operation time and preciseness. In this context, focused ion beam and scanning electron microscopy (FIB–SEM) allows for fast processing and high resolution of the cell-nanomaterial interface. Here, in fact, a novel approach is shown to prepare large-area 3D spheroid cell culture specimens for FIB–SEM. Sectioning procedures are explored to preserve the peculiar structure of spheroids and their interaction with magnetic nanovectors. The results pave the way for advanced investigations of 3D cellular systems with nano and micromaterials relevant to tissue engineering, bioelectronics, and diagnostics

Ultrasound Triggered ZnO-Based Devices for Tunable and Multifaceted Biomedical Applications

Smart materials able to respond to an external stimulus or an environmental condition represent milestone developments in modern medicine. Among them, zinc oxide (ZnO) is a highly intriguing inorganic material with versatile morphologies/shapes and multifunctional properties like piezoelectricity, enhanced reactive oxygen species (ROS) generation, and antimicrobial ones. Here, the fabrication of smart ZnO-based films is shown that can remotely be activated by ultrasound (US). US exposure induces electrical potentials on the fabricated devices that can be exploited to stimulate electrically responsive cells or promote ROS generation for cancer treatment. ZnO microparticles with surface nanostructuring are thus synthesized and processed in the form of a paste to deposit thin films on flexible polymeric supports. ZnO paste formulation and the fabrication procedure of the final device are optimized in terms of uniformity, hydrophilicity, and purity. Graphene oxide and poly(2-hydroxyethyl methacrylate) are also layered onto the ZnO films in order to provide the devices with additional functionalities. ROS generation and electro-mechanical performances upon US stimulation are evaluated for all of the developed devices. Finally, biocompatibility studies are conducted with osteoblast-like cell cultures for possible applications in the contexts of bone tissue engineering/therapy

Design, fabrication, and characterization of a multimodal reconfigurable bioreactor for bone tissue engineering

In the past decades, bone tissue engineering developed and exploited many typologies of bioreactors, which, besides providing proper culture conditions, aimed at integrating those bio-physical stimulations that cells experience in vivo, to promote osteogenic differentiation. Nevertheless, the highly challenging combination and deployment of many stimulation systems into a single bioreactor led to the generation of several unimodal bioreactors, investigating one or at mostly two of the required biophysical stimuli. These systems miss the physiological mimicry of bone cells environment, and often produced contrasting results, thus making the knowledge of bone mechanotransduction fragmented and often inconsistent. To overcome this issue, in this study we developed a perfusion and electroactive-vibrational reconfigurable stimulation bioreactor to investigate the differentiation of SaOS-2 bone-derived cells, hosting a piezoelectric nanocomposite membrane as cell culture substrate. This multimodal perfusion bioreactor is designed based on a numerical (finite element) model aimed at assessing the possibility to induce membrane nano-scaled vibrations (with ~12 nm amplitude at a frequency of 939 kHz) during perfusion (featuring 1.46 dyn cm−2 wall shear stress), large enough for inducing a physiologically-relevant electric output (in the order of 10 mV on average) on the membrane surface. This study explored the effects of different stimuli individually, enabling to switch on one stimulation at a time, and then to combine them to induce a faster bone matrix deposition rate. Biological results demonstrate that the multimodal configuration is the most effective in inducing SaOS-2 cell differentiation, leading to 20-fold higher collagen deposition compared to static cultures, and to 1.6- and 1.2-fold higher deposition than the perfused- or vibrated-only cultures. These promising results can provide tissue engineering scientists with a comprehensive and biomimetic stimulation platform for a better understanding of mechanotransduction phenomena beyond cells differentiation

Barium titanate nanoparticles and hypergravity stimulation improve differentiation of mesenchymal stem cells into osteoblasts.

BACKGROUND: Enhancement of the osteogenic potential of mesenchymal stem cells (MSCs) is highly desirable in the field of bone regeneration. This paper proposes a new approach for the improvement of osteogenesis combining hypergravity with osteoinductive nanoparticles (NPs). MATERIALS AND METHODS: In this study, we aimed to investigate the combined effects of hypergravity and barium titanate NPs (BTNPs) on the osteogenic differentiation of rat MSCs, and the hypergravity effects on NP internalization. To obtain the hypergravity condition, we used a large-diameter centrifuge in the presence of a BTNP-doped culture medium. We analyzed cell morphology and NP internalization with immunofluorescent staining and coherent anti-Stokes Raman scattering, respectively. Moreover, cell differentiation was evaluated both at the gene level with quantitative real-time reverse-transcription polymerase chain reaction and at the protein level with Western blotting. RESULTS: Following a 20 g treatment, we found alterations in cytoskeleton conformation, cellular shape and morphology, as well as a significant increment of expression of osteoblastic markers both at the gene and protein levels, jointly pointing to a substantial increment of NP uptake. Taken together, our findings suggest a synergistic effect of hypergravity and BTNPs in the enhancement of the osteogenic differentiation of MSCs. CONCLUSION: The obtained results could become useful in the design of new approaches in bone-tissue engineering, as well as for in vitro drug-delivery strategies where an increment of nanocarrier internalization could result in a higher drug uptake by cell and/or tissue constructs

Investigation of interactions between poly-l-lysine-coated boron nitride nanotubes and C2C12 cells: up-take, cytocompatibility, and differentiation

Boron nitride nanotubes (BNNTs) have generated considerable interest within the scientific community by virtue of their unique physical properties, which can be exploited in the biomedical field. In the present in vitro study, we investigated the interactions of poly-l-lysine-coated BNNTs with C2C12 cells, as a model of muscle cells, in terms of cytocompatibility and BNNT internalization. The latter was performed using both confocal and transmission electron microscopy. Finally, we investigated myoblast differentiation in the presence of BNNTs, evaluating the protein synthesis of differentiating cells, myotube formation, and expression of some constitutive myoblastic markers, such as MyoD and Cx43, by reverse transcription – polymerase chain reaction and Western blot analysis. We demonstrated that BNNTs are highly internalized by C2C12 cells, with neither adversely affecting C2C12 myoblast viability nor significantly interfering with myotube formation