Understanding the influence of experimental factors on bio-interactions of nanoparticles: Towards improving correlation between in vitro and in vivo studies

Tackling breast cancer with gold nanoparticles: twinning synthesis and particle engineering with efficacy

The World Health Organization identifies breast cancer as the most prevalent cancer despite predominantly affecting women. Surgery, hormonal therapy, chemotherapy, and radiation therapy are the current treatment modalities. Site-directed nanotherapeutics, engineered with multidimensional functionality are now the frontrunners in breast cancer diagnosis and treatment. Gold nanoparticles with their unique colloidal, optical, quantum, magnetic, mechanical, and electrical properties have become the most valuable weapon in this arsenal. Their advantages include facile modulation of shape and size, a high degree of reproducibility and stability, biocompatibility, and ease of particle engineering to induce multifunctionality. Additionally, the surface plasmon oscillation and high atomic number of gold provide distinct advantages for tailor-made diagnosis, therapy or theranostic applications in breast cancer such as photothermal therapy, radiotherapy, molecular labeling, imaging, and sensing. Although pre-clinical and clinical data are promising for nano-dimensional gold, their clinical translation is hampered by toxicity signs in major organs like the liver, kidneys and spleen. This has instigated global scientific brainstorming to explore feasible particle synthesis and engineering techniques to simultaneously improve the efficacy and versatility and widen the safety window of gold nanoparticles. The present work marks the first study on gold nanoparticle design and maneuvering techniques, elucidating their impact on the pharmacodynamics character and providing a clear-cut scientific roadmap for their fast-track entry into clinical practice.

Metallic nanoparticles and treatment of cutaneous leishmaniasis: A systematic review

BACKGROUND

Cutaneous leishmaniasis (LC) is an infectious vector-borne disease caused by parasites belonging to the genus Leishmania. Metallic nanoparticles (MNPs) have been investigated as alternatives for the treatment of LC owing to their small size and high surface area. Here, we aimed to evaluate the effect of MNPs in the treatment of LC through experimental, in vitro and in vivo investigations.

METHODS

The databases used were MEDLINE/ PubMed, Scopus, Web of Science, Embase, and Science Direct. Manual searches of the reference lists of the included studies and grey literature were also performed. English language and experimental in vitro and in vivo studies using different Leishmania species, both related to MNP treatment, were included. This study was registered in PROSPERO (CRD42021248245).

RESULTS

A total of 93 articles were included. Silver nanoparticles are the most studied MNPs, and L. tropica is the most studied species. Among the mechanisms of action of MNPs in vitro, we highlight the production of reactive oxygen species, direct contact of MNPs with the biomolecules of the parasite, and release of metal ions.

CONCLUSION

MNPs may be considered a promising alternative for the treatment of LC, but further studies are needed to define their efficacy and safety.

Biodistribution Analysis of Peptide-Coated Magnetic Iron Nanoparticles: A Simple and Quantitative Method

Biodistribution tracks compounds or molecules of interest in vivo to understand a compound's anticipated efficacy and safety. Nanoparticles deliver nucleic acid and drug payloads and enhance tumor permeability due to multiple properties such as high surface area to volume ratio, surface functionalization, and modifications. Studying the in vivo biodistribution of nanoparticles documents the effectiveness and safety of nanoparticles and facilitates a more application-driven approach for nanoparticle development that allows for more successful translation into clinical use. In this study, we present a relatively simple method to determine the biodistribution of magnetic iron nanoparticles in mice. In vitro, cells take up branched amphiphilic peptide-coated magnetic nanobeads (BAPc-MNBs) like their counterparts, i.e., branched amphiphilic peptide capsules (BAPCs) with a hollow water-filled core. Both BAPc-MNBs and BAPCs have widespread applications as a nanodelivery system. We evaluated the BAPc-MNBs tissue distribution in wild-type mice injected intravenously (i.v.), intraperitoneally (i.p.), or orally gavaged to understand the biological interactions and to further the development of branched amphiphilic peptide-based nanoparticles. The magnetic nanoparticles allowed collection of the BAPc-MNBs from multiple organs by magnetic bead sorting, followed by a high-throughput screening for iron content. When injected i.v., nanoparticles were distributed widely to various organs before elimination from the system via the intestines in feces. The spleen accumulated the highest amount of BAPc-MNBs in mice administered NPs via i.v. and i.p. but not via oral gavage. Taken together, these data demonstrate that the magnetic sorting not only allowed quantification of the BAPc-MNBs but also identified the distribution of BAPc-MNBs after distinct administration methods.

Nanoparticles cellular uptake, trafficking, activation, toxicity and in vitro evaluation

Nanoparticles (NPs) physicochemical properties, such as size, shape, surface chemistry, charge, etc., play a critical role in biological systems interactions, which include NPs' cellular uptake, trafficking, activation, and toxicity. Although nano-bio interactions are multifaceted and complex, their assessment is essential for future therapeutic and diagnostic use since being carriers that deliver specific molecules (i.e., active pharmaceutical ingredients and imaging agents) in intracellular sites. The journey of NPs begins by reaching the plasma membrane and entering the cell mainly through endocytosis. After vesicles pinch off the cell membrane, the intracellular trafficking is mediated by a network of cellular endosomes which direct NPs to the different cellular components. Otherwise, NPs or their contents are released into the cytoplasm. In both cases, NPs can pass undetected or be recognized by the cell leading to a pro or anti-inflammatory response. Indeed, the cell response mostly depends on cell type and NPs physicochemical properties. The principal mechanism by which NPs activate the cell response is RONS production. Other mechanism includes signaling pathways modulation related to metabolic and enzymatic reactions, cell transduction, and immune modulation. Hence, the underlying mechanisms of cellular and subcellular interactions in vitro should be performed to provide insights into NPs' effect. This information helps us to improve their synthesis and design to maximize the clinical benefits while minimizing side effects. Most in vitro tests to evaluate NPs' effect in cells were developed focusing on cell dysfunctions, cytotoxicity, genotoxicity, immunogenicity, and cell death.

Biodistribution Analysis of Peptide-Coated Magnetic Iron Nanoparticles: A Simple and Quantitative Method

Biodistribution is the tracking of compounds or molecules of interest in the subject which is integral to understanding their anticipated efficacy and safety. Nanoparticles are highly desirable delivery systems which have the ability to deliver higher nucleic acid and drug payloads and they have enhanced tumor permeability due to their unique properties such as high surface area to volume ratio. Studying the biodistribution of nanoparticles is crucial to understand their effectiveness and safety in vivo, facilitate a more application driven approach for nanoparticle development which will lead to their successful translation into clinical use. In this study, we present a relatively simple method to determine the biodistribution of magnetic iron nanoparticles in mice. Branched Amphiphilic Peptide coated Magnetic Nanobeads BAPc-MNBs like their counterpart i.e., Branched Amphiphilic Peptide capsules (BAPCs) with a hollow water-filled core, are readily taken up by cells in vitro and have widespread application as a nanodelivery systems. We evaluated the BAPc-MNBs tissue distribution in wildtype mice injected intravenously (i.v.), intraperitoneally (i.p.) or orally gavaged to understand the biological interactions of the peptide nanoparticles and to further the development of branched amphiphilic peptides-based nanoparticles. BAPc-MNBs were distributed widely to various organs when injected i.v. and were eliminated from the system via the intestines in feces. The spleen was found to accumulate the highest amount of BAPc-MNBs in mice administered the NPs i.v. and i.p. while they were not absorbed into the system via oral gavage. This study not only presents a relatively simple quantification method to determine in vivo biodistribution of magnetic iron nanoparticles that can be widely applied but also demonstrates the potential of Branched Amphiphilic Peptides in the form of BAPCs or BAPc-MNBs as a delivery system.

Physiological relevance of in-vitro cell-nanoparticle interaction studies as a predictive tool in cancer nanomedicine research

Cell uptake study is a routine experiment used as a surrogate to predict in vivo response in cancer nanomedicine research. Cell culture conditions should be designed in such a way that it emulates 'real' physiological conditions and avoid artefacts. It is critical to dissect the steps involved in cellular uptake to understand the physical, chemical, and biological factors responsible for particle internalization. The two-dimensional model (2D) of cell culture is overly simplistic to mimic the complexity of cancer tissues that exist in vivo. It cannot simulate the critical tissue-specific properties like cell-cell interaction and cell-extracellular matrix (ECM) interaction and its influences on the temporal and spatial distribution of nanoparticles (NPs). The three dimensional model organization of heterogenous cancer and normal cells with the ECM acts as a formidable barrier to NP penetration and cellular uptake. The three dimensional cell culture (3D) technology is a breakthrough in this direction that can mimic the barrier properties of the tumor microenvironment (TME). Herein, we discuss the physiological factors that should be considered to bridge the translational gap between in and vitro cell culture studies and in-vivo studies in cancer nanomedicine.

In vivo Preclinical Tumor-Specific Imaging of Superparamagnetic Iron Oxide Nanoparticles Using Magnetic Particle Imaging for Cancer Diagnosis

Purpose

Magnetic particle imaging (MPI) is an emerging radiation-free, non-invasive three-dimensional tomographic technology that can visualize the concentrations of superparamagnetic iron oxide nanoparticles (SPIONs). To verify the applicability of the previously proposed point-of-care testing MPI (PoCT-MPI) in medical diagnosis and therapeutics, we imaged SPIONs in animal tumor models.

Methods

CT26 or MC38 mouse colon carcinoma cells (2 × 10⁶ cells) were subcutaneously injected into the right flank of BALB/c mice. SPIONs were either injected directly into the tumor lesions in the intratumoral group or through tail veins in the intravenous group. CT26 and MC38 tumor models were examined both intratumorally and intravenously to confirm the biological availability of SPIONs using PoCT-MPI.

Results

Signals were observed in the tumor lesions from day 1 to day 7. This is the first study to successfully image the pathological region and show the biodistribution of SPIONs in CT26 tumor models using the recently developed PoCT-MPI technology. Furthermore, MC38 tumor models were examined, resulting in similar images to those of the CT26 tumor model in both intratumoral and intravenous groups.

Conclusion

The present study demonstrates the biological applicability of PoCT-MPI, which promises to be a powerful diagnostic and therapeutic technique in biomedical imaging.

Optical Microscopy Systems for the Detection of Unlabeled Nanoparticles

Label-free detection of nanoparticles is essential for a thorough evaluation of their cellular effects. In particular, nanoparticles intended for medical applications must be carefully analyzed in terms of their interactions with cells, tissues, and organs. Since the labeling causes a strong change in the physicochemical properties and thus also alters the interactions of the particles with the surrounding tissue, the use of fluorescently labeled particles is inadequate to characterize the effects of unlabeled particles. Further, labeling may affect cellular uptake and biocompatibility of nanoparticles. Thus, label-free techniques have been recently developed and implemented to ensure a reliable characterization of nanoparticles.

This review provides an overview of frequently used label-free visualization techniques and highlights recent studies on the development and usage of microscopy systems based on reflectance, darkfield, differential interference contrast, optical coherence, photothermal, holographic, photoacoustic, total internal reflection, surface plasmon resonance, Rayleigh light scattering, hyperspectral and reflectance structured illumination imaging. Using these imaging modalities, there is a strong enhancement in the reliability of experiments concerning cellular uptake and biocompatibility of nanoparticles, which is crucial for preclinical evaluations and future medical applications.

Metallic Nanoparticles: A New Frontier in the Fight Against Leishmaniasis

Abstract:

Leishmaniasis is a cutaneous, mucocutaneous, or visceral parasitic disease caused by protozoa of the Leishmania genus. According to the World Health Organization, Leishmaniasis causes approximately 20–40 thousand deaths annually, and Brazil, India, and some countries in Africa are the most affected by this neglected disease. In addition to parasite’s ability to evade the host’s immune system, the incidence of vectors, the genetics of different hosts, and the large number of deaths are mainly due to failures in conventional treatments that have high toxicity, low effectiveness, and prolonged therapeutic regimens. Thus, the development of new alternative therapeutics with more effective and safer actions has become one of the main challenges for researchers studying leishmaniasis. Among the many research and tested options, metallic nanoparticles, such as gold, silver, zinc oxide, and titanium dioxide, have been shown to be one of the most promising therapeutic tool because they are easily prepared and chemically modified, have a broad spectrum of action, low toxicity, and can generate reactive oxygen species and other immune responses that favor their use against different species of Leishmania. This review explores the progress of the use of metallic nanoparticles as a new tool in the treatment of leishmaniasis, as well as discusses the gaps in knowledge that need to be addressed to consolidate a safe, effective, and definitive therapeutic intervention against these infections.

Novel insights and perspectives for the diagnosis and treatment of hearing loss through the implementation of magnetic nanotheranostics

Hearing loss (HL) is a sensory disability that affects 5% of the world's population. HL predominantly involves damage and death to the cochlear cells. Currently, there is no cure or specific medications for HL. Furthermore, the arrival of therapeutic molecules to the inner ear represents a challenge due to the limited blood supply to the sensory cells and the poor penetration of the blood-cochlear barrier. Superparamagnetic iron oxide nanoparticles (SPIONs) perfectly coordinate with the requirements for controlled drug delivery along with magnetic resonance imaging (MRI) diagnostic and monitoring capabilities. Besides, they are suitable tools to be applied to HL, expecting to be more effective and non-invasive. So far, the published literature only refers to some preclinical studies of SPIONs for HL management. This contribution aims to provide an integrated view of the best options and strategies that can be considered for future research punctually in the field of magnetic nanotechnology applied to HL.