Nanotoxicity in Cancer Research: Technical Protocols and Considerations for the Use of 3D Tumour Spheroids

The poor clinical translation of oncological nanomedicine products is one of the greatest challenges faced by research today. The use of reductionist in vitro models of human cancer and non-predictive animal models is generally considered as one of the main causes of such very low translation rate. The integration of three-dimensional (3D) tumour spheroids in the early stages of the preclinical screening pipeline could significantly facilitate the translation of nanomedicine candidates into clinical practice, by allowing for a more reliable prediction of their efficacy and safety in humans. To lead a successful integration of 3D spheroids, protocols that satisfy issues of ease-of-use, reproducibility and compatibility with conventional and high-throughput assays, without losing the advantages offered by two-dimensional (2D) cell systems, are still needed. To address such need, protocols for the formation and characterisation of scaffold-free 3D tumour spheroids of human adenocarcinoma cells were developed and optimised in this study for their application in nanomedicine safety testing. The protocols reported in this chapter provide the ground on how 3D tumour spheroids could be implemented to design nanomedicine products and speed up experimental cancer research, eliminating those candidates that are likely to be ineffective or unsafe in human at early development stages

Editorial: Use of 3D Models in Drug Development and Precision Medicine - Advances and Outlook

Three-dimensional (3D) in vitro models in the drug development pipeline can help selecting the most promising and safe drug candidates at the pre-clinical stage, prior to clinical trials, reducing and sometimes even replacing animal studies in accordance with the “3Rs (Reduction, Refinement and Replacement) principle”

Towards the Identification of an In Vitro Tool for Assessing the Biological Behavior of Aerosol Supplied Nanomaterials

Nanoparticles (NP)-based inhalation systems for drug delivery can be administered in liquid form, by nebulization or using pressurized metered dose inhalers, and in solid form by means of dry powder inhalers. However, NP delivery to the lungs has many challenges including the formulation instability due to particle-particle interactions and subsequent aggregation, causing poor deposition in the small distal airways and subsequent alveolar macrophages activity, which could lead to inflammation. This work aims at providing an in vitro experimental design for investigating the correlation between the physico-chemical properties of NP, and their biological behavior, when they are used as NP-based inhalation treatments, comparing two different exposure systems. By means of an aerosol drug delivery nebulizer, human lung cells cultured at air-liquid interface (ALI) were exposed to two titanium dioxide NP (NM-100 and NM-101), obtained from the JRC repository. In parallel, ALI cultures were exposed to NP suspension by direct inoculation, i.e., by adding the NP suspensions on the apical side of the cell cultures with a pipette. The formulation stability of NP, measured as hydrodynamic size distributions, the cell viability, cell monolayer integrity, cell morphology and pro-inflammatory cytokines secretion were investigated. Our results demonstrated that the formulation stability of NM-100 and NM-101 was strongly dependent on the aggregation phenomena that occur in the conditions adopted for the biological experiments. Interestingly, comparable biological data between the two exposure methods used were observed, suggesting that the conventional exposure coupled to ALI culturing conditions offers a relevant in vitro tool for assessing the correlation between the physico-chemical properties of NP and their biological behavior, when NP are used as drug delivery systems

Conjugated Quantum Dots Inhibit the Amyloid β (1–42) Fibrillation Process

Nanoparticles have enormous potential in diagnostic and therapeutic studies. We have demonstrated that the amyloid beta mixed with and conjugated to dihydrolipoic acid- (DHLA) capped CdSe/ZnS quantum dots (QDs) of size approximately 2.5 nm can be used to reduce the fibrillation process. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used as tools for analysis of fibrillation. There is a significant change in morphology of fibrils when amyloid β (1–42) (Aβ (1–42)) is mixed or conjugated to the QDs. The length and the width of the fibrils vary under modified conditions. Thioflavin T (ThT) fluorescence supports the decrease in fibril formation in presence of DHLA-capped QDs

Towards More Predictive, Physiological and Animal-free In Vitro Models: Advances in Cell and Tissue Culture 2020 Conference Proceedings

Experimental systems that faithfully replicate human physiology at cellular, tissue and organ level are crucial to the development of efficacious and safe therapies with high success rates and low cost. The development of such systems is challenging and requires skills, expertise and inputs from a diverse range of experts, such as biologists, physicists, engineers, clinicians and regulatory bodies. Kirkstall Limited, a biotechnology company based in York, UK, organised the annual conference, Advances in Cell and Tissue Culture (ACTC), which brought together people having a variety of expertise and interests, to present and discuss the latest developments in the field of cell and tissue culture and in vitro modelling. The conference has also been influential in engaging animal welfare organisations in the promotion of research, collaborative projects and funding opportunities. This report describes the proceedings of the latest ACTC conference, which was held virtually on 30th September and 1st October 2020, and included sessions on in vitro models in the following areas: advanced skin and respiratory models, neurological disease, cancer research, advanced models including 3-D, fluid flow and co-cultures, diabetes and other age-related disorders, and animal-free research. The roundtable session on the second day was very interactive and drew huge interest, with intriguing discussion taking place among all participants on the theme of replacement of animal models of disease

Proinflammatory Effects of Pyrogenic and Precipitated Amorphous Silica Nanoparticles in Innate Immunity Cells.

Amorphous silica nanoparticles (ASNP) can be synthetized via several processes, 2 of which are the thermal route (to yield pyrogenic silica) and the wet route from a solution containing silicate salts (to obtain precipitated, colloidal, mesoporous silica, or silica gel). Both methods of synthesis lead to ASNP that are applied as food additive (E551). Current food regulation does not require that production methods of additives are indicated on the product label, and, thus, the ASNP are listed without mentioning the production method. Recent results indicate, however, that pyrogenic ASNP are more cytotoxic than ASNP synthesized through the wet route. The present study was aimed at clarifying if 2 representative preparations of ASNP, NM-203 (pyrogenic) and NM-200 (precipitated), of comparable size, specific surface area, surface charge, and hydrodynamic radius in complete growth medium, had different effects on 2 murine macrophage cell lines (MH-S and RAW264.7 cells). Our results show that, when incubated in protein-rich fluids, NM-203 adsorbed on their surface more proteins than NM-200 and, once incubated with macrophages, elicited a greater oxidative stress, assessed from Hmox1 induction and ROS production. Flow cytometry and helium ion microscopy indicated that pyrogenic NM-203 interacted with macrophages more strongly than the precipitated NM-200 and triggered a more evident inflammatory response, evaluated with Nos2 induction, NO production and the secretion of TNF-?, IL-6 and IL-1?. Moreover, both ASNP synergized macrophage activation by bacterial lipopolysaccharide (LPS), with a higher effect observed for NM-203. In conclusion, the results presented here demonstrate that, compared to precipitated, pyrogenic ASNP exhibit enhanced interaction with serum proteins and cell membrane, and cause a larger oxidative stress and stronger proinflammatory effects in macrophages. Therefore, these 2 nanomaterials should not be considered biologically equivalent

Unraveling the Safety Profile of Nanoscale Particles and Materials - From Biomedical to Environmental Applications

The poor clinical translation of oncological nanomedicine products is one of the greatest challenges faced by research today. The use of reductionist in vitro models of human cancer and non-predictive animal models is generally considered as one of the main causes of such very low translation rate. The integration of three-dimensional (3D) tumour spheroids in the early stages of the preclinical screening pipeline could significantly facilitate the translation of nanomedicine candidates into clinical practice, by allowing for a more reliable prediction of their efficacy and safety in humans. To lead a successful integration of 3D spheroids, protocols that satisfy issues of ease-of-use, reproducibility and compatibility with conventional and high-throughput assays, without losing the advantages offered by two-dimensional (2D) cell systems, are still needed. To address such need, protocols for the formation and characterisation of scaffold-free 3D tumour spheroids of human adenocarcinoma cells were developed and optimised in this study for their application in nanomedicine safety testing. The protocols reported in this chapter provide the ground on how 3D tumour spheroids could be implemented to design nanomedicine products and speed up experimental cancer research, eliminating those candidates that are likely to be ineffective or unsafe in human at early development stages