Advanced biomaterial platform for alternative animal testing

When a biomaterial or medical device is introduced to the body, it can interact with various biological components, such as cells, tissues, proteins, and fluids. It is therefore paramount that they coexist harmoniously with living tissues and biological systems without causing any adverse effects. This concept, called biocompatibility, is crucial in the development of biomaterials and medical devices to ensure patient safety and optimal performance. It helps minimise the risk of harmful reactions, enhances device functionality, and facilitates regulatory approval for clinical use.

The challenges of biocompatibility

The assessment of biocompatibility for biomaterials and medical devices involves a series of in vitro and in vivo tests and evaluations, as well as physicochemical characterisation. Researchers and regulatory agencies continually work to improve testing methodologies and establish guidelines for thorough and reliable assessments. However, the process is still mined with challenges such as – among other -, a lack of standardisation that can lead to inconsistencies and difficulties in comparing results across studies, and ethical considerations related to the use of animal testing, as there are currently no alternative methods enabling to reduce or replace the use of animals without compromising the accuracy and reliability of the biocompatibility assessment.

How 3D-bioprinting can help

3D-printed tissues and models have emerged as valuable tools in assessing the biocompatibility of new materials and reducing the reliance on animal testing. For example, they allow to replicate the structural and functional complexity of human tissues, providing a more accurate representation of the specific tissue environment where the biomaterial or medical device will be implanted. They can incorporate multiple cell types to recreate the cellular interactions and complexity found in vivo, and they can be cultured over extended periods, enabling long-term studies to assess the durability and stability of materials. They can be produced in large quantities, facilitating high-throughput screening of multiple materials simultaneously and therefore reducing the number of materials that need to be tested in animals.

The CUBIBOX project

In this context, the Technopole Mario Veronesi (TPM) together with its research partners Laboratory for Advanced Therapy Technologies (LTTA) and Romagnolo Institute for the Study of Cancer (IRST) developed the Customized Biological Box (CUBIBOX). This new technological platform consists of a bioreactor that houses a three-dimensional tissue (of either skin – the SkinBox, or blood vessel – the VesselBox) that was obtained using bioprinting technology that deposits an ink composed of homogeneously distributed biomaterials and cells in space, thereby recapitulating the desired architecture and physiology. The platform enables easy access for the insertion of compounds or materials to be tested, and therefore represents an innovative tool for studying the biocompatibility of materials, starting from the cytotoxic effects up to the analysis of more complex phenomena such as irritation and sensitisation [1].

Innovations brought by CUBIBOX

The CUBIBOX platform uses biomimetic biological tissues to rapidly test the efficacy and safety of compounds, drugs and materials without using animal models. This allows to obtain more accurate and predictive results regarding the biological effect of a compound on the human organism, reducing the experimental limits due to the interspecies variability typical of the animal models. It also reduces the use of animal models by satisfying the ethical principles of the 3Rs (refine, reduce, replace), and consequently also the resources and time required for in vivo experimentation.

“CUBIBOX represents a promising technology tool to accelerate time to market of materials, drugs and compounds thanks to biomimetic human tissues generated by bioprinting” (Dr. Elena Veronesi, Manager of the Applied Microscopy and Cell Biology laboratory)

Currently at Technology Readiness Level 5, the CUBIBOX platform offers developers of biomaterials and medical devices a screening tool capable of predicting the biological effect of a material or compound. In detail, the team of researchers was able to recapitulate human fibrosis, a pathology where the cells of dermis (fibroblasts) secrete an abnormal amount of scaring molecules, reducing the elasticity of tissues that results in organ failure. 2D culture and animal models show limitations to recapitulate the pathology. Thanks to CUBIBOX, they were able to develop a living biomaterial that mimics phytopathogenic features of fibrosis for drug screening. Administration of commercially available drugs against fibrosis (pirfenidone and nintedanib) was able to reduce the pathology development. A patent application has been filed for the pathological phenotype of the dermis generated with the SkinBox.

Authors: Clémence Foltz, Nicole Ticchi

Links

[1] CUBIBOX (Customized Biological Box): piattaforma di nuova generazione per testing in vitro. Available from: https://www.retealtatecnologia.it/technology-report/cubibox-customized-biological-box-piattaforma-di-nuova-generazione-testing-vitro

[2] Petrachi T, et al “Novel bioprinted 3D model to human fibrosis investigation” Biomed Pharmacother. 2023 Jul 17. Available from: https://pubmed.ncbi.nlm.nih.gov/37467651/

Keywords

3d-bioprinting, testing, biocompatibility, medical devices