Next generation in vitro liver model design: Combining a permeable polystyrene membrane with a transdifferentiated cell line

Prospective life cycle assessment of a bioprocess design for cultured meat production in hollow fiber bioreactors

The aim of cellular agriculture is to use cell-culturing technologies to produce alternatives to agricultural products. Cultured meat is an example of a cellular agriculture product, made by using tissue engineering methods. This study aims to improve the understanding of the potential environmental impacts of cultured meat production by comparing between different bioprocess design scenarios. This was done by carrying out a life cycle assessment (LCA) for a bioprocess system using hollow fiber bioreactors, and utilizing bench-scale experimental data for C2C12 cell proliferation, differentiation and media metabolism. Scenario and sensitivity analyses were used to test the impact of changes in the system design, data sources, and LCA methods on the results to support process design decision making. We compared alternative scenarios to a baseline of C2C12 cells cultured in hollow fiber bioreactors using media consisting of DMEM with serum, for a 16-day proliferation stage and 7-day differentiation stage. The baseline LCA used the average UK electricity mix as the energy source, and heat treatment for wastewater sterilization. The greatest reduction in environmental impacts were achieved with the scenarios using CHO cell metabolism instead of C2C12 cell metabolisim (64-67 % reduction); achieving 128 % cell biomass increase during differentiation instead of no increase (42-56 % reduction); using wind electricity instead of average UK electricity (6-39 % reduction); and adjusting the amino acid use based on experimental data (16-27 % reduction). The use of chemical wastewater treatment instead of heat treatment increased all environmental impacts, except energy demand, by 1-16 %. This study provides valuable insights for the cultured meat field to understand the effects of different process design scenarios on environmental impacts, and therefore provides a framework for deciding where to focus development efforts for improving the environmental performance of the production system.

Hollow Fiber and Nanofiber Membranes in Bioartificial Liver and Neuronal Tissue Engineering

To date, the creation of biomimetic devices for the regeneration and repair of injured or diseased tissues and organs remains a crucial challenge in tissue engineering. Membrane technology offers advanced approaches to realize multifunctional tools with permissive environments well-controlled at molecular level for the development of functional tissues and organs. Membranes in fiber configuration with precisely controlled, tunable topography, and physical, biochemical, and mechanical cues, can direct and control the function of different kinds of cells toward the recovery from disorders and injuries. At the same time, fiber tools also provide the potential to model diseases in vitro for investigating specific biological phenomena as well as for drug testing. The purpose of this review is to present an overview of the literature concerning the development of hollow fibers and electrospun fiber membranes used in bioartificial organs, tissue engineered constructs, and in vitro bioreactors. With the aim to highlight the main biomedical applications of fiber-based systems, the first part reviews the fibers for bioartificial liver and liver tissue engineering with special attention to their multifunctional role in the long-term maintenance of specific liver functions and in driving hepatocyte differentiation. The second part reports the fiber-based systems used for neuronal tissue applications including advanced approaches for the creation of novel nerve conduits and in vitro models of brain tissue. Besides presenting recent advances and achievements, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.

Engineering liver microtissues for disease modeling and regenerative medicine

The burden of liver diseases is increasing worldwide, accounting for two million deaths annually. In the past decade, tremendous progress has been made in the basic and translational research of liver tissue engineering. Liver microtissues are small, three-dimensional hepatocyte cultures that recapitulate liver physiology and have been used in biomedical research and regenerative medicine. This review summarizes recent advances, challenges, and future directions in liver microtissue research. Cellular engineering approaches are used to sustain primary hepatocytes or produce hepatocytes derived from pluripotent stem cells and other adult tissues. Three-dimensional microtissues are generated by scaffold-free assembly or scaffold-assisted methods such as macroencapsulation, droplet microfluidics, and bioprinting. Optimization of the hepatic microenvironment entails incorporating the appropriate cell composition for enhanced cell-cell interactions and niche-specific signals, and creating scaffolds with desired chemical, mechanical and physical properties. Perfusion-based culture systems such as bioreactors and microfluidic systems are used to achieve efficient exchange of nutrients and soluble factors. Taken together, systematic optimization of liver microtissues is a multidisciplinary effort focused on creating liver cultures and on-chip models with greater structural complexity and physiological relevance for use in liver disease research, therapeutic development, and regenerative medicine.

Cellular agriculture in the UK: a review

This review details the core activity in cellular agriculture conducted in the UK at the end of 2019, based upon a literature review by, and community contacts of the authors. Cellular agriculture is an emergent field in which agricultural products—most typically animal-derived agricultural products—are produced through processes operating at the cellular level, as opposed to (typically farm-based) processes operating at the whole organism level. Figurehead example technologies include meat, leather and milk products manufactured from a cellular level. Cellular agriculture can be divided into two forms: ‘tissue-engineering based cellular agriculture’ and ‘fermentation-based cellular agriculture’. Products under development in this category are typically valued for their environmental, ethical, and sometimes health and safety advantages over the animal-derived versions.

There are university laboratories actively pursuing research on meat products through cellular agriculture at the universities of Bath, Newcastle, Aberystwyth, and Aston University in Birmingham. A cellular agriculture approach to producing leather is being pursued at the University of Manchester, and work seeking to produce a palm oil substitute is being conducted at the University of Bath. The UK cellular agriculture companies working in the meat space are Higher Steaks, Cellular Agriculture Ltd, CellulaRevolution, Multus Media and Biomimetic Solutions. UK private investors include CPT Capital, Agronomics Ltd, Atomico, Backed VCs, and Breakoff Capital. The UK also has a strong portfolio of social science research into diverse aspects of cellular agriculture, with at least ten separate projects being pursued over the previous decade. Three analyses of the environmental impact of potential cellular agriculture systems have been conducted in the UK. The first dedicated third-sector group in this sector in the UK is Cultivate (who produced this report) followed by Cellular Agriculture UK. International groups New Harvest and the Good Food Institute also have a UK presence.

Cellular agriculture in the UK: a review

This review details the core activity in cellular agriculture conducted in the UK at the end of 2019, based upon a literature review by, and community contacts of the authors. Cellular agriculture is an emergent field in which agricultural products-most typically animal-derived agricultural products-are produced through processes operating at the cellular level, as opposed to (typically farm-based) processes operating at the whole organism level. Figurehead example technologies include meat, leather and milk products manufactured from a cellular level. Cellular agriculture can be divided into two forms: 'tissue-based cellular agriculture' and 'fermentation-based cellular agriculture'. Products under development in this category are typically valued for their environmental, ethical, and sometimes health and safety advantages over the animal-derived versions. There are university laboratories actively pursuing research on meat products through cellular agriculture at the universities of Bath, Newcastle, Aberystwyth, and Aston University in Birmingham. A cellular agriculture approach to producing leather is being pursued at the University of Manchester, and work seeking to produce a palm oil substitute is being conducted at the University of Bath. The UK cellular agriculture companies working in the meat space are Higher Steaks, Cellular Agriculture Ltd, CellulaRevolution, Multus Media and Biomimetic Solutions. UK private investors include CPT Capital, Agronomics Ltd, Atomico, Backed VCs, and Breakoff Capital. The UK also has a strong portfolio of social science research into diverse aspects of cellular agriculture, with at least ten separate projects being pursued over the previous decade. Three analyses of the environmental impact of potential cellular agriculture systems have been conducted in the UK. The first dedicated third-sector group in this sector in the UK is Cultivate (who produced this report) followed by Cellular Agriculture UK. International groups New Harvest and the Good Food Institute also have a UK presence.