Moving Beyond Animals

On December 29, 2022, President Biden signed the FDA Modernization Act 2.0  into law after it passed the US Senate (29 Sep. 2022) and the House of Representatives (23 Dec 2022) with bipartisan support. The new law updates the Federal Food, Drug, and Cosmetic Act from 1938, which required that all drugs must be tested on animals prior to human clinical trials.

The FDA Modernization Act 2.0 replaces the word “animal” with “nonclinical tests, which is a term that “means a test conducted in vitro, in silico, or in chemico, or a non-human in vivo test that occurs before or during the clinical trial phase of the investigation of the safety and effectiveness of a drug, and may include animal tests, or non-animal or human biology-based test methods, such as cell-based assays, microphysiological systems, or bioprinted or computer models”.

The original 1938 Federal Food, Drug, and Cosmetics act was passed after more than 100 people died in the United States after oral ingestion of “Elixir Sulfanilamide”, which contained poisonous diethylene glycol. No animal safety testing was required prior to 1938. Since then, animal testing had to be performed for all new drugs. Therefore, in vivo animal models and 2D in vitro cell culture models (mostly with cells derived from animals) were at the center of the pre-clinical (or non-clinical) phase of drug development for decades. Neither model is a good predicator for the efficacy of drugs in humans as more than 90% of clinical trials for new drugs fail either due to a lack of efficacy or inacceptable toxicity.

Significant improvements in two areas of technology over the past 20 years were needed to enable drug development without sacrificing animals: cell generation and microfabrication.

Cell generation

In 2007, Shinya Yamanaka discovered how to reprogram specialized human somatic cells to a pluripotent embryonic stem cell-like state. These human induced pluripotent stem cells (hiPSCs) enable the generation of patient-specific stem cells that can then be further differentiated to the target specialized cells for modeling diseases, drug development, and personalized medicine. This discovery solved the previous problem in pre-clinical research that the cells used in 2D cultures were mostly derived from animals. Now, not only could human cells be used without the ethical issues presented by using embryonic human cells, but, importantly, these cells could be derived from the exact patient population that the drug is designed to treat.

Another leap forward in replacing animals in pre-clinical research was the discovery of the generation of 3D structures from hiPSC derived specialized cells that mimic organ-like features in vitro. These so-called organoids self-assemble in vitro under specific conditions. Depending on the conditions, organoids have been grown from hiPSC-derived cells to replicate functional properties of the brain, lung, gut, retina, and others . The idea of individual cells self-organizing to form larger aggregates is not new. In 1906, Henry Van Peters Wilson discovered that siliceous sponge cells can degenerate into undifferentiated tissue that could self-organize and differentiate into sponges again. Self-organization was demonstrated in the following decades by in numerous other species, including vertebrates. The discovery that cells can self-organize without the need for external guidance demonstrates that the cells themselves contain the required information to form multi-cellular three-dimensional structures. The combination of self-organization and deriving specialized cells from hiPSCs enables researchers now to create 3D organoid models from human cells for drug development and mechanistic studies.

 Microfabrication

While the discovery of hiPSCs and the creation of organoids from different organs was a great advancement for biomedical research and drug development, the progress in microfabrication technology synergistically augmented the capabilities to a level required for the elimination of animal testing in drug development. In particular, the development of Organ-on-Chip models enabled a higher level of control over the cellular microenvironment in a culture to investigate diseases and pathophysiologies. David Ingber at the Wyss Institute was the first to develop a lung-on-a-chip in 2007. Since then, numerous single-organ and multi-organ systems have been developed for research and commercial applications.

Critical for the fabrication of most Organ-on-Chip models was the invention of soft lithography, which describes a family of techniques used for fabricating soft and elastomeric stamps and structures from a patterned mold. The technique is called soft lithography because it allows the patterning of soft materials. While a large variety of materials have been used in soft lithography, the silicone elastomer poly(dimethylsiloxane), or PDMS, is the most widely used material. There are also a large number of formulations from different vendors covering a large range of physical and chemical properties. The PDMS variant that is most often used in soft lithography is the Sylgard 184 from Dow Corning. BMSEED’s uses Sylgard 184 in the fabrication of stretchable microelectrode arrays.

Our Mission

BMSEED’s mission is provide innovative products that contribute to the elimination of animals in pharmaceutical research and drug development. Our goal is to make pre-clinical research more effective in accurately predicting clinical outcomes than animal models.

Our core technology is the reliable manufacturing of proprietary stretchable microelectrode arrays (sMEAs). Our MEASSuRE platform greatly improves the validity of in vitro experiments by replicating the electrical and mechanical environment of cells in vivo in a controlled environment in vitro, both for 2D and 3D cultures. This is important for in vitro research because bioelectrical and biomechanical cues affect phenotype and function in hiPSC-derived lineages. In the absence of biophysical (i.e., electrical or mechanical) cues, cells in vitro will differ from their in vivo counterpart.  For instance, Nunes et al. demonstrated that electrical stimulation of hiPSCs improved cardiomyocyte (CM) structure, induced sarcomere maturation, and enhanced electrophysiological properties compared to a non-stimulated control. Tulloch et al. demonstrated that cyclic mechanical stretch of hESCs promoted a 2-fold increase in cardiomyocyte differentiation yield and matrix fiber alignment, a 2.2-fold increase in cardiomyocyte hypertrophy, and a 21% increase in proliferation rates compared to unstretched controls. These mounting evidences indicate that cardiomyocytes differentiated from stem cells with added electrical or mechanical stimulation are more representative of the native phenotype within the adult myocardium.

 MEASSuRE combines three crucial modules for studying the effects of mechanical stretch on tissue electrophysiology. This device integrates:

●        A cell-stretching apparatus to apply physiological and mechanical stretch

●        A data-acquisition module for extracellular electrophysiology to assess the cell’s health, function, and maturity before and after stretching

●        A live-cell imaging system to visualize cells and cellular processes during the injury

These three paradigms are applied concurrently and independently. The key to these unique capabilities of this electrophysiology, imaging, and mechanics module is the proprietary stretchable microelectrode array (sMEA). Currently, BMSEED is the only company offering stretchable microelectrodes for in vitro research applications.