From Mice to Monkeys? Beyond Orthodox Approaches to the Ethics of Animal Model Choice

Beyond Anthropocentrism: The Moral and Strategic Philosophy behind Russell and Burch's 3Rs in Animal Experimentation

The 3Rs framework in animal experimentation- "replace, reduce, refine" - has been alleged to be expressive of anthropocentrism, the view that only humans are directly morally relevant. After all, the 3Rs safeguard animal welfare only as far as given human research objectives permit, effectively prioritizing human use interests over animal interests. This article acknowledges this prioritization, but argues that the characterization as anthropocentric is inaccurate. In fact, the 3Rs prioritize research purposes even more strongly than an ethical anthropocentrist would. Drawing on the writings of Universities Federation for Animal Welfare (UFAW) founder Charles W. Hume, who employed Russell and Burch, it is argued that the 3Rs originally arose from an animal-centered ethic which was however restricted by an organizational strategy aiming at the voluntary cooperation of animal researchers. Research purposes thus had to be accepted as given. While this explains why the 3Rs focus narrowly on humane method selection, not on encouraging animal-free question selection in the first place, it suggests that governments should (also) focus on the latter if they recognize animals as deserving protection for their own sake.

siRNA-mediated reduction of a circulating protein in swine using lipid nanoparticles

Genetic manipulation of animal models is a fundamental research tool in biology and medicine but is challenging in large animals. In rodents, models can be readily developed by knocking out genes in embryonic stem cells or by knocking down genes through in vivo delivery of nucleic acids. Swine are a preferred animal model for studying the cardiovascular and immune systems, but there are limited strategies for genetic manipulation. Lipid nanoparticles (LNPs) efficiently deliver small interfering RNA (siRNA) to knock down circulating proteins, but swine are sensitive to LNP-induced complement activation-related pseudoallergy (CARPA). We hypothesized that appropriately administering optimized siRNA-LNPs could knock down circulating levels of plasminogen, a blood protein synthesized in the liver. siRNA-LNPs against plasminogen (siPLG) reduced plasma plasminogen protein and hepatic plasminogen mRNA levels to below 5% of baseline values. Functional assays showed that reducing plasminogen levels modulated systemic blood coagulation. Clinical signs of CARPA were not observed, and occasional mild and transient hepatotoxicity was present in siPLG-treated animals at 5 h post-infusion, which returned to baseline by 7 days. These findings advance siRNA-LNPs in swine models, enabling genetic engineering of blood and hepatic proteins, which can likely expand to proteins in other tissues in the future.

The Development and Validation of Radiopharmaceuticals Targeting Bacterial Infection

The International Atomic Energy Agency organized a technical meeting at its headquarters in Vienna, Austria, in 2022 that included 17 experts representing 12 countries, whose research spanned the development and use of radiolabeled agents for imaging infection. The meeting focused largely on bacterial pathogens. The group discussed and evaluated the advantages and disadvantages of several radiopharmaceuticals, as well as the science driving various imaging approaches. The main objective was to understand why few infection-targeted radiotracers are used in clinical practice despite the urgent need to better characterize bacterial infections. This article summarizes the resulting consensus, at least among the included scientists and countries, on the current status of radiopharmaceutical development for infection imaging. Also included are opinions and recommendations regarding current research standards in this area. This and future International Atomic Energy Agency-sponsored collaborations will advance the goal of providing the medical community with innovative, practical tools for the specific image-based diagnosis of infection.

Recent Progress in Biomedical Sensors Based on Conducting Polymer Hydrogels

Biosensors are increasingly taking a more active role in health science. The current needs for the constant monitoring of biomedical signals, as well as the growing spending on public health, make it necessary to search for materials with a combination of properties such as biocompatibility, electroactivity, resorption, and high selectivity to certain bioanalytes. Conducting polymer hydrogels seem to be a very promising materials, since they present many of the necessary properties to be used as biosensors. Furthermore, their properties can be shaped and enhanced by designing conductive polymer hydrogel-based composites with more specific functionalities depending on the end application. This work will review the recent state of the art of different biological hydrogels for biosensor applications, discuss the properties of the different components alone and in combination, and reveal their high potential as candidate materials in the fabrication of all-organic diagnostic, wearable, and implantable sensor devices.

In vitro benchtop mock circulatory loop for heart failure with preserved ejection fraction emulation

In this work, a novel mock circulatory loop (MCL) is presented that is capable of simulating both healthy cardiac function and Heart Failure with preserved Ejection Fraction (HFpEF). This MCL differs from others presented in the literature as it features two independently actuated heart chambers, representing the left atrium and the left ventricle. This is an important improvement over other designs as it allows for potential HFpEF treatments to be examined, not just in relation to their effect on the left ventricle but also on the left atrium. The aim of this work was to show that novel MCL designs could be developed to allow for testing of new mechanical circulatory support devices for the treatment of HFpEF. Two loop configurations are presented, one featuring hard PVC cylindrical chambers and one that features soft silicone chambers which are anatomically analogous to the native heart. We show that both MCLs are capable of simulating the onset of HFpEF with a sustained increase in diastolic pressure of 62.03% and a sustained decrease in end diastolic volume (EDV) of 14.24%.

A survey on the use of mice, pigs, dogs and monkeys as animal models in biomedical research in Spain

Background

The use of animals in biomedical science remains controversial. An individual’s level of concern is generally influenced by their culture, previous or current experience with animals, and the specific animal species in question. In this study we aimed to explore what people in Spain who had never or who no longer worked with laboratory animals thought of the use of mice, pigs, dogs and monkeys for biomedical research purposes. We also aimed to determine whether or not people currently involved in biomedical research with the aforementioned species felt their work was justified.

Results

The study comprised a total of 807 participants (never worked = 285, used to work = 56, currently working = 466), almost two thirds of whom were women. Our results revealed that the phylogenetic scale is an important factor in people’s opinions of the use of certain species in research. The percentage of people who were against the use of dogs or monkeys was higher than that of those who were against the use of mice or pigs. The main reasons given for having stopped working with laboratory animals were change of professional career and change in research project. Participants who were currently working with animals believed that their work was justified, but said they did not talk about it with people outside their immediate social circle.

Conclusions

Our findings suggest that there is a difference in moral status between monkeys and mice, as well as between companion animals (dogs) and farm animals (pigs). Our results support the idea that working with laboratory animals is a sensitive issue in Spain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42826-022-00124-5.

Invasive Research on Non-Human Primates-Time to Turn the Page

Simple Summary

Despite increasing ethical concerns, primates are still often used in invasive research (i.e., laboratory research that causes body manipulations causing them pain or distress and not aimed at directly improving their well-being). Here, we will review previous studies showing that primates have complex behaviour and cognition, and that they suffer long-term consequences after being used in invasive research. We will discuss the ethical problems that invasive research on primates posit, the legal protection that they are, to date, granted in different countries, and summarize the past and current attempts to ban this kind of research on primates. We will conclude why, in our opinion, invasive research on primates should be banned, and non-invasive methods should be considered the only possible approach to the study of primates.

Abstract

Invasive research on primates (i.e., laboratory research that implies body manipulations causing pain or distress that is not aimed to directly improve the individuals’ well-being) has a long history. Although some invasive studies have allowed answering research questions that we could not have addressed with other methods (or at least not as quickly), the use of primates in invasive research also raises ethical concerns. In this review, we will discuss (i) recent advances in the study of primates that show evidence of complex behaviour and cognition, (ii) welfare issues that might arise when using primates in invasive research, (iii) the main ethical issues that have been raised about invasive research on primates, (iv) the legal protection that primates are granted in several countries, with a special focus on the principle of the 3Rs, and (v) previous and current attempts to ban the use of primates in invasive research. Based on this analysis, we suggest that the importance of a research question cannot justify the costs of invasive research on primates, and that non-invasive methods should be considered the only possible approach in the study of primates.

3D Bioprinting-Based Vascularized Tissue Models Mimicking Tissue-Specific Architecture and Pathophysiology for in vitro Studies

A wide variety of experimental models including 2D cell cultures, model organisms, and 3D in vitro models have been developed to understand pathophysiological phenomena and assess the safety and efficacy of potential therapeutics. In this sense, 3D in vitro models are an intermediate between 2D cell cultures and animal models, as they adequately reproduce 3D microenvironments and human physiology while also being controllable and reproducible. Particularly, recent advances in 3D in vitro biomimicry models, which can produce complex cell structures, shapes, and arrangements, can more similarly reflect in vivo conditions than 2D cell culture. Based on this, 3D bioprinting technology, which enables to place the desired materials in the desired locations, has been introduced to fabricate tissue models with high structural similarity to the native tissues. Therefore, this review discusses the recent developments in this field and the key features of various types of 3D-bioprinted tissues, particularly those associated with blood vessels or highly vascularized organs, such as the heart, liver, and kidney. Moreover, this review also summarizes the current state of the three categories: (1) chemical substance treatment, (2) 3D bioprinting of lesions, and (3) recapitulation of tumor microenvironments (TME) of 3D bioprinting-based disease models according to their disease modeling approach. Finally, we propose the future directions of 3D bioprinting approaches for the creation of more advanced in vitro biomimetic 3D tissues, as well as the translation of 3D bioprinted tissue models to clinical applications.

Animal and Cell Culture Models for Cystic Fibrosis: Which Model Is Right for Your Application?

Over the past 30 years, a range of cystic fibrosis (CF) animal models have been generated for research purposes. Different species, including mice, rats, ferrets, rabbits, pigs, sheep, zebrafish, and fruit flies, have all been used to model CF disease. While access to such a variety of animal models is a luxury for any research field, it also complicates the decision-making process when it comes to selecting the right model for an investigation. The purpose of this review is to provide a guide for selecting the most appropriate CF animal model for any given application. In this review, the characteristics and phenotypes of each animal model are described, along with a discussion of the key considerations that must be taken into account when choosing a suitable animal model. Available in vitro systems of CF are also described and can offer a useful alternative to using animal models. Finally, the future of CF animal model generation and its use in research are speculated upon.

Virtue Ethics and Laboratory Animal Research

This article appeals to virtue ethics to help guide laboratory animal research by considering the role of character and flourishing in these practices. Philosophical approaches to animal research ethics have typically focused on animal rights or on the promotion of welfare for all affected, while animal research itself has been guided in its practice by the 3Rs (reduction, refinement, replacement). These different approaches have sometimes led to an impasse in debates over animal research where the philosophical approaches are focused on whether or when animal studies are justifiable, while the 3Rs assume a general justification for animal work but aim to reduce harm to sentient animals and increase their welfare in laboratory spaces. Missing in this exchange is a moral framework that neither assumes nor rejects the justifiability of animal research and focuses instead on the habits and structures of that work. I shall propose a place for virtue ethics in laboratory animal research by considering examples of relevant character traits, the moral significance of human-animal bonds, mentorship in the laboratory, and the importance of animals flourishing beyond mere welfare.