NCCR MoleCulaR SySteMS eNgiNeeRiNg CHIMIA 2016, 70, No. 6 443 doi:10.2533/chimia.2016.443 Chimia 70 (2016) 443–448 © Swiss Chemical Society Artificial Cell Research as a Field that Connects Chemical, Biological and Philosophical Questions Anna Deplazes-Zemp* Abstract: This review article discusses the interdisciplinary nature and implications of artificial cell research. It starts from two historical theories: Gánti’s chemoton model and the autopoiesis theory by Maturana and Varela. They both explain the transition from chemical molecules to biological cells. These models exemplify two different ways in which disciplines of chemistry, biology and philosophy can profit from each other. In the chemoton model, conclusions from one disciplinary approach are relevant for the other disciplines. In contrast, the autopoiesis model itself (rather than its conclusions) is transferred from one discipline to the other. The article closes by underpinning the relevance of artificial cell research for philosophy with reference to the on-going philosophical debates on emergence, biological functions and biocentrism. Keywords: Artificial cell research · Autopoiesis · Chemoton · Interdisciplinary research · Philosophy With the ambition of producing a sim- alytically, the two material categories and between chemistry and biology in the two ple albeit living cell starting from non-liv- research approaches can still be separated. models and the implications for philosophy ing molecules, scientists move from the Sometimes, studying molecules and stud- that their authors are considering. Finally, I classical domain of chemistry to that of ying living organisms go hand in hand, and will give some examples of philosophical- biology. On the one hand, this transition research findings of one classical disci- ly relevant concepts that profit from find- happens at the level of the research subject, pline are often highly relevant for the oth- ings in artificial cell research. This article which changes from non-living molecules er. This does, however, not invalidate the will not provide a complete history of arti- to a living entity. On the other hand, there analytical difference between the chemical ficial cell research nor will it cover all the is a shift at the conceptual level concern- and biological categories with respect to interactions and influences that take place ing the research approach. Chemists tra- material, research approach and addressed between the discussed disciplines. Rather, ditionally study specific molecules and questions. Chemical as well as biological the aim of this article is to raise the reader’s singular reactions. In contrast, biological results and models in the context of this awareness and interest for the inter- and research concepts, models and questions shift raise interesting questions for philos- trans-disciplinary nature of artificial cell focus on the living entity and biologists ophy. More specifically, they are relevant research, and to use this research field as an are most interested in the function that for the philosophy of science and bioeth- example to illustrate fruitful interactions chemical molecules and reactions fulfil ics. The first field reflects on different and influences between the disciplines of in maintaining the life of such entities. methods, concepts, models and findings chemistry, biology and philosophy. This being said, it must be added that the of the sciences in question, and the latter emergence of disciplines such as molecu- deals with ethical implications related to lar biology or biochemistry, have blurred the discussed scientific research. The Transition from Chemistry to the strict separation between chemistry In this short review article, I would Biology in Artificial Cell Research and biology in practice. Nevertheless, an- like to discuss artificial cell research in the context of the three disciplines of chem- In this article, the phrase ‘artificial cell istry, biology and philosophy. Questions research’ is used for research approaches, about life have been the research subject which aim at producing minimal living not only of scientific disciplines but also cells starting from lipid vesicles. The dif- philosophy, social sciences, humanities, ferent contributions to this special issue arts and religions.[1] It will not be possi- show that research on and with artificial ble to address the relationship between all cells can pursue different research objec- of these approaches in detail within such tives and address different research ques- a review article. I thus decided to address tions. It would be inaccurate to describe the relationship between chemistry, biolo- research on artificial cells as a field driven gy and philosophy in two historical mod- by the unique aim to produce living cells. It els that are repeatedly being consulted and is not likely that this ambitious aim will be quoted by current artificial cell research- achieved in the near future; further, scien- ers. As models that describe and explain tists focus on more specific and often more the transition from chemical molecules to applied research questions. Nevertheless, *Correspondence: Dr. A. Deplazes-Zemp biological cells, they directly relate the lab- at least some artificial cell scientists are in- Institute of Biomedical Ethics and History of Medicine oratory work of artificial researchers to the terested in the very general – and cross-dis- University of Zurich Winterthurerstr. 30, CH-8006 Zurich more general questions about life. After an ciplinary – question about the conditions E-mail: [email protected] introduction, I will compare the relation and basic principles of life as well as the 444 CHIMIA 2016, 70, No. 6 NCCR MoleCulaR SySteMS eNgiNeeRiNg origin of life. In order to be able to produce The chemoton model is an abstraction realistic size and complexity to serve as a an artificial living cell, one needs to start of the minimal living system; it describes source of all other components.[6] What is from a model that outlines the conditions the simplest version of a system that can important with regards to the relation be- and criteria that a minimal cell needs to be called alive. It is present in every liv- tween chemistry, biology and philosophy fulfil in order to be considered as ‘alive’. ing being and absent in non-living entities. in artificial cell research, is the implication The two historical models that I would like Gánti starts from observations of simple of this chemical model for research on life to introduce are being used by influential unicellular organisms and states that all at the other levels. artificial cell researchers as a starting point living cells contain the three subsystems: As previously mentioned, Gánti’s work to develop their model on how a living cytoplasm, membrane and genetic materi- also includes some reflections on the bio- cell could be synthesised from non-living al.[4] For the chemoton model, he reduces logical (rather than chemical) research ap- molecules. The chemoton theory by Tibor these components into the following three proach to study life, which focuses on the Gánti received, for instance, significant at- abstract subsystems (Fig. 1): first, the met- criteria of life. The most inventive aspect tention in the textbook on protocells edited abolic subsystem found in the cytoplasm. of this part of his theory consists in his by Steen Rasmussen and colleagues.[2] The It forms a reaction network that, starting distinction between absolute and poten- second example is the autopoiesis theory from a nutrient X, produces all compo- tial life criteria. The former must apply to by Humberto Maturana and Francisco nents to reproduce itself as well as the other every living organism, while the latter are Varela, which has repetitively been con- two subsystems. Moreover, it releases the not applicable to every individual organism sulted and discussed by Pier Luigi Luisi waste productY. Second, there is the mem- but necessary for the “survival of the living and his collaborators.[3] brane subsystem, which is capable of auto- world”.[4] He lists five absolute life criteria: catalytic growth, and third the information (1) A living organism is an inherent unity Chemoton Model subsystem, a reaction system that can pro- with new qualitative properties compared The chemoton model was developed duce macromolecules by template poly- to its parts; (2) Metabolism provides for by Tibor Gánti, a chemical engineer from condensation. Byproducts of this subsys- transformation of external material and Hungary. He first published this mod- tem are used to form the membrane. Gánti energy by the system; (3) Inherent stability el in his book ‘The principle of life’ in explains that this third subsystem thereby means that the organisation of a living sys- Hungarian in 1971; it was published in is able to control and couple the other two tem remains stable in spite of changes in English in 1987.[4] In this book, Gánti de- subsystems stoichiometrically and to syn- its environment; (4) An information-car- velops the idea that life can be studied at chronise growth.[5] He understands it as the rying subsystem contains the instructions different levels. He speaks of life criteria, abstraction of the genetic material. Modern for origin, function and development of the which fall into the research field of biolo- protocell scientists refer to this model as system; (5) Regulation and control of its gy, the principle of life concerning the laws an early schematic model and honour the processes is characteristic for living sys- behind these criteria that he describes in stoichiometric coupling of the function- tems. The first of the three potential life his chemical chemoton theory, and finally, al elements. However, they also identify criteria is (1) growth and reproduction, an approach to study life as a philosophical limitations of the model, for instance, that which are indispensable for the survival of category.[4] Gánti explicitly discusses and the chemoton model only considers the a species but cannot be found in each or- separates research on life along the three role of metabolism for growth but not for ganism.