This preprint presents a conceptual and theoretical examination of metabolic water and entropy dissipation in living systems, with a particular focus on the extracellular matrix (ECM) as a hydrated gel structure. While cellular respiration is well understood biochemically, the physical fate of metabolic water and its role in non-equilibrium maintenance remain insufficiently discussed. By integrating classical physiological descriptions of interstitial water with perspectives from polymer physics and thermodynamics, this work describes the ECM as a mesoscopic configuration in which metabolic water, heat, and entropy are temporarily embedded and redistributed. Rather than treating entropy dissipation as a localized or purely circulatory process, the paper emphasizes the interstitial matrix as a structural prerequisite for the coexistence of metabolically active cells and microcirculatory transport. The manuscript does not propose new experimental data or therapeutic claims. Instead, it reorganizes established biological knowledge into a coherent physical framework, describing life not by its molecular components but by a non-equilibrium configuration that preserves connectivity between past structure and future updateability. This preprint is intended for researchers and readers interested in biophysics, theoretical biology, and non-equilibrium thermodynamics, and serves as a conceptual foundation for further interdisciplinary discussion.
Fukushi et al. (Wed,) studied this question.