Tsugumi Fukushi
The interstitial matrix of multicellular organisms - a polyanionic hydrogel embedded within connective tissue - undergoes volume phase transitions (VPT) between a swollen phase and a collapsed phase, as described by Tanaka (1978) for synthetic gels and extended to biological systems by Verdugo and others. We propose that this phase transition constitutes the mesoscale physical mechanism by which thermodynamic closure occurs in living tissue: the collapsed gel physically isolates embedded cells from the thermal, osmotic, and ionic gradients that drive entropy export, thereby attenuating the dissipative structures and the self-generated temporal order - internal time, in Prigogine's framework - that define the living state. On this account, chronic disease is not primarily a catalogue of molecular lesions but a thermodynamic state: one in which interstitial gel collapse has reduced cellular entropy-export capacity below the threshold required to sustain dissipative structures and internal time. The characteristic clinical features of chronic disease - persistent pain, functional limitation, treatment resistance, progressive deterioration - are the expected signatures of a system whose internal time is attenuating. This framework generates testable predictions concerning the relaxation time spectrum of interstitial gels, entropy-production markers in cells embedded in collapsed versus swollen matrix, and the nonlinear vibrational dynamics observable during effective physical intervention. We acknowledge that mathematical unification of Prigogine's statistical-mechanical formalism with the soft-matter physics of gel phase transition remains to be achieved; the correspondence we identify is structural. Nevertheless, the framework reframes the goal of therapeutic intervention: to restore thermodynamic openness - returning the gel to the swollen phase and thereby restarting the conditions for the living system's temporal self-organization.