The synthesis of novel thermo-responsive ABA triblock copolymers in which the outer A blocks comprise poly(2-hydroxypropyl methacrylate) and the central B block is poly(2-(methacryloyloxy)ethyl phosphorylcholine) is achieved using atom transfer radical polymerization. These novel triblock copolymers form thermo-reversible, free-standing physical gels with critical gelation temperatures and mechanical properties that are highly dependent on the copolymer composition and concentration. TEM studies on dried dilute copolymer solutions indicate the presence of colloidal aggregates, which is consistent with micellar gel structures. This hypothesis is consistent with the observation that incorporating a central disulfide bond within the B block leads to thermo-responsive gels that can be efficiently degraded using mild reductants such as dithiothreitol (DTT) over time scales of minutes at 37 °C. Moreover, the rate of gel dissolution increases at higher DTT/disulfide molar ratios. Finally, the resulting gels have been shown to be highly biocompatible towards cell monolayers: only a modest reduction in cell proliferation was observed with little, if any, evidence for cytotoxicity. These gels had practically no deleterious effects when used in combination with 3D reconstructed skin models and may have potential applications as wound dressings.