A qualitative study of what motivates and enables climate-engaged physicians in Canada to engage in health-care sustainability, advocacy, and action.

Increasing numbers of health-care professionals are aware of the need to deliver low-carbon sustainable health systems. We aimed to explore how physicians can be motivated and supported to pursue this ambition by conducting an exploratory qualitative descriptive study that involved individual in-depth interviews with climate-engaged Canadian physicians participating in health-care sustainability advocacy and action. Interview transcripts were analysed to identify themes related to the actions that physicians can take to promote sustainable health care, and the motivators and enablers of physician engagement in sustainable health care. Participants (n=19) engaged in a spectrum of health-care sustainability initiatives ranging from reducing health-care waste to lobbying and political action. They were motivated to advance health-care sustainability by their concern about the health implications of climate change, frustration with health-care waste, and recognition of their locus of influence as physicians. Participants articulated that policy and system, organisational and team, and knowledge generation and translation supports are required to strengthen their capacity to advance health-care sustainability. These findings can provide inspiration for engagement opportunities in health-care sustainability, guide service delivery and educational innovations to promote health-care professionals' interest in becoming sustainability champions, and extend the capacity of health-care professionals to reduce the climate impact of health care.

Synthesis of an Enzyme-Mediated Reversible Cross-linked Hydrogel for Cell Culture.

Detachment of fragile cell types cultured on two-dimensional (2D) surfaces has been shown to be detrimental to their viability. For example, detachment of induced pluripotent stem cell (iPSC)-derived neurons grown in vitro in 2D typically results in loss of neuronal connections and/or cell death. Avoiding cell detachment altogether by changing the properties of the substrate on which the cells are grown is a compelling strategy to maintain cell viability. Here, we present the synthesis of a reversible cross-linked hydrogel that is sufficiently stable for cell culture and differentiation and is cleaved by an external stimulus, facilitating injection. Specifically, hyaluronan (HA) and methylcellulose (MC) were modified with ketone and aldehyde groups, respectively, and a TEV protease-degradable peptide was synthesized via solid-state synthesis and modified at both termini with oxyamine groups to cross-link HA-ketone and MC-aldehyde to produce oxime-cross-linked HA × MC. The HA × MC hydrogel demonstrated good stability, enzyme-sensitive degradation, and cytocompatibility with iPSC-derived neural progenitor cells, laying the framework for broad applicability.

Photocontrol of ion permeation in lipid vesicles with (bola)amphiphilic spirooxazines.

Three (bola)amphiphilic spirooxazines have been synthesized and their photochromism has been characterized. The large biphotochromic structure of 2 significantly affects its conformational flexibility and the rate constants for thermal ring closure are particularly dependent on the lipid phase state. Two comprehensive ion permeation studies were performed to examine the effect of spirooxazine inclusion and isomerization on membrane permeability. In all cases, the open-ring isomers of these spirooxazines are more disruptive in bilayer membranes than their closed-ring isomers. Further, the rate of ion permeation and net release are highly dependent on the lipid bilayer phase state and the relative position of the photochromic moiety in the bilayer membrane. Moreover, the difference in potassium ion permeability under UV and visible irradiation is more pronounced than previously reported photoresponsive membrane disruptors with reversible photocontrols.