Oxygenation and Temperature Conditioning Alter the Vascular Morphology of Microvascular Constructs.

Revascularization remains a challenge for regenerative medicine strategies. Extensive research has been done to identify key moments of the dynamic wound healing cascade where targeted therapies can elicit a proregenerative response. However, the influence of oxygenation, temperature, and their temporal variation during healing are often challenging to promote tissue regeneration. This study investigated the effects of temporally varied oxygenation and temperature conditions on angiogenesis using an in vitro model of rat-derived, intact microvascular fragments in a collagen type-I hydrogel. By generating culture conditions that are similar to the accepted wound healing time course, the angiogenic response depended critically on both the timing of stimulus initiation and the magnitude of deviation from model conditions. Dynamic stimuli activated distinct biological pathways, as evidenced by qPCR analysis, revealing mechanistic links between environmental perturbations and the angiogenic response. This work emphasizes the need for regenerative medicine strategies to consider varying environmental stimuli to improve revascularization outcomes. Impact Statement This work demonstrated the impact of time-varying oxygenation and temperature conditions on self-assembling three-dimensional microvascular networks in vitro that mimic the physiological time course of wound healing. These findings suggest an important temporal relationship in angiogenesis where unresolved oxygen and temperature environments inhibit vascular network formation, cellular viability, proliferation, and environment-specific transcriptional factors.