In vivo photothermal reconfiguration of liquid crystalline elastomer nanocomposites

Medical implants with fixed geometry have many clinical applications but are limited by the dynamic nature of human physiology. To overcome this barrier, focus has shifted to stimuli-responsive materials capable of changing their geometry on demand, such as liquid crystalline elastomers (LCEs). Here, we report on the development and biological performance of LCE-gold nanorod (LCE-AuNR) nanocomposites engineered for use in optically reconfigurable medical devices. First, we maximized the strain response and force output of 3D-printed LCE-AuNR within a physiologically relevant temperature window of 37°C-50°C. LCE-AuNR are shown to be cytocompatible and induce a comparable foreign body response to medical grade silicone when implanted subcutaneously in mice. Upon transcutaneous near-infrared irradiation, implanted LCE-AuNR exhibit rapid and reversible photothermal actuation. Furthermore, controlled photothermal actuation in vivo does not result in the pathology of adjacent tissues. This approach opens new horizons for designing dynamic medical implants across a wide range of clinical applications.