Spatiotemporally Resolved Heat Dissipation in 3D Patterned Magnetically Responsive Hydrogels

Multifunctional nanocomposites that exhibit well-defined physical properties and encode spatiotemporally controlled responses are emerging as components for advanced responsive systems, for example, in soft robotics or drug delivery. Here an example of such a system, based on simple magnetic hydrogels composed of iron oxide magnetic nanoflowers and Pluronic F127 that generates heat upon alternating magnetic field irradiation is described. Rules for heat-induction in bulk hydrogels and the heat-dependence on particle concentration, gel volume, and gel exposed surface area are established, and the dependence on external environmental conditions in closed as compared to open (cell culture) system, with controllable heat jumps, of increment T 0-12 degrees C, achieved within <= 10 min and maintained described. Furthermore the use of extrusion-based 3D printing for manipulating the spatial distribution of heat in well-defined printed features with spatial resolution <150 mu m, sufficiently fine to be of relevance to tissue engineering, is presented. Finally, localized heat induction in printed magnetic hydrogels is demonstrated through spatiotemporally-controlled release of molecules (in this case the dye methylene blue). The study establishes hitherto unobserved control over combined spatial and temporal induction of heat, the applications of which in developing responsive scaffold remodeling and cargo release for applications in regenerative medicine are discussed.

Automated summary

This study demonstrates the use of multifunctional nanocomposites based on magnetic hydrogels for heat generation under alternating magnetic field irradiation, as well as the manipulation of spatial heat distribution through 3D printing. The research discusses the dependence of heat induction on various factors, such as particle concentration, gel volume, exposed surface area, and environmental conditions, and explores the potential applications in responsive scaffold remodeling and cargo release for regenerative medicine.