Ultrasensitive and robust mechanoluminescent living composites

Abstract

Mechanosensing, the transduction of extracellular mechanical stimuli into intracellular biochemical signals, is a fundamental property of living cells. However, endowing synthetic materials with mechanosensing capabilities comparable to biological levels is challenging. Here, we developed ultrasensitive and robust mechanoluminescent living composites using hydrogels embedded with dinoflagellates, unicellular microalgae with a near-instantaneous and ultrasensitive bioluminescent response to mechanical stress. Not only did embedded dinoflagellates retain their intrinsic mechanoluminescence, but with hydrophobic coatings, living composites had a lifetime of ~5 months under harsh conditions with minimal maintenance. We 3D-printed living composites into large-scale mechanoluminescent structures with high spatial resolution, and we also enhanced their mechanical properties with double-network hydrogels. We propose a counterpart mathematical model that captured experimental mechanoluminescent observations to predict mechanoluminescence based on deformation and applied stress. We also demonstrated the use of the mechanosensing composites for biomimetic soft actuators that emitted colored light upon magnetic actuation. These mechanosensing composites have substantial potential in biohybrid sensors and robotics.

Mechanoluminescent Light Sources Based on Nanostructured Systems for Biomedical Applications: A Review

“…To address these limitations, Cai et al recently designed a new type of dinoflagellates-based ML light source, ultrasensitive ML living composites achieved by embedding dinoflagellates into a biocompatible hydrogel matrix. 44 To fabricate the ML living composite, a homogeneous mixture was created by initially combining biocompatible alginate hydrogel with dinoflagellates (Figure 4d). After immersing the mixture in a CaCl 2 solution, Ca 2+ gradually diffused into the mixture, resulting in ionic cross-linking of alginate chains, which effectively trap dinoflagellates inside the hydrogel matrix.…”

“…A biohybrid strategy has emerged to fabricate soft robotics and devices with diverse functionalities. Recently, Cai et al designed a robust, highly stretchable, and ultrasensitive ML device through integrating bioluminescent dinoflagellates with soft elastomers via biohybrid strategy. , Such a biohybrid ML device exhibits bright ML emission in response to mechanical stress. The ML mechanism of the biohybrid device originates from bioluminescence-based mechanoluminescence.…”

“…In this process, the biohybrid ink containing cells was extruded directly onto a substrate to create the desired structures, followed by immersion in a CaCl 2 solution for the formation of Ca 2+ -alginate hydrogel through ionic cross-linking. Reproduced with permission from ref . Available under a CC-BY 4.0 license.…”

“…The previously reported ML device prepared through the biohybrid method has exhibited certain drawbacks, including potential issues of leakage, complexities in fabrication for intricate shapes, and a moderate operational lifespan. To address these limitations, Cai et al recently designed a new type of dinoflagellates-based ML light source, ultrasensitive ML living composites achieved by embedding dinoflagellates into a biocompatible hydrogel matrix . To fabricate the ML living composite, a homogeneous mixture was created by initially combining biocompatible alginate hydrogel with dinoflagellates (Figure d).…”

Bio-Hybrid Magnetic Robots: From Bioengineering to Targeted Therapy

“…Microalgae are a group of photosynthetic organisms that are mainly present in aquatic environments, and contain various photosynthetic pigments, such as chlorophyll, which allows them to harness sunlight and convert it into chemical energy through photosynthesis [73,74]. Green algae-based bio-hybrid robots have numerous advantages over synthetic robots, including simple production processes, sustained propulsion without external actuation, and easy cargo conjugation [75].…”