Search

Complete skeletal muscle regeneration after traumatic injuries remains a challenge due to impaired regenerative capability and dysregulated microenvironments. Autophagy plays a crucial role in the muscle regeneration process by regulating myogenic and non-myogenic cells. Herein, we report a bioactive MXene hydrogel (FPGM) capable of upregulating autophagy and increasing muscle innervation to restore skeletal muscle structure and function. FPGM possessed excellent electrical conductivity, tissue adhesive ability and antioxidation, which could eliminate excess reactive oxygen species to reduce oxidative stress and decrease the secretion of pro-inflammatory cytokine. FPGM upregulated the autophagy level of myoblasts and promoted the migration and tube formation of endothelial cells as well as myogenic differentiation with negligible toxicity. FPGM accelerated muscle fiber formation and skeletal muscle regeneration by improving autophagy, which could regulate microenvironment through raising M2 macrophages to alleviate excessive inflammation, facilitating angiogenesis and decreasing fibrous scar tissue formation in vivo. Importantly, FPGM could efficiently restore muscle function by improving muscle innervation, tibialis anterior compound muscle action potential amplitude and neuromuscular conduction. This work demonstrates that bioactive MXene hydrogel should be a promising candidate for complete skeletal muscle regeneration.

In many collaborative tasks, the need for joint attention arises when one of the users wants to guide others to a specific location or target in space. If the collaborators are co-located and the target position is in close range, it is almost instinctual for users to refer to the target location by pointing with their bare hands. While such pointing gestures can be efficient and effective in real life, performance will be impacted if the target is in augmented reality (AR), where depth cues like occlusion may be missing if the pointer’s hand is not tracked and modeled in 3D. In this paper, we present a study utilizing head-worn AR displays to examine the effects of incorrect occlusion cues on spatial target identification in a collaborative barehanded referencing task. We found that participants’ performance in AR was reduced compared to a real-world condition, but also that they developed new strategies to cope with the limitations of AR. Our work also identified mixed results of the effect of spatial relationships between users.