Bioinks and bioprinting strategies for skeletal muscle tissue engineering.

Skeletal muscles play important roles in critical body functions and their injury or diseases can lead to limitation of mobility and loss of independence. Current treatment modalities result in variable functional recovery, while reconstructive surgery, as the gold standard approach, is limited due to donor shortage, donor site morbidity and limited functional recovery. Skeletal muscle tissue engineering (SMTE) has generated enthusiasm as an alternative solution for treatment of diseased or lost tissue and serve as functional disease models. In recent years, bioprinting has emerged as a promising tool for recapitulating the complex and highly organized architecture of skeletal muscles at clinically relevant sizes. Here, we discuss skeletal muscle physiology, muscle regeneration following injury, current treatments following muscle loss, and then critically review bioprinting strategies implemented for SMTE. Subsequently, we discuss recent advancements that have led to improvement of bioprinting strategies to construct large muscle structures, boost myogenesis in vitro and in vivo, and enhance tissue integration. Bioinks for muscle bioprinting, as an essential part of any bioprinting strategy, are discussed and their benefits, limitations, and areas to be improved are highlighted. Finally, the directions that field should expand to make bioprinting strategies more translational and overcome the clinical unmet needs are discussed. This article is protected by copyright. All rights reserved.