Biomimetic engineered muscle with capacity for vascular integration and functional maturation in vivo

Abstract

Tissue-engineered skeletal muscle can serve as a physiological model of natural muscle and a potential therapeutic vehicle for rapid repair of severe muscle loss and injury. Here, we describe a platform for engineering and testing highly functional biomimetic muscle tissues with a resident satellite cell niche and capacity for robust myogenesis and self-regeneration in vitro. Using a mouse dorsal window implantation model and transduction with fluorescent intracellular calcium indicator, GCaMP3, we nondestructively monitored, in real time, vascular integration and the functional state of engineered muscle in vivo. During a 2-wk period, implanted engineered muscle exhibited a steady ingrowth of blood-perfused microvasculature along with an increase in amplitude of calcium transients and force of contraction. We also demonstrated superior structural organization, vascularization, and contractile function of fully differentiated vs. undifferentiated engineered muscle implants. The described in vitro and in vivo models of biomimetic engineered muscle represent enabling technology for novel studies of skeletal muscle function and regeneration.tissue engineering | contractile force | self-repair | angiogenesis | window chamber

Endothelial Network Formation Within Human Tissue-Engineered Skeletal Muscle

“…15 To our knowledge, however, prevascularization of human aligned myofibers has not been described. In this work, we aimed to determine suitable culture conditions allowing both aligned myofiber formation and endothelial network formation as a first step toward a human vascularized BAM.…”

“…These findings open perspectives toward culture of larger prevascularized BAMs with potential for human muscle transplantations as well as a physiologically relevant in vitro model for studying diseases and therapies. 5,42,43 Host blood vessels are able to invade avascular muscle bundles 15 ; however, this still limits the size of muscle bundles that can be kept in culture preimplantation. Ideally, anastomosis of the preimplantation network with host vessels occurs.…”

3D culture models of tissues under tension

“…In particular, progress has been made in developing a model for skeletal muscle (Juhas et al, 2014;Sakar et al, 2012;Uzel et al, 2014), which could be useful for understanding and modeling dystrophic muscle diseases. Constrained microtissues also have been applied to model airway smooth muscle (West et al, 2013), aortic valve tissue (Kural and Billiar, 2016) and lung (Chen et al, 2016b).…”

Cell Density and Joint microRNA-133a and microRNA-696 Inhibition Enhance Differentiation and Contractile Function of Engineered Human Skeletal Muscle Tissues

“…16,17 Velcro was used as anchor points at either end of the mold. A hydrogel mixture (45 mL per myobundle) of 20% Matrigel (BD Biosciences), 4 mg/mL fibrinogen (Sigma), 50 U/mL thrombin (Sigma), and passage 5-7 HSkM (5, 10 or 15 · 10 6 cells/mL) gelled at 37°C and 5% CO 2 for 1 h before addition of GM.…”

“…16,17 Force output was recorded for electrical stimuli at 1, 5, 10, 20, and 40 Hz at 5.9 V/cm in 5% increments of length from 100% to 120% of initial construct length (8 mm). Force traces were recorded using LabVIEW and exported to Microsoft Excel files.…”