Muscle stem cell intramuscular delivery within hyaluronan methylcellulose improves engraftment efficiency and dispersion

Abstract

Adult skeletal muscle tissue harbors the capacity for self-repair due to the presence of tissue resident muscle stem cells (MuSCs). Advances in the area of prospective MuSC isolation demonstrated the potential of cell transplantation therapy as a regenerative medicine strategy to restore strength and long-term regenerative capacity to aged, injured, or diseased skeletal muscle tissue. However, cell loss during ejection, limits to post-injection proliferation, and poor donor cell dispersion distal to the injection site are amongst hurdles to overcome to maximize MuSC transplant impact. Here, we assess a physical blend of hyaluronan and methylcellulose (HAMC) as a bioactive, shear thinning hydrogel cell delivery system to improve MuSC transplantation efficiency. Using in vivo transplantation studies, we found that the HAMC delivery system results in a >45% increase in the number of donor-derived fibers as compared to saline delivery. Furthermore, we observed a significant improvement in donor fiber dispersion when transplanted MuSCs were delivered in the HAMC hydrogel. Studies to assess primary myoblast and MuSC viability in HAMC culture revealed no differences compared to the media control even when the cells were first ejected through a syringe and needle or exposed to regenerating skeletal muscle extract to mimic the transplantation procedure. However, when we quantified absolute numbers, we found that more cells pass through the syringe and needle when delivered in HAMC. Culture in HAMC also increased the proportion of MuSCs in cell cycle, via a CD44-independent mechanism. An effect on myoblast proliferation was not observed, suggesting a hierarchical effect. Finally, a series of transplant studies indicated that HAMC delivery does not influence passive cell clearance or alter the host immune response, but instead may serve to support in vivo expansion by delaying differentiation following transplant. Therefore, we conclude that MuSC engraftment efficacy is improved by delivering the therapeutic cell population within HAMC.

Cell therapy to improve regeneration of skeletal muscle injuries

“…169,170 Davoudi et al reported that using an injectable hyaluronan-based and methyl cellulose-based hydrogel for intramuscular delivery significantly improved proliferation of MDSCs, retained their presence at the site of injury, and showed a significant benefit over injection-based administration. 171 In another study, Sleep and colleagues utilized a nanofiber-containing self-assembled hydrogel to guide the alignment and engraftment of SCs into injured tissue. 172 External stimulation of cell function especially holds true for MSCs, which respond to a variety of biophysical cues.…”

Three-dimensional niche stiffness synergizes with Wnt7a to modulate the extent of satellite cell symmetric self-renewal divisions

“…Primary myoblast cell lines were generated from Tg(CAG-EGFP) hindlimb muscles and the cultures were maintained as described before ( Davoudi et al. , 2018 ).…”

Towards stem cell therapies for skeletal muscle repair

“…Progress towards tackling this obstacle has been made with the generation of injectable, encapsulating, 3D biomaterials that mirror the structural architecture of muscle and can be loaded with a cocktail of growth factors to enhance transplantation efficiency of MuSCs. Examples have included synthetic macromers 30 , bioactive hydrogels [31][32][33][34] and other biomimetic scaffolds 35 (reviewed by Wolf et al 36 ) An impressive illustration of this approach was by Han et al 30 who through a series of iterative design optimization steps, recently engineered a fully synthetic, degradable, poly(ethylene glycol) (PEG)-4MAL hydrogel functionalized with integrin-binding Arg-Gly-Asp (RGD) peptides. When co-injected with MuSCs, this biomaterial resulted in boosted MuSC proliferation, survival and in vivo engraftment into dystrophic and aged mouse skeletal muscle.…”