Sustained Released of Bioactive Mesenchymal Stromal Cell-Derived Extracellular Vesicles from 3D-Printed Gelatin Methacrylate Hydrogels

Abstract

Extracellular vesicles (EVs) represent an emerging class of therapeutics with significant potential and broad applicability. However, a general limitation is their rapid clearance after administration. Thus, methods to enable sustained EV release are of great potential value. Here, we demonstrate that EVs from mesenchymal stem/stromal cells (MSCs) can be incorporated into 3D-printed gelatin methacrylate (GelMA) hydrogel bioink, and that the initial burst release of EVs can be reduced by increasing the concentration of crosslinker during gelation. Further, the data show that MSC EV bioactivity in an endothelial gap closure assay is retained after the 3D printing and photocrosslinking processes. Our group previously showed that MSC EV bioactivity in this assay correlates with pro-angiogenic bioactivity in vivo, thus these results indicate therapeutic potential of MSC EV-laden GelMA bioinks.

Extracellular vesicle-loaded hydrogels for tissue repair and regeneration

“…In contrast, gelatin is more biocompatible and has better thermal stability than collagen. In addition, several methods to enhance properties of gelatin, such as hybridization with other polymers, crosslinking strategies, and chemical modifications, are currently being assessed [ [96] , [97] , [98] ]; these are likely to broaden the scope of gelatin hydrogel applications. In 2000, Bulcke et al.…”

“…In particular, Born et al. [ 97 ] evaluated the feasibility of GelMA hydrogels loaded with MSC-EVs for 3D bioprinting. The results showed that experiencing 3D bioprinting and light curing did not affect the activity of EVs, and indicated that 7% GelMA may be a more appropriate bioink concentration.…”

“…In both cases, the release was essentially complete by 14 days. [ 97 ] HA-tyramine (HA-Tyr) human cardiomyocyte 50 ​nm 5 days 3% HA-Tyr: retained almost half of EVs in the first 2 days, while the cumulative release was found until nearly 5 days. [ 86 ] Self-assembling peptides (SAPs) BMSC 120.1 ​± ​55.4 ​nm 168 ​h The release rate of EVs was dose-dependently accelerated in the presence of MMP2 compared to the blank group.…”

Optimization of methacrylated gelatin /layered double hydroxides nanocomposite cell‐laden hydrogel bioinks with high printability for 3D extrusion bioprinting

“…Among various hydrogel bioprinting materials, GelMA biopolymer has become most widely used material owing to its unique features such as outstanding biocompatibility and tunable characteristics and mechanical properties to better mimic native ECM 20,21 . Currently, Born and coworkers developed GelMA bioink for the release of extracellular vesicles and reduced initial burst release by increasing the concentration of cross linker during gelation 22 . Nevertheless, hydrogel based bioinks generally cannot meet all needs for direct bioprinting with high fidelity of constructs because of their limited printability, 6,23 insufficient rheological properties, slow gelation, 24 and inadequate mechanical strength 25,26 .…”

“…20,21 Currently, Born and coworkers developed GelMA bioink for the release of extracellular vesicles and reduced initial burst release by increasing the concentration of cross linker during gelation. 22 Nevertheless, hydrogel based bioinks generally cannot meet all needs for direct bioprinting with high fidelity of constructs because of their limited printability, 6,23 insufficient rheological properties, slow gelation, 24 and inadequate mechanical strength. 25,26 In particular, it is demonstrated that GelMA bioinks could be printed at higher concentrations, but high concentrations exhibit a challenge for the survival of encapsulating cells.…”