Desktop-stereolithography 3D printing of a radially oriented extracellular matrix/mesenchymal stem cell exosome bioink for osteochondral defect regeneration

Abstract

Mitochondrial dysfunction and oxidative stress damage are hallmarks of osteoarthritis (OA). Mesenchymal stem cell (MSC)-derived exosomes are important in intercellular mitochondria communication. However, the use of MSC exosomes for regulating mitochondrial function in OA has not been reported. This study aimed to explore the therapeutic effect of MSC exosomes in a three dimensional (3D) printed scaffold for early OA therapeutics. Methods : We first examined the mitochondria-related proteins in normal and OA human cartilage samples and investigated whether MSC exosomes could enhance mitochondrial biogenesis in vitro . We subsequently designed a bio-scaffold for MSC exosomes delivery and fabricated a 3D printed cartilage extracellular matrix (ECM)/gelatin methacrylate (GelMA)/exosome scaffold with radially oriented channels using desktop-stereolithography technology. Finally, the osteochondral defect repair capacity of the 3D printed scaffold was assessed using a rabbit model. Results : The ECM/GelMA/exosome scaffold effectively restored chondrocyte mitochondrial dysfunction, enhanced chondrocyte migration, and polarized the synovial macrophage response toward an M2 phenotype. The 3D printed scaffold significantly facilitated the cartilage regeneration in the animal model. Conclusion : This study demonstrated that the 3D printed, radially oriented ECM/GelMA/exosome scaffold could be a promising strategy for early OA treatment.

Exosomes in osteoarthritis and cartilage injury: advanced development and potential therapeutic strategies

“…Improving the productivity and functions of exosomes [57]; Designing scaffolds with more optimized geometric structure; Bone defect repair [72]; Osteoangiogenesis [73]; Cartilage repair [74];…”

“…The other is to design advanced bio-mimic scaffolds with more optimized geometric structure and better incorporate with exosomes, thus enhancing the therapeutic effects of exosomes or EVs [72][73] . For instance, Chen et al reported the interaction between 3D printing scaffold and exosome in cartilage repair [74] . They fabricated a 3D printed cartilage ECM/gelatin methacrylate/exosome scaffold with radially oriented channels using desktop-stereolithography technology.…”

“…Nevertheless, the current therapy requests repeatedly local administration for maintaining the effective concentration, which increase pain and the risk of side effects to the subjects. To solve this problem, local controlled release of exosomes with bio-scaffold has begun to be valued [74] . Controlled delivery of therapeutic agents on local joint lesion possesses two advantages.…”

Engineered 3D Polymer and Hydrogel Microenvironments for Cell Culture Applications

“…Photo-patterned (including the use of TPP) GelMA scaffolds, have been produced down to~50 µm feature size. For SLA, chondrocytes were encapsulated within a GelMA bioink and 3D structures printed with~500 µm feature size [214,327]. The addition of PEGDA with GelMA greatly improved the SLA printing resolution to 300 µm.…”

“…By combining GelMA with different concentrations of methacrylated hyaluronic acid and chondroitin sulphate, encapsulation of chondrocytes, bioprinting the mixture, and in situ UV curing layer-by-layer, a glycosaminoglycan-graded hydrogel was fabricated with good cell viability resulting in its own chondrocyte matrix after 28 days [333]. Chondrocytes encapsulated in a GelMA bioink and 3D printed via SLA showed chondrocyte differentiation after 14 days [214,327]. Finally, a dynamic optical projection SLA system was used to print a vascular network with encapsulated living cells [334].…”