Mineral-Doped Poly(L-lactide) Acid Scaffolds Enriched with Exosomes Improve Osteogenic Commitment of Human Adipose-Derived Mesenchymal Stem Cells

Abstract

Exosomes derived from mesenchymal stem cells are extracellular vesicles released to facilitate cell communication and function. Recently, polylactic acid (PLA), calcium silicates (CaSi), and dicalcium phosphate dihydrate (DCPD) have been used to produce bioresorbable functional mineral-doped porous scaffolds-through thermally induced phase separation technique, as materials for bone regeneration. The aim of this study was to investigate the effect of mineral-doped PLA-based porous scaffolds enriched with exosome vesicles (EVs) on osteogenic commitment of human adipose mesenchymal stem cells (hAD-MSCs). Two different mineral-doped scaffolds were produced: PLA-10CaSi-10DCPD and PLA-5CaSi-5DCPD. Scaffolds surface micromorphology was investigated by ESEM-EDX before and after 28 days immersion in simulated body fluid (HBSS). Exosomes were deposited on the surface of the scaffolds and the effect of exosome-enriched scaffolds on osteogenic commitment of hAD-MSCs cultured in proximity of the scaffolds has been evaluated by real time PCR. In addition, the biocompatibility was evaluated by direct-contact seeding hAD-MSCs on scaffolds surface-using MTT viability test. In both formulations, ESEM showed pores similar in shape (circular and elliptic) and size (from 10–30 µm diameter). The porosity of the scaffolds decreased after 28 days immersion in simulated body fluid. Mineral-doped scaffolds showed a dynamic surface and created a suitable bone-forming microenvironment. The presence of the mineral fillers increased the osteogenic commitment of hAD-MSCs. Exosomes were easily entrapped on the surface of the scaffolds and their presence improved gene expression of major markers of osteogenesis such as collagen type I, osteopontin, osteonectin, osteocalcin. The experimental scaffolds enriched with exosomes, in particular PLA-10CaSi-10DCPD, increased the osteogenic commitment of MSCs. In conclusion, the enrichment of bioresorbable functional scaffolds with exosomes is confirmed as a potential strategy to improve bone regeneration procedures.

In Vitro Generation of Novel Functionalized Biomaterials for Use in Oral and Dental Regenerative Medicine Applications

“…Although a combined mechanism is likely, future works should determine the origin of these components. In addition, recent works reported the use of biomaterials enriched in human cell exosomes, and exosome-enriched natural and synthetic scaffolds demonstrated to provide internal and external modulation factors able to enhance regeneration of dental tissues [31]. These findings point out the possibility that exosomes released from the tissue explants could play a beneficial role on development, maturation, and differentiation of the fibrin-garose biomaterial used in our functionalized tissue model.…”

Vascular Wall–Mesenchymal Stem Cells Differentiation on 3D Biodegradable Highly Porous CaSi-DCPD Doped Poly (α-hydroxy) Acids Scaffolds for Bone Regeneration

“…Highly porous poly-lactic acid scaffolds doped with bioactive calcium silicates and calcium phosphates have been recently designed [28,29] and demonstrated the ability to be colonized by oral derived mesenchymal stem cells and to stimulate their shift through osteogenic lineage [27,36]. Calcium silicates/poly-e-caprolactone 3D printed scaffolds designed for dental pulp tissues revascularization purposes showed good dental pulp stem cell proliferation and osteogenic differentiation [37].…”

The Delivery of Extracellular Vesicles Loaded in Biomaterial Scaffolds for Bone Regeneration

“…This indicated that EHG could effectively retain exosomes inside the hydrogel, and over 1 × 10 10 mL –1 of exosomes per day were released, resulting in the acceleration of cartilage defect repair ( Liu X. et al, 2017b ). Another study by Gandolfi et al (2020) produced mineral-doped PLA-based scaffolds enriched with EVs to evaluate the osteogenic effects on hAD-MSCs. They showed a dynamic change after depositing exosomes on the surface of the scaffold; as the PLA matrix partially degraded, the formation of a calcium phosphate layer partially filled the pores and led to a decrease in porosity, which influenced the biological behavior of the hAD-MSCs.…”

“…Another study by Gandolfi et al (2020) produced mineral-doped PLA-based scaffolds enriched with EVs to evaluate the osteogenic effects on hAD-MSCs. They showed a dynamic change after depositing exosomes on the surface of the scaffold; as the PLA matrix partially degraded, the formation of a calcium phosphate layer partially filled the pores and led to a decrease in porosity, which influenced the biological behavior of the hAD-MSCs.…”