Diseased Tendon Models Demonstrate Influence of Extracellular Matrix Alterations on Extracellular Vesicle Profile

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Tendons possess a highly aligned extracellular matrix (ECM), primarily collagen I, crucial for movement.
• Tendinopathies involve collagen fragmentation, disorganization, increased glycosaminoglycans, and microvasculature, impairing function.
• Extracellular vesicles (EVs) are implicated in cellular communication within the tendon microenvironment, potentially influencing tendon fate.

Purpose of the Study:

• To investigate how tendon microenvironment mechanics affect extracellular vesicle (EV) functionality.
• To elucidate the role of EVs in maintaining tendon homeostasis versus disease progression.

Main Methods:

• Utilized polycaprolactone (PCL) electrospun scaffolds to mimic healthy and pathological tendon matrices.
• Characterized scaffolds for fiber alignment, mechanical properties, and cellular activity.
• Isolated and analyzed EVs for concentration, heterogeneity, and protein content.

Main Results:

• Mimicked healthy tendon scaffolds showed increased EV secretion and baseline metabolic activity.
• Mimicked diseased tendon scaffolds exhibited reduced EV secretion but a significant increase in metabolic activity over 5 days.
• Scaffold mechanics appear to influence EV secretion and metabolic activity.

Conclusions:

• Tendon microenvironment mechanics, replicated by PCL scaffolds, significantly impact EV functionality.
• Findings suggest a link between scaffold mechanics, EV behavior, and tendon homeostasis.
• Further research is needed to explore the specific cargo of EVs and their effects on the tendon microenvironment.