Assessing Bioprinted Functionalized Grafts for Biological Tendon Augmentation In Vitro

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Tendinopathy poses significant challenges in sports medicine due to limitations in conservative treatments.
• Bioprinting offers a promising approach for developing functional tendon grafts.

Purpose of the Study:

• To investigate the paracrine signaling of bioprinted tendon grafts infused with platelet-rich plasma (PRP) in inflamed and non-inflamed environments.
• To understand the role of PRP in graft-mediated interactions within host tissues.

Main Methods:

• Extrusion bioprinting of tendon cells within PRP-infused methacrylate gelatin (GelMA) hydrogels.
• Bioinformatic analysis of overexpressed proteins to predict functional enrichment.
• Assessment of graft behavior in both inflamed and non-inflamed host tissues.

Main Results:

• PRP grafts activated inflammatory pathways (e.g., IL-17, IL-33) and signaling cascades (MAPK, NF-kB, VEGF).
• Enriched biological functions included cell chemotaxis, collagen turnover, cell migration, and angiogenesis.
• Acellular PRP grafts promoted increased vessel length, area, and density compared to nude grafts.

Conclusions:

• Paracrine signaling from PRP grafts, particularly chemokine activity, modulates cell migration, inflammation, and angiogenesis.
• Newly synthesized IL-8, in conjunction with IL-1b, regulates vascularization in cellular grafts under inflammatory conditions.