Texturing Hierarchical Tissues by Gradient Assembling of Microengineered Platelet-Lysates Activated Fibers

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Hierarchical tissues necessitate complex, multi-part engineered constructs for effective replacement.
• Tendon-to-bone interfaces present a significant challenge in regenerative medicine due to their distinct microstructures.

Purpose of the Study:

• To fabricate functionally graded 3D scaffolds incorporating platelet lysate (PL) for heterotypic tissue regeneration, specifically targeting tendon-to-bone interfaces.
• To investigate the potential of PL-functionalized scaffolds in guiding stem cell differentiation towards tenogenic and osteogenic lineages.

Main Methods:

• Fabrication of anisotropic yarns (A-Yarns) and isotropic threads with nanohydroxyapatite (I-Threads/PL@nHAp) via emulsion electrospinning, incorporating PL for sustained growth factor delivery.
• Weaving technique to assemble yarns and threads into 3D gradient scaffolds with controlled composition and topography.
• In vitro evaluation using human adipose-derived stem cells to assess tenogenic and osteogenic differentiation markers.

Main Results:

• A-Yarns/PL significantly upregulated scleraxis (tenogenic marker) expression in stem cells.
• I-Threads/PL@nHAp demonstrated higher alkaline phosphatase activity and matrix mineralization, indicating osteogenic commitment without biochemical supplementation.
• Fabricated 3D gradient scaffolds guided stem cell differentiation into chondrogenic and osteochondrogenic phenotypes at the interface.

Conclusions:

• PL-functionalized 3D gradient scaffolds offer a promising solution for regenerating the tendon-to-bone interface.
• The developed scaffolds provide precise delivery of bioactive cues and in situ biophysical cues to guide tissue formation.
• This approach demonstrates a viable strategy for creating hierarchical tissue constructs for complex regenerative applications.