An additive manufacturing-based PCL-alginate-chondrocyte bioprinted scaffold for cartilage tissue engineering

TLDR

Regenerative medicine seeks to restore damaged tissues using cells, materials, and growth factors, while tissue engineering and developmental biology focus on tissue self‑assembly and extracellular matrix deposition. The study presents an innovative cell‑printed scaffold for cartilage regeneration fabricated by advanced bioprinting technology. Additive manufacturing with a multi‑head deposition system was used to layer‑by‑layer print PCL and chondrocyte‑encapsulated alginate hydrogel scaffolds, optimizing cell dispensing and alginate concentration for viability, assessing ECM components in vitro, and implanting the constructs subcutaneously in nude mice. PCL–alginate gels supplemented with TGFβ produced higher extracellular matrix, and after four weeks in vivo the hybrid scaffold exhibited enhanced cartilage tissue and type II collagen fibril formation. © 2013 John Wiley & Sons, Ltd.

Abstract

Regenerative medicine is targeted to improve, restore or replace damaged tissues or organs using a combination of cells, materials and growth factors. Both tissue engineering and developmental biology currently deal with the process of tissue self-assembly and extracellular matrix (ECM) deposition. In this investigation, additive manufacturing (AM) with a multihead deposition system (MHDS) was used to fabricate three-dimensional (3D) cell-printed scaffolds using layer-by-layer (LBL) deposition of polycaprolactone (PCL) and chondrocyte cell-encapsulated alginate hydrogel. Appropriate cell dispensing conditions and optimum alginate concentrations for maintaining cell viability were determined. In vitro cell-based biochemical assays were performed to determine glycosaminoglycans (GAGs), DNA and total collagen contents from different PCL–alginate gel constructs. PCL–alginate gels containing transforming growth factor-β (TGFβ) showed higher ECM formation. The 3D cell-printed scaffolds of PCL–alginate gel were implanted in the dorsal subcutaneous spaces of female nude mice. Histochemical [Alcian blue and haematoxylin and eosin (H&E) staining] and immunohistochemical (type II collagen) analyses of the retrieved implants after 4 weeks revealed enhanced cartilage tissue and type II collagen fibril formation in the PCL–alginate gel (+TGFβ) hybrid scaffold. In conclusion, we present an innovative cell-printed scaffold for cartilage regeneration fabricated by an advanced bioprinting technology. Copyright © 2013 John Wiley & Sons, Ltd.