Efficient engineering of human auricular cartilage through mesenchymal stem cell chaperoning

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Tissue Engineering

Background:

• Clinical translation of ear reconstruction using tissue-engineered scaffolds is hindered by limited human auricular chondrocyte (hAuC) yield.
• Expansion of limited hAuCs leads to dedifferentiation and phenotype loss, complicating cartilage engineering.

Purpose of the Study:

• To develop a method for engineering shaped human elastic cartilage using a reduced number of hAuCs.
• To investigate the efficacy of co-culturing hAuCs with human mesenchymal stem cells (hMSCs) for elastic cartilage formation.

Main Methods:

• hAuCs and hMSCs were co-encapsulated in Type I collagen at various ratios (10/90 to 50/50) within 3D-printed polylactic acid (PLA) scaffolds.
• Scaffolds were implanted subcutaneously in nude rats for 1, 3, and 6 months.
• Constructs were analyzed for volume preservation, topographic maintenance, histological characteristics, and mechanical properties.

Main Results:

• All co-culture ratios maintained scaffold volume and topography after 6 months.
• Mature elastic cartilage with chondrocytes in lacunae, Type II collagen, proteoglycans, and a neoperichondrium formed by 3 months.
• Achieved compressive mechanical properties comparable to native human elastic cartilage after 6 months.

Conclusions:

• Co-implantation of hAuCs and hMSCs in collagen within external scaffolds efficiently produces shaped human elastic cartilage.
• This approach enables successful elastic cartilage engineering even with a low percentage (10%) of hAuCs.
• This represents a significant advancement towards the clinical application of auricular tissue engineering.