POLYVINYL ALCOHOL/GELATIN SPONGES FOR AURICULAR CARTILAGE ENGINEERING

Reconstructing auricle resulting from trauma, neoplasm, or congenital defects is one of the most challenging and diverse tasks in aesthetic and reconstructive surgery due to the highly complex three‐dimensional anatomy of the outer ear [1]. We aimed at providing alternatives to overcome the shortcomings of the standard surgical reconstructive procedures using tissue engineering. Emulsion and freeze‐drying were used to produce poly(vinyl alcohol)/gelatin (PVA/G) sponges at different weight ratios (100/0 ‐ 50/50 w/w%), which were cross‐linked by exposure to glutaraldehyde vapors. PVA/G sponges with highly round‐shaped interconnected pores, highly swelling capacity (> 200%), and an essentially elastic mechanical behaviour were obtained. Different culture conditions were applied to obtain elastic cartilage: , undifferentiated versus chondrogenic pre‐differentiated bone marrow derived human mesenchymal stromal cells (hMSCs), commercial versus hand‐made chondrogenic differentiation medium and static versus dynamic culture [i.e. ultrasound (US) or bioreactor stimulation] were used. After three weeks, the constructs were analyzed via immunohistochemistry (IHC). Intense glycosaminoglycan, glycoprotein and collagen syntheses by hMSCs were most frequently observed using the commercial medium, while round morphology was observed when pre‐differentiated hMSCs were seeded. The application of US stimulation during the culture on cell/scaffold constructs enhanced extracellular matrix deposition and led to 30% higher collagen type II expression at gene level. However, at protein level, collagen type II, aggrecan and elastin formation were observed via IHC only by using bioreactor culture. Results showed that 70/30 (w/w%) PVA/G sponge is a suitable scaffold for auricle reconstruction.