[Reconstruction of nasal cartilage defects using a tissue engineering technique based on combination of high-density polyethylene and hydrogel].

[AIM OF THE STUDY] Nasal reconstruction remains a challenge for any surgeon. The surgical indications for nasal reconstruction after oncologic resection, trauma or as part of cosmetic rhinoplasty, are steadily increasing. The current attitude for reconstruction is the use of autologous cartilage grafts of various origins (septal, ear or rib) trying to restore a physiological anatomy but their quantity is limited. Thus, in order to produce an implantable cartilaginous model, we developed a study protocol involving human nasal chondrocytes, growth factors and a composite biomaterial and studied at the molecular, cellular and tissue level the phenotype of the chondrocytes cultured in this model.

[MATERIALS AND METHODS] After extraction of chondrocytes and their amplification on plastic, the cells were cultured for 15 days either in monolayer or within an agarose hydrogel or a composite biomaterial (agarose/high density polyethylene: Medpor(®)) in the presence or not of a cocktail of soluble factors (BIT): bone morphogenetic protein-2 (BMP-2), insulin and triiodothyronine (T3). The quality of the chondrocyte phenotype was analyzed by PCR, western blotting and immunohistochemistry.

[RESULTS] During their amplification in monolayer, chondrocytes dedifferentiate. However, our results show that the BIT cocktail induces redifferentiation of chondrocytes cultured in agarose/Medpor with synthesis of mature chondrogenic markers. Thereby, chondrocytes associated with the agarose hydrogel will colonize Medpor and synthesize an extracellular matrix characteristic of nasal cartilage.

[CONCLUSION] This nasal cartilage tissue engineering protocol provides the first interesting results for nasal reconstruction.