Nasal septal cartilage can be easily obtained by septoplasty and many trials have used it for cartilage tissue engineering. Fusing small aggregates to form larger pieces of cartilage with controlled shapes may be required for this technique to be viable for producing cartilage suitable for use in craniofacial reconstruction. Cartilage produced from aggregates has an uncontrolled shape and limited size. When aggregates or pellets are formed and cartilage tissues are produced, chondrocytes proliferate minimally, except under specific culture conditions. Aggregate culture can induce redifferentiation of chondrocytes that have expanded in monolayer culture. The merits of rotational culture include improved diffusion of nutrients and gas compared to static culture. In contrast, pellet culture utilizes high-speed centrifugation for a few minutes to produce cell pellets from cell-suspended media. Rotational culture uses slow rotation with a prolonged duration (60 rpm for several days to weeks). There are two types of aggregate culture. Rotational force is applied to cells in a suspension culture to produce cell aggregates. A previous study found that PLLA was superior to PLGA in cartilage tissue engineering. PLGA breaks down rapidly and releases substances that interfere with cartilage regeneration. PLLA also has been used in plates and screws for fracture fixation, and PLGA has been used in absorbable surgical sutures. PLLA, PGA, and PLA-PGA copolymer (PLGA) are widely used in cartilage tissue engineering because of their effectiveness as scaffolds and for chondrocyte delivery. Its hydrophobic nature also leads to insufficient cell attachment and poor tissue integration. PCL is highly hydrophobic and has a longer degradation time than PLLA. It has been used in absorbable plates and screws for fracture fixation in surgery. PCL has a relatively low melting point (55☌–60☌) and excellent blend-compatibility with different additives. The polyester polymers most widely used for scaffolds are PCL, poly-L-lactic acid (PLLA), and polyglycolic acid (PGA). However, synthetic polymers have relatively poor biological properties and cause foreign body reactions due to the release of bio-incompatible substances during degradation. Polyesters are synthetic polymers that can easily be produced according to specific needs. Thus, new strategies for craniofacial restoration need to be developed. Alloplastic materials have been developed to replace autologous cartilage grafts, but they frequently become exposed through the skin and cause infections. Tissues obtained from cadavers pose a risk of infection and immune response. However, the amount of donor bone, cartilage, skin, and soft tissue is restricted and their harvest can lead to significant morbidity. The standard treatment strategies are to replace the defects or damaged structures with autologous tissue. Craniofacial defects and anomalies have a serious impact on quality of life, and performing functional and aesthetically satisfactory reconstructions of facial structures are challenging. Moreover, congenital malformations such as microtia require large amounts of autologous tissue for reconstruction. However, craniofacial areas are frequently invaded by tumors and altered by trauma. The craniofacial structure is highly individualized and of paramount functional and aesthetic importance. Keywords: Cartilage / Tissue / Engineering / Chondrocyte / Stem cell Progress should be made in designing fully biocompatible scaffolds with a minimal immune response to regenerate tissue effectively. The limited proliferation of chondrocytes and their tendency to dedifferentiate necessitate further developments in stem cell technology and chondrocyte molecular biology. Despite the promising prospects of cartilage tissue engineering, problems and challenges still exist due to certain limitations. ![]() Generally, the cartilage tissue engineering process includes the following steps: harvesting autologous chondrogenic cells, cell expansion, redifferentiation, in vitro incubation with a scaffold, and transfer to patients. The basic concepts of tissue engineering consist of cells, scaffolds, and stimuli. This article introduces the basic concepts of cartilage tissue engineering and reviews recent progress in the field, with a focus on craniofacial reconstruction and facial aesthetics. Tissue engineering offers many advantages over conventional treatments, as therapy can be tailored to specific defects using abundant bioengineered resources. Severe cartilage defects and congenital anomalies affect millions of people and involve considerable medical expenses.
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