BACKGROUND: Laryngeal cartilage defect has a higher incidence, mainly presenting with pain, swelling, and dysfunction after onset. Currently, surgical treatment is the most used in clinical treatment of laryngeal cartilage defect. Although conventional materials can effectively improve symptoms, there is a poor long-term efficacy. In recent years, there are many clinical studies on cartilage tissue engineering, but less about the actual use in the otorhinolaryngology department.
OBJECTIVE: To investigate the effect of polyhydroxyalkanoate polymer carrying chondrocytes on the repair of allogeneic laryngeal cartilage defects.
METHODS: Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHH) served as the extracellular matrix. Tissue engineering technology was used to prepare cell-material composite. Primary tissue-engineered cartilage tissue was transplanted directly into rabbit thyroid cartilage defect (experimental group A), or implanted into a more mature tissue-engineered cartilage for the repair of thyroid cartilage defect (experimental group B). In the experiment, PHBHH group and simple chondrocyte group were set as controls. Repairing effects on thyroid cartilage defect were evaluated through gross and histological observation.
RESULTS AND CONCLUSION: Chondrocytes in the primary tissue-engineered cartilage tissues were beaded under scanning electron microscope, and after 4 weeks of culture, a large amount of jelly-shaped substrates were visible. Findings from electron microscope observation showed that the cells were distributed on the surface of composite material and cavernous voids, displaying a plurality of small round projections. Surgical treatment was successful in all the rabbits, and there was no dyspnea and eating difficulties after surgery. One rabbit appeared to have brief wheezing in the experimental group A, two rabbits died of diarrhea in the experimental B group at 2 weeks after surgery. PHBHH composite carrying chondrocytes had certain hardness. At 4 weeks after subcutaneous implantation, mature cells were shaped as white sheets, and the material had elasticity. After 4 and 8 weeks, the space between repair zone and original cartilage tissue was smooth and plain, but the repair zone was colored yellow. In the simple PHBHH and chondrocyte groups, the repair zones were both depressed, only the connective tissues could be seen. Rabbits in the two experimental groups showed less adverse reactions compared with the two control groups (P < 0.05). These findings indicate that PHBHH composite carrying chondrocytes has better effects to repair allogeneic laryngeal cartilage defects.