Experiment And Research On Porous Artificial Scaffolds For Repair Of Thyroid Cartilage Injury

The larynx possesses exquisite and complex structure as an important organ for the human body,include arytenoid cartilage,thyroid cartilage,ring cartilage,epiglottis cartilage,hyoid bone.Lesions and congenital malformations of laryngeal cartilage defects are common injuries for ear-nose-throat department(ENT),and self-regeneration and self-repair ability for cartilage is limited,which effect serious psychological and physical harm to patients.At present,cartilage tissue scaffolds were constructed in vitro,then transplanted into the defect site for treatment of injury,which is becoming an ideal permanent treatment for tissue defects.In this paper,artificial porous thyroid cartilage scaffolds were prepared via rapid prototyping technology based on the previous numerical simulation of thyroid cartilage.First half of the article introduced additive manufacturing technology and analyzed the advantages and disadvantages of various tissue engineering materials,Finally,chitosan,hydroxyapatite,gelatin and sodium alginate were selected as the material.Biological scaffolds were fabricated respectively using low temperature Forming technology and controlled assembly technology,and then the corresponding physical and chemical properties of biological scaffolds were evaluated and biocompatibility was verified by cell-scaffold co-culturing cell-scaffolds in vitro.The second part of the paper mainly exhibited that animal experiments were carried out to verify the effect of biological scaffold repairing thyroid cartilage.In the first part,different proportions of chitosan-hydroxyapatite scaffolds were prepared by low-temperature deposition manufacturing(LDM),and micro-structure for scaffolds was observed via scanning electron microscopy.The result showed biological scaffolds possess an exquisite mesh-like three-dimensional porous structure and high permeability.The biological scaffolds fabricated via additive manufacturing technology possess high porosity and the ideal degradation rate,which provides plenty of space for the adhesion and proliferation of seed cells.The biocompatibility of the bio-scaffolds was verified by cell compatibility test.The composite scaffolds were fabricated directly with mixed chondrocytes and gelatin-sodium alginate-hydroxyapatite via controlled assembly technology.Results after incubating composite scaffolds indicated that chondrocytes possessed excellent morphology and showed considerable proliferation.In the second part,animal experiment for repairing thyroid cartilage injury was carried out.Twelve white New Zealand rabbits(amount for male and female is six respectively,weighing was 2-2.5kg for each animal)were randomly divided into two groups,and the side of thyroid cartilage was removed,slices of Chi-HAP composite scaffolds were implanted into the cartilage defect as the experimental group A.Group B was treated for thyroid cartilage defects without any treatment.After 10 weeks,HE,S-O and Masson staining were carried out upon the injured tissues.Result indicated that newborn chondrocytes were found in repaired areas in group A,and the damage recovery of group A was significantly better than that of group B,and no new cartilage cells were found at the injury site in group B.Therefore,Chi-HAP composite scaffolds fabricated by LDM possess biological activity for repairing injury cartilage.