Development of a Method for Scaffold-Free Elastic Cartilage Creation.

Microtia is a congenital aplasia of the auricular cartilage. Conventionally, autologous costal cartilage grafts are collected and shaped for transplantation. However, in this method, excessive invasion occurs due to limitations in the costal cartilage collection. Due to deformation over time after transplantation of the shaped graft, problems with long-term morphological maintenance exist. Additionally, the lack of elasticity with costal cartilage grafts is worth mentioning, as costal cartilage is a type of hyaline cartilage. Medical plastic materials have been transplanted as alternatives to costal cartilage, but transplant rejection and deformation over time are inevitable. It is imperative to create tissues for transplantation using cells of biological origin. Hence, cartilage tissues were developed using a biodegradable scaffold material. However, such materials suffer from transplant rejection and biodegradation, causing the transplanted cartilage tissue to deform due to a lack of elasticity. To address this problem, we established a method for creating elastic cartilage tissue for transplantation with autologous cells without using scaffold materials. Chondrocyte progenitor cells were collected from perichondrial tissue of the ear cartilage. By using a multilayer culture and a three-dimensional rotating suspension culture vessel system, we succeeded in creating scaffold-free elastic cartilage from cartilage progenitor cells.

Uso de fáscia peitoral maior em preenchimento de dorso nasal: relato de caso / Use of pectoralis major fascia in dorsal nasal augmentation: case report

O aumento do dorso nasal nas rinoplastias é foco de estudo de diversos trabalhos que buscam as melhores fontes de enxerto e técnicas cirúrgicas. A utilização de cartilagem já é consagrada para este fim, a partir do septo nasal, da concha auricular ou dos arcos costais. Nos últimos anos, têm-se buscado meios para reduzir a palpabilidade e dispersibilidade dos enxertos cartilaginosos. Assim, são descritos materiais sintéticos, como o SURGICEL®; e, autólogos, representados pelas fáscias. A fáscia temporal é mais amplamente utilizada, porém requer uma nova incisão cirúrgica, aumentando o tempo e a morbidade da cirurgia. É também descrito o uso de fáscia lata e fáscia reto abdominal, comparativamente mais espessas e menos flexíveis. Em muitos casos de rinoplastia fazse necessária a retirada da cartilagem costal, o que permite a coleta de fáscia do músculo peitoral maior pela mesma incisão cirúrgica. Dessa forma, descrevemos a utilização da fáscia do músculo peitoral maior envolvendo cartilagem costal picada, em uma rinoplastia estruturada com aumento do dorso.

Increasing the nasal dorsum in rhinoplasty is the focus of several studies that seek the best graft sources and surgical techniques. The use of cartilage from the nasal septum, ear shell, or costal arches is already established for this purpose. In recent years, methods have been sought to reduce the palpability and dispersibility of cartilaginous grafts. Thus, synthetic materials such as SURGICEL® and autologous materials such as fascia have been explored. Temporal fascia are more widely used but require a new surgical incision, increasing surgical time and morbidity. Also described is the use of fascia lata and rectus abdominis fascia, which are comparatively thicker and less flexible. In many rhinoplasty procedures, it is necessary to remove the costal cartilage, which allows the collection of fascia from the major chest muscles through the same surgical incision. Thus, we describe the use of major chest muscle fascia and chopped costal cartilage in structured rhinoplasty to increase the dorsum.

Histological study of costal cartilage after transplantation and reasons for avoidance of postoperative resorption and retention of cartilage structure in rats.

BACKGROUND: Limited information is available on the biological status of transplanted cartilage from which the perichondrium has been removed. This article describes the histological and three-dimensional structural picture of cartilage, using green fluorescent protein (GFP) transgenic rats and normal wild rats. METHODS: Three sections of costal cartilage were harvested from 10-week-old wild rats. One section was used as a specimen while two were subcutaneously collected from the dorsal region of 10-week-old GFP rats at 4 and 8 weeks post-transplant. The experiment was performed in two randomized groups. The perichondrium was removed from transplanted cartilage in the first group and perichondrium of transplanted cartilage remained intact in the second group. Histology and focused ion beam/scanning electron microscope (FIB/SEM) tomography were used to evaluate the transplanted cartilage. RESULTS: All 40 transplanted sections were harvested and no infections, exposure or qualitative change of cartilage matrix were seen following transplant. Histological analyses showed that the surface layer of the GFP-negative transplanted cartilage was replaced with GFP-positive chondrocytes 8 weeks post-transplant in the first group. A three-dimensional layer of perichondrium-like tissue reconstructed around the cartilage at 8 weeks was confirmed, resembling normal perichondrium. However, the GFP-positive chondrocytes were not replaced in the second group. CONCLUSIONS: The cell renewal of chondrocytes is necessary for subcutaneously transplanted cartilage to maintain its tissue composition over a long period of time. The histological and ultrastructural analyses revealed that cells from recipient tissue generated new chondrocytes even when cartilage was implanted after removing the perichondrium.