PLGA 종류와 담체의 형성 방법에 따른 인간의 조직공학적 연골형성 = Tissue Engineered Cartilage Formation on Various PLGA Scaffolds

국문 초록 (Abstract)

본 연구에서는 관상의 Poly(lactic-co-glycolic acid)(PLGA) 담체에 대한 인간의 초자연골과 탄성연골의 형성정도를 살펴보았다. 담체는 PLGA의 분자량에 따라서는 110,000g/mol과 220,000g/mol을 비교하였고 내경 유지를 위하여 내경측에는 220,000g/mol, 외경측에는 110,000g/mol의 복합체를 만들거나, 비분해성 고분자 폴리에틸렌 튜브와 110,000g/mol PLGA의 담체와의 결합도 시도하였다. PLGA 담체들은 주사전자현미경으로 단면 구조를 관찰하였다. 각각의 담체에 20세 미만의 환자들의 비중격에서 채취된 초자연골과 귀에서 채취된 탄성연골에서 분리한 연골세포를 심었다. 분리된 연골세포는 두 번의 계대배양을 거쳐 각각의 PLGA 담체에 심었고 일주일동안 생체 외 환경에서 배양하였다. 각각의 세포와 담체의 복합체를 nude mouse의 배부 좌, 우로 피하조직에 이식하고 8주 뒤 H&E 염색으로 조직 검사를 시행하였다. 110,000g/mol의 PLGA 담체의 연골조직은 잘 형성되어 있었지만 그 내경은 유지되지 못하였다. 반면 220,000g/mol PLGA 담체를 내경측에 110,000g/mol PLGA 담체를 외경측으로 한 담체에서는 연골조직 형성이 잘 되지 않았으나 내경측에 폴리에틸렌 튜브를 끼운 110,000g/mol PLGA 담체에서는 조직 형성과 내경유지가 잘 되었고 원래의 담체와 거의 유사한 형태로 유지되었다. 분화된 연골세포도 조직 소견으로 확인할 수 있었다. 이 1㎜ 내경의 관상 연골조직은 인공 기관지나 식도 등을 위한 동물 실험과 인공 합성 튜브의 대체 등 앞으로 많은 응용분야가 기대된다.

다국어 초록 (Multilingual Abstract)

The purpose of this study was to evaluate the effect of different types of Poly(lactic-co-glycolic acid)(PLGA) scaffolds on the formation of human auricular and septal cartilages. All of the scaffolds were formed in a tubular shape for potential application for artificial trachea or esophagus with either 110,000g/mol PLGA. 220,000g/mol PLGA, or a combination of both. In order to maintain the tubular shape in vivo, two methods were used. One method was inserting polyethylene tube at the center of scaffolds made of 110,000g/mol PLGA. The other method involved combination of the two different molecular weight PLGA's. The inner surface of tubular shaped scaffold made with 110,000g/mol PLGA was coated with 220,000g/mol PLGA to give more mechanical rigidity. Elastic cartilage was taken from the ear of a patient aged under 20 years old and hyaline cartilage was taken from the nasal septum.
The chondrocytes were then isolated. After second passage, the chondrocytes were seeded on the PLGA scaffolds followed by in vitro culture for one week. The cells-PLGA scaffold complex were implanted subcutaneously on the back of nude mice for 8 weeks. The tissue engineered cartilages were separated from nude mice and examined histologically after staining with the Hematoxylin Eosin The morphology of the scaffolds were examined by scanning electron microscopy The pores were well formed and uniformly distributed in the various PLGA scaffolds After 8 weeks in vivo culture, cartilage was well formed with 110,000g/mol PLGA, however lumen had collapsed. In contrast, a minimal amount of neocartilage was formed with 220,000g/mol PLGA, while the architecture of scaffold and lumen were well preserved. Elastic cartilage formed more neocartilage than hyaline Hyaline and elastic neocartilage were well formed on 110,000g/mol PLGA with the polyethylene tube, exhibiting mature chondrocytes and preservation of the tubular shape. It was found that 110,000g/mol PLGA was more appropriate for cartilage formation but higher molecular weight polymer was necessary to maintain the three dimensional shape of the scaffold.