Culture of Chondrocytes on Scaffolds with Different Pore Network of PLGA and PLLA

This study was performed to investigate the in vitro proliferation and migration of rabbit auricular chondrocytes into the various sized pore of PLLA and PLGA scaffolds. The chondrocytes were harvested, expanded, and seeded onto PLGA(50 : 50, 75 : 25, 85 : 15) and PLLA scaffold having either small(50 - 100 micrometer) or large(300 - 350 micrometer) pores. On the 4th and 8th week after culture, histologic observation and quantitative DNA assay were done. We noted that the largest amount of DNA was found in the 85 : 15 PLGA sponges than others, and in the 4th and 8th week, some amount of DNA was detected in the lower portion of 85 : 15 PLGA sponge only, and DNA amounts were increased during the culture period in the 85 : 15 PLGA, significantly. We also found that the numbers of cells were low in middle portion of scaffolds, and in large pore-sized group of 85 : 15 PLGA, there were many cells in the lower portion of the scaffolds more than that of small pore group. In conclusion, the pore size of the scaffold for chondrocyte culture is important for cell migration and proliferation, and PLGA, especially 85 : 15 PLGA with 300- 350 micrometer sized pore is the more suitable biomatrix for proliferation and migration of the chondrocytes.

In Vivo Implantation of Chondrocytes Seeded into a Three-dimensional PLGA Sponge: Is in Vitro Culture before Implantation Necessary?

For tissue-engineered neocartilage formation in vivo, most studies have cultured chondrocytes within a biodegradable polymer in vitro before implantation of cell-polymer complex into an animal. The present study was performed to investigate the necessity of in vitro culture (preconditioning). Cell-polymer complex was made of chondrocytes obtained from a rabbit ear and a 85:15 poly(DL-lactic-co- glycolic acid) (PLGA) sponge. The complex was implanted into a nude mouse either after or without in vitro preconditioning. For control groups, PLGA sponge without chondrocytes was used. One, 2, and 4 weeks after the implantation, each group was examined by measurement of weight and volume of sponges as well as histologic study with Safranin-O staining. The control groups showed loss of weight as time passed. The non-preconditioned group, on the other hand, showed weight loss for the first week, but increased in weight afterwards. The preconditioned group also had weight loss in the first week after the implantation with no noticeable weight changes thereafter. Neither weight nor volume of PLGA sponges in preconditioned group was significantly different from those in non-preconditioned group until the 2nd week. In the 4th week, volume of sponges in non-preconditioned group was significantly larger than that in preconditioned group. On histological observation, chondrocytes seeded into a PLGA sponges proliferated and differentiated into cartilage tissues both in preconditioned and non-preconditioned groups, but non-preconditioned group formed cartilage tissue more extensively than the preconditioned group. Based on the above results, it is suggested that new cartilage tissues can be formed successfully following the implantation of cell- polymer complex into a living body without any prior conditioning in a separate culture system.

A Case with Perforated Gastric Leiomyoma / 대한소화기내시경학회지

Gastric leiomyomas, which arise from smooth muscle tissue, are the most common non-epi- thelial tumors occurring in the stomach. This tumor is most commonly found incidentally at surgery or autopsy. The incidence of the leiomyoma is about 1-3% of all gastric tumors and sex distribution is equal. We have recently experienced a 59-year-old housewife who had epigastric pain and soreness of one month's duration. Physical examination disclosed tenderness with palpated mass in the left upper quadrant. Gastrofiberscopic finding revealed esophageal diverticulum in the mid-esophagus and 2 x 2 x 1 cm sized submucosal intramural mass with centrally depressed umbilication through ulcerative change on the greater curvature of lower body. Within the umbilication, there were food materials and blood clots. The sleeve segmental resection of stomach was performed. The histopathologic and post operative findings were atypical leiomyoma, perforated with abscess formation to the omentum.

A Case with Perforated Gastric Leiomyoma / 대한소화기내시경학회지

Gastric leiomyomas, which arise from smooth muscle tissue, are the most common non-epi- thelial tumors occurring in the stomach. This tumor is most commonly found incidentally at surgery or autopsy. The incidence of the leiomyoma is about 1-3% of all gastric tumors and sex distribution is equal. We have recently experienced a 59-year-old housewife who had epigastric pain and soreness of one month's duration. Physical examination disclosed tenderness with palpated mass in the left upper quadrant. Gastrofiberscopic finding revealed esophageal diverticulum in the mid-esophagus and 2 x 2 x 1 cm sized submucosal intramural mass with centrally depressed umbilication through ulcerative change on the greater curvature of lower body. Within the umbilication, there were food materials and blood clots. The sleeve segmental resection of stomach was performed. The histopathologic and post operative findings were atypical leiomyoma, perforated with abscess formation to the omentum.