Introduction. The aim of this study was to investigate whether methylene blue dye, commonly used in sterile surgical marker pens, would have an effect on human chondrocyte viability, when cultured on a collagen membrane in-vitro. Methods. Bilayered collagen membranes were seeded in duplicate with 12 million human chondrocytes per ml and cultured for 24 hours under standard conditions. Group A consisted of a membrane marked with methylene blue ink on its smooth side, group B marked on its porous side, and group C acting as an unmarked control. At the end of the culture period the membranes were qualitatively analysed for cell survival by live/dead fluorescent staining under confocal microscopy. Results. The control membranes of group C showed normal ‘live’ staining of cells. A marked reduction in chondrocyte viability was seen in groups A and B, with a significant reduction in viability seen opposite to the ink mark on the smooth side in A, and practically no cell viability in the same position on the porous side in group B. Conclusions. Methylene blue dye in surgical marker pen ink has been shown to be cytotoxic to chondrocytes cultured on bilayered collagen membranes. Sterile surgical marker pens are commonly used in cartilage repair surgery to aid in the placement of periosteal patches or collagen membranes in autologous chondrocyte transplantation. Surgeons need to be aware of the potential harmful effects of methylene blue dye when using surgical marker pens in cell based
Meniscal injuries are common and often induce knee pain requiring surgical intervention. To develop effective strategies for meniscus regeneration, we hypothesized that a minced meniscus embedded in an atelocollagen gel, a firm gel-like material, may enhance meniscus regeneration through cell migration and proliferation in the gel. Hence, the objective of this study was to investigate cell migration and proliferation in atelocollagen gels seeded with autologous meniscus fragments in vitro and examine the therapeutic potential of this combination in an in vivo rabbit model of massive meniscus defect. A total of 34 Japanese white rabbits (divided into defect and atelocollagen groups) were used to produce the massive meniscus defect model through a medial patellar approach. Cell migration and proliferation were evaluated using immunohistochemistry. Furthermore, histological evaluation of the sections was performed, and a modified Pauli’s scoring system was used for the quantitative evaluation of the regenerated meniscus.Aims
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