Pharmaceutical composition for preventing or treating osteoarthritis

A composition comprising:

• a transformed mammalian cell population prepared by a process comprising collecting a cell suspension in which a transformed mammalian cell is cultured and sieving the cell suspension with a cell strainer having pore sizes ranging from 70 μm to less than 200 μm to remove any aggregate having a diameter larger than 70 μm to 200 μm, and
• an untransformed mammalian cell population prepared by collecting a cell suspension in which an untransformed mammalian cell is cultured and sieving the cell suspension with a cell strainer having pore sizes equal to or less than 300 μm to remove any aggregates having a diameter larger than 300 μm,
• wherein transformed mammalian cell population have a particle diameter D90 of less than 200 μm, and the untransformed mammalian cell population have a particle diameter D90 of less than 300 μm,
• wherein the transformed mammalian cell is transformed with a transforming growth factor beta (TGF-β) coding gene, and the untransformed mammalian cell is a chondrocyte or a chondroprogenitor cell;
• and
• the composition is intraarticular injectable.