TISSUE-CULTURE SURFACE CHARACTERISTICS INFLUENCE THE EXPANSION OF HUMAN BONE-MARROW CELLS

Human cell therapy applications in tissue engineering, such as the ex vivo production of hematopoietic cells for transplantation, have recen tly entered the clinic. Although considerable effort has been focused on the development of biological processes to generate therapeutic cel ls, little has been published on the design and manufacture of devices for implementation of these processes in a robust and reproducible fa shion at a clinical scale. In this study, the effect of tissue culture surface chemistry and texture was assessed in human bone marrow (BM) mononuclear cell (MNC) and CD34-enriched cell cultures. Growth and dif ferentiation was assessed by total, progenitor (CFU-GM), stromal (C-FU -F), and primitive (LTC-IC) cell output. Tissue culture treated (TCT) plastic significantly increased MNC culture output as compared with no n-TCT plastic, whereas CD34-enriched cell cultures gave lower output ( than MNC cultures) that was unaffected by TCT plastic. Interestingly, the level of MNC culture output was significantly different on four co mmercial TCT surfaces, with the best performing surface giving output that was 1.6- to 2.8-fold greater than the worst one. The surface givi ng the highest output was the best at supporting development of a dist inct morphological feature in the adherent layer (i.e. cobblestone are a) indicative of primitive cells, and X-ray photoelectron spectroscopy (XPS) was used to characterize this surface. For custom injection mol ding of culture devices, the use of three different resins resulted in MNC culture output that was equivalent to commercial cultureware cont rols, whereas CD34-enriched cell cultures were highly sensitive to res ins containing additives. When the texture of molded parts was roughen ed by sandblasting of the tool, MNC culture output was significantly r educed and higher spikes of IL-6 and G-CSF production were observed, p resumably due to macrophage activation. In conclusion, the manufacture of BM MNC culture devices for clinical applications was optimized by consideration of plastic resin, surface treatment, and texture of the culture substratum. Although CD34-enriched cells were insensitive to s urface treatment, they were considerably more sensitive to biocompatib ility issues related to resin selection. The development of robust sys tems for BM MNC expansion will enable clinical trials designed to test the safety and efficacy of cells produced in this novel tissue engine ering application. (C) 1998 Elsevier Science Ltd. All rights reserved.