Subaqueous 3D stem cell spheroid levitation culture using anti-gravity bioreactor based on sound wave superposition

Abstract

Abstract Background Recently, various studies have revealed that 3D cell spheroids have several advantages over 2D cells in stem cell culture. However, conventional 3D spheroid culture methods have some disadvantages and limitations such as time required for spheroid formation and complexity of the experimental process. Here, we used acoustic levitation as cell culture platform to overcome the limitation of conventional 3D culture methods. Methods In our anti-gravity bioreactor, continuous standing sonic waves created pressure field for 3D culture of human mesenchymal stem cells (hMSCs). hMSCs were trapped and aggerated in pressure field and consequently formed spheroids. We injected hMSC spheroids fabricated by anti-gravity bioreactor into the mouse hindlimb ischemia model. Results The acoustic levitation in anti-gravity bioreactor made spheroids faster and more compact compared to the conventional hanging drop method, which resulted in the upregulation of angiogenic paracrine factors of hMSCs. Injected hMSCs spheroids cultured in anti-gravity bioreactor exhibited improved therapeutic efficacy for mouse hindlimb ischemia model compared to spheroids formed by the conventional hanging drop method. Conclusion Our stem cell culture system using acoustic levitation will be proposed as a new platform for the future 3D cell culture system.