Preparation of collagen/chitosan microspheres for 3D macrophage proliferation in vitro

Macrophages, as an important member of immune cells, have now become a research hotspot in the field of immunotherapy, which requires prominent proliferation in vitro for clinical use. Herein, we reported the fabrication of collagen/chitosan microspheres via emulsification for 3D macrophages proliferation. With glutaraldehyde (GA) as cross-linker, the microspheres have an average diameter of 200 μm and positively charged surfaces, which are of great stability and biocompatibility. Compared with 2D cell proliferation, the 3D microspheres could dramatically enhance macrophages proliferation rate and promote their biological functions. Furthermore, macrophages on the surface of microspheres could be easily collected by blowing and suction, without the need of trypsin digesting or the degradation of microsphere. Hence the microspheres could be reused for macrophage proliferation repeatedly. This study highlights opportunities for development of high-effective cell proliferation approach and provides a great promise in immune cell based immunotherapy.