Human bladder carcinoma cell line 5637 encapsulated in alginate microbeads: release of interleukins, chemokines and growth factors.

We have developed a microencapsulation procedure for the entrapment and manipulation of the human bladder carcinoma cell line 5637. This cell line is a well-known source of hematopoietic cytokines. For istance 5637 cell line-conditioned medium (5637 CM) is used for the culture of growth factor–dependent hematopoietic primary cells and cell lines. The applied method is based on the generation of monodisperse droplets by a vibrational nozzle; for the microbeads hardening, an ionic alginate encapsulation procedure was utilized. Our results demonstrate that the microencapsulation procedure do not alter the viability of the encapsulated 5637 cells. Moreover, the encapsulated 5637 cells have been characterized for secretomic profile using Bio-Plex system. The obtained results demonstrated that most of the analyzed proteins were secreted by both the free and encapsulated cells with an almost superimposable pattern. In both cases, the most released proteins were G-CSF, VEGF, IL-8, GM-CSF, IP-10, IL-6, PDGF-BB, IL1ra, INF-gamma Finally, we determined whether 5637 CM obtained from encapsulated 5637 cells sustain the proliferation of primary erythroid cell cultures isolated from normal donors. The results demonstrate this 5637 CM stimulates the proliferation of erythroid precursor cells and maintain their capacity of erytho-differentiate and produce Hb. In conclusion, the described encapsulation procedure represents a promising strategy to utilize encapsulation of secreting cells in alginate microbeads, as a very interesting approach for biotechnology applications in tissue engineering and biomedicine.