Viability of coaxial atomization for disintegration of cell solutions in cell spray applications

Treating Leukemia with intravenous stem cell transplantation represents a well-established therapy technique. For applications, that require high local cell concentrations, transplantation by conventional intravenous injection is less potent, due to cell distribution with blood circulation. Instead, spraying them directly onto the injured or diseased area shows promising results in various applications, e.g. superficial treatment of topographically challenging wounds, in situ seeding of cells on implants, deposition of cells in tubular organs for stem cell therapy.The present work aims for a basic knowledge about viability boundaries for coaxial cell-spray atomization and the reciprocal influence between cells in solution and primary breakup mechanics. A generic modular nozzle is developed, to ensures reproducible boundary conditions. Investigations are conducted regarding primary breakup and relations between resulting droplet size distribution and cell survival. Measurements are performed, utilizing microscopic high-speed visualization with suitable image post processing. Cell viability is analyzed using phase contrast microscopy prior and after atomization. A relation between Rayleigh-Taylor instability wavelength and droplet size distributions by means of Sauter mean diameter (SMD) and cell survival rate (CSR) is suggested. A power law is presented, exclusively dependent on dimensionless measures (lambda(perpendicular to) similar to Re(-1/2)We(-1/3)) which is found to be proportional to SMD and CSR.