• Sosnowski, Tomasz Robert
• Kurowska, Anita
• Butruk, Beata Aleksandra
• Jabłczyńska, Katarzyna

Abstract

Aerosols are often used as vehicles of medicines and their most important application is related to inhalation of anti-asthmatic or anti-inflammatory drugs. Aerosols are also convenient in topical applications, i.e. applied on skinor mucous membranes (e.g. of nasal or oral cavity). Recently, it has been shown that use of a therapeutic bioaerosolcan be beneficial in the speeding up of healing processes of the skin. In this context, cell suspensions areconsidered as the material for which the suitable spraying method must be established in order to assure thathydrodynamic stress related to liquid atomization will not destroy the living cells. The current work is focused ontesting of the influence of selected spraying techniques on the integrity and the survival of different types of cellsin the atomized bio-colloid. Medical nebulizers and similar spraying devices have been characterized in respect ofthe size distribution of emitted droplets, and used to aerosolize selected (i.e. model) cell colloids: suspensions ofyeast, bacteria and murine fibroblasts. Cell viability after spraying has been determined via direct microscopicobservations and specific microbiological assays. The results shows that droplets generated from the commonlyused medical inhalers (nebulizers) are too fine to contain whole living cells (median diameter of drops is around 5m). Because the generation of small droplets requires high hydrodynamic stresses, viability of cells in theatomized suspension is strongly reduced even if cells are mechanically resistant and small in size. Tested nasalatomizer (spray pump) and Microsprayer devices produce larger droplets (median diameter of drops 50-80 um)which can contain integral fibroblast cells. Owing to lower shear stresses during atomization in these two devices,the aerosolized cells remain viable and capable of proliferation. The studies allow to conclude that only selectedtechniques can be effective in the atomization of bio-colloid for medical applications. Moreover, the atomizationmethod must be accompanied by proper techniques of aerosol transfer to the bronchial tree which will preventdroplets from deposition in the upper airways. Technical concepts of such cell delivery are proposed. This paperis an extended version of our recent work published in Chemical Engineering Transactions (Sosnowski et al.,2013).

Topics

• Deposition
• impedance spectroscopy
• atomization