Performance of different materials and their coating for use in in-vitro tests to simulate particle deposition in 3D printed lung models

Abstract

Inhalation therapy is the standard and preferred method of administering drugs for the treatment of respiratory diseases as it provides rapid and localised action in the airways, reduces systemic side effects and improves therapeutic efficacy by requiring lower doses compared to other routes of administration. Despite the great interest in developing models of human airways for the testing of drug inhalation systems, a low-cost and straightforward procedure for the development of such model would be desirable. In this work, different materials have been tested for manufacturing of lung models, using a radioactive solution of sodium pertechnetate as model drug. The solution was introduced into an inhaler and was nebulised in half of the testing surface. Then, the radiological activity was measured to see migration to the other surface half and surface affinity. Safety procedures must be considered during the tests, as part of the radioactivity gets lost in the surrounding air. The best material for developing an experimental model of human airways with additive manufacturing was found to be polylactic acid coated with alumina.