Pieter Edmond Oomen

INTRODUCTION The drug market is complex and highly dynamic, especially as new psychoactive substances (NPS) continue to appear. NPS, often referred to as research chemicals, designer drugs or legal highs, are newly emerging psychotropic compounds initially not governed by the 1961 United Nations Single Convention on Narcotic Drugs or the 1971 United Nations Convention on Psychotropic Substances [1].

Oxygen is essential in the energy metabolism of cells, as well as being an important regulatory parameter influencing cell differentiation and function. Interest in precise oxygen control for in vitro cultures of tissues and cells continues to grow, especially with the emergence of the organ-on-a-chip and the desire to emulate in vivo conditions. This was recently discussed in this journal in a Critical Review by Brennan et al. (Lab Chip (2014). doi:10.1039/C4LC00853G).