Cellular interactions with NIR EM energy.

The electrical and electrochemical nature of cellular components, structure and function makes it important for the possible influences by externally applied electromagnetic fields to be studied thoroughly. This is an important aspect of cellular engineering. Thermal and non-thermal influences of EM, electric and magnetic fields on biological tissues are under investigation by several groups, to improve both diagnostic and therapeutic techniques. Within the EM spectrum there is an interesting band in the infra-red, from about 700 nm to 1000 nm, where absorption by enzymes within the intracellular respiratory chain can take place. This absorption phenomenon is now used as the basis for quantitative analysis of enzyme dynamics, both in vitro and in vivo, but implications for both therapeutic and potentially damaging influences on cellular behaviour and viability also need to be considered.