Large molecule photodynamic properties

In a series on the evolution of size effects, it is inescapable that the term size be further investigated. This chapter reports on some spectroscopic and photodynamic properties of relatively large molecules. What do we mean by large, or even more explicitly, what do we mean by relatively large ... 

It will be shown that this terminology is critically dependent on the way one performs experiments. Properties that are taken as characteristic for large systems appear in photodynamics when one uses a broad laser as the excitation source, while properties usually taken as characteristic for small molecules are obtained when one uses a narrow laser. In this chapter we will define relatively large molecules as those molecules in which, with existing optical sources, both situations can be realized. We can then study the transition from large to small in one molecule just by changing the excitation source. 

Photodynamic treatment equally affects viral particles and protein components in biological fluid, but virions, being large supramolecular structures, are more vulnerable compared to protein molecules. For this reason, damage to one of the components of a virion leads to inactivation of the entire viral particle without affecting the growth properties of semm or the electrophoretic pattern of the proteins. 

Curcumin 6 is the main component of the Indian spice turmeric, and is thus found in large amounts in curry powders and sauces. This is a very interesting compound, as it has been shown to exhibit a wide array of beneficial health effects, including antibacterial, antioxidant, and anticancer properties [89]. It is sold in health food stores in pill form as a dietary supplement. It is also a potential photosensitizer for photodynamic therapy for oral lesions and cancers [90]. This fascinating molecule is of particular interest to my work for two reasons it has a very low aqueous solubility, which might be enhanced by CD inclusion, and it exhibits highly polarity-sensitive fluorescence [91], which gives us an excellent way to study its CD inclusion. 

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