Diatoms are single cellular photosynthetic algae that can be found anywhere there is water including oceans, lakes and even damp soils. They can form colonies characterised by pretty shapes (e.g. filaments, ribbons, zigzag, fan or even stars) and can take thousands of different forms. There are over 200,000 species of diatoms that we know of, however .
Diatoms first showed up in the fossil record right around the Jurassic period, 65 million years ago. Diatoms survived the mass extinction of dinosaurs!
Not only are they incredibly beautiful but they also provide us with 20% of the Earths oxygen! More than the Earths rainforests! It is estimated that 40% of the primary production in the oceans is accomplished by diatoms.
During the Victorian era artists would lay them out in beautiful arrangements under their microscopes, like this one by Klaus Kemp.
Diatoms can be helpful for a wide range of applications such as environmental indication, oil exploration, forensic examination, bioenergy, nanotechnology and medicine.
Diatoms as filters
Filtration is a very common use for diatoms. The safety and fine structures of diatom shells trap foreign particles in fluids, such as dirt, lint, hair and some other microscopic organisms. Diatoms are often used for water filtration, particularly water in hot tubs and swimming pools. However, a vast variety of fluids can be filtered with diatoms, including different syrups, alcoholic beverages, medicines, solvents and other chemicals.
Diatoms as drug delivery system
Many disease treatments target specific tissues, organs or cells but also harm healthy cells, causing side effects for patients.
To reduce side effects, targeted drug delivery system to selectively transport drugs to the designated the body parts have been developed. Despite some success in this area by using silica-based nanoparticles, the production process is expensive and involves the use of toxic chemicals.
Luckily, nature has provided diatoms. Diatoms are suitable for use in drug delivery due to their large surface area, high porosity and biocompatibility. They can be used for targeted drug delivery with minimised side effects.