Dinoflagellates as cellulose-based bio-hybrid materials

M.Sc Amina Alizade1 //, Dr.rer.nat. Anne Jantschke1,2

  1 TU Dresden Bioanalytical Chemistry

  1,2 JGU Mainz, Biomineralization/Crystallography, Institute of Geosciences

Dinoflagellates are unicellular, eukaryotic microorganisms that are familiar for their bioluminescence or algal bloom (the so-called “red tides”). One of the most remarkable features of the dinoflagellates is their fascinating morphology which inspired the drawings of Ernst Haeckel at the beginning of the 20th century. Currently, 250-300 dinoflagellate species are known. and physiology. Dinoflagellates can have variety of forms with cell sizes ranging from 10 µm up to 400 µm.

Many dinoflagellates are covered by cellulose plates (Figure 1) with regularly arranged pores (approximately 100-150 nm). This complex arrangement is called the theca and consists of at least two (Fig. 1b) or up to 100 plates (Fig. 1a). This unique cell covering makes dinoflagellates a very interesting new natural sources of cellulose and cellulose-based materials.

Figure 1. Cellulose theca of the dinoflagellate species: a) Peridinium sp. and b) Prorencentrum micans

Some special properties of cellulose such as renewability and biocompatibility are receiving special attention for various chemical applications, such as water purification, tissue engineering, drug delivery, or food packaging. Compared to the other potential natural sources, cellulose derived from algae has gained significant attention due to its effortless accessibility, easy algal cultivation, and a high degree of purity. Furthermore, in contrast to plant-based cellulose, the amount of lignin in algal cellulose is significantly lower which alleviates the cellulose extraction conditions.

The main focus of our work is to explore dinoflagellates as new cellulose source and modify them using different drug carrier nanoparticles for a possible biomedical application. First results show that the cultivation, extraction and modification of dinoflagellate-based cellulose is reproducible and successful. The extracted cellulose theca was characterized using SEM, TFIR and ICP-OES. After the extraction method was optimized, the resulting cellulose showed a high degree of purity while maintaining the porous morphology.

During the modification of cellulose with noble metal nanoparticles, it becomes clear that the gold nanoparticles can be attached to the cellulose theca with chemical and electrostatic interaction. This phenomenon gives us the opportunity to obtain cellulose-based biocompatible hybrid materials to use in drug delivery, absorbance, and catalysis.

As a next step, the stability of the cellulose based hybrid material in water and at the different pH values will be analysed. We aim to create a smart drug delivery system that will give us the opportunity to control its stability depending on the pH value of the system.