Microalgae, in general, have received increasing interest as the extracts have exhibited anti-cancer (anti-proliferative) activities in several types of cancer [2,27]. safe nanocarrier in nano-medicine applications. This review presents an overview of diatoms microalgae possessing anti-cancer activities and the potential role of the diatoms and biosilica in the delivery of anticancer drugs. Diatoms-based antibodies and vitamin B12 as drug carriers are also elaborated. has shown anticancer activity through the induction of apoptosis. The high phenolic contents may contribute towards the free radical scavenging activities observed . As shown in Physique 3, Rabbit polyclonal to ITLN2 the diatom cell wall (frustule) contains two thecae over-lapped structures, akin to a petri-dish, each half consisting of a valve and different girdle-bands, extending around the circumference of the cell . Bretylium tosylate The frustule consists of silica and organic materials such as carbohydrates and glycoproteins. The decomposition of the diatom frustules has resulted in the sea bottom being covered with sediments called diatomite or diatomaceous earth (DE). These highly porous materials are suitable to be developed as adsorbents, mineral filters, abrasives, anticaking factors, or for materials isolation . The frustules of diatoms can be used as complex molds in the decoration of biomolecules at both the micro and/or nano-scale, taking advantage of their complex structural engineering . The diatomaceous filters have found several applications such as in fluid filtration, DNA purification, and adsorption of heavy metals . In nanotechnology, the complex nanoscale structure of the silica shell is usually beyond the existing human engineering capabilities. The formation of bio-glass diatoms is usually achieved in moderate physiological conditions, without any need for high pressure, high temperatures, or the use of acidic or toxic chemicals. Other organisms such as some plants, chrysophytes, and desmosponges have similar capabilities of manufacturing the silica-based structures, but diatoms are shown to be at the top in the world of silica-cycles . The metabolic pathways associated with silica cell wall Bretylium tosylate formation are largely unknown. This could open up possibilities of discovering new proteins and enzymes that may be commercially useful . Open in a separate window Physique 3 Image of the diatoms cell wall (frustule) showing that they contain two thecae over-lapped structures, similar to a petri-dish, each half consisting of a valve and different girdle-bands, extending around the circumference of the cell, with nanopores at different scales (Modified from ). The frustule morphology and size may change with vegetative cell division. For instance, forms broad chains, with full silicate frustules . shows many shapes such as oval, triradiate and fusiform, and can change from one shape to another over time. When grown in cultures, the triradiate and fusiform can produce long chains where the frustules are completely organic. In the oval Bretylium tosylate type, the valves may be organic, or one of the valves may have a small silica frustule covered by an organic wall . cells are characterized by narrow and spindle Bretylium tosylate shapes, with apically asymmetric valves combined in stepwise chains, with interlaced valve ends. The valve face is usually surrounded by slits and pores (striae, fibulae, interstriae). The raphe is usually outside of the center and not raised above the valve . 3. Anticancer Compounds from Diatoms The identification of cytotoxic metabolites for many years has led to the advancement in anti-cancer treatments. However, progress in cancer therapy has been hampered by the inability to identify the unique biochemical features of malignant tumors, which can be utilized to selectively target the cancer cells . The detection and evolution of anti-cancer drugs (with cytotoxic factors), is very different from the drug development for many other diseases. Cytotoxic brokers with highly toxic effects around the cancer cells could have also affected the healthy normal cells . Microalgae, in general, have received increasing interest as the extracts have exhibited anti-cancer (anti-proliferative) activities in several types of cancer [2,27]. However, despite increasing efforts, only a number of these specific metabolites with anticancer activities show potential to be developed further as anticancer drugs. A study to discover new diatoms as potential sources of anticancer compounds has examined 21 diatoms, 4 flagellates, and 7 dinoflagellates grown in various cultivation conditions [9,28]. Only one extract (FE60),.