Natural Diatom Biosilica as Microshuttles in Drug Delivery Systems

Abstract

Unicellular diatom microalgae are a promising natural resource of porous biosilica. These microorganisms produce around their membrane a highly porous and extremely structured silica shell called frustule. Once harvested from living algae or from fossil sediments of diatomaceous earth, this biocompatible and non-toxic material offers an exceptional potential in the field of micro/nano-devices, drug delivery, theranostics, and other medical applications. The present review focused on the use of diatoms in the field of drug delivery systems, with the aim of presenting the different strategies implemented to improve the biophysical properties of this biosilica in terms of drug loading and release efficiency, targeted delivery, or site-specific binding capacity by surface functionalization. The development of composite materials involving diatoms for drug delivery applications is also described.

Anticancer Compounds Derived from Marine Diatoms

“…Different strategies may be devised to modify the biophysical properties of biosilica, including the development of surface functionalization and composite materials, to improve drug loading, release efficiency, targeted delivery, and site-specific binding. [62]. However, despite the biocompatibility and purported safe use of diatomite biosilica, efforts must be made to understand the effects of overdoses and particle accumulation in key tissues and organs, especially in the animal model.…”

Diatoms’ Breakthroughs in Biotechnology: <i>Phaeodactylum tricornutum</i> as a Model for Producing High-Added Value Molecules

“…Cell walls or frustules are composed of amorphous silica [15] so they are known for their main role within the biogeochemical cycling of minerals, as it's the case for silicates that can be integrated into their frustules [16]. These important structures can be harnessed to their flexibility of being incorporated into nanodevices as well as for the bio encapsulation and the delivery of therapeutic molecules [17] [18] [19] [20].…”

Highly Potent Rhenium(I) Tricarbonyl Complexes with Dual Anticancer and Anti-Angiogenic Activity Against Colorectal Carcinoma

“…With the aim of identify potentially new anticancer agents and to guide the formulation of new composite drug delivery systems, we have recently began a program centred on the use of frustules derived from unicellular microalgae for the targeted delivery of anticancer transition metal drugs to cancers, in particular, of the colorectum. 4,5 Among inorganic and organometallic anticancer compounds, cisplatin and other platinum-based drugs have been used for decades in the treatment of a variety of neoplastic diseases. However, the clinical success of these drugs is limited by significant side effects, especially inherent nephrotoxicity and ototoxicity originating from the platinum element.…”