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Competing interests The authors declare no competing interests. Authors’ contributions The work presented here was carried out in collaboration between all authors. All authors have contributed to, seen, and approved the manuscript.”
“Background Modern medicine has been revolutionized by the use of micro/nanocarriers that, acting theoretically as ‘magic Epigenetics inhibitor bullets’ [1], operate in site-specific delivery mechanism to spare normal cells and tissues. A kind of natural microcarriers developed for innovative drug delivery is represented by Selleckchem Lazertinib diatomite silica microparticles [2]. Diatomite is a fossil material of sedimentary origin formed by fragments of diatom skeletons, called frustules. Frustules of diatoms, single-cell photosynthetic algae largely diffused in aquatic environments, are mainly constituted by amorphous silica and are characterized by MK-8776 cell line a specific surface area up to 200 m2/g [3]. In nature, there are different kinds of diatoms (about 110,000 species) varying in size (from 2 μm to 2 mm) and morphology [4]. The low cost, abundance, easy availability,

excellent biocompatibility, non-toxicity, thermal stability, and chemical inertness make diatomite an intriguing material for several applications ranging from filtration to pharmaceutics [5–8]. Diatomite is composed by 70 to 90% of silica, clay, some metallic oxides, such as Al2O3 and Fe2O3, and other organic components [4]. Usually, Avelestat (AZD9668) diatomite mined from geological deposits must be purified before to be used; thermal pre-calcination and HCl washing are the treatments generally used to increase powder quality and to make the biomaterial inert as filter support [9, 10]. The diatomite silica surface presents reactive Si-OH groups that can be chemically modified in order to achieve a functionalized surface with proper chemical groups, such as − NH2, −COOH, −SH, and − CHO, which can be used for small interfering RNA (siRNA), microRNA (miRNA),

decoy oligo, and drug loading [11, 12]. In the present work, diatomite nanoparticles (DNPs) with a diameter lower than 300 nm were prepared by mechanical crushing, sonication, and filtering of micrometric diatomite powder. Nanoparticles, once purified from organic and inorganic impurities, were functionalized by using 3-aminopropyltriethoxysilane (APTES) and labeled with tetramethylrhodamine isothiocyanate (TRITC) in order to verify their cellular uptake. Confocal microscopy was used to investigate nanocarrier internalization in lung epidermoid cancer cells (H1355). Results demonstrated effective cellular uptake of nanoparticles and highlighted their potentiality in nanomedicine as carriers able to improve drug delivery. Methods Materials Calcined diatomite was obtained by DEREF S.p.A (Castiglione in Teverina, Viterbo, Italy). 3-aminopro-pyltriethoxysilane (APTES), H2SO4, and tetramethylrhodamine isothiocyanate (TRITC) were purchased from Sigma-Aldrich (St. Louis, MO, USA).