Synthesis, Antiproliferative Activity, and DNA Binding Studies of Nucleoamino Acid-Containing Pt(II) Complexes

State of art in the chemistry of nucleoside-based Pt(II) complexes

After the fortuitous discovery of the anticancer properties of cisplatin, many Pt(II) complexes have been synthesized, to obtain less toxic leads which could overcome the resistance phenomena. Given the importance of nucleosides and nucleotides as antimetabolites, studying their coordinating properties towards Pt(II) ions is challenging for bioorganic and medicinal chemistry. This review aims to describe the results achieved so far in the aforementioned field, paying particular attention to the synthetic aspects, the chemical-physical characterization, and the biological activities of the nucleoside-based Pt(II) complexes.

Bioengineered lipophilic Ru(III) complexes as potential anticancer agents

Lipid-conjugated Ru(III) complexes - designed to obtain lipophilic analogues of the low molecular weight derivative AziRu, which is a NAMI-A-like anticancer agent - have been synthesized and fully characterized. A detailed biophysical investigation, including multiple, integrated techniques, allowed determining their molecular and self-assembling properties in aqueous solutions mimicking the extracellular environment, showing that our design produced a protective effect from hydrolysis of the Ru(III) complexes. In vitro biological experiments, carried out in comparison with AziRu, demonstrated that, among the novel lipophilic Ru(III) complexes synthesized, the compounds derivatized with palmitic and stearic acid, that we named PalmiPyRu and StePyRu respectively, showed attractive features and a promising antiproliferative activity, selective on specific breast cancer phenotypes. To get a deeper insight into their interactions with potential biomacromolecular targets, their ability to bind both bovine serum albumin (BSA), an abundant serum carrier protein, and some DNA model systems, including duplex and G-quadruplex structures, has been investigated by spectroscopic techniques. Inductively coupled plasma-mass spectrometry (ICP-MS) analysis of the ruthenium amount incorporated in human MCF-7 and MDA-MB-231 breast cancer cells, after incubation in parallel experiments with PalmiPyRu and AziRu, showed a markedly higher cell uptake of the lipophilic Ru(III) complex with respect to AziRu. These data confirmed that the proper lipidic tail decorating the metal complex not only favoured the formation of aggregates in the extracellular media but also improved their cell membrane penetration, thus leading to higher antiproliferative activity selective on breast cancer cells.

Nanoparticle-Guided Brain Drug Delivery: Expanding the Therapeutic Approach to Neurodegenerative Diseases

Neurodegenerative diseases (NDs) represent a heterogeneous group of aging-related disorders featured by progressive impairment of motor and/or cognitive functions, often accompanied by psychiatric disorders. NDs are denoted as 'protein misfolding' diseases or proteinopathies, and are classified according to their known genetic mechanisms and/or the main protein involved in disease onset and progression. Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD) are included under this nosographic umbrella, sharing histopathologically salient features, including deposition of insoluble proteins, activation of glial cells, loss of neuronal cells and synaptic connectivity. To date, there are no effective cures or disease-modifying therapies for these NDs. Several compounds have not shown efficacy in clinical trials, since they generally fail to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells that greatly limits the brain internalization of endogenous substances. By engineering materials of a size usually within 1-100 nm, nanotechnology offers an alternative approach for promising and innovative therapeutic solutions in NDs. Nanoparticles can cross the BBB and release active molecules at target sites in the brain, minimizing side effects. This review focuses on the state-of-the-art of nanoengineered delivery systems for brain targeting in the treatment of AD, PD and HD.