Synthesis and anticancer activity of silver(I)– N-heterocyclic carbene complexes derived from the natural xanthine products caffeine, theophylline and theobromine

A new library of silver(I)–N-heterocyclic carbene complexes prepared from the natural products caffeine, theophylline and theobromine is reported. The complexes have been fully characterised using a combi- nation of NMR spectroscopy, mass spectrometry, elemental analysis and X-ray diffraction analysis. Fur- thermore, the hydrophobicity of the complexes has been measured. The silver(I)–N-heterocyclic carbenes have been evaluated for their antiproliferative properties against a range of cancer cell lines of different histological types, and compared to cisplatin. The data shows different profiles of response when compared to cisplatin in the same panel of cells, indicating a different mechanism of action. Furthermore, it appears that the steric effect of the ligand and the hydrophobicity of the complex both play a role in the chemosensitivity of these compounds, with greater steric bulk and greater hydrophilicity delivering higher cytotoxicity

The electron conduction of photosynthetic protein complexes embedded in a membrane

The conductivity of two photosynthetic protein–pigment complexes, a light harvesting 2 complex and a reaction center, was measured with an atomic force microscope capable of performing electrical measurements. Current–voltage measurements were performed on complexes embedded in their natural environment. Embedding the complexes in lipid bilayers made it possible to discuss the different conduction behaviors of the two complexes in light of their atomic structure

Microbial Symbionts of Antarctic Marine Benthic Invertebrates

The microbial colonization of living surfaces may be affected by several environmental and biological factors and may play an important role in the development and evolution of the holobiont. Antarctica, as an extreme and isolated environment, offers a unique opportunity to study the peculiar and often strict interactions that are established between a benthic host and its symbionts. Despite this, to date the association between microbes and Antarctic benthic invertebrates has been only seldom investigated, resulting in fragmented and poor information. This chapter will be devoted to showcase our current knowledge on prokaryotic (Bacteria and Archaea) and eukaryotic (yeasts and diatoms) microbial symbionts of Antarctic benthic invertebrate hosts, including mainly Porifera and, at to a lesser extent, Cnidaria, Echinodermata and Annelida

Lipid-Coated Cisplatin Nanoparticles Induce Neighboring Effect and Exhibit Enhanced Anticancer Efficacy

Encapsulation of cisplatin (CDDP) into nanoparticles (NPs) with high drug loading and encapsulation efficiency has been difficult due to the poor solubility of CDDP. However, this barrier has been overcome with a reverse microemulsion method appropriating CDDP’s poor solubility to our advantage promoting the synthesis of a pure cisplatin nanoparticle with a high drug loading capacity (approximately 80.8wt%). Actively targeted CDDP NPs exhibited significant accumulation in human A375M melanoma tumor cells in vivo. In addition, CDDP NPs achieved potent anti-tumor efficacy through the neighboring effect at a dose of 1 mg/kg when injected weekly via IV without inducing nephrotoxicity. The neighboring effect regards an observation made in vivo when the tumor cells that took up CDDP NPs released active drug following apoptosis. Via diffusion, surrounding cells that were previously unaffected showed intake of the released drug and their apoptosis soon followed. This observation was also made in vitro when A375M melanoma tumor cells incubated with CDDP NPs exhibited release of active drug and induced apoptosis on untreated neighboring cells. However, the neighboring effect was unique to rapidly proliferating tumor cells. Liver functional parameters and H&E staining of liver tissue in vivo failed to detect any difference between CDDP NP treated and control groups in terms of tissue health. By simultaneously promoting an increase in cytotoxicity and a lesser degree of side effects over free CDDP, CDDP NPs show great therapeutic potential with lower doses of drug while enhancing anti-cancer effectiveness