Natural Biopolymers as Smart Coating Materials of Mesoporous Silica Nanoparticles for Drug Delivery.

In recent years, the functionalization of mesoporous silica nanoparticles (MSNs) with different types of responsive pore gatekeepers have shown great potential for the formulation of drug delivery systems (DDS) with minimal premature leakage and site-specific controlled release. New nanotechnological approaches have been developed with the objective of utilizing natural biopolymers as smart materials in drug delivery applications. Natural biopolymers are sensitive to various physicochemical and biological stimuli and are endowed with intrinsic biodegradability, biocompatibility, and low immunogenicity.

Novel phosphine sulphide gold(i) complexes: topoisomerase I inhibitors and antiproliferative agents.

This work describes the synthesis of the gold(i) complexes of phosphine sulphides. The formation of these new derivatives has been confirmed by X-ray crystallography. The coordination of gold(i) with the sulphur atom of the phosphine sulphides favors the inhibition of topoisomerase I as well as a high cytotoxicity of the gold(i)-complexed compounds against the cancer line A549 with IC values in the nanomolar range and IC values below 5 μM against the SKOV3 cell line.

4-Pyridylisocyanide gold(i) and gold(i)-plus-silver(i) luminescent and mechanochromic materials: the silver role.

Crystallographic and DFT examination of the metalloligands [AuAr(CNPy-4)] (Ar = C6F5 (1), C6F3Cl2-3,5 (2)) and their silver complexes [Ag[AuAr(CNPy-4)]2](BF4) (3 and 4) support that the marked luminescence red-shifts observed on moving from 1 to 2, from 1,2 to 3,4, or upon grinding, are not caused by electronic differences (either by changing the aryls C6F5/C6F3Cl2, or by N coordination to silver), nor by non-existent AuAg interactions. They are always due to structural changes disturbing stronger π-π stackings in order to allow for shorter AuAu interactions.

dd RhAu interactions in Rh 2,6-xylylisocyanide complexes with [Au(CN)]: bond analysis and crystal effects.

The well-known [RhL4]n(anion)n structures, with RhIRhI d8d8 interactions, are replaced by others with RhIAuI d8d10 interactions such as [{RhL4}{Au(CN)2}] (L = 2,6-xylylisocyanide) or [{RhL4}{Au(CN)2}{RhL4}{Au2(CN)3}·4(CHCl3)]∞ when the anion is [Au(CN)2]-. Orbital (RhAu), coulombic, and inter-unit π-π aryl stacking interactions stabilize these crystal structures.