Cytostatic and Cytotoxic Effects of Hollow-Shell Mesoporous Silica Nanoparticles Containing Magnetic Iron Oxide.

Among the different types of nanoparticles used in biomedical applications, Fe nanoparticles and mesoporous siliceous materials have been extensively investigated because of their possible theranostic applications. Here, we present hollow-shell mesoporous silica nanoparticles that encapsulate iron oxide and that are prepared using a drug-structure-directing agent concept (DSDA), composed of the model drug tryptophan modified by carbon aliphatic hydrocarbon chains. The modified tryptophan can behave as an organic template that allows directing the hollow-shell mesoporous silica framework, as a result of its micellisation and subsequent assembly of the silica around it.

Engineering hollow mesoporous silica nanoparticles to increase cytotoxicity.

Hollow mesoporous silica nanoparticles (HMSNs) consist of a network of cavities confined by mesoporous shells that have emerged as promising tools for drug delivery or diagnostic. The physicochemical properties of HMSNs are dictated by the synthesis conditions but which conditions affect which property and how it impacts on biological interactions is unclear. Here by changing the concentration of the structure-directing agent (SDA), the pH and the ratio between SDA and added salt (NaCl) we determine the effects in size, morphology, surface charge and density or degree of compaction (physicochemical properties) of HMSNs and define their impact on their biological interactions with human colon cancer or healthy cells at the level of cellular uptake and viability.

Design and assembly procedures for large-sized biohybrid scaffolds as patches for myocardial infarct.

Objective: To assemble a biohybrid cardiac patch consisting of a large (5 × 5 cm) elastomer scaffold whose pores are filled with a self-assembling peptide (SAP) gel entrapping adipose stem cells, to be used as a novel implant in a big animal model (sheep) of myocardial infarction. The study focuses on the way to determine optimal procedures for incorporating the SAP solution and the cells in the patch to ensure cell colonization and a homogeneous cell distribution in the construct before implantation. The problems associated with the scale-up of the different procedures raised by the large size of the construct are discussed.

One-dimensional migration of olfactory ensheathing cells on synthetic materials: experimental and numerical characterization.

Olfactory ensheathing cells (OECs) are of great interest for regenerative purposes since they are believed to aid axonal growth. With the view set on the strategies to achieve reconnection between neuronal structures, it is of great importance to characterize the behaviour of these cells on long thread-like structures that may efficiently guide cell spread in a targeted way. Here, rat OECs were studied on polycaprolactone (PCL) long monofilaments, on long bars and on discs.

Fibronectin distribution on demixed nanoscale topographies.

Purpose: It is known that surface nanotopography influences cell adhesion and differentiation. Our aim is to analyze the effect of nanoscale topography on fibronectin adsorption and, afterwards, on cell adhesion in order to rationalize the cell-material interaction by focusing on the state of the intermediate layer of adsorbed fibronectin at the material interphase.

Methods: Nanotopographic surfaces were produced by demixing of thin film polymer blends - PLLA and PS - during a high speed spin-casting process.