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INTRODUCTION Magnetic responsive materials are the topic of intense research due to their potential breakthrough applications in the biomedical, coatings, microfluidics and microelectronics fields. By merging magnetic and polymer materials one can obtain composites with exceptional magnetic responsive features. Magnetic actuation provides unique capabilities as it can be spatially and temporally controlled, and can additionally be operated externally to the system, providing a non-invasive approach to remote control.[1] Porous biomaterials fabricated from natural and synthetic polymers have been intensively studied and widely used as drug delivery vehicles and scaffolds for tissue regeneration. Collagen is a natural polymer with an excellent biocompatibility and low antigenicity but with a rapid degradation and poor mechanical properties. These drawbacks limit its use in biomedical applications. In this context, a hybrid system, formed by a porous collagen scaffold and magnetite nanoparticles with a TiO2 shell (NPs@TiO2), was prepared in order to merge the potentiality of the paramagnetic material and the biocompatibility of the protein scaffold. The core/shell nanoparticles were also used as a novel crosslinker agent, as TiO2 guaranteed the binding to carboxylic groups[2] of collagen. In this way, scaffold mechanical properties and stability were also improved by the embedded nanoparticles. EXPERIMENTAL METHODS Synthesis of Porous Collagen Scaffold. An aqueous suspension of 1% w/v Type I collagen from bovine dermis was prepared by stirring for 5-6 hours at 10°C. A porous collagen scaffold was then obtained by casting, freeze-drying and dehydrothermal crosslinking (DHT). Synthesis of Porous Paramagnetic Collagen Scaffold. An aqueous solution of NPs@TiO2 was added to the collagen slurry while stirring. The suspension was then treated as reported above for the porous collagen scaffold. Characterization experiments. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetrical analysis (TGA) and swelling studies were carried out. The release of NPs@TiO2 from the collagen scaffold was studied by means of inductively coupled plasma mass spectroscopy analysis (ICP-MS). RESULTS AND DISCUSSION Paramagnetic iron oxide nanoparticles with a shell of TiO2 were incorporated within a collagen scaffold to obtain a hybrid porous material. This collagen-based matrix was highly sensitive to an external magnetic field. The optimal NPs@TiO2 concentration was determined by incorporating different amounts of nanoparticles into the collagen matrix, as quantified by means of TGA. The interaction among nanoparticles and the collagen fibers was studied by FTIR spectroscopy. As widely reported in the literature[2], TiO2 is able to bind carboxyl groups. In addition, we activated collagen carboxyl groups using N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide (EDC), to prompt the connection of these groups to the TiO2 coating. In order to evaluate the effect of NPs@TiO2 on the morphology of the collagen scaffold, scanning electron microscopy (SEM) was carried out. In the presence of NPs@TiO2, the average pore size of the collagen matrices was significantly reduced. This finding seemed to suggest that paramagnetic NPs worked as crosslinkers among the collagen fibers, inducing a rearrangement of the whole matrix. Swelling studies confirmed the fact that the NPs@TiO2, interacting with the collagen polymer matrix, played the role of crosslinkers [3]. The release of NPs@TiO2 from the matrix was monitored by incubating the samples in a phosphate buffered saline solution (pH 7.4) for 4 weeks at 37 °C. At each time point, iron release from the samples was determined using ICP-MS. The bond between NPs@TiO2 and collagen was thus found to be highly stable. CONCLUSION The results obtained in this study suggest the possibility to use a collagen matrices crosslinked with TiO2 coated paramagnetic iron oxide nanoparticles as potential biocompatible actuators that can be driven by external magnetic fields. Such characteristics make these innovative materials very appealing for different applications, such as drug delivery and tissue engineering.

The development and characterization of a novel bioactive polymer based on the immobilization of glucose oxidase enzyme (GOx) in a polyvinyl alcohol (PVA) film showing antibacterial activity is presented. The PVA-GOx composite material was extensively characterized by UV-vis, X-ray Photoelectron (XPS) spectroscopy and by Fourier Transform Infrared (FTIR) spectroscopy to verify the preservation of enzyme structural integrity and activity. The antimicrobial activity of this composite material against Escherichia coli and Vibrio alginolyticus was assessed. Furthermore the lysozyme-like activity of PVA-GOx was highlighted by a standard assay on Petri dishes employing Micrococcus lysodeikticus cell walls. The findings from this study have implications for future investigations related to the employment of PVA-GOx system as a composite material of pharmaceutical and technological interest. (c) 2013 Wiley Periodicals, Inc. Biopolymers 101: 461-470, 2014.

The evolution of the connections between Art and Science have been continually developing over the last few years. These links have led to many scientific characterisation and analysis techniques becoming increasingly applied to study works of art and artifacts. Today’s science and technology developments have led to many different approaches being used in the study of Cultural Heritage. New non-destructive methodologies allow one to apply physical and chemical analysis methods to valuable objects. Fourier transform infrared (FT-IR) spectroscopy has become a particularly useful technique in this field for the characterization of material composition; in particular, the use of the attenuated total reflection (ATR) sampling technique allows one to analyse a wide range and type of valuable objects without causing any damage to the samples. Capable of seeing beyond the careful eye of the restorer or of the art historian, the FT-IR/ ATR technique has been successfully employed in the material characterization of many different samples coming from the world of art. The first systematic studies using spectroscopic investigations on stamps were performed using both the FT-IR and Raman spectroscopic techniques. The immediate and detailed response from this type of study has led to a large and very significant amount of data and informainformation becoming available. Information which gives, not only an insight into the materials that compose a particular work of art, but also provide guidelines that supply further awareness important to conservative and restoration treatments. Discovering the ancient secrets of the artists and the real composition of art objects can be the key enlightening cases under study, which until that moment had been unresolved.

From the inscription of the General Post Office in Washington DC: “The stamp is the propagator of news, links between distant families, messenger between friends, solace in solitude, a vehicle for commerce and industry, an element of human progress, promoting brotherhood, peace, goodwill among men and nations”. It’s hard to imagine how much history can be held in a small piece of paper and how many purposes this little object was destined to have. This is why postage stamps have reached so much importance and interest, which they began to be considered as work of art actually. In order to see beyond the careful eye of the philatelist, FTIR (Fourier Transform Infrared Spectroscopy) in ATR (Attenuated Total Reflection) mode has been successfully employed in material characterization of many stamps. Samples since 1861, year of the unification of the Kingdom of Italy, until to date, across a vast philatelic collection, has been characterized in this study. The immediate response of this type of spectroscopic technique let to achieve significant data information, which led to design history changes in paper making technologies. The first mail stamps published in Italy portrayed King Vittorio Emanuele II and it showed to be made of sheet of cellulose paper. Going forward in years, many differences were detected in paper composition. The mail stamps were also observed by fluorescence microscopy, in order to determine differences in the application of fluorescence. The analyses were performed without any alteration of the samples and no removal of material was needed, which represents the “conditio sine qua non” for investigations on these kinds of Cultural Heritage.