Maria Victoria Tuttolomondo

A functional material that combines the Cr(VI) reduction activity of Burkholderia sp. with the adsorbent capacity of sol–gel materials

In the present work, Cr(VI) reduction in aqueous as well as in soil environments has been studied using free and sol–gel immobilized Burkholderia sp. Enhanced reduction rates were achieved by immobilized cells, which are found to be protected from the deleterious effects of high Cr(VI) concentrations. Immobilized bacteria showed enhanced performance in comparison with free cells because of the combination of bacteria biotransformation effect and chromium adsorption on silica matrices. Moreover, bacteria did not lose any activity after four cycles of reutilization. Bacteria immobilized in silica matrices had the ability to completely reduce 100 µg ml−1Cr(VI) after 4 days of incubation in aqueous media and to transform 200 µg ml−1Cr(VI) after 7 days in sterile soil. Immobilized bacteria demonstrated highly efficient Cr(VI) reduction over the Cr(VI) concentration range 50–500 µg g−1 and 200–800 µg g−1 in aqueous and soil environments, respectively. These results highlight the potential of this functional material that combines the biological activity of bacterial cells with the adsorbent capacity of sol–gel materials.

Sol-gel Encapsulation of Biomolecules and Cells for Medicinal Applications

The sol-gel process provides a robust and versatile technology for the immobilization of biologicals. A wide range of inorganic, composites and hybrid materials can be prepared to encapsulate molecular drugs, proteins, antibodies/antigens, enzymes, nucleic acids, prokaryotic and eukaryotic cells into bulk gels, particles and films. This review describes the applications of sol-gel encapsulation relevant to medicinal chemistry focusing on the recent development of biosensors as well as systems for production, screening and delivery of bioactive compounds and biomaterials.

Advances in collagen, chitosan and silica biomaterials for oral tissue regeneration: from basics to clinical trials

Different materials have distinct surface and bulk characteristics; each of them potentially useful for the treatment of a particular wound or disease. By reviewing those materials that have reached a clinical stage the reader will have a broad panorama of the possibilities a particular material can offer, regarding its ability to support fast tissue regeneration. This review covers the most recent advances made towards the development of biomaterials aimed to support regenerative processes. Indeed, we highlight key examples, from basic research to clinical trials, of biomaterials for a specific biomedical application. In this context, the focus is made on collagen, chitosan and silica which are key representatives of a protein, a polysaccharide and an inorganic material usually employed as biomaterials. Particularly, this review article presents an overview of their potential therapeutics in the treatment of disorders within the oral mucosa and tooth supporting tissues. Finally, the importance of in vivo and in vitro studies, clinical evidence studies, systematic reviews and meta-analyses as an adequate guidance for biomaterial design and development is highlighted.

Nanoparticles and capillary electrophoresis: A marriage with environmental impact

The impact of nanomaterials in the environment and human health is a cause of big concern and even though intensive studies are currently being carried out, there is still a lot to elucidate. The development of validated methods for the characterization and quantification of nanomaterials and their impact on the environment should be encouraged to achieve a proper, safe, and sustainable use of nanoparticles (NPs). Recently, CE emerged as a well‐adapted technique for the analysis of environmental samples. This review presents the application of NPs together with CE systems for environmental pollutants analysis, as well as the application of CE techniques for the analysis of various types of NPs.

Dye-collagen interactions. Mechanism, kinetic and thermodynamic analysis

A large family of azo dyes have been developed and used in the textile industry, including for leather tainting, and are therefore expected to exhibit strong interactions with collagen-based materials. Here we investigate the mechanisms of adsorption of the Remazol black B dye on type I collagen hydrogel. Higher and stronger retention of the dye is achieved in alkaline conditions, correlated with enhanced thermal and mechanical stability of the hydrogel. The formation of a covalent bond between the dye and the protein network via a Michael reaction is suggested and supported by the detailed analysis of the kinetics and thermodynamics of the sorption reaction. Type I collagen hydrogels combine low cost, fast sorption, high loading and strong retention capacity together with low storage volume, making them promising materials for dye remediation. Dye-modified hydrogels may also find applications in the biomedical field.

Exhausted Yerba Mate Leaves (Ilex paraguariensis) as Biosorbent for the Removal of Metals from Aqueous Solutions

Yerba mate is the most popular tea-like beverage of South America. Consequently, there is a huge generation of residues of exhausted yerba mate and these may be used for removal of metals. The capability of exhausted yerba mate leaves in the removal of metals was evaluated in this study. The greatest adsorption was found to be at pHs below 5 and the adsorption capacity was 12.28, 11.77 and 8.80 mg g-1 for Pb(II), Cr(III) and Cr(VI), respectively.

Innovative Immobilization Matrices.

We present a brief survey of some of the recent work of Professor Luis E. Díaz, performed together with his students and collaborators at the University of Buenos Aires. Dr Luis E. Díaz has been involved in research on biochemical and pharmaceutical sciences solving scientific and industry problems for over 40 years until he passed away. Prof. Díaz scientific interests included various topics from NMR spectroscopy to biomedicine but fundamentally he focused in various aspects of chemistry (analytical, organic, inorganic and environmental). This is not a complete survey but a sampling of prominent projects related to sol-gel chemistry with a focus on some of his recent publications.