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Anti-infective properties of biomedical materials are often achieved by loading or coating them with powerful bactericides. Undesirably, these bioactive molecules can damage the host cells at the biomaterial-tissues interface and, sometimes, even determine systemic toxic effects. The search for biomaterials able to actively resist infection while displaying a safe cytocompatibility profile toward eukaryotic cells is being progressively developed. Poly-( d, l)lactic acid (PLA) is a broadly used resorbable material with established biocompatibility properties. The dissolving surfaces of a biodegradable material tend to be per se elusive for bacteria. Here, films of pristine PLA, of PLA blended with vitamin E (VitE) and PLA blended with vitamin E acetate (VitE ac) were challenged in vitro with the biofilm-producers Staphylococcus epidermidis RP62A and Staphylococcus aureus ATCC25923. The bacterial adhesion properties of the different materials were investigated on small film disc specimens by a method based on microtiter plates. Adherent bacteria were quantified by both CFU plating and bioluminescence. Significant decrease in bacterial adhesion and biofilm accumulation was found on the surface of both the enriched polymers. These findings, together with the favorable intrinsic properties of PLA and the desirable bioactivities conferred by VitE, point up the VitE-blended PLA polymers as gentle anti-infective biomaterials. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1447-1458, 2015. [ABSTRACT FROM AUTHOR]

ABSTRACT Mechanical properties of poly( d,l)lactic acid films enriched with Vitamin E and Vitamin E Acetate (5-40% w/w) were investigated. The addition of both formulations resulted in increased polymer Young's modulus and tensile strength. Human foreskin fibroblasts and murine pre-osteoblasts were used to assess the biocompatibility of polymers. Pre-osteoblasts adhesion and proliferation were strongly decreased by Vitamin E, whereas Vitamin E Acetate did not alter cell proliferation. Collagen deposition was lower onto Vitamin E blended polymers than onto native and Vitamin E Acetate blended ones. Fibroblasts adhesion and proliferation were increased by both Vitamin E and Vitamin E Acetate addition. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39970. [ABSTRACT FROM AUTHOR]

Biocompatible and resorbable polylactic acid (PLA) derived polymers are used for clinical applications. Antioxidant vitamin E (Vit.E) and vitamin E acetate (Vit.E Ac), a Vit.E commercial analog, were added to PLA during films preparation. Wettability, protein adsorption analysis, platelet adhesion and whole blood coagulation experiments highlighted that Vit.E incorporation improved PLA hemocompatibility. NMR analysis showed that Vit.E and Vit.E Ac blending differentially altered PLA polymer organization with Vit.E leading to the formation of microcavities, as observed by SEM analysis, while reducing surface hydrophobicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Novel hydrogel composites based on natural gelatin matrix and containing different loading of a water soluble octa-ammonium POSS (POSS-NH3+), (from 0.5 to 2 wt%) have been prepared in this work and their biocompatibility and mechanical behavior have been tested. The presence of 1 wt% of POSS-NH3+ molecules in the hydrogel matrix increased the amount of human plasma proteins adsorption and human keratinocyte adhesion at 24 hours. In addition, the presence of increasing amounts of POSS in the hydrogel matrix allowed to a significantly increase of the matrix swelling degree at acid and neutral pH. Finally, a significant modulation of the mechanical characteristics (Young modulus, strain at break) of the hydrogel matrix induced by the presence of different amounts of POSS-NH3+ was observed. The novel ability of POSS-NH3+ to modulate both biological and mechanical properties of a natural hydrogel could be useful for the production of new composites of interest for soft tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA)-derived polymers are widely used in many biotechnological fields, thanks to their biocompatibility and resorbability through natural pathways. Moreover, PLA is one of the few polymers in which both the properties and the stereochemical structure can be easily modified, making possible a specific ‘tailoring’ of the final polymer according to the desired use. In this study, we obtained, by salt leaching technique, P(d,l)LA sponges in which various concentrations of α-tocopherol (Vit. E 10–40%, w/w) were incorporated. Vit.E is a natural biological antioxidant, also known to have anti-inflammatory activity, which has been extensively used to improve biostability and biocompatibility of different biomaterials. To assess whether Vit.E could modify the main physical–chemical properties of P(d,l)LA sponges, their morphology, water uptake and hydrolytic degradation kinetics, along with protein loading and releasing attitudes, were investigated. Our results highlighted that incorporation of Vit.E into P(d,l)LA sponges modified the sponge morphology, decreased P(d,l)LA water uptake and degradation, and modified protein releasing kinetics. These Vit.E-related effects could make P(d,l)LA more suitable as drug delivery system and tissue engineering scaffold. [ABSTRACT FROM AUTHOR]

UDP-glucose dehydrogenase (UGDH) supplies the cell with UDP-glucuronic acid (UDP-GlcUA), a precursor of glycosaminoglycan and proteoglycan synthesis. Here we reported the cloning and the characterization of the UGDH from the amphibian Xenopus laevis that is one of the model organisms for developmental biology. We found that X. laevis UGDH (xUGDH) maintained a very high degree of similarity with other known UGDH sequences both at the genomic and the protein levels. Also its kinetic parameters are similar to those of UGDH from other species. During X. laevis development, UDGH is always expressed but clearly increases its mRNA levels at the tail bud stage (i.e. 30 h post-fertilization). This result fits well with our previous observation that hyaluronan, a glycosaminoglycan that is synthesized using UDP-GlcUA and UDP-N-acetylglucosamine, is abundantly detected at this developmental stage. The expression of UGDH was found to be related to hyaluronan synthesis. In human smooth muscle cells the overexpression of xUGDH or endogenous abrogation of UGDH modulated hyaluronan synthesis specifically. Our findings were confirmed by in vivo experiments where the silencing of xUGDH in X. laevis embryos decreased glycosaminoglycan synthesis causing severe embryonic malformations because of a defective gastrulation process. [ABSTRACT FROM AUTHOR]

Medical treatment with low ozone concentrations proved to exert therapeutic effects in various diseases by inducing a cytoprotective antioxidant response through the nuclear factor erythroid derived-like 2 (Nrf2) transcription factor pathway. Low ozone doses are increasingly administered to oncological patients as a complementary treatment to mitigate some adverse side-effects of antitumor treatments. However, a widespread concern exists about the possibility that the cytoprotective effect of Nrf2 activation may confer drug resistance to cancer cells or at least reduce the efficacy of antitumor agents. In this study, the effect of low ozone concentrations on tamoxifen-treated MCF7 human breast cancer cells has been investigated in vitro by histochemical and molecular techniques. Results demonstrated that cell viability, proliferation and migration were generally similar in tamoxifen-treated cells as in cells concomitantly treated with tamoxifen and ozone. Notably, low ozone concentrations were unable to overstimulate the antioxidant response through the Nfr2 pathway, thus excluding a possible ozone-driven cytoprotective effect that would lead to increased tumor cell survival during the antineoplastic treatment. These findings, though obtained in an in vitro model, support the hypothesis that low ozone concentrations do not interfere with the tamoxifen-induced effects on breast cancer cells.

Anti-infective properties of biomedical materials are often achieved by loading or coating them with powerful bactericides. Undesirably, these bioactive molecules can damage the host cells at the biomaterial-tissues interface and, sometimes, even determine systemic toxic effects. The search for biomaterials able to actively resist infection while displaying a safe cytocompatibility profile toward eukaryotic cells is being progressively developed. Poly-(D,L)lactic acid (PLA) is a broadly used resorbable material with established biocompatibility properties. The dissolving surfaces of a biodegradable material tend to be per se elusive for bacteria. Here, films of pristine PLA, of PLA blended with vitamin E (VitE) and PLA blended with vitamin E acetate (VitE ac) were challenged in vitro with the biofilm-producers Staphylococcus epidermidis RP62A and Staphylococcus aureus ATCC25923. The bacterial adhesion properties of the different materials were investigated on small film disc specimens by a method based on microtiter plates. Adherent bacteria were quantified by both CFU plating and bioluminescence. Significant decrease in bacterial adhesion and biofilm accumulation was found on the surface of both the enriched polymers. These findings, together with the favorable intrinsic properties of PLA and the desirable bioactivities conferred by VitE, point up the VitE-blended PLA polymers as gentle anti-infective biomaterials., (© 2014 Wiley Periodicals, Inc.)

Organically modified mesoporous silica nanoparticles (MSNs) containing rose bengal (RB), a xanthene dye, were successfully synthesized. RB-modified MSNs have shown a relevant photostability and a high efficiency in the photoproduction and delivery of singlet oxygen ((1)O2), which is particularly promising for photodynamic therapy (PDT) applications. In vitro tests have evidenced that RB-MSNs are able to reduce cell proliferation in one of the most aggressive skin cancer types (SK-MEL-28) after green-light irradiation., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The development of vascular pathology is often coupled to dramatic alterations of the extracellular matrix (ECM), which provides critical support for vascular tissue as a scaffold for maintaining the organization of vascular cells into blood vessels, for blood vessel stabilization, morphogenesis, and for cell proliferation, migration, and survival. Hyaluronan (HA) is an important component of the ECM that has generated increasing interest because of its multitude of functions. HA is a linear polymer belonging to the family of glycosaminoglycans (GAGs), which comprises the major fraction of carbohydrates in ECM. Evidence supports the hypothesis that HA is an important contributor to human aortic smooth muscle cell (AoSMC) migration which represents a crucial point in the onset of pathology. By reducing HA synthesis and therefore the AoSMC motility, 4-Metyllumbelliferone (4-MU) could represent a new molecule with additional beneficial pharmacological effects in vivo.