Annaclaudia Esposito

Second University of Naples, Caserta, Campania, Italy

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Publications (4)14.56 Total impact

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    ABSTRACT: In the last decade, cellulose-based hydrogels have been receiving increasing attention for a number of applications because of their smart swelling behavior, biodegradability, and biocompatibility. Given the dramatic spreading of obesity and overweight in the industrialized countries and the lack of scientific consensus over currently available dietary supplements, it was recently proposed that such hydrogels might be used as orally administered bulking agents in hypocaloric diets, because the hydrogel swelling in the stomach may greatly reduce the space available for food intake, thus giving a sense of fullness. This study is focused on the synthesis of cellulose-based hydrogels, starting from pharmaceutical and food grade cellulose derivatives, and shows that such hydrogels possess good swelling properties in water solutions mimicking the environmental conditions of the stomach and the intestine, as well as a good biocompatibility. The crosslinking agent used was a “zero-length” crosslinker, that is, a water soluble carbodiimide, which is washed out from the gel after the synthesis and does not affect the gel compatibility, as shown by preliminary biocompatibility assays. The experimental results confirmed that cellulose-based hydrogels might be a scientifically valid dietary adjuvant in the treatment of obesity and overweight, and provide further scientific evidence for future experiments on humans. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
    Journal of Applied Polymer Science 10/2009; 115(3):1438 - 1444. · 1.40 Impact Factor
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    ABSTRACT: Novel p(HEMA-co-METAC)/alginate semi-interpenetrating hydrogels (semi-IPNs) were developed in the attempt to improve poly(hydroxyethylmethacrylate) biological response, extending its applications in the biomedical field. Materials with different alginate contents were synthesized by copolymerization of 2-hydroxyethylmethacrylate and 2-methacryloxy ethyltrimethyl ammonium chloride monomers in the presence of aqueous solutions of alginate and characterized with respect to p(HEMA-co-METAC) synthesized in the presence of water. Swelling studies in water revealed high values of water uptake (>100%) with marked differences in the swelling degree at increasing polysaccharide content. The effect of ionic strength and of pH on the swelling behavior of hydrogels was also investigated. Higher ionic strengths resulted in a minor swelling degree accordingly with hydrogels polyelectrolyte nature. The introduction of the natural ionizable polysaccharide into the network made the semi-IPNs swelling depending on pH values of the solutions. A biological characterization was performed in terms of protein absorption on hydrogel surfaces, cytotoxicity (ISO 10993-5) and cell adhesion and proliferation studies using both murine 3T3 and human fibroblasts. Hydrogels proved noncytotoxic; moreover, semi-IPN surfaces allowed cell attachment and proliferation, thus supporting their potential biomedical use.
    Journal of Biomedical Materials Research Part A 06/2008; 90(1):292-302. · 2.83 Impact Factor
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    ABSTRACT: The elimination of water from the body represents a fundamental therapeutic goal in those diseases in which oedemas occur. Aim of this work is the design of a material able to absorb large amount of water to be used, by oral administration, in those cases in which resistance to diuretics appears. Sorption and mechanical properties of the cellulose based superabsorbent hydrogel acting as a water elimination system have been modulated through the insertion of molecular spacers between the crosslinks. Starting polymers are the sodium salt of carboxymethylcellulose (CMCNa), a polyelectrolyte cellulose derivative, and the hydroxyethylcellulose (HEC), a non-polyelectrolyte derivative. Polyethyleneglycol (PEG) with various molecular weights, has been linked by its free ends at two divinylsulfone (DVS) crosslinker molecules, in order to increase the average distance between two crosslinking sites and thus acting as spacer. Both the effect of concentration and molecular weight of the spacer resulted to significantly affect the hydrogel final sorption properties and thus the efficiency of the body water elimination system. Biocompatibility studies have been performed to test the hydrogel compatibility with respect to intestinal and macrophages cell lines. To investigate the effects of intestinal cells conditioned media after the contact with the gel on macrophages nitric oxide release tests have been carried out.
    Biomaterials 08/2005; 26(19):4101-10. · 8.31 Impact Factor
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    ABSTRACT: John Allen, a British physician of the eighteenth century, deserves being remembered for a series of inventions, but most importantly -- from a 'medical' point of view -- for his highly praised manuscript, the 'Universae Medicinae Practicae,sive Doctissimorum Virorum de Morbis Eorumque Causis ac Remediis Judicia', which long served as a text-book for medical students of the time, and also as a reference book for practitioners throughout European countries, for several decades after its original first publication. It contains the opinions ('Sententiae') of the most celebrated authors of all ages, from Hippocrates, Galen and Avicenna up to Allen's contemporaries, concerning a wide number of diseases, their causes, signs, symptoms, and therapeutical remedies where available. The present paper deals mostly with parts of the Synopsis concerning renal diseases and related clinical signs.
    Journal of nephrology 19 Suppl 10:S98-101. · 2.02 Impact Factor