New graft copolymers of hyaluronic acid and polylactic acid: Synthesis and characterization

New graft copolymers have been synthesized, using hyaluronic acid (HA) as a hydrophilic backbone and polylactic acid (PLA) as an aliphatic polyester in order to obtain new polymeric derivatives of HA able to hydrophobically associate in an aqueous medium. Hyaluronic acid with low molecular weight was made soluble in organic solvent by transformation to its tetrabutylammonium (TBA) salt. Using the HA-TBA derivative, the reaction was performed in dimethylsulfoxide adding as a reagent the N-hydroxysuccinimide derivative of PLA. Two HA-PLA graft copolymers have been synthesized and characterized by FT-IR, H-1 NMR spectroscopy and gel permeation chromatography. The interaction between these samples and an aqueous medium has been evaluated by rheological measurements. The obtained data evidenced that both HA-PLA graft copolymers show in aqueous medium a clear tendency for hydrophobic interaction dependent on the amount of PLA chains linked to the HA backbone. (c) 2006 Elsevier Ltd. All rights reserved

Inulin as a multifaceted (active)substance and its chemical functionalization: From plant extraction to applications in pharmacy, cosmetics and food

This review is aimed at critically discussing a collection of research papers on Inulin (INU)in different scientific fields. The first part of this work gives an overview on the main characteristics of native INU, including production, applications in food or cosmetics industries, its benefits on human health as well as its main nutraceutical properties. A particular focus is dedicated to the extraction techniques and to the specific effects of INU on intestinal microbiota. Other than in food industry, the number of INU applications increases dramatically in the pharmaceutical field especially due to its simple chemical functionalization. Thus, aim of this review is also to give practical examples of chemical functionalization performed on INU also by including critical comments based on the direct experience of the Authors. With this aim, a full paragraph is dedicated to practical chemical experiences useful to reduce the efforts when establishing new experimental conditions. Moreover, the pharmaceutical technology is also taken in special consideration by underlining the aspects leading at the preparation of formulations based on INU. At the end of the review, a critical paragraph is intended to feed the scientists’ curiosity on this versatile polysaccharide