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The present paper focuses on the synthesis and characterization of new hydrogels and drug delivery systems, designed for local therapy. The hydrogels were obtained by reacting PEG-ylated chitosan derivatives with citral in different molar ratios of their functionalities. The drug delivery systems were obtained by the in situ hydrogelation of PEG-ylated chitosan derivatives with citral, in the presence of a hydrophilic anti-inflammatory drug, diclofenac sodium salt. The hydrogels and the drug delivery systems were characterized from the structural, supramolecular and morphological points of view by FTIR spectroscopy, wide angle X-ray diffraction, polarized optical microscopy and scanning electron microscopy. The in vitro release kinetics of the drug has been monitored in physiological conditions, while the in vivo release was evaluated by the somatic pain model on rats. The in vitro enzymatic degradability of the hydrogels was evaluated in the presence of lysozyme, leading to a significant mass loss of 47% in 21 days. All the findings, recommend the investigated materials as promising candidates for local drug delivery applications. Unlabelled Image [ABSTRACT FROM AUTHOR]

The paper reports a series of three new PEGylated phenothiazine derivatives which keep the potential of valuable building blocks for preparing eco-materials addressed to a large realm of fields, from bio-medicine to opto-electronics. They were synthetized by connecting the hydrophilic poly(ethylene glycol) to the hydrophobic phenothiazine via an ether, ester, or amide linking group. The successful synthesis of the targeted polymers and their purity were demonstrated by NMR and FTIR spectroscopy methods. Their capacity to self-assembly in water was studied by DLS and UV–vis techniques and the particularities of the formed aggregates were investigated by fluorescence spectroscopy, SEM, AFM, POM and UV light microscopy. The biocompatibility was assessed on normal human dermal fibroblasts and human cervical cancer cells. The synthetized compounds showed the formation of luminescent aggregates and proved excellent biocompatibility on normal cells. In addition, a concentration dependent cytotoxicity against HeLa cancer cells was noticed for the PEGylated phenothiazine containing an ester unit. Unlabelled Image • PEG was successfully grafted on phenothiazine via ether, ester of amide linking unit. • The PEGylated phenothiazines were water soluble and formed stable luminescent aggregates. • They presented in vitro biocompatibility on normal cells. • The ester containing polymer presented concentration dependent cytotoxicity against HeLa cells. [ABSTRACT FROM AUTHOR]