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The paper deals with the design and investigation of the morphology, in vitro drug release and biocompatibility of some new formulations based on polyvinyl alcohol boric acid (PVAB) and diclofenac sodium salt (DCF), with the aim to explore the ability of PVAB to act as a matrix for controlled drug delivery systems. A series of three formulations was obtained by mixing the drug and the polymeric matrix in different mass ratios, with high drug content from 10% w/w to 30% w/w. Their structural and supramolecular characterization, performed by FTIR spectroscopy and X-ray diffraction, revealed important physical interactions between the drug and the polymeric matrix. The morphological data, obtained by X-ray diffraction, polarized optical microscopy and scanning electron microscopy revealed the presence of the drug into the PVAB polymeric matrix, as micrometric polycrystals with a mean diameter in the range 10–15 μm, depending on the drug/polymer ratio. The investigation of their surface peculiarities indicated highly hydrophilic surfaces with a water to air contact angle between 29.9 and 41.4 deg and a surface free energy of 45.6–54.2 N/m2. The in vitro release kinetics was monitored by UV-VIS spectroscopy and the cytotoxic effect was investigated in vitro on fibroblasts and HeLa cells. The PVAB proved excellent cytocompatibility, a relative cell viability of the fibroblasts higher than 90% being recorded for concentrations of PVAB up to 7.5% w/v. The drug has been strongly anchored into the electron deficient PVAB matrix, fact which led to its prolonged release up to 5 days. These findings recommend PVAB as a versatile tool for the development of sustained release drug delivery systems with real chances to cross the gap from theory to applications. The biocompatible PVAB polymer led to sustained release drug delivery systems by anchoring the DCF drug into the polymeric matrix through strong physical interactions. Image 1 • Poly(vinyl alcohol boric acid) (PVAB) was used for the development of drug delivery systems. • Diclofenac (DCF) drug was anchored by electrostatic interactions in the polymeric matrix. • The drug delivery systems released the encapsulated drug in a sustained manner. • The evaluation of the PVAB cytotoxicity revealed high potential for bioapplications. [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]