In this study, pH indicative films were successfully synthesized from hydrogels made by blending 1% poly(vinyl alcohol) (PVA) and 1% chitosan (CS) with anthocyanin (ATH) and sodium tripolyphosphate (STPP). Particularly, ATH extracted from red cabbage was used as the pH indicator, while STPP was utilized as the cross-linking agent to provide better mechanical properties of the cast films. FT-IR spectra confirmed the existence of the ATH in the cast films. Moreover, the tensile strength, the elongation-at-break, and the swelling indices of the cast films were measured. In general, these properties of pH indicative films were profoundly influenced by the compositions of PVA/CS and the STPP dosage applied in the hydrogels. For example, the tensile strength could change from 43.27 MPa on a film cast from pure PVA hydrogel to 29.89 MPa, if 35% of the PVA hydrogel was substituted with CS. The cast films were applied as a food wrap that could be used to monitor visually the quality of the enwrapped food via the color change of the film upon the variation in pH values of the enwrapped food. In practice, a sequential change in color was successfully observed on the pH indicative films partially enwrapping the pork belly, indicating the spoilage of the meat.

A 58S bioglass with a composition in the ternary system 58SiO2-33CaO-9P2O5 (wt.%) was prepared by an innovation sol-gel process in which a small amount of ammonia was used to facilitate the condensation reactions within an acidic solution prepared by tetraethyl orthosilicate, triethyl phosphate and calcium nitrate tetrahydrate. The properties of synthetic glass were investigated by several techniques. The amorphous nature and high specific surface area (99.1m2/g) of the obtained glass were confirmed by using X-ray diffraction and low-temperature nitrogen adsorption techniques, respectively. In vitro experiments were performed by soaking glass samples in the simulated body fluid (SBF). The XRD patterns and SEM images confirmed the bioactivity of the synthesized bioglass by formation of a dense and visible hydroxyapatite layer on its surface after 2 days of in vitro assays. The ICP-OES data illustrated the ion exchange behaviours between the bioglass 58S and the SBF solution.

Bioactive glass 70SiO₂-30CaO (mol.%) was successfully synthesized by modified sol–gel in hot water without using an acid catalyst. TG-DSC analysis showed that the amorphous glass could be synthesized by sintering the sample at 700 °C for three hours. The N₂ adsorption/desorption and TEM investigations highlighted that the synthetic glass had a mesoporous structure, consisting of spherical particles with sizes in the range of 11–20 nm. The specific surface area, pore volume, and average pore diameter of synthetic glass were 150.13 m²/g, 0.37 cm³/g, and 11.84 nm, respectively. Moreover, synthetic bioactive glass presented interesting bioactivity and good biocompatibility after in vitro experiments in simulated body fluid (SBF) and in cellular medium.