The paper proposed a new porous material for wound healing based on chitosan and C-phycocyanin (C-PC). In this work, C-PC was extracted from the cyanobacteria Arthrospira platensis biomass and purified through ammonium sulfate precipitation. The obtained C-PC with a purity index (PI) of 3.36 ± 0.24 was loaded into a chitosan sponge from aqueous solutions of various concentrations (250, 500, and 1000 mg/L). According to the FTIR study, chitosan did not form new bonds with C-PC, but acted as a carrier. The encapsulation efficiency value exceeded 90%, and the maximum loading capacity was 172.67 ± 0.47 mg/g. The release of C-PC from the polymer matrix into the saline medium was estimated, and it was found 50% of C-PC was released in the first hour and the maximum concentration was reached in 5–7 h after the sponge immersion. The PI of the released C-PC was 3.79 and 4.43 depending on the concentration of the initial solution.

In this paper, we describe mechanochemical approach as an environmentally friendly method to obtain chitosan and gallic acid derivatives. Covalent cross-linking with a polysaccharide is one way to stabilize antioxidants and improve their bioavailability. Since gallic acid is a solid compound with limited solubility and a high melting point (220-240 °C), it was of interest to conduct its interaction with chitosan using solid-state synthesis technique under shear deformations. The experimental conditions were selected using a pilot twin-screw extruder designed for processing solid dispersions. The insertion of gallate groups onto the polymeric backbones was confirmed by 1H NMR, FTIR and UV–vis analyses. Dynamometry was used for study of rheological properties. Depending on the synthesis conditions, the amount of bound gallic acid was more than 600 mg per 1 g of chitosan. It was found that gallate groups are predominantly linked to chitosan via salt bonds. Carrying out the process at a moderate temperature (100-120 °C) led to the formation of amide bonds between chitosan and gallic acid. In contrast to the physical mixing of components, the resulting products swelled well and partially dissolved in water, and tended to form aggregates with an average size of 206±36 µm in aqueous media.

Immobilized microalgae (MA) are widely used for the production of biomass and high value-added metabolites, the biocapture of nutrients and heavy metals, and for the destruction of organic pollutants in wastewater