The main goal of this research was to create biocompatible hydrogels using gelatin and a double cross-linking technique involving both covalent and ionic bonds to immobilize propolis. The covalent bonds were formed through Schiff base cross-links between protein-free amino groups (NH) from the lysine residue and aldehyde groups (CHO) produced by oxidizing sodium alginate with NaIO, while the ionic bonds were achieved using Mg ions. Hydrogel films were obtained by varying the molar ratios of -CHO/-NH under different pH conditions (3.
View Article and Find Full Text PDFAdding carbonyl groups into the hydrogel matrix improves the stability and biocompatibility of the hydrogels, making them suitable for different biomedical applications. In this review article, we will discuss the use of hydrogels based on polysaccharides modified by oxidation, with particular attention paid to the introduction of carbonyl groups. These hydrogels have been developed for several applications in tissue engineering, drug delivery, and wound healing.
View Article and Find Full Text PDFThe physicochemical properties of "smart" or stimuli-sensitive amphiphilic copolymers can be modeled as a function of their environment. In special, pH-sensitive copolymers have practical applications in the biomedical field as drug delivery systems. Interactions between the structural units of any polymer-drug system imply mutual constraints at various scale resolutions and the nonlinearity is accepted as one of the most fundamental properties.
View Article and Find Full Text PDFThe wound-healing capacity of ointments based on bee products was investigated in vivo on three experimental models of incision, excision and heat burn. For this purpose, four ointments were prepared with propolis, honey, apilarnil (drone brood homogenate) and a mixture of these three apitherapy products. The ointments were applied topically for 21 days.
View Article and Find Full Text PDFCross-linked chitosan (CS) films with aldehyde groups obtained by oxidation of carboxymethyl cellulose (CMC) with NaIO were prepared using different molar ratios between the CHO groups from oxidized carboxymethyl cellulose (CMCOx) and NH groups from CS (from 0.25:1 to 2:1). Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy demonstrated the aldehyde groups' presence in the CMCOx.
View Article and Find Full Text PDFIn this paper we report on the production of microbioreactors using ionically cross-linked gellan containing immobilized yeast cells with potential application in glucose fermentation. Cross-linking was achieved through a novel extrusion process in capillary by ionotropic gelation under the action of magnesium acetate. Compared to commonly used methods, this provides a host of practical advantages.
View Article and Find Full Text PDF