Comparative properties of composite poly(lactic-co-glycolic acid)/poly(acrylic acid) implants synthesized using ultraviolet and gamma irradiation

Composite implants comprising a biodegradable hydrophobic polymer matrix and crosslinked hydrogel with fixed ion exchange groups are promising materials for the construction of controlled drug delivery systems. Poly(lactic-co-glycolic acid)/poly(acrylic acid) (PLGA/PAA) composite implants in our study were synthesized using the sequential application of irradiation and immersion precipitation. Precursor solutions with all functional components were dispensed into a disc-shaped non-stick mold and cured either by ultraviolet (UV) or gamma irradiation. Cured disks were subsequently immersed in the phosphate buffer saline bath to finalize phase separation and solidification of the implants. The synthesized implants were characterized by FTIR-ATR and DSC, and their basic properties such as ion exchange capacity, swelling degree, and swelling kinetics were examined. Synthesis using gamma irradiation resulted in implants with similar ion exchange capacity, but the greater swelling degree and faster swelling kinetics compared to the implants prepared with UV irradiation. Gamma irradiation also resulted in altered and less homogeneous chemical composition compared to the implants synthesized with UV irradiation. Further investigations are required to determine the differences in drug release kinetics and degradation behavior of the synthesized implants

Use of low-energy electron-beam in the treatment of special food products with a high protein content

Special high-protein foods suitable for diabetics must be treated to ensure the complete absence of microorganisms and bacteria. It is also important to achieve that this treatment does not change the nutritional value of the product. Among the new decontamination technologies, low-energy electron-beam treatment has proven to be an effective technique for inactivating bacteria with minimal impact on food quality. The paper aims to analyze the influence of low-energy electron-beam irradiation on the microbiological properties and nutritional value of high-protein foods

Dose mapping of products with different density irradiated in 60co irradiation facility of the Vinca institute, Serbia

The distribution of the absorbed dose within the irradiated product is a complex function of the product density and homogeneity, the position and shape of the radiation source, as well as the design of the irradiator. In this paper, detailed mapping of absorbed radiation doses in products of different density: gauze, plastic, and soil, is performed. Positions of minimum and maximum absorbed radiation dose were determined, and the homogeneity of irradiation of products was calculated using the ethanol-monochlorobenzene oscillotitrator dosimetry system

Accuracy in determining absorbed irradiation dose at different temperature measurements using ethanol chlorobenzene - oscillotitrator system

Ethanol-chlorobenzene/oscillotitrator dosimetry system is widely used in controlling the irradiation process in gamma facilities. The ethanol-chlorobenzene dosimetry system provides a reliable means of measuring absorbed dose. It is based on a process of radiolytic formation of hydrochloric acid in aqueous ethanolic solutions of chlorobenzene by ionizing radiation. The irradiation temperature dependence of dosimeter response is a complex function of dose and temperature for each concentration of chlorobenzene. At different temperature the mobility of conducting species from hydrochloric acid is changed leading to different oscillotitrator deflections during high-frequency conductometric readout. In this paper, we examined the influence of temperature on the calculation of the radiation dose. We showed that the temperature significantly influenced the measurement results, and that the calibration curve has to be formed at the irradiation temperature in order to obtain precise values of the absorbed dose