Takinami Patricia Y I, Mastro Nelida L Del, Ashfaq Aiysha, Al-Sheikhly Mohamad
Center of Radiation Technology, Institute of Energy and Radiation Research-IPEN/CNEN, Av. Prof. Lineu Prestes, 2242, Cidade Universitária, Sao Paulo 05508-910, Brazil.
Department of Chemistry and Biochemistry, University of Maryland College Park, College Park, MD 20742, USA.
Polymers (Basel). 2023 Oct 18;15(20):4128. doi: 10.3390/polym15204128.
Nanohydrogel particles of polyethylene glycol (PEG), gelatin (GEL), and PEG-GEL mixtures (MIXs) were synthesized with a high electron beam and Co gamma-ray radiation. The relatively novel technique of Asymmetrical Flow Field Flow Fractionation (AF4 or AFFFF) coupled to a Multi-Angle Laser Light Scattering (MALLS) detector was mainly used to determine the hydrodynamic diameter (D) of the radiation-synthesized PEG, GEL, and PEG-GEL nanohydrogel particles. Our approach to achieving nanohydrogel particles is to enhance the intracrosslinking reactions and decrease the intercrosslinking reactions of the C-centered radicals of the PEG and GEL. The intracrosslinking reactions of these free radicals were enhanced via irradiation at temperatures of 77-80 °C and using a high dose rate and pulsed irradiation. The shorter average distance between the C-centered free radicals on the backbone of the thermally collapsed PEG and GEL chain, due to the destruction of hydrogen bonds, enhances the intracrosslinking reactions. It was observed that increasing the dose and dose rate decreased the D. DLS results lined up with AF4 measurements. This study provides researchers with a clean method to produce GEL-PEG hydrogels without the use of toxic reagents. Particle size can be tuned with dose, dose rate, and temperature as demonstrated in this work. This is ideal for medical applications as the use of ionizing radiation eliminates toxicity concerns and provides simultaneous sterilization of the material.
采用高电子束和钴伽马射线辐射合成了聚乙二醇（PEG）、明胶（GEL）以及PEG - GEL混合物（MIXs）的纳米水凝胶颗粒。主要使用与多角度激光光散射（MALLS）检测器联用的相对新颖的不对称流场流分级法（AF4或AFFFF）来测定辐射合成的PEG、GEL和PEG - GEL纳米水凝胶颗粒的流体动力学直径（D）。我们制备纳米水凝胶颗粒的方法是增强PEG和GEL以碳为中心的自由基的内交联反应并减少其交联反应。通过在77 - 80°C的温度下、使用高剂量率和脉冲辐射进行辐照，增强了这些自由基的内交联反应。由于氢键的破坏，热塌陷的PEG和GEL链主链上以碳为中心的自由基之间较短的平均距离增强了内交联反应。观察到增加剂量和剂量率会使D减小。动态光散射（DLS）结果与AF4测量结果一致。本研究为研究人员提供了一种无需使用有毒试剂即可制备GEL - PEG水凝胶的清洁方法。如本工作所示，粒径可通过剂量、剂量率和温度进行调节。这对于医疗应用来说是理想的，因为电离辐射的使用消除了毒性问题，并能同时对材料进行灭菌。
