Dry eye is a common eye disease that imposes a huge economic and medical burden on society. Oxidative stress is closely related to the occurrence of dry eye disease, but due to low efficiency, toxicity and poor bioavailability, there are few antioxidants available in clinical practice. Cerium-based nanozymes have good enzyme mimetic activity and can scavenge reactive oxygen species. In addition, the ultra-small metal-organic frameworks (MOFs) have higher drug delivery efficiency, reactive oxygen species scavenging capacity, and ** effect. However, due to the challenges of the synthesis process and stability, the development of ultra-small cerium-based MOFs is still limited.
Based on the above questions,Eye and Otolaryngology Hospital Affiliated to Fudan UniversityZhou XingtaoProfessor, School of Materials and Chemistry, University of Shanghai for Science and TechnologyLi GuishengProfessor, Eye and Otolaryngology Hospital of Fudan UniversityYang MeiProfessors andHuang JinhaiTeam of professorsAn ultra-small cerium organic framework nanozyme for dry eye disease was constructed as a high-efficiency antioxidant**. The study, titled "Engineering Ultra-Small Cerium-Based Metal Organic Frameworks Nazymes for Efficient Antioxidative Treatment of Dry Eye Disease", was published in Advanced Functional Materials.
In the past, the strategies for the preparation of size-controllable inorganic nanocrystals were mainly initial nucleation, growth and maturation, such as high-temperature injection and liquid-solid phase transfer. In this study, the particle size of CE-MOFs was controlled only by the raw material concentration (Figure 1A). The reaction volume of 32ml of different concentrations of raw materials was introduced into a PTFE-lined hydrothermal autoclave, and the reaction was heated at 100 for 1h to obtain CE-MOF10.708g H2BDC and 232 g (NH4)2CE(NO3)6, high concentration、ce-mof20.354g H2BDC and 116 g (NH4)2CE(NO3)6, medium concentrationand ce-mof30.177g H2BDC and 0558 g (NH4)2CE(NO3)6, low concentration。The morphology of the resulting CE-MOFs was identified as nanoparticles with different characteristics. Scanning electron microscopy (SEM) imaging preliminarily showed that CEMOFs were composed of homogeneous nanoparticles of different sizes, and the input mass of CE-MOF1 and CE-MOF3 was halved in CE-MOF1, CE-MOF2 and CE-MOF3, and the particle size was significantly reduced (Fig. 1A, SEM). The transmission electron microscopy (TEM) observations were consistent with the SEM results, and the sizes of CE-MOF1, CE-MOF2, and CE-MOF3 were approximately 2 nm, respectively, indicating that the raw material concentration had a significant effect on the morphology of the final product (Fig. 1A, TEM).
Since the amount of raw material added will affect the morphology of the product, the authors further studied the internal structural changes of CE-MOFS. The three-dimensional crystal structure of Ce-Mofs is formed by the coordination between a pair of carboxyl groups of H2BDC and positively charged cerium ions (Figure 2A).
Figure 1Schematic diagram of the formation and anti-DED** mechanism of ultra-small Ce-mof-3 nanozyme.
Dry eye disease is a common lifelong eye disease that imposes considerable medical and economic burden on humans. In this study, three different sizes of CE-MOF were prepared by adjusting the concentration of raw materials. Compared with CE-MOF1 and CE-MOF2, CE-MOF3 was obtained with the smallest size, but there was no difference in XRD and FTIR results. All Ce-MOFs had strong in vitro scavenging O2 and H2O2 activities, and had SOD and CAT simulation activities, respectively. It is worth noting that CE-MOF3 is superior to CE-MOF1 and CE-MOF2 in terms of ROS clearance, inhibition of intracellular ROS and cytotoxicity. In addition, the ultra-small CE-MOF3 nanozyme can effectively penetrate into the ocular tissue, alleviate DED symptoms, and has excellent short- and long-term biocompatibility for clinical translation.
Original link:
Material Treasure Box.
Declaration:It only represents the author's personal point of view, the author's level is limited, if there is anything unscientific, please leave a message below to correct!