Therapeutic Effect of Platinum Nanoparticles on Atherosclerosis Research Model Based on Microfluidics and Determination of Injury

Nanozymes for Regenerative Medicine

Nanozymes refer to nanomaterials that catalyze enzyme substrates into products under relevant physiological conditions following enzyme kinetics. Compared to natural enzymes, nanozymes possess the characteristics of higher stability, easier preparation, and lower cost. Importantly, nanozymes possess the magnetic, fluorescent, and electrical properties of nanomaterials, making them promising replacements for natural enzymes in industrial, biological, and medical fields. On account of the rapid development of nanozymes recently, their application potentials in regeneration medicine are gradually being explored. To highlight the achievements in the regeneration medicine field, this review summarizes the catalytic mechanism of four types of representative nanozymes. Then, the strategies to improve the biocompatibility of nanozymes are discussed. Importantly, this review covers the recent advances in nanozymes in tissue regeneration medicine including wound healing, nerve defect repair, bone regeneration, and cardiovascular disease treatment. In addition, challenges and prospects of nanozyme researches in regeneration medicine are summarized.

Intra-Epidural Space Injection of OX26-PEGylated Selenium Nanoparticles Enhances Motor Function and Decrease the Risk of Neural Damage in Animal Model of Subarachnoid Hemorrhage

Objective: To evaluate the effectiveness of PEGylated (PEG) OX26 loaded with Selenium (Se) on locomotor activity and brain function and exploring underlying mechanism in animal model of subarachnoid hemorrhage (SAH). Methods: Thoracis spinal cord injury in Wistar rats was used to induce SAH and intra-epidural injection of OX26-PEG-Se nanoparticles (NPs) was then applied. Locomotor function test was used to evaluate the behavioral outcome in addition, ELISA kit was used to evaluate the serum level of NSE and S100B. Immunofluorescent imaging was used to detect the expression of eNOS and NT-1. In addition, NeuN staing was used to assess the neural damage. Results: The locomotor function of animals with SAH was significantly increase afgter treating with OX26-PEG-Se NPs. In addition, the expression levels of NSE and S100B were significantly decrease after treating animals with OX26-PEG-Se NPs in comparison to sham operated animals. We observed that OX26-PEG-Se NPs decrease the neural damage and the level of NT-1, while increase the eNOS in brain. Conclusion: Intra-epidural injection of OX26-PEG-Se NPs improved the locomotor activity and also inhibit the risk of neural damage through ET-1/eNOS pathway after subarachnoid hemorrhage.

Metformin-Loaded Alginate Nanoparticles Inhibits Mouse Atherosclerosis by Regulating Macrophage Differentiation by Activating the Adenosine Monophosphate-Activated Protein Kinase/Signal Transducer and Activator of Transcription 3 Pathway

Objective: By modulating macrophage phenotype and the adenylate-activated protein kinase/signal transducer and activator of transcription 3 (STAT3) signaling pathway, metformin-loaded alginate nanoparticles may prevent atherosclerosis (As). Methods: Flow cytometry was used to determine the percentage of macrophages with distinct phenotypes (CD86 and CD206). Analysis of protein expression levels of iNOS, arginase 1, AMPK, pAMPK, STAT3 and phosphorylated STAT3 were performed by Western Blot. To confirm the in vitro findings, ApoE−/− mice were employed. Results: AMPK activity and the fraction of M2 macrophages dramatically increased in cells treated with Met, but STAT3 activity was considerably reduced. It was also shown that the Met group had much shorter aortas and lower levels of lipid deposition than that of the control group; also, the fraction of M1 macrophages in the lipid plaques of the animals treated with Met was dramatically reduced by using immunofluorescence labeling. There was a considerable increase in AMPK activity in the Met group, but STAT3 activity was dramatically lowered. Conclusion: According to the results of this study, STAT3 activity is regulated by activation of AMPK and macrophage development in plaques is prevented in mice by metformin-loaded alginate nanoparticles.