Reconstruction of TNF-α with specific isoelectric point released from SPIONs basing on variable charge to enhance pH-sensitive controlled-release.

The clinical application of tumor necrosis factor-α (TNF-α) is limited by its short half-life, subeffective concentration in the targeted area and severe systemic toxicity. In this study, the recombinant polypeptide S4-TNF-α was constructed and coupled with chitosan-modified superparamagnetic iron oxide nanoparticles (S4-TNF-α-SPIONs) to achieve pH-sensitive controlled release and active tumor targeting activity. The isoelectric point (pI) of S4-TNF-α was reconstructed to approach the pH of the tumor microenvironment. The negative-charge S4-TNF-α was adsorbed to chitosan-modified superparamagnetic iron oxide nanoparticles (CS-SPIONs) with a positive charge through electrostatic adsorption at physiological pH. The acidic tumor microenvironment endowed S4-TNF-α with a zero charge, which accelerated S4-TNF-α release from CS-SPIONs. Our studies showed that S4-TNF-α-SPIONs displayed an ideal pH-sensitive controlled release capacity and improved antitumor effects. Our study presents a novel approach to enhance the pH-sensitive controlled-release of genetically engineered drugs by adjusting their pI to match the pH of the tumor microenvironment.

Recent Advances in Hepatic Metabolic Regulation by the Nuclear Factor Rev-erbɑ.

Rev-erbɑ (NR1D1) is a nuclear receptor superfamily member that plays a vital role in mammalian molecular clocks and metabolism. Rev-erbɑ can regulate the metabolism of drugs and the body's glucose metabolism, lipid metabolism, and adipogenesis. It is even one of the important regulatory factors regulating the occurrence of metabolic diseases (e.g., diabetes, fatty liver). Metabolic enzymes mediate most drug metabolic reactions in the body. Rev-erbɑ has been recognized to regulate drug metabolic enzymes (such as Cyp2b10 and Ugt1a9). Therefore, this paper mainly reviewed that Rev-erbɑ regulates I and II metabolic enzymes in the liver to affect drug pharmacokinetics. The expression of these drug metabolic enzymes (up-regulated or down-regulated) is related to drug exposure and effects/ toxicity. In addition, our discussion extends to Rev-erbɑ regulating some transporters (such as P-gp, Mrp2, and Bcrp), as they also play an essential role in drug metabolism. Finally, we briefly describe the role and mechanism of nuclear receptor Rev-erbɑ in lipid and glucose homeostasis, obesity, and metabolic disorders syndrome. In conclusion, this paper aims to understand better the role and mechanism of Rev-erbɑ in regulating drug metabolism, lipid, glucose homeostasis, obesity, and metabolic disorders syndrome, which explores how to target Rev-erbɑ to guide the design and development of new drugs and provide scientific reference for the molecular mechanism of new drug development, rational drug use, and drug interaction.

Controlled SPION-Exosomes Loaded with Quercetin Preserves Pancreatic Beta Cell Survival and Function in Type 2 Diabetes Mellitus.

Introduction: Quercetin has an ideal therapeutic effect on islet function improvement in type 2 diabetes mellitus (T2DM). However, the therapeutic benefit of quercetin is hindered by its poor bioavailability and limited concentration in pancreatic islets. In this study, superparamagnetic iron oxide nanoparticle (SPION)-modified exosomes were prepared to load quercetin, hoping to endow quercetin with enhanced water solubility and active targeting capacity with the help of magnetic force (MF). Methods: Transferrin-modified SPIONs (Tf-SPIONs) were synthesized by exploiting N-hydroxysuccinimidyl (NHS) conjugation chemistry, and quercetin-loaded exosomes (Qu-exosomes) were acquired by electroporation. Tf-SPION-modified quercetin-loaded exosomes (Qu-exosome-SPIONs) were generated by the self-assembly of transferrin (Tf) and the transferrin receptor (TfR). The solubility of quercetin was determined by high-performance liquid chromatography (HPLC) analysis. The pancreatic islet targeting capacity and insulin secretagogue and antiapoptotic activities of Qu-exosome-SPIONs/MF were evaluated both in vitro and in vivo. Results: The Qu-exosome-SPIONs were well constructed and harvested by magnetic separation with a uniform size and shape in a diameter of approximately 86.2 nm. The water solubility of quercetin increased 1.97-fold when loaded into the SPION-modified exosomes. The application of SPIONs/MF endowed the Qu-exosomes with favorable targeting capacity. In vitro studies showed that Qu-exosome-SPIONs/MF more effectively inhibited or attenuated ß cell apoptosis and promoted insulin secretion in response to elevated glucose (GLC) compared with quercetin or Qu-exosome-SPIONs. In vivo studies demonstrated that Qu-exosome-SPIONs/MF displayed an ideal pancreatic islet targeting capacity, thereby leading to the restoration of islet function. Conclusion: The Qu-exosome-SPIONs/MF nano-delivery system significantly enhanced the quercetin concentration in pancreatic islets and thereby improved pancreatic islet protection.

The Neuroprotective Effects of Decursin Isolated from Angelica gigas Nakai Against Amyloid ß-Protein-Induced Apoptosis in PC 12 Cells via a Mitochondria-Related Caspase Pathway.

Decursin, purified from Angelica gigas Nakai, has been proven to exert neuroprotective property. Previous study revealed decursin protected the PC12 cells from Aß25-35-induced oxidative cytotoxicity. The present study aimed to investigate whether decursin could protect PC12 cells from apoptosis caused by Aß. Our results indicated that pretreatment of PC12 cells with decursin significantly inhibited Aß25-35-induced cytotoxicity and apoptosis. The mechanism of action is likely to reverse Aß25-35-induced mitochondrial dysfunction, including the reduction of mitochondrial membrane potential, the inhibition of reactive oxygen species production, and the decrease of mitochondrial release of cytochrome c in PC12 cells. In addition, decursin significantly suppressed the activity of caspase-3 and moderated the ratio of Bcl-2/Bax induced by Aß25-35. These findings indicate that decursin exerts a neuroprotective effect against Aß25-35-induced neurotoxicity in PC12 cells, at least in part, via suppressing the mitochondrial pathway of cellular apoptosis.