The blood-brain barrier (BBB) plays a crucial role in maintaining the homeostasis of the brain's internal environment, which poses challenges to the treatment of central nervous system diseases. Drug carriers can aid in the delivery of therapeutic agents across the BBB to exert their pharmacological effects. The article reviewed the pathways for drug delivery across the BBB, the intracerebral fate and the classification of drug carriers and focuses on the functions and characteristics of liposomes, exosomes, apoptotic bodies, cell-penetrating peptides, and cell-targeting peptides. The review will provide an outlook on the future and challenge of research in the field of drug delivery across the BBB.

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder characterized by chronic hyperglycemia, hyperlipidemia, and peripheral insulin resistance. Endoplasmic reticulum stress (ERS), a response to cellular stress, is activated across various tissues during the progression of T2DM, leading to disruptions in protein synthesis. Notably, epithelial and endocrine cells with hormone-secreting functions are particularly vulnerable to functional impairments induced by ERS. The gut-pancreas axis is essential for regulating metabolism and the progression of T2DM. Intestinal epithelial L cells, integral to the intestinal barrier, can secrete the glucagon-like peptide-1 (GLP-1). This hormone promotes insulin secretion from pancreatic β-cells and plays a critical role in glucose metabolism. Importantly, ERS plays a critical role in regulating glucolipid-induced dysfunction of gut-pancreas axis. For instance, ERS is involved in regulating the intestinal barrier and the secretion of GLP-1 as well as insulin. Therefore, ERS can be a potential target for T2DM treatment. In this paper, we review the regulatory roles of ERS in the gut-pancreas axis during the development of T2DM, and summarize the therapeutic drugs and strategies targeting ERS for T2DM treatment.

In this study, the CHO_INSR_1284 transgenic cell line was employed as the target cell, utilizing homogeneous time-resolved fluorescence technology to establish a method for detecting the biological activity of insulin degludec. Key parameters were optimized, and validation was conducted in accordance with general principles 9401 and 1431 of the fourth section of the 2020 edition of the Chinese Pharmacopoeia. Results indicated a good dose-response relationship for insulin degludec in this method, aligning with a four-parameter curve. Following optimization, the cell seeding density was set at 3.5×10⁵ cell·mL^-1, the initial concentration of insulin degludec at 57.18 μg·mL^-1, with a four-fold dilution, a stimulation period of 45 minutes, and an incubation duration of 4 hours. This method demonstrated strong specificity, with the geometric variation coefficient (GCV%) for the five potency levels ranging from 4.1% to 10.6%. The linear regression equation from the linear fitting was y = 1.015x - 0.027 7, and R² = 0.999 6. The results confirmed the method's good intermediate precision and linearity. The regression term was highly significant (P < 0.01), neither the deviation from parallel terms nor the model mismatch terms were significant (P ≥ 0.05), complying with general rule 1431 of the fourth section of the 2020 edition of the Chinese Pharmacopoeia. This study established a method for detecting the biological activity of insulin degludec using homogeneous time-resolved fluorescence technology, suitable for evaluating the biological activity and quality control of insulin degludec products.

The Dionex CaboPac^TM PA10 BioLC^TM Analyical 2 mm × 250 mm column was used with a protective column (Dionex CaboPac^TM PA10 BioLC^TM Guard 2 mm × 50 mm). 100 mmol·L^-1 sodium hydroxide solution was used as eluent; the flow rate was 0.25 mL·min^-1. Sample tray temperature: 35 ℃. The pulse amperometric detector was adopted, and the waveform was Gold CWE, Ag-AgCl RE, Carbo, Quad. The samples were cultured with 8 concentrations of glycogen substrates (0.31, 1.25, 2.5, 5, 10, 20, 30, and 40 mg·mL^-1). D-Glucose concentrations were measured at 5 different time points (T0, T1, T2, T3 and T4). The glucose concentration from T1 to T4 minus the glucose concentration at T0. The reaction rate was calculated at different glycogen substrate concentrations. These reaction rates are plotted against substrate concentrations using Michaelis-Menten equation. The kinetic parameters were expressed as V_max (nmol·mg^-1·min^-1) and K_m (mg·mL^-1). The RSD of glucose standard curve R² (n = 6, linear range: 1.25-500 μmol·L^-1) was 0.1% and the RSD (n = 6) of the slope of the standard curve was 2.2%. The mean limit of quantitation was 0.14 μmol·L^-1, and the mean limit of detection was 0.05 μmol·L^-1. The RSD of K_m and V_max were 4.4% and 4.6% respectively in three separate experiments. The durability of the method was good. The method was developed for the on-line automatic determination of the hydrolysis kinetics of acid α-glucosidase (GAA) for injection by ion chromatography. The method has good precision, repeatability and durability, and can be used for the determination of glycogen hydrolysis kinetics of GAA for injection, and could reference value for the enzyme kinetics evaluation of recombinant enzyme replacement therapy.

The 95% ethanol extract of Poria cocos was separated and purified by ODS, MCI gel CHP20 and silica gel column chromatography combined with the semi-preparative HPLC. The chemical structures of the isolated compounds were identified by NMR, MS, IR, and calculated NMR methods. Seven compounds were isolated from Poria cocos and identified as 20S-2β, 3α, 15α, 19, 20-hydroxy-pregnane-7-ene (1), dehydroeburicoic acid monoacetate (2), eburicoic acid acetate (3), dehydroeburicoic acid (4), eburicoic acid (5), dehydropachymic acid (6), pachymic acid (7). Compound 1 is a new pregnane steroid.

The blood-brain barrier limits the brain delivery of most drugs and affects the treatment of central nervous system disorders. The transnasal drug delivery allows the drug to bypass the blood-brain barrier and reach the brain directly through pathways such as the olfactory and trigeminal nerves, thus improving the therapeutic efficacy of the drug while reducing drug degradation and avoiding hepatic first pass effect. With the rise of nanotechnology, the combination of nanoformulations with transnasal routes of administration is expected to achieve better brain targeting and treatment of brain diseases. On the basis of summarizing the characteristics of the various nose-to-brain pathways, this review summarizes the researches on novel transnasal nanopreparations such as exosomes and liquid crystals in recent years as well as new strategies to improve the efficiency of brain entry including focused ultrasound-mediated techniques. We also review the recent studies on transnasal brain entry nanopreparations in the treatment of various brain disorders and current research dilemmas, looking forward to the prospect of their future clinical applications.

The microsphere drug delivery systems have been extensively exploited for providing controllable drug release kinetics, enhancing drug stability and localized drug delivery. In past decade, dozens of microsphere drug delivery systems have been developed for clinical therapy of cancer, schizophrenia and neurodegenerative diseases (e.g., Alzheimer's disease and Parkinsonism). In this review article, we comprehensively summarized the fabrication methods of drug delivery systems and highlighted their advances for clinical application. Furthermore, we analyzed the potential and the challenges for clinical translation of the drug delivery systems.

According to the requirements of the regulatory authorities, degree of modification (DP) should be included in the characterisation of the PEGylated protein drug substance, and is one of the critical quality attributes for quality control. In this study, based on the fundamental assumption that the refractive index (RI) signal and the ultraviolet (UV) signal of PEGylated protein are equal to the sum of the corresponding signal produced by the polyethylene glycol (PEG) and protein parts of the conjugates in their uncoupled state, we developed a method to determine the DP of PEGylated recombinant human growth hormone (inpegsomatropin). In this method, 20 μL of 1 mg·mL^-1 human growth hormone (hGH) standard, 2 mg·mL^-1 PEG reference substance and 1 mg·mL^-1 drug substance solution were each injected to size exclusion chromatographic (SEC) column for separation, detected with ultraviolet and refractive index (UV-RI) detectors in series. Finally, the DP was calculated as the formula derived from the fundamental assumption. The developed SEC-UV-RI method showed good specificity, repeatability (RSD = 0.63%, n = 9) and accuracy, with a recovery of 100.0%, compared with the result obtained from the simultaneously established classical acid hydrolysis method, demonstrating pretty handleability and accessibility, and is appropriate for quality control test of DP for this drug substance.

Invasive fungal infections threaten the lives and health of humans, especially immunodeficient patients or hospitalized patients with serious underlying diseases, and impose a heavy economic burden on society. The emergence of drug-resistant fungi, the formation of biofilms, and the limits and side effects of existing antifungal drugs increase the difficulty of clinical treatment, and there is an urgent need for the development of novel antifungal drugs. Therefore, based on previous kinase chemical library antifungal activity screening studies, this paper further investigates the activity of anaplastic lymphoma kinase (ALK) inhibitor 3-[5-chloro-2-({2-methoxy-4-[4-(4-methylpiperazin-1-yl)hexahydropyridin-1-yl]phenyl}amino)pyrimidin-4-yl]-1H-indole (HG-14-10-04, HG) against various fungi and elucidates its mechanism of action. The in vitro antifungal activity of HG was evaluated by micro liquid-dilution method, time-killing curve, mycelium formation and biofilm formation assays. The results showed that HG exhibited inhibitory and even fungicidal effects against sensitive and resistant Candida albicans, Candida krusei, Cryptococcus neoformans, Candida tropicalis, Candida glabrata and Candida parapsilosis (MICs = 8-16 μg·mL^-1); HG significantly inhibited the mycelium and biofilm formation, and destroyed the mature biofilm; and it exhibited synergistic antifungal effects with amphotericin B. The antifungal mechanism of HG was investigated by flow cytometry and transmission electron microscopy, etc. Sequencing analysis showed a total of 1 041 differentially expressed genes, of which 666 were up-regulated and 375 were down-regulated. According to the GO functional classification results, the up-regulated genes were mainly involved in ribosome production, oxidation-reduction and other functions, while the down-regulated genes were mainly involved in the synthesis of carbohydrate, glycoproteins, glycolipids and their metabolism, GPI anchor synthesis, and cytoskeleton and other functions. In addition, HG could significantly increase the level of reactive oxygen species (ROS), induce the fungal necrosis, block the cell cycle at the G0/G1 phase, and change the ultrastructure of the fungi, especially the structure of the fungal cell wall. Therefore, the enhanced inhibitory and fungicidal activity of HG may be related to the elevation of ROS, alteration of cellular ultrastructure (especially cell wall structure) and cell cycle arrest at the G0/G1 phase. Further optimization of its structure will provide a basis for the discovery of novel antifungal drugs or lead compounds.

A new alkaloid (1) and six known compounds (2-7) were isolated from the solid fermentation extract of the endophytic fungus Alternaria tenuissima Pas85 of Phragmites australis by silica gel column chromatography, Sephadex LH-20 column chromatography, high performance liquid chromatography and other chromatographic techniques. The structures of these compounds were determined by HREIMS, NMR, IR spectroscopy, and literature comparison, and the anti MRSA (methicillin-resistant Staphylococcus aureus) activity of 1-5 were tested. Compounds 1, 2, 3 and 4 exhibited certain inhibitory activity with MIC values of 64, 4, 32 and 32 μg·mL^-1, respectively, and compound 5 showed no significant inhibitory activity.