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Carrier-free nanoparticulate formulations are an advantageous platform for the oral administration of insoluble drugs with the expectation of improving their bioavailability. However, the key limitation of exploiting carrier-free nanoparticulate formulations is the controlled preparation of drug nanoparticles on the basis of rational prescription design. In the following study, we used curcumin (Cur) and piperine (Pip) as model water-insoluble drugs and developed a new method for the controlled preparation of carrier-free drug nanoparticles via multidrug co-assembly in a high-gravity environment. Encouraged by the controlled regulation of the nucleation and crystal growth rate of high-gravity technology accomplished by a rotating packed bed, co-amorphous Cur-Pip co-assembled multidrug nanoparticles with a uniform particle size of 130 nm were successfully prepared, exhibiting significantly enhanced dissolution performance and in vitro cytotoxicity. Moreover, the hydrogen bonding interactions between Cur and Pip in nanoparticles provide them with excellent re-dispersibility and storage stability. Moreover, the oral bioavailability of Cur was dramatically enhanced as a result of the smaller particle size of the co-assembled nanoparticles and the effective metabolic inhibitory effect of Pip. The present study provides a controlled approach to preparing a carrier-free nanoparticulate formulation through a multidrug co-assembly process in the high-gravity field to improve the oral bioavailability of insoluble drugs. [ABSTRACT FROM AUTHOR]

A pharmacokinetic comparison was made to evaluate the influence from other components in the Radix Puerariae Extract on pharmacokinetic behavior of Puerarin. Samples of blood and brain were collected by microdialysis and determined by high-performance liquid chromatography–mass spectrometry (MS)/MS. Pharmacokinetic parameters were estimated from the concentration versus time data using non-compartmental methods. In addition, a comparative pharmacokinetic study of Puerarin in stroke rats was studied after administration of the Radix Puerariae Extract via different routes to find an effective way to deliver drug into brain. Obvious pharmacokinetic differences were also observed in comparison between the Puerarin group and the Radix Puerariae Extract group based on middle cerebral artery occlusion (MCAO) rats. The Cmax and area under the curve (AUC) of Puerarin in olfactory bulb of the Extract group significantly reduced when it was intravenously administered. However, the AUCs of Puerarin in plasma are 134.72 and 1707.02 mg/L min, via intranasal and intravenous administration of the Radix Puerariae Extract, respectively. The AUC of the intranasal group in brain is seven times higher than that of intravenous administration. Other ingredients in the Extract may affect the disposition of Puerarin and its transportation through the blood–brain barrier via intravenous administration. But intranasal administration is an effective route to deliver isoflavone-C-glycoside with poor hydrophilicity into brain.

In transdermal drug delivery systems, the physicochemical properties of the drug affect its percutaneous permeability. However, whether the physicochemical properties of drugs change their transdermal permeability in the presence of pores in the presence of solid microneedles (MNs) has been less studied in this area. In this project, cinnamaldehyde, curcumin, ferulic acid and geniposide were selected as model drugs for the study of their transdermal permeability under the action of MNs, and a combination of classical experiments and visualization means such as scanning electron microscopy and laser confocal was used to investigate the permeation-promoting mechanism of MNs. The results showed that the MNs had significant permeation-promoting effects on different properties of drugs, with the permeation-promoting effects on cinnamaldehyde, curcumin, ferulic acid and geniposide being 6.36, 17.43, 29.54 and 8.91 times, respectively, and the permeation-promoting effects were more pronounced for lipid-soluble and amphiphilic drugs. Using scanning electron microscopy, transmission electron microscopy and other means to confirm that MNs can promote the penetration by acting on the skin to produce pores, and their effect on skin structure is greater than that of drugs. In addition, the existence of pores increases the amount of drug transdermal, which may enhance the diffusion of drug on the skin, and has no effect on lipid exchange and transdermal route. Through the research, it has been found that MNs is equivalent to direct peeling of the stratum corneum (SC), but it is simpler and safer for the patient. [ABSTRACT FROM AUTHOR]

Objective: Dermaseptin‐PP is a newly discovered anticancer peptide with a unique antitumour mechanism and remarkable effect. However, this α‐helix anticancer peptide risks haemolysis when used at high doses, which limits its further application. This study aims to prepare a pH‐responsive liposome, Der‐loaded‐pHSL, using nanotechnology to avoid the haemolysis risk of Dermaseptin‐PP and increase its accumulation in tumour sites to enhance efficacy and reduce toxicity. Methods: The characterisation of Der‐loaded‐pHSL was carried out employing preparation. The effect of haemolysis and tumour inhibition were investigated by in vitro haemolysis assay and cytotoxicity assay. The cell uptake under different pH conditions was investigated by flow cytometry, and the effect of pH on tumour cell selectivity was evaluated. In order to evaluate the in vivo targeting and antitumour effect of Der‐loaded‐pHSL, the in vivo distribution experiment and the pharmacodynamic experiment were performed using the nude mouse tumour model. Results: The preparation method of the Der‐loaded‐pHSL is simple, and the liposome has good nanoparticle characteristics. When Dermaseptin‐PP was prepared as liposome, haemolysis was significantly decreased, and tumour cell inhibition was significantly enhanced. Compared with ordinary liposomes, this change was more significant in Der‐loaded‐pHSL. The uptake of pH‐sensitive liposomes was higher in the simulated acidic tumour microenvironment, and the uptake showed a specific acid dependence. In vivo experiments showed that Der‐loaded‐pHSL had a significant tumour‐targeting effect and could significantly enhance the antitumour effect of Dermaseptin‐PP. Conclusion: Der‐loaded‐pHSL designed in this study is a liposome with a quick, simple, effective preparation method, which can significantly reduce the haemolytic toxicity of Dermaseptin‐PP and enhance its antitumour effect by increasing the tumour accumulation and cell intake. It provides a new idea for applying Dermaseptin‐PP and other anticancer peptides with α‐helical structure. [ABSTRACT FROM AUTHOR]

Primer extension analysis was employed to show that the divergently transcribed regB and senC-regA-hvrA transcripts contain stable 5' ends 43 nucleotides apart within the regB-senC intergenic region in Rhodobacter capsulatus. Findings indicated that autoregulation by RegA is a factor contributing to the maintenance of an optimal low level of RegA expression that permits responsiveness to activation by phosphorylation.

Purpose: The external preparation of the Tibetan medicine formula, Baimai ointment (BMO), has great therapeutic effects on osteoarthritis (OA). However, its molecular mechanism remains almost elusive. Here, a comprehensive strategy combining network pharmacology and molecular docking with pharmacological experiments was adopted to reveal the molecular mechanism of BMO against OA. Methods: The traditional Chinese medicine for systems pharmacology (TCMSP) database and analysis platform, traditional Chinese medicine integrated database (TCMID), GeneCards database, and DisGeNET database were used to screen the active components and targets of BMO in treating OA. A component–target (C-T) network was built with the help of Cytoscape, and the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment through STRING. Autodock Tools which was used to dock the key components and key target proteins was analyzed. Animal experiments were performed to verify the key targets of BMO. Hematoxylin–eosin and toluidine blue staining were used to observe the pathology of joints. Protein expression was determined using enzyme-linked immunosorbent assay. Results: Bioactive compounds and targets of BMO and OA were screened. The network analysis revealed that 17-β-estradiol, curcumin, licochalone A, quercetin, and glycyrrhizic acid were the candidate key components, and IL6, tumor necrosis factor (TNF), MAPK1, VEGFA, CXCL8, and IL1B were the candidate key targets in treating OA. The KEGG indicated that the TNF signaling pathway, NF-κB signaling pathway, and HIF-1 signaling pathway were the potential pathways. Molecular docking implied a strong combination between key components and key targets. The pathology and animal experiments showed BMO had great effects on OA via regulating IL6, TNF, MAPK1, VEGFA, CXCL8, and IL1B targets. These findings were consistent with the results obtained from the network pharmacology approach. Conclusion: This study preliminarily illustrated the candidate key components, key targets, and potential pathways of BMO against OA. It also provided a promising method to study the Tibetan medicine formula or external preparations. [ABSTRACT FROM AUTHOR]

Background: To understand the cumulative effect of topical formulations after medication, evaluate the therapeutic effect of microneedle-assisted (MN-assisted) paeoniflorin-loaded ethosomes (TGP-E), and explore the potential for deep penetration of drugs, this paper uses microdialysis to systematically study the percutaneous pharmacokinetics of TGP-E. Methods: First, optical coherence tomography (OCT) was used to study the effectiveness of microneedle puncture. Second, a microdialysis method and a UPLC-MS method for determining the amount of paeoniflorin (Pae) in dialysate were established. Finally, the transdermal pharmacokinetics of TGP-E was studied using in vivo microdialysis in rats under the above MN-assisted conditions. Results: The optimal MN-assisted conditions were obtained at a microneedle length of 500 μm, a pressure of 3 N, and an action time of 3 min. The pharmacokinetic results demonstrated that the maximum drug concentration (Cmax) and the area under the curve (AUC) of the TGP-E gel were higher than the TGP-saline solution gel, and the mean retention time was lower. These indicated that microneedle can promote the entry of the ethosomes into the skin for in vivo experiments and greatly improve the possibility of deep penetration of the water-soluble Pae. Conclusion: Therefore, the microneedle-ethosomes delivery system is a more ideal means for promoting the deep penetration of Pae. These findings may provide a reference for the combination of multiple penetration-enhancement ways to promote drug absorption, and also provide a new insight to realize the development of novel, safe, and more effective dosage forms and administration routes of drugs. [ABSTRACT FROM AUTHOR]

Maytansine (DM1) is a potent anticancer drug and limited in clinical application due to its poor water solubility and toxic side effects. Zein is widely used in nano drug delivery systems due to its good biocompatibility. In this study, we prepared DM1-loaded zein nanoparticles (ZNPs) to achieve tumor targeting and reduce toxic side effects of DM1. Methods: ZNPs were prepared by phase separation and Box-Behnken design was used to optimize the formulation. Then, confocal fluorescence microscope and flow cytometry were used to determine cellular uptake of ZNPs. A549 cells were cultured in vitro to study cytotoxicity and used to establish tumor xenografts in nude mice. Biodistribution and antitumor activity of ZNPs were performed in vivo experiments. In addition, we also performed histological and immunohistochemical examinations on tumors and viscera. Results: The optimal prescription was obtained by using 120 μL zein added to 2 mL water under stirring in 300 rpm. The encapsulation efficiency and drug loading were 82.97 ± 0.80% and 3.32 ± 0.03%, respectively. We found that DM1-loaded ZNPs have a strong inhibitory effect on A549 cells, which stemmed from the ability of ZNPs to enhance cellular uptake. Furthermore, we demonstrated that DM1-loaded ZNPs exhibits a better antitumor efficacy than DM1, which tumor inhibition rate were 97.3% and 92.7%, respectively. The biodistribution revealed that ZNPs could targeted to tumor. Finally, we confirmed by histological that DM1-loaded ZNPs are nontoxic. Conclusion: DM1-loaded ZNPs have considerable antitumor activity. Thus, DM1-loaded ZNPs are a promising treatment of non-small cell lung cancer. [ABSTRACT FROM AUTHOR]