Engineered Microrobots for Targeted Delivery of Bacterial Outer Membrane Vesicles (OMV) in Thrombus Therapy.

In the realm of thrombosis treatment, bioengineered outer membrane vesicles (OMVs) offer a novel and promising approach, as they have rich content of bacterial-derived components. This study centers on OMVs derived from Escherichia coli BL21 cells, innovatively engineered to encapsulate the staphylokinase-hirudin fusion protein (SFH). SFH synergizes the properties of staphylokinase (SAK) and hirudin (HV) to enhance thrombolytic efficiency while reducing the risks associated with re-embolization and bleeding. Building on this foundation, this study introduces two cutting-edge microrobotic platforms: SFH-OMV@H for venous thromboembolism (VTE) treatment, and SFH-OMV@MΦ, designed specifically for cerebral venous sinus thrombosis (CVST) therapy. These platforms have demonstrated significant efficacy in dissolving thrombi, with SFH-OMV@H showcasing precise vascular navigation and SFH-OMV@MΦ effectively targeting cerebral thrombi. The study shows that the integration of these bioengineered OMVs and microrobotic systems marks a significant advancement in thrombosis treatment, underlining their potential to revolutionize personalized medical approaches to complex health conditions.

Distribution and metabolism of daidzein and its benzene sulfonates in vivo (in mice) based on MALDI-TOF MSI.

Daidzein (D1) has been proved to be of great benefit to human health. More and more attention was paid to the metabolic process of D1. Most studies focused on the metabolites of D1 and analogs were determined through the excretion of animals and humans by traditional HPLC-MS, while their in situ distribution and metabolism in organs in vivo has not been reported. In our group, novel daidzein sulfonate derivatives were synthesized and confirmed to have excellent pharmaceutical properties. They exhibited good anti-inflammatory, inhibitory activities on human vascular smooth muscle cell proliferation and other bioactivities. Compared with traditional analytical methods, matrix-assisted laser desorption ionization time-of-flight mass spectrometry imaging (MALDI-TOF MSI) can directly analyze the distribution of compounds in tissues and organs. In this study, we investigate the in situ distribution and metabolism of D1 and its derivatives (DD2, DD3) in the organs of mice based on MALDI-TOF MSI for the first time. Trace prototype compounds were detected in the plasma 4 h after the intravenous injection of D1, DD2, and DD3. Seven phase I metabolites and seven phase II metabolites were detected. D1 sulfates were found in the plasma and in organs except the heart. The presence of D1 and DD3 monosulfates in the brain indicated that they could penetrate the blood-brain barrier. DD2 and DD3 could be hydrolyzed into D1 and their metabolic pathways were similar to those of D1. In addition, a ligand-receptor docking of D1 and DD2 with mitogen-activated protein kinase 8 (JNK1) was performed because of their significant anti-inflammatory activities through the JNK signaling pathway. It showed that the binding energy of DD2 with JNK1 was obviously lower than that of D1 which was consistent with their anti-inflammatory activities. It provided a theoretical basis for further validation of their anti-inflammatory mechanism at the protein level. In summary, the research will provide beneficial guidance for further pharmacological, toxicological studies and the clinical-use research of these compounds.

Study on pharmacological properties and cell absorption metabolism of novel daidzein napsylates.

Novel daidzein napsylates (DD4 and DD5) were synthesized by microwave irradiation, according to structural modification of daidzein (DAI) using the principle of pharmacokinetic transformation. The pharmacological properties of DD4 and DD5 were evaluated via high performance liquid chromatography (HPLC) and calculated based on the drug design software ChemAxon 16.1.18. The cell uptake changes of DD4 and DD5 were investigated to analyse the structure-property relationship. The metabolisms of DD4 and DD5 were analysed by HPLC-mass spectrometry in human aortic vascular smooth muscle cells (HAVSMCs) and their possible metabolic pathways were inferred in vivo. The results showed that the solubility of DD4 and DD5 was increased by 2.79 × 105 and 2.16 × 105 times compared to that of DAI, separately, in ethyl acetate. The maximum absorption rates of DD4 and DD5 were enhanced by 4.3-4.5 times relative to DAI. Preliminary studies on metabolites of DD4 and DD5 in HAVSMCs showed that DD4 and DD5 were hydrolysed into DAI under the action of intracellular hydrolase in two ways, ester hydrolysis or ether hydrolysis. Then, DAI was combined with glucuronic acid to form daidzein monoglucuronate under the action of uridine diphosphate (UDP)-glucuronidase. Meanwhile, it was also found that metabolite M5 of DD5 could undergo glucuronidation under the action of UDP-glucuronosyltransferase and competitive sulphation under the action of sulphotransferase to produce its sulfate conjugate M7. Analysis of structure-property relationships indicated that the absorption and utilization of drugs is closely relative to the physical properties and could be improved by adjusting the liposolubility. The pharmaceutical properties were optimized comprehensively after DAI was modified by naphthalene sulphonate esterification. This indicates that this kind of derivatives may have relatively good absorption and transport characteristics and biological activities in vivo. The research on biological activities of the new derivatives (DD4 and DD5) is ongoing in our laboratory.

A newly synthesized Ligustrazine stilbene derivative inhibits PDGF-BB induced vascular smooth muscle cell phenotypic switch and proliferation via delaying cell cycle progression.

Vascular Smooth muscle cells (VSMCs) possess remarkable phenotype plasticity that allows it to rapidly adapt to fluctuating environmental cues, including the period of development and progression of vascular diseases such as atherosclerosis and restenosis subsequent to vein grafting or coronary intervention. Although VSMC phenotypic switch is an attractive target, there is no effective drug so far. Using rat aortic VSMCs, we investigate the effects of Ligustrazine and its synthetic derivatives on platelet-derived growth factor-BB (PDGF-BB) induced proliferation and phenotypic switch by a cell image-based screening of 60 Ligustrazine stilbene derivatives. We showed that one of the Ligustrazine stilbene derivatives TMP-C4a markedly inhibited PDGF-BB-induced VSMCs proliferation in a time and dose-dependent manner, which is more potent than Ligustrazine. Stimulation of contractile VSMCs with PDGF-BB significantly reduced the contractile marker protein α-smooth muscle actin expression and increased the synthetic marker proteins osteopontin expression. However, TMP-C4a effectively reversed this phenotypic switch, which was accompanied by a decreased expression of Matrix metalloproteinase 2 and 9 (MMP2 and MMP9) and cell cycle related proteins, including cyclin D1 and CDK4. In conclusion, the present study showed that a new Ligustrazine stilbene derivative TMP-C4a suppressed PDGF-induced VSMC proliferation and phenotypic switch, indicating that it has a potential to become a promising therapeutic agent for treating VSMC-related atherosclerosis and restenosis.

Tandem C-N Bond Formation through Condensation and Metal-Free N-Arylation: Protocol for Synthesizing Diverse Functionalized Quinoxalines.

Diverse functionalized quinoxalines were synthesized in good yields from arylamines and readily available ß-keto oximes through condensation and metal-free N-arylation. The reaction was compatible with various functional groups, such as halides, cyano, and esters. A mechanism was proposed based on the experimental results. These quinoxalines were easily obtained on a gram scale and converted to various useful scaffolds. Compound LASSBio-1022 was prepared in 83% yield in two steps.

Synthesis and in vitro antiproliferative evaluation of some ring B abeo-sterols.

Using cholesterol, ß-sitosterol, dehydroisoandrosterone and pregnenolone as starting materials, a series of 5(6→7)abeo-sterols with different substituted groups and various side chains were synthesized and the antiproliferative activity of these compounds against HeLa, SMMC 7404 and MGC 7901 cells was investigated. The results revealed that the presence of a cholesterol-type side chain was very important for their cytotoxicity, and in particular a thiosemicarbazone at the C-6 position significantly enhanced the antiproliferative activity of these compounds. Although the elimination of 5-hydroxyl has no an obvious effect on their cytotoxic function, removal of the hydroxyl at the C-3 position decreased markedly the antiproliferative activity of the compounds. Some compounds have similar cytotoxic capability as cisplatin does.