OBJECTIVE To investigate the absorption and distribution of chitosan capsule filled with dexamethasone sodium phosphate (DSP) liposome lyophilized powder in rats.METHODS DSP liposome was prepared by duplicated emulsification method. Its formula was determined with the orthogonal experiment. The quality of DSP liposome, such as the encapsulation rate, drug-loading, morphology and size distribution, was estimated. The chosen liposome, made into its lyophilized powder, was then filled into the capsule coated with HPMCP.The capsules as well as the other DSP dosage forms were administered orally. Blood and colon tissue were collected periodically. The concentration of DSP was measured by HPLC, and used to calculate the relative targeting drug delivery index(DDI) of DSP.RESULTS The prepared DSP liposome was characterized by its average encapsulation rate of 54.82%, drug-loading of 8.67%, and the size distribution from 120 nm to 265 nm(averaged 178 nm). After oral administration, the blood level of DSP lyophilized liposome capsule was the lowest in all the DSP dosage forms, but the distribution of DSP in colon was the highest. The relative targeting DDI of DSP lyophilized liposome capsule was 29.18 or 2.28, against DSP solution or DSP powder capsule, respectively.CONCLUSION DSP lyophilized liposome chitosan capsule may be more helpful in treating colitis than DSP powder chitosan capsule. Hence, it is worth studying further.
Monodisperse hydrophilic quantum dots (QDs) are promising labeling materials for biomedical applications. However, the controllable preparation of monodisperse hydrophilic QDs with amphiphilic polymers remains a challenge. Herein, the molecular structures of amphiphilic polymers assembled on different-sized QDs are investigated. Both the experimental results and the molecular dynamics (MD) calculation suggest that the grafting ratio of amphiphilic polymers assembled on QDs increases as the size of QDs increases. Thus, the controllable preparation of different-sized monodisperse hydrophilic QDs can be achieved by simply varying the grafting ratio of amphiphilic molecules and applied in the simultaneous labeling of three tumor biomarkers.
By using multifunctional optical tweezers (OT) equipped with a 980 nm continuous-wave single-mode diode laser and multiple detectors, we are able to trap single upconversion nanoparticles stably as well as synchronously analyze their luminescence properties. Successive trapping of individual octylamine-modified poly(acrylic acid) encapsulated UCNPs (OPA-UCNPs) is proved by real-time monitoring of forward scattering (FSC), luminescence intensity and spectra, and the results verify that these nanoparticles possess excellent colloidal stability and uniform luminescence properties. Besides, ligand/solvent-dependent surface quenching effect of single UCNPs is investigated, and the results show that OPA-UCNPs by hydrophobic encapsulation strategy possess outstanding luminescence properties and the property of OPA to reduce the quenching effect of ligands and water molecules are well identified. Upconversion luminescence decay lifetime also explains the mechanism that the presence of OPA molecules reduces surface quenching effect, thus OPA-UCNPs exhibit longer luminescence decay lifetime. Therefore, we not only provide a new method to evaluate the luminescence properties of single nanoparticles by using multifunctional OT but also prove that encapsulating hydrophobic UCNPs with amphiphilic molecules is an alternative strategy to prepare monodisperse hydrophilic UCNPs while significantly maintaining their luminescence properties.
Polygonatum sibiricum is a traditional medicinal and dietary plant of the family Liliaceae. The main functional macromolecules of P. sibiricum are polysaccharides, which function in antioxidation and regulating immunity. Previous studies have shown that insulin resistance (IR), oxidative stress, and inflammation are important factors in the induction of lipid metabolic diseases such as obesity. Therefore, in this study, we established a high-fat diet-induced rat model of obesity and nonalcoholic fatty liver disease (NAFLD) to explore the potential protective effect of P. sibiricum polysaccharides (PSPs) and the mechanisms behind it. After 4 weeks of high-fat diet feeding to induce obesity, the rats were treated with different doses of PSP solution or distilled water for 6 weeks. Compared with untreated obese rats, PSP-treated obese rats showed a decrease in body weight, serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels, hepatic aspartate aminotransferase and alanine aminotransferase activity, hepatic malondialdehyde content, and hepatic levels of the pro-inflammatory factors tumor necrosis factor-α, interleukin-1β, and interleukin-6, as well as increased serum high-density lipoprotein cholesterol levels and hepatic superoxide dismutase, catalase, and glutathione peroxidase activity. Pathological analysis and immunoblotting of the liver tissues indicated that mechanistically, PSPs reduced obesity and NAFLD in rats by upregulating insulin receptor expression, increasing adenosine monophosphate-activated protein kinase phosphorylation, and downregulating sterol regulatory element-binding protein 2 and low-density lipoprotein receptor expression, thus promoting lipid metabolism, decreasing body weight, and reducing inflammation and oxidative stress caused by lipid accumulation. Based on these results, PSPs may have the potential to reduce obesity and NAFLD associated with a high-fat diet.
A protein modification strategy was developed based on a thiol-yne click reaction using an electron-deficient yne reagent. This approach demonstrated exceptional selectivity towards thiols and exhibited rapid kinetics, resulting in conjugates with superior acid stability. The conjugation of IgG with an indole-derived fluorophore was achieved for the imaging of PD-L1 in cancer cells.
High on-current field effect transistors (FETs) are highly desirable for driving information displays such as active matrix organic light-emitting diode displays.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)