Enhancement of cellular uptake,transport and oral absorption of protease inhibitor saquinavir by nanocrystal formulation

Aim:

Saquinavir (SQV) is the first protease inhibitor for the treatment of HIV infection, but with poor solubility. The aim of this study was to prepare a colloidal nanocrystal suspension for improving the oral absorption of SQV.

Methods:

SQV nanocrystals were prepared using anti-solvent precipitation–high pressure homogenization method. The nanocrystals were characterized by a Zetasizer and transmission electron microscopy (TEM). Their dissolution, cellular uptake and transport across the human colorectal adenocarcinoma cell line (Caco-2) monolayer were investigated. Bioimaging of ex vivo intestinal sections of rats was conducted with confocal laser scanning microscopy. Pharmacokinetic analysis was performed in rats administered nanocrystal SQV suspension (50 mg/kg, ig), and the plasma SQV concentrations were measured with HPLC.

Results:

The SQV nanocrystals were approximately 200 nm in diameter, with a uniform size distribution. The nanocrystals had a rod-like shape under TEM. The dissolution, cellular uptake, and transport across a Caco-2 monolayer of the nanocrystal formulation were significantly improved compared to those of the coarse crystals. The ex vivo intestinal section study revealed that the fluorescently labeled nanocrystals were located in the lamina propria and the epithelium of the duodenum and jejunum. Pharmacokinetic study showed that the maximal plasma concentration (C_max) was 2.16-fold of that for coarse crystalline SQV suspension, whereas the area under the curve (AUC) of nanocrystal SQV suspension was 1.95-fold of that for coarse crystalline SQV suspension.

Conclusion:

The nanocrystal drug delivery system significantly improves the oral absorption of saquinavir.     

Potential ecological impacts of climate intervention by reflecting sunlight to cool Earth

As the effects of anthropogenic climate change become more severe, several approaches for deliberate climate intervention to reduce or stabilize Earth’s surface temperature have been proposed. Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth’s albedo. While climate science research has focused on the predicted climate effects of SRM, almost no studies have investigated the impacts that SRM would have on ecological systems. The impacts and risks posed by SRM would vary by implementation scenario, anthropogenic climate effects, geographic region, and by ecosystem, community, population, and organism. Complex interactions among Earth’s climate system and living systems would further affect SRM impacts and risks. We focus here on stratospheric aerosol intervention (SAI), a well-studied and relatively feasible SRM scheme that is likely to have a large impact on Earth’s surface temperature. We outline current gaps in knowledge about both helpful and harmful predicted effects of SAI on ecological systems. Desired ecological outcomes might also inform development of future SAI implementation scenarios. In addition to filling these knowledge gaps, increased collaboration between ecologists and climate scientists would identify a common set of SAI research goals and improve the communication about potential SAI impacts and risks with the public. Without this collaboration, forecasts of SAI impacts will overlook potential effects on biodiversity and ecosystem services for humanity.     

GATA3基因变异导致甲状旁腺功能减退症患者的临床特征和分子机制

目的分析GATA3基因变异导致甲状旁腺功能减退症(hypoparathyroidism, HP)患者的临床特点及分子机制。方法在1975年至2020年间于北京协和医院内分泌科随诊并行靶向基因捕获联合二代测序的198例未成年人(≤18岁)起病的非手术性HP患者中筛查到5例GATA3基因致病/可疑致病性变异, 回顾性收集分析其临床资料, 并对基因检测结果进行生物信息学分析。结果 5例患者HP的起病年龄为0.5(0.1, 1.3)岁, 发病至诊断为HP和甲状旁腺功能减退-耳聋-肾发育不良(hypoparathyroidism-deafness-renal dysplasia, HDR)综合征的时间分别为(7.0±5.2)年和(15.0±5.4)年。临床表现为手足搐搦伴癫痫样发作、颅内钙化各5例, 白内障1例, 听力减退4例, 肾脏畸形或缺如2例。治疗前血钙和血甲状旁腺激素(PTH)分别为(1.65±0.31)mmol/L和(4.64±2.63)ng/L。5例患者GATA3基因的杂合变异, 分别引起无义突变、移码突变和剪接位点突变, 经Clin Var数据库预测及美国医学遗传学和基因组学学会(...     

Bioinformatics analyses of gene expression profile identify key genes and functional pathways involved in cutaneous lupus erythematosus

Clinical Rheumatology - Lupus erythematosus is an autoimmune disease that causes damage to multiple organs ranging from skin lesions to systemic manifestations. Cutaneous lupus erythematosus (CLE)...     

Colchicine may become a new cornerstone therapy for coronary artery disease: a meta‐analysis of randomized controlled trials

Clinical Rheumatology - Colchicine is an ancient anti-inflammatory drug. In recent years, an increasing number of studies have shown that colchicine improves the prognosis of patients with coronary...     

Interstitial nephritis without glomerulonephritis in ANCA-associated vasculitis: a case series and literature review

Clinical Rheumatology - The typical nephrological presentation of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) is rapidly progressive glomerulonephritis....     

The Protective Role of Bmal1-Regulated Autophagy Mediated by HDAC3/SIRT1 Pathway in Myocardial Ischemia/Reperfusion Injury of Diabetic Rats

Cardiovascular Drugs and Therapy - Histone deacetylase 3 (HDAC3) and silent information regulator 1 (SIRT1) are histone deacetylases that regulate important metabolic pathways and play important...     

香烟提取物通过减少HDAC2表达诱导小鼠C2C12成肌细胞衰老

目的:探讨香烟提取物(CSE)能否引起小鼠C2C12成肌细胞衰老,并研究成肌细胞衰老与组蛋白去乙酰化酶2(HDAC2)的关系。方法:培养C2C12细胞株,分化为成熟成肌细胞,观察CSE干预对成肌细胞衰老和HDAC2表达的影响,采用real-time PCR和Western blot方法分别检测HDAC2 mRNA和蛋白的表达;β-半乳糖苷酶染色检测衰老细胞的百分率。结果:MTT法测定最佳CSE浓度与干预时间分别为60 m L/L和24 h。CSE干预后β-半乳糖苷酶染色阳性细胞数增加,同时伴有HDAC2 mRNA和蛋白表达的减少。四溴苯三唑(TBB)在促进HDAC2 mRNA和蛋白表达的同时,β-半乳糖苷酶染色阳性细胞数减少;用HDAC2的特异性阻滞剂丙戊酸抑制HDAC2 mRNA和蛋白的表达时,β-半乳糖苷酶染色阳性细胞数增加。结论:香烟提取物可通过减少小鼠C2C12成肌细胞HDAC2的表达促进细胞老化。