Microfluidic chip interfacing microdialysis and mass spectrometry for in vivo monitoring of nanomedicine pharmacokinetics in real time

Simultaneous and dynamic measurement of Schisandrol A changes in rat blood and brain and its comparative pharmacokinetic study in control and Parkinson's disease rats by dual-probe in vivo microdialysis

Schisandrol A (SchA) is the main active ingredient of Schisandra chinensis (Turcz.) Baill., which is a famous traditional Chinese herbal medicine. SchA can penetrate the blood-brain barrier and has a significant neuroprotective effect. A group of multiplexed stable isotope mass tags (MSIMTs, m/z 332, 338, 346, 349, 351, 354, 360, 363, 374 and 377) were synthesized to perform multiplexed stable isotope labeling derivatization (MSILD) of SchA in rat microdialysates and standards. A new magnetic molecularly imprinted polymer was prepared using MSIMT-375-SchA as dummy template. All the 10-plexed derivatives of MSIMTs-SchA can be efficiently and selectively enriched and purified using this adsorbent by magnetic dispersive solid phase extraction (MDSPE) before ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis. It should be pointed out that the MSIMT-346-SchA standard derivative was used as internal standard in the process of MDSPE and UHPLC-MS/MS. On these bases, 9 different rat microdialysate samples can be determined by UHPLC-MS/MS in a single run. The utilization of MSIMTs significantly increased the sensitivity, accuracy, selectivity and analysis throughput. Under the optimized conditions, satisfactory linearity (R²> 0.987), limit of detection (LODs, 0.15-0.26 pg/mL) and lower limit of quantitative (LLOQ, 0.8-2.0 pg/mL) were obtained. Intra- and inter-day precisions were in the range of 2.2% -12.5%, and recoveries 94.2% -106.2%. The matrix effects were very low, and the average derivatization efficiency of 10-plex MSIMTs to SchA was as high as 97.8%. Using the developed dual-probe in vivo microdialysis sampling technique, the proposed analytical method has been applied for comparative pharmacokinetics of SchA in the brain and blood of control and Parkinson's disease (PD) rats.

Dummy-template Pickering emulsion imprinted microspheres online pretreatment and analysis for the estrogens in cosmetics

Estrogens are a class of steroid hormone with strong physiological activity. Due to the pronounced beauty effect, such drugs are highly susceptible to illegal addition and cause other adverse effects. To avoid template leakage and the negative impacts on the environment caused by the estrogens, diosgenin was selected as the dummy template due to its similar skeleton structure. The Pickering emulsion polymerization was used to obtain the dummy-template molecularly imprinted polymers (dt-MIPs). Scanning electron microscopy, optical microscopy, specific surface area testing, Fourier transform infrared spectroscopy and adsorption experiments were used to characterize the apparent morphology and the recognition performance of the microspheres. Then, the prepared microspheres and commercial fillers were used to construct an on-line solid phase extraction (on-line SPE) analytical system coupled with HPLC via a two-position switching valve. On-line solid phase extraction-HPLC analytical methods were established and verified, for the simultaneous determination of four estrogens in cosmetic samples. The accuracy and precision RSDs for the established methods using the imprinted sorbents were 92.00-104.02% and less than 9.12%, respectively. All four estrogens exhibited good linearity in the range of 0.05 to 5 µg/mL with a coefficient of determination R² greater than 0.9810. The method comparison results suggest that the established analytical method is simple in pre-treatment, easy to automate, and has excellent sensitivity to meet the analytical requirements of complex samples.

A Nanomedicine Structure-Activity Framework for Research, Development, and Regulation of Future Cancer Therapies

Despite their clinical success in drug delivery applications, the potential of theranostic nanomedicines is hampered by mechanistic uncertainty and a lack of science-informed regulatory guidance. Both the therapeutic efficacy and the toxicity of nanoformulations are tightly controlled by the complex interplay of the nanoparticle's physicochemical properties and the individual patient/tumor biology; however, it can be difficult to correlate such information with observed outcomes. Additionally, as nanomedicine research attempts to gradually move away from large-scale animal testing, the need for computer-assisted solutions for evaluation will increase. Such models will depend on a clear understanding of structure-activity relationships. This review provides a comprehensive overview of the field of cancer nanomedicine and provides a knowledge framework and foundational interaction maps that can facilitate future research, assessments, and regulation. By forming three complementary maps profiling nanobio interactions and pathways at different levels of biological complexity, a clear picture of a nanoparticle's journey through the body and the therapeutic and adverse consequences of each potential interaction are presented.