7 research outputs found
Comparison of voltage support services by means of STATCOM and smart transformer in medium voltage grid
Measurement and analysis of cellular viscoelastic properties using atomic force microscopy
Hydrogen Peroxide Biosensor Based on the Direct Electrochemistry of Myoglobin Immobilized in Poly-3-Hydroxybutyrate Film
quantifyingtheadhesionforcesoflymphomacellsbyafmsinglecellforcespectroscopy
Cell adhesion plays an important role in regulating diverse physiological functions of cells, and quantitatively characterizing the adhesive behaviors at single-cell level benefits understanding the biology of cells. The advent of atomic force microscopy (AFM) provides a powerful method for investigating the biophysical properties of biological systems at micro/nanoscale under aqueous conditions, and particularly AFM-based single-cell force spectroscopy (SCFS) is able to measure the adhesion forces of single cells. Nevertheless, current SCFS assays are commonly performed on adherent cells, and SCFS studies on mammalian suspended cells are still scarce. In this work, AFM-based SCFS was utilized to measure the adhesion forces of lymphoma cells. First, the adhesion forces between lymphoma cells and rituximab (an antibody which binds to the CD20 antigen on lymphoma cells to activate immunotherapy) were investigated. Then the effects of antibody concentration and experimental parameters on the adhesion force measurements were investigated. Next, the intercellular adhesion forces between lymphoma cells were quantified. The research demonstrates the capabilities of AFM-based SCFS in detecting the adhesive behaviors of mammalian suspended cells and also provides novel insights into the adhesion of lymphoma cells, which will have potential impacts on single-cell biomechanical assays
Enteric Polymer Based on pH-Responsive Aliphatic Polycarbonate Functionalized with Vitamin E To Facilitate Oral Delivery of Tacrolimus
To improve the bioavailability of
orally administered drugs, we synthesized a pH-sensitive polymer (polyÂ(ethylene
glycol)–polyÂ(2-methyl-2-carboxyl-propylene carbonate)–vitamin
E, mPEG–PCC–VE) attempting to integrate the advantages of enteric coating and P-glycoprotein
(P-gp) inhibition. The aliphatic polycarbonate chain was functionalized
with carboxyl groups and vitamin E via postpolymerization modification.
Optimized by comparison and central composite design, mPEG<sub>113</sub>–PCC<sub>32</sub>–VE<sub>4</sub> exhibited low critical
micelle concentration of 1.7 × 10<sup>–6</sup> mg/mL and
high drug loading ability for tacrolimus (21.2% ± 2.7%, w/w).
The pH-responsive profile was demonstrated by pH-dependent swelling
and <i>in vitro</i> drug release. Less than 4.0% tacrolimus
was released under simulated gastric fluid after 2.5 h, whereas an
immediate release was observed under simulated intestinal fluid. The
mPEG<sub>113</sub>–PCC<sub>32</sub>–VE<sub>4</sub> micelles
significantly increased the absorption of P-gp substrate tacrolimus
in the whole intestine. The oral bioavailability of tacrolimus micelles
was 6-fold higher than that of tacrolimus solution in rats. This enteric
polymer therefore has the potential to become a useful nanoscale carrier
for oral delivery of drugs