This study revealed significant differences in the relative estimated PK parameters of the plasma, SC, peri-, and intratumoral zones. Additionally, this study demonstrated that the coadministration of MTX with CsA can enhance the intratumoral exposure levels of the drug, whereas coadministration of MTX with probenecid alone, or with a combination of probenecid and CsA, increases intratumoral half-life.
ABSTRACT-Purpose. Efflux and influx proteins play a major role in chemo-resistance by affecting the net cellular uptake of anti-cancer drugs. Hence, alteration of the efflux and influx protein expression may result in variations of chemotherapeutics uptake and consequently cell death rate. The present study investigated the effects of pre-treatment of capan-2 pancreatic cancer cells with calcitriol, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) or silibinin on the induction of three major efflux proteins and the main gemcitabine influx protein. The influence of the pre-treatments on the net cellular uptake of gemcitabine, total ATPase activity, and cell death rate were also evaluated. Methods. Capan-2 pancreatic cancer cells were pre-treated for 24 h with calcitriol, BHT, BHA, or silibinin, followed by gemcitabine treatment. The concentration of gemcitabine was quantified using ultra-performance liquid chromatography (UPLC). Real-time polymerase chain reaction (RT-PCR) was utilized in order to investigate the expression of the mRNAs. The expression of the proteins was assessed using western blotting. Measurement of the ATPase activity was conducted utilizing a colorimetric method and viability of the cells was determined using a luminescent cell viability assay. Results. Protein expression studies showed that BHT, silibinin, and BHA increased expression of the efflux proteins and decreased the overall uptake of gemcitabine, whereas calcitriol significantly inhibited expression of the efflux proteins and increased gemcitabine uptake. Expression of specific mRNAs correlated reasonably well with the levels of corresponding proteins. Additionally, the expression of efflux proteins and ATPase activity were well correlated, signifying that the induced efflux proteins are functionally active. Moreover, pre-treatment with calcitriol resulted in a significant increase in cell death with gemcitabine treatment, whereas, BHA significantly reduced the cell death rate. On the other hand, pre-treatment with BHT and silibinin had no significant effect on the cell death rate. Conclusions. Pre-treatment of the pancreatic cancer cells with calcitriol significantly increased gemcitabine cellular uptake and consequently decreased cell viability after treatment with gemcitabine, whereas BHA significantly reduced gemcitabine uptake and decreased cell death rate, which were at least partially attributed to the alteration of expression of efflux and influx proteins.
The objective of this work was to develop uniformly distributed poly(ethylene glycol) grafted poly(lactide-co-glycolide) (PEG-PLGA) nanoparticles of mean size range approximately 100-200 nm using ethyl acetate as the solvent. In the multiple emulsion solvent evaporation method a high pressure microfluidization process was adopted to produce the W/O/W multiple emulsion. Non-toxic ethyl acetate was used to solubilize PEG-PLGA. The mean size of nanoparticles obtained was less than 180 nm. The particle size and size distribution were dependent on the microfluidization conditions applied. Mean particle size steadily increased from 121 nm at three passes to 172 nm at 20 passes of the microfluidizer, indicating that over-processing may be detrimental to PEG-PLGA nanoparticles prepared using this technique. There was no significant alteration of the PEG-PLGA matrix, as evidenced from the differential scanning calorimetric studies.
Understanding the interaction between cancer and endothelial cells is a key element to more effective chemotherapeutics.A microfluidic cellular co-culture biosensor capable of simultaneous optical and electrical impedance measurements is therefore proposed. Using microfabrication methods, an array of optically thin electrically conductive biosensors is designed capable of monitoring cancer and endothelial cell interactions. Computer aided design methods were used to layout out a microfluidic channel compatible with the working bio-electrode array. The microfluidic channel allowed cancer cell spheroids and pharmaceutical agents to be injected into an inlet port. Both the optical and electrical properties of the micro-fluidic device have been examined. The proposed system has a number of applications where cancer and endothelial cell interactions need to be studied. The results of this study demonstrate the feasibility of the multiplexed biosensor for studying cancer and endothelial cell interactions under static and dynamic shear flow conditions.
In vitro drug testing utilizing live cancer cell cultures has enormous potential in drug discovery and personalized medicine. Cancer grows as heterogeneous three dimensional clusters in vivo. As a result, traditional two dimensional cancer cell layer cultures are not physiologically representative of their in vivo growth. To provide better process control and more physiologically realistic cancer cell cultures, a modified hanging drop culture plate was designed. The culture plate allows three dimensional cancer cell spheroids to be cultivated and accurately placed over the working electrodes of multiplexed biosensor arrays. The results of this study are expected to demonstrate the formation of consistently sized cancer cell spheroids with proper positioning over working electrodes. Impedance measurements from biosensor arrays on 96-well plates will be obtained and compared to two dimensional cultures to demonstrate the utility of the hanging drop plate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.