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Silica Nanoparticles for Drug Delivery
Published in Vladimir Torchilin, Handbook of Materials for Nanomedicine, 2020
Ross and co-workers used MCM-48, which has a cubic pore structure, coated with succinylated ε-polylysine for the colon specific release of prednisolone. At the relatively acidic pH values in the stomach and small intestine (1.9 and 5.0, respectively), the polymer covers the pore entrances. Ionization of the polylysine at pH 7.4, similar to what is observed in the colon, leads to expansion of the polymer matrix and thus drug release. Carrier toxicity was evaluated in RAW 264.7 macrophages as well as LS 174T and Caco-2 adenocarcinoma intestinal epithelial cells and the particles were found to be biocompatible up to 100 μg mL−1. Using the cell membrane impermeable dye sulforhodamine B, it was found that the polymer-coated particles were successfully internalized into all three cell lines through active transport [49].
Tracers
Published in Werner Käss, Tracing Technique in Geohydrology, 2018
These investigations in Wilerwald and in Merdingen, as well as laboratory tests indicate that sulforhodamine B is very suitable as a hydrological tracer. It has low sorption properties; it is not sensitive to light nor pH. The most important advantage however is that it is easily detected when used along with uranine. Sulforhodamine B has the longest excitation and fluorescence of all the rhodamines used in hydrological tracing techniques. The wavelength difference between excitation and fluorescence is 21 nm for uranine, for sulforhodamine B it is 18 nm. Thus, especially when using a synchronscan, both substances can be used at one time and each easily detected. Nevertheless, sulforhodamine B has been rarely used, perhaps partly since scientists are unacquainted with its advantages and partly due to hardships with its delivery. Figure 18 displays the fact that sulforhodamine B, compared to uranine, has only low sorption properties. A retardation factor, Rt, of 1.4 was determined.
Nanoparticles: Formulation Aspects and Applications
Published in Anil K. Sharma, Raj K. Keservani, Rajesh K. Kesharwani, Nanobiomaterials, 2018
Sushama Talegaonkar, Lalit Mohan Negi, Harshita Sharma, Sobiya Zafar
The pH sensitive polymeric nanoparticles are prepared using pH sensitive polymers, which contain an acidic or a basic group in their chain and thus undergo a change in their ionization state with the variation in environmental pH (James et al., 2013). Several pH sensitive polymers used for preparing nanoparticles are: poly (amino acids), aliphatic polyesters, polyanhydrides, poly (vinylpyridine), poly (vinylimidazole). Some pH sensitive polymers are biocompatible and biodegradable such as chitosan, poly (aspartic acid) (PASP) and its derivates, a Poly (amino acids) containing pendant carboxylic groups (Nemethy et al., 2013). A pH responsive cyclodextrin-containing star polymer was developed by Xiong et al., via host-guest interaction. The cyclodextrin polymer and pH-sensitive poly (2-(dimethylamino)ethyl methacrylate) serve as the core and poly (ethylene glycol) as the arm for the star polymer loaded with doxorubicin. A sustained release of doxorubicin was obtained. The in-vivo anti-tumor studies conducted on BALB/c mice bearing cervical tumor showed that the nanoparticles could effectively suppress the growth of tumor and hence reducing the significant side effects (Xiong et al., 2014). Zheng et al., prepared pH-sensitive poly (l-glutamic acid) grafted mesoporous silica nanoparticles encapsulating doxorubicin. The release of drug from the nanoparticles was found to be pH dependent. A higher drug release was observed at pH 5.5 than at pH 7.4. The Sulforhodamine B (SRB) colorimetric assay was performed on HeLa cells and the prepared nanoparticles were found to be biocompatible with enhanced Cytotoxicity (Zheng et al., 2013).
Ultrasound-assisted green synthesis of triazole-based azomethine/thiazolidin-4-one hybrid inhibitors for cancer therapy through targeting dysregulation signatures of some Rab proteins
Published in Green Chemistry Letters and Reviews, 2023
Aboubakr H. Abdelmonsef, Ahmed M. El-Saghier, Asmaa M. Kadry
Twelve compounds 1a, 1b, 3a-3d, 4a–4d, 5c, and 6c were selected by National Cancer Institute (NCI) according to the protocol of the Drug Evaluation Branch of the National Cancer Institute, Bethesda, USA, for in vitro anticancer screening (42,43). The prepared analogs were tested at single concentration of 10−5 M and the culture was incubated for 48 hours. End-point determinations were made with a protein binding dye, Sulforhodamine B (SRB). All the screened compounds reduced the growth of most cancer cell lines to 32% or less. Additionally, they are called active and subsequently passed for further evaluation toward NCI-60 human tumor cell lines derived from nine different cancers: leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate, and breast.
Schiff base complexes, cancer cell lines, and anticancer evaluation: a review
Published in Journal of Coordination Chemistry, 2022
Sheikh Abdul Majid, Jan Mohammad Mir, Gowhar Jan, Aabid Hussain Shalla
A bright pink dye-aminoxanthene (Sulforhodamine-B) binds in mild acidic conditions to basic amino acids and in alkaline conditions dissociation occurs. Cells are plated in plates with a flat bottom (96-well) at 5000–10,000 per well and allowed to stick to well-plates overnight, then addition of sample is done in serial with 3-fold dilutions to triplicate wells. At 1:10 dilution water is added to medium. Incubation of these plates is done for 3 days at 37 °C, 5% CO2, and then using SRB (Sulforhodamine B assay), growth inhibition of cells is analyzed. By addition of cold trichloroacetic acid cells are fixed to the final concentration of 10% and incubated for 1 h at 4 °C. Then the cells are washed with distilled water (5 times) and stain cells with SRB (0.4%) mixed with acetic acid (1%) for 20–35 min, then washed with acetic acid (1%) to remove the stain that remained unbound. At room temperature the plates are dried and bound dye is solubilized with 10 mm of Tris base. The plates are screened on a device (micro plate reader) at 595 nm [69].
Synthesis and evaluation of Zn(II) dithiocarbamate complexes as potential antibacterial, antibiofilm, and antitumor agents
Published in Journal of Coordination Chemistry, 2019
Vinay Kumar Maurya, Ashish Kumar Singh, Ravi Pratap Singh, Shivangi Yadav, Krishna Kumar, Pradyot Prakash, Lal Bahadur Prasad
Cell proliferation was determined using the sulforhodamine B (SRB) assay. Growing HCT116 cells were seeded into 96-well plates at a density of 5 × 103 cells per well and allowed to adhere overnight. Twenty-four hours later, cells were incubated for 48 h with a range of concentrations of complexes A2 and A3 (2–256 µg mL−1). Cells were fixed with 50% (w/v) TCA and stained with 0.4% (w/v) sulforhodamine B (SRB) for 30 min before washing with 1% (v/v) acetic acid. SRB was solubilized with 10 mM Tris pH ∼10.5, the absorbance read at 510 nm, and cell growth expressed as the percentage (%) of the growth of untreated cells. The concentration of QDs that resulted in 50% growth inhibition (GI50) was calculated by interpolation from the growth inhibition versus concentration curves using GraphPad Prism version 5.01 for Windows (GraphPad Software Inc., San Diego, CA).