1. Potential molecular targets in chemopreventative action of celecoxib: a proteomics analysis of J774.A1 macrophage-like cell line
Faegheh Rezaie, Mona Salimi,* Mohammad Hossein Ghahremani and Behrouz Vaziri*. Mol. BioSyst., 2011, 7, 1306–1311
There are reports of the possible relation of COX-2 expression in macrophages and the progression of some cancers such as colorectal adenoma. In lung cancer, overexpression of COX-2 has been shown to be associated with an imbalance between the production of interleukins by both tumor and macrophages. Moreover, COX-2 over-expression has been reported to inhibit apoptosis and promotes tumor angiogenesis. It has been shown that celecoxib, a selective inhibitor of COX-2, not only prevents neoplasia but also reverses the process of carcinogenesis. Celecoxib is also capable of impacting on tumor microenvironment by blocking PGE2. These efficacies of celecoxib are believed to be a consequence of its COX-2 dependent and COX-2 independent effects on a variety of cellular processes. Proteomics proﬁling of a colorectal cancer cell line, which has no expression of COX-2, has been used previously to deﬁne the possible COX-2 independent chemopreventative effects of celecoxib.
2. Drug-loaded nanoparticles and supramolecular nanotubes formed from a volatile microemulsion with bile salt derivatives
Katrin Margulis-Goshen, Maria Chiara di Gregorio, Shlomo Magdassi* and Luciano Galantini*. Phys. Chem. Chem. Phys., 2013, 15, 6016—6024
The samples were prepared by weighing appropriate amounts of surfactant (modified or natural bile salt), nBuOH (co-surfactant), nBuAc (oil) and water, carefully mixing them, and waiting for equilibrium to be attained. Microemulsion formation was determined when the resultant mixture had low-viscosity and was optically clear and stable. After detecting formation of the microemulsion at the specific composition, the system was loaded with celecoxib by simply adding the drug to the preformed system. Drug loading in the microemulsion was calculated as the weight fraction of celecoxib in the total weight of all microemulsion components.
3. The heat–chill method for preparation of self-assembled amphiphilic poly(3-caprolactone)–poly(ethylene glycol) block copolymer based micellar nanoparticles for drug delivery
Sanal Sebastian Payyappilly, Santanu Dharab and Santanu Chattopadhyay*. Soft Matter,2014, 10,2150–2159
The encapsulation efficiency of the micellar nanoparticle solution was determined using the method described elsewhere. In brief, 10 mg of polymer micellar nanoparticle solutions containing 1 mg celecoxib were prepared. The prepared nanoparticle based suspension was filtered through a 0.22 mm filter to remove any crystallized unencapsulated drug. The undissolved celecoxib drug was filtered away. The unsieved nanoparticle suspension and sieved solutions were dissolved in tetrahydrofuran and kept overnight to ensure complete dissolution of the nanoparticles. Samples were analysed using a UV-vis spectrophotometer to determine the celecoxib content. The encapsulation efficiency (EE%) and percent drug loading (DL%) were calculated using eqn (1) and (2).
4. Self-assemblies of the six-armed star triblock ABC copolymer: pH-tunable morphologies and drug release
Ping Zhou, Yu-Yang Liu,* Lu-Ying Niu and Jie Zhu. Polym. Chem.,2015, 6,2934–2944
We herein report novel multiple morphologies of self-assemblies of the six-armed star triblock copolymer s-(PDEA-b-PMMA-b-PPEGMA)6. The star block polymers exhibit a very low CAC value in aqueous solution. Interestingly, not only the morphologies of self-assemblies could be controlled by varying preparative pH, but also the obtained vesicles could exhibit a vesicle–micelle transition by simply tuning the environmental pH. The transition exhibited good reversibility. Using the hydrophobic drug celecoxib as a model molecule, the encapsulation capacity of self-assemblies prepared under different pH conditions was investigated. At pH 7.4 the vesicles exhibited high drug loading capacity. The celecoxib release from the loaded self-assemblies was pH tunable.