Design and synthesis of a star-like polymeric micelle modified with AS1411 aptamer for targeted delivery of camptothecin for cancer therapy.

Improving of tumor targeting and decreasing side effects at normal cells of antitumor drugs are necessary to promote the cancer chemotherapy efficacy. Herein, we have synthesized a novel 21-arm star like diblock polymer of ß-cyclodextrin-{poly(ε-caprolactone)-poly(2-aminoethylmethacrylate)}21 which decorated with nucleolin aptamer (AS1411). The diblock polymer was prepared by combined ROP with electron transfer atom transfer radical polymerization (ARGET ATRP) methods followed camptothecin (CPT) encapsulation with high entrapment efficiency (65%). Subsequently, the attachment of AS1411 aptamer via covalent bond led to the formation of the final product ß-CD-(PCL-PAEMA)21/AS1411/CPT. In vitro drug release experiment demonstrated almost 50% of CPT was released in 72 h at acidic tumoral environment. The data of cellular toxicity (MTT) showed that the final product remarkably enhanced cell death in MCF-7 and 4T1 cells while normal cells (L929) showed high viability toward the prepared complex. Also, the finding of flow cytometry analysis and fluorescence imaging indicated successful internalization of complex into the target cells but not the nontarget cells. The in vivo experiments revealed the fact that ß-CD-(PCL-PAEMA)21/AS1411/CPT micelles showed high tumor inhibitory potential in comparison with free CPT. These findings exhibited the excellent ability of the novel star-like polymeric micelle with targeting agent for the targeted and effective delivery of CPT in cancer treatment.

Recent Advances on Synthetic Methodology Merging C-H Functionalization and C-C Cleavage.

The functionalization of C-H bonds has become a major thread of research in organic synthesis that can be assessed from different angles, for instance depending on the type of catalyst employed or the overall transformation that is carried out. This review compiles recent progress in synthetic methodology that merges the functionalization of C-H bonds along with the cleavage of C-C bonds, either in intra- or intermolecular fashion. The manuscript is organized in two main sections according to the type of substrate in which the cleavage of the C-C bond takes place, basically attending to the scission of strained or unstrained C-C bonds. Furthermore, the related research works have been grouped on the basis of the mechanistic aspects of the different transformations that are carried out, i.e.,: (a) classic transition metal catalysis where organometallic intermediates are involved; (b) processes occurring via radical intermediates generated through the use of radical initiators or photochemically; and (c) reactions that are catalyzed or mediated by suitable Lewis or Brønsted acid or bases, where molecular rearrangements take place. Thus, throughout the review a wide range of synthetic approaches show that the combination of C-H and C-C cleavage in single synthetic operations can serve as a platform to achieve complex molecular skeletons in a straightforward manner, among them interesting carbo- and heterocyclic scaffolds.

Pd-catalyzed cascade reactions involving skipped dienes: from double carbopalladation to remote C-C cleavage.

We report two ligand-controlled cascade reactions relying on the intramolecular carbopalladation of skipped dienes. The use of a bulky monodentate phosphine ligand affords [4,5]-spirocycles via sequential double carbopalladation, however bidentate phosphines promote a remote ß-C-elimination process which does not rely on the use of strained or sterically hindered substrates.

Efficacy of proton pump inhibitors and H2 blocker in the treatment of symptomatic gastroesophageal reflux disease in infants.

PURPOSE: Gastroesophageal reflux disease (GERD) occurs in pediatric patients when reflux of gastric contents presents with troublesome symptoms. The present study compared the effects of omeprazole and ranitidine for the treatment of symptomatic GERD in infants of 2-12 months. METHODS: This study was a clinical randomized double-blind trial and parallel-group comparison of omeprazole and ranitidine performed at Children Training Hospital in Tabriz, Iran. Patients received a standard treatment for 2 weeks. After 2 weeks, the patients with persistent symptoms were enrolled in this randomized study. RESULTS: We enrolled 76 patients in the present study and excluded 16 patients. Thirty patients each were included in group A (ranitidine) and in group B (omeprazole). GERD symptom score for groups A and B was 47.17±5.62 and 51.93±5.42, respectively, with a P value of 0.54, before the treatment and 2.47±0.58 and 2.43±1.15, respectively, after the treatment (P=0.98). No statistically significant differences were found between ranitidine and omeprazole in their efficacy for the treatment of GERD. CONCLUSION: The safety and efficacy of ranitidine and omeprazole have been demonstrated in infants. Both groups of infants showed a statistically significant decrease in the score of clinical variables after the treatment.