ABSTRACT
A cation molecular exchanger has been developed that consists of the bipyridine and crown ether receptor subunits. It has been shown that binding of the zinc(II) cation to the bipyridine subunit induces the conformational switching of the crown ether subunits, which results in a release of the potassium cation. Two conformational states of the cation exchanger have been supported by the results from solution- and solid-state studies. It has been demonstrated that the cation exchanger is able to communicate with a cation sensor induced by a chemical stimulus.
ABSTRACT
A number of diseases can result from abnormal gene expression. One of the approaches for treating such diseases is gene therapy to inhibit expression of a particular gene in a specific cell population by RNA interference. Use of efficient delivery vehicles increases the safety and success of gene therapy. Here we report the development of functionalized biocompatible fluorescent nanoparticles from para amino benzoic acid nanoparticles for efficient delivery of short interfering RNA (siRNA). These nanoparticles were non-toxic and did not interfere with progression of the cell cycle. The intrinsic fluorescent nature of these nanoparticles allows easy tracking and an opportunity for diagnostic applications. Human Bcl-2 siRNA was complexed with these nanoparticles to inhibit expression in cells at both the transcriptional and translational levels. Our findings indicated high gene transfection efficiency. These biocompatible nanoparticles allow targeted delivery of siRNA, providing an efficient vehicle for gene delivery.
Subject(s)
Benzoates/chemistry , Biocompatible Materials/administration & dosage , Drug Delivery Systems , Nanoparticles/administration & dosage , Neoplasms/drug therapy , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , RNA, Small Interfering/administration & dosage , Apoptosis , Biocompatible Materials/chemistry , Blotting, Western , Cell Cycle , Cell Proliferation , Endocytosis , Flow Cytometry , Gene Silencing , Genetic Therapy , HeLa Cells , Humans , Immunoenzyme Techniques , Nanoparticles/chemistry , Neoplasms/pathology , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, CulturedABSTRACT
Highly stereoselective total syntheses of polyrhacitide A and epi-cryptocaryolone have been achieved in 11 steps with high overall yield of 24% and 28%, respectively, following a recently developed strategy for the construction of trans-2,6-disubstituted-3,4-dihydropyrans. In this report, the versatility of iodo-cyclization for the total syntheses of polyrhacitide A and epi-cryptocaryolone is demonstrated.
