RESUMO
Polymers of guanidinylated disulfide containing poly(amido amine)s (Gua-SS-PAAs), have shown high transfection efficiency and low cytotoxicity. Previously, we synthesized two Gua-SS-PAA polymers, using guanidino containing monomers (i.e., arginine and agmatine, denoted as ARG and AGM, respectively) and N,N'-cystaminebisacrylamide (CBA). In this study, these two polymers, AGM-CBA and ARG-CBA were complexed with plasmid DNA, and their uptake pathway was investigated. Complexes distribution in MCF-7 cells, and changes on cell endosomes/lysosomes and membrane after the cells were exposed to complexes were tested. In addition, how the transfection efficiency changed with the cell cycle status as well as endocytosis inhibitors were studied. The polymers of AGM-CBA and ARG-CBA can avoid endosomal/lysosomal trap, therefore, greatly delivering plasmid DNA (pDNA) to the cell nucleoli. It is the guanidine groups in the polymers that enhanced complexes' permeation through cell membrane with slight membrane damage, and targeting to the nucleoli. J. Cell. Biochem. 118: 903-913, 2017. © 2016 Wiley Periodicals, Inc.
Assuntos
DNA/administração & dosagem , Transfecção/métodos , Transporte Ativo do Núcleo Celular , Ciclo Celular , Nucléolo Celular/metabolismo , DNA/genética , Dissulfetos , Sistemas de Liberação de Medicamentos , Endocitose , Técnicas de Transferência de Genes , Guanidina , Humanos , Células MCF-7 , Peptidomiméticos/síntese química , Peptidomiméticos/química , Peptidomiméticos/farmacocinética , Plasmídeos/administração & dosagem , Plasmídeos/genética , Polímeros/síntese química , Polímeros/química , Polímeros/farmacocinéticaRESUMO
Most of the newly developed drug candidates are lipophilic and poorly water-soluble. Enhancing the dissolution and bioavailability of these drugs is a major challenge for the pharmaceutical industry. Liquisolid technique, which is based on the conversion of the drug in liquid state into an apparently dry, non-adherent, free flowing and compressible powder, is a novel and advanced approach to tackle the issue. The objective of this article is to present an overview of liquisolid technique and summarize the progress of its applications in pharmaceutics. Low cost, simple processing and great potentials in industrial production are main advantages of this approach. In addition to the enhancement of dissolution rate of poorly water-soluble drugs, this technique is also a fairly new technique to effectively retard drug release. Furthermore, liquisolid technique has been investigated as a tool to minimize the effect of pH variation on drug release and as a promising alternative to conventional coating for the improvement of drug photostability in solid dosage forms. Overall, liquisolid technique is a newly developed and promising tool for enhancing drug dissolution and sustaining drug release, and its potential applications in pharmaceutics are still being broadened.
RESUMO
Poly(amido amine)s' (PAAs) versatility are nearly unique among stepwise polymers. Different functional groups can be easily introduced into these polymers to add functionality such as cell internalization, charge-shift, bioreducibility, "stealth" properties, and targeting moieties, while maintaining the bulk structural integrity of these polymers. The poly(amido amine)s are used as a unique research platform to elucidate their complex structure-function relationship. It is shown that guanidinium group, carboxyl group, disulfide bond, alkyl chain, branching, acetyl groups, benzoyl groups, and quaternary nicotinamide moieties can influence many steps of gene delivery, such as DNA condensation, cellular uptake, endosomal escape, nuclear entry, and finally gene expression. The authors systematically discuss the structure-function correlations of PAAs for gene delivery, and elaborate how the properties of polymers can be adjusted by changing the polymeric structure.