DDAB cationic lipid-mPEG, PCL copolymer hybrid nano-carrier synthesis and application for delivery of siRNA targeting IGF-1R into breast cancer cells

Background and objective To use siRNA molecule as a therapeutic agent in gene silencing, an efficient delivery system is necessary. Stability and clearance by reticuloendothelial of siRNA still remains the major challenges for clinical application. Herein, we could develop new lipid-polymer hybrid nanoparticles (LPHNP) as a siRNA carrier to silence insulin-like growth factor type I (IGF-1R) gene overexpression in MCF-7 human breast cancer cell line. Methods Dimethyldioctadecylammonium bromide-methoxy poly(ethylene glycol)-poly (ε-caprolactone) (DDAB-mPEG-PCL) LPHNPs were synthesized using a single step nanoprecipitation method and characterized by dynamic light scattering (DLS) and atomic force microscopy (AFM) microscope. Cytotoxicity of the nanoparticles was assessed in the MCF7 cell line using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Desired LPHNP-siRNA complex was determined using different Nitrogen:Phosphate ratio (N/P) ratios and gel retardation. To determine the encapsulation efficiency of siRNA (%) in LPHNP, its absorbance was measured. The effect of the siRNA-LPHNP complex on IGF-1R silencing was assessed by reverse transcription-polymerase chain reaction (RT-PCR) Results LPHNP was synthesized using a single-step sonication method with a size below 100 nM. The viability of cells treated with hybrid nanoparticles was significantly greater than the corresponding cationic lipid (P < 0.01). As demonstrated by gel retardation assay, efficient siRNA binding to LPHNP occurred at N/P equal to 40 and siRNA encapsulation efficiency was found to be 95% ± 4 at this ratio. LPHNP-IGF-1R siRNA complex could be able to down-regulate the target more efficiently when it compared with the corresponded controls (P < 0.001). Conclusion In conclusion, our results suggest that DDAB cationic lipid and mPEG-PCL copolymer hybrid nanoparticle may be a good candidate for efficient siRNA delivery (AU)

Receptores metabotrópicos de glutamato: nuevas dianas moleculares en la terapia de enfermedades neurológicas y psiquiátricas / Metabotropic glutamate receptors: new molecular targets in the treatment of neurological and psychiatric diseases

Objetivo. Describir el estado actual de conocimientos sobre los procesos de señalización neuronal mediados por los receptores metabotrópicos de glutamato (mGlu) y su potencial papel en el tratamiento de enfermedades neurológicas y psiquiátricas. Desarrollo. Los receptores mGlu son una gran familia de receptores acoplados a proteínas G que modulan la transmisión sináptica excitadora a través de varias vías de transducción. Las investigaciones centradas en conocer la biología molecular, fisiología y farmacología de los receptores mGlu han puesto de manifiesto su implicación en varios trastornos del sistema nervioso central, entre los que destacan la epilepsia, el dolor, la isquemia y las enfermedades neurodegenerativas. Estos descubrimientos han permitido demostrar que la modulación de la transmisión glutamatérgica con fármacos que actúan selectivamente sobre los receptores mGlu puede tener importantes efectos beneficiosos. Los resultados obtenidos son muy prometedores y están siendo aprovechados para el desarrollo de nuevos medicamentos que han permitido solucionar los múltiples efectos secundarios producidos por los fármacos que actúan sobre los receptores ionotrópicos de glutamato. En esta dirección, existen claras evidencias del uso potencial de agonistas y antagonistas selectivos de los distintos tipos de receptores mGlu como agentes neuroprotectores. Conclusiones. Determinar el papel de los receptores mGlu en condiciones fisiológicas y patológicas es de especial relevancia para el desarrollo de nuevos tratamientos de enfermedades producidas por alteraciones en la neurotransmisión glutamatérgica. En este sentido, los progresos actuales indican que los receptores mGlu constituyen nuevas y prometedoras dianas para la terapia de enfermedades neurológicas y psiquiátricas

Aim. To describe the current state of knowledge about the processes of neuronal signalling mediated by the metabotropic glutamate (mGlu) receptors and their potential role in the treatment of neurological and psychiatric disorders. Development. The mGlu receptors are a large family of G-protein coupled receptors that modulate excitatory synaptic transmission through several transduction mechanisms. Recent advances in the molecular biology, physiology and pharmacology of these receptors revealed their potential role in a variety of central nervous system disorders such as epilepsy, pain, ischemia, and neurodegenerative diseases. These findings have shown that modulating glutamatergic transmission with drugs interacting selectively on mGlu receptors might have important beneficial effects. A number of results in this direction are very promising and are used to develop new drugs that overcome the multiple side-effects produced by the drugs acting on ionotropic glutamate receptors. Thus, several evidence have provided clear indications of the potential use of selective agonists and antagonists of the different mGlu receptor subtypes as neuroprotective agents. Conclusions. Determining the role of mGlu receptors in physiological as well as in pathophysiological states will be relevant to develop new treatments for diseases in which glutamatergic neurotransmission is altered. In this sense, the current progress indicates that mGlu receptors are novel and promising therapeutic targets for neurological and psychiatric disorders