Transfection of lung cells in vitro and in vivo: effect of antioxidants and intraliposomal bFGF

Co-delivery Systems of Multiple Drugs Using Nanotechnology for Future Cancer Therapy

Cancer treatments have improved significantly during the last decade but are not yet satisfactory. Combination therapy is often administered to improve efficacy and safety. Drug delivery systems can also improve efficacy and safety. To control the spatiotemporal distribution of drugs, nanotechnology involving liposomes, solid lipid nanoparticles, and polymeric micelles has been developed. Co-delivery systems of multiple drugs are a promising approach to combat cancer. Synergistic effects and reduced side effects are expected from the use of co-delivery systems. In this review, we summarize various co-delivery systems for multiple drugs, including small-molecule drugs, nucleic acids, genes, and proteins. Co-delivery of drugs with different properties is relatively difficult, but some researchers have succeeded in developing such co-delivery systems. Environment-responsive carrier designs can control the release of cargos. Although their preparation is more complicated than that of mono-delivery systems, co-delivery systems can simplify clinical procedures and improve patient QOL.

Chronic lung injury in the neonatal rat: up-regulation of TGFβ1 and nitration of IGF-R1 by peroxynitrite as likely contributors to impaired alveologenesis

Postnatal alveolarization is regulated by a number of growth factors, including insulin-like growth factor-I (IGF-I) acting through the insulin-like growth factor receptor-1 (IGF-R1). Exposure of the neonatal rat lung to 60% O2 for 14 days results in impairments of lung cell proliferation, secondary crest formation, and alveologenesis. This lung injury is mediated by peroxynitrite and is prevented by treatment with a peroxynitrite decomposition catalyst. We hypothesized that one of the mechanisms by which peroxynitrite induces lung injury in 60% O2 is through nitration and inactivation of critical growth factors or their receptors. Increased nitration of both IGF-I and IGF-R1 was evident in 60% O2-exposed lungs, which was reversible by concurrent treatment with a peroxynitrite decomposition catalyst. Increased nitration of the IGF-R1 was associated with its reduced activation, as assessed by IGF-R1 phosphotyrosine content. IGF-I displacement binding plots were conducted in vitro using rat fetal lung distal epithelial cells which respond to IGF-I by an increase in DNA synthesis. When IGF-I was nitrated to a degree similar to that observed in vivo there was minimal, if any, effect on IGF-I displacement binding. In contrast, nitrating cell IGF-R1 to a similar degree to that observed in vivo completely prevented specific binding of IGF-I to the IGF-R1, and attenuated an IGF-I-mediated increase in DNA synthesis. Additionally, we hypothesized that peroxynitrite also impairs alveologenesis by being an upstream regulator of the growth inhibitor, TGFβ1. That 60% O2-induced impairment of alveologenesis was mediated in part by TGFβ1 was confirmed by demonstrating an improvement in secondary crest formation when 60% O2-exposed pups received concurrent treatment with the TGFß1 activin receptor-like kinase, SB 431542. That the increased TGFβ1 content in lungs of pups exposed to 60% O2 was regulated by peroxynitrite was confirmed by its attenuation by concurrent treatment with a peroxynitrite decomposition catalyst. We conclude that peroxynitrite contributes to the impaired alveologenesis observed following the exposure of neonatal rats to 60% O2 both by preventing binding of IGF-I to the IGF-R1, secondary to nitration of the IGF-R1, and by causing an up-regulation of the growth inhibitor, TGFβ1.