ABSTRACT
Inhalation delivery of prostaglandin E (PGE2) in combination with selected siRNA(s) was proposed for the efficient treatment of idiopathic pulmonary fibrosis (IPF). Nanostructured lipid carriers (NLC) were used as a delivery system for PGE2 with and without siRNAs targeted to MMP3, CCL12, and HIF1Alpha mRNAs. The model of IPF was developed in SKH1 mice by intratracheal administration of bleomycin at a dose of 1.5U/kg. Results showed that NLC-PGE2 in combination with three siRNAs delivered locally to the lungs by inhalation markedly reduced mouse body mass, substantially limited hydroxyproline content in the lungs and disturbances of the mRNAs and protein expression, restricted lung tissue damage and prevented animal mortality. Our data provide evidence that IPF can be effectively treated by inhalation of the NLC-PGE2 in combination with siRNAs delivered locally into the lungs. This effect could not be achieved by using NLC containing just PGE2 or siRNA(s) alone.
Subject(s)
Drug Delivery Systems/methods , Idiopathic Pulmonary Fibrosis/therapy , Nanoparticles/administration & dosage , Prostaglandins/therapeutic use , RNA, Small Interfering/administration & dosage , Administration, Inhalation , Animals , Antibiotics, Antineoplastic/pharmacology , Bleomycin/pharmacology , Combined Modality Therapy , Idiopathic Pulmonary Fibrosis/genetics , Idiopathic Pulmonary Fibrosis/pathology , Lipids/chemistry , Mice , Mice, Hairless , RNA, Small Interfering/geneticsABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal form of interstitial lung disease. We hypothesized that the local pulmonary delivery of prostaglandin E2 (PGE2) by liposomes can be used for the effective treatment of IPF. To test this hypothesis, we used a murine model of bleomycin-induced IPF to evaluate liposomal delivery of PGE2 topically to the lungs. Animal survival, body weight, hydroxyproline content in the lungs, lung histology, mRNA, and protein expression were studied. After inhalation delivery, liposomes accumulated predominately in the lungs. In contrast, intravenous administration led to the accumulation of liposomes mainly in kidney, liver, and spleen. Liposomal PGE2 prevented the disturbances in the expression of many genes associated with the development of IPF, substantially restricted inflammation and fibrotic injury in the lung tissues, prevented decrease in body weight, limited hydroxyproline accumulation in the lungs, and virtually eliminated mortality of animals after intratracheal instillation of bleomycin. In summary, our data provide evidence that pulmonary fibrosis can be effectively treated by the inhalation administration of liposomal form of PGE2 into the lungs. The results of the present investigations make the liposomal form of PGE2 an attractive drug for the effective inhalation treatment of idiopathic pulmonary fibrosis.
Subject(s)
Dinoprostone/administration & dosage , Idiopathic Pulmonary Fibrosis/drug therapy , Administration, Intravenous , Animals , Bleomycin/toxicity , Body Weight/drug effects , Disease Models, Animal , Hydroxyproline/metabolism , Idiopathic Pulmonary Fibrosis/chemically induced , Immunohistochemistry , Kidney/drug effects , Liposomes/administration & dosage , Liposomes/metabolism , Liver/drug effects , Lung/drug effects , Lung/metabolism , Mice , RNA, Messenger/metabolism , Spleen/drug effects , Time Factors , Tissue DistributionABSTRACT
A lactocrine mechanism for delivery of maternally derived relaxin (RLX) into the neonatal circulation as a consequence of nursing was proposed for the pig. Immunoreactive RLX was detected in colostrum and in the serum of newborn pigs only if they were allowed to nurse. Milk-borne RLX concentrations are highest during early lactation (9-19 âng/ml), declining to <2 âng/ml by postnatal day 14. Whether milk-borne RLX is bioactive is unknown. Evidence that RLX concentrations in milk are higher than in maternal circulation in several species suggests the mammary gland as a site of local RLX production. It is unknown whether the porcine mammary gland is a source of RLX. Therefore, objectives were to evaluate RLX bioactivity in porcine milk during the first 2 weeks of lactation, identify the form of RLX in porcine milk, and determine whether mammary tissue from early lactation is a source of milk-borne RLX. Milk RLX bioactivity was determined using an in vitro bioassay in which cAMP production by human embryonic kidney (HEK293T) cells transfected with the human RLX receptor (RXFP1) was measured. RLX bioactivity was highest at lactation day (LD) 0, decreasing to undetectable levels by LD 4. Immunoblot analysis of milk proteins revealed an 18 âkDa band, indicating proRLX as the primary form of RLX in porcine milk. ProRLX protein and transcripts were detected in porcine mammary tissue on LD 0 and 7. Results support the lactocrine hypothesis by defining the nature and a potential source for bioactive proRLX in porcine colostrum/milk.
Subject(s)
Milk/chemistry , Relaxin/analysis , Relaxin/physiology , Animals , Biological Assay/methods , Biopsy , Cells, Cultured , Colostrum/chemistry , Colostrum/metabolism , Female , Humans , Lactation/metabolism , Lactation/physiology , Mammary Glands, Animal/metabolism , Mammary Glands, Animal/pathology , Milk/metabolism , Protein Precursors/genetics , Protein Precursors/metabolism , RNA, Messenger/analysis , Relaxin/genetics , Relaxin/metabolism , Swine , Time Factors , Validation Studies as TopicABSTRACT
The relationship between microparticle (MP) size and lung targeting efficiency, intra-lung distribution and retention time was systematically studied after intravenous administration of rigid fluorescent polystyrene MPs of various sizes (2, 3, 6 and 10 microm) to Sprague Dawley rats. Total fluorescence was assessed and it was found that 2 microm and 3 microm MPs readily passed through the lung to the liver and spleen while 10 microm MPs were completely entrapped in the lung for the one-week duration of the study. Approximately 84% of 6 microm MPs that were initially entrapped in the lung were cleared over the next 2 days and 15% were cleared over the remaining 5 days. A Caliper IVIS 100 small animal imaging system confirmed that 3 microm MPs were not retained in the lung but that 6 microm and 10 microm MPs were widely distributed throughout the lung. Moreover, histologic examination showed MP entrapment in capillaries but not arterioles. These studies suggest that for rigid MPs the optimal size range required to achieve transient but highly efficiently targeting to pulmonary capillaries after IV injection is >6 microm but <10 microm in rats and that systemic administration of optimally sized MPs may be an efficient alternative to currently used inhalation-based delivery to the lung.
Subject(s)
Drug Carriers , Lung/blood supply , Polystyrenes/administration & dosage , Animals , Capillaries/anatomy & histology , Chemistry, Pharmaceutical , Fluorescent Dyes/administration & dosage , Injections, Intravenous , Liver/metabolism , Lung/metabolism , Male , Particle Size , Polystyrenes/chemistry , Polystyrenes/metabolism , Rats , Rats, Sprague-Dawley , Spectrometry, Fluorescence , Spleen/metabolism , Surface Properties , Technology, Pharmaceutical/methods , Time Factors , Tissue DistributionABSTRACT
PURPOSE: To compare systemic intravenous and local intratracheal delivery of doxorubicin (DOX), antisense oligonucleotides (ASO) and small interfering RNA (siRNA). METHODS: "Neutral" and cationic liposomes were used to deliver DOX, ASO, and siRNA. Liposomes were characterized by dynamic light scattering, zeta-potential, and atomic force microscopy. Cellular internalization of DOX, ASO and siRNA was studied by confocal microscopy on human lung carcinoma cells. In vivo experiments were carried out on nude mice with an orthotopic model of human lung cancer. RESULTS: Liposomes provided for an efficient intracellular delivery of DOX, ASO, and siRNA in vitro. Intratracheal delivery of both types of liposomes in vivo led to higher peak concentrations and much longer retention of liposomes, DOX, ASO and siRNA in the lungs when compared with systemic administration. It was found that local intratracheal treatment of lung cancer with liposomal DOX was more efficient when compared with free and liposomal DOX delivered intravenously. CONCLUSIONS: The present study outlined the clear advantages of local intratracheal delivery of liposomal drugs for the treatment of lung cancer when compared with systemic administration of the same drug.