In gene therapy, it is important to develop an effective and safe gene delivery system. Especially, from the viewpoint of reducing side effects, gene delivery into a specific site is essential. We previously, developed liposomal bubbles (Bubble liposomes) containing perfluoropropane. Bubble liposomes were useful as ultrasound enhanced gene delivery tools in vitro and in vivo. In this review, we introduced the characteristics of Bubble liposomes as ultrasound imaging agents and ultrasound enhanced gene delivery tools. Bubble liposomes worked as ultrasound imaging agents in cardiosonography. In addition, their combination with ultrasound exposure was able to deliver plasmid DNA in the femoral artery. The gene expression was only observed at the site of ultrasound exposure. Moreover, the gene delivery by Bubble liposomes and ultrasound exposure was more efficient than that by conventional lipofection method using Lipofectamine 2000. Therefore, it was suggested that Bubble liposomes might be a new class of tools for site specific gene delivery.
Boron neutron capture therapy (BNCT) is a binary cancer treatment based on the nuclear reaction of two essentially nontoxic species, 10B and thermal neutrons. High accumulation and selective delivery of boron into tumor tissue are the most important requirements to achieve efficient neutron capture therapy of cancers. This review focuses on the liposomal boron delivery system (BDS) as a recent promising approach that meets these requirements for BNCT. BDS involves two strategies: (1) encapsulation of boron in the aqueous core of liposomes and (2) accumulation of boron in the liposomal bilayer. Various boronated liposomes have been developed and significant boron accumulation into tumor tissue with high tumor/blood boron ratios has been achieved by BDS.
NFκB regulate several inflammatory related molecules and evoke immune and inflammatory response by several stimuli, therefore inhibition of NFκB activation would be a novel therapeutic strategy. To date, there are many conventional drugs including nonsteroldal or steroldal anti-inflammatory drugs or immune suppressors etc. were known to inhibit NFκB activation, however, several side effects were also reported. Recently, double stranded oligonucleotide including NFκB binding sequence, called NFκB decoy, was developed to prevent NFκB activation, which is powerful tool in a new class of anti-gene strategy for molecular therapy with low side effect. However, NFκB decoy is easily degraded by nuclease and rapidly excreted to urine, therefore it is necessary to develop carrier for NFκB decoy therapy. Here, we shall review delivery system for NFκB decoy and introduce our cell-selective delivery system for NFκB decoy using sugar decorated cationic liposomes.
Non-viral vectors need to overcome several barriers such as the plasma membrane, the endosomal membrane and the nuclear membrane for efficient gene delivery to the nucleus of target cells. To overcome these obstacles, the delivery system must be equipped with various functional devices. However, it is difficult to package all these needed devices into a single system to exert each of their functions at the appropriate time and at the correct location. Thus, our group proposed a new packaging concept, “Programmed Packaging”. A multifunctional envelope-type nano device (MEND) was developed for use as an efficient non-viral system for the delivery of plasmid DNA (pDNA), oligodeoxynucleotide (ODN) and siRNA. Various types of MEND were developed as to strategy and situations. For example, the octaarginine (R8)-modified MEND (R8-MEND) encapsulating pDNA showed significantly high transfection activity comparable to adenovirus, and the up-take pathway of the R8-MEND was macropinocytosis, which can avoid lysosomal degradation. The R8-MEND successfully delivered a gene to hair follicles of mouse skin by in vivo topical application. Consequently, our group succeeded in the development of the MEND based on the Programmed Packaging, and found this to be a promising new delivery system of pDNA and functional nucleic acids.
PEGylated liposomes (approximately 100 nm in diameter) lose their long-circulating characteristic upon repeated injection at certain intervals in the same animal (referred to as the “accelerated blood clearance (ABC) phenomenon”), as described by our group and by researchers in the Netherlands. Recently, it was demonstrated by our group that anti-PEG IgM, induced by the first dose of PEGylated liposomes, is responsible for the ABC phenomenon. The IgM produced in this manner then selectively bound to the surface of subsequently injected PEGylated liposomes, leading to substantial complement activation. It is generally believed that nanocarriers coated with a polymer, such as PEG, have no immunogenicity. However, unexpected immune responses occurred even in response to polymer-coated liposomes. This immunogenicity to PEGylated liposomes presents a serious concern in the development and clinical use of liposomal formulations. In this review, we demonstrate our recent observations regarding with the ABC phenomenon against liposomes.
Histamine is well known for its roles in allergic diseases and anaphylaxis through H1-receptor stimulation. The H1-receptor stimulation by histamine results in an increase in vascular permeability, vasodilatation, and stimulation of nerve terminals in primary sensory neurons, thereby accelerating the inflammatory responses. On the other hand, histamine has been demonstrated to be involved in the regulation of innate and acquired immune responses through H2-receptors. In a previous study with human peripheral blood mononuclear cells, we observed that histamine exerts various regulatory effects on monocyte/macrophage function. In this review, we discuss how inducible histamine protects mice from lethal hepatitis, induced by heat-killed P.acnes (1 mg, i.v.) followed by challenge with a low dose of lipopolysaccharide (1 μg), by reducing the excessive cytokine response in the liver. In addition, from in vivo studies with histidine decarboxylase knockout and H1-, H2-receptor knockout mice, the protective effect of histamine against fulminant hepatitis is shown to be elicited through H2-receptor stimulation.
Nonsteroidal antiinflammatory drugs (NSAIDs) are one of the most frequently used classes of medicines worldwide. The major clinical problem encountered with the use of NSAIDs is gastrointestinal complications. In the USA, about 16,500 people per year die as a result of NSAID-associated gastrointestinal complications. COX-2-specific NSAIDs have been developed as safer for the gastrointestinal tract, although the risk of cardiovascular thrombotic disease has recently been noted with the use of COX-2-specific NSAIDs. To find the strategy for the development of gastrointestinally safe NSAIDs other than COX-2-specific NSAIDs, we examined the molecular mechanism for NSAID-induced gastric ulcer formation. We found that NSAIDs induce gastric mucosal cell death in a manner independent of COX inhibition and that this cytotoxic effect is due to their membrane permeabilization activity, which is not required for the antiinflammatory activity of NSAIDs. Furthermore, we showed that in addition to COX inhibition by NSAIDs, direct cytotoxicity of NSAIDs is required for NSAID-induced gastric ulcer formation. These results suggest that NSAIDs that have neither membrane permeabilization activity nor COX-2 specificity would be safe for both the gastrointestinal tract and cardiovascular system and we are now chemically synthesizing such NSAIDs.
Recent advances in post-genomic technology enable us to analyze gene expression and protein modification comprehensively in tissues and cells, resulting in new developments in the analysis of molecular events of diseases. We have been studying the pathogenic and progressive mechanisms of diseases from the aspect of signalling pathways of cells. Inflammatory cytokines such as TNF-alpha and IL-1 produced from activated macrophages stimulate the overgrowth of synoviocytes and induce osteoclast differentiation in rheumatoid arthritis (RA). As a consequence, cartilage and bone destruction in joints is observed in RA patients. Recently, the pathogenic mechanisms are beginning to be discussed at the molecular level. For example, up-regulation of synoviolin, an ER-localizing E3 ubiquitin ligase, in synoviocytes is involved in RA because rheumatoid synoviocytes produce synoviolin and overexpression of human synoviolin in mice causes arthropathy. So far little is known about ligands inducing arthropathy and their receptors in the disease. We characterized rheumatoid synoviocytes by profiling gene expression with genome-wide DNA chips, and found that a cluster antigen is involved in the proteins up-regulated in rheumatoid synoviocytes. We have been analyzing the relationship between synoviolin expression and the activation of cluster antigen. The cluster antigen and its signal pathways could become a novel therapeutic target for RA. We discuss the possibility of direct induction of synoviolin expression via activation of signal pathways directed by the cluster antigen in RA synoviocytes.
Lipid based carriers have attracted increasing scientific and commercial attention during the last few years as an alternative material for the delivery of peptides and proteins concerned with stability issues. This article presents an overview of different types of biocompatible and versatile lipid-based carriers employed for the delivery of therapeutic proteins and peptides. Such delivery systems are discussed and exemplified regarding both more traditional lipid based delivery systems such as liposomes and lipid emulsions as well as more novel structures, e.g., lipid microtubules, microbubbles, and solid lipid nanoparticles.
Crystallization in the presence of additives like surfactants and polymers is a relatively less explored area but is important for polymorphic screening of a compound during its developmental stage. Surfactants and polymers act by various mechanisms to influence either the growth or the nucleation phase, resulting in modification of either the polymorphic form or the crystal habit. The present study was aimed at understanding the crystallization behavior of the model drug mebendazole (MBZ) in the presence of an inert polymer polyvinyl pyrrolidone (PVP) and an anionic surfactant sodium lauryl sulphate (SLS). Crystals were generated by the antisolvent approach using the surfactant and polymer solutions in water as the antisolvents. Change in habit from needles to plates took place as a result of modification of the crystallization process in the presence of additive molecules. This was confirmed by quantification of these additives using specific analytical methods, which revealed their presence in small amounts in the final product (0.02, 0.15, and 0.24% w/w SLS in crystals generated using 0.5, 1.0, and 2.0% SLS, respectively, and 0.94, and 1.24% w/w PVP K30 and PVP K90, respectively). Their presence in the crystals led to modification in the dissolution of the drug. SLS improved the extent of dissolution while PVP had a negative impact and led to reduction in the amount of MBZ released even below that of the pure drug. The study highlights the influence of polymeric and surfactant additives on the crystallization process leading to modified performance.
After the dosage form of tamsulosin hydrochloride was changed from a capsule to on orally disintegrating tablet (ODT, Harnal® D), we often received patient complaints and noted an increase in noncompliance with medication regimens. The change in dosage form appeared to cause poor compliance by patients who had become accustomed to the light pink/white capsule over many years. Therefore, we carried out a questionnaire survey of patients taking the ODT form to determine the effects of changing the dosage form and the usefulness of the ODT. Most (92%) of respondents took the ODT with water. In addition, 16% missed taking the medicine after the change in dosage form. ODT is a dosage form that is easy to take for patient with dysphagia, or those on restricted water intake. However, it appears that elderly men and patients with visual disorders cannot distinguish the ODT from other medicines and this affects patient compliance. In conclusion, all pharmaceutical companies should consider the design of medications in terms of coloration, indications, or shape in anticipation of the aging society in future, so that patients can distinguish them. Furthermore, sufficient pharmaceutical care is needed to improve both compliance and safety management for the elderly.
We established the Terminal Care Study Group, consisting of physicians, pharmacists, and nurses, in September 2001, and developed the group into the Palliative Care Team. We have surveyed the state of concomitant medications immediately before and at the beginning of opioid usage (except injections) to assess the role of the Palliative Care Team. The survey period was 3 years from October 1, 2002 to September 30, 2005. While the frequency of the prescription of non-steroidal anti-inflammatory drugs (NSAIDs), laxatives, or antiemetics before the beginning of opioid administration did not differ significantly among the 3 periods, that at the beginning of opioid administration increased significantly in 2003 compared with 2002, and increased further in 2004. Many of the drugs used were those that were recommended in our cancer pain management program. Thus, the activities of the Palliative Care Team are considered to have led to proper measures for the control of the major adverse effects of opioids such as constipation and nausea/vomiting in addition to pain control in accordance with the WHO's pain ladder, and also contributed to improvements of the patients' QOL.