Pharmacokinetic analysis of lectin-dependent biodistribution of fucosylated bovine serum albumin: a possible carrier for Kupffer cells

Twenty Years of Research on Cyclodextrin Conjugates with PAMAM Dendrimers

Recently, the number of gene and oligonucleotide drugs are increasing. Of various drug delivery systems (DDSs) for gene and oligonucleotide drugs, few examples of the clinical application of polymer as drug carriers are known, despite development of the novel polymers has been progressing. Cyclodextrin (CD) conjugates with starburst polyamidoamine (PAMAM) dendrimer (CDEs), as a new type of polymer-based carriers, were first published in 2001. After that, galactose-, lactose-, mannose-, fucose-, folate-, and polyethyleneglycol (PEG)-appended CDEs have been prepared for passive and active targeting for gene, oligonucleotide, and low-molecular-weight drugs. PEG-appended CDE formed polypsuedorotaxanes with α-CD and γ-CD, which are useful for a sustained release system of gene and oligonucleotide drugs. Interestingly, CDEs were found to have anti-inflammatory effects and anti-amyloid effects themselves, which have potential as active pharmaceutical ingredients. Most recently, CDE is reported to be a useful Cas9-RNA ribonucleoproteins (Cas9 RNP) carrier that induces genome editing in the neuron and brain. In this review, the history and progression of CDEs are overviewed.

Applications of Nanobiomaterials in the Therapy and Imaging of Acute Liver Failure

This review focuses on the therapeutic mechanisms, targeting strategies of various nanomaterials in acute liver failure, and recent advances of diverse nanomaterials for acute liver failure therapy, diagnosis, and imaging. This review provides an outlook on the applications of nanomaterials, especially on the new horizons in acute liver failure therapy, and inspires broader interests across various disciplines. Acute liver failure (ALF), a fatal clinical disease featured with overwhelming hepatocyte necrosis, is a grand challenge in global health. However, a satisfactory therapeutic option for curing ALF is still absent, other than liver transplantation. Nanobiomaterials are currently being developed for the diagnosis and treatment of ALF. The liver can sequester most of nanoparticles from blood circulation, which becomes an intrinsic superiority for nanobiomaterials targeting hepatic diseases. Nanobiomaterials can enhance the bioavailability of free drugs, thereby significantly improving the therapeutic effects in ALF. Nanobiomaterials can also increase the liver accumulation of therapeutic agents and enable more effective targeting of the liver or specific liver cells. In addition, stimuli-responsive, optical, or magnetic nanomaterials exhibit great potential in the therapeutical, diagnostic, and imaging applications in ALF. Therefore, therapeutic agents in combination with nanobiomaterials increase the specificity of ALF therapy, diminish adverse systemic effects, and offer a multifunctional theranostic platform. Nanobiomaterial holds excellent significance and prospects in ALF theranostics. In this review, we summarize the therapeutic mechanisms and targeting strategies of various nanobiomaterials in ALF. We highlight recent developments of diverse nanomedicines for ALF therapy, diagnosis, and imaging. Furthermore, the challenges and future perspectives in the theranostics of ALF are also discussed.

Conjugates of small targeting molecules to non-viral vectors for the mediation of siRNA

To use siRNA (small interfering RNA) for gene therapy, a gene delivery system is often necessary to overcome several challenging requirements including rapid excretion, low stability in blood serum, non-specific accumulation in tissues, poor cellular uptake and inefficient intracellular release. Active and/or passive targeting should help the delivery system to reach the desired tissue or cell, to be internalized, and to deliver siRNA to the cytoplasm so that siRNA can inhibit protein synthesis. This review covers conjugates of small targeting molecules and non-viral delivery systems for the mediation of siRNA, with a focus on their transfection properties in order to help the development of new and efficient siRNA delivery systems, as the therapeutic solutions of tomorrow.

STATEMENT OF SIGNIFICANCE

The delivery of siRNA into cells or tissues remains to be a challenge for its applications, an alternative strategy for siRNA delivery systems is direct conjugation of non-viral vectors with targeting moieties for cellular delivery. In comparison to macromolecules, small targeting molecules have attracted great attention due to their many potential advantages including significant simplicity and ease of production, good repeatability and biodegradability. This review will focus on the most recent advances in the delivery of siRNA using conjugates of small targeting molecules and non-viral delivery systems. Based the editor's suggestions, we hope the revised manuscript could provide more profound understanding to the conjugates of targeting molecules to vectors for mediation of siRNA.

Exploring the glycan interaction in vivo: Future prospects of neo-glycoproteins for diagnostics

Herein the biodistributions and in vivo kinetics of chemically prepared neoglycoproteins are reviewed. Chemical methods can be used to conjugate various mono- and oligosaccharides onto a protein surface. The kinetics and organ-specific accumulation profiles of these glycoconjugates, which are introduced through intravenous injections, have been analyzed using conventional dissection studies as well as noninvasive methods such as single photon emission computed tomography, positron emission tomography and fluorescence imaging. These studies suggest that glycan-dependent protein distribution kinetics may be useful for pharmacological and diagnostic applications.

Chemically synthesized glycoconjugates on proteins: effects of multivalency and glycoform in vivo

The biodistributions and in vivo kinetics of chemically prepared glycoconjugates on proteins are reviewed.

Potential use of fucose-appended dendrimer/α-cyclodextrin conjugates as NF-κB decoy carriers for the treatment of lipopolysaccharide-induced fulminant hepatitis in mice

The purpose of the present study is to treat lipopolysaccharide (LPS)-induced fulminant hepatitis by NF-κB decoy complex with fucose-appended dendrimer (generation 2; G2) conjugate with α-cyclodextrin (Fuc-S-α-CDE (G2)). Fuc-S-α-CDE (G2, average degree of substitution of fucose (DSF2))/NF-κB decoy complex significantly suppressed nitric oxide and tumor necrosis factor-α (TNF-α) production from LPS-stimulated NR8383 cells, a rat alveolar macrophage cell line, by adequate physicochemical properties and fucose receptor-mediated cellular uptake. Intravenous injection of Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex extended the survival of LPS-induced fulminant hepatitis model mice. In addition, Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex administered intravenously highly accumulated in the liver, compared to naked NF-κB decoy alone. Furthermore, the liver accumulation of Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex was inhibited by the pretreatment with GdCl3, a specific inhibitor of Kupffer cell uptake. Also, the serum aspartate aminotransferase, alanine aminotransferase and TNF-α levels in LPS-induced fulminant hepatitis model mice were significantly attenuated by the treatment with Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex, compared with naked NF-κB decoy alone. Taken together, these results suggest that Fuc-S-α-CDE (G2, DSF2) has the potential for a novel Kupffer cell-selective NF-κB decoy carrier for the treatment of LPS-induced fulminant hepatitis in mice.

Assessment of the metabolism of therapeutic proteins and antibodies

INTRODUCTION

In the last decade, our increased knowledge of factors governing the pharmacokinetics and metabolism of biologics (recombinant therapeutic proteins) has driven, and will continue to support, biological engineering and the design of delivery systems for more efficient biologics. Further research in analytical methods for assessing their in vitro and/or in vivo metabolism will also support these developments.

AREAS COVERED

In this review we will discuss the main components affecting the metabolism of biologics, and try to demonstrate how novel analytical evaluations will facilitate their future development. We will focus on the use of radiolabeled drugs, ligand-binding assays and mass spectrometry.

EXPERT OPINION

Future marketed biologics will be complex structures, such as glycoengineered, fused, or chemically modified proteins. Their in vivo efficiencies will be strongly dependent on their metabolic stabilities. Similarly to small molecular drugs, for which in vitro and in vivo biochemical platforms and analytical techniques have helped to rationalize preclinical and clinical developments, we would expect this also to translate to effective approaches to study the metabolism of biologics in the near future. Mass spectrometry should emerge as a standard technique for in vivo characterization of the biotransformation products of biologics.

Biodistribution characteristics of mannosylated and fucosylated O/W emulsions in mice

Cell-specific drug delivery is one of the most promising strategies for improving therapeutic efficiency and minimizing systemic toxicity. Carrier systems devoted to receptor-mediated targeting need to be developed. In the case of liver-non-parenchymal cell-specific targeting systems, glycosylated emulsions have been developed as carriers for lipophilic drugs and/or peptides. This present study demonstrates the in vivo disposition behaviour and pharmacokinetic characteristics of mannosylated (Man-) and fucosylated (Fuc-) emulsions incorporated with cholesten-5-yloxy-N-(4-((1-imino-2-D-thiomannosylethyl)amino)alkyl)formamide (Man-C4-Chol) and its fucosylated derivatives (Fuc-C4-Chol), respectively. Man- (or Fuc-) emulsions are composed of soybean oil, EggPC and Man-C4-Chol (or Fuc-C4-Chol) in a weight ratio of 70:25:5. After intravenous administration to mice, these two types of [(3)H]cholesteryl hexadecyl ether (CHE)-labelled glycosylated emulsions were rapidly eliminated from the blood circulation and preferentially recovered in the liver. In contrast, bare (Bare-) emulsions composed of soybean oil:EggPC:cholesterol (Chol) in a weight ratio of 70:25:5 were more retained in the blood circulation. The hepatic uptake clearances of Man- and Fuc-emulsions were 3.3- and 4.0-times greater than that of Bare-emulsions. Interestingly, the hepatic uptake clearance of Fuc-emulsions was significantly higher that that of Man-emulsions. The uptake ratios by non-parenchymal cells (NPC) and parenchymal cells (PC) (NPC/PC ratio) for Bare-, Man- and Fuc-emulsions were found to be 0.4, 2.0 and 2.9, respectively. The hepatic uptakes of [(3)H]CHE-labelled Man- and Fuc-emulsions were reduced by pre-dosing with glycosylated proteins and liposomes. These results clearly support the conclusion that Man- and Fuc-emulsions are promising carrier systems for liver NPC-specific targeting via receptor-mediated mechanism.

[Development of cell-selective targeting systems of NFkappaB decoy for inflammation therapy]

NFkappaB regulate several inflammatory related molecules and evoke immune and inflammatory response by several stimuli, therefore inhibition of NFkappaB 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 NFkappaB activation, however, several side effects were also reported. Recently, double stranded oligonucleotide including NFkappaB binding sequence, called NFkappaB decoy, was developed to prevent NFkappaB activation, which is powerful tool in a new class of anti-gene strategy for molecular therapy with low side effect. However, NFkappaB decoy is easily degraded by nuclease and rapidly excreted to urine, therefore it is necessary to develop carrier for NFkappaB decoy therapy. Here, we shall review delivery system for NFkappaB decoy and introduce our cell-selective delivery system for NFkappaB decoy using sugar decorated cationic liposomes.

Amphiphilic N-Glycosyl-thiocarbamoyl Cyclodextrins: Synthesis, Self-Assembly, and Fluorimetry of Recognition by Lens culinaris Lectin

Amphiphilic beta-cyclodextrins have been synthesized bearing hexylthio, dodecylthio, and hexadecylthio chains at the 6-positions and glycosylthiocarbamoyl-oligo(ethylene glycol) units at the 2-positions. The glycosyl residues (alpha-D-mannosyl and beta-L-fucosyl) are intended for cell-targeting. Self-assembly of these new amphiphilic glycosylated cyclodextrins in water to form vesicles was investigated by dynamic light scattering and transmission electron microscopy. Selective binding of the hexylthio assemblies to a protein receptor (Lens culinaris lectin) was confirmed by fluorescence spectroscopy.

The potential role of fucosylated cationic liposome/NFkappaB decoy complexes in the treatment of cytokine-related liver disease

Cytokine production by Kupffer cells, which is regulated by NFkappaB, causes severe liver injury in endotoxin syndrome. NFkappaB decoy has been reported to inhibit NFkappaB-mediated transcription. The purpose of this study is to inhibit LPS-induced cytokine production by Kupffer cell-targeted delivery of NFkappaB decoy using fucosylated cationic liposomes (Fuc-liposomes). Cholesten-5-yloxy-N-{4-[(1-imino-2-L-thiofucosyl-ethyl)-amino] butyl-}formamide (Fuc-C4-Chol) was synthesized to prepare Fuc-liposomes. Tissue accumulation, intrahepatic distribution and serum cytokine concentrations were investigated after intravenous injection of Fuc-liposomes/NFkappaB decoy complexes. Intravenously injected Fuc-liposome complexes rapidly and highly accumulated in the liver while little naked NFkappaB decoy accumulated in the liver. An intrahepatic distribution study showed that Fuc-liposome complexes are mainly taken up by non-parenchymal cells. The liver accumulation of Fuc-liposome complexes was inhibited by GdCl(3) pretreatment, which selectively inhibited Kupffer cell uptake. This result suggested that Kupffer cells contribute to liver accumulation. TNFalpha, IFNgamma, ALT and AST serum levels in LPS-infected mice were significantly attenuated by treatment with Fuc-liposome complexes compared with naked NFkappaB decoy. Fuc-liposome complexes also reduced the amount of activated NFkappaB in the liver nuclei. Fuc-liposomes would be a useful carrier for Kupffer cell-selective delivery of NFkappaB decoy by intravenous injection.

Intravenous administration of mannosylated cationic liposome/NFκB decoy complexes effectively prevent LPS-induced cytokine production in a murine liver failure model

The purpose of this study was to inhibit endotoxin induced cytokines production and liver injury by liver non-parenchymal cell (NPC) selective delivery of nuclear factor kappaB (NFkappaB) decoy using mannosylated cationic liposomes (Man-liposomes). In this study, we examined the distribution, inhibitory effect on cytokines production and ALT/AST of intravenously injected Man-liposome/NFkappaB decoy complex. Man-liposome/[(32)P] NFkappaB decoy complexes mostly accumulated in the liver, preferentially in NPC. In a murine lipopolysaccharide-induced liver failure model, the production of tumor necrosis factor-alpha (TNFalpha), IFNgamma, IL1-beta, ALT and AST were effectively reduced by Man-liposome complexes. However, cationic or galactosylated cationic liposome complexes could not inhibit TNFalpha production.

Analysis of the molecular interaction of glycosylated proteins with rabbit liver asialoglycoprotein receptors using surface plasmon resonance spectroscopy

A sensitive, accurate, and efficient biosensor analysis using surface plasmon resonance (SPR) spectroscopy was used for delineating the molecular interaction between rabbit liver asialoglycoprotein receptors (ASGPR) and glycosylated proteins. Isolated rabbit liver ASGPR obtained by affinity column chromatography was dissolved in buffer solution containing TritonX-100 and immobilized on the SPR sensor chip by amine coupling. The SPR study demonstrated that the association rate constants (ka) of galactosylated proteins with ASGPR are dependent on the number of galactose residues, while the dissociation rate constants (kd) are influenced not only by the surface density of the galactose moieties but also by their steric configuration. In addition, it was demonstrated that D-fucosylated BSA had a higher binding affinity to ASGPR than Gal-BSA, when the degree of sugar modification was equivalent.

Uptake characteristics of mannosylated and fucosylated bovine serum albumin in primary cultured rat sinusoidal endothelial cells and Kupffer cells

The purpose of this study is to delineate uptake characteristics of mannosylated and fucosylated proteins in primary cultured sinusoidal endothelial cells and Kupffer cells. In cultured sinusoidal endothelial cells, uptake of mannosylated and fucosylated bovine serum albumin (BSA) was significantly inhibited by excess mannosylated and fucosylated BSAs but not by galactosylated BSA, suggesting that both glycosylated proteins might be primarily taken up via mannose receptors. In cultured Kupffer cells, uptake of fucosylated BSA was significantly inhibited by excess galactosylated BSA as well as mannosylated and fucosylated BSAs, although that of mannosylated BSA was inhibited only by mannosylated and fucosylated BSAs. This suggests that uptake of fucosylated BSA by Kupffer cells might be mediated by both Kupffer cell lectin (fucose receptor) and mannose receptor. On the other hand, in vivo hepatic uptake of fucosylated BSA was inhibited to a greater extent by GdCl3 pretreatment than that of mannosylated BSA. Based on in vitro and in vivo experiments, it was concluded that fucosylated BSA is more Kupffer cell-selective because it exhibited a lower sinusoidal endothelial cell uptake than mannosylated BSA.

Lipid Carrier Systems for Targeted Drug and Gene Delivery

For effective chemotherapy, it is necessary to deliver therapeutic agents selectively to their target sites, since most drugs are associated with both beneficial effects and side effects. The use of lipid dispersion carrier systems, such as lipid emulsions and liposomes, as carriers of lipophilic drugs has attracted particular interest. A drug delivery system can be defined as a methodology for manipulating drug distribution in the body. Since drug distribution depends on the carrier, administration route, particle size of the carrier, lipid composition of the carrier, electric charge of the carrier and ligand density of the targeting carrier, these factors must be optimized. Recently, the lipid carrier system has also been applied to gene delivery systems for gene therapy. However, in both drug and gene medicine cases, a lack of cell-selectivity limits the wide application of this kind of drug and/or gene therapy. Therefore, lipid carrier systems for targeted drug and gene delivery must be developed for the rational therapy. In this review, we shall focus on the progress of research into lipid carrier systems for drug and gene delivery following systemic or local injection.