Bridging the gap: From petri dish to patient - Advancements in translational drug discovery.

Translational research serves as the bridge between basic research and practical applications in clinical settings. The journey from "bench to bedside" is fraught with challenges and complexities such as the often-observed disparity between how compounds behave in a laboratory setting versus in the complex systems of living organisms. The challenge is further compounded by the limited ability of in vitro models to mimic the specific biochemical environment of human tissues.

mRNA-Loaded Lipid Nanoparticles Targeting Immune Cells in the Spleen for Use as Cancer Vaccines.

mRNA delivery has recently gained substantial interest for possible use in vaccines. Recently approved mRNA vaccines are administered intramuscularly where they transfect antigen-presenting cells (APCs) near the site of administration, resulting in an immune response. The spleen contains high numbers of APCs, which are located near B and T lymphocytes.

GALA-Modified Lipid Nanoparticles for the Targeted Delivery of Plasmid DNA to the Lungs.

This study describes the development of lipid nanoparticles (LNPs) for the efficient and selective delivery of plasmid DNA (pDNA) to the lungs. The GALA peptide was used as a ligand to target the lung endothelium and as an endosomal escape device. Transfection activity in the lungs was significantly improved when pDNA was encapsulated in double-coated LNPs.

Ultra-small lipid nanoparticles encapsulating sorafenib and midkine-siRNA selectively-eradicate sorafenib-resistant hepatocellular carcinoma in vivo.

Hepatocellular carcinoma (HCC) is a fatal disease with limited therapeutic choices. The stroma-rich tumor microenvironment hinders the in vivo delivery of most nanomedicines. Ultra-small lipid nanoparticles (usLNPs) were designed for the selective co-delivery of the cytotoxic drug, sorafenib (SOR), and siRNA against the Midkine gene (MK-siRNA) to HCC in mice.

Novel lipid combination for delivery of plasmid DNA to immune cells in the spleen.

This study reports on the development of a novel lipid combination that permits the efficient and highly selective delivery of plasmid DNA (pDNA) to immune cells in the spleen. Using DODAP, an ionizable lipid that was previously thought to be inefficient for gene delivery, we show for the first time, that this ignored lipid can be successfully used for efficient and targeted gene delivery in vivo, but only when combined with DOPE, a specific helper lipid. Using certain DODAP and DOPE ratios resulted in the formation of lipid nanoparticles (LNPs) with a ~ 1000-fold higher gene expression, and this expression was specific for the spleen, making it the most spleen-selective system for transfection using pDNA.

A novel dual-targeted rosiglitazone-loaded nanoparticle for the prevention of diet-induced obesity via the browning of white adipose tissue.

Adipose tissue in the body is classified as white adipose tissue (WAT); a fat-accumulating tissue, or brown adipose tissue (BAT); an energy-dissipating tissue. Transforming WAT-to-BAT (browning) is a promising strategy for the treatment of obesity, since it would lead to an increase in energy expenditure. Rosiglitazone (Rosi), an agonist of the peroxisome proliferator-activated receptor γ (PPARγ), is known to be a potent browning inducer in subcutaneous WAT.

Lipid Nanoparticles for Cell-Specific in Vivo Targeted Delivery of Nucleic Acids.

The last few years have witnessed a great advance in the development of nonviral systems for in vivo targeted delivery of nucleic acids. Lipid nanoparticles (LNPs) are the most promising carriers for producing clinically approved products in the future. Compared with other systems used for nonviral gene delivery, LNPs provide several advantages including higher stability, low toxicity, and greater efficiency.

Spleen selective enhancement of transfection activities of plasmid DNA driven by octaarginine and an ionizable lipid and its implications for cancer immunization.

Efficiently delivering plasmid DNA (pDNA) to the spleen is particularly significant for DNA immunization. However, increasing the efficiency of gene expression in spleen cells for achieving a therapeutic effect remains a serious challenge. An ideal spleen-targeted system should avoid liver uptake and should efficiently transfect specific functional spleen cells.

Recent advances in the targeting of systemically administered non-viral gene delivery systems.

: Systemically administered non-viral gene delivery systems face multiple biological barriers that decrease their efficiency. These systems are rapidly cleared from the circulation and sufficient concentrations do not accumulate in diseased tissues. A number of targeting strategies can be used to provide for sufficient accumulation in the desired tissues to achieve a therapeutic effect.

A Multifunctional Lipid-Based Nanodevice for the Highly Specific Codelivery of Sorafenib and Midkine siRNA to Hepatic Cancer Cells.

Hepatocellular carcinoma (HCC), a common deadly malignancy, requires novel therapeutic strategies to improve the survival rate. Combining chemotherapy and gene therapy is a promising approach for increasing efficiency and reducing side effects. We report on the design of highly specific lipid nanoparticles (LNPs) encapsulating both the chemotherapeutic drug, sorafenib (SOR), and siRNA against the midkine gene (MK), thereby conferring a novel highly efficient anticancer effect on HCC.

Innovative nanotechnologies for enhancing nucleic acids/gene therapy: Controlling intracellular trafficking to targeted biodistribution.

Nanomedicine promises to play an important role in next generation therapy, including Nucleic acid/Gene therapy. To accomplish this, innovative nanotechnologies will be needed to support nanomedicine by controlling not only the biodistribution but also the intracellular trafficking of macromolecules such as RNA/DNA. A multifunctional envelope-type nano device (MEND) was developed to meet this requirement.

A study of the endocytosis mechanism and transendothelial activity of lung-targeted GALA-modified liposomes.

The GALA peptide (WEAALAEALAEALAEHLAEALAEALEALAA) was originally designed to induce the destabilization of endosomal membranes based on its ability to undergo a pH-dependent conformational change from a random coil to an α-helix. We recently found that liposomes modified with GALA peptide (GALA-LPs) extensively accumulate in lung endothelial cells (ECs) after intravenous injection. However, the uptake mechanism of GALA-LPs and their ability to reach alveolar epithelium was unclear.

Optimization of siRNA delivery to target sites: issues and future directions.

Introduction: The discovery of RNA interference (RNAi) earned the 2006 Nobel Prize in Physiology or Medicine for its biological significance and potential for developing novel therapeutics. The small interfering RNA (siRNA) is the most promising tool for translating RNAi to clinical use. Efforts are ongoing to improve siRNA delivery through developing novel biomaterials and delivery strategies.

Synergism between a cell penetrating peptide and a pH-sensitive cationic lipid in efficient gene delivery based on double-coated nanoparticles.

We report on the development of a highly efficient gene delivery system based on synergism between octaarginine (R8), a representative cell penetrating peptide, and YSK05, a recently developed pH-sensitive cationic lipid. Attaching a high density of R8 on the surface of YSK05 nanoparticles (NPs) that contained encapsulated plasmid DNA resulted in the formation of positively charged NPs with improved transfection efficiency. To avoid the development of a net positive charge, we controlled the density and topology of the R8 peptide through the use of a two-step coating methodology, in which the inner lipid coat was modified with a low density of R8 which was then covered with an outer neutral YSK05 lipid layer.

An efficient PEGylated gene delivery system with improved targeting: Synergism between octaarginine and a fusogenic peptide.

Because of their ability to translocate different cargos into cells, arginine-rich cell penetrating peptides (CPPs) are promising vehicles for drug and gene delivery. The use of CPP-based carriers, however, is hampered by the lack of specificity and by interactions with negative serum components. Polyethylene glycol (PEG) is used to decrease such non-specific interactions, albeit its use is associated with reduced transfection efficiency.

Octaarginine- and pH sensitive fusogenic peptide-modified nanoparticles for liver gene delivery.

We previously reported that octaarginine peptide modified liposomes (R8-liposomes) largely accumulated in the liver after intravenous administration and that this is dependent on the R8-density. We report herein on the development of a Multifunctional Envelope-type Nano Device modified with R8 and GALA, as a pH-sensitive fusogenic peptide (R8-GALA-MEND) for liver gene delivery. An R8-MEND encapsulating pDNA prepared using two different cores (negatively or positively charged pDNA/polyethylene imine condensed particles) failed to produce a high gene expression in the liver.

Cell penetrating peptide-mediated systemic siRNA delivery to the liver.

The cell-penetrating peptide (CPP) is one of the most attractive tools for efficiently delivering biomolecules to a target organelle. Here, we describe the use of octaarginine (R8)-modified lipid nanoparticles for the efficient and targeted in vivo delivery of siRNA to the liver. In this study, SR-BI (a scavenger receptor class B, member 1) was targeted by this nanoparticle.

Novel lipidated sorbitol-based molecular transporters for non-viral gene delivery.

In this study, we investigated the possible use of novel lipidated sorbitol-based transporters as functional devices for the improvement of non-viral gene delivery. These transporters are composed of a sorbitol scaffold bearing 8 guanidine moieties that mimic the arginine residues of well-known cell-penetrating peptides. In addition, the transporters carry different lipid groups to aid DNA condensation and facilitate lipid vesicle-binding.

Multi-layered nanoparticles for penetrating the endosome and nuclear membrane via a step-wise membrane fusion process.

Efficient targeting of DNA to the nucleus is a prerequisite for effective gene therapy. The gene-delivery vehicle must penetrate through the plasma membrane, and the DNA-impermeable double-membraned nuclear envelope, and deposit its DNA cargo in a form ready for transcription. Here we introduce a concept for overcoming intracellular membrane barriers that involves step-wise membrane fusion.

Octaarginine- and octalysine-modified nanoparticles have different modes of endosomal escape.

The present study examines the role of surface modification with an octaarginine peptide (R8) in liposomal escape from endocytic vesicles, using octalysine (K8) as a control cationic peptide; the mechanism of endosomal escape of liposomes was also investigated. Gene expression of condensed plasmid DNA encapsulated in R8-modified nanoparticles was more than 1 order of magnitude higher than that of K8-modified nanoparticles, and 2 orders of magnitude higher than gene expression using unmodified nanoparticles. The difference in gene expression could not be attributed to differences in uptake, as R8- and K8-modified liposomes were taken up primarily via macropinocytosis with comparable efficiency.

Octaarginine-modified liposomes: enhanced cellular uptake and controlled intracellular trafficking.

Gene therapy is a promising new approach for treating a variety of genetic and acquired diseases. While viral vectors are highly efficient for gene therapy, their use is associated with high toxicity and immunogenicity. Synthetic or nonviral vectors are attractive alternatives to viral vectors because of their low immunogenicity and low acute toxicity.

Positively charged polyethylenimines enhance nasal absorption of the negatively charged drug, low molecular weight heparin.

This study tests the hypothesis that positively charged polyethylenimines (PEIs) enhance nasal absorption of low molecular weight heparin (LMWH) by reducing the negative surface charge of the drug molecule. Physical interactions between PEIs and LMWH were studied by Fourier transform infrared (FTIR) spectroscopy, particle size analysis, conductivity measurements, zeta potential analysis, and azure A assay. The efficacy of PEIs in enhancing nasal absorption of LMWH was studied by administering LMWH formulated with PEI into the nose of anesthetized rats and monitoring drug absorption by measuring plasma anti-factor Xa activity.

Uptake pathways and subsequent intracellular trafficking in nonviral gene delivery.

The successful delivery of therapeutic genes to the designated target cells and their availability at the intracellular site of action are crucial requirements for successful gene therapy. Nonviral gene delivery is currently a subject of increasing attention because of its relative safety and simplicity of use; however, its use is still far from being ideal because of its comparatively low efficiency. Most of the currently available nonviral gene vectors rely on two main components, cationic lipids and cationic polymers, and a variety of functional devices can be added to further optimize the systems.

High density of octaarginine stimulates macropinocytosis leading to efficient intracellular trafficking for gene expression.

The mechanism of the arginine-rich peptide-mediated cellular uptake is currently a controversial issue. Several factors, including the type of peptide, the nature of the cargo, and the linker between them, appear to affect uptake. One of the less studied factors, which may affect the uptake mechanism, is the effect of peptide density on the surface of the cargo.

Pharmacokinetic analysis of the tissue distribution of octaarginine modified liposomes in mice.

We recently found that octaarginine modified liposomes (R8-Lip) can be efficiently internalized by cultured cells. The purpose of the present study was to quantitatively determine the effect of R8-density on the tissue distribution of R8-Lip in mice, using their clearance as an index. R8 was introduced in the form of stearylated R8 (STR-R8).