The Experts below are selected from a list of 3768 Experts worldwide ranked by ideXlab platform
Rudolph L. Juliano - One of the best experts on this subject based on the ideXlab platform.
-
Chemical Manipulation of the Endosome Trafficking Machinery: Implications for Oligonucleotide Delivery
Biomedicines, 2021Co-Authors: Rudolph L. JulianoAbstract:Antisense Oligonucleotides (ASOs), siRNA and splice switching Oligonucleotides (SSOs) all have immense potential as therapeutic agents, potential that is now being validated as Oligonucleotides enter the clinic. However, progress in Oligonucleotide-based therapeutics has been limited by the difficulty in delivering these complex molecules to their sites of action in the cytosol or nucleus of cells within specific tissues. There are two aspects to the Delivery problem. The first is that most types of Oligonucleotides have poor uptake into non-hepatic tissues. The second is that much of the Oligonucleotide that is taken up by cells is entrapped in endosomes where it is pharmacologically inert. It has become increasingly recognized that endosomal trapping is a key constraint on Oligonucleotide therapeutics. Thus, many approaches have been devised to address this problem, primarily ones based on various nanoparticle technologies. However, recently an alternative approach has emerged that employs small molecules to manipulate intracellular trafficking processes so as to enhance Oligonucleotide actions. This review presents the current status of this chemical biology approach to Oligonucleotide Delivery and seeks to point out possible paths for future development.
-
The Delivery of therapeutic Oligonucleotides.
Nucleic Acids Research, 2016Co-Authors: Rudolph L. JulianoAbstract:: The Oligonucleotide therapeutics field has seen remarkable progress over the last few years with the approval of the first antisense drug and with promising developments in late stage clinical trials using siRNA or splice switching Oligonucleotides. However, effective Delivery of Oligonucleotides to their intracellular sites of action remains a major issue. This review will describe the biological basis of Oligonucleotide Delivery including the nature of various tissue barriers and the mechanisms of cellular uptake and intracellular trafficking of Oligonucleotides. It will then examine a variety of current approaches for enhancing the Delivery of Oligonucleotides. This includes molecular scale targeted ligand-Oligonucleotide conjugates, lipid- and polymer-based nanoparticles, antibody conjugates and small molecules that improve Oligonucleotide Delivery. The merits and liabilities of these approaches will be discussed in the context of the underlying basic biology.
-
cellular uptake and intracellular trafficking of Oligonucleotides
Advanced Drug Delivery Reviews, 2015Co-Authors: Rudolph L. Juliano, Kyle CarverAbstract:Oligonucleotides manifest much promise as potential therapeutic agents. However, understanding of how Oligonucleotides function within living organisms is still rather limited. A major concern in this regard is the mechanisms of cellular uptake and intracellular trafficking of both ‘free’ Oligonucleotides and Oligonucleotides associated with various polymeric or nanocarrier Delivery systems. Here we review basic aspects of the mechanisms of endocytosis and intracellular trafficking and how insights from these processes can be used to understand Oligonucleotide Delivery. In particular we discuss opportunities for escape of Oligonucleotides from endomembrane compartments and describe recent studies using small molecules to enhance Oligonucleotide effects.
-
Multicellular Tumor Spheroids as a Model for Assessing Delivery of Oligonucleotides in Three Dimensions
Molecular therapy. Nucleic acids, 2014Co-Authors: Kyle Carver, Xin Ming, Rudolph L. JulianoAbstract:Oligonucleotides have shown promise in selectively manipulating gene expression in vitro, but that success has not translated to the clinic for cancer therapy. A potential reason for this is that cells behave differently in monolayer than in the three-dimensional tumor, resulting in limited penetration and distribution of Oligonucleotides in the tumor. This may be especially true when Oligonucleotides are associated with nanocarriers such as lipoplexes and polyplexes, commonly used Delivery vehicles for Oligonucleotides. The multicellular tumor spheroid (MCTS), a three-dimensional model that closely resembles small avascular tumors and micrometastases, has been utilized as an intermediate between monolayer culture and in vivo studies for the screening of small-molecule drugs. However, spheroids have been little used for the study of various Oligonucleotide Delivery formulations. Here, we have evaluated the uptake and efficacy of splice-switching antisense Oligonucleotides using various Delivery modalities in two- and three-dimensional culture models. We find that the size of the Delivery agent dramatically influences penetration into the spheroid and thus the biological effect of the Oligonucleotides. We hypothesize that the MCTS model will prove to be a useful tool in the future development of Oligonucleotide Delivery formulations.
-
Peptide-Oligonucleotide conjugates for the Delivery of antisense and siRNA
Current opinion in molecular therapeutics, 2005Co-Authors: Rudolph L. JulianoAbstract:Conjugation of Oligonucleotides to certain types of peptides provides an interesting approach for enhancing Delivery of antisense and siRNA to cells and tissues. This article will provide a perspective on issues in Oligonucleotide Delivery, and will examine recent literature on the preparation and use of several types of peptide-Oligonucleotide conjugates.
Michele Laus - One of the best experts on this subject based on the ideXlab platform.
-
Core-shell nanospheres for Oligonucleotide Delivery. V: adsorption/release behavior of 'stealth' nanospheres.
Journal of Biomaterials Science-polymer Edition, 2003Co-Authors: Luisa Tondelli, Marco Ballestri, Laura Magnani, Daniela Vivarelli, Aurora Cerasi, Laura Chiarantini, Katia Sparnacci, Adamo Fini, Michele LausAbstract:The adsorption/release behavior of oligodeoxynucleotides (ODNs) on new PEGylated core-shell polymethylmethacrylate nanospheres is described. The outer shell consists of alkyl chains containing quaternary ammonium groups and of poly(ethylene glycol) chains, both covalently bound to the inner core. Ion pair formation between negatively charged ODN phosphate groups and positively charged groups on the nanosphere surface is the main interaction mechanism. No cellular toxicity in HL60 cells is observed at nanosphere concentrations required for biologically active ODN Delivery. These results indicate that these novel cationic polymeric nanoparticles are safe and represent promising vectors for Oligonucleotide Delivery.
-
Core-shell functional nanospheres for Oligonucleotide Delivery. III. Stealth nanospheres
Journal of Polymer Science Part A: Polymer Chemistry, 2000Co-Authors: Katia Sparnacci, Luisa Tondelli, Michele LausAbstract:Polymethyl methacrylate-based stealth and functional nanospheres, specifically designed for the reversible adsorption of Oligonucleotides (ODN), were prepared by emulsion polymerization of methyl methacrylate in the presence of an ionic comonomer, namely a quaternary ammonium salt of 2-(dimethylamino)ethyl methacrylate, and a nonionic comonomer, namely a poly(ethylene glycol) methacrylate. The nanosphere size is substantially affected by the amount of both the nonionic and ionic comonomers. By appropriately adjusting the concentrations of the ionic and nonionic comonomers, the quaternary ammonium group and PEG chain surface densities can be finely tuned. Accordingly, a great variety of core-shell-type nanospheres, able to bind ODN and to induce dysopsonic effect, can be obtained. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3347–3354, 2000
-
Core‐shell functional nanospheres for Oligonucleotide Delivery. II
Journal of Polymer Science Part A: Polymer Chemistry, 2000Co-Authors: Michele Laus, Katia Sparnacci, Marco Lelli, R. Vannini, Luisa TondelliAbstract:Two polymethylmethacrylate functional nanosphere series, specifically designed for the reversible adsorption of Oligonucleotides, were prepared by emulsion polymerization in the presence of two structurally different ionic comonomers, namely two quaternary ammonium salts of 2-(dimethylamino)ethyl methacrylate. The nanosphere size is substantially affected by the ionic comonomer structure and amount. The width of the size distribution tends to decrease with increasing the comonomer amount in solution, and monosized nanosphere samples are obtained at a high comonomer amount. The ionic comonomer weight percentage on the nanospheres increases monotonically in both sample series as the comonomer concentration increases. In contrast, the trend of the quaternary ammonium group surface density is different in the two sample series displaying a regular increase or a maximum value as the ionic comonomer concentration increases. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1110–1117, 2000
Robert J. Lee - One of the best experts on this subject based on the ideXlab platform.
-
Polyethylenimine-based Formulations for Delivery of Oligonucleotides.
Current medicinal chemistry, 2019Co-Authors: Fei Hao, Robert J. Lee, Lesheng Teng, Zhaogang Yang, Jing Zhu, Jingyao Sun, Brian Marshall, Jing XieAbstract:Polyethyleneimine (PEI) is well-known as a non-viral gene Delivery vector, especially for Oligonucleotide Delivery. However, its clinical applications are significantly limited due to its high cationic charge, lack of specificity, and interaction with the proteins and nontarget cells in the biological fluids, resulting in high cytotoxicity, poor stability and low transfection efficiency for Oligonucleotides transporting. It has been shown that the molecular weight (MW) of PEI, degree of branching, N/P ratio, buffer capacity, Oligonucleotide structure, culture medium pH, serum, presence or absence of and method of preparation make a significant difference in the cytoxicity, stability, and transfection efficiency for the PEI-based Oligonucleotides Delivery systems. Ligands, hydrophobic, hydrophilic, and amphiphilic modification of PEI have been investigated to reduce the cytoxicity and improve the stability, the transfection efficiency, and therapeutic effect. Moreover, various intelligent modifications of PEI, such as pH-responsive (hydrazone bond) and redox sensitive linkers (disulfide bond) can control Oligonucleotides release and have attracted much attention. In general, more efficient Oligonucleotide Delivery can be achieved by the introduction of modifications to PEI and by optimization of parameters of PEI or PEI-based formulations.
-
The role of helper lipids in lipid nanoparticles (LNPs) designed for Oligonucleotide Delivery.
Advanced drug delivery reviews, 2016Co-Authors: Xinwei Cheng, Robert J. LeeAbstract:Lipid nanoparticles (LNPs) have shown promise as Delivery vehicles for therapeutic Oligonucleotides, including antisense oligos (ONs), siRNA, and microRNA mimics and inhibitors. In addition to a cationic lipid, LNPs are typically composed of helper lipids that contribute to their stability and Delivery efficiency. Helper lipids with cone-shape geometry favoring the formation hexagonal II phase, such as dioleoylphosphatidylethanolamine (DOPE), can promote endosomal release of ONs. Meanwhile, cylindrical-shaped lipid phosphatidylcholine can provide greater bilayer stability, which is important for in vivo application of LNPs. Cholesterol is often included as a helper that improves intracellular Delivery as well as LNP stability in vivo. Inclusion of a PEGylating lipid can enhance LNP colloidal stability in vitro and circulation time in vivo but may reduce uptake and inhibit endosomal release at the cellular level. This problem can be addressed by choosing reversible PEGylation in which the PEG moiety is gradually released in blood circulation. pH-sensitive anionic helper lipids, such as fatty acids and cholesteryl hemisuccinate (CHEMS), can trigger low-pH-induced changes in LNP surface charge and destabilization that can facilitate endosomal release of ONs. Generally speaking, there is no correlation between LNP activity in vitro and in vivo because of differences in factors limiting the efficiency of Delivery. Designing LNPs requires the striking of a proper balance between the need for particle stability, long systemic circulation time, and the need for LNP destabilization inside the target cell to release the Oligonucleotide cargo, which requires the proper selection of both the cationic and helper lipids. Customized design and empirical optimization is needed for specific applications.
-
A novel reduction-sensitive modified polyethylenimine Oligonucleotide vector.
International journal of pharmaceutics, 2015Co-Authors: Shuang Yang, Robert J. Lee, Xuewei Yang, Bin Zheng, Jing Xie, Lingjun Meng, Yan Liu, Lesheng TengAbstract:Abstract A reduction-sensitive cross-linked polyethylenimine derivative PEI-SS-OA was synthesized and evaluated for Oligonucleotide Delivery. PEI-SS-OA was shown to condense LOR-2501, an Oligonucleotide targeting ribonucleotide reductase R1 subunit (RRM1), into positively charged complexes. The reductive degradation of the PEI-SS-OA induced by dithiothreitol was confirmed by a gel retardation assay. In vitro experiments revealed that the reduction-sensitive PEI-SS-OA was less cytotoxic and more effective in Oligonucleotide Delivery than the control 25 kDa PEI. This study demonstrates that a reducibly degradable cationic polymer PEI-SS-OA possesses both higher Oligonucleotide Delivery efficiency and lower cytotoxicity than PEI (25 kDa), therefore is an attractive candidate for further in vivo evaluation.
-
Targeted lipid nanoparticles for antisense Oligonucleotide Delivery.
Current pharmaceutical biotechnology, 2014Co-Authors: Raquel Petrilli, Josimar O. Eloy, Juliana Maldonado Marchetti, Renata Fonseca Vianna Lopez, Robert J. LeeAbstract:Antisense Oligonucleotides (AS-ODNs) are short, single-stranded DNA molecules designed to bind specifically to a target messenger RNA (mRNA) and down-regulate gene expression. Despite being a promising class of therapeutics for a variety of diseases, they face major hurdles limiting their clinical application, including low intracellular Delivery and poor in vivo stability. Among strategies available to enhance Delivery, lipid nanoparticles have gained considerable attention. Active targeting of carriers of AS-ODNs is likely to further enhance Delivery efficiency. For that, ligands for overexpressed receptors on the cell surface can be linked to the lipid nanoparticle, facilitating intracellular uptake, resulting in improved efficacy and reduced systemic toxicity. These include cell penetrating peptides (CPPs), transferrin, folate, oligosaccharides, polysaccharides and antibodies. Although targeted-lipid nanoparticles have been shown to enhance intracellular Delivery and therapeutic effect of AS-ODNs, no clinical evaluation has been conducted yet. Therefore, more efforts are needed to turn these promising tools into clinical products.
-
A Polyethylenimine-Linoleic Acid Conjugate for Antisense Oligonucleotide Delivery
BioMed research international, 2013Co-Authors: Jing Xie, Lesheng Teng, Zhaogang Yang, Chenguang Zhou, Yang Liu, Bryant C. Yung, Robert J. LeeAbstract:A novel antisense Oligonucleotide (ASO) carrier, polyethylenimine conjugated to linoleic acid (PEI-LA), was synthesized and evaluated for Delivery of LOR-2501 to tumor cells. LOR-2501 is an ASO targeting ribonucleotide reductase R1 subunit (RRM1). In this study, PEI-LA was synthesized by reacting PEI (Mw ~ 800) with linoleoyl chloride. Gel retardation assay showed complete complexation between PEI-LA and LOR-2501 at N/P ratio above 8. No significant cytotoxicity was observed with these complexes at the tested dosage levels. Interestingly, at N/P ratio of >6, levels of cellular uptake of PEI-LA/LOR-2501 were double that of PEI/LOR-2501 complexes of the same N/P ratio. PEI-LA/LOR-2501 induced downregulation of 64% and 70% of RRM1 at mRNA and protein levels, respectively. The highest transfection activity was shown by PEI-LA/LOR-2501 complexes at N/P ratio of 10. Finally, using pathway specific inhibitors, clathrin-mediated endocytosis was shown to be the principle mechanism of cellular internalization of these complexes. In conclusion, PEI-LA is a promising agent for the Delivery of ASOs and warrants further investigation.
Luisa Tondelli - One of the best experts on this subject based on the ideXlab platform.
-
Core-shell nanospheres for Oligonucleotide Delivery. V: adsorption/release behavior of 'stealth' nanospheres.
Journal of Biomaterials Science-polymer Edition, 2003Co-Authors: Luisa Tondelli, Marco Ballestri, Laura Magnani, Daniela Vivarelli, Aurora Cerasi, Laura Chiarantini, Katia Sparnacci, Adamo Fini, Michele LausAbstract:The adsorption/release behavior of oligodeoxynucleotides (ODNs) on new PEGylated core-shell polymethylmethacrylate nanospheres is described. The outer shell consists of alkyl chains containing quaternary ammonium groups and of poly(ethylene glycol) chains, both covalently bound to the inner core. Ion pair formation between negatively charged ODN phosphate groups and positively charged groups on the nanosphere surface is the main interaction mechanism. No cellular toxicity in HL60 cells is observed at nanosphere concentrations required for biologically active ODN Delivery. These results indicate that these novel cationic polymeric nanoparticles are safe and represent promising vectors for Oligonucleotide Delivery.
-
Core-shell functional nanospheres for Oligonucleotide Delivery. III. Stealth nanospheres
Journal of Polymer Science Part A: Polymer Chemistry, 2000Co-Authors: Katia Sparnacci, Luisa Tondelli, Michele LausAbstract:Polymethyl methacrylate-based stealth and functional nanospheres, specifically designed for the reversible adsorption of Oligonucleotides (ODN), were prepared by emulsion polymerization of methyl methacrylate in the presence of an ionic comonomer, namely a quaternary ammonium salt of 2-(dimethylamino)ethyl methacrylate, and a nonionic comonomer, namely a poly(ethylene glycol) methacrylate. The nanosphere size is substantially affected by the amount of both the nonionic and ionic comonomers. By appropriately adjusting the concentrations of the ionic and nonionic comonomers, the quaternary ammonium group and PEG chain surface densities can be finely tuned. Accordingly, a great variety of core-shell-type nanospheres, able to bind ODN and to induce dysopsonic effect, can be obtained. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3347–3354, 2000
-
Core‐shell functional nanospheres for Oligonucleotide Delivery. II
Journal of Polymer Science Part A: Polymer Chemistry, 2000Co-Authors: Michele Laus, Katia Sparnacci, Marco Lelli, R. Vannini, Luisa TondelliAbstract:Two polymethylmethacrylate functional nanosphere series, specifically designed for the reversible adsorption of Oligonucleotides, were prepared by emulsion polymerization in the presence of two structurally different ionic comonomers, namely two quaternary ammonium salts of 2-(dimethylamino)ethyl methacrylate. The nanosphere size is substantially affected by the ionic comonomer structure and amount. The width of the size distribution tends to decrease with increasing the comonomer amount in solution, and monosized nanosphere samples are obtained at a high comonomer amount. The ionic comonomer weight percentage on the nanospheres increases monotonically in both sample series as the comonomer concentration increases. In contrast, the trend of the quaternary ammonium group surface density is different in the two sample series displaying a regular increase or a maximum value as the ionic comonomer concentration increases. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1110–1117, 2000
Crispin R. Dass - One of the best experts on this subject based on the ideXlab platform.
-
Oligonucleotide Delivery to tumours using macromolecular carriers.
Biotechnology and applied biochemistry, 2004Co-Authors: Crispin R. DassAbstract:Microparticles have been used for Delivery of chemo- and radio-therapeutic agents to tumours in patients for more than a decade, whereas cationic liposomes have been used for introducing nucleic acids into mammalian cells for the same period of time. This minireview discusses the potential of delivering therapeutic ONs (Oligonucleotides) to tumours using cationic liposomes and the major obstacles to such Delivery. It also proposes how microparticles can be utilized for Delivery of ONs to solid tumours. Prospects for improved ON Delivery using these carriers and ways to achieve this are discussed.
-
Cyclodextrins and Oligonucleotide Delivery to solid tumours.
Journal of drug targeting, 2004Co-Authors: Crispin R. DassAbstract:Cyclodextrins (CyDs) have traditionally been used for dissolving hydrophobic chemicals into aqueous media, and more recently, for inducing cholesterol efflux from lipid-laden cells as a proposed mechanism for reversal of cardiovascular disease. This review discusses the potential of delivering therapeutic Oligonucleotides to solid tumours using CyD molecules. The physicochemical properties of these oligosaccharide molecules, and the barriers posed by the solid tumour itself, factors that affect may affect the uptake of Oligonucleotides by CyDs, are the major foci of this review.
-
Vehicles for Oligonucleotide Delivery to tumours.
The Journal of pharmacy and pharmacology, 2002Co-Authors: Crispin R. DassAbstract:The vasculature of a tumour provides the most effective route by which neoplastic cells may be reached and eradicated by drugs. The fact that a tumour's vasculature is relatively more permeable than healthy host tissue should enable selective Delivery of drugs to tumour tissue. Such Delivery is relevant to carrier-mediated Delivery of genetic medicine to tumours. This review discusses the potential of delivering therapeutic Oligonucleotides (ONs) to tumours using cationic liposomes and cyclodextrins (CyDs), and the major hindrances posed by the tumour itself on such Delivery. Cationic liposomes are generally 100-200 nm in diameter, whereas CyDs typically span 1.5 nm across. Cationic liposomes have been used for the introduction of nucleic acids into mammalian cells for more than a decade. CyD molecules are routinely used as agents that engender cholesterol efflux from lipid-laden cells, thus having an efficacious potential in the management of atherosclerosis. A recent trend is to employ these oligosaccharide molecules for delivering nucleic acids in cells both in-vitro and in-vivo. Comparisons are made with other ON Delivery agents, such as porphyrin derivatives ( 1 microm), in the context of Delivery to solid tumours. A discourse on how the chemical and physical properties of these carriers may affect the uptake of ONs into cells, particularly in-vivo, forms a major basis of this review.
