1
|
Challenges and strategies for the delivery of biologics to the cornea. J Control Release 2021; 333:560-578. [PMID: 33857565 DOI: 10.1016/j.jconrel.2021.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 04/05/2021] [Accepted: 04/10/2021] [Indexed: 02/07/2023]
Abstract
Biologics, like peptides, proteins and nucleic acids, have proven to be promising drugs for the treatment of numerous diseases. However, besides the off label use of the monoclonal antibody bevacizumab for the treatment of corneal neovascularization, to date no other biologics for corneal diseases have reached the market. Indeed, delivering biologics in the eye remains a challenge, especially at the level of the cornea. While it appears to be a rather accessible tissue for the administration of drugs, the cornea in fact presents several anatomical barriers to delivery. In addition, also intracellular delivery barriers need to be overcome to achieve a promising therapeutic outcome with biologics. This review outlines efforts that have been reported to successfully deliver biologics into the cornea. Biochemical and physical methods for achieving delivery of biologics in the cornea are discussed, with a critical view on their efficacy in overcoming corneal barriers.
Collapse
|
2
|
Abstract
Theranostics is a promising field that combines therapeutics and diagnostics into single multifunctional formulations. This field is driven by advancements in nanoparticle systems capable of providing the necessary functionalities. By utilizing these powerful nanomedicines, the concept of personalized medicine can be realized by tailoring treatment strategies to the individual. This review gives a brief overview of the components of a theranostic system and the challenges that designing truly multifunctional nanoparticles present. Considerations when choosing a class of nanoparticle include the size, shape, charge, and surface chemistry, while classes of nanoparticles discussed are polymers, liposomes, dendrimers, and polymeric micelles. Targeting to disease states can be achieved either through passive or active targeting which uses specific ligands to target receptors that are overexpressed in tumors and common targeting elements are presented. To image the interactions with disease states, contrast agents are included in the nanoparticle formulation. Imaging options include optical imaging techniques, computed tomography, nuclear based, and magnetic resonance imaging. The interplay between all of these components needs to be carefully considered when designing a theranostic system.
Collapse
|
3
|
Alkane-modified low-molecular-weight polyethylenimine with enhanced gene silencing for siRNA delivery. Int J Pharm 2013; 450:44-52. [PMID: 23608201 DOI: 10.1016/j.ijpharm.2013.04.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/23/2013] [Accepted: 04/08/2013] [Indexed: 11/23/2022]
Abstract
Small interfering RNA (siRNA) has tremendous potential as a therapeutic agent for diverse diseases; however, due to its susceptibility to degradation and poor cellular uptake, the low efficiency of administration has been the most important limiting factor for clinical applications of siRNA. Herein, we synthesized alkyl chain modified low-molecular-weight polyethylenimines (LMW PEIs) and found that hydrophobically modified PEIs displayed enhanced efficiency in siRNA-mediated knockdown of target genes. To elucidate the mechanism for increased delivery, we characterized the polymers' physicochemical properties and bioactivity via nuclear magnetic resonance (NMR), gel retardation assay, dynamic laser scattering (DLS) analysis, confocal laser scanning microscopy and flow cytometry. The hydrophobic modification reduced siRNA binding affinity but facilitated the formation of nanoparticles in contrast to the original PEI. The PEIs with eight and thirteen alkyl tails were able to self-assemble into nanoparticles and yielded higher cellular uptake, which leaded to even similar efficiencies of 80-90% knockdown as Lipofectamine™ 2000 control. These results suggested that the status of polymers in aqueous solution, which depended on the degree of hydrophobic modification, played an important role in the uptake of siRNA. Therefore, we provided new information on the role of hydrophobic content in the enhanced gene silencing activity.
Collapse
|
4
|
Chang JH, Garg NK, Lunde E, Han KY, Jain S, Azar DT. Corneal neovascularization: an anti-VEGF therapy review. Surv Ophthalmol 2012; 57:415-29. [PMID: 22898649 DOI: 10.1016/j.survophthal.2012.01.007] [Citation(s) in RCA: 261] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 01/14/2012] [Accepted: 01/16/2012] [Indexed: 01/02/2023]
Abstract
Corneal neovascularization is a serious condition that can lead to a profound decline in vision. The abnormal vessels block light, cause corneal scarring, compromise visual acuity, and may lead to inflammation and edema. Corneal neovascularization occurs when the balance between angiogenic and antiangiogenic factors is tipped toward angiogenic molecules. Vascular endothelial growth factor (VEGF), one of the most important mediators of angiogenesis, is upregulated during neovascularization. In fact, anti-VEGF agents have efficacy in the treatment of neovascular age-related macular degeneration, diabetic retinopathy, macular edema, neovascular glaucoma, and other neovascular diseases. These same agents have great potential for the treatment of corneal neovascularization. We review some of the most promising anti-VEGF therapies, including bevacizumab, VEGF trap, siRNA, and tyrosine kinase inhibitors.
Collapse
Affiliation(s)
- Jin-Hong Chang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago 60612, USA.
| | | | | | | | | | | |
Collapse
|
5
|
Delivery and biodistribution of siRNA for cancer therapy: challenges and future prospects. Ther Deliv 2012; 3:245-61. [DOI: 10.4155/tde.11.155] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
RNAi-based approaches provide a promising therapeutic modality for the treatment of cancer. The inaccessibility of tumors in different cancer types necessitates the development of safe, specific and efficient systemic delivery systems to meet therapeutic need. The translation of siRNA-based cancer therapeutics to the clinic is hindered by several challenges associated with the cargo (siRNA) and the delivery system, including susceptibility to nucleases; insufficient circulation half-life due to phagocytosis by the reticuloendothelial system, transient and poor biodistribution in the tumor tissue; cellular uptake; inability to escape endosomes and release into the cytosolic compartment for an RNAi-mediated effect; microRNA-like unintended off-target effects; undesirable immune stimulation; and carrier-related toxicity. This review provides an overview of the pharmacokinetic and biodistribution challenges witnessed in the delivery of siRNA when administered systemically. It also describes the current delivery approaches using liposome-, polymer- and peptide-based delivery systems shown to elicit significant gene silencing and tumor growth regression in proof-of-concept studies. As part of future perspectives, delivery agents that showed significant efficacy in preclinical rodent models and clinical trials are also reviewed.
Collapse
|
6
|
Beloor J, Choi CS, Nam HY, Park M, Kim SH, Jackson A, Lee KY, Kim SW, Kumar P, Lee SK. Arginine-engrafted biodegradable polymer for the systemic delivery of therapeutic siRNA. Biomaterials 2012; 33:1640-50. [DOI: 10.1016/j.biomaterials.2011.11.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/07/2011] [Indexed: 01/31/2023]
|
7
|
Oh YK, Park TG. siRNA delivery systems for cancer treatment. Adv Drug Deliv Rev 2009; 61:850-62. [PMID: 19422869 DOI: 10.1016/j.addr.2009.04.018] [Citation(s) in RCA: 468] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 04/28/2009] [Indexed: 02/07/2023]
Abstract
With increasing knowledge on the molecular mechanisms of endogenous RNA interference, small interfering RNAs (siRNAs) have been emerging as innovative nucleic acid medicines for treatment of incurable diseases such as cancers. Although several siRNA candidates for the treatment of ocular and respiratory diseases are undergoing clinical trials, there are challenges inherent in the further development of siRNAs for anti-cancer therapeutics, because systemic administration will be required in most cases. In addition to nonspecific off-target and immune stimulation problems, appropriate delivery remains a major hurdle. The technologies developed for delivery of nucleic acid medicines such as plasmid DNA and antisense oligonucleotides have paved the way to rapid progress for in vivo delivery of siRNAs. Here, we review various in vivo delivery strategies including chemical modification, conjugation, lipid-based techniques, polymer-based nanosystems, and physical methods. Moreover, the current progress in siRNA delivery systems for gynecologic, liver, lung, and prostate cancers is discussed.
Collapse
|
8
|
Merkel OM, Germershaus O, Wada CK, Tarcha PJ, Merdan T, Kissel T. Integrin ανβ3 Targeted Gene Delivery Using RGD Peptidomimetic Conjugates with Copolymers of PEGylated Poly(ethylene imine). Bioconjug Chem 2009; 20:1270-80. [DOI: 10.1021/bc9001695] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Olivia M. Merkel
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Oliver Germershaus
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Carol K. Wada
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Peter J. Tarcha
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Thomas Merdan
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Thomas Kissel
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| |
Collapse
|
9
|
Merkel OM, Librizzi D, Pfestroff A, Schurrat T, Buyens K, Sanders NN, De Smedt SC, Béhé M, Kissel T. Stability of siRNA polyplexes from poly(ethylenimine) and poly(ethylenimine)-g-poly(ethylene glycol) under in vivo conditions: effects on pharmacokinetics and biodistribution measured by Fluorescence Fluctuation Spectroscopy and Single Photon Emission Computed Tomography (SPECT) imaging. J Control Release 2009; 138:148-59. [PMID: 19463870 DOI: 10.1016/j.jconrel.2009.05.016] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 04/15/2009] [Accepted: 05/08/2009] [Indexed: 01/22/2023]
Abstract
In search of optimizing siRNA delivery systems for systemic application, one critical parameter remains their stability in blood circulation. In this study, we have traced pharmacokinetics and biodistribution of each component of siRNA polyplexes formed with polyethylenimine 25 kDa (PEI) or PEGylated PEIs by in vivo real-time gamma camera recording, SPECT imaging, and scintillation counting of blood samples and dissected organs. In vivo behavior of siRNA and polymers were compared and interpreted in the context of in vivo stability of the polyplexes which had been measured by fluorescence fluctuation spectroscopy (FFS). Both pharmacokinetics and biodistribution of polymer-complexed siRNA were dominated by the polymer. PEGylated polymers and their siRNA polyplexes showed significantly less uptake into liver (13.6-19.7% ID of PEGylated polymer and 9.5-10.2% ID of siRNA) and spleen compared to PEI 25 kDa (liver deposition: 36.2% ID of polymer and 14.6% ID of siRNA). With non-invasive imaging methods we were able to predict both kinetics and deposition in living animals allowing the investigation of organ distribution in real time and at different time points. FFS measurements proved stability of the applied polyplexes under in vivo conditions which explained the different behavior of complexed from free siRNA. Despite their stability in circulation, we observed that polyplexes dissociated upon liver passage. Therefore, siRNA/(PEG-)PEI delivery systems are not suitable for systemic administration, but instead may be useful when the first-pass effect is circumvented, which is the case in local application.
Collapse
Affiliation(s)
- Olivia M Merkel
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35037 Marburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Merkel OM, Librizzi D, Pfestroff A, Schurrat T, Béhé M, Kissel T. In vivo SPECT and real-time gamma camera imaging of biodistribution and pharmacokinetics of siRNA delivery using an optimized radiolabeling and purification procedure. Bioconjug Chem 2009; 20:174-82. [PMID: 19093855 DOI: 10.1021/bc800408g] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Single photon emission computed tomography (SPECT) imaging provides a three-dimensional method for exactly locating gamma emitters in a noninvasive procedure under in vivo conditions. For characterization of siRNA delivery systems, molecular imaging techniques are extremely helpful to follow biodistribution under in experimental animal studies. Quantification of biodistribution of siRNA and nonviral delivery systems using this technique requires efficient methods to stably label siRNA with a gamma emitter (e.g., 111In or 99mTc) and to purify labeled material from excesses of radiolabel or linkers. In the following study, we have optimized labeling and purification of siRNA, which was then applied as free siRNA or after complexation with polyethylenimine (PEI) 25 kDa for in vivo real-time gamma camera and SPECT imaging. Quantification of scintillation counts in regions of interest(ROIs) was compared to conventional scintillation counting of dissected organs, and the data acquired by imaging was shown to corroborate that of scintillation counting. This optimization and proof of principle study demonstrates that biodistribution and pharmacokinetics of siRNA and the corresponding polyplexes can be determined using SPECT, leading to comparable results as conventional methodology.
Collapse
Affiliation(s)
- Olivia M Merkel
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35037 Marburg, Germany
| | | | | | | | | | | |
Collapse
|
11
|
Sonoke S, Ueda T, Fujiwara K, Sato Y, Takagaki K, Hirabayashi K, Ohgi T, Yano J. Tumor regression in mice by delivery of Bcl-2 small interfering RNA with pegylated cationic liposomes. Cancer Res 2008; 68:8843-51. [PMID: 18974128 DOI: 10.1158/0008-5472.can-08-0127] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The pharmacokinetics and antitumor activity of pegylated small interfering RNA (siRNA)/cationic liposome complexes were studied after systemic administration to mice. We designed pegylated-lipid carriers for achieving increased plasma concentrations of RNA and hence improved accumulation of RNA in tumors by the enhanced permeability and retention effect. We compared the pharmacokinetics of siRNA complexed with liposomes incorporating pegylated lipids with longer (C-17 or C-18), shorter (C-12 to C-16), or unsaturated (C-18:1) acyl chains. When longer acyl chains were used, the plasma concentrations of siRNA obtained were dramatically higher than when shorter or unsaturated chains were used. This may be explained by the higher gel-to-liquid-crystalline phase-transition temperature (Tc) of lipids with longer acyl chains, which may form more rigid liposomes with reduced uptake by the liver. We tested a siRNA that is sequence specific for the antiapoptotic bcl-2 mRNA complexed with a pegylated liposome incorporating a C-18 lipid (PEG-LIC) by i.v. administration in a mouse model of human prostate cancer. Three-fold higher accumulation of RNA in the tumors was achieved when PEG-LIC rather than nonpegylated liposomes was used, and sequence-specific antitumor activity was observed. Our siRNA/PEG-LIC complex showed no side effects on repeated administration and the strength of its antitumor activity may be attributed to its high uptake by the tumors. Pegylation of liposomes improved the plasma retention, uptake by s.c. tumors, and antitumor activity of the encapsulated siRNA. PEG-LIC is a promising candidate for siRNA cancer therapy.
Collapse
Affiliation(s)
- Satoru Sonoke
- Discovery Research Laboratories, Nippon Shinyaku Co Ltd, Tsukuba, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Bhindi R, Fahmy RG, Lowe HC, Chesterman CN, Dass CR, Cairns MJ, Saravolac EG, Sun LQ, Khachigian LM. Brothers in arms: DNA enzymes, short interfering RNA, and the emerging wave of small-molecule nucleic acid-based gene-silencing strategies. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:1079-88. [PMID: 17717148 PMCID: PMC1988859 DOI: 10.2353/ajpath.2007.070120] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The past decade has seen the rapid evolution of small-molecule gene-silencing strategies, driven largely by enhanced understanding of gene function in the pathogenesis of disease. Over this time, many genes have been targeted by specifically engineered agents from different classes of nucleic acid-based drugs in experimental models of disease to probe, dissect, and characterize further the complex processes that underpin molecular signaling. Arising from this, a number of molecules have been examined in the setting of clinical trials, and several have recently made the successful transition from the bench to the clinic, heralding an exciting era of gene-specific treatments. This is particularly important because clear inadequacies in present therapies account for significant morbidity, mortality, and cost. The broad umbrella of gene-silencing therapeutics encompasses a range of agents that include DNA enzymes, short interfering RNA, antisense oligonucleotides, decoys, ribozymes, and aptamers. This review tracks current movements in these technologies, focusing mainly on DNA enzymes and short interfering RNA, because these are poised to play an integral role in antigene therapies in the future.
Collapse
MESH Headings
- Animals
- Aptamers, Nucleotide/chemistry
- Aptamers, Nucleotide/therapeutic use
- DNA, Catalytic/chemistry
- DNA, Catalytic/metabolism
- DNA, Catalytic/therapeutic use
- Gene Silencing
- Gene Targeting
- Genetic Therapy/methods
- Humans
- Mice
- Oligonucleotides, Antisense/chemistry
- Oligonucleotides, Antisense/therapeutic use
- RNA, Catalytic/chemistry
- RNA, Catalytic/therapeutic use
- RNA, Small Interfering/chemistry
- RNA, Small Interfering/metabolism
- RNA, Small Interfering/therapeutic use
- Rabbits
- Rats
Collapse
Affiliation(s)
- Ravinay Bhindi
- Centre for Vascular Research, The University of New South Wales, Sydney, NSW 2052, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Chang Z, Babiuk LA, Hu J. Therapeutic and prophylactic potential of small interfering RNAs against severe acute respiratory syndrome: progress to date. BioDrugs 2007; 21:9-15. [PMID: 17263585 PMCID: PMC7099728 DOI: 10.2165/00063030-200721010-00002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Severe acute respiratory syndrome (SARS), caused by the novel coronavirus SARS-CoV, produced a scare when it appeared in 2003 in China and later quickly spread to other countries around the world. Although it has since disappeared, its threat to human health remains. Therefore, studies on the prevention and treatment of SARS are important for dealing with epidemics of this and other infectious diseases. The most promising newly developed technology for intervention in SARS may be RNA interference, an endogenous cellular process for the inhibition of gene expression mediated by sequence-specific double-stranded RNAs. Numerous studies have reported the therapeutic potential of RNA interference for the treatment of various human diseases ranging from cancers to infectious diseases such as HIV and hepatitis. To date, most studies on inhibition of SARS-CoV replication using small interfering RNAs (siRNAs) have been conducted in cell lines in vitro. One study using siRNAs to inhibit SARS-CoV infection in Rhesus macaques demonstrated that siRNAs were effective both prophylactically and therapeutically with no adverse effects in the animals. Challenges remaining for the application of siRNA in vivo for SARS prevention and treatment include the specificity of the siRNAs and the efficiency of delivery. However, with improvements in siRNA design and delivery methods, RNA interference has the potential to become another major weapon for combating dangerous infections due to viruses such as SARS-CoV.
Collapse
Affiliation(s)
- Zhijie Chang
- School of Medicine, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China
| | | | | |
Collapse
|
14
|
Verstovsek S, Quintás-Cardama A, Kantarjian H, Tefferi A. Experimental therapy in myelofibrosis with myeloid metaplasia. Expert Opin Investig Drugs 2007; 15:1555-63. [PMID: 17107281 DOI: 10.1517/13543784.15.12.1555] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Myelofibrosis with myeloid metaplasia (MMM) is a Philadelphia chromosome-negative myeloproliferative disorder that is characterised by constitutional symptoms, progressive anaemia and extramedullary haematopoiesis. There are no curative therapies available for patients with MMM apart from stem cell transplantation, which is associated with significant morbidity and mortality, and for which most patients are not suitable candidates. Traditional pharmacological therapy of MMM has focused on the palliation of symptoms associated with myeloproliferation and correction of cytopoenias. Recently, new findings regarding the molecular basis of MMM and the pathogenesis of the associated bone marrow stromal reaction have provided both basic and clinical researchers with invaluable tools to develop effective targeted therapies for patients with MMM. Several novel treatment strategies are being investigated including antiangiogenic agents, signal transduction inhibitors, inhibitors of fibrogenesis and small-molecule inhibitors of the JAK2(V617F )mutation. This article reviews the current status of experimental novel therapies for MMM.
Collapse
Affiliation(s)
- Srdan Verstovsek
- The University of Texas, Department of Leukemia, MD Anderson Cancer Center, USA
| | | | | | | |
Collapse
|