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Zimmer O, Goepferich A. On the uncertainty of the correlation between nanoparticle avidity and biodistribution. Eur J Pharm Biopharm 2024; 198:114240. [PMID: 38437906 DOI: 10.1016/j.ejpb.2024.114240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/05/2024] [Accepted: 02/28/2024] [Indexed: 03/06/2024]
Abstract
The specific delivery of a drug to its site of action also known as targeted drug delivery is a topic in the field of pharmaceutics studied for decades. One approach extensively investigated in this context is the use ligand functionalized nanoparticles. These particles are modified to carry receptor specific ligands, enabling them to accumulate at a desired target site. However, while this concept initially appears straightforward to implement, in-depth research has revealed several challenges hindering target site specific particle accumulation - some of which remain unresolved to this day. One of these challenges consists in the still incomplete understanding of how nanoparticles interact with biological systems. This knowledge gap significantly compromises the predictability of particle distribution in biological systems, which is critical for therapeutic efficacy. One of the most crucial steps in delivery is the attachment of nanoparticles to cells at the target site. This attachment occurs via the formation of multiple ligand receptor bonds. A process also referred to as multivalent interaction. While multivalency has been described extensively for individual molecules and macromolecules respectively, little is known on the multivalent binding of nanoparticles to cells. Here, we will specifically introduce the concept of avidity as a measure for favorable particle membrane interactions. Also, an overview about nanoparticle and membrane properties affecting avidity will be given. Thereafter, we provide a thorough review on literature investigating the correlation between nanoparticle avidity and success in targeted particle delivery. In particular, we want to analyze the currently uncertain data on the existence and nature of the correlation between particle avidity and biodistribution.
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Affiliation(s)
- Oliver Zimmer
- Department of Pharmaceutical Technology, University of Regensburg, Regensburg, Bavaria 93053, Germany
| | - Achim Goepferich
- Department of Pharmaceutical Technology, University of Regensburg, Regensburg, Bavaria 93053, Germany.
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2
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Rana A, Bhatnagar S. Advancements in folate receptor targeting for anti-cancer therapy: A small molecule-drug conjugate approach. Bioorg Chem 2021; 112:104946. [PMID: 33989916 DOI: 10.1016/j.bioorg.2021.104946] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/17/2021] [Accepted: 04/22/2021] [Indexed: 10/21/2022]
Abstract
Targeted delivery combined with controlled release of drugs has a crucial role in future of personalized medicine. The majority of cancer drugs are intended to interfere with one or more cellular events. Anticancer agents can also be toxic to healthy cells, as healthy cells may also need to proliferate and avoid apoptosis. The focus of this review covers the principles, advantages, drawbacks and summarize criteria that must be met for design of small molecule-drug conjugates (SMDCs) to achieve the desired therapeutic potency with minimal toxicity. SMDCs are composed of a targeting ligand, a releasable bridge, a spacer, and a therapeutic payload. We summarize the criteria for the effective design that influences the selection of tumor specific receptor and optimum elements in the design of SMDCs. We also discuss the criteria for selecting the optimal therapeutic drug payload, spacer and linker. The linker chemistries and cleavage strategies are also discussed. Finally, we review the folate receptor targeting SMDCs that are in preclinical development and in clinical trials.
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Affiliation(s)
- Abhilash Rana
- Amity Institute of Biotechnology, Amity University, Sector125, Noida, Uttar Pradesh, India.
| | - Seema Bhatnagar
- Amity Institute of Biotechnology, Amity University, Sector125, Noida, Uttar Pradesh, India.
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3
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Böhmer VI, Szymanski W, Feringa BL, Elsinga PH. Multivalent Probes in Molecular Imaging: Reality or Future? Trends Mol Med 2021; 27:379-393. [PMID: 33436332 DOI: 10.1016/j.molmed.2020.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/17/2020] [Accepted: 12/08/2020] [Indexed: 01/25/2023]
Abstract
The rapidly developing field of molecular medical imaging focuses on specific visualization of (patho)physiological processes through the application of imaging agents (IAs) in multiple clinical modalities. Although our understanding of the principles underlying efficient IAs design has increased tremendously, many IAs still show poor in vivo imaging performance because of low binding affinity and/or specificity. These limitations can be addressed by taking advantage of multivalency, in which multiple copies of a ligand are employed to strengthen the interaction. We critically address specific challenges associated with the application of multivalent compounds in molecular imaging, and we give directions for a stepwise approach to the design of multivalent imaging probes to improve their target binding and pharmacokinetics (PK) for improved diagnostic potential.
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Affiliation(s)
- Verena I Böhmer
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, Hanzeplein 1, 9713, GZ, Groningen, The Netherlands; Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747, AF, Groningen, The Netherlands
| | - Wiktor Szymanski
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747, AF, Groningen, The Netherlands; Department of Radiology, Medical Imaging Center, University Medical Center Groningen, Hanzeplein 1, 9713, GZ, Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747, AF, Groningen, The Netherlands
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, Hanzeplein 1, 9713, GZ, Groningen, The Netherlands.
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Xu Z, Zhu G, Chen P, Dai X, Yan LT. Optimal ligand-receptor binding for highly efficient capture of vesicles in nanofluidic transportation. NANOSCALE 2019; 11:22305-22315. [PMID: 31746900 DOI: 10.1039/c9nr07337j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Optimizing ligand-receptor binding is essential for exploiting advanced biomedical applications from targeting drug delivery to biosensing. A key challenge is how optimized ligand-receptor binding can be realized during the transport of ligand-modified soft materials through a nanofluidic channel. Here, by combining computer simulations and theoretical analysis, we report that the ligand-receptor binding and resulting capture probability of ligand-functionalized vesicles nonmonotonically depend on their some intrinsic properties, e.g., chain stiffness and vesicle rigidity, during their transport through a nanochannel with imposed Poiseuille flow. Particularly, we find that the systems with semiflexible ligand and receptor chains possess the optimal ligand-receptor binding and capture probability. An analytical model of the blob theory is developed to capture the simulation results quantitatively, leading to a mechanistic interpretation of the optimal vesicle capture based on the conformational-entropy effect. Examination of the detailed dynamics reveals the active rearrangement of ligand-receptor binding during the transport process. Furthermore, the hairy vesicle with moderate rigidity is found to display an enhanced capture probability superior to that of both its soft and hard counterparts, which is rationalized by the faster and more periodic tumbling motion of the semi-rigid vesicle. Our findings highlight that precise control of the intrinsic properties of ligands and receptors as well as the vesicle rigidity can be a versatile strategy in optimizing the ligand-receptor binding in nanofluidic transportation towards advantageous biomedical applications.
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Affiliation(s)
- Ziyang Xu
- State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China.
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5
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Tito NB. Multivalent “attacker and guard” strategy for targeting surfaces with low receptor density. J Chem Phys 2019; 150:184907. [DOI: 10.1063/1.5086277] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Nicholas B. Tito
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
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6
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Hart NJ, Weber C, Papas KK, Limesand SW, Vagner J, Lynch RM. Multivalent activation of GLP-1 and sulfonylurea receptors modulates β-cell second-messenger signaling and insulin secretion. Am J Physiol Cell Physiol 2018; 316:C48-C56. [PMID: 30404557 DOI: 10.1152/ajpcell.00209.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Linking two pharmacophores that bind different cell surface receptors into a single molecule can enhance cell-targeting specificity to cells that express the complementary receptor pair. In this report, we developed and tested a synthetic multivalent ligand consisting of glucagon-like peptide-1 (GLP-1) linked to glibenclamide (Glb) (GLP-1/Glb) for signaling efficacy in β-cells. Expression of receptors for these ligands, as a combination, is relatively specific to the β-cell in the pancreas. The multivalent GLP-1/Glb increased both intracellular cAMP and Ca2+, although Ca2+ responses were significantly depressed compared with the monomeric Glb. Moreover, GLP-1/Glb increased glucose-stimulated insulin secretion in a dose-dependent manner. However, unlike the combined monomers, GLP-1/Glb did not augment insulin secretion at nonstimulatory glucose concentrations in INS 832/13 β-cells or human islets of Langerhans. These data suggest that linking two binding elements, such as GLP-1 and Glb, into a single bivalent ligand can provide a unique functional agent targeted to β-cells.
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Affiliation(s)
| | - Craig Weber
- Department of Physiology, University of Arizona , Tucson, Arizona
| | | | - Sean W Limesand
- School of Animal and Comparative Biomedical Sciences, University of Arizona , Tucson, Arizona.,BIO5 Institute, University of Arizona , Tucson, Arizona
| | - Josef Vagner
- BIO5 Institute, University of Arizona , Tucson, Arizona
| | - Ronald M Lynch
- Department of Physiology, University of Arizona , Tucson, Arizona.,Department of Pharmacology, University of Arizona , Tucson, Arizona.,BIO5 Institute, University of Arizona , Tucson, Arizona
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Abstract
Naturally occurring differences in the optical properties of normal and cancerous tissue have been exploited frequently in optical detection systems. However, optical biopsy of cancer can be improved by using targeted, optically active and bright contrast agents to enhance the optical signal from disease-specific molecular markers. Nanotechnology has advanced greatly in recent years and can be applied to variety of biomedical research areas, as well as optical biopsy in clinical settings. Quantum dots (QDs) are stable, bright fluorophores that, under ideal conditions, can have high quantum yields, narrow fluorescence emission bands, high absorbency, very large effective Stokes shifts, high resistance to photobleaching, and can provide excitation of several different emission colours using a single wavelength for excitation. Optically efficient, cancer specific QDs provide a new tool to enable non-invasive visualization of disease-specific molecular and tissue changes with subcellular spatial resolution. Nanotechnology is in a unique position to transform cancer diagnostics and to produce a new generation of fluorescent markers and medical imaging techniques with higher sensitivity and precision of recognition.
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Affiliation(s)
- Ricardas Rotomskis
- Laboratory of Biomedical Physics, Institute of Oncology, and Laser Research Center of Vilnius University, Vilnius, Lithuania
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8
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David A. Peptide ligand-modified nanomedicines for targeting cells at the tumor microenvironment. Adv Drug Deliv Rev 2017; 119:120-142. [PMID: 28506743 DOI: 10.1016/j.addr.2017.05.006] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/17/2017] [Accepted: 05/09/2017] [Indexed: 02/06/2023]
Abstract
Since their initial discovery more than 30years ago, tumor-homing peptides have become an increasingly useful tool for targeted delivery of therapeutic and diagnostic agents into tumors. Today, it is well accepted that cells at the tumor microenvironment (TME) contribute in many ways to cancer development and progression. Tumor-homing peptide-decorated nanomedicines can interact specifically with surface receptors expressed on cells in the TME, improve cellular uptake of nanomedicines by target cells, and impair tumor growth and progression. Moreover, peptide ligand-modified nanomedicines can potentially accumulate in the target tissue at higher concentrations than would small conjugates, thus increasing overall target tissue exposure to the therapeutic agent, enhance therapeutic efficacy and reduce side effects. This review describes the most studied peptide ligands aimed at targeting cells in the TME, discusses major obstacles and principles in the design of ligands for drug targeting and provides an overview of homing peptides in ligand-targeted nanomedicines that are currently in development for cancer therapy and diagnosis.
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Affiliation(s)
- Ayelet David
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, and the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
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Affiliation(s)
- Madduri Srinivasarao
- Purdue Institute for Drug
Discovery, Purdue University, West Lafayette, Indiana 47907, United States
| | - Philip S. Low
- Purdue Institute for Drug
Discovery, Purdue University, West Lafayette, Indiana 47907, United States
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10
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Reubi JC, Maecke HR. Approaches to Multireceptor Targeting: Hybrid Radioligands, Radioligand Cocktails, and Sequential Radioligand Applications. J Nucl Med 2017; 58:10S-16S. [DOI: 10.2967/jnumed.116.186882] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/19/2017] [Indexed: 01/21/2023] Open
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Optimal multivalent targeting of membranes with many distinct receptors. Proc Natl Acad Sci U S A 2017; 114:7210-7215. [PMID: 28652338 DOI: 10.1073/pnas.1704226114] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cells can often be recognized by the concentrations of receptors expressed on their surface. For better (targeted drug treatment) or worse (targeted infection by pathogens), it is clearly important to be able to target cells selectively. A good targeting strategy would result in strong binding to cells with the desired receptor profile and barely binding to other cells. Using a simple model, we formulate optimal design rules for multivalent particles that allow them to distinguish target cells based on their receptor profile. We find the following: (i) It is not a good idea to aim for very strong binding between the individual ligands on the guest (delivery vehicle) and the receptors on the host (cell). Rather, one should exploit multivalency: High sensitivity to the receptor density on the host can be achieved by coating the guest with many ligands that bind only weakly to the receptors on the cell surface. (ii) The concentration profile of the ligands on the guest should closely match the composition of the cognate membrane receptors on the target surface. And (iii) irrespective of all details, the effective strength of the ligand-receptor interaction should be of the order of the thermal energy [Formula: see text], where [Formula: see text] is the absolute temperature and [Formula: see text] is Boltzmann's constant. We present simulations that support the theoretical predictions. We speculate that, using the above design rules, it should be possible to achieve targeted drug delivery with a greatly reduced incidence of side effects.
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12
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Levine RM, Kokkoli E. Dual-ligand α5β1 and α6β4 integrin targeting enhances gene delivery and selectivity to cancer cells. J Control Release 2017; 251:24-36. [DOI: 10.1016/j.jconrel.2017.02.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/20/2017] [Accepted: 02/15/2017] [Indexed: 12/18/2022]
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Abstract
Receptor-targeted drug delivery has been extensively explored for active targeting. However, the scarce clinical applications of such delivery systems highlight the implicit hurdles in development of such systems. These hurdles begin with lack of knowledge of differential expression of receptors, their accessibility and identification of newer receptors. Similarly, ligand-specific challenges range from proper choice of ligand and conjugation chemistry, to release of drug/delivery system from ligand. Finally, nanocarrier systems, which offer improved loading, biocompatibility and reduced premature degradation, also face multiple challenges. This review focuses on understanding these challenges, and means to overcome such challenges to develop efficient, targeted drug-delivery systems.
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Gokhale AS, Satyanarayanajois S. Peptides and peptidomimetics as immunomodulators. Immunotherapy 2015; 6:755-74. [PMID: 25186605 DOI: 10.2217/imt.14.37] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Peptides and peptidomimetics can function as immunomodulating agents by either blocking the immune response or stimulating the immune response to generate tolerance. Knowledge of B- or T-cell epitopes along with conformational constraints is important in the design of peptide-based immunomodulating agents. Work on the conformational aspects of peptides, synthesis and modified amino acid side chains have contributed to the development of a new generation of therapeutic agents for autoimmune diseases and cancer. The design of peptides/peptidomimetics for immunomodulation in autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, systemic lupus and HIV infection is reviewed. In cancer therapy, peptide epitopes are used in such a way that the body is trained to recognize and fight the cancer cells locally as well as systemically.
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Affiliation(s)
- Ameya S Gokhale
- Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
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15
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Steyn LV, Ananthakrishnan K, Anderson MJ, Patek R, Kelly A, Vagner J, Lynch RM, Limesand SW. A Synthetic Heterobivalent Ligand Composed of Glucagon-Like Peptide 1 and Yohimbine Specifically Targets β Cells Within the Pancreas. Mol Imaging Biol 2015; 17:461-70. [PMID: 25604385 DOI: 10.1007/s11307-014-0817-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 12/11/2014] [Accepted: 12/18/2014] [Indexed: 12/15/2022]
Abstract
PURPOSE β Cell specificity for a heterobivalent ligand composed of glucagon-like peptide-1 (GLP-1) linked to yohimbine (GLP-1/Yhb) was evaluated to determine its utility as a noninvasive imaging agent. PROCEDURES Competition binding assays were performed on βTC3 cells and isolated rat islets. Immunostaining for insulin was used to co-localized intravenously injected Cy5-labeled GLP-1/Yhb in β cells of Sprague-Dawley rats. Rats were intravenously injected with In-111-labeled GLP-1/Yhb to determine clearance rates and tissue biodistribution. Tissue-specific binding was confirmed by competition with pre-administration of unlabeled GLP-1/Yhb and in Streptozotocin-induced diabetic rats. RESULTS In βTC3 cells, high affinity binding of GLP-1/Yhb required interactions with both receptors because monovalent competition or receptor knockdown with RNAi lowered specificity and avidity of the heterobivalent ligand. Binding specificity for isolated islets was 2.6-fold greater than that of acinar tissue or islets pre-incubated with excess unlabeled GLP-1/Yhb. Immunofluorescent localization of Cy5-labeled GLP-1/Yhb was restricted to pancreatic islets. Within 30 min, ~90% of the In-111-labeled GLP-1/Yhb was cleared from blood. Tissue-specific accumulation of radiolabeled ligand was apparent in the pancreas, but not in other tissues within the abdominal imaging field. Pancreas specificity was lost in Streptozotocin-induced diabetic rats. CONCLUSIONS The GLP-1/Yhb exhibits high specificity for β cells, rapid blood clearance rates, and low non-specific uptake by other tissues within the abdominal imaging field. These characteristics of GLP-1/Yhb are desirable for application to β cell imaging in vivo and provide a basis for developing additional multivalent β cell-specific targeting agents to aid in the management of type 1 diabetes.
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Affiliation(s)
- Leah V Steyn
- School of Animal and Comparative Biomedical Sciences, William J. Parker Agricultural Research Center, The University of Arizona, 4101 N Campbell Ave, Tucson, AZ, 85719, USA
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Hart NJ, Chung WJ, Weber C, Ananthakrishnan K, Anderson M, Patek R, Zhang Z, Limesand SW, Vagner J, Lynch RM. Hetero-bivalent GLP-1/glibenclamide for targeting pancreatic β-cells. Chembiochem 2013; 15:135-45. [PMID: 24259278 DOI: 10.1002/cbic.201300375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Indexed: 01/15/2023]
Abstract
G protein-coupled receptor (GPCR) cell signalling cascades are initiated upon binding of a specific agonist ligand to its cell surface receptor. Linking multiple heterologous ligands that simultaneously bind and potentially link different receptors on the cell surface is a unique approach to modulate cell responses. Moreover, if the target receptors are selected based on analysis of cell-specific expression of a receptor combination, then the linked binding elements might provide enhanced specificity of targeting the cell type of interest, that is, only to cells that express the complementary receptors. Two receptors whose expression is relatively specific (in combination) to insulin-secreting pancreatic β-cells are the sulfonylurea-1 (SUR1) and the glucagon-like peptide-1 (GLP-1) receptors. A heterobivalent ligand was assembled from the active fragment of GLP-1 (7-36 GLP-1) and glibenclamide, a small organic ligand for SUR1. The synthetic construct was labelled with Cy5 or europium chelated in DTPA to evaluate binding to β-cells, by using fluorescence microscopy or time-resolved saturation and competition binding assays, respectively. Once the ligand binds to β-cells, it is rapidly capped and presumably removed from the cell surface by endocytosis. The bivalent ligand had an affinity approximately fivefold higher than monomeric europium-labelled GLP-1, likely a result of cooperative binding to the complementary receptors on the βTC3 cells. The high-affinity binding was lost in the presence of either unlabelled monomer, thus demonstrating that interaction with both receptors is required for the enhanced binding at low concentrations. Importantly, bivalent enhancement was accomplished in a cell system with physiological levels of expression of the complementary receptors, thus indicating that this approach might be applicable for β-cell targeting in vivo.
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Affiliation(s)
- Nathaniel J Hart
- Department of Physiological Sciences, University of Arizona, 1656 E. Mabel St., Tucson, AZ 85721 (USA)
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17
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Nap R, Szleifer I. How to Optimize Binding of Coated Nanoparticles: Coupling of Physical Interactions, Molecular Organization and Chemical State. Biomater Sci 2013; 1:814-823. [PMID: 23930222 PMCID: PMC3733403 DOI: 10.1039/c3bm00181d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
One of the key challenges in the development of nano carriers for drug delivery and imaging is the design of a system that selectively binds to target cells. A common strategy is to coat the delivery device with specific ligands that bind strongly to overexpressed receptors. However such devices are usually unable to discriminate between receptors found on benign and malignant cells. We demonstrate, theoretically, how one can achieve enhanced binding to target cells by using multiple physical and chemical interactions. We study the effective interactions between a polymer decorated nano micelle or nanoparticle with three types of model lipid membranes that differ in the composition of their outer leaflet. They are: i) lipid membranes with overexpressed receptors, ii) membranes with a given fraction of negatively charged lipids and iii) membranes with both overexpressed receptors and negatively charged lipids. The coating contains a mixtures of two short polymers, one neutral for protection and the other a polybase with a functional end-group to optimize specific binding with the overexpressed receptors and electrostatic interactions with charged lipid head-groups. The strength of the binding for the combined system is much larger than the sum of the independent electrostatic or specific interactions binding. We find a range of distances where the addition of two effective repulsive interactions become an attraction in the combined case. The changes in the strength and shape of the effective interaction are due to the coupling that exists between molecular organization, physical interactions and chemical state, e.g., protonation. The predictions provide guidelines for the design of carrier devices for targeted drug and nanoparticle delivery and give insight in the competing and highly non-additive nature of the different effective interactions in nanoscale systems in constrained environments that are ubiquitous in synthetic and biological systems.
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Affiliation(s)
| | - I. Szleifer
- Department of Biomedical Engineering, Department of Chemistry and Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208-3100, United States
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18
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Ying CT, Wang J, Lamm RJ, Kamei DT. Mathematical Modeling of Vesicle Drug Delivery Systems 2. ACTA ACUST UNITED AC 2013; 18:46-62. [DOI: 10.1177/2211068212458265] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Heterobivalent ligands target cell-surface receptor combinations in vivo. Proc Natl Acad Sci U S A 2012; 109:21295-300. [PMID: 23236171 DOI: 10.1073/pnas.1211762109] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A challenge in tumor targeting is to deliver payloads to cancers while sparing normal tissues. A limited number of antibodies appear to meet this challenge as therapeutics themselves or as drug-antibody conjugates. However, antibodies suffer from their large size, which can lead to unfavorable pharmacokinetics for some therapeutic payloads, and that they are targeted against only a single epitope, which can reduce their selectivity and specificity. Here, we propose an alternative targeting approach based on patterns of cell surface proteins to rationally develop small, synthetic heteromultivalent ligands (htMVLs) that target multiple receptors simultaneously. To gain insight into the multivalent ligand strategy in vivo, we have generated synthetic htMVLs that contain melanocortin (MSH) and cholecystokinin (CCK) pharmacophores that are connected via a fluorescent labeled, rationally designed synthetic linker. These ligands were tested in an experimental animal model containing tumors that expressed only one (control) or both (target) MSH and CCK receptors. After systemic injection of the htMVL in tumor-bearing mice, label was highly retained in tumors that expressed both, compared with one, target receptors. Selectivity was quantified by using ex vivo measurement of Europium-labeled htMVL, which had up to 12-fold higher specificity for dual compared with single receptor expressing cells. This proof-of-principle study provides in vivo evidence that small, rationally designed bivalent htMVLs can be used to selectively target cells that express both, compared with single complimentary cell surface targets. These data open the possibility that specific combinations of targets on tumors can be identified and selectively targeted using htMVLs.
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20
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Wang S, Dormidontova EE. Selectivity of ligand-receptor interactions between nanoparticle and cell surfaces. PHYSICAL REVIEW LETTERS 2012; 109:238102. [PMID: 23368269 DOI: 10.1103/physrevlett.109.238102] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Indexed: 05/20/2023]
Abstract
Selectivity of interactions between nanoparticles functionalized by tethered ligands and cell surfaces with different densities of receptors plays an essential role in biorecognition and its implementation in nanobiomedicine. We show that the onset of nanoparticle adsorption has a universal character for a range of nanoparticles: the onset receptor density decreases exponentially with the energy of ligand-receptor binding and inversely with the ligand density. We demonstrate that a bimodal tether distribution, which permits shielding ligands by longer nonfunctional tethers, leads to extra loss of entropy at the adsorption onset, enhancing the selectivity.
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Affiliation(s)
- Shihu Wang
- Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Road, Cleveland, Ohio 44106-7202, USA
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21
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Brabez N, Lynch RM, Xu L, Gillies RJ, Chassaing G, Lavielle S, Hruby VJ. Design, synthesis, and biological studies of efficient multivalent melanotropin ligands: tools toward melanoma diagnosis and treatment. J Med Chem 2011; 54:7375-84. [PMID: 21928837 DOI: 10.1021/jm2009937] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To achieve early detection and specific cancer treatment, we propose the use of multivalent interactions in which a series of binding events leads to increased affinity and consequently to selectivity. Using melanotropin (MSH) ligands, our aim is to target melanoma cells which overexpress melanocortin receptors. In this study, we report the design and efficient synthesis of new trivalent ligands bearing MSH ligands. Evaluation of these multimers on a cell model engineered to overexpress melanocortin 4 receptors (MC4R) showed up to a 350-fold increase in binding compared to the monomer, resulting in a trivalent construct with nanomolar affinity starting from a micromolar affinity ligand. Cyclic adenosine monophosphate (cAMP) production was also investigated, leading to more insights into the effects of multivalent compounds on transduction mechanisms.
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Affiliation(s)
- Nabila Brabez
- UPMC Paris06, UMR 7203, Laboratoire des BioMolécules, Université P. et M. Curie, 75005 Paris France
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22
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Chittasupho C, Siahaan TJ, Vines CM, Berkland C. Autoimmune therapies targeting costimulation and emerging trends in multivalent therapeutics. Ther Deliv 2011; 2:873-89. [PMID: 21984960 PMCID: PMC3186944 DOI: 10.4155/tde.11.60] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Proteins participating in immunological signaling have emerged as important targets for controlling the immune response. A multitude of receptor-ligand pairs that regulate signaling pathways of the immune response have been identified. In the complex milieu of immune signaling, therapeutic agents targeting mediators of cellular signaling often either activate an inflammatory immune response or induce tolerance. This review is primarily focused on therapeutics that inhibit the inflammatory immune response by targeting membrane-bound proteins regulating costimulation or mediating immune-cell adhesion. Many of these signals participate in larger, organized structures such as the immunological synapse. Receptor clustering and arrangement into organized structures is also reviewed and emerging trends implicating a potential role for multivalent therapeutics is posited.
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Affiliation(s)
- Chuda Chittasupho
- Department of Pharmaceutical Chemistry, University of Kansas, KS, USA
- Department of Pharmaceutical Technology, Srinakharinwirot University, Nakhonnayok, Thailand
| | - Teruna J Siahaan
- Department of Pharmaceutical Chemistry, University of Kansas, KS, USA
| | - Charlotte M Vines
- Department of Microbiology, Molecular Genetics & Immunology, University of Kansas Medical Center, KS, USA
| | - Cory Berkland
- Department of Pharmaceutical Chemistry, University of Kansas, KS, USA
- Department of Pharmaceutical Chemistry, Department of Chemical & Petroleum Engineering, 2030 Becker Drive, Lawrence, KS 66047, USA
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23
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Josan JS, Handl HL, Sankaranarayanan R, Xu L, Lynch RM, Vagner J, Mash EA, Hruby VJ, Gillies RJ. Cell-specific targeting by heterobivalent ligands. Bioconjug Chem 2011; 22:1270-8. [PMID: 21639139 DOI: 10.1021/bc1004284] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Current cancer therapies exploit either differential metabolism or targeting to specific individual gene products that are overexpressed in aberrant cells. The work described herein proposes an alternative approach--to specifically target combinations of cell-surface receptors using heteromultivalent ligands ("receptor combination approach"). As a proof-of-concept that functionally unrelated receptors can be noncovalently cross-linked with high avidity and specificity, a series of heterobivalent ligands (htBVLs) were constructed from analogues of the melanocortin peptide ligand ([Nle(4), dPhe(7)]-α-MSH) and the cholecystokinin peptide ligand (CCK-8). Binding of these ligands to cells expressing the human Melanocortin-4 receptor and the Cholecystokinin-2 receptor was analyzed. The MSH(7) and CCK(6) were tethered with linkers of varying rigidity and length, constructed from natural and/or synthetic building blocks. Modeling data suggest that a linker length of 20-50 Å is needed to simultaneously bind these two different G-protein coupled receptors (GPCRs). These ligands exhibited up to 24-fold enhancement in binding affinity to cells that expressed both (bivalent binding), compared to cells with only one (monovalent binding) of the cognate receptors. The htBVLs had up to 50-fold higher affinity than that of a monomeric CCK ligand, i.e., Ac-CCK(6)-NH(2). Cell-surface targeting of these two cell types with labeled heteromultivalent ligand demonstrated high avidity and specificity, thereby validating the receptor combination approach. This ability to noncovalently cross-link heterologous receptors and target individual cells using a receptor combination approach opens up new possibilities for specific cell targeting in vivo for therapy or imaging.
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Affiliation(s)
- Jatinder S Josan
- Department of Chemistry & Biochemistry, 1306 E. University Blvd., The University of Arizona, Tucson, Arizona 85721, United States
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24
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Jordan VC, Caplan MR, Bennett KM. Simplified synthesis and relaxometry of magnetoferritin for magnetic resonance imaging. Magn Reson Med 2011; 64:1260-6. [PMID: 20677230 DOI: 10.1002/mrm.22526] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Magnetoferritin nanoparticles have been developed as high-relaxivity, functional contrast agents for MRI. Several previous techniques have relied on unloading native ferritin and re-incorporation of iron into the core, often resulting in a polydisperse sample. Here, a simplified technique is developed using commercially available horse spleen apoferritin to create monodisperse magnetoferritin. Iron oxide atoms were incorporated into the protein core via a step-wise Fe(II)Chloride addition to the protein solution under low O(2) conditions; subsequent filtration steps allow for separation of completely filled and superparamagnetic magnetoferritin from the partially filled ferritin. This method yields a monodisperse and homogenous solution of spherical particles with magnetic properties that can be used for molecular magnetic resonance imaging. With a transverse per-iron and per-particle relaxivity of 78 mM(-1) sec(-1) and 404,045 mM(-1) sec(-1), respectively, it is possible to detect ∼ 10 nM nanoparticle concentrations in vivo.
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Affiliation(s)
- Veronica Clavijo Jordan
- School of Biological and Health Systems Engineering, Ira A. Fulton School of Engineering, Arizona State University, Tempe, Arizona 85287-9709, USA
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25
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McDaniel JR, Callahan DJ, Chilkoti A. Drug delivery to solid tumors by elastin-like polypeptides. Adv Drug Deliv Rev 2010; 62:1456-67. [PMID: 20546809 PMCID: PMC2940962 DOI: 10.1016/j.addr.2010.05.004] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 05/11/2010] [Accepted: 05/13/2010] [Indexed: 01/08/2023]
Abstract
Thermally responsive elastin-like polypeptides (ELPs) are a promising class of recombinant biopolymers for the delivery of drugs and imaging agents to solid tumors via systemic or local administration. This article reviews four applications of ELPs to drug delivery, with each delivery mechanism designed to best exploit the relationship between the characteristic transition temperature (T(t)) of the ELP and body temperature (T(b)). First, when T(t)≫T(b), small hydrophobic drugs can be conjugated to the C-terminus of the ELP to impart the amphiphilicity needed to mediate the self-assembly of nanoparticles. These systemically delivered ELP-drug nanoparticles preferentially localize to the tumor site via the EPR effect, resulting in reduced toxicity and enhanced treatment efficacy. The remaining three approaches take direct advantage of the thermal responsiveness of ELPs. In the second strategy, where T(b)
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Affiliation(s)
- Jonathan R. McDaniel
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708-0181, USA
| | - Daniel J. Callahan
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708-0181, USA
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708-0181, USA
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26
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Ledin PA, Friscourt F, Guo J, Boons GJ. Convergent assembly and surface modification of multifunctional dendrimers by three consecutive click reactions. Chemistry 2010; 17:839-46. [PMID: 21226098 DOI: 10.1002/chem.201002052] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Indexed: 11/06/2022]
Abstract
Multifunctional dendrimers bearing two or more surface functionalities have the promise to provide smart drug delivery devices that can for example combine tissue targeting and imaging or be directed more precisely to a specific tissue or cell type. We have developed a concise synthetic methodology for efficient dendrimer assembly and heterobifunctionalization based on three sequential azide-alkyne cycloadditions. The methodology is compatible with biologically important compounds rich in chemical functionalities such as peptides, carbohydrates, and fluorescent tags. In the approach, a strain-promoted azide-alkyne cycloaddition (SPAAC) between polyester dendrons modified at the focal point with an azido and 4-dibenzocyclooctynol (DIBO) moiety provided dendrimers bearing terminal and TMS-protected (TMS=trimethylsilyl) alkynes at the periphery. The terminal alkynes were outfitted with azido-modified polyethylene glycol (PEG) chains or galactosyl residues by using Cu(I) -catalyzed azide-alkyne cycloadditions (CuAAC). Next, a one-pot TMS deprotection and second click reaction of the resulting terminal alkyne with azido-containing compounds gave multifunctional dendrimers bearing complex biologically active moieties at the periphery.
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Affiliation(s)
- Petr A Ledin
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens GA 30602, USA
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27
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Wang S, Dormidontova EE. Nanoparticle design optimization for enhanced targeting: Monte Carlo simulations. Biomacromolecules 2010; 11:1785-95. [PMID: 20536119 PMCID: PMC2999362 DOI: 10.1021/bm100248e] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Using computer simulations, we systematically studied the influence of different design parameters of a spherical nanoparticle tethered with monovalent ligands on its efficiency of targeting planar cell surfaces containing mobile receptors. We investigate how the nanoparticle affinity can be affected by changing the binding energy, the percent of functionalization by ligands, tether length, grafting density, and nanoparticle core size. In general, using a longer tether length or increasing the number of tethered chains without increasing the number of ligands increases the conformational penalty for tether stretching/compression near the cell surface and leads to a decrease in targeting efficiency. At the same time, using longer tethers or a larger core size allows ligands to interact with receptors over a larger cell surface area, which can enhance the nanoparticle affinity toward the cell surface. We also discuss the selectivity of nanoparticle targeting of cells with a high receptor density. Based on the obtained results, we provide recommendations for improving the nanoparticle binding affinity and selectivity, which can guide future nanoparticle development for diagnostic and therapeutic purposes.
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Affiliation(s)
- Shihu Wang
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106
| | - Elena E. Dormidontova
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106
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28
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Simnick AJ, Valencia CA, Liu R, Chilkoti A. Morphing low-affinity ligands into high-avidity nanoparticles by thermally triggered self-assembly of a genetically encoded polymer. ACS NANO 2010; 4:2217-27. [PMID: 20334355 PMCID: PMC2862343 DOI: 10.1021/nn901732h] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Multivalency is the increase in avidity resulting from the simultaneous interaction of multiple ligands with multiple receptors. This phenomenon, seen in antibody-antigen and virus-cell membrane interactions, is useful in designing bioinspired materials for targeted delivery of drugs or imaging agents. While increased avidity offered by multivalent targeting is attractive, it can also promote nonspecific receptor interaction in nontarget tissues, reducing the effectiveness of multivalent targeting. Here, we present a thermal targeting strategy--dynamic affinity modulation (DAM)--using elastin-like polypeptide diblock copolymers (ELP(BC)s) that self-assemble from a low-affinity to high-avidity state by a tunable thermal "switch", thereby restricting activity to the desired site of action. We used an in vitro cell binding assay to investigate the effect of the thermally triggered self-assembly of these ELP(BC)s on their receptor-mediated binding and cellular uptake. The data presented herein show that (1) ligand presentation does not disrupt ELP(BC) self-assembly; (2) both multivalent ligand presentation and upregulated receptor expression are needed for receptor-mediated interaction; (3) increased size of the hydrophobic segment of the block copolymer promotes multivalent interaction with membrane receptors, potentially due to changes in the nanoscale architecture of the micelle; and (4) nanoscale presentation of the ligand is important, as presentation of the ligand by micrometer-sized aggregates of an ELP showed a low level of binding/uptake by receptor-positive cells compared to its presentation on the corona of a micelle. These data validate the concept of thermally triggered DAM and provide rational design parameters for future applications of this technology for targeted drug delivery.
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Affiliation(s)
- Andrew J. Simnick
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - C. Alexander Valencia
- School of Pharmacy and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, NC 275992
| | - Rihe Liu
- School of Pharmacy and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, NC 275992
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
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29
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Lee B, Schubert R, Cheung Y, Zannier F, Wei Q, Sacchi D, Sia S. Strongly Binding Cell-Adhesive Polypeptides of Programmable Valencies. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200906482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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Stukel JM, Li RC, Maynard HD, Caplan MR. Two-step synthesis of multivalent cancer-targeting constructs. Biomacromolecules 2010; 11:160-7. [PMID: 19924844 DOI: 10.1021/bm9010276] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Selective targeting of constructs to pathological cells by conjugating one or more ligands for an overexpressed receptor has been proposed to enhance the delivery of therapeutics to and imaging of specific cells of interest. Previous work in our lab has demonstrated the efficacy of targeting glioblastoma cells with a multivalent, biomacromolecular construct targeted to the alpha(6)beta(1)-integrin. However, solid-phase synthesis of this construct was inefficient in terms of cost and number of steps. Here we show proof-of-concept of a two-step synthesis that can be used to create similar constructs targeted to glioblastoma cells. Specifically, a well-defined aldehyde side chain polymer was synthesized and oxime chemistry was employed to conjugate ligands specific for the alpha(6)beta(1)-integrin. These constructs were then tested in competitive binding, fluorescence binding, and toxicity assays, through which we demonstrate that constructs are multivalent, preferentially target glioblastoma cells, and are nontoxic. Rapid, potentially low-cost synthesis of targeting constructs will enable their use in the clinic and for personalized medicine.
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Affiliation(s)
- Jill M Stukel
- School of Biological and Health Systems Engineering, Center for Interventional Biomaterials, Arizona State University, Tempe, Arizona, USA
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31
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Lee B, Schubert R, Cheung Y, Zannier F, Wei Q, Sacchi D, Sia S. Strongly Binding Cell-Adhesive Polypeptides of Programmable Valencies. Angew Chem Int Ed Engl 2010; 49:1971-5. [DOI: 10.1002/anie.200906482] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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MacEwan SR, Chilkoti A. Elastin-like polypeptides: Biomedical applications of tunable biopolymers. Biopolymers 2010; 94:60-77. [DOI: 10.1002/bip.21327] [Citation(s) in RCA: 313] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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33
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Rosca EV, Gillies RJ, Caplan MR. Glioblastoma targeting via integrins is concentration dependent. Biotechnol Bioeng 2009; 104:408-17. [PMID: 19575417 DOI: 10.1002/bit.22424] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel approach to treat cancer more selectively is achieved by targeting drugs to cells via conjugating the drug or imaging agent to an antibody or ligand for a cell surface receptor that is over-expressed by the target cell population. Previous work by us has suggested that enhanced specificity can be obtained by multivalency of binding moieties. In this study we investigated the binding specificity of a multivalent construct including three peptides segments (TWYKIAFQRNRK), which bind the alpha(6)beta(1)-integrin, linked by poly(ethylene glycol) spacers. The binding specificity of the constructs was calculated by quantifying their binding to target cells (glioma cells, SF 767) relative to non-targeted cells (normal human astrocytes, NHA). Dodecapeptide constructs (monovalent) exhibit specificity equal to the ratio of receptor expression at all concentrations. However, trivalent constructs demonstrated a sharp increase in specificity at concentrations less than the affinity of the receptor-ligand bond (4.28 microM). These experiments (conducted at 4 degrees C) were consistent with the theoretical prediction and indicate that the biophysical model captures the basic trend of the data in the absence of receptor internalization, although the concentration at which increased specificity is observed is greater than predicted. The biophysical model does not predict the results of 37 degrees C experiments, and this is shown to be due to internalization which occurs at 37 degrees C but not at 4 degrees C.
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Affiliation(s)
- Elena V Rosca
- Harrington Department of Bioengineering, Arizona State University, PO Box 879709, Tempe, Arizona 85287-9709, USA
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34
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Stukel JM, Caplan MR. Targeted drug delivery for treatment and imaging of glioblastoma multiforme. Expert Opin Drug Deliv 2009; 6:705-18. [PMID: 19538036 DOI: 10.1517/17425240902988470] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Glioblastoma multiforme is a grade IV astrocytic tumor with a very high mortality rate. Although current treatment often includes surgical resection, this rarely removes all primary tumor cells, so is usually followed by radiation and/or chemotherapy. Remaining migratory tumor cells invade surrounding healthy tissue and contribute to secondary and tertiary tumor recurrence; therefore, despite significant research into glioma removal and treatment, prognosis remains poor. A variety of treatment modalities have been investigated to deliver drug to these cells, including systemic, diffusive and convection-enhanced delivery (CED). As systemic delivery is limited by molecules larger than approximately 500 Da being unable to cross the blood-brain barrier (BBB), therapeutic concentrations are difficult to attain; thus, localized delivery options relying on diffusion and CED have been used to circumvent the BBB. Although CED enables delivery to a greater volume of tissue than diffusive delivery alone, limitations still exist, requiring that these delivery strategies be improved. This review enumerates the strengths and weaknesses of these currently used strategies and details how predictive mathematical modeling can be used to aid investigators in optimizing these delivery modalities for clinical application.
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Affiliation(s)
- Jill M Stukel
- Arizona State University, Center for Interventional Biomaterials, Harrington Department of Bioengineering, Tempe, AZ 85287, USA
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35
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Lanthanide complexes on Ag nanoparticles: Designing contrast agents for magnetic resonance imaging. J Colloid Interface Sci 2009; 337:88-96. [DOI: 10.1016/j.jcis.2009.04.096] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 04/28/2009] [Accepted: 04/29/2009] [Indexed: 02/02/2023]
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36
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Xu L, Vagner J, Josan J, Lynch RM, Morse DL, Baggett B, Han H, Mash EA, Hruby VJ, Gillies RJ. Enhanced targeting with heterobivalent ligands. Mol Cancer Ther 2009; 8:2356-65. [PMID: 19671749 DOI: 10.1158/1535-7163.mct-08-1183] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A novel approach to specifically target tumor cells for detection and treatment is the proposed use of heteromultivalent ligands, which are designed to interact with, and noncovalently crosslink, multiple different cell surface receptors. Although enhanced binding has been shown for synthetic homomultivalent ligands, proof of cross-linking requires the use of ligands with two or more different binding moieties. As proof-of-concept, we have examined the binding of synthetic heterobivalent ligands to cell lines that were engineered to coexpress two different G-protein-coupled human receptors, i.e., the human melanocortin 4 receptor (MC4R) expressed in combination with either the human delta-opioid receptor (deltaOR) or the human cholecystokinin-2 receptor (CCK2R). Expression levels of these receptors were characterized by time-resolved fluorescence saturation binding assays using Europium-labeled ligands; Eu-DPLCE, Eu-NDP-alpha-MSH, and Eu-CCK8 for the deltaOR, MC4R, and CCK2R, respectively. Heterobivalent ligands were synthesized to contain a MC4R agonist connected via chemical linkers to either a deltaOR or a CCK2R agonist. In both cell systems, the heterobivalent constructs bound with much higher affinity to cells expressing both receptors, compared with cells with single receptors or to cells where one of the receptors was competitively blocked. These results indicate that synthetic heterobivalent ligands can noncovalently crosslink two unrelated cell surface receptors, making feasible the targeting of receptor combinations. The in vitro cell models described herein will lead to the development of multivalent ligands for target combinations identified in human cancers.
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Affiliation(s)
- Liping Xu
- Department of Pharmaceutical Analytics, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany
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37
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Heterobivalent ligands crosslink multiple cell-surface receptors--a step towards personal medicine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 611:413-4. [PMID: 19400245 DOI: 10.1007/978-0-387-73657-0_178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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38
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Satterfield BC, Caplan MR, West JAA. Tentacle probe sandwich assay in porous polymer monolith improves specificity, sensitivity and kinetics. Nucleic Acids Res 2008; 36:e129. [PMID: 18790801 PMCID: PMC2577359 DOI: 10.1093/nar/gkn564] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 08/18/2008] [Accepted: 08/19/2008] [Indexed: 12/02/2022] Open
Abstract
Nucleic acid sandwich assays improve low-density array analysis through the addition of a capture probe and a specific label, increasing specificity and sensitivity. Here, we employ photo-initiated porous polymer monolith (PPM) as a high-surface area substrate for sandwich assay analysis. PPMs are shown to enhance extraction efficiency by 20-fold from 2 microl of sample. We further compare the performance of labeled linear probes, quantum dot labeled probes, molecular beacons (MBs) and tentacle probes (TPs). Each probe technology was compared and contrasted with traditional hybridization methods using labeled sample. All probes demonstrated similar sensitivity and greater specificity than traditional hybridization techniques. MBs and TPs were able to bypass a wash step due to their 'on-off' signaling mechanism. TPs demonstrated reaction kinetics 37.6 times faster than MBs, resulting in the fastest assay time of 5 min. Our data further indicate TPs had the most sensitive detection limit (<1 nM) as well as the highest specificity (>1 x 10(4) improvement) among all tested probes in these experiments. By matching the enhanced extraction efficiencies of PPM with the selectivity of TPs, we have created a format for improved sandwich assays.
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Affiliation(s)
- Brent C. Satterfield
- Harrington Department of Bioengineering, Arizona State
University Tempe, AZ, Cooperative Diagnostics, Greenwood, SC and
Arcxis Biotechnologies, Pleasanton, CA, USA
| | - Michael R. Caplan
- Harrington Department of Bioengineering, Arizona State
University Tempe, AZ, Cooperative Diagnostics, Greenwood, SC and
Arcxis Biotechnologies, Pleasanton, CA, USA
| | - Jay A. A. West
- Harrington Department of Bioengineering, Arizona State
University Tempe, AZ, Cooperative Diagnostics, Greenwood, SC and
Arcxis Biotechnologies, Pleasanton, CA, USA
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39
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Shewmake TA, Solis FJ, Gillies RJ, Caplan MR. Effects of Linker Length and Flexibility on Multivalent Targeting. Biomacromolecules 2008; 9:3057-64. [DOI: 10.1021/bm800529b] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas A. Shewmake
- Harrington Department of Bioengineering and Center for Interventional Biomaterials, Arizona State University, Tempe, Arizona 85287, Department of Integrated Natural Sciences, Arizona State University West, Phoenix, Arizona 85032, and Department of Radiology, University of Arizona, Tucson, Arizona 85721
| | - Francisco J. Solis
- Harrington Department of Bioengineering and Center for Interventional Biomaterials, Arizona State University, Tempe, Arizona 85287, Department of Integrated Natural Sciences, Arizona State University West, Phoenix, Arizona 85032, and Department of Radiology, University of Arizona, Tucson, Arizona 85721
| | - Robert J. Gillies
- Harrington Department of Bioengineering and Center for Interventional Biomaterials, Arizona State University, Tempe, Arizona 85287, Department of Integrated Natural Sciences, Arizona State University West, Phoenix, Arizona 85032, and Department of Radiology, University of Arizona, Tucson, Arizona 85721
| | - Michael R. Caplan
- Harrington Department of Bioengineering and Center for Interventional Biomaterials, Arizona State University, Tempe, Arizona 85287, Department of Integrated Natural Sciences, Arizona State University West, Phoenix, Arizona 85032, and Department of Radiology, University of Arizona, Tucson, Arizona 85721
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40
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Josan JS, Vagner J, Handl HL, Sankaranarayanan R, Gillies RJ, Hruby VJ. Solid-Phase Synthesis of Heterobivalent Ligands Targeted to Melanocortin and Cholecystokinin Receptors. Int J Pept Res Ther 2008; 14:293-300. [PMID: 19714261 DOI: 10.1007/s10989-008-9150-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heteromultivalency provides a route to increase binding avidity and to high specificity when compared to monovalent ligands. The enhanced specificity can potentially serve as a unique platform to develop diagnostics and therapeutics. To develop new imaging agents based upon multivalency, we employed heterobivalent constructs of optimized ligands. In this report, we describe synthetic methods we have developed for the preparation of heterobivalent constructs consisting of ligands targeted simultaneously to the melanocortin receptor, hMC4R, and the cholecystokinin receptors, CCK-2R. Modeling data suggest that a linker distance span of 20-50 Å is needed to crosslink these two G-protein coupled receptors (GPCRs). The two ligands were tethered with linkers of varying rigidity and length, and flexible polyethylene glycol based PEGO chain or semi-rigid [poly(Pro-Gly)] linkers were employed for this purpose. The described synthetic strategy provides a modular way to assemble ligands and linkers on solid-phase supports. Examples of heterobivalent ligands are provided to illustrate the increased binding avidity to cells that express the complementary receptors.
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Affiliation(s)
- Jatinder S Josan
- Department of Chemistry, The University of Arizona, 1306 E. University Blvd, Tucson, AZ 85721, USA, e-mail: ;
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41
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Balagurunathan Y, Morse DL, Hostetter G, Shanmugam V, Stafford P, Shack S, Pearson J, Trissal M, Demeure MJ, Von Hoff DD, Hruby VJ, Gillies RJ, Han H. Gene expression profiling-based identification of cell-surface targets for developing multimeric ligands in pancreatic cancer. Mol Cancer Ther 2008; 7:3071-80. [PMID: 18765825 DOI: 10.1158/1535-7163.mct-08-0402] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Multimeric ligands are ligands that contain multiple binding domains that simultaneously target multiple cell-surface proteins. Due to cooperative binding, multimeric ligands can have high avidity for cells (tumor) expressing all targeting proteins and only show minimal binding to cells (normal tissues) expressing none or only some of the targets. Identifying combinations of targets that concurrently express in tumor cells but not in normal cells is a challenging task. Here, we describe a novel approach for identifying such combinations using genome-wide gene expression profiling followed by immunohistochemistry. We first generated a database of mRNA gene expression profiles for 28 pancreatic cancer specimens and 103 normal tissue samples representing 28 unique tissue/cell types using DNA microarrays. The expression data for genes that encode proteins with cell-surface epitopes were then extracted from the database and analyzed using a novel multivariate rule-based computational approach to identify gene combinations that are expressed at an efficient binding level in tumors but not in normal tissues. These combinations were further ranked according to the proportion of tumor samples that expressed the sets at efficient levels. Protein expression of the genes contained in the top ranked combinations was confirmed using immunohistochemistry on a pancreatic tumor tissue and normal tissue microarrays. Coexpression of targets was further validated by their combined expression in pancreatic cancer cell lines using immunocytochemistry. These validated gene combinations thus encompass a list of cell-surface targets that can be used to develop multimeric ligands for the imaging and treatment of pancreatic cancer.
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Abstract
This article provides an overview of principles and barriers relevant to intracellular drug and gene transport, accumulation and retention (collectively called as drug delivery) by means of nanovehicles (NV). The aim is to deliver a cargo to a particular intracellular site, if possible, to exert a local action. Some of the principles discussed in this article apply to noncolloidal drugs that are not permeable to the plasma membrane or to the blood-brain barrier. NV are defined as a wide range of nanosized particles leading to colloidal objects which are capable of entering cells and tissues and delivering a cargo intracelullarly. Different localization and targeting means are discussed. Limited discussion on pharmacokinetics and pharmacodynamics is also presented. NVs are contrasted to micro-delivery and current nanotechnologies which are already in commercial use. Newer developments in NV technologies are outlined and future applications are stressed. We also briefly review the existing modeling tools and approaches to quantitatively describe the behavior of targeted NV within the vascular and tumor compartments, an area of particular importance. While we list "elementary" phenomena related to different level of complexity of delivery to cancer, we also stress importance of multi-scale modeling and bottom-up systems biology approach.
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Affiliation(s)
- Ales Prokop
- Department of Chemical Engineering, 24th Avenue & Garland Avenues, 107 Olin Hall, Vanderbilt University, Nashville, Tennessee 37235, USA.
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Stukel JM, Heys JJ, Caplan MR. Optimizing Delivery of Multivalent Targeting Constructs for Detection of Secondary Tumors. Ann Biomed Eng 2008; 36:1291-304. [DOI: 10.1007/s10439-008-9498-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 04/04/2008] [Indexed: 11/29/2022]
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Vagner J, Xu L, Handl H, Josan J, Morse D, Mash E, Gillies R, Hruby V. Heterobivalent Ligands Crosslink Multiple Cell-Surface Receptors: The Human Melanocortin-4 and δ-Opioid Receptors. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200702770] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Vagner J, Xu L, Handl HL, Josan JS, Morse DL, Mash EA, Gillies RJ, Hruby VJ. Heterobivalent ligands crosslink multiple cell-surface receptors: the human melanocortin-4 and delta-opioid receptors. Angew Chem Int Ed Engl 2008; 47:1685-8. [PMID: 18205159 PMCID: PMC2716288 DOI: 10.1002/anie.200702770] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Josef Vagner
- Department of Chemistry, University of Arizona, 1306 E. University, Tucson, AZ 85721 (USA), Fax: (+1)520-621-8407, E-mail: , Homepage: http://www.chem.arizona.edu/faculty/profile/profile.php?fid_call = hrub
| | - Liping Xu
- Arizona Health Sciences Center, University of Arizona, Tucson, AZ 85719 (USA)
| | - Heather L. Handl
- Arizona Health Sciences Center, University of Arizona, Tucson, AZ 85719 (USA)
| | - Jatinder S. Josan
- Department of Chemistry, University of Arizona, 1306 E. University, Tucson, AZ 85721 (USA), Fax: (+1)520-621-8407, E-mail: , Homepage: http://www.chem.arizona.edu/faculty/profile/profile.php?fid_call = hrub
| | - David L. Morse
- Arizona Health Sciences Center, University of Arizona, Tucson, AZ 85719 (USA)
| | - Eugene A. Mash
- Department of Chemistry, University of Arizona, 1306 E. University, Tucson, AZ 85721 (USA), Fax: (+1)520-621-8407, E-mail: , Homepage: http://www.chem.arizona.edu/faculty/profile/profile.php?fid_call = hrub
| | - Robert J. Gillies
- Arizona Health Sciences Center, University of Arizona, Tucson, AZ 85719 (USA)
| | - Victor J. Hruby
- Department of Chemistry, University of Arizona, 1306 E. University, Tucson, AZ 85721 (USA), Fax: (+1)520-621-8407, E-mail: , Homepage: http://www.chem.arizona.edu/faculty/profile/profile.php?fid_call = hrub
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Rosca EV, Stukel JM, Gillies RJ, Vagner J, Caplan MR. Specificity and mobility of biomacromolecular, multivalent constructs for cellular targeting. Biomacromolecules 2007; 8:3830-5. [PMID: 18039007 DOI: 10.1021/bm700791a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Effective targeting of drugs to cells requires that the drug reach the target cell and interact specifically with it. In this study, we synthesized a biomacromolecular, multivalent construct intended to target glioblastoma tumors. The construct was created by linking three dodecapeptides, reported to bind the alpha 6beta1 integrin, with poly(ethylene glycol) linkers. The construct is intended to be delivered locally, and it demonstrates a more homogeneous and more rapid perfusion profile in comparison with quantum dots. The binding specificity of the construct was investigated by using glioblastoma cells and normal human astrocyte cells. The results reveal qualitative differences in binding between glioma and normal human astrocyte cells, with a moderate increase in binding avidity due to multivalency (0.79 microM for the trivalent construct versus 4.28 microM for the dodecapeptide). Overall, biomacromolecular constructs appear to be a promising approach for targeting with high biocompatibility, good perfusion abilities, and specificity.
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Affiliation(s)
- Elena V Rosca
- Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona 85287-9709, USA
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Josan JS, Vagner J, Xu L, Morse DL, Gillies RJ, Hruby VJ. CMR 2007: 4.02: A novel targeting approach to molecular imaging based on heteromultivalency. CONTRAST MEDIA & MOLECULAR IMAGING 2007. [DOI: 10.1002/cmmi.174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Rhyner MN, Smith AM, Gao X, Mao H, Yang L, Nie S. Quantum dots and multifunctional nanoparticles: new contrast agents for tumor imaging. Nanomedicine (Lond) 2007; 1:209-17. [PMID: 17716110 DOI: 10.2217/17435889.1.2.209] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nanometer-sized particles, such as semiconductor quantum dots and iron oxide nanocrystals, have novel optical, electronic, magnetic or structural properties that are not available from either molecules or bulk solids. When linked with tumor-targeting ligands, such as monoclonal antibodies, peptide fragments of tumor-specific proteins or small molecules, these nanoparticles can be used to target tumor antigens (biomarkers) and tumor vasculatures with high affinity and specificity. In the mesoscopic size range of 5-100 nm diameter, quantum dots and related nanoparticles have large surface areas and functional groups that can be linked to multiple diagnostic (e.g., optical, radioisotopic or magnetic) and therapeutic (e.g., anticancer) agents. In this review, recent advances in the development and applications of bioconjugated quantum dots and multifunctional nanoparticles for in vivo tumor imaging and targeting are discussed.
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Affiliation(s)
- Matthew N Rhyner
- Department of Biomedical Engineering, Chemistry, Hematology and Oncology, and the Winship Cancer Institute, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA
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Satterfield BC, Kulesh DA, Norwood DA, Wasieloski LP, Caplan MR, West JAA. Tentacle Probes: differentiation of difficult single-nucleotide polymorphisms and deletions by presence or absence of a signal in real-time PCR. Clin Chem 2007; 53:2042-50. [PMID: 17932130 DOI: 10.1373/clinchem.2007.091488] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND False-positive results are a common problem in real-time PCR identification of DNA sequences that differ from near neighbors by a single-nucleotide polymorphism (SNP) or deletion. Because of a lack of sufficient probe specificity, post-PCR analysis, such as a melting curve, is often required for mutation differentiation. METHODS Tentacle Probes, cooperative reagents with both a capture and a detection probe based on specific cell-targeting principles, were developed as a replacement for 2 chromosomal TaqMan-minor groove binder (MGB) assays previously developed for Yersinia pestis and Bacillus anthracis detection. We compared TaqMan-MGB probes to Tentacle Probes for SNP and deletion detection based on the presence or absence of a growth curve. RESULTS With the TaqMan-MGB Y. pestis yp48 assays, false-positive results for Yersinia pseudotuberculosis occurred at every concentration tested, and with the TaqMan-MGB B. anthracis gyrA assays, false-positive results occurred in 21 of 29 boil preps of environmental samples of near neighbors. With Tentacle Probes no false-positive results occurred. CONCLUSIONS The high specificity exhibited by Tentacle Probes may eliminate melting curve analysis for SNP and deletion mutation detection, allowing the diagnostic use of previously difficult targets.
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Affiliation(s)
- Brent C Satterfield
- Harrington Department of Bioengineering, Arizona State University, Tempe, AZ 85287-9709, USA
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Satterfield BC, West JA, Caplan MR. Tentacle probes: eliminating false positives without sacrificing sensitivity. Nucleic Acids Res 2007; 35:e76. [PMID: 17517788 PMCID: PMC1904288 DOI: 10.1093/nar/gkm113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The majority of efforts to increase specificity or sensitivity in biosensors result in trade-offs with little to no gain in overall accuracy. This is because a biosensor cannot be more accurate than the affinity interaction it is based on. Accordingly, we have developed a new class of reagents based on mathematical principles of cooperativity to enhance the accuracy of the affinity interaction. Tentacle probes (TPs) have a hairpin structure similar to molecular beacons (MBs) for enhanced specificity, but are modified by the addition of a capture probe for increased kinetics and affinity. They produce kinetic rate constants up to 200-fold faster than MB with corresponding stem strengths. Concentration-independent specificity was observed with no false positives at up to 1 mM concentrations of variant analyte. In contrast, MBs were concentration dependent and experienced false positives above 3.88 μM of variant analyte. The fast kinetics of this label-free reagent may prove important for extraction efficiency, hence sensitivity and detection time, in microfluidic assays. The concentration-independent specificity of TPs may prove extremely useful in assays where starting concentrations and purities are unknown as would be the case in bioterror or clinical point of care diagnostics.
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Affiliation(s)
- Brent C. Satterfield
- Harrington Department of Bioengineering, Arizona State University Tempe, AZ, USA and Arcxis Biotechnologies, Pleasanton CA, USA
| | - Jay A.A. West
- Harrington Department of Bioengineering, Arizona State University Tempe, AZ, USA and Arcxis Biotechnologies, Pleasanton CA, USA
- *To whom correspondence should be addressed. Tel: +1-925-461-1300; Fax: +1-925-265-9000;
| | - Michael R. Caplan
- Harrington Department of Bioengineering, Arizona State University Tempe, AZ, USA and Arcxis Biotechnologies, Pleasanton CA, USA
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