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Đorđević S, Medel M, Hillaert J, Masiá E, Conejos-Sánchez I, Vicent MJ. Critical Design Strategies Supporting Optimized Drug Release from Polymer-Drug Conjugates. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2303157. [PMID: 37752780 DOI: 10.1002/smll.202303157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 08/19/2023] [Indexed: 09/28/2023]
Abstract
The importance of an adequate linking moiety design that allows controlled drug(s) release at the desired site of action is extensively studied for polymer-drug conjugates (PDCs). Redox-responsive self-immolative linkers bearing disulfide moieties (SS-SIL) represent a powerful strategy for intracellular drug delivery; however, the influence of drug structural features and linker-associated spacers on release kinetics remains relatively unexplored. The influence of drug/spacer chemical structure and the chemical group available for conjugation on drug release and the biological effect of resultant PDCs is evaluated. A "design of experiments" tool is implemented to develop a liquid chromatography-mass spectrometry method to perform the comprehensive characterization required for this systematic study. The obtained fit-for-purpose analytical protocol enables the quantification of low drug concentrations in drug release studies and the elucidation of metabolite presence. and provides the first data that clarifies how drug structural features influence the drug release from SS-SIL and demonstrates the non-universal nature of the SS-SIL. The importance of rigorous linker characterization in understanding structure-function correlations between linkers, drug chemical functionalities, and in vitro release kinetics from a rationally-designed polymer-drug nanoconjugate, a critical strategic crafting methodology that should remain under consideration when using a reductive environment as an endogenous drug release trigger.
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Affiliation(s)
- Snežana Đorđević
- Polymer Therapeutics Laboratory, Príncipe Felipe Research Center (CIPF) and CIBERONC, Eduardo Primo Yúfera 3, Valencia, 46012, Spain
| | - María Medel
- Polymer Therapeutics Laboratory, Príncipe Felipe Research Center (CIPF) and CIBERONC, Eduardo Primo Yúfera 3, Valencia, 46012, Spain
| | - Justine Hillaert
- Polymer Therapeutics Laboratory, Príncipe Felipe Research Center (CIPF) and CIBERONC, Eduardo Primo Yúfera 3, Valencia, 46012, Spain
| | - Esther Masiá
- Polymer Therapeutics Laboratory, Príncipe Felipe Research Center (CIPF) and CIBERONC, Eduardo Primo Yúfera 3, Valencia, 46012, Spain
- Screening Platform, Príncipe Felipe Research Center (CIPF), Eduardo Primo Yúfera 3, Valencia, 46012, Spain
| | - Inmaculada Conejos-Sánchez
- Polymer Therapeutics Laboratory, Príncipe Felipe Research Center (CIPF) and CIBERONC, Eduardo Primo Yúfera 3, Valencia, 46012, Spain
| | - María J Vicent
- Polymer Therapeutics Laboratory, Príncipe Felipe Research Center (CIPF) and CIBERONC, Eduardo Primo Yúfera 3, Valencia, 46012, Spain
- Screening Platform, Príncipe Felipe Research Center (CIPF), Eduardo Primo Yúfera 3, Valencia, 46012, Spain
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De Tito S, Turacchio G, Valente C. Negative Staining Electron Microscopy for Morpho-Functional Characterization of Purified Golgi Membranes from Mammalian Cells. Methods Mol Biol 2022; 2557:225-234. [PMID: 36512218 DOI: 10.1007/978-1-0716-2639-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Golgi apparatus is a highly dynamic organelle that controls lipid and protein sorting in the endocytic and exocytic cellular pathways. Perturbation of the lipid homeostasis or of the molecular machineries that regulate membrane remodeling/trafficking events on the Golgi membranes can dramatically change the morphology and functions of the Golgi apparatus. So far, several approaches have been described to characterize and define the Golgi morphology in intact cells and in vitro. Here, we describe the application of negative staining (NS) electron microscopy (EM) on purified Golgi membranes from HeLa cells. This approach allows to quantify and functionally characterize membrane remodeling events upon specific treatments that alter the Golgi morphology.
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Affiliation(s)
- Stefano De Tito
- Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Gabriele Turacchio
- Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Carmen Valente
- Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.
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Jeon J, Lodge MS, Dawson BD, Ishigami M, Shewmaker F, Chen B. Superb resolution and contrast of transmission electron microscopy images of unstained biological samples on graphene-coated grids. Biochim Biophys Acta Gen Subj 2013; 1830:3807-15. [DOI: 10.1016/j.bbagen.2013.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 11/26/2022]
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4
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Glaeser RM. Electron microscopy of biological specimens in liquid water. Biophys J 2012; 103:163-4; author reply 165-6. [PMID: 22828343 DOI: 10.1016/j.bpj.2012.05.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 04/13/2012] [Accepted: 05/17/2012] [Indexed: 11/17/2022] Open
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Electron microscopy of nanoemulsions: An essential tool for characterisation and stability assessment. Micron 2012; 43:85-103. [DOI: 10.1016/j.micron.2011.07.014] [Citation(s) in RCA: 182] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 07/18/2011] [Accepted: 07/19/2011] [Indexed: 12/12/2022]
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New and unconventional approaches for advancing resolution in biological transmission electron microscopy by improving macromolecular specimen preparation and preservation. Micron 2011; 42:141-51. [DOI: 10.1016/j.micron.2010.05.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 05/16/2010] [Accepted: 05/17/2010] [Indexed: 11/21/2022]
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De Carlo S, Harris JR. Negative staining and cryo-negative staining of macromolecules and viruses for TEM. Micron 2010; 42:117-31. [PMID: 20634082 DOI: 10.1016/j.micron.2010.06.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/14/2010] [Accepted: 06/15/2010] [Indexed: 10/19/2022]
Abstract
In this review we cover the technical background to negative staining of biomolecules and viruses, and then expand upon the different possibilities and limitations. Topics range from conventional air-dry negative staining of samples adsorbed to carbon support films, the variant termed the "negative staining-carbon film" technique and negative staining of samples spread across the holes of holey-carbon support films, to a consideration of dynamic/time-dependent negative staining. For each of these approaches examples of attainable data are given. The cryo-negative staining technique for the specimen preparation of frozen-hydrated/vitrified samples is also presented. A detailed protocol to successfully achieve cryo-negative staining with ammonium molybdate is given, as well as examples of data, which support the claim that cryo-negative staining provides a useful approach for the high-resolution study of macromolecular and viral structure.
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Affiliation(s)
- Sacha De Carlo
- Department of Chemistry, and Institute for Macro Molecular Assemblies, The City College of CUNY, 160 Convent Ave, New York, NY, USA.
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8
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Massover WH. Electron beam-induced radiation damage: the bubbling response in amorphous dried sodium phosphate buffer. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2010; 16:346-357. [PMID: 20374678 DOI: 10.1017/s1431927610000140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Irradiation of an amorphous layer of dried sodium phosphate buffer (pH = 7.0) by transmission electron microscopy (100-120 kV) causes rapid formation of numerous small spherical bubbles [10-100 A (= 1-10 nm)] containing an unknown gas. Bubbling is detected even with the first low-dose exposure. In a thin layer (ca. 100-150 A), bubbling typically goes through nucleation, growth, possible fusion, and end-state, after which further changes are not apparent; co-irradiated adjacent areas having a slightly smaller thickness never develop bubbles. In moderately thicker regions (ca. over 200 A), there is no end-state. Instead, a complex sequence of microstructural changes is elicited during continued intermittent high-dose irradiation: nucleation, growth, early simple fusions, a second round of extensive multiple fusions, general reduction of matrix thickness (producing flattening and expansion of larger bubbles, occasional bubble fission, and formation of very large irregularly-shaped bubbles by a third round of compound fusion events), and slow shrinkage of all bubbles. The ongoing lighter appearance of bubble lumens, maintenance of their rounded shape, and extensive changes in size and form indicate that gas content continues throughout their surprisingly long lifetime; the thin dense boundary layer surrounding all bubbles is proposed to be the main mechanism for their long lifetime.
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Affiliation(s)
- William H Massover
- Department of Biological Sciences, Rutgers University-Newark, Newark, NJ 07102-1811, USA.
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Kim YK, Yiu CKY, Kim JR, Gu L, Kim SK, Weller RN, Pashley DH, Tay FR. Failure of a glass ionomer to remineralize apatite-depleted dentin. J Dent Res 2010; 89:230-5. [PMID: 20110510 DOI: 10.1177/0022034509357172] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Remineralization of demineralized dentin lesions adjacent to glass-ionomer cements (GICs) has been reported in the literature. This study tested the hypothesis that a strontium-based GIC can remineralize completely demineralized dentin by nucleation of new apatite crystallites within an apatite-free dentin matrix. Human dentin specimens were acid-etched, bonded with Fuji IX(GP), and immersed in a calcium-and-phosphate-containing 1.5X simulated body fluid (SBF) for 1-4 months. Polyacrylic acid and polyvinylphosphonic acid biomimetic analogs were added to the SBFs to create 2 additional remineralization media. Specimens were processed by transmission electron microscopy (TEM). No apatite deposition could be identified in the completely demineralized dentin in any of the specimens immersed in the 3 remineralization media, despite TEM/EDX evidence of diffusion of ions specific to the strontium-based GIC into the demineralized dentin. The hypothesis was rejected; mineral concentration alone is not a sufficient endpoint for assessing the success of contemporary remineralization strategies.
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Affiliation(s)
- Y K Kim
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea
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Abstract
Cryoelectron microscopy (cryo-EM) combined with single-particle reconstruction methods is a powerful technique to study the structure of biological assemblies at molecular resolution (i.e., 3-10 Å). Since electron micrographs of frozen-hydrated biological particles are usually very noisy, improvement of the signal-to-noise ratio (SNR) is necessary and is usually achieved by image processing. We propose an alternative method to improve the contrast at the specimen preparation stage: cryonegative staining. Cryonegative staining aims to increase the SNR while preserving the biological samples in the frozen-hydrated state. Here, we present two alternative procedures to efficiently perform cryonegative staining on macromolecular assemblies. The first is very similar to conventional cryo-EM, the main difference being that the samples are observed in the presence of an additional contrasting agent, ammonium molybdate. The second is based on a carbon-sandwich method and is typically used with uranyl formate or acetate. Compared to air-dried negative staining at room temperature, the advantage of both cryonegative-staining procedures presented here is that the sample is kept hydrated at all steps and observed at liquid nitrogen temperature in the electron microscope. The advantage over conventional cryo-EM is that the SNR is improved by at least a factor of three. For each of these approaches, a few examples of attainable data are given. We cover the technical background to cryonegative staining of macromolecular assemblies, and then expand upon the different possibilities and limitations.
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Affiliation(s)
- Sacha De Carlo
- Department of Chemistry, Institute for Macromolecular Assemblies, City University of New York, City College Campus, New York, USA
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Koh AL, Shachaf CM, Elchuri S, Nolan GP, Sinclair R. Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells. Ultramicroscopy 2008; 109:111-21. [PMID: 18995965 DOI: 10.1016/j.ultramic.2008.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 07/15/2008] [Accepted: 09/09/2008] [Indexed: 12/21/2022]
Abstract
We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic nanoparticle (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet scanning electron microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both cases, the backscattered electron (BSE) detector was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution transmission electron microscopy (TEM) images and scanning Auger electron spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens.
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Affiliation(s)
- Ai Leen Koh
- Department of Materials Science and Engineering, Stanford University, Durand Building Room 139, 496 Lomita Mall, Stanford, CA 94305, USA.
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