Fluorescence Approaches in Drug Delivery

A special issue of Pharmaceuticals (ISSN 1424-8247). This special issue belongs to the section "Pharmaceutical Technology".

Deadline for manuscript submissions: closed (31 October 2023) | Viewed by 11631

Special Issue Editor


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Guest Editor
Center for Interdisciplinary Biosciences, Pavol Jozef Safarik University, Kosice, Slovakia
Interests: transport systems; cancer targeting; oxidative stress; apoptosis; photodynamic therapy; bioimaging; fluorescence microscopy

Special Issue Information

Dear Colleagues,

At present, the targeted treatment of diseases is of great importance in the daily care of patients due to its minimal invasiveness and side effects. The platform under consideration includes various materials, from native to synthetic products, capable of encapsulating most drug molecules and reliably delivering them to the target tissue. Fluorescence is a fascinating phenomenon that has been the focus of the scientific community for decades. Fluorescence techniques are widely developed and used to improve instrumentation, diagnostics, imaging, and fluorescent labelling. These applications include protein interaction; enzymatic activity; the expression of genes, proteins and receptors in cells; and changes in cellular metabolism due to various disorders. Special attention is given to microscopic techniques that allow the identification of cancer cells, organelle dysfunction, cell response to various treatments, as well as transport pathways and modalities of how drugs enter cells. Fluorescence techniques generally help to answer specific questions about the materials, environments, interactions, distribution, and localization of fluorescent molecules. In this Special Issue, we invite experts involved in the development and application of fluorescence techniques that can be used in various areas of their field. The preferred topic might be cancer targeting, but it is not mandatory. Techniques used to study drug delivery include steady-state and time-resolved fluorescence and phosphorescence spectroscopy, fluorescence microscopy and super-resolution techniques, flow cytometry, and fluorescence intensity methods. Fluorescence can be caused by the drug or by the delivery system. New modalities for the study and evaluation of delivery systems using fluorescence techniques are welcome.

Dr. Veronika Huntosova
Guest Editor

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Keywords

  • nanoparticles identification
  • fluorescence pharmacokinetics
  • fluorescence imaging
  • monitoring of targeted delivery
  • multimodal fluorescent compounds
  • photodiagnostics
  • photodynamic treatment

Published Papers (6 papers)

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Research

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15 pages, 7276 KiB  
Article
Putting a “C60 Ball” and Chain to Chlorin e6 Improves Its Cellular Uptake and Photodynamic Performances
by Manuele Di Sante, Alena Kaltenbrunner, Marco Lombardo, Alberto Danielli, Paolo Emidio Costantini, Matteo Di Giosia and Matteo Calvaresi
Pharmaceuticals 2023, 16(9), 1329; https://doi.org/10.3390/ph16091329 - 20 Sep 2023
Cited by 1 | Viewed by 1030
Abstract
Chlorin e6 (Ce6) and fullerene (C60) are among the most used photosensitizers (PSs) for photodynamic therapy (PDT). Through the combination of the chemical and photophysical properties of Ce6 and C60, in principle, we can obtain an “ideal” photosensitizer that [...] Read more.
Chlorin e6 (Ce6) and fullerene (C60) are among the most used photosensitizers (PSs) for photodynamic therapy (PDT). Through the combination of the chemical and photophysical properties of Ce6 and C60, in principle, we can obtain an “ideal” photosensitizer that is able to bypass the limitations of the two molecules alone, i.e., the low cellular uptake of Ce6 and the scarce solubility and absorption in the red region of the C60. Here, we synthesized and characterized a Ce6–C60 dyad. The UV-Vis spectrum of the dyad showed the typical absorption bands of both fullerene and Ce6, while a quenching of Ce6 fluorescence was observed. This behavior is typical in the formation of a fullerene–antenna system and is due to the intramolecular energy, or electron transfer from the antenna (Ce6) to the fullerene. Consequently, the Ce6–C60 dyad showed an enhancement in the generation of reactive oxygen species (ROS). Flow cytometry measurements demonstrated how the uptake of the Ce6 was strongly improved by the conjugation with C60. The Ce6–C60 dyad exhibited in A431 cancer cells low dark toxicity and a higher PDT efficacy than Ce6 alone, due to the enhancement of the uptake and the improvement of ROS generation. Full article
(This article belongs to the Special Issue Fluorescence Approaches in Drug Delivery)
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25 pages, 5038 KiB  
Article
Investigation of the Interaction between Mechanosynthesized ZnS Nanoparticles and Albumin Using Fluorescence Spectroscopy
by Zdenka Lukáčová Bujňáková, Erika Dutková, Jana Jakubíková, Danka Cholujová, Rastislav Varhač, Larysa Borysenko and Inna Melnyk
Pharmaceuticals 2023, 16(9), 1219; https://doi.org/10.3390/ph16091219 - 29 Aug 2023
Viewed by 973
Abstract
In this paper, ZnS nanoparticles were bioconjugated with bovine serum albumin and prepared in a form of nanosuspension using a wet circulation grinding. The stable nanosuspension with monomodal particle size distribution (d50 = 137 nm) and negative zeta potential (−18.3 mV) was [...] Read more.
In this paper, ZnS nanoparticles were bioconjugated with bovine serum albumin and prepared in a form of nanosuspension using a wet circulation grinding. The stable nanosuspension with monomodal particle size distribution (d50 = 137 nm) and negative zeta potential (−18.3 mV) was obtained. The sorption kinetics and isotherm were determined. Interactions between ZnS and albumin were studied using the fluorescence techniques. The quenching mechanism, describing both static and dynamic interactions, was investigated. Various parameters were calculated, including the quenching rate constant, binding constant, stoichiometry of the binding process, and accessibility of fluorophore to the quencher. It has been found that tryptophan, in comparison to tyrosine, can be closer to the binding site established by analyzing the synchronous fluorescence spectra. The cellular mechanism in multiple myeloma cells treated with nanosuspension was evaluated by fluorescence assays for quantification of apoptosis, assessment of mitochondrial membrane potential and evaluation of cell cycle changes. The preliminary results confirm that the nontoxic nature of ZnS nanoparticles is potentially applicable in drug delivery systems. Additionally, slight changes in the secondary structure of albumin, accompanied by a decrease in α-helix content, were investigated using the FTIR method after analyzing the deconvoluted Amide I band spectra of ZnS nanoparticles conjugated with albumin. Thermogravimetric analysis and long-term stability studies were also performed to obtain a complete picture about the studied system. Full article
(This article belongs to the Special Issue Fluorescence Approaches in Drug Delivery)
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14 pages, 4887 KiB  
Article
Triarylborane-“Click” Fluorescent Tag for Orthogonal Amino Acid Labelling, Interactions with DNA, Protein, and Cyclodextrins
by Marta Jurković, Matthias Ferger, Isabela Drašković, Todd B. Marder and Ivo Piantanida
Pharmaceuticals 2023, 16(9), 1208; https://doi.org/10.3390/ph16091208 - 25 Aug 2023
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Abstract
The innovative design of a triarylborane (TB)-dye with one NMe2-alkylated (propargylated) group and one NMe2 group yielded a system that is both an NMe2 π-donor and an inductive NMe2-alkyl cationic acceptor. Consequently, the new TB-dye was highly [...] Read more.
The innovative design of a triarylborane (TB)-dye with one NMe2-alkylated (propargylated) group and one NMe2 group yielded a system that is both an NMe2 π-donor and an inductive NMe2-alkyl cationic acceptor. Consequently, the new TB-dye was highly sensitive to a “click” reaction with an azide-substituted lysine side chain (yielding TB-lysine), resulting in a bathochromic shift of emission of 100 nm. In addition, fluorene attached to the lysine C-terminus showed FRET with the TB-chromophore, also sensitive to interactions with targets. Both the TB-dye and TB-lysine showed high affinities towards both DNA and proteins, reporting binding by an opposite fluorimetric response for DNA/RNA (quenching) vs. BSA (increase). Thus, the novel TB-dye is an ideal fluorimetric probe for orthogonal incorporation into bio-targets by “click” reactions due to fluorescence reporting of the progress of the “click” reaction and further sensing of the binding site composition. The TB-dye is moderately toxic to human cell lines after 2–3 days of exposure, but efficiently enters cells in 90 min, being non-toxic at short exposure. The most important product of the “click” reaction, TB-lysine, was non-toxic to cells and showed equal distribution between mitochondria and lysosomes. Further studies would focus particularly on the very convenient monitoring of the progress of “click” conjugation of the TB-dye with biorelevant targets inside living cells by confocal microscopy. Full article
(This article belongs to the Special Issue Fluorescence Approaches in Drug Delivery)
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21 pages, 8764 KiB  
Article
Live Cell Imaging by Förster Resonance Energy Transfer Fluorescence to Study Trafficking of PLGA Nanoparticles and the Release of a Loaded Peptide in Dendritic Cells
by Mengshan Liu, Chun Yin Jerry Lau, Irene Trillo Cabello, Johan Garssen, Linette E. M. Willemsen, Wim E. Hennink and Cornelus F. van Nostrum
Pharmaceuticals 2023, 16(6), 818; https://doi.org/10.3390/ph16060818 - 31 May 2023
Viewed by 1515
Abstract
Our previous study demonstrated that a selected β-lactoglobulin-derived peptide (BLG-Pep) loaded in poly(lactic-co-glycolic acid) (PLGA) nanoparticles protected mice against cow’s milk allergy development. However, the mechanism(s) responsible for the interaction of the peptide-loaded PLGA nanoparticles with dendritic cells (DCs) and their [...] Read more.
Our previous study demonstrated that a selected β-lactoglobulin-derived peptide (BLG-Pep) loaded in poly(lactic-co-glycolic acid) (PLGA) nanoparticles protected mice against cow’s milk allergy development. However, the mechanism(s) responsible for the interaction of the peptide-loaded PLGA nanoparticles with dendritic cells (DCs) and their intracellular fate was/were elusive. Förster resonance energy transfer (FRET), a distance-dependent non-radioactive energy transfer process mediated from a donor to an acceptor fluorochrome, was used to investigate these processes. The ratio of the donor (Cyanine-3)-conjugated peptide and acceptor (Cyanine-5) labeled PLGA nanocarrier was fine-tuned for optimal (87%) FRET efficiency. The colloidal stability and FRET emission of prepared NPs were maintained upon 144 h incubation in PBS buffer and 6 h incubation in biorelevant simulated gastric fluid at 37 °C. A total of 73% of Pep-Cy3 NP was internalized by DCs as quantified using flow cytometry and confirmed using confocal fluorescence microscopy. By real-time monitoring of the change in the FRET signal of the internalized peptide-loaded nanoparticles, we observed prolonged retention (for 96 h) of the nanoparticles-encapsulated peptide as compared to 24 h retention of the free peptide in the DCs. The prolonged retention and intracellular antigen release of the BLG-Pep loaded in PLGA nanoparticles in murine DCs might facilitate antigen-specific tolerance induction. Full article
(This article belongs to the Special Issue Fluorescence Approaches in Drug Delivery)
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14 pages, 2116 KiB  
Article
Measurement of Patient-Derived Glioblastoma Cell Response to Temozolomide Using Fluorescence Lifetime Imaging of NAD(P)H
by Diana V. Yuzhakova, Daria A. Sachkova, Marina V. Shirmanova, Artem M. Mozherov, Anna V. Izosimova, Anna S. Zolotova and Konstantin S. Yashin
Pharmaceuticals 2023, 16(6), 796; https://doi.org/10.3390/ph16060796 - 26 May 2023
Viewed by 1245
Abstract
Personalized strategies in glioblastoma treatment are highly necessary. One of the possible approaches is drug screening using patient-derived tumor cells. However, this requires reliable methods for assessment of the response of tumor cells to treatment. Fluorescence lifetime imaging microscopy (FLIM) is a promising [...] Read more.
Personalized strategies in glioblastoma treatment are highly necessary. One of the possible approaches is drug screening using patient-derived tumor cells. However, this requires reliable methods for assessment of the response of tumor cells to treatment. Fluorescence lifetime imaging microscopy (FLIM) is a promising instrument to detect early cellular response to chemotherapy using the autofluorescence of metabolic cofactors. Here, we explored FLIM of NAD(P)H to evaluate the sensitivity of patient-derived glioma cells to temozolomide (TMZ) in vitro. Our results demonstrate that the more-responsive cell cultures displayed the longest mean fluorescence lifetime τm after TMZ treatment due to an increase in the protein-bound NAD(P)H fraction α2 associated with a shift to oxidative phosphorylation. The cell cultures that responded poorly to TMZ had generally shorter τm, i.e., were more glycolytic, and showed no or insignificant changes after treatment. The FLIM data correlate well with standard measurements of cellular drug response—cell viability and proliferation index and clinical response in patients. Therefore, FLIM of NAD(P)H provides a highly sensitive, label-free assay of treatment response directly on patient-derived glioblastoma cells and can become an innovative platform for individual drug screening for patients. Full article
(This article belongs to the Special Issue Fluorescence Approaches in Drug Delivery)
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Review

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49 pages, 23991 KiB  
Review
Fluorescent Probes as a Tool in Diagnostic and Drug Delivery Systems
by Nikolai I. Georgiev, Ventsislav V. Bakov, Kameliya K. Anichina and Vladimir B. Bojinov
Pharmaceuticals 2023, 16(3), 381; https://doi.org/10.3390/ph16030381 - 01 Mar 2023
Cited by 15 | Viewed by 5015
Abstract
Over the last few years, the development of fluorescent probes has received considerable attention. Fluorescence signaling allows noninvasive and harmless real-time imaging with great spectral resolution in living objects, which is extremely useful for modern biomedical applications. This review presents the basic photophysical [...] Read more.
Over the last few years, the development of fluorescent probes has received considerable attention. Fluorescence signaling allows noninvasive and harmless real-time imaging with great spectral resolution in living objects, which is extremely useful for modern biomedical applications. This review presents the basic photophysical principles and strategies for the rational design of fluorescent probes as visualization agents in medical diagnosis and drug delivery systems. Common photophysical phenomena, such as Intramolecular Charge Transfer (ICT), Twisted Intramolecular Charge Transfer (TICT), Photoinduced Electron Transfer (PET), Excited-State Intramolecular Proton Transfer (ESIPT), Fluorescent Resonance Energy Transfer (FRET), and Aggregation-Induced Emission (AIE), are described as platforms for fluorescence sensing and imaging in vivo and in vitro. The presented examples are focused on the visualization of pH, biologically important cations and anions, reactive oxygen species (ROS), viscosity, biomolecules, and enzymes that find application for diagnostic purposes. The general strategies regarding fluorescence probes as molecular logic devices and fluorescence–drug conjugates for theranostic and drug delivery systems are discussed. This work could be of help for researchers working in the field of fluorescence sensing compounds, molecular logic gates, and drug delivery. Full article
(This article belongs to the Special Issue Fluorescence Approaches in Drug Delivery)
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