Agostina Lina Capodilupo1, Viviana Vergaro2, Francesca Baldassarre3, Antonio Cardone4, Giuseppina Anna Corrente5, Claudia Carlucci6, Stefano Leporatti6, Paride Papadia7, Giuseppe Gigli8, Giuseppe Ciccarella9. 1. Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy. Electronic address: agostina.capodilupo@nano.cnr.it. 2. Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy. Electronic address: viviana.vergaro@unisalento.it. 3. Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy; Centro di Ricerche 2HE, Università del Salento, Via Monteroni, 73100 Lecce, Italy. Electronic address: frabal84@alice.it. 4. Istituto di Chimica dei Composti OrganoMetallici (ICCOM) - Consiglio Nazionale delle Ricerche CNR, Via Orabona, 4-70125 Bari, Italy. Electronic address: cardone@ba.iccom.cnr.it. 5. Università della Calabria, via Pietro Bucci, 87036 Arcavacata di Rende, Cosenza, Italy. Electronic address: giusycorrente86@yahoo.it. 6. Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy. 7. Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Prov. Le Lecce-Monteroni - Centro Ecotekne, 73100 Lecce, Italy. Electronic address: paride.papadia@unisalento.it. 8. Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy; Center for Biomolecular Nanotechnologies (CBN) Fondazione Istituto Italiano di Tecnologia (IIT), Via Barsanti 1, Arnesano 73010, Italy; Dipartimento di Matematica e Fisica "Ennio De Giorgi", Università del Salento, Via Monteroni, 73100 Lecce, Italy. Electronic address: giuseppe.gigli@unisalento.it. 9. Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy; Dipartimento di Ingegneria dell'Innovazione, Università del Salento, Via Monteroni, 73100 Lecce, Italy. Electronic address: giuseppe.ciccarella@unisalento.it.
Abstract
BACKGROUND: Selective imaging of lysosomes by fluorescence microscopy using specific fluorescent probes allows the study of biological processes and it is potentially useful also for diagnosis. Lysosomes are involved in numerous physiological processes, such as bone and tissue remodeling, plasma membrane repair, and cholesterol homeostasis, along with cell death and cell signaling. Despite the great number of dyes available today on the market, the search for new fluorescent dyes easily up-taken by cells, biocompatible and bearing bright and long-lasting fluorescence is still a priority. METHODS: Two thiophene-based fluorescent dyes, TC1 and TC2, were synthetized as lysosome-specific probes. RESULTS: The new dyes showed high selectivity for fluorescent staining and imaging of lysosomes and disclosed high photostability, low toxicity and pH insensitivity in the range 2-10. CONCLUSIONS: The TC dyes exhibited high co-localization coefficients (>95%) and moderate quantum yields. They showed high biocompatibility and long-term retention, important features for biological applications. GENERAL SIGNIFICANCE: The results of the present work disclose a new class of organic dyes with potential wide applications as specific and efficient lysosome probes in the study of various biological processes.
BACKGROUND: Selective imaging of lysosomes by fluorescence microscopy using specific fluorescent probes allows the study of biological processes and it is potentially useful also for diagnosis. Lysosomes are involved in numerous physiological processes, such as bone and tissue remodeling, plasma membrane repair, and cholesterol homeostasis, along with cell death and cell signaling. Despite the great number of dyes available today on the market, the search for new fluorescent dyes easily up-taken by cells, biocompatible and bearing bright and long-lasting fluorescence is still a priority. METHODS: Two thiophene-based fluorescent dyes, TC1 and TC2, were synthetized as lysosome-specific probes. RESULTS: The new dyes showed high selectivity for fluorescent staining and imaging of lysosomes and disclosed high photostability, low toxicity and pH insensitivity in the range 2-10. CONCLUSIONS: The TC dyes exhibited high co-localization coefficients (>95%) and moderate quantum yields. They showed high biocompatibility and long-term retention, important features for biological applications. GENERAL SIGNIFICANCE: The results of the present work disclose a new class of organic dyes with potential wide applications as specific and efficient lysosome probes in the study of various biological processes.