Polyfluorene-Based Multicolor Fluorescent Nanoparticles Activated by Temperature for Bioimaging and Drug Delivery

Abstract

Multifunctional nanoparticles have been attracting growing attention in recent years because of their capability to integrate materials with different features in one entity, which leads them to be considered as the next generation of nanomedicine. In this work, we have taken advantage of the interesting properties of conjugated polyelectrolytes to develop multicolor fluorescent nanoparticles with integrating imaging and therapeutic functionalities. With this end, thermosensitive liposomes were coated with three recently synthesized polyfluorenes: copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(phenylene)) bromide (HTMA-PFP), copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-4,7-(2- (phenyl)benzo(d) (1,2,3) triazole)) bromide (HTMA-PFBT) and copoly-((9,9-bis(6′-N,N,N- trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(naphtho(2,3c)-1,2,5-thiadiazole)) bromide (HTMA-PFNT), in order to obtain blue, green and red fluorescent drug carriers, respectively. The stability, size and morphology of the nanoparticles, as well as their thermotropic behavior and photophysical properties, have been characterized by Dynamic Light Scattering (DLS), Zeta Potential, transmission electron microscope (TEM) analysis and fluorescence spectroscopy. In addition, the suitability of the nanostructures to carry and release their contents when triggered by hyperthermia has been explored by using carboxyfluorescein as a hydrophilic drug model. Finally, preliminary experiments with mammalian cells demonstrate the capability of the nanoparticles to mark and visualize cells with different colors, evidencing their potential use for imaging and therapeutic applications.

Formation of Multicolor Nanogels Based on Cationic Polyfluorenes and Poly(methyl vinyl ether-alt-maleic monoethyl ester): Potential Use as pH-Responsive Fluorescent Drug Carriers

“…Polyanhydrides represent an important class of polymers that has been used for medical purposes including encapsulation of drugs in nanoparticles [11][12][13]. They can be prepared easily from available, low-cost resources and can be manipulated to meet markers for bioimaging and sensing devices and have recently been used to develop multicolor fluorescent liposomal nanoparticles activated by temperature, capable of being excited at the same wavelength [35][36][37][38][39][40][41]. In the present work, we take advantage of the attractive properties of CPEs, together with those of PMVEMA-Es and our previous experience in both types of polymers, to prepare and characterize fluorescent nanoplatforms with emission in different visible bands and potential applications as drug carriers and multiplexed bioimaging agents.…”

A conjugated polymer‐liposome complex: A contiguous water‐stable, electronic, and optical interface

“…The objective of coupling a conjugated polymer with the lipid bilayer has been mainly to exploit the optical properties of the polymer, relevant in applications such as bioimaging, biosensing, and photothermal therapy (PTT). [ 10–17 ] However, the advantages of introducing electronic conductivity in liposomes using a conjugated polymer in its doped state has also been demonstrated. [ 18–23 ] In addition, a recent research direction explores interfacing supported lipid bilayers (SLBs) with a conductive film based on conjugated polymers with promising results.…”

“…[ 10,15 ] Overcoming this limitation can be achieved by a variety of strategies; a promising approach is via the complexation with lipid bilayers. [ 10,13–15,17 ] Calver et al interacted the cationic lipid, 1,2‐dioleoyl‐3‐trimethylammonium‐propane (DOTAP), with the conjugated polyanion MPS‐PPV, which was adsorbed onto individual SiO 2 nanoparticles in order to promote deaggregation via the formation of surface‐immobilised charging scaffolds. [ 17 ] Conformational changes in MPS‐PPV liposome complex elicited fluorescence intensity enhancements.…”

Functional Nanostructures for Sensors, Optoelectronic Devices, and Drug Delivery

“…The scope of the Special Issue “Functional Nanostructures for Sensors, Optoelectronic Devices, and Drug Delivery” was to provide an overview of the current research activities in the field of nanostructured materials, with a particular emphasis on their potential applications for sensors [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ], optoelectronic devices [ 10 , 11 , 12 , 13 , 14 , 15 ], and biomedical systems [ 16 , 17 , 18 ]. The Special Issue welcomed the submission of original research articles [ 1 , 2 , 3 , 4 , 5 , 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ] and comprehensive reviews that demonstrated or summarized significant advances in the above-mentioned research fields. Next, the Special Issue collected fifteen selected original research papers and three comprehensive reviews [ 7 , 8 , 18 ] on various topics of nanostructured materials and relative characterization spanning from fundamental research to technological applications.…”

“…These systems showed stable fluorescence signals, good colloidal stability, spherical morphology, and ability to transport and control drug delivery. Preliminary experiments with mammalian cells showed the capability of the nanoparticles to mark and visualize cells in blue, green, and red colors, extending their applications as bioimaging probes [ 16 ].…”