MRI/Photoluminescence Dual-Modal Imaging Magnetic PLGA Nanocapsules for Theranostics

Abstract

Developing multifunctional and biocompatible drug delivery nanoplatforms that integrate high drug loads and multiple imaging modalities avoiding cross-interferences is extremely challenging. Here we report on the successful chemical reaction of the high quantum yield biodegradable and photoluminescent polyester (BPLP) with the poly(lactic-co-glycolic acid) (PLGA) polymer to fabricate biocompatible photoluminescent nanocapsules (NCs). Furthermore, we transform the PLGA-BPLP NCs into a magnetic resonance (MR)/photoluminescence dual-modal imaging theranostic platform by incorporating superparamagnetic iron oxide nanoparticles (SPIONs) into the polymeric shell. In vitro phantoms confirmed the excellent MRI-r2 relaxivity values of the NCs whilst the cellular uptake of these NCs was clearly observed by fluorescence optical imaging. Besides, the NCs (mean size ~270 nm) were loaded with ~1 wt% of a model protein (BSA) and their PEGylation provided a more hydrophilic surface. The NCs show biocompatibility in vitro, as hCMEC/D3 endothelial cells viability was not affected for particle concentration up to 500 μg/mL. Interestingly, NCs decorated with SPIONs can be exploited for magnetic guiding and retention.

Polymer Capsules with Hydrophobic Liquid Cores as Functional Nanocarriers

“…Such an approach was successfully applied to prepare emulsion-based carriers capable of protecting enzymes against degradation [45,46] or delivering active pharmaceutical ingredients such as carvedilol, meloxicam, doxorubicin, methotrexate [47][48][49][50]. After the encapsulation of fluorescent dyes or quantum dots, they may serve as imaging vesicles [51,52], while the incorporation of magnetic particles allows for the precise navigation of nanocapsules using the external magnetic field [53,54]. Polymer nanocapsules can also serve as carriers releasing the cargo upon a given stimulus and nanoreactors for the reactions requiring a confined environment [55][56][57].…”

Endovascular administration of magnetized nanocarriers targeting brain delivery after stroke

“…VEGF, SDF, BDNF or albumin), showing successful encapsulation efficiencies, and posterior in vitro release with preserved functionality of the released factors. [46][47][48] This supports the encapsulation of therapeutic molecules for tissue repair, for example, however any potential restriction on the molecular weight of the cargo proteins should be further studied for specific neuroprotective or neurorestorative agents, always in balance with suitable nanoformulation sizes for a safe endovascular delivery and proving its advantage in front of free drug deliveries. The present study proves the advantage and safety of intraarterially delivered magnetized nanocarriers for specific brain targeting in the context of cerebral ischemia.…”

Nano-Medicine in the Cardiovascular System

“…High biocompatibility and low cytotoxicity are attributed to the degradation byproducts—lactate and glycolate—which can easily be incorporated into cellular metabolic pathways ( Figure 1 ) ( Chereddy et al, 2018 ). Due to these highly desirable properties, PLGA has been widely studied as both a therapeutic and diagnostic agent in the cardiac field as well ( Oduk et al, 2018 ; Zhang et al, 2019 ; Fan et al, 2020a ; Fan et al, 2020b ). With improvements in processing and production techniques, PLGA has also enjoyed a lot of attention due to the relative ease with which comparatively large batches of nano-medicines can be produced via emulsion polymerization.…”