Facile Functionalization of Gold Nanoparticles with PLGA Polymer Brushes and Efficient Encapsulation into PLGA Nanoparticles: Toward Spatially Precise Bioimaging of Polymeric Nanoparticles

Abstract

Nanocarriers prepared from poly(lactide‐co‐glycolide) (PLGA) have broad biomedical applications. Understanding their cellular uptake and distribution requires appropriate visualization in complex biological compartments with high spatial resolution, which cannot be offered by traditional imaging techniques based on fluorescent or radioactive probes. Herein, the encapsulation of gold nanoparticles (GNPs) into PLGA nanoparticles is proposed, which should allow precise spatial visualization in cells using electron microscopy. Available protocols for encapsulating GNPs into polymeric matrices are limited and associated with colloidal instability and low encapsulation efficiency. In this report, the following are described: 1) a facile protocol to functionalize GNPs with PLGA polymer followed by 2) encapsulation of the prepared PLGA‐capped GNPs into PLGA nanocarriers with 100% encapsulation efficiency. The remarkable encapsulation of PLGA‐GNPs into PLGA matrix obeys the general rule in chemistry “like dissolves like” as evident from poor encapsulation of GNPs capped with other polymers. Moreover, it is shown that how the encapsulated gold nanoparticles serve as nanoprobes to visualize PLGA polymeric hosts inside cancer cells at the spatial resolution of the electron microscope. The described methods should be applicable to a wide range of inorganic nanoprobes and provide a new method of labeling pharmaceutical polymeric nanocarriers to understand their biological fate at high spatial resolution.

Facile Hydrophobication of Glutathione-Protected Gold Nanoclusters and Encapsulation into Poly(lactide-co-glycolide) Nanocarriers

“…As prepared GSH-AuNCs are extremely hydrophilic and thus it is clear that surface hydrophobication of these nanoclusters is required for their efficient encapsulation into PLGA nanoparticles. Recently, we reported the necessity of hydrophobication of larger gold nanoparticles (15 nm) to ensure efficient encapsulation into PLGA nanocarriers 23 . Accordingly, we aimed first to develop a simple and efficient protocol to render these peptide-capped nanoclusters hydrophobic.…”

“…The concentration of gold in samples was measured with ICP-MS according to previous report 23 . For the sample preparation, 150 µL of freshly prepared aqua regia (HCl:HNO 3 = 3:1) was added to 50 µL of the sample, and the mixture were kept in an auto-shaker for overnight at room temperature.…”

“…Moreover, and beyond their outstanding florescence-based applications, GSH-AuNCs have been evaluated recently as a photothermal 22 and radio-sensitization 20 therapeutic platforms for cancer treatment 20 . Motivated by these fascinating properties of GSH-AuNCs and in light of our interest to fabricate functional inorganic-organic nanohybrids 23 , we aim in this work to develop a facile protocol that allow an efficient encapsulation of GSH-AuNCs into PLGA nanocarriers and evaluate the feasibility of visualizing the labeled PLGA nanocarriers using confocal fluorescence microscopy.…”

[Retracted] The Study of Expanded Polytetrafluoroethylene New Material in Dural Repair

“…Polylactic acid-glycolic acid (PLGA) is a biodegradable polymer compound, which is polymerized by lactic acid and glycolic acid. It has been widely used as tissue engineering materials, implant materials, or drug carriers [24][25][26][27]. The use of PLGA can make up for the structural and performance defects of most materials to increase the penetration rate of existing materials.…”

Delivery of drugs, proteins, and nucleic acids using inorganic nanoparticles

“…The authors reported accumulation at the tumor site after intravenous injection and increased local temperature at the tumor up to 44 °C, resulting in inhibited tumor growth. Magnetic nanoparticles have also been utilized by several groups for cancer detection and ablation through tandem MRI and hyperthermic treatment after localization at the tumor site [292][293][294][295][296][297][298]. Today these properties are used synergistically with therapeutics, as discussed here.…”