PLGA nanoparticles

A similar technique, the so-called spontaneous emulsification solvent diffusion method, is derived from the solvent injection method to prepare liposomes [161]. Kawashima et al. [162] used a mixed-solvent system of methylene chloride and acetone to prepare PLGA nanoparticles. The addition of the water-miscible solvent acetone results in nanoparticles in the submicrometer range this is not possible with only the water-immiscible organic solvent. The addition of acetone decreases the interfacial tension between the organic and the aqueous phase and, in addition, results in the perturbation of the droplet interface because of the rapid diffusion of acetone into the aqueous phase. 

Vaccination Using Antigen-Loaded PLGA Nanoparticles. 54... 

Preparation of Biodegradable Polymeric Nanoparticles 2.1 PLGA Nanoparticles... 

In vitro studies have shown that y-PGA-Phe or PLGA nanoparticle-pulsed DCs result in DC maturation by upregulation of co-stimulatory molecule expression and cytokine production (Fig. 14). To determine whether the uptake of y-PGA-Phe... 

Hamdy S, Molavi O, Ma Z et al (2008) Co-delivery of cancer-associated antigen and Toll-like receptor 4 ligand in PLGA nanoparticles induces potent CD8+ T cell-mediated anti-tumor immunity. Vaccine 26 5046-5057... 

Chong CS, Cao M, Wong WW et al (2005) Enhancement of T helper type 1 immune responses against hepatitis B virus core antigen by PLGA nanoparticle vaccine delivery. J Control Release 102 85-99... 

Fig. 10 Multifunctional solid biodegradable PLGA nanoparticles attached to several moieties such as T-cell antibodies, magnetic resonance contrast agent (biotin-BSA-Gd-DTPA) and encapsulated immunosuppressive drug (doxorubicin). (Adapted from [48])...

M. G. Qaddoumi, H. J. Gukasyan, J. Davda, V. Labhasetwar, K. J. Kim, and V. H. Lee. Clathrin and caveolin-1 expression in primary pigmented rabbit conjunctival epithelial cells role in PLGA nanoparticle endocytosis. Mol Vis 9 559-568 (2003)... 

The fluorescent labels reported for investigation of intracellular uptake and distribution by CLSM comprise Nile red [13], Texas Red, and 6-coumarin [14]. Not only for fluorescence microscopy but also for transmission electron microscopy (TEM), the loading of markers proved to be useful. Osmium tetroxid as an electron dense marker and bovine serum albumin (BSA) as a model protein were entrapped in PLGA-nanoparticles to elucidate their uptake and intracellular distribution in human vascular smooth muscle cells [15]. 

Vandervoort, J., Ludwig, A. (2002). Biocompatible stabilizers in the preparation of PLGA nanoparticles a factorial design study. Int. J. Pharm., 238(1-2), 77-92. 

Qaddoumi et al. [65] studied the uptake of PLGA nanoparticles in rabbit conjunctival epithelial cell culture. The highest uptake by cultured conjunctival cells was achieved for the smallest particles (100 nm), compared to larger 800 nm and 10 pm particles. A study of the fate of the tiny 100-nm particles following 2 h of cultured cells exposure to a 0.5 mg/mL dose showed that 6% was internalized by conjunctival epithelial cells, 1.5% was surface-bound, whereas the remainder of the dose was found in the donor medium. In an in vivo rabbit eye study [66] on the uptake of poly(hexyl cyanoacrylate) nanoparticles, 6 h postinstillation into the conjunctival sac, it was found that the fraction that was internalized by conjunctival epithelial cells was only 1% of the dose reflecting in vivo precorneal elimination... 

Qaddoumi, M.G., et al. 2004. The characteristics and mechanisms of uptake of PLGA nanoparticles in rabbit conjunctival epithelial cell layers. Pharm Res 21 641. 

Dillen, K., J. Vandervoort, et al. (2004). Factorial design, physicochemical characterisation and activity of ciprofloxacin-PLGA nanoparticles. Int J Pharm 275(1-2) 171-87. 

Fonseca, C., S. Simoes, et al. (2002). Paclitaxel-loaded PLGA nanoparticles preparation, physicochemical characterization and in vitro anti-tumoral activity. J Control Release 83(2) 273-286. 

A most important factor needing to be considered when using surfactants is that they are non-bio degradable, non-digestible, and moreover, tend to induce allergic reactions in humans. Recently, Jeon et al. [24] proposed a surfactant-free method for the preparation of PLGA nanoparticles as an alternative. 

The surfactant-free PLGA nanoparticles were prepared by a dialysis method using various solvents and their physiochemical properties were investigated with regard to the used solvent. Release kinetics of NFX showed that higher drug contents tend to larger particle sizes and slower release [25]. 

Bilati, U., Pasquarello, C., Corthals, C. L., Hochstrasser, D. F., Allemann, E., and Doelker, E. (2005), Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for quantitation and molecular stability assessment of insulin entrapped within PLGA nanoparticles, J. Pharm. Sci., 94,1-7. 

Nanoparticles that are internalized into cells by these mechanisms first enter the primary endosomes of the cell and are then transported into sorting endosomes. While some nanoparticles in the sorting endosomes are transported out of the cell by recycling endosomes, the remaining nanoparticles are transported into secondary endosomes that fuse with the lysosomes [107].The surface charge of PLGA nanoparticles is reversed in the acidic lysosome, resulting in their escape into the cytoplasm... 

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