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Lacasse, François-Xavier; Filion, Mario; Phillips, Nigel C.; Escher, Emanuel; McMullen, J.N.; Hildgen, Patrice

doi:10.1023/a:1011935222652

Cited by 74 publications

(24 citation statements)

References 16 publications

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“…Despite the variable charge and size of proteins present in full serum, IgG is an established model to check for resistance to serum protein adsorption. 39,45 In particular, class G immunoglobulins are the principal "heat-stable" opsonic proteins. [17][18][19] In addition, opsonization with complement was found to be insufficient for phagocytosis unless the studied particles also contained IgG.…”

Section: A Characterization Of Coated Microspheresmentioning

confidence: 99%

“…35,37 PEGylation of nano-and microparticles does not only reduce plasma protein adsorption but also inhibits the nonspecific internalization by phagocytes. 22,[43][44][45] Recent publications report the modification of microparticles with PLLg-PEG and ligand modified PLL-g-PEG polymers that showed excellent protein resistance. 39,46 In addition, it was shown for DC and M⌽ cell cultures that phagocytosis of such particles could be abolished with PLL-g-PEG coatings.…”

Section: Introductionmentioning

confidence: 99%

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Phagocytosis of poly(L-lysine)-graft-poly (ethylene glycol) coated microspheres by antigen presenting cells: Impact of grafting ratio and poly (ethylene glycol) chain length on cellular recognition

et al. 2006

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Microparticulate carrier systems have significant potential for antigen delivery. The authors studied how microspheres coated with the polycationic copolymer poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) can be protected against unspecific phagocytosis by antigen presenting cells, a prerequisite for selective targeting of phagocytic receptors. For this aim the authors explored the influence of PLL-g-PEG architecture on recognition of coated microspheres by antigen presenting cells with regard to both grafting ratio and molecular weight of the grafted PEG chains. Carboxylated polystyrene microspheres (5 μm) were coated with a small library of PLL-g-PEG polymers with PLL backbones of 20 kDa, grafting ratios from 2 to 20, and PEG side chains of 1–5 kDa. The coated microspheres were characterized by their ζ-potential and resistance to IgG adsorption. Phagocytosis of these microspheres by human monocyte derived dendritic cells (DCs) and macrophages (MΦ) was quantified by phase contrast microscopy and by analysis of the cells’ side scattering in a flow cytometer. Generally, increasing grafting ratios impaired the protein resistance of coated microspheres, leading to higher phagocytosis rates. For DC, long PEG chains of 5 kDa decreased the phagocytosis of coated microspheres even in the case of considerable IgG adsorption. In addition, preferential adsorption of dysopsonins is discussed as another factor for decreased phagocytosis rates. For comparison, the authors studied the cellular adhesion of DC and Mζ to PLL-g-PEG coated microscopy slides. Remarkably, DC and Mζ were found to adhere to relatively protein-resistant PLL-g-PEG adlayers, whereas phagocytosis of microspheres coated with the same copolymers was inefficient. Overall, PLL(20)-[3.5]-PEG(2) was identified as the optimal copolymer to ensure resistance to both phagocytosis and cell adhesion. Finally, the authors studied coatings made from binary mixtures of PLL-g-PEG type copolymers that led to microspheres with combined properties. This enables future studies on cell targeting with ligand modified copolymers.

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Section: A Characterization Of Coated Microspheresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phagocytosis of poly(L-lysine)-graft-poly (ethylene glycol) coated microspheres by antigen presenting cells: Impact of grafting ratio and poly (ethylene glycol) chain length on cellular recognition

et al. 2006

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“…In comparison to implants, microspheres (or nanospheres) do not require surgical insertion or removal (22), can carry multiple drugs (20,23), and are phagocytosed by antigen presenting cells (APCs) (24). Inhalation and intranasal delivery can be realized with particles that are small enough to pass through the finely porous networks of the nasal, tracheal, and pulmonary filtration systems (25,26).…”

Section: Introductionmentioning

confidence: 99%

Polymer Chemistry Influences Monocytic Uptake of Polyanhydride Nanospheres

et al. 2008

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“…Polymer micropheres have been extensively studied as carriers of bioactive compounds, in particular as carriers of proteins and oligonucleotides [12][13][14][15][16][17][18][19][20][21][22]. In many instances the particles bearing antibodies (or antigens) were used for diagnostic purposes, most often for simple aggregation tests [23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Covalent immobilization of urease on polypyrrole microspheres for application as a urea biosensor

et al. 2002

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Urease has been covalently immobilized on polypyrrole microspheres chemically linked to conducting polypyrrole-polyvinyl sulfonate (PPY-PVS) films. These films were electrochemically prepared during 5 -7 min at a constant current of 2 mA using indium -tin oxide (ITO) glass plates as the working electrode, and a standard calomel electrode as the reference electrode. Urease covalently linked to polypyrrole microspheres (by reaction of protein amino groups with aldehyde groups on the surface of the microspheres) was entrapped/adsorbed onto electrochemically prepared conducting PPY-PVS films deposited on ITO. Potentiometric measurements undertaken on these conducting polymer electrodes using an ammonium ion analyzer reveal that they can be used for estimating the urea concentration in solutions from 5·10 -3 mol/l to 6·10 -2 mol/l.

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Abstract: These results demonstrate that spray-dried PEG-containing microspheres can be manufactured and that an appropriate concentration of this excipient in microspheres results in decreased phagocytosis.

Cited by 74 publications

References 16 publications

Phagocytosis of poly(L-lysine)-graft-poly (ethylene glycol) coated microspheres by antigen presenting cells: Impact of grafting ratio and poly (ethylene glycol) chain length on cellular recognition

Phagocytosis of poly(L-lysine)-graft-poly (ethylene glycol) coated microspheres by antigen presenting cells: Impact of grafting ratio and poly (ethylene glycol) chain length on cellular recognition

Polymer Chemistry Influences Monocytic Uptake of Polyanhydride Nanospheres

Covalent immobilization of urease on polypyrrole microspheres for application as a urea biosensor

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