Endothelial protein C–targeting liposomes show enhanced uptake and improved therapeutic efficacy in human retinal endothelial cells

TY - JOUR

T1 - Endothelial protein C–targeting liposomes show enhanced uptake and improved therapeutic efficacy in human retinal endothelial cells

AU - Arta, Anthoula

AU - Eriksen, Anne Z.

AU - Melander, Fredrik

AU - Kempen, Paul

AU - Larsen, Michael

AU - Andresen, Thomas L.

AU - Urquhart, Andrew J.

PY - 2018

Y1 - 2018

N2 - PURPOSE. To determine whether human retinal endothelial cells (HRECs) express the endothelial cell protein C receptor (EPCR) and to realize its potential as a targeting moiety by developing novel single and dual corticosteroid–loaded functionalized liposomes that exhibit both enhanced uptake by HRECs and superior biologic activity compared to nontargeting liposomes and free drug. METHODS. EPCR expression of HRECs was investigated through flow cytometry and Western blot assays. EPCR-targeting liposomes were developed by functionalizing EPCR-specific antibodies onto liposomes, and the uptake of liposomes was assessed with flow cytometry and confocal laser scanning microscopy. The therapeutic potential of EPCR-targeting liposomes was determined by loading them with prednisolone either through bilayer insertion and/or by remote loading into the aqueous core. The carrier efficacy was assessed in two ways through its ability to inhibit secretion of interleukins in cells stimulated with high glucose and angiogenesis in vitro by using an endothelial cell tube formation assay. RESULTS. HRECs express EPCR at a similar level in both human aortic and umbilic vein endothelial cells. The EPCR-targeting liposomes displayed at least a 3-fold higher uptake compared to nontargeting liposomes. This enhanced uptake was translated into superior antiinflammatory efficacy, as the corticosteroid-loaded EPCR-targeting liposomes significantly reduced the secretion of IL-8 and IL-6 and inhibited the development of cell tube formations in contrast to nontargeting liposomes. CONCLUSIONS. We show that HRECs express EPCR and this receptor could be a promising nanomedicine target in ocular diseases where the endothelial barrier of the retina is compromised.

AB - PURPOSE. To determine whether human retinal endothelial cells (HRECs) express the endothelial cell protein C receptor (EPCR) and to realize its potential as a targeting moiety by developing novel single and dual corticosteroid–loaded functionalized liposomes that exhibit both enhanced uptake by HRECs and superior biologic activity compared to nontargeting liposomes and free drug. METHODS. EPCR expression of HRECs was investigated through flow cytometry and Western blot assays. EPCR-targeting liposomes were developed by functionalizing EPCR-specific antibodies onto liposomes, and the uptake of liposomes was assessed with flow cytometry and confocal laser scanning microscopy. The therapeutic potential of EPCR-targeting liposomes was determined by loading them with prednisolone either through bilayer insertion and/or by remote loading into the aqueous core. The carrier efficacy was assessed in two ways through its ability to inhibit secretion of interleukins in cells stimulated with high glucose and angiogenesis in vitro by using an endothelial cell tube formation assay. RESULTS. HRECs express EPCR at a similar level in both human aortic and umbilic vein endothelial cells. The EPCR-targeting liposomes displayed at least a 3-fold higher uptake compared to nontargeting liposomes. This enhanced uptake was translated into superior antiinflammatory efficacy, as the corticosteroid-loaded EPCR-targeting liposomes significantly reduced the secretion of IL-8 and IL-6 and inhibited the development of cell tube formations in contrast to nontargeting liposomes. CONCLUSIONS. We show that HRECs express EPCR and this receptor could be a promising nanomedicine target in ocular diseases where the endothelial barrier of the retina is compromised.

KW - Corticosteroids

KW - Endothelial cells

KW - EPCR

KW - Liposomes

KW - Retina

U2 - 10.1167/iovs.18-23800

DO - 10.1167/iovs.18-23800

M3 - Journal article

C2 - 29677376

AN - SCOPUS:85045850683

SN - 0146-0404

VL - 59

SP - 2119

EP - 2132

JO - Investigative Ophthalmology & Visual Science

JF - Investigative Ophthalmology & Visual Science

IS - 5

ER -