title: Disregarded Effect of Biological Fluids in siRNA Delivery: Human Ascites Fluid Severely Restricts Cellular Uptake of Nanoparticles.
abstract: Small interfering RNA (siRNA) offers a great potential for the treatment of various diseases and disorders. Nevertheless, inefficient in vivo siRNA delivery hampers its translation into the clinic. While numerous successful in vitro siRNA delivery stories exist in reduced-protein conditions, most studies so far overlook the influence of the biological fluids present in the in vivo environment. In this study, we compared the transfection efficiency of liposomal formulations in Opti-MEM (low protein content, routinely used for in vitro screening) and human undiluted ascites fluid obtained from a peritoneal carcinomatosis patient (high protein content, representing the in vivo situation). In Opti-MEM, all formulations are biologically active. In ascites fluid, however, the biological activity of all lipoplexes is lost except for lipofectamine RNAiMAX. The drop in transfection efficiency was not correlated to the physicochemical properties of the nanoparticles, such as premature siRNA release and aggregation of the nanoparticles in the human ascites fluid. Remarkably, however, all of the formulations except for lipofectamine RNAiMAX lost their ability to be taken up by cells following incubation in ascites fluid. To take into account the possible effects of a protein corona formed around the nanoparticles, we recommend always using undiluted biological fluids for the in vitro optimization of nanosized siRNA formulations next to conventional screening in low-protein content media. This should tighten the gap between in vitro and in vivo performance of nanoparticles and ensure the optimal selection of nanoparticles for further in vivo studies.
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmacy, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium.
authors.forename: George R
authors.initials: GR
authors.lastname: Dakwar
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmacy, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium.|Centre for Nano- and Biophotonics, Ghent University , Ottergemsesteenweg 460 , 9000 Ghent, Belgium.
authors.forename: Kevin
authors.initials: K
authors.lastname: Braeckmans
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmacy, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium.
authors.forename: Joseph
authors.initials: J
authors.lastname: Demeester
authors.affiliation: Department of Surgery, Ghent University Hospital , De Pintelaan 185, 9000 Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Ceelen
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmacy, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium.
authors.forename: Stefaan C
authors.initials: SC
authors.lastname: De Smedt
authors.affiliation: Laboratory for General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmacy, Ghent University , Ottergemsesteenweg 460, 9000 Ghent, Belgium.
authors.forename: Katrien
authors.initials: K
authors.lastname: Remaut
mesh_terms: D001201:Ascites / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D009362:Neoplasm Metastasis; D010051:Ovarian Neoplasms / Q000378:metabolism; D010316:Particle Size; D011506:Proteins / Q000737:chemistry; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D014162:Transfection
chemical_list: D008055:Lipids; C086724:Lipofectamine; D008081:Liposomes; D011506:Proteins; D034741:RNA, Small Interfering
keywords: ascites; lipofectamine; liposomes; peritoneal metastasis; protein corona; siRNA delivery