The intensity of internalization and cytotoxicity of superparamagnetic iron oxide nanoparticles with different surface modifications in human tumor and diploid lung cells.

The human lung adenocarcinoma epithelial (A549) cells and the human embryo lung (HEL 12469) cells were used to investigate the uptake and cytotoxicity of magnetite nanoparticles (MNPs) with different chemically modified surfaces. MNPs uptake was an energy-dependent process substantially affected by the serum concentration in the culture medium. Internalized MNPs localized in vesicle-bound aggregates were observed in the cytoplasm, none in the nucleus or in mitochondria. All MNPs induced a dose- and time-dependent increase in cytotoxicity in both human lung cell lines. The cytotoxicity of MNPs increased proportionally with the particle size. Since the cytotoxicity of MNPs was nearly identical when the doses were equalized based on particle surface area, we suppose that the particle surface area rather than the surface modifications per se underlay the cytotoxicity of MNPs. In general, higher internalized amount of MNPs was found in HEL 12469 cells compared with A549 cells. Accordingly, the viability of the human embryo lung cells was reduced more substantially than that of the adenocarcinoma lung cells. The weak MNPs uptake into A549 cells might be of biomedical relevance in cases where MNPs should be used as nanocarriers for targeted drug delivery in tumor tissue derived from alveolar epithelial cells.

[Retinal tamponade with silicone oil - long term results]. / Tamponáda sietnice silikónovým olejom - dlhodobé výsledky.

AIM: The aim of this study is to evaluate the frequency and efficacy of silicone oil (SO) retinal tamponade in various retinal diseases. The incidence of silicone oil tamponade according to individual indications, incidence of complications and duration of tamponade were evaluated in the study. MATERIAL AND METHODS: A retrospective study included 510 eyes that were operated on pars plana vitrectomy (PPV) from January 2010 to December 2012. In our group we evaluated 241 men and 189 women, age 4-84 years, mean 62 years . Follow-up period was 12 to 48 months, an average of 27.5 months . We evaluated 253 eyes with diabetic retinopathy, 201 eyes with regmatogenous retinal detachment, 34 eyes with endophthalmitis and 22 eyes after the injury. RESULTS: In 253 diabetic retinopathy eyes (DR) silicone oil tamponade was indicated in 56 eyes (22.1 %). Silicone oil removal was done on 22 eyes (39.3 %), the average length of SO tamponade was 9.7 months. After SO removal BCVA (best corrected visual acuity) 0,1 and worse had 12 eyes (54,6 %), 0,2 - 0,4 had 5 eyes (22,7 %) and 0,5 or better had 5 eyes (22,7 %). Permanent SO tamponade was left in 34 diabetic retinopathy eyes (60.7 %). Secondary glaucoma (SG) was present in 40 eyes (71.5 %). In 201 retinal detachment (RD) eyes silicone oil tamponade was used in 76 eyes (37.8 %). Secondary glaucoma was present in 31 eyes (40.8 %). Silicone oil was successfully removed in 40 eyes (52.6 %), the average length of tamponade was 9.2 months. In this group BCVA 0,1 and worse had 22 eyes (55,0 %), 0,2 - 0,4 had 15 eyes (37,5 %) and 0,5 or better had 3 eyes (7,5 %). 36 eyes (47,4 %) RD eyes had permanent silicone oil tamponade. In a group of 34 eyes with endophthalmitis SO tamponade was used in 16 eyes (47 %). Secondary glaucoma was present in 3 eyes (18.8 %). Silicone oil removal we did in 11 eyes (68.8 %), the average length of SO tamponade was 5.5 months. After SO removal BCVA 0,1 and worse had 3 eyes (27,2 %), 0,2 - 0,4 had 4 eyes (36,4 %) and 0,5 or better had 4 eyes (36,4 %). 5 eyes (31.2 %) with endophthalmitis had permanent SO tamponade. Out of 22 eyes with eye injuries SO tamponade was used in 14 eyes (63.6 %). 5 eyes (35.7 %) had secondary glaucoma. In 9 eyes (64.3 %) silicone oil was removed, the average length of tamponade was 9.1 months. In this group BCVA 0,1 and worse had 6 eyes (66,7 %), 0,2-0,4 had 1 eye (11,1 %) and 0,5 or better had 2 eyes (22,2 %). Permanent silicone oil tamponade had 5 eyes (35,7 %). In group of 56 phakic eyes (100 %) with silicone oil tamponade we followed cataract progression. 26 eyes (40 %) had cataract surgery in 6 month follow up, 47 eyes (72.3 %) in 1 year follow up and 57 eyes (87.7 %) had cataract surgery in 3 years follow up. CONCLUSION: Silicone oil tamponade is the method of choice for long-term and stable retinal tamponade, which is important for good functional outcomes of the surgical intervention. The silicone oil tamponade of the retina is nowadays irreplaceable, despite of its potential risks and complications.