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Poly(2-dimethylamino-ethylmethacrylate) (PDMAEMA), a cationic polymer, has been widely reported as a nonviral carrier. Despite the fact that the cytotoxicity of this polymer has been extensively studied, there is a lack of information about its blood compatibility. Hence, this work evaluates the hemocompatibility of free-form PDMAEMA homopolymers differing in molecular weight (Mw) with or without a poly(ethylene glycol) (PEG) sequence in the form of a palm tree-like structure. Poly(ethylenimine) (PEI) was used as a reference in order to compare its hemoreactivity. Hemagglutination, hemolysis, platelet number, blood coagulation, and the complement systems were assessed in normal human whole blood according to the ISO 10993-4. Results showed that Mw, concentration, and incubation time strongly affected the hemocompatibility of the polymers evaluated. Our in vitro observations highlight that PDMAEMA homopolymers interacted strongly with the surface of the red blood cells but not with the inner structure of the membrane, while PEI behaved in the opposite way. No clear correlation has been evidenced between PDMAEMA-induced hemagglutination, PEI-induced hemagglutination, and hemolysis. Interestingly, if these polyelectrolytes strongly affect the platelets and blood coagulation cascades in a dose dependent way, none of them significantly affects the complement system. Our work reveals new knowledge on the toxicology of 2 families of polycations largely explored for gene delivery and on their mechanisms of cellular and humoral interactions.

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Size tunable aqueous Ag2S quantum dots emitting in the near-infrared region were synthesized through decomposition of meso-2,3-dimercaptosuccinic acid (DMSA) in water. The resulting NIR QDs are highly cyto- and hemocompatible, have quantum yields as high as 6.5% and are effective optical imaging agents based on in vitro evaluation.

In this work, there is a detailed description of the whole process of biocompatible CIS/ZnS QDs production. Special attention was paid to the stability of QDs against photooxidation. It was shown that Cu/In ratio greatly affected not only nanocrystals PLQYs but photostability as well. CIS/ZnS QDs with Cu/In = 1:4 ratio showed high photostability under UV illumination both in toluene and aqueous solutions. Meanwhile, photoluminescence of CIS/ZnS QDs with Cu/In = 1:1 ratio was completely quenched after several hours under UV illumination, though their initial QY was as high as 40% with peak maximum at 740 nm. QDs were transferred to water by polymer encapsulation and were subsequently modified with polyethers Jeffamines, cheap analogues of PEG-derivatives. Three types of hydrophilic QDs differing in size, PEG content, and surface charge were obtained for further investigation and comparison of their cytotoxicity and hemocompatibility. It was shown that both leucocytes size distribution and coagulation activation change after introduction of polyethers into QDs polymeric shell, while red blood cells and platelets size distribution as well as hemolysis rate did not show any different results among different QDs and the polymer itself. All three types of QDs showed only slight cytotoxicity. Confocal microscopy proves penetration of hydrophilic CIS/ZnS QDs inside cells, so the low QDs cytotoxocity cannot be explained by low cellular uptake of the QDs and indicated low QDs toxicity in general.

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