Sex affects the response of Wistar rats to polyvinyl pyrrolidone (PVP)-coated silver nanoparticles in an oral 28 days repeated dose toxicity study

Novel PLGA-based nanoformulation decreases doxorubicin-induced cardiotoxicity

Nanotechnology has the potential to provide formulations of antitumor agents with increased selectivity towards cancer tissue thereby decreasing systemic toxicity. This in vivo study evaluated the potential of novel nanoformulation based on poly(lactic-co-glycolic acid) (PLGA) to reduce the cardiotoxic potential of doxorubicin (DOX). In vivo toxicity of PLGADOX was compared with clinically approved non-PEGylated, liposomal nanoformulation of DOX (LipoDOX) and conventional DOX form (ConvDOX). The study was performed using Wistar Han rats of both sexes that were treated intravenously for 28 days with 5 doses of tested substances at intervals of 5 days. Histopathological analyses of heart tissues showed the presence of myofiber necrosis, degeneration processes, myocytolysis, and hemorrhage after treatment with ConvDOX, whereas only myofiber degeneration and hemorrhage were present after the treatment with nanoformulations. All DOX formulations caused an increase in the troponin T with the greatest increase caused by convDOX. qPCR analyses revealed an increase in the expression of inflammatory markers IL-6 and IL-8 after ConvDOX and an increase in IL-8 expression after lipoDOX treatments. The mass spectra imaging (MSI) of heart tissue indicates numerous metabolic and lipidomic changes caused by ConvDOX, while less severe cardiac damages were found after treatment with nanoformulations. In the case of LipoDOX, autophagy and apoptosis were still detectable, whereas PLGADOX induced only detectable mitochondrial toxicity. Cardiotoxic effects were frequently sex-related with the greater risk of cardiotoxicity observed mostly in male rats.

Particle surface functionalization affects mechanism of endocytosis and adverse effects of silver nanoparticles in mammalian kidney cells

Silver nanoparticles (AgNPs) show a plethora of possible applications due to their antimicrobial properties. Different coatings of AgNPs are used in order to increase stability, availability, and activity. However, the question about the toxicity after prolonged exposure still remains. Here, we show that different surface coatings affect in vitro toxicity and internalization of AgNPs in porcine kidney (PK15) cells. AgNPs coated with cetyltrimethylammonium bromide (CTAB), poly(vinylpyrrolidone) (PVP), sodium bis(2-ethylhexyl)-sulfosuccinate (AOT), poly-L-lysine (PLL), and bovine serum albumin (BSA) were toxic at the concentration of 10 mg Ag/L and higher. The toxicity increased in the following manner: PVP-AgNPs < CTAB-AgNPs < PLL-AgNPs < AOT-AgNPs < BSA-AgNPs. All types of AgNPs were internalized by the PK15 cells in a dose-dependent manner with greater internalization of AgNPs bearing positive surface charge. Transmission electron microscopy (TEM) experiments showed that AgNPs were located in the lysosomal compartments, while the co-treatment with known inhibitors of endocytosis pathways suggested macropinocytosis as the preferred internalization pathway. When inside the cell, all types of AgNPs induced the formation of reactive oxygen species while decreasing the concentration of the cell's endogenous antioxidant glutathione. The comet assay indicated possible genotoxicity of tested AgNPs starting at the concentration of 2 mg Ag/L or higher, depending on the surface functionalization. This study demonstrates the toxicity of AgNPs pointing to the importance of biosafety evaluation when developing novel AgNPs-containing materials.

Amphiphilic Poly-N-vinylpyrrolidone Nanoparticles as Carriers for Nonsteroidal, Anti-Inflammatory Drugs: Pharmacokinetic, Anti-Inflammatory, and Ulcerogenic Activity Study

Nanoparticles are increasingly utilized as drug delivery agents. Previously, we have developed a drug delivery system based on amphiphilic derivatives of poly-N-vinylpyrrolidone (PVP-OD4000) with excellent biocompatibility. In the current study, we assessed the pharmacokinetics, anti-inflammatory profile, and ulcerogenic potential of indomethacin (IMC)-loaded PVP-OD4000 nanoparticles compared to the free drug. Wistar male rats were utilized for a pharmacokinetics study and an anti-inflammatory study. Loaded IMC exhibited a slower elimination rate (p < 0.05) and a higher blood plasma concentration at 8 and 24 h after intraperitoneal injection compared with free IMC. In addition, decreased uptake of loaded IMC in the liver and kidney compared to free IMC (p < 0.05) was detected. Furthermore, PVP-OD4000 nanoparticles loaded with IMC showed an enhanced anti-inflammatory effect compared to free IMC (p < 0.05) in carrageenan-induced and complete Freund’s adjuvant-induced−(CFA) sub-chronic and chronic paw edema treatment (p < 0.01; p < 0.01). Notably, upon oral administration of loaded IMC, animals had a significantly lower ulcer score and Paul’s Index (3.9) compared to the free drug (p < 0.05). The obtained results suggest that IMC loaded to PVP nanoparticles exhibit superior anti-inflammatory activity in vivo and a safe gastrointestinal profile and pose a therapeutic alternative for the currently available NSAIDs’ administration.