Accumulation Of Nanoparticles Research Articles

Behavioural changes, DNA damage and histological alterations in Labeo rohita fingerlings in response to organic-coated silver nanoparticles.

Silver nanoparticles (AgNPs) have garnered significant global attention from researchers due to their unique physicochemical properties and wide-ranging applications in industry and medicine. However, their release into aquatic ecosystems has raised concerns regarding potential ecotoxicological consequences. The present study investigated the effects of polyvinyl pyrrolidone-coated silver nanoparticles on Labeo rohita fingerlings, focusing on behavioural reactions, genotoxic effects, histological changes and bioaccumulation. L. rohita fingerlings were exposed to polyvinyl pyrrolidone-coated silver nanoparticles with sizes ranging from 18 to 29nm for 7days at concentrations of 100, 200, 400 and 800 ug/l. The nanoparticle zeta potential was found to be extremely negative, measuring - 55.5mV for 18nm and - 31.4mV for 29nm. Behavioural abnormalities, including respiratory distress, reduced responsiveness and erratic swimming, were observed in exposed groups compared to controls, with severity increasing with higher nanoparticle concentrations. Genotoxicity assessment revealed significantly higher DNA damage in kidney cells compared to gill cells. Histological examination of gill tissues showed clogging in primary and secondary lamellae, along with distorted anatomy, necrosis and vacuolar atrophy in peripheral tubules of the kidneys. The kidneys exhibited greater nanoparticle accumulation than the gills with prolonged exposure. Moreover, 18nm AgNPs induced more pronounced DNA damage and histological alterations in the kidney and gill tissues compared to 29nm nanoparticles. This study elucidates the critical role of monitoring AgNPs in aquatic systems, providing essential data on their behaviour and environmental impacts. The findings highlight the need for improved detection techniques and effective management of AgNP contamination. Future research should focus on developing more sensitive analytical methods, understanding long-term ecological effects and exploring innovative remediation strategies.

PH-Triggered Hydrogel Nanoparticles for Efficient Anticancer Drug Delivery and Bioimaging Applications.

In this work, we developed multifunctional hydrogel nanoparticles (NPs) that can encapsulate anticancer drugs and imaging contrast agents as well. Mitomycin C (MMC) and rhodamine B (RB) were selected as models for anticancer drugs and imaging contrasting agents, respectively. Both MMC and RB were linked to the succinated polyvinyl alcohol polymer (PVA-SA). The selected labeled hydrogel NPs ((0.5% RB)-PVA-SA NPs and (1.5% RB)-PVA-SA NPs) improved the RB quantum yield from 29.8% to a minimum of 42.7%. Moreover, they showed higher emission stability compared to free RB when they were repeatedly excited at 554 nm for 2 h. Furthermore, the dye polymeric interactions significantly increased the RB fluorescence lifetime by approximately twofold. All these optical properties pave the way for our labeled hydrogel NPs to be used in imaging-guided therapy. For the labeled MMC-loaded NPs, the MMC-binding efficiency was found to be exceedingly high in all synthesized samples: a minimum of 92% was achieved. In addition, the obtained pH-dependent drug release profiles as well as the cytotoxicity evaluation demonstrated the high potential of releasing MMC under acidic cancerous conditions. Moreover, the in vitro cellular uptake experiment confirmed the accumulation of MMC NPs throughout the cytoplasm.

Basic magnesium carbonate template assisted co-carbonization of potassium citrate toward hierarchical porous carbon for supercapacitors

Hierarchical porous carbon (HPC) as the ideal host material for supercapacitors has received extensive attention. However, traditional methods of fabricating HPC often rely on organic macromolecules and complex procedures. Herein, a simple and straightforward approach is developed for the synthesis of HPC through basic magnesium carbonate template assisted co-carbonization of potassium citrate. Potassium citrate can be effectively embedded and encapsulated with basic magnesium carbonate due to the large bulk density difference between them. In the pyrolysis process, the carbon-containing small molecules produced by the pyrolysis of potassium citrate are deposited on the surface of MgO surface obtained from the decomposition of basic magnesium carbonate, and the etching reaction of potassium salt, CO2 and primary carbon structure occurs. The competitive rate of carbon deposition reaction and etching reaction can be easily controlled by changing the ratio of potassium citrate and basic magnesium carbonate. The obtained carbon materials show the morphology changes of nanoparticle accumulations, discontinuous carbon frames and carbon planar blocks, and the hierarchical porous structure of carbon materials can also be controlled in a wide range. HPC-2 exhibits the morphology of nanoparticle accumulation and generates abundant meso-macropores, which accelerates the rapid transport of electrolytic ions. The micropores inside the nanoparticles provide an accessible room for ionic adsorption. Benefited from this unique microstructural framework, HPC-2 shares a high capacitance of 305.5Fg-1 at 0.5Ag-1 and 173.1Fg-1 at 50Ag-1. Furthermore, the assembled symmetric supercapacitors exhibit a high energy density and power density than YP-50F throughout the test range. The versatility of this synthetic strategy provides an insight into directional tailoring fine pore structure and micro-morphology of carbon materials based on small molecule deposition.

Reformulating lipid nanoparticles for organ-targeted mRNA accumulation and translation

Fully targeted mRNA therapeutics necessitate simultaneous organ-specific accumulation and effective translation. Despite some progress, delivery systems are still unable to fully achieve this. Here, we reformulate lipid nanoparticles (LNPs) through adjustments in lipid material structures and compositions to systematically achieve the pulmonary and hepatic (respectively) targeted mRNA distribution and expression. A combinatorial library of degradable-core based ionizable cationic lipids is designed, following by optimisation of LNP compositions. Contrary to current LNP paradigms, our findings demonstrate that cholesterol and phospholipid are dispensable for LNP functionality. Specifically, cholesterol-removal addresses the persistent challenge of preventing nanoparticle accumulation in hepatic tissues. By modulating and simplifying intrinsic LNP components, concurrent mRNA accumulation and translation is achieved in the lung and liver, respectively. This targeting strategy is applicable to existing LNP systems with potential to expand the progress of precise mRNA therapy for diverse diseases.

Reformulating lipid nanoparticles for organ-targeted mRNA accumulation and translation

Fully targeted mRNA therapeutics necessitate simultaneous organ-specific accumulation and effective translation. Despite some progress, delivery systems are still unable to fully achieve this. Here, we reformulate lipid nanoparticles (LNPs) through adjustments in lipid material structures and compositions to systematically achieve the pulmonary and hepatic (respectively) targeted mRNA distribution and expression. A combinatorial library of degradable-core based ionizable cationic lipids is designed, following by optimisation of LNP compositions. Contrary to current LNP paradigms, our findings demonstrate that cholesterol and phospholipid are dispensable for LNP functionality. Specifically, cholesterol-removal addresses the persistent challenge of preventing nanoparticle accumulation in hepatic tissues. By modulating and simplifying intrinsic LNP components, concurrent mRNA accumulation and translation is achieved in the lung and liver, respectively. This targeting strategy is applicable to existing LNP systems with potential to expand the progress of precise mRNA therapy for diverse diseases.

Noninvasive Photothermal Therapy of Nasopharyngeal Cancer Guided by High Efficiency Optical-Absorption Nanomaterial Enhanced by NIR-II Photoacoustic Imaging.

Photothermal therapy (PTT) guided by photoacoustic imaging (PAI) using nanoplatforms has emerged as a promising strategy for cancer treatment due to its efficiency and accuracy. This study aimed to develop and synthesize novel second near-infrared region (NIR-II) absorption-conjugated polymer acceptor acrylate-substituted thiadiazoloquinoxaline-diketopyrrolopyrrole polymers (PATQ-DPP) designed specifically as photothermal and imaging contrast agents for nasopharyngeal carcinoma (NPC). The PATQ-DPP nanoparticles were synthesized and characterized for their optical properties, including low optical band gaps. Their potential as PTT agents and imaging contrast agents for NPC was evaluated both in vitro and in vivo. The accumulation of nanoparticles at tumor sites was assessed post-injection, and the efficacy of PTT under near-infrared laser irradiation was investigated in a mouse model of NPC. Experimental results indicated that the PATQ-DPP nanoparticles exhibited significant photoacoustic contrast enhancement and favorable PTT performance. Safety and non-toxicity evaluations confirmed the biocompatibility of these nanoparticles. In vivo studies showed that PATQ-DPP nanoparticles effectively accumulated at NPC tumor sites and demonstrated excellent tumor growth inhibition upon exposure to near-infrared laser irradiation. Notably, complete elimination of nasopharyngeal tumors was observed within 18 days following PTT. The findings suggest that PATQ-DPP nanoparticles are a promising theranostic agent for NIR-II PAI and PTT of tumors. This innovative approach utilizing PATQ-DPP nanoparticles provides a powerful tool for the early diagnosis and precise treatment of NPC, offering a new avenue in the management of this challenging malignancy.

Raman microscopy allows to follow internalization, subcellular accumulation and fate of iron oxide nanoparticles in cells

An important issue in the context of both potenial toxicity of iron oxide nanoparticles (IONP) and their medical applications is tracking of the internalization process of these nanomaterials into living cells, as well as their localization and fate within cells. The typical methods used for this purpose are transmission electron microscopy, confocal fluorescence microscopy as well as light-scattering techniques including dark-field microscopy and flow cytometry. All the techniques mentioned have their advantages and disadvantages. Among the problems it is necessary to mention complicated sample preparation, difficult interpretation of experimental data requiring qualified and experienced personnel, different behavior of fluorescently labeled IONP comparing to those label-free or finally the lack of possibility of chemical composition characteristics of nanomaterials.The purpose of the present investigation was the assessment of the usefulness of Raman microscopy for the tracking the internalization of IONP into cells, as well as the optimization of this process. Moreover, the study focused on identification of the potential differences in the cellular fate of superparamagnetic nanoparticles having magnetite and maghemite core.The Raman spectra of U87MG cells which internalized IONP presented additional bands which position depended on the used laser wavelength. They occurred at the wavenumber range 1700–2400 cm−1 for laser 488 nm and below the wavenumber of 800 cm−1 in case of laser 532 nm. The intensity of the mentioned Raman bands was higher for the green laser (532 nm) and their position, was independent and not characteristic on the primary core material of IONP (magnetite, maghemite).The obtained results showed that Raman microscopy is an excellent, non-destructive and objective technique that allows monitoring the process of internalization of IONP into cells and visualizing such nanoparticles and/or their metabolism products within them cells at low exposure levels. What is more, the process of tracking IONP using the technique may be further improved by using appropriate wavelength and power of the laser source.

Basic magnesium carbonate template assisted co-carbonization of potassium citrate toward hierarchical porous carbon for supercapacitors

Hierarchical porous carbon (HPC) as the ideal host material for supercapacitors has received extensive attention. However, traditional methods of fabricating HPC often rely on organic macromolecules and complex procedures. Herein, a simple and straightforward approach is developed for the synthesis of HPC through basic magnesium carbonate template assisted co-carbonization of potassium citrate. Potassium citrate can be effectively embedded and encapsulated with basic magnesium carbonate due to the large bulk density difference between them. In the pyrolysis process, the carbon-containing small molecules produced by the pyrolysis of potassium citrate are deposited on the surface of MgO surface obtained from the decomposition of basic magnesium carbonate, and the etching reaction of potassium salt, CO2 and primary carbon structure occurs. The competitive rate of carbon deposition reaction and etching reaction can be easily controlled by changing the ratio of potassium citrate and basic magnesium carbonate. The obtained carbon materials show the morphology changes of nanoparticle accumulations, discontinuous carbon frames and carbon planar blocks, and the hierarchical porous structure of carbon materials can also be controlled in a wide range. HPC-2 exhibits the morphology of nanoparticle accumulation and generates abundant meso-macropores, which accelerates the rapid transport of electrolytic ions. The micropores inside the nanoparticles provide an accessible room for ionic adsorption. Benefited from this unique microstructural framework, HPC-2 shares a high capacitance of 305.5Fg-1 at 0.5Ag-1 and 173.1Fg-1 at 50Ag-1. Furthermore, the assembled symmetric supercapacitors exhibit a high energy density and power density than YP-50F throughout the test range. The versatility of this synthetic strategy provides an insight into directional tailoring fine pore structure and micro-morphology of carbon materials based on small molecule deposition.

Biocompatibility of nano/micro-sized pyrophyllite particles by pulmo, liver, kidney and gastric mucosis cells

Pyrophyllite is the least studied natural clay in terms of its potential in biomedical applications, although there are many deposits of this aluminosilicate around the world. Genotoxicity study was performed in vitro for this mineral. Subsequently, Wister rats were exposed to the pyrophyllite micronized to below 100 µm. After the exposure period, histology of the lung, liver, kidney and gastric tissues were performed, followed by the stereological and hematological analysis. The physicochemical analyses revealed typical XRD characteristics of pyrophyllite clay with particle-size distribution ranging 50 nm–100 μm with stable mineral composition and unique buffering property to pH around 8. The results showed that there were no cytotoxic effects on to THP-1 cells, or genotoxicity of pyrophyllite measured by the Comet assay. In vivo studies are accompanied by the thorough physicochemical characterization of the micronized pyrophyllite. Histology of the lung tissue proved presence of an inflammatory reaction. On the other hand, gastric tissue has shown the selective accumulation of nanoparticles in enterocytes of the stomach only, as supported by ultrastructural analysis. Liver and kidney tissues have shown tolerability for pyrophyllite particles. The results give directions for further comprehensive studies of potential biomedical applications of the pyrophyllite.

The influence of various polymer coatings on the in vitro and in vivo properties of PLGA nanoparticles: Comprehensive study

Nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) with various surface chemistry are widely used in biomedicine for theranostic applications. The nature of the external coating of nanoparticles has a significant influence on their efficiency as drug carriers or visualization agents. However, information about the mechanisms of nanoparticle accumulation in tumors and the influence of their surface properties on biodistribution is scarce due to the lack of systematic evaluation. Here we investigate the effect of different polymer coatings of the surface on in vitro and in vivo properties of PLGA nanoparticles. Namely, cell binding efficiency, cytotoxicity, efficiency of fluorescent bioimaging, and tumor accumulation were tested. The highest binding efficiency in vitro and cytotoxicity were observed for positively charged polymers. Interestingly, in vivo fluorescent visualization of tumor-bearing mice and quantitative measurements of biodistribution of magnetite-loaded nanoparticles indicated different dependences of accumulation in tumors on the coating of PLGA nanoparticles. This means that nanoparticle surface properties can simultaneously enhance imaging efficiency and decrease quantitative accumulation in tumors. The obtained data demonstrate the complexity of the dependence of nanoparticles’ effectiveness for theranostic applications on surface features. We believe that this study will contribute to the rational design of nanoparticles for effective cancer diagnostics and therapy.

Ultrastructural investigation of iron oxide nanoparticles accumulation in the liver of common carp (Cyprinus carpio Linnaeus, 1758)

In recent years, the intensive production of nanoparticles with a wide application has led to their transfer to the environment, including the water ecosystem. The accumulation of nanoparticles in fish, causing various pathological changes in the host, raises certain concerns. In the current study, we investigated the penetration and bioaccumulation of Fe3O4 nanoparticles, in the liver of common carp (Cyprinus carpio Linnaeus, 1758). Common carp juveniles were exposed to Fe3O4 nanoparticles at concentrations of 10 and 100 mg. After 7 days, their livers were examined by light and transmission electron microscopes. Compared to normal fish's liver, after using a small concentration (10 mg) of nanoparticles, changes were observed in erythrocytes, hepatocytes, intracellular canaliculi, and bile ducts of the liver. At a high concentration (100 mg), the intensity of changes increased significantly. The liver's capsule was damaged, and a considerable number of hepatocytes were completely destroyed. Additionally, the walls of blood vessels and biliary ductule walls was notably disturbed. It was found that the intensity of pathologies occurring in the liver, increases proportionally with higher concentrations of nanoparticles. Confirmation via electron microscopic methods revealed that Fe3O4 nanoparticles, when administered with food to common carp, enter the fish's liver through erythrocytes localized in the lumen of blood vessels. From there, they traverse through the endothelium of vessels, proceed to hepatocytes, including cytoplasmic organelles, intracellular canaliculi, biliary ductules, and eventually reach the bile ducts. Fe3O4 nanoparticles in all structural elements of fish liver was up to 20 nm. Therefore, high concentrations of nanoparticles in the environment harms the bodies of aquatic organisms, including fish. The changes identified in the liver of common carp in the present study are valuable information in assessing possible risks to other components of the aquatic ecosystem and organisms.

Numerical simulation of heat transfer and nanoparticle transport in a nanofluid within a tumour surrounding a blood vessel

A Newtonian nanofluid containing suspended nanoparticles can substantially improve heat transfer due to enhanced energy transport mechanisms. This theoretical study investigates heat and mass transfer in biological tissues using such a nanofluid under a magnetic field. These properties have promising medical and engineering applications. The nonlinear governing equations were transformed into ordinary differential equations using similarity variables and numerically solved with MATLAB boundary value problem solver bvp4c, subject to appropriate boundary conditions. Results demonstrated increasing the heat source parameter dramatically raised tumor interstitial temperature. This heating, along with improved nanoparticle accumulation within the tumor due to the thermal effects, are together essential for effective hyperthermia treatment. The model provides new insights into tuning heat and mass transport mechanisms in biological tissues via nanofluids for therapeutic applications. Therefore, the findings of this study may improve the efficacy of thermal therapy in treating cancer.

Impact of protein corona and PEGylation on the accumulation and efficacy of lysosome-disrupting lipid nanoparticles in KRAS-mutated cancer

Nanomedicines offer promising approaches for targeted drug delivery to tumor cells but their clinical translation is hindered by limited delivery efficacy in heterogenous clinical tumors. Protein corona adsorbed to the surface of nanoparticles (NPs) would cause opsonization and accelerate blood clearance, posing a significant barrier to effective drug delivery. Polyethylene glycol (PEG) modification is widely employed to prolong the NPs’ circulation time and improve the delivery efficacy. Nevertheless, the clinical efficacy of PEG-based nanomedicines is still debatable. Here, we prepared non-PEGylated lysosomal-disrupting dimeric chloroquine (CQ) lipid nanoparticles (DCLNPs) and PEGylated DCLNPs (PEG-DCLNPs) and systematically studied the impact of PEGylation on DCLNPs’ delivery efficacy in KRAS-mutant (MT) and -wildtype (WT) cancers. We found that the protein corona facilitates KRAS-MT cancer-specific targeted delivery of DCLNPs by exploiting extracellular protein engulfment preference. In contrast, PEGylation hindered delivery and efficacy of DCLNPs. Proteomics analysis highlighted apolipoproteins, particular apolipoprotein E, as key factors promoting the uptake of DCLNPs. Additionally, DCLNPs sensitized immunosuppressive KRAS-MT cancers to anti-PD1 immunotherapy. These results underscore the importance of comprehending the context-dependent role of the protein corona in regulating nanoparticle biodistribution, suggesting that PEGylation may not be suitable across all cancer types.

Comparison of passive targeted delivery of inorganic and organic nanocarriers among different types of tumors

In this study, we have considered four types of nanoparticles (NPs): polylactic acid (PLA), gold (Au), calcium carbonate (CaCO3), and silica (SiO2) with similar sizes (TEM: 50–110 nm and DLS: 110–140 nm) to examine their passive accumulation in three different tumors: colon (CT26), melanoma (B16-F10), and breast (4T1) cancers. Our results demonstrate that each tumor model showed a different accumulation of NPs, in the following order: CT26 > B16-F10 > 4T1. The Au and PLA NPs were evidently characterized by a higher delivery efficiency in case of CT26 tumors compared to CaCO3 and SiO2 NPs. The Au NPs demonstrated the highest accumulation in B16-F10 cells compared to other NPs. These results were verified using SPECT, ex vivo fluorescence bioimaging, direct radiometry and histological analysis. Thus, this work contributes to new knowledge in passive tumor targeting of NPs and can be used for the development of new strategies for delivery of bioactive compounds.

Autologous patient-derived exhausted nano T-cells exploit tumor immune evasion to engage an effective cancer therapy

BackgroundActive targeting by surface-modified nanoplatforms enables a more precise and elevated accumulation of nanoparticles within the tumor, thereby enhancing drug delivery and efficacy for a successful cancer treatment. However, surface functionalization involves complex procedures that increase costs and timelines, presenting challenges for clinical implementation. Biomimetic nanoparticles (BNPs) have emerged as unique drug delivery platforms that overcome the limitations of actively targeted nanoparticles. Nevertheless, BNPs coated with unmodified cells show reduced functionalities such as specific tumor targeting, decreasing the therapeutic efficacy. Those challenges can be overcome by engineering non-patient-derived cells for BNP coating, but these are complex and cost-effective approaches that hinder their wider clinical application. Here we present an immune-driven strategy to improve nanotherapeutic delivery to tumors. Our unique perspective harnesses T-cell exhaustion and tumor immune evasion to develop a groundbreaking new class of BNPs crafted from exhausted T-cells (NExT) of triple-negative breast cancer (TNBC) patients by specific culture methods without sophisticated engineering.MethodsNExT were generated by coating PLGA (poly(lactic-co-glycolic acid)) nanoparticles with TNBC-derived T-cells exhausted in vitro by acute activation. Physicochemical characterization of NExT was made by dynamic light scattering, electrophoretic light scattering and transmission electron microscopy, and preservation and orientation of immune checkpoint receptors by flow cytometry. The efficacy of chemotherapy-loaded NExT was assessed in TNBC cell lines in vitro. In vivo toxicity was made in CD1 mice. Biodistribution and therapeutic activity of NExT were determined in cell-line- and autologous patient-derived xenografts in immunodeficient mice.ResultsWe report a cost-effective approach with a good performance that provides NExT naturally endowed with immune checkpoint receptors (PD1, LAG3, TIM3), augmenting specific tumor targeting by engaging cognate ligands, enhancing the therapeutic efficacy of chemotherapy, and disrupting the PD1/PDL1 axis in an immunotherapy-like way. Autologous patient-derived NExT revealed exceptional intratumor accumulation, heightened chemotherapeutic index and efficiency, and targeted the tumor stroma in a PDL1+ patient-derived xenograft model of triple-negative breast cancer.ConclusionsThese advantages underline the potential of autologous patient-derived NExT to revolutionize tailored adoptive cancer nanotherapy and chemoimmunotherapy, which endorses their widespread clinical application of autologous patient-derived NExT.

Fabrication of hydrophobic surface from zein-based nanostructure and rosin to functionalize cotton textiles

A double-layer hydrophobic coating based on zein nanoparticles (ZNPs) and rosin was successfully developed as a simple and non-toxic process for textile functionalization. The bottom layer of the coating was a highly rough surface formed by the accumulation of zein nanoparticles prepared with an antisolvent method. The top layer was made of rosin to reduce the surface energy. The fabric treated with ZNPs and rosin (ZNPs/R/cotton) exhibited good hydrophobic behavior with a water contact angle (WCA) of 131.5 ± 2.3° and the hydrophobicity was long-lasting. The micromorphology and chemical composition of hydrophobic cotton fabric surface were characterized by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), respectively. The results demonstrated that zein and rosin deposited on the surface of the fabric to form a rough micro/nano-scale structure. The functional ZNPs/R/cotton retained excellent mechanical properties, air permeability and water vapor permeability. The practical application tests indicated that the fabric displayed good stain resistance ability. Even after 10 soaking cycles and 50 rubbing cycles, the fabric still retained good hydrophobic property with WCAs of 124.7 ± 2.9° and 90.3 ± 3.5°. This work offered a potential method for the clean production of functionalized textiles.

Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies.

To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process. Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations. Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point. Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.

Charge-Switchable nanoparticles to enhance tumor penetration and accumulation

Nanoparticle-based drug delivery systems hold potential in chemotherapy, but their limited accumulation in tumor tissues hinders effective drug concentration for combating tumor growth. Hence, altering the physicochemical properties of nanoparticles, particularly their surface charge, can enhance their performance. This study utilized a computational model to explore a nanoparticle drug delivery system capable of dynamically adjusting its surface charge. In the model, nanoparticles in the bloodstream were assigned a neutral or positive charge, which, upon reaching the tumor microenvironment, switched to a neutral or negative charge, and releasing chemotherapy drugs into the extracellular space. Results revealed that circulating nanoparticles with a positive surface charge, despite having a shorter circulation and high clearance rate compared to their neutral counterparts, could accumulate significantly in the tissue due to their high transvascular rate. After extravasation, neutralized surface-charged nanoparticles tended to accumulate only near blood microvessels due to their low diffusion rate, resulting in substantial released drug drainage back into the bloodstream. On the other hand, nanoparticles with a negative surface charge in the tumor’s extracellular space, due to the reduction of nano-bio interactions, were able to penetrate deeper into the tumor, and increasing drug bioavailability by reducing the volume of drained drugs. Furthermore, the analysis suggested that burst drug release yields a higher drug concentration than sustained drug release, however their creation of bioavailability dependent on nanoparticle accumulation in the tissue. The study’s findings demonstrate the potential of this delivery system and offer valuable insights for future research in this area.

Long-Term Accumulation, Biological Effects and Toxicity of BSA-Coated Gold Nanoparticles in the Mouse Liver, Spleen, and Kidneys.

Gold nanoparticles are promising candidates as vehicles for drug delivery systems and could be developed into effective anticancer treatments. However, concerns about their safety need to be identified, addressed, and satisfactorily answered. Although gold nanoparticles are considered biocompatible and nontoxic, most of the toxicology evidence originates from in vitro studies, which may not reflect the responses in complex living organisms. We used an animal model to study the long-term effects of 20 nm spherical AuNPs coated with bovine serum albumin. Mice received a 1 mg/kg single intravenous dose of nanoparticles, and the biodistribution and accumulation, as well as the organ changes caused by the nanoparticles, were characterized in the liver, spleen, and kidneys during 120 days. The amount of nanoparticles in the organs remained high at 120 days compared with day 1, showing a 39% reduction in the liver, a 53% increase in the spleen, and a 150% increase in the kidneys. The biological effects of chronic nanoparticle exposure were associated with early inflammatory and fibrotic responses in the organs and were more pronounced in the kidneys, despite a negligible amount of nanoparticles found in renal tissues. Our data suggest, that although AuNPs belong to the safest nanomaterial platforms nowadays, due to their slow tissue elimination leading to long-term accumulation in the biological systems, they may induce toxic responses in the vital organs, and so understanding of their long-term biological impact is important to consider their potential therapeutic applications.

Low toxicity of magnetite-based modified bionanocomposites with potential application for wastewater treatment: Evaluation in a zebrafish animal model

In recent years, the escalating concerns surrounding environmental pollution and the need for sustainable wastewater treatment solutions have underscored the significance of developing technologies that can efficiently treat wastewater while also reducing negative ecological effects. In this context, our study aims to contribute to the advancement of sustainable technologies for wastewater treatment, by investigating the effects that bare magnetite nanoparticles and those functionalized with the enzyme laccase could have in an aquatic animal, zebrafish, at various life cycle stages. Exposure to magnetite nanoparticles shows some effects on embryo hatching, survival rates, or larval behavior at higher concentrations. For both treatments, the hatching percentages were close to 80% compared to 93% for the control group. At the end of the observations in larvae, survival in all the evaluated groups was higher than 90%. Additionally, we evaluated the accumulation of nanoparticles in various stages of zebrafish. We found that, although there was accumulation during embryonic stages, it did not affect normal development or subsequent hatching. Iron levels in different organs such as gills, muscles, gastrointestinal tract, and brain were also evaluated in adults. Animals treated with a mix of food and nanoparticles at 10 μg/mL (Food group) presented a higher concentration of iron accumulation in muscle, gastrointestinal tract, and gills compared to the untreated control group. Although iron levels increased depending on the dose and exposure method applied, they were not statistically significant from the control groups. Our findings suggest that bionanocomposites evaluated here can be considered safe for removal of contaminants in wastewater without toxic effects or detrimental accumulation fish's health.