Surface Charge Of Nanoparticles Research Articles

Green Synthesis of Silver Nanoparticles using Coriandrum sativum and Murraya koenigii Leaf Extract and its Thrombolytic Activity.

Plants have been used for ages in traditional medicine, and it is exciting to perceive how recent research has recognized the bioactive compounds liable for their beneficial effects. Green synthesis of metal nanoparticles is a hastily emergent research area in nanotechnology. This study describes the synthesis of silver nanoparticles (AgNPs) using Coriandrum sativum and Murraya koenigii leaf extract and its thrombolytic activity. The aim of the study was to determine the clot lysis activity of Coriandrum sativum and Murraya koenigii synthesized silver nanoparticles. Leaves of Coriandrum sativum and Murraya koenigii were collected. Methanolic extraction of the plant sample was done through a Soxhlet extractor. The methanolic extract obtained from both the leaves was subjected to GC-MS analysis. The synthesized NPs from leaf extracts were monitored for analysis, where the typical X-ray diffraction pattern and its diffraction peaks were identified. 3D image of the NPs was analysed by Atomic Force Microscopy. The surface charge of nanoparticles was identified by Zeta potential. The Clot lysis activity of Coriandrum sativum and Murraya koenigii synthesized silver nanoparticles were analysed by the modified Holmstorm method. The thrombolytic property of the methanolic extract of plants Coriandrum sativum showed clot lysis activity at 2.5 mg/mL with 45.99% activity, and Murraya koenigii extract with 66.56% activity. The nanoparticles (Nps) from Coriandrum sativum showed clot lysis activity at 2.5 mg/mL with 58.29% activity, and NPs from Murraya koenigii with 54.04% activity. Coriandrum sativum in GC-MS exhibited 3 peaks, whereas Murraya koenigii extract showed five peaks with notable bioactive compounds. These NPs were further used for biomedical applications after being fixed by an organic encapsulation agent. The present research reveals the usefulness of Coriandrum sativum and Murraya koenigii for the environmentally friendly manufacture of silver nanoparticles.

Impact of coated and non-coated magnetic nanoparticles on oil-water separation in green surfactant-based emulsions

This study investigates the efficacy of magnetite nanoparticles as a means of demulsifying surfactant-based emulsions, focusing on light and medium crude oil emulsions. The demulsification capabilities of bare, amine-coated, and oleic acid-coated magnetite nanoparticles were tested. Nanoparticle concentrations ranged from 0.25 % to 8 %. The emulsions used Alpha Olefin Sulfonate and two environmentally friendly surfactants, Coco Glucoside and Greenzyme with sodium and potassium formate as eco-friendly alternatives and sodium chloride as the standard brine. Magnetic demulsification efficacy is highly dependent on the interplay between the nanoparticle surface charge and surfactant, thereby affecting surfactant adsorption onto the particle surface. While gravimetric separation alone has partial effectiveness, the magnetic field enhances particle movement, promoting greater instability. The nanoparticles play a key role in adsorbing surfactant species from the interfacial region, thus facilitating demulsification. Notably, magnetic demulsification is more effective with environmentally friendly surfactants, achieving 100 % separation in most cases. Demulsification of emulsions containing synthetic surfactants is most successful with light crude oil emulsions, and in select cases, achieves 100 % separation with medium crude oil emulsions.

A Review on Investigating the Interactions between Nanoparticles and the Pulmonary Surfactant Monolayer with Coarse-Grained Molecular Dynamics Method.

Pulmonary drug delivery has garnered significant attention due to its targeted local lung action, minimal toxic side effects, and high drug utilization. However, the physicochemical properties of inhaled nanoparticles (NPs) used as drug carriers can influence their interactions with the pulmonary surfactant (PS) monolayer, potentially altering the fate of the NPs and impairing the biophysical function of the PS monolayer. Thus, the objective of this review is to summarize how the physicochemical properties of NPs affect their interactions with the PS monolayer. Initially, the definition and properties of NPs, as well as the composition and characteristics of the PS monolayer, are introduced. Subsequently, the coarse-grained molecular dynamics (CGMD) simulation method for studying the interactions between NPs and the PS monolayer is presented. Finally, the implications of the hydrophobicity, size, shape, surface charge, surface modification, and aggregation of NPs on their interactions with the PS monolayer and on the composition of biomolecular corona are discussed. In conclusion, gaining a deeper understanding of the effects of the physicochemical properties of NPs on their interactions with the PS monolayer will contribute to the development of safer and more effective nanomedicines for pulmonary drug delivery.

Green synthesis of NiFe2O4 nanoparticles and evaluation of their photocatalytic activities

Studies on the potential applications of nanoparticles (NPs) synthesized by biological methods attract the attention of researchers. First time in this study, photocatalytic activities of NiFe2O4 NPs synthesized with pomegranate fruit peel extract were determined against brilliant blue. Surface charge and dynamic size of NPs were detected at −11 mV, and 405 nm, respectively. According to scanning electron microscopy images, NiFe2O4 NPs have spherical morphology with a diameter of 75 nm. Energy dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used for the determination of elemental composition, crystallinity, and functional groups of NPs, respectively. As a result, it was determined that NiFe2O4 NPs were effective for remediation (65%, for 3 h) of dye. The catalytic activity of NiFe2O4 NPs refers to the Fenton mechanism.

Metal-Phenolic Network-Coated Nanoparticles as Stabilizers for the Engineering of Pickering Emulsions with Bioactivity.

Pickering emulsions stabilized by functional nanoparticles (NPs) have received considerable attention for improving the physical stability and biological function of NPs. Herein, hydrophobic polyphenols were chosen as phenolic ligands to form metal-phenolic network (MPN) coatings on NPs (e.g., silica, polystyrene) mediated by the sono-Fenton reaction. The MPN coatings modulated the surface wettability and charges of NPs and achieved emulsification behavior for preparing Pickering emulsions with pH responsiveness and oxidation resistance. A series of polyphenols, including resveratrol, rutin, naringin, and curcumin, were used to form MPN coatings on NPs, which served as stabilizers for the engineering of functionalized oil-in-water (O/W) Pickering emulsions. This work provides a new avenue for the use of hydrophobic polyphenols to modulate NP emulsifiers, which broadens the application of polyphenols for constructing Pickering emulsions with antioxidant properties.

Enhancements in thermal properties of binary alkali chloride salt by Al2O3 nanoparticles for thermal energy storage

The cost-effective molten chloride salts are promising heat transfer fluids for next-generation concentrating solar plants. However, their limited specific heat capacities and thermal conductivities hinder their applications. In this paper, molten salt-based nanofluids based on a binary chloride (50 mol.% NaCl, 50 mol.% KCl) with Al2O3 nanoparticles were proposed to enhance the thermal properties. Firstly, molecular dynamics simulations were employed to investigate the thermal properties of these nanofluids, focusing on various nanoparticle volume fractions within 1100∼1600 K. The findings reveal that as the nanoparticle fraction increases from 0% to 7%, the specific heat capacity and dynamic viscosity improve by≈14.9% and 34.8%–38.6%, respectively. Concurrently, the thermal conductivity increases by 10.0%–16.5%. Then, microstructure evolution was analyzed to elucidate the enhancing mechanism of the thermal conductivity. Specifically, the negatively charged nanoparticle surface selectively attracts Na+ and K+, resulting in the formation of a compressed layer around the nanoparticle where the short-range order of ions was intensified. As a result, the compressed layer serves as a thermal conduit between the Al2O3 nanoparticle and the surrounding salt, resulting in the enhancement of the thermal conductivity. Furthermore, additional analyses of thermal diffusion properties and energy density distributions provide indirect evidence for the existence of the compressed layer where ionic motion is restricted, further validating the enhancing mechanism.

Size, polyglycerol grafting, and net surface charge of iron oxide nanoparticles determine their interaction and toxicity in Caenorhabditis elegans

The widespread application of engineered nanoparticles (NPs) in environmental remediation has raised public concerns about their toxicity to aquatic organisms. Although appropriate surface modification can mitigate the ecotoxicity of NPs, the lack of polymer coating to inhibit toxicity completely and the insufficient knowledge about charge effect hinder the development of safe nanomaterials. Herein, we explored the potential of polyglycerol (PG) functionalization in alleviating the environmental risks of NPs. Iron oxide NPs (ION) of 20, 100, and 200 nm sizes (IONS, IONM and IONL, respectively) were grafted with PG to afford ION-PG. We examined the interaction of ION and ION-PG with Caenorhabditis elegans (C. elegans) and found that PG suppressed non-specific interaction of ION with C. elegans to reduce their accumulation and to inhibit their translocation. Particularly, IONS-PG was completely excluded from worms of all developmental stages. By covalently introducing sulfate, carboxyl and amino groups onto IONS-PG, we further demonstrated that positively charged IONS-PG-NH3+ induced high intestinal accumulation, cuticle adhesion and distal translocation, whereas the negatively charged IONS-PG-OSO3– and IONS-PG-COO– were excreted out. Consequently, no apparent deleterious effects on brood size and life span were observed in worms treated by IONS-PG and IONS-PG bearing negatively charged groups. This study presents new surface functionalization approaches for developing ecofriendly nanomaterials.

Comparative survival study of Bacillus coagulans and Enterococcus faecium microencapsulated in chitosan-alginate nanoparticles in simulated gastrointestinal condition

Probiotics have poor gastrointestinal delivery because they lose their viability during intestinal passage. Microencapsulation has a significant effect on the survival of probiotic bacteria. This study aimed to synthesize chitosan-alginate nanoparticles and encapsulate Bacillus coagulans NBRC-12583 and Enterococcus faecium MGFR1 in alginate (Alg), chitosan (Cht) and inulin (Inu) by micro- and nano-encapsulation to investigate the viability of encapsulated strains in simulated gastrointestinal condition. The survival of free and encapsulated bacteria was studied for 120 min. The population of B. coagulans encapsulated in Cht-Alg only decreased by 0.86 log CFU, while that of E. faecium encapsulated in Cht-Alg nanoparticles only decreased by 0.27 log CFU. Treated with simulated intestinal fluid, B. coagulans and E. faecium populations decreased by 1.03 and 0.17 log CFU, respectively. E. faecium microencapsulated in Cht-Alg and Inu had a maximum encapsulation efficiency of 96.78%. E. faecium encapsulated in Cht-Alg nanoparticles and Inu was more viable than other encapsulated bacteria. Scanning electron microscopy was done to investigate the microcapsules' surface morphology, structure, internal cross-sectional view, and the zeta potential for the surface charge of Cht-Alg nanoparticles. The viability of the probiotic bacteria was enhanced significantly by microencapsulation and nanomaterial-based encapsulation within the chitosan-alginate and inulin matrix.

Photocatalytic Degradation of Crystal Violet Dye Using Iron Oxide Nanoparticles

Increased industrial population causes water pollution. The release of toxic waste products from various industries become a major environmental issue. There are several methods for water decontamination and the advanced oxidation process (AOP) is one of them. The AOP’s rate can be increased using a variety of nanoparticles as a catalyst to degrade contaminants dyes like Crystal violet (CV). Magnetic nanoparticles (MNPs) are one of the most suitable materials to deal with this environmental issue because of their easy reusability along with high reactive surface area and easy to synthesize. Considering this, using the co-precipitation method iron oxide nanoparticles (IONPs) were synthesised in the present work. The as-prepared nanoparticles are then systematically characterized by various analytical tools. The XRD and FTIR suggest the crystalline structure and surface functional groups of the IONPs. The zeta potential study depicts the surface charge of nanoparticles within the colloidal solution. Additionally, the catalytic activity of IONPs was studied by the photo-Fenton process. The utilization of various catalytic parameters like pH (3–7), catalyst dosage (100–400 mg), dye concentration (0.025–0.1 mM) and H2O2 concentration (2–8 mM) has enhanced the effectiveness of the photo-Fenton process for the efficient removal of organic pollutant. Degradation efficiency was observed to be 94% after 90 minutes in the treatment of 5 mg nanoparticles with 0.05 mM dye solution. This magnetically recyclable catalyst will facilitate the advancement of water treatment in an environmentally sustainable and cost-effective manner, with notable potential.

Effectiveness of gold nanoparticles in prevention and treatment of oral mucositis in animal models: a systematic review

BackgroundOral mucositis remains a significant complication during cancer therapy with no effective treatment. Gold nanoparticles offer anti-inflammatory, antioxidant properties with low toxicity. This study systematically reviews the literature assessing gold nanoparticles in the management of oral mucositis in animal models.MethodsA literature search was undertaken using MEDLINE, Embase, PubMed, and Web of Science databases, using the format for Systematic Review Centre for Laboratory Animal Experimentation. Prior to the review, the protocol was registered in the systematic review register, PROSPERO (registration no. CRD42021272169). Outcome measures included ulceration, histopathological scores, inflammatory mediators, microbial growth, and pain. Study quality was analysed by SYRCLE risk-of-bias tool.ResultsOnly one study met the inclusion criteria, documenting reduction in ulceration, inflammatory, and oxidative biomarkers. Exposure to AuNPs prevented inflammatory response induced by 5-fluorouracil in oral mucosa of hamsters. However, a high risk of bias necessitates further research.ConclusionThis review identifies a potential therapeutic strategy for prevention and management of oral mucositis. It also provides future direction for gold nanoparticle research in oral mucositis; however, there is lack of sufficient evidence to derive any conclusion. Research with standardized parameters including nanoparticle size, capping agent, surface charge, and appropriate oral mucositis animal models will establish risk–benefit balance and margin of safety for therapeutic use of gold nanoparticles for oral mucositis.

The effect of nanoparticle surface charge on freshwater algae growth, reproduction, and lipid production

Using functionalized carbon dots as models, positively charged nanoparticles were found to cause growth inhibition and aggregation in microalgae. Negative and near-neutral negative particles were associated with morphological changes.

PH/redox responsive size‐switchable intelligent nanovehicle for tumor microenvironment targeted DOX release

Tumor microenvironment (TME) targeted strategy could control the drug release in tumor cells more accurately and creates a new opportunity for enhanced site-specific targeted delivery. In this study, (PAA-b-PCL-S-S-PCL-b-PAA) copolymeric nanoparticles (NPs) with size-switchable ability and dual pH/redox-triggered drug release behavior were designed to significantly promote cancer uptake (cell internalization of around 100% at 30 min) and site-specific targeted doxorubicin (DOX) delivery in MDA-MB-231 tumor cells. NPs surface charge was shifted from − 17.8 to − 2.4 and their size shrunk from 170.3 to 93 nm in TME. The cell cycle results showed that DOX-loaded NPs showed G2/M (68%) arrest, while free DOX showed sub-G1 arrest (22%). Apoptosis tests confirmed that the cells treated with DOX-loaded NPs showed a higher amount of apoptosis (71.6%) than the free DOX (49.8%). Western blot and RT-PCR assays revealed that the apoptotic genes and protein levels were significantly upregulated using the DOX-loaded NPs vs. the free DOX (Pvalue < 0.001). In conclusion, dual pH/redox-responsive and size-switchable DOX-loaded NPs developed here showed outstanding anti-tumoral features compared with free DOX that might present a prospective platform for tumor site-specific accumulation and drug release that suggest further in vivo research.

Dual Self-Amplification Homogeneous Electrochemiluminescence Biosensor for Terminal Deoxynucleotidyl Transferase Activity Based on Controlling the Surface Morphology and Charge of Reporter Nanoparticles.

Terminal deoxynucleotidyl transferase (TdT) is upregulated in several types of leukemia and is considered a disease biomarker and a potential therapeutic target for leukemia. In this research, a homogeneous electrochemiluminescence (ECL) method based on the control of surface charge and morphology of tris (2,2'-bipyridine) ruthenium(II) chloride hexahydrate-doped silica nanoparticles (Ru@SiO2 NPs) has been designed for TdT activity detection. A small amount of short single-stranded DNA (ssDNA) was modified onto the surface of Ru@SiO2 NPs, and the nanoparticles with a slight positive charge experienced electrostatic attraction with the indium tin oxide (ITO) electrode with a negative charge, so relatively high ECL signals had been detected. Under the action of TdT, the ssDNA was significantly elongated, carrying numerous negative charges on its phosphate backbone, so the overall negative charge of the reporter nanoparticles was enhanced, resulting in a strong electrostatic repulsion with the ITO electrode. Simultaneously, the long ssDNA wrapped around the nanoparticles hindered the approach of the coreactant. Due to the dual effects, the ECL response of the system decreased. The constructed biosensor exhibited excellent sensitivity toward TdT over a range spanning from 1 to 100 U/L. The limit of detection is as low as 1.78 U/L. The developed approach was effectively applied to detect TdT activity in leukemic patients' leukocyte extracts.

YAP Signaling Regulates the Cellular Uptake and Therapeutic Effect of Nanoparticles.

Interactions between living cells and nanoparticles are extensively studied to enhance the delivery of therapeutics. Nanoparticles size, shape, stiffness, and surface charge are regarded as the main features able to control the fate of cell-nanoparticle interactions. However, the clinical translation of nanotherapies has so far been limited, and there is a need to better understand the biology of cell-nanoparticle interactions. This study investigates the role of cellular mechanosensitive components in cell-nanoparticle interactions. It is demonstrated that the genetic and pharmacologic inhibition of yes-associated protein (YAP), a key component of cancer cell mechanosensing apparatus and Hippo pathway effector, improves nanoparticle internalization in triple-negative breast cancer cells regardless of nanoparticle properties or substrate characteristics. This process occurs through YAP-dependent regulation of endocytic pathways, cell mechanics, and membrane organization. Hence, the study proposes targeting YAP may sensitize triple-negative breast cancer cells to chemotherapy and increase the selectivity of nanotherapy.

First-Principles Prediction of Amorphous Silica Nanoparticle Surface Charge: Effect of Size, pH, and Ionic Strength.

The quantification of surface charge properties of silica nanoparticles is essential for several applications. To determine these properties, many experimental and theoretical methods have been introduced, which are time-consuming and/or challenging to use. In this study, a first-principles approach is developed to determine the surface charge properties of amorphous silica nanoparticles against the nanoparticle size, pH, and ionic strength without relying on experimental data. An amorphous silica nanoparticle of 1.34 nm diameter is simulated by using integrated molecular dynamics and Monte Carlo methods. A detailed analysis of the nanoparticle structure is provided by analyzing the types of silanol groups on the surface. Moreover, a model is developed to estimate the probability distribution of the surface silanol groups based on the nearest neighbor distances and the diameter of the nanoparticle to determine the number of surface silanols on larger nanoparticles. Thereafter, a computational chemistry approach is used to calculate the acid dissociation constants of the corresponding deprotonation reactions. The calculated constants and the point of zero charge value are in excellent agreement with experiments. The surface charge properties of the nanoparticle with various diameters are then estimated by using a mean-field model at different pH and ionic strength values. The results of the developed model are compared to the Poisson-Boltzmann equation as a reference model. The developed model predictions agree well with the reference model for low and mid-electrolyte concentrations (1 and 10 mM) and small nanoparticles (smaller than 100 nm). However, the developed model seems to qualitatively predict the surface charge properties more accurately than the Poisson-Boltzmann model for high electrolyte concentrations.

Thermally stabilized chondroitin sulfate-hemoglobin nanoparticles and their interaction with bioactive compounds

The preparation of nanoparticles (NPs) based on hemoglobin (Hb) with a fully biocompatible methodology is presented. The spontaneous formation of electrostatic complexes of Hb with chondroitin sulfate (CS) at pH 4 in the polysaccharide/protein mass ratio regime where charge neutrality is met leads to spherical nanostructures with monomodal hydrodynamic radii distribution in the range of 50–100 nm. The integrity of the electrostatic complexes is disturbed at pH 7 as the net electric charge of Hb is very low. Treating the NPs at mildly elevated temperature stabilizes them against the pH increase taking advantage of Hb's ability of unfolding and self-associating upon thermal treatment. The NPs surface charge is pH-tunable and changes from positive to strongly negative upon pH increase to 7 proving the presence of negative surface patches of Hb and CS segments in their exterior. The α-helix content of Hb does not change significantly by thermal treatment. The NPs are found to bind the bioactive compounds curcumin and β-carotene and are stable in solutions with high salt content. This investigation introduces a straightforward method to formulate Hb in NPs with possibilities in the nanodelivery of nutrients and drugs.

Enhanced Heat Flow between Charged Nanoparticles and an Aqueous Electrolyte.

Heat transfer through the interface between a metallic nanoparticle and an electrolyte solution has great importance in a number of applications, ranging from nanoparticle-based cancer treatments to nanofluids and solar energy conversion devices. However, the impact of the surface charge and dissolved ions on heat transfer has been scarcely explored so far. In this study, we compute the interface thermal conductance between hydrophilic and hydrophobic charged gold nanoparticles immersed in an electrolyte using equilibrium molecular dynamics simulations. Compared with an uncharged nanoparticle, we report a 3-fold increase of the Kapitza conductance for a nanoparticle surface charge of +320 mC/m2. This enhancement is shown to be approximately independent of the surface wettability, charge spatial distribution, and salt concentration. This allows us to express the Kapitza conductance enhancement in terms of the surface charge density on a master curve. Finally, we interpret the increase of the Kapitza conductance as a combined result of the shift of the water density distribution toward the charged nanoparticle and an accumulation of the counterions around the nanoparticle surface which increase the Coulombic interaction between the liquid and the charged nanoparticle. These considerations help us to apprehend the role of ions in heat transfer close to electrified surfaces.

Nonlinear dependence (on ionic strength, pH) of surface charge density and zeta potential in microchannel electrokinetic flow

In this work, a numerical method is proposed to predict the electrokinetic phenomena and combined with an experimental study of the surface charge density (ρs) and zeta potential (ζ) behavior is investigated for borosilicate immersed in KCl and NaCl electrolytes, and for imogolite immersed in KCl, CaCl2, and MgCl2 electrolytes. Simulations and experiments of the electrokinetic flows with electrolyte solutions were performed to accurately determine the electric double layer (EDL), ζ, and ρs at various electrolyte concentrations and pH. The zeta potential was experimentally determined and numerically predicted by solving the coupled governing equations of mass, species, momentum, and electrical field iteratively. Our numerical prediction shows that ζ for borosilicate develops strong nonlinear behavior with the ion concentration following a power-law. Likewise, the ρs obeys a nonlinear behavior, decreasing as the concentration increases. Moreover, for imogolite, both ζ and the ρs behave nonlinearly with the pH. The EDL for borosilicate and imogolite becomes thinner as the electrolyte concentration and pH increase; this behavior is caused by increased ρs, resulting in the higher attraction of the free charges. The reported nonlinear behavior describes more accurately the interaction of the nanoparticle surface charge with the electrolytes and its effect on the electrolyte transport properties.

Modulating in vitro gastrointestinal digestion of nanocellulose-stabilized pickering emulsions by altering particle surface charge

An in vitro model of human gastrointestinal digestion was introduced to investigate the effects of surface charge of cellulose nanoparticles on emulsion structure during gastric phase, lipase activity, bile salt diffusion, and free fatty acid (FFA) release. Four carboxymethylated cellulose nanofibrils (CNF; C0, C0.36, C0.72, and C1.24) were used, showing different surface charge (p < 0.05). First, four carboxymethylated CNFs had no inhibition effects on lipase activity and bile salt diffusion. Moreover, we found that the lipid emulsion containing CNF formed gel structure to induce oil droplets aggregation during simulated gastric phase. Additionally, the particle surface charge greatly influenced the gel structure of emulsion where a denser gel structure was observed in the C0 (lowest surface charged CNF) stabilized emulsion. Finally, the released FFA results showed that the formed gel structure lowered the lipid emulsion digestion attributed to the restricted adherent area of oil droplets for lipase and bile salt.

Specific Tumor Localization of Immunogenic Lipid-Coated Mesoporous Silica Nanoparticles following Intraperitoneal Administration in a Mouse Model of Serous Epithelial Ovarian Cancer.

Immunogenic lipid-coated mesoporous silica nanoparticles (ILM) present pathogen-associated molecular patterns (PAMPs) on the nanoparticle surface to engage pathogen-associated receptors on immune cells. The mesoporous core is capable of loading additional immunogens, antigens or drugs. In this study, the impact of lipid composition, surface potential and intercalation of lipophilic monophosphoryl lipid A (MPL-A) in the lipid coat on nanoparticle properties and cellular interactions is presented. Loading and retention of the model antigen ovalbumin into the mesoporous silica core were found to be similar for all nanoparticle formulations, with presentation of ova peptide (SIINFEKL) by major histocompatibility complex (MHC) evaluated to facilitate the selection of an anionic nanoparticle composition. ILM were able to induce lysosomal tubulation and streaming of lysosomes towards the cell surface in dendritic cells, leading to an enhanced surface presentation of MHC. Myeloid cells robustly internalized all ILM formulations; however, non-myeloid cells selectively internalized cationic ILM in vitro in the presence of 20% serum. Interestingly, ILM administration to the peritoneal cavity of mice with disseminated ovarian cancer resulted in selective accumulation of ILM in tumor-associated tissues (>80%), regardless of nanoparticle surface charge or the presence of MPL-A. Immunofluorescence analysis of the omental tumor showed that ILMs, regardless of surface charge, were localized within clusters of CD11b+ myeloid cells 24 h post administration. Selective uptake of ILMs by myeloid cells in vivo indicates that these cells outcompete other cell populations in the ovarian tumor microenvironment, making them a strong target for therapeutic interventions.