Effects of core size and PEG coating layer of iron oxide nanoparticles on the distribution and metabolism in mice

Development and characterization of magnetic hydrogels loaded with greenly synthesized iron-oxide nanoparticles conjugated with cisplatin

A novel approach was devised to address the challenges in delivering cisplatin (CIS) for lung cancer treatment. This involved the development of a non-invasive hydrogel delivery system, aiming to minimize side effects associated with its administration. Using carbopol 971 (CP) and chitosan (CH) at varying ratios, the hydrogels were prepared and loaded with eco-friendly iron oxide nanoparticles (IONPs) conjugated to CIS. The physical properties, yield, drug loading, and cytotoxicity against lung cancer cell lines (A549) were assessed, along with hydrogel rheological properties and in vitro drug diffusion. Hydrogel A1 that composed of 1:1 of CP:CH hydrogel loaded with 100 mg IONPs and 250 µg CIS demonstrated distinctive properties that indicate its suitability for potential delivery. The loaded greenly synthesized IONPs@CIS exhibited a particle size of 23.0 nm, polydispersity index of 0.47, yield of 71.6%, with 88.28% drug loading. They displayed significant cytotoxicity (61.7%) against lung cancer cell lines (A549), surpassing free CIS cytotoxicity (28.1%). Moreover, they demonstrated shear-thinning behaviour, viscoelastic properties, and Fickian drug release profile over 24 h (flux 2.34 µg/cm2/h, and permeability 0.31 cm/h).

Cancer cell membrane-coated nanoparticles: a promising anti-tumor bionic platform

Nanoparticle (NP) drug delivery systems have shown promise in tumor therapy. However, limitations such as susceptibility to immune clearance and poor targeting in a complex intercellular environment still exist. Recently, cancer cell membrane-encapsulated nanoparticles (CCM-NPs) constructed using biomimetic nanotechnology have been developed to overcome these problems. Proteins on the membrane surface of cancer cells can provide a wide range of activities for CCM-NPs, including immune escape and homologous cell recognition properties. Meanwhile, the surface of the cancer cell membrane exhibits obvious antigen enrichment, so that CCM-NPs can transmit tumor-specific antigen, activate a downstream immune response, and produce an effective anti-tumor effect. In this review, we first provided an overview of the functions of cancer cell membranes and summarized the preparation techniques and characterization methods of CCM-NPs. Then, we focused on the application of CCM-NPs in tumor therapy. In addition, we summarized the functional modifications of cancer cell membranes and compiled the patent applications related to CCM-NPs in recent years. Finally, we proposed the future challenges and directions of this technology in order to provide guidance for researchers in this field.

Novel Strategies Using Sagacious Targeting for Site-Specific Drug Delivery in Breast Cancer Treatment: Clinical Potential and Applications

For more than a decade, researchers have been working to achieve new strategies and smart targeting drug delivery techniques and technologies to treat breast cancer (BC). Nanotechnology presents a hopeful strategy for targeted drug delivery into the building of new therapeutics using the properties of nanomaterials. Nanoparticles are of high regard in the field of diagnosis and the treatment of cancer. The use of these nanoparticles as an encouraging approach in the treatment of various cancers has drawn the interest of researchers in recent years. In order to achieve the maximum therapeutic effectiveness in the treatment of BC, combination therapy has also been adopted, leading to minimal side effects and thus an enhancement in the quality of life for patients. This review article compares, discusses and criticizes the approaches to treat BC using novel design strategies and smart targeting of site-specific drug delivery systems.

Green synthesis, characterization of melatonin-like drug bioconjugated CoS quantum dots and its antiproliferative effect on different cancer cells

BACKGROUND

Quantum dots are usually particles smaller than 100 nm and have a low toxic effect. This study aimed to bioconjugate the anticancer effective melatonin agonist to quantum dots and demonstrate its effects in two cancer lines. This is the first study that aims to examine the anticancer activity of ramelteon bioconjugation to quantum dots, providing a new perspective on the use of Melatonin and its derivatives in cancer.

METHODS AND RESULTS

For this purpose, first of all, cobalt sulfide (CoS) quantum dots were synthesized, bioconjugated and characterized with Punica granatum extract by green synthesis method. The effects of synthesized nanomaterials on neuroblastoma and prostate cancer cells were investigated. It was noted that nanomaterials reduced cell viability by 50% in neuroblastoma and prostate cancer lines at a dose of 50 µg/mL. Ramelteon bioconjugated nanomaterials reduced cancer cell viability by 1.4 times more than free melatonin. CoS quantum dots were determined to double the oxidative stress in the neuroblastoma cell line compared to the control, while no change was observed in prostate cancer. In the gene expression findings, it was observed that CoS nanoparticles caused an increase in the expression levels of apoptosis-related genes in the neuroblastoma cell line and induced key protein expression levels of pathways such as ROR-alpha in the prostate cancer cell line.

CONCLUSION

As a result, it was observed that the viability of the neuroblastoma cell line decreased with apoptosis induced by oxidative stress, while this effect was observed in the DU-145 cell line via the ROR-alpha pathway.

Iron Oxide Nanoparticles in Cancer Treatment: Cell Responses and the Potency to Improve Radiosensitivity

The main concept of radiosensitization is making the tumor tissue more responsive to ionizing radiation, which leads to an increase in the potency of radiation therapy and allows for decreasing radiation dose and the concomitant side effects. Radiosensitization by metal oxide nanoparticles is widely discussed, but the range of mechanisms studied is not sufficiently codified and often does not reflect the ability of nanocarriers to have a specific impact on cells. This review is focused on the magnetic iron oxide nanoparticles while they occupied a special niche among the prospective radiosensitizers due to unique physicochemical characteristics and reactivity. We collected data about the possible molecular mechanisms underlying the radiosensitizing effects of iron oxide nanoparticles (IONPs) and the main approaches to increase their therapeutic efficacy by variable modifications.

Effect of sp3/sp2 carbon ratio and hydrodynamic size on the biodistribution kinetics of nanodiamonds in mice via intravenous injection

BACKGROUND

Nanodiamonds (NDs) have gained a rapidly growing interest in biomedical applications; however, little is known regarding their biokinetics owing to difficulties in measurements and limited synthesis/purification technologies. In this study, we investigated the distribution kinetics of detonation-synthesized NDs in mice via intravenous injection to evaluate the parameters that determine the behavior of the particles. We prepared two distinctive NDs that controlled the sp3/sp2 carbon ratio and particle size by coating them with serum proteins. The four control samples were intravenously injected into mice, and tissue distribution and clearance were evaluated at 30 min and 1, 7, and 28 days post-injection.

RESULTS

The sp3/sp2 carbon ratio showed no correlation with the organ distribution of the NDs. However, hydrodynamic size showed an excellent correlation with organ distribution levels: a negative correlation in the liver and positive correlations in the spleen and lungs. Furthermore, the deposition levels of NDs in the lung suggest that particles smaller than 300 nm could avoid lung deposition. Finally, a similar organ distribution pattern was observed in mice injected with carbon black nanoparticles controlled hydrodynamic size.

CONCLUSIONS

In conclusion, the tissue distribution of NDs is modulated not by the sp3/sp2 carbon ratio but by the hydrodynamic size, which can provide helpful information for targeting the tissue of NDs. Furthermore, the organ distribution pattern of the NDs may not be specific to NDs but also can apply to other nanoparticles, such as carbon black.

Size effect of fluorescent thiol-organosilica particles on their distribution in the mouse spleen

We investigated the distribution of intravenously administered thiol-organosilica particle (thiol-OS) in the spleen to evaluate their size effect in mice. A single administration of particles of thiol-OS containing rhodamine B (Rh) (90, 280, 340, 450, 630, 1110, 1670, and 3030 nm in diameter) was performed. After 24 h, we conducted a combination analysis using histological studies by fluorescent microscopy and quantitative inductively coupled plasma optical emission spectrometry (ICP-OES), which revealed no clear correlation between the particle size and spleen uptake of particle weight and number per tissue weight, and the injection dose. Moreover, Rh with 450 nm diameter (Rh450) showed the highest uptake, and Rh with 340 nm diameter (Rh340) showed the lowest uptake. Histologically, large fluorescent areas in the marginal zone (MZ) and red pulp (RP) of the spleen were observed for all particle sizes, but less in the follicle of white pulp. Using combination analysis using the particle weights of ICP-OES and the fluorescent area, we compared the distributions of each particle in each region. Rh450 had the largest accumulated weight in the MZ and RP. Particles larger than Rh450 showed negative correlations between their sizes and accumulated weight in the MZ and RP. Simultaneous dual administration of particles using Rhs and thiol-OS containing fluorescein (90 nm in diameter) showed the size-dependent difference in cellular distribution and intracellular localization. Immunohistochemical staining against macrophage markers, CD169, and F4/80 showed various colocalization patterns with macrophages that uptook particles, indicating differences in particle uptake in each macrophage may have novel significance.

Magnetic Iron Oxide Nanoparticles for Brain Imaging and Drug Delivery

Central nervous system (CNS) disorders affect as many as 1.5 billion people globally. The limited delivery of most imaging and therapeutic agents into the brain is a major challenge for treatment of CNS disorders. With the advent of nanotechnologies, controlled delivery of drugs with nanoparticles holds great promise in CNS disorders for overcoming the blood-brain barrier (BBB) and improving delivery efficacy. In recent years, magnetic iron oxide nanoparticles (MIONPs) have stood out as a promising theranostic nanoplatform for brain imaging and drug delivery as they possess unique physical properties and biodegradable characteristics. In this review, we summarize the recent advances in MIONP-based platforms as imaging and drug delivery agents for brain diseases. We firstly introduce the methods of synthesis and surface functionalization of MIONPs with emphasis on the inclusion of biocompatible polymers that allow for the addition of tailored physicochemical properties. We then discuss the recent advances in in vivo imaging and drug delivery applications using MIONPs. Finally, we present a perspective on the remaining challenges and possible future directions for MIONP-based brain delivery systems.

Iron Oxide@Mesoporous Silica Core-Shell Nanoparticles as Multimodal Platforms for Magnetic Resonance Imaging, Magnetic Hyperthermia, Near-Infrared Light Photothermia, and Drug Delivery

The design of core-shell nanocomposites composed of an iron oxide core and a silica shell offers promising applications in the nanomedicine field, especially for developing efficient theranostic systems which may be useful for cancer treatments. This review article addresses the different ways to build iron oxide@silica core-shell nanoparticles and it reviews their properties and developments for hyperthermia therapies (magnetically or light-induced), combined with drug delivery and MRI imaging. It also highlights the various challenges encountered, such as the issues associated with in vivo injection in terms of NP-cell interactions or the control of the heat dissipation from the core of the NP to the external environment at the macro or nanoscale.

Engineering a potent boron-10-enriched polymeric nanoparticle for boron neutron capture therapy

Background: Boron neutron capture therapy (BNCT) is a promising cancer treatment that eliminates tumor cells by triggering high-energy radiation within cancer cells. Aim: In vivo evaluation of poly(vinyl alcohol)/boric acid crosslinked nanoparticles (PVA/BA NPs) for BNCT. Materials & methods: PVA/BA NPs were synthesized and intravenously injected into tumor-bearing mice for BNCT. Results: The in vitro boron uptake of PVA/BA NPs in tumor cells was 70-fold higher than the required boron uptake for successful BNCT. In an in vivo study, PVA/BA NPs showed a 44.29% reduction in tumor size compared with clinically used boronophenylalanine for oral cancer in a murine model. Conclusion: PVA/BA NPs exhibited effective therapeutic results for oral cancer treatments in BNCT.

In Vitro Studies of Pegylated Magnetite Nanoparticles in a Cellular Model of Viral Oncogenesis: Initial Studies to Evaluate Their Potential as a Future Theranostic Tool

Magnetic nanosystems represent promising alternatives to the traditional diagnostic and treatment procedures available for different pathologies. In this work, a series of biological tests are proposed, aiming to validate a magnetic nanoplatform for Kaposi's sarcoma treatment. The selected nanosystems were polyethylene glycol-coated iron oxide nanoparticles (MAG.PEG), which were prepared by the hydrothermal method. Physicochemical characterization was performed to verify their suitable physicochemical properties to be administered in vivo. Exhaustive biological assays were conducted, aiming to validate this platform in a specific biomedical field related to viral oncogenesis diseases. As a first step, the MAG.PEG cytotoxicity was evaluated in a cellular model of Kaposi's sarcoma. By phase contrast microscopy, it was found that cell morphology remained unchanged regardless of the nanoparticles' concentration (1-150 µg mL^-1). The results, arising from the crystal violet technique, revealed that the proliferation was also unaffected. In addition, cell viability analysis by MTS and neutral red assays revealed a significant increase in metabolic and lysosomal activity at high concentrations of MAG.PEG (100-150 µg mL^-1). Moreover, an increase in ROS levels was observed at the highest concentration of MAG.PEG. Second, the iron quantification assays performed by Prussian blue staining showed that MAG.PEG cellular accumulation is dose dependent. Furthermore, the presence of vesicles containing MAG.PEG inside the cells was confirmed by TEM. Finally, the MAG.PEG steering was achieved using a static magnetic field generated by a moderate power magnet. In conclusion, MAG.PEG at a moderate concentration would be a suitable drug carrier for Kaposi's sarcoma treatment, avoiding adverse effects on normal tissues. The data included in this contribution appear as the first stage in proposing this platform as a suitable future theranostic to improve Kaposi's sarcoma therapy.

Superparamagnetic Iron Oxide Nanoparticles (SPION): From Fundamentals to State-of-the-Art Innovative Applications for Cancer Therapy

Despite significant advances in cancer therapy over the years, its complex pathological process still represents a major health challenge when seeking effective treatment and improved healthcare. With the advent of nanotechnologies, nanomedicine-based cancer therapy has been widely explored as a promising technology able to handle the requirements of the clinical sector. Superparamagnetic iron oxide nanoparticles (SPION) have been at the forefront of nanotechnology development since the mid-1990s, thanks to their former role as contrast agents for magnetic resonance imaging. Though their use as MRI probes has been discontinued due to an unfavorable cost/benefit ratio, several innovative applications as therapeutic tools have prompted a renewal of interest. The unique characteristics of SPION, i.e., their magnetic properties enabling specific response when submitted to high frequency (magnetic hyperthermia) or low frequency (magneto-mechanical therapy) alternating magnetic field, and their ability to generate reactive oxygen species (either intrinsically or when activated using various stimuli), make them particularly adapted for cancer therapy. This review provides a comprehensive description of the fundamental aspects of SPION formulation and highlights various recent approaches regarding in vivo applications in the field of cancer therapy.

Formation of hydrated PEG layers on magnetic iron oxide nanoflowers shows internal magnetisation dynamics and generates high in-vivo efficacy for MRI and magnetic hyperthermia

Multicore magnetic iron oxide nanoparticles, nanoflowers (NFs), have potential biomedical applications as efficient mediators for AC-magnetic field hyperthermia and as contrast agents for magnetic resonance imaging due to their strong magnetic responses arising from complex internal magnetic ordering. To realise these applications amenable surface chemistry must be engineered that maintain particle dispersion. Here a catechol-derived grafting approach is described to strongly bind polyethylene glycol (PEG) to NFs and provide stable hydrogen-bonded hydrated layers that ensure good long-term colloidal stability in buffers and media even at clinical MRI field strength and high concentration. The approach enables the first comprehensive study into the MRI (relaxivity) and hyperthermic (SAR) efficiencies of fully dispersed NFs. The predominant role of internal magnetisation dynamics in providing high relaxivity and SAR is confirmed, and it is shown that these properties are unaffected by PEG molecular weight or corona formation in biological environments. This result is in contrast to traditional single core nanoparticles which have significantly reduced SAR and relaxivity upon PEGylation and on corona formation, attributed to reduced Brownian contributions and weaker NP solvent interactions. The PEGylated NF suspensions described here exhibit usable blood circulation times and promising retention of relaxivity in-vivo due to the strongly anchored PEG layer. This approach to biomaterials design addresses the challenge of maintaining magnetic efficiency of magnetic nanoparticles in-vivo for applications as theragnostic agents. STATEMENT OF SIGNIFICANCE: : Application of multicore magnetic iron-oxide nanoflowers (NFs) as efficient mediators for AC-field hyperthermia and as contrast agents for MR imaging has been limited by lack of colloidal stability in complex media and biosystems. The optimized materials design presented is shown to reproducibly provide PEG grafted NF suspensions of exceptional colloidal stability in buffers and complex media, with significant hyperthermic and MRI utility which is unaffected by PEG length, anchoring group or bio-molecular adsorption. Deposition in the selected pancreatic model mirrors liposomal formulations providing a quantifiable probe of tissue-level liposome deposition and relaxivity is retained in the tumour microenvironment. Hence the biomaterials design addresses the longstanding challenges of maintaining the in vivo magnetic efficiency of nanoparticles as theragnostic agents.

Pharmacokinetics of magnetic iron oxide nanoparticles for medical applications

Magnetic iron oxide nanoparticles (MNPs) have been under intense investigation for at least the last five decades as they show enormous potential for many biomedical applications, such as biomolecule separation, MRI imaging and hyperthermia. Moreover, a large area of research on these nanostructures is concerned with their use as carriers of drugs, nucleic acids, peptides and other biologically active compounds, often leading to the development of targeted therapies. The uniqueness of MNPs is due to their nanometric size and unique magnetic properties. In addition, iron ions, which, along with oxygen, are a part of the MNPs, belong to the trace elements in the body. Therefore, after digesting MNPs in lysosomes, iron ions are incorporated into the natural circulation of this element in the body, which reduces the risk of excessive storage of nanoparticles. Still, one of the key issues for the therapeutic applications of magnetic nanoparticles is their pharmacokinetics which is reflected in the circulation time of MNPs in the bloodstream. These characteristics depend on many factors, such as the size and charge of MNPs, the nature of the polymers and any molecules attached to their surface, and other. Since the pharmacokinetics depends on the resultant of the physicochemical properties of nanoparticles, research should be carried out individually for all the nanostructures designed. Almost every year there are new reports on the results of studies on the pharmacokinetics of specific magnetic nanoparticles, thus it is very important to follow the achievements on this matter. This paper reviews the latest findings in this field. The mechanism of action of the mononuclear phagocytic system and the half-lives of a wide range of nanostructures are presented. Moreover, factors affecting clearance such as hydrodynamic and core size, core morphology and coatings molecules, surface charge and technical aspects have been described.

Understanding the Phagocytosis of Particles: the Key for Rational Design of Vaccines and Therapeutics

A robust comprehension of phagocytosis is crucial for understanding its importance in innate immunity. A detailed description of the molecular mechanisms that lead to the uptake and clearance of endogenous and exogenous particles has helped elucidate the role of phagocytosis in health and infectious or autoimmune diseases. Furthermore, knowledge about this cellular process is important for the rational design and development of particulate systems for the administration of vaccines or therapeutics. Depending on these specific applications and the required biological responses, particles must be designed to encourage or avoid their phagocytosis and prolong their circulation time. Functionalization with specific polymers or ligands and changes in the size, shape, or surface of particles have important effects on their recognition and internalization by professional and nonprofessional phagocytes and have a major influence on their fate and safety. Here, we review the phagocytosis of particles intended to be used as carrier or delivery systems for vaccines or therapeutics, the cells involved in this process depending on the route of administration, and the strategies employed to obtain the most desirable particles for each application through the manipulation of their physicochemical characteristics. We also offer a view of the challenges and potential opportunities in the field and give some recommendations that we expect will enable the development of improved approaches for the rational design of these systems.

Influence of PEG-coated Bismuth Oxide Nanoparticles on ROS Generation by Electron Beam Radiotherapy

Introduction: Nanoparticles (NPs) have been proven to enhance radiotherapy doses as radiosensitizers. The introduction of coating materials such as polyethylene glycol (PEG) to NPs could impact the NPs’ biocompatibility and their effectiveness as radiosensitizers. Optimization of surface coating is a crucial element to ensure the successful application of NPs as a radiosensitizer in radiotherapy. This study aims to investigate the influence of bismuth oxide NPs (BiONPs) coated with PEG on reactive oxygen species (ROS) generation on HeLa cervical cancer cell line.

Material and methods: Different PEG concentrations (0.05, 0.10, 0.15 and 0.20 mM) were used in the synthesis of the NPs. The treated cells were irradiated with 6 and 12 MeV electron beams with a delivered dose of 3 Gy. The reactive oxygen species (ROS) generation was measured immediately after and 3 hours after irradiation.

Results: The intracellular ROS generation was found to be slightly influenced by electron beam energy and independent of the PEG concentrations. Linear increments of ROS percentages over the 3 hours of incubation time were observed.

Conclusions: Finally, the PEG coating might not substantially affect the ROS generated and thus emphasizing the functionalized BiONPs application as the radiosensitizer for electron beam therapy.

Designing the Surface Chemistry of Inorganic Nanocrystals for Cancer Imaging and Therapy

Inorganic nanocrystals, such as gold, iron oxide and semiconductor quantum dots, offer promising prospects for cancer diagnostics, imaging and therapy, due to their specific plasmonic, magnetic or fluorescent properties. The organic coating, or surface ligands, of these nanoparticles ensures their colloidal stability in complex biological fluids and enables their functionalization with targeting functions. It also controls the interactions of the nanoparticle with biomolecules in their environment. It therefore plays a crucial role in determining nanoparticle biodistribution and, ultimately, the imaging or therapeutic efficiency. This review summarizes the various strategies used to develop optimal surface chemistries for the in vivo preclinical and clinical application of inorganic nanocrystals. It discusses the current understanding of the influence of the nanoparticle surface chemistry on its colloidal stability, interaction with proteins, biodistribution and tumor uptake, and the requirements to develop an optimal surface chemistry.

Gafchromic™ EBT3 Film Measurements of Dose Enhancement Effects by Metallic Nanoparticles for 192Ir Brachytherapy, Proton, Photon and Electron Radiotherapy

Interest in combining metallic nanoparticles, such as iron (SPIONs), gold (AuNPs) and bismuth oxide (BiONPs), with radiotherapy has increased due to the promising therapeutic advantages. While the underlying physical mechanisms of NP-enhanced radiotherapy have been extensively explored, only a few research works were motivated to quantify its contribution in an experimental dosimetry setting. This work aims to explore the feasibility of radiochromic films to measure the physical dose enhancement (DE) caused by the release of secondary electrons and photons during NP–radiotherapy interactions. A 10 mM each of SPIONs, AuNPs or BiONPs was loaded into zipper bags packed with GAFCHROMIC™ EBT3 films. The samples were exposed to a single radiation dose of 4.0 Gy with clinically relevant beams. Scanning was conducted using a flatbed scanner in red-component analysis for optimum sensitivity. Experimental dose enhancement factors (DEFExperimental) were then calculated using the ratio of absorbed doses (with/without NPs) converted from the films’ calibration curves. DEFExperimental for all NPs showed no significant physical DE beyond the uncertainty limits (p > 0.05). These results suggest that SPIONs, AuNPs and BiONPs might potentially enhance the dose in these clinical beams. However, changes in NPs concentration, as well as dosimeter sensitivity, are important to produce observable impact.

Kupffer Cells and Blood Monocytes Orchestrate the Clearance of Iron-Carbohydrate Nanoparticles from Serum

Intravenous (IV) iron nanoparticle preparations are widely used to treat iron deficiency. The mechanism of mononuclear phagocyte system-mediated clearance of IV iron nanoparticles is unknown. The early uptake and homeostasis of iron after injection of ferric carboxymaltose (FCM) in mice was studied. An increase in serum iron was observed at 2.5 h followed by a return to baseline by 24 h. An increase in circulating monocytes was observed, particularly Ly6C^hi and Ly6C^low. FCM was also associated with a time-dependent decrease in liver Kupffer cells (KCs) and increase in liver monocytes. The increase in liver monocytes suggests an influx of iron-rich blood monocytes, while some KCs underwent apoptosis. Adoptive transfer experiments demonstrated that following liver infiltration, blood monocytes differentiated to KCs. KCs were also critical for IV iron uptake and biodegradation. Indeed, anti-Colony Stimulating Factor 1 Receptor (CSF1R)-mediated depletion of KCs resulted in elevated serum iron levels and impaired iron uptake by the liver. Gene expression profiling indicated that C-C chemokine receptor type 5 (CCR5) might be involved in monocyte recruitment to the liver, confirmed by pharmaceutical inhibition of CCR5. Liver KCs play a pivotal role in the clearance and storage of IV iron and KCs appear to be supported by the expanded blood monocyte population.

A facile aqueous production of bisphosphonated-polyelectrolyte functionalized magnetite nanoparticles for pH-specific targeting of acidic-bone cells

Bone malignancy treatment is being hindered due to the insufficient selectivity of therapeutic nanoparticles towards malignant bone sites. Polyelectrolyte functionalized magnetic nanoparticles having dually specific pH-sensing ability and bisphosphonate moieties, can be an effective solution for selective targeting of bone malignancies. First, polyelectrolyte was prepared via N-carboxycitraconyzation of chitosan (NCCS) followed by successive functionalization with alendronic acid (AL) and fluorescein isothiocyanate (FITC). Then, Fe₃O₄-NCCS-FITC-AL nanoparticles were synthesized by a facile one-step microwave-assisted aqueous method via in situ surface functionalization. The formation, crystal structure, and surface conjugation of Fe₃O₄ nanoparticles with polyelectrolytic stabilizer were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analyses. Synthesized Fe₃O₄-NCCS-FITC-AL nanoparticles were superparamagnetic, colloidally stable and highly hemocompatible under physiological conditions. Moreover, at pH 5.0, Fe₃O₄-NCCS-FITC-AL nanoparticles formed a precipitate due to inversion of their surface charge. This pH-dependent charge-inversion drastically changed the interactions with erythrocytes and bones. Selective membranolysis of erythrocytes occurred at pH 5.0. The designed nanoparticles showed enough potential for selective targeting of pathological bone sites in early-stage magnetofluorescent imaging and as a therapeutics carrier to treat malignant bone diseases.

Synthesis of a bisphosphonated polyelectrolytic stabilizer to in situ fabricate and functionalize Fe₃O₄ nanoparticles and their pH-dependent hemolysis and bone-cell adhesion.

Biotransformation and toxicity evaluation of functionalized manganese doped iron oxide nanoparticles

Safe inorganic nanomaterials are tremendously used for diagnosis and therapies. However, essential processing in the microbiological environment changed the physical properties and in situ degradability, which is evaluated meticulously. In this research article, bare, Polyethylene glycol, and citrate coated manganese doped iron oxide nanoparticles are synthesized through the coprecipitation route. Structural, magnetic, optical, and morphological analyses are performed through different characterization tools. X-ray diffraction confirmed the formation of single-phase FeMnO3 with a crystallite size of 48.91 nm. Vibrating sample magnetometer analysis confirmed the formation of soft ferromagnetic behavior of bare and coated nanoparticles (NPs). Scanning electron microscopy and transmission electron microscopy confirmed the formation of spherical shaped nanoparticles. Single-dose in vivo acute toxicity testing is performed through the intraperitoneal route of administration on groups of healthy albino rats. Elevated enzyme levels of kidney and liver are observed at day 1 but a transient decrease is observed at later stages. Through optical follow-up, degradation effects are studied by adding prepared NPs in lysosomal like medium. Finally, metabolization of degraded products based on manganese/iron ions is studied by adding apoferritin into a lysosome like solution. These studies showed partial storage of manganese ions from NPs, while no substantial transfer is observed in the case of manganese salt.

Recent Advances in Multimodal Molecular Imaging of Cancer Mediated by Hybrid Magnetic Nanoparticles

Cancer is the second leading cause of death in the world, which is why it is so important to make an early and very precise diagnosis to obtain a good prognosis. Thanks to the combination of several imaging modalities in the form of the multimodal molecular imaging (MI) strategy, a great advance has been made in early diagnosis, in more targeted and personalized therapy, and in the prediction of the results that will be obtained once the anticancer treatment is applied. In this context, magnetic nanoparticles have been positioned as strong candidates for diagnostic agents as they provide very good imaging performance. Furthermore, thanks to their high versatility, when combined with other molecular agents (for example, fluorescent molecules or radioisotopes), they highlight the advantages of several imaging techniques at the same time. These hybrid nanosystems can be also used as multifunctional and/or theranostic systems as they can provide images of the tumor area while they administer drugs and act as therapeutic agents. Therefore, in this review, we selected and identified more than 160 recent articles and reviews and offer a broad overview of the most important concepts that support the synthesis and application of multifunctional magnetic nanoparticles as molecular agents in advanced cancer detection based on the multimodal molecular imaging approach.

Biodegradable Zinc Oxide Nanoparticles Doped with Iron as Carriers of Exogenous Iron in the Living Organism

Iron plays an important role in various crucial processes in the body and its deficiency is considered currently as a serious health problem. Thus, iron supplementation strategies for both humans and animals need to be effective and safe. According to our previous studies, zinc-based nanoparticles provide safe, biodegradable, fast and efficient transport system of orally given substances to the tissues. In the current manuscript we present results of a study aimed at investigation of the ZnO nanoparticle-based Fe supplementation system (average size 100 × 250 nm). Nanostructures were orally (gavage) administered to adult mice. Animals were sacrificed at different time points with collection of blood and internal organs for analyses (tissue iron concentration, hepatic level of hepcidin, blood parameters, liver and spleen levels of ferritin, histopathology). Initial experiment was performed to compare the biological effect of doping type (Fe³⁺ doping vs. a mixture of Fe³⁺ and Fe²⁺). Then, the effect of acute/chronic exposure models was determined. The increase in ferritin, along with improved, crucial hematological parameters and lack of the influence on hepcidin expression indicated the chronic application of Fe^3+,2+ doped ZnO nanostructures to be the most effective among tested.

Pharmacokinetics of Single Domain Antibodies and Conjugated Nanoparticles Using a Hybrid near Infrared Method

Iron oxide nanoparticles and single domain antibodies from camelids (VHHs) have been increasingly recognized for their potential uses for medical diagnosis and treatment. However, there have been relatively few detailed characterizations of their pharmacokinetics (PK). The aim of this study was to develop imaging methods and pharmacokinetic models to aid the future development of a novel family of brain MRI molecular contrast agents. An efficient near-infrared (NIR) imaging method was established to monitor VHH and VHH conjugated nanoparticle kinetics in mice using a hybrid approach: kinetics in blood were assessed by direct sampling, and kinetics in kidney, liver, and brain were assessed by serial in vivo NIR imaging. These studies were performed under "basal" circumstances in which the VHH constructs and VHH-conjugated nanoparticles do not substantially interact with targets nor cross the blood brain barrier. Using this approach, we constructed a five-compartment PK model that fits the data well for single VHHs, engineered VHH trimers, and iron oxide nanoparticles conjugated to VHH trimers. The establishment of the feasibility of these methods lays a foundation for future PK studies of candidate brain MRI molecular contrast agents.

Nanotechnological interventions for treatment of trypanosomiasis in humans and animals

Trypanosomiasis is a parasitic infection caused by Trypanosoma. It is one of the major causes of deaths in underprivileged, rural areas of Africa, America and Asia. Depending on the parasite species responsible for the disease, it can take two forms namely African trypanosomiasis (sleeping sickness) and American trypanosomiasis (Chagas disease). The complete life-cycle stages of trypanosomes span between insect vector (tsetse fly, triatomine bug) and mammalian host (humans, animals). Only few drugs have been approved for the treatment of trypanosomiasis. Moreover, current trypanocidal therapy has major limitations of poor efficacy, serious side effects and drug resistance. Due to the lack of economic gains from tropical parasitic infection, it has always been neglected by the researchers and drug manufacturers. There is an immense need of more effective innovative strategies to decrease the deaths associated with this diseases. Nanotechnological approaches for delivery of existing drugs have shown significant improvement in efficacy with many-fold decrease in their dose. The review emphasizes on nanotechnological interventions in the treatment of trypanosomiasis in both humans and animals. Current trypanocidal therapy and their limitations have also been discussed briefly. Graphical abstract.

Synergistic combination therapy of lung cancer using lipid-layered cisplatin and oridonin co-encapsulated nanoparticles

Lung cancer treatment using cisplatin (DDP) in combination with other drugs are effective for the treatment of non-small cell lung cancer (NSCLC). The aim of this study was to prepare a layer-by-layer nanoparticles (NPs) for the co-loading of DDP and oridonin (ORI) and to evaluate the antitumor activity of the system in vitro and in vivo. Novel DDP and ORI co-loaded layer-by-layer NPs (D/O-NPs) were constructed. The mean diameter, surface change stability and drug release behavior of NPs were evaluated. In vitro cytotoxicity of D/O-NPs was investigated against DDP resistant human lung cancer cell line (A549/DDP cells), and in vivo anti-tumor efficiency of D/O-NPs was tested on mice bearing A549/DDP cells xenografts. D/O-NPs have a diameter of 139.6 ± 4.4 nm, a zeta potential value of +13.8 ± 1.6 mV. D/O-NPs could significantly enhance in vitro cell toxicity and in vivo antitumor effect against A549/DDP cells and lung cancer animal model compared to the single drug loaded NPs and free drugs. The results demonstrated that the D/O-NPs could be used as a promising lung cancer treatment system.

Innate Immune Invisible Ultrasmall Gold Nanoparticles-Framework for Synthesis and Evaluation

Nanomedicine is seen as a potential central player in the delivery of personalized medicine. Biocompatibility issues of nanoparticles have largely been resolved over the past decade. Despite their tremendous progress, less than 1% of applied nanosystems can hit their intended target location, such as a solid tumor, and this remains an obstacle to their full ability and potential with a high translational value. Therefore, achieving immune-tolerable, blood-compatible, and biofriendly nanoparticles remains an unmet need. The translational success of nanoformulations from bench to bedside involves a thorough assessment of their design, compatibility beyond cytotoxicity such as immune toxicity, blood compatibility, and immune-mediated destruction/rejection/clearance profile. Here, we report a one-pot process-engineered synthesis of ultrasmall gold nanoparticles (uGNPs) suitable for better body and renal clearance delivery of their payloads. We have obtained uGNP sizes of as low as 3 nm and have engineered the synthesis to allow them to be accurately sized (almost nanometer by nanometer). The synthesized uGNPs are biocompatible and can easily be functionalized to carry drugs, peptides, antibodies, and other therapeutic molecules. We have performed in vitro cell viability assays, immunotoxicity assays, inflammatory cytokine analysis, a complement activation study, and blood coagulation studies with the uGNPs to confirm their safety. These can help to set up a long-term safety-benefit framework of experimentation to reveal whether any designed nanoparticles are immune-tolerable and can be used as payload carriers for next-generation vaccines, chemotherapeutic drugs, and theranostic agents with better body clearance ability and deep tissue penetration.

Multifunctional lipid-based nanocarriers with antibacterial and anti-inflammatory activities for treating MRSA bacteremia in mice

Background

Bacteremia-induced sepsis is a leading cause of mortality in intensive care units. To control a bacterial infection, an immune response is required, but this response might contribute to organ failure. Kidneys are one of the main organs affected by bacteremia. Combination therapies with antibacterial and anti-inflammatory effects may be beneficial in treating bacteremia. This study aimed to develop nanostructured lipid carriers (NLCs) loaded with ciprofloxacin and rolipram that exert a combination of anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-inflammatory effects. Retinol was incorporated into the nanoparticles to transport retinol-binding protein 4 (RBP4) to the kidneys, which abundantly express RBP receptors. The NLCs were fabricated by high-shear homogenization and sonication, and neutrophils were used as a model to assess their anti-inflammatory effects. Mice were injected with MRSA to establish a model of bacteremia with organ injury.

Results

The mean nanoparticle size and zeta potential of the NLCs were 171 nm and − 39 mV, respectively. Ciprofloxacin (0.05%, w/v) and rolipram (0.02%) achieved encapsulation percentages of 88% and 96%, respectively, in the nanosystems. The minimum bactericidal concentration of free ciprofloxacin against MRSA increased from 1.95 to 15.63 µg/ml when combined with rolipram, indicating a possible drug-drug interaction that reduced the antibacterial effect. Nanoparticle inclusion promoted the anti-MRSA activity of ciprofloxacin according to time-kill curves. The NLCs were found to be largely internalized into neutrophils and exhibited superior superoxide anion inhibition than free drugs. Retinol incorporation into the nanocarriers facilitated their efficient targeting to the kidneys. The NLCs significantly mitigated MRSA burden and elastase distribution in the organs of MRSA-infected animals, and the greatest inhibition was observed in the kidneys. Bacterial clearance and neutrophil infiltration suppression attenuated the bacteremia-induced cytokine overexpression, leading to an improvement in the survival rate from 22% to 67%.

Conclusions

The dual role of our NLCs endowed them with greater efficacy in treating MRSA bacteremia than that of free drugs.

Influence of Dextran Molecular Weight on the Physical Properties of Magnetic Nanoparticles for Hyperthermia and MRI Applications

Dextran-coated magnetic nanoparticles are promising biocompatible agents in various biomedical applications, including hyperthermia and magnetic resonance imaging (MRI). However, the influence of dextran molecular weight on the physical properties of dextran-coated magnetic nanoparticles has not been described sufficiently. We synthesise magnetite nanoparticles with a dextran coating using a co-precipitation method and study their physical properties as a function of dextran molecular weight. Several different methods are used to determine the size distribution of the particles, including microscopy, dynamic light scattering, differential centrifugal sedimentation and magnetic measurements. The size of the dextran-coated particles increases with increasing dextran molecular weight. We find that the molecular weight of dextran has a significant effect on the particle size, efficiency, magnetic properties and specific absorption rate. Magnetic hyperthermia measurements show that heating is faster for dextran-coated particles with higher molecular weight. The different molecular weights of the coating also significantly affected its MRI relaxation properties, especially the transversal relaxivity r₂. Linear regression analysis reveals a statistically significant dependence of r₂ on the differential centrifugal sedimentation diameter. This allows the targeted preparation of dextran-coated magnetic nanoparticles with the desired MRI properties. These results will aid the development of functionalised magnetic nanoparticles for hyperthermia and MRI applications.

Surface modifications affect iron oxide nanoparticles' biodistribution after multiple-dose administration in rats

Iron oxide nanoparticles (IONPs) possess many utilizable physical and chemical properties and have an acceptable level of biocompatibility. Therefore, they are extensively used in different medical applications. Hence, the challenge is to modify the surfaces of prepared iron oxide nanoformulations with a biocompatible coat to enhance their biosafety. In this study, different formulations of IONPs with different capping agents (citrate [Cit-IONPs], curcumin [Cur-IONPs], and chitosan [CS-IONPs]) were prepared and characterized using various physicochemical techniques. The biodistribution of iron and the histopathology of affected tissues were assessed after Cit-IONPs, Cur-IONPs, CS-IONPs, and commercial ferrous sulfate were orally administered to adult female Wistar rats for 10 consecutive days at a dose of 4 mg/kg of body weight/day. The results were compared with a control group injected orally with saline. The iron content in the kidneys, liver, and spleen was measured by atomic absorption spectroscopy. Histopathological alterations were also examined. The biodistribution results demonstrate that iron accumulated mainly in the liver tissue, whereas the lowest liver accumulation was observed after the administration of Cit-IONPs or CS-IONPs, respectively. In contrast, the administration of CS-IONPs displayed the highest spleen iron accumulation. The ferrous sulfate (FeSO₄ )-treated group showed the highest kidney iron accumulation as compared with the other groups. The histopathological examination revealed that signs of toxicity were predominant for groups treated with Cit-IONPs or commercial FeSO₄ . However, Cur-IONPs and CS-IONPs showed mild toxicity when administered at the same doses. The results obtained in the present study will provide insights into the expected in vivo effects after administration of each nanoformulation.

Understanding the influence of experimental factors on bio-interactions of nanoparticles: Towards improving correlation between in vitro and in vivo studies

Bionanotechnology has developed rapidly over the past two decades, owing to the extensive and versatile, functionalities and applicability of nanoparticles (NPs). Fifty-one nanomedicines have been approved by FDA since 1995, out of the many NPs based formulations developed to date. The general conformation of NPs consists of a core with ligands coating their surface, that stabilizes them and provides them with added functionalities. The physicochemical properties, especially the surface composition of NPs influence their bio-interactions to a large extent. This review discusses recent studies that help understand the nano-bio interactions of iron oxide and gold NPs with different surface compositions. We discuss the influence of the experimental factors on the outcome of the studies and, thus, the importance of standardization in the field of nanotechnology. Recent studies suggest that with careful selection of experimental parameters, it is possible to improve the positive correlation between in vitro and in vivo studies. This provides a fundamental understanding of the NPs which helps in assessing their potential toxic side effects and may aid in manipulating them further to improve their biocompatibility and biosafety.

Effects of carbon nanotube-mediated Caspase3 gene silencing on cardiomyocyte apoptosis and cardiac function during early acute myocardial infarction

RNA interference (RNAi) technology can achieve efficient and specific silencing of Caspase3 gene expression, thus providing new options for anti-apoptosis treatment. However, delivering siRNA to specific cells and tissues in the body is a significant challenge. Therefore, we aim to construct a functionalized single-walled carbon nanotube (F-CNT) bound to siRNA from Caspase3. The obtained gene transfer carrier F-CNT-siCas3 not only demonstrated a good water solubility and biocompatibility, but also had a high transfection efficiency of up to 82%, which significantly downregulated the expression level of the Caspase3 gene miRNA and protein in primary cardiomyocytes. Furthermore, it was verified by in vivo experiments that Caspase3 gene silencing had obvious protective effects on myocardial cell apoptosis, ventricular remodeling, and cardiac function in Sprague-Dawley (SD) rats after coronary artery ligation. This study may provide an important theoretical basis for the application of F-CNT in vivo siRNA gene therapy to treat cardiovascular diseases.

Rational design of adjuvants for subunit vaccines: The format of cationic adjuvants affects the induction of antigen-specific antibody responses

A range of cationic delivery systems have been investigated as vaccine adjuvants, though few direct comparisons exist. To investigate the impact of the delivery platform, we prepared four cationic systems (emulsions, liposomes, polymeric nanoparticles and solid lipid nanoparticles) all containing equal concentrations of the cationic lipid dimethyldioctadecylammonium bromide in combination with the Neisseria adhesin A variant 3 subunit antigen. The formulations were physicochemically characterized and their ability to associate with cells and promote antigen processing (based on degradation of DQ-OVA, a substrate for proteases which upon hydrolysis is fluorescent) was compared in vitro and their vaccine efficacy (antigen-specific antibody responses and IFN-γ production) and biodistribution (antigen and adjuvant) were evaluated in vivo. Due to their cationic nature, all delivery systems gave high antigen loading (> 85%) with liposomes, lipid nanoparticles and emulsions being <200 nm, whilst polymeric nanoparticles were larger (~350 nm). In vitro, the particulate systems tended to promote cell uptake and antigen processing, whilst emulsions were less effective. Similarly, whilst the particulate delivery systems induced a depot (of both delivery system and antigen) at the injection site, the cationic emulsions did not. However, out of the systems tested the cationic emulsions induced the highest antibody responses. These results demonstrate that while cationic lipids can have strong adjuvant activity, their formulation platform influences their immunogenicity.

Sequentially-targeted biomimetic nano drug system for triple-negative breast cancer ablation and lung metastasis inhibition

As a breast cancer subtype with high mortality in women, the efficient treatment of Triple-negative breast cancer (TNBC) is still a challenge due to its unique metastatic mode and poor prognosis. In this study, we developed a biomimetic nanodelivery system (denoted as GTDC@M-R NPs) based on erythrocyte membrane (M)-camouflaged graphene oxide quantum dots (GOQDs, G) for TNBC therapy. The TAT (T) and RGD (R) peptides were used to endow targeting accumulation ability of Gamabufotalin (CS-6, C) and doxorubicin (DOX, D) in tumor tissue. In vitro assay indicated good biocompatibility, prolonged blood circulation time (3-fold longer than GT NPs), and effectively enhanced cell and nucleus targeting capability of this nanosystem. Fluorescence activated cell sorter (FACS) analysis indicated that the combination of DOX and CS-6 induced TNBC cell apoptosis more than 89 % under the ratio of 10:1. In vivo assay indicated that the accumulation of GTDC@M-R NPs in tumor sites increased about 2-fold compared to naked GTDC NPs, which was accompanied by high tumor apoptosis rates through blocking chemotherapy-activated cyclooxygenase-2 (COX-2) and enhancing DOX's anti-tumor activity of chemical drugs (85%). Moreover, comparing with the control, the average number of lung metastatic nodules in tumor-bearing mice reduced 84%, the molecular mechanism of which is related to the down expression of COX-2, matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF). Taken together, our results proved that the developed GTDC@M-R NPs can inhibit the growth and suppress metastasis of TNBC, which broaden our insights into the application of combinational strategy for efficient TNBC therapy. STATEMENT OF SIGNIFICANCE: In this study, we developed a biomimetic nanodelivery system (denoted as GTDC@M-R NPs) based on erythrocyte membrane (M)-camouflaged graphene oxide quantum dots (GOQDs, G) for TNBC therapy. The TAT (T) and RGD (R) peptides were used to endow targeting accumulation ability of Gamabufotalin (CS-6, C) and doxorubicin (DOX, D) in tumor tissue. These GTDC@M-R NPs indicated synergistic chemotherapy against TNBC cells through the precise cell and nuclear targeting, immune escape, and improved DOX sensitivity. A effective inhibition of tumor growth and metastasis was achieved by inhibiting Bcl-2/BAX, COX-2 and VEGF related signal pathways. Our finding suggests that the developed GTDC@M-R NPs present great treating effects in the preclinical models of TNBC, which broaden our insights into the application of combinational strategy for efficient TNBC therapy.

Efficient uptake and retention of iron oxide-based nanoparticles in HeLa cells leads to an effective intracellular delivery of doxorubicin

The purpose of this study was to construct and characterize iron oxide nanoparticles (IONP_CO) for intracellular delivery of the anthracycline doxorubicin (DOX; IONP_DOX) in order to induce tumor cell inactivation. More than 80% of the loaded drug was released from IONP_DOX within 24 h (100% at 70 h). Efficient internalization of IONP_DOX and IONP_CO in HeLa cells occurred through pino- and endocytosis, with both IONP accumulating in a perinuclear pattern. IONP_CO were biocompatible with maximum 27.9% ± 6.1% reduction in proliferation 96 h after treatment with up to 200 µg/mL IONP_CO. Treatment with IONP_DOX resulted in a concentration- and time-dependent decrease in cell proliferation (IC₅₀ = 27.5 ± 12.0 μg/mL after 96 h) and a reduced clonogenic survival (surviving fraction, SF = 0.56 ± 0.14; versus IONP_CO (SF = 1.07 ± 0.38)). Both IONP constructs were efficiently internalized and retained in the cells, and IONP_DOX efficiently delivered DOX resulting in increased cell death vs IONP_CO.

Biodistribution and toxicity of epitope-functionalized dextran iron oxide nanoparticles in a pregnant murine model

In pursuit of a preventive therapeutic for maternal autoantibody-related (MAR) autism, we assessed the toxicity, biodistribution, and clearance of a MAR specific peptide-functionalized dextran iron oxide nanoparticle system in pregnant murine dams. We previously synthesized ~15 nm citrate-coated dextran iron oxide nanoparticles (DIONPs), surface-modified with polyethylene glycol and MAR peptides to produce systems for nanoparticle-based autoantibody reception and entrapments (SNAREs). First, we investigated their immunogenicity and MAR lactate dehydrogenase B antibody uptake in murine serum in vitro. To assess biodistribution and toxicity, as well as systemic effects, we performed in vivo clinical and post mortem pathological evaluations. We observed minimal production of inflammatory cytokines-interleukin 10 (IL-10) and IL-12 following in vitro exposure of macrophages to SNAREs. We established the maximum tolerated dose of SNAREs to be 150 mg/kg at which deposition of iron was evident in the liver and lungs by histology and magnetic resonance imaging but no concurrent evidence of liver toxicity or lung infarction was detected. Further, SNAREs exhibited slower clearance from the maternal blood in pregnant dams compared to DIONPs based on serum total iron concentration. These findings demonstrated that the SNAREs have a prolonged presence in the blood and are safe for use in pregnant mice as evidenced by no associated organ damage, failure, inflammation, and fetal mortality. Determination of the MTD dose sets the basis for future studies investigating the efficacy of our nanoparticle formulation in a MAR autism mouse model.

Oleic acid-based nanosystems for mitigating acute respiratory distress syndrome in mice through neutrophil suppression: how the particulate size affects therapeutic efficiency

Background

Oleic acid (OA) is reported to show anti-inflammatory activity toward activated neutrophils. It is also an important material in nanoparticles for increased stability and cellular internalization. We aimed to evaluate the anti-inflammatory activity of injectable OA-based nanoparticles for treating lung injury. Different sizes of nanocarriers were prepared to explore the effect of nanoparticulate size on inflammation inhibition.

Results

The nanoparticles were fabricated with the mean diameters of 105, 153, and 225 nm. The nanocarriers were ingested by isolated human neutrophils during a 5-min period, with the smaller sizes exhibiting greater uptake. The size reduction led to the decrease of cell viability and the intracellular calcium level. The OA-loaded nanosystems dose-dependently suppressed the superoxide anion and elastase produced by the stimulated neutrophils. The inhibition level was comparable for the nanoparticles of different sizes. In the ex vivo biodistribution study, the pulmonary accumulation of nanoparticles increased following the increase of particle size. The nanocarriers were mainly excreted by the liver and bile clearance. Mice were exposed to intratracheal lipopolysaccharide (LPS) to induce acute respiratory distress syndrome (ARDS), like lung damage. The lipid-based nanocarriers mitigated myeloperoxidase (MPO) and cytokines more effectively as compared to OA solution. The larger nanoparticles displayed greater reduction on MPO, TNF-α, and IL-6 than the smaller ones. The histology confirmed the decreased pulmonary neutrophil recruitment and lung-architecture damage after intravenous administration of larger nanoparticles.

Conclusions

Nanoparticulate size, an essential property governing the anti-inflammatory effect and lung-injury therapy, had different effects on activated neutrophil inhibition and in vivo therapeutic efficacy.

Optimizing PEGylation of TiO2 Nanocrystals through a Combined Experimental and Computational Study

PEGylation of metal oxide nanoparticles is the common approach to improve their biocompatibility and in vivo circulation time. In this work, we present a combined experimental and theoretical study to determine the operating condition that guarantee very high grafting densities, which are desirable in any biomedical application. Moreover, we present an insightful conformational analysis spanning different coverage regimes and increasing polymer chain lengths. Based on 13C NMR measurements and molecular dynamics simulations, we show that classical and popular models of polymer conformation on surfaces fail in determining the mushroom-to-brush transition point and prove that it actually takes place only at rather high grafting density values.

Intravital microscopy reveals a novel mechanism of nanoparticles excretion in kidney

Developing nanocarriers that accumulate in targeted organs and are harmlessly eliminated still remains a big challenge. Nanoparticles (NP) biodistribution is governed by their size, composition, surface charge and coverage. The current thinking in bionanotechnology is that renal clearance is limited by glomerular basement membrane pore size (≈6 nm), although there is a growing evidence that NP exceeding the threshold can also be excreted with urine. Here we compare biodistribution of PEGylated 140 nm iron oxide cubes and clusters with a special focus on renal accumulation and excretion. Atomic emission spectroscopy, fluorescent microscopy and magnetic resonance imaging revealed rapid and transient accumulation of magnetic NP in kidney. Using intravital microscopy we tracked in real time NP translocation from peritubular capillaries to basal compartment of tubular cells and subsequent excretion to the lumen within 60 min after systemic administration. Transmission electron microscopy revealed persistence of intact full-sized NP in urine 2 h post injection. The results suggest that translocation through peritubular endothelium to tubular epithelial cells is an alternative mechanism of renal clearance enabling excretion of NP above glomerular cut-off size.

Plasma protein adsorption on Fe3O4-PEG nanoparticles activates the complement system and induces an inflammatory response

BACKGROUND

Understanding of iron oxide nanoparticles (IONP) interaction with the body milieu is crucial to guarantee their efficiency and biocompatibility in nanomedicine. Polymer coating to IONP, with polyethyleneglycol (PEG) and polyvinylpyrrolidone (PVP), is an accepted strategy to prevent toxicity and excessive protein binding.

AIM

The aim of this study was to investigate the feature of IONP adsorption of complement proteins, their activation and consequent inflammatory response as a strategy to further elucidate their biocompatibility.

METHODS

Three types of IONP with different surface characteristics were used: bare (IONP-bare), coated with PVP (IONP-PVP) and PEG-coated (IONP-PEG). IONPs were incubated with human plasma and adsorbed proteins were identified. BALB/c mice were intravenously exposed to IONP to evaluate complement activation and proinflammatory response.

RESULTS

Protein corona fingerprinting showed that PEG surface around IONP promoted a selective adsorption of complement recognition molecules which would be responsible for the complement system activation. Furthermore, IONP-PEG activated in vitro, the complement system and induced a substantial increment of C3a and C4a anaphylatoxins while IONP-bare and IONP-PVP did not. In vivo IONP-PEG induced an increment in complement activation markers (C5a and C5b-9), and proinflammatory cytokines (IL-1β, IL-6, TNF-α).

CONCLUSION

The engineering of nanoparticles must incorporate the association between complement proteins and nanomedicines, which will regulate the immunostimulatory effects through a selective adsorption of plasma proteins and will enable a safer application of IONP in human therapy.

A review of small molecules and drug delivery applications using gold and iron nanoparticles

Conventional cancer treatment techniques show several limitations including low or no specificity and consequently a low efficacy in discriminating between cancer cells and healthy cells. Recent nanotechnology developments have introduced smart and novel therapeutic nanomaterials that take advantage of various targeting approaches. The use of nanotechnology in medicine and, more specifically, drug delivery is set to spread even more rapidly than it has over the past two decades. Currently, many nanoparticles (NPs) are under investigation for drug delivery including those for cancer therapy. Targeted nanomaterials bind selectively to cancer cells and greatly affect them with only a minor effect on healthy cells. Gold nanoparticles (Au-NPs), specifically, have been identified as significant candidates for new cancer therapeutic modalities because of their biocompatibility, easy functionalization and fabrication, optical tunable characteristics, and chemophysical stability. In the last decade, there has been significant research on Au-NPs and their biomedical applications. Functionalized Au-NPs represent highly attractive and promising candidates for drug delivery, owing to their unique dimensions, tunable surface functionalities, and controllable drug release. Further, iron oxide NPs due to their "superparamagnetic" properties have been studied and have demonstrated successful employment in numerous applications. In targeted drug delivery systems, drug-loaded iron oxide NPs can accumulate at the tumor site with the aid of an external magnetic field. This can lead to incremental effectiveness in drug release to the tumor site and vanquish cancer cells without harming healthy cells. In order for the application of iron oxide NPs in the human body to be realized, they should be biodegradable and biocompatible to minimize toxicity. This review illustrates recent advances in the field drug and small molecule delivery such as fluorouracil, folic acid, doxorubicin, paclitaxel, and daunorubicin, specifically when using gold and iron oxide NPs as carriers of anticancer therapeutic agents.