Magnetic nanoparticles as new diagnostic tools in medicine

Interaction between polydopamine-based IONPs and human serum albumin (HSA): a spectroscopic analysis with cytotoxicity impact

Iron oxide nanoparticles (IONPs) have been extensively explored in biomedicine, bio-sensing, hyperthermia, and drug/gene delivery, attributed to their versatile and tunable properties. However, owing to its numerous applications, the functionalization of IONPs with appropriate materials is in demand. To achieve optimal functionalization of IONPs, polydopamine (PDA) was utilized due to its ability to provide a superior functionalized surface, near-infrared light absorption, and adhesive nature to customize desired functionalized IONPs. This notion of involving PDA led to the successful synthesis of magnetite-PDA nanoparticles, where PDA is surface-coated on magnetite (Fe3O4@PDA). The Fe3O4@PDA nanoparticles were characterized using techniques like TEM, FESEM, PXRD, XPS, VSM, and FTIR, suggesting PDA's successful attachment with magnetite crystal structure retention. Human serum albumin (HSA), the predominant protein in blood plasma, interacts with the delivered nanoparticles. Therefore, we have employed various spectroscopic techniques, along with cytotoxicity, to inspect the effect of Fe3O4@PDA NPs on the stability and structure of HSA. The structural alterations were examined using circular dichroism (CD) and synchronous fluorescence spectroscopy (SFS). It has been observed that there are no structural perturbations in the secondary structure of the HSA protein after interaction with Fe3O4@PDA. Studies using steady-state fluorescence revealed that the inherent fluorescence intensities of HSA were suppressed after interaction with Fe3O4@PDA. In addition, temperature-dependent fluorescence measurements suggested that the type of quenching consists of both static and dynamic quenching simultaneously. A cytotoxicity study in Drosophila melanogaster larvae revealed no cytotoxic effects but did show a minor genotoxic effect only at higher concentrations.

Nano-pulling stimulates axon regeneration in dorsal root ganglia by inducing stabilization of axonal microtubules and activation of local translation

Introduction

Axonal plasticity is strongly related to neuronal development as well as regeneration. It was recently demonstrated that active mechanical tension, intended as an extrinsic factor, is a valid contribution to the modulation of axonal plasticity.

Methods

In previous publications, our team validated a the "nano-pulling" method used to apply mechanical forces to developing axons of isolated primary neurons using magnetic nanoparticles (MNP) actuated by static magnetic fields. This method was found to promote axon growth and synaptic maturation. Here, we explore the use of nano-pulling as an extrinsic factor to promote axon regeneration in a neuronal tissue explant.

Results

Whole dorsal root ganglia (DRG) were thus dissected from a mouse spinal cord, incubated with MNPs, and then stretched. We found that particles were able to penetrate the ganglion and thus become localised both in the somas and in sprouting axons. Our results highlight that nano-pulling doubles the regeneration rate, and this is accompanied by an increase in the arborizing capacity of axons, an accumulation of cellular organelles related to mass addition (endoplasmic reticulum and mitochondria) and pre-synaptic proteins with respect to spontaneous regeneration. In line with the previous results on isolated hippocampal neurons, we observed that this process is coupled to an increase in the density of stable microtubules and activation of local translation.

Discussion

Our data demonstrate that nano-pulling enhances axon regeneration in whole spinal ganglia exposed to MNPs and external magnetic fields. These preliminary data represent an encouraging starting point for proposing nano-pulling as a biophysical tool for the design of novel therapies based on the use of force as an extrinsic factor for promoting nerve regeneration.

Synergistic anticancer effect of Pistacia lentiscus essential oils and 5-Fluorouracil co-loaded onto biodegradable nanofibers against melanoma and breast cancer

Chemoresistance and severe toxicities represent major drawbacks of chemotherapy. Natural extracts, including the essential oils of Pistacia lentiscus (PLEO), exhibit substantial anticancer and anti-inflammatory activities where different cancers are reported to dramatically recess following targeting with PLEO. PLEO has promising antimicrobial, anticancer, and anti-inflammatory properties. However, the therapeutic properties of PLEO are restricted by limited stability, bioavailability, and targeting ability. PLEO nanoformulation can maximize their physicochemical and therapeutic properties, overcoming their shortcomings. Hence, PLEO was extracted and its chemical composition was determined by GC-MS. PLEO and 5-Fluorouracil (5FU) were electrospun into poly-ε-caprolactone nanofibers (PCL-NFs), of 290.71 nm to 680.95 nm diameter, to investigate their anticancer and potential synergistic activities against triple-negative breast cancer cells (MDA-MB-231), human adenocarcinoma breast cancer cells (MCF-7), and human skin melanoma cell line (A375). The prepared nanofibers (NFs) showed enhanced thermal stability and remarkable physical integrity and tensile strength. Biodegradability studies showed prolonged stability over 42 days, supporting the NFs use as a localized therapy of breast tissues (postmastectomy) or melanoma. Release studies revealed sustainable release behaviors over 168 h, with higher released amounts of 5FU and PLEO at pH 5.4, indicating higher targeting abilities towards cancer tissues. NFs loaded with PLEO showed strong antioxidant properties. Finally, NFs loaded with either PLEO or 5FU depicted greater anticancer activities compared to free compounds. The highest anticancer activities were observed with NFs co-loaded with PLEO and 5FU. The developed 5FU-PLEO-PCL-NFs hold potential as a local treatment of breast cancer tissues (post-mastectomy) and melanoma to minimize their  possible recurrence.

Inulin-based formulations as an emerging therapeutic strategy for cancer: A comprehensive review

Cancer stands as the second leading cause of death in the United States (US). Most chemotherapeutic agents exhibit severe adverse effects that are attributed to exposure of drugs to off-target tissues, posing a significant challenge in cancer therapy management. In recent years, inulin, a naturally occurring prebiotic fiber has gained substantial attention for its potential in cancer treatment owing to its multitudinous health values. Its distinctive structure, stability, and nutritional properties position it as an effective adjuvant and carrier for drug delivery in cancer therapy. To address some of the above unmet clinical issues, this review summarizes the recent efforts towards the development of inulin-based nanomaterials and nanocomposites for healthcare applications with special emphasis on the multifunctional role of inulin in cancer therapy as a synergist, signaling molecule, immunomodulatory and anticarcinogenic molecule. Furthermore, the review provides a concise overview of ongoing clinical trials and observational studies associated with inulin-based therapy. In conclusion, the current review offers insights on the significant role of inulin interventions in exploring its potential as a therapeutic agent to treat cancer.

Characteristics and Antimicrobial Activities of Iron Oxide Nanoparticles Obtained via Mixed-Mode Chemical/Biogenic Synthesis Using Spent Hop (Humulus lupulus L.) Extracts

Iron oxide nanoparticles (IONPs) have many practical applications, ranging from environmental protection to biomedicine. IONPs are being investigated due to their high potential for antimicrobial activity and lack of toxicity to humans. However, the biological activity of IONPs is not uniform and depends on the synthesis conditions, which affect the shape, size and surface modification. The aim of this work is to synthesise IONPs using a mixed method, i.e., chemical co-precipitation combined with biogenic surface modification, using extracts from spent hops (Humulus lupulus L.) obtained as waste product from supercritical carbon dioxide hop extraction. Different extracts (water, dimethyl sulfoxide (DMSO), 80% ethanol, acetone, water) were further evaluated for antioxidant activity based on the silver nanoparticle antioxidant capacity (SNPAC), total phenolic content (TPC) and total flavonoid content (TFC). The IONPs were characterised via UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Spent hop extracts showed a high number of flavonoid compounds. The efficiency of the solvents used for the extraction can be classified as follows: DMSO > 80% ethanol > acetone > water. FT-IR/ATR spectra revealed the involvement of flavonoids such as xanthohumol and/or isoxanthohumol, bitter acids (i.e., humulones, lupulones) and proteins in the surface modification of the IONPs. SEM images showed a granular, spherical structure of the IONPs with diameters ranging from 81.16 to 142.5 nm. Surface modification with extracts generally weakened the activity of the IONPs against the tested Gram-positive and Gram-negative bacteria and yeasts by half. Only the modification of IONPs with DMSO extract improved their antibacterial properties against Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Bacillus cereus) from a MIC value of 2.5-10 mg/mL to 0.313-1.25 mg/mL.

Biomaterials for Drug Delivery and Human Applications

Biomaterials embody a groundbreaking paradigm shift in the field of drug delivery and human applications. Their versatility and adaptability have not only enriched therapeutic outcomes but also significantly reduced the burden of adverse effects. This work serves as a comprehensive overview of biomaterials, with a particular emphasis on their pivotal role in drug delivery, classifying them in terms of their biobased, biodegradable, and biocompatible nature, and highlighting their characteristics and advantages. The examination also delves into the extensive array of applications for biomaterials in drug delivery, encompassing diverse medical fields such as cancer therapy, cardiovascular diseases, neurological disorders, and vaccination. This work also explores the actual challenges within this domain, including potential toxicity and the complexity of manufacturing processes. These challenges emphasize the necessity for thorough research and the continuous development of regulatory frameworks. The second aim of this review is to navigate through the compelling terrain of recent advances and prospects in biomaterials, envisioning a healthcare landscape where they empower precise, targeted, and personalized drug delivery. The potential for biomaterials to transform healthcare is staggering, as they promise treatments tailored to individual patient needs, offering hope for improved therapeutic efficacy, fewer side effects, and a brighter future for medical practice.

Spermine Oxidase-Substrate Electrostatic Interactions: The Modulation of Enzyme Function by Neighboring Colloidal ɣ-Fe2O3

Protein-nanoparticle hybridization can ideally lead to novel biological entities characterized by emerging properties that can sensibly differ from those of the parent components. Herein, the effect of ionic strength on the biological functions of recombinant His-tagged spermine oxidase (i.e., SMOX) was studied for the first time. Moreover, SMOX was integrated into colloidal surface active maghemite nanoparticles (SAMNs) via direct self-assembly, leading to a biologically active nano-enzyme (i.e., SAMN@SMOX). The hybrid was subjected to an in-depth chemical-physical characterization, highlighting the fact that the protein structure was perfectly preserved. The catalytic activity of the nanostructured hybrid (SAMN@SMOX) was assessed by extracting the kinetics parameters using spermine as a substrate and compared to the soluble enzyme as a function of ionic strength. The results revealed that the catalytic function was dominated by electrostatic interactions and that they were drastically modified upon hybridization with colloidal ɣ-Fe2O3. The fact that the affinity of SMOX toward spermine was significantly higher for the nanohybrid at low salinity is noteworthy. The present study supports the vision of using protein-nanoparticle conjugation as a means to modulate biological functions.

Magnetically Controlled Hyaluronic Acid-Maghemite Nanocomposites with Embedded Doxorubicin

The controllable delivery of drugs is a key task of pharmacology. For this purpose, a series of polymer composites was synthesized via the cross-linking of hyaluronate and a hyaluronate/polyacrylate mixture with Fe2O3 nanoparticles. The cross-linking imparts magnetic properties to the composites, which are more pronounced for the ternary hyaluronate/polyacrylate/γ-Fe2O3 composites compared with the binary hyaluronate/Fe2O3 composites. When dispersed in water, the composites produce microsized hydrogel particles. Circulation of the ternary microgels in an aqueous solution at a speed of 1.84 cm/s can be stopped using a permanent external magnet with a magnetic flux density of 400 T. The composite hydrogels can absorb the antitumor antibiotic doxorubicin (Dox); the resulting constructs show their cytotoxicity to tumor cells to be comparable to the cytotoxicity of Dox itself. The addition of the hyaluronidase enzyme induces degradation of the binary and ternary microgels down to smaller particles. This study presents prospectives for the preparation of magnetically controlled biodegradable polymer carriers for the encapsulation of bioactive substances.

Advancements of Nanotechnology and Nanomaterials in Environmental and Human Protection for Combatting the COVID-19 During and Post-pandemic Era: A Comprehensive Scientific Review

In December 2019, an outbreak of unknown pneumonia emerged in Wuhan City, Hubei Province, China. It was later identified as the SARS-CoV-2 virus and has since infected over 9 million people in more than 213 countries worldwide. Massive papers on the topic of SARS-CoV-2 that have already been published are necessary to be analyzed and discussed. This paper used the combination of systematic literature network analysis and content analysis to develop a comprehensive discussion related to the use of nanotechnology and materials in environmental and human protection. Its is shown that various efforts have been made to control the transmission of this pandemic. Nanotechnology plays a crucial role in modern vaccine design, as nanomaterials are essential tools for antigen delivery, adjuvants, and mimics of viral structures. In addition, nanomaterials and nanotechnology also reported a crucial role in environmental protection for defence and treating the pandemic. To eradicate pandemics now and in the future, successful treatments must enable rapid discovery, scalable manufacturing, and global distribution. In this review, we discuss the current approaches to COVID-19 development and highlight the critical role of nanotechnology and nanomaterials in combating the virus in the human body and the environment.

Nanotechnology-Based Diagnostics for Diseases Prevalent in Developing Countries: Current Advances in Point-of-Care Tests

The introduction of point-of-care testing (POCT) has revolutionized medical testing by allowing for simple tests to be conducted near the patient's care point, rather than being confined to a medical laboratory. This has been especially beneficial for developing countries with limited infrastructure, where testing often involves sending specimens off-site and waiting for hours or days for results. However, the development of POCT devices has been challenging, with simplicity, accuracy, and cost-effectiveness being key factors in making these tests feasible. Nanotechnology has played a crucial role in achieving this goal, by not only making the tests possible but also masking their complexity. In this article, recent developments in POCT devices that benefit from nanotechnology are discussed. Microfluidics and lab-on-a-chip technologies are highlighted as major drivers of point-of-care testing, particularly in infectious disease diagnosis. These technologies enable various bioassays to be used at the point of care. The article also addresses the challenges faced by these technological advances and interesting future trends. The benefits of point-of-care testing are significant, especially in developing countries where medical care is shifting towards prevention, early detection, and managing chronic conditions. Infectious disease tests at the point of care in low-income countries can lead to prompt treatment, preventing infections from spreading.

Application of Iron Nanoparticle-Based Materials in the Food Industry

Due to their different properties compared to other materials, nanoparticles of iron and iron oxides are increasingly used in the food industry. Food technologists have especially paid attention to their ease of separation by magnetic fields and biocompatibility. Unfortunately, the consumption of increasing amounts of nanoparticles has raised concerns about their biotoxicity. Hence, knowledge about the applicability of iron nanoparticle-based materials in the food industry is needed not only among scientists, but also among all individuals who are involved in food production. The first part of this article describes typical methods of obtaining iron nanoparticles using chemical synthesis and so-called green chemistry. The second part of this article describes the use of iron nanoparticles and iron nanoparticle-based materials for active packaging, including the ability to eliminate oxygen and antimicrobial activity. Then, the possibilities of using the magnetic properties of iron nano-oxides for enzyme immobilization, food analysis, protein purification and mycotoxin and histamine removal from food are described. Other described applications of materials based on iron nanoparticles are the production of artificial enzymes, process control, food fortification and preserving food in a supercooled state. The third part of the article analyzes the biocompatibility of iron nanoparticles, their impact on the human body and the safety of their use.

Ecotoxicological assessment of magnetite and magnetite/Ag nanoparticles on terrestrial and aquatic biota from different trophic levels

The aim of the study is an ecotoxicological assessment of magnetite iron oxide-based nanoparticles (NPs), which have risen in popularity in the last decade, on selected terrestrial and aquatic organisms from various levels of the food chain. In the presented study various organisms, from both the terrestrial and aquatic environment, were used as targets for the assessment of NPs ecotoxicity. Plants (radish, oat), marine bacteria (A. fischeri) and crustacean (H. incongruens) were used to represent producers, decomposers, and consumers, respectively. It was found that examined NPs were harmful (to a different degree) to biota from three different trophic levels. Physicochemical characterization (size/morphology, crystallinity, composition, and magnetic properties) of the tested nanoparticles was performed by: transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Mossbauer spectroscopy, respectively. Phytotoxicity was evaluated according to the OECD 208 Guideline, while acute and chronic toxicity of NPs was conducted using bioassays employing bacteria and crustacea, respectively. The phytotoxicity of all investigated iron oxide-based NPs was dependent on concentration and type of NPs formulation and was measured via biomass, seed germination, root length, shoot height, and content of plant pigments. Increasing the concentration of NPs increased phytotoxicity and mortality of aquatic organisms. Ecotoxicity of iron oxide/silver was dependent on the size and content of silver. Iron oxide NPs coated with nanosilver in a percentage ratio of 69/31 were found to be the most toxic on tested terrestrial and aquatic biota.

Rapid microwave synthesis of magnetic nanoparticles in physiological serum

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are more and more used in biomedical applications such as therapy (treatment for certain cancers, hyperthermia), diagnostic (contrast agent for Magnetic Resonance Imaging) or both. For these applications, SPIONs must be stable in an aqueous solution, monodisperse, with a narrow size distribution and without aggregation. To obtain these nanoparticles, a microwave process is carried out in this study as an easy, fast and reproducible synthesis method. Currently, in the literature, most synthesis of SPIONs are in ultra-pure water or another solvent. To consider the use of SPIONs in biomedical applications, it is essential to ensure the preservation of the physico-chemical parameters of the nanoparticles in the physiological medium to validate a synthesis process. With this objective, this study reports a comparison between the SPIONs synthesis in ultra-pure water and the SPIONs direct synthesis in a physiological serum (containing NaCl). To complete this comparison, the dispersion of SPIONs in physiological serum after an elaboration in ultra-pure water is reported. Characterizations of these different SPIONs samples are carried out to determine the physico-chemical parameters and magnetic properties. SPIONs are characterized by Transmission Electronic Microscopy, Dynamic Light Scattering, X-Ray Diffraction, Raman spectroscopy and magnetic measurements. Finally, to check if SPIONs can be used as contrast agent for MRI, a relaxometry measurement is performed.

Nanomaterials-Based Combinatorial Therapy as a Strategy to Combat Antibiotic Resistance

Since the discovery of antibiotics, humanity has been able to cope with the battle against bacterial infections. However, the inappropriate use of antibiotics, the lack of innovation in therapeutic agents, and other factors have allowed the emergence of new bacterial strains resistant to multiple antibiotic treatments, causing a crisis in the health sector. Furthermore, the World Health Organization has listed a series of pathogens (ESKAPE group) that have acquired new and varied resistance to different antibiotics families. Therefore, the scientific community has prioritized designing and developing novel treatments to combat these ESKAPE pathogens and other emergent multidrug-resistant bacteria. One of the solutions is the use of combinatorial therapies. Combinatorial therapies seek to enhance the effects of individual treatments at lower doses, bringing the advantage of being, in most cases, much less harmful to patients. Among the new developments in combinatorial therapies, nanomaterials have gained significant interest. Some of the most promising nanotherapeutics include polymers, inorganic nanoparticles, and antimicrobial peptides due to their bactericidal and nanocarrier properties. Therefore, this review focuses on discussing the state-of-the-art of the most significant advances and concludes with a perspective on the future developments of nanotherapeutic combinatorial treatments that target bacterial infections.

Polymeric Nanocomposites for Environmental and Industrial Applications

Polymeric nanocomposites (PNC) have an outstanding potential for various applications as the integrated structure of the PNCs exhibits properties that none of its component materials individually possess. Moreover, it is possible to fabricate PNCs into desired shapes and sizes, which would enable controlling their properties, such as their surface area, magnetic behavior, optical properties, and catalytic activity. The low cost and light weight of PNCs have further contributed to their potential in various environmental and industrial applications. Stimuli-responsive nanocomposites are a subgroup of PNCs having a minimum of one promising chemical and physical property that may be controlled by or follow a stimulus response. Such outstanding properties and behaviors have extended the scope of application of these nanocomposites. The present review discusses the various methods of preparation available for PNCs, including in situ synthesis, solution mixing, melt blending, and electrospinning. In addition, various environmental and industrial applications of PNCs, including those in the fields of water treatment, electromagnetic shielding in aerospace applications, sensor devices, and food packaging, are outlined.

A Comprehensive Updated Review on Magnetic Nanoparticles in Diagnostics

Magnetic nanoparticles (MNPs) have been studied for diagnostic purposes for decades. Their high surface-to-volume ratio, dispersibility, ability to interact with various molecules and superparamagnetic properties are at the core of what makes MNPs so promising. They have been applied in a multitude of areas in medicine, particularly Magnetic Resonance Imaging (MRI). Iron oxide nanoparticles (IONPs) are the most well-accepted based on their excellent superparamagnetic properties and low toxicity. Nevertheless, IONPs are facing many challenges that make their entry into the market difficult. To overcome these challenges, research has focused on developing MNPs with better safety profiles and enhanced magnetic properties. One particularly important strategy includes doping MNPs (particularly IONPs) with other metallic elements, such as cobalt (Co) and manganese (Mn), to reduce the iron (Fe) content released into the body resulting in the creation of multimodal nanoparticles with unique properties. Another approach includes the development of MNPs using other metals besides Fe, that possess great magnetic or other imaging properties. The future of this field seems to be the production of MNPs which can be used as multipurpose platforms that can combine different uses of MRI or different imaging techniques to design more effective and complete diagnostic tests.

Study of the influence of autoclave sterilization on the properties of citrate functionalized iron oxide nanoparticles

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are widely used in various areas of the biomedical field: for diagnosis (Magnetic Resonance Imaging), for therapeutic applications (hyperthermia, nanovectorization). These applications require a good stability in water and no aggregation of SPIONs, with well-controlled physicochemical and magnetic properties. In this work, SPIONs functionalized by citrate ligands are synthesized in a one-step process with the aim of producing stable water-dispersible nanoparticles with a well-crystallized spinel structure. Microwave technology is implemented to achieve this objective given the ease, speed and reproducibility of the method. For their future use in biomedical applications, the sterilization of these SPIONs are essential by an autoclave treatment. The influence of this treatment on the physicochemical and magnetic properties of the SPIONs is determined by a systematic characterization before and after sterilization by Transmission Electronic Microscopy, Dynamic Light Scattering, X-ray Diffraction, Fourier Transformed Infra-Red, ThermoGravimetric Analysis and magnetic measurements.

Cancer nanotechnology: current status and perspectives

Modern medicine has been waging a war on cancer for nearly a century with no tangible end in sight. Cancer treatments have significantly progressed, but the need to increase specificity and decrease systemic toxicities remains. Early diagnosis holds a key to improving prognostic outlook and patient quality of life, and diagnostic tools are on the cusp of a technological revolution. Nanotechnology has steadily expanded into the reaches of cancer chemotherapy, radiotherapy, diagnostics, and imaging, demonstrating the capacity to augment each and advance patient care. Nanomaterials provide an abundance of versatility, functionality, and applications to engineer specifically targeted cancer medicine, accurate early-detection devices, robust imaging modalities, and enhanced radiotherapy adjuvants. This review provides insights into the current clinical and pre-clinical nanotechnological applications for cancer drug therapy, diagnostics, imaging, and radiation therapy.

Recent development for biomedical applications of magnetic nanoparticles

In recent decades, the use of engineered nanoparticles has been increasing in various sectors, including biomedicine, diagnosis, water treatment, and environmental remediation leading to significant public concerns. Among these nanoparticles, magnetic nanoparticles (MNPs) have gained many attentions in medicine, pharmacology, drug delivery system, molecular imaging, and bio-sensing due to their various properties. In addition, various studies have reviewed MNPs main applications in the biomedical engineering area with intense progress and recent achievements. Nanoparticles, especially the magnetic nanoparticles, have recently been confirmed with excellent antiviral activity against different viruses, including SARS-CoV-2(Covid-19) and their recent development against Covid-19 also has also been discussed. This review aims to highlight the recent development of the magnetic nanoparticles and their biomedical applications such as diagnosis of diseases, molecular imaging, hyperthermia, bio-sensing, gene therapy, drug delivery and the diagnosis of Covid-19.

Magnetic Particles with Polymeric Shells Bearing Cholesterol Moieties Sensitize Breast Cancer Cells to Low Doses of Doxorubicin

One of the promising strategies for improvement of cancer treatment is application of a combination therapy. The aim of this study was to investigate the anticancer activity of nanoformulations containing doxorubicin and iron oxide particles covered with polymeric shells bearing cholesterol moieties. It was postulated that due to high affinity to cell membranes, particles comprising poly(cholesteryl acrylate) can sensitize cancer cells to doxorubicin chemotherapy. The performed analyses revealed that the developed systems are effective against the human breast cancer cell lines MCF-7 and MDA-MB-231 even at low doses of the active compound applied (0.5 µM). Additionally, high compatibility and lack of toxicity of the tested materials against human red blood cells, immune (monocytic THP-1) cells, and cardiomyocyte H9C2(2-1) cells was demonstrated. Synergistic effects observed upon administration of doxorubicin with polymer–iron oxide hybrids comprising poly(cholesteryl acrylate) may provide an opportunity to limit toxicity of the drug and to improve its therapeutic efficiency at the same time.

Effects of labeling human mesenchymal stem cells with superparamagnetic zinc-nickel ferrite nanoparticles on cellular characteristics and adipogenesis/osteogenesis differentiation

OBJECTIVE

An attractive cell source for stem cell-based therapy are WJ-MSCs. Hence, tracking WJ-MSCs using non-invasive imaging procedures (such as MRI) and contrast agents (Zn0.5Ni0.5Fe2O4, NFNPs) are required to evaluate cell distribution, migration, and differentiation.

RESULTS

Results showed that the bare and dextrin-coated NFNPs were internalized inside the WJ-MSCs and had no effect on the cell viability, proliferation, apoptosis, karyotyping, and morphology of WJ-MSCs up to 125 µg/mL. Besides, treated WJ-MSCs were differentiated into osteo/adipocyte-like cells. The expression of RUNX 2, SPP 1 (P < 0.05), and OCN (P > 0.05) genes in the WJ-MSCs treated with dextrin-coated NFNPs was higher than the untreated WJ-MSCs; and the expression of CFD, LPL, and PPAR-γ genes was reduced in WJ-MSCs treated with both NFNPs in comparison with the untreated WJ-MSCs (P > 0.05).

CONCLUSION

Overall, results showed that dextrin-coated NFNPs had no adverse effect on the cellular characteristics, proliferation, and differentiation of WJ-MSCs, and suggesting their potential clinical efficacy.

All That Glitters Is Not Silver-A New Look at Microbiological and Medical Applications of Silver Nanoparticles

Silver and its nanoparticles (AgNPs) have different faces, providing different applications. In recent years, the number of positive nanosilver applications has increased substantially. It has been proven that AgNPs inhibit the growth and survival of bacteria, including human and animal pathogens, as well as fungi, protozoa and arthropods. Silver nanoparticles are known from their antiviral and anti-cancer properties; however, they are also very popular in medical and pharmaceutical nanoengineering as carriers for precise delivery of therapeutic compounds, in the diagnostics of different diseases and in optics and chemistry, where they act as sensors, conductors and substrates for various syntheses. The activity of AgNPs has not been fully discovered; therefore, we need interdisciplinary research to fulfil this knowledge. New forms of products with silver will certainly find application in the future treatment of many complicated and difficult to treat diseases. There is still a lack of appropriate and precise legal condition regarding the circulation of nanomaterials and the rules governing their safety use. The relatively low toxicity, relative biocompatibility and selectivity of nanoparticle interaction combined with the unusual biological properties allow their use in animal production as well as in bioengineering and medicine. Despite a quite big knowledge on this topic, there is still a need to organize the data on AgNPs in relation to specific microorganisms such as bacteria, viruses or fungi. We decided to put this knowledge together and try to show positive and negative effects on prokaryotic and eukaryotic cells.

In vivo time-course biocompatibility assessment of biomagnetic nanoparticles-based biomaterials for tissue engineering applications

Novel artificial tissues with potential usefulness in local-based therapies have been generated by tissue engineering using magnetic-responsive nanoparticles (MNPs). In this study, we performed a comprehensive in vivo characterization of bioengineered magnetic fibrin-agarose tissue-like biomaterials. First, in vitro analyses were performed and the cytocompatibility of MNPs was demonstrated. Then, bioartificial tissues were generated and subcutaneously implanted in Wistar rats and their biodistribution, biocompatibility and functionality were analysed at the morphological, histological, haematological and biochemical levels as compared to injected MNPs. Magnetic Resonance Image (MRI), histology and magnetometry confirmed the presence of MNPs restricted to the grafting area after 12 weeks. Histologically, we found a local initial inflammatory response that decreased with time. Structural, ultrastructural, haematological and biochemical analyses of vital organs showed absence of damage or failure. This study demonstrated that the novel magnetic tissue-like biomaterials with improved biomechanical properties fulfil the biosafety and biocompatibility requirements for future clinical use and support the use of these biomaterials as an alternative delivery route for magnetic nanoparticles.

Quantification of Synergistic Effects of Ceragenin CSA-131 Combined with Iron Oxide Magnetic Nanoparticles Against Cancer Cells

BACKGROUND

Therapeutic efficiency of ceragenins against cancers may be limited by lack of their hemocompatibility when high concentrations of molecules are required to reach a desired result. Synergistic effects observed upon administration of anticancer agents and metal nanoparticles may provide an opportunity to limit toxicity of immobilized ceragenins on the surface of metal nanoparticles and to improve their therapeutic efficiency at the same time. The aim of present work is to investigate the anticancer activities and hemocompatibility of nanoformulations consisting of ceragenin CSA-131 united with aminosilane-modified iron oxide-based magnetic nanoparticles (MNP) and prepared by 1) covalent bonding (MNP@CSA-131) or 2) by combining CSA-131 with MNP in 1:1 ratio (CSA-131 + MNP). Possible synergistic interactions between CSA-131 and magnetic nanoparticles were also quantified.

METHODS

MNP@CSA-131 and CSA-131+MNP were tested in vitro against selected lung and colon cancer cells using colorimetric, fluorimetric and flow cytometry methods.

RESULTS

Performed analysis demonstrates that MNP-based nanosystems significantly improve the killing efficiency of tested ceragenin, decreasing the viability of extra 1.37±4.72% to 76.07±15.30% cancer cells when compared to free CSA-131. Quantification of synergistic effects indicates the favorable interactions between CSA-131 and magnetic nanoparticles (CI < 1 for all tested doses), revealing at the same time a reduction in effective doses of ceragenin from 1.17 ± 0.61 to 34.57 ± 12.78 times when combined with MNP. We demonstrate that both MNP@CSA-131 and CSA-131+MNP induce significantly apoptosis of cancer cells and prevent the division of colon cancer cells even at relatively low doses of the active compound (10 µg/mL). Importantly, combining CSA-131 with MNP decreases the hemolytic activity of free ceragenin 4.72 to 7.88 times, which indicates a considerable improvement of hemotoxicity profile.

CONCLUSION

Comparative analyses have revealed that both developed CSA-containing nanoformulations due to the utility of synergistic interactions between MNP and CSA-131, which are effective against lung and colon cancer cells. This indicates the new directions in preparation of MNP-based therapeutics, which are relatively easy to synthetize, cost-effective and safe when intravenously administrated.

Enzyme Immobilization on Maghemite Nanoparticles with Improved Catalytic Activity: An Electrochemical Study for Xanthine

Generally, enzyme immobilization on nanoparticles leads to nano-conjugates presenting partially preserved, or even absent, biological properties. Notwithstanding, recent research demonstrated that the coupling to nanomaterials can improve the activity of immobilized enzymes. Herein, xanthine oxidase (XO) was immobilized by self-assembly on peculiar naked iron oxide nanoparticles (surface active maghemite nanoparticles, SAMNs). The catalytic activity of the nanostructured conjugate (SAMN@XO) was assessed by optical spectroscopy and compared to the parent enzyme. SAMN@XO revealed improved catalytic features with respect to the parent enzyme and was applied for the electrochemical studies of xanthine. The present example supports the nascent knowledge concerning protein conjugation to nanoparticle as a means for the modulation of biological activity.

Bare Iron Oxide Nanoparticles: Surface Tunability for Biomedical, Sensing and Environmental Applications

Surface modification is widely assumed as a mandatory prerequisite for the real applicability of iron oxide nanoparticles. This is aimed to endow prolonged stability, electrolyte and pH tolerance as well as a desired specific surface chemistry for further functionalization to these materials. Nevertheless, coating processes have negative consequences on the sustainability of nanomaterial production contributing to high costs, heavy environmental impact and difficult scalability. In this view, bare iron oxide nanoparticles (BIONs) are arousing an increasing interest and the properties and advantages of pristine surface chemistry of iron oxide are becoming popular among the scientific community. In the authors’ knowledge, rare efforts were dedicated to the use of BIONs in biomedicine, biotechnology, food industry and environmental remediation. Furthermore, literature lacks examples highlighting the potential of BIONs as platforms for the creation of more complex nanostructured architectures, and emerging properties achievable by the direct manipulation of pristine iron oxide surfaces have been little studied. Based on authors’ background on BIONs, the present review is aimed at providing hints on the future expansion of these nanomaterials emphasizing the opportunities achievable by tuning their pristine surfaces.

Optimization of the Synthesis of Copper Ferrite Nanoparticles by a Polymer-Assisted Sol-Gel Method

Magnetic ferrites are used in a wide range of technological applications, such as biomedicine, electronics, or energy. They also present interesting magnetic properties, especially for high-frequency applications. These materials have been prepared by a large variety of methods, from basic solid-state reaction to advanced wet chemical methods. However, most of these approaches are complex and have low production rates. In this work, a deep analysis of an easy polymer-assisted sol-gel synthesis of copper ferrite (CuFe₂O₄) nanoparticles is done. A multivariate analysis, by means of the design of experiments approach, is carried out to account for two variables at a time. Moreover, a wide experimental domain is explored, and the impact of each variable on the chemical composition and magnetic properties is determined. This work results in an optimization of the synthesis method to obtain high-purity nanoparticles (∼96%).

Pharmaceutical Applications of Iron-Oxide Magnetic Nanoparticles

Advances of nanotechnology led to the development of nanoparticulate systems with many advantages due to their unique physicochemical properties. The use of iron-oxide magnetic nanoparticles (IOMNPs) in pharmaceutical areas increased in the last few decades. This article reviews the conceptual information about iron oxides, magnetic nanoparticles, methods of IOMNP synthesis, properties useful for pharmaceutical applications, advantages and disadvantages, strategies for nanoparticle assemblies, and uses in the production of drug delivery, hyperthermia, theranostics, photodynamic therapy, and as an antimicrobial. The encapsulation, coating, or dispersion of IOMNPs with biocompatible material(s) can avoid the aggregation, biodegradation, and alterations from the original state and also enable entrapping the bioactive agent on the particle via adsorption or covalent attachment. IOMNPs show great potential for target drug delivery, improving the therapy as a consequence of a higher drug effect using lower concentrations, thus reducing side effects and toxicity. Different methodologies allow IOMNP synthesis, resulting in different structures, sizes, dispersions, and surface modifications. These advantages support their utilization in pharmaceutical applications, and getting suitable drug release control on the target tissues could be beneficial in several clinical situations, such as infections, inflammations, and cancer. However, more toxicological clinical investigations about IOMNPs are necessary.

Stealth Iron Oxide Nanoparticles for Organotropic Drug Targeting

The ability of peculiar iron oxide nanoparticles (IONPs) to evade the immune system was investigated in vivo. The nanomaterial was provided directly into the farming water of zebrafish ( Danio rerio) and the distribution of IONPs and the delivery of oxytetracycline (OTC) was studied evidencing the successful overcoming of the intestinal barrier and the specific and prolonged (28 days) organotropic delivery of OTC to the fish ovary. Noteworthy, no sign of adverse effects was observed. In fish blood, IONPs were able to specifically bind apolipoprotein A1 (Apo A1) and molecular modeling showed the structural analogy between the IONP@Apo A1 nanoconjugate and high-density lipoprotein (HDL). Thus, the preservation of the biological identity of the protein suggests a plausible explanation of the observed overcoming of the intestinal barrier, of the great biocompatibity of the nanomaterial, and of the prolonged drug delivery (benefiting of the lipoprotein transport route). The present study promises novel and unexpected stealth materials in nanomedicine.

Enzyme self-assembly on naked iron oxide nanoparticles for aminoaldehyde biosensing

The preservation of enzymatic activity is a fundamental requirement for exploiting hybrid nano-bio-conjugates, and the control over protein-nanoparticle interactions, leading to stable and catalytically active hybrids, represents the key for designing new biosensing platforms. In this scenario, surface active maghemite nanoparticles (SAMNs) represent a new class of naked magnetic nanoparticles, displaying peculiar electrocatalytic features and the ability to selectively bind proteins. Recombinant aminoaldehyde dehydrogenase from tomato (SlAMADH1) was used as a model protein, and successfully immobilized by self-assembly on the surface of naked SAMNs, where its enzymatic activity resulted preserved for more than 6 months. The hybrid nanomaterial (SAMN@SlAMADH1) was characterized by UV-Vis spectroscopy, mass spectrometry, and TEM microscopy, and applied for the development of a biosensor for the determination of aminoaldehydes in alcoholic beverages. Measurements were carried out in a low volume electrochemical flow cell comprising a SAMN modified carbon paste electrode for the coulometric determination of the NADH produced during the enzymatic catalysis. The present findings, besides representing the first example of an electrochemical biosensor for aminoaldehydes in an alcoholic matrix, open the door to the use of immobilized enzymes on naked metal oxides nanomaterials for biosensing.

Novel diagnostics for point-of-care bacterial detection and identification

In addition to limiting the effectiveness of antimicrobial agents, antimicrobial resistance (AMR) is a significant global health concern as it is responsible for significant mortality/morbidity and increased economic burdens on healthcare systems. Diagnostic tests have been suggested as a means of prolonging the effectiveness of current antimicrobials; culture and other conventional diagnostics are hindered in their practicality as they are time- and labour intensive to perform. Point-of-care (POC) testing is performed near where the patient is being treated and can provide timely results that allow evidence based clinical interventions to be made. This review aims to outline the chemical principles behind some novel and emerging diagnostic techniques which have the required speed, simplicity, effectiveness and low-cost for incorporation into POC devices which can be used to inform and optimize antimicrobial use.

The WHO global action plan on antimicrobial resistance outlines the need for new diagnostic tools. Point-of-care testing for bacterial infections would enable clinically meaningful interventions using methods that are rapid, low-cost, easy-to-operate, and portable.

Bactericidal and immunomodulatory properties of magnetic nanoparticles functionalized by 1,4-dihydropyridines

Background

1,4-Dihydropyridine (1,4-DHP) and its derivatives are well-known calcium channel blockers with antiarrhythmic and antihypertensive activities. These compounds exhibit pleiotropic effects including antimicrobial activities that rely on their positive charge and amphipathic nature. Use of magnetic nanoparticles (MNPs) as carriers of 1,4-DHP modulates their properties and enables improved formulations with higher efficacy and less toxicity.

Methods

In this study, the antimicrobial and immunomodulatory activities of novel 1,4-DHP derivatives in free form and immobilized on MNPs were determined by evaluating pathogen outgrowth and proinflammatory cytokine release in experimental settings that involve incubation of various 1,4-DHPs with clinical isolates of bacteria or fungi as well as mammalian cell culture models.

Results

Conventional immobilization of 1,4-DHP on aminosilane-coated MNPs markedly enhances their antimicrobial activity compared to nonimmobilized molecules, in part because of the higher affinity of these nanosystems for bacterial cell wall components in the presence of human body fluids.

Conclusion

Optimized nanosystems are characterized by improved biocompatibility and higher anti-inflammatory properties that provide new opportunities for the therapy of infectious diseases.

Iron Oxide Nanoparticles for Biomedical Applications: A Perspective on Synthesis, Drugs, Antimicrobial Activity, and Toxicity

Medical applications and biotechnological advances, including magnetic resonance imaging, cell separation and detection, tissue repair, magnetic hyperthermia and drug delivery, have strongly benefited from employing iron oxide nanoparticles (IONPs) due to their remarkable properties, such as superparamagnetism, size and possibility of receiving a biocompatible coating. Ongoing research efforts focus on reducing drug concentration, toxicity, and other side effects, while increasing efficacy of IONPs-based treatments. This review highlights the methods of synthesis and presents the most recent reports in the literature regarding advances in drug delivery using IONPs-based systems, as well as their antimicrobial activity against different microorganisms. Furthermore, the toxicity of IONPs alone and constituting nanosystems is also addressed.

Spiky gold shells on magnetic particles for DNA biosensors

Combined separation and detection of biomolecules has the potential to speed up and improve the sensitivity of disease detection, environmental testing, and biomolecular analysis. In this work, we synthesized magnetic particles coated with spiky nanostructured gold shells and used them to magnetically separate out and detect oligonucleotides using SERS. The distance dependence of the SERS signal was then harnessed to detect DNA hybridization using a Raman label bound to a hairpin probe. The distance of the Raman label from the surface increased upon complementary DNA hybridization, leading to a decrease in signal intensity. This work demonstrates the use of the particles for combined separation and detection of oligonucleotides without the use of an extrinsic tag or secondary hybridization step.

Use of magnetic nanoparticles as a drug delivery system to improve chlorhexidine antimicrobial activity

Nanotechnology offers new tools for developing therapies to prevent and treat oral infections, particularly biofilm-dependent disorders, such as dental plaques and endodontic and periodontal diseases. Chlorhexidine (CHX) is a well-characterized antiseptic agent used in dentistry with broad spectrum activity. However, its application is limited due to inactivation in body fluid and cytotoxicity toward human cells, particularly at high concentrations. To overcome these limitations, we synthesized nanosystems composed of aminosilane-coated magnetic nanoparticles functionalized with chlorhexidine (MNP@CHX). In the presence of human saliva, MNPs@CHX displayed significantly greater bactericidal and fungicidal activity against planktonic and biofilm-forming microorganisms than free CHX. In addition, CHX attached to MNPs has an increased ability to restrict the growth of mixed-species biofilms compared to free CHX. The observed depolarization of mitochondria in fungal cells treated with MNP@CHX suggests that induction of oxidative stress and oxidation of fungal structures may be a part of the mechanism responsible for pathogen killing. Nanoparticles functionalized by CHX did not affect host cell proliferation or their ability to release the proinflammatory cytokine, IL-8. The use of MNPs as a carrier of CHX has great potential for the development of antiseptic nanosystems.

Zwitterion-coated ultrasmall iron oxide nanoparticles for enhanced T1-weighted magnetic resonance imaging applications

We report a convenient strategy to prepare ultrasmall Fe₃O₄ nanoparticles (NPs) coated with zwitterion l-cysteine (Cys) for enhanced T₁-weighted magnetic resonance (MR) imaging applications. The formed Fe₃O₄-PEG-Cys NPs possess antifouling properties, good r₁ relaxivity, excellent cytocompatibility and hemocompatibility, and can be used as a contrast agent for enhanced blood pool and tumor MR imaging.

Gold-loaded nanoporous iron oxide nanocubes: a novel dispersible capture agent for tumor-associated autoantibody analysis in serum

Autoantibodies are produced against tumor associated antigens (TAAs) long before the appearance of any symptoms and thus can serve as promising, non-invasive biomarkers for early diagnosis of cancer. Current conventional methods for autoantibody detection are highly invasive and mostly provide diagnosis in the later stages of cancer. Herein we report a new electrochemical method for early detection of p53 autoantibodies against colon cancer using a strategy that combines the strength of gold-loaded nanoporous iron oxide nanocube (Au@NPFe₂O₃NC)-based capture and purification while incorporating the inherent simplicity, inexpensive, and portable nature of the electrochemical and naked-eye colorimetric readouts. After the functionalisation of Au@NPFe₂O₃NC with p53 antigens, our method utilises a two-step strategy that involves (i) magnetic capture and isolation of autoantibodies using p53/Au@NPFe₂O₃NC as 'dispersible nanocapture agents' in serum samples and (ii) subsequent detection of autoantibodies through a peroxidase-catalyzed reaction on a commercially available disposable screen-printed electrode or naked-eye detection in an Eppendorf tube. This method has demonstrated a good sensitivity (LOD = 0.02 U mL^-1) and reproducibility (relative standard deviation, %RSD = <5%, for n = 3) for detecting p53 autoantibodies in serum and has also been successfully applied to analyse a small cohort of clinical samples obtained from colorectal cancer. We believe that the highly inexpensive, rapid, sensitive, and specific nature of our assay could potentially aid in the development of an early diagnostic tool for cancer and related diseases.

Carrageenan Based Bionanocomposites as Drug Delivery Tool with Special Emphasis on the Influence of Ferromagnetic Nanoparticles

Over the past few years, considerable attention has been focused on carrageenan based bionanocomposites due to their multifaceted properties like biodegradability, biocompatibility, and nontoxicity. Moreover, these composites can be tailored according to the desired purpose by using different nanofillers. The role of ferromagnetic nanoparticles in drug delivery is also discussed here in detail. Moreover, this article also presents a short review of recent research on the different types of the carrageenan based bionanocomposites and applications.

Conjugation Magnetic PAEEP-PLLA Nanoparticles with Lactoferrin as a Specific Targeting MRI Contrast Agent for Detection of Brain Glioma in Rats

The diagnosis of malignant brain gliomas is largely based on magnetic resonance imaging (MRI) with contrast agents. In recent years, nano-sized contrast agents have been developed for improved MRI diagnosis. In this study, oleylamine-coated Fe3O4 magnetic nanoparticles (OAM-MNPs) were synthesized with thermal decomposition method and encapsulated in novel amphiphilic poly(aminoethyl ethylene phosphate)/poly(L-lactide) (PAEEP-PLLA) copolymer nanoparticles. The OAM-MNP-loaded PAEEP-PLLA nanoparticles (M-PAEEP-PLLA-NPs) were further conjugated with lactoferrin (Lf) for glioma tumor targeting. The Lf-conjugated M-PAEEP-PLLA-NPs (Lf-M-PAEEP-PLLA-NPs) were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The average size of OAM-MNPs, M-PAEEP-PLLA-NPs, and Lf-M-PAEEP-PLLA-NPs were 8.6 ± 0.3, 165.7 ± 0.6, and 218.2 ± 0.4 nm, with polydispersity index (PDI) of 0.185 ± 0.023, 0.192 ± 0.021, and 0.224 ± 0.036, respectively. TEM imaging showed that OAM-MNPs were monodisperse and encapsulated in Lf-M-PAEEP-PLLA-NPs. TGA analysis showed that the content of iron oxide nanoparticles was 92.8 % in OAM-MNPs and 45.2 % in Lf-M-PAEEP-PLLA-NPs. VSM results indicated that both OAM-MNPs and Lf-M-PAEEP-PLLA-NPs were superparamagnetic, and the saturated magnetic intensity were 77.1 and 74.8 emu/g Fe. Lf-M-PAEEP-PLLA-NPs exhibited good biocompatibility in cytotoxicity assay. The high cellular uptake of Lf-M-PAEEP-PLLA-NPs in C6 cells indicated that Lf provided effective targeting for the brain tumor cells. The T 2 relaxation rate (r 2) of M-PAEEP-PLLA-NPs and Lf-M-PAEEP-PLLA-NPs were calculated to be 167.2 and 151.3 mM(-1) s(-1). In MRI on Wistar rat-bearing glioma tumor, significant contrast enhancement could clearly appear at 4 h after injection and last 48 h. Prussian blue staining of the section clearly showed the retention of Lf-M-PAEEP-PLLA-NPs in tumor tissues. The results from the in vitro and in vivo MRI indicated that Lf-M-PAEEP-PLLA-NPs possessed strong, long-lasting, tumor targeting, and enhanced tumor MRI contrast ability. Lf-M-PAEEP-PLLA-NPs represent a promising nano-sized MRI contrast agent for brain glioma targeting MRI.

Core-shell magnetic nanoparticles display synergistic antibacterial effects against Pseudomonas aeruginosa and Staphylococcus aureus when combined with cathelicidin LL-37 or selected ceragenins

Core–shell magnetic nanoparticles (MNPs) are promising candidates in the development of new treatment methods against infections, including those caused by antibiotic-resistant pathogens. In this study, the bactericidal activity of human antibacterial peptide cathelicidin LL-37, synthetic ceragenins CSA-13 and CSA-131, and classical antibiotics vancomycin and colistin, against methicillin-resistant Staphylococcus aureus Xen 30 and Pseudomonas aeruginosa Xen 5, was assessed alone and in combination with core–shell MNPs. Fractional inhibitory concentration index and fractional bactericidal concentration index were determined by microdilution methods. The potential of combined therapy using nanomaterials and selected antibiotics was confirmed using chemiluminescence measurements. Additionally, the ability of tested agents to prevent bacterial biofilm formation was evaluated using crystal violet staining. In most conditions, synergistic or additive effects were observed when combinations of core–shell MNPs with ceragenins or classical antibiotics were used. Our study revealed that a mixture of membrane-active agents such as LL-37 peptide or ceragenin CSA-13 with MNPs potentialized their antibacterial properties and might be considered as a method of delaying and overcoming bacterial drug resistance.

Magnetic nanoparticles as a drug delivery system that enhance fungicidal activity of polyene antibiotics

This study was designed to assess the antifungal/anti-biofilm and hemolytic properties of two polyene antibiotics, amphotericin B (AMF) and nystatin (NYS), attached to the surface of magnetic nanoparticles (MNP) against clinical isolates of Candida species and human red blood cells, respectively. The developed nanosystems, MNP@AMF and MNP@NYS, displayed stronger fungicidal activity than unbound AMF or NYS. Synergistic activity was observed with a combination of polyenes and MNPs against all tested Candida strains. Nanosystems were more potent than unbound agents when tested against Candida strains in the presence of pus, and as agents able to prevent Candida biofilm formation. The observed inactivation of catalase Cat1 in Candida cells upon treatment with the nanosystems suggests that disruption of the oxidation-reduction balance is a mechanism leading to inhibition of Candida growth. The significant decrease of polyenes lytic activity against host cells after their attachment to MNPs surface indicates improvement in their biocompatibility.

Lab-on-chip systems for integrated bioanalyses

Biomolecular detection systems based on microfluidics are often called lab-on-chip systems. To fully benefit from the miniaturization resulting from microfluidics, one aims to develop 'from sample-to-answer' analytical systems, in which the input is a raw or minimally processed biological, food/feed or environmental sample and the output is a quantitative or qualitative assessment of one or more analytes of interest. In general, such systems will require the integration of several steps or operations to perform their function. This review will discuss these stages of operation, including fluidic handling, which assures that the desired fluid arrives at a specific location at the right time and under the appropriate flow conditions; molecular recognition, which allows the capture of specific analytes at precise locations on the chip; transduction of the molecular recognition event into a measurable signal; sample preparation upstream from analyte capture; and signal amplification procedures to increase sensitivity. Seamless integration of the different stages is required to achieve a point-of-care/point-of-use lab-on-chip device that allows analyte detection at the relevant sensitivity ranges, with a competitive analysis time and cost.