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Phytoferritin was explored as an attractive nanocarrier to encapsulate bioactive compounds due to its excellent stability and biocompatibility. In the present study, a novel phytoferritin derived from alfalfa (Medicago sativa) was successfully expressed, purified and characterized. Results confirmed that alfalfa ferritin, self-assembled by 24 subunits, formed a spherical hollow structure. Baicalein exhibits superior antioxidant properties and nutritious values, but low bioavailability and solubility limit its application. Herein, we fabricated water-soluble chitosan-ferritin-baicalein nanoparticles to overcome its drawbacks. It was calculated that one apoferritin cage could encapsulate 52 molecules of baicalein. Moreover, chitosan-ferritin-baicalein nanoparticles prolonged the release of baicalein in simulated gastrointestinal tract digestion. Caco-2 cell monolayer absorption analysis demonstrated that baicalein encapsulated within ferritin-chitosan double layers was more efficient in cellular transportation. These results indicated that alfalfa ferritin, as a novel cage-like protein, has potential application in improving the bioavailability of insoluble bioactive molecules., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Abstract: The magnetic chitosan nanoparticles of 13.5nm were prepared as a magnetic nano-adsorbent by the carboxymethylation of chitosan and the followed binding on the surface of Fe3O4 nanoparticles via carbodiimide activation. Their saturation magnetization, remanent magnetization, coercivity, and squareness were 62emu/g, 1.8emu/g, 6.0Oe, and 0.029, respectively, reflecting their superparamagnetic property. The binding reaction of carboxymethyl chitosan on the surface of Fe3O4 nanoparticles was much faster than the self-crosslinking of carboxymethyl chitosan, and the appropriate reaction time was 1h. At low carboxymethyl chitosan concentrations, the binding efficiency could be as high as 100%. The maximum amount of chitosan bound on the Fe3O4 nanoparticles was 4.92wt%. In addition, magnetic chitosan nano-adsorbent was shown to be quite efficient for the fast removal of Co(II) ions at pH 3–7 and 20–45°C. The maximum adsorption capacity for Co(II) ions occurred at pH 5.5, and the adsorption process was exothermic in nature with an enthalpy change of −12.04kJ/mol. The equilibrium was achieved within 1min, and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 27.5mg/g (557mg/g based on the weight of chitosan) and a Langmuir adsorption equilibrium constant of 0.034l/mg at 25°C. Such fast adsorption rate and high adsorption capacity could be attributed to the absence of internal diffusion resistance and the high specific surface area. [Copyright &y& Elsevier]

Chitosan/fucoidan nanoparticles were created using two fucoidans from the Fucus evanescens algae. One of them was a regular fucoidan obtained for the first time from the alga harvested at the reproductive growth stage, using only standard extraction methods, without additional modifications. Its structure was established via NMR spectroscopy to consist of the repeating →3)-α-L-Fuc p - (2,4SO 3 −)-(1 → 4)-α-L-Fuc p - (2SO 3 −)-(1→ fragment. Such fragment also coustituted 55% of the other fucoidan's structure, however it also included long sequences of α-L-fucopyranose residues sulfated only at C2. The nanoparticles were re-dispersed in water and the influence of fucoidan/chitosan mass ratio on the nanoparticles' size and zeta potential was investigated. 3D models of the regular fucoidan and chitosan's sections were created and their molecular docking was performed, showing that either polymer could occupy the exterior of the complex, depending on their ratio. Thermodynamic parameters of fucoidan-chitosan binding process were accessed, with the results indicating that significant conformational changes of fucoidan and chitosan molecules take place during the interaction, presumably to allow for more effective binding. • A regular fucoidan from Fucus evanescens was used for nanoparticle creation. • A fucoidan's ability to form nanoparticles is related to its structure and molecular weight. • Fucoidan-chitosan binding process involves two binding events. • Thermodynamic parameters of fucoidan-chitosan binding depend on the fucoidan's structural characteristics. [ABSTRACT FROM AUTHOR]

Background/Objectives: Crickets are recognized as an alternative source of chitosan. This study aimed to assess the potential of cricket-derived chitosan as a natural source to develop chitosan nanoparticles (CNPs). Methods: Chitosan were isolated from different cricket species, including Gryllus bimaculatus, Teleogryllus mitratus, and Acheta domesticus. The isolated chitosan were characterized by their functional groups, crystallographic and thermal properties, molecular structure, morphology, water solubility, molecular weight, binding capacity, irritation potential, and cytotoxicity in comparison to commercial shrimp-based chitosan. CNPs were developed through an ionotropic gelation method, followed by the evaluation of particle size, polydispersity index (PDI), and zeta potential. Results: The findings of this study indicate that chitosan can be successfully isolated from the three cricket species, with yields ranging from 4.35% to 5.22% w/w of the dried material. The characteristics of cricket-based chitosan were similar to those of commercial chitosan, except that the cricket-based chitosan displayed a higher crystallinity and a lower molecular weight. Additionally, CPNs were successfully produced from cricket-based chitosan using sodium citrate as a crosslinking agent. All cricket-based chitosan exhibited no irritation or cytotoxicity. Chitosan derived from A. domesticus however was found to be the most suitable to develop CPNs, as it produced the smallest particle size (522.0 ± 12.1 nm) with a comparatively narrow PDI (0.388 ± 0.026) and an acceptable positive zeta potential (34.2 ± 4.4 mV). Conclusions: Cricket-derived chitosan compares favorably with crustacean-derived chitosan and showed potential for a range of applications, including the use as a nanocosmeceutical delivery system in topical and cosmetic formulations. [ABSTRACT FROM AUTHOR]

Inspired by the fact that chitosan is a representative constituent of the ectocellular structure of Cryptococcus neoformans and a typical biomaterial for improving drug oral absorption, we designed an elegant and efficient C. neoformans-targeted drug delivery system via oral administration. A chitosan-binding peptide screened by phage display was used as the targeting moiety, followed by conjugation to the surface of poly(lactic- co-glycolic acid) nanoparticles as the drug carrier, which was then incubated with free chitosan. The noncovalently bound chitosan adheres to mucus layers and significantly enhances penetration of nanoparticles through the oral absorption barrier into circulation and then re-exposed the targeting ligand for later recognition of the fungal pathogen at the site of infection. After loading itraconazole as a model drug, our drug delivery system remarkably cleared lung infections of C. neoformans and increased survival of model mice. Currently, targeted drug delivery is mainly performed intravenously; however, the system described in our study may provide a universal means to facilitate drug targeting to specific tissues and disease sites by oral administration and may be especially powerful in the fight against increasingly severe fungal infections.

The study included the extraction of Chitin (Ch) from shrimp shells and preparation of Chitin nanoparticles (NCh) using acid hydrolysis and ultrasound method. In addition, the preparation of chitosan (Chs) and Chitosan nanoparticles (NChs) by Deacetylation method, then we study some of the characteristics, including yield, diameter by Size Analyzer, Field Emission Scanning Electron Microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, XRay Diffractometer (X-RD), Viscosity, Water Binding Capacity (WBC) and Fat Binding Capacity (FBC). The results showed, (a) decreased the percentage of yield of NChs to 8.20%, (b) the effective diameter of the natural chitosan using a Size Analyzer and was 28121.5 nm, (c) FESEM analysis revealed that the NChs displayed a nanoscale structure with diameters ranged from 20.93 - 30.20 nm (d) the degree of deacetylation (DD%) using FT-IR spectroscopy device, of NChs was (80.21%) compared to Chs 71.45%, and in addition, from the X-ray spectrum, two peaks in spectra of (Ch, NCh) and (Chs, NChs) were observed at the diffraction angles (2θ) which are (10.70-10.99) and (19.99-20.37). Results show increasing the crystallization coefficient of NCh and NChs, while viscosity, WBC and FBC of NChs decreased compared to Chs. The NChs did not show any toxic effect on human blood cells at concentrations of 100-1000 µg. ml-1. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze binding of chitosan and chitosan nanoparticles onto cellulose via oxidized cellulose. The ability of chitosan and chitosan nanoparticles to be adsorbed onto surfaces was determined by the use of the XPS spectroscopy which provided information about chemical composition of the fiber surface. On the other hand, the gravimetric method was also used by which the amount of chitosan and chitosan nanoparticles bounded onto surface was calculated based on the difference in masses before and after functionalization. The most important was to study the influence of aldehyde groups on the stability of chitosan binding onto cellulose. Thus, desorption of chitosan/chitosan nanoparticles from the fiber surfaces was evaluated by the presence of total nitrogen (TN) in desorption bath as well as by polyelectrolyte titrations. Together with these two methods, desorption was evaluated also by gravimetric method, where the extent of desorption was evaluated on the basis of the differences in the masses of fibers before and after desorption. It is concluded that the chitosan and chitosan nanoparticles are more efficiently bounded onto oxidized cellulose in comparison with the nonoxidized (reference) ones. Despite the binding of the positively-charged amino groups with the negative groups of cellulose and consequently smaller amount of available/residual protonated amino groups that are responsible for bioactivity, such functionalized fibers are still specifically antimicrobial. [ABSTRACT FROM AUTHOR]

This review systematically investigates the critical role of natural binding proteins (NBPs), encompassing DNA-, RNA-, carbohydrate-, fatty acid-, and chitin-binding proteins, in the realms of oncology and diagnostics. In an era where cancer continues to pose significant challenges to healthcare systems worldwide, the innovative exploration of NBPs offers a promising frontier for advancing both the diagnostic accuracy and therapeutic efficacy of cancer management strategies. This manuscript provides an in-depth examination of the unique mechanisms by which NBPs interact with specific molecular targets, highlighting their potential to revolutionize cancer diagnostics and therapy. Furthermore, it discusses the burgeoning research on aptamers, demonstrating their utility as 'nucleic acid antibodies' for targeted therapy and precision diagnostics. Despite the promising applications of NBPs and aptamers in enhancing early cancer detection and developing personalized treatment protocols, this review identifies a critical knowledge gap: the need for comprehensive studies to understand the diverse functionalities and therapeutic potentials of NBPs across different cancer types and diagnostic scenarios. By bridging this gap, this manuscript underscores the importance of NBPs and aptamers in paving the way for next-generation diagnostics and targeted cancer treatments. [ABSTRACT FROM AUTHOR]

Presently, the food industry continues to be major contributor of plastic waste across the globe. The food industry is in great demand of sustainable food packaging material due to increase environmental and health consciousness. Biobased polymers which are degradable promise to be a key solution. Use of nanotechnological advancements in biopolymers provide a wide range of additional benefit and makes them a suitable packaging material. The benefits include barrier to oxygen permeability, moisture permeability, crystalline structure, other barrier properties, morphology, thermal stability, optical properties, mechanical properties, improving shelf life of the packaged food and antimicrobial characteristics. Polymeric materials (matrix) have been infused with nanofillers such as silicates, carbon, cellulose and starch nanoparticles. This review aims to focus on new and effectual polymeric materials for food packaging that are technologically advanced with nanotechnology as a solution to the challenges faced by food industry with regard to the product safety and materials performance. [ABSTRACT FROM AUTHOR]

Tailorable cationic chitosan/PLGA nanoparticles (CPNP) were used for the delivery of an antisense 2'-O-methyl-RNA (2OMR) directed against RNA template of human telomerase. Here, we describe the influence of the chitosan content on binding efficiency, complex stability, uptake in different human lung cell types and finally demonstrate the efficacy of this nanoplex system. CPNPs were prepared by the emulsion-solvent evaporation method using different amounts of chitosan and purified by preparative size exclusion chromatography. The characterization by photon correlation spectroscopy and zeta potential measurements showed a small increase in size and an increase of zeta potential with increasing amounts of chitosan. Binding efficiency and complex stability with 2OMR was high in water and correlated well with the chitosan content of particles but was weak in physiologically relevant media (PBS and RPMI cell culture medium). However, flow cytometry analysis showed that the uptake of 2OMR into A549 lung cancer cells was considerably higher in combination with nanoparticles and dependent on the amount of chitosan when compared to 2OMR alone. Confocal laser scanning microscopy revealed that the uptake into A549 cells is mediated via complexes of 2OMR and chitosan/PLGA nanoparticles despite the weak binding in cell culture medium. The nanoparticles were well tolerated and efficient in inhibiting telomerase activity.

This comprehensive review illuminates the various methods of chitosan extraction, its antibacterial properties, and its multifarious applications in diverse sectors. We delve into chemical, physical, biological, hybrid, and green extraction techniques, each of which presents unique advantages and disadvantages. The choice of method is dictated by multiple variables, including the desired properties of chitosan, resource availability, cost, and environmental footprint. We explore the intricate relationship between chitosan's antibacterial activity and its properties, such as cationic density, molecular weight, water solubility, and pH. Furthermore, we spotlight the burgeoning applications of chitosan-based materials like films, nanoparticles, nonwoven materials, and hydrogels across the food, biomedical, and agricultural sectors. The review concludes by highlighting the promising future of chitosan, underpinned by technological advancements and growing sustainability consciousness. However, the critical challenges of optimizing chitosan's production for sustainability and efficiency remain to be tackled. [ABSTRACT FROM AUTHOR]

The conjugation of chitosan 15 and 100 KD with anticancer drugs cis– and trans–Pt (NH3)2Cl2 (abbreviated cis–Pt and trans–Pt) were studied at pH 5–6. Using multiple spectroscopic methods and thermodynamic analysis to characterize the nature of drug–chitosan interactions and the potential application of chitosan nanoparticles in drug delivery. Analysis showed that both hydrophobic and hydrophilic contacts are involved in drug–polymer interactions, while chitosan size and charge play a major role in the stability of drug–polymer complexes. The overall binding constants are Kch–15–cis–Pt = 1.44 (±0.6) × 105 M−1, Kch–100–cis–Pt = 1.89 (±0.9) × 105 M−1 and Kch–15–trans–Pt = 9.84 (±0.5) × 104 M−1, and Kch–100–trans–Pt = 1.15 (±0.6) × 105 M−1. More stable complexes were formed with cis–Pt than with trans–Pt–chitosan adducts, while stronger binding was observed for chitosan 100 in comparison to chitosan 15 KD. This study indicates that polymer chitosan 100 is a stronger drug carrier than chitosan 15 KD in vitro. [ABSTRACT FROM AUTHOR]

In the last decades, nanotechnology-based tools have attracted attention in the scientific community, due to their potential applications in different areas from medicine to engineering, but several toxicological effects mediated by these advanced materials have been shown on the environment and human health. At present, the effects of engineered nanomaterials on gametogenesis have not yet been well understood. In the present study, we addressed this issue using the yeast Saccharomyces cerevisiae as a model eukaryote to evaluate the effects of cadmium sulfide quantum dots (CdS QDs) on sporulation, a process equivalent to gametogenesis in higher organisms. We have observed that CdS QDs cause a strong inhibition of spore development with the formation of aberrant, multinucleated cells. In line with these observations, treatment with CdS QDs down-regulates genes encoding crucial regulators of sporulation process, in particular, the transcription factor Ndt80 that coordinates different genes involved in progression through the meiosis and spore morphogenesis. Down-regulation of NDT80 mediated by CdS QDs causes a block of the meiotic cell cycle and a return to mitosis, leading to the formation of aberrant, multinucleated cells. These results indicate that CdS QDs inhibit gametogenesis in an irreversible manner, with adverse effects on cell-cycle progression. [ABSTRACT FROM AUTHOR]

Purpose: The ginger root extract has shown remarkable antimicrobial effects. Nanocarriers based on biodegradable polymers (like chitosan) are promising drug delivery vehicles for antibacterial compounds. In this study, aqueous and methanolic extracts of ginger root were prepared, loaded on chitosan nanoparticles (NPs), and their antimicrobial effects were investigated. Methods: The NPs were prepared using the ionic gelation technique. The central composite design model was employed to optimize the formulation variables and achieve the minimum particle size and maximum zeta potential. The total phenol content of the powdered extracts was determined. The antimicrobial activity of the NPs was evaluated by the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results: The optimum size of NPs containing methanolic or aqueous extract were 188.3 and 154.7 nm, with a zeta potential of 29.1 and 32.1 mv, and entrapment efficiency percent (E.E.%) of 61.57±3.12% and 44.26±2.57%, respectively. Transmission electronic microscopy images confirmed the spherical particles in the low nanometer range. The phenol content of methanol extract was higher than the aqueous one (60.216 ± 1.83 and 39.835 ± 1.72 mg gallic acid equivalent/100 g), respectively). According to the results of the MIC and MBC, methanol extract NPs showed more potent antimicrobial effects, which seems to be associated with higher concentrations of phenolic compounds. The FTIR spectrophotometry showed no chemical interaction between the extracts and other ingredients. Conclusion: The results demonstrated that current NPs significantly increased the antibacterial effects of ginger extracts and could be selected for further evaluation. [ABSTRACT FROM AUTHOR]

With the development of nanotechnology, self-assembled chitosan/phospholipid nanoparticles (SACPNs) show great promise in a broad range of applications, including therapy, diagnosis, in suit imaging and on-demand drug delivery. Here, a brief review of the SACPNs is presented, and its critical underlying formation mechanisms are interpreted with an emphasis on the intrinsic physicochemical properties. The state-of-art preparation methods of SACPNs are summarized, with particular descriptions about the classic solvent injection method. Then SACPNs microstructures are characterized, revealing the unique spherical core-shell structure and the drug release mechanisms. Afterwards, a comprehensive and in-depth depiction of their emerging applications, with special attention to drug delivery areas, are categorized and reviewed. Finally, conclusions and outlooks on further advancing the SACPNs toward a more powerful and versatile platform for investigations covering from fundamental understanding to developing multi-functional drug delivery systems are discussed. [ABSTRACT FROM AUTHOR]

Treatment modalities for systemic mycoses are still limited. Currently, the main antifungal 18 therapeutics include polyenes, azoles, and echinocandins. However, even in the setting of 19 appropriate administration of antifungals, mortality rates remain unacceptably high. Moreover, 20 antifungal therapy is expensive, treatment periods can range from weeks to years, and toxicity 21 is also a serious concern. In recent years, the increased number of immunocompromised 22 individuals has contributed to the high global incidence of systemic fungal infections. Given 23 the high morbidity and mortality rates, the complexity of treatment strategies, drug toxicity, 24 and the worldwide burden of disease, there is a need for new and efficient therapeutic means 25 to combat invasive mycoses. One promising avenue that is actively being pursued is 26 nanotechnology, to develop new antifungal therapies and efficient vaccines, since it allows for 27 a targeted delivery of drugs and antigens, which can reduce toxicity and treatment costs. The 28 goal of this review is to discuss studies using nanoparticles to develop new therapeutic options, 29 including vaccination methods, to combat systemic mycoses caused by Candida sp., 30 Cryptococcus sp., Paracoccidioides sp., Histoplasma sp., Coccidioides sp., and Aspergillus sp., 31 in addition to providing important information on the use of different types of nanoparticles, 32 nanocarriers and their corresponding mechanisms of action. [ABSTRACT FROM AUTHOR]

Biodegradable polymers are popularly being used in an increasing number of fields in the past few decades. The popularity and favorability of these materials are due to their remarkable properties, enabling a wide range of applications and market requirements to be met. Polymer biodegradable systems are a promising arena of research for targeted and site-specific controlled drug delivery, for developing artificial limbs, 3D porous scaffolds for cellular regeneration or tissue engineering and biosensing applications. Several natural polymers have been identified, blended, functionalized and applied for designing nanoscaffolds and drug carriers as a prerequisite for enumerable bionano technological applications. Apart from these, natural polymers have been well studied and are widely used in material science and industrial fields. The present review explains the prominent features of commonly used natural polymers (polysaccharides and proteins) in various nanomedical applications and reveals the current status of the polymer research in bionanotechnology and science sectors. [ABSTRACT FROM AUTHOR]

In the last decade, there has been a growing interest on chitosan-based nanomaterials. Chitosan is a polymer exceptionally versatile, biodegradable, biocompatible and with good capacity of mucoadhesivity and permeation-enhancing effect. These features make chitosan a perfect material for the fabrication of polymeric nanoparticles for a variety of applications in the field of pharmaceutics, nutraceutics or cosmetics. This paper discuss on the role of isothermal titration calorimetry (ITC) in the creation of protocols for the preparation of chitosan-based nanoparticles, as well as the role of calorimetry to find chitosan-coating conditions to offer to nanoparticles the desired proprieties for the delivery of drugs, biologics and vaccines. Although several papers of the current literature show the employment of ITC in chitosan-based nanosystems, most of them lack a thermodynamic description. Here, we highlight on two types of systems: chitosan-coating nanoparticles and chitosan-containing nanoparticles. The thermodynamic properties and the energetic aspects of the overall interactions are discussed. [ABSTRACT FROM AUTHOR]

Chitosan (CHT) is a natural, safe, and cheap product of chitin deacetylation, widely used by several industries because of its interesting features. The availability of industrial quantities of CHT in the late 1980s enabled it to be tested in agriculture. CHT has been proven to stimulate plant growth, to protect the safety of edible products, and to induce abiotic and biotic stress tolerance in various horticultural commodities. The stimulating effect of different enzyme activities to detoxify reactive oxygen species suggests the involvement of hydrogen peroxide and nitric oxide in CHT signaling. CHT could also interact with chromatin and directly affect gene expression. Recent innovative uses of CHT include synthesis of CHT nanoparticles as a valuable delivery system for fertilizers, herbicides, pesticides, and micronutrients for crop growth promotion by a balanced and sustained nutrition. In addition, CHT nanoparticles can safely deliver genetic material for plant transformation. This review presents an overview on the status of the use of CHT in plant systems. Attention was given to the research that suggested the use of CHT for sustainable crop productivity. [ABSTRACT FROM AUTHOR]

The development of polymer-based nanoparticles to ferry siRNA continues to evolve. It is becoming increasingly apparent that gene silencing nanoparticles produced by conventional bulk manufacturing techniques often exhibit physicochemical heterogeneity within and between batches that can affect the biological performance. Here a new facile and robust 'chip-free' method is presented, termed chip-free agitation-generated droplets (CAD) preparation, using chitosan-based gene silencing nanoparticles as an example. The CAD-prepared silencing particles, in comparison to the particles prepared by the conventional bulk protocol, exhibit lower surface charge (9 mV vs 21 mV at N/P = 5), higher stability (≈40% higher binding affinity and up to 30% less morphological deformation), and are less prone to aggregation measured by nanoparticle tracking analysis over a period of one month. Furthermore, these physical attributes contribute up to 19% higher in cell viability at N/P = 5, while the gene silencing of enhanced green fluorescent protein remains constant in a human cell line. Control of particle properties is necessary to advance siRNA-based delivery; the CAD preparation represents a physical complement to chemical design modifications, which can be readily transferred among research labs and utilized for alternative polymer systems. [ABSTRACT FROM AUTHOR]

Alzheimer disease involves genetic and non-genetic factors and hence it is rational to be treated with genetic and non-genetic therapeutic agents. Nigella sativa has multiple therapeutic properties including neuroregeneration. Nigella sativa oil (NSO) was encapsulated in PLGA nanoparticles and pDNA was loaded either by adsorption on chitosan-modified particles or encapsulation within PLGA nanoparticles. The particle size and zeta potential of NSO-pDNA-chitosan-PLGA nanoparticles were highly dependent on the medium and exhibited high burst release. Meanwhile, NSO-pDNA-PLGA nanoparticles were more consistent with lower burst release. The fabricated nanoparticles revealed the expected outcomes of both pDNA and NSO. The pDNA transfected N2a cell while the encapsulated NSO promoted neurite outgrowth that is crucial for neuroregeneration. Results from this study suggest that NSO could be added to the gene delivery carrier to enhance treatment benefits for Alzheimer disease. [ABSTRACT FROM PUBLISHER]

In this work, we investigate the influence of chitosan hydrophobization on the formation, physicochemical properties, solubilization, and release profiles of chitosan-based nanoparticles (NPs) complexed with the protein insulin, used as a protein model. We use an alkylation procedure to insert 8, 10, and 12 carbon chains along the chitosan macromolecule with a final 5, 10, or 50% substitution degree. Nuclear magnetic resonance (NMR) and infrared spectroscopes (IR) were used to evaluate the success and extent of the hydrophobization procedure. The size, shape, and charge of bare polymer and polymer-insulin NPs were evaluated by dynamic light scattering (DLS), transmission electron (TEM), and atomic force (AFM) microscopes, and zeta potential, respectively. DLS and zeta potential data demonstrated that polymeric NPs made with hydrophobized chitosans possess smaller sizes and higher positive charges than NPs obtained with unmodified chitosan. Also, TEM and AFM images showed that modified chitosan-made NPs have more elongated structures. Isothermal titration calorimetry (ITC) was used to determine the type and extent of the existing interactions between the different constituting components of complexed insulin-hydrophobized chitosan nanoparticles. The association efficiency and loading capacity of insulin into the polymeric nanoparticles were also investigated under different solution conditions. Our results showed that hydrophobized chitosan-based NPs possess both higher association efficiencies and protein loading capacities at pH 6 in comparison with unmodified chitosan-based ones. In vitro protein release studies at pH 5.3, 6, and 7.4 demonstrated that insulin is released more slowly from hydrophobized chitosan NPs, which would favor a more sustained protein release. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

The chitosan-coated magnetic nanoparticles (CS MNPs) were in situ synthesized by cross-linking method. In this method; during the adsorption of cationic chitosan molecules onto the surface of anionic magnetic nanoparticles (MNPs) with electrostatic interactions, tripolyphosphate (TPP) is added for ionic cross-linking of the chitosan molecules with each other. The characterization of synthesized nanoparticles was performed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS/ESCA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and vibrating sample magnetometry (VSM) analyses. The XRD and XPS analyses proved that the synthesized iron oxide was magnetite (FeO). The layer of chitosan on the magnetite surface was confirmed by FTIR. TEM results demonstrated a spherical morphology. In the synthesis, at higher NHOH concentrations, smaller sized nanoparticles were obtained. The average diameters were generally between 2 and 8 nm for CS MNPs in TEM and between 58 and 103 nm in DLS. The average diameters of bare MNPs were found as around 18 nm both in TEM and DLS. TGA results indicated that the chitosan content of CS MNPs were between 15 and 23 % by weight. Bare and CS MNPs were superparamagnetic. These nanoparticles were found non-cytotoxic on cancer cell lines (SiHa, HeLa). The synthesized MNPs have many potential applications in biomedicine including targeted drug delivery, magnetic resonance imaging (MRI), and magnetic hyperthermia. [ABSTRACT FROM AUTHOR]

Most anticancer drugs are greatly limited by the serious side effects that they cause. Tamoxifen is toxic to cancer cells and used against breast cancer. However, it may lead to irreversible cardio toxicity, which could even result in congestive heart failure. It decreases white blood cells count with increased risk of infections, hair loss, nausea, vomiting, loss of appetite, mouth or lip sores, diarrhoea, no menstruation. In order to avoid these harmful side effects to the patients and to improve the therapeutic efficacy of tamoxifen, we developed tamoxifen loaded - chitosan enhanced human serum albumin (HSA) nanoparticles. HSA is the most abundant plasma protein (35-50 g/l human serum) with an average half life of 19 days. HSA is a very soluble globular monomeric proteins consisting of 585 amino acid residues and 35 cysteinyl residues. When HSA is broken down the amino acid will provide nutrition to peripheral tissues. These properties as well as its preferential uptake in tumor and flamed tissues, biodegradability and lack of toxicity make it an ideal candidate for drug delivery. The formed nanoparticles were 137 nm in size with a surface zeta potential of ∼+15 mV, prepared using 30 μg of chitosan added per mg of HSA. Cytotoxicity was not observed with empty chitosan enhanced HSA nanoparticles, formed with low-molecular weight (250) kDa chitosan, indicating biocompatibility and safety of the nanoparticle formulation. Under optimized transfection conditions, approximately 80% of cells were transfected with HSA nanoparticles containing tetramethyl rhodamine-conjugated bovine serum albumin. Conclusively, chitosan enhanced HSA nanoparticles show potential for developing into an effective carrier for anticancer drugs. [ABSTRACT FROM AUTHOR]

As a biomaterial, chitosan has been widely used in tissue engineering, wound healing, drug delivery, and other biomedical applications. It can be formulated in a variety of forms, such as powder, film, sphere, gel, and fiber. These features make chitosan an almost ideal biomaterial in cell culture applications, and cell cultures arguably constitute the most practical way to evaluate biocompatibility and biotoxicity. The advantages of cell cultures are that they can be performed under totally controlled environments, allow high throughput functional screening, and are less costly, as compared to other assessment methods. Chitosan can also be modified into multilayer composite by combining with other polymers and moieties to alter the properties of chitosan for particular biomedical applications. This review briefly depicts and discusses applications of chitosan and nanoparticles in cell culture, in particular, the effects of chitosan and nanoparticles on cell adhesion, cell survival, and the underlying molecular mechanisms: both stimulatory and inhibitory influences are discussed. Our aim is to update the current status of how nanoparticles can be utilized to modify the properties of chitosan to advance the art of tissue engineering by using cell cultures. [ABSTRACT FROM AUTHOR]

The authors present an overview with critical analysis of technical applicability of various nanoadsorbents such as carbon nanotubes, nano-zerovalent iron, and metal oxides–based and polymeric nanoparticles in treating contaminated water. To highlight their performance, selected information such as synthesis method, pH, dose required, pollutant's concentrations, reaction time, and treatment efficiency is presented based on the literature survey of 276 articles (1989–2010). Their advantages and drawbacks in applications are evaluated. Nanoadsorbents that stand out for outstanding performance are compared to bulk activated carbon. The implications of nanoadsorbents to public health and their way forward for facilitating environmental sustainability are also discussed. [ABSTRACT FROM PUBLISHER]

This study reports a two-steps route for obtaining magnetic nanoparticles-polysaccharide hybrid materials consisting of FeO, NiFeO and CuFeO nanoparticles synthesis by coprecipitation method in the presence of a soft template followed by coating of ferrite nanoparticles of 8-10-nm size range with polysaccharide type polymers-sodium alginate or chitosan. Magnetic oxide nanoparticles and the corresponding hybrid materials were characterized by X-ray diffraction (XRD), Mössbauer spectroscopy, atomic absorption spectroscopy (AAS), FTIR spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and specific surface area measurements. The vibrating sample magnetometry confirms the superparamagnetic properties of the synthesized ferrites and hybrids. Using this route, the percent of magnetic nanoparticles retained in chitosan-based hybrid materials is nearly double in comparison with that of sodium alginate-based materials. The biological activity tests on Escherichia coli ATCC 25922, Pseudomonas aeroginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Candida scotti microorganisms show the non-toxic properties of prepared hybrid materials. [ABSTRACT FROM AUTHOR]

Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbon has been the most popular. A number of minerals, clays and waste materials have been regularly used for the removal of metallic pollutants from water and industrial effluents. Recently there has been emphasis on the application of nanoparticles and nanostructured materials as efficient and viable alternatives to activated carbon. Carbon nanotubes also have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions. Because of their importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu. Separation of the used nanoparticles from aqueous solutions and the health aspects of the separated nanoparticles have also been discussed. A significant number of the latest articles have been critically scanned for the present review to give a vivid picture of these exotic materials for water remediation. [ABSTRACT FROM AUTHOR]

Abstract  This paper reviews the design and development of magnetothermally-triggered drug delivery systems, whereby magnetic nanoparticles are combined with thermally-activated materials. By combining superparamagnetic nanoparticles with lower critical solution temperature (LCST) polymers, an alternating current (AC) magnetic field can be used to trigger localized heating in vivo, which in turn causes a phase change in the host polymer to allow diffusion and release of drugs. The use of magnetic nanoparticles for biomedical applications is reviewed, as well as the design of thermally-activated polymeric systems. Current research on externally-triggered delivery is highlighted, with a focus on the design and challenges in developing magnetothermally-activated systems. [ABSTRACT FROM AUTHOR]

Thin chitosan–carbon nanoparticle films (ca. 2 nm average thickness increase per layer) are assembled onto tin-doped indium oxide (ITO) electrode substrates in a layer-by-layer deposition process employing carbon nanoparticles of ca. 8 nm average diameter and an aqueous solution of chitosan (poly-d-glucosamine, low molecular weight, 75–85% deacetylated). Chitosan introduces amine/ammonium functionalities which are employed for the immobilization of redox systems (i) via physisorption of indigo carmine and (ii) via chemisorption of 2-methyleneanthraquinone. The number of binding sites within the chitosan–carbon nanoparticle film is controlled by changing the thickness of the film deposit or by changing the chitosan content, which is varied by changing the chitosan concentration during layer-by-layer deposition. Voltammetric characteristics and stability of the chemisorbed and physisorbed redox systems are reported as a function of pH. The physisorbed redox system is expelled from the film at a pH consistent with the pKA of chitosan (approximately 6.5). However, the 2-methyleneanthraquinone redox system remains stable even in alkaline media and only a minor inflection in the plot of midpoint potentials vs. pH indicates the film deprotonation process at the pKA of chitosan. [ABSTRACT FROM AUTHOR]

Crosslinked chitosan-bound FeC nanoparticles (CCBFeCNP) were prepared, and the adsorptive behavior of Cr(III) and Cr(VI) on CCBFeCNP were assessed. At pH 6.0–10.0, CCBFeCNP is selective towards Cr(III) but hardly selective towards Cr(VI). The retained Cr(III) is subsequently eluted with 0.5 mol L−1 HCl. Total chromium is determined after reduction of Cr(VI) to Cr(III) by ascorbic acid. A new method of flow injection using a micro-column packed with CCBFeCNP as solid phase extractant has been developed for speciation of Cr(III) and Cr(VI) in water samples, followed by flame atomic absorption spectrometry. The effects of pH, sample flow rate and volume, elution solution and interfering ions on the recoveries of Cr(III) were systematically investigated. Under optimum conditions, the adsorption capacity of CCBFeCNP for Cr(III) is 10.5 mg g−1 at pH 7.5. The procedure presented was applied to chromium speciation in water samples, and the results were satisfactory. [ABSTRACT FROM AUTHOR]

Compared with other nanocarriers such as liposomes, mesoporous silica, and cyclodextrin, ferritin as a typical protein nanocage has received considerable attention in the field of food, nutrition, and medicine owing to its inherent cavity size, excellent water solubility, and biocompatibility. Additionally, ferritin nanocage also serves as a versatile bio-template for the synthesis of a variety of nanoparticles. Recently, scientists have explored the ferritin nanocage structure for encapsulation and delivery of guest molecules such as nutrients, bioactive molecules, anticancer drugs, and mineral metal ions by taking advantage of its unique reversible disassembly and reassembly property and biomineralization. In this review, we mainly focus on the preparation and structure of ferritin-based nanocarriers, and regulation of their self-assembly. Moreover, the recent advances of their applications in food nutrient delivery and medical diagnostics are highlighted. Finally, the main challenges and future development in ferritin-directed nanoparticles' synthesis and multifunctional applications are discussed. [ABSTRACT FROM AUTHOR]

Over the last decades, cerium oxide nanoparticles (CeO2 NPs) have gained great interest due to their potential applications, mainly in the fields of agriculture and biomedicine. Promising effects of CeO2 NPs are recently shown in some neurodegenerative diseases, but the mechanism of action of these NPs in Parkinson's disease (PD) remains to be investigated. This issue is addressed in the present study by using a yeast model based on the heterologous expression of the human α-synuclein (α-syn), the major component of Lewy bodies, which represent a neuropathological hallmark of PD. We observed that CeO2 NPs strongly reduce α-syn-induced toxicity in a dose-dependent manner. This effect is associated with the inhibition of cytoplasmic α-syn foci accumulation, resulting in plasma membrane localization of α-syn after NP treatment. Moreover, CeO2 NPs counteract the α-syn-induced mitochondrial dysfunction and decrease reactive oxygen species (ROS) production in yeast cells. In vitro binding assay using cell lysates showed that α-syn is adsorbed on the surface of CeO2 NPs, suggesting that these NPs may act as a strong inhibitor of α-syn toxicity not only acting as a radical scavenger, but through a direct interaction with α-syn in vivo. [ABSTRACT FROM AUTHOR]