Adsorption of diuretic furosemide onto chitosan nanoparticles prepared with a water-in-oil nanoemulsion system

Preparation of chitosan-SiO2 nanoparticles by ultrasonic treatment and its effect on the properties of starch film

The ultrasonic treatment could decrease the particles size of chitosan-SiO₂ particles. The EDS of samples with ultrasonic treatment for 0 min and 10 min indicated that the SiO₂ was present in prepared chitosan-SiO₂ particles. When the ultrasonic time reached 10 min, the chitosan-SiO₂ nanoparticles formed and the mean size was 506.7 ± 3.42 nm and the Zeta potential of the chitosan-SiO₂ nanoparticles was greater than 30 mV, showing the suspension was a stable dispersed liquid. The chitosan-SiO₂ nanoparticles were used as reinforcement in thermoplastic starch films to further verify their performance in enhanced films. The water contact angle of thermoplastic starch film reinforced with chitosan-SiO₂ nanoparticles was 44.13 ± 5.02° and had a good mechanical property with tensile strength of 8.91 ± 0.49 MPa. This study indicates that chitosan-SiO₂ nanoparticles could be used as a reinforcement to prepare thermoplastic starch films and promote the application of chitosan nanoparticles in nanocomposite films.

Using Chitosan or Chitosan Derivatives in Cancer Therapy

Cancer is one of the major causes of death worldwide. Chemotherapeutic drugs have become a popular choice as anticancer agents. Despite the therapeutic benefits of chemotherapeutic drugs, patients often experience side effects and drug resistance. Biopolymers could be used to overcome some of the limitations of chemotherapeutic drugs, as well as be used either as anticancer agents or drug delivery vehicles. Chitosan is a biocompatible polymer derived from chitin. Chitosan, chitosan derivatives, or chitosan nanoparticles have shown their promise as an anticancer agent. Additionally, functionally modified chitosan can be used to deliver nucleic acids, chemotherapeutic drugs, and anticancer agents. More importantly, chitosan-based drug delivery systems improved the efficacy, potency, cytotoxicity, or biocompatibility of these anticancer agents. In this review, we will investigate the properties of chitosan and chemically tuned chitosan derivatives, and their application in cancer therapy.

Nanochitosan: Commemorating the Metamorphosis of an ExoSkeletal Waste to a Versatile Nutraceutical

Chitin (poly-N-acetyl-D-glucosamine) is the second (after cellulose) most abundant organic polymer. In its deacetylated form-chitosan-becomes a very interesting material for medical use. The chitosan nano-structures whose preparation is described in this article shows unique biomedical value. The preparation of nanochitosan, as well as the most vital biomedical applications (antitumor, drug delivery and other medical uses), have been discussed in this review. The challenges confronting the progress of nanochitosan from benchtop to bedside clinical settings have been evaluated. The need for inclusion of nano aspects into chitosan research, with improvisation from nanotechnological inputs has been prescribed for breaking down the limitations. Future perspectives of nanochitosan and the challenges facing nanochitosan applications and the areas needing research focus have been highlighted.

Investigations on characteristics of polyurethane foam impregnated with nanochitosan and nanosilver/silver oxide and its effectiveness in phosphate removal

A novel potential adsorbent, produced with chitosan nanoparticles and silver/silver oxide nanoparticles impregnated on polyurethane foam (PFCA), is developed for phosphate removal in aqueous solutions. The ultraviolet-visible (UV-Vis) spectroscopy uncovered the emergence of nanoparticles. The field emission scanning electron microscopy (FESEM) provided the mean size of chitosan nanoparticles between 56 and 112 nm and that of silver-silver oxide nanoparticles between 44 and 75 nm. Energy dispersive X-ray (EDX) spectroscopy determined the presence of specific elements (C, O, P and Ag) in the adsorbent before and after treatment. Fourier transform infrared (FTIR) spectroscopy revealed the interplay between the N-H bond of amino group in PFCA and phosphate ions during adsorption. X-ray diffraction (XRD) analysis of PFCA showed nearly the same pattern before and after treatment, indicating the stability of PFCA. The silver ion concentration in the effluent from inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis was found to be very less and below the drinking water limits. The surface area estimated by Brunauer-Emmett-Teller (BET) studies was found to be 2.17 m²/g. The experimental studies showed that PFCA can remove 61.24% of phosphate from an influent phosphate phosphorus concentration of 50 mg P/L, at its propitious condition. Even after 7 cycles of reuse, PFCA proved to be effective in removing 20.58% of phosphate. Hence, PFCA can be considered to be a potential sorbent for removing phosphate from surface water. Graphical abstract.

Chitosan film as recyclable adsorbent membrane to remove/recover hazardous pharmaceutical pollutants from water: the case of the emerging pollutant Furosemide

Due to the negative effects of emerging contaminants on the environment, that can potentially induce deleterious effects in aquatic and human life, this paper focuses on the removal from the water of Furosemide, through the adsorption process. Indeed, only a few papers are available in the literature about the Furosemide adsorption and, chitosan films are thus proposed for this purpose as safe, sustainable, and recyclable adsorbent materials. In the present work, the effects on the adsorption process of several experimental parameters such as the pH values, ionic strength, amount of adsorbent/pollutant, and temperature values were investigated. The kinetics models, isotherms of adsorption, and the thermodynamic parameters were studied showing that the Furosemide physisorption occurred on the heterogeneous Chitosan surface, endothermically (ΔH° = +31.27 ± 3.40 kJ mol^-1) and spontaneously (ΔS° = +150.00 ± 10.00 J mol^-1 K^-1), following a pseudo-second-order kinetic model. The 90% of the pollutant was adsorbed in 2 h, with a maximum adsorption capacity of 3.5 mg × g^-1. Despite these relatively low adsorption capacities, experiments of desorption were performed and 100% of adsorbed Furosemide was recovered by using concentrated NaCl solutions, proposing a low-cost and green approach, with respect to the previous literature relative to the Furosemide adsorption, fundamental for the pollutant recovery and adsorbent reuse.

Development of orally administered insulin-loaded polymeric-oligonucleotide nanoparticles: statistical optimization and physicochemical characterization

INTRODUCTION

Therapeutic peptides are administered via parenteral route due to poor absorption in the gastrointestinal (GI) tract, instability in gastric acid, and GI enzymes. Polymeric drug delivery systems have achieved significant interest in pharmaceutical research due to its feasibility in protecting proteins, tissue targeting, and controlled drug release pattern.

MATERIALS AND METHODS

In this study, the size, polydispersity index, and zeta potential of insulin-loaded nanoparticles were characterized by dynamic light scattering and laser Doppler micro-electrophoresis. The main and interaction effects of chitosan concentration and Dz13Scr concentration on the physicochemical properties of the prepared insulin-loaded nanoparticles (size, polydispersity index, and zeta potential) were evaluated statistically using analysis of variance. A robust procedure of reversed-phase high-performance liquid chromatography was developed to quantify insulin release in simulated GI buffer. Results and discussion: We reported on the effect of two independent parameters, including polymer concentration and oligonucleotide concentration, on the physical characteristics of particles. Chitosan concentration was significant in predicting the size of insulin-loaded CS-Dz13Scr particles. In terms of zeta potential, both chitosan concentration and squared term of chitosan were significant factors that affect the surface charge of particles, which was attributed to the availability of positively-charged amino groups during interaction with negatively-charged Dz13Scr. The excipients used in this study could fabricate nanoparticles with negligible toxicity in GI cells and skeletal muscle cells. The developed formulation could conserve the physicochemical properties after being stored for 1 month at 4 °C.

CONCLUSION

The obtained results revealed satisfactory results for insulin-loaded CS-Dz13Scr nanoparticles (159.3 nm, pdi 0.331, -1.08 mV). No such similar study has been reported to date to identify the main and interactive significance of the above parameters for the characterization of insulin-loaded polymeric-oligonucleotide nanoparticles. This research is of importance for the understanding and development of protein-loaded nanoparticles for oral delivery.

Carbohydrate-based nanocarriers and their application to target macrophages and deliver antimicrobial agents

Many deadly infections are produced by microorganisms capable of sustained survival in macrophages. This reduces exposure to chemadrotherapy, prevents immune detection, and is akin to criminals hiding in police stations. Therefore, the use of glyco-nanoparticles (GNPs) as carriers of therapeutic agents is a burgeoning field. Such an approach can enhance the penetration of drugs into macrophages with specific carbohydrate targeting molecules on the nanocarrier to interact with macrophage lectins. Carbohydrates are natural biological molecules and the key constituents in a large variety of biological events such as cellular communication, infection, inflammation, enzyme trafficking, cellular migration, cancer metastasis and immune functions. The prominent characteristics of carbohydrates including biodegradability, biocompatibility, hydrophilicity and the highly specific interaction of targeting cell-surface receptors support their potential application to drug delivery systems (DDS). This review presents the 21^st century development of carbohydrate-based nanocarriers for drug targeting of therapeutic agents for diseases localized in macrophages. The significance of natural carbohydrate-derived nanoparticles (GNPs) as anti-microbial drug carriers is highlighted in several areas of treatment including tuberculosis, salmonellosis, leishmaniasis, candidiasis, and HIV/AIDS.

Novel lignin nanoparticles for oral drug delivery

Lignin nanoparticles (LNPs) were prepared with the objective of evaluating their application as a novel oral drug delivery system.

Inverse-micelle synthesis of doxorubicin-loaded alginate/chitosan nanoparticles and in vitro assessment of breast cancer cytotoxicity

Naturally-derived polysaccharides, such as alginate and chitosan, can be assembled to form nanocarriers for the delivery of therapeutic agents. Here we exploit the electrostatic complexation of alginate/chitosan in a water-in-oil (w/o) emulsion process to produce doxorubicin (DOX)-loaded nanoparticles (~80 nm) with exceptional spherical morphology and uniformity. This robust synthetic route utilizes an aqueous phase dispersed in a cyclohexane/dodecylamine organic phase and is capable of encapsulating DOX in the nanoparticle solution. The uptake and efficacy of this novel formulation was evaluated in a murine breast cancer cell line, 4T1, with comparable 72 h IC₅₀ values of the nanoparticle solution (0.15 μg/mL) and free DOX (0.13 μg/mL). Overall, the favorable performance, physiochemical properties, and their facile production support these nanocarriers as promising platform for the delivery of aqueous soluble drugs.

Experimental and QSAR studies on adsorptive interaction of anionic nonsteroidal anti-inflammatory drugs with activated charcoal

Adsorptive interactions, namely adsorption capacity (q_m) and affinity (b), between nonsteroidal anti-inflammatory drugs (NSAIDs) in anionic forms and commercial activated charcoal (AC), were estimated by isotherm experiment in a batch, and the properties were modeled based on the concept of quantitative structure-activity relationship (QSAR). Experimental results showed that AC had a high q_m (0.38-0.67 mmol g^-1) and b (14.03-930.8 L mmol^-1) for the selected NSAIDs. In QSAR modeling, linear free energy relationship (LFER) descriptors of excess molar refraction (E), dipolarity/polarizability (S), and Coulombic interactions of anions (J^-) were highly related to log q_m, and the combination of the three terms could predict log q_m in R² of 0.97 and SE of 0.015 log unit. In the case of b, only single B term showed a good correlation with log b in R² of 0.81. Additionally, the combination of hydrogen-bonding acceptors (HBAs) and molar volume (MV), which are easily calculable parameters, could also derive good predictability in R² = 0.81 and SE = 0.26 log unit. Afterwards, validation of the QSAR models based on the leave-one-out cross-validation (Q²_LOO) method showed that the models were acceptable.

Radiation grafting of N-vinylcaprolactam onto nano and macrogels of chitosan: Synthesis and characterization

The aim of this study was to synthesize chitosan hydrogels, in macro- and nano-size, grafted with N-vinylcaprolactam (NVCL) using gamma radiation, and evaluate their potential application as a drug delivery system, using 5-fluorouracil (5-FU) as a model drug. The effect of dose and monomer concentration in the grafting process was studied, and the materials were characterized by FTIR, TGA, DLS, SEM and AFM. Higher grafting percentages were observed for the nanogels system. Although both the grafted macro- and nanogels, (net-CS)-g-NVCL, showed a response to pH (4.75) and temperature (31-33°C), the nanogels showed a better swelling response to both stimuli because of their higher surface area. Both systems were able to load 5-FU in small amounts (2-3.5mgg^-1) and the release was sustained for more than 12h, showing that the modified macro and nanogels can be a potential alternative for the administration of drugs.

Nanoparticles from renewable polymers

The use of polymers from natural resources can bring many benefits for novel polymeric nanoparticle systems. Such polymers have a variety of beneficial properties such as biodegradability and biocompatibility, they are readily available on large scale and at low cost. As the amount of fossil fuels decrease, their application becomes more interesting even if characterization is in many cases more challenging due to structural complexity, either by broad distribution of their molecular weights (polysaccharides, polyesters, lignin) or by complex structure (proteins, lignin). This review summarizes different sources and methods for the preparation of biopolymer-based nanoparticle systems for various applications.

Design and evaluation of chitosan nanoparticles as novel drug carrier for the delivery of rivastigmine to treat Alzheimer's disease

AIM

The objective of the study was to develop chitosan nanoparticles of the drug rivastigmine and to study the effect of polysorbate 80 coating on its biodistribution.

RESULTS

Chitosan nanoparticles containing rivastigmine were prepared by spontaneous emulsification. The mean size of the particles was 47 +/- 4 nm. Zeta potential analysis demonstrated a positive charge for the particles and coating with polysorbate 80 slightly reduced the surface charge of the particles. A biphasic release pattern was observed for the release of drug from the nanoparticles. Release of the drug from nanoparticles was diffusion controlled and the mechanism of drug release was Fickian.

CONCLUSION

The biodistribution studies demonstrated that coating of nanoparticles with 1% polysorbate 80 altered the uptake of nanoparticles by different organs.

A novel method to chemically bind thiazolidine-2,4-dione through cross-linked chitosan nanoparticles using malanodialdehyde as a cross-linker

Chitosan is a biodegradable natural polymer with great potential for pharmaceutical applications because of its biocompatibility, high charge density, nontoxicity and mucoadhesion. It has been shown that it not only improves the dissolution of poorly soluble drugs but also exerts a significant effect on fat metabolism in the body. Gel formation can be obtained by interactions of chitosans with low molecular counterions such as polyphosphates, sulfates, and cross-linkers. This gelling property of chitosan allows a wide range of applications such as the coating of pharmaceuticals and food products, gel entrapment of biochemicals, plant embryos, whole cells, microorganisms, and algae. This manuscript is an insight into the exploitation of its properties for microencapsulating drugs. Herein, we report a novel method to chemically bind thiazolidine-2,4-dione through cross-linked chitosan nanoparticles using malanodialdehyde as a new cross-linker and well characterized by FT-IR, NMR, TGA, DSC, powder X-ray diffraction, TEM, and cyclic voltametry.

Chitosan nanoparticles: a promising system in novel drug delivery

The ability of nanoparticles to manipulate the molecules and their structures has revolutionized the conventional drug delivery system. The chitosan nanoparticles, because of their biodegradability, biocompatibility, better stability, low toxicity, simple and mild preparation methods, offer a valuable tool to novel drug delivery systems in the present scenario. Besides ionotropic gelation method, other methods such as microemulsion method, emulsification solvent diffusion method, polyelectrolyte complex method, emulsification cross-linking method, complex coacervation method and solvent evaporation method are also in use. The chitosan nanoparticles have also been reported to have key applications in parentral drug delivery, per-oral administration of drugs, in non-viral gene delivery, in vaccine delivery, in ocular drug delivery, in electrodeposition, in brain targeting drug delivery, in stability improvement, in mucosal drug delivery in controlled drug delivery of drugs, in tissue engineering and in the effective delivery of insulin. The present review describes origin and properties of chitosan and its nanoparticles along with the different methods of its preparation and the various areas of novel drug delivery where it has got its application.

Effect of solvents and precipitant on the properties of chitosan nanoparticles in a water-in-oil microemulsion and its lipase immobilization performance

When chitosan nanoparticles were prepared in a water-in-oil (W/O) microemulsion by using 2% (wt) acetic acid (HAc) and 30% (wt) tri-n-octylamine (TOA) as solvent and precipitant, respectively, particle diameters of 7 nm were observed and the particles formed ovoid shaped aggregates. Using 0.05% HCl and 5.0M NaOH as solvent and precipitant produced nanoparticles 10nm in size that aggregated in the form of snowflakes. These two types of nanoparticles were used to immobilize lipase, the lipase adsorption capacity using nanoparticles 7 nm in size reached 156 mg/g and activity retention compared to free enzyme was as high as 66.7%, and the residual activity of the immobilized lipase was 91% after 5 runs of reaction. In additional, the activity retention of nanoparticles 10nm in size also could reach 62.8%. This indicated that the chitosan nanoparticles prepared in a W/O microemulsion were suitable for lipase immobilization.

Ultra-small water-dispersible fluorescent chitosan nanoparticles: synthesis, characterization and specific targeting

A robust water-in-oil microemulsion method of making water-dispersible ultra-small (<30 nm) size fluorescent chitosan nanoparticles is reported for the first time and specific targeting of these FCNPs to human leukemia cells via aptamer recognition is demonstrated.

Polysaccharides-based nanoparticles as drug delivery systems

Natural polysaccharides, due to their outstanding merits, have received more and more attention in the field of drug delivery systems. In particular, polysaccharides seem to be the most promising materials in the preparation of nanometeric carriers. This review relates to the newest developments in the preparation of polysaccharides-based nanoparticles. In this review, four mechanisms are introduced to prepare polysaccharides-based nanoparticles, that is, covalent crosslinking, ionic crosslinking, polyelectrolyte complex, and the self-assembly of hydrophobically modified polysaccharides.

Adsorption of bovin serum albumin (BSA) onto the magnetic chitosan nanoparticles prepared by a microemulsion system

The adsorption characteristics of BSA onto the magnetic chitosan nanoparticles have been investigated in this paper. The magnetic chitosan nanoparticles were prepared by adding the basic precipitant of NaOH solution into a W/O microemulsion system. The morphology of magnetic chitosan nanoparticles was observed by transmission electron microscope (TEM). It was found that the diameter of magnetic chitosan nanoparticles was from 10nm to 20 nm, and the nanoparticles suspending in the aqueous solution could easily aggregate by a magnet, which suggested that the nanoparticles had good magnetic characteristics. The BSA adsorption experiment indicated that when pH of BSA solution was equal to 4, the maximum adsorption loading reached 110 mg/g. Through measuring the zeta potential of BSA solution and the magnetic nanoparticles, it was found that under this situation the surface of BSA took the negative charge, but the magnetic nanoparticles took the positive charge. Due to the small diameter, the adsorption equilibrium of BSA onto the nanoparticles reached very quickly within 10 min. The adsorption equilibrium of BSA onto the magnetic chitosan nanoparticles fitted well with the Freundlich model. The experimental results showed that the magnetic chitosan nanoparticles have potential to be used for the quick pretreatment in the protein analysis process.

Alginate microparticles as novel carrier for oral insulin delivery

Alginate microparticles produced by emulsification/internal gelation were investigated as a promising carrier for insulin delivery. The procedure involves the dispersion of alginate solution containing insulin protein, into a water immiscible phase. Gelation is triggered in situ by instantaneous release of ionic calcium from carbonate complex via gentle pH adjustment. Particle size is controlled through the emulsification parameters, yielding insulin-loaded microparticles. Particle recovery was compared using several washing protocols. Recovery strategies are proposed and the influence on particle mean size, morphology, recovery yield (RY), encapsulation efficiency, insulin release profile, and structural integrity of released insulin were evaluated. Spherical micron-sized particles loaded with insulin were produced. The recovery process was optimized, improving yield, and ensuring removal of residual oil from the particle surface. The optimum recovery strategy consisted in successive washing with a mixture of acetone/hexane/isopropanol coupled with centrifugation. This strategy led to small spherical particles with an encapsulation efficiency of 80% and a RY around 70%. In vitro release studies showed that alginate itself was not able to suppress insulin release in acidic media; however, this strategy preserves the secondary structure of insulin. Particles had a mean size lower than the critical diameter necessary to be orally absorbed through the intestinal mucosa followed by their passage to systemic circulation and thus can be considered as a promising technology for insulin delivery.