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Sample records for magnetic chitosan nanoparticles

  1. Preparation and characterization of magnetic nanoparticles with chitosan coating

    NASA Astrophysics Data System (ADS)

    Dung, Doan Thi Kim; Hoang Hai, Tran; Phuc, Le Hong; Long, Bui Duc; Khanh Vinh, Le; Nha Truc, Phan

    2009-09-01

    Magnetic chitosan nanoparticles were prepared by the suspension cross-linking technique for use in the application of magnetic carrier technology. The Fe3O4 magnetic nanoparticles were synthesized by co-precipitation of FeCl2 and FeCl3 solution in base medium for using in the preparation of the magnetic chitosan. The morphological and magnetic properties of the magnetic nanoparticles were characterized by different techniques (TEM, XRD, VSM, FTIR, etc.). The magnetic properties of chitosan - magnetic nanoparticles were analyzed by VSM, and MS around 15 emu/g.

  2. Synthesis and application of magnetic chitosan nanoparticles in oilfield

    NASA Astrophysics Data System (ADS)

    Lian, Qi; Zheng, Xuefang

    2016-01-01

    The novel magnetic Co0.5Mn0.5Fe2O4-chitosan nanoparticles has the advantage of excellent biodegradation and a high level of controllability. The Co0.5Mn0.5Fe2O4-chitosan nanoparticles was prepared successfully. The size of the Co0.5Mn0.5Fe2O4-chitosan nanoparticles were all below 100 nm. The saturated magnetization of the Co0.5Mn0.5Fe2O4-chitosan nanoparticles could reach 80 emu/g and showed the characteristics of superparamagnetism at the same time. The image of TEM and SEM electron microscopy showed that the cubic-shape magnetic Co0.5Mn0.5Fe2O4 particles were encapsulated by the spherical chitosan nanoparticles. The evaluation on the interfacial properties of the product showed that the interfacial tension between crude oil and water could be reduce to ultra-low values as low as 10-3 mN/m when the magnetic Co0.5Mn0.5Fe2O4-chitosan nanoparticle was used in several blocks in Shengli Oilfield without other additives. Meanwhile, the magnetic Co0.5Mn0.5Fe2O4-chitosan nanoparticles possessed good salt-resisting capacity.

  3. Thermal and magnetic properties of chitosan-iron oxide nanoparticles.

    PubMed

    Soares, Paula I P; Machado, Diana; Laia, César; Pereira, Laura C J; Coutinho, Joana T; Ferreira, Isabel M M; Novo, Carlos M M; Borges, João Paulo

    2016-09-20

    Chitosan is a biopolymer widely used for biomedical applications such as drug delivery systems, wound healing, and tissue engineering. Chitosan can be used as coating for other types of materials such as iron oxide nanoparticles, improving its biocompatibility while extending its range of applications. In this work iron oxide nanoparticles (Fe3O4 NPs) produced by chemical precipitation and thermal decomposition and coated with chitosan with different molecular weights were studied. Basic characterization on bare and chitosan-Fe3O4 NPs was performed demonstrating that chitosan does not affect the crystallinity, chemical composition, and superparamagnetic properties of the Fe3O4 NPs, and also the incorporation of Fe3O4 NPs into chitosan nanoparticles increases the later hydrodynamic diameter without compromising its physical and chemical properties. The nano-composite was tested for magnetic hyperthermia by applying an alternating current magnetic field to the samples demonstrating that the heating ability of the Fe3O4 NPs was not significantly affected by chitosan.

  4. Preparation and optimization of chitosan nanoparticles and magnetic chitosan nanoparticles as delivery systems using Box-Behnken statistical design.

    PubMed

    Elmizadeh, Hamideh; Khanmohammadi, Mohammadreza; Ghasemi, Keyvan; Hassanzadeh, Gholamreza; Nassiri-Asl, Marjan; Garmarudi, Amir Bagheri

    2013-06-01

    Chitosan nanoparticles and magnetic chitosan nanoparticles can be applied as delivery systems for the anti-Alzheimer drug tacrine. Investigation was carried out to elucidate the influence of process parameters on the mean particle size of chitosan nanoparticles produced by spontaneous emulsification. The method was optimized using design of experiments (DOE) by employing a 3-factor, 3-level Box-Behnken statistical design. This statistical design is used in order to achieve the minimum size and suitable morphology of nanoparticles. Also, magnetic chitosan nanoparticles were synthesized according to optimal method. The designed nanoparticles have average particle size from 33.64 to 74.87nm, which were determined by field emission scanning electron microscopy (FE-SEM). Drug loading in the nanoparticles as drug delivery systems has been done according to the presented optimal method and appropriate capacity of drug loading was shown by ultraviolet spectrophotometry. Chitosan and magnetic chitosan nanoparticles as drug delivery systems were characterized by Diffuse Reflectance Fourier Transform Mid Infrared spectroscopy (DR-FTMIR).

  5. Preparation and characterization of magnetic Fe3O4-chitosan nanoparticles loaded with isoniazid

    NASA Astrophysics Data System (ADS)

    Qin, H.; Wang, C. M.; Dong, Q. Q.; Zhang, L.; Zhang, X.; Ma, Z. Y.; Han, Q. R.

    2015-05-01

    A novel and simple method has been proposed to prepare magnetic Fe3O4-chitosan nanoparticles loaded with isoniazid (Fe3O4/CS/INH nanocomposites). Efforts have been made to develop isoniazid (INH) loaded chitosan (CS) nanoparticles by ionic gelation of chitosan with tripolyphosphate (TPP). The factors that influence the preparation of chitosan nanoparticles, including the TPP concentration, the chitosan/TPP weight ratio and the chitosan concentration on loading capacity and encapsulation efficiency of chitosan nanoparticles were studied. The magnetic Fe3O4 nanoparticles were prepared by co-precipitation method of Fe2+ and Fe3+. Then the magnetic Fe3O4/CS/INH nanocomposites were prepared by ionic gelation method. The magnetic Fe3O4 nanoparticles and magnetic Fe3O4/CS/INH nanocomposites were characterized by XRD, TEM, FTIR and SQUID magnetometry. The in vitro release of Fe3O4/CS/INH nanocomposites showed an initial burst release in the first 10 h, followed by a more gradual and sustained release for 48 h. It is suggested that the magnetic Fe3O4/CS/INH nanocomposites may be exploited as potential drug carriers for controlled-release applications in magnetic targeted drugs delivery system.

  6. Activation of tumor suppressor p53 gene expression by magnetic thymine-imprinted chitosan nanoparticles.

    PubMed

    Lee, Mei-Hwa; Thomas, James L; Chen, Jian-Zhou; Jan, Jeng-Shiung; Lin, Hung-Yin

    2016-02-01

    Chitosan is a natural biodegradable polysaccharide that has been used to enhance gene delivery, owing to the ease with which chitosan nanoparticles enter the nucleus of cells. To study the effects of nuclear delivery of telomeric gene sequences, which contain thymine, we formed magnetic thymine-imprinted chitosan nanoparticles (TIPs) by the precipitation of chitosan, mixed with thymine and magnetic nanoparticles (to aid in separations). The mean size of the TIPS was 116 ± 18 nm; the dissociation constant for thymine was 21.8 mg mL(-1). We then treated human hepatocellular carcinoma (HepG2) with TIPs nanoparticles bearing bound thymine or a bound telomeric DNA sequence. The expression of the tumor suppressor p53 gene increased when TIPs were applied and decreased when telomere-bound TIPs were applied.

  7. Chitosan-Coated Magnetic Nanoparticles Prepared in One Step by Reverse Microemulsion Precipitation

    PubMed Central

    López, Raúl G.; Pineda, María G.; Hurtado, Gilberto; de León, Ramón Díaz; Fernández, Salvador; Saade, Hened; Bueno, Darío

    2013-01-01

    Chitosan-coated magnetic nanoparticles (CMNP) were obtained at 70 °C and 80 °C in a one-step method, which comprises precipitation in reverse microemulsion in the presence of low chitosan concentration in the aqueous phase. X-ray diffractometry showed that CMNP obtained at both temperatures contain a mixture of magnetite and maghemite nanoparticles with ≈4.5 nm in average diameter, determined by electron microscopy, which suggests that precipitation temperature does not affect the particle size. The chitosan coating on nanoparticles was inferred from Fourier transform infrared spectrometry measurements; furthermore, the carbon concentration in the nanoparticles allowed an estimation of chitosan content in CMNP of 6%–7%. CMNP exhibit a superparamagnetic behavior with relatively high final magnetization values (≈49–53 emu/g) at 20 kOe and room temperature, probably due to a higher magnetite content in the mixture of magnetic nanoparticles. In addition, a slight direct effect of precipitation temperature on magnetization was identified, which was ascribed to a possible higher degree of nanoparticles crystallinity as temperature at which they are obtained increases. Tested for Pb2+ removal from a Pb(NO3)2 aqueous solution, CMNP showed a recovery efficacy of 100%, which makes them attractive for using in heavy metals ion removal from waste water. PMID:24084716

  8. Chitosan-coated nickel-ferrite nanoparticles as contrast agents in magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Ahmad, Tanveer; Bae, Hongsub; Iqbal, Yousaf; Rhee, Ilsu; Hong, Sungwook; Chang, Yongmin; Lee, Jaejun; Sohn, Derac

    2015-05-01

    We report evidence for the possible application of chitosan-coated nickel-ferrite (NiFe2O4) nanoparticles as both T1 and T2 contrast agents in magnetic resonance imaging (MRI). The coating of nickel-ferrite nanoparticles with chitosan was performed simultaneously with the synthesis of the nickel-ferrite nanoparticles by a chemical co-precipitation method. The coated nanoparticles were cylindrical in shape with an average length of 17 nm and an average width of 4.4 nm. The bonding of chitosan onto the ferrite nanoparticles was confirmed by Fourier transform infrared spectroscopy. The T1 and T2 relaxivities were 0.858±0.04 and 1.71±0.03 mM-1 s-1, respectively. In animal experimentation, both a 25% signal enhancement in the T1-weighted mage and a 71% signal loss in the T2-weighted image were observed. This demonstrated that chitosan-coated nickel-ferrite nanoparticles are suitable as both T1 and T2 contrast agents in MRI. We note that the applicability of our nanoparticles as both T1 and T2 contrast agents is due to their cylindrical shape, which gives rise to both inner and outer sphere processes of nanoparticles.

  9. Magnetic chitosan nanoparticles as a drug delivery system for targeting photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Sun, Yun; Chen, Zhi-long; Yang, Xiao-xia; Huang, Peng; Zhou, Xin-ping; Du, Xiao-xia

    2009-04-01

    Photodynamic therapy (PDT) has become an increasingly recognized alternative to cancer treatment in clinic. However, PDT therapy agents, namely photosensitizer (PS), are limited in application as a result of prolonged cutaneous photosensitivity, poor water solubility and inadequate selectivity, which are encountered by numerous chemical therapies. Magnetic chitosan nanoparticles provide excellent biocompatibility, biodegradability, non-toxicity and water solubility without compromising their magnetic targeting. Nevertheless, no previous attempt has been reported to develop an in vivo magnetic drug delivery system with chitosan nanoparticles for magnetic resonance imaging (MRI) monitored targeting photodynamic therapy. In this study, magnetic targeting chitosan nanoparticles (MTCNPs) were prepared and tailored as a drug delivery system and imaging agents for PS, designated as PHPP. Results showed that PHPP-MTCNPs could be used in MRI monitored targeting PDT with excellent targeting and imaging ability. Non-toxicity and high photodynamic efficacy on SW480 carcinoma cells both in vitro and in vivo were achieved with this method at the level of 0-100 µM. Notably, localization of nanoparticles in skin and hepatic tissue was significantly less than in tumor tissue, therefore photosensitivity and hepatotoxicity can be attenuated.

  10. Toxicity of magnetic chitosan micro and nanoparticles as carriers for biologically active substances.

    PubMed

    Leitgeb, Maja; Heržič, Katja; Podrepšek, Gordana Hojnik; Hojski, Aljaž; Crnjac, Anton; Knez, Zeljko

    2014-01-01

    Nanoparticles of inorganic magnetic core surrounded by layers of functional coatings are potential representatives of nanostructures for immobilization of bio-substances. Magnetic nanoparticles (MNPs) are often bound in aggregates due to a strong magnetic dipole, which has a lot of advantages, such as large surface area for binding biologically active substances. Chitosan is a polysaccharide polymer that is non-toxic, hydrophilic, biocompatible and has hydroxy and amino groups in its structure. Because of these chemical and biological properties it is a desirable bio-product for immobilization of enzymes and for binding of other biologically active substances. Magnetic micro and nanoparticles were synthesized with chitosan by three different methods; microemulsion process, suspension cross-linking technique and covalent binding of chitosan. Toxic effect of the prepared magnetic particles was determined as well and was examined on five different bacterial cultures; Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis and Klebsiella pneumoniae. At concentrations of 10-30 mg of magnetic particles per 0.5 McFarland Standard solution of E. coli and per 400 CFU of S. aureus, P. aeruginosa, E. faecalis in K. pneumonia, no inhibition on the chosen bacterial cultures was detected. PMID:24664338

  11. Preparation and characterization of biofunctionalized chitosan/Fe3O4 magnetic nanoparticles for application in liver magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Song, Xiaoli; Luo, Xiadan; Zhang, Qingqing; Zhu, Aiping; Ji, Lijun; Yan, Caifeng

    2015-08-01

    Biofunctionalized chitosan@Fe3O4 nanoparticles are synthesized by combining Fe3O4 and CS chemically modified with PEG and lactobionic acid in one step. The biofunctionalized nanoparticles are characterized by TEM, X-ray, DLS, zeta-potential and magnetic measurements. The in vitro and in vivo behaviors of the biofunctionalized nanoparticles, especially, the cytotoxicity, the protein resistance, metabolism and iron toxicity are assessed. The functional groups, PEG enable the nanoparticles more biocompatible and the lactobionic acid groups enable liver targeting. The potential applications of the nanoparticles in liver magnetic resonance imaging are confirmed. The results demonstrated that the nanoparticles are suspension stability, non-cytotoxicity, non-tissue toxicity and sensitive in liver magnetic resonance imaging, representing potential tools for applications in the biomedical field.

  12. Elucidation on enhanced application of synthesised kojic acid immobilised magnetic and chitosan tri-polyphosphate nanoparticles as antibacterial agents.

    PubMed

    Chaudhary, Jignesh; Lakhawat, Sudarshan; Pathak, Amrendra Nath

    2015-12-01

    Kojic acid (KA) is a secondary metabolite which is secreted by several aspergillus species. It is a multi-functional skeleton from which many derivatives can be synthesised and applied in various areas of biotechnology. KA grafting on synthesised magnetic nanoparticles (MNPs) and chitosan tri-polyphosphate (chitosan-TPP) nanoparticles was successfully done and characterised by Fourier transformation infrared spectroscopy. It was observed that amino propyl triethoxy silane-coated MNPs and chitosan-TPP nanoparticles enhanced the antibacterial activity of KA against both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa). The organic constitution and significant antibacterial activity of KA-chitosan-TPP nanoparticles can be applicable in the field of medical biotechnology.

  13. Potentiometric urea biosensor utilizing nanobiocomposite of chitosan-iron oxide magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Ali, A.; AlSalhi, M. S.; Atif, M.; Ansari, Anees A.; Israr, M. Q.; Sadaf, J. R.; Ahmed, E.; Nur, O.; Willander, M.

    2013-02-01

    The iron oxide (Fe3O4) magnetic nanoparticles have been fabricated through a simple, cheap and reproducible approach. Scanning electron microscope, x-rays powder diffraction of the fabricated nanoparticles. Furthermore, the fabrication of potentiometric urea biosensor is carried out through drop casting the initially prepared isopropanol and chitosan solution, containing Fe3O4 nanoparticles, on the glass fiber filter with a diameter of 2 cm and a copper wire (of thickness -500 μm) has been utilized to extract the voltage signal from the functionalized nanoparticles. The functionalization of surface of the Fe3O4 nanoparticles is obtained by the electrostatically immobilization of urease onto the nanobiocomposite of the chitosan- Fe3O4 in order to enhance the sensitivity, specificity, stability and reusability of urea biosensor. Electrochemical detection procedure has been adopted to measure the potentiometric response over the wide logarithmic concentration range of the 0.1 mM to 80 mM. The Fe3O4 nanoparticles based urea biosensor depicts good sensitivity with ~42 mV per decade at room temperature. Durability of the biosensor could be considerably enhanced by applying a thin layer of the nafion. In addition, the reasonably stable output response of the biosensor has been found to be around 12 sec.

  14. Influence of chitosan coating on magnetic nanoparticles in endothelial cells and acute tissue biodistribution.

    PubMed

    Agotegaray, Mariela; Campelo, Adrián; Zysler, Roberto; Gumilar, Fernanda; Bras, Cristina; Minetti, Alejandra; Massheimer, Virginia; Lassalle, Verónica

    2016-08-01

    Chitosan coating on magnetic nanoparticles (MNPs) was studied on biological systems as a first step toward the application in the biomedical field as drug-targeted nanosystems. Composition of MNPs consists of magnetite functionalized with oleic acid and coated with the biopolymer chitosan or glutaraldehyde-cross-linked chitosan. The influence of the biopolymeric coating has been evaluated by in vitro and in vivo assays on the effects of these MNPs on rat aortic endothelial cells (ECs) viability and on the random tissue distribution in mice. Results were correlated with the physicochemical properties of the nanoparticles. Nitric oxide (NO) production by ECs was determined, considering that endothelial NO represents one of the major markers of ECs function. Cell viability was studied by MTT assay. Different doses of the MNPs (1, 10 and 100 μg/mL) were assayed, revealing that MNPs coated with non-cross-linked chitosan for 6 and 24 h did not affect neither NO production nor cell viability. However, a significant decrease in cell viability was observed after 36 h treatment with the highest dose of this nanocarrier. It was also revealed that the presence and dose of glutaraldehyde in the MNPs structureimpact on the cytotoxicity. The study of the acute tissue distribution was performed acutely in mice after 24 h of an intraperitoneal injection of the MNPs and sub acutely, after 28 days of weekly administration. Both formulations greatly avoided the initial clearance by the reticuloendothelial system (RES) in liver. Biological properties found for N1 and N2 in the performed assays reveal that chitosan coating improves biocompatibility of MNPs turning these magnetic nanosystems as promising devices for targeted drug delivery.

  15. Development of Gd(III) porphyrin-conjugated chitosan nanoparticles as contrast agents for magnetic resonance imaging.

    PubMed

    Jahanbin, Tania; Sauriat-Dorizon, Hélène; Spearman, Peter; Benderbous, Soraya; Korri-Youssoufi, Hafsa

    2015-01-01

    A novel magnetic resonance imaging (MRI) contrast agent based on gadolinium meso-tetrakis(4-pyridyl)porphyrin [Gd(TPyP)] conjugated with chitosan nanoparticles has been developed. The chitosan nanoparticles were synthesized following an ionic gelation method and the conditions optimized to generate small nanoparticles (CNs) with a narrow size distribution of 35-65 nm. The gadolinium meso-tetrakis(4-pyridyl)porphyrin [Gd(TPyP)] was loaded into chitosan nanoparticles by passive adsorption. The interaction of chitosan with Gd(TPyP) has been examined by UV-visible, Fourier transform infrared spectroscopies (FT-IR) and inductively coupled plasma mass spectrometry (ICP-MS), which indicate the successful association of Gd(TPyP) without any structural distortion throughout the chitosan nanoparticles. The potential of Gd(TPyP)-CNs as MRI contrast agent has been investigated by magnetic resonance imaging (MRI) in-vitro. Relaxivities of Gd(TPyP)-CNs obtained from T1-weighted images, increased with Gd concentration and attained an optimum r1 of 38.35 mM(-1) s(-1), which is 12-fold higher compared to commercial Gd-DOTA (~4 mM(-1) s(-1) at 3T). The combination of such strong MRI contrast with the known properties of porphyrins in photodynamic therapy and biocompatibility of chitosan, presents a new perspective in using these compounds in cancer theranostics.

  16. Biodegradable Chitosan Magnetic Nanoparticle Carriers for Sub-Cellular Targeting Delivery of Artesunate for Efficient Treatment of Breast Cancer

    NASA Astrophysics Data System (ADS)

    Subramanian, Natesan; Abimanyu, Sugumaran; Vinoth, Jeevanesan; Sekar, Ponnusamy Chandra

    2010-12-01

    Artesunate is a semi-synthetic derivative of artemisinin, the active principle extracted from Artemisia annua. It possesses good anti-proliferative activity and anti-angiogenic activity with very low toxicity to normal healthy cells. The drawback of most cancer drugs is their inability to accumulate selectively in the cancerous cells. So, large quantities of doses have to be administered to get the required therapeutic concentration in the target site and it resulted in many serious side effects due to the exposure of healthy cells to higher concentrations of cytotoxic drugs. The problem may be solved by selectively and quantitatively accumulating the drug at target site using magnetic nanoparticles guided by an externally applied magnetic field. A modest attempt has been made in this present study, the artesunate magnetic nanoparticle was successfully formulated using two forms of chitosan and evaluated for its in-vitro characteristics like surface morphology, particle size and distribution, zeta potential, magnetic susceptibility, encapsulation efficiency, loading capacity and in-vitro drug release. The synthesized magnetite size was 73 nm and the size of developed magnetic nanoparticles of artesunate was in the range of 90 to 575 nm. Acetic acid soluble chitosan at low concentration exhibit highest encapsulation efficiency and drug loading whereas increase in water soluble chitosan concentration increases the encapsulation efficiency and drug loading in formulations. The developed chitosan magnetic nanoparticles of artesunate shows better release characteristics and may be screened for its in-vivo breast cancer activity.

  17. Construction of Ang2-siRNA chitosan magnetic nanoparticles and the effect on Ang2 gene expression in human malignant melanoma cells

    PubMed Central

    LIU, ZHAO-LIANG; YOU, CAI-LIAN; WANG, BIAO; LIN, JIAN-HONG; HU, XUE-FENG; SHAN, XIU-YING; WANG, MEI-SHUI; ZHENG, HOU-BING; ZHANG, YAN-DING

    2016-01-01

    The aim of the present study was to construct angiopoietin-2 (Ang2)-small interfering (si)RNA chitosan magnetic nanoparticles and to observe the interference effects of the nanoparticles on the expression of the Ang2 gene in human malignant melanoma cells. Ang2-siRNA chitosan magnetic nanoparticles were constructed and transfected into human malignant melanoma cells in vitro. Red fluorescent protein expression was observed, and the transfection efficiency was analyzed. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to assess the inhibition efficiency of Ang2 gene expression. Ang2-siRNA chitosan magnetic nanoparticles were successfully constructed, and at a mass ratio of plasmid to magnetic chitosan nanoparticles of 1:100, the transfection efficiency into human malignant melanoma cells was the highest of the ratios assessed, reaching 61.17%. RT-qPCR analysis showed that the magnetic chitosan nanoparticles effectively inhibited Ang2 gene expression in cells, and the inhibition efficiency reached 59.56% (P<0.05). Ang2-siRNA chitosan magnetic nanoparticles were successfully constructed. The in vitro studies showed that the nanoparticles inhibited Ang2 gene expression in human malignant melanoma tumor cells, which laid the foundation and provided experimental evidence for additional future in vivo studies of intervention targeting malignant melanoma tumor growth in nude mice. PMID:27313729

  18. Immobilization of invertase on chitosan coated γ-Fe2O3 magnetic nanoparticles to facilitate magnetic separation.

    PubMed

    Waifalkar, P P; Parit, S B; Chougale, A D; Sahoo, Subasa C; Patil, P S; Patil, P B

    2016-11-15

    Industrially important invertase enzyme was immobilized on chitosan coated sol gel derived γ-Fe2O3 magnetic nanoparticles (MNPs) to enable it for repetitive use by magnetic separation. MNPs were characterized by X-ray diffraction (XRD), dynamic light scattering (DLS), field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FTIR) spectrometer and magnetic measurements. FTIR studies confirmed successful immobilization of invertase on MNPs. The ability to convert sucrose into invert syrup was enhanced in immobilized invertase compared to that of free enzyme. Further it was found that invertase immobilized on MNPs (IIMNPs) were more stable at varying pH and temperature conditions. Magnetic separation technique was successfully employed for reuse of the IIMNPs for 20 times without significant loss of activity. PMID:27501039

  19. Magnetic removal of Entamoeba cysts from water using chitosan oligosaccharide-coated iron oxide nanoparticles.

    PubMed

    Shukla, Sudeep; Arora, Vikas; Jadaun, Alka; Kumar, Jitender; Singh, Nishant; Jain, Vinod Kumar

    2015-01-01

    Amebiasis, a major health problem in developing countries, is the second most common cause of death due to parasitic infection. Amebiasis is usually transmitted by the ingestion of Entamoeba histolytica cysts through oral-fecal route. Herein, we report on the use of chitosan oligosaccharide-functionalized iron oxide nanoparticles for efficient capture and removal of pathogenic protozoan cysts under the influence of an external magnetic field. These nanoparticles were synthesized through a chemical synthesis process. The synthesized particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and zeta potential analysis. The particles were found to be well dispersed and uniform in size. The capture and removal of pathogenic cysts were demonstrated by fluorescent microscopy, transmission electron microscopy, and scanning electron microscopy (SEM). Three-dimensional modeling of various biochemical components of cyst walls, and thereafter, flexible docking studies demonstrate the probable interaction mechanism of nanoparticles with various components of E. histolytica cyst walls. Results of the present study suggest that E. histolytica cysts can be efficiently captured and removed from contaminated aqueous systems through the application of synthesized nanoparticles.

  20. Fabrication and Characterization of Gd-DTPA-Loaded Chitosan-Poly(Acrylic Acid) Nanoparticles for Magnetic Resonance Imaging.

    PubMed

    Ahmed, Arsalan; Zhang, Chao; Guo, Jian; Hu, Yong; Jiang, Xiqun

    2015-08-01

    Gd-DTPA-loaded chitosan-poly(acrylic acid) nanoparticles (Gd-DTPA@CS-PAA NPs) were formulated based on the reaction system of water-soluble polymer-monomer pairs of acrylic acid in chitosan solution followed by sorption of Gd-DTPA. Morphological investigations revealed the spherical shape of these NPs with about 220 nm particle size. These NPs showed charge reversal characteristic in acidic solution. In vitro and in vivo magnetic characteristics of these NPs were explored to estimate their utilization in targeted enhanced magnetic resonance imaging. Relaxation studies showed that these NPs possessed pH susceptible relaxation properties, which could introduce in vivo-specific distribution of contrast agent. MRI experiment showed that these nanoparticles had better results in contrast enhancement, and the concentration of contrast agent increased in liver and brain with increment in time. Thus, these NPs could maintain in vivo long circulation and high relaxation rate and were suitable agents for magnetic resonance imaging.

  1. Loading of Gemcitabine on chitosan magnetic nanoparticles increases the anti-cancer efficacy of the drug.

    PubMed

    Parsian, Maryam; Unsoy, Gozde; Mutlu, Pelin; Yalcin, Serap; Tezcaner, Aysen; Gunduz, Ufuk

    2016-08-01

    Targeted delivery of anti-cancer drugs increase the efficacy, while decreasing adverse effects. Among various delivery systems, chitosan coated iron oxide nanoparticles (CsMNPs) gained attention with their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. This study aimed to increase the cellular uptake and efficacy of Gemcitabine. CsMNPs were synthesized by in situ co-precipitation and Gemcitabine was loaded onto the nanoparticles. Nanoparticle characterization was performed by TEM, FTIR, XPS, and zeta potential. Gemcitabine release and stability was analyzed. The cellular uptake was shown. Cytotoxicity of free-Gemcitabine and Gem-CsMNPs were examined on SKBR and MCF-7 breast cancer cells by XTT assay. Gemcitabine loading was optimized as 30µM by spectrophotometric analyses. Drug release was highest (65%) at pH 4.2, while it was 8% at pH 7.2. This is a desired release characteristic since pH of tumor-tissue and endosomes are acidic, while the blood-stream and healthy-tissues are neutral. Peaks reflecting the presence of Gemcitabine were observed in FTIR and XPS. At neutral pH, zeta potential increased after Gemcitabine loading. TEM images displayed, Gem-CsMNPs were 4nm with uniform size-distribution and have spherical shape. The cellular uptake and targetability of CsMNPs was studied on MCF-7 breast cancer cell lines. IC50 value of Gem-CsMNPs was 1.4 fold and 2.6 fold lower than free-Gem on SKBR-3 and MCF-7 cell lines respectively, indicating the increased efficacy of Gemcitabine when loaded onto nanoparticles. Targetability by magnetic field, stability, size distribution, cellular uptake and toxicity characteristics of CsMNPs in this study provides a useful targeted delivery system for Gemcitabine in cancer therapy. PMID:27181067

  2. Chitosan magnetic nanoparticles for pH responsive Bortezomib release in cancer therapy.

    PubMed

    Unsoy, Gozde; Yalcin, Serap; Khodadust, Rouhollah; Mutlu, Pelin; Onguru, Onder; Gunduz, Ufuk

    2014-06-01

    The use of nanotechnology in cancer treatment offers exciting opportunities, including the possibility of destroying tumors with minimal damage to healthy tissue by novel targeted drug delivery systems. pH differences between healthy and tumor microenvironment provide pH responsive release of drugs at tumor site via smart nanoparticles. In this study, chitosan coated superparamagnetic iron oxide nanoparticles (CS MNPs) were in situ synthesized by ionic crosslinking method as nanocarrier systems and loaded with the drug Bortezomib (Velcade(®)). The drug loading capacity, drug release and stability of CS MNPs were analyzed. CS MNPs were visualized inside the cells by fluorescence microscopy. The cytotoxicity of Bortezomib, CS MNPs and Bortezomib loaded CS MNPs were tested by XTT analyses in vitro. Gene expression analyses revealed that pro-apoptotic PUMA and NOXA genes were upregulated while anti-apoptotic BCL-2, SURVIVIN and cIAP-2 genes were downregulated at Bortezomib loaded CS MNP treated cells. Immunocytochemical analyses demonstrated an increase in p53 tumor suppressor protein levels at treated cells, which supports the upregulation of PUMA and NOXA genes, while Survivin protein level did not significantly change. This study points out that the pH responsive magnetic targeting of Bortezomib is more efficacious than free drug treatment. Moreover, targeted delivery of Bortezomib would reduce the frequency of drug administration by lowering the required amount of drug dose.

  3. Surface functionalization of chitosan-coated magnetic nanoparticles for covalent immobilization of yeast alcohol dehydrogenase from Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Li, Gui-yin; Zhou, Zhi-de; Li, Yuan-jian; Huang, Ke-long; Zhong, Ming

    2010-12-01

    A novel and efficient immobilization of yeast alcohol dehydrogenase (YADH, EC1.1.1.1) from Saccharomyces cerevisiae has been developed by using the surface functionalization of chitosan-coated magnetic nanoparticles (Fe 3O 4/KCTS) as support. The magnetic Fe 3O 4/KCTS nanoparticles were prepared by binding chitosan alpha-ketoglutaric acid (KCTS) onto the surface of magnetic Fe 3O 4 nanoparticles. Later, covalent immobilization of YADH was attempted onto the Fe 3O 4/KCTS nanoparticles. The effect of various preparation conditions on the immobilized YADH process such as immobilization time, enzyme concentration and pH was investigated. The influence of pH and temperature on the activity of the free and immobilized YADH using phenylglyoxylic acid as substrate has also been studied. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized YADH were 30 °C and 7.4, respectively. Compared to the free enzyme, the immobilized YADH retained 65% of its original activity and exhibited significant thermal stability and good durability.

  4. Radiation synthesis and magnetic properties of novel Co 0.7Fe 0.3/Chitosan compound nanoparticles for targeted drug carrier

    NASA Astrophysics Data System (ADS)

    Kang, Bin; Chang, Shu-quan; Dai, Yao-dong; Chen, Da

    2007-06-01

    Chitosan coated Co 0.7Fe 0.3 compound nanoparticles were successfully synthesized through a γ-radiation route in inverse microemulsion system. An observation of transmission electron microscope (TEM) showed that the diameter of these nanoparticles was about 50 nm with narrow size-distribution. Investigations of properties of nanoparticles were also conducted with fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and energy dispersion spectrum (EDS). Analysis of vibrating sample magnetometer (VSM) indicated that the nanoparticles were superparamagnetic with a saturation magnetization of 24 emu/g. These compound nanoparticles were undertaken to allow for the magnetically targeted cancer.

  5. Adsorption of Cu2+ ions using chitosan-modified magnetic Mn ferrite nanoparticles synthesized by microwave-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Meng, Yuying; Chen, Deyang; Sun, Yitao; Jiao, Dongling; Zeng, Dechang; Liu, Zhongwu

    2015-01-01

    Chitosan-modified Mn ferrite nanoparticles were synthesized by a one-step microwave-assisted hydrothermal method. These Mn ferrite magnetic composite nanoparticles were employed to absorb Cu2+ ions in water. XRD verified the spinel structure of the MnFe2O4 nanoparticles. Chitosan modification does not result in any phase change of MnFe2O4. FTIR and zeta potentials curves for all samples suggest that chitosan can be successfully coated on the Mn ferrites. TEM characterization showed that the modified MnFe2O4 nanoparticles have a cubic shape with a mean diameter of ∼100 nm. For adsorption behavior, the effects of experiment parameters such as solution pH value, contact time and initial Cu2+ ions concentration on the adsorption efficiency were systematically investigated. The results showed that increasing solution pH value and extending contact time are favorable for improving adsorption efficiency. Especially, adsorption efficiency can reach up to 100% and 96.7% after 500 min adsorption at pH 6.5 for the solutions with initial Cu2+ ions concentration of 50 mg/L and 100 mg/L. Adsorption data fits well with the Langmuir isotherm models with a maximum adsorption capacity (qm) and a Langmuir adsorption equilibrium constant (K) of 65.1 mg/g and 0.090 L/mg, respectively. The adsorption kinetic agrees well with pseudo second order model with the pseudo second rate constants (K2) of 0.0468 and 0.00189 g/mg/min for solutions with initial Cu2+ ions of 50 and 100 mg/L, respectively.

  6. Preparation of magnetic composite based on zinc oxide nanoparticles and chitosan as a photocatalyst for removal of reactive blue 198

    NASA Astrophysics Data System (ADS)

    Nguyen, Van Cuong; Giang Nguyen, Ngoc Lam; Hue Pho, Quoc

    2015-09-01

    In this study a novel magnetic composite used as a photocatalyst with combination of zinc oxide nanoparticles and chitosan (ZnO/Fe3O4/CS) was synthesized by a simple co-precipitation method. The role of the prepared magnetic nanocomposite is to improve the removal efficiency of textile dye due to the photocatalytic activity of zinc oxide nanoparticles and reusable capacity of Fe3O4 magnetic nanoparticles. Constituents and structure properties of ZnO/Fe3O4/CS were investigated by scanning electron microscopy (SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Magnetic property of the prepared composite was determined by vibrating sample magnetometer (VSM). The results demonstrated that ZnO/Fe3O4/CS nanocomposite dramatically improved the removal efficiency of reactive blue 198 dye (RB198) with high photocatalytic activity and easy separation by a permanent magnet. In addition, the photocatalytic activity of the prepared composite was also performed under different parameters such as contact time, initial pH, the amount of composite and initial concentration of RB198. Interestingly, ZnO/Fe3O4/CS nanocomposite still showed high removal efficiency after recycling three times and performed in a real textile dyeing wastewater.

  7. Facile synthesis of magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan hydrogel as MTX carriers for controlled drug release.

    PubMed

    Wu, Juan; Jiang, Wei; Tian, Renbing; Shen, Yewen; Jiang, Wei

    2016-10-01

    In the present study, methotrexate (MTX)-encapsulated magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan were successfully prepared through a one-step gelation process, which is a very facile, economic and environmentally friendly route. The developed hydrogel beads exhibited homogeneous porous structure and super-paramagnetic responsibility. MTX can be successfully encapsulated into magnetic chitosan hydrogel beads, and the drug encapsulation efficiency (%) and encapsulation content (%) were 93.8 and 6.28%, respectively. In addition, the drug release studies in vitro indicated that the MTX-encapsulated magnetic chitosan hydrogel beads had excellent pH-sensitivity, 90.6% MTX was released from the magnetic chitosan hydrogel beads within 48 h at pH 4.0. WST-1 assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the MTX-encapsulated magnetic chitosan hydrogel beads had good cytocompatibility and high anti-tumor activity. Therefore, our results revealed that the MTX-encapsulated magnetic chitosan hydrogel beads would be a competitive candidate for controlled drug release in the area of targeted cancer therapy in the near future.

  8. Facile synthesis of magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan hydrogel as MTX carriers for controlled drug release.

    PubMed

    Wu, Juan; Jiang, Wei; Tian, Renbing; Shen, Yewen; Jiang, Wei

    2016-10-01

    In the present study, methotrexate (MTX)-encapsulated magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan were successfully prepared through a one-step gelation process, which is a very facile, economic and environmentally friendly route. The developed hydrogel beads exhibited homogeneous porous structure and super-paramagnetic responsibility. MTX can be successfully encapsulated into magnetic chitosan hydrogel beads, and the drug encapsulation efficiency (%) and encapsulation content (%) were 93.8 and 6.28%, respectively. In addition, the drug release studies in vitro indicated that the MTX-encapsulated magnetic chitosan hydrogel beads had excellent pH-sensitivity, 90.6% MTX was released from the magnetic chitosan hydrogel beads within 48 h at pH 4.0. WST-1 assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the MTX-encapsulated magnetic chitosan hydrogel beads had good cytocompatibility and high anti-tumor activity. Therefore, our results revealed that the MTX-encapsulated magnetic chitosan hydrogel beads would be a competitive candidate for controlled drug release in the area of targeted cancer therapy in the near future. PMID:27464586

  9. Chitosan-coated magnetic nanoparticles prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion.

    PubMed

    Pineda, María Guadalupe; Torres, Silvia; López, Luis Valencia; Enríquez-Medrano, Francisco Javier; de León, Ramón Díaz; Fernández, Salvador; Saade, Hened; López, Raúl Guillermo

    2014-07-02

    Chitosan-coated magnetic nanoparticles (CMNP) were prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion in the presence of chitosan. The high-aqueous phase concentration led to productivities close to 0.49 g CMNP/100 g microemulsion; much higher than those characteristic of precipitation in reverse microemulsions for preparing magnetic nanoparticles. The obtained nanoparticles present a narrow particle size distribution with an average diameter of 4.5 nm; appearing to be formed of a single crystallite; furthermore they present superparamagnetism and high magnetization values; close to 49 emu/g. Characterization of CMNP suggests that chitosan is present as a non-homogeneous very thin layer; which explains the slight reduction in the magnetization value of CMNP in comparison with that of uncoated magnetic nanoparticles. The prepared nanoparticles show high heavy ion removal capability; as demonstrated by their use in the treatment of Pb2+ aqueous solutions; from which lead ions were completely removed within 10 min.

  10. Applications of chitosan nanoparticles in drug delivery.

    PubMed

    Tajmir-Riahi, H A; Nafisi, Sh; Sanyakamdhorn, S; Agudelo, D; Chanphai, P

    2014-01-01

    We have reviewed the binding affinities of several antitumor drugs doxorubicin (Dox), N-(trifluoroacetyl) doxorubicin (FDox), tamoxifen (Tam), 4-hydroxytamoxifen (4-Hydroxytam), and endoxifen (Endox) with chitosan nanoparticles of different sizes (chitosan-15, chitosan-100, and chitosan-200 KD) in order to evaluate the efficacy of chitosan nanocarriers in drug delivery systems. Spectroscopic and molecular modeling studies showed the binding sites and the stability of drug-polymer complexes. Drug-chitosan complexation occurred via hydrophobic and hydrophilic contacts as well as H-bonding network. Chitosan-100 KD was the more effective drug carrier than the chitosan-15 and chitosan-200 KD. PMID:24567139

  11. Removal of Pb2+, Hg2+, and Cu2+ by Chain-Like Fe3O4@SiO2@Chitosan Magnetic Nanoparticles.

    PubMed

    Shi, Haowei; Yang, Junya; Zhu, Lizhong; Yang, Yuxiang; Yuan, Hongming; Yang, Yubing; Liu, Xiangnong

    2016-02-01

    In this paper, the chain-like core-shell structure Fe3O4@SiO2@Chitosan composite nanoparticles were synthesized by a two-step coating and following crosslinking glutaraldehyde on chitosan shell. The composite particles showed nearly monodisperse 105 sized particles with a core diameter of 80 nm and chitosan shell thickness of 12 nm. The synthesis conditions of the product were studied, and the morphology and properties of the composite nanoparticles were characterized by IR, XRD, TEM, SEM, EDS and VSM. The adsorption properties of Hg2+, Pb2+ or Cu2+ ions on Fe3O4, Fe3O4@SiO2 and the composite particles were in detail studied using the colorimetric method based on forming colored mercuric dithizone, rhodamine-Pb2+ complex and DDTC-Cu(2+) complex. The results showed, adsorption isotherm, kinetics and separation coefficient of heavy metal ions on these three magnetic nanoparticles were concerned with pH, metal ions' electronic configuration, silica coating and chitosan shell respectively. In addition, the recycle efficiency was also studied. The findings demonstrated that Fe3O4@SiO2@Chitosan composite nanoparticles have great application value in the adsorption and separation of heavy metal ions. PMID:27433691

  12. Synthesis and characterisation of chitosan crosslinked-β-cyclodextrin grafted silylated magnetic nanoparticles for controlled release of Indomethacin

    NASA Astrophysics Data System (ADS)

    Anirudhan, T. S.; Dilu, D.; Sandeep, S.

    2013-10-01

    In this work, a novel hydrogel, chitosan crosslinked β-cyclodextrin grafted silylated magnetic nanoparticle (CTSCD-g-SilylMNP) was synthesised as a drug delivery system onto which Indomethacin (IND) drug was loaded. Characterisation of the drug delivery system was carried out by Tunnelling electron microscopy, Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, Dynamic light scattering and a Vibrating sample magnetometer. Swelling behaviour, in vitro drug release kinetics, and encapsulation efficiency of CTSCD-g-SilylMNP were studied. Swelling behaviour varied according to pH. In vitro release studies revealed that CTSCD-g-SilylMNP demonstrated a swelling and diffusion controlled release. Dependence of pH was also studied. Encapsulation efficiency (EE) at different percentages of drug loadings was studied. The results collectively suggest that the hydrogel has promising application in the field of controlled drug release. The biodegradability also adds to the advantage.

  13. Separation and extraction of Co(II) using magnetic chitosan nanoparticles grafted with β-cyclodextrin and determination by FAAS

    NASA Astrophysics Data System (ADS)

    Moghimi, Ali

    2014-12-01

    A novel and selective method for the fast determination of trace amounts of Co(II) ions in water samples has been developed. The procedure is based on the selective sorption of Co(II) ions using magnetic chitosan nanoparticles grafted with β-cyclodextrin at different pH followed by elution with organic eluents and determination by atomic absorption spectrometry The preconcentration factor was 100 (1 mL elution volume) for a 100 mL sample volume. The limit of detection of the proposed method is 1.0 ng mL-1. The maximum sorption capacity of sorbent under optimum conditions has been found to be 5 mg of Co per gram of sorbent. The relative standard deviation under optimum conditions was 3.0% ( n = 10). Accuracy and applicability of the method was estimated using test samples of natural and model water with different amounts of Co(II).

  14. Synthesis and optimization of chitosan nanoparticles: Potential applications in nanomedicine and biomedical engineering

    PubMed Central

    Ghadi, Arezou; Mahjoub, Soleiman; Tabandeh, Fatemeh; Talebnia, Farid

    2014-01-01

    Background: Chitosan nanoparticles have become of great interest for nanomedicine, biomedical engineering and development of new therapeutic drug release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity. The aim of the present study was to synthesis and optimize of the chitosan nanoparticles for industrial and biomedical applications. Methods: Fe3O4 was synthesized and optimized as magnetic core nanoparticles and then chitosan covered this magnetic core. The size and morphology of the nano-magnetic chitosan was analyzed by scanning electron microscope (SEM). Topography and size distribution of the nanoparticles were shown with two-dimensional and three-dimensional images of atomic force microscopy (AFM). The nanoparticles were analyzed using transmission electron microscopy (TEM). Results: The chitosan nanoparticles prepared in the experiment exhibited white powder shape. The SEM micrographs of the nano-magnetic chitosan showed that they were approximately uniform spheres. The unmodified chitosan nanoparticles composed of clusters of nanoparticles with sizes ranging from 10 nm to 80 nm. AFM provides a three-dimensional surface profile. The TEM image showed physical aggregation of the chitosan nanoparticles. Conclusion: The results show that a novel chitosan nanoparticle was successfully synthesized and characterized. It seems that this nanoparticle like the other chitosan nano particles has potential applications for nanomedicine, biomedical engineering, industrial and pharmaceutical fields. PMID:25202443

  15. In Situ Mineralization of Magnetite Nanoparticles in Chitosan Hydrogel

    NASA Astrophysics Data System (ADS)

    Wang, Yongliang; Li, Baoqiang; Zhou, Yu; Jia, Dechang

    2009-09-01

    Based on chelation effect between iron ions and amino groups of chitosan, in situ mineralization of magnetite nanoparticles in chitosan hydrogel under ambient conditions was proposed. The chelation effect between iron ions and amino groups in CS-Fe complex, which led to that chitosan hydrogel exerted a crucial control on the magnetite mineralization, was proved by X-ray photoelectron spectrum. The composition, morphology and size of the mineralized magnetite nanoparticles were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and thermal gravity. The mineralized nanoparticles were nonstoichiometric magnetite with a unit formula of Fe2.85O4 and coated by a thin layer of chitosan. The mineralized magnetite nanoparticles with mean diameter of 13 nm dispersed in chitosan hydrogel uniformly. Magnetization measurement indicated that superparamagnetism behavior was exhibited. These magnetite nanoparticles mineralized in chitosan hydrogel have potential applications in the field of biotechnology. Moreover, this method can also be used to synthesize other kinds of inorganic nanoparticles, such as ZnO, Fe2O3 and hydroxyapatite.

  16. Fabrication and characterization of core-shell magnetic chitosan nanoparticles as a novel carrier for immobilization of Burkholderia cepacia lipase.

    PubMed

    Ghadi, Arezoo; Tabandeh, Fatemeh; Mahjoub, Soleiman; Mohsenifar, Afshin; Roshan, Farid Talebnia; Alavije, Razieh Shafiee

    2015-01-01

    In this study, the chitosan magnetic core-shell nanoparticles (CMNPs) was synthesized and then used as a support for immobilization of lipase. The characteristics of CMNPs, including morphology, topography and spectra type before and after immobilization were determined. The scanning electron micrographs of the CMNPs showed that they were approximately uniform spheres and the distribution chart indicated that the particles have the mean diameter of 100 nm. Kinetic parameters of Km and Vm were calculated as 1.07 mM and 29.43 U/mg for free B. cepacia lipase and 1.29 mM and 25.82 U/mg for immobilized lipase on CMNPs, respectively. The activity of immobilized lipase was 32 U/mg under optimum temperature and pH. CMNP's were used in trasesterification reaction in order to evaluate the activity of the immobilized enzyme compared to the free enzyme. Immobilization of lipase on CMNPs improved stability and total relative activity of the enzyme. It could be concluded that CMNPs be considered as a suitable carrier for enzyme immobilization.

  17. Carbon Dots Embedded Magnetic Nanoparticles @Chitosan @Metal Organic Framework as a Nanoprobe for pH Sensitive Targeted Anticancer Drug Delivery.

    PubMed

    Chowdhuri, Angshuman Ray; Singh, Tanya; Ghosh, Sudip Kumar; Sahu, Sumanta Kumar

    2016-07-01

    Recently, nanoscale metal organic frameworks (NMOFs) have been demonstrated as a promising carrier for drug delivery, as they possess many advantages like large surface area, high porosity, and tunable functionality. However, there are no reports about the functionalization of NMOFs, which combines cancer-targeted drug delivery/imaging, magnetic property, high drug loading content, and pH-sensitive drug release into one system. Existing formulations for integrating target molecules into NMOF are based on multistep synthetic processes. However, in this study, we report an approach that combines NMOF (IRMOF-3) synthesis and target molecule (Folic acid) encapsulation on the surface of chitosan modified magnetic nanoparticles in a single step. A noticeable feature of chitosan is control and pH responsive drug release for several days. More importantly, doxorubicin (DOX) was incorporated into magnetic NMOF formulation and showed high drug loading (1.63 g DOX g(-1) magnetic NMOFs). To demonstrate the optical imaging, carbon dots (CDs) are encapsulated into the synthesized magnetic NMOF, thereby endowing fluorescence features to the nanoparticles. These folate targeted magnetic NMOF possess more specific cellular internalization toward folate-overexpressed cancer (HeLa) cells in comparison to normal (L929) cells.

  18. Design and construction of polymerized-chitosan coated Fe3O4 magnetic nanoparticles and its application for hydrophobic drug delivery.

    PubMed

    Ding, Yongling; Shen, Shirley Z; Sun, Huadong; Sun, Kangning; Liu, Futian; Qi, Yushi; Yan, Jun

    2015-03-01

    In this study, a novel hydrogel, chitosan (CS) crosslinked carboxymethyl-β-cyclodextrin (CM-β-CD) polymer modified Fe3O4 magnetic nanoparticles was synthesized for delivering hydrophobic anticancer drug 5-fluorouracil (CS-CDpoly-MNPs). Carboxymethyl-β-cyclodextrin being grafted on the Fe3O4 nanoparticles (CDpoly-MNPs) contributed to an enhancement of adsorption capacities because of the inclusion abilities of its hydrophobic cavity with insoluble anticancer drugs through host-guest interactions. Experimental results indicated that the amounts of crosslinking agent and bonding times played a crucial role in determining morphology features of the hybrid nanocarriers. The nanocarriers exhibited a high loading efficiency (44.7±1.8%) with a high saturation magnetization of 43.8emu/g. UV-Vis spectroscopy results showed that anticancer drug 5-fluorouracil (5-Fu) could be successfully included into the cavities of the covalently linked CDpoly-MNPs. Moreover, the free carboxymethyl groups could enhance the bonding interactions between the covalently linked CDpoly-MNPs and anticancer drugs. In vitro release studies revealed that the release behaviors of CS-CDpoly-MNPs carriers were pH dependent and demonstrated a swelling and diffusion controlled release. A lower pH value led to swelling effect and electrostatic repulsion contributing to the protonation amine impact of NH3(+), and thus resulted in a higher release rate of 5-Fu. The mechanism of 5-Fu encapsulated into the magnetic chitosan nanoparticles was tentatively proposed.

  19. Production of Galactooligosaccharides Using β-Galactosidase Immobilized on Chitosan-Coated Magnetic Nanoparticles with Tris(hydroxymethyl)phosphine as an Optional Coupling Agent.

    PubMed

    Chen, Su-Ching; Duan, Kow-Jen

    2015-01-01

    β-Galactosidase was immobilized on chitosan-coated magnetic Fe3O4 nanoparticles and was used to produce galactooligosaccharides (GOS) from lactose. Immobilized enzyme was prepared with or without the coupling agent, tris(hydroxymethyl)phosphine (THP). The two immobilized systems and the free enzyme achieved their maximum activity at pH 6.0 with an optimal temperature of 50 °C. The immobilized enzymes showed higher activities at a wider range of temperatures and pH. Furthermore, the immobilized enzyme coupled with THP showed higher thermal stability than that without THP. However, activity retention of batchwise reactions was similar for both immobilized systems. All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w · v(-1)) lactose on a dry weight basis. The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study.

  20. Production of Galactooligosaccharides Using β-Galactosidase Immobilized on Chitosan-Coated Magnetic Nanoparticles with Tris(hydroxymethyl)phosphine as an Optional Coupling Agent

    PubMed Central

    Chen, Su-Ching; Duan, Kow-Jen

    2015-01-01

    β-Galactosidase was immobilized on chitosan-coated magnetic Fe3O4 nanoparticles and was used to produce galactooligosaccharides (GOS) from lactose. Immobilized enzyme was prepared with or without the coupling agent, tris(hydroxymethyl)phosphine (THP). The two immobilized systems and the free enzyme achieved their maximum activity at pH 6.0 with an optimal temperature of 50 °C. The immobilized enzymes showed higher activities at a wider range of temperatures and pH. Furthermore, the immobilized enzyme coupled with THP showed higher thermal stability than that without THP. However, activity retention of batchwise reactions was similar for both immobilized systems. All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w·v−1) lactose on a dry weight basis. The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study. PMID:26047337

  1. Construction of a sensitive and selective sensor for morphine using chitosan coated Fe3O4 magnetic nanoparticle as a modifier.

    PubMed

    Dehdashtian, Sara; Gholivand, Mohammad Bagher; Shamsipur, Mojtaba; Kariminia, Samira

    2016-01-01

    A simple and sensitive sensor based on carbon paste electrode (CPE) modified by chitosan-coated magnetic nanoparticle (CMNP) was developed for the electrochemical determination of morphine (MO). The proposed sensor was characterized with scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electrooxidation of MO was studied on modified carbon paste electrode using cyclic voltammetry, chronoamperometry and differential pulse voltammetry as diagnostic techniques. The oxidation peak potential of morphine on the CMNP/CPE appeared at 380 mV which was accompanied with smaller overpotential and increase in oxidation peak current compared to that obtained on the bare carbon paste electrode (CPE). Under optimum conditions the sensor provides two linear DPV responses in the range of 10-2000 nM and 2-720 μM for MO with a detection limit of 3 nM. The proposed sensor was successfully applied for monitoring of MO in serum and urine samples and satisfactory results were obtained.

  2. Preparations, characterizations and applications of chitosan-based nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Chenguang; Tan, Yulong; Liu, Chengsheng; Chen, Xiguang; Yu, Lejun

    2007-07-01

    Chitosan is a natural polysaccharide prepared by the N-deacetylation of chitin. In this paper we have reviewed the methods of preparation of chitosan-based nanoparticles and their pharmaceutical applications. There are five methods of their preparations: emulsion cross-linking, emulsion-droplet coalescence, ionic gelation, reverse micellar method and chemically modified chitosan method. Chitosan nanoparticles are used as carriers for low molecular weight drug, vaccines and DNA. Releasing characteristics, biodistribution and applications are also summarized.

  3. Separation of lysozyme using superparamagnetic carboxymethyl chitosan nanoparticles.

    PubMed

    Sun, Jun; Su, Yujie; Rao, Shengqi; Yang, Yanjun

    2011-08-01

    Functionalized Fe(3)O(4) nanoparticles conjugated with polyethylene glycol (PEG) and carboxymethyl chitosan (CM-CTS) were developed and used as a novel magnetic absorbing carrier for the separation and purification of lysozyme from the aqueous solution and chicken egg white, respectively. The morphology of magnetic CM-CTS nanoparticles was observed by transmission electron microscope (TEM). It was found that the diameter of superparamagnetic carboxymethyl chitosan nanoparticles (Fe(3)O(4) (PEG+CM-CTS)) was about 15 nm, and could easily aggregate by a magnet when suspending in the aqueous solution. The adsorption capacity of lysozyme onto the superparamagnetic Fe(3)O(4) (PEG+CM-CTS) nanoparticles was determined by changing the medium pH, temperature, ionic strength and the concentration of lysozyme. The maximum adsorption loading reached 256.4 mg/g. Due to the small diameter, the adsorption equilibrium of lysozyme onto the nanoparticles reached very quickly within 20 min. The adsorption equilibrium of lysozyme onto the superparamagnetic nanoparticles fitted well with the Langmuir model. The nanoparticles were stable when subjected to six repeated adsorption-elution cycles. Separation and purification were monitored by determining the lysozyme activity using Micrococcus lysodeikticus as substrate. The lysozyme was purified from chicken egg white in a single step had higher purity, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Considering that the superparamagnetic nanoparticles possess the advantages of high efficiency, cost-effectiveness and excellent binding of a larger amount of lysozyme and easier separation from the reaction system, thus this type of superparamagnetic nanoparticles would bring advantages to the conventional separation techniques of lysozyme from chicken egg white.

  4. The Use of chitosan in The Formation of Silver Nanoparticles, Chitosanic Nanoparticles and Fibrous Structures

    NASA Astrophysics Data System (ADS)

    Abdelgawad, Abdelrahman Mohamed

    Nanoscale materials have attracted much attention in the last two decades due to their unique properties. The size effect attains new chemical and physical properties to these materials. Nanoparticles and nanofiber are major component of nanomaterials and they have heavily investigated in the literature for different applications. Nanoparticles could be produced from both metals as well as polymers. Chitosan, which is a natural polymer, can be used as capping agent in the preparation of metallic nanoparticles and itself, can produce nanoparticles. The utilization of nanoparticles and nanofibers for wound dressing materials is a very popular approach. Acquiring antibacterial properties to the wound dressing materials could be obtained either by formulation of nanomaterials composites or direct chemical modification of the substance. To improve the antibacterial properties of chitosan two approaches were applied. First, is through the formulation of chitosan with silver nanoparticles and the formation of nanofiber mats. In this study, the concepts of green chemistry were applied and silver nanoparticles were prepared in high concentration using chitosan as a capping polymer and glucose as a reducing agent. Nanofiber mats of polyvinyl alcohol/chitosan/silvernanoparticles were produced via electrospinning. The antibacterial activity of these fibers shows bactericidal effect against E. coli at low concentrations of Ag-NPs. In the second approach, direct chemical modification of chitosan was performed by grafting of Iodoacetic acid to the amino group at carbon-2. The chemical structure of chitosan Iodoacetamide derivative (CIA) was confirmed by FTIR and H1-NMR. The derivative was amorphous and water soluble at neutral pH. The minimum inhibitory concentration of CIA, against E. coli, was 400ig/mL and the derivative was bacteriostatic after 4h of treatment. Nanofiber mats of polyvinyl alcohol/chitosan/chitosan Iodoacetamide were produced via electrospinning. The

  5. Preparation and characterization of magnetic chitosan particles for hyperthermia application

    NASA Astrophysics Data System (ADS)

    Park, Ji-Ho; Im, Ki-Hyeong; Lee, Se-Ho; Kim, Dong-Hyun; Lee, Doug-Youn; Lee, Yong-Keun; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2005-05-01

    The size and shape of magnetic chitosan particles were found to be dependent on both the barium ferrite/chitosan (BF/C) ratio and viscosity of a chitosan solution. The saturation magnetization of magnetic chitosan particles varied directly with the BF/C ratio, while coercivity remained almost constant. Notably, incorporated chitosan was shown to exert substantial activity with regard to low cytotoxicity and high heating rate.

  6. Direct electrochemistry and electrocatalysis of heme proteins immobilised in carbon-coated nickel magnetic nanoparticle-chitosan-dimethylformamide composite films in room-temperature ionic liquids.

    PubMed

    Wang, Ting; Wang, Lu; Tu, Jiaojiao; Xiong, Huayu; Wang, Shengfu

    2013-12-01

    The direct electrochemistry and electrocatalysis of heme proteins entrapped in carbon-coated nickel magnetic nanoparticle-chitosan-dimethylformamide (CNN-CS-DMF) composite films were investigated in the hydrophilic ionic liquid [bmim][BF4]. The surface morphologies of a representative set of films were characterised via scanning electron microscopy. The proteins immobilised in the composite films were shown to retain their native secondary structure using UV-vis spectroscopy. The electrochemical performance of the heme proteins-CNN-CS-DMF films was evaluated via cyclic voltammetry and chronoamperometry. A pair of stable and well-defined redox peaks was observed for the heme protein films at formal potentials of -0.151 V (HRP), -0.167 V (Hb), -0.155 V (Mb) and -0.193 V (Cyt c) in [bmim][BF4]. Moreover, several electrochemical parameters of the heme proteins were calculated by nonlinear regression analysis of the square-wave voltammetry. The addition of CNN significantly enhanced not only the electron transfer of the heme proteins but also their electrocatalytic activity toward the reduction of H2O2. Low apparent Michaelis-Menten constants were obtained for the heme protein-CNN-CS-DMF films, demonstrating that the biosensors have a high affinity for H2O2. In addition, the resulting electrodes displayed a low detection limit and improved sensitivity for detecting H2O2, which indicates that the biocomposite film can serve as a platform for constructing new non-aqueous biosensors for real detection.

  7. A recyclable and regenerable magnetic chitosan absorbent for dye uptake.

    PubMed

    Zhao, Weifeng; Huang, Xuelian; Wang, Yilin; Sun, Shudong; Zhao, Changsheng

    2016-10-01

    A recyclable and regenerable magnetic polysaccharide absorbent for methylene blue (MB) removal was prepared by coating magnetic polyethyleneimine nanoparticles (PEI@MNPs) with sulfonated chitosan (SCS) and further cross-linked with glutaraldehyde. The driving force for coating is the electrostactic interaction between positively charged PEI and negatively charged SCS. Infrared spectra, zeta potential, thermal gravimetric analysis and X-ray diffraction demonstrated the successful synthesis of magnetic polysaccharide absorbent. The self-assembly of polysaccharide with magnetic nanopartices did not alter the saturation magnetization value of the absorbent confirmed by vibrating sample magnetometer. The nanoparticles showed fast removal (about 30min reached equilibrium) of MB. In particular, the removal ability of MB after desorption did not reduce, demonstrating an excellent regeneration ability. Our study provides new insights into utilizing polysaccharides for environmental remediation and creating advanced magnetic materials for various promising applications. PMID:27312630

  8. Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

    PubMed Central

    Ahmed, Tarek A; Aljaeid, Bader M

    2016-01-01

    Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated. PMID:26869768

  9. Magnetic nanoparticles with surfaces modified with chitosan-poly[N-benzyl-2-(methacryloxy)-N,N-dimethylethanaminium bromide] for lipase immobilization

    NASA Astrophysics Data System (ADS)

    Ziegler-Borowska, Marta; Siódmiak, Tomasz; Chełminiak, Dorota; Cyganiuk, Aleksandra; Marszałł, Michał P.

    2014-01-01

    Superparamagnetic nanoparticles were surface-modified with a mixture of two polymers for lipase immobilization. Magnetite (Fe3O4)-chitosan (CS)-poly[N-benzyl-2-(methacryloxy)-N,N-dimethylethanaminium bromide] (PQ) nanoparticles with various polymers weight ratios were prepared by co-precipitation method via glutaraldehyde CS cross-linking reaction. Both of polymers have been successfully coated on the surface of magnetite nanoparticles and characterized. Prepared nanoparticles were also used for lipase immobilization. Obtained results demonstrate that application of the support prepared with the use of polymeric quaternized ammonium salt (CS-PQ (1:1)) allows to obtain high activity recovery (higher than 80%) in comparison with other tested nanoparticles.

  10. Quaternized Chitosan/Alginate-Fe3O4 Magnetic Nanoparticles Enhance the Chemosensitization of Multidrug-Resistant Gastric Carcinoma by Regulating Cell Autophagy Activity in Mice.

    PubMed

    Li, Xiujuan; Feng, Jing; Zhang, Ran; Wang, Jinda; Su, Tao; Tian, Zuhong; Han, Dong; Zhao, Chuanxu; Fan, Miaomiao; Li, Congye; Liu, Bing; Feng, Xuyang; Nie, Yongzhan; Wu, Kaichun; Chen, Yundai; Deng, Hongbing; Cao, Feng

    2016-05-01

    Multidrug resistance (MDR) and targeted therapies present major challenges in tumor chemotherapy. Nanoparticles (NPs) hold promise for use in cancer theranostics due to their advantages in terms of tumor-targeted cytotoxicity and imaging. In this study, we developed N-((2-hydroxy-3-trimethylammonium) propyl) chitosan chloride (HTCC)/alginate-encapsulated Fe3O4 magnetic NPs (HTCC-MNPs) and applied them to MDR gastric cancer both in vivo and in vitro. HTCC-MNPs were fabricated from sodium alginate (ALG), Fe3O4 and HTCC using an ionic gelation method. The sizes and physical characteristics of the NPs were determined using dynamic light scattering, transmission electron microscopy (TEM) and zeta potential analysis. The HTCC-MNPs exhibited excellent water solubility and biocompatibility as well as significantly reduced cell viability in the drug-resistant cancer cell line SGC7901/ADR, but not in normal gastric cells (P < 0.05). An analysis of LC3 expression demonstrated the involvement of autophagy in HTCC-MNP cytotoxicity. Additionally, apoptosis was verified using a DNA content assay. HTCC-MNPs led to mitochondrial membrane potential loss, decreased ATP production and excessive reactive oxygen species (ROS) generation compared to a control group (P < 0.05). Magnetic resonance imaging showed enrichment of HTCC-MNPs in tumor-bearing mice. In vivo bioluminescence imaging and tumor volume measurements revealed that HTCC-MNPs markedly inhibited in vivo tumor growth (P < 0.05). In conclusion, HTCC-MNPs significantly inhibited MDR gastric tumor growth and reduced tumor volume via the induction of cellular autophagy and apoptosis, which was attributed to mitochondrial dysfunction and excessive ROS accumulation. PMID:27305817

  11. Preparation of iron oxide-entrapped chitosan nanoparticles for stem cell labeling.

    PubMed

    Chaleawlert-Umpon, Saowaluk; Mayen, Varissaporn; Manotham, Krissanapong; Pimpha, Nuttaporn

    2010-01-01

    This study intended to prepare iron oxide nanoparticle-entrapped chitosan (CS) nanoparticles for stem cell labeling. The nanoparticles were synthesized by polymerizing iron oxide nanoparticle-associated methacrylic acid monomer in the presence of CS. TEM revealed that the well-defined iron oxide nanoparticles were successfully encapsulated inside the CS nanoparticles. The effect of CS at different [NH(2)]/[COOH] molar ratios on particle size, surface charge, thermal stability and magnetic properties was determined systematically. Internalization and localization of the coated nanoparticles were evaluated by atomic absorption spectrometry and confocal laser scanning microscopy. The Kusa O cell line was chosen as a stem cell model. Interestingly, the uptake of iron oxide-entrapped CS nanoparticles was remarkably enhanced under magnetization and the nanoparticles were mostly located inside cellular compartments. It can be concluded that the iron oxide-entrapped CS nanoparticles have a strong potential for stem cell labeling. PMID:20537238

  12. In vitro study on apoptotic cell death by effective magnetic hyperthermia with chitosan-coated MnFe₂O₄.

    PubMed

    Oh, Yunok; Lee, Nohyun; Kang, Hyun Wook; Oh, Junghwan

    2016-03-18

    Magnetic nanoparticles (MNPs) have been widely investigated as a hyperthermic agent for cancer treatment. In this study, thermally responsive Chitosan-coated MnFe2O4 (Chitosan-MnFe2O4) nanoparticles were developed to conduct localized magnetic hyperthermia for cancer treatment. Hydrophobic MnFe2O4 nanoparticles were synthesized via thermal decomposition and modified with 2,3-dimercaptosuccinic acid (DMSA) for further conjugation of chitosan. Chitosan-MnFe2O4 nanoparticles exhibited high magnetization and excellent biocompatibility along with low cell cytotoxicity. During magnetic hyperthermia treatment (MHT) with Chitosan-MnFe2O4 on MDA-MB 231 cancer cells, the targeted therapeutic temperature was achieved by directly controlling the strength of the external AC magnetic fields. In vitro Chitosan-MnFe2O4-assisted MHT at 42 °C led to drastic and irreversible changes in cell morphology and eventual cellular death in association with the induction of apoptosis through heat dissipation from the excited magnetic nanoparticles. Therefore, the Chitosan-MnFe2O4 nanoparticles with high biocompatibility and thermal capability can be an effective nano-mediated agent for MHT on cancer.

  13. In vitro characterization of magnetic electrospun IDA-grafted chitosan nanofiber composite for hyperthermic tumor cell treatment.

    PubMed

    Lin, Ta-Chun; Lin, Feng-Huei; Lin, Jui-Che

    2013-01-01

    Magnetic nanoparticles were the thermoseeds under an alternating magnetic field and can be used to produce highly localized hyperthermia effect on deep-seated tumor. Nevertheless, effective and precisive delivery of nanoparticles to the treatment-intended site remains a challenge. In this study, Fe3O4 nanoparticles were incorporated onto the crosslinked electrospun chitosan nanofibers using chemical co-precipitation from the Fe ions adsorbed. Such magnetic nanoparticle-nanofiber composites could be delivered to the treatment site precisely by surgical or endoscopic method. Iminodiacetic acid (IDA) functionality was grafted onto the chitosan with an aim to increase the amount of magnetic nanoparticles formed in the electrospun magnetic nanofiber composite. The morphology, crystalline phase as well as the magnetism characteristic of the magnetic electrospun nanofiber matrixes, was analyzed. Results have indicated that, with the incorporation of IDA functionality, more magnetic nanoparticles were formed in the electrospun chitosan nanofiber matrix. In addition, the magnetic IDA-grafted chitosan nanofiber composite can effectively reduced the tumor cell proliferation under the application of magnetic field. This finding suggested the magnetic electrospun chitosan nanofiber composite can be of potential for hyperthermia treatment.

  14. Evaluation of antibacterial efficiency of chitosan and chitosan nanoparticles on cariogenic streptococci: an in vitro study

    PubMed Central

    Aliasghari, Azam; Rabbani Khorasgani, Mohammad; Vaezifar, Sedigheh; Rahimi, Fateh; Younesi, Habibollah; Khoroushi, Maryam

    2016-01-01

    Background and Objectives: The most prevalent and worldwide oral disease is dental caries that affects a significant proportion of the world population. There are some classical approaches for control, prevention and treatment of this pathologic condition; however, the results are still not completely successful. Therefore new methods are needed for better management of this important challenge. Chitosan is a natural and non-toxic polysaccharide with many biological applications, particularly as an antimicrobial agent. Chitosan nanoparticle is a bioactive and environment friendly material with unique physicochemical properties. The aim of the present study was to investigate the antimicrobial effect of chitosan and nano-chitosan on the most important cariogenic streptococci. Materials and Methods: For evaluation of antimicrobial effect of chitosan and nano-chitosan against oral streptococci broth micro-dilution method was carried out for four bacterial species; Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguis and Streptococcus salivarius. Also the effect of these materials on adhesion of above bacteria was evaluated. One-way ANOVA and post hoc Tukey test were used for statistical analysis. Results: The MICs of chitosan for S. mutans, S. sanguis, S. salivarius and S. sobrinus were 1.25, 1.25, 0.625 and 0.625 mg/mL, respectively. The MIC of chitosan nanoparticle for S. mutans, S. salivarius and S. sobrinus was 0.625 mg/mL and for S. sanguis was 0.312 mg/mL. Chitosan and chitosan nanoparticles at a concentration of 5 mg/mL also reduced biofilm formation of S. mutans up to 92.5% and 93.4%, respectively. Conclusion: The results of this study supported the use of chitosan and chitosan nanoparticles as antimicrobial agents against cariogenic Streptococci. PMID:27307974

  15. Comperative study of catalase immobilization on chitosan, magnetic chitosan and chitosan-clay composite beads.

    PubMed

    Başak, Esra; Aydemir, Tülin; Dinçer, Ayşe; Becerik, Seda Çınar

    2013-12-01

    Catalase was immobilized on chitosan and modified chitosan. Studies were carried out on free-immobilized catalase concerning the determination of optimum temperature, pH, thermal, storage stability, reusability, and kinetic parameters. Optimum temperature and pH for free catalase and catalase immobilized were found as 35°C and 7.0, respectively. After 100 times of repeated tests, the immobilized catalases on chitosan-clay and magnetic chitosan maintain over 50% and 60% of the original activity, respectively. The ease of catalase immobilization on low-cost matrices and good stability upon immobilization in the present study make it a suitable product for further use in the food industry.

  16. Evaluation of Hemagglutination Activity of Chitosan Nanoparticles Using Human Erythrocytes

    PubMed Central

    de Lima, Jefferson Muniz; Sarmento, Ronaldo Rodrigues; de Souza, Joelma Rodrigues; Brayner, Fábio André; Feitosa, Ana Paula Sampaio; Padilha, Rafael; Alves, Luiz Carlos; Porto, Isaque Jerônimo; Batista, Roberta Ferreti Bonan Dantas; de Oliveira, Juliano Elvis; de Medeiros, Eliton Souto; Bonan, Paulo Rogério Ferreti; Castellano, Lúcio Roberto

    2015-01-01

    Chitosan is a polysaccharide composed of randomly distributed chains of β-(1-4) D-glucosamine and N-acetyl-D-glucosamine. This compound is obtained by partial or total deacetylation of chitin in acidic solution. The chitosan-based hemostatic agents have been gaining much attention in the management of bleeding. The aim of this study was to evaluate in vitro hemagglutination activity of chitosan nanoparticles using human erythrocytes. The preparation of nanoparticles was achieved by ionotropic gelification technique followed by neutralization with NaOH 1 mol/L−1. The hemagglutination activity was performed on a solution of 2% erythrocytes (pH 7.4 on PBS) collected from five healthy volunteers. The hemolysis determination was made by spectrophotometric analysis. Chitosan nanoparticle solutions without NaOH addition changed the reddish colour of the wells into brown, suggesting an oxidative reaction of hemoglobin and possible cell lysis. All neutralized solutions of chitosan nanoparticles presented positive haemagglutination, without any change in reaction color. Chitosan nanoparticles presented hemolytic activity ranging from 186.20 to 223.12%, while neutralized solutions ranged from 2.56 to 72.54%, comparing to distilled water. Results highlight the need for development of new routes of synthesis of chitosan nanoparticles within human physiologic pH. PMID:25759815

  17. Evaluation of hemagglutination activity of chitosan nanoparticles using human erythrocytes.

    PubMed

    de Lima, Jefferson Muniz; Sarmento, Ronaldo Rodrigues; de Souza, Joelma Rodrigues; Brayner, Fábio André; Feitosa, Ana Paula Sampaio; Padilha, Rafael; Alves, Luiz Carlos; Porto, Isaque Jerônimo; Batista, Roberta Ferreti Bonan Dantas; de Oliveira, Juliano Elvis; de Medeiros, Eliton Souto; Bonan, Paulo Rogério Ferreti; Castellano, Lúcio Roberto

    2015-01-01

    Chitosan is a polysaccharide composed of randomly distributed chains of β-(1-4) D-glucosamine and N-acetyl-D-glucosamine. This compound is obtained by partial or total deacetylation of chitin in acidic solution. The chitosan-based hemostatic agents have been gaining much attention in the management of bleeding. The aim of this study was to evaluate in vitro hemagglutination activity of chitosan nanoparticles using human erythrocytes. The preparation of nanoparticles was achieved by ionotropic gelification technique followed by neutralization with NaOH 1 mol/L(-1). The hemagglutination activity was performed on a solution of 2% erythrocytes (pH 7.4 on PBS) collected from five healthy volunteers. The hemolysis determination was made by spectrophotometric analysis. Chitosan nanoparticle solutions without NaOH addition changed the reddish colour of the wells into brown, suggesting an oxidative reaction of hemoglobin and possible cell lysis. All neutralized solutions of chitosan nanoparticles presented positive haemagglutination, without any change in reaction color. Chitosan nanoparticles presented hemolytic activity ranging from 186.20 to 223.12%, while neutralized solutions ranged from 2.56 to 72.54%, comparing to distilled water. Results highlight the need for development of new routes of synthesis of chitosan nanoparticles within human physiologic pH.

  18. Evaluation of hemagglutination activity of chitosan nanoparticles using human erythrocytes.

    PubMed

    de Lima, Jefferson Muniz; Sarmento, Ronaldo Rodrigues; de Souza, Joelma Rodrigues; Brayner, Fábio André; Feitosa, Ana Paula Sampaio; Padilha, Rafael; Alves, Luiz Carlos; Porto, Isaque Jerônimo; Batista, Roberta Ferreti Bonan Dantas; de Oliveira, Juliano Elvis; de Medeiros, Eliton Souto; Bonan, Paulo Rogério Ferreti; Castellano, Lúcio Roberto

    2015-01-01

    Chitosan is a polysaccharide composed of randomly distributed chains of β-(1-4) D-glucosamine and N-acetyl-D-glucosamine. This compound is obtained by partial or total deacetylation of chitin in acidic solution. The chitosan-based hemostatic agents have been gaining much attention in the management of bleeding. The aim of this study was to evaluate in vitro hemagglutination activity of chitosan nanoparticles using human erythrocytes. The preparation of nanoparticles was achieved by ionotropic gelification technique followed by neutralization with NaOH 1 mol/L(-1). The hemagglutination activity was performed on a solution of 2% erythrocytes (pH 7.4 on PBS) collected from five healthy volunteers. The hemolysis determination was made by spectrophotometric analysis. Chitosan nanoparticle solutions without NaOH addition changed the reddish colour of the wells into brown, suggesting an oxidative reaction of hemoglobin and possible cell lysis. All neutralized solutions of chitosan nanoparticles presented positive haemagglutination, without any change in reaction color. Chitosan nanoparticles presented hemolytic activity ranging from 186.20 to 223.12%, while neutralized solutions ranged from 2.56 to 72.54%, comparing to distilled water. Results highlight the need for development of new routes of synthesis of chitosan nanoparticles within human physiologic pH. PMID:25759815

  19. Polyaniline-coated chitosan-functionalized magnetic nanoparticles: Preparation for the extraction and analysis of endocrine-disrupting phenols in environmental water and juice samples.

    PubMed

    Jiang, Xilan; Cheng, Jing; Zhou, Hongbin; Li, Feng; Wu, Wenlin; Ding, Kerong

    2015-08-15

    In the present study, chitosan (CHI) functionalized Fe3O4 magnetic microspheres coated with polyaniline (PANI) were synthesized for the first time. The chitosan-functionalized magnetic microspheres (Fe3O4@CHI) were synthesized by a co-precipitation method, and then aniline was polymerized on the magnetic core. The obtained Fe3O4@CHI@PANI microspheres were spherical core-shell structure with uniform size at about 100nm with 20-30nm diameter core. The microspheres had a high saturation magnetization of 32emu g(-)(1), which was sufficient for magnetic separation. The obtained Fe3O4@CHI@PANI magnetic microspheres were applied as magnetic adsorbents for the extraction of aromatic compounds via π-π interaction between polyaniline shell and aromatic compounds. Three endocrine-disrupting phenols, including bisphenol A (BPA), 2, 4-dichlorophenol (2, 4-DCP), and triclosan (TCS) were selected as the model analytes to verify the extraction ability of Fe3O4@CHI@PANI. The hydrophilic chitosan-functionalized Fe3O4 core (Fe3O4@CHI) improved the dispersibility of Fe3O4@CHI@PANI microspheres, and then improve its extraction efficiency. The dominant parameters affecting enrichment efficiency were investigated and optimized. Under optimal condition, the proposed method was evaluated, and applied to the analysis of phenols in real water and juice samples. The results demonstrated the method based on Fe3O4@CHI@PANI magnetic microspheres had good linearity (R(2)>0.996), and limits of detection (0.10-0.13ng mL(-1)), high repeatability (RSD<6.6%) and good recovery (85.0-106.7%). PMID:25966409

  20. Polyaniline-coated chitosan-functionalized magnetic nanoparticles: Preparation for the extraction and analysis of endocrine-disrupting phenols in environmental water and juice samples.

    PubMed

    Jiang, Xilan; Cheng, Jing; Zhou, Hongbin; Li, Feng; Wu, Wenlin; Ding, Kerong

    2015-08-15

    In the present study, chitosan (CHI) functionalized Fe3O4 magnetic microspheres coated with polyaniline (PANI) were synthesized for the first time. The chitosan-functionalized magnetic microspheres (Fe3O4@CHI) were synthesized by a co-precipitation method, and then aniline was polymerized on the magnetic core. The obtained Fe3O4@CHI@PANI microspheres were spherical core-shell structure with uniform size at about 100nm with 20-30nm diameter core. The microspheres had a high saturation magnetization of 32emu g(-)(1), which was sufficient for magnetic separation. The obtained Fe3O4@CHI@PANI magnetic microspheres were applied as magnetic adsorbents for the extraction of aromatic compounds via π-π interaction between polyaniline shell and aromatic compounds. Three endocrine-disrupting phenols, including bisphenol A (BPA), 2, 4-dichlorophenol (2, 4-DCP), and triclosan (TCS) were selected as the model analytes to verify the extraction ability of Fe3O4@CHI@PANI. The hydrophilic chitosan-functionalized Fe3O4 core (Fe3O4@CHI) improved the dispersibility of Fe3O4@CHI@PANI microspheres, and then improve its extraction efficiency. The dominant parameters affecting enrichment efficiency were investigated and optimized. Under optimal condition, the proposed method was evaluated, and applied to the analysis of phenols in real water and juice samples. The results demonstrated the method based on Fe3O4@CHI@PANI magnetic microspheres had good linearity (R(2)>0.996), and limits of detection (0.10-0.13ng mL(-1)), high repeatability (RSD<6.6%) and good recovery (85.0-106.7%).

  1. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    NASA Astrophysics Data System (ADS)

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Burboa, María G.; Taboada, Pablo; Juárez, Josué; Valdez, Miguel A.

    2015-09-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air-water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction.

  2. Synthesis, characterization and biocompatibility of chitosan functionalized superparamagnetic nanoparticles for heat activated curing of cancer cells.

    PubMed

    Thorat, N D; Otari, S V; Patil, R M; Bohara, R A; Yadav, H M; Koli, V B; Chaurasia, A K; Ningthoujam, R S

    2014-12-14

    Surface functionalization, colloidal stability and biocompatibility of magnetic nanoparticles are crucial for their biological applications. Here, we report a synthetic approach for the direct preparation of superparamagnetic nanoparticles consisting of a perovskite LSMO core modified with a covalently linked chitosan shell that provides colloidal stability in aqueous solutions for cancer hyperthermia therapy. The characterization of the core-shell nanostructure using Fourier transform infrared spectroscopy; thermo-gravimetric analysis to assess the chemical bonding of chitosan to nanoparticles; field-emission scanning electron microscopy and transmission electron microscopy for its size and coating efficiency estimation; and magnetic measurement for their magnetization properties was performed. Zeta potential and light scattering studies of the core shell revealed it to possess good colloidal stability. Confocal microscopy and MTT assay are performed for qualitative and quantitative measurement of cell viability and biocompatibility. In depth cell morphology and biocompatibility is evaluated by using multiple-staining of different dyes. The magnetic@chitosan nanostructure system is found to be biocompatible up to 48 h with 80% cell viability. Finally, an in vitro cancer hyperthermia study is done on the MCF7 cell line. During in vitro hyperthermia treatment of cancer cells, cell viability is reduced upto 40% within 120 min with chitosan coated nanoparticles. Our results demonstrate that this simplified and facile synthesis strategy shows potential for designing a colloidal stable state and biocompatible core shell nanostructures for cancer hyperthermia therapy.

  3. Biological preparation of chitosan nanoparticles and its in vitro antifungal efficacy against some phytopathogenic fungi.

    PubMed

    Sathiyabama, M; Parthasarathy, R

    2016-10-20

    The aim of the present study was to prepare Chitosan nanoparticles through biological method with high antifungal activities. Chitosan nanoparticles were prepared by the addition of anionic proteins isolated from Penicillium oxalicum culture to chitosan solutions. The formation of chitosan nanoparticles was preliminary confirmed by UV-vis spectrophotometric analysis. The physico-chemical properties of the chitosan nanoparticles were determined by size and zeta potential analysis, FTIR analysis, HRTEM and XRD pattern. The chitosan nanoparticles were evaluated for its potential to inhibit the growth of phytopathogens viz., Pyricularia grisea, Alternaria solani, Fusarium oxysporum. It is evident from our results that chitosan nanoparticles inhibit the growth of phytopathogens tested. Chitosan nanoparticle treated chickpea seeds showed positive morphological effects such as enhanced germination%, seed vigor index and vegetative biomass of seedlings. All these results indicate that chitosan nanoparticle can be used further under field condition to protect various crops from the devastating fungal pathogens as well as growth promoters.

  4. Biological preparation of chitosan nanoparticles and its in vitro antifungal efficacy against some phytopathogenic fungi.

    PubMed

    Sathiyabama, M; Parthasarathy, R

    2016-10-20

    The aim of the present study was to prepare Chitosan nanoparticles through biological method with high antifungal activities. Chitosan nanoparticles were prepared by the addition of anionic proteins isolated from Penicillium oxalicum culture to chitosan solutions. The formation of chitosan nanoparticles was preliminary confirmed by UV-vis spectrophotometric analysis. The physico-chemical properties of the chitosan nanoparticles were determined by size and zeta potential analysis, FTIR analysis, HRTEM and XRD pattern. The chitosan nanoparticles were evaluated for its potential to inhibit the growth of phytopathogens viz., Pyricularia grisea, Alternaria solani, Fusarium oxysporum. It is evident from our results that chitosan nanoparticles inhibit the growth of phytopathogens tested. Chitosan nanoparticle treated chickpea seeds showed positive morphological effects such as enhanced germination%, seed vigor index and vegetative biomass of seedlings. All these results indicate that chitosan nanoparticle can be used further under field condition to protect various crops from the devastating fungal pathogens as well as growth promoters. PMID:27474573

  5. Phenylboronic Acid-Mediated Tumor Targeting of Chitosan Nanoparticles

    PubMed Central

    Wang, Xin; Tang, Huang; Wang, Chongzhi; Zhang, Jialiang; Wu, Wei; Jiang, Xiqun

    2016-01-01

    The phenylboronic acid-conjugated chitosan nanoparticles were prepared by particle surface modification. The size, zeta potential and morphology of the nanoparticles were characterized by dynamic light scattering, zeta potential measurement and transmission electron microscopy. The cellular uptake, tumor penetration, biodistribution and antitumor activity of the nanoparticles were evaluated by using monolayer cell model, 3-D multicellular spheroid model and H22 tumor-bearing mice. The incorporation of phenylboronic acid group into chitosan nanoparticles impart a surface charge-reversible characteristic to the nanoparticles. In vitro evaluation using 2-D and 3-D cell models showed that phenylboronic acid-decorated nanoparticles were more easily internalized by tumor cells compared to non-decorated chitosan nanoparticles, and could deliver more drug into tumor cells due to the active targeting effect of boronic acid group. Furthermore, the phenylboronic acid-decorated nanoparticles displayed a deeper penetration and persistent accumulation in the multicellular spheroids, resulting in better inhibition growth to multicellular spheroids than non-decorated nanoparticles. Tumor penetration, drug distribution and near infrared fluorescence imaging revealed that phenylboronic acid-decorated nanoparticles could penetrate deeper and accumulate more in tumor area than non-decorated ones. In vivo antitumor examination demonstrated that the phenylboronic acid-decorated nanoparticles have superior efficacy in restricting tumor growth and prolonging the survival time of tumor-bearing mice than free drug and drug-loaded chitosan nanoparticles. PMID:27375786

  6. Synthesis and evaluation of PEG-O-chitosan nanoparticles for delivery of poor water soluble drugs: ibuprofen.

    PubMed

    Hassani Najafabadi, Alireza; Abdouss, Majid; Faghihi, Shahab

    2014-08-01

    Current methods for preparation of PEGylated chitosan have limitations such as harsh de protecting step and several purification cycles. In the present study, a facile new method for conjugating methoxy polyethylene glycol (mPEG) to chitosan under mild condition is introduced to improve water solubility of chitosan and control the release of poor water soluble drugs. The method consists of chitosan modification by grafting the C6 position of chitosan to mPEG which is confirmed by Fourier transformed-infrared (FT-IR) and proton nuclear magnetic resonance ((1)HNMR) analyses. The amine groups at the C2 position of chitosan are protected using sodium dodecylsulfate (SDS) which is removed by dialyzing the precipitation against Tris solution. The chemical structure of the prepared polymer is characterized by FTIR and (1)HNMR. The synthesized polymer is then employed to prepare nanoparticles which are characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and dynamic light scattering (DLS) for their size and morphology. The nanoparticles are used for encapsulation of ibuprofen followed by in vitro release investigation in gastrointestinal and simulated biological fluids. The chitosan nanoparticles are used as control. The PEGylated nanoparticles show a particle size of 80 nm with spherical morphology. The results clearly show that drug release from PEGylated chitosan nanoparticles is remarkably slower than chitosan. In addition, drug encapsulation and encapsulation efficiency in PEGylated nanoparticles are dependent on the amount of drug added to the formulation being significantly higher than chitosan nanoparticles. This study provides an efficient, novel, and facile method for preparing a nano carrier system for delivery of water insoluble drugs.

  7. Analytical characteristics and application of novel chitosan coated magnetic nanoparticles as an efficient drug delivery system for ciprofloxacin. Enhanced drug release kinetics by low-frequency ultrasounds.

    PubMed

    Kariminia, Samira; Shamsipur, Ali; Shamsipur, Mojtaba

    2016-09-10

    A pH-responsive drug carrier based on chitosan coated iron oxide nanoparticles (CS-Fe3O4) for prolonged antibiotic release in a controlled manner is reported. As an antibiotic drug model, ciprofloxacin was loaded onto the nanocarrier via H-bonding interactions. The nanoparticles were characterized using scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, photon correlation spectroscopy and Fourier transform infrared spectroscopy. The particle size of CS-Fe3O4 nanoparticles were found to lie in the range of 30-80nm. The analytical characteristics of the designed system were thoroughly investigated. The in vitro drug loading at pH 4.8 and release kinetics at pH 7.4 studies revealed that the drug delivery system can take 99% of ciprofloxacin load and quantitatively release the drug over a sustained period of 5 days. The release kinetics study indicated that the system follows a zero order kinetics via a diffusion-controlled mechanism. These results indicated that CS-Fe3O4 nanoparticles have the potential for use as controlled antibiotic delivery systems through oral administration by avoiding the drug release in the highly acidic gastric fluid region of the stomach. Furthermore, the ability of low-frequency ultrasound in fast release of the encapsulated drug in less than 60min from the CS-Fe3O4 nanoparticles in a controlled manner was confirmed. PMID:27497305

  8. Physicochemical and biofunctional properties of crab chitosan nanoparticles.

    PubMed

    Nguyen, The Han; Kwak, Hae Soo; Kim, Sang Moo

    2013-08-01

    The physicochemical and biofunctional properties of crab chitosan nanoparticles of two different sizes (Nano A and B) manufactured by dry milling method were evaluated for commercialization. The deacetylation degrees (DD) of Nano A, B and the control chitosan were 90.9, 93.0, and 92.7% respectively whereas their molecular weights (M(w)) were 43.9, 44.7 and 208.8 kDa. The average sizes of the dispersed Nano A, B and the control chitosan in cetyltrimethylammonium chloride were 735.9, 849.4 and 2,382.4 nm, respectively, which were lower than 1441.7, 2935.6 and 6832.9 nm of the intact chitosans. Chitosan nanoparticles had mild tyrosinase, antioxidant and angiotensin I converting enzyme (ACE), but weak collagenase, elastase and beta-glucuronidase inhibitory activity. However, Nano A had strong alpha-glucosidase inhibitory activity, which was comparable to that of acarbose, a commercial alpha-glucosidase inhibitor. In addition, the minimum inhibitory concentrations (MICs) of chitosan and its nanoparticles ranged from 30 to > 200 microg/mL against each four gram-positive and gram-negative bacteria. Therefore, crab chitosan nanoparticles could be used as a nutraceutical, cosmeceutical or pharmaceutical product.

  9. Chitosan Nanoparticles for SiRNA Delivery In Vitro.

    PubMed

    Ragelle, Héloïse; Vanvarenberg, Kevin; Vandermeulen, Gaëlle; Préat, Véronique

    2016-01-01

    RNA interference, the process in which small interfering RNAs (SiRNAs) silence a specific gene and thus inhibit the associated protein, has opened new doors for the treatment of a wide range of diseases. However, efficient delivery of SiRNAs remains a challenge, especially due to their instability in biological environments and their inability to cross cell membranes. To protect and deliver SiRNAs to mammalian cells, a variety of polymeric nanocarriers have been developed. Among them, the polysaccharide chitosan has generated great interests. This derivative of natural chitin is biodegradable and biocompatible, and can complex SiRNAs into nanoparticles on account of its positive charges. However, chitosan presents some limitations that need to be taken into account when designing chitosan/SiRNA nanoparticles. Here, we describe a method to prepare SiRNA/chitosan nanoparticles with high gene silencing efficiency and low cytotoxicity by using the ionic gelation technique.

  10. Chitosan Nanoparticles for SiRNA Delivery In Vitro.

    PubMed

    Ragelle, Héloïse; Vanvarenberg, Kevin; Vandermeulen, Gaëlle; Préat, Véronique

    2016-01-01

    RNA interference, the process in which small interfering RNAs (SiRNAs) silence a specific gene and thus inhibit the associated protein, has opened new doors for the treatment of a wide range of diseases. However, efficient delivery of SiRNAs remains a challenge, especially due to their instability in biological environments and their inability to cross cell membranes. To protect and deliver SiRNAs to mammalian cells, a variety of polymeric nanocarriers have been developed. Among them, the polysaccharide chitosan has generated great interests. This derivative of natural chitin is biodegradable and biocompatible, and can complex SiRNAs into nanoparticles on account of its positive charges. However, chitosan presents some limitations that need to be taken into account when designing chitosan/SiRNA nanoparticles. Here, we describe a method to prepare SiRNA/chitosan nanoparticles with high gene silencing efficiency and low cytotoxicity by using the ionic gelation technique. PMID:26472448

  11. Cell outer membrane mimetic chitosan nanoparticles: preparation, characterization and cytotoxicity.

    PubMed

    Zhao, Jing; Liang, Fei; Kong, Lingheng; Zheng, Lina; Fan, Tao

    2015-01-01

    A negatively charged copolymer poly (MPC-co-AMPS) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-acrylamide-2-methyl propane sulfonic acid (AMPS) was designed and synthesized. Chitosan nanoparticles with cell outer membrane mimetic structure were prepared by electrostatic interaction between the sulfonic acid groups of poly (MPC-co-AMPS) and the protonated amino groups of chitosan. Effects of factors on influencing the particle size, distribution, and stability were investigated. The experimental results showed that cell membrane mimetic chitosan nanoparticles with controllable and homogeneous size ranged from 100 to 300 nm were prepared at the concentration of 0.1-2.0 mg/mL and the charge ratio of 0.5-1.1. Chitosan nanoparticles prepared can exist stably for more than 45 days when placed at 4 °C and pH < 7.5. The cytotoxicity of the chitosan nanoparticles reduced significantly after surface modification with cell membrane mimetic structure, meeting the basic requirements of biomedical materials. The results suggest cell membrane mimetic chitosan nanoparticles prepared with polyanion and polycation obtain good biological compatibility and immune stealth ability, which has important academic significance and great application prospects.

  12. Formation and dissolution of chitosan/pyrophosphate nanoparticles: is the ionic crosslinking of chitosan reversible?

    PubMed

    Cai, Yuhang; Lapitsky, Yakov

    2014-03-01

    Ionically crosslinked chitosan particles with submicron dimensions attract widespread interest as materials for controlled release. To this end, we have examined the formation and dissolution of nanoparticles prepared by crosslinking chitosan with pyrophosphate (PPi). The formation of these particles required a critical PPi concentration (which increased with the chitosan concentration), and their z-average hydrodynamic diameters could be predictably tuned from roughly 60 to 220 nm by varying the concentration of the parent chitosan solutions. Unlike the nanoparticles crosslinked with the commonly used tripolyphosphate (TPP), which coagulated and precipitated when TPP was in excess, the chitosan/PPi nanoparticles remained colloidally stable even at high PPi concentrations. Moreover, the analysis of their dissolution revealed hysteresis in the particle formation/dissolution cycle, where portions of the crosslinked chitosan/PPi complexes remained stably intact at PPi concentrations below those required for their formation. This irreversible behavior was surmised to reflect the cooperativity of chitosan/PPi binding and was qualitatively modeled using the Bragg-Williams theory.

  13. Metallic magnetic nanoparticles.

    PubMed

    Hernando, A; Crespo, P; García, M A

    2005-12-22

    In this paper, we reviewed some relevant aspects of the magnetic properties of metallic nanoparticles with small size (below 4 nm), covering the size effects in nanoparticles of magnetic materials, as well as the appearance of magnetism at the nanoscale in materials that are nonferromagnetic in bulk. These results are distributed along the text that has been organized around three important items: fundamental magnetic properties, different fabrication procedures, and characterization techniques. A general introduction and some experimental results recently obtained in Pd and Au nanoparticles have also been included. Finally, the more promising applications of magnetic nanoparticles in biomedicine are indicated. Special care was taken to complete the literature available on the subject.

  14. Synthesis of chitosan-stabilized gold nanoparticles by atmospheric plasma.

    PubMed

    Jin, Yong; Li, Zepeng; Hu, Lijuan; Shi, Xiaowen; Guan, Weimin; Du, Yumin

    2013-01-01

    We report a facile method to prepare gold nanoparticles by atmospheric plasma. Chitosan, was used as a stabilizing agent and gold precursor. In chitosan solution was reduced by atmospheric plasma at room temperature. We find the plasma treatment is effective for reducing the gold precursor and the process only takes minutes. The obtained gold nanoparticles were characterized with UV-vis spectroscopy and transmission electron microscopy. The results indicated that the morphology and size distribution of gold nanoparticles prepared varied with treatment time and the ratio of chitosan to precursor metal salts. Additionally, a preliminary study on air component analysis indicated that the moisture in air plays an important role in producing the active ingredient for the production of gold nanoparticles.

  15. Docetaxel loaded chitosan nanoparticles: formulation, characterization and cytotoxicity studies.

    PubMed

    Jain, Ankit; Thakur, Kanika; Kush, Preeti; Jain, Upendra K

    2014-08-01

    The primary objective of the present investigation was to explore biodegradable chitosan as a polymeric material for formulating docetaxel nanoparticles (DTX-NPs) to be used as a delivery system for breast cancer treatment. Docetaxel loaded chitosan nanoparticles were formulated by water-in-oil nanoemulsion system and characterized in terms of particle size, zeta potential, polydispersity index, drug entrapment efficiency (EE), loading capacity (LC), scanning electron microscopy (SEM), in vitro release study and drug release kinetics. Further, to evaluate the potential anticancer efficacy of docetaxel loaded chitosan nanoparticulate system, in vitro cytotoxicity studies on human breast cancer cell line (MDA-MB-231) were carried out. The morphological studies revealed the spherical shape of docetaxel loaded chitosan nanoparticles having an average size of 170.1±5.42-227.6±7.87nm, polydispersity index in the range of 0.215±0.041-0.378±0.059 and zeta potential between 28.3 and 31.4mV. Nanoparticles exhibited 65-76% of drug entrapment and 8-12% loading capacity releasing about 68-83% of the drug within 12h following Higuchi's square-root kinetics. An increase of 20% MDA-MB-231 cell line growth inhibition was determined by docetaxel loaded chitosan nanoparticles with respect to the free drug after 72h incubation.

  16. Uptake and cytotoxicity of chitosan nanoparticles in human liver cells

    SciTech Connect

    Loh, Jing Wen; Yeoh, George; Saunders, Martin; Lim, Lee-Yong

    2010-12-01

    Despite extensive research into the biomedical and pharmaceutical applications of nanoparticles, and the liver being the main detoxifying organ in the human body, there are limited studies which delineate the hepatotoxicity of nanoparticles. This paper reports on the biological interactions between liver cells and chitosan nanoparticles, which have been widely recognised as biocompatible. Using the MTT assay, human liver cells were shown to tolerate up to 4 h of exposure to 0.5% w/v of chitosan nanoparticles (18 {+-} 1 nm, 7.5 {+-} 1.0 mV in culture medium). At nanoparticle concentrations above 0.5% w/v, cell membrane integrity was compromised as evidenced by leakage of alanine transaminase into the extracellular milieu, and there was a dose-dependent increase in CYP3A4 enzyme activity. Uptake of chitosan nanoparticles into the cell nucleus was observed by confocal microscopic analysis after 4 h exposure with 1% w/v of chitosan nanoparticles. Electron micrographs further suggest necrotic or autophagic cell death, possibly caused by cell membrane damage and resultant enzyme leakage.

  17. In vitro study on apoptotic cell death by effective magnetic hyperthermia with chitosan-coated MnFe2O4

    NASA Astrophysics Data System (ADS)

    Oh, Yunok; Lee, Nohyun; Kang, Hyun Wook; Oh, Junghwan

    2016-03-01

    Magnetic nanoparticles (MNPs) have been widely investigated as a hyperthermic agent for cancer treatment. In this study, thermally responsive Chitosan-coated MnFe2O4 (Chitosan-MnFe2O4) nanoparticles were developed to conduct localized magnetic hyperthermia for cancer treatment. Hydrophobic MnFe2O4 nanoparticles were synthesized via thermal decomposition and modified with 2,3-dimercaptosuccinic acid (DMSA) for further conjugation of chitosan. Chitosan-MnFe2O4 nanoparticles exhibited high magnetization and excellent biocompatibility along with low cell cytotoxicity. During magnetic hyperthermia treatment (MHT) with Chitosan-MnFe2O4 on MDA-MB 231 cancer cells, the targeted therapeutic temperature was achieved by directly controlling the strength of the external AC magnetic fields. In vitro Chitosan-MnFe2O4-assisted MHT at 42 °C led to drastic and irreversible changes in cell morphology and eventual cellular death in association with the induction of apoptosis through heat dissipation from the excited magnetic nanoparticles. Therefore, the Chitosan-MnFe2O4 nanoparticles with high biocompatibility and thermal capability can be an effective nano-mediated agent for MHT on cancer.

  18. Asymmetric Collagen/chitosan Membrane Containing Minocycline-loaded Chitosan Nanoparticles for Guided Bone Regeneration

    PubMed Central

    Ma, Shiqing; Adayi, Aidina; Liu, Zihao; Li, Meng; Wu, Mingyao; Xiao, Linghao; Sun, Yingchun; Cai, Qing; Yang, Xiaoping; Zhang, Xu; Gao, Ping

    2016-01-01

    Infections caused by pathogens colonization at wound sites in the process of bone healing are considered as one of the major reasons for the failure of guided bone regeneration (GBR). The objective of this study was to prepare a novel asymmetric collagen/chitosan GBR membrane containing minocycline-loaded chitosan nanoparticles. The morphologies of the membranes and nanoparticles were observed by SEM and TEM, respectively. The characterization and biocompatibility of the membranes was evaluated. The effect of the membrane on bone regeneration was assessed using the critical-size at cranial defect model. TEM images showed the spherical morphology of the nanoparticles. The results of SEM indicated that the asymmetric membrane contained a dense collagen layer and a loose chitosan layer. An in vitro experiment showed that the membrane can inhibit bacterial growth and promote osteoblasts and fibroblasts growth. The membrane showed the ability to promote angiogenesis and enhance bone regeneration in vivo. An asymmetric collagen/chitosan GBR membrane can be fabricated by loading minocycline encapsulated chitosan nanoparticles, and shows satisfactory biocompatibility and barrier function, which enhances bone regeneration. Therefore, this antibacterial GBR membrane is a promising therapeutic approach to prevent infection and guide bone regeneration. PMID:27546177

  19. Asymmetric Collagen/chitosan Membrane Containing Minocycline-loaded Chitosan Nanoparticles for Guided Bone Regeneration.

    PubMed

    Ma, Shiqing; Adayi, Aidina; Liu, Zihao; Li, Meng; Wu, Mingyao; Xiao, Linghao; Sun, Yingchun; Cai, Qing; Yang, Xiaoping; Zhang, Xu; Gao, Ping

    2016-01-01

    Infections caused by pathogens colonization at wound sites in the process of bone healing are considered as one of the major reasons for the failure of guided bone regeneration (GBR). The objective of this study was to prepare a novel asymmetric collagen/chitosan GBR membrane containing minocycline-loaded chitosan nanoparticles. The morphologies of the membranes and nanoparticles were observed by SEM and TEM, respectively. The characterization and biocompatibility of the membranes was evaluated. The effect of the membrane on bone regeneration was assessed using the critical-size at cranial defect model. TEM images showed the spherical morphology of the nanoparticles. The results of SEM indicated that the asymmetric membrane contained a dense collagen layer and a loose chitosan layer. An in vitro experiment showed that the membrane can inhibit bacterial growth and promote osteoblasts and fibroblasts growth. The membrane showed the ability to promote angiogenesis and enhance bone regeneration in vivo. An asymmetric collagen/chitosan GBR membrane can be fabricated by loading minocycline encapsulated chitosan nanoparticles, and shows satisfactory biocompatibility and barrier function, which enhances bone regeneration. Therefore, this antibacterial GBR membrane is a promising therapeutic approach to prevent infection and guide bone regeneration. PMID:27546177

  20. Intranasal Delivery of Chitosan Nanoparticles for Migraine Therapy

    PubMed Central

    Gulati, Neha; Nagaich, Upendra; Saraf, Shubhini A.

    2013-01-01

    Objective The objective of the research was to formulate and evaluate sumatriptan succinate-loaded chitosan nanoparticles for migraine therapy in order to improve its therapeutic effect and reduce dosing frequency. Material and Methods The Taguchi method design of experiments (L9 orthogonal array) was applied to obtain the optimized formulation. The sumatriptan succinate-loaded chitosan nanoparticles (CNPs) were prepared by ionic gelation of chitosan with tripolyphosphate anions (TPP) and Tween 80 as surfactant. Results The CNPs had a mean size of 306.8 ± 3.9 nm, a zeta potential of +28.79 mV, and entrapment efficiency of 75.4 ± 1.1%. The in vitro drug release of chitosan nanoparticles was evaluated in phosphate buffer saline pH 5.5 using goat nasal mucosa and found to be 76.7 ± 1.3% within 28 hours. Discussion The release of the drug from the nanoparticles was anomalous, showing non-Fickian diffusion indicating that drug release is controlled by more than one process i.e. the superposition of both phenomena, a diffusion-controlled as well as a swelling-controlled release. This is clearly due to the characteristics of chitosan which easily dissolves at low pH, thus a nasal pH range of 5.5 ± 0.5 supports it very well. The mechanism of pH-sensitive swelling involves protonation of the amine groups of chitosan at low pH. This protonation leads to chain repulsion, diffusion of protons and counter ions together with water inside the gel, and the dissociation of secondary interactions. Conclusion The results suggest that sumatriptan succinate-loaded chitosan nanoparticles are the most suitable mode of drug delivery for promising therapeutic action. PMID:24106677

  1. Magnetic Nanoparticle Sensors

    PubMed Central

    Koh, Isaac; Josephson, Lee

    2009-01-01

    Many types of biosensors employ magnetic nanoparticles (diameter = 5–300 nm) or magnetic particles (diameter = 300–5,000 nm) which have been surface functionalized to recognize specific molecular targets. Here we cover three types of biosensors that employ different biosensing principles, magnetic materials, and instrumentation. The first type consists of magnetic relaxation switch assay-sensors, which are based on the effects magnetic particles exert on water proton relaxation rates. The second type consists of magnetic particle relaxation sensors, which determine the relaxation of the magnetic moment within the magnetic particle. The third type is magnetoresistive sensors, which detect the presence of magnetic particles on the surface of electronic devices that are sensitive to changes in magnetic fields on their surface. Recent improvements in the design of magnetic nanoparticles (and magnetic particles), together with improvements in instrumentation, suggest that magnetic material-based biosensors may become widely used in the future. PMID:22408498

  2. In vitro feasibility study of the use of a magnetic electrospun chitosan nanofiber composite for hyperthermia treatment of tumor cells.

    PubMed

    Lin, Ta-Chun; Lin, Feng-Huei; Lin, Jui-Che

    2012-07-01

    Hyperthermia has been reported to be an effective cancer treatment modality, as tumor cells are more temperature-sensitive than their normal counterparts. Since the ambient temperature can be increased by placing magnetic nanoparticles in an alternating magnetic field it has become of interest to incorporate these magnetic nanoparticles into biodegradable nanofibers for possible endoscopic hyperthermia treatment of malignant tumors. In this preliminary investigation we have explored various characteristics of biodegradable electrospun chitosan nanofibers containing magnetic nanoparticles prepared by different methods. These methods included: (1) E-CHS-Fe(3)O(4), with electrospun chitosan nanofibers directly immersed in a magnetic nanoparticle solution; (2) E-CHS-Fe(2+), with the electrospun chitosan nanofibers initially immersed in Fe(+2)/Fe(+3) solution, followed by chemical co-precipitation of the magnetic nanoparticles. The morphology and crystalline phase of the magnetic electrospun nanofiber matrices were determined by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and X-ray diffraction spectroscopy. The magnetic characteristics were measured using a superconducting quantum interference device. The heating properties of these magnetic electrospun nanofiber matrices in an alternating magnetic field were investigated at a frequency of 750 kHz and magnetic intensity of 6.4 kW. In vitro cell incubation experiments indicated that these magnetic electrospun nanofiber matrices are non-cytotoxic and can effectively reduce tumor cell proliferation upon application of a magnetic field.

  3. Enhanced surface imprinting of lysozyme over a new kind of magnetic chitosan submicrospheres.

    PubMed

    Guo, Hao; Yuan, Dongying; Fu, Guoqi

    2015-02-15

    Surface protein imprinting over nano- or micron-sized substrates is an effective approach for improving the biomacromolecule mass transfer and rebinding capacity. For achieving high recognition performance, it is necessary to introduce certain functional groups onto the surface of the support materials which can interact with the template protein. Herein, we report a surface protein imprinting approach using a new kind of core-shell magnetic chitosan submicrospheres as the supports. The surface of these magnetic chitosan particles is tethered with uncross-linked chitosan chains, hence bearing plenty of amino and hydroxyl groups, where a large amount of functional ligands can be readily coupled for capturing of the protein template. With lysozyme as a model print protein, the magnetic supports were functionalized with maleic acid and then coated with imprinted polymer layers. The resulting imprinted microspheres show significantly selective rebinding for lysozyme. In particular, they exhibit a specific rebinding capacity about three times higher than achieved with our previous lysozyme-imprinted particles synthesized in similar way but with maleic acid modified silica nanoparticles as the supports. This can be attributed to the much higher template binding capacity to the modified magnetic chitosan submicrospheres. Also, the resultant imprinted particles can be easily collected by a magnet. Therefore, such kind of chitosan submicrospheres may be a versatile carrier for constructing high-capacity and magnetically recyclable surface protein-imprinted particles.

  4. Optimization of preparation of chitosan-coated iron oxide nanoparticles for biomedical applications by chemometrics approaches

    NASA Astrophysics Data System (ADS)

    Honary, Soheila; Ebrahimi, Pouneh; Rad, Hossein Asgari; Asgari, Mahsa

    2013-08-01

    Functionalized magnetic nanoparticles are used in several biomedical applications, such as drug delivery, magnetic cell separation, and magnetic resonance imaging. Size and surface properties of iron oxide nanoparticles are the two important factors which could dramatically affect the nanoparticle efficiency as well as their stability. In this study, the chemometrics approach was applied to optimize the coating process of iron oxide nanoparticles. To optimize the size of nanoparticles, the effect of two experimental parameters on size was investigated by means of multivariate analysis. The factors considered were chitosan molecular weight and chitosan-to-tripolyphosphate concentration ratio. The experiments were performed according to face-centered cube central composite response surface design. A second-order regression model was obtained which characterized by both descriptive and predictive abilities. The method was optimized with respect to the percent of Z average diameter's increasing after coating as response. It can be concluded that experimental design provides a suitable means of optimizing and testing the robustness of iron oxide nanoparticle coating method.

  5. Design of chitosan-based nanoparticles functionalized with gallic acid.

    PubMed

    Lamarra, J; Rivero, S; Pinotti, A

    2016-10-01

    Active nanoparticles based on chitosan could be applied as a support for the modulation of gallic acid delivery. In this sense, these nanostructures could be employed in different fields such as food, packaging, and pharmaceutical areas. The design parameters of chitosan-based nanoparticles functionalized with gallic acid (GA) were optimized through RSM by means of the analysis of zeta potential (ZP) and percentage encapsulation efficiency (PEE). The nanoparticles were prepared by ionotropic gelation using tripolyphosphate (TPP), at different combinations of chitosan (CH) concentration, CH:TPP ratio and GA. Global desirability methodology allowed finding the optimum formulation that included CH 0.76% (w/w), CH:TPP ratio of 5 and 37mgGA/gCH leading to ZP of +50mV and 82% of PEE. Analysis through QuickScan and turbidity demonstrated that the most stable nanoparticle suspensions were achieved combining concentrations of chitosan ranging between 0.5 and 0.75% with CH:TPP ratios higher than 3. These suspensions had high stability confirmed by means ZP and transmittance values which were higher than +25mV and 0.21 on average, respectively, as well as nanoparticle diameters of about 140nm. FTIR revealed the occurrence of both hydrogen bond and ionic interactions of CH-TPP which allowed the encapsulation and the improvement of the stability of the active agent. PMID:27287172

  6. Multimodal in vivo MRI and NIRF imaging of bladder tumor using peptide conjugated glycol chitosan nanoparticles

    NASA Astrophysics Data System (ADS)

    Key, Jaehong; Dhawan, Deepika; Knapp, Deborah W.; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Leary, James F.

    2012-03-01

    Exact detection and complete removal of cancer is a key point to minimize cancer recurrence. However, it is currently very difficult to detect small tumors inside human body and continuously monitor tumors using a non-invasive imaging modality. Presently, positron emission tomography (PET) can provide the most sensitive cancer images in the human body. However, PET imaging has very limited imaging time because they typically use isotopes with short halflives. PET imaging cannot also visualize anatomical information. Magnetic resonance imaging (MRI) can provide highresolution images inside the body but it has a low sensitivity, so MRI contrast agents are necessary to enhance the contrast of tumor. Near infrared fluorescent (NIRF) imaging has a good sensitivity to visualize tumor using optical probes, but it has a very limited tissue penetration depth. Therefore, we developed multi-modality nanoparticles for MRI based diagnosis and NIRF imaging based surgery of cancer. We utilized glycol chitosan of 350 nm as a vehicle for MRI contrast agents and NIRF probes. The glycol chitosan nanoparticles were conjugated with NIRF dye, Cy5.5 and bladder cancer targeting peptides to increase the internalization of cancer. For MR contrast effects, iron oxide based 22 nm nanocubes were physically loaded into the glycol chitosan nanoparticles. The nanoparticles were characterized and evaluated in bladder tumor bearing mice. Our study suggests the potential of our nanoparticles by both MRI and NIRF imaging for tumor diagnosis and real-time NIRF image-guided tumor surgery.

  7. Vancomycin loaded superparamagnetic MnFe2O4 nanoparticles coated with PEGylated chitosan to enhance antibacterial activity.

    PubMed

    Esmaeili, Akbar; Ghobadianpour, Sepideh

    2016-03-30

    Increasing prevalence of antibiotic-resistant and failed-treatment make more investigations to deal with these problems. Hence new therapeutic approaches for effective treatment are necessary. Ferrite superparamagnetic nanoparticles have potentially antibacterial activity. In this study we prepared MnFe2O4 superparamagnetic nanoparticles as core by precipitation method and used chitosan crosslinked by glutaraldehyde as shell, then modified with PEG to increase stability of particles against RES. Chitosan coating not only improves the properties of ferrit nanoparticles but also has antibacterial activity. FT-IR confirmed this surface modification; XRD and SEM were developed to demonstrate particle size approximately 25 nm and characteristics of crystal structure of these nanoparticles. Magnetic properties of nanoparticles were evaluated by VSM. Actual drug loading and releasing were examined by UV-vis spectroscopy method. We employed liquid broth dilution method to assessment antibacterial activity of nanoparticles against microorganisms. Significant antibacterial effect against gram negative bacteria was developed.

  8. Cytotoxicity of monodispersed chitosan nanoparticles against the Caco-2 cells

    SciTech Connect

    Loh, Jing Wen; Saunders, Martin; Lim, Lee-Yong

    2012-08-01

    Published toxicology data on chitosan nanoparticles (NP) often lack direct correlation to the in situ size and surface characteristics of the nanoparticles, and the repeated NP assaults as experienced in chronic use. The aim of this paper was to breach these gaps. Chitosan nanoparticles synthesized by spinning disc processing were characterised for size and zeta potential in HBSS and EMEM at pHs 6.0 and 7.4. Cytotoxicity against the Caco-2 cells was evaluated by measuring the changes in intracellular mitochondrial dehydrogenase activity, TEER and sodium fluorescein transport data and cell morphology. Cellular uptake of NP was observed under the confocal microscope. Contrary to established norms, the collective data suggest that the in vitro cytotoxicity of NP against the Caco-2 cells was less influenced by positive surface charges than by the particle size. Particle size was in turn determined by the pH of the medium in which the NP was dispersed, with the mean size ranging from 25 to 333 nm. At exposure concentration of 0.1%, NP of 25 ± 7 nm (zeta potential 5.3 ± 2.8 mV) was internalised by the Caco-2 cells, and the particles were observed to inflict extensive damage to the intracellular organelles. Concurrently, the transport of materials along the paracellular pathway was significantly facilitated. The Caco-2 cells were, however, capable of recovering from such assaults 5 days following NP removal, although a repeat NP exposure was observed to produce similar effects to the 1st exposure, with the cells exhibiting comparable resiliency to the 2nd assault. -- Highlights: ► Chitosan nanoparticles reduced mitochondrial dehydrogenase activity. ► Cellular uptake of chitosan nanoparticles was observed. ► Chitosan nanoparticles inflicted extensive damage to the cell morphology. ► The transport of materials along the paracellular pathway was facilitated.

  9. Towards the development of multifunctional chitosan-based iron oxide nanoparticles: Optimization and modelling of doxorubicin release.

    PubMed

    Soares, Paula I P; Sousa, Ana Isabel; Ferreira, Isabel M M; Novo, Carlos M M; Borges, João Paulo

    2016-11-20

    In the present work composite nanoparticles with a magnetic core and a chitosan-based shell were produced as drug delivery systems for doxorubicin (DOX). The results show that composite nanoparticles with a hydrodynamic diameter within the nanometric range are able to encapsulate more DOX than polymeric nanoparticles alone corresponding also to a higher drug release. Moreover the synthesis method of the iron oxide nanoparticles influences the total amount of DOX released and a high content of iron oxide nanoparticles inhibits DOX release. The modelling of the experimental results revealed a release mechanism dominated by Fickian diffusion. PMID:27561489

  10. Towards the development of multifunctional chitosan-based iron oxide nanoparticles: Optimization and modelling of doxorubicin release.

    PubMed

    Soares, Paula I P; Sousa, Ana Isabel; Ferreira, Isabel M M; Novo, Carlos M M; Borges, João Paulo

    2016-11-20

    In the present work composite nanoparticles with a magnetic core and a chitosan-based shell were produced as drug delivery systems for doxorubicin (DOX). The results show that composite nanoparticles with a hydrodynamic diameter within the nanometric range are able to encapsulate more DOX than polymeric nanoparticles alone corresponding also to a higher drug release. Moreover the synthesis method of the iron oxide nanoparticles influences the total amount of DOX released and a high content of iron oxide nanoparticles inhibits DOX release. The modelling of the experimental results revealed a release mechanism dominated by Fickian diffusion.

  11. In Vivo Magnetic Resonance Imaging and Microwave Thermotherapy of Cancer Using Novel Chitosan Microcapsules.

    PubMed

    Tang, Shunsong; Du, Qijun; Liu, Tianlong; Tan, Longfei; Niu, Meng; Gao, Long; Huang, Zhongbing; Fu, Changhui; Ma, Tengchuang; Meng, Xianwei; Shao, Haibo

    2016-12-01

    Herein, we develop a novel integrated strategy for the preparation of theranostic chitosan microcapsules by encapsulating ion liquids (ILs) and Fe3O4 nanoparticles. The as-prepared chitosan/Fe3O4@IL microcapsules exhibit not only significant heating efficacy in vitro under microwave (MW) irradiation but also obvious enhancement of T2-weighted magnetic resonance (MR) imaging, besides the excellent biocompatibility in physiological environments. The chitosan/Fe3O4@IL microcapsules show ideal temperature rise and therapeutic efficiency when applied to microwave thermal therapy in vivo. Complete tumor elimination is realizing after MW irradiation at an ultralow power density (1.8 W/cm(2)), while neither the MW group nor the chitosan microcapsule group has significant influence on the tumor development. The applicability of the chitosan/Fe3O4@IL microcapsules as an efficient contrast agent for MR imaging is proved in vivo. Moreover, the result of in vivo systematic toxicity shows that chitosan/Fe3O4@IL microcapsules have no acute fatal toxicity. Our study presents an interesting type of multifunctional platform developed by chitosan microcapsule promising for imaging-guided MW thermotherapy. PMID:27422776

  12. In Vivo Magnetic Resonance Imaging and Microwave Thermotherapy of Cancer Using Novel Chitosan Microcapsules

    NASA Astrophysics Data System (ADS)

    Tang, Shunsong; Du, Qijun; Liu, Tianlong; Tan, Longfei; Niu, Meng; Gao, Long; Huang, Zhongbing; Fu, Changhui; Ma, Tengchuang; Meng, Xianwei; Shao, Haibo

    2016-07-01

    Herein, we develop a novel integrated strategy for the preparation of theranostic chitosan microcapsules by encapsulating ion liquids (ILs) and Fe3O4 nanoparticles. The as-prepared chitosan/Fe3O4@IL microcapsules exhibit not only significant heating efficacy in vitro under microwave (MW) irradiation but also obvious enhancement of T2-weighted magnetic resonance (MR) imaging, besides the excellent biocompatibility in physiological environments. The chitosan/Fe3O4@IL microcapsules show ideal temperature rise and therapeutic efficiency when applied to microwave thermal therapy in vivo. Complete tumor elimination is realizing after MW irradiation at an ultralow power density (1.8 W/cm2), while neither the MW group nor the chitosan microcapsule group has significant influence on the tumor development. The applicability of the chitosan/Fe3O4@IL microcapsules as an efficient contrast agent for MR imaging is proved in vivo. Moreover, the result of in vivo systematic toxicity shows that chitosan/Fe3O4@IL microcapsules have no acute fatal toxicity. Our study presents an interesting type of multifunctional platform developed by chitosan microcapsule promising for imaging-guided MW thermotherapy.

  13. Chitosan as template for the synthesis of ceria nanoparticles

    SciTech Connect

    Sifontes, A.B.; Gonzalez, G.; Ochoa, J.L.; Tovar, L.M.; Zoltan, T.; Canizales, E.

    2011-11-15

    Graphical abstract: Cerium oxide nanoparticles with cubic fluorite structure were prepared using chitosan as template, cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. Calcinated powders at 350 {sup o}C contain agglomerated particles with average particle size of {approx}4 nm, very high porosity and foam-like morphology formed by open and close pores. Highlights: {yields} Pure CeO{sub 2} nanoparticles can take place using chitosan as template. {yields} A porous material was obtained. {yields} Blueshifts in the ultraviolet absorption spectra have been observed in cerium oxide nanocrystallites. -- Abstract: Cerium oxide (CeO{sub 2}), nanoparticles were prepared using chitosan as template, cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. The resultant ceria-chitosan spheres were calcined at 350 {sup o}C. The synthesized powders were characterized by, XRD, HRTEM, UV-vis, FTIR, and TG-DTA. The average size of the nanoparticles obtained was {approx}4 nm and BET specific surface area {approx}105 m{sup 2} g{sup -1}. Blueshifts in the ultraviolet absorption spectra have been observed in cerium oxide nanocrystallites. The band-gap was found to be 4.5 eV. The blueshifts are well explained for diameters down to less than a few nanometers by the change in the electronic band structure.

  14. Multifunctional Magnetic Nanoparticles for Targeted Delivery

    PubMed Central

    Kumar, Arun; Jena, Prasanna K.; Behera, Sumita; Lockey, Richard F.; Mohapatra, Subhra; Mohapatra, Shyam

    2012-01-01

    A major problem associated with therapy is the inability to deliver pharmaceuticals to a specific site of the body without causing nonspecific toxicity. Development of magnetic nanoparticles and techniques for their safe transport and concentration in specific sites in the body would constitute a powerful tool for gene/drug therapy in vivo. Furthermore, drug delivery in vitro could improve further if the drugs were modified with antibodies, proteins or ligands. For in vivo experiments, magnetic nanoparticles were conjugated with plasmid DNA expressing GFP and then coated with chitosan. These particles were injected into mice through tail vein and directed to heart and kidney by means of external magnets of 25 gauss or 2kA –kA/m. These particles were concentrated in the lungs, heart, and kidney of mice and the expression of GFP in these sites were monitored. The expression of GFP in specific locations was visualized by whole-body fluorescent imaging and the concentration of these particles in the designated body locations was confirmed by transmission electron microscopy. In another model system, we used atrial natriuretic peptide (ANP) and Carcino Embryonic Antigen (CEA) antibodies coupled to the chitosan coated magnetic nanoparticles to target cells in vitro. The present work demonstrates that a simple external magnetic field is all that is necessary to target a drug to a specific site inside the body without the need to functionalize the nanoparticles. However, the option to use magnetic targeting with external magnets on functionalized nanoparticles could prove as a more efficient means of drug delivery. PMID:19446653

  15. Development and evaluation of chitosan and chitosan derivative nanoparticles containing insulin for oral administration.

    PubMed

    Hecq, J; Siepmann, F; Siepmann, J; Amighi, K; Goole, J

    2015-01-01

    Chitosan and chitosan derivative-based nanoparticles loaded with insulin were prepared by self-assembly, via electrostatic interactions between the negatively charged drug and the positively charged polymers. In the investigated chitosan derivatives, the amine groups were substituted to different extents (33, 52 or 99%) by 2-hydroxypropyl-3-trimethyl ammonium groups, rendering the polymers permanently positively charged, irrespective of the pH. This is an important property for this type of advanced drug delivery system, since the pH value changes throughout the gastrointestinal tract and electrostatic interactions are of crucial importance for the stability of the nanoparticles. Permanent positive charges are also in favor of mucoadhesion. In contrast, the electric charges of chitosan molecules depend on the pH of the surrounding medium. Since the solubility of the chitosan derivatives increased due to the introduction of quaternary ammonium groups, sodium tripolyphosphate (TPP) was added to the systems to create supplementary cross-links and stabilize the nanoparticles. The presence of TPP influenced both the dissolution of the polymer matrix as well as the resulting release kinetics. The underlying drug release mechanisms were found to be more complex than simple diffusion under constant conditions, likely involving also ionic interactions and matrix dissolution. The most promising formulation was based on a chitosan derivative with 33% substitution degree and characterized by a Z-average of 142 ± 10 nm, a zeta potential of 29 ± 1 mV, an encapsulation efficacy of 52 ± 3% and, most importantly, the release of insulin was sustained for more than 210 min. PMID:26006329

  16. Synthesis of chitosan based nanoparticles and their in vitro evaluation against phytopathogenic fungi.

    PubMed

    Saharan, Vinod; Mehrotra, Akanksha; Khatik, Rajesh; Rawal, Pokhar; Sharma, S S; Pal, Ajay

    2013-11-01

    The main aim of present study was to prepare chitosan, chitosan-saponin and Cu-chitosan nanoparticles to evaluate their in vitro antifungal activities. Various nanoparticles were prepared using ionic gelation method by interaction of chitosan, sodium tripolyphosphate, saponin and Cu ions. Their particle size, polydispersity index, zeta potential and structures were confirmed by DLS, FTIR, TEM and SEM. The antifungal properties of nanoparticles against phytopathogenic fungi namely Alternaria alternata, Macrophomina phaseolina and Rhizoctonia solani were investigated at various concentrations ranging from 0.001 to 0.1%. Among the various formulations of nanoparticles, Cu-chitosan nanoparticles were found most effective at 0.1% concentration and showed 89.5, 63.0 and 60.1% growth inhibition of A. alternata, M. phaseolina and R. solani, respectively in in vitro model. At the same concentration, Cu-chitosan nanoparticles also showed maximum of 87.4% inhibition rate of spore germination of A. alternata. Chitosan nanoparticles showed the maximum growth inhibitory effects (87.6%) on in vitro mycelial growth of M. phaseolina at 0.1% concentration. From our study it is evident that chitosan based nanoparticles particularly chitosan and Cu-chitosan nanoparticles have tremendous potential for further field screening towards crop protection. PMID:24141067

  17. Synthesis of chitosan based nanoparticles and their in vitro evaluation against phytopathogenic fungi.

    PubMed

    Saharan, Vinod; Mehrotra, Akanksha; Khatik, Rajesh; Rawal, Pokhar; Sharma, S S; Pal, Ajay

    2013-11-01

    The main aim of present study was to prepare chitosan, chitosan-saponin and Cu-chitosan nanoparticles to evaluate their in vitro antifungal activities. Various nanoparticles were prepared using ionic gelation method by interaction of chitosan, sodium tripolyphosphate, saponin and Cu ions. Their particle size, polydispersity index, zeta potential and structures were confirmed by DLS, FTIR, TEM and SEM. The antifungal properties of nanoparticles against phytopathogenic fungi namely Alternaria alternata, Macrophomina phaseolina and Rhizoctonia solani were investigated at various concentrations ranging from 0.001 to 0.1%. Among the various formulations of nanoparticles, Cu-chitosan nanoparticles were found most effective at 0.1% concentration and showed 89.5, 63.0 and 60.1% growth inhibition of A. alternata, M. phaseolina and R. solani, respectively in in vitro model. At the same concentration, Cu-chitosan nanoparticles also showed maximum of 87.4% inhibition rate of spore germination of A. alternata. Chitosan nanoparticles showed the maximum growth inhibitory effects (87.6%) on in vitro mycelial growth of M. phaseolina at 0.1% concentration. From our study it is evident that chitosan based nanoparticles particularly chitosan and Cu-chitosan nanoparticles have tremendous potential for further field screening towards crop protection.

  18. Synthesis, characterization and magnetic properties of Fe3O4 doped chitosan polymer

    NASA Astrophysics Data System (ADS)

    Karaca, E.; Şatır, M.; Kazan, S.; Açıkgöz, M.; Öztürk, E.; Gürdağ, G.; Ulutaş, D.

    2015-01-01

    Fe3O4 nanoparticles doped into chitosan films were prepared by the solution casting technique. Various samples were synthesized in atmospheric medium and in vacuum. The morphological properties of the samples were characterized by high resolution transmission electron microscopy (HR-TEM) and Scanning Electron Microscopy (SEM). The structural, magnetic, and microwave absorption properties of magnetic chitosan films have been carried out using the Vibrating Sample Magnetometer (VSM) and Ferromagnetic Resonance (FMR). It is shown that the composite polymer behaves like a superparamagnetic material with high blocking temperature. The effective magnetization shows gradual increments with the concentration of dopant Fe3O4 nanoparticles. The microwave absorption characteristic of superparamagnetic composite polymer shows low reflection loss.

  19. One-step synthesis of magnetic chitosan for controlled release of 5-hydroxytryptophan

    NASA Astrophysics Data System (ADS)

    Santos Menegucci, Jucély dos; Santos, Mac-Kedson Medeiros Salviano; Dias, Diego Juscelino Santos; Chaker, Juliano Alexandre; Sousa, Marcelo Henrique

    2015-04-01

    In this work, nanoparticles of chitosan embedded with 25% (w/w) of iron oxide magnetic nanoparticles (magnetite/maghemite) with narrow size-distribution and with a loading efficiency of about 80% for 5-hydroxytryptophan (5-HTP), which is a chemical precursor in the biosynthesis of important neurotransmitters as serotonin, were synthesized with an initial mass ratio of 5-HTP/magnetic chitosan=1.2, using homogeneous precipitation by urea decomposition, in an efficient one-step procedure. Characterization of morphology, structure and surface were performed by XRD, TEM, FTIR, TGA, magnetization and zeta potential measurements, while drug loading and drug releasing were investigated using UV-vis spectroscopy. Kinetic drug release experiments under different pH conditions revealed a pH-sensitivecontrolled-release system, ruled by polymer swelling and/or particle dissolution.

  20. Collagen/chitosan film containing biotinylated glycol chitosan nanoparticles for localized drug delivery.

    PubMed

    Chen, Ming-Mao; Huang, Yu-Qing; Cao, Huan; Liu, Yan; Guo, Hao; Chen, Lillian S; Wang, Jian-Hua; Zhang, Qi-Qing

    2015-04-01

    The objective of this study was to design a drug delivery system consisting of biotinylated cholesterol-modified glycol chitosan (Bio-CHGC) nanoparticles and fish collagen/chitosan (Col/Ch) film for localized chemotherapy. Bio-CHGC was synthesized, and then its self-assembled nanoparticles were prepared by probe sonication. Doxorubicin (DOX)-loaded Bio-CHGC (DBC) nanoparticles prepared by dialysis had spherical shape, and their sizes were in the range of 330-397 nm. Col/Ch/DBC nanoparticle films were fabricated by freeze-drying. SEM showed that the DBC nanoparticles were uniformly distributed into the films, and the films retained their structural integrity. A higher degradation and swelling rate of the drug films led to a higher diffusion rate of the nanoparticles from the films, resulting in an increase in the drug release from nanoparticles. The release of DOX from the films or Bio-CHGC nanoparticles was sensitive to the pH value of the release medium. In addition, the DOX release ratio of the drug films was lower than that of the nanoparticles alone, suggesting that the drug films had a double-sustained effect on the drug release. MTT assay implied that the DBC nanoparticle film showed a higher inhibitory ratio than the film containing nanoparticles without biotin, indicating that biotin moieties in the nanoparticles played an important role in exerting a cytotoxic effect. These data demonstrate that Col/Ch/DBC nanoparticle film has the potential to be used as a localized delivery system for hydrophobic antitumor drugs.

  1. Chitosan nanoparticle based delivery systems for sustainable agriculture.

    PubMed

    Kashyap, Prem Lal; Xiang, Xu; Heiden, Patricia

    2015-01-01

    Development of technologies that improve food productivity without any adverse impact on the ecosystem is the need of hour. In this context, development of controlled delivery systems for slow and sustained release of agrochemicals or genetic materials is crucial. Chitosan has emerged as a valuable carrier for controlled delivery of agrochemicals and genetic materials because of its proven biocompatibility, biodegradability, non-toxicity, and adsorption abilities. The major advantages of encapsulating agrochemicals and genetic material in a chitosan matrix include its ability to function as a protective reservoir for the active ingredients, protecting the ingredients from the surrounding environment while they are in the chitosan domain, and then controlling their release, allowing them to serve as efficient gene delivery systems for plant transformation or controlled release of pesticides. Despite the great progress in the use of chitosan in the area of medical and pharmaceutical sciences, there is still a wide knowledge gap regarding the potential application of chitosan for encapsulation of active ingredients in agriculture. Hence, the present article describes the current status of chitosan nanoparticle-based delivery systems in agriculture, and to highlight challenges that need to be overcome.

  2. A rational approach towards the design of chitosan-based nanoparticles obtained by ionotropic gelation.

    PubMed

    Kleine-Brueggeney, H; Zorzi, G K; Fecker, T; El Gueddari, N E; Moerschbacher, B M; Goycoolea, F M

    2015-11-01

    Chitosan is a linear aminopolysaccharide that has been widely used for the formation of chitosan-based nanoparticles by ionic gelation with sodium tripolyphosphate (TPP). Often, the experimental design used to obtain these systems does not take into consideration important variables, such as the degree of acetylation (DA) and the molecular weight (Mw) of chitosan. In this work, we studied the formation of chitosan-TPP nanoparticles with chitosan samples of varying DA and Mw (DA0 ∼ 0-47% and Mw ∼ 2.5-282 kDa). We addressed the influence the degree of space occupancy and the degree of crosslinking on the physical properties of chitosan-TPP nanoparticles. Nanoparticles that comprised chitosan of DA ∼ 0-21.7% behaved differently than those made of chitosan of DA ∼ 34.7-47%. We attributed these differences to the polymer conformation and chain flexibility of the distinct chitosans in solution. Moreover, chitosan of high Mw were found to have a stronger preference for incorporating into the formed nanoparticles than do low-Mw ones, as determined by SEC-HPLC. These results open new perspectives to understand the formation of chitosan nanoparticles by the ionic gelation technique.

  3. Magnetic nanoparticle temperature estimation

    SciTech Connect

    Weaver, John B.; Rauwerdink, Adam M.; Hansen, Eric W.

    2009-05-15

    The authors present a method of measuring the temperature of magnetic nanoparticles that can be adapted to provide in vivo temperature maps. Many of the minimally invasive therapies that promise to reduce health care costs and improve patient outcomes heat tissue to very specific temperatures to be effective. Measurements are required because physiological cooling, primarily blood flow, makes the temperature difficult to predict a priori. The ratio of the fifth and third harmonics of the magnetization generated by magnetic nanoparticles in a sinusoidal field is used to generate a calibration curve and to subsequently estimate the temperature. The calibration curve is obtained by varying the amplitude of the sinusoidal field. The temperature can then be estimated from any subsequent measurement of the ratio. The accuracy was 0.3 deg. K between 20 and 50 deg. C using the current apparatus and half-second measurements. The method is independent of nanoparticle concentration and nanoparticle size distribution.

  4. Preparation of Chitosan nanoparticles and its effect on detached rice leaves infected with Pyricularia grisea.

    PubMed

    Manikandan, Appu; Sathiyabama, Muthukrishnan

    2016-03-01

    The aim of the present study was to prepare chitosan nanoparticles to evaluate their effect on protection of rice plants from blast fungus. Nanoparticles were prepared using the ionic gelation method by the interaction of Chitosan and sodium tripolyphosphate. The particle size, polydispersity index, zetapotential and structure was confirmed by DLS, FTIR, TEM and XRD. The Chitosan nanoparticle was evaluated for suppression of rice blast fungus (Pyricularia grisea) under the detached leaf condition. It is evident from our results that chitosan nanoparticle have potential in suppressing blast disease of rice which can be used further under field condition to protect rice plants from the devastating fungus.

  5. Biotemplated magnetic nanoparticle arrays.

    PubMed

    Galloway, Johanna M; Bramble, Jonathan P; Rawlings, Andrea E; Burnell, Gavin; Evans, Stephen D; Staniland, Sarah S

    2012-01-23

    Immobilized biomineralizing protein Mms6 templates the formation of uniform magnetite nanoparticles in situ when selectively patterned onto a surface. Magnetic force microscopy shows that the stable magnetite particles maintain their magnetic orientation at room temperature, and may be exchange coupled. This precision-mixed biomimetic/soft-lithography methodology offers great potential for the future of nanodevice fabrication.

  6. Biotemplated magnetic nanoparticle arrays.

    PubMed

    Galloway, Johanna M; Bramble, Jonathan P; Rawlings, Andrea E; Burnell, Gavin; Evans, Stephen D; Staniland, Sarah S

    2012-01-23

    Immobilized biomineralizing protein Mms6 templates the formation of uniform magnetite nanoparticles in situ when selectively patterned onto a surface. Magnetic force microscopy shows that the stable magnetite particles maintain their magnetic orientation at room temperature, and may be exchange coupled. This precision-mixed biomimetic/soft-lithography methodology offers great potential for the future of nanodevice fabrication. PMID:22052737

  7. Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

    PubMed

    Yu, Chen; Geng, Jianqiang; Zhuang, Yunxia; Zhao, Jian; Chu, Liqiu; Luo, Xiaoxuan; Zhao, Ying; Guo, Yanwen

    2016-11-01

    Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential. The dye adsorption characteristics of the CTS-g-PTMAAC/SC-Fe3O4 nanoparticles were determined using the food yellow 3 aqueous solutions as a model food effluent. Effect of pH of the dye solution on the adsorption of food yellow 3 was determined and compared with N-2-hydroxylpropyl trimethyl ammonium chloride chitosan coated sodium citrate-Fe3O4 (CTS-g-HTCC/SC-Fe3O4) composite magnetic nanoparticles. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and desorption and reusability of the magnetic nanoparticles were investigated. PMID:27516279

  8. Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

    PubMed

    Yu, Chen; Geng, Jianqiang; Zhuang, Yunxia; Zhao, Jian; Chu, Liqiu; Luo, Xiaoxuan; Zhao, Ying; Guo, Yanwen

    2016-11-01

    Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential. The dye adsorption characteristics of the CTS-g-PTMAAC/SC-Fe3O4 nanoparticles were determined using the food yellow 3 aqueous solutions as a model food effluent. Effect of pH of the dye solution on the adsorption of food yellow 3 was determined and compared with N-2-hydroxylpropyl trimethyl ammonium chloride chitosan coated sodium citrate-Fe3O4 (CTS-g-HTCC/SC-Fe3O4) composite magnetic nanoparticles. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and desorption and reusability of the magnetic nanoparticles were investigated.

  9. Dietary chitosan nanoparticles protect crayfish Procambarus clarkii against white spot syndrome virus (WSSV) infection.

    PubMed

    Sun, Baozhen; Quan, Haizhi; Zhu, Fei

    2016-07-01

    Chitosan nanoparticles have exhibited potential antibacterial activity or anticancer activity as their unique character. In this study, we investigated the effect of chitosan nanoparticles protect crayfish Procambarus clarkii against WSSV. Chitosan (from crab shell) nanoparticles were prepared by ultrafine milling. The physicochemical properties of the nanoparticles were determined by particle size measure, zeta potential analysis and scanning electron microscope observation. The total hemocyte count (THC), phenoloxidase (PO) and superoxide dismutase (SOD) activity were measured at days 1, 4, 9 and 12, and the survival rate was also recorded after WSSV challenge. The results showed that chitosan nanoparticles could enhance the survival rate of WSSV-challenged crayfish. And crayfish fed diets supplemented with 10 mg/g chitosan nanoparticles (65% mortality) showed a significantly higher survival rate when compared to the control group (100% mortality). The analysis of immunological parameters revealed that 10 mg/g chitosan nanoparticles showed significantly higher level of prophenoloxidase (proPO), superoxide dismutase (SOD) and total hemocyte count (THC) when compared to the control group. It was found that chitosan nanoparticles could inhibit WSSV replication in crayfish. Our results demonstrated that dietary chitosan nanoparticles effectively improve innate immunity and survival of P. clarkii challenged with WSSV. PMID:27071520

  10. Dietary chitosan nanoparticles protect crayfish Procambarus clarkii against white spot syndrome virus (WSSV) infection.

    PubMed

    Sun, Baozhen; Quan, Haizhi; Zhu, Fei

    2016-07-01

    Chitosan nanoparticles have exhibited potential antibacterial activity or anticancer activity as their unique character. In this study, we investigated the effect of chitosan nanoparticles protect crayfish Procambarus clarkii against WSSV. Chitosan (from crab shell) nanoparticles were prepared by ultrafine milling. The physicochemical properties of the nanoparticles were determined by particle size measure, zeta potential analysis and scanning electron microscope observation. The total hemocyte count (THC), phenoloxidase (PO) and superoxide dismutase (SOD) activity were measured at days 1, 4, 9 and 12, and the survival rate was also recorded after WSSV challenge. The results showed that chitosan nanoparticles could enhance the survival rate of WSSV-challenged crayfish. And crayfish fed diets supplemented with 10 mg/g chitosan nanoparticles (65% mortality) showed a significantly higher survival rate when compared to the control group (100% mortality). The analysis of immunological parameters revealed that 10 mg/g chitosan nanoparticles showed significantly higher level of prophenoloxidase (proPO), superoxide dismutase (SOD) and total hemocyte count (THC) when compared to the control group. It was found that chitosan nanoparticles could inhibit WSSV replication in crayfish. Our results demonstrated that dietary chitosan nanoparticles effectively improve innate immunity and survival of P. clarkii challenged with WSSV.

  11. MRI traceability of superparamagnetic iron oxide nanoparticle-embedded chitosan microspheres as an embolic material in rabbit uterus

    PubMed Central

    Choi, Sun Young; Kwak, Byung Kook; Shim, Hyung Jin; Lee, Jaehwi; Hong, Soon Uk; Kim, Kyung Ah

    2015-01-01

    PURPOSE We aimed to compare polyvinyl alcohol (PVA) particles with calibrated superparamagnetic iron oxide (SPIO) nanoparticle-loaded chitosan microspheres in a rabbit model, specifically regarding the relative distribution of embolic agents within the uterus based on magnetic resonance imaging (MRI) and pathological evaluation. METHODS Twelve New Zealand white rabbits underwent uterine artery embolization using either standard PVA particles (45–150 µm or 350–500 µm) or calibrated SPIO-embedded chitosan microspheres (45–150 µm or 300–500 µm). MRI and histopathological findings were compared one week after embolization. RESULTS Calibrated SPIO-loaded chitosan microspheres 45–150 µm in size were detected on T2-weighted images. On histological analysis, calibrated SPIO-embedded chitosan microspheres were found in both myometrium and endometrium, whereas PVA particles were found only in the perimyometrium or extrauterine fat pads. A proportional relationship was noted between the calibrated SPIO-embedded chitosan microsphere size and the size of the occluded artery. CONCLUSION Calibrated SPIO-embedded chitosan microspheres induced greater segmental arterial occlusion than PVA particles and showed great potential as a new embolic material. SPIO-embedded chitosan microspheres can be used to follow distribution of embolic particles through MRI studies. PMID:25333216

  12. Improved barrier and mechanical properties of novel hydroxypropyl methylcellulose edible films with chitosan/tripolyphosphate nanoparticles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chitosan/tripolyphosphate nanoparticles were prepared and incorporated in hydroxypropyl methylcellulose (HPMC) films. FT-IR and transmission electron microscopy (TEM) analyses of the nanoparticles, mechanical properties, water vapor permeability, thermal stability, scanning electron microscopy (SEM...

  13. Echogenic Glycol Chitosan Nanoparticles for Ultrasound-Triggered Cancer Theranostics.

    PubMed

    Min, Hyun Su; You, Dong Gil; Son, Sejin; Jeon, Sangmin; Park, Jae Hyung; Lee, Seulki; Kwon, Ick Chan; Kim, Kwangmeyung

    2015-01-01

    Theranostic nanoparticles hold great promise for simultaneous diagnosis of diseases, targeted drug delivery with minimal toxicity, and monitoring of therapeutic efficacy. However, one of the current challenges in developing theranostic nanoparticles is enhancing the tumor-specific targeting of both imaging probes and anticancer agents. Herein, we report the development of tumor-homing echogenic glycol chitosan-based nanoparticles (Echo-CNPs) that concurrently execute cancer-targeted ultrasound (US) imaging and US-triggered drug delivery. To construct this novel Echo-CNPs, an anticancer drug and bioinert perfluoropentane (PFP), a US gas precursor, were simultaneously encapsulated into glycol chitosan nanoparticles using the oil in water (O/W) emulsion method. The resulting Echo-CNPs had a nano-sized particle structure, composing of hydrophobic anticancer drug/PFP inner cores and a hydrophilic glycol chitosan polymer outer shell. The Echo-CNPs had a favorable hydrodynamic size of 432 nm, which is entirely different from the micro-sized core-empty conventional microbubbles (1-10 μm). Furthermore, Echo-CNPs showed the prolonged echogenicity via the sustained microbubble formation process of liquid-phase PFP at the body temperature and they also presented a US-triggered drug release profile through the external US irradiation. Interestingly, Echo-CNPs exhibited significantly increased tumor-homing ability with lower non-specific uptake by other tissues in tumor-bearing mice through the nanoparticle's enhanced permeation and retention (EPR) effect. Conclusively, theranostic Echo-CNPs are highly useful for simultaneous cancer-targeting US imaging and US-triggered delivery in cancer theranostics. PMID:26681985

  14. Echogenic Glycol Chitosan Nanoparticles for Ultrasound-Triggered Cancer Theranostics

    PubMed Central

    Min, Hyun Su; You, Dong Gil; Son, Sejin; Jeon, Sangmin; Park, Jae Hyung; Lee, Seulki; Kwon, Ick Chan; Kim, Kwangmeyung

    2015-01-01

    Theranostic nanoparticles hold great promise for simultaneous diagnosis of diseases, targeted drug delivery with minimal toxicity, and monitoring of therapeutic efficacy. However, one of the current challenges in developing theranostic nanoparticles is enhancing the tumor-specific targeting of both imaging probes and anticancer agents. Herein, we report the development of tumor-homing echogenic glycol chitosan-based nanoparticles (Echo-CNPs) that concurrently execute cancer-targeted ultrasound (US) imaging and US-triggered drug delivery. To construct this novel Echo-CNPs, an anticancer drug and bioinert perfluoropentane (PFP), a US gas precursor, were simultaneously encapsulated into glycol chitosan nanoparticles using the oil in water (O/W) emulsion method. The resulting Echo-CNPs had a nano-sized particle structure, composing of hydrophobic anticancer drug/PFP inner cores and a hydrophilic glycol chitosan polymer outer shell. The Echo-CNPs had a favorable hydrodynamic size of 432 nm, which is entirely different from the micro-sized core-empty conventional microbubbles (1-10 μm). Furthermore, Echo-CNPs showed the prolonged echogenicity via the sustained microbubble formation process of liquid-phase PFP at the body temperature and they also presented a US-triggered drug release profile through the external US irradiation. Interestingly, Echo-CNPs exhibited significantly increased tumor-homing ability with lower non-specific uptake by other tissues in tumor-bearing mice through the nanoparticle's enhanced permeation and retention (EPR) effect. Conclusively, theranostic Echo-CNPs are highly useful for simultaneous cancer-targeting US imaging and US-triggered delivery in cancer theranostics. PMID:26681985

  15. Synthesis and in vitro antifungal efficacy of oleoyl-chitosan nanoparticles against plant pathogenic fungi.

    PubMed

    Xing, Ke; Shen, Xiaoqiang; Zhu, Xiao; Ju, Xiuyun; Miao, Xiangmin; Tian, Jun; Feng, Zhaozhong; Peng, Xue; Jiang, Jihong; Qin, Sheng

    2016-01-01

    An antifungal dispersion system was prepared by oleoyl-chitosan (O-chitosan) nanoparticles, and the antifungal activity against several plant pathogenic fungi was investigated. Under scanning electron microscopy, the nanoparticles formulation appeared to be uniform with almost spherical shape. The particle size of nanoparticles was around 296.962 nm. Transmission electron microscopy observation showed that nanoparticles could be well distributed in potato dextrose agar medium. Mycelium growth experiment demonstrated that Nigrospora sphaerica, Botryosphaeria dothidea, Nigrospora oryzae and Alternaria tenuissima were chitosan-sensitive, while Gibberella zeae and Fusarium culmorum were chitosan-resistant. The antifungal index was increased as the concentration of nanoparticles increased for chitosan-sensitive fungi. Fatty acid analyses revealed that plasma membranes of chitosan-sensitive fungi were shown to have lower levels of unsaturated fatty acid than chitosan-resistant fungi. Phylogenetic analysis based on ITS gene sequences indicated that two chitosan-resistant fungi had a near phylogenetic relationship. Results showed that O-chitosan nanoparticles could be a useful alternative for controlling pathogenic fungi in agriculture.

  16. Orally Administered Chitosan-Coated Polycaprolactone Nanoparticles Containing Curcumin Attenuate Metastatic Melanoma in the Lungs.

    PubMed

    Loch-Neckel, Gecioni; Santos-Bubniak, Lorena; Mazzarino, Letícia; Jacques, Amanda V; Moccelin, Bárbara; Santos-Silva, Maria Claúdia; Lemos-Senna, Elenara

    2015-10-01

    The study was aimed to evaluate the effect of orally administered chitosan-coated nanoparticles containing curcumin on metastatic melanoma. Chitosan-coated nanoparticles containing curcumin were prepared, and their antimetastatic activity was investigated both in vitro and in vivo. Curcumin decreased cell viability and induced apoptosis of B16F10 melanoma cells. We observed that curcumin significantly decreased the expression of metalloproteinases, which are known to be associated with migration and proliferation of cancer cells. Importantly, treatment with chitosan-coated nanoparticles containing curcumin decreased pulmonary tumor formation in a murine model of experimental metastasis. Histological analyses confirmed the macroscopic results in which lungs of mice treated with curcumin-loaded chitosan-coated polycaprolactone nanoparticles had only a few small nodules and most of them were free of melanoma. Our findings indicate that nanoparticles coated with the mucoadhesive polymer chitosan containing curcumin may be a promising approach and/or intervention for the treatment of malignant melanoma.

  17. Ligand fishing using new chitosan based functionalized Androgen Receptor magnetic particles.

    PubMed

    Marszałł, Michał Piotr; Sroka, Wiktor Dariusz; Sikora, Adam; Chełminiak, Dorota; Ziegler-Borowska, Marta; Siódmiak, Tomasz; Moaddel, Ruin

    2016-08-01

    Superparamagnetic nanoparticles with chemically modified chitosan has been proposed as a potential support for the immobilization of the androgen receptor (AR). The study involved comparison of different AR carriers like commercially available magnetic beads coated with silica (BcMag) and chitosan coated nanoparticles with different amount of amino groups. The immobilization was carried out through covalent immobilization of the AR through the terminal amino group or through available carboxylic acids. The initial characterization of the AR coated magnetic beads was carried out with dihydrotestosterone, a known AR ligand. Subsequently, chitosan modified nanporticles with long-distanced primary amino groups (Fe3O4CS-(NH2)3) (upto 8.34mM/g) were used for further study to isolate known AR ligands (bicalutamide, flutamide, hydroxyflutamide and levonogestrel) from a mixture of tested compounds in ammonium acetate buffer [10mM, pH 7.4]. The results showed that the selected nanoparticles are a promising semi-quantitative tool for the identification of high affinity compounds to AR and might be of special importance in the identification of novel agonists or antiandrogens. PMID:27156644

  18. Preparation Fe3O4@chitosan magnetic particles for covalent immobilization of lipase from Thermomyces lanuginosus.

    PubMed

    Wang, Xiang-Yu; Jiang, Xiao-Ping; Li, Yue; Zeng, Sha; Zhang, Ye-Wang

    2015-04-01

    Magnetic Fe3O4@chitosan nanoparticles were prepared by a simple in situ co-precipitation method and characterized by transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). The prepared Fe3O4@chitosan nanoparticles were used for covalent immobilization of lipase from Thermomyces lanuginosus by chemical conjugation after electrostatic entrapment (CCEE). The optimal immobilization conditions were obtained as follows: enzyme/support 19.8 mg/g, pH 5.0, time 4h and temperature 30 °C. Under these conditions, a high immobilization efficiency of 75% and a protein loading of 16.8 mg/g-support were obtained. Broad pH tolerance and high thermostability could be achieved by immobilization. The immobilized lipase retained 70% initial activity after ten cycles. Kinetic parameters Vmax and Km of free and immobilized lipase were determined as 5.72 mM/min, 2.26 mM/min and 21.25 mM, 28.73 mM, respectively. Ascorbyl palmitate synthesis with immobilized lipase was carried out in tert-butanol at 50 °C, and the conversion of ascorbic acid was obtained higher than 50%. These results showed that the immobilization of lipase onto magnetic chitosan nanoparticles by the method of CCEE is an efficient and simple way for preparation of stable lipase. PMID:25603148

  19. Magnetoacoustic Sensing of Magnetic Nanoparticles.

    PubMed

    Kellnberger, Stephan; Rosenthal, Amir; Myklatun, Ahne; Westmeyer, Gil G; Sergiadis, George; Ntziachristos, Vasilis

    2016-03-11

    The interaction of magnetic nanoparticles and electromagnetic fields can be determined through electrical signal induction in coils due to magnetization. However, the direct measurement of instant electromagnetic energy absorption by magnetic nanoparticles, as it relates to particle characterization or magnetic hyperthermia studies, has not been possible so far. We introduce the theory of magnetoacoustics, predicting the existence of second harmonic pressure waves from magnetic nanoparticles due to energy absorption from continuously modulated alternating magnetic fields. We then describe the first magnetoacoustic system reported, based on a fiber-interferometer pressure detector, necessary for avoiding electric interference. The magnetoacoustic system confirmed the existence of previously unobserved second harmonic magnetoacoustic responses from solids, magnetic nanoparticles, and nanoparticle-loaded cells, exposed to continuous wave magnetic fields at different frequencies. We discuss how magnetoacoustic signals can be employed as a nanoparticle or magnetic field sensor for biomedical and environmental applications.

  20. Magnetoacoustic Sensing of Magnetic Nanoparticles.

    PubMed

    Kellnberger, Stephan; Rosenthal, Amir; Myklatun, Ahne; Westmeyer, Gil G; Sergiadis, George; Ntziachristos, Vasilis

    2016-03-11

    The interaction of magnetic nanoparticles and electromagnetic fields can be determined through electrical signal induction in coils due to magnetization. However, the direct measurement of instant electromagnetic energy absorption by magnetic nanoparticles, as it relates to particle characterization or magnetic hyperthermia studies, has not been possible so far. We introduce the theory of magnetoacoustics, predicting the existence of second harmonic pressure waves from magnetic nanoparticles due to energy absorption from continuously modulated alternating magnetic fields. We then describe the first magnetoacoustic system reported, based on a fiber-interferometer pressure detector, necessary for avoiding electric interference. The magnetoacoustic system confirmed the existence of previously unobserved second harmonic magnetoacoustic responses from solids, magnetic nanoparticles, and nanoparticle-loaded cells, exposed to continuous wave magnetic fields at different frequencies. We discuss how magnetoacoustic signals can be employed as a nanoparticle or magnetic field sensor for biomedical and environmental applications. PMID:27015511

  1. Formation mechanism of monodisperse, low molecular weight chitosan nanoparticles by ionic gelation technique.

    PubMed

    Fan, Wen; Yan, Wei; Xu, Zushun; Ni, Hong

    2012-02-01

    Chitosan nanoparticles have been extensively studied for drug and gene delivery. In this paper, monodisperse, low molecular weight (LMW) chitosan nanoparticles were prepared by a novel method based on ionic gelation using sodium tripolyphosphate (TPP) as cross-linking agent. The objective of this study was to solve the problem of preparation of chitosan/TPP nanoparticles with high degree of monodispersity and stability, and investigate the effect of various parameters on the formation of LMW chitosan/TPP nanoparticles. It was found that the particle size distribution of the nanoparticles could be significantly narrowed by a combination of decreasing the concentration of acetic acid and reducing the ambient temperature during cross-linking process. The optimized nanoparticles exhibited a mean hydrodynamic diameter of 138 nm with a polydispersity index (PDI) of 0.026 and a zeta potential of +35 mV, the nanoparticles had good storage stability at room temperature up to at least 20 days.

  2. Ultraviolet-assisted synthesis of polyacrylamide-grafted chitosan nanoparticles and flocculation performance.

    PubMed

    Ma, Jiangya; Fu, Kun; Shi, Jun; Sun, Yongjun; Zhang, Xinxi; Ding, Lei

    2016-10-20

    In the present work, a new flocculant, polyacrylamide-grafted chitosan nanoparticles (NCS-g-PAM), was synthesized by the copolymerization of acrylamide (AM) and chitosan nanoparticle (NCS) under ultraviolet irradiation using 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone as photo-initiator. The NCS was prepared by the ionic gelation between chitosan and sodium tripolyphosphate. The structure and morphology of NCS-g-PAM were characterized by Fourier Transform Infraredspectroscopy (FT-IR), X-ray diffraction, (1)H-nuclear magnetic resonance spectrometry, scanning electron microscopy, and thermogravimetric analysis. The factors affecting the intrinsic viscosity and the yield of copolymer were studied, which showed that the optimum conditions for the synthesis of NCS-g-PAM were mAM:mNCS=8:1, 0.15g of initiator dosage, mCS:mTPP=4.5:1, 1min of ultrasonication time, 4h of illumination time, and 30min of stirring time. The NCS-g-PAM was found to be more effective than NC-g-PAM in the flocculation of both kaolin suspension and Cu(2+) simulated wastewater. With 5mg/L of polyaluminium chloride (PAC) coordinated and 1mg/L of NCS-g-PAM it was confirmed to be appropriate for flocculating kaolin suspension. PMID:27474601

  3. DNA templated magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Kinsella, Joseph M.

    Recent discoveries in nanoscience are predicted to potentially revolutionize future technologies in an extensive number of fields. These developments are contingent upon discovering new and often unconventional methods to synthesize and control nanoscale components. Nature provides several examples of working nanotechnology such as the use of programmed self assembly to build and deconstruct complex molecular systems. We have adopted a method to control the one dimensional assembly of magnetic nanoparticles using DNA as a scaffold molecule. With this method we have demonstrated the ability to organize 5 nm particles into chains that stretch up to ˜20 mum in length. One advantage of using DNA compared is the ability of the molecule to interact with other biomolecules. After assembling particles onto DNA we have been able to cleave the molecule into smaller fragments using restriction enzymes. Using ligase enzymes we have re-connected these fragments, coated with either gold or iron oxide, to form long one-dimensional arrangements of the two different types of nanoparticles on a single molecular guide. We have also created a sensitive magnetic field sensor by incorporating magnetic nanoparticle coated DNA strands with microfabricated electrodes. The IV characteristics of the aligned nanoparticles are dependant on the magnitude of an externally applied magnetic field. This transport phenomenon known as tunneling magnetoresistance (TMR) shows room temperature resistance of our devices over 80% for cobalt ferrite coated DNA when a field of 20 kOe is applied. In comparison, studies using two dimensional nanoparticle films of irox oxides xii only exhibit a 35% MR effect. Confinement into one dimension using the DNA guide produces a TMR mechanism which produces significant increases in magnetoresistance. This property can be utilized for applications in magnetic field sensing, data storage, and logic elements.

  4. Modified-chitosan nanoparticles: Novel drug delivery systems improve oral bioavailability of doxorubicin.

    PubMed

    Khdair, Ayman; Hamad, Islam; Alkhatib, Hatim; Bustanji, Yasser; Mohammad, Mohammad; Tayem, Rabab; Aiedeh, Khaled

    2016-10-10

    The efficacy of most anticancer drugs is highly limited in vivo due mainly to poor pharmacokinetics behavior including poor bioavailability after extravascular administration. We have developed novel chitosan-modified polymeric nanoparticles for oral as well as i.v. administration. Nanoparticles were developed utilizing the double emulsion solvent evaporation technique for sustained delivery of various anticancer drugs. Chitosan diacetate (CDA) and chitosan triacetate (CTA) polymers were previously modified in our laboratory and used as novel matrix. Nanoparticles, loaded with various anticancer drugs, were characterized for particle size using dynamic light scattering as well as transmission electron microscopy and net surface charge using dynamic light scattering. Particles size was below 100nm in diameter and zeta potential ranged - (25-30). Encapsulation efficiency of anticancer drugs varied considerably and was dependent on the physicochemical characteristics of the encapsulated drug. However, chitosan triacetate nanoparticles showed relatively higher encapsulation efficiency than chitosan diacetate nanoparticles. In vitro release of encapsulated drugs was sustained over a period of 14days. Nanoparticles enhanced cellular accumulation of encapsulated drugs, compared to the free drugs, in vitro in MCF-7 and Caco-II tumor cell lines. In conclusion, diacetate and triacetate chitosan are novel polymers that can be used to formulate nanoparticles which efficiently encapsulated anticancer drugs, and sustained the release and enhanced tumor cellular uptake of these drugs. Further, chitosan triacetate nanoparticles enhanced oral bioavailability of doxorubicin. CDA and CTA nanoparticles can be used to efficiently deliver anticancer drugs and improve their in vivo profile. PMID:27473308

  5. Transdermal delivery of propranolol hydrochloride through chitosan nanoparticles dispersed in mucoadhesive gel.

    PubMed

    Al-Kassas, Raida; Wen, Jingyuan; Cheng, Angel En-Miao; Kim, Amy Moon-Jung; Liu, Stephanie Sze Mei; Yu, Joohee

    2016-11-20

    This study aimed at improving the systemic bioavailability of propranolol-HCl by the design of transdermal drug delivery system based on chitosan nanoparticles dispersed into gels. Chitosan nanoparticles were prepared by ionic gelation technique using tripolyphosphate (TPP) as a cross-linking agent. Characterization of the nanoparticles was focused on particle size, zeta potential, surface texture and morphology, and drug encapsulation efficiency. The prepared freeze dried chitosan nanoparticles were dispersed into gels made of poloxamer and carbopol and the rheological behaviour and the adhesiveness of the gels were investigated. The results showed that smallest propranolol loaded chitosan nanoparticles were achieved with 0.2% chitosan and 0.05% TPP. Nanoparticles were stable in suspension with a zeta potential (ZP) above ±30mV to prevent aggregation of the colloid. Zeta potential was found to increase with increasing chitosan concentration due to its cationic nature. At least 70% of entrapment efficiency and drug loading were achieved for all prepared nanoparticles. When chitosan nanoparticles dispersed into gel consisting of poloxamer and carbopol, the resultant formulation exhibited thixotropic behaviour with a prolonged drug release properties as shown by the permeation studies through pig ear skin. Our study demonstrated that the designed nanoparticles-gel transdermal delivery system has a potential to improve the systemic bioavailability and the therapeutic efficacy of propranolol-HCl. PMID:27561485

  6. Development of drug-loaded chitosan-vanillin nanoparticles and its cytotoxicity against HT-29 cells.

    PubMed

    Li, Pu-Wang; Wang, Guang; Yang, Zi-Ming; Duan, Wei; Peng, Zheng; Kong, Ling-Xue; Wang, Qing-Huang

    2016-01-01

    Chitosan as a natural polysaccharide derived from chitin of arthropods like shrimp and crab, attracts much interest due to its inherent properties, especially for application in biomedical materials. Presently, biodegradable and biocompatible chitosan nanoparticles are attractive for drug delivery. However, some physicochemical characteristics of chitosan nanoparticles still need to be further improved in practice. In this work, chitosan nanoparticles were produced by crosslinking chitosan with 3-methoxy-4-hydroxybenzaldehyde (vanillin) through a Schiff reaction. Chitosan nanoparticles were 200-250 nm in diameter with smooth surface and were negatively charged with a zeta potential of - 17.4 mV in neutral solution. Efficient drug loading and drug encapsulation were achieved using 5-fluorouracil as a model of hydrophilic drug. Drug release from the nanoparticles was constant and controllable. The in vitro cytotoxicity against HT-29 cells and cellular uptake of the chitosan nanoparticles were evaluated by methyl thiazolyl tetrazolium method, confocal laser scanning microscope and flow cytometer, respectively. The results indicate that the chitosan nanoparticles crosslinked with vanillin are a promising vehicle for the delivery of anticancer drugs.

  7. Synthesis, characterization, and controlled release of selenium nanoparticles stabilized by chitosan of different molecular weights.

    PubMed

    Zhang, Chunyue; Zhai, Xiaona; Zhao, Guanghua; Ren, Fazheng; Leng, Xiaojing

    2015-12-10

    Chitosan-stabilized selenium nanoparticles (SeNPs) have been reported, but there is no information on the effect of the chitosan molecular weight on the structure, stability, and selenium release properties of the SeNPs. Herein, we compared the uniform Se(0) spherical nanoparticles prepared through the reduction of seleninic acid with ascorbic acid in the presence of chitosan with different molecular weights (Mws). We found that both low and high molecular weight chitosan-stabilized selenium nanoparticles exhibited core-shell microstructures with a size of about 103 nm after 30 days growing through the "bottom-up approach" and "top-down approach," respectively. Moreover, both chitosan SeNPs processed excellent stability towards pH and enzyme treatment. In contrast, selenium was easily released to different extents from these two chitosan SeNPs upon treatment with different free radicals. This makes these materials potentially useful as oral antioxidant supplements. PMID:26428112

  8. Synthesis, characterization, and controlled release of selenium nanoparticles stabilized by chitosan of different molecular weights.

    PubMed

    Zhang, Chunyue; Zhai, Xiaona; Zhao, Guanghua; Ren, Fazheng; Leng, Xiaojing

    2015-12-10

    Chitosan-stabilized selenium nanoparticles (SeNPs) have been reported, but there is no information on the effect of the chitosan molecular weight on the structure, stability, and selenium release properties of the SeNPs. Herein, we compared the uniform Se(0) spherical nanoparticles prepared through the reduction of seleninic acid with ascorbic acid in the presence of chitosan with different molecular weights (Mws). We found that both low and high molecular weight chitosan-stabilized selenium nanoparticles exhibited core-shell microstructures with a size of about 103 nm after 30 days growing through the "bottom-up approach" and "top-down approach," respectively. Moreover, both chitosan SeNPs processed excellent stability towards pH and enzyme treatment. In contrast, selenium was easily released to different extents from these two chitosan SeNPs upon treatment with different free radicals. This makes these materials potentially useful as oral antioxidant supplements.

  9. Multicomponent, peptide-targeted glycol chitosan nanoparticles containing ferrimagnetic iron oxide nanocubes for bladder cancer multimodal imaging.

    PubMed

    Key, Jaehong; Dhawan, Deepika; Cooper, Christy L; Knapp, Deborah W; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Park, Kinam; Decuzzi, Paolo; Leary, James F

    2016-01-01

    While current imaging modalities, such as magnetic resonance imaging (MRI), computed tomography, and positron emission tomography, play an important role in detecting tumors in the body, no single-modality imaging possesses all the functions needed for a complete diagnostic imaging, such as spatial resolution, signal sensitivity, and tissue penetration depth. For this reason, multimodal imaging strategies have become promising tools for advanced biomedical research and cancer diagnostics and therapeutics. In designing multimodal nanoparticles, the physicochemical properties of the nanoparticles should be engineered so that they successfully accumulate at the tumor site and minimize nonspecific uptake by other organs. Finely altering the nano-scale properties can dramatically change the biodistribution and tumor accumulation of nanoparticles in the body. In this study, we engineered multimodal nanoparticles for both MRI, by using ferrimagnetic nanocubes (NCs), and near infrared fluorescence imaging, by using cyanine 5.5 fluorescence molecules. We changed the physicochemical properties of glycol chitosan nanoparticles by conjugating bladder cancer-targeting peptides and loading many ferrimagnetic iron oxide NCs per glycol chitosan nanoparticle to improve MRI contrast. The 22 nm ferrimagnetic NCs were stabilized in physiological conditions by encapsulating them within modified chitosan nanoparticles. The multimodal nanoparticles were compared with in vivo MRI and near infrared fluorescent systems. We demonstrated significant and important changes in the biodistribution and tumor accumulation of nanoparticles with different physicochemical properties. Finally, we demonstrated that multimodal nanoparticles specifically visualize small tumors and show minimal accumulation in other organs. This work reveals the importance of finely modulating physicochemical properties in designing multimodal nanoparticles for bladder cancer imaging. PMID:27621615

  10. Multicomponent, peptide-targeted glycol chitosan nanoparticles containing ferrimagnetic iron oxide nanocubes for bladder cancer multimodal imaging

    PubMed Central

    Key, Jaehong; Dhawan, Deepika; Cooper, Christy L; Knapp, Deborah W; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Park, Kinam; Decuzzi, Paolo; Leary, James F

    2016-01-01

    While current imaging modalities, such as magnetic resonance imaging (MRI), computed tomography, and positron emission tomography, play an important role in detecting tumors in the body, no single-modality imaging possesses all the functions needed for a complete diagnostic imaging, such as spatial resolution, signal sensitivity, and tissue penetration depth. For this reason, multimodal imaging strategies have become promising tools for advanced biomedical research and cancer diagnostics and therapeutics. In designing multimodal nanoparticles, the physicochemical properties of the nanoparticles should be engineered so that they successfully accumulate at the tumor site and minimize nonspecific uptake by other organs. Finely altering the nano-scale properties can dramatically change the biodistribution and tumor accumulation of nanoparticles in the body. In this study, we engineered multimodal nanoparticles for both MRI, by using ferrimagnetic nanocubes (NCs), and near infrared fluorescence imaging, by using cyanine 5.5 fluorescence molecules. We changed the physicochemical properties of glycol chitosan nanoparticles by conjugating bladder cancer-targeting peptides and loading many ferrimagnetic iron oxide NCs per glycol chitosan nanoparticle to improve MRI contrast. The 22 nm ferrimagnetic NCs were stabilized in physiological conditions by encapsulating them within modified chitosan nanoparticles. The multimodal nanoparticles were compared with in vivo MRI and near infrared fluorescent systems. We demonstrated significant and important changes in the biodistribution and tumor accumulation of nanoparticles with different physicochemical properties. Finally, we demonstrated that multimodal nanoparticles specifically visualize small tumors and show minimal accumulation in other organs. This work reveals the importance of finely modulating physicochemical properties in designing multimodal nanoparticles for bladder cancer imaging.

  11. Multicomponent, peptide-targeted glycol chitosan nanoparticles containing ferrimagnetic iron oxide nanocubes for bladder cancer multimodal imaging

    PubMed Central

    Key, Jaehong; Dhawan, Deepika; Cooper, Christy L; Knapp, Deborah W; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Park, Kinam; Decuzzi, Paolo; Leary, James F

    2016-01-01

    While current imaging modalities, such as magnetic resonance imaging (MRI), computed tomography, and positron emission tomography, play an important role in detecting tumors in the body, no single-modality imaging possesses all the functions needed for a complete diagnostic imaging, such as spatial resolution, signal sensitivity, and tissue penetration depth. For this reason, multimodal imaging strategies have become promising tools for advanced biomedical research and cancer diagnostics and therapeutics. In designing multimodal nanoparticles, the physicochemical properties of the nanoparticles should be engineered so that they successfully accumulate at the tumor site and minimize nonspecific uptake by other organs. Finely altering the nano-scale properties can dramatically change the biodistribution and tumor accumulation of nanoparticles in the body. In this study, we engineered multimodal nanoparticles for both MRI, by using ferrimagnetic nanocubes (NCs), and near infrared fluorescence imaging, by using cyanine 5.5 fluorescence molecules. We changed the physicochemical properties of glycol chitosan nanoparticles by conjugating bladder cancer-targeting peptides and loading many ferrimagnetic iron oxide NCs per glycol chitosan nanoparticle to improve MRI contrast. The 22 nm ferrimagnetic NCs were stabilized in physiological conditions by encapsulating them within modified chitosan nanoparticles. The multimodal nanoparticles were compared with in vivo MRI and near infrared fluorescent systems. We demonstrated significant and important changes in the biodistribution and tumor accumulation of nanoparticles with different physicochemical properties. Finally, we demonstrated that multimodal nanoparticles specifically visualize small tumors and show minimal accumulation in other organs. This work reveals the importance of finely modulating physicochemical properties in designing multimodal nanoparticles for bladder cancer imaging. PMID:27621615

  12. Biocompatible and target specific hydrophobically modified glycol chitosan nanoparticles.

    PubMed

    Yin, Wei; Li, Weiyi; Rubenstein, David A; Meng, Yizhi

    2016-01-01

    Cardiovascular disease is the leading cause of death in the United States. Atherosclerosis is a major cause for cardiovascular diseases. Drugs that treat atherosclerosis usually act nonspecifically. To enhance drug delivery specificity, the authors developed a hydrophobically modified glycol chitosan (HGC) nanoparticle that can specifically target activated endothelial cells. The biocompatibility of these nanoparticles toward red blood cells and platelets was evaluated through hemolysis, platelet activation, platelet thrombogenicity, and platelet aggregation assays. The biocompatibility of these nanoparticles toward vascular endothelial cells was evaluated by their effects on endothelial cell growth, metabolic activity, and activation. The results demonstrated that HGC nanoparticles did not cause hemolysis, or affect platelet activation, thrombogenicity, and aggregation capability in vitro. The nanoparticles did not impair vascular endothelial cell growth or metabolic activities in vitro, and did not cause cell activation either. When conjugated with intercellular adhesion molecular 1 antibodies, HGC nanoparticles showed a significantly increased targeting specificity toward activated endothelial cells. These results suggested that HGC nanoparticles are likely compatible toward red blood cells, platelets, and endothelial cells, and they can be potentially used to identify activated endothelial cells at atherosclerotic lesion areas within the vasculature, and deliver therapeutic drugs.

  13. Thiolated chitosan-modified PLA-PCL-TPGS nanoparticles for oral chemotherapy of lung cancer

    NASA Astrophysics Data System (ADS)

    Jiang, Liqin; Li, Xuemin; Liu, Lingrong; Zhang, Qiqing

    2013-02-01

    Oral chemotherapy is a key step towards `chemotherapy at home', a dream of cancer patients, which will radically change the clinical practice of chemotherapy and greatly improve the quality of life of the patients. In this research, three types of nanoparticle formulation from commercial PCL and self-synthesized d-α-tocopheryl polyethylene glycol 1000 succinate (PLA-PCL-TPGS) random copolymer were prepared in this research for oral delivery of antitumor agents, including thiolated chitosan-modified PCL nanoparticles, unmodified PLA-PCL-TPGS nanoparticles, and thiolated chitosan-modified PLA-PCL-TPGS nanoparticles. Firstly, the PLA-PCL-TPGS random copolymer was synthesized and characterized. Thiolated chitosan greatly increases its mucoadhesiveness and permeation properties, thus increasing the chances of nanoparticle uptake by the gastrointestinal mucosa and improving drug absorption. The PLA-PCL-TPGS nanoparticles were found by FESEM that they are of spherical shape and around 200 nm in diameter. The surface charge of PLA-PCL-TPGS nanoparticles was reversed from anionic to cationic after thiolated chitosan modification. The thiolated chitosan-modified PLA-PCL-TPGS nanoparticles have significantly higher level of the cell uptake than that of thiolated chitosan-modified PLGA nanoparticles and unmodified PLA-PCL-TPGS nanoparticles. In vitro cell viability studies showed advantages of the thiolated chitosan-modified PLA-PCL-TPGS nanoparticles over Taxol® in terms of cytotoxicity against A549 cells. It seems that the mucoadhesive nanoparticles can increase paclitaxel transport by opening tight junctions and bypassing the efflux pump of P-glycoprotein. In conclusion, PLA-PCL-TPGS nanoparticles modified by thiolated chitosan could enhance the cellular uptake and cytotoxicity, which revealed a potential application for oral chemotherapy of lung cancer.

  14. Thiolated chitosan-modified PLA-PCL-TPGS nanoparticles for oral chemotherapy of lung cancer.

    PubMed

    Jiang, Liqin; Li, Xuemin; Liu, Lingrong; Zhang, Qiqing

    2013-02-09

    Oral chemotherapy is a key step towards 'chemotherapy at home', a dream of cancer patients, which will radically change the clinical practice of chemotherapy and greatly improve the quality of life of the patients. In this research, three types of nanoparticle formulation from commercial PCL and self-synthesized d-α-tocopheryl polyethylene glycol 1000 succinate (PLA-PCL-TPGS) random copolymer were prepared in this research for oral delivery of antitumor agents, including thiolated chitosan-modified PCL nanoparticles, unmodified PLA-PCL-TPGS nanoparticles, and thiolated chitosan-modified PLA-PCL-TPGS nanoparticles. Firstly, the PLA-PCL-TPGS random copolymer was synthesized and characterized. Thiolated chitosan greatly increases its mucoadhesiveness and permeation properties, thus increasing the chances of nanoparticle uptake by the gastrointestinal mucosa and improving drug absorption. The PLA-PCL-TPGS nanoparticles were found by FESEM that they are of spherical shape and around 200 nm in diameter. The surface charge of PLA-PCL-TPGS nanoparticles was reversed from anionic to cationic after thiolated chitosan modification. The thiolated chitosan-modified PLA-PCL-TPGS nanoparticles have significantly higher level of the cell uptake than that of thiolated chitosan-modified PLGA nanoparticles and unmodified PLA-PCL-TPGS nanoparticles. In vitro cell viability studies showed advantages of the thiolated chitosan-modified PLA-PCL-TPGS nanoparticles over Taxol® in terms of cytotoxicity against A549 cells. It seems that the mucoadhesive nanoparticles can increase paclitaxel transport by opening tight junctions and bypassing the efflux pump of P-glycoprotein. In conclusion, PLA-PCL-TPGS nanoparticles modified by thiolated chitosan could enhance the cellular uptake and cytotoxicity, which revealed a potential application for oral chemotherapy of lung cancer.

  15. Thiolated chitosan-modified PLA-PCL-TPGS nanoparticles for oral chemotherapy of lung cancer.

    PubMed

    Jiang, Liqin; Li, Xuemin; Liu, Lingrong; Zhang, Qiqing

    2013-01-01

    Oral chemotherapy is a key step towards 'chemotherapy at home', a dream of cancer patients, which will radically change the clinical practice of chemotherapy and greatly improve the quality of life of the patients. In this research, three types of nanoparticle formulation from commercial PCL and self-synthesized d-α-tocopheryl polyethylene glycol 1000 succinate (PLA-PCL-TPGS) random copolymer were prepared in this research for oral delivery of antitumor agents, including thiolated chitosan-modified PCL nanoparticles, unmodified PLA-PCL-TPGS nanoparticles, and thiolated chitosan-modified PLA-PCL-TPGS nanoparticles. Firstly, the PLA-PCL-TPGS random copolymer was synthesized and characterized. Thiolated chitosan greatly increases its mucoadhesiveness and permeation properties, thus increasing the chances of nanoparticle uptake by the gastrointestinal mucosa and improving drug absorption. The PLA-PCL-TPGS nanoparticles were found by FESEM that they are of spherical shape and around 200 nm in diameter. The surface charge of PLA-PCL-TPGS nanoparticles was reversed from anionic to cationic after thiolated chitosan modification. The thiolated chitosan-modified PLA-PCL-TPGS nanoparticles have significantly higher level of the cell uptake than that of thiolated chitosan-modified PLGA nanoparticles and unmodified PLA-PCL-TPGS nanoparticles. In vitro cell viability studies showed advantages of the thiolated chitosan-modified PLA-PCL-TPGS nanoparticles over Taxol® in terms of cytotoxicity against A549 cells. It seems that the mucoadhesive nanoparticles can increase paclitaxel transport by opening tight junctions and bypassing the efflux pump of P-glycoprotein. In conclusion, PLA-PCL-TPGS nanoparticles modified by thiolated chitosan could enhance the cellular uptake and cytotoxicity, which revealed a potential application for oral chemotherapy of lung cancer. PMID:23394588

  16. Thiolated chitosan-modified PLA-PCL-TPGS nanoparticles for oral chemotherapy of lung cancer

    PubMed Central

    2013-01-01

    Oral chemotherapy is a key step towards ‘chemotherapy at home’, a dream of cancer patients, which will radically change the clinical practice of chemotherapy and greatly improve the quality of life of the patients. In this research, three types of nanoparticle formulation from commercial PCL and self-synthesized d-α-tocopheryl polyethylene glycol 1000 succinate (PLA-PCL-TPGS) random copolymer were prepared in this research for oral delivery of antitumor agents, including thiolated chitosan-modified PCL nanoparticles, unmodified PLA-PCL-TPGS nanoparticles, and thiolated chitosan-modified PLA-PCL-TPGS nanoparticles. Firstly, the PLA-PCL-TPGS random copolymer was synthesized and characterized. Thiolated chitosan greatly increases its mucoadhesiveness and permeation properties, thus increasing the chances of nanoparticle uptake by the gastrointestinal mucosa and improving drug absorption. The PLA-PCL-TPGS nanoparticles were found by FESEM that they are of spherical shape and around 200 nm in diameter. The surface charge of PLA-PCL-TPGS nanoparticles was reversed from anionic to cationic after thiolated chitosan modification. The thiolated chitosan-modified PLA-PCL-TPGS nanoparticles have significantly higher level of the cell uptake than that of thiolated chitosan-modified PLGA nanoparticles and unmodified PLA-PCL-TPGS nanoparticles. In vitro cell viability studies showed advantages of the thiolated chitosan-modified PLA-PCL-TPGS nanoparticles over Taxol® in terms of cytotoxicity against A549 cells. It seems that the mucoadhesive nanoparticles can increase paclitaxel transport by opening tight junctions and bypassing the efflux pump of P-glycoprotein. In conclusion, PLA-PCL-TPGS nanoparticles modified by thiolated chitosan could enhance the cellular uptake and cytotoxicity, which revealed a potential application for oral chemotherapy of lung cancer. PMID:23394588

  17. Multifunctional glucose biosensors from Fe3O4 nanoparticles modified chitosan/graphene nanocomposites

    NASA Astrophysics Data System (ADS)

    Zhang, Wenjing; Li, Xiaojian; Zou, Ruitao; Wu, Huizi; Shi, Haiyan; Yu, Shanshan; Liu, Yong

    2015-06-01

    Novel water-dispersible and biocompatible chitosan-functionalized graphene (CG) has been prepared by a one-step ball milling of carboxylic chitosan and graphite. Presence of nitrogen (from chitosan) at the surface of graphene enables the CG to be an outstanding catalyst for the electrochemical biosensors. The resulting CG shows lower ID/IG ratio in the Raman spectrum than other nitrogen-containing graphene prepared using different techniques. Magnetic Fe3O4 nanoparticles (MNP) are further introduced into the as-synthesized CG for multifunctional applications beyond biosensors such as magnetic resonance imaging (MRI). Carboxyl groups from CG is used to directly immobilize glucose oxidase (GOx) via covalent linkage while incorporation of MNP further facilitated enzyme loading and other unique properties. The resulting biosensor exhibits a good glucose detection response with a detection limit of 16 μM, a sensitivity of 5.658 mA/cm2/M, and a linear detection range up to 26 mM glucose. Formation of the multifunctional MNP/CG nanocomposites provides additional advantages for applications in more clinical areas such as in vivo biosensors and MRI agents.

  18. Multifunctional glucose biosensors from Fe₃O₄ nanoparticles modified chitosan/graphene nanocomposites.

    PubMed

    Zhang, Wenjing; Li, Xiaojian; Zou, Ruitao; Wu, Huizi; Shi, Haiyan; Yu, Shanshan; Liu, Yong

    2015-01-01

    Novel water-dispersible and biocompatible chitosan-functionalized graphene (CG) has been prepared by a one-step ball milling of carboxylic chitosan and graphite. Presence of nitrogen (from chitosan) at the surface of graphene enables the CG to be an outstanding catalyst for the electrochemical biosensors. The resulting CG shows lower ID/IG ratio in the Raman spectrum than other nitrogen-containing graphene prepared using different techniques. Magnetic Fe3O4 nanoparticles (MNP) are further introduced into the as-synthesized CG for multifunctional applications beyond biosensors such as magnetic resonance imaging (MRI). Carboxyl groups from CG is used to directly immobilize glucose oxidase (GOx) via covalent linkage while incorporation of MNP further facilitated enzyme loading and other unique properties. The resulting biosensor exhibits a good glucose detection response with a detection limit of 16 μM, a sensitivity of 5.658 mA/cm(2)/M, and a linear detection range up to 26 mM glucose. Formation of the multifunctional MNP/CG nanocomposites provides additional advantages for applications in more clinical areas such as in vivo biosensors and MRI agents. PMID:26052919

  19. Synthesis and anti-fungal effect of silver nanoparticles-chitosan composite particles.

    PubMed

    Wang, Lung-Shuo; Wang, Chih-Yu; Yang, Chih-Hui; Hsieh, Chen-Ling; Chen, Szu-Yu; Shen, Chi-Yen; Wang, Jia-Jung; Huang, Keng-Shiang

    2015-01-01

    Silver nanoparticles have been used in various fields, and several synthesis processes have been developed. The stability and dispersion of the synthesized nanoparticles is vital. The present article describes a novel approach for one-step synthesis of silver nanoparticles-embedded chitosan particles. The proposed approach was applied to simultaneously obtain and stabilize silver nanoparticles in a chitosan polymer matrix in-situ. The diameter of the synthesized chitosan composite particles ranged from 1.7 mm to 2.5 mm, and the embedded silver nanoparticles were measured to be 15 ± 3.3 nm. Further, the analyses of ultraviolet-visible spectroscopy, energy dispersive spectroscopy, and X-ray diffraction were employed to characterize the prepared composites. The results show that the silver nanoparticles were distributed over the surface and interior of the chitosan spheres. The fabricated spheres had macroporous property, and could be used for many applications such as fungicidal agents in the future.

  20. Facile Synthesis of Silver Nanoparticles Under {gamma}-Irradiation: Effect of Chitosan Concentration

    SciTech Connect

    Huang, N. M.; Radiman, S.; Ahmad, A.; Idris, H.; Lim, H. N.; Khiew, P. S.; Chiu, W. S.; Tan, T. K.

    2009-06-01

    In the present study, a biopolymer, low molecular weight chitosan had been utilized as a 'green' stabilizing agent for the synthesis of silver nanoparticles under {gamma}-irradiation. The as-synthesized silver nanoparticles have particle diameters in the range of 5 nm-30 nm depending on the percentage of chitosan used (0.1 wt%, 0.5 wt%, 1.0 wt% and 2.0 wt%). It was found that the yield of the silver nanoparticles was in accordance with the concentration of chitosan presence in the solution due to the reduction by the chitosan radical during irradiation. The highly stable chitosan encapsulated silver nanoparticles were characterized using transmission electron microscopy (TEM), UV-Visible spectrophotometer (UV-VIS) and X-ray diffraction spectroscopy (XRD)

  1. An effective and recyclable adsorbent for the removal of heavy metal ions from aqueous system: Magnetic chitosan/cellulose microspheres.

    PubMed

    Luo, Xiaogang; Zeng, Jian; Liu, Shilin; Zhang, Lina

    2015-10-01

    Development of highly cost-effective, highly operation-convenient and highly efficient natural polymer-based adsorbents for their biodegradability and biocompatibility, and supply of safe drinking water are the most threatening problems in water treatment field. To tackle the challenges, a new kind of efficient recyclable magnetic chitosan/cellulose hybrid microspheres was prepared by sol-gel method. By embedding magnetic γ-Fe2O3 nanoparticles in chitosan/cellulose matrix drops in NaOH/urea aqueous solution, it combined renewability and biocompatibility of chitosan and cellulose as well as magnetic properties of γ-Fe2O3 to create a hybrid system in heavy metal ions removal.

  2. Intracellular sorting of differently charged chitosan derivatives and chitosan-based nanoparticles

    NASA Astrophysics Data System (ADS)

    Zubareva, A. A.; Shcherbinina, T. S.; Varlamov, V. P.; Svirshchevskaya, E. V.

    2015-04-01

    Chitosan (Chi) is a biodegradable nontoxic polycation with multiple reactive groups that is easily used to obtain derivatives with a desired charge and hydrophobic properties. The aim of this work was to study the intracellular traffic of positively charged hexanoyl-chitosan (HC) or HC-based nanoparticles (HCNPs) and negatively charged succinoyl-chitosan (SC) and SCNPs in epithelial and macrophage cell lines. By using flow cytometry we demonstrated that positively charged HC adhered to cell membranes quicker and more efficiently than negatively charged SC or NPs. However confocal studies showed that SC and SCNPs penetrated cells much more efficiently than HC while HCNPs did not enter the epithelial cells. Macrophages also phagocyted better negatively charged material but were able to engulf both HC and HCNPs. Upon entering the cells, SC and SCNPs were co-localized with endosomes and lysosomes while HC was found in mitochondria and, to a lesser extent, in lysosomes of epithelial cells. Macrophages, RAW264.7, more efficiently transported all Chi samples to the lysosomal compartment while some positively charged material was still found in mitochondria. Incubation of Chi derivatives and ChiNPs at pH specific to mitochondria (8.0) and lysosomes (4.5) demonstrated the neutralization of Chi charge. We concluded that epithelial cells and, to a lesser extent, macrophages sort charged material to the organelles neutralizing Chi charge.

  3. Chitosan-modified cobalt oxide nanoparticles stimulate TNF-α-mediated apoptosis in human leukemic cells.

    PubMed

    Chattopadhyay, Sourav; Dash, Sandeep Kumar; Kar Mahapatra, Santanu; Tripathy, Satyajit; Ghosh, Totan; Das, Balaram; Das, Debasis; Pramanik, Panchanan; Roy, Somenath

    2014-03-01

    The objective of this study was to develop chitosan-based delivery of cobalt oxide nanoparticles to human leukemic cells and investigate their specific induction of apoptosis. The physicochemical properties of the chitosan-coated cobalt oxide nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. The solubility of chitosan-coated cobalt oxide nanoparticles was higher at acidic pH, which helps to release more cobalt ions into the medium. Chitosan-coated cobalt oxide nanoparticles showed good compatibility with normal cells. However, our results showed that exposure of leukemic cells (Jurkat cells) to chitosan-coated cobalt oxide nanoparticles caused an increase in reactive oxygen species generation that was abolished by pretreatment of cells with the reactive oxygen species scavenger N-acetyl-L-cysteine. The apoptosis of Jurkat cells was confirmed by flow-cytometric analysis. Induction of TNF-α secretion was observed from stimulation of Jurkat cells with chitosan-coated cobalt oxide nanoparticles. We also tested the role of TNF-α in the induction of Jurkat cell death in the presence of TNF-α and caspase inhibitors. Treatment of leukemic cells with a blocker had a greater effect on cancer cell viability. From our findings, oxidative stress and caspase activation are involved in cancer cell death induced by chitosan-coated cobalt oxide nanoparticles.

  4. O-2'-hydroxypropyltrimethyl ammonium chloride chitosan nanoparticles for the delivery of live Newcastle disease vaccine.

    PubMed

    Dai, Chunxiao; Kang, Hong; Yang, Wanqiu; Sun, Jinyan; Liu, Chunlong; Cheng, Guogang; Rong, Guangyu; Wang, Xiaohua; Wang, Xin; Jin, Zheng; Zhao, Kai

    2015-10-01

    A novel complex chitosan derivative, O-2'-hydroxypropyltrimethyl ammonium chloride chitosan (O-2'-HACC), was synthesized and used to make nanoparticles as a delivery vehicle for live attenuated Newcastle disease vaccine. We found that O-2'-HACC had high antimicrobial activity, low toxicity, and a high safety level. Newcastle disease virus (NDV) was then encapsulated in the O-2'-HACC nanoparticles (NDV/La Sota-O-2'-HACC-NPs) by the ionic crosslinking method, and the properties of the resulting nanoparticles were determined by transmission electron microscopy, Zeta potential analysis, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and X-ray diffraction. NDV/La Sota-O-2'-HACC-NPs had regular spherical morphologies and high stability, with an encapsulation efficiency of 95.68 ± 2.2% and a loading capacity of 58.75 ± 4.03%. An in vitro release assay indicated that release of NDV from NDV/La Sota-O-2'-HACC-NPs occurred slowly. Specific pathogen-free chickens immunized with NDV/La Sota-O-2'-HACC-NPs intranasally had much stronger cellular, humoral and mucosal immune responses than did those immunized intramuscularly or with live attenuated Newcastle disease vaccine. NDV/La Sota-O-2'-HACC-NPs are a novel drug delivery carrier with immense potential in medical applications.

  5. Synthesis and antioxidant properties of chitosan and carboxymethyl chitosan-stabilized selenium nanoparticles.

    PubMed

    Chen, Wanwen; Li, Yanfang; Yang, Shuo; Yue, Lin; Jiang, Qixing; Xia, Wenshui

    2015-11-01

    Monodispersible selenium nanoparticles (SeNPs) were synthesized by using chitosan (CS) and carboxymethyl chitosan (CCS) as the stabilizer and capping agent using a facile synthetic approach. The structure, size, morphology and antioxidant activity of the nanocomposites were characterized by transmission electron microscopy (TEM), Ultraviolet-visible spectroscopy (UV-vis), Dynamic Light Scattering (DLS), Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA). The results revealed that the monodispersible SeNPs (mean particle size of about 50 nm) were ligated with CS and CCS to form nanocomposites in aqueous solution for at least 30 days, and for 120 days the nanoparticles increased to 180 nm or so in size. The DPPH scavenging ability of CS-SeNPs was higher than that of CCS-SeNPs, and could reach 93.5% at a concentration of 0.6 mmol/L. Moreover, SeNPs, CS-SeNPs and CCS-SeNPs exhibited a higher ABTS scavenging ability in comparison to Na2SeO3.

  6. Synthesis and antioxidant properties of chitosan and carboxymethyl chitosan-stabilized selenium nanoparticles.

    PubMed

    Chen, Wanwen; Li, Yanfang; Yang, Shuo; Yue, Lin; Jiang, Qixing; Xia, Wenshui

    2015-11-01

    Monodispersible selenium nanoparticles (SeNPs) were synthesized by using chitosan (CS) and carboxymethyl chitosan (CCS) as the stabilizer and capping agent using a facile synthetic approach. The structure, size, morphology and antioxidant activity of the nanocomposites were characterized by transmission electron microscopy (TEM), Ultraviolet-visible spectroscopy (UV-vis), Dynamic Light Scattering (DLS), Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA). The results revealed that the monodispersible SeNPs (mean particle size of about 50 nm) were ligated with CS and CCS to form nanocomposites in aqueous solution for at least 30 days, and for 120 days the nanoparticles increased to 180 nm or so in size. The DPPH scavenging ability of CS-SeNPs was higher than that of CCS-SeNPs, and could reach 93.5% at a concentration of 0.6 mmol/L. Moreover, SeNPs, CS-SeNPs and CCS-SeNPs exhibited a higher ABTS scavenging ability in comparison to Na2SeO3. PMID:26256384

  7. Magnetic nanoparticles for theragnostics

    PubMed Central

    Shubayev, Veronica I.; Pisanic, Thomas R.; Jin, Sungho

    2009-01-01

    Engineered magnetic nanoparticles (MNPs) represent a cutting-edge tool in medicine because they can be simultaneously functionalized and guided by a magnetic field. Use of MNPs has advanced magnetic resonance imaging (MRI), guided drug and gene delivery, magnetic hyperthermia cancer therapy, tissue engineering, cell tracking and bioseparation. Integrative therapeutic and diagnostic (i.e., theragnostic) applications have emerged with MNP use, such as MRI-guided cell replacement therapy or MRI-based imaging of cancer-specific gene delivery. However, mounting evidence suggests that certain properties of nanoparticles (e.g., enhanced reactive area, ability to cross cell and tissue barriers, resistance to biodegradation) amplify their cytotoxic potential relative to molecular or bulk counterparts. Oxidative stress, a 3-tier paradigm of nanotoxicity, manifests in activation of reactive oxygen species (ROS) (tier I), followed by a pro-inflammatory response (tier II) and DNA damage leading to cellular apoptosis and mutagenesis (tier III). In vivo administered MNPs are quickly challenged by macrophages of the reticuloendothelial system (RES), resulting in not only neutralization of potential MNP toxicity but also reduced circulation time necessary for MNP efficacy. We discuss the role of MNP size, composition and surface chemistry in their intracellular uptake, biodistribution, macrophage recognition and cytotoxicity, and review current studies on MNP toxicity, caveats of nanotoxicity assessments and engineering strategies to optimize MNPs for biomedical use. PMID:19389434

  8. Folatereceptor targeted, carboxymethyl chitosan functionalized iron oxide nanoparticles: a novel ultradispersed nanoconjugates for bimodal imaging

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Dipsikha; Das, Manasmita; Mishra, Debashis; Banerjee, Indranil; Sahu, Sumanta K.; Maiti, Tapas K.; Pramanik, Panchanan

    2011-04-01

    This article delineates the design and synthesis of a novel, bio-functionalized, magneto-fluorescent multifunctional nanoparticles suitable for cancer-specific targeting, detection and imaging. Biocompatible, hydrophilic, magneto-fluorescent nanoparticles with surface-pendant amine, carboxyl and aldehyde groups were designed using o-carboxymethyl chitosan (OCMC). The free aminegroups of OCMC stabilized magnetite nanoparticles on the surface allow for the covalent attachment of a fluorescent dye such as rhodamine isothiocyanate (RITC) with the aim to develop a magneto-fluorescent nanoprobe for optical imaging. In order to impart specific cancer cell targeting properties, folic acid and its aminated derivative was conjugated onto these magneto-fluorescent nanoparticles using different pendant groups (-NH2, -COOH, -CHO). These newly synthesized iron-oxide folate nanoconjugates (FA-RITC-OCMC-SPIONs) showed excellent dispersibility, biocompatibility and good hydrodynamic sizes under physiological conditions which were extensively studied by a variety of complementary techniques. The cellular internalization efficacy of these folate-targeted and its non-targeted counterparts were studied using a folate-overexpressed (HeLa) and a normal (L929fibroblast) cells by fluorescence microscopy and magnetically activated cell sorting (MACS). Cell-uptake behaviors of nanoparticles clearly demonstrate that cancer cells over-expressing the human folatereceptor internalized a higher level of these nanoparticle-folate conjugates than normal cells. These folate targeted nanoparticles possess specific magnetic properties in the presence of an external magnetic field and the potential of these nanoconjugates as T2-weighted negative contrast MR imaging agent were evaluated in folate-overexpressed HeLa and normal L929fibroblastcells.

  9. Synthesis and in vitro antifungal efficacy of Cu-chitosan nanoparticles against pathogenic fungi of tomato.

    PubMed

    Saharan, Vinod; Sharma, Garima; Yadav, Meena; Choudhary, Manju Kumari; Sharma, S S; Pal, Ajay; Raliya, Ramesh; Biswas, Pratim

    2015-04-01

    Cu-chitosan nanoparticles were synthesized and evaluated for their growth promotory and antifungal efficacy in tomato (Solanum lycopersicum Mill). Physico-chemical characterization of the developed Cu-chitosan nanoparticles was carried out by DLS, FTIR, TEM, SEM-EDS and AAS. The study highlighted the stability and porous nature of Cu-chitosan nanoparticles. Laboratory synthesized nanoparticles showed substantial growth promotory effect on tomato seed germination, seedling length, fresh and dry weight at 0.08, 0.10 and 0.12% level. At 0.12% concentration these nanoparticles caused 70.5 and 73.5% inhibition of mycelia growth and 61.5 and 83.0% inhibition of spore germination in Alternaria solani and Fusarium oxysporum, respectively, in an in vitro model. In pot experiments, 0.12% concentration of Cu-chitosan nanoparticles was found most effective in percentage efficacy of disease control (PEDC) in tomato plants with the values of 87.7% in early blight and 61.1% in Fusarium wilt. The overall results confirm the significant growth promotory as well as antifungal capabilities of Cu-chitosan nanoparticles. Our model demonstrated the synthesis of Cu-chitosan nanoparticles and open up the possibility to use against fungal disease at field level. Further, developed porous nanomaterials could be exploited for delivery of agrochemicals. PMID:25617841

  10. Conjugation of chitosan nanoparticles with biogenic and synthetic polyamines: A delivery tool for antitumor polyamine analogues.

    PubMed

    Chanphai, P; Tajmir-Riahi, H A

    2016-11-01

    We report the conjugation of chitosan nanoparticles with biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) in aqueous solution. Multiple spectroscopic methods, thermodynamic parameters and molecular modeling were used to analyse polyamine bindings to chitosan nanoparticles. Thermodynamic parameters ΔS, ΔH and ΔG showed that polyamines bind protein through H-bonding and hydrophobic contacts with biogenic polyamines form more stable conjugates than synthetic polyamines. As polymer size increases the stability of polyamine-chitosan conjugate increases. The loading efficacy was 40-50% for polyamine-chitosan conjugates. Modeling showed that polyamine-protein interaction is spontaneous and chitosan nanoparticles can be used for delivery of antitumor polyamine analogues. PMID:27516317

  11. Chitosan nanoparticles synthesis caught in action using microdroplet reactions.

    PubMed

    Kamat, Vivek; Bodas, Dhananjay; Paknikar, Kishore

    2016-01-01

    The ionic gelation process for the synthesis of chitosan nanoparticles was carried out in microdroplet reactions. The synthesis could be stopped instantaneously at different time points by fast dilution of the reaction mixture with DI water. Using this simple technique, the effect of temperature and reactant concentrations on the size and distribution of the nanoparticles formed, as a function of time, could be investigated by DLS and SEM. Results obtained indicated very early (1-5 s) nucleation of the particles followed by growth. The concentration of reactants, reaction temperature as well as time, were found to (severally and collectively) determine the size of nanoparticles and their distribution. Nanoparticles obtained at 4 °C were smaller (60-80 nm) with narrower size distribution. Simulation experiments using Comsol software showed that at 4 °C 'droplet synthesis' of nanoparticles gets miniaturised to 'droplet-core synthesis', which is being reported for the first time. PMID:26924801

  12. Oral delivery of curcumin bound to chitosan nanoparticles cured Plasmodium yoelii infected mice.

    PubMed

    Akhtar, Feroz; Rizvi, M Moshahid Alam; Kar, Santosh Kumar

    2012-01-01

    Curcumin has been shown to have anti malarial activity, but poor bioavailability and chemical instability has hindered its development as a drug. We have bound curcumin to chitosan nanoparticles to improve its bioavailability and chemical stability. We found that curcumin bound to chitosan nanoparticles did not degrade that rapidly in comparison to free curcumin when such particles were incubated in mouse plasma in vitro at room temperature. The uptake of bound curcumin from chitosan nanoparticles by mouse RBC was much better than from free curcumin. Oral delivery of curcumin bound chitosan nanoparticles to normal mice showed that they can cross the mucosal barrier intact and confocal microscopy detected the nanoparticles in the blood. Curcumin loaded chitosan nanoparticles when delivered orally improved the bioavailability of curcumin in the plasma and RBC. While mice infected with a lethal strain of Plasmodium yoelii (N-67) died between 8 and 9 days post infection, feeding of chitosan nanoparticles alone made them to survive for five more days. Feeding 1mg of native curcumin to infected mice per day for seven days resulted in survival of one third of mice but under the same condition when 1mg of curcumin bound to chitosan nanoparticles was fed all the mice survived. Like chloroquine, curcumin inhibited parasite lysate induced heme polymerization in vitro in a dose dependent manner and curcumin had a lower IC(50) value than chloroquine. We believe that binding of curcumin to chitosan nanoparticles increases its chemical stability and enhances its bioavailability when fed to mice. In vitro data suggest that it can inhibit hemozoin synthesis which is lethal for the parasite.

  13. Thermo-therapeutic applications of chitosan- and PEG-coated NiFe2O4 nanoparticles.

    PubMed

    Hoque, S Manjura; Tariq, Mehrin; Liba, S I; Salehin, F; Mahmood, Z H; Khan, M N I; Chattopadhayay, K; Islam, Rafiqul; Akhter, S

    2016-07-15

    The paper reports the thermo-therapeutic applications of chitosan- and PEG-coated nickel ferrite (NiFe2O4) nanoparticles. In this study NiFe2O4 nanoparticles were synthesized by the co-precipitation method, tuning the particle size through heat treatment in the temperature range from 200-800 °C for 3 h. XRD and TEM analysis revealed that the the ultrafine nanoparticles were of size 2-58 nm. Crystallinity of the NiFe2O4 nanoparticles in the as-dried condition with the particle size ∼2-3 nm was confirmed from the presence of a lattice fringe in the HRTEM image. VSM measurements showed that a superparamagnetic/ferromagnetic transition occurs with increasing particle size, which was further confirmed by Mössbauer spectroscopy. The nickel ferrite nanoparticles with optimum particle size of 10 nm were then coated with materials commonly used for biomedical applications, i.e. chitosan and PEG, to form homogeneous suspensions. The hydrodynamic diameter and the polydispersity index (PDI) were analyzed by dynamic light scattering at the physiological temperature of 37 °C and found to be 187 nm and 0.21 for chitosan-coated nanoparticles and 285 nm and 0.32 for PEG-coated ones. The specific loss power of rf induction heating by the set-up for hyperthermia and r 2 relaxivity by the nuclear magnetic resonance were determined. The results of induction heating measurements showed that the temperature attained by the nanoparticles of size 10 nm and concentration of about 20 mg ml(-1) was >70 °C (for chitosan) and >64 °C (for PEG). It has been demonstrated that the required temperature for hyperthermia heating could be tuned by tuning the particle size, shape and magnetization and the concentration of solution. For other potential biomedical applications of the NiFe2O4 nanoparticle solution, e.g. magnetic resonance imaging, the NMR studies yielded the T 1 and T 2 relaxivities as 0.348 and 89 mM(-1) s(-1) respectively. The fact that the T 2 relaxivity is orders of magnitude

  14. Thermo-therapeutic applications of chitosan- and PEG-coated NiFe2O4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Manjura Hoque, S.; Tariq, Mehrin; Liba, S. I.; Salehin, F.; Mahmood, Z. H.; Khan, M. N. I.; Chattopadhayay, K.; Islam, Rafiqul; Akhter, S.

    2016-07-01

    The paper reports the thermo-therapeutic applications of chitosan- and PEG-coated nickel ferrite (NiFe2O4) nanoparticles. In this study NiFe2O4 nanoparticles were synthesized by the co-precipitation method, tuning the particle size through heat treatment in the temperature range from 200-800 °C for 3 h. XRD and TEM analysis revealed that the the ultrafine nanoparticles were of size 2-58 nm. Crystallinity of the NiFe2O4 nanoparticles in the as-dried condition with the particle size ˜2-3 nm was confirmed from the presence of a lattice fringe in the HRTEM image. VSM measurements showed that a superparamagnetic/ferromagnetic transition occurs with increasing particle size, which was further confirmed by Mössbauer spectroscopy. The nickel ferrite nanoparticles with optimum particle size of 10 nm were then coated with materials commonly used for biomedical applications, i.e. chitosan and PEG, to form homogeneous suspensions. The hydrodynamic diameter and the polydispersity index (PDI) were analyzed by dynamic light scattering at the physiological temperature of 37 °C and found to be 187 nm and 0.21 for chitosan-coated nanoparticles and 285 nm and 0.32 for PEG-coated ones. The specific loss power of rf induction heating by the set-up for hyperthermia and r 2 relaxivity by the nuclear magnetic resonance were determined. The results of induction heating measurements showed that the temperature attained by the nanoparticles of size 10 nm and concentration of about 20 mg ml-1 was >70 °C (for chitosan) and >64 °C (for PEG). It has been demonstrated that the required temperature for hyperthermia heating could be tuned by tuning the particle size, shape and magnetization and the concentration of solution. For other potential biomedical applications of the NiFe2O4 nanoparticle solution, e.g. magnetic resonance imaging, the NMR studies yielded the T 1 and T 2 relaxivities as 0.348 and 89 mM-1 s-1 respectively. The fact that the T 2 relaxivity is orders of magnitude higher

  15. Thermo-therapeutic applications of chitosan- and PEG-coated NiFe2O4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Manjura Hoque, S.; Tariq, Mehrin; Liba, S. I.; Salehin, F.; Mahmood, Z. H.; Khan, M. N. I.; Chattopadhayay, K.; Islam, Rafiqul; Akhter, S.

    2016-07-01

    The paper reports the thermo-therapeutic applications of chitosan- and PEG-coated nickel ferrite (NiFe2O4) nanoparticles. In this study NiFe2O4 nanoparticles were synthesized by the co-precipitation method, tuning the particle size through heat treatment in the temperature range from 200–800 °C for 3 h. XRD and TEM analysis revealed that the the ultrafine nanoparticles were of size 2–58 nm. Crystallinity of the NiFe2O4 nanoparticles in the as-dried condition with the particle size ∼2–3 nm was confirmed from the presence of a lattice fringe in the HRTEM image. VSM measurements showed that a superparamagnetic/ferromagnetic transition occurs with increasing particle size, which was further confirmed by Mössbauer spectroscopy. The nickel ferrite nanoparticles with optimum particle size of 10 nm were then coated with materials commonly used for biomedical applications, i.e. chitosan and PEG, to form homogeneous suspensions. The hydrodynamic diameter and the polydispersity index (PDI) were analyzed by dynamic light scattering at the physiological temperature of 37 °C and found to be 187 nm and 0.21 for chitosan-coated nanoparticles and 285 nm and 0.32 for PEG-coated ones. The specific loss power of rf induction heating by the set-up for hyperthermia and r 2 relaxivity by the nuclear magnetic resonance were determined. The results of induction heating measurements showed that the temperature attained by the nanoparticles of size 10 nm and concentration of about 20 mg ml‑1 was >70 °C (for chitosan) and >64 °C (for PEG). It has been demonstrated that the required temperature for hyperthermia heating could be tuned by tuning the particle size, shape and magnetization and the concentration of solution. For other potential biomedical applications of the NiFe2O4 nanoparticle solution, e.g. magnetic resonance imaging, the NMR studies yielded the T 1 and T 2 relaxivities as 0.348 and 89 mM‑1 s‑1 respectively. The fact that the T 2 relaxivity is orders of

  16. In situ synthesis of polysaccharide nanoparticles via polyion complex of carboxymethyl cellulose and chitosan.

    PubMed

    Kaihara, Sachiko; Suzuki, Yoichi; Fujimoto, Keiji

    2011-07-01

    Biocompatible polymer-magnetite hybrid nanoparticles were prepared by means of in situ synthesis of magnetite within polysaccharide hydrogel nanoparticles. Hydrogel nanoparticles were first fabricated by blending high-molecular-weight carboxymethyl cellulose as an anionic polymer, and low-molecular-weight chitosan as a cationic polymer to form polyion complexes (CC particles). These polyion complexes were then chemically crosslinked using genipin, a bio-based cross-linker, to form stable nanoparticles having a semi-IPN structure (CCG particles). Magnetite was lastly synthesized within CCG particles by the coprecipitation method to obtain polymer-magnetite hybrid nanoparticles (CCGM particles). The formations of CC, CCG and CCGM particles were mainly observed by transmittance, absorbance of genipin and TEM, respectively, and their hydrodynamic diameters and zeta-potentials were analyzed. It was confirmed that the hydrodynamic diameters and the zeta-potentials of these particles were significantly influenced by pH of the suspension, which was attributed to the charges of polymers. The diameters of CCGM particles were smaller than 200 nm at any pH conditions, suggesting the possibility to apply them as drug delivery carriers. CCGM particles exhibited the responsiveness to a magnetic field in addition to their high dispersion stability, indicating their potential to be utilized as a biomaterial for hyperthermia.

  17. The ability of streptomycin-loaded chitosan-coated magnetic nanocomposites to possess antimicrobial and antituberculosis activities.

    PubMed

    El Zowalaty, Mohamed Ezzat; Hussein Al Ali, Samer Hassan; Husseiny, Mohamed I; Geilich, Benjamin M; Webster, Thomas J; Hussein, Mohd Zobir

    2015-01-01

    Magnetic nanoparticles (MNPs) were synthesized by the coprecipitation of Fe(2+) and Fe(3+) iron salts in alkali media. MNPs were coated by chitosan (CS) to produce CS-MNPs. Streptomycin (Strep) was loaded onto the surface of CS-MNPs to form a Strep-CS-MNP nanocomposite. MNPs, CS-MNPs, and the nanocomposites were subsequently characterized using X-ray diffraction and were evaluated for their antibacterial activity. The antimicrobial activity of the as-synthesized nanoparticles was evaluated using different Gram-positive and Gram-negative bacteria, as well as Mycobacterium tuberculosis. For the first time, it was found that the nanoparticles showed antimicrobial activities against the tested microorganisms (albeit with a more pronounced effect against Gram-negative than Gram-positive bacteria), and thus, should be further studied as a novel nano-antibiotic for numerous antimicrobial and antituberculosis applications. Moreover, since these nanoparticle bacteria fighters are magnetic, one can easily envision magnetic field direction of these nanoparticles to fight unwanted microorganism presence on demand. Due to the ability of magnetic nanoparticles to increase the sensitivity of imaging modalities (such as magnetic resonance imaging), these novel nanoparticles can also be used to diagnose the presence of such microorganisms. In summary, although requiring further investigation, this study introduces for the first time a new type of magnetic nanoparticle with microorganism theranostic properties as a potential tool to both diagnose and treat diverse microbial and tuberculosis infections. PMID:25995633

  18. The ability of streptomycin-loaded chitosan-coated magnetic nanocomposites to possess antimicrobial and antituberculosis activities

    PubMed Central

    El Zowalaty, Mohamed Ezzat; Hussein Al Ali, Samer Hassan; Husseiny, Mohamed I; Geilich, Benjamin M; Webster, Thomas J; Hussein, Mohd Zobir

    2015-01-01

    Magnetic nanoparticles (MNPs) were synthesized by the coprecipitation of Fe2+ and Fe3+ iron salts in alkali media. MNPs were coated by chitosan (CS) to produce CS-MNPs. Streptomycin (Strep) was loaded onto the surface of CS-MNPs to form a Strep-CS-MNP nanocomposite. MNPs, CS-MNPs, and the nanocomposites were subsequently characterized using X-ray diffraction and were evaluated for their antibacterial activity. The antimicrobial activity of the as-synthesized nanoparticles was evaluated using different Gram-positive and Gram-negative bacteria, as well as Mycobacterium tuberculosis. For the first time, it was found that the nanoparticles showed antimicrobial activities against the tested microorganisms (albeit with a more pronounced effect against Gram-negative than Gram-positive bacteria), and thus, should be further studied as a novel nano-antibiotic for numerous antimicrobial and antituberculosis applications. Moreover, since these nanoparticle bacteria fighters are magnetic, one can easily envision magnetic field direction of these nanoparticles to fight unwanted microorganism presence on demand. Due to the ability of magnetic nanoparticles to increase the sensitivity of imaging modalities (such as magnetic resonance imaging), these novel nanoparticles can also be used to diagnose the presence of such microorganisms. In summary, although requiring further investigation, this study introduces for the first time a new type of magnetic nanoparticle with microorganism theranostic properties as a potential tool to both diagnose and treat diverse microbial and tuberculosis infections. PMID:25995633

  19. Chitosan coating of copper nanoparticles reduces in vitro toxicity and increases inflammation in the lung

    PubMed Central

    Worthington, Kristan L.S.; Dodd, Andrea A.; Wongrakpanich, Amaraporn; Mudunkotuwa, Imali A.; Mapuskar, Kranti A.; Joshi, Vijaya B.; Guymon, C. Allan; Spitz, Douglas R.; Grassian, Vicki H.; Thorne, Peter S.; Salem, Aliasger K.

    2013-01-01

    Despite their potential for a variety of applications, copper nanoparticles induce very strong inflammatory responses and cellular toxicity following aerosolized delivery. Coating metallic nanoparticles with polysaccharides, such as biocompatible and antimicrobial chitosan, has the potential to reduce this toxicity. In this study, copper nanoparticles were coated with chitosan using a newly developed and facile method. The presence of coating was confirmed using x-ray photoelectron spectroscopy (XPS), rhodamine tagging of chitosan followed by confocal fluorescence imaging of coated particles, observed increases in particle size and zeta potential. Further physical and chemical characteristics were evaluated using dissolution and x-ray diffraction (XRD) studies. The chitosan coating was shown to significantly reduce the toxicity of copper nanoparticles after 24 and 52 hours and the generation of reactive oxygen species as assayed by DHE oxidation after 24 hours in vitro. Conversely, inflammatory response, measured using the number of white blood cells, total protein, and cytokines/chemokines in the broncheoalveolar fluid of mice exposed to chitosan coated versus uncoated copper nanoparticles, was shown to increase, as was the concentration of copper ions. These results suggest that coating metal nanoparticles with mucoadhesive polysaccharides (e.g. chitosan) could increase their potential for use in controlled release of copper ions to cells, but will result in a higher inflammatory response if administered via the lung. PMID:24008224

  20. Poly(lactic acid)/chitosan hybrid nanoparticles for controlled release of anticancer drug.

    PubMed

    Wang, Wenlong; Chen, Shu; Zhang, Liang; Wu, Xi; Wang, Jiexin; Chen, Jian-Feng; Le, Yuan

    2015-01-01

    Poly(lactic acid) (PLA) is a kind of non-toxic biological materials with excellent absorbability, biocompatibility and biodegradability, which can be used for drug release, tissue engineering and surgical treatment applications. In this study, we prepared chitosan modified PLA nanoparticles as carriers for encapsulation of docetaxel by anti-solvent precipitation method. The morphology, particle size, zeta potential and composition of the PLA/chitosan were characterized by SEM, DLS, FTIR and XPS. As-prepared PLA/chitosan particles exhibited average size of 250 nm and showed very narrow distribution with polydispersity index of 0.098. Their large surface charge-ability was confirmed by zeta potential value of 53.9 mV. Docetaxel was released from PLA/chitosan nanoparticles with 40% initial burst release in 5 h and 70% cumulative release within 24 h, while from PLA nanoparticles 65% of docetaxel was released in 5h. In vitro drug release study demonstrated that PLA/chitosan nanoparticles prolonged drug release and decreased the burst release over the unmodified PLA nanoparticles. These results illustrated high potential of chitosan modified PLA nanoparticles for usage as anticancer drug carriers. PMID:25492016

  1. Chitosan coating of copper nanoparticles reduces in vitro toxicity and increases inflammation in the lung

    NASA Astrophysics Data System (ADS)

    Worthington, Kristan L. S.; Adamcakova-Dodd, Andrea; Wongrakpanich, Amaraporn; Mudunkotuwa, Imali A.; Mapuskar, Kranti A.; Joshi, Vijaya B.; Guymon, C. Allan; Spitz, Douglas R.; Grassian, Vicki H.; Thorne, Peter S.; Salem, Aliasger K.

    2013-10-01

    Despite their potential for a variety of applications, copper nanoparticles induce very strong inflammatory responses and cellular toxicity following aerosolized delivery. Coating metallic nanoparticles with polysaccharides, such as biocompatible and antimicrobial chitosan, has the potential to reduce this toxicity. In this study, copper nanoparticles were coated with chitosan using a newly developed and facile method. The presence of coating was confirmed using x-ray photoelectron spectroscopy, rhodamine tagging of chitosan followed by confocal fluorescence imaging of coated particles and observed increases in particle size and zeta potential. Further physical and chemical characteristics were evaluated using dissolution and x-ray diffraction studies. The chitosan coating was shown to significantly reduce the toxicity of copper nanoparticles after 24 and 52 h and the generation of reactive oxygen species as assayed by DHE oxidation after 24 h in vitro. Conversely, inflammatory response, measured using the number of white blood cells, total protein, and cytokines/chemokines in the bronchoalveolar fluid of mice exposed to chitosan coated versus uncoated copper nanoparticles, was shown to increase, as was the concentration of copper ions. These results suggest that coating metal nanoparticles with mucoadhesive polysaccharides (e.g. chitosan) could increase their potential for use in controlled release of copper ions to cells, but will result in a higher inflammatory response if administered via the lung.

  2. Poly(lactic acid)/chitosan hybrid nanoparticles for controlled release of anticancer drug.

    PubMed

    Wang, Wenlong; Chen, Shu; Zhang, Liang; Wu, Xi; Wang, Jiexin; Chen, Jian-Feng; Le, Yuan

    2015-01-01

    Poly(lactic acid) (PLA) is a kind of non-toxic biological materials with excellent absorbability, biocompatibility and biodegradability, which can be used for drug release, tissue engineering and surgical treatment applications. In this study, we prepared chitosan modified PLA nanoparticles as carriers for encapsulation of docetaxel by anti-solvent precipitation method. The morphology, particle size, zeta potential and composition of the PLA/chitosan were characterized by SEM, DLS, FTIR and XPS. As-prepared PLA/chitosan particles exhibited average size of 250 nm and showed very narrow distribution with polydispersity index of 0.098. Their large surface charge-ability was confirmed by zeta potential value of 53.9 mV. Docetaxel was released from PLA/chitosan nanoparticles with 40% initial burst release in 5 h and 70% cumulative release within 24 h, while from PLA nanoparticles 65% of docetaxel was released in 5h. In vitro drug release study demonstrated that PLA/chitosan nanoparticles prolonged drug release and decreased the burst release over the unmodified PLA nanoparticles. These results illustrated high potential of chitosan modified PLA nanoparticles for usage as anticancer drug carriers.

  3. Synthesis of ferrofluid with magnetic nanoparticles by sonochemical method for MRI contrast agent

    NASA Astrophysics Data System (ADS)

    Hee Kim, Eun; Sook Lee, Hyo; Kook Kwak, Byung; Kim, Byung-Kee

    2005-03-01

    Superparamagnetic iron oxide nanoparticles (SPIO) having high magnetization (83 emu/g) and crystallinity were synthesized by using a sonochemical method. Ferrofluids from these nanoparticles coated with oleic acid as a surfactant were prepared for magnetic resonance imaging (MRI) contrast agent. The coated SPIO could be easily dispersed in chitosan, and the hydrodynamic diameter of the coated SPIO in the chitosan solution was estimated to be 65 nm. The ferrofluids of various concentrations did not agglomerate for 30 days, indicating their good stability. The T1- and T2-weighted MR images of these ferrofluids were obtained and the MRI image contrasts were similar to those of Resovist ®.

  4. Chitosan Nanoparticles Prepared by Ionotropic Gelation: An Overview of Recent Advances.

    PubMed

    Desai, Kashappa Goud

    2016-01-01

    The objective of this review is to summarize recent advances in chitosan nanoparticles prepared by ionotropic gelation. Significant progress has occurred in this area since the method was first reported. The gelation technique has been improved through a number of creative methodological modifications. Ionotropic gelation via electrospraying and spinning disc processing produces nanoparticles with a more uniform size distribution. Large-scale manufacturing of the nanoparticles can be achieved with the latter approach. Hydrophobic and hydrophilic drugs can be simultaneously encapsulated with high efficiency by emulsification followed by ionic gelation. The turbulent mixing approach facilitates nanoparticle formation at a relatively high polymer concentration (5 mg/mL). The technique can be easily tuned to achieve the desired polymer/surface modifications (e.g., blending, coating, and surface conjugation). Using factorial-design-based approaches, optimal conditions for nanoparticle formation can be determined with a minimum number of experiments. New insights have been gained into the mechanism of chitosan-tripolyphosphate nanoparticle formation. Chitosan nanoparticles prepared by ionotropic gelation tend to aggregate/agglomerate in unfavorable environments. Factors influencing this phenomenon and strategies that can be adopted to minimize the instability are discussed. Ionically cross-linked nanoparticles based on native chitosan and modified chitosan have shown excellent efficacy for controlled and targeted drug-delivery applications. PMID:27651100

  5. Plasma-Synthesized Silver Nanoparticles on Electrospun Chitosan Nanofiber Surfaces for Antibacterial Applications.

    PubMed

    Annur, Dhyah; Wang, Zhi-Kai; Liao, Jiunn-Der; Kuo, Changshu

    2015-10-12

    Chitosan nanofibers have been electrospun with poly(ethylene oxide) and silver nitrate, as a coelectrospinning polymer and silver nanoparticle precursor, respectively. The average diameter of the as-spun chitosan nanofibers with up to 2 wt % silver nitrate loading was approximately 130 nm, and there was no evidence of bead formation or polymer agglomeration. Argon plasma was then applied for surface etching and synthesis of silver nanoparticles via precursor decomposition. Plasma surface bombardment induced nanoparticle formation primarily on the chitosan nanofiber surfaces, and the moderate surface plasma etching further encouraged maximum exposure of silver nanoparticles. UV-vis spectra showed the surface plasmon resonance signature of silver nanoparticles. The surface-immobilized nanoparticles were visualized by TEM and were found to have average particle diameters as small as 1.5 nm. Surface analysis by infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the interactions between the silver nanoparticles and chitosan molecules, as well as the effect of plasma treatment on the nanofiber surfaces. Finally, a bacteria inhibition study revealed that the antibacterial activity of the electrospun chitosan nanofibers correspondingly increased with the plasma-synthesized silver nanoparticles. PMID:26366749

  6. Synthesis and ultraviolet visible spectroscopy studies of chitosan capped gold nanoparticles and their reactions with analytes.

    PubMed

    Mohd Sultan, Norfazila; Johan, Mohd Rafie

    2014-01-01

    Gold nanoparticles (AuNPs) had been synthesized with various molarities and weights of reducing agent, monosodium glutamate (MSG), and stabilizer chitosan, respectively. The significance of chitosan as stabilizer was distinguished through transmission electron microscopy (TEM) images and UV-Vis absorption spectra in which the interparticles distance increases whilst retaining the surface plasmon resonance (SPR) characteristics peak. The most stable AuNPs occurred for composition with the lowest (1 g) weight of chitosan. AuNPs capped with chitosan size stayed small after 1 month aging compared to bare AuNPs. The ability of chitosan capped AuNPs to uptake analyte was studied by employing amorphous carbon nanotubes (α-CNT), copper oxide (Cu2O), and zinc sulphate (ZnSO4) as the target material. The absorption spectra showed dramatic intensity increased and red shifted once the analyte was added to the chitosan capped AuNPs.

  7. Chitosan nanoparticles for siRNA delivery: optimizing formulation to increase stability and efficiency.

    PubMed

    Ragelle, H; Riva, R; Vandermeulen, G; Naeye, B; Pourcelle, V; Le Duff, C S; D'Haese, C; Nysten, B; Braeckmans, K; De Smedt, S C; Jérôme, C; Préat, V

    2014-02-28

    This study aims at developing chitosan-based nanoparticles suitable for an intravenous administration of small interfering RNA (siRNA) able to achieve (i) high gene silencing without cytotoxicity and (ii) stability in biological media including blood. Therefore, the influence of chitosan/tripolyphosphate ratio, chitosan physicochemical properties, PEGylation of chitosan as well as the addition of an endosomal disrupting agent and a negatively charged polymer was assessed. The gene silencing activity and cytotoxicity were evaluated on B16 melanoma cells expressing luciferase. We monitored the integrity and the size behavior of siRNA nanoparticles in human plasma using fluorescence fluctuation spectroscopy and single particle tracking respectively. The presence of PEGylated chitosan and poly(ethylene imine) was essential for high levels of gene silencing in vitro. Chitosan nanoparticles immediately released siRNA in plasma while the inclusion of hyaluronic acid and high amount of poly(ethylene glycol) in the formulation improved the stability of the particles. The developed formulations of PEGylated chitosan-based nanoparticles that achieve high gene silencing in vitro, low cytotoxicity and high stability in plasma could be promising for intravenous delivery of siRNA. PMID:24389132

  8. A method for top down preparation of chitosan nanoparticles and nanofibers.

    PubMed

    Wijesena, Ruchira N; Tissera, Nadeeka; Kannangara, Yasun Y; Lin, Yuan; Amaratunga, Gehan A J; de Silva, K M Nalin

    2015-03-01

    A method of top down preparation of chitosan nanoparticles and nanofibers is proposed. Chitin nanofibrils (chitin NFs) were prepared using ultrasonic assisted method from crab shells with an average diameter of 5 nm and the length less than 3 μm as analyzed by atomic force microscopy and transmission electron microscopy. These chitin nanofibers were used as the precursor material for the preparation of chitosan nanoparticles and nanofibers. The degree of deacetylation of these prepared chitosan nanostructures were found to be approximately 98%. In addition these chitosan nanostructures showed amorphous crystallinity. Transmission electron microscopic studies revealed that chitosan nanoparticles were roughly spherical in nature and had diameters less than 300 nm. These larger particles formed through self-assembly of much smaller 25 nm particles as evidenced by the TEM imaging. The diameter and the length of the chitosan nanofibers were found to be less than 100 nm and 3 μm respectively. It is envisaged that due to the cavitation effect, the deacetylated chitin nanofibers were broken down to small pieces to form seed particles. These seed particles can then be self-assembled to form larger chitosan nanoparticles.

  9. Non-monotonic wetting behavior of chitosan films induced by silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Praxedes, A. P. P.; Webler, G. D.; Souza, S. T.; Ribeiro, A. S.; Fonseca, E. J. S.; de Oliveira, I. N.

    2016-05-01

    The present work is devoted to the study of structural and wetting properties of chitosan-based films containing silver nanoparticles. In particular, the effects of silver concentration on the morphology of chitosan films are characterized by different techniques, such as atomic force microscopy (AFM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). By means of dynamic contact angle measurements, we study the modification on surface properties of chitosan-based films due to the addition of silver nanoparticles. The results are analyzed in the light of molecular-kinetic theory which describes the wetting phenomena in terms of statistical dynamics for the displacement of liquid molecules in a solid substrate. Our results show that the wetting properties of chitosan-based films are high sensitive to the fraction of silver nanoparticles, with the equilibrium contact angle exhibiting a non-monotonic behavior.

  10. Water dispersible cross-linked magnetic chitosan beads for increasing the antimicrobial efficiency of aminoglycoside antibiotics.

    PubMed

    Grumezescu, Alexandru Mihai; Andronescu, Ecaterina; Holban, Alina Maria; Ficai, Anton; Ficai, Denisa; Voicu, Georgeta; Grumezescu, Valentina; Balaure, Paul Cătălin; Chifiriuc, Carmen Mariana

    2013-09-15

    The aim of this study was to obtain a nano-active system to improve antibiotic activity of certain drugs by controlling their release. Magnetic composite nanomaterials based on magnetite core and cross-linked chitosan shell were synthesized via the co-precipitation method and characterized by Fourier transform infrared spectroscopy (FT-IR), infrared microscopy (IRM), scanning electron microscopy (SEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The prepared magnetic composite nanomaterials exhibit a significant potentiating effect on the activity of two cationic (kanamycin and neomycin) drugs, reducing the amount of antibiotics necessary for the antimicrobial effect. The increase in the antimicrobial activity was explained by the fact that the obtained nanosystems provide higher surface area to volume ratio, resulting into higher surface charge density thus increasing affinity to microbial cell and also by controlling their release. In addition to the nano-effect, the positive zeta potential of the synthesized magnetite/cross-linked chitosan core/shell magnetic nanoparticles allows for a more favorable interaction with the usually negatively charged cell wall of bacteria. The novelty of the present contribution is just the revealing of this synergistic effect exhibited by the synthesized water dispersible magnetic nanocomposites on the activity of different antibiotics against Gram-positive and Gram-negative bacterial strains. The results obtained in this study recommend these magnetic water dispersible nanocomposite materials for applications in the prevention and treatment of infectious diseases. PMID:23830944

  11. Water dispersible cross-linked magnetic chitosan beads for increasing the antimicrobial efficiency of aminoglycoside antibiotics.

    PubMed

    Grumezescu, Alexandru Mihai; Andronescu, Ecaterina; Holban, Alina Maria; Ficai, Anton; Ficai, Denisa; Voicu, Georgeta; Grumezescu, Valentina; Balaure, Paul Cătălin; Chifiriuc, Carmen Mariana

    2013-09-15

    The aim of this study was to obtain a nano-active system to improve antibiotic activity of certain drugs by controlling their release. Magnetic composite nanomaterials based on magnetite core and cross-linked chitosan shell were synthesized via the co-precipitation method and characterized by Fourier transform infrared spectroscopy (FT-IR), infrared microscopy (IRM), scanning electron microscopy (SEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The prepared magnetic composite nanomaterials exhibit a significant potentiating effect on the activity of two cationic (kanamycin and neomycin) drugs, reducing the amount of antibiotics necessary for the antimicrobial effect. The increase in the antimicrobial activity was explained by the fact that the obtained nanosystems provide higher surface area to volume ratio, resulting into higher surface charge density thus increasing affinity to microbial cell and also by controlling their release. In addition to the nano-effect, the positive zeta potential of the synthesized magnetite/cross-linked chitosan core/shell magnetic nanoparticles allows for a more favorable interaction with the usually negatively charged cell wall of bacteria. The novelty of the present contribution is just the revealing of this synergistic effect exhibited by the synthesized water dispersible magnetic nanocomposites on the activity of different antibiotics against Gram-positive and Gram-negative bacterial strains. The results obtained in this study recommend these magnetic water dispersible nanocomposite materials for applications in the prevention and treatment of infectious diseases.

  12. Chitosan-lignosulfonates sono-chemically prepared nanoparticles: characterisation and potential applications.

    PubMed

    Kim, Suyeon; Fernandes, Margarida M; Matamá, Teresa; Loureiro, Ana; Gomes, Andreia C; Cavaco-Paulo, Artur

    2013-03-01

    Due to their recognised properties of biocompatibility, biodegradability and sustainability, chitosan nanocarriers have been successfully used as new delivery systems. In this work, nanoparticles combining chitosan and lignosulfonates were developed for the first time for cosmetic and biomedical applications. The ability of lignosulfonates to act as a counter polyion for stabilisation of chitosan particles, generated using high intensity ultrasound, was investigated. Several conditions for particles preparation were tested and optimised and the resulting nanoparticles were comprehensively characterised by measuring particle size, zeta potential and polydispersity index. The pH of chitosan solution, sonication time and the presence of an adequate surfactant, poloxamer 407, were determinant factors on the development of smaller particles with low polydispersity index (an average particle size of 230 nm was obtained at pH 5 after 8 min of sonication). The beneficial effects of lignosulfonates complex on chitosan nanoparticles were further characterised. Greater stability to lysozyme degradation, biocompatibility with human cells and antimicrobial activity was found upon lignosulfonates incorporation into chitosan nanoparticles. Furthermore, these particles were able to incorporate a hydrophilic model protein - RNase A. A burst release was observed when nanoparticles were loaded with low amount of protein while with high protein content, a sustained release was found, suggesting that the protein cargo maybe loaded both at the surface as in the bulk of the particle, depending on the concentration of drug incorporated.

  13. Dual responsive PNIPAM-chitosan targeted magnetic nanopolymers for targeted drug delivery

    NASA Astrophysics Data System (ADS)

    Yadavalli, Tejabhiram; Ramasamy, Shivaraman; Chandrasekaran, Gopalakrishnan; Michael, Isaac; Therese, Helen Annal; Chennakesavulu, Ramasamy

    2015-04-01

    A dual stimuli sensitive magnetic hyperthermia based drug delivery system has been developed for targeted cancer treatment. Thermosensitive amine terminated poly-N-isopropylacrylamide complexed with pH sensitive chitosan nanoparticles was prepared as the drug carrier. Folic acid and fluorescein were tagged to the nanopolymer complex via N-hydroxysuccinimide and ethyl-3-(3-dimethylaminopropyl)carbodiimide reaction to form a fluorescent and cancer targeting magnetic carrier system. The formation of the polymer complex was confirmed using infrared spectroscopy. Gadolinium doped nickel ferrite nanoparticles prepared by a hydrothermal method were encapsulated in the polymer complex to form a magnetic drug carrier system. The proton relaxation studies on the magnetic carrier system revealed a 200% increase in the T1 proton relaxation rate. These magnetic carriers were loaded with curcumin using solvent evaporation method with a drug loading efficiency of 86%. Drug loaded nanoparticles were tested for their targeting and anticancer properties on four cancer cell lines with the help of MTT assay. The results indicated apoptosis of cancer cell lines within 3 h of incubation.

  14. Formation of enriched black tea extract loaded chitosan nanoparticles via electrospraying

    NASA Astrophysics Data System (ADS)

    Hammond, Samuel James

    Creating nanoparticles of beneficial nutraceuticals and pharmaceuticals has had a large surge of research due to the enhancement of absorption and bioavailability by decreasing their size. One of these ways is by electrohydrodynamic atomization, also known as electrospraying. In general, this novel process is done by forcing a liquid through a capillary nozzle and which is subjected to an electrical field. While there are different ways to create nanoparticles, the novel method of electrospraying can be beneficial over other types of nanoparticle formation. Reasons include high control over particle size and distribution by altering electrospray parameters (voltage, flow rate, distance, and time), higher encapsulation efficiency than other methods, and also it is a one step process without exposure to extreme conditions (Gomez-Estaca et. al. 2012, Jaworek and Sobcyzk 2008). The current study aimed to create a chitosan encapsulated theaflavin-2 enriched black tea extract (BTE) nanoparticles via electrospraying. The first step of this process was to create the smallest chitosan nanoparticles possible by altering the electrospray parameters and the chitosan-acetic acid solution parameters. The solution properties altered include chitosan molecular weight, acetic acid concentration, and chitosan concentration. Specifically, the electrospray parameters such as voltage, flow rate and distance from syringe to collector are the most important in determining particle size. After creating the smallest chitosan particles, the TF-2 enriched black tea extract was added to the chitosan-acetic acid solution to be electrosprayed. The particles were assessed with the following procedures: Atomic force microscopy (AFM) and scanning electron microscopy (SEM) for particle morphology and size, and loading efficiency with ultraviolet--visible spectrophotometer (UV-VIS). Chitosan-BTE nanoparticles were successfully created in a one step process. Diameter of the particles on average

  15. Development of Cy5.5-Labeled Hydrophobically Modified Glycol Chitosan Nanoparticles for Protein Delivery

    NASA Astrophysics Data System (ADS)

    Chin, Amanda

    Therapeutic proteins are often highly susceptible to enzymatic degradation, thus restricting their in vivo stability. To overcome this limitation, delivery systems designed to promote uptake and reduce degradation kinetics have undergone a rapid shift from macro-scale systems to nanomaterial based carriers. Many of these nanomaterials, however, elicit immune responses and may have cytotoxic effects both in vitro and in vivo. The naturally derived polysaccharide chitosan has emerged as a promising biodegradable material and has been utilized for many biomedical applications; nevertheless, its function is often constrained by poor solubility. Glycol chitosan, a derivative of chitosan, can be hydrophobically modified to impart amphiphilic properties that enable the self-assembly into nanoparticles in aqueous media at neutral pH. This nanoparticle system has shown initial success as a therapeutic agent in several model cell culture systems, but little is known about its stability against enzymatic degradation. Therefore, the goal of this research was to investigate the resistance of hydrophobically modified glycol chitosan against enzyme-catalyzed degradation using an in vivo simulated system containing lysozyme. To synthesize the nanoparticles, hydrophobic cholanic acid was first covalently conjugated to glycol chitosan using of N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Conjugates were purified by dialysis, lyophilized, and ultra-sonicated to form nanoparticles. Fourier transform infrared (FT-IR) spectroscopy confirmed the binding of 5beta-cholanic acid to the glycol chitosan. Particle size and stability over time were determined with dynamic light scattering (DLS), and particle morphology was evaluated by transmission electron microscopy (TEM). The average diameter of the nanoparticles was approximately 200 nm, which remained stable at 4°C for up to 10 days. Additionally, a near infrared fluorescent (NIRF) dye

  16. The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment

    NASA Astrophysics Data System (ADS)

    Jeong, Eun Ju; Choi, Moonhwan; Lee, Jangwook; Rhim, Taiyoun; Lee, Kuen Yong

    2015-11-01

    Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of R9Gn-chitosan/siRNA nanoparticles were investigated in vitro. Increasing the spacing arm length did not significantly affect the complex formation between R9Gn-chitosan and siRNA. However, R9G10-chitosan was much more effective in delivering genes both in vitro and in vivo compared with non-modified chitosan (without the peptide) and R9-chitosan (without the spacer arm). Chitosan derivatives modified with oligoarginine containing a spacer arm can be considered as potential delivery vehicles for various genes.Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of

  17. Functional enhancement of chitosan and nanoparticles in cell culture, tissue engineering, and pharmaceutical applications

    PubMed Central

    Gao, Wenjuan; Lai, James C. K.; Leung, Solomon W.

    2012-01-01

    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. PMID:22934070

  18. Size selected synthesis of CoFe{sub 2}O{sub 4} nanoparticles prepared in a chitosan matrix

    SciTech Connect

    Gurgel, A. L.; Soares, J. M.; Chaves, D. S.; Xavier, M. M. Jr.; Morales, M. A.; Baggio-Saitovitch, E. M.; Chaves, D. S.

    2010-05-15

    In this paper we report the synthesis and magnetic properties of CoFe{sub 2}O{sub 4} nanoparticles. The nanoparticles with sizes ranging from 6 to 20 nm were prepared in a chitosan matrix. Size selection was achieved by introducing a nonionic surfactant Tween-X, where X={l_brace}20, 60, 80, and 85{r_brace}. Aqueous dispersions of Tween-X show micelles with increasing hydrodynamic sizes as X increases. Moessbauer spectroscopy measurements at 300 K show superparamagnetic behavior for the small particles, changing gradually to a blocked magnetic regime as the particle size increases. Magnetization measurements at 300 K show increasing values for the ratio M{sub r}/M{sub Hmax} and coercive fields (H{sub c}).

  19. Magnetic catechol-chitosan with bioinspired adhesive surface: preparation and immobilization of ω-transaminase.

    PubMed

    Ni, Kefeng; Zhou, Xu; Zhao, Li; Wang, Hualei; Ren, Yuhong; Wei, Dongzhi

    2012-01-01

    The magnetic chitosan nanocomposites have been studied intensively and been used practically in various biomedical and biological applications including enzyme immobilization. However, the loading capacity and the remained activity of immobilized enzyme based on existing approaches are not satisfied. Simpler and more effective immobilization strategies are needed. Here we report a simple catechol modified protocol for preparing a novel catechol-chitosan (CCS)-iron oxide nanoparticles (IONPs) composites carrying adhesive moieties with strong surface affinity. The ω-transaminase (ω-TA) was immobilized onto this magnetic composite via nucleophilic reactions between catechol and ω-TA. Under optimal conditions, 87.5% of the available ω-TA was immobilized on the composite, yielding an enzyme loading capacity as high as 681.7 mg/g. Furthermore, the valuation of enzyme activity showed that ω-TA immobilized on CCS-IONPs displayed enhanced pH and thermal stability compared to free enzyme. Importantly, the immobilized ω-TA retained more than 50% of its initial activity after 15 repeated reaction cycles using magnetic separation and 61.5% of its initial activity after storage at 4°C in phosphate buffered saline (PBS) for 15 days. The results suggested that such adhesive magnetic composites may provide an improved platform technology for bio-macromolecules immobilized.

  20. Magnetic catechol-chitosan with bioinspired adhesive surface: preparation and immobilization of ω-transaminase.

    PubMed

    Ni, Kefeng; Zhou, Xu; Zhao, Li; Wang, Hualei; Ren, Yuhong; Wei, Dongzhi

    2012-01-01

    The magnetic chitosan nanocomposites have been studied intensively and been used practically in various biomedical and biological applications including enzyme immobilization. However, the loading capacity and the remained activity of immobilized enzyme based on existing approaches are not satisfied. Simpler and more effective immobilization strategies are needed. Here we report a simple catechol modified protocol for preparing a novel catechol-chitosan (CCS)-iron oxide nanoparticles (IONPs) composites carrying adhesive moieties with strong surface affinity. The ω-transaminase (ω-TA) was immobilized onto this magnetic composite via nucleophilic reactions between catechol and ω-TA. Under optimal conditions, 87.5% of the available ω-TA was immobilized on the composite, yielding an enzyme loading capacity as high as 681.7 mg/g. Furthermore, the valuation of enzyme activity showed that ω-TA immobilized on CCS-IONPs displayed enhanced pH and thermal stability compared to free enzyme. Importantly, the immobilized ω-TA retained more than 50% of its initial activity after 15 repeated reaction cycles using magnetic separation and 61.5% of its initial activity after storage at 4°C in phosphate buffered saline (PBS) for 15 days. The results suggested that such adhesive magnetic composites may provide an improved platform technology for bio-macromolecules immobilized. PMID:22815930

  1. Magnetic Nanoparticles for Biomedical Applications

    NASA Astrophysics Data System (ADS)

    Jing, Ying

    Nanotechnology is revolutionizing human's life. Synthesis and application of magnetic nanoparticles is a fast burgeoning field which has potential to bring significant advance in many fields, for example diagnosis and treatment in biomedical area. Novel nanoparticles to function efficiently and intelligently are in desire to improve the current technology. We used a magnetron-sputtering-based nanocluster deposition technique to synthesize magnetic nanoparticles in gas phase, and specifically engineered nanoparticles for different applications. Alternating magnetic field heating is emerging as a technique to assist cancer treatment or drug delivery. We proposed high-magnetic-moment Fe3Si particles with relatively large magnetic anisotropy energy should in principle provide superior performance. Such nanoparticles were experimentally synthesized and characterized. Their promising magnetic properties can contribute to heating performance under suitable alternating magnetic field conditions. When thermal energy is used for medical treatment, it is ideal to work in a designed temperature range. Biocompatible and "smart" magnetic nanoparticles with temperature self-regulation were designed from both materials science and biomedicine aspects. We chose Fe-Si material system to demonstrate the concept. Temperature dependent physical property was adjusted by tuning of exchange coupling between Fe atoms through incorporation of various amount of Si. The magnetic moment can still be kept in a promising range. The two elements are both biocompatible, which is favored by in-vivo medical applications. A combination of "smart" magnetic particles and thermo-sensitive polymer were demonstrated to potentially function as a platform for drug delivery. Highly sensitive diagnosis for point-of-care is in desire nowadays. We developed composition- and phase-controlled Fe-Co nanoparticles for bio-molecule detection. It has been demonstrated that Fe70Co30 nanoparticles and giant

  2. Chitosan-based nanoparticles for rosmarinic acid ocular delivery--In vitro tests.

    PubMed

    da Silva, Sara Baptista; Ferreira, Domingos; Pintado, Manuela; Sarmento, Bruno

    2016-03-01

    In this study, chitosan nanoparticles were used to encapsulate antioxidant rosmarinic acid, Salvia officinalis (sage) and Satureja montana (savory) extracts as rosmarinic acid natural vehicles. The nanoparticles were prepared by ionic gelation using chitosan and sodium tripolyphosphate (TPP) in a mass ratio of 7:1, at pH 5.8. Particle size distribution analysis and transmission electron microscopy (TEM) confirmed the size ranging from 200 to 300 nm, while surface charge of nanoparticles ranged from 20 to 30 mV. Nanoparticles demonstrate to be safe without relevant cytotoxicity against retina pigment epithelium (ARPE-19) and human cornea cell line (HCE-T). The permeability study in HCE monolayer cell line showed an apparent permeability coefficient Papp of 3.41±0.99×10(-5) and 3.24±0.79×10(-5) cm/s for rosmarinic acid loaded chitosan nanoparticles and free in solution, respectively. In ARPE-19 monolayer cell line the Papp was 3.39±0.18×10(-5) and 3.60±0.05×10(-5) cm/s for rosmarinic acid loaded chitosan nanoparticles and free in solution, respectively. Considering the mucin interaction method, nanoparticles indicate mucoadhesive proprieties suggesting an increased retention time over the ocular mucosa after instillation. These nanoparticles may be promising drug delivery systems for ocular application in oxidative eye conditions.

  3. Biomedical and environmental applications of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Tran, Dai Lam; Le, Van Hong; Linh Pham, Hoai; Nhung Hoang, Thi My; Quy Nguyen, Thi; Luong, Thien Tai; Thu Ha, Phuong; Phuc Nguyen, Xuan

    2010-12-01

    This paper presents an overview of syntheses and applications of magnetic nanoparticles (MNPs) at the Institute of Materials Science, Vietnam Academy of Science and Technology. Three families of oxide MNPs, magnetite, manganite and spinel ferrite materials, were prepared in various ways: coprecipitation, sol-gel and high energy mechanical milling. Basic properties of MNPs were characterized by Vibrating Sample Magnetometer (VSM) and Physical Properties Measurement Systems (PPMS). As for biomedical application, the aim was to design a novel multifunctional, nanosized magnetofluorescent water-dispersible Fe3O4-curcumin conjugate, and its ability to label, target and treat tumor cells was described. The conjugate possesses a magnetic nano Fe3O4 core, chitosan (CS) or Oleic acid (OL) as an outer shell and entrapped curcumin (Cur), serving the dual function of naturally autofluorescent dye as well as antitumor model drug. Fe3O4-Cur conjugate exhibited a high loading cellular uptake with the help of a macrophage, which was clearly visualized dually by Fluorescence Microscope and Laser Scanning Confocal Microscope (LSCM), as well as by magnetization measurement (PPMS). A preliminary magnetic resonance imaging (MRI) study also showed a clear contrast enhancement by using the conjugate. As for the environmental aspect, the use of magnetite MNPs for the removal of heavy toxic metals, such as Arsenic (As) and Lead (Pb), from contaminated water was studied.

  4. Preparation and testing of quaternized chitosan nanoparticles as gene delivery vehicles.

    PubMed

    Li, Guang-Feng; Wang, Jing-Cheng; Feng, Xin-Min; Liu, Zhen-Dong; Jiang, Chao-Yong; Yang, Jian-Dong

    2015-04-01

    The aim of this study was to synthesize a chitosan (CS) derivative, a quaternary ammonium salt crystal called N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HACC), and test a series of HACC and pEGFP-DNA complexes at different weight ratios for their efficiency of gene delivery into human cells. CS was modified with cationic etherifying agent to obtain the CS derivative. Fourier transform infrared spectra were recorded on KBr pellets with a spectrometer. (1)H nuclear magnetic resonance (NMR) spectra of HACC were obtained using a spectrometer. HACC was subsequently used to prepare HACC/DNA complexes at different weight ratios by coacervation method. The resulting particle size and surface charge were assessed by laser light scattering using a zeta potential analyzer. The HACC/DNA complex formation and DNA protection in the nanoparticle complex was investigated by gel mobility shift assay and DNase I protection assay, respectively. The cytotoxicity of HACC and HACC/DNA nanoparticles was evaluated by MTT assay using (mesenchymal stem cell) MSC lines. The nanoscale structure of the particles was obtained by transmission electron microscope (TEM). The FTIR spectrum of HACC showed the characteristic quaternary ammonium group absorption band at 1475 cm(-1), which indicated the presence of quaternary ammonium group. The successful synthesis of HACC was also confirmed by (1)H NMR spectrum. HACC showed good solubility in water and was electropositive. HACC efficiently packed and protected pEGFP-DNA at a weight ratio of 10. With increased weight ratios, the surface charge of the composite particle increased from negative to positive, the average particle size increased, and HACC nanoparticle had a higher carrying efficiency. The nanoparticles released DNA in two distinct phases, and 55 % was released within the first 20 h of solubilization. The nanoparticles under TEM showed circular or oval shapes. The particles exhibited no cytotoxicity against human cells. No

  5. Preparation and testing of quaternized chitosan nanoparticles as gene delivery vehicles.

    PubMed

    Li, Guang-Feng; Wang, Jing-Cheng; Feng, Xin-Min; Liu, Zhen-Dong; Jiang, Chao-Yong; Yang, Jian-Dong

    2015-04-01

    The aim of this study was to synthesize a chitosan (CS) derivative, a quaternary ammonium salt crystal called N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HACC), and test a series of HACC and pEGFP-DNA complexes at different weight ratios for their efficiency of gene delivery into human cells. CS was modified with cationic etherifying agent to obtain the CS derivative. Fourier transform infrared spectra were recorded on KBr pellets with a spectrometer. (1)H nuclear magnetic resonance (NMR) spectra of HACC were obtained using a spectrometer. HACC was subsequently used to prepare HACC/DNA complexes at different weight ratios by coacervation method. The resulting particle size and surface charge were assessed by laser light scattering using a zeta potential analyzer. The HACC/DNA complex formation and DNA protection in the nanoparticle complex was investigated by gel mobility shift assay and DNase I protection assay, respectively. The cytotoxicity of HACC and HACC/DNA nanoparticles was evaluated by MTT assay using (mesenchymal stem cell) MSC lines. The nanoscale structure of the particles was obtained by transmission electron microscope (TEM). The FTIR spectrum of HACC showed the characteristic quaternary ammonium group absorption band at 1475 cm(-1), which indicated the presence of quaternary ammonium group. The successful synthesis of HACC was also confirmed by (1)H NMR spectrum. HACC showed good solubility in water and was electropositive. HACC efficiently packed and protected pEGFP-DNA at a weight ratio of 10. With increased weight ratios, the surface charge of the composite particle increased from negative to positive, the average particle size increased, and HACC nanoparticle had a higher carrying efficiency. The nanoparticles released DNA in two distinct phases, and 55 % was released within the first 20 h of solubilization. The nanoparticles under TEM showed circular or oval shapes. The particles exhibited no cytotoxicity against human cells. No

  6. Development of chitosan-pullulan composite nanoparticles for nasal delivery of vaccines: in vivo studies.

    PubMed

    Cevher, Erdal; Salomon, Stefan K; Somavarapu, Satyanarayana; Brocchini, Steve; Alpar, H Oya

    2015-01-01

    Here, we aimed at developing chitosan/pullulan composite nanoparticles and testing their potential as novel systems for the nasal delivery of diphtheria toxoid (DT). All the chitosan derivatives [N-trimethyl (TMC), chloride and glutamate] and carboxymethyl pullulan (CMP) were synthesised and antigen-loaded composites were prepared by polyion complexation of chitosan and pullulan derivatives (particle size: 239-405 nm; surface charge: +18 and +27 mV). Their immunological effects after intranasal administration to mice were compared to intramuscular route. Composite nanoparticles induced higher levels of IgG responses than particles formed with chitosan derivative and antigen. Nasally administered TMC-pullulan composites showed higher DT serum IgG titre when compared with the other composites. Co-encapsulation of CpG ODN within TMC-CMP-DT nanoparticles resulted in a balanced Th1/Th2 response. TMC/pullulan composite nanoparticles also induced highest cytokine levels compared to those of chitosan salts. These findings demonstrated that TMC-CMP-DT composite nanoparticles are promising delivery system for nasal vaccination. PMID:26480962

  7. Enzymatic Synthesis of Magnetic Nanoparticles

    PubMed Central

    Kolhatkar, Arati G.; Dannongoda, Chamath; Kourentzi, Katerina; Jamison, Andrew C.; Nekrashevich, Ivan; Kar, Archana; Cacao, Eliedonna; Strych, Ulrich; Rusakova, Irene; Martirosyan, Karen S.; Litvinov, Dmitri; Lee, T. Randall; Willson, Richard C.

    2015-01-01

    We report the first in vitro enzymatic synthesis of paramagnetic and antiferromagnetic nanoparticles toward magnetic ELISA reporting. With our procedure, alkaline phosphatase catalyzes the dephosphorylation of l-ascorbic-2-phosphate, which then serves as a reducing agent for salts of iron, gadolinium, and holmium, forming magnetic precipitates of Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5. The nanoparticles were found to be paramagnetic at 300 K and antiferromagnetic under 25 K. Although weakly magnetic at 300 K, the room-temperature magnetization of the nanoparticles found here is considerably greater than that of analogous chemically-synthesized LnxFeyOz (Ln = Gd, Ho) samples reported previously. At 5 K, the nanoparticles showed a significantly higher saturation magnetization of 45 and 30 emu/g for Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5, respectively. Our approach of enzymatically synthesizing magnetic labels reduces the cost and avoids diffusional mass-transfer limitations associated with pre-synthesized magnetic reporter particles, while retaining the advantages of magnetic sensing. PMID:25854425

  8. Enzymatic synthesis of magnetic nanoparticles.

    PubMed

    Kolhatkar, Arati G; Dannongoda, Chamath; Kourentzi, Katerina; Jamison, Andrew C; Nekrashevich, Ivan; Kar, Archana; Cacao, Eliedonna; Strych, Ulrich; Rusakova, Irene; Martirosyan, Karen S; Litvinov, Dmitri; Lee, T Randall; Willson, Richard C

    2015-01-01

    We report the first in vitro enzymatic synthesis of paramagnetic and antiferromagnetic nanoparticles toward magnetic ELISA reporting. With our procedure, alkaline phosphatase catalyzes the dephosphorylation of l-ascorbic-2-phosphate, which then serves as a reducing agent for salts of iron, gadolinium, and holmium, forming magnetic precipitates of Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5. The nanoparticles were found to be paramagnetic at 300 K and antiferromagnetic under 25 K. Although weakly magnetic at 300 K, the room-temperature magnetization of the nanoparticles found here is considerably greater than that of analogous chemically-synthesized LnxFeyOz (Ln = Gd, Ho) samples reported previously. At 5 K, the nanoparticles showed a significantly higher saturation magnetization of 45 and 30 emu/g for Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5, respectively. Our approach of enzymatically synthesizing magnetic labels reduces the cost and avoids diffusional mass-transfer limitations associated with pre-synthesized magnetic reporter particles, while retaining the advantages of magnetic sensing. PMID:25854425

  9. Enzymatic synthesis of magnetic nanoparticles.

    PubMed

    Kolhatkar, Arati G; Dannongoda, Chamath; Kourentzi, Katerina; Jamison, Andrew C; Nekrashevich, Ivan; Kar, Archana; Cacao, Eliedonna; Strych, Ulrich; Rusakova, Irene; Martirosyan, Karen S; Litvinov, Dmitri; Lee, T Randall; Willson, Richard C

    2015-01-01

    We report the first in vitro enzymatic synthesis of paramagnetic and antiferromagnetic nanoparticles toward magnetic ELISA reporting. With our procedure, alkaline phosphatase catalyzes the dephosphorylation of l-ascorbic-2-phosphate, which then serves as a reducing agent for salts of iron, gadolinium, and holmium, forming magnetic precipitates of Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5. The nanoparticles were found to be paramagnetic at 300 K and antiferromagnetic under 25 K. Although weakly magnetic at 300 K, the room-temperature magnetization of the nanoparticles found here is considerably greater than that of analogous chemically-synthesized LnxFeyOz (Ln = Gd, Ho) samples reported previously. At 5 K, the nanoparticles showed a significantly higher saturation magnetization of 45 and 30 emu/g for Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5, respectively. Our approach of enzymatically synthesizing magnetic labels reduces the cost and avoids diffusional mass-transfer limitations associated with pre-synthesized magnetic reporter particles, while retaining the advantages of magnetic sensing.

  10. Shear thinning three-dimensional colloidal assemblies of chitosan and poly(lactic acid) nanoparticles.

    PubMed

    Roux, Rémi; Ladavière, Catherine; Montembault, Alexandra; David, Laurent; Delair, Thierry

    2013-06-20

    In this study, new materials capable of reversible self-assembly, based on concentrated negatively charged poly(lactic acid) nanoparticles and chitosan, a natural polycationic polymer, were successfully fabricated. Electrostatic interactions between oppositely charged components along with weaker interactions led to the formation of a 3D network. The resulting macroscopic assemblies were characterized by dynamic mechanical measurements, and the influences of various parameters such as chitosan/poly(lactic acid) weight ratio, duration and temperature of the mixture, and molecular weight or chitosan degree of acetylation were studied. Our results showed that the mechanical properties of assemblies were highly dependent on the nanoparticle solid content and chitosan/nanoparticle ratio. In particular, at an optimum weight ratio the colloidal assemblies exhibited remarkable high elastic moduli (about 300 kPa) for a particle solid content of 18% w/w. Thanks to the weak and reversible nature of the interactions, these materials exhibited shear thinning properties, and could instantly recover their cohesiveness at rest. The mode of interactions between PLA particles and chitosan was shown to be in part due to electrostatic interactions, but the cross-linking of chitosan-covered particles was attributed to hydrogen bonding. These materials could be envisaged as good candidates for injectable scaffolds for tissue engineering, taking advantage of the biocompatibility and bioactivity of both components. However, some issues concerning temperature stability must be resolved before applying these colloidal assemblies to cell growth in physiological conditions.

  11. Permeability of exendin-4-loaded chitosan nanoparticles across MDCK cell monolayers and rat small intestine.

    PubMed

    Wang, Mengshu; Zhang, Yong; Sun, Bingxue; Sun, Yanan; Gong, Xin; Wu, Yongge; Zhang, Xizhen; Kong, Wei; Chen, Yan

    2014-01-01

    The purpose of this study was to investigate the permeability of exendin-4-loaded chitosan nanoparticles using the Madin Darby canine kidney (MDCK) cell monolayer as an in vitro model and the rat intestine as an ex vivo model of the human intestinal barrier. A series of formulations of sodium tripolyphosphate (TPP) and chitosan with different molecular weights and degrees of deacetylation was evaluated. The formulation consisting of 0.1% TPP and 0.2% chitosan (400 kDa, 95% degree of deacetylation), which gave optimized monodispersed particle size (303.1±10.36 nm), zeta potential (18.37±1.15 mV) and encapsulation efficiency (38.0±2.6%), was used for further analysis. After determining their biocompatibility, the transport potential of drug-loaded chitosan nanoparticles was evaluated and compared with free exendin-4 using both MDCK cell monolayers and different rat intestinal segments. Mechanisms underlying enhanced transport of exendin-4 in the cell model were also explored. Compared with free exendin-4, the absorption of optimized chitosan nanoparticles was enhanced by 4.7-fold in MDCK cell monolayers and by 2.0-2.78-fold in different rat intestinal segments, with no significant difference between the duodenum, jejunum and ileum. As supported by confocal laser scanning microscopic analysis, the lower enhancement of absorption in the intestine compared to the cell monolayer likely resulted from the chitosan nanoparticle-mediated opening of cellular tight junctions and not through intracellular transport. These findings suggest that the potential application of chitosan nanoparticles as delivery carriers of exendin-4 is limited and may need further modifications.

  12. Polythiophene-Chitosan Magnetic Nanocomposite as a Highly Efficient Medium for Isolation of Fluoxetine from Aqueous and Biological Samples.

    PubMed

    Feizbakhsh, Alireza; Sarrafi, Amir Hossein Mohsen; Ehteshami, Shokooh

    2016-01-01

    Polythiophene/chitosan magnetic nanocomposite as an adsorbent of magnetic solid phase extraction was proposed for the isolation of fluoxetine in aqueous and biological samples prior to fluorescence detection at 246 nm. The synthesized nanoparticles, chitosan and polythiophene magnetic nanocomposite, were characterized by scanning electron microscopy, FT-IR, TGA, and EDAX. The separation of the target analyte from the aqueous solution containing the fluoxetine and polythiophene/chitosan magnetic nanocomposite was simply achieved by applying external magnetic field. The main factors affecting the extraction efficiency including desorption conditions, extraction time, ionic strength, and sample solution pH were optimized. The optimum extraction conditions were obtained as 10 min for extraction time, 25 mg for sorbent amount, 50 mL for initial sample volume, methanol as desorption solvent, 1.5 mL for desorption solvent volume, 3 min for desorption time, and being without salt addition. Under the optimum conditions, good linearity was obtained within the range of 15-1000 μg L(-1) for fluoxetine, with correlation coefficients 0.9994. Furthermore, the method was successfully applied to the determination of fluoxetine in urine and human blood plasma samples. Compared with other methods, the current method is characterized with highly easy, fast separation and low detection limits. PMID:27672478

  13. Polythiophene-Chitosan Magnetic Nanocomposite as a Highly Efficient Medium for Isolation of Fluoxetine from Aqueous and Biological Samples

    PubMed Central

    Sarrafi, Amir Hossein Mohsen

    2016-01-01

    Polythiophene/chitosan magnetic nanocomposite as an adsorbent of magnetic solid phase extraction was proposed for the isolation of fluoxetine in aqueous and biological samples prior to fluorescence detection at 246 nm. The synthesized nanoparticles, chitosan and polythiophene magnetic nanocomposite, were characterized by scanning electron microscopy, FT-IR, TGA, and EDAX. The separation of the target analyte from the aqueous solution containing the fluoxetine and polythiophene/chitosan magnetic nanocomposite was simply achieved by applying external magnetic field. The main factors affecting the extraction efficiency including desorption conditions, extraction time, ionic strength, and sample solution pH were optimized. The optimum extraction conditions were obtained as 10 min for extraction time, 25 mg for sorbent amount, 50 mL for initial sample volume, methanol as desorption solvent, 1.5 mL for desorption solvent volume, 3 min for desorption time, and being without salt addition. Under the optimum conditions, good linearity was obtained within the range of 15–1000 μg L−1 for fluoxetine, with correlation coefficients 0.9994. Furthermore, the method was successfully applied to the determination of fluoxetine in urine and human blood plasma samples. Compared with other methods, the current method is characterized with highly easy, fast separation and low detection limits. PMID:27672478

  14. Polythiophene-Chitosan Magnetic Nanocomposite as a Highly Efficient Medium for Isolation of Fluoxetine from Aqueous and Biological Samples

    PubMed Central

    Sarrafi, Amir Hossein Mohsen

    2016-01-01

    Polythiophene/chitosan magnetic nanocomposite as an adsorbent of magnetic solid phase extraction was proposed for the isolation of fluoxetine in aqueous and biological samples prior to fluorescence detection at 246 nm. The synthesized nanoparticles, chitosan and polythiophene magnetic nanocomposite, were characterized by scanning electron microscopy, FT-IR, TGA, and EDAX. The separation of the target analyte from the aqueous solution containing the fluoxetine and polythiophene/chitosan magnetic nanocomposite was simply achieved by applying external magnetic field. The main factors affecting the extraction efficiency including desorption conditions, extraction time, ionic strength, and sample solution pH were optimized. The optimum extraction conditions were obtained as 10 min for extraction time, 25 mg for sorbent amount, 50 mL for initial sample volume, methanol as desorption solvent, 1.5 mL for desorption solvent volume, 3 min for desorption time, and being without salt addition. Under the optimum conditions, good linearity was obtained within the range of 15–1000 μg L−1 for fluoxetine, with correlation coefficients 0.9994. Furthermore, the method was successfully applied to the determination of fluoxetine in urine and human blood plasma samples. Compared with other methods, the current method is characterized with highly easy, fast separation and low detection limits.

  15. In vitro release and biological activities of Carum copticum essential oil (CEO) loaded chitosan nanoparticles.

    PubMed

    Esmaeili, Akbar; Asgari, Azadeh

    2015-11-01

    In recent years, the unparalleled and functional properties of essential oils have been extensively reported, but the sensitivity of essential oils to environmental factors and their poor aqueous solubility have limited their applications in industries. Hence, we encapsulated CEO in chitosan nanoparticles by an emulsion-ionic gelation with pantasodium tripolyphosphate (TPP) and sodium hexametaphosphte (HMP), separately, as crosslinkers. The nanoparticles were analyzed by Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and dynamic light scattering (DLS). The encapsulation efficiency (EE) and loading capacity (LC) of CEO in chitosan nanoparticles increased with the increase of initial CEO amount. The nanoparticles displayed an average size of 30-80nm with a spherical shape and regular distribution. In vitro release profiles exhibited an initial burst release and followed by a sustained CEO release at different pH conditions. The amount of CEO release from chitosan nanoparticles was higher in acidic pH to basic or neutral pH, respectively. The biological properties of CEO, before and after the encapsulation process were evaluated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and agar disk diffusion method, respectively. The results indicated the encapsulation of CEO in chitosan nanoparticles could be protected the quality. PMID:26257380

  16. In vitro release and biological activities of Carum copticum essential oil (CEO) loaded chitosan nanoparticles.

    PubMed

    Esmaeili, Akbar; Asgari, Azadeh

    2015-11-01

    In recent years, the unparalleled and functional properties of essential oils have been extensively reported, but the sensitivity of essential oils to environmental factors and their poor aqueous solubility have limited their applications in industries. Hence, we encapsulated CEO in chitosan nanoparticles by an emulsion-ionic gelation with pantasodium tripolyphosphate (TPP) and sodium hexametaphosphte (HMP), separately, as crosslinkers. The nanoparticles were analyzed by Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and dynamic light scattering (DLS). The encapsulation efficiency (EE) and loading capacity (LC) of CEO in chitosan nanoparticles increased with the increase of initial CEO amount. The nanoparticles displayed an average size of 30-80nm with a spherical shape and regular distribution. In vitro release profiles exhibited an initial burst release and followed by a sustained CEO release at different pH conditions. The amount of CEO release from chitosan nanoparticles was higher in acidic pH to basic or neutral pH, respectively. The biological properties of CEO, before and after the encapsulation process were evaluated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and agar disk diffusion method, respectively. The results indicated the encapsulation of CEO in chitosan nanoparticles could be protected the quality.

  17. Chitosan-based nanoparticles as drug delivery systems for doxorubicin: Optimization and modelling.

    PubMed

    Soares, Paula I P; Sousa, Ana Isabel; Silva, Jorge Carvalho; Ferreira, Isabel M M; Novo, Carlos M M; Borges, João Paulo

    2016-08-20

    In the present work, two drug delivery systems were produced by encapsulating doxorubicin into chitosan and O-HTCC (ammonium-quaternary derivative of chitosan) nanoparticles. The results show that doxorubicin release is independent of the molecular weight and is higher at acidic pH (4.5) than at physiological pH. NPs with an average hydrodynamic diameter bellow 200nm are able to encapsulate up to 70% and 50% of doxorubicin in the case of chitosan and O-HTCC nanoparticles, respectively. O-HTCC nanoparticles led to a higher amount of doxorubicin released than chitosan nanoparticles, for the same experimental conditions, although the release mechanism was not altered. A burst effect occurs within the first hours of release, reaching a plateau after 24h. Fitting mathematical models to the experimental data led to a concordant release mechanism between most samples, indicating an anomalous or mixed release, which is in agreement with the swelling behavior of chitosan described in the literature.

  18. Collagen-chitosan scaffold modified with Au and Ag nanoparticles: Synthesis and structure

    NASA Astrophysics Data System (ADS)

    Rubina, M. S.; Kamitov, E. E.; Zubavichus, Ya. V.; Peters, G. S.; Naumkin, A. V.; Suzer, S.; Vasil'kov, A. Yu.

    2016-03-01

    Nowadays, the dermal biomimetic scaffolds are widely used in regenerative medicine. Collagen-chitosan scaffold one of these materials possesses antibacterial activity, good compatibility with living tissues and has been already used as a wound-healing material. In this article, collagen-chitosan scaffolds modified with Ag and Au nanoparticles have been synthesized using novel method - the metal-vapor synthesis. The nanocomposite materials are characterized by XPS, TEM, SEM and synchrotron radiation-based X-ray techniques. According to XRD data, the mean size of the nanoparticles (NPs) is 10.5 nm and 20.2 nm in Au-Collagen-Chitosan (Au-CollCh) and Ag-Collagen-Chitosan (Ag-CollCh) scaffolds, respectively in fair agreement with the TEM data. SAXS analysis of the composites reveals an asymmetric size distribution peaked at 10 nm for Au-CollCh and 25 nm for Ag-CollCh indicative of particle's aggregation. According to SEM data, the metal-carrying scaffolds have layered structure and the nanoparticles are rather uniformly distributed on the surface material. XPS data indicate that the metallic nanoparticles are in their unoxidized/neutral states and dominantly stabilized within the chitosan-rich domains.

  19. Composite particles formed by complexation of poly(methacrylic acid) - stabilized magnetic fluid with chitosan: Magnetic material for bioapplications.

    PubMed

    Safarik, Ivo; Stepanek, Miroslav; Uchman, Mariusz; Slouf, Miroslav; Baldikova, Eva; Nydlova, Leona; Pospiskova, Kristyna; Safarikova, Mirka

    2016-10-01

    A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates. PMID:27287146

  20. Composite particles formed by complexation of poly(methacrylic acid) - stabilized magnetic fluid with chitosan: Magnetic material for bioapplications.

    PubMed

    Safarik, Ivo; Stepanek, Miroslav; Uchman, Mariusz; Slouf, Miroslav; Baldikova, Eva; Nydlova, Leona; Pospiskova, Kristyna; Safarikova, Mirka

    2016-10-01

    A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates.

  1. Targeting silymarin for improved hepatoprotective activity through chitosan nanoparticles

    PubMed Central

    Gupta, Swati; Singh, Shailendra Kumar; Girotra, Priti

    2014-01-01

    Introduction: Silymarin is one of the best known hepatoprotective drugs, which is obtained from the seeds of Silybum marianum L., Family: Asteraceae or Compositae. The plant has traditionally been used for centuries as a natural remedy for liver and biliary tract diseases. The aim of the present investigation was to enhance the hepatoprotective activity of silymarin by incorporating it in chitosan (Ch) nanoparticles (NPs) for passive targeted delivery, thereby prolonging its retention time. Materials and Methods: Silymarin loaded NPs were prepared by ionic gelation technique, which were then optimized using a central composite design in order to minimize the particle size and maximize the drug entrapment efficiency. The optimized formulation was evaluated for in vitro drug release study and in vitro study on Swiss Albino mice using carbon tetrachloride (CCL4) induced hepatotoxicity model. Results: In vitro dissolution studies illustrated sustained, zero order drug release from optimized formulation; also its therapeutic potential was amplified during in vitro studies on Swiss Albino mice using CCL4 induced hepatotoxicity model. Conclusion: The results suggested that NPs of silymarin could successfully enhance its hepatoprotective effect by passive targeting and sustained release. PMID:25426436

  2. Chitosan/bioactive glass nanoparticle composite membranes for periodontal regeneration.

    PubMed

    Mota, Joana; Yu, Na; Caridade, Sofia G; Luz, Gisela M; Gomes, Manuela E; Reis, Rui L; Jansen, John A; Walboomers, X Frank; Mano, João F

    2012-11-01

    Barrier membranes are used in periodontal applications with the aim of supporting periodontal regeneration by physically blocking migration of epithelial cells. The present work proposes a combination of chitosan (CHT) with bioactive glass nanoparticles (BG-NPs) in order to produce a novel guided tissue and bone regeneration membrane, fabricated by solvent casting. The CHT/BG-NP nanocomposite membranes are characterized in terms of water uptake, in mechanical tests, under simulated physiological conditions and in in vitro bioactivity tests. The addition of BG-NPs to CHT membranes decreased the mechanical potential of these membranes, but on the other hand the bioactivity improved. The membranes containing the BG-NPs induced the precipitation of bone-like apatite in simulated body fluid (SBF). Biological tests were carried out using human periodontal ligament cells and human bone marrow stromal cells. CHT/BG-NP composite membranes promoted cell metabolic activity and mineralization. The results indicate that the CHT/BG-NP composite membrane could potentially be used as a temporary guided tissue regeneration membrane in periodontal regeneration, with the possibility to induce bone regeneration. PMID:22771458

  3. Regioselective Sequential Modification of Chitosan via Azide-Alkyne Click Reaction: Synthesis, Characterization, and Antimicrobial Activity of Chitosan Derivatives and Nanoparticles.

    PubMed

    Sarwar, Atif; Katas, Haliza; Samsudin, Siti Noradila; Zin, Noraziah Mohamad

    2015-01-01

    Recently, the attention of researchers has been drawn toward the synthesis of chitosan derivatives and their nanoparticles with enhanced antimicrobial activities. In this study, chitosan derivatives with different azides and alkyne groups were synthesized using click chemistry, and these were further transformed into nanoparticles by using the ionotropic gelation method. A series of chitosan derivatives was successfully synthesized by regioselective modification of chitosan via an azide-alkyne click reaction. The amino moieties of chitosan were protected during derivatization by pthaloylation and subsequently unblocked at the end to restore their functionality. Nanoparticles of synthesized derivatives were fabricated by ionic gelation to form complexes of polyanionic penta-sodium tripolyphosphate (TPP) and cationic chitosan derivatives. Particle size analysis showed that nanoparticle size ranged from 181.03 ± 12.73 nm to 236.50 ± 14.32 nm and had narrow polydispersity index and positive surface charge. The derivatives and corresponding nanoparticles were evaluated in vitro for antibacterial and antifungal activities against three gram-positive and gram-negative bacteria and three fungal strains, respectively. The minimum inhibitory concentration (MIC) of all derivatives ranged from 31.3 to 250 µg/mL for bacteria and 188 to1500 µg/mL for fungi and was lower than that of native chitosan. The nanoparticles with MIC ranging from 1.56 to 25 µg/mLfor bacteria and 94 to 750 µg/mL for fungi exhibited higher activity than the chitosan derivatives. Chitosan O-(1-methylbenzene) triazolyl carbamate and chitosan O-(1-methyl phenyl sulfide) triazolyl carbamate were the most active against the tested bacterial and fungal strains. The hemolytic assay on erythrocytes and cell viability test on two different cell lines (Chinese hamster lung fibroblast cells V79 and Human hepatic cell line WRL68) demonstrated the safety; suggesting that these derivatives could be used in future

  4. Chitosan and carboxymethyl-chitosan capping ligands: Effects on the nucleation and growth of hydroxyapatite nanoparticles for producing biocomposite membranes.

    PubMed

    Dumont, Vitor C; Mansur, Alexandra A P; Carvalho, Sandhra M; Medeiros Borsagli, Fernanda G L; Pereira, Marivalda M; Mansur, Herman S

    2016-02-01

    Synthetic biomaterials based on calcium phosphates (CaP) have been widely studied for bone tissue reconstruction therapies, but no definitive solution that fulfills all of the required properties has been identified. Thus, this study reports the synthesis of composite membranes based on nanohydroxyapatite particles (nHA) embedded in chitosan (CHI) and O-carboxymethyl chitosan (CMC) matrices produced using a one-step co-precipitation method in water media. Biopolymers were used as capping ligands for simultaneously controlling the nucleation and growth of the nHA particles during the precipitation process and also to form the polymeric network of the biocomposites. The bionanocomposites were extensively characterized using light microscopy (LM), scanning and transmission electron microscopy (SEM/TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray micro-CT analysis (μCT), andMTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazoliumbromide) cell proliferation assays for cell cytotoxicity. The results demonstrated that the ligands used during the synthesis highly affected the composites produced, primarily due the changes in the mechanisms and kinetics of nucleation and growth of the HA particles at the nanoscale level. The SEMimages revealed that the use of carboxyl-functionalized chitosan (CMC) ligands significantly reduced the average size of theHA nanoparticles and caused the formation of a narrower size distribution (90±20nm) compared to theHAnanoparticles producedwith chitosan ligands (220±50nm). The same trend was verified by the AFM analysis,where the nHA particles were formed evenly dispersed in the polymer matrix. However, the CMC-based composites were more homogeneously distributed, which was endorsed by the images collected via X-ray micro-CT. The FTIR spectra and the XRD analysis indicated that nanosized hydroxyapatite was the predominant calcium

  5. Chitosan and carboxymethyl-chitosan capping ligands: Effects on the nucleation and growth of hydroxyapatite nanoparticles for producing biocomposite membranes.

    PubMed

    Dumont, Vitor C; Mansur, Alexandra A P; Carvalho, Sandhra M; Medeiros Borsagli, Fernanda G L; Pereira, Marivalda M; Mansur, Herman S

    2016-02-01

    Synthetic biomaterials based on calcium phosphates (CaP) have been widely studied for bone tissue reconstruction therapies, but no definitive solution that fulfills all of the required properties has been identified. Thus, this study reports the synthesis of composite membranes based on nanohydroxyapatite particles (nHA) embedded in chitosan (CHI) and O-carboxymethyl chitosan (CMC) matrices produced using a one-step co-precipitation method in water media. Biopolymers were used as capping ligands for simultaneously controlling the nucleation and growth of the nHA particles during the precipitation process and also to form the polymeric network of the biocomposites. The bionanocomposites were extensively characterized using light microscopy (LM), scanning and transmission electron microscopy (SEM/TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray micro-CT analysis (μCT), andMTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazoliumbromide) cell proliferation assays for cell cytotoxicity. The results demonstrated that the ligands used during the synthesis highly affected the composites produced, primarily due the changes in the mechanisms and kinetics of nucleation and growth of the HA particles at the nanoscale level. The SEMimages revealed that the use of carboxyl-functionalized chitosan (CMC) ligands significantly reduced the average size of theHA nanoparticles and caused the formation of a narrower size distribution (90±20nm) compared to theHAnanoparticles producedwith chitosan ligands (220±50nm). The same trend was verified by the AFM analysis,where the nHA particles were formed evenly dispersed in the polymer matrix. However, the CMC-based composites were more homogeneously distributed, which was endorsed by the images collected via X-ray micro-CT. The FTIR spectra and the XRD analysis indicated that nanosized hydroxyapatite was the predominant calcium

  6. Preparation and characterization of ferrofluid stabilized with biocompatible chitosan and dextran sulfate hybrid biopolymer as a potential magnetic resonance imaging (MRI) T2 contrast agent.

    PubMed

    Tsai, Zei-Tsan; Tsai, Fu-Yuan; Yang, Wei-Cheng; Wang, Jen-Fei; Liu, Chao-Lin; Shen, Chia-Rui; Yen, Tzu-Chen

    2012-11-01

    Chitosan is the deacetylated form of chitin and used in numerous applications. Because it is a good dispersant for metal and/or oxide nanoparticle synthesis, chitosan and its derivatives have been utilized as coating agents for magnetic nanoparticles synthesis, including superparamagnetic iron oxide nanoparticles (SPIONs). Herein, we demonstrate the water-soluble SPIONs encapsulated with a hybrid polymer composed of polyelectrolyte complexes (PECs) from chitosan, the positively charged polymer, and dextran sulfate, the negatively charged polymer. The as-prepared hybrid ferrofluid, in which iron chloride salts (Fe³⁺ and Fe²⁺) were directly coprecipitated inside the hybrid polymeric matrices, was physic-chemically characterized. Its features include the z-average diameter of 114.3 nm, polydispersity index of 0.174, zeta potential of −41.5 mV and iron concentration of 8.44 mg Fe/mL. Moreover, based on the polymer chain persistence lengths, the anionic surface of the nanoparticles as well as the high R2/R1 ratio of 13.5, we depict the morphology of SPIONs as a cluster because chitosan chains are chemisorbed onto the anionic magnetite surfaces by tangling of the dextran sulfate. Finally, the cellular uptake and biocompatibility assays indicate that the hybrid polymer encapsulating the SPIONs exhibited great potential as a magnetic resonance imaging T2 contrast agent for cell tracking. PMID:23203267

  7. Chitosan nanoparticle induced defense responses in fingermillet plants against blast disease caused by Pyricularia grisea (Cke.) Sacc.

    PubMed

    Sathiyabama, Muthukrishnan; Manikandan, Appu

    2016-12-10

    The in vitro antifungal properties of chitosan nanoparticle and its role in protection of fingermillet plants from blast disease were evaluated. Chitosan nanoparticle inhibited the radial growth of Pyricularia grisea indicating the antifungal property. Application of chitosan nanoparticle delayed blast symptom expression on fingermillet leaves for 25days while it was on 15day in control plants. Chitosan naoparticle was able to induce the reactive oxygen species and the level of peroxidase actvitiy in leaves of fingermillet, which might be the reason for delayed symptom. The treated plants showed reduced disease incidence when compared to untreated control plants. These results suggested the role of chitosan nanoparticle in protecting fingermillet plants from P. grisea infection. PMID:27577915

  8. Magnetic nanoparticles for "smart liposomes".

    PubMed

    Nakayama, Yoshitaka; Mustapić, Mislav; Ebrahimian, Haleh; Wagner, Pawel; Kim, Jung Ho; Hossain, Md Shahriar Al; Horvat, Joseph; Martinac, Boris

    2015-12-01

    Liposomal drug delivery systems (LDDSs) are promising tools used for the treatment of diseases where highly toxic pharmacological agents are administered. Currently, destabilising LDDSs by a specific stimulus at a target site remains a major challenge. The bacterial mechanosensitive channel of large conductance (MscL) presents an excellent candidate biomolecule that could be employed as a remotely controlled pore-forming nanovalve for triggered drug release from LDDSs. In this study, we developed superparamagnetic nanoparticles for activation of the MscL nanovalves by magnetic field. Synthesised CoFe2O4 nanoparticles with the radius less than 10 nm were labelled by SH groups for attachment to MscL. Activation of MscL by magnetic field with the nanoparticles attached was examined by the patch clamp technique showing that the number of activated channels under ramp pressure increased upon application of the magnetic field. In addition, we have not observed any cytotoxicity of the nanoparticles in human cultured cells. Our study suggests the possibility of using magnetic nanoparticles as a specific trigger for activation of MscL nanovalves for drug release in LDDSs. PMID:26184724

  9. Investigation of Size and Morphology of Chitosan Nanoparticles Used in Drug Delivery System Employing Chemometric Technique

    PubMed Central

    Khanmohammadi, Mohammadreza; Elmizadeh, Hamideh; Ghasemi, Keyvan

    2015-01-01

    The polymeric nanoparticles are prepared from biocompatible polymers in size between 10-1000 nm. Chitosan is a biocompatible polymer that - can be utilized as drug delivery systems. In this study, chitosan nanoparticles were synthesized using an optimized spontaneous emulsification method. Determining particle size and morphology are two critical parameters in nanotechnology. The aim of this study is to introduce methodology based on relation between particle size and diffuse reflectance infrared fourier transform (DRIFT) spectroscopy technique. Partial least squares (PLS) technique was used to estimate the average particle size based on DRIFT spectra. Forty two different chitosan nanoparticle samples with different particle sizes were analyzed using DRIFT spectrometry and the obtained data were processed by PLS. Results obtained from the real samples were compared to those obtained using field emission scanning electron microscope(FE-SEM) as a reference method. It was observed that PLS could correctly predict the average particle size of synthesized sample. Nanoparticles and their morphological state were determined by FE-SEM. Based on morphological characteristics analyzing with proposed method the samples were separated into two groups of "appropriate" and "inappropriate". Chemometrics methods such as principal component analysis, cluster analysis (CA) and linear discriminate analysis (LDA) were used to classify chitosan nanoparticles in terms of morphology. The percent of correctly classified samples using LDA were 100 %and 90% for training and test sets, respectively. PMID:26330855

  10. Hexavalent chromium removal from water using chitosan-Fe0 nanoparticles

    NASA Astrophysics Data System (ADS)

    Tielong, Li; Bing, Geng; Na, Zhang; Zhaohui, Jin; Xinhua, Qi

    2009-09-01

    Chitosan-Fe0 nanoparticles (chitosan-Fe0) were prepared using nontoxic and biodegradable chitosan as a stabilizer. Laboratory batch and column experiments were conducted to investigate the feasibility of using chitosan-Fe0 for in situ reductive removal of Cr(VI) from water. Batch kinetic tests indicated that the overall disappearance of Cr(VI) may include both physical adsorption of Cr(VI) onto the chitosan-Fe0 surface and subsequent reduction of Cr(VI) to Cr(III). The rate of reduction of Cr(VI) to Cr(III) can be expressed by a pseudo-first-order reaction kinetics and the rate constants increase with the increase in iron loading. Column experiments indicated that the chitosan-Fe0 were highly deliverable in the column. When the column was treated with Cr(VI) -contaminated deionized water, the removal capacity of chitosan-Fe0 was found to be about 32 mg Cr/g Fe(0). A 25% drop in the Cr(VI) removal capacity was found when treated with Cr(VI)-contaminated surface water.

  11. Chitosan-mediated synthesis of gold nanoparticles by UV photoactivation and their characterization.

    PubMed

    Wei, Dongwei; Qian, Weiping

    2006-08-01

    Recent researches have largely been focused on chitosan, which is deacetylated chitin, the most abundant natural polysaccharide after cellulose. In this paper, we report the fabrication of gold nanoparticles (GNPs) by UV photoactivation in the presence of biopolymeric chitosan and the tracing of the gold salt solution aging. Detailed UV-visible spectroscopy study witnessed the evolution of the surface plasmon resonance (SPR) adsorption during the GNP growth. The effect of chitosan in aqueous solution for the GNP preparation was investigated in detail. The results indicated the size and distribution of GNPs could be controlled over by altering the concentration of chitosan, and the GNP growth during aging was a chitosan-mediated autocatalytic process. Fourier transform infrared spectroscopy (FTIR) showed the hydroxyl in molecular chitosan was oxidized to carbonyl groups in the fabrication of GNPs after aging and nitrogen atoms are the main sites for the complexation of chitosan with Au atoms. Our synthesis method in the present way can be used to form self-assemble monolayers of GNPs and fabricate biosensors based on surface plasmon resonance effect.

  12. Synthesis, characterization and anticorrosion potentials of chitosan-g-PEG assembled on silver nanoparticles.

    PubMed

    Hefni, Hassan H H; Azzam, Eid M; Badr, Emad A; Hussein, M; Tawfik, Salah M

    2016-02-01

    Chitosan (Ch) grafted with poly(ethylene glycol) (Ch-g-mPEG) were synthesized using mPEG with molecular weights 2000 g/mol. The synthesized Ch-g-mPEG was characterized using gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and X-ray diffraction (XRD) techniques. Ch-g-mPEG silver nanoparticles has been synthesized and characterized by high-resolution transmission electron microscopy (HRTEM) and energy dispersive analysis of X-rays (EDAX). The synthesized Ch-g-mPEG and its nanostructure were examined as corrosion inhibitors for carbon steel in 1M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results revealed that the inhibition efficiency obtained by Ch-g-mPEG self-assembled on silver nanoparticles is greater than that obtained by Ch-g-mPEG only. Potentiodynamic polarization results reveal that the synthesized compound could be classified as mixed-type corrosion inhibitors with predominant control of the cathodic reaction. The results of EIS indicate that the both charge transfer resistance and inhibition efficiency tend to increase by increasing the inhibitor concentration.

  13. Alginate/chitosan nanoparticles for encapsulation and controlled release of vitamin B2.

    PubMed

    Azevedo, Maria A; Bourbon, Ana I; Vicente, António A; Cerqueira, Miguel A

    2014-11-01

    This work aims at evaluating encapsulation and controlled release of vitamin B2 from alginate/chitosan nanoparticles. Ionotropic polyelectrolyte pre-gelation was used as production method being chitosan and alginate used as main materials. Nanoparticles were characterized in terms of average size, polydispersity index (PDI), zeta potential and vitamin entrapment efficiency. The average size for alginate/chitosan nanoparticles was 119.5±49.9nm for samples without vitamin B2 and 104.0±67.2nm with the encapsulation of vitamin B2, presenting a PDI of 0.454±0.066 and 0.319±0.068, respectively. The nanoparticles showed encapsulation efficiency and loading capacity values of 55.9±5.6% and 2.2±0.6%, respectively. Release profiles were evaluated at different conditions showing that the polymeric relaxation was the most influent phenomenon in vitamin B2 release. In order to study their stability nanoparticles were stored at 4°C being particles sizes and PDI evaluated during 5 months showing the results that vitamin B2-loaded nanoparticles are more stable (in terms of size and PDI) than nanoparticles without vitamin B2.

  14. Chitosan/sulfobutylether-β-cyclodextrin nanoparticles as a potential approach for ocular drug delivery.

    PubMed

    Mahmoud, Azza A; El-Feky, Gina S; Kamel, Rabab; Awad, Ghada E A

    2011-07-15

    Development of efficient ocular delivery nanosystems remains a major challenge to achieve sustained therapeutic effect. The purpose of this work was to develop chitosan nanoparticles using sulfobutylether-β-cyclodextrin (SBE-β-CD) as polyanionic crosslinker and to investigate the potential of using those nanostructures as ocular drug delivery systems. Econazole nitrate (ECO) was chosen as model drug molecule. The influence of different process variables (chitosan molecular weight and the concentration of the two ionic agents) on particle size, polydispersity index, zeta potential, drug content, in vitro release and mucoadhesive properties was investigated. The results showed that the prepared nanoparticles were predominant spherical in shape having average particle diameter from 90 to 673 nm with positive zeta potential values from 22 to 33 mV and drug content values ranging from 13 to 45%. Drug release from optimized nanoparticles was controlled with approximately 50% of the original amount released over a 8h period. The release profile of nanoparticles followed a zero-order release kinetics. The optimized nanoparticles were tested for their use as ocular drug delivery systems on albino rabbits. The in vivo studies revealed that the prepared mucoadhesive nanoparticles had better ability in sustaining the antifungal effect of ECO than the ECO solution. Therefore, chitosan/SBE-β-CD nanoparticles developed showed a promising carrier for controlled delivery of drug to the eye.

  15. Magnetic Separation Dynamics of Colloidal Magnetic Nanoparticles

    SciTech Connect

    Kaur, M.; Huijin Zhang,; You Qiang,

    2013-01-01

    Surface functionalized magnetic nanoparticles (MNPs) are appealing candidates for analytical separation of heavy metal ions from waste water and separation of actinides from spent nuclear fuel. This work studies the separation dynamics and investigates the appropriate magnetic-field gradients. A dynamic study of colloidal MNPs was performed for steady-state flow. Measurements were conducted to record the separation time of particles as a function of magnetic field gradient. The drag and magnetic forces play a significant role on the separation time. A drop in saturation magnetization and variation of particle size occurs after surface functionalization of the MNPs; these are the primary factors that affect the separation time and velocity of the MNPs. The experimental results are correlated to a theoretical one-dimensional model.

  16. Comparison of PLGA and lecithin/chitosan nanoparticles for dermal targeting of betamethasone valerate.

    PubMed

    Özcan, Ipek; Azizoğlu, Erkan; Senyiğit, Taner; Özyazici, Mine; Özer, Özgen

    2013-07-01

    Poly(lactide-co-glycolide) (PLGA) and lecithin/chitosan (LC) nanoparticles were prepared to evaluate the difference in the behavior upon administration on skin, for steroidal treatment. For this purpose, betamethasone-17-valerate (BMV)-loaded nanoparticles with a narrow size distribution and high entrapment efficiency were prepared. Permeation studies showed that both polymeric nanoparticles enhanced the amount of BMV in epidermis, which is the target site of topical steroidal treatment, when compared with commercial formulation. 1.58-Fold increase was determined in the epidermis concentration of BMV by LC nanoparticles with respect to PLGA nanoparticles. Nanoparticles were diluted in chitosan gel (10%, w/w) to prepare suitable formulation for topical application. Accumulation from both gel formulations were found significantly higher than commercial formulation in skin layers (p < 0.05). In addition, pharmacodynamic responses were also investigated as anti-inflammatory and skin-blanching parameters. Both formulations significantly improved these parameters although they contained 10 times less amount of BMV than commercial cream. Moreover, TEWL measurement exhibited no barrier function changes upon the application of nanoparticles on skin. Overall, both nanoparticles improved the localization of BMV within skin layers; but when compared with PLGA nanoparticles, the LC nanoparticles could be classified as a better candidate for topical delivery vehicle in the treatment of various dermatological inflammatory diseases.

  17. Red fluorescent chitosan nanoparticles grafted with poly(2-methacryloyloxyethyl phosphorylcholine) for live cell imaging.

    PubMed

    Wang, Ke; Fan, Xingliang; Zhang, Xiaoyong; Zhang, Xiqi; Chen, Yi; Wei, Yen

    2016-08-01

    Poly(2-methacryloyloxyethyl phosphorylcholine) conjugated red fluorescent chitosan nanoparticles (GCC-pMPC) were facilely fabricated by "grafting from" method via surface initiated atom transfer radical polymerization (ATRP). Firstly, glutaraldehyde crosslinked red fluorescent chitosan nanoparticles (GCC NPs) with many amino groups and hydroxyl groups on their surface were prepared, which were then reacted with 2-bromoisobutyryl bromide to form GCC-Br; subsequently, poly(MPC) (pMPC) brushes were grafted onto GCC NPs surface using GCC-Br as initiator via ATRP. Compared with PEGylated nanoparticles, zwitterionic polymers modified nanoparticles demonstrated better performance in their cellular uptake. Moreover, the obtained GCC-pMPC demonstrated excellent water-dispersibility, biocompatibility, and photostability, which made them highly potential for long-term tracing applications. Importantly, the successful live cell imaging of GCC-pMPC would remarkably advance the research of their further bioapplications.

  18. Magnetic chitosan nanocomposite for hyperthermia therapy application: Preparation, characterization and in vitro experiments

    NASA Astrophysics Data System (ADS)

    Shete, P. B.; Patil, R. M.; Thorat, N. D.; Prasad, A.; Ningthoujam, R. S.; Ghosh, S. J.; Pawar, S. H.

    2014-01-01

    Nanocrystals of magnetite (Fe3O4) were prepared by alkaline precipitation. The precursor used for synthesis was ferrous chloride only and the reaction was carried out in absence of any oxidant. The synthesized pure phase magnetic nanoparticles (MNPs) were coated with a biocompatible polymer, chitosan (CS). FTIR and TGA confirm coating of CS on MNPs. Both bare and coated MNPs (Fe3O4 and CS-Fe3O4) show particle size 21.8 ± 5.3 and 15.1 ± 5.0 nm respectively. The magnetization values of both the MNPs are 51.68 and 49.96 emu/g at room temperature respectively. Negligible Coercivity and Remenance values at room temperature imply superparamagnetic behavior of the MNPs. The MNPs are studied for their induction heating abilities at 167.6, 251.4 and 335.2 Oe (equivalent to 13.3, 20.0 and 26.7 kA m-1 respectively), in order to use them in magnetic fluid hyperthermia therapy. At 335.2 Oe, CS coated nanoparticles (NPs) show maximum SAR of 118.85 W/g, while bare NPs show SAR of 79.32 W/g. Low cytotoxic effects of both the MNPs on L929 cell line proved their suitability for in vivo applications. NH2 group rendered by CS can further be used for conjugation of biomolecules to make them suitable candidates for biosensing and targeted drug delivery.

  19. Chelating and antibacterial properties of chitosan nanoparticles on dentin

    PubMed Central

    Bramante, Clovis Monteiro; Duarte, Marco Antonio Hungaro; de Moura, Marcia Regina; Aouada, Fauze Ahmad; Kishen, Anil

    2015-01-01

    Objectives The use of chitosan nanoparticles (CNPs) in endodontics is of interest due to their antibiofilm properties. This study was to investigate the ability of bioactive CNPs to remove the smear layer and inhibit bacterial recolonization on dentin. Materials and Methods One hundred bovine dentin sections were divided into five groups (n = 20 per group) according to the treatment. The irrigating solutions used were 2.5% sodium hypochlorite (NaOCl) for 20 min, 17% ethylenediaminetetraacetic acid (EDTA) for 3 min and 1.29 mg/mL CNPs for 3 min. The samples were irrigated with either distilled water (control), NaOCl, NaOCl-EDTA, NaOCl-EDTA-CNPs or NaOCl-CNPs. After the treatment, half of the samples (n = 50) were used to assess the chelating effect of the solutions using portable scanning electronic microscopy, while the other half (n = 50) were infected intra-orally to examine the post-treatment bacterial biofilm forming capacity. The biovolume and cellular viability of the biofilms were analysed under confocal laser scanning microscopy. The Kappa test was performed for examiner calibration, and the non-parametric Kruskal-Wallis and Dunn tests (p < 0.05) were used for comparisons among the groups. Results The smear layer was significantly reduced in all of the groups except the control and NaOCl groups (p < 0.05). The CNPs-treated samples were able to resist biofilm formation significantly better than other treatment groups (p < 0.05). Conclusions CNPs could be used as a final irrigant during root canal treatment with the dual benefit of removing the smear layer and inhibiting bacterial recolonization on root dentin. PMID:26295022

  20. Magnetic nanoparticle sensing: decoupling the magnetization from the excitation field

    PubMed Central

    Reeves, Daniel B.; Weaver, John B.

    2014-01-01

    Remote sensing of magnetic nanoparticles has exciting applications for magnetic nanoparticle hyperthermia and molecular detection. We introduce, simulate, and experimentally demonstrate an innovation—a sensing coil that is geometrically decoupled from the excitation field—for magnetic nanoparticle spectroscopy that increases the flexibility and capabilities of remote detection. The decoupling enhances the sensitivity absolutely; to small amounts of nanoparticles, and relatively; to small changes in the nanoparticle dynamics. We adapt a previous spectroscopic method that measures the relaxation time of nanoparticles and demonstrate a new measurement of nanoparticle temperature that could potentially be used concurrently during hyperthermia. PMID:24610961

  1. One-step synthesis of magnetic chitosan polymer composite films

    NASA Astrophysics Data System (ADS)

    Cesano, Federico; Fenoglio, Gaia; Carlos, Luciano; Nisticò, Roberto

    2015-08-01

    In this study, a magnetic iron oxide-chitosan composite film is synthesized by one-step method and thoroughly investigated in order to better understand its inorganic/organic properties. A deep physico-chemical characterization of the magnetic films has been performed. In particular, the material composition was evaluated by means of XRD and ATR-FTIR spectroscopy, whereas the thermal stability and the subsequent inorganic phase transitions involving iron oxide species were followed by TGA analyses carried out at different experimental conditions (i.e. inert and oxidative atmosphere). The magnetic properties of the films were tested at the bulk and at the surface level, performing respectively magnetization hysteresis curve and magnetic force microscopy (MFM) surface mapping. Results indicate that the synthesized material can be prepared through a very simple synthetic procedure and suggests that it can be successfully applied for instance to environmental applications, such as the adsorption of contaminants from solid and liquid media thanks to its pronounced magnetic properties, which favour its recover.

  2. Synthesis, characterization and antibacterial activity of superparamagnetic nanoparticles modified with glycol chitosan

    NASA Astrophysics Data System (ADS)

    Inbaraj, Baskaran Stephen; Tsai, Tsung-Yu; Chen, Bing-Huei

    2012-02-01

    Iron oxide nanoparticles (IONPs) were synthesized by coprecipitation of iron salts in alkali media followed by coating with glycol chitosan (GC-coated IONPs). Both bare and GC-coated IONPs were subsequently characterized and evaluated for their antibacterial activity. Comparison of Fourier transform infrared spectra and thermogravimetric data of bare and GC-coated IONPs confirmed the presence of GC coating on IONPs. Magnetization curves showed that both bare and GC-coated IONPs are superparamagnetic and have saturation magnetizations of 70.3 and 59.8 emu g-1, respectively. The IONP size was measured as ~8-9 nm by transmission electron microscopy, and their crystal structure was assigned to magnetite from x-ray diffraction patterns. Both bare and GC-coated IONPs inhibited the growths of Escherichia coli ATCC 8739 and Salmonella enteritidis SE 01 bacteria better than the antibiotics linezolid and cefaclor, as evaluated by the agar dilution assay. GC-coated IONPs showed higher potency against E. coli O157:H7 and Staphylococcus aureus ATCC 10832 than bare IONPs. Given their biocompatibility and antibacterial properties, GC-coated IONPs are a potential nanomaterial for in vivo applications.

  3. Biodegradable Chitosan Nanoparticle Coatings on Titanium for the Delivery of BMP-2

    PubMed Central

    Poth, Nils; Seiffart, Virginia; Gross, Gerhard; Menzel, Henning; Dempwolf, Wibke

    2015-01-01

    A simple method for the functionalization of a common implant material (Ti6Al4V) with biodegradable, drug loaded chitosan-tripolyphosphate (CS-TPP) nanoparticles is developed in order to enhance the osseointegration of endoprostheses after revision operations. The chitosan used has a tailored degree of acetylation which allows for a fast biodegradation by lysozyme. The degradability of chitosan is proven via viscometry. Characteristics and degradation of nanoparticles formed with TPP are analyzed using dynamic light scattering. The particle degradation via lysozyme displays a decrease in particle diameter of 40% after 4 days. Drug loading and release is investigated for the nanoparticles with bone morphogenetic protein 2 (BMP-2), using ELISA and the BRE luciferase test for quantification and bioactivity evaluation. Furthermore, nanoparticle coatings on titanium substrates are created via spray-coating and analyzed by ellipsometry, scanning electron microscopy and X-ray photoelectron spectroscopy. Drug loaded nanoparticle coatings with biologically active BMP-2 are obtained in vitro within this work. Additionally, an in vivo study in mice indicates the dose dependent induction of ectopic bone growth through CS-TPP-BMP-2 nanoparticles. These results show that biodegradable CS-TPP coatings can be utilized to present biologically active BMP-2 on common implant materials like Ti6Al4V. PMID:25581889

  4. Intravenous magnetic nanoparticle cancer hyperthermia

    PubMed Central

    Huang, Hui S; Hainfeld, James F

    2013-01-01

    Magnetic nanoparticles heated by an alternating magnetic field could be used to treat cancers, either alone or in combination with radiotherapy or chemotherapy. However, direct intratumoral injections suffer from tumor incongruence and invasiveness, typically leaving undertreated regions, which lead to cancer regrowth. Intravenous injection more faithfully loads tumors, but, so far, it has been difficult achieving the necessary concentration in tumors before systemic toxicity occurs. Here, we describe use of a magnetic nanoparticle that, with a well-tolerated intravenous dose, achieved a tumor concentration of 1.9 mg Fe/g tumor in a subcutaneous squamous cell carcinoma mouse model, with a tumor to non-tumor ratio > 16. With an applied field of 38 kA/m at 980 kHz, tumors could be heated to 60°C in 2 minutes, durably ablating them with millimeter (mm) precision, leaving surrounding tissue intact. PMID:23901270

  5. Chitosan coated sodium alginate-chitosan nanoparticles loaded with 5-FU for ocular delivery: in vitro characterization and in vivo study in rabbit eye.

    PubMed

    Nagarwal, Ramesh C; Kumar, Rakesh; Pandit, J K

    2012-11-20

    The objective of the study was to develop chitosan (CH) coated sodium alginate-chitosan (SA-CH) nanoparticles, i.e. CH-SA-CH NPs loaded with 5-FU for ophthalmic delivery. Drug loaded nanoparticles (DNPs) were prepared by ionic gelation technique using sodium alginate (SA) and chitosan (CH) and then suspended in chitosan solution. The mean size of nanoparticles and morphology were characterized by dynamic light scattering, scanning electron microscopy, atomic force microscopy and zeta potential. The in vitro release was studied by dialysis membrane technique. The size and drug encapsulation efficiency were dependent on molar ratio of SA and CH. The size of SA-CH nanoparticles was significantly increased with changed morphology after CH coating. SA-CH nanoparticles did not show any interaction with mucin while an enhanced viscosity was observed on coating of nanoparticles with CH. CH-SA-CH DNPs presented a sustained release of 5-FU compared to the 5-FU solution with high burst effect. In vivo study in rabbit eye showed significantly greater level of 5-FU in aqueous humor compared to 5-FU solution. The enhanced mucoadhesiveness of CH-SA-CH DNPs results in higher bioavailability as compared to the uncoated nanoparticles. Optimized formulation was found non-irritant and tolerable when tested by modified Draize test in rabbit eye. PMID:22922098

  6. Preparation and characterization of nanoparticles formed by chitosan-caseinate interactions.

    PubMed

    Anal, Anil Kumar; Tobiassen, Astrid; Flanagan, John; Singh, Harjinder

    2008-06-15

    Intermacromolecular complexation between chitosan and sodium caseinate in aqueous solutions was studied as a function of pH (3-6.5), using absorbance measurements (at 600 nm), dynamic light scattering (DLS), and transmission electron microscopy (TEM). The chitosan-caseinate complexes formed were stable and soluble in the pH range 4.8-6.0. In this pH range, the biopolymers had opposite charges. At higher concentrations of chitosan (0.15 wt%), the soluble complexes associated to form larger particles. DLS data showed that, between pH 4.8 and 6.0, the particles formed by the complexation of chitosan and caseinate had sizes between 250 and 350 nm and these nanoparticles were visualized using negative staining TEM. Above pH 6.0, the nanoparticles associated to form larger particles, causing phase separation. Addition of NaCl increased the particle size. The pH dependence of the zeta potential of the mixture solutions was appreciably different from that of the pure protein and pure chitosan solutions.

  7. Chitosan/TPP Nanoparticles as a Gene Delivery Agent For Tumor Suppressant P53

    NASA Astrophysics Data System (ADS)

    Liu, Gaojun

    In the last decade, non-viral polymeric vectors have become more attractive than their viral counterparts due to their nontoxicity and good biocompatibility. However, one of the major drawbacks is the low transfection efficiency when compared to viruses. In this work, a naturally cationic polysaccharide, chitosan, was cross-linked with negatively charged tripolyphosphate (TPP) to synthesize chitosan/TPP nanoparticles (CNPs) for delivery of plasmid DNA (pDNA). Particle size and zeta potential were characterized for CNPs with chitosan-TPP mass ratios of 4:1 and 6:1 (w/w) using benchtop dynamic light scattering. And both potentiometric titration method and FTIR spectrometer were applied to measure the degree of deacetylation of chitosan. Release kinetics of a model protein (bovine serum albumin, BSA) showed a steady release that reached 7% after 6 days. Besides that, we also assessed the in vitro transfection efficiency of the CNP-pDNA system using fluorescence microscopy, as well as the effect of tumor suppressant p53. Later the release kinetics and encapsulation efficiency of plasmid DNA bound to the CNPs will be investigated. Additionally, we will try to improve the gene transfection efficiency in both MC3T3-E1 and osteosarcoma cells by applying Sonicator 740 therapeutic ultrasound. Key words: gene therapy, non-viral gene vector, chitosan/TPP nanoparticles, ionic gelation, p53.

  8. Pushing the science forward: chitosan nanoparticles and functional repair of CNS tissue after spinal cord injury

    PubMed Central

    2013-01-01

    Background We continue our exploration of the large polysaccharide polymer Chitosan as an acute therapy for severe damage to the nervous system. We tested the action of subcutaneously injected nanoparticles (~ 100 – 200 nanometers in diameter; 1 mg per ml) against control injections (silica particle of the same size and concentration) in a standardized in vivo spinal cord injury model. These functional tests used standardized physiological measurements of evoked potentials arriving at the sensorimotor cortex subsequent to stimulation of the tibial nerve of the contralateral hindlimb. We further explored the degree of acetylation and molecular weight of chitosan on the success of sealing cell damage using specific probes of membrane integrity. Results Not one of the control group showed restored conduction of evoked potentials stimulated from the tibial nerve of the hindleg – through the lesion – and recorded at the sensorimotor cortex of the brain. Investigation if the degree of acetylation and molecular weight impacted “membrane sealing” properties of Chitosan were unsuccessful. Dye - exchange membrane probes failed to show a difference between the comparators in the function of Chitosan in ex vivo injured spinal cord tests. Conclusions We found that Chitosan nanoparticles effectively restore nerve impulse transmission through the crushed adult guinea pig spinal cord in vivo after severe crush/compression injury. The tests of the molecular weight (MW) and degree of acetylation did not produce any improvement in Chitosan’s membrane sealing properties. PMID:23731718

  9. A high throughput method for quantification of cell surface bound and internalized chitosan nanoparticles.

    PubMed

    Tammam, Salma N; Azzazy, Hassan M E; Lamprecht, Alf

    2015-11-01

    Chitosan has become a popular polymer for drug delivery. It's hydro solubility and mild formulation conditions have made it an attractive polymer for macromolecular delivery. Accurate quantification of internalized chitosan nanoparticles (NPs) is imperative for fair assessment of the nano-formulation where it is important to determine the exact amount of drug actually being delivered into the cell, especially for macromolecular drugs where cellular entry is limited by molecule size and/or charge. The preferential affinity of wheat germ agglutinin tagged with fluorescein isothiocyanate (WGA-FITC) to chitosan is exploited in the development of a simple and rapid method for the differentiation between and quantification of cell surface bound and internalized chitosan NPs. The percentage of cell surface bound NPs could be easily determined and corrected NP uptake could be calculated accordingly. The developed method is applicable in several cell lines and has successfully been tested with NPs with different sizes (25 and 150nm) and with very low NP concentrations (20μg/mL). The method will allow for the correct evaluation of chitosan NP uptake and could be further used to evaluate chitosan based nanomedicine and provide guidelines on how to modify NPs for enhanced internalization, and improved drug delivery.

  10. [Magnetic nanoparticles and intracellular delivery of biopolymers].

    PubMed

    Kornev, A A; Dubina, M V

    2014-03-01

    The basic methods of intracellular delivery of biopolymers are present in this review. The structure and synthesis of magnetic nanoparticles, their stabilizing surfactants are described. The examples of the interaction of nanoparticles with biopolymers such as nucleic acids and proteins are considered. The final part of the review is devoted to problems physiology and biocompatibility of magnetic nanoparticles.

  11. Magnetically separable Cu2O/chitosan-Fe3O4 nanocomposites: Preparation, characterization and visible-light photocatalytic performance

    NASA Astrophysics Data System (ADS)

    Cao, Chunhua; Xiao, Ling; Chen, Chunhua; Cao, Qihua

    2015-04-01

    A novel magnetically-separable visible-light-induced photocatalyst, Cu2O/chitosan-Fe3O4 nanocomposite (Cu2O/CS-Fe3O4 NC), was prepared via a facile one-step precipitation-reduction process by using magnetic chitosan chelating copper ions as precursor. The structure and properties of Cu2O/CS-Fe3O4 NCs were characterized by XRD, FT-IR, SEM, HRTEM, SAED, EDS, BET, VSM, XPS and UV-vis/DRS. The photocatalytic activity of Cu2O/CS-Fe3O4 NCs was evaluated by decolorization of reactive brilliant red X-3B (X-3B) under visible light irradiation. The characterization results indicated that Cu2O/CS-Fe3O4 NCs exhibited relatively large specific surface areas and special dimodal pore structure because Cu2O was wrapped in chitosan matrix embedded with Fe3O4 nanoparticles. The tight combination of magnetic Fe3O4 and semiconductor Cu2O through chitosan made the nanocomposites show good superparamagnetism and photocatalytic activity. It was found that X-3B could be decolorized more efficiently in acidic media than in neutral or alkaline media. The decolorization of X-3B was ascribed to the synergistic effect of photocatalysis and adsorption. Cu2O/CS-Fe3O4 NCs could be easily separated from the solution by an external magnet, and the decolorization rates of X-3B were still above 87% after five reaction cycles, indicating that Cu2O/CS-Fe3O4 NCs had excellent reusability and stability.

  12. In vitro cytotoxicity of Fe-Cr-Nb-B magnetic nanoparticles under high frequency electromagnetic field

    NASA Astrophysics Data System (ADS)

    Chiriac, Horia; Petreus, Tudor; Carasevici, Eugen; Labusca, Luminita; Herea, Dumitru-Daniel; Danceanu, Camelia; Lupu, Nicoleta

    2015-04-01

    The heating potential, cytotoxicity, and efficiency of Fe68.2Cr11.5Nb0.3B20 magnetic nanoparticles (MNPs), as such or coated with a chitosan layer, to decrease the cell viability in a cancer cell culture model by using high frequency alternating magnetic fields (AMF) have been studied. The specific absorption rate varied from 215 W/g for chitosan-free MNPs to about 190 W/g for chitosan-coated ones, and an equilibrium temperature of 46 °C was reached when chitosan-coated MNPs were subjected to AMF. The chitosan-free Fe68.2Cr11.5Nb0.3B20 MNPs proved a good biocompatibility and low cytotoxicity in all testing conditions, while the chitosan-coated ones induced strong tumoricidal effects when a cell-particle simultaneous co-incubation approach was used. In high frequency AMF, the particle-mediated heat treatment has proved to be a critical cause for decreasing in vitro the viability of a cancer cell line.

  13. Selective removal of erythromycin by magnetic imprinted polymers synthesized from chitosan-stabilized Pickering emulsion.

    PubMed

    Ou, Hongxiang; Chen, Qunhui; Pan, Jianming; Zhang, Yunlei; Huang, Yong; Qi, Xueyong

    2015-05-30

    Magnetic imprinted polymers (MIPs) were synthesized by Pickering emulsion polymerization and used to adsorb erythromycin (ERY) from aqueous solution. The oil-in-water Pickering emulsion was stabilized by chitosan nanoparticles with hydrophobic Fe3O4 nanoparticles as magnetic carrier. The imprinting system was fabricated by radical polymerization with functional and crosslinked monomer in the oil phase. Batches of static and dynamic adsorption experiments were conducted to analyze the adsorption performance on ERY. Isotherm data of MIPs well fitted the Freundlich model (from 15 °C to 35 °C), which indicated heterogeneous adsorption for ERY. The ERY adsorption capacity of MIPs was about 52.32 μmol/g at 15 °C. The adsorption kinetics was well described by the pseudo-first-order model, which suggested that physical interactions were primarily responsible for ERY adsorption. The Thomas model used in the fixed-bed adsorption design provided a better fit to the experimental data. Meanwhile, ERY exhibited higher affinity during adsorption on the MIPs compared with the adsorption capacity of azithromycin and chloramphenicol. The MIPs also exhibited excellent regeneration capacity with only about 5.04% adsorption efficiency loss in at least three repeated adsorption-desorption cycles. PMID:25704432

  14. Attenuated effects of chitosan-capped gold nanoparticles on LPS-induced toxicity in laboratory rats.

    PubMed

    Stefan, Marius; Melnig, Viorel; Pricop, Daniela; Neagu, Anca; Mihasan, Marius; Tartau, Liliana; Hritcu, Lucian

    2013-01-01

    The impact of nanoparticles in medicine and biology has increased rapidly in recent years. Gold nanoparticles (AuNP) have advantageous properties such as chemical stability, high electron density and affinity to biomolecules. However, the effects of AuNP on human body after repeated administration are still unclear. Therefore, the purpose of the present study was to evaluate the effects of gold-11.68 nm (AuNP1, 9.8 μg) and gold-22.22 nm (AuNP2, 19.7 μg) nanoparticles capped with chitosan on brain and liver tissue reactivity in male Wistar rats exposed to lipopolysaccharide (LPS from Escherichia coli serotype 0111:B4, 250 μg) upon 8 daily sessions of intraperitoneal administration. Our results suggest that the smaller size of chitosan-capped AuNP shows the protective effects against LPS-induced toxicity, suggesting a very high potential for biomedical applications. PMID:25428109

  15. Glucose Biosensor Based on Immobilization of Glucose Oxidase in Platinum Nanoparticles/Graphene/Chitosan Nanocomposite Film

    SciTech Connect

    Wu, Hong; Wang, Jun; Kang, Xinhuang; Wang, Chong M.; Wang, Donghai; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2009-09-01

    The bionanocomposite film consisting of glucose oxidase/Pt/functional graphene sheets/chitosan (GOD/Pt/FGS/chitosan) for glucose sensing was described. With the electrocatalytic synergy of FGS and Pt nanoparticles to hydrogen peroxide, a sensitive biosensor with detection limit of 0.6 µM glucose was achieved. The biosensor also had good reproducibility, long term stability and negligible interfering signals from ascorbic acid and uric acid comparing to the response to glucose. The large surface area and good conductivity of graphene suggests that graphene is a potential candidate for sensor material. The hybrid nanocomposite glucose sensor provides new opportunity for clinical diagnosis and point-of-care applications.

  16. Microwave-synthesized magnetic chitosan microparticles for the immobilization of yeast cells.

    PubMed

    Safarik, Ivo; Pospiskova, Kristyna; Maderova, Zdenka; Baldikova, Eva; Horska, Katerina; Safarikova, Mirka

    2015-01-01

    An extremely simple procedure has been developed for the immobilization of Saccharomyces cerevisiae cells on magnetic chitosan microparticles. The magnetic carrier was prepared using an inexpensive, simple, rapid, one-pot process, based on the microwave irradiation of chitosan and ferrous sulphate at high pH. Immobilized yeast cells have been used for sucrose hydrolysis, hydrogen peroxide decomposition and the adsorption of selected dyes. PMID:24753015

  17. Laccase encapsulation in chitosan nanoparticles enhances the protein stability against microbial degradation.

    PubMed

    Koyani, Rina D; Vazquez-Duhalt, Rafael

    2016-09-01

    A novel concept with the result of enzyme stabilization against microbial degradation in real bioremediation processes was developed through the encapsulation of laccase in chitosan nanoparticles. Besides of abundant information on laccase-chitosan conjugates, we report the laccase encapsulation into nanoparticles based in chitosan. The chitosan-tripolyphosphate technique was applied for the production of morphologically homogeneous enzymatic nanoparticles, with high enzyme encapsulation efficiency, small asymmetric sizes (from 40 to 90 nm), and rough surfaces. Contrary to macroscopic immobilized enzymes, temperature and pH activity profiles of nano-sized laccase were similar to those of free enzyme. The substrate affinity constant (K M) of nano-encapsulated laccase was similar to these from free enzyme, while its activity rate constant (k cat) represented 60 % of these obtained with free enzyme. Importantly, stability of nano-encapsulated laccase against microbial degradation in soil, compost, and wastewater was significantly increased. After 24 h exposure to wastewater from a treatment plant, the laccase activity of the nanoparticles was 82.8 % of initial activity, compared with only 7.8 % retained activity for free enzyme. After 36 h incubation in compost extract, the laccase nanoparticles showed 72.4 % of the initial activity, while the free enzyme was almost completely inactivated. Finally, after 84 h incubation in soil extract, the nanoparticles and free preparations showed 57.9 and 17.3 % of the initial activity, respectively. Thus, the nanoencapsulation of enzymes able to transform pollutants is an alternative to improve the operational lifetime of enzymes in real environmental applications.

  18. Laccase encapsulation in chitosan nanoparticles enhances the protein stability against microbial degradation.

    PubMed

    Koyani, Rina D; Vazquez-Duhalt, Rafael

    2016-09-01

    A novel concept with the result of enzyme stabilization against microbial degradation in real bioremediation processes was developed through the encapsulation of laccase in chitosan nanoparticles. Besides of abundant information on laccase-chitosan conjugates, we report the laccase encapsulation into nanoparticles based in chitosan. The chitosan-tripolyphosphate technique was applied for the production of morphologically homogeneous enzymatic nanoparticles, with high enzyme encapsulation efficiency, small asymmetric sizes (from 40 to 90 nm), and rough surfaces. Contrary to macroscopic immobilized enzymes, temperature and pH activity profiles of nano-sized laccase were similar to those of free enzyme. The substrate affinity constant (K M) of nano-encapsulated laccase was similar to these from free enzyme, while its activity rate constant (k cat) represented 60 % of these obtained with free enzyme. Importantly, stability of nano-encapsulated laccase against microbial degradation in soil, compost, and wastewater was significantly increased. After 24 h exposure to wastewater from a treatment plant, the laccase activity of the nanoparticles was 82.8 % of initial activity, compared with only 7.8 % retained activity for free enzyme. After 36 h incubation in compost extract, the laccase nanoparticles showed 72.4 % of the initial activity, while the free enzyme was almost completely inactivated. Finally, after 84 h incubation in soil extract, the nanoparticles and free preparations showed 57.9 and 17.3 % of the initial activity, respectively. Thus, the nanoencapsulation of enzymes able to transform pollutants is an alternative to improve the operational lifetime of enzymes in real environmental applications. PMID:27318485

  19. Magnetic and degradable polymer/bioactive glass composite nanoparticles for biomedical applications.

    PubMed

    Jayalekshmi, A C; Victor, Sunita Prem; Sharma, Chandra P

    2013-01-01

    The present study focuses on the development of a biocompatible and biodegradable iron oxide incorporated chitosan-gelatin bioglass composite nanoparticles [Fe-BG]. The developed composite nanoparticle was analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, thermo gravimetric analysis (TG) and differential scanning calorimetry analysis (DSC). The size of the negatively charged composite nanoparticle was in the range of 43-51 nm. The in vitro analysis of the composite nanoparticles was carried out by cell aggregation, protein adsorption and haemolytic activity. The magnetic hysteresis value of the composite nanoparticle showed that it is a soft magnetic material. The presence of iron oxide in the chitosan-gelatin bioglass [BG] matrix enhances biodegradability as indicated in the TG studies. Iron-oxide in equal amount to bioglass in the polymer matrix has been obtained as the optimized system. The developed composite nanoparticle is a soft magnetic material and is suitable for the magnetic hyperthermia treatment and drug delivery. More detailed in vivo studies are needed to confirm the biodegradation profile and biological activity of the material.

  20. Magnetite and magnetite/silver core/shell nanoparticles with diluted magnet-like behavior

    SciTech Connect

    Garza-Navarro, Marco; Gonzalez, Virgilio; Ortiz, Ubaldo; De la Rosa, Elder

    2010-01-15

    In the present work is reported the use of the biopolymer chitosan as template for the preparation of magnetite and magnetite/silver core/shell nanoparticles systems, following a two step procedure of magnetite nanoparticles in situ precipitation and subsequent silver ions reduction. The crystalline and morphological characteristics of both magnetite and magnetite/silver core/shell nanoparticles systems were analyzed by high resolution transmission electron microscopy (HRTEM) and nanobeam diffraction patterns (NBD). The results of these studies corroborate the core/shell morphology and the crystalline structure of the magnetite core and the silver shell. Moreover, magnetization temperature dependent, M(T), measurements show an unusual diluted magnetic behavior attributed to the dilution of the magnetic ordering in the magnetite and magnetite/silver core/shell nanoparticles systems. - Graphical abstract: Biopolymer chitosan was used as stabilization media to synthesize both magnetite and magnetite/silver core/shell nanoparticles. Results of HRTEM and NBD patterns confirm core/shell morphology of the obtained nanoparticles. It was found that the composites show diluted magnet-like behavior.

  1. Development and characterization of a new plasmid delivery system based on chitosan-sodium deoxycholate nanoparticles.

    PubMed

    Cadete, A; Figueiredo, L; Lopes, R; Calado, C C R; Almeida, A J; Gonçalves, L M D

    2012-03-12

    Chitosan is one of the most promising polymers for drug delivery through the mucosal routes because of its polycationic, biocompatible, and biodegradable nature, and particularly due to its mucoadhesive and permeation-enhancing properties. Bile salts are known to interact with lipid membranes, increasing their permeability. The addition of bile salts to chitosan matrices may improve the delivery characteristics of the system, making it suitable for mucosal administration of bioactive substances. In the present study we have developed chitosan nanoparticles using sodium deoxycholate as a counter ion and evaluated their potential as gene delivery carriers. Chitosan-sodium deoxycholate nanoparticles (CS/DS) obtained via a mild ionic gelation procedure using different weight ratios were used to encapsulate plasmid DNA (pDNA) expressing a "humanized" secreted Gaussia Luciferase as reporter gene (pGLuc, 5.7 kDa). Mean particle size, polydispersity index and zeta potential were evaluated in order to select the best formulation for further in vitro studies. The nanoparticles presented an average size of 153-403 nm and a positive zeta potential ranging from +33.0 to +56.9 mV, for nanoparticles produced with CS/DS ratios from 1:4 to 1:0.6 (w:w), respectively. The pDNA was efficiently encapsulated and AFM studies showed that pDNA-loaded nanoparticles presented a more irregular surface due to the interaction between cationic chitosan and negatively charged pDNA which results in a more compact structure when compared to empty nanoparticles. Transfection efficiency of CS/DS-pDNA nanoparticles into moderately (AGS) and well differentiated (N87) gastric adenocarcinoma cell lines was determined by measuring the expression of luciferase, while cell viability was assessed using the MTT reduction. The CS/DS nanoparticles containing encapsulated pDNA were able to transfect both AGS and N87 cell lines, being more effective with AGS cells, the less differentiated cell line. The highest

  2. Synergistic Combination of Chitosan Acetate with Nanoparticle Silver as a Topical Antimicrobial: Efficacy against Bacterial Burn Infections ▿

    PubMed Central

    Huang, Liyi; Dai, Tianhong; Xuan, Yi; Tegos, George P.; Hamblin, Michael R.

    2011-01-01

    Chitosan and nanoparticle silver are both materials with demonstrated antimicrobial properties and have been proposed singly or in combination as constituents of antimicrobial burn dressings. Here, we show that they combine synergistically to inhibit the in vitro growth of Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria (Pseudomonas aeruginosa, Proteus mirabilis, and Acinetobacter baumannii), as judged by bioluminescence monitoring and isobolographic analysis, and also produce synergistic killing after 30 min of incubation, as measured by a CFU assay. The hypothesized explanation involves chitosan-mediated permeabilization of bacterial cells, allowing better penetration of silver ions into the cell. A dressing composed of freeze-dried chitosan acetate incorporating nanoparticle silver was compared with a dressing of chitosan acetate alone in an in vivo burn model infected with bioluminescent P. aeruginosa. The survival rates of mice treated with silver-chitosan or regular chitosan or left untreated were 64.3% (P = 0.0082 versus regular chitosan and P = 0.0003 versus the control), 21.4%, and 0%, respectively. Most of the fatalities occurred between 2 and 5 days postinfection. Silver-chitosan dressings effectively controlled the development of systemic sepsis, as shown by blood culture. These data suggest that a dressing combining chitosan acetate with silver leads to improved antimicrobial efficacy against fatal burn infections. PMID:21502618

  3. Fabrication of chitosan-silver nanoparticle hybrid 3D porous structure as a SERS substrate for biomedical applications

    NASA Astrophysics Data System (ADS)

    Jung, Gyeong-Bok; Kim, Ji-Hye; Burm, Jin Sik; Park, Hun-Kuk

    2013-05-01

    We propose a simple, low-cost, large-area, and functional surface enhanced Raman scattering (SERS) substrate for biomedical applications. The SERS substrate with chitosan-silver nanoparticles (chitosan-Ag NPs) hybrid 3D porous structure was fabricated simply by a one-step method. The chitosan was used as a template for the Ag NPs deposition. SERS enhancement by the chitosan-Ag NPs substrate was experimentally verified using rhodamine B as an analyte. Thiolated single stranded DNA was also measured for atopic dermatitis genetic markers (chemokines CCL17) at a low concentration of 5 pM. We successfully designed a novel SERS substrate with silver nanoparticle hybridized 3D porous chitosan that has the potential to become a highly sensitive and selective tool for biomedical applications.

  4. Chitosan Nanoparticles for Nuclear Targeting: The Effect of Nanoparticle Size and Nuclear Localization Sequence Density.

    PubMed

    Tammam, Salma N; Azzazy, Hassan M E; Breitinger, Hans G; Lamprecht, Alf

    2015-12-01

    Many recently discovered therapeutic proteins exert their main function in the nucleus, thus requiring both efficient uptake and correct intracellular targeting. Chitosan nanoparticles (NPs) have attracted interest as protein delivery vehicles due to their biocompatibility and ability to escape the endosomes offering high potential for nuclear delivery. Molecular entry into the nucleus occurs through the nuclear pore complexes, the efficiency of which is dependent on NP size and the presence of nuclear localization sequence (NLS). Chitosan nanoparticles of different sizes (S-NPs ≈ 25 nm; L-NP ≈ 150 nm) were formulated, and they were modified with different densities of the octapeptide NLS CPKKKRKV (S-NPs, 0.25, 0.5, 2.0 NLS/nm(2); L-NPs, 0.6, 0.9, 2 NLS/nm(2)). Unmodified and NLS-tagged NPs were evaluated for their protein loading capacity, extent of cell association, cell uptake, cell surface binding, and finally nuclear delivery efficiency in L929 fibroblasts. To avoid errors generated with cell fractionation and nuclear isolation protocols, nuclear delivery was assessed in intact cells utilizing Förster resonance energy transfer (FRET) fluorometry and microscopy. Although L-NPs showed ≈10-fold increase in protein loading per NP when compared to S-NPs, due to higher cell association and uptake S-NPs showed superior protein delivery. NLS exerts a size and density dependent effect on nanoparticle uptake and surface binding, with a general reduction in NP cell surface binding and an increase in cell uptake with the increase in NLS density (up to 8.4-fold increase in uptake of High-NLS-L-NPs (2 NLS/nm(2)) compared to unmodified L-NPs). However, for nuclear delivery, unmodified S-NPs show higher nuclear localization rates when compared to NLS modified NPs (up to 5-fold by FRET microscopy). For L-NPs an intermediate NLS density (0.9 NLS/nm(2)) seems to provide highest nuclear localization (3.7-fold increase in nuclear delivery compared to High

  5. MMT-supported Ag nanoparticles for chitosan nanocomposites: structural properties and antibacterial activity.

    PubMed

    Lavorgna, M; Attianese, I; Buonocore, G G; Conte, A; Del Nobile, M A; Tescione, F; Amendola, E

    2014-02-15

    Multifunctional bionanocomposites have been prepared by loading chitosan matrix with silver-montmorillonite antimicrobial nanoparticles obtained by replacing Na(+) ions of natural montmorillonite with silver ions. This filler has been chosen for its twofold advantage to serve as silver supporting material and to confer new and better performance to the obtained material. It has been proved that the achievement of the intercalation of chitosan into the silicate galleries of montomorillonite as well as the interaction between chitosan and Ag ions and silver particles lead to an enhancement of the thermal stability, to an improvement of mechanical strengths and to a reduction of the liquid water uptake of the obtained bionanocomposites. Results also show that silver ions are released in a steady and prolonged manner providing, after 24 h, a significant reduction in the microbial growth of Pseudomonas spp. PMID:24507295

  6. Fabrication and durable antibacterial properties of electrospun chitosan nanofibers with silver nanoparticles.

    PubMed

    Liu, Yanan; Liu, Yang; Liao, Nina; Cui, Fuhai; Park, Mira; Kim, Hak-Yong

    2015-08-01

    Non-precipitation chitosan/silver nanoparticles (AgNPs) in 1% acetic acid aqueous solution was prepared from chitosan colloidal gel with various contents of silver nitrate via electron beam irradiation (EBI). Electrospun chitosan-based nanofibers decorated with AgNPs were successfully performed by blending poly(vinyl alcohol). The morphology of as-prepared nanofibers and the size of AgNPs in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The presence of AgNPs in as-obtained nanofibers was also confirmed by ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR) spectroscopy, EDX spectrum and metal mapping. Silver ion release behavior indicated that these hybrid nanofibers continually release adequate silver to exhibit antibacterial activity over 16 days. These biocomposite nanofibers showed pronounced antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). PMID:26047897

  7. Fabrication and durable antibacterial properties of electrospun chitosan nanofibers with silver nanoparticles.

    PubMed

    Liu, Yanan; Liu, Yang; Liao, Nina; Cui, Fuhai; Park, Mira; Kim, Hak-Yong

    2015-08-01

    Non-precipitation chitosan/silver nanoparticles (AgNPs) in 1% acetic acid aqueous solution was prepared from chitosan colloidal gel with various contents of silver nitrate via electron beam irradiation (EBI). Electrospun chitosan-based nanofibers decorated with AgNPs were successfully performed by blending poly(vinyl alcohol). The morphology of as-prepared nanofibers and the size of AgNPs in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The presence of AgNPs in as-obtained nanofibers was also confirmed by ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR) spectroscopy, EDX spectrum and metal mapping. Silver ion release behavior indicated that these hybrid nanofibers continually release adequate silver to exhibit antibacterial activity over 16 days. These biocomposite nanofibers showed pronounced antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

  8. Magnetic nanoparticles for gene and drug delivery

    PubMed Central

    McBain, Stuart C; Yiu, Humphrey HP; Dobson, Jon

    2008-01-01

    Investigations of magnetic micro- and nanoparticles for targeted drug delivery began over 30 years ago. Since that time, major progress has been made in particle design and synthesis techniques, however, very few clinical trials have taken place. Here we review advances in magnetic nanoparticle design, in vitro and animal experiments with magnetic nanoparticle-based drug and gene delivery, and clinical trials of drug targeting. PMID:18686777

  9. Enzyme encapsulation in magnetic chitosan-Fe3O4 microparticles.

    PubMed

    Costa-Silva, Tales Alexandre; Marques, Polyana Samorano; Souza, Cláudia Regina Fernandes; Said, Suraia; Oliveira, Wanderley Pereira

    2015-01-01

    Two simple procedures for the preparation of magnetic chitosan enzyme microparticles have been investigated and used for the immobilisation of endophytic fungus Cercospora kikuchii lipase as model enzyme. In the first case, lipase was entrapped in Fe3O4-chitosan microparticles by cross-linking method, while in the second case magnetic immobilised derivatives were produced using spray drying. Immobilised enzymes showed high enzyme activity retention and stability during storage without significant loss of activity. Glutaraldehyde Fe3O4-chitosan powders presented a higher lipase activity retention and storage stability than the others preparations. However, the immobilised derivatives produced by cross-linking showed higher enzyme activity after reuse cycles. The results proved that the magnetic Fe3O4-chitosan microparticles are an effective support for the enzyme immobilisation since the immobilised lipase showed best properties than the free form.

  10. Preparation, characterization and magnetic properties of the BaFe12O19 @ chitosan composites

    NASA Astrophysics Data System (ADS)

    Li, Lei; Zhang, Zunju; Xie, Yu; Zhao, Jie

    2016-07-01

    The BaFe12O19 @ chitosan composites are synthesized by the crosslinking reaction through chitosan and glutaraldehyde onto the surface of BaFe12O19. The structures of the samples were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The shape and size were observed by scanning electron microscopy and transmission electron microscopy. These results showed that chitosan has been decorated onto the surface of BaFe12O19, and the chitosan-glutaraldehyde Schiff-base composites have also been formed within the chitosan layers. Then, the magnetic properties of the samples were tested with the vibrating sample magnetometer. The magnetic saturation (MS), residual magnetization (Mr) and coercive force (Hc) values of the BaFe12O19 @ chitosan Schiff-base composite have achieved 44.94 emu/g, 27.82 emu/g and 3580.7 Oe, respectively. Compared with single BaFe12O19, the MS, and Mr of the BaFe12O19 @ chitosan composites decreases 12.31 emu/g and 8.58 emu/g, respectively. Finally, based on the experimental results, the probable formation mechanism of this composite has been investigated.

  11. Hexavalent chromium removal in contaminated water using reticulated chitosan micro/nanoparticles from seafood processing wastes.

    PubMed

    Dima, Jimena Bernadette; Sequeiros, Cynthia; Zaritzky, Noemi E

    2015-12-01

    Chitosan particles (CH) were obtained from seafood processing wastes (shrimp shells) and physicochemically characterized; deacetylation degree of CH was measured by Infrared Spectroscopy (FTIR) and potentiometric titration; polymer molecular weight was determined by intrinsic viscosity measurements. Reticulated micro/nanoparticles of chitosan (MCH) with an average diameter close to 100nm were synthesized by ionic gelation of chitosan using tripolyphosphate (TPP), and characterized by SEM, size distribution and Zeta-potential. Detoxification capacities of CH and MCH were tested analyzing the removal of hexavalent chromium Cr(VI) from contaminated water, at different initial chromium concentrations. The effect of pH on adsorption capacity of CH and MCH was experimentally determined and analyzed considering the Cr(VI) stable complexes (anions) formed, the presence of protonated groups in chitosan particles and the addition of the reticulating agent (TPP). Chitosan crosslinking was necessary to adsorb Cr(VI) at pH<2 due to the instability of CH particles in acid media. Langmuir isotherm described better than Freundlich and Temkin equations the equilibrium adsorption data. Pseudo-second order rate provided the best fitting to the kinetic data in comparison to pseudo-first order and Elovich equations. Chemical analysis to determine the oxidation state of the adsorbed Cr, showed that Cr(VI) was adsorbed on CH particles without further reduction; in contrast Cr(VI) removed from the solution was reduced and bound to the MCH as Cr(III). The reduction of toxic Cr(VI) to the less or nontoxic Cr(III) by the reticulated chitosan micro/nanoparticles can be considered a very efficient detoxification technique for the treatment of Cr(VI) contaminated water. PMID:26151484

  12. Hexavalent chromium removal in contaminated water using reticulated chitosan micro/nanoparticles from seafood processing wastes.

    PubMed

    Dima, Jimena Bernadette; Sequeiros, Cynthia; Zaritzky, Noemi E

    2015-12-01

    Chitosan particles (CH) were obtained from seafood processing wastes (shrimp shells) and physicochemically characterized; deacetylation degree of CH was measured by Infrared Spectroscopy (FTIR) and potentiometric titration; polymer molecular weight was determined by intrinsic viscosity measurements. Reticulated micro/nanoparticles of chitosan (MCH) with an average diameter close to 100nm were synthesized by ionic gelation of chitosan using tripolyphosphate (TPP), and characterized by SEM, size distribution and Zeta-potential. Detoxification capacities of CH and MCH were tested analyzing the removal of hexavalent chromium Cr(VI) from contaminated water, at different initial chromium concentrations. The effect of pH on adsorption capacity of CH and MCH was experimentally determined and analyzed considering the Cr(VI) stable complexes (anions) formed, the presence of protonated groups in chitosan particles and the addition of the reticulating agent (TPP). Chitosan crosslinking was necessary to adsorb Cr(VI) at pH<2 due to the instability of CH particles in acid media. Langmuir isotherm described better than Freundlich and Temkin equations the equilibrium adsorption data. Pseudo-second order rate provided the best fitting to the kinetic data in comparison to pseudo-first order and Elovich equations. Chemical analysis to determine the oxidation state of the adsorbed Cr, showed that Cr(VI) was adsorbed on CH particles without further reduction; in contrast Cr(VI) removed from the solution was reduced and bound to the MCH as Cr(III). The reduction of toxic Cr(VI) to the less or nontoxic Cr(III) by the reticulated chitosan micro/nanoparticles can be considered a very efficient detoxification technique for the treatment of Cr(VI) contaminated water.

  13. Synthesis and characterization of chitosan and grape polyphenols stabilized palladium nanoparticles and their antibacterial activity.

    PubMed

    Amarnath, Kanchana; Kumar, Jayanthi; Reddy, Tejesh; Mahesh, Vakka; Ayyappan, Senniyanallur Rathakrishnan; Nellore, Jayshree

    2012-04-01

    Based on enhanced effectiveness, the new age drugs are nanoparticles of polymers, metals or ceramics, which can combat conditions like cancer and fight human pathogens like bacteria. In this present study we aimed for a green approach to synthesize palladium nanoparticles by reducing palladium chloride salts with nontoxic and biodegradable polymeric chitosan and grape polyphenols and confirmed by FTIR, TEM, SEM and UV-spectroscopy. We also extended our study to show the efficacy of the grape and chitosan impregnated palladium nanoparticles as an antibacterial agent against Escherichia coli. Antibacterial assays were carried out with a representative gram-negative bacterium, E. coli and a gram-positive bacterium, Staphylococcus aureus. Commendable efforts have been made to explore this property using electron microscopy, which has revealed size dependent interaction of palladium nanoparticles conjugates with bacteria by disrupting cell membranes and the leakage of cytoplasm. Therefore, the observed results imply that grape and chitosan-based nano palladium conjugates prepared in our present system are promising candidates for a wide range of biomedical and general applications. PMID:22225943

  14. Fighting cancer with magnetic nanoparticles and immunotherapy

    NASA Astrophysics Data System (ADS)

    Gutiérrez, L.; Mejías, R.; Barber, D. F.; Veintemillas-Verdaguer, S.; Serna, C. J.; Lázaro, F. J.; Morales, M. P.

    2012-03-01

    IFN-γ-adsorbed DMSA-coated magnetite nanoparticles can be used as an efficient in vivo drug delivery system for tumor immunotherapy. Magnetic nanoparticles, with adsorbed interferon-γ, were targeted to the tumor site by application of an external magnetic field. A relevant therapeutic dosage of interferon in the tumor was detected and led to a notable reduction in tumor size. In general, only 10% of the total injected nanoparticles after multiple exposures were found in tissues by AC susceptibility measurements of the corresponding resected tissues. Magnetic nanoparticle biodistribution is affected by the application of an external magnetic field.

  15. Magnetic Nanoparticles in Non-magnetic CNTs and Graphene

    NASA Astrophysics Data System (ADS)

    Kayondo, Moses; Seifu, Dereje

    Magnetic nanoparticles were embedded in non-magnetic CNTs and graphene matrix to incorporate all the advantages and the unique properties of CNTs and graphene. Composites of CNTs and graphene with magnetic nanoparticles may offer new opportunities for a wide variety of potential applications such as magnetic data storage, magnetic force microscopy tip, electromagnetic interference shields, thermally conductive films, reinforced polymer composites, transparent electrodes for displays, solar cells, gas sensors, magnetic nanofluids, and magnetically guided drug delivery systems. Magnetic nanoparticles coated CNTs can also be used as an electrode in lithium ion battery to replace graphite because of the higher theoretical capacity. Graphene nanocomposites, coated with magnetic sensitive nanoparticles, have demonstrated enhanced magnetic property. We would like to acknowledge support by NSF-MRI-DMR-1337339.

  16. Thiolated chitosan nanoparticles for enhancing oral absorption of docetaxel: preparation, in vitro and ex vivo evaluation

    PubMed Central

    Saremi, Shahrooz; Atyabi, Fatemeh; Akhlaghi, Seyedeh Parinaz; Ostad, Seyed Nasser; Dinarvand, Rassoul

    2011-01-01

    The aim of this study was to prepare and evaluate mucoadhesive core-shell nanoparticles based on copolymerization of thiolated chitosan coated on poly methyl methacrylate cores as a carrier for oral delivery of docetaxel. Docetaxel-loaded nanoparticles with various concentrations were prepared via a radical emulsion polymerization method using cerium ammonium nitrate as an initiator. The physicochemical properties of the obtained nanoparticles were characterized by: dynamic light-scattering analysis for their mean size, size distribution, and zeta potential; scanning electron microscopy and transmission electron microscopy for surface morphology; and differential scanning calorimetry analysis for confirmation of molecular dispersity of docetaxel in the nanoparticles. Nanoparticles were spherical with mean diameter below 200 nm, polydispersity of below 0.15, and positive zeta potential values. The entrapment efficiency of the nanoparticles was approximately 90%. In vitro release studies showed a sustained release characteristic for 10 days after a burst release at the beginning. Ex vivo studies showed a significant increase in the transportation of docetaxel from intestinal membrane of rat when formulated as nanoparticles. Cellular uptake of nanoparticles was investigated using fluoresceinamine-loaded nanoparticles. Docetaxel nanoparticles showed a high cytotoxicity effect in the Caco-2 and MCF-7 cell lines after 72 hours. It can be concluded that by combining the advantages of both thiolated polymers and colloidal particles, these nanoparticles can be proposed as a drug carrier system for mucosal delivery of hydrophobic drugs. PMID:21289989

  17. Enhanced dermal delivery of diflucortolone valerate using lecithin/chitosan nanoparticles: in-vitro and in-vivo evaluations.

    PubMed

    Özcan, Ipek; Azizoğlu, Erkan; Senyiğit, Taner; Özyazıcı, Mine; Özer, Özgen

    2013-01-01

    The objective of this study was to prepare a suitable formulation for dermal delivery of diflucortolone valerate (DFV) that would maintain the localization in skin layers without any penetration and to optimize efficiency of DFV. Drug-loaded lecithin/chitosan nanoparticles with high entrapment efficiency (86.8%), were successfully prepared by ionic interaction technique. Sustained release of DFV was achieved without any initial burst release. Nanoparticles were also incorporated into chitosan gel at different ratios for preparing a more suitable formulation for topical drug delivery with adequate viscosity. In ex-vivo permeation studies, nanoparticles increased the accumulation of DFV especially in the stratum corneum + epidermis of rat skin without any significant permeation. Retention of DFV from nanoparticle in chitosan gel formulation (0.01%) was twofold higher than commercial cream, although it contained ten times less DFV. Nanoparticles in gel formulations produced significantly higher edema inhibition in rats compared with commercial cream in in-vivo studies. Skin blanching assay using a chromameter showed vasoconstriction similar to that of the commercial product. There were no barrier function changes upon application of nanoparticles. In-vitro and in-vivo results demonstrated that lecithin/chitosan nanoparticles in chitosan gel may be a promising carrier for dermal delivery of DFV in various skin disorders. PMID:23390364

  18. Enhanced dermal delivery of diflucortolone valerate using lecithin/chitosan nanoparticles: in-vitro and in-vivo evaluations

    PubMed Central

    Özcan, İpek; Azizoğlu, Erkan; Şenyiğit, Taner; Özyazıcı, Mine; Özer, Özgen

    2013-01-01

    The objective of this study was to prepare a suitable formulation for dermal delivery of diflucortolone valerate (DFV) that would maintain the localization in skin layers without any penetration and to optimize efficiency of DFV. Drug-loaded lecithin/chitosan nanoparticles with high entrapment efficiency (86.8%), were successfully prepared by ionic interaction technique. Sustained release of DFV was achieved without any initial burst release. Nanoparticles were also incorporated into chitosan gel at different ratios for preparing a more suitable formulation for topical drug delivery with adequate viscosity. In ex-vivo permeation studies, nanoparticles increased the accumulation of DFV especially in the stratum corneum + epidermis of rat skin without any significant permeation. Retention of DFV from nanoparticle in chitosan gel formulation (0.01%) was twofold higher than commercial cream, although it contained ten times less DFV. Nanoparticles in gel formulations produced significantly higher edema inhibition in rats compared with commercial cream in in-vivo studies. Skin blanching assay using a chromameter showed vasoconstriction similar to that of the commercial product. There were no barrier function changes upon application of nanoparticles. In-vitro and in-vivo results demonstrated that lecithin/chitosan nanoparticles in chitosan gel may be a promising carrier for dermal delivery of DFV in various skin disorders. PMID:23390364

  19. Chitosan-capped gold nanoparticles for selective and colorimetric sensing of heparin.

    PubMed

    Chen, Zhanguang; Wang, Zhen; Chen, Xi; Xu, Haixiong; Liu, Jinbin

    2013-01-01

    In this contribution, novel chitosan-stabilized gold nanoparticles (AuNPs) were prepared by mixing chitosan with citrate-reductive AuNPs under appropriate conditions. The as-prepared chitosan-stabilized AuNPs were positively charged and highly stably dispersed in aqueous solution. They exhibited weak resonance light scattering (RLS) intensity and a wine red color. In addition, the chitosan-stabilized AuNPs were successfully utilized as novel sensitive probes for the detection of heparin for the first time. It was found that the addition of heparin induced a strong increase of RLS intensity for AuNPs and the color change from red to blue. The increase in RLS intensity and the color change of chitosan-stabilized AuNPs caused by heparin allowed the sensitive detection of heparin in the range of 0.2-60 μM (~6.7 U/mL). The detection limit for heparin is 0.8 μM at a signal-to-noise ratio of 3. The present sensor for heparin detection possessed a low detection limit and wide linear range. Additionally, the proposed method was also applied to the detection of heparin in biological media with satisfactory results. PMID:24078791

  20. Electrochemically deposited chitosan hydrogel for horseradish peroxidase immobilization through gold nanoparticles self-assembly.

    PubMed

    Luo, Xi-Liang; Xu, Jing-Juan; Zhang, Qing; Yang, Gong-Jun; Chen, Hong-Yuan

    2005-07-15

    A new strategy for immobilization of horseradish peroxidase (HRP) has been presented by self-assembling gold nanoparticles on chitosan hydrogel modified Au electrode. From a mildly acidic chitosan solution, a chitosan film is electrochemically deposited on Au electrode surface via a negative voltage bias. This process is accompanied by the hydrogen evolution reaction, and the released hydrogen gas made the deposited chitosan film with porous structure, which facilitates the assembly of gold nanoparticles and HRP. The resulting substrates were characterized by atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). The immobilized HRP displayed an excellent catalytic property to the reduction of H2O2 in the presence of methylene blue mediator. The resulting biosensor (HRP-modified electrode) showed a wide dynamic range of 8.0 microM-15 mM H2O2, and the linear ranges were 8.0 microM-0.12 mM and 0.50-12 mM, with a detection limit of 2.4 microM estimated at a signal-to-noise ratio of 3. Moreover, the biosensor remained about 85% of its original sensitivity after four weeks' storage.

  1. Comparative studies on chitosan and polylactic-co-glycolic acid incorporated nanoparticles of low molecular weight heparin.

    PubMed

    Yang, Tianzhi; Nyiawung, Divine; Silber, Alexandra; Hao, Jiukuan; Lai, Leanne; Bai, Shuhua

    2012-12-01

    This study was performed to test the feasibility of chitosan and polylactic-co-glycolic acid (PLGA) incorporated nanoparticles as sustained-release carriers for the delivery of negatively charged low molecular weight heparin (LMWH). Fourier transform infrared (FTIR) spectrometry was used to evaluate the interactions between chitosan and LMWH. The shifts, intensity, and broadening of the characteristic peaks for the functional groups in the FTIR spectra indicated that strong interactions occur between the positively charged chitosans and the negatively charged LMWHs. Three types of LMWH nanoparticles (NP-1, NP-2, and NP-3) were prepared using chitosan with or without PLGA: NP-1 nanoparticles were formed by polyelectrolyte complexation after single mixing, NP-2 nanoparticles were prepared by polyelectrolyte complexation after single emulsion-diffusion-evaporation, and NP-3 nanoparticles were optimized by double emulsion-diffusion-evaporation. NP-3 nanoparticles of LMWH prepared by the emulsion-diffusion-evaporation method showed significant differences in particle morphology, size, zeta potential, and drug release profile compared to NP-1 nanoparticles formed by polyelectrolyte complexation. Another ionic complex of LMWH with chitosan-incorporated PLGA nanoparticles (NP-2) showed lower drug entrapment efficiency than that of NP-1 and NP-3. The drug release rate of NP-3 was slower than the release rates of NP-1 and NP-2, although particle morphology of NP-3 was similar to that of NP-2. Cell viability was not adversely affected when cells were treated with all three types of nanoparticles. The data presented in this study demonstrate that nanoparticles formulated with chitosan-PLGA could be a safe sustained-release carrier for the delivery of LMWH.

  2. Antibacterial activity of hybrid chitosan-cupric oxide nanoparticles on cotton fabric.

    PubMed

    Dhineshbabu, Nattanmi Raman; Rajendran, Venkatachalam

    2016-02-01

    In this study, cupric oxide (CuO) nanoparticles were prepared using sonochemical method. The prepared nanoparticles were studied using X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. The colloidal chitosan (CS) solution was prepared using ultrasound irradiation method and simultaneously mixed with CuO nanoparticles. The coatings of colloidal solution with and without CuO nanoparticles were studied through TEM images. The cotton fabrics were separately soaked in the prepared nanoparticle-containing (hybrid) solutions by sonication method followed by pad-dry-cure method. The structural, functional, and morphological analyses of the coated and uncoated fabrics were performed using XRD, FTIR-attenuated total reflectance, and SEM analyses, respectively. The hybrid-coated cotton fabrics showed better antibacterial activity against Staphylococcus aureus and Escherichia coli. The bioactivity performance of the coated fabrics was in the order of CuO-coated fabric > CS-coated fabric.

  3. Evaluation of Chitosan-Tripolyphosphate Nanoparticles as a p-shRNA Delivery Vector: Formulation, Optimization and Cellular Uptake Study

    PubMed Central

    Karimi, Mahdi; Avci, Pinar; Ahi, Mohsen; Gazori, Tarane; Hamblin, Michael R.; Naderi-Manesh, Hossein

    2015-01-01

    Polysaccharides (especially chitosan) have recently attracted much attention as gene therapy delivery vehicles for their unique properties such as biocompatibility, biodegradability, low toxicity, and controlled release. Nanoparticles have strong potential as a carrier of plasmid short hairpin RNA (p-shRNA). This study aimed to find the optimum conditions for obtaining Chitosan/triphosphate (TPP)/p-shRNA nanoparticles by the ionic gelation method, and investigating the cellular uptake of the optimized nanoparticles. After applying the central composite design of response surface methodology (RSM), the optimum conditions for preparation of nanoparticles with small size and high loading efficiency were: chitosan/TPP ratio = 10, pH = 5.5 and N/P ratio = 11. The resulting nanoparticles had an average size of 172.8 ± 7 nm and loading efficiency of 71.5 ± 5%. SEM images showed spherical and smooth nanoparticles. The nanoparticles complexed with p-shRNA and may protect it against nuclease digestion. Cytotoxicity studies with HeLa and PC3 human cancer cells demonstrated that chitosan/TPP nanoparticles had low toxicity. Cellular uptake studies using HeLa cells showed that the nanoparticles entered the cells (cellular uptake) and delivered DNA, probably due to their favorable Zeta potential (approximately +28 mV) and small size. PMID:26989641

  4. Preparation and evaluation of quercetin-loaded lecithin-chitosan nanoparticles for topical delivery

    PubMed Central

    Tan, Qi; Liu, Weidong; Guo, Chenyu; Zhai, Guangxi

    2011-01-01

    Background The purpose of this study was to investigate lecithin-chitosan nanoparticles as a topical delivery system for quercetin. Methods Tocopheryl propylene glycol succinate was chosen to be the surfactant for the nanosystem. The mean particle size of the nanoparticles was 95.3 nm, and the entrapment efficiency and drug loading for quercetin were 48.5% and 2.45%, respectively. Topical delivery in vitro and in vivo of the quercetin-loaded nanoparticles was evaluated using quercetin propylene glycol solution as the control. Results Compared with quercetin solution, the quercetin-loaded nanoparticles showed higher permeation ability, and significantly increased accumulation of quercetin in the skin, especially in the epidermis. Microstructure observation of the skin surface after administration indicated that the interaction between ingredients of the nanoparticles and the skin surface markedly changed the morphology of the stratum corneum and disrupted the corneocyte layers, thus facilitating the permeation and accumulation of quercetin in skin. Conclusion Lecithin-chitosan nanoparticles are a promising carrier for topical delivery of quercetin. PMID:21904452

  5. Development and in vitro characterization of galactosylated low molecular weight chitosan nanoparticles bearing doxorubicin.

    PubMed

    Jain, Nitin K; Jain, Sanjay K

    2010-06-01

    The aim of the present research was to evaluate the potential of galactosylated low molecular weight chitosan (Gal-LMWC) nanoparticles bearing positively charged anticancer, doxorubicin (DOX) for hepatocyte targeting. The chitosan from crab shell was depolymerized, and the lactobionic acid was coupled with LMWC using carbodiimide chemistry. The depolymerized and galactosylated polymers were characterized. Two types of Gal-LMWC(s) with variable degree of substitution were employed to prepare the nanoparticles using ionotropic gelation with pentasodium tripolyphosphate anions. Factors affecting nanoparticles formation were discussed. The nanoparticles were characterized by transmission electron microscopy and photon correlation spectroscopy and found to be spherical in the size range 106-320 nm. Relatively higher percent DOX entrapment was obtained for Gal-LMWC(s) nanoparticles than for LMWC nanoparticles. A further increase in drug entrapment was found with nanoparticles prepared by Gal-LMWC with higher degree of substitution. A hypothesis which correlates the ionic concentration of DOX in nanoparticles preparation medium and percent DOX entrapment in cationic polymer has been proposed to explain the enhanced DOX entrapment. In-vitro drug release study demonstrated an initial burst release followed by a sustained release. The targeting potential of the prepared nanoparticles was assessed by in vitro cytotoxicity study using the human hepatocellular carcinoma cell line (HepG(2)) expressing the ASGP receptors on their surfaces. The enthusiastic results showed the feasibility of Gal-LMWC(s) to entrap the cationic DOX and targeting potential of developed Gal-LMWC(s) nanoparticles to HepG(2) cell line.

  6. Hierarchical targeted hepatocyte mitochondrial multifunctional chitosan nanoparticles for anticancer drug delivery.

    PubMed

    Chen, Zhipeng; Zhang, Liujie; Song, Yang; He, Jiayu; Wu, Li; Zhao, Can; Xiao, Yanyu; Li, Wei; Cai, Baochang; Cheng, Haibo; Li, Weidong

    2015-06-01

    The overwhelming majority of drugs exert their pharmacological effects after reaching their target sites of action, however, these target sites are mainly located in the cytosol or intracellular organelles. Consequently, delivering drugs to the specific organelle is the key to achieve maximum therapeutic effects and minimum side-effects. In the work reported here, we designed, synthesized, and evaluated a novel mitochondrial-targeted multifunctional nanoparticles (MNPs) based on chitosan derivatives according to the physiological environment of the tumor and the requirement of mitochondrial targeting drug delivery. The intelligent chitosan nanoparticles possess various functions such as stealth, hepatocyte targeting, multistage pH-response, lysosomal escape and mitochondrial targeting, which lead to targeted drug release after the progressively shedding of functional groups, thus realize the efficient intracellular delivery and mitochondrial localization, inhibit the growth of tumor, elevate the antitumor efficacy, and reduce the toxicity of anticancer drugs. It provides a safe and efficient nanocarrier platform for mitochondria targeting anticancer drug delivery.

  7. Hierarchical targeted hepatocyte mitochondrial multifunctional chitosan nanoparticles for anticancer drug delivery.

    PubMed

    Chen, Zhipeng; Zhang, Liujie; Song, Yang; He, Jiayu; Wu, Li; Zhao, Can; Xiao, Yanyu; Li, Wei; Cai, Baochang; Cheng, Haibo; Li, Weidong

    2015-06-01

    The overwhelming majority of drugs exert their pharmacological effects after reaching their target sites of action, however, these target sites are mainly located in the cytosol or intracellular organelles. Consequently, delivering drugs to the specific organelle is the key to achieve maximum therapeutic effects and minimum side-effects. In the work reported here, we designed, synthesized, and evaluated a novel mitochondrial-targeted multifunctional nanoparticles (MNPs) based on chitosan derivatives according to the physiological environment of the tumor and the requirement of mitochondrial targeting drug delivery. The intelligent chitosan nanoparticles possess various functions such as stealth, hepatocyte targeting, multistage pH-response, lysosomal escape and mitochondrial targeting, which lead to targeted drug release after the progressively shedding of functional groups, thus realize the efficient intracellular delivery and mitochondrial localization, inhibit the growth of tumor, elevate the antitumor efficacy, and reduce the toxicity of anticancer drugs. It provides a safe and efficient nanocarrier platform for mitochondria targeting anticancer drug delivery. PMID:25818430

  8. Preparation of chitosan-graft-polyacrylamide magnetic composite microspheres for enhanced selective removal of mercury ions from water.

    PubMed

    Li, Kun; Wang, Yawen; Huang, Mu; Yan, Han; Yang, Hu; Xiao, Shoujun; Li, Aimin

    2015-10-01

    A novel magnetic composite microsphere based on polyacrylamide (PAM)-grafted chitosan and silica-coated Fe3O4 nanoparticles (CS-PAM-MCM) was successfully synthesized by a simple method. The molecular structure, surface morphology, and magnetic characteristics of the composite microsphere were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), and scanning electron microscopy (SEM). The prepared CS-PAM-MCM was applied as an efficient adsorbent for the removal of copper(II), lead(II), and mercury(II) ions from aqueous solutions in respective single, binary, and ternary metal systems. Compared with chitosan magnetic composite microsphere (CS-MCM) without modification, CS-PAM-MCM showed improved adsorption capacity for each metal ion and highly selective adsorption for Hg from Pb and Cu. This improvement is attributed to the formation of stronger interactions between Hg and the amide groups of PAM branches for chelating effects. The adsorption isotherms of Hg/Cu and Hg/Pb binary metal systems onto CS-PAM-MCM are both well-described by extended and modified Langmuir models, indicating that the removal of the three aforementioned metal ions may follow a similar adsorption manner; that is, through a homogeneous monolayer chemisorption process. Furthermore, these magnetic adsorbents could be easily regenerated in EDTA aqueous solution and reused virtually without any adsorption capacity loss. PMID:26073848

  9. Effect of hydroxyapatite nano-particles on morphology, rheology and thermal behavior of poly(caprolactone)/chitosan blends.

    PubMed

    Ghorbani, Fereshte Mohammad; Kaffashi, Babak; Shokrollahi, Parvin; Akhlaghi, Shahin; Hedenqvist, Mikael S

    2016-02-01

    The effect of hydroxyapatite nano-particles (nHA) on morphology, and rheological and thermal properties of PCL/chitosan blends was investigated. The tendency of nHA to reside in the submicron-dispersed chitosan phase is determined using SEM and AFM images. The presence of electrostatic interaction between amide sites of chitosan and ionic groups on the nHA surface was proved by FTIR. It is shown that the chitosan phase is thermodynamically more favorable for the nano-particles to reside than the PCL phase. Lack of implementation of Cox-Merz theory for this system shows that the polymer-nano-particle network is destructed by the flow. Results from dynamic rheological measurements and Zener fractional model show that the presence of nHA increases the shear moduli and relaxation time of the PCL/chitosan blends. DSC measurements showed that nHA nano-particles are responsible for the increase in melting and crystallization characteristics of the PCL/chitosan blends. Based on thermogravimetric analysis, the PCL/chitosan/nHA nano-composites exhibited a greater thermal stability compared to the nHA-free blends.

  10. Synthesis of chitosan supported palladium nanoparticles and its catalytic activity towards 2-nitrophenol reduction

    NASA Astrophysics Data System (ADS)

    Dhanavel, S.; Nivethaa, E. A. K.; Esther, G.; Narayanan, V.; Stephen, A.

    2016-05-01

    Chitosan supported Palladium nanoparticles were synthesized by a simple cost effective chemical reduction method using NaBH4. The prepared nanocomposite was characterized by X-Ray diffraction analysis, FESEM and Energy dispersive spectroscopy analysis of X-rays (EDAX). The catalytic performance of the nanocomposite was evaluated on the reduction of 2-Nitrophenol to the 2-Amino phenol with rate constant 1.08 × 10-3 S-1 by NaBH4 using Spectrophotometer.

  11. High molecular weight chitosan derivative polymeric micelles encapsulating superparamagnetic iron oxide for tumor-targeted magnetic resonance imaging

    PubMed Central

    Xiao, Yunbin; Lin, Zuan Tao; Chen, Yanmei; Wang, He; Deng, Ya Li; Le, D Elizabeth; Bin, Jianguo; Li, Meiyu; Liao, Yulin; Liu, Yili; Jiang, Gangbiao; Bin, Jianping

    2015-01-01

    Magnetic resonance imaging (MRI) contrast agents based on chitosan derivatives have great potential for diagnosing diseases. However, stable tumor-targeted MRI contrast agents using micelles prepared from high molecular weight chitosan derivatives are seldom reported. In this study, we developed a novel tumor-targeted MRI vehicle via superparamagnetic iron oxide nanoparticles (SPIONs) encapsulated in self-aggregating polymeric folate-conjugated N-palmitoyl chitosan (FAPLCS) micelles. The tumor-targeting ability of FAPLCS/SPIONs was demonstrated in vitro and in vivo. The results of dynamic light scattering experiments showed that the micelles had a relatively narrow size distribution (136.60±3.90 nm) and excellent stability. FAPLCS/SPIONs showed low cytotoxicity and excellent biocompatibility in cellular toxicity tests. Both in vitro and in vivo studies demonstrated that FAPLCS/SPIONs bound specifically to folate receptor-positive HeLa cells, and that FAPLCS/SPIONs accumulated predominantly in established HeLa-derived tumors in mice. The signal intensities of T2-weighted images in established HeLa-derived tumors were reduced dramatically after intravenous micelle administration. Our study indicates that FAPLCS/SPION micelles can potentially serve as safe and effective MRI contrast agents for detecting tumors that overexpress folate receptors. PMID:25709439

  12. The antibacterial properties of a novel chitosan-Ag-nanoparticle composite.

    PubMed

    Sanpui, Pallab; Murugadoss, A; Prasad, P V Durga; Ghosh, Siddhartha Sankar; Chattopadhyay, Arun

    2008-05-31

    Escherichia coli expressing recombinant green fluorescent protein was used to test the bactericidal efficacy of a newly synthesized chitosan-Ag-nanoparticle composite. The composite was found to have significantly higher antimicrobial activity than its components at their respective concentrations. The one-pot synthesis method led to the formation of small Ag nanoparticles attached to the polymer which can be dispersed in media of pH< or =6.3. The presence of a small percentage (2.15%, w/w) of metal nanoparticles in the composite was enough to significantly enhance inactivation of E. coli as compared with unaltered chitosan. Fluorescence spectroscopy indicated that bacterial growth stopped immediately after exposure of E. coli to the composite, with release of cellular green fluorescent protein into the medium at a faster rate than with chitosan. Fluorescence confocal laser scanning and scanning electron microscopy showed attachment of the bacteria to the composite and their subsequent fragmentation. Native protein gel electrophoresis experiments indicated no effect of the composite on bacterial proteins.

  13. Effect of basic fibroblast growth factor released from chitosan-fucoidan nanoparticles on neurite extension.

    PubMed

    Huang, Yi-Cheng; Yang, Ya-Ting

    2016-05-01

    Exogenous growth factors are an integral part of an effective nerve tissue-engineering strategy. Basic fibroblast growth factor (bFGF) has a marked positive effect on angiogenesis and neuronal cell survival. However, bFGF is limited by its short half-life and easy degradation by enzymes. Therefore, in this study novel biodegradable chitosan-fucoidan nanoparticles (CS-F NPs) were designed to carry bFGFs and maintain their activities. The experimental results indicated that chitosan and fucoidan form stable nanoparticles approximately 200 nm in size via electrostatic interactions. Additionally, the effectiveness of nanoparticles is related to their chitosan:fucoidan weight ratio. The CS-F NPs control the release of bFGFs and protect bFGF from deactivation by heat and enzymes. In vitro cell studies demonstrate that CS-F NPs have no cytotoxicity to PC12 cells, as the concentration of NPs is 125 ng/ml. Moreover, the CS-F NPs significantly decrease the amount of bFGF needed for neurite extension. The cumulative release of bFGF from CS-F NPs at 24 h is 0.168 ng/ml, markedly lower than that in solution (4.2 ng/ml). Importantly, CS-F NPs are potential carriers for delivering bFGFs for nerve tissue engineering. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Transformation of thiolated chitosan-templated gold nanoparticles to huge microcubes

    SciTech Connect

    Sun, Yudie; Liu, Honglin; Yang, Liangbao; Sun, Bai; Liu, Jinhuai

    2014-05-01

    Graphical abstract: - Highlights: • Mercapto groups were grafted to chitosan molecule by a reactive amine reduction. • Functional polymer with well-defined monomer units controls AuNPs assembly. • Assembled morphologies depend on the ratio of AuNPs to thiolate groups. • Microcubes with side length of ∼20 μm was synthesized through a dialysis step. • A edge-to-middle growth mechanism of gold microcubes was observed. - Abstract: The L-cysteine molecules were successfully grafted to the 2-amino group of chitosan by a reactive amine reduction, and the as-synthesized thiolated chitosan (TC) molecules were used as the templates to direct the self-assembly of gold nanoparticles and induce the transformation of these assemblies to gold microcubes through a deep-going dialysis. We found that the ratio of gold nanoparticles to TC molecules could greatly affect the shape of the assembled clusters. Different stages of these clusters and microstructures during the dialysis process were characterized by scanning electron microscope (SEM), and the microcubes with average side length of about 20 μm were successfully synthesized. According to the morphology evolution of the assembly, it could be concluded that the microcubes were formed from external to internal. The SERS area mapping images of microcubes and some clusters were also collected to study the formation mechanism of gold microcubes. Our work demonstrates a simple and highly effective way to assemble gold nanoparticles into microcubes with unique properties.

  15. Chitosan based nanoparticles as protein carriers for efficient oral antigen delivery.

    PubMed

    Gao, Ping; Xia, Guixue; Bao, Zixian; Feng, Chao; Cheng, Xiaojie; Kong, Ming; Liu, Ya; Chen, Xiguang

    2016-10-01

    This study aimed to investigate the efficacy of nanoparticles based on chitosan as a vehicle for oral antigen delivery in fish vaccination. Carboxymethyl chitosan/chitosan nanoparticles (CMCS/CS-NPs) loaded extracellular products (ECPs) of Vibrio anguillarum were successfully developed by ionic gelation method. The prepared ECPs-loaded CMCS/CS-NPs were characterized for various parameters including morphology, particle size (312±7.18nm), zeta potential (+17.4±0.38mV), loading efficiency (57.8±2.54%) and stability under the simulated gastrointestinal (GI) tract conditions in turbot. The in vitro profile showed that the cumulative release of ECPs from nanoparticles was higher in pH 7.4 (58%) than in pH 2.0 (37%) and pH 4.5 (29%) after 48h. Fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) was used as model protein antigen and encapsulated in CMCS/CS-NPs for investigating the biodistribution of antigen after oral delivery to turbot in 24h. Oral immunization of ECPs-loaded CMCS/CS-NPs group in turbot showed elevated specific antibody and higher concentrations of lysozyme activity and complement activity in fish serum than ECPs solution. CMCS/CS-NPs loaded with ECPs could enhance both adaptive and innate immune responses than the group treated with ECPs solution and suggested to be a potential antigen delivery system. PMID:27287772

  16. Bioinspired synthesis of magnetic nanoparticles

    SciTech Connect

    David, Anand

    2009-01-01

    The synthesis of magnetic nanoparticles has long been an area of active research. Magnetic nanoparticles can be used in a wide variety of applications such as magnetic inks, magnetic memory devices, drug delivery, magnetic resonance imaging (MRI) contrast agents, and pathogen detection in foods. In applications such as MRI, particle uniformity is particularly crucial, as is the magnetic response of the particles. Uniform magnetic particles with good magnetic properties are therefore required. One particularly effective technique for synthesizing nanoparticles involves biomineralization, which is a naturally occurring process that can produce highly complex nanostructures. Also, the technique involves mild conditions (ambient temperature and close to neutral pH) that make this approach suitable for a wide variety of materials. The term 'bioinspired' is important because biomineralization research is inspired by the naturally occurring process, which occurs in certain microorganisms called 'magnetotactic bacteria'. Magnetotactic bacteria use biomineralization proteins to produce magnetite crystals having very good uniformity in size and morphology. The bacteria use these magnetic particles to navigate according to external magnetic fields. Because these bacteria synthesize high quality crystals, research has focused on imitating aspects of this biomineralization in vitro. In particular, a biomineralization iron-binding protein found in a certain species of magnetotactic bacteria, magnetospirillum magneticum, AMB-1, has been extracted and used for in vitro magnetite synthesis; Pluronic F127 gel was used to increase the viscosity of the reaction medium to better mimic the conditions in the bacteria. It was shown that the biomineralization protein mms6 was able to facilitate uniform magnetite synthesis. In addition, a similar biomineralization process using mms6 and a shorter version of this protein, C25, has been used to synthesize cobalt ferrite particles. The overall

  17. Preparation and cytotoxicity of N,N,N-trimethyl chitosan/alginate beads containing gold nanoparticles.

    PubMed

    Martins, Alessandro F; Facchi, Suelen P; Monteiro, Johny P; Nocchi, Samara R; Silva, Cleiser T P; Nakamura, Celso V; Girotto, Emerson M; Rubira, Adley F; Muniz, Edvani C

    2015-01-01

    Polyelectrolyte complex beads based on N,N,N-trimethyl chitosan (TMC) and sodium alginate (ALG) were obtained. This biomaterial was characterised by FTIR, TGA/DTG, DSC and SEM analysis. The good properties of polyelectrolyte complex hydrogel beads were associated, for the first time, with gold nanoparticles (AuNPs). Through a straightforward methodology, AuNPs were encapsulated into the beads. The in vitro cytotoxicity assays on the Caco-2 colon cancer cells and healthy VERO cells showed that the beads presented good biocompatibility on both cell lines, whereas the beads loaded with gold nanoparticles (beads/AuNPs) was slightly cytotoxic on the Caco-2 and VERO cells.

  18. Dual immobilization and magnetic manipulation of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Yang, S. Y.; Jian, Z. F.; Horng, H. E.; Hong, Chin-Yih; Yang, H. C.; Wu, C. C.; Lee, Y. H.

    By suitably bio-functionalizing the surfaces, magnetic nanoparticles are able to bind specific biomolecules, and may serve as vectors for delivering bio-entities to target tissues. In this work, the synthesis of bio-functionalized magnetic nanoparticles with two kinds of bio-probes is developed. Here, the stem cell is selected as a to-be-delivered bio-entity and infarcted myocardium is the target issue. Thus, cluster designation-34 (CD-34) on stem cell and creatine kinase-MB (CK-MB) (or troponin I) on infarcted myocardium are the specific biomolecules to be bound with bio-functionalized magnetic nanoparticles. In addition to demonstrating the co-coating of two kinds of bio-probes on a magnetic nanoparticle, the feasibility of manipulation on bio-functionalized magnetic nanoparticles by external magnetic fields is investigated.

  19. Magnetic relaxation in dipolar magnetic nanoparticle clusters

    NASA Astrophysics Data System (ADS)

    Hovorka, Ondrej; Barker, Joe; Chantrell, Roy; Friedman, Gary; York-Drexel Collaboration

    2013-03-01

    Understanding the role of dipolar interactions on thermal relaxation in magnetic nanoparticle (MNP) systems is of fundamental importance in magnetic recording, for optimizing the hysteresis heating contribution in the hyperthermia cancer treatment in biomedicine, or for biological and chemical sensing, for example. In this talk, we discuss our related efforts to quantify the influence of dipolar interactions on thermal relaxation in small clusters of MNPs. Setting up the master equation and solving the associated eigenvalue problem, we identify the observable relaxation time scale spectra for various types of MNP clusters, and demonstrate qualitatively different spectral characteristics depending on the point group of symmetries of the particle arrangement within the cluster - being solely a dipolar interaction effect. Our findings provide insight into open questions related to magnetic relaxation in bulk MNP systems, and may prove to be also of practical relevance, e.g., for improving robustness of methodologies in biological and chemical sensing. OH gratefully acknowledges support from a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme under grant agreement PIEF-GA-2010-273014

  20. Nanoparticles Based on Chitosan as Carriers for the Combined Herbicides Imazapic and Imazapyr

    NASA Astrophysics Data System (ADS)

    Maruyama, Cintia Rodrigues; Guilger, Mariana; Pascoli, Mônica; Bileshy-José, Natalia; Abhilash, P. C.; Fraceto, Leonardo Fernandes; de Lima, Renata

    2016-01-01

    The use of lower concentrations and fewer applications of herbicides is one of the prime objectives of the sustainable agriculture as it decreases the toxicity to non-targeted organisms and the risk of wider environmental contamination. In the present work, nanoparticles were developed for encapsulation of the herbicides imazapic and imazapyr. Alginate/chitosan and chitosan/tripolyphosphate nanoparticles were manufactured, and their physicochemical stability was evaluated. Determinations were made of the encapsulation efficiency and release kinetics, and the toxicity of the nanoparticles was evaluated using cytotoxicity and genotoxicity assays. The effects of herbicides and herbicide-loaded nanoparticles on soil microorganisms were studied in detail using real-time polymerase chain reactions. The nanoparticles showed an average size of 400 nm and remained stable during 30 days of storage at ambient temperature. Satisfactory encapsulation efficiencies of between 50 and 70% were achieved for both types of particles. Cytotoxicity assays showed that the encapsulated herbicides were less toxic, compared to the free compounds, and genotoxicity was decreased. Analyses of soil microbiota revealed changes in the bacteria of the soils exposed to the different treatments. Our study proves that encapsulation of the herbicides improved their mode of action and reduced their toxicity, indicating their suitability for use in future practical applications.

  1. Nanoparticles Based on Chitosan as Carriers for the Combined Herbicides Imazapic and Imazapyr.

    PubMed

    Maruyama, Cintia Rodrigues; Guilger, Mariana; Pascoli, Mônica; Bileshy-José, Natalia; Abhilash, P C; Fraceto, Leonardo Fernandes; de Lima, Renata

    2016-01-01

    The use of lower concentrations and fewer applications of herbicides is one of the prime objectives of the sustainable agriculture as it decreases the toxicity to non-targeted organisms and the risk of wider environmental contamination. In the present work, nanoparticles were developed for encapsulation of the herbicides imazapic and imazapyr. Alginate/chitosan and chitosan/tripolyphosphate nanoparticles were manufactured, and their physicochemical stability was evaluated. Determinations were made of the encapsulation efficiency and release kinetics, and the toxicity of the nanoparticles was evaluated using cytotoxicity and genotoxicity assays. The effects of herbicides and herbicide-loaded nanoparticles on soil microorganisms were studied in detail using real-time polymerase chain reactions. The nanoparticles showed an average size of 400 nm and remained stable during 30 days of storage at ambient temperature. Satisfactory encapsulation efficiencies of between 50 and 70% were achieved for both types of particles. Cytotoxicity assays showed that the encapsulated herbicides were less toxic, compared to the free compounds, and genotoxicity was decreased. Analyses of soil microbiota revealed changes in the bacteria of the soils exposed to the different treatments. Our study proves that encapsulation of the herbicides improved their mode of action and reduced their toxicity, indicating their suitability for use in future practical applications. PMID:26813942

  2. Nanoparticles Based on Chitosan as Carriers for the Combined Herbicides Imazapic and Imazapyr

    PubMed Central

    Maruyama, Cintia Rodrigues; Guilger, Mariana; Pascoli, Mônica; Bileshy-José, Natalia; Abhilash, P.C.; Fraceto, Leonardo Fernandes; de Lima, Renata

    2016-01-01

    The use of lower concentrations and fewer applications of herbicides is one of the prime objectives of the sustainable agriculture as it decreases the toxicity to non-targeted organisms and the risk of wider environmental contamination. In the present work, nanoparticles were developed for encapsulation of the herbicides imazapic and imazapyr. Alginate/chitosan and chitosan/tripolyphosphate nanoparticles were manufactured, and their physicochemical stability was evaluated. Determinations were made of the encapsulation efficiency and release kinetics, and the toxicity of the nanoparticles was evaluated using cytotoxicity and genotoxicity assays. The effects of herbicides and herbicide-loaded nanoparticles on soil microorganisms were studied in detail using real-time polymerase chain reactions. The nanoparticles showed an average size of 400 nm and remained stable during 30 days of storage at ambient temperature. Satisfactory encapsulation efficiencies of between 50 and 70% were achieved for both types of particles. Cytotoxicity assays showed that the encapsulated herbicides were less toxic, compared to the free compounds, and genotoxicity was decreased. Analyses of soil microbiota revealed changes in the bacteria of the soils exposed to the different treatments. Our study proves that encapsulation of the herbicides improved their mode of action and reduced their toxicity, indicating their suitability for use in future practical applications. PMID:26813942

  3. Fabrication, characterization and cytotoxicity studies of ionically cross-linked docetaxel loaded chitosan nanoparticles.

    PubMed

    Jain, Ankit; Thakur, Kanika; Sharma, Gajanand; Kush, Preeti; Jain, Upendra K

    2016-02-10

    The present investigation aimed at the fabrication and characterization of ionically cross-linked docetaxel (DTX) loaded chitosan nanoparticles (DTX-CH-NP) using ionic gelation technique with sodium tripolyphosphate (TPP) as the cross-linking agent. The formulated nanoparticles were characterized in terms of particle size, drug entrapment efficiency (EE), scanning electron microscopy (SEM), in vitro release and cytotoxicity studies. Formulation factors (chitosan, TPP and drug concentration) were examined systematically for their effects on size of the nanoparticles. The average size of the nanoparticles was observed to be in the range of 159.2 ± 3.31 to 220.7 ± 2.23 nm with 78-92% encapsulation efficiency (EE). The in vitro cytotoxicity studies on breast cancer cell lines (MDA-MB-231) revealed the advantages of DTX-CH-NP over pure DTX with approximately 85% cell viability reduction. The results indicate that systematic modulation of the surface charge and particle size of ionically cross-linked nanoparticles can be readily achieved with the right control of critical processing parameters. Thus, DTX-CH-NP presents a promising delivery alternative for breast cancer treatment.

  4. Preparation, physical-chemical and biological characterization of chitosan nanoparticles loaded with lysozyme.

    PubMed

    Piras, Anna Maria; Maisetta, Giuseppantonio; Sandreschi, Stefania; Esin, Semih; Gazzarri, Matteo; Batoni, Giovanna; Chiellini, Federica

    2014-06-01

    A commercially available chitosan (CS) was employed in the formulation of nanoparticles loaded with lysozyme (LZ) as antimicrobial protein drug model. Due to the variability of commercially available batches of chitosans and to the strict dependence of their physical and biological properties to the molecular weight (Mw) and deacetylation degree (DD) of the material, the CS was fully characterized resulting in weight-average molecular weight of 108,120g/mol and DD of 92%. LZ-loaded nanoparticles (LZ-NPs) of 150nm diameter were prepared by inotropic gelation. The nanoparticles were effectively preserving the antibacterial activity of the loaded enzyme, which was slowly released over 3 weeks in vitro and remained active toward Staphylococcus epidermidis up to 5 days of incubation. Beyond the intrinsic antibacterial activity of CS and LZ, the LZ-NPs evidenced a sustained antibacterial activity that resulted in about 2 log reduction of the number of viable S. epidermidis compared to plain CS nanoparticles. Furthermore, the LZ-NPs showed a full in vitro cytocompatibility toward murine fibroblasts and, in addition to the potential antimicrobial applications of the developed system, the proposed study could serve as an optimal model for development of CS nanoparticles carrying antimicrobial peptides for biomedical applications. PMID:24661890

  5. Synthesis and characterization of functionalized magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Biswal, Dipti; Peeples, Brianna N.; Spence, Destiny D.; Peeples, Caryn; Bell, Crystal N.; Pradhan, A. K.

    2012-04-01

    Magnetic nanoparticles have been used in a wide array of industrial and biomedical applications due to their unique properties at the nanoscale level. They are extensively used in magnetic resonance imaging (MRI), magnetic hyperthermia treatment, drug delivery, and in assays for biological separations. Furthermore, superparamagnetic nanoparticles are of large interest for in vivo applications. However, these unmodified nanoparticles aggregate and consequently lose their superparamagnetic behaviors, due to high surface to volume ratio and strong dipole to dipole interaction. For these reasons, surface coating is necessary for the enhancement and effectiveness of magnetic nanoparticles to be used in various applications. In addition to providing increased stability to the nanoparticles in different solvents or media, stabilizers such as surfactants, organic/inorganic molecules, polymer and co-polymers are employed as surface coatings, which yield magnetically responsive systems. In this work we present the synthesis and magnetic characterization of Fe3O4 nanoparticles coated with 3-aminopropyltriethoxy silane (APS) and citric acid. The particles magnetic hysteresis was measured by a superconducting quantum interference device (SQUID) magnetometer with an in-plane magnetic field. The uncoated and coated magnetic nanoparticles were characterized by using fourier transform infrared (FTIR), UV-vis, X-ray diffraction, transmission electron microscopy, and thermo-gravimetric analysis.

  6. Self-assembled nanoparticles based on hydrophobically modified chitosan as carriers for doxorubicin.

    PubMed

    Zhang, Jing; Chen, Xi Guang; Li, Yan Yan; Liu, Cheng Sheng

    2007-12-01

    In this study self-assembled nanoparticles based on oleoyl-chitosan (OCH) were prepared with a mean diameter of 255.3 nm and an almost spherical shape. The toxicity profile of OCH nanoparticles was evaluated in vitro via hemolysis test and MTT assay. The hemolysis rates of OCH nanoparticles tested in different conditions came well within permissible limits (5%). The OCH nanoparticles showed no cytotoxicity to mouse embryo fibroblasts. Doxorubicin (DOX) was efficiently loaded into OCH nanoparticles with an encapsulation efficiency of 52.6%. The drug was rapidly and completely released from the nanoparticles (DOX-OCH nanoparticles) at pH 3.8, whereas at pH 7.4 there was a sustained release after a burst release. The inhibitory rates of DOX-OCH nanoparticle suspension to different human cancer cells (A549, Bel-7402, HeLa, and SGC-7901) significantly outperformed that of DOX solution. These results revealed the potential of OCH nanoparticles as carriers for hydrophobic antitumor agents.

  7. Development of a novel drug delivery system: chitosan nanoparticles entrapped in alginate microparticles.

    PubMed

    Garrait, Ghislain; Beyssac, Eric; Subirade, Muriel

    2014-01-01

    A novel carrier using chitosan nanoparticles entrapped into alginate microparticles is proposed for protecting molecules of interest from degradation in the digestive tract. The effects of polymer concentration, sonication, stirring, pH, and processing conditions on the physical characteristics of the carrier were studied. FITC and RBITC were used to localise the polymers within particles using CLSM. Diffusion of amaranth red (AR) from nanoparticles was quantified during dissolution under gastric and intestinal conditions. Under optimal preparation conditions, the size distribution of nanoparticles loaded with AR was uniform (690 nm) with an encapsulation efficacy of 21.9%. Alginate microparticles (285 µm) containing a homogenous distribution of nanoparticles and polymers were obtained. At gastric pH, the carrier released less than 5% of the loaded AR and, at intestinal pH, the release was rapid and complete. The drug carriers developed shows a promising use as a vehicle suitable to protect molecules of interest after oral administration.

  8. Magnetic Nanoparticles in Cancer Theranostics

    PubMed Central

    Gobbo, Oliviero L.; Sjaastad, Kristine; Radomski, Marek W.; Volkov, Yuri; Prina-Mello, Adriele

    2015-01-01

    In a report from 2008, The International Agency for Research on Cancer predicted a tripled cancer incidence from 1975, projecting a possible 13-17 million cancer deaths worldwide by 2030. While new treatments are evolving and reaching approval for different cancer types, the main prevention of cancer mortality is through early diagnosis, detection and treatment of malignant cell growth. The last decades have seen a development of new imaging techniques now in widespread clinical use. The development of nano-imaging through fluorescent imaging and magnetic resonance imaging (MRI) has the potential to detect and diagnose cancer at an earlier stage than with current imaging methods. The characteristic properties of nanoparticles result in their theranostic potential allowing for simultaneous detection of and treatment of the disease. This review provides state of the art of the nanotechnological applications for cancer therapy. Furthermore, it advances a novel concept of personalized nanomedical theranostic therapy using iron oxide magnetic nanoparticles in conjunction with MRI imaging. Regulatory and industrial perspectives are also included to outline future perspectives in nanotechnological cancer research. PMID:26379790

  9. Preparation of Fe3O4 magnetic nanoparticles coated with gallic acid for drug delivery

    PubMed Central

    Dorniani, Dena; Hussein, Mohd Zobir Bin; Kura, Aminu Umar; Fakurazi, Sharida; Shaari, Abdul Halim; Ahmad, Zalinah

    2012-01-01

    Background and methods Magnetic iron oxide nanoparticles were prepared using a sonochemical method under atmospheric conditions at a Fe2+ to Fe3+ molar ratio of 1:2. The iron oxide nanoparticles were subsequently coated with chitosan and gallic acid to produce a core-shell structure. Results X-ray diffraction demonstrated that the magnetic nanoparticles were pure Fe3O4 with a cubic inverse spinel structure. Transmission electron microscopy showed that the Fe3O4 nanoparticles were of spherical shape with a mean diameter of 11 nm, compared with 13 nm for the iron oxide-chitosan-gallic acid (FCG) nanocarriers. Conclusion The magnetic nanocarrier enhanced the thermal stability of the drug, gallic acid. Release of the active drug from the FCG nanocarrier was found to occur in a controlled manner. The gallic acid and FCG nanoparticles were not toxic in a normal human fibroblast (3T3) line, and anticancer activity was higher in HT29 than MCF7 cell lines. PMID:23166439

  10. Simultaneous removal of acid green 25 and mercury ions from aqueous solutions using glutamine modified chitosan magnetic composite microspheres.

    PubMed

    Tao, Xue; Li, Kun; Yan, Han; Yang, Hu; Li, Aimin

    2016-02-01

    In this current work, the magnetic composite microsphere containing glutamine modified chitosan and silica coated Fe3O4 nanoparticles (CS-Gln-MCM) has been successfully prepared and extensively characterized, which is a kind of biodegradable materials. CS-Gln-MCM shows enhanced removal efficiency for both acid green 25 (AG25), an amphoteric dye, and mercury ions (Hg(2+)) from water in the respective while measured pH range compared with chitosan magnetic composite microsphere (CS-MCM) without modification. It is due to the fact that the grafted amino acid provides a variety of additional adsorption active sites and diverse adsorption mechanisms are involved. In AG25 and Hg(2+) aqueous mixture, the modified adsorbents bear preferential adsorption for AG25 over Hg(2+) in strong acidic solutions ascribed to multiple interactions between AG25 and CS-Gln-MCM, such as hydrogen bonding and electrostatic interactions. While, in weak acidic conditions, an efficient simultaneous removal is observed for different adsorption effects involved in aforementioned two pollutants. Besides, CS-Gln-MCM illuminates not only short equilibrium time for adsorption of each pollutant less than 20.0 min but also rapid magnetic separation from water and efficient regeneration after saturated adsorption. Therefore, CS-Gln-MCM bears great application potentials in water treatment. PMID:26618263

  11. Simultaneous removal of acid green 25 and mercury ions from aqueous solutions using glutamine modified chitosan magnetic composite microspheres.

    PubMed

    Tao, Xue; Li, Kun; Yan, Han; Yang, Hu; Li, Aimin

    2016-02-01

    In this current work, the magnetic composite microsphere containing glutamine modified chitosan and silica coated Fe3O4 nanoparticles (CS-Gln-MCM) has been successfully prepared and extensively characterized, which is a kind of biodegradable materials. CS-Gln-MCM shows enhanced removal efficiency for both acid green 25 (AG25), an amphoteric dye, and mercury ions (Hg(2+)) from water in the respective while measured pH range compared with chitosan magnetic composite microsphere (CS-MCM) without modification. It is due to the fact that the grafted amino acid provides a variety of additional adsorption active sites and diverse adsorption mechanisms are involved. In AG25 and Hg(2+) aqueous mixture, the modified adsorbents bear preferential adsorption for AG25 over Hg(2+) in strong acidic solutions ascribed to multiple interactions between AG25 and CS-Gln-MCM, such as hydrogen bonding and electrostatic interactions. While, in weak acidic conditions, an efficient simultaneous removal is observed for different adsorption effects involved in aforementioned two pollutants. Besides, CS-Gln-MCM illuminates not only short equilibrium time for adsorption of each pollutant less than 20.0 min but also rapid magnetic separation from water and efficient regeneration after saturated adsorption. Therefore, CS-Gln-MCM bears great application potentials in water treatment.

  12. Physico-chemical characterization and cytotoxicity evaluation of curcumin loaded in chitosan/chondroitin sulfate nanoparticles.

    PubMed

    Jardim, Katiúscia Vieira; Joanitti, Graziella Anselmo; Azevedo, Ricardo Bentes; Parize, Alexandre Luis

    2015-11-01

    In this study, chitosan (CTS)/chondroitin sulfate (CS) nanoparticles, both pure and curcumin-loaded, were synthesized by ionic gelation. This method is simple and efficient for obtaining nanoparticles with a low polydispersity index (0.151±0.03 to 0.563±0.07) and hydrodynamic diameter in the range of 175.7±2.5 to 710.2±8.9nm, for this study. Samples have a relatively high zeta potential value, a fact that indicates that the colloidal system has good physical and chemical stabilities. The efficiency of the curcumin encapsulation in nanoparticles, which ranged from 62.4±0.61% to 68.3±0.88%, depends on the pH of the chitosan solution. The release of curcumin from the nanoparticles was enabled by a diffusion mechanism, with fast release in a phosphate buffer solution at pH6.8. The assaying of cell viability by the MTT test showed that the presence of both free curcumin and curcumin in the nanoencapsulated form leads to a statistically significant reduction in the viability of A549 cells, by comparison with the control group. The most significant reductions in cell viability of 41.1% and 60.4% (p<0.0001) were observed after 72h, by using 40μmol∙L(-1) free curcumin and curcumin encapsulated in CTS/CS nanoparticles with the chitosan solution at pH6.0, respectively.

  13. Platinum dendritic nanoparticles with magnetic behavior

    SciTech Connect

    Li, Wenxian; Sun, Ziqi; Nevirkovets, Ivan P.; Dou, Shi-Xue; Tian, Dongliang

    2014-07-21

    Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ∼4 nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a mixed paramagnetic and ferromagnetic state, originating from the core and surface, respectively. The 3D nanodendrite structure is suitable for surface modification and high amounts of drug loading if the transition temperature was enhanced to room temperature properly.

  14. Engineering biofunctional magnetic nanoparticles for biotechnological applications

    NASA Astrophysics Data System (ADS)

    Moros, Maria; Pelaz, Beatriz; López-Larrubia, Pilar; García-Martin, Maria L.; Grazú, Valeria; de La Fuente, Jesus M.

    2010-09-01

    Synthesis and characterization of magnetic nanoparticles with excellent size control are showed here. Their functionalization using an amphiphilic polymer is also described. This strategy allows the stabilization of magnetic nanoparticles in aqueous solvents and in addition, the polymer shell serves as a platform to incorporate relevant biomolecules, such as poly(ethylene glycol) and a number of carbohydrates. Nanoparticles functionalized with carbohydrates show the ability to avoid unspecific interactions between proteins present in the working medium and the nanoparticles, so can be used as an alternative to poly(ethylene glycol) molecules. Results confirm these nanoparticles as excellent contrast agents for magnetic resonance imaging. Changes in the spin-spin transversal relaxation times of the surrounding water protons due to nanoparticle aggregation demonstrates the bioactivity of these nanoparticles functionalized with carbohydrates. To finish with, nanoparticle toxicity is evaluated by means of MTT assay. The obtained results clearly indicate that these nanoparticles are excellent candidates for their further application in nanomedicine or nanobiotechnology.Synthesis and characterization of magnetic nanoparticles with excellent size control are showed here. Their functionalization using an amphiphilic polymer is also described. This strategy allows the stabilization of magnetic nanoparticles in aqueous solvents and in addition, the polymer shell serves as a platform to incorporate relevant biomolecules, such as poly(ethylene glycol) and a number of carbohydrates. Nanoparticles functionalized with carbohydrates show the ability to avoid unspecific interactions between proteins present in the working medium and the nanoparticles, so can be used as an alternative to poly(ethylene glycol) molecules. Results confirm these nanoparticles as excellent contrast agents for magnetic resonance imaging. Changes in the spin-spin transversal relaxation times of the

  15. Thyrotropin-Releasing Hormone Loaded and Chitosan Engineered Polymeric Nanoparticles: Towards Effective Delivery of Neuropeptides.

    PubMed

    Kaur, Sarabjit; Bhararia, Avani; Sharma, Krishna; Mittal, Sherry; Jain, Rahul; Wangoo, Nishima; Sharma, Rohit K

    2016-05-01

    Thyrotropin-Releasing Hormone (TRH), a tripeptide amide with molecular formula L-pGlu-L-His-L- Pro-NH2, is used in the treatment of brain/spinal injury and certain central nervous system (CNS) disorders, including schizophrenia, Alzheimer's disease, epilepsy, depression, shock and ischemia due to its profound effects on the CNS. However, TRH's therapeutic activity is severely hampered because of instability and hydrophilicity owing to its peptidic nature which results into ineffective penetration into the blood brain barrier. In the present study, we report the synthesis and stability studies of novel chitosan engineered TRH encapsulated poly(lactide-co-glycolide) (PLGA) based nanoformulation. The aim of such an encapsulation is to allow effective delivery of TRH in biological systems as the peptidase degrade naked TRH. The synthesis of TRH was carried out manually in solution phase followed by its encapsulation using PLGA to form polymeric nanoparticles (NPs) via nanoprecipitation technique. Different parameters such as type of organic phase, concentration of stabilizer, ratio of organic phase and aqueous phase, rate of addition of organic phase were optimized, tested and evaluated for particle size, encapsulation efficiency, and stability of NPs. The TRH-PLGA NPs were then surface modified with chitosan to achieve positive surface charge rendering them potential membrane penetrating agents. PLGA, PLGA-TRH, Chitosan-PLGA and Chitosan-PLGA-TRH NPs were characterized and analyzed using Dynamic Light Scattering (DLS), Transmissiom Electron Microscopy (TEM) and Infra-red spectroscopic techniques. PMID:27483926

  16. Polyethylene glycol-modified arachidyl chitosan-based nanoparticles for prolonged blood circulation of doxorubicin.

    PubMed

    Termsarasab, Ubonvan; Yoon, In-Soo; Park, Ju-Hwan; Moon, Hyun Tae; Cho, Hyun-Jong; Kim, Dae-Duk

    2014-04-10

    Doxorubicin (DOX)-loaded nanoparticles based on polyethylene glycol-conjugated chitosan oligosaccharide-arachidic acid (CSOAA-PEG) were explored for potential application to leukemia therapy. PEG was conjugated with CSOAA backbone via amide bond formation and the final product was verified by (1)H NMR analysis. Using the synthesized CSOAA-PEG, nanoparticles having characteristics of a 166-nm mean diameter, positive zeta potential, and spherical shape were produced for the delivery of DOX. The mean diameter of CSOAA-PEG nanoparticles in the serum solution (50% fetal bovine serum) remained relatively constant over 72 h as compared with CSOAA nanoparticles (changes of 20.92% and 223.16%, respectively). The sustained release pattern of DOX from CSOAA-PEG nanoparticles was displayed at physiological pH, and the release rate increased under the acidic pH conditions. The cytotoxicity of the CSOAA-PEG conjugate was negligible in human leukemia cells (K562) at the concentrations tested (∼ 100 μg/ml). The uptake rate of DOX from the nanoparticles by K562 cells was higher than that from the solution. Judging from the results of pharmacokinetic studies in rats, in vivo clearance rate of DOX from the CSOAA-PEG nanoparticle group was slower than other groups, subsequently extending the circulation period. The PEGylated CSOAA-based nanoparticles could represent an effective nano-sized delivery system for DOX which has been used for the treatment of blood malignancies.

  17. Structural characterization of copolymer embedded magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Nedelcu, G. G.; Nastro, A.; Filippelli, L.; Cazacu, M.; Iacob, M.; Rossi, C. Oliviero; Popa, A.; Toloman, D.; Dobromir, M.; Iacomi, F.

    2015-10-01

    Small magnetic nanoparticles (Fe3O4) were synthesized by co-precipitation and coated by emulsion polymerization with poly(methyl methacrylate-co-acrylic acid) (PMMA-co-AAc) to create surface functional groups that can attach drug molecules and other biomolecules. The coated and uncoated magnetite nanoparticles were stored for two years in normal closed ships and than characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, and electron paramagnetic resonance spectroscopy. The solid phase transformation of magnetite to maghemite, as well as an increase in particle size were evidenced for the uncoated nanoparticles. The coated nanoparticles preserved their magnetite structure and magnetic properties. The influences of monomers and surfactant layers on interactions between the magnetic nanoparticles evidenced that the thickness of the polymer has a significant effect on magnetic properties.

  18. Chitosan nanoparticles: A positive modulator of innate immune responses in plants.

    PubMed

    Chandra, Swarnendu; Chakraborty, Nilanjan; Dasgupta, Adhiraj; Sarkar, Joy; Panda, Koustubh; Acharya, Krishnendu

    2015-01-01

    The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant's innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation. PMID:26471771

  19. Chitosan nanoparticles: A positive modulator of innate immune responses in plants

    PubMed Central

    Chandra, Swarnendu; Chakraborty, Nilanjan; Dasgupta, Adhiraj; Sarkar, Joy; Panda, Koustubh; Acharya, Krishnendu

    2015-01-01

    The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant’s innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation. PMID:26471771

  20. Chitosan nanoparticles: A positive modulator of innate immune responses in plants.

    PubMed

    Chandra, Swarnendu; Chakraborty, Nilanjan; Dasgupta, Adhiraj; Sarkar, Joy; Panda, Koustubh; Acharya, Krishnendu

    2015-10-16

    The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant's innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.

  1. Photoactivated rose bengal functionalized chitosan nanoparticles produce antibacterial/biofilm activity and stabilize dentin-collagen

    PubMed Central

    Shrestha, Annie; Hamblin, Michael R.; Kishen, Anil

    2014-01-01

    Treatment of infected teeth presents two major challenges: persistence of the bacterial-biofilm within root canals after treatment and compromised structural integrity of the dentin hard-tissue. In this study bioactive polymeric chitosan nanoparticles functionalized with rose-bengal, CSRBnp was developed to produce antibiofilm effects as well as stabilize structural-integrity by photocrosslinking dentin-collagen. CSRBnp was less toxic to fibroblasts and had significant antibacterial activity even in the presence of bovine serum albumin. CSRBnp exerted antibacterial mechanism by adhering to bacterial cell surface, permeabilizing the membrane and lysing the cells subsequent to photodynamic treatment. Photoactivated CSRBnp resulted in reduced viability of Enterococcus faecalis biofilms and disruption of biofilm structure. Incorporation of CSRBnp and photocrosslinking significantly improved resistance to degradation and mechanical strength of dentin-collagen (p<0.05). The functionalized chitosan nanoparticles provided a single-step treatment of infected root dentin by combining the properties of chitosan and that of photosensitizer to eliminate bacterial-biofilms and stabilize dentin-matrix. PMID:24200522

  2. Chitosan nanoparticles: A positive modulator of innate immune responses in plants

    NASA Astrophysics Data System (ADS)

    Chandra, Swarnendu; Chakraborty, Nilanjan; Dasgupta, Adhiraj; Sarkar, Joy; Panda, Koustubh; Acharya, Krishnendu

    2015-10-01

    The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant’s innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.

  3. In situ preparation of high relaxivity iron oxide nanoparticles by coating with chitosan: A potential MRI contrast agent useful for cell tracking

    NASA Astrophysics Data System (ADS)

    Tsai, Zei-Tsan; Wang, Jen-Fei; Kuo, Hsiao-Yun; Shen, Chia-Rui; Wang, Jiun-Jie; Yen, Tzu-Chen

    2010-01-01

    Iron oxide nanocrystals are of considerable interest in nanoscience and nanotechnology because of their nanoscale dimensions, nontoxic nature, and superior magnetic properties. Colloidal solutions of magnetic nanoparticles (ferrofluids) with a high magnetite content are highly desirable for most molecular imaging applications. In this paper, we present a method for in situ coating of superparamagnetic iron oxide (SPIO) with chitosan in order to increase the content of magnetite. Iron chloride salts (Fe 3+ and Fe 2+) were directly coprecipitated inside a porous matrix of chitosan by Co-60 γ-ray irradiation in an aqueous solution of acetic acid. Following sonication, iron oxide nanoparticles were formed inside the chitosan matrix at a pH value of 9.5 and a temperature of 50 °C. The [Fe 3+]:[Fe 2+]:[NH 4OH] molar ratio was 1.6:1:15.8. The final ferrofluid was formed with a pH adjustment to approximately 2.0/3.0, alongside with the addition of mannitol and lactic acid. We subsequently characterized the particle size, the zeta potential, the iron concentration, the magnetic contrast, and the cellular uptake of our ferrofluid. Results showed a z-average diameter of 87.2 nm, a polydispersity index (PDI) of 0.251, a zeta potential of 47.9 mV, and an iron concentration of 10.4 mg Fe/mL. The MRI parameters included an R1 value of 22.0 mM -1 s -1, an R2 value of 202.6 mM -1 s -1, and a R2/R1 ratio of 9.2. An uptake of the ferrofluid by mouse macrophages was observed. Altogether, our data show that Co-60 γ-ray radiation on solid chitosan may improve chitosan coating of iron oxide nanoparticles and tackle its aqueous solubility at pH 7. Additionally, our methodology allowed to obtain a ferrofluid with a higher content of magnetite and a fairly unimodal distribution of monodisperse clusters. Finally, MRI and cell experiments demonstrated the potential usefulness of this product as a potential MRI contrast agent that might be used for cell tracking.

  4. Magnetic iron oxide nanoparticles for biomedical applications.

    PubMed

    Laurent, Sophie; Bridot, Jean-Luc; Elst, Luce Vander; Muller, Robert N

    2010-03-01

    Due to their high magnetization, superparamagnetic iron oxide nanoparticles induce an important decrease in the transverse relaxation of water protons and are, therefore, very efficient negative MRI contrast agents. The knowledge and control of the chemical and physical characteristics of nanoparticles are of great importance. The choice of the synthesis method (microemulsions, sol-gel synthesis, laser pyrolysis, sonochemical synthesis or coprecipitation) determines the magnetic nanoparticle's size and shape, as well as its size distribution and surface chemistry. Nanoparticles can be used for numerous in vivo applications, such as MRI contrast enhancement and hyperthermia drug delivery. New developments focus on targeting through molecular imaging and cell tracking. PMID:21426176

  5. Electrospinning of PVA/chitosan nanocomposite nanofibers containing gelatin nanoparticles as a dual drug delivery system.

    PubMed

    Fathollahipour, Shahrzad; Abouei Mehrizi, Ali; Ghaee, Azadeh; Koosha, Mojtaba

    2015-12-01

    Nanofibrous core-sheath nanocomposite dual drug delivery system based on poly(vinyl alcohol) (PVA)/chitosan/lidocaine hydrochloride loaded with gelatin nanoparticles were successfully prepared by the electrospinning method. Gelatin nanoparticles were prepared by nanoprecipitation and were then loaded with erythromycin antibiotic agent with the average particle size of ∼175 nm. The morphology of gelatin nanoparticles observed by field emission scanning electron microscopy (FE-SEM) was shown to be optimal at the concentration of 1.25 wt % of gelatin in aqueous phase by addition of 20 µL of glutaraldehyde 5% as the crosslinking agent. The nanoparticles were also characterized by dynamic light scattering, zeta potential measurement, and Fourier transform infrared spectroscopy (FTIR). The best bead free morphology for the PVA/chitosan nanofibrous mats were obtained at the solution weight ratio of 96/4. The nanofibrous mats were analyzed by swelling studies, FTIR and antibacterial tests. In vitro dual release profile of the core-sheath nanofibers was also studied within 72 h and showed the release efficiency equal to 84.69 and 75.13% for lidocaine hydrochloride and erythromycin, respectively. According to release exponent n, the release of lidocaine hydrochloride from the sheath part of the matrix is quasi-Fickian diffusion mechanism, while the release of erythromycin is based on anomalous or non-Fickian mechanisms.

  6. Carbopol gel containing chitosan-egg albumin nanoparticles for transdermal aceclofenac delivery.

    PubMed

    Jana, Sougata; Manna, Sreejan; Nayak, Amit Kumar; Sen, Kalyan Kumar; Basu, Sanat Kumar

    2014-02-01

    In the present work, various aceclofenac-loaded chitosan-egg albumin nanoparticles were prepared through heat coagulation method. These aceclofenac-loaded nanoparticles were characterized by FE-SEM, FTIR, DSC and P-XRD analyses. The in vitro drug release from nanoparticles showed sustained drug release over 8h. Aceclofenac-loaded nanoparticles (prepared using 200mg chitosan, 500 mg egg albumin and 2% (w/v) NaTPP) showed highest drug entrapment (96.32±1.52%), 352.90 nm average particle diameter and -22.10 mV zeta potential, which was used for further preparation of Carbopol 940 gel for transdermal application. The prepared gel exhibited sustained ex vivo permeation of aceclofenac over 8h through excised mouse skin. The in vivo anti-inflammatory activity in carrageenean-induced rats demonstrated comparative higher inhibition of swelling of rat paw edema by the prepared gel compared with that of the marketed aceclofenac gel over 4 h. PMID:24161504

  7. Amphotericin-B entrapped lecithin/chitosan nanoparticles for prolonged ocular application.

    PubMed

    Chhonker, Yashpal S; Prasad, Yarra Durga; Chandasana, Hardik; Vishvkarma, Akhilesh; Mitra, Kalyan; Shukla, Praveen K; Bhatta, Rabi S

    2015-01-01

    Fungal keratitis is the major cause of vision loss worldwide. Amphotericin-B is considered as the drug of choice for fungal infections. However, its use in ophthalmic drug delivery is limited by the low precorneal residence at ocular surface as a result of blinking reflex, tear turnover and nasopharyngeal drainage. We report Amphotericin-B loaded lecithin/chitosan nanoparticles for prolonged ocular application. The prepared nanoparticles were in the size range of 161.9-230.5 nm, entrapment efficiency of 70-75%, theoretical drug loading of 5.71% with positive zeta potential of 26.6-38.3 mV. As demonstrated by antifungal susceptibility against Candida albicans and Aspergillus fumigatus, nanoparticles were more effective than marketed formulation. They exhibited pronounced mucoadhesive properties. In-vivo pharmacokinetic studies in New Zealand albino rabbit eyes indicated improved bioavailablity (∼ 2.04 fold) and precorneal residence time (∼ 3.36 fold) by nanoparticles prepared from low molecular weight chitosan as compared with marketed formulation.

  8. Carbopol gel containing chitosan-egg albumin nanoparticles for transdermal aceclofenac delivery.

    PubMed

    Jana, Sougata; Manna, Sreejan; Nayak, Amit Kumar; Sen, Kalyan Kumar; Basu, Sanat Kumar

    2014-02-01

    In the present work, various aceclofenac-loaded chitosan-egg albumin nanoparticles were prepared through heat coagulation method. These aceclofenac-loaded nanoparticles were characterized by FE-SEM, FTIR, DSC and P-XRD analyses. The in vitro drug release from nanoparticles showed sustained drug release over 8h. Aceclofenac-loaded nanoparticles (prepared using 200mg chitosan, 500 mg egg albumin and 2% (w/v) NaTPP) showed highest drug entrapment (96.32±1.52%), 352.90 nm average particle diameter and -22.10 mV zeta potential, which was used for further preparation of Carbopol 940 gel for transdermal application. The prepared gel exhibited sustained ex vivo permeation of aceclofenac over 8h through excised mouse skin. The in vivo anti-inflammatory activity in carrageenean-induced rats demonstrated comparative higher inhibition of swelling of rat paw edema by the prepared gel compared with that of the marketed aceclofenac gel over 4 h.

  9. Glucose-conjugated chitosan nanoparticles for targeted drug delivery and their specific interaction with tumor cells

    NASA Astrophysics Data System (ADS)

    Li, Jing; Ma, Fang-Kui; Dang, Qi-Feng; Liang, Xing-Guo; Chen, Xi-Guang

    2014-12-01

    A novel targeted drug delivery system, glucose-conjugated chitosan nanoparticles (GCNPs), was developed for specific recognition and interaction with glucose transporters (Gluts) over-expressed by tumor cells. GC was synthesized by using succinic acid as a linker between glucosamine and chitosan (CS), and successful synthesis was confirmed by NMR and elemental analysis. GCNPs were prepared by ionic crosslinking method, and characterized in terms of morphology, size, and zeta potential. The optimally prepared nanoparticles showed spherical shapes with an average particle size of (187.9 ± 3.8) nm and a zeta potential of (- 15.43 ± 0.31) mV. The GCNPs showed negligible cytotoxicity to mouse embryo fibroblast and 4T1 cells. Doxorubicin (DOX) could be efficiently entrapped into GCNPs, with a loading capacity and encapsulation efficiency of 20.11% and 64.81%, respectively. DOX-loaded nanoparticles exhibited sustained-release behavior in phosphate buffered saline (pH 7.4). In vitro cellular uptake studies showed that the GCNPs had better endocytosis ability than CSNPs, and the antitumor activity of DOX/GCNPs was 4-5 times effectiveness in 4T1 cell killing than that of DOX/CSNPs. All the results demonstrate that nanoparticles decorated with glucose have specific interactions with cancer cells via the recognition between glucose and Gluts. Therefore, Gluts-targeted GCNPs may be promising delivery agents in cancer therapies.

  10. A New Strategy Based on Smrho Protein Loaded Chitosan Nanoparticles as a Candidate Oral Vaccine against Schistosomiasis

    PubMed Central

    Oliveira, Carolina R.; Rezende, Cíntia M. F.; Silva, Marina R.; Pêgo, Ana Paula; Borges, Olga; Goes, Alfredo M.

    2012-01-01

    Background Schistosomiasis is one of the most important neglected tropical diseases and an effective control is unlikely in the absence of improved sanitation and vaccination. A new approach of oral vaccination with alginate coated chitosan nanoparticles appears interesting because their great stability and the ease of target accessibility, besides of chitosan and alginate immunostimulatory properties. Here we propose a candidate vaccine based on the combination of chitosan-based nanoparticles containing the antigen SmRho and coated with sodium alginate. Methods and Findings Our results showed an efficient performance of protein loading of nanoparticles before and after coating with alginate. Characterization of the resulting nanoparticles reported a size around 430 nm and a negative zeta potential. In vitro release studies of protein showed great stability of coated nanoparticles in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Further in vivo studies was performed with different formulations of chitosan nanoparticles and it showed that oral immunization was not able to induce high levels of antibodies, otherwise intramuscular immunization induced high levels of both subtypes IgG1 and IgG2a SmRho specific antibodies. Mice immunized with nanoparticles associated to CpG showed significant modulation of granuloma reaction. Mice from all groups immunized orally with nanoparticles presented significant levels of protection against infection challenge with S. mansoni worms, suggesting an important role of chitosan in inducing a protective immune response. Finally, mice immunized with nanoparticles associated with the antigen SmRho plus CpG had 38% of the granuloma area reduced and also presented 48% of protection against of S. mansoni infection. Conclusions Taken together, this results support this new strategy as an efficient delivery system and a potential vaccine against schistosomiasis. PMID:23209848

  11. Chitosan nanoparticles for targeting and sustaining minoxidil sulphate delivery to hair follicles.

    PubMed

    Matos, Breno Noronha; Reis, Thaiene Avila; Gratieri, Taís; Gelfuso, Guilherme Martins

    2015-04-01

    This work developed minoxidil sulphate-loaded chitosan nanoparticles (MXS-NP) for targeted delivery to hair follicles, which could sustain drug release and improve the topical treatment of alopecia. Chitosan nanoparticles were obtained using low-molecular weight chitosan and tripolyphosphate as crosslink agent. MXS-NP presented a monomodal distribution with hydrodynamic diameter of 235.5 ± 99.9 nm (PDI of 0.31 ± 0.01) and positive zeta potential (+38.6 ± 6.0 mV). SEM analysis confirmed nanoparticles average size and spherical shape. A drug loading efficiency of 73.0 ± 0.3% was obtained with polymer:drug ratio of 1:1 (w/w). Drug release through cellulose acetate membranes from MXS-NP was sustained in about 5 times in comparison to the diffusion rate of MXS from the solution (188.9 ± 6.0 μg/cm(2)/h and 35.4 ± 1.8 μg/cm(2)/h). Drug permeation studies through the skin in vitro, followed by selective recovery of MXS from the hair follicles, showed that MXS-NP application resulted in a two-fold MXS increase into hair follicles after 6h in comparison to the control solution (5.9 ± 0.6 μg/cm(2) and 2.9 ± 0.8 μg/cm(2)). MXS-loading in nanoparticles appears as a promising and easy strategy to target and sustain drug delivery to hair follicles, which may improve the topical treatment of alopecia. PMID:25647618

  12. Chitosan nanoparticles for targeting and sustaining minoxidil sulphate delivery to hair follicles.

    PubMed

    Matos, Breno Noronha; Reis, Thaiene Avila; Gratieri, Taís; Gelfuso, Guilherme Martins

    2015-04-01

    This work developed minoxidil sulphate-loaded chitosan nanoparticles (MXS-NP) for targeted delivery to hair follicles, which could sustain drug release and improve the topical treatment of alopecia. Chitosan nanoparticles were obtained using low-molecular weight chitosan and tripolyphosphate as crosslink agent. MXS-NP presented a monomodal distribution with hydrodynamic diameter of 235.5 ± 99.9 nm (PDI of 0.31 ± 0.01) and positive zeta potential (+38.6 ± 6.0 mV). SEM analysis confirmed nanoparticles average size and spherical shape. A drug loading efficiency of 73.0 ± 0.3% was obtained with polymer:drug ratio of 1:1 (w/w). Drug release through cellulose acetate membranes from MXS-NP was sustained in about 5 times in comparison to the diffusion rate of MXS from the solution (188.9 ± 6.0 μg/cm(2)/h and 35.4 ± 1.8 μg/cm(2)/h). Drug permeation studies through the skin in vitro, followed by selective recovery of MXS from the hair follicles, showed that MXS-NP application resulted in a two-fold MXS increase into hair follicles after 6h in comparison to the control solution (5.9 ± 0.6 μg/cm(2) and 2.9 ± 0.8 μg/cm(2)). MXS-loading in nanoparticles appears as a promising and easy strategy to target and sustain drug delivery to hair follicles, which may improve the topical treatment of alopecia.

  13. Smart Magnetically Responsive Hydrogel Nanoparticles Prepared by a Novel Aerosol-Assisted Method for Biomedical and Drug Delivery Applications

    PubMed Central

    El-Sherbiny, Ibrahim M.; Smyth, Hugh D. C.

    2011-01-01

    We have developed a novel spray gelation-based method to synthesize a new series of magnetically responsive hydrogel nanoparticles for biomedical and drug delivery applications. The method is based on the production of hydrogel nanoparticles from sprayed polymeric microdroplets obtained by an air-jet nebulization process that is immediately followed by gelation in a crosslinking fluid. Oligoguluronate (G-blocks) was prepared through the partial acid hydrolysis of sodium alginate. PEG-grafted chitosan was also synthesized and characterized (FTIR, EA, and DSC). Then, magnetically responsive hydrogel nanoparticles based on alginate and alginate/G-blocks were synthesized via aerosolization followed by either ionotropic gelation or both ionotropic and polyelectrolyte complexation using CaCl2 or PEG-g-chitosan/CaCl2 as crosslinking agents, respectively. Particle size and dynamic swelling were determined using dynamic light scattering (DLS) and microscopy. Surface morphology of the nanoparticles was examined using SEM. The distribution of magnetic cores within the hydrogels nanoparticles was also examined using TEM. In addition, the iron and calcium contents of the particles were estimated using EDS. Spherical magnetic hydrogel nanoparticles with average particle size of 811 ± 162 to 941 ± 2 nm were obtained. This study showed that the developed method is promising for the manufacture of hydrogel nanoparticles, and it represents a relatively simple and potential low-cost system. PMID:21808638

  14. Preparation and characterization of EDTAD-modified magnetic-Fe3O4 chitosan composite: application of comparative adsorption of dye wastewater with magnetic chitosan.

    PubMed

    Yang, Hongyu; Li, Yunchun; Ho, Steven Sai Hang; Tian, Xiumei; Xia, Yunxue; Shen, Yaou; Zhao, Maojun; Pan, Guangtang

    2013-01-01

    Ethylenediaminetetraacetic dianhydride (EDTAD)-modified magnetic-Fe3O4 chitosan (EMC), prepared using the cross-link agent glutaraldehyde and chemicals Fe3O4, chitosan, and EDTAD, was used to compare the adsorption of methylene blue (MB) with magnetic chitosan (MC). The composite structure was confirmed by multiple characterization techniques, including scanning electron microscopy (SEM), X-ray powder diffraction, Fourier transform infrared spectroscopy (FTIR), and potentiometric titration methods. The characterization results suggest that Fe3O4 particles successfully bound on the surface of chitosan, and the EDTAD thoroughly modified the MC. Furthermore, EMC had more amino, carboxyl, and hydroxy groups than typical MC. Adsorption conditions, such as pH values, initial concentrations of MB, reaction temperature, and contact time were systematically examined. In comparison, the maximum adsorption capacity of EMC was approximately twice as much as that of MC. The recovery efficiency for EMC was >80% using 0.1 M HCl as an eluent solution. Therefore, the results reported herein indicate that EMC is very attractive and imply a practical application for dye wastewater treatment. PMID:23823557

  15. Chitosan nanoparticles enhance the antibacterial activity of chlorhexidine in collagen membranes used for periapical guided tissue regeneration.

    PubMed

    Barreras, Uriel Soto; Méndez, Fernando Torres; Martínez, Rita Elizabeth Martínez; Valencia, Carolina Samano; Rodríguez, Panfilo Raymundo Martinez; Rodríguez, Juan Pablo Loyola

    2016-01-01

    Endodontic failure is mainly associated with the persistence of microbial infection in the root canal system and/or the periradicular area. Microorganisms and their toxins located in the root canal system may trigger apical periodontitis and tissue destruction. Tissue regeneration in periapical surgery by using membrane barriers has shown an improved healing and bone closure. However, bacterial membrane contamination is a main reason of failure. In this in vitro study, different brands of chlorhexidine, a combination of chitosan nanoparticles containing chlorhexidine were tested against Enterococcus faecalis on agar plate's cultures and infected collagen membranes. Our results indicated that chitosan nanoparticles acted synergistically with chlorhexidine, inhibiting and eliminating significantly a greater amount of colony former units in both BHI-agar cultures and infected collagen membranes. These results suggested that chitosan nanoparticles could be used to improve regenerative procedures in periapical surgery. PMID:26478419

  16. Chitosan nanoparticles enhance the antibacterial activity of chlorhexidine in collagen membranes used for periapical guided tissue regeneration.

    PubMed

    Barreras, Uriel Soto; Méndez, Fernando Torres; Martínez, Rita Elizabeth Martínez; Valencia, Carolina Samano; Rodríguez, Panfilo Raymundo Martinez; Rodríguez, Juan Pablo Loyola

    2016-01-01

    Endodontic failure is mainly associated with the persistence of microbial infection in the root canal system and/or the periradicular area. Microorganisms and their toxins located in the root canal system may trigger apical periodontitis and tissue destruction. Tissue regeneration in periapical surgery by using membrane barriers has shown an improved healing and bone closure. However, bacterial membrane contamination is a main reason of failure. In this in vitro study, different brands of chlorhexidine, a combination of chitosan nanoparticles containing chlorhexidine were tested against Enterococcus faecalis on agar plate's cultures and infected collagen membranes. Our results indicated that chitosan nanoparticles acted synergistically with chlorhexidine, inhibiting and eliminating significantly a greater amount of colony former units in both BHI-agar cultures and infected collagen membranes. These results suggested that chitosan nanoparticles could be used to improve regenerative procedures in periapical surgery.

  17. Sensitive electrochemical detection of Salmonella with chitosan-gold nanoparticles composite film.

    PubMed

    Xiang, Cuili; Li, Ran; Adhikari, Bimalendu; She, Zhe; Li, Yongxin; Kraatz, Heinz-Bernhard

    2015-08-01

    An ultrasensitive electrochemical immunosensor for detection of Salmonella has been developed based on using high density gold nanoparticles (GNPs) well dispersed in chitosan hydrogel and modified glassy carbon electrode. The composite film has been oxidized in NaCl solution and used as a platform for the immobilization of capture antibody (Ab1) for biorecognition. After incubation in Salmonella suspension and horseradish peroxidase (HRP) conjugated secondary antibody (Ab2) solution, a sandwich electrochemical immunosensor has been constructed. The electrochemical signal was obtained and improved by comparing the composite film with chitosan film. The result has shown that the constructed sensor provides a wide linear range from 10 to 10(5) CFU/mL with a low detection limit of 5 CFU/mL (at the ratio of signal to noise, S/N=3:1). Furthermore, the proposed immunosensor has demonstrated good selectivity and reproducibility, which indicates its potential in the clinical diagnosis of Salmonella contaminations. PMID:26048833

  18. Preparation and properties of hybrid monodispersed magnetic α-Fe2O3 based chitosan nanocomposite film for industrial and biomedical applications.

    PubMed

    Singh, Jay; Srivastava, M; Dutta, Joydeep; Dutta, P K

    2011-01-01

    In this study, hydrothermally prepared magnetic α-Fe2O3 nanoparticles were dispersed in chitosan (CH) solution to fabricate nanocomposite film. X-ray diffraction (XRD) patterns indicated that the α-Fe2O3 nanoparticles were pure α-Fe2O3 with rhombohedral structures, and the fabrication of CH did not result in a phase change. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) results showed that the hexagonal and spherical monodispersed α-Fe2O3 nanoparticles were encapsulated into the spherical dumb shaped CH-α-Fe2O3 nanocomposite film with a mean diameter of ∼87 and ∼110 nm respectively. The α-Fe2O3 nanoparticles and CH-α-Fe2O3 nanocomposite film were also characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and vibrating sample magnetometer (VSM). Magnetic measurements revealed that the saturated magnetization (Ms) and remanent magnetization (Mr) of the pure α-Fe2O3 nanoparticles reached 0.573 emu/g and 0.100 emu/g respectively and the nanoparticles showed the characteristics of weak ferromagnetic before and after coating with CH.

  19. Improved mucoadhesion and cell uptake of chitosan and chitosan oligosaccharide surface-modified polymer nanoparticles for mucosal delivery of proteins.

    PubMed

    Dyawanapelly, Sathish; Koli, Uday; Dharamdasani, Vimisha; Jain, Ratnesh; Dandekar, Prajakta

    2016-08-01

    The main aim of the present study was to compare mucoadhesion and cellular uptake efficiency of chitosan (CS) and chitosan oligosaccharide (COS) surface-modified polymer nanoparticles (NPs) for mucosal delivery of proteins. We have developed poly (D, L-lactide-co-glycolide) (PLGA) NPs, surface-modified COS-PLGA NPs and CS-PLGA NPs, by using double emulsion solvent evaporation method, for encapsulating bovine serum albumin (BSA) as a model protein. Surface modification of NPs was confirmed using physicochemical characterization methods such as particle size and zeta potential, SEM, TEM and FTIR analysis. Both surface-modified PLGA NPs displayed a slow release of protein compared to PLGA NPs. Furthermore, we have explored the mucoadhesive property of COS as a material for modifying the surface of polymeric NPs. During in vitro mucoadhesion test, positively charged COS-PLGA NPs and CS-PLGA NPs exhibited enhanced mucoadhesion, compared to negatively charged PLGA NPs. This interaction was anticipated to improve the cell interaction and uptake of NPs, which is an important requirement for mucosal delivery of proteins. All nanoformulations were found to be safe for cellular delivery when evaluated in A549 cells. Moreover, intracellular uptake behaviour of FITC-BSA loaded NPs was extensively investigated by confocal laser scanning microscopy and flow cytometry. As we hypothesized, positively charged COS-PLGA NPs and CS-PLGA NPs displayed enhanced intracellular uptake compared to negatively charged PLGA NPs. Our results demonstrated that CS- and COS-modified polymer NPs could be promising carriers for proteins, drugs and nucleic acids via nasal, oral, buccal, ocular and vaginal mucosal routes. PMID:27106502

  20. Thiolated chitosan nanoparticles for the nasal administration of leuprolide: bioavailability and pharmacokinetic characterization.

    PubMed

    Shahnaz, Gul; Vetter, Anja; Barthelmes, Jan; Rahmat, Deni; Laffleur, Flavia; Iqbal, Javed; Perera, Glen; Schlocker, Wolfgang; Dünnhaput, Sarah; Augustijns, Patrick; Bernkop-Schnürch, Andreas

    2012-05-30

    The purpose of this study was to develop thiolated nanoparticles to enhance the bioavailability for the nasal application of leuprolide. Thiolated chitosan-thioglycolic acid (chitosan-TGA) and unmodified chitosan nanoparticles (NPs) were developed via ionic gelation with tripolyphosphate (TPP). Leuprolide was incorporated during the formulation process of NPs. The thiolated (chitosan-TGA) NPs had a mean size of 252 ± 82 nm, a zeta potential of +10.9 ± 4 mV, and payload of leuprolide was 12 ± 2.8. Sustained release of leuprolide from thiolated NPs was demonstrated over 6h, which might be attributed to inter- and/or intramolecular disulfide formation within the NPs network. Ciliary beat frequency (CBF) study demonstrated that thiolated NPs can be considered as suitable additives for nasal drug delivery systems. Compared to leuprolide solution, unmodified NPs and thiolated NPs provoked increased leuprolide transport through porcine nasal mucosa by 2.0 and 5.2 folds, respectively. The results of a pharmacokinetic study in male Sprague-Dawley rats showed improved transport of leuprolide from thiolated NPs as compared to leuprolide solution. Thiolated NPs had a 6.9-fold increase in area under the curve, more than 4-fold increase in elimination half-life, and a ∼3.8-fold increase in maximum plasma concentration compared to nasal solution alone. The relative nasal bioavailability (versus s.c. injection) of leuprolide thiolated NPs calculated on the basis of AUC((0-6)) was about 19.6% as compared to leuprolide solution 2.8%. The enhanced bioavailability of leuprolide is likely due to facilitated transport by thiolated NPs rather than improved release.

  1. Horseradish peroxidase-encapsulated chitosan nanoparticles for enzyme-prodrug cancer therapy.

    PubMed

    Cao, Xiaodan; Chen, Chao; Yu, Haijun; Wang, Ping

    2015-01-01

    Among various enzyme-based therapies, enzyme-prodrug therapy (EPT) promises minimized side effects in that it activates non-toxic prodrugs locally where the enzymes are placed. The success of such an approach requires high enzyme stability against both structural denaturation and potential immunogenicity. This work examines the efficiency of nanoparticles for enzyme protection in EPT applications. Specifically, horseradish peroxidase (HRP)-encapsulated chitosan nanoparticles (HRP-CSNP) were constructed and examined with respect to stability enhancement. HRP-CSNP retained enzyme activity and had improved stability at 37 °C in the presence of a denaturant, urea. The nanoparticles effectively bound to the surface of human breast cancer cell Bcap37 and led to over 80 % cell death when applied with a prodrug indole-3-acetic acid. PMID:25257586

  2. Enhancing the stability and antibiofilm activity of DspB by immobilization on carboxymethyl chitosan nanoparticles.

    PubMed

    Tan, Yulong; Ma, Su; Liu, Chenguang; Yu, Wengong; Han, Feng

    2015-09-01

    A β-N-acetyl-glucosaminidase (DspB) from Aggregatibacter actinomycetemcomitans CU1000 has been proved to inhibit and detach the biofilms formed by Staphylococcus epidermidis, Staphylococcus aureus and A. actinomycetemcomitans. However, the application of this enzyme is limited by its poor stability. In the present study, a β-N-acetyl-glucosaminidase encoding gene, dspB, was cloned from A. actinomycetemcomitans HK1651 and expressed in Escherichia coli. The recombinant DspB was loaded on hydrogel nanoparticles, which was prepared by using linoleic acid (LA) modified carboxymethyl chitosan (CMCS) after sonication. The nanoparticles were almost saturated by DspB at 0.3 mg/ml, which gave a loading capacity of 76.7%. The immobilization enhanced thermal stability, storage stability and reusability of DspB significantly. Moreover, it also increased antibiofilm activity due to the dual mechanism, including the improvement of the enzyme stability and the antibiofilm activity of CMCS nanoparticles. PMID:26302845

  3. Synthesis and characterization of antimicrobial crosslinked carboxymethyl chitosan nanoparticles loaded with silver.

    PubMed

    Mohamed, Riham R; Sabaa, Magdy W

    2014-08-01

    Carboxymethyl chitosan (CMCh)-silver nanoparticle (Ag) hydrogels with high antibacterial activity against three Gram +ve bacteria (Staphylococcus aureus, Bacillus subtilis and Streptococcus faecalis), three Gram -ve bacteria (Escherichia coli, Pseudomonas aeruginosa and Neisseria gonorrhoeae) and a Candida albicans fungus were prepared. The in situ preparation reaction involved crosslinking of CMCh with epichlorohydrin in alkaline medium containing silver nitrate to yield silver nanoparticles loaded CMCh hydrogel giving pale brown or darker hydrogels when the silver content increases. FTIR spectroscopy, SEM and TEM were done for the prepared hydrogels. Silver nanoparticles hydrogels exhibited higher antimicrobial activity than virgin CMCh. TEM analysis showed the small size of the prepared hydrogels to be in the range of 9-16nm in size.

  4. Glutaraldehyde cross-linked magnetic chitosan nanocomposites: Reduction precipitation synthesis, characterization, and application for removal of hazardous textile dyes.

    PubMed

    Kadam, Avinash A; Lee, Dae Sung

    2015-10-01

    Magnetic chitosan nanocomposites (MCNCs) were synthesized by an inexpensive reduction precipitation technique using a glutaraldehyde cross-linking agent at room temperature. Successful chitosan coating of iron oxide nanoparticles was confirmed by X-ray photoemission spectroscopy. X-ray diffraction data revealed crystalline particle sizes for the iron oxide and MCNCs to be around 6-7 and 8-9 nm, respectively. In addition, the MCNCs exhibited supermagnetic properties having magnetic saturation of 17.5 emu/g. The synthesized MCNCs showed 91.60% absorption of Acid Red 2, while iron oxide 16.40% absorption; enhanced performance in MCNCs was resulted from presence of free amino and hydroxyl groups. Furthermore, the optimum pH and adsorbent concentration were 3 and 1.0 g/L, respectively. The Redlich-Peterson isotherm fit experimental data better than Langmuir and Freundlich models, based on non-linear regression. Finally, MCNCs showed 96% American Dye Manufacturing Institute (ADMI) value removal and gave recovery efficiency of 100%, making them attractive for further practical applications.

  5. A novel green one-step synthesis of silver nanoparticles using chitosan: catalytic activity and antimicrobial studies

    NASA Astrophysics Data System (ADS)

    Venkatesham, Maragoni; Ayodhya, Dasari; Madhusudhan, Alle; Veera Babu, Nagati; Veerabhadram, Guttena

    2014-01-01

    Stable silver nanoparticles were synthesized using chitosan acting as both reducing and stabilizing agent without using any toxic chemicals. This reaction was carried out in an autoclave at a pressure of 15 psi and 120 °C temperature by varying the time. The influence of different parameters such as time, change of concentration of silver nitrate and concentration of chitosan on the formation of silver nanoparticles were studied. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, Fourier transform infrared, X-ray diffraction and transmission electron microscopy. The results of catalytic reduction of 4-nitrophenol by sodium borohydride in the presence of green synthesized silver nanoparticles were presented. The antimicrobial activity of silver nanoparticles was tested against Escherichia coli and Micrococcus luteus and was found to be possessing inhibiting property.

  6. Terahertz magnetic modulator based on magnetically clustered nanoparticles

    NASA Astrophysics Data System (ADS)

    Shalaby, Mostafa; Peccianti, Marco; Ozturk, Yavuz; Al-Naib, Ibraheem; Hauri, Christoph P.; Morandotti, Roberto

    2014-10-01

    Random orientation of liquid-suspended magnetic nanoparticles (Ferrofluids) gives rise to a zero net magnetic orientation. An external magnetic field tends to align these nanoparticles into clusters, leading to a strong linear dichroism on a propagating wave. Using 10 nm-sized Fe3O4, we experimentally realize a polarization-sensitive magnetic modulator operating at terahertz wavelengths. We reached a modulation depth of 66% using a field as low as 35 mT. The proposed concept offers a solution towards fundamental terahertz magnetic modulators.

  7. Evaluation of the genotoxicity of chitosan nanoparticles for use in food packaging films.

    PubMed

    De Lima, Renata; Feitosa, Leandro; do Espírito Santo Pereira, Anderson; de Moura, Márcia Regina; Ahmad Aouada, Fauze; Henrique Capparelli Mattoso, Luiz; Fernandes Fraceto, Leonardo

    2010-08-01

    The use of nanoparticles in food packaging has been proposed on the basis that it could improve protection of foods by, for example, reducing permeation of gases, minimizing odor loss, and increasing mechanical strength and thermal stability. Consequently, the impacts of such nanoparticles on organisms and on the environment need to be investigated to ensure their safe use. In an earlier study, Moura and others (2008a) described the effect of addition of chitosan (CS) and poly(methacrylic acid) (PMAA) nanoparticles on the mechanical properties, water vapor, and oxygen permeability of hydroxypropyl methylcellulose films used in food packaging. Here, the genotoxicity of different polymeric CS/PMAA nanoparticles (size 60, 82, and 111 nm) was evaluated at different concentration levels, using the Allium cepa chromosome damage test as well as cytogenetic tests employing human lymphocyte cultures. Test substrates were exposed to solutions containing nanoparticles at polymer mass concentrations of 1.8, 18, and 180 mg/L. Results showed no evidence of DNA damage caused by the nanoparticles (no significant numerical or structural changes were observed), however the 82 and 111 nm nanoparticles reduced mitotic index values at the highest concentration tested (180 mg/L), indicating that the nanoparticles were toxic to the cells used at this concentration. In the case of the 60 nm CS/PMAA nanoparticles, no significant changes in the mitotic index were observed at the concentration levels tested, indicating that these particles were not toxic. The techniques used show promising potential for application in tests of nanoparticle safety envisaging the future use of these materials in food packaging. PMID:20722945

  8. Synthesis and characterisation of alginate/chitosan nanoparticles as tamoxifen controlled delivery systems.

    PubMed

    Martínez, A; Arana, P; Fernández, A; Olmo, R; Teijón, C; Blanco, M D

    2013-01-01

    Polysaccharides have shown ideal features for their application in nanomedicine as nanoparticulated systems. Nanoparticles based on mixtures of alginate and chitosan (A/Q-50/50, formed by 50% alginate and 50% chitosan, and A/Q-70/30, formed by 70% alginate and 30% alginate) have been synthesised by an emulsification method and stabilised by amide bond formation. Tamoxifen (TMX) was loaded into these systems, and they were assayed as controlled delivery formulations. Results showed the formation of spherical nanoparticles with very small size (19-28 nm). The presence of amide bonds was determined by FT-IR and confirmed by Thermogravimetric analysis studies. TMX incorporation was achieved successfully (2-3 µg TMX per mg NP), and maximum TMX release took place between 8 and 24 h. This study shows that interaction between TMX and the system was dependent on nanoparticle composition, being the composition with higher proportion of alginate the one which showed the best release control of the drug. PMID:23489017

  9. Genipin-cross-linked fucose-chitosan/heparin nanoparticles for the eradication of Helicobacter pylori.

    PubMed

    Lin, Yu-Hsin; Tsai, Shih-Chang; Lai, Chih-Ho; Lee, Che-Hsin; He, Zih Sian; Tseng, Guan-Chin

    2013-06-01

    Helicobacter pylori is a significant human pathogen that recognizes specific carbohydrate receptors, such as the fucose receptor, and produces the vacuolating cytotoxin, which induces inflammatory responses and modulates the cell-cell junction integrity of the gastric epithelium. The clinical applicability of topical antimicrobial agents was needed to complete the eradication of H. pylori in the infected fundal area. In the present study, we combined fucose-conjugated chitosan and genipin-cross-linking technologies in preparing multifunctional genipin-cross-linked fucose-chitosan/heparin nanoparticles to encapsulate amoxicillin of targeting and directly make contact with the region of microorganism on the gastric epithelium. The results show that the nanoparticles effectively reduced drug release at gastric acids and then released amoxicillin in an H. pylori survival situation to inhibit H. pylori growth and reduce disruption of the cell-cell junction protein in areas of H. pylori infection. Furthermore, with amoxicillin-loaded nanoparticles, a more complete H. pylori clearance effect was observed, and H. pylori-associated gastric inflammation in an infected animal model was effectively reduced. PMID:23499480

  10. Genipin-cross-linked fucose-chitosan/heparin nanoparticles for the eradication of Helicobacter pylori.

    PubMed

    Lin, Yu-Hsin; Tsai, Shih-Chang; Lai, Chih-Ho; Lee, Che-Hsin; He, Zih Sian; Tseng, Guan-Chin

    2013-06-01

    Helicobacter pylori is a significant human pathogen that recognizes specific carbohydrate receptors, such as the fucose receptor, and produces the vacuolating cytotoxin, which induces inflammatory responses and modulates the cell-cell junction integrity of the gastric epithelium. The clinical applicability of topical antimicrobial agents was needed to complete the eradication of H. pylori in the infected fundal area. In the present study, we combined fucose-conjugated chitosan and genipin-cross-linking technologies in preparing multifunctional genipin-cross-linked fucose-chitosan/heparin nanoparticles to encapsulate amoxicillin of targeting and directly make contact with the region of microorganism on the gastric epithelium. The results show that the nanoparticles effectively reduced drug release at gastric acids and then released amoxicillin in an H. pylori survival situation to inhibit H. pylori growth and reduce disruption of the cell-cell junction protein in areas of H. pylori infection. Furthermore, with amoxicillin-loaded nanoparticles, a more complete H. pylori clearance effect was observed, and H. pylori-associated gastric inflammation in an infected animal model was effectively reduced.

  11. Thermal and morphological behavior of chitosan/PEO blends containing gold nanoparticles. Experimental and theoretical studies.

    PubMed

    Bonardd, Sebastián; Schmidt, Mathias; Saavedra-Torres, Mario; Leiva, Angel; Radic, Deodato; Saldías, César

    2016-06-25

    Using solution-casting method, binary blends of chitosan (CS) and poly (ethylene oxide) (PEO 100,000) containing Au nanoparticles (AuNPs) were prepared. Shifts in the melting temperature (Tm) and crystallization temperature (Tc) values for CS/PEO and CS/PEO/AuNPs blends were observed by calorimetric analysis. In general, CS/PEO/AuNPs blends tended to decompose at higher temperatures than neat polymers. From the FT-IR spectra, shifts in the main signals, such as -NH2, -OH and COC, were detected in the blends and were attributed to the polymer interactions and the incorporation of gold nanoparticles. In addition, the analysis of the blend topographies by atomic force microscopy (AFM) showed that at a higher CS content, more homogenous surfaces were observed. This behavior was attributed to the interactions present in the CS/PEO/AuNPs blends. Finally, theoretical analyses helped to confirm that the gold nanoparticles would be preferentially adsorbed onto the chitosan microdomains due to the interactions between acetyl and hydroxyl groups and Au atoms. PMID:27083823

  12. Properties and biomedical applications of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Regmi, Rajesh Kumar

    Magnetic nanoparticles have a number of unique properties, making them promising agents for applications in medicine including magnetically targeted drug delivery, magnetic hyperthermia, magnetic resonance imaging, and radiation therapy. They are biocompatible and can also be coated with biocompatible surfactants, which may be further functionalized with optically and therapeutically active molecules. These nanoparticles can be manipulated with non-invasive external magnetic field to produce heat, target specific site, and monitor their distribution in vivo. Within this framework, we have investigated a number of biomedical applications of these nanoparticles. We synthesized a thermosensitive microgel with iron oxide adsorbed on its surface. An alternating magnetic field applied to these nanocomposites heated the system and triggered the release of an anticancer drug mitoxantrone. We also parameterized the chain length dependence of drug release from dextran coated iron oxide nanoparticles, finding that both the release rate and equilibrium release fraction depend on the molecular mass of the surfactant. Finally, we also localized dextran coated iron oxide nanoparticles labeled with tat peptide to the cell nucleus, which permits this system to be used for a variety of biomedical applications. Beyond investigating magnetic nanoparticles for biomedical applications, we also studied their magnetohydrodynamic and dielectric properties in solution. Magnetohydrodynamic properties of ferrofluid can be controlled by appropriate selection of surfactant and deielctric measurement showed magnetodielectric coupling in this system. We also established that some complex low temperature spin structures are suppressed in Mn3O4 nanoparticles, which has important implications for nanomagnetic devices. Furthermore, we explored exchange bias effects in Ni-NiO core-shell nanoparticles. Finally, we also performed extensive magnetic studies in nickel metalhydride (NiMH) batteries to

  13. Delivery of chitosan/dsRNA nanoparticles for silencing of wing development vestigial (vg) gene in Aedes aegypti mosquitoes.

    PubMed

    Ramesh Kumar, D; Saravana Kumar, P; Gandhi, M Rajiv; Al-Dhabi, Naif Abdullah; Paulraj, M Gabriel; Ignacimuthu, S

    2016-05-01

    RNA interference (RNAi) has been used as a gene silencing strategy by the introduction of long double stranded RNA (dsRNA) for the control of pest insects. The aim of the present study was to examine whether the expression of vg gene which is responsible for wing development, can be repressed by chitosan/dsRNA based nanoparticles in Aedes aegypti. The vestigial gene (vg) was amplified from adult mosquito and cloned in pLitmus28i vector. Genetically engineered recombinant plasmid was transformed into RNase III deficient strain for synthesis of bacterially expressed dsRNA. Nanoparticles were prepared via electrostatic interaction between cationic polymer chitosan and anionic nucleic acids (dsRNA). The formation of chitosan/dsRNAnanoparticles and their size were confirmed by Atomic force microscopy (AFM). Chitosan/dsRNA mediated knockdown of Enhanced Green Fluorescence Protein (EGFP) was demonstrated in Sf21 cells. Further, we tested whether such an approach could be used to target vg gene in Ae. aegypti. The results showed that chitosan/dsRNA caused significant mortality, delayed growth development and caused adult wing-malformation. A qRT-PCR analysis confirmed that the chitosan/dsRNA mediated transcriptional level was downregulated. Our findings suggest that vg gene intervention strategies through RNAi can emerge as viable option for pest control. PMID:26794313

  14. Effective method of chitosan-coated alginate nanoparticles for target drug delivery applications.

    PubMed

    Wang, Fang; Yang, Siqian; Yuan, Jian; Gao, Qinwei; Huang, Chaobo

    2016-07-01

    In the present study, alginate nanoparticles were firstly prepared for paclitaxel (PTX) delivery with an average size of 200 ± 21 nm. To improve the stability and targeting effect, the chitosan (CS) and folate-chitosan (FA-CS) were introduced to form PTX-loaded CS/ALG NPs and FA-CS/ALG NPs by a new double emulsion cross-linking electrostatic attraction method. The optimization chitosan concentration was 0.5% obtained from the experiment results. The CS/ALG-PTX NPs and FA-CS/ALG-PTX NPs had the average particle size of 306.9 ± 12.9 nm and 283.6 ± 19.2 nm with the zeta potential of 31.1 ± 1.3 mV and -2.98 ± 0.7 mV, and had higher drug loading and entrapment efficiencies than ALG-PTX NPs. The in vitro drug release profile along with release kinetics and mechanism from PTX-loaded NPs were studied under two simulated physiological conditions. Further, the in vitro anti-cancer activity of nanoparticles and the cellular uptake of nanoparticles on HepG2 cells were investigated. The results demonstrated that alginate, CS/ALG and FA-CS/ALG can be used as nanoformulation drug carriers by our new method, and FA-CS/ALG was a promising vehicle for anticancer drug targeted delivery system. PMID:27164869

  15. Magnetic-Plasmonic Core-Shell Nanoparticles

    PubMed Central

    Levin, Carly S.; Hofmann, Cristina; Ali, Tamer A.; Kelly, Anna T.; Morosan, Emilia; Nordlander, Peter; Whitmire, Kenton H.; Halas, Naomi J.

    2013-01-01

    Nanoparticles composed of magnetic cores with continuous Au shell layers simultaneously possess both magnetic and plasmonic properties. Faceted and tetracubic nanocrystals consisting of wüstite with magnetite-rich corners and edges retain magnetic properties when coated with an Au shell layer, with the composite nanostructures showing ferrimagnetic behavior. The plasmonic properties are profoundly influenced by the high dielectric constant of the mixed-iron-oxide nanocrystalline core. A comprehensive theoretical analysis that examines the geometric plasmon tunability over a range of core permittivities enables us to identify the dielectric properties of the mixed-oxide magnetic core directly from the plasmonic behavior of the core-shell nanoparticle. PMID:19441794

  16. Multifunctional biocompatible coatings on magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Bychkova, A. V.; Sorokina, O. N.; Rosenfeld, M. A.; Kovarski, A. L.

    2012-11-01

    Methods for coating formation on magnetic nanoparticles used in biology and medicine are considered. Key requirements to the coatings are formulated, namely, biocompatibility, stability, the possibility of attachment of pharmaceutical agents, and the absence of toxicity. The behaviour of nanoparticle/coating nanosystems in the body including penetration through cellular membranes and the excretion rates and routes is analyzed. Parameters characterizing the magnetic properties of these systems and their magnetic controllability are described. Factors limiting the applications of magnetically controlled nanosystems for targeted drug delivery are discussed. The bibliography includes 405 references.

  17. Role of Au(III) coordination by polymer in "green" synthesis of gold nanoparticles using chitosan derivatives.

    PubMed

    Pestov, Alexander; Nazirov, Alexander; Privar, Yuliya; Modin, Evgeny; Bratskaya, Svetlana

    2016-10-01

    Here we report "green" synthesis of gold nanoparticles in solutions of heterocyclic chitosan derivatives (N-(4-imidazolyl)methylchitosan (IMC), N-2-(2-pyridyl)ethylchitosan (2-PEC), and N-2-(4-pyridyl)ethylchitosan (4-PEC)) and show how efficiency of Au(III) binding to polymer influences the Au(III) reduction rate and the size of the gold nanoparticles formed using only the reducing power of these chitosan derivatives. Rheology measurements and (1)H NMR spectroscopy data have confirmed that cleavage of glycosidic bond is a common mechanism of reducing species generation in solutions of chitosan and its N-heterocyclic derivatives. However, the emerging additional reducing species in 2-PEC and 4-PEC solutions due to vinylpyridine elimination promotes Au(III) reduction and gold nanoparticles growth despite lower efficiency of glycosidic bond cleavage in pyridyl derivatives. The decrease of the average size of gold nanoparticles in the row chitosan>2-PEC>IMC supported assumption that the increase of ligand nucleophilicity and stability of Au(III)-polymer complex results in formation of smaller nanoparticles.

  18. Role of Au(III) coordination by polymer in "green" synthesis of gold nanoparticles using chitosan derivatives.

    PubMed

    Pestov, Alexander; Nazirov, Alexander; Privar, Yuliya; Modin, Evgeny; Bratskaya, Svetlana

    2016-10-01

    Here we report "green" synthesis of gold nanoparticles in solutions of heterocyclic chitosan derivatives (N-(4-imidazolyl)methylchitosan (IMC), N-2-(2-pyridyl)ethylchitosan (2-PEC), and N-2-(4-pyridyl)ethylchitosan (4-PEC)) and show how efficiency of Au(III) binding to polymer influences the Au(III) reduction rate and the size of the gold nanoparticles formed using only the reducing power of these chitosan derivatives. Rheology measurements and (1)H NMR spectroscopy data have confirmed that cleavage of glycosidic bond is a common mechanism of reducing species generation in solutions of chitosan and its N-heterocyclic derivatives. However, the emerging additional reducing species in 2-PEC and 4-PEC solutions due to vinylpyridine elimination promotes Au(III) reduction and gold nanoparticles growth despite lower efficiency of glycosidic bond cleavage in pyridyl derivatives. The decrease of the average size of gold nanoparticles in the row chitosan>2-PEC>IMC supported assumption that the increase of ligand nucleophilicity and stability of Au(III)-polymer complex results in formation of smaller nanoparticles. PMID:27259650

  19. Magnetic nanoparticles in magnetic resonance imaging and diagnostics.

    PubMed

    Rümenapp, Christine; Gleich, Bernhard; Haase, Axel

    2012-05-01

    Magnetic nanoparticles are useful as contrast agents for magnetic resonance imaging (MRI). Paramagnetic contrast agents have been used for a long time, but more recently superparamagnetic iron oxide nanoparticles (SPIOs) have been discovered to influence MRI contrast as well. In contrast to paramagnetic contrast agents, SPIOs can be functionalized and size-tailored in order to adapt to various kinds of soft tissues. Although both types of contrast agents have a inducible magnetization, their mechanisms of influence on spin-spin and spin-lattice relaxation of protons are different. A special emphasis on the basic magnetism of nanoparticles and their structures as well as on the principle of nuclear magnetic resonance is made. Examples of different contrast-enhanced magnetic resonance images are given. The potential use of magnetic nanoparticles as diagnostic tracers is explored. Additionally, SPIOs can be used in diagnostic magnetic resonance, since the spin relaxation time of water protons differs, whether magnetic nanoparticles are bound to a target or not.

  20. One-pot green synthesis of luminescent gold nanoparticles using imidazole derivative of chitosan.

    PubMed

    Nazirov, Alexander; Pestov, Alexander; Privar, Yuliya; Ustinov, Alexander; Modin, Evgeny; Bratskaya, Svetlana

    2016-10-20

    Water soluble luminescent gold nanoparticles with average size 2.3nm were for the first time synthesized by completely green method of Au(III) reduction using chitosan derivative-biocompatible nontoxic N-(4-imidazolyl)methylchitosan (IMC) as both reducing and stabilizing agent. Reduction of Au(III) to gold nanoparticles in IMC solution is a slow process, in which coordination power of biopolymer controls both reducing species concentration and gold crystal growth rate. Gold nanoparticles formed in IMC solution do not manifest surface plasmon resonance, but exhibit luminescence at 375nm under UV light excitation at 230nm. Due to biological activity of imidazolyl-containing polymers and their ability to bind proteins and drugs, the obtained ultra-small gold nanoparticles can find an application for biomolecules detection, bio-imaging, drug delivery, and catalysis. Very high catalytic activity (as compared to gold nanoparticles obtained by other green methods) was found for Au/IMC nanoparticles in the model reaction of p-nitrophenol reduction providing complete conversion of p-nitrophenol to p-aminophenol within 180-190s under mild conditions.

  1. Cu-Chitosan Nanoparticle Mediated Sustainable Approach To Enhance Seedling Growth in Maize by Mobilizing Reserved Food.

    PubMed

    Saharan, Vinod; Kumaraswamy, R V; Choudhary, Ram Chandra; Kumari, Sarita; Pal, Ajay; Raliya, Ramesh; Biswas, Pratim

    2016-08-10

    Food crop seedlings often have susceptibility to various abiotic and biotic stresses. Therefore, in the present study, we investigated the impact of Cu-chitosan nanoparticles (NPs) on physiological and biochemical changes during maize seedling growth. Higher values of percent germination, shoot and root length, root number, seedling length, fresh and dry weight, and seed vigor index were obtained at 0.04-0.12% concentrations of Cu-chitosan NPs as compared to water, CuSO4, and bulk chitosan treatments. Cu-chitosan NPs at the same concentrations induced the activities of α-amylase and protease enzymes and also increased the total protein content in germinating seeds. The increased activities of α-amylase and protease enzymes corroborated with decreased content of starch and protein, respectively, in the germinating seeds. Cu-chitosan NPs at 0.16% and CuSO4 at 0.01% concentrations showed inhibitory effect on seedling growth. The observed results on seedling growth could be explained by the toxicity of excess Cu and growth promotory effect of Cu-chitosan NPs. Physiological and biochemical studies suggest that Cu-chitosan NPs enhance the seedling growth of maize by mobilizing the reserved food, primarily starch, through the higher activity of α-amylase. PMID:27460439

  2. Adsorption of Silver Nanoparticles onto Different Surface Structures of Chitin/Chitosan and Correlations with Antimicrobial Activities

    PubMed Central

    Ishihara, Masayuki; Nguyen, Vinh Quang; Mori, Yasutaka; Nakamura, Shingo; Hattori, Hidemi

    2015-01-01

    Size-controlled spherical silver nanoparticles (Ag NPs) can be simply prepared by autoclaving mixtures of glass powder containing silver with glucose. Moreover, chitins with varying degrees of deacetylation (DDAc < 30%) and chitosan powders and sheets (DDAc > 75%) with varying surface structure properties have been evaluated as Ag NP carriers. Chitin/chitosan-Ag NP composites in powder or sheet form were prepared by mixing Ag NP suspensions with each of the chitin/chitosan-based material at pH 7.3, leading to homogenous dispersion and stable adsorption of Ag NPs onto chitin carriers with nanoscale fiber-like surface structures, and chitosan carriers with nanoscale porous surface structures. Although these chitins exhibited mild antiviral, bactericidal, and antifungal activities, chitin powders with flat/smooth film-like surface structures had limited antimicrobial activities and Ag NP adsorption. The antimicrobial activities of chitin/chitosan-Ag NP composites increased with increasing amounts of adsorbed Ag NPs, suggesting that the surface structures of chitin/chitosan carriers strongly influence adsorption of Ag NPs and antimicrobial activities. These observations indicate that chitin/chitosan-Ag NPs with nanoscale surface structures have potential as antimicrobial biomaterials and anti-infectious wound dressings. PMID:26096004

  3. Fabrication of chitosan-magnetite nanocomposite strip for chromium removal

    NASA Astrophysics Data System (ADS)

    Sureshkumar, Vaishnavi; Kiruba Daniel, S. C. G.; Ruckmani, K.; Sivakumar, M.

    2016-02-01

    Environmental pollution caused by heavy metals is a serious threat. In the present work, removal of chromium was carried out using chitosan-magnetite nanocomposite strip. Magnetite nanoparticles (Fe3O4) were synthesized using chemical co-precipitation method at 80 °C. The nanoparticles were characterized using UV-visible spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction spectrometer, atomic force microscope, dynamic light scattering and vibrating sample magnetometer, which confirm the size, shape, crystalline nature and magnetic behaviour of nanoparticles. Atomic force microscope revealed that the particle size was 15-30 nm and spherical in shape. The magnetite nanoparticles were mixed with chitosan solution to form hybrid nanocomposite. Chitosan strip was casted with and without nanoparticle. The affinity of hybrid nanocomposite for chromium was studied using K2Cr2O7 (potassium dichromate) solution as the heavy metal solution containing Cr(VI) ions. Adsorption tests were carried out using chitosan strip and hybrid nanocomposite strip at different time intervals. Amount of chromium adsorbed by chitosan strip and chitosan-magnetite nanocomposite strip from aqueous solution was evaluated using UV-visible spectroscopy. The results confirm that the heavy metal removal efficiency of chitosan-magnetite nanocomposite strip is 92.33 %, which is higher when compared to chitosan strip, which is 29.39 %.

  4. Biomedical Applications of Magnetic Nanoparticles and Fluids.

    NASA Astrophysics Data System (ADS)

    Leslie-Pelecky, Diandra

    2006-03-01

    Nanomaterials play an increasingly important role in the research, diagnosis and treatment of numerous pathologies. Biomedical applications such as drug delivery, magnetic resonance imaging and hyperthermia require magnetic nanoparticles with a large saturation magnetization that are biocompatible, form stable suspensions in water-based fluids, and can be functionalized. We use chemical synthesis and inert-gas condensation into fluids to produce biocompatible magnetic nanoparticle fluids that allow magnetic targeting of drugs and simultaneous magnetic resonance imaging. We have developed a water-dispersible oleic-acid/Pluronic/iron-oxide nanoparticle formulation that can be loaded with high doses of water-insoluble anti-cancer drugs. An external magnetic field is used to attract the nanoparticles to the treatment region and MRI is used to verify their location. A primary limitation on magnetic targeting, however, is the low moment of iron-oxide nanoparticles. Inert-gas-condensation into fluids produces iron and cobalt nanoparticles from 5-45 nm in diameter. Coating or passivation of these materials is required to prevent oxidation; however, the interaction between surface atoms and surfactant or other functionalizing molecules can greatly diminish the magnetic moment. A study of surfactant interactions with iron nanoparticles shows that the physical barrier provided by a concentric shell of polymeric surfactant offers significantly more protection against oxidation than the radial barrier formed by most linear surfactants. The talk will conclude with a brief overview of the opportunities and challenges for condensed matter and materials physicists in biomagnetic materials. This work is done in collaboration with V. Labhasetwar and T. Jain at the University of Nebraska Medical Center, and Marco Morales, Nguyen Hai, Shannon Fritz, Kishore Sreenivasan and David Schmitter at the University of Nebraska -- Lincoln.

  5. Thermal potentiation of chemotherapy by magnetic nanoparticles

    PubMed Central

    Torres-Lugo, Madeline; Rinaldi, Carlos

    2014-01-01

    Clinical studies have demonstrated the effectiveness of hyperthermia as an adjuvant for chemotherapy and radiotherapy. However, significant clinical challenges have been encountered, such as a broader spectrum of toxicity, lack of patient tolerance, temperature control and significant invasiveness. Hyperthermia induced by magnetic nanoparticles in high-frequency oscillating magnetic fields, commonly termed magnetic fluid hyperthermia, is a promising form of heat delivery in which thermal energy is supplied at the nanoscale to the tumor. This review discusses the mechanisms of heat dissipation of iron oxide-based magnetic nanoparticles, current methods and challenges to deliver heat in the clinic, and the current work related to the use of magnetic nanoparticles for the thermal-chemopotentiation of therapeutic drugs. PMID:24074390

  6. Thermal potentiation of chemotherapy by magnetic nanoparticles.

    PubMed

    Torres-Lugo, Madeline; Rinaldi, Carlos

    2013-10-01

    Clinical studies have demonstrated the effectiveness of hyperthermia as an adjuvant for chemotherapy and radiotherapy. However, significant clinical challenges have been encountered, such as a broader spectrum of toxicity, lack of patient tolerance, temperature control and significant invasiveness. Hyperthermia induced by magnetic nanoparticles in high-frequency oscillating magnetic fields, commonly termed magnetic fluid hyperthermia, is a promising form of heat delivery in which thermal energy is supplied at the nanoscale to the tumor. This review discusses the mechanisms of heat dissipation of iron oxide-based magnetic nanoparticles, current methods and challenges to deliver heat in the clinic, and the current work related to the use of magnetic nanoparticles for the thermal-chemopotentiation of therapeutic drugs.

  7. Competitive fluorescence assay for specific recognition of atrazine by magnetic molecularly imprinted polymer based on Fe3O4-chitosan.

    PubMed

    Liu, Guangyang; Li, Tengfei; Yang, Xin; She, Yongxin; Wang, Miao; Wang, Jing; Zhang, Min; Wang, Shanshan; Jin, Fen; Jin, Maojun; Shao, Hua; Jiang, Zejun; Yu, Hailong

    2016-02-10

    A novel fluorescence sensing strategy for determination of atrazine in tap water involving direct competition between atrazine and 5-(4,6-dichlorotriazinyl) aminofluorescein (5-DTAF), and which exploits magnetic molecularly imprinted polymer (MMIP), has been developed. The MMIP, based on Fe3O4-chitosan nanoparticles, was synthesized to recognize specific binding sites of atrazine. The recognition capability and selectivity of the MMIP for atrazine and other triazine herbicides was investigated. Under optimal conditions, the competitive reaction between 5-DTAF and atrazine was performed to permit quantitation. Fluorescence intensity changes at 515 nm was linearly related to the logarithm of the atrazine concentration for the range 2.32-185.4 μM. The detection limit for atrazine was 0.86μM (S/N=3) and recoveries were 77.6-115% in spiked tap water samples.

  8. Antiviral activity of silver nanoparticle/chitosan composites against H1N1 influenza A virus

    NASA Astrophysics Data System (ADS)

    Mori, Yasutaka; Ono, Takeshi; Miyahira, Yasushi; Nguyen, Vinh Quang; Matsui, Takemi; Ishihara, Masayuki

    2013-02-01

    Silver nanoparticle (Ag NP)/chitosan (Ch) composites with antiviral activity against H1N1 influenza A virus were prepared. The Ag NP/Ch composites were obtained as yellow or brown floc-like powders following reaction at room temperature in aqueous medium. Ag NPs (3.5, 6.5, and 12.9 nm average diameters) were embedded into the chitosan matrix without aggregation or size alternation. The antiviral activity of the Ag NP/Ch composites was evaluated by comparing the TCID50 ratio of viral suspensions treated with the composites to untreated suspensions. For all sizes of Ag NPs tested, antiviral activity against H1N1 influenza A virus increased as the concentration of Ag NPs increased; chitosan alone exhibited no antiviral activity. Size dependence of the Ag NPs on antiviral activity was also observed: antiviral activity was generally stronger with smaller Ag NPs in the composites. These results indicate that Ag NP/Ch composites interacting with viruses exhibit antiviral activity.

  9. Cupreous Complex-Loaded Chitosan Nanoparticles for Photothermal Therapy and Chemotherapy of Oral Epithelial Carcinoma.

    PubMed

    Lin, Min; Wang, Dandan; Liu, Shuwei; Huang, Tingting; Sun, Bin; Cui, Yan; Zhang, Daqi; Sun, Hongchen; Zhang, Hao; Sun, Hui; Yang, Bai

    2015-09-23

    Electron transition materials on the basis of transition metal ions usually possess higher photothermal transduction efficiency but lower extinction ability, which have not been considered as efficient photothermal agents for therapeutic applications. In this work, we demonstrate a facile and feasible approach for enhancing 808 nm photothermal conversion effect of d orbits transition Cu(II) ions by forming Cu-carboxylate complexes. The coordination with carboxylate groups greatly enlarges the splitting energy gap of Cu(II) and the capability of electron transition, thus enhancing the extinction ability in near-infrared region. The cupreous complexes are further loaded in biocompatible and biodegradable polymer nanoparticles (NPs) of chitosan to temporarily lower the toxicity, which allows the photothermal therapy of human oral epithelial carcinoma (KB) cells in vitro and KB tumors in vivo. Animal experiments indicate the photothermal tumor inhibition rate of 100%. In addition, the gradual degradation of chitosan NPs leads to the release of cupreous complexes, thus exhibiting additional chemotherapeutic behavior in KB tumor treatment. Onefold chemotherapy experiments indicate the tumor inhibition rate of 93.1%. The combination of photothermal therapy and chemotherapy of cupreous complex-loaded chitosan NPs indicates the possibility of inhibiting tumor recurrence. PMID:26339804

  10. Cupreous Complex-Loaded Chitosan Nanoparticles for Photothermal Therapy and Chemotherapy of Oral Epithelial Carcinoma.

    PubMed

    Lin, Min; Wang, Dandan; Liu, Shuwei; Huang, Tingting; Sun, Bin; Cui, Yan; Zhang, Daqi; Sun, Hongchen; Zhang, Hao; Sun, Hui; Yang, Bai

    2015-09-23

    Electron transition materials on the basis of transition metal ions usually possess higher photothermal transduction efficiency but lower extinction ability, which have not been considered as efficient photothermal agents for therapeutic applications. In this work, we demonstrate a facile and feasible approach for enhancing 808 nm photothermal conversion effect of d orbits transition Cu(II) ions by forming Cu-carboxylate complexes. The coordination with carboxylate groups greatly enlarges the splitting energy gap of Cu(II) and the capability of electron transition, thus enhancing the extinction ability in near-infrared region. The cupreous complexes are further loaded in biocompatible and biodegradable polymer nanoparticles (NPs) of chitosan to temporarily lower the toxicity, which allows the photothermal therapy of human oral epithelial carcinoma (KB) cells in vitro and KB tumors in vivo. Animal experiments indicate the photothermal tumor inhibition rate of 100%. In addition, the gradual degradation of chitosan NPs leads to the release of cupreous complexes, thus exhibiting additional chemotherapeutic behavior in KB tumor treatment. Onefold chemotherapy experiments indicate the tumor inhibition rate of 93.1%. The combination of photothermal therapy and chemotherapy of cupreous complex-loaded chitosan NPs indicates the possibility of inhibiting tumor recurrence.

  11. Quantifying the complex permittivity and permeability of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Yao, B. M.; Gui, Y. S.; Worden, M.; Hegmann, T.; Xing, M.; Chen, X. S.; Lu, W.; Wroczynskyj, Y.; van Lierop, J.; Hu, C.-M.

    2015-04-01

    The complex permittivity and permeability of superparamagnetic iron-oxide nanoparticles has been quantified using a circular waveguide assembly with a static magnetic field to align the nanoparticle's magnetization. The high sensitivity of the measurement provides the precise resonant feature of nanoparticles. The complex permeability in the vicinity of ferromagnetic resonance is in agreement with the nanoparticle's measured magnetization via conventional magnetometry. A rigorous and self-consistent measure of complex permittivities and permeabilities of nanoparticles is crucial to ascertain accurately the dielectric behaviour as well as the frequency response of nanoparticle magnetization, necessary ingredients when designing and optimizing magnetic nanoparticles for biomedical applications.

  12. Formation of chitosan-fucoidan nanoparticles and their electrostatic interactions: Quantitative analysis.

    PubMed

    Lee, Eun Ju; Lim, Kwang-Hee

    2016-01-01

    The stoichiometric distributions of both positive amino groups and negative sulfate ions loaded in chitosan-fucoidan nanoparticles (CFNs) were predicted quantitatively by correlating the separate yields of loaded chitosan and fucoidan, and a proposed relative charge density model (case 1). In addition, those distributions of both positive amino groups and negative sulfate ions loaded in CFNs were obtained by deriving the expression of their loaded concentrations directly from the experimental data (case 2). Both the model-prediction and experimental derivations were remarkably consistent with each other except at pH 2. The discrepancy between cases 1 and 2 at pH 2 was explained by an increase in the sulfate group loading because of the most intensive electrostatic (specific ion) interactions at pH 2. The ratio of the CFN-free net charge density shielded by counter-ions in the solution entrapped in CFNs to their counter-ion-crosslinking charge density was suggested to be a quantitative criterion for determining the size distribution of CFNs. The formation of CFNs ranked according to size was predicted well and explained reasonably by the suggested criterion, considering both the ionic strength of the entrapped solution in CFNs and the nonspecific binding (interaction) of the positive amino groups among the chitosan molecules. Furthermore, the fraction of nonspecifically-bound positive amino groups causing hysteresis was quantified from the positive net charged amino groups per unit-mass CFN. Thus, its magnitude was predicted to have a strong correlation with the CFN-preparation conditions, such as pH and fucoidan to chitosan mass ratio.

  13. Application of Magnetic Nanoparticles to Gene Delivery

    PubMed Central

    Kami, Daisuke; Takeda, Shogo; Itakura, Yoko; Gojo, Satoshi; Watanabe, Masatoshi; Toyoda, Masashi

    2011-01-01

    Nanoparticle technology is being incorporated into many areas of molecular science and biomedicine. Because nanoparticles are small enough to enter almost all areas of the body, including the circulatory system and cells, they have been and continue to be exploited for basic biomedical research as well as clinical diagnostic and therapeutic applications. For example, nanoparticles hold great promise for enabling gene therapy to reach its full potential by facilitating targeted delivery of DNA into tissues and cells. Substantial progress has been made in binding DNA to nanoparticles and controlling the behavior of these complexes. In this article, we review research on binding DNAs to nanoparticles as well as our latest study on non-viral gene delivery using polyethylenimine-coated magnetic nanoparticles. PMID:21747701

  14. Using magnetic nanoparticles to manipulate biological objects

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Gao, Yu; Xu, Chenjie

    2013-09-01

    The use of magnetic nanoparticles (MNPs) for the manipulation of biological objects, including proteins, genes, cellular organelles, bacteria, cells, and organs, are reviewed. MNPs are popular candidates for controlling and probing biological objects with a magnetic force. In the past decade, progress in the synthesis and surface engineering of MNPs has further enhanced this popularity.

  15. Enteric trimethyl chitosan nanoparticles containing hepatitis B surface antigen for oral delivery

    PubMed Central

    Farhadian, Asma; Dounighi, Naser Mohammadpour; Avadi, Mohammadreza

    2015-01-01

    Oral vaccination is the preferred route of immunization. However, the degradative condition of the gastrointestinal tract and the higher molecular size of peptides pose major challenges in developing an effective oral vaccination system. One of the most excellent methods used in the development of oral vaccine delivery system relies on the entrapment of the antigen in polymeric nanoparticles. In this work, trimethyl chitosan (TMC) nanoparticles were fabricated using ionic gelation teqnique by interaction hydroxypropyl methylcellulose phthalate (HPMCP), a pH-sensitive polymer, with TMC and the utility of the particles in the oral delivery of hepatitis B surface antigen (HBsAg) was evaluated employing solutions that simulated gastric and intestinal conditions. The particle size, morphology, zeta potential, loading capacity, loading efficiency, in vitro release behavior, structure, and morphology of nanoparticles were evaluated, and the activity of the loaded antigen was assessed. Size of the optimized TMC/HPMCP nanoparticles and that of the antigen-loaded nanoparticles were 85 nm and 158 nm, respectively. Optimum loading capacity (76.75%) and loading efficiency (86.29%) were achieved at 300 µg/mL concentration of the antigen. SEM images revealed a spherical shape as well as a smooth and near-homogenous surface of nanoparticles. Results of the in vitro release studies showed that formulation with HPMCP improved the acid stability of the TMC nanoparticles as well as their capability to preserve the loaded HBsAg from gastric destruction. The antigen showed good activity both before and after loading. The results suggest that TMC/HPMCP nanoparticles could be used in the oral delivery of HBsAg vaccine. PMID:26158754

  16. New trimethyl chitosan-based composite nanoparticles as promising antibacterial agents.

    PubMed

    El-Sherbiny, Ibrahim; Salih, Ehab; Reicha, Fikry

    2016-01-01

    In the present study, densely dispersed silver nanoparticles (Ag NPs) were rapidly green synthesized in the presence of Rumex dentatus aqueous extract, followed by UV-irradiation reduction. The Ag NPs were characterized using UV-vis spectroscopy, FTIR, XRD, and TEM. Then, the Ag NPs were incorporated into interpenetrating polymeric networks based on cationic trimethyl chitosan (TMCS) and anionic poly(acrylamide-co-sodium acrylate) copolymer to develop a new series of composite nanoparticles as potential antibacterial agents. Both TMCS and poly(acrylamide-co-sodium acrylate) were prepared in the study, and characterized using FTIR, DSC, and SEM. The synthesized Ag NPs showed high purity and uniform particle size distribution with particle size ranged between 5 and 30 nm. The composite nanoparticles demonstrated homogeneous spherical shape with size in the range of 378-402 nm. Both Ag NPs and the composite nanoparticles showed promising bactericidal activity as compared with the control. Moreover, the antibacterial activity of the composite nanoparticles increased along with increasing the concentrations of Ag NPs and the TMCS. PMID:26289003

  17. Combinatorial photothermal and immuno cancer therapy using chitosan-coated hollow copper sulfide nanoparticles.

    PubMed

    Guo, Liangran; Yan, Daisy D; Yang, Dongfang; Li, Yajuan; Wang, Xiaodong; Zalewski, Olivia; Yan, Bingfang; Lu, Wei

    2014-06-24

    Near-infrared light-responsive inorganic nanoparticles have been shown to enhance the efficacy of cancer photothermal ablation therapy. However, current nanoparticle-mediated photothermal ablation is more effective in treating local cancer at the primary site than metastatic cancer. Here, we report the design of a near-infrared light-induced transformative nanoparticle platform that combines photothermal ablation with immunotherapy. The design is based on chitosan-coated hollow CuS nanoparticles that assemble the immunoadjuvants oligodeoxynucleotides containing the cytosine-guanine (CpG) motifs. Interestingly, these structures break down after laser excitation, reassemble, and transform into polymer complexes that improve tumor retention of the immunotherapy. In this "photothermal immunotherapy" approach, photothermal ablation-induced tumor cell death reduces tumor growth and releases tumor antigens into the surrounding milieu, while the immunoadjuvants potentiate host antitumor immunity. Our results indicated that combined photothermal immunotherapy is more effective than either immunotherapy or photothermal therapy alone against primary treated and distant untreated tumors in a mouse breast cancer model. These hollow CuS nanoparticles are biodegradable and can be eliminated from the body after laser excitation.

  18. Preparation and characterization of chitosan/β-cyclodextrin nanoparticles containing plasmid DNA encoding interleukin-12.

    PubMed

    Nahaei, M; Valizadeh, H; Baradaran, B; Nahaei, M R; Asgari, D; Hallaj-Nezhadi, S; Dastmalchi, S; Lotfipour, F

    2013-01-01

    Interleukin-12 (IL-12) as a cytokine has been proved to possess antitumor effects via stimulating the immune system. Non-viral gene delivery systems offer several advantages, including easiness in production, low cost, safety; low immunogenicity and can carry higher amounts of genetic material without limitation on their sizes.pUMVC3-hIL12 loaded Low Molecular Weight chitosan/β-cyclodextrin (LMW CS/CD) nanoparticles were prepared using ionotropic gelation method and characterized in terms of size, zeta potential, polydispersity index, morphology, loading efficiency and cytotoxicity against the CT-26 colon carcinoma cell line.All prepared particles were spherical in shape and nano-sized (171.3±2.165 nm, PdI: 0.231±0.014) and exhibited a positive zeta potential (34.3±1.55). The nanoparticles demonstrated good DNA encapsulation efficiencies (83.315%±2.067). Prepared pUMVC3-hIL12 loaded LMW CS/CD nanoparticles showed no cell toxicity in murine CT-26 colon carcinoma cells. At the concentration of 0.1 µg/ml of nanoparticles, the transfection ability was obviously higher than that of the naked DNA.LMW CS/CD-plasmid DNA nanoparticles encoding IL-12 prepared using ionotropic gelation method with no toxic effect on the tested cells can be considered as a basis for further gene delivery studies both in vitro and in vivo to enhance the expression of IL-12.

  19. Evaluation of neuropeptide loaded trimethyl chitosan nanoparticles for nose to brain delivery.

    PubMed

    Kumar, Manoj; Pandey, Ravi Shankar; Patra, Kartik Chandra; Jain, Sunil Kumar; Soni, Muarai Lal; Dangi, Jawahar Singh; Madan, Jitender

    2013-10-01

    Leucine-enkephalin (Leu-Enk) is a neurotransmitter or neuromodulator in pain transmission. Due to non-addictive opioid analgesic activity of this peptide, it might have great potential in pain management. Leu-Enk loaded N-trimethyl chitosan (TMC) nanoparticles were prepared and evaluated as a brain delivery vehicle via nasal route. TMC biopolymer was synthesized and analyzed by (1)H NMR spectroscopy. TMC nanoparticles were prepared by ionic gelation method. Mean peptide encapsulation efficiency and loading capacity were 78.28±3.8% and 14±1.3%, respectively. Mean particle size, polydispersity index and zeta potential were found to be 443±23 nm, 0.317±0.17 and +15±2 mV respectively for optimized formulations. Apparent permeability coefficient (Papp) of Leu-Enk released from nanoparticles across the porcine nasal mucosa was determined to be 7.45±0.30×10(-6) cm s(-1). Permeability of Leu-Enk released from nanoparticles was 35 fold improved from the nasal mucosa as compared to Leu-Enk solution. Fluorescent microscopy of brain sections of mice showed higher accumulation of fluorescent marker NBD-F labelled Leu-Enk, when administered nasally by TMC nanoparticles, while low brain uptake of marker solution was observed. Furthermore, enhancement in brain uptake resulted into significant improvement in the observed antinociceptive effect of Leu-Enk as evidenced by hot plate and acetic acid induced writhing assay.

  20. Violacein/poly(epsilon-caprolactone)/chitosan nanoparticles against bovine mastistis: Antibacterial and ecotoxicity evaluation

    NASA Astrophysics Data System (ADS)

    Berni, E.; Marcato, P. D.; Nakazato, G.; Kobayashi, R. K. T.; Vacchi, F. I.; Umbuzeiro, G. A.; Durán, N.

    2013-04-01

    The nanocarrier was synthesized by nanoprecipitation, using poly(epsilon-caprolactone) (PCL) as polymer, Tween 80 as surfactant and the biopolymer chitosan (CS) as a charge modification agent. Charge, size and morphology were analyzed by zeta potential, photo correlation spectroscopy (PCS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Bactericidal assays were carried out using a resistant strain of Staphylococcus aureus, and the acute ecotoxicity tests were performed with Daphnia similis. The nanoparticle without CS (PCLnp) exhibited an average size of 200 nm and zeta potential of -4.28 mV, while the nanoparticle with 0.04% (w/v) of CS (CS_PCLnp) had 250 nm and +21.3 mV. Both were stables for at least 30 days. 200 μg mL-1 violacein was encapsulated in CS_PCLnp, which was dissolved in the polymer matrix, a shown by DSC analysis. The minimal inhibitory concentration against S. aureus of CS_PCLnp-vio was 25 μmol L-1, while for free violacein it was > 25 μmol L-1. Nanoparticles exhibited an EC50 between 0.3 - 1.1 μmol L-1 with Daphnia, while free violacein was around 3.3 - 5.0 μmol L-1. Thus, it was possible to control the charge of the nanoparticles, without extreme changes in size and that it is possible also to encapsulate a powerful antibactericidal compound such as violacein in nanoparticle.

  1. Antibacterial activity of hybrid chitosan-cupric oxide nanoparticles on cotton fabric.

    PubMed

    Dhineshbabu, Nattanmi Raman; Rajendran, Venkatachalam

    2016-02-01

    In this study, cupric oxide (CuO) nanoparticles were prepared using sonochemical method. The prepared nanoparticles were studied using X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. The colloidal chitosan (CS) solution was prepared using ultrasound irradiation method and simultaneously mixed with CuO nanoparticles. The coatings of colloidal solution with and without CuO nanoparticles were studied through TEM images. The cotton fabrics were separately soaked in the prepared nanoparticle-containing (hybrid) solutions by sonication method followed by pad-dry-cure method. The structural, functional, and morphological analyses of the coated and uncoated fabrics were performed using XRD, FTIR-attenuated total reflectance, and SEM analyses, respectively. The hybrid-coated cotton fabrics showed better antibacterial activity against Staphylococcus aureus and Escherichia coli. The bioactivity performance of the coated fabrics was in the order of CuO-coated fabric > CS-coated fabric. PMID:26766868

  2. Enhanced Oral Delivery of Docetaxel Using Thiolated Chitosan Nanoparticles: Preparation, In Vitro and In Vivo Studies

    PubMed Central

    Saremi, Shahrooz; Kebriaeezadeh, Abbas; Ostad, Seyed Nasser; Atyabi, Fatemeh

    2013-01-01

    The aim of this study was to evaluate a nanoparticulate system with mucoadhesion properties composed of a core of polymethyl methacrylate surrounded by a shell of thiolated chitosan (Ch-GSH-pMMA) for enhancing oral bioavailability of docetaxel (DTX), an anticancer drug. DTX-loaded nanoparticles were prepared by emulsion polymerization method using cerium ammonium nitrate as an initiator. Physicochemical properties of the nanoparticles such as particle size, size distribution, morphology, drug loading, and entrapment efficiency were characterized. The pharmacokinetic study was carried out in vivo using wistar rats. The half-life of DTX-loaded NPs was about 9 times longer than oral DTX used as positive control. The oral bioavailability of DTX was increased to 68.9% for DTX-loaded nanoparticles compared to 6.5% for positive control. The nanoparticles showed stronger effect on the reduction of the transepithelial electrical resistance (TEER) of Caco-2 cell monolayer by opening the tight junctions. According to apparent permeability coefficient (Papp) results, the DTX-loaded NPs showed more specific permeation across the Caco-2 cell monolayer in comparison to the DTX. In conclusion, the nanoparticles prepared in this study showed promising results for the development of an oral drug delivery system for anticancer drugs. PMID:23971023

  3. Combinatorial Photothermal and Immuno Cancer Therapy Using Chitosan-Coated Hollow Copper Sulfide Nanoparticles

    PubMed Central

    2015-01-01

    Near-infrared light-responsive inorganic nanoparticles have been shown to enhance the efficacy of cancer photothermal ablation therapy. However, current nanoparticle-mediated photothermal ablation is more effective in treating local cancer at the primary site than metastatic cancer. Here, we report the design of a near-infrared light-induced transformative nanoparticle platform that combines photothermal ablation with immunotherapy. The design is based on chitosan-coated hollow CuS nanoparticles that assemble the immunoadjuvants oligodeoxynucleotides containing the cytosine-guanine (CpG) motifs. Interestingly, these structures break down after laser excitation, reassemble, and transform into polymer complexes that improve tumor retention of the immunotherapy. In this “photothermal immunotherapy” approach, photothermal ablation-induced tumor cell death reduces tumor growth and releases tumor antigens into the surrounding milieu, while the immunoadjuvants potentiate host antitumor immunity. Our results indicated that combined photothermal immunotherapy is more effective than either immunotherapy or photothermal therapy alone against primary treated and distant untreated tumors in a mouse breast cancer model. These hollow CuS nanoparticles are biodegradable and can be eliminated from the body after laser excitation. PMID:24801008

  4. Development of bioactive and biodegradable chitosan-based injectable systems containing bioactive glass nanoparticles.

    PubMed

    Couto, Daniela S; Hong, Zhongkui; Mano, João F

    2009-01-01

    There is increasing interest in the development of new tissue engineering strategies to deliver cells and bioactive agents encapsulated in a biodegradable matrix through minimally invasive procedures. The present work proposes to combine chitosan-beta-glycerophosphate salt formulations with bioactive glass nanoparticles in order to conceive novel injectable thermo-responsive hydrogels for orthopaedic reconstructive and regenerative medicine applications. The initial rheological properties and the gelation points of the developed organic-inorganic in situ thermosetting systems were revealed to be adequate for intracorporal injection. In vitro bioactivity tests, using incubation protocols in simulated body fluid (SBF), allowed the observation of bone-like apatite formation in the hydrogel formulations containing bioactive nanoparticles. The density of the apatite formed increased with increasing bioactive glass content and soaking time in SBF. These results indicate that the stimuli-responsive hydrogels could potentially be used as temporary injectable scaffolds in bone tissue engineering applications. PMID:18835230

  5. Fabrication and characterization of gold nanoparticle reinforced Chitosan nanocomposites for biomedical applications

    NASA Astrophysics Data System (ADS)

    Patel, Nimitt G.

    Chitosan is a naturally derived polymer, which represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Polymeric materials can be regarded as promising candidates for next generation devices due to their low energy payback time. These devices can be fabricated by high-throughput processing methodologies, such as spin coating, inkjet printing, gravure and flexographic printing onto flexible substrates. However, the extensive applications of polymeric films are still limited because of disadvantages such as poor electromechanical properties, high brittleness with a low strain at break, and sensitivity to water. For certain critical applications the need for modification of physical, mechanical and electrical properties of the polymer is essential. When blends of polymer films with other materials are used, as is commonly the case, device performance directly depends on the nanoscale morphology and phase separation of the blend components. To prepare nanocomposite thin films with the desired functional properties, both the film composition and microstructure have to be thoroughly characterized and controlled. Chitosan reinforced bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through a solution casting method. Gold nanoparticles (˜ 32 nm diameter) were synthesized via a citrate reduction method from chloroauric acid and incorporated in the prepared Chitosan solution. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed by SEM images. Synthesis outcomes and prepared nanocomposites were characterized using TEM, SAED, SEM, EDX, XRD, UV-Vis, particle size analysis, zeta potential and FT-IR for their physical, morphological and structural properties. Nanoscale mechanical properties of the nanocomposite films were characterized at room temperature, human body temperatures and higher

  6. Approaches for modeling magnetic nanoparticle dynamics

    PubMed Central

    Reeves, Daniel B; Weaver, John B

    2014-01-01

    Magnetic nanoparticles are useful biological probes as well as therapeutic agents. There have been several approaches used to model nanoparticle magnetization dynamics for both Brownian as well as Néel rotation. The magnetizations are often of interest and can be compared with experimental results. Here we summarize these approaches including the Stoner-Wohlfarth approach, and stochastic approaches including thermal fluctuations. Non-equilibrium related temperature effects can be described by a distribution function approach (Fokker-Planck equation) or a stochastic differential equation (Langevin equation). Approximate models in several regimes can be derived from these general approaches to simplify implementation. PMID:25271360

  7. MAGNETIC NANOPARTICLE HYPERTHERMIA IN CANCER TREATMENT

    PubMed Central

    Giustini, Andrew J.; Petryk, Alicia A.; Cassim, Shiraz M.; Tate, Jennifer A.; Baker, Ian; Hoopes, P. Jack

    2013-01-01

    The activation of magnetic nanoparticles (mNPs) by an alternating magnetic field (AMF) is currently being explored as technique for targeted therapeutic heating of tumors. Various types of superparamagnetic and ferromagnetic particles, with different coatings and targeting agents, allow for tumor site and type specificity. Magnetic nanoparticle hyperthermia is also being studied as an adjuvant to conventional chemotherapy and radiation therapy. This review provides an introduction to some of the relevant biology and materials science involved in the technical development and current and future use of mNP hyperthermia as clinical cancer therapy. PMID:24348868

  8. Hepatitis B surface antigen nanoparticles coated with chitosan and trimethyl chitosan: Impact of formulation on physicochemical and immunological characteristics.

    PubMed

    Tafaghodi, Mohsen; Saluja, Vinay; Kersten, Gideon F A; Kraan, Heleen; Slütter, Bram; Amorij, Jean-Pierre; Jiskoot, Wim

    2012-08-01

    Mucosal immunization offers various advantages over parenteral vaccination, but typically requires potent delivery systems and/or adjuvants to result in protective immunity. Here we report on the preparation of trimethylated chitosan (TMC) and chitosan (CHT) nanoparticles (NPs) loaded with hepatitis B surface antigen (HB), by a simple and scalable method. TMC:HB and CHT:HB NPs were prepared by direct coating of antigen by polymer. The impact of buffer, pH and tonicity of the dispersion medium on NPs' polydispersity, zeta potential and association percentage of polymer with antigen was evaluated. Moreover, biological properties of both NPs were addressed in vitro by studying their effect on cell viability, transepithelial electrical resistance (TEER) and dendritic cell (DC) maturation. Finally, immunogenicity was assessed by evaluating IgG, IgG1, IgG2a, IgA titers and sIgA after both mucosal (nasal) as well intramuscular (i.m.) vaccination in a murine model. TMC:HB and CHT:HB NPs, prepared in acetate buffer pH 6.7 of three different tonicities, had comparable size, polydispersity, zeta potential and association percentage. TMC:HB NPs, but not CHT:HB NPs, had a mild negative effect on cell viability and TEER, and a considerable positive effect on DC maturation. After nasal and i.m. immunization, TMC:HB NPs in hypotonic medium and CHT:HB NPs in all media induced higher serum and nasal antibody titers compared with HB solution (P<0.001). After i.m. injection, both TMC:HB and CHT:HB NPs induced higher IgG and IgG2a titers compared with alum adsorbed HB (P<0.001). For CHT:HB NPs, the tonicity of the dispersion medium did not affect the mucosal and systemic immune responses. In conclusion, TMC NPs and CHT NPs are similarly potent mucosal immunoadjuvants for HB. Moreover, both polymers are potent immunoadjuvants for i.m. administered isotonic HB, resulting in higher IgG2a/IgG1 ratios compared with alum adjuvanted HB. PMID:22749834

  9. Hepatitis B surface antigen nanoparticles coated with chitosan and trimethyl chitosan: Impact of formulation on physicochemical and immunological characteristics.

    PubMed

    Tafaghodi, Mohsen; Saluja, Vinay; Kersten, Gideon F A; Kraan, Heleen; Slütter, Bram; Amorij, Jean-Pierre; Jiskoot, Wim

    2012-08-01

    Mucosal immunization offers various advantages over parenteral vaccination, but typically requires potent delivery systems and/or adjuvants to result in protective immunity. Here we report on the preparation of trimethylated chitosan (TMC) and chitosan (CHT) nanoparticles (NPs) loaded with hepatitis B surface antigen (HB), by a simple and scalable method. TMC:HB and CHT:HB NPs were prepared by direct coating of antigen by polymer. The impact of buffer, pH and tonicity of the dispersion medium on NPs' polydispersity, zeta potential and association percentage of polymer with antigen was evaluated. Moreover, biological properties of both NPs were addressed in vitro by studying their effect on cell viability, transepithelial electrical resistance (TEER) and dendritic cell (DC) maturation. Finally, immunogenicity was assessed by evaluating IgG, IgG1, IgG2a, IgA titers and sIgA after both mucosal (nasal) as well intramuscular (i.m.) vaccination in a murine model. TMC:HB and CHT:HB NPs, prepared in acetate buffer pH 6.7 of three different tonicities, had comparable size, polydispersity, zeta potential and association percentage. TMC:HB NPs, but not CHT:HB NPs, had a mild negative effect on cell viability and TEER, and a considerable positive effect on DC maturation. After nasal and i.m. immunization, TMC:HB NPs in hypotonic medium and CHT:HB NPs in all media induced higher serum and nasal antibody titers compared with HB solution (P<0.001). After i.m. injection, both TMC:HB and CHT:HB NPs induced higher IgG and IgG2a titers compared with alum adsorbed HB (P<0.001). For CHT:HB NPs, the tonicity of the dispersion medium did not affect the mucosal and systemic immune responses. In conclusion, TMC NPs and CHT NPs are similarly potent mucosal immunoadjuvants for HB. Moreover, both polymers are potent immunoadjuvants for i.m. administered isotonic HB, resulting in higher IgG2a/IgG1 ratios compared with alum adjuvanted HB.

  10. Ultrasound associated uptake of chitosan nanoparticles in MC3T3-E1 cells

    NASA Astrophysics Data System (ADS)

    Wu, Junyi

    Chitosan is a natural linear polysaccharide that has been well known for its applications in drug delivery system due to its unique physicochemical and biological properties. However, challenges still remain for it to become a fully realized therapeutic agent. In this study, we investigated the uptake of chitosan nanoparticles (CNP) under the ultrasound stimulation, using a model cell culture system (MC3T3-E1 mouse pre-osteoblasts). The CNP were fabricated by an ionic gelation method and were lyophilized prior to characterization and delivery to cells. Particle size and zeta potential were measured using Dynamic Light Scattering (DLS); the efficiency of chitosan complexation was measured using the ninhydrin assay. Cytotoxicity was examined by neutral red assay within 48 hours after delivery. The effect of ultrasound (US) on the efficiency of nanoparticle delivery to the MC3T3-E1 cells was examined at 1MHz and at either 1 or 2 W/cm2. Fluorescein isothiocyanate (FITC)-conjugated-CNP were used to visualize the internalized particles within the cytosol. The uptake of FITC-CNP exhibits a dose and time dependent effect, a strong FITC fluorescence was detected at the concentration of 500microg/mL under fluorescence microscope. Ultrasound assisted uptake of FITC-CNP performed a significant positive effect at 2W/cm2 with 60s of ultrasound exposure time. CNP displayed a slightly decrease in cell viability from 25microg/mL to 100microg/mL, while higher concentration of CNP facilitates the proliferation of MC3T3-E1 cells. Less than 10% of reduction in cell viability was observed for US at 1W/cm2 and 2W/cm2 with 30s and 60s of exposure time, which suggest a mild effect of US to MC3T3-E1 cell line.

  11. Thermogelling chitosan-collagen-bioactive glass nanoparticle hybrids as potential injectable systems for tissue engineering.

    PubMed

    Moreira, Cheisy D F; Carvalho, Sandhra M; Mansur, Herman S; Pereira, Marivalda M

    2016-01-01

    Recently, stimuli-responsive nanocomposite-derived hydrogels have gained prominence in tissue engineering because they can be applied as injectable scaffolds in bone and cartilage repair. Due to the great potential of these systems, this study aimed to synthesize and characterize novel thermosensitive chitosan-based composites, chemically modified with collagen and reinforced by bioactive glass nanoparticles (BG) on the development of injectable nanohybrids for regenerative medicine applications. Thus, the composite hydrogels were extensively characterized by structural, morphological, rheological, and biological testing. The composites showed thermosensitive response with the gelation temperature at approximately 37 °C, which is compatible with the human body temperature. In addition, scanning electron microscopy (SEM) analysis indicated that the chitosan hydrogels exhibited 3D-porous structures, and the incorporation of collagen in the system caused increase on the average pore size. Fourier transform infrared spectroscopy (FTIR) analysis indicated the main functional groups of each component of the composite system and their chemical interactions forming the scaffold. Moreover, rheological measurements were employed to assess the viscoelastic behavior of the hydrogels as a function of the temperature. The results demonstrated that the addition of collagen and bioactive glass increases the mechanical properties after the gelation process. The addition of 2 wt.% of BG nanoparticles caused an increase of approximately 39% on stiffness compared to pure chitosan and the addition of 30 wt.% collagen caused a further increase on the stiffness by 95%. The cytotoxicity and cell viability of the hydrogels were assessed by MTT and LIVE/DEAD® assays, where the results demonstrated no toxic effect of the composites on the human osteosarcoma cell culture (SAOS) and kidney cells line of human embryo (HEK 293 T). Hence, it can be stated that innovative composites were

  12. Hexanoyl-Chitosan-PEG Copolymer Coated Iron Oxide Nanoparticles for Hydrophobic Drug Delivery

    PubMed Central

    Hsiao, Meng-Hsuan; Mu, Qingxin; Stephen, Zachary R.; Fang, Chen; Zhang, Miqin

    2015-01-01

    Nanoparticle (NP) formulations may be used to improve in vivo efficacy of hydrophobic drugs by circumventing solubility issues and providing targeted delivery. In this study, we developed a hexanoyl-chitosan-PEG (CP6C) copolymer coated, paclitaxel (PTX)-loaded, and chlorotoxin (CTX) conjugated iron oxide NP (CTX-PTX-NP) for targeted delivery of PTX to human glioblastoma (GBM) cells. We modified chitosan with polyethylene glycol (PEG) and hexanoyl groups to obtain the amphiphilic CP6C. The resultant copolymer was then coated onto oleic acid-stabilized iron oxide NPs (OA-IONP) via hydrophobic interactions. PTX, a model hydrophobic drug, was loaded into the hydrophobic region of IONPs. CTX-PTX-NP showed high drug loading efficiency (>30%), slow drug release in PBS and the CTX-conjugated NP was shown to successfully target GBM cells. Importantly, the NPs showed great therapeutic efficacy when evaluated in GBM cell line U-118 MG. Our results indicate that this nanoparticle platform could be used for loading and targeted delivery of hydrophobic drugs. PMID:26900510

  13. Preparation of Chitosan/Polystyrene Sulfonate Multilayered Composite Metal Nanoparticles and Its Application.

    PubMed

    Xiong, Fangxin; Chen, Chunxiao; Liu, Shantang

    2016-06-01

    Metal-Chitosan (CTS) composite was first synthesized through the metal composition of chitosan (CTS) and metal ions. The formed composite was alternately deposited on the base with sodium polystyrene sulfonate (PSS) through a layer-by-layer self-assembling technique, followed by an in situ reduction by sodium borohydride to produce a polyelectrolyte nanocomposite thin film containing metal nanoparticles. Assembly, surface morphology and electrochemical properties of the composite membrane were analyzed by UV-visible absorption spectroscopy (UV-vis), atomic force microscopy (AFM) and cyclic voltammetry (CV). The UV-Vis results indicated that the absorbance of the multilayer film at the characteristic absorption peak increased as the membrane bilayers increased, in a good linear relationship, which demonstrated that the multilayer film was uniformly assembled on the base. AFM images showed that the surface of the multilayer thin-film composite had some degree of roughness and metal nanoparticles of 10-20 nm in size were generated on the membrane. The CV results indicated that the metal nanocomposite film had excellent electrocatalytic activity to glucose and had a potential for applications in electrochemical sensors.

  14. Preparation and characterization of SDF-1α-chitosan-dextran sulfate nanoparticles.

    PubMed

    Bader, Andrew R; Li, Tina; Wang, Weiping; Kohane, Daniel S; Loscalzo, Joseph; Zhang, Ying-Yi

    2015-01-01

    Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under appropriate conditions. The glycan nanoparticles are useful carriers for protein factors, which facilitate the in vivo delivery of the proteins and sustain their retention in the targeted tissue. The glycan polyelectrolyte complexes are also ideal for protein delivery, as the incorporation is carried out in aqueous solution, which reduces the likelihood of inactivation of the proteins. Proteins with a heparin-binding site adhere to dextran sulfate readily, and are, in turn, stabilized by the binding. These particles are also less inflammatory and toxic when delivered in vivo. In the protocol described below, SDF-1α (Stromal cell-derived factor-1α), a stem cell homing factor, is first mixed and incubated with dextran sulfate. Chitosan is added to the mixture to form polyelectrolyte complexes, followed by zinc sulfate to stabilize the complexes with zinc bridges. The resultant SDF-1α-DS-CS particles are measured for size (diameter) and surface charge (zeta potential). The amount of the incorporated SDF-1α is determined, followed by measurements of its in vitro release rate and its chemotactic activity in a particle-bound form. PMID:25650558

  15. Efficacy of ferulic acid encapsulated chitosan nanoparticles against Candida albicans biofilm.

    PubMed

    Panwar, Richa; Pemmaraju, Suma C; Sharma, Asvene K; Pruthi, Vikas

    2016-06-01

    Candida albicans, an opportunistic fungal pathogen is a major causative agent of superficial to systemic life-threating biofilm infections on indwelling medical devices. These biofilms acts as double edge swords owing to their resistance towards antibiotics and immunological barriers. To overcome this threat ferulic acid encapsulated chitosan nanoparticles (FA-CSNPs) were formulated to assess its efficacy as an antibiofilm agent against C. albicans. These FA-CSNPs were synthesized using ionotropic gelation method and observed through field emission scanning electron microscopy (FESEM) and fluorescent microscopy. Assessment of successful encapsulation and stability of ferulic acid into chitosan nanoparticles was made using Fourier transform infrared spectrum (FTIR), (1)H NMR and thermal analyses. Synthesized FA-CSNPs, were found to be cytocompatible, when tested using Human Embryonic Kidney (HEK-293) cell lines. XTT assay revealed that FA-CSNPs reduced the cell metabolic activity of C. albicans upto 22.5% as compared to native ferulic acid (63%) and unloaded CSNPs (88%) after 24 h incubation. Disruption of C. albicans biofilm architecture was visualized by FESEM. Results highlighted the potential of FA-CSNPs to be used as an effective alternative to the conventional antifungal therapeutics. PMID:26930164

  16. Enhanced antiproliferative activity of carboplatin-loaded chitosan-alginate nanoparticles in a retinoblastoma cell line.

    PubMed

    Parveen, Suphiya; Mitra, Moutushy; Krishnakumar, S; Sahoo, Sanjeeb K

    2010-08-01

    In the present study the potential of carboplatin-loaded chitosan-alginate nanoparticles (CANPs) for the treatment of retinoblastoma was investigated. The carboplatin-loaded CANPs were approximately 300 nm in size, exhibited a high zeta potential of approximately 36 mV and drug encapsulation of approximately 20 wt.%. The CANPs were further characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry and transmission electron microscopy. In vitro release studies revealed fast release of approximately 25% of the drug during the first 24h, followed by sustained release. CANPs demonstrated greater and sustained antiproliferative activity of the drug in a dose- and time-dependent manner (carboplatin IC(50)=0.56 microg ml(-1), carboplatin-loaded CANPs IC(50)=0.004 microg ml(-1)), as well as an enhanced apoptotic effect as compared with the drug in solution in a retinoblastoma cell line (Y79). The higher cytotoxic effect of CANPs may be due to their greater cellular uptake as compared with native carboplatin. It was also demonstrated that clathrin-mediated endocytosis plays a key role in the internalization of CANPs in the Y79 cell line. In conclusion, biodegradable chitosan nanoparticles could be used as an effective ocular drug delivery system for sustained intracellular delivery of carboplatin for the treatment of retinoblastoma. PMID:20149903

  17. Preparation of Chitosan/Polystyrene Sulfonate Multilayered Composite Metal Nanoparticles and Its Application.

    PubMed

    Xiong, Fangxin; Chen, Chunxiao; Liu, Shantang

    2016-06-01

    Metal-Chitosan (CTS) composite was first synthesized through the metal composition of chitosan (CTS) and metal ions. The formed composite was alternately deposited on the base with sodium polystyrene sulfonate (PSS) through a layer-by-layer self-assembling technique, followed by an in situ reduction by sodium borohydride to produce a polyelectrolyte nanocomposite thin film containing metal nanoparticles. Assembly, surface morphology and electrochemical properties of the composite membrane were analyzed by UV-visible absorption spectroscopy (UV-vis), atomic force microscopy (AFM) and cyclic voltammetry (CV). The UV-Vis results indicated that the absorbance of the multilayer film at the characteristic absorption peak increased as the membrane bilayers increased, in a good linear relationship, which demonstrated that the multilayer film was uniformly assembled on the base. AFM images showed that the surface of the multilayer thin-film composite had some degree of roughness and metal nanoparticles of 10-20 nm in size were generated on the membrane. The CV results indicated that the metal nanocomposite film had excellent electrocatalytic activity to glucose and had a potential for applications in electrochemical sensors. PMID:27427666

  18. Chitosan nanoparticles for siRNA delivery: optimization of processing/formulation parameters.

    PubMed

    Esmaeilzadeh Gharehdaghi, Elina; Amani, Amir; Khoshayand, Mohammad Reza; Banan, Mehdi; Esmaeilzadeh Gharehdaghi, Elika; Amini, Mohammad Ali; Faramarzi, Mohammad Ali

    2014-12-01

    Chitosan nanoparticles were prepared using ultrasonication methodology at specific amplitudes and times of sonication. Subsequently, small interfering RNA (siRNA) was added to the solution at predetermined values of nitrogen to phosphorous ratio (N/P), and stirring time. Employing response surfaces generated from a statistical model, the effect of sonication time and amplitude, stirring time, and N/P ratio was studied on the particle size, polydispersity, and loading efficiency of prepared siRNA/chitosan nanoparticles. It was found that to obtain the smallest size, amplitude and time of sonication as well as stirring time should be kept at ∼45%, 165 seconds, and 50 minutes, respectively. Minimum polydispersity values were also obtained at similar values of sonication time/amplitude and stirring time in addition to N/P values of ∼28. Also, the maximum proportion of siRNA loading was observed at approximate values of 300 seconds, 80% and 280 for sonication time, amplitude, and N/P ratio, respectively. The optimum conditions (i.e., to prepare a sample with minimum values of particle size and polydispersity index and maximum values of loading efficiency) were determined as 60.6, 30.0 (seconds), 28.0, and 12.5 (minutes) for amplitude, time of sonication, N/P, and stirring time, respectively. In this scrutiny, the predicted values of optimum formulation were 456 nm size, 89.6% loading efficiency, and 0.4 polydispersity index.

  19. Characterization of magnetically fractionated magnetic nanoparticles for magnetic particle imaging

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Othman, N. B.; Enpuku, K.

    2013-11-01

    We have characterized fractionated magnetic nanoparticles (MNPs) for magnetic particle imaging. Original Ferucarbotran particles were magnetically divided into three fractionated MNPs called MS1, MS2, and MS3. Harmonic spectra from the three fractionated MNPs were measured at excitation fields of 2.8 and 28 mT with a frequency of 10 kHz. MS1 showed a 2.5-fold increase in the harmonic spectrum over that of the original MNPs. To understand the origin of the enhancement in the harmonic spectrum from MS1, we explored the magnetic properties of the MS series, such as distributions of effective core size and anisotropy energy barrier, and the correlation between them. Using these results, we performed numerical simulations of the harmonic spectra based on the Langevin equation. The simulation results quantitatively explained the experimental results of the fractionated MS series. It was also clarified that MS1 includes a large portion of the MNPs that are responsible for the harmonic spectrum.

  20. Targeting intracellular compartments by magnetic polymeric nanoparticles.

    PubMed

    Kocbek, Petra; Kralj, Slavko; Kreft, Mateja Erdani; Kristl, Julijana

    2013-09-27

    Superparamagnetic iron oxide nanoparticles (SPIONs) show a great promise for a wide specter of bioapplications, due to their characteristic magnetic properties exhibited only in the presence of magnetic field. Their advantages in the fields of magnetic drug targeting and imaging are well established and their safety is assumed, since iron oxide nanoparticles have already been approved for in vivo application, however, according to many literature reports the bare metal oxide nanoparticles may cause toxic effects on treated cells. Therefore, it is reasonable to prevent the direct interactions between metal oxide core and surrounding environment. In the current research ricinoleic acid coated maghemite nanoparticles were successfully synthesized, characterized and incorporated in the polymeric matrix, resulting in nanosized magnetic polymeric particles. The carrier system was shown to exhibit superparamagnetic properties and was therefore responsive towards external magnetic field. Bioevaluation using T47-D breast cancer cells confirmed internalization of magnetic polymeric nanoparticles (MNPs) and their intracellular localization in various subcellular compartments, depending on presence/absence of external magnetic field. However, the number of internalized MNPs observed by fluorescent and transmission electron microscopy was relatively low, making such way of targeting effective only for delivery of highly potent drugs. The scanning electron microscopy of treated cells revealed that MNPs influenced the cell adhesion, when external magnetic field was applied, and that treatment resulted in damaged apical plasma membrane right after exposure to the magnetic carrier. On the other hand, MNPs showed only reversibly reduced cellular metabolic activity in concentrations up to 200 μg/ml and, in the tested concentration the cell cycle distribution was within the normal range, indicating safety of the established magnetic carrier system for the treated cells.

  1. Delivery of human NKG2D-IL-15 fusion gene by chitosan nanoparticles to enhance antitumor immunity

    SciTech Connect

    Yan, Chen; Jie, Leng; Yongqi, Wang; Weiming, Xiao; Juqun, Xi; Yanbing, Ding; Li, Qian; Xingyuan, Pan; Mingchun, Ji; Weijuan, Gong

    2015-07-31

    Nanoparticles are becoming promising carriers for gene delivery because of their high capacity in gene loading and low cell cytotoxicity. In this study, a chitosan-based nanoparticle encapsulated within a recombinant pcDNA3.1-dsNKG2D-IL-15 plasmid was generated. The fused dsNKG2D-IL-15 gene fragment consisted of double extracellular domains of NKG2D with IL-15 gene at downstream. The average diameter of the gene nanoparticles ranged from 200 nm to 400 nm, with mean zeta potential value of 53.8 ± 6.56 mV. The nanoparticles which were loaded with the dsNKG2D-IL-15 gene were uptaken by tumor cells with low cytotoxicity. Tumor cells pre-transfected by gene nanopartilces stimulated NK and T cells in vitro. Intramuscular injection of gene nanoparticles suppressed tumor growth and prolonged survival of tumor-bearing mice through activation of NK and CD8{sup +} T cells. Thus, chitosan-based nanoparticle delivery of dsNKG2D-IL-15 gene vaccine can be potentially used for tumor therapy. - Highlights: • Generation of a nanoparticle for delivery of dsNKG2D-IL-15 gene. • Characterization of the gene nanoparticle. • Antitumor activity mediated by the gene nanoparticle.

  2. Biological cell manipulation by magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Gertz, Frederick; Khitun, Alexander

    2016-02-01

    We report a manipulation of biological cells (erythrocytes) by magnetite (Fe3O4) nanoparticles in the presence of a magnetic field. The experiment was accomplished on the top of a micro-electromagnet consisting of two magnetic field generating contours. An electric current flowing through the contour(s) produces a non-uniform magnetic field, which is about 1.4 mT/μm in strength at 100 mA current in the vicinity of the current-carrying wire. In responses to the magnetic field, magnetic nanoparticles move towards the systems energy minima. In turn, magnetic nanoparticles drag biological cells in the same direction. We present experimental data showing cell manipulation through the control of electric current. This technique allows us to capture and move cells located in the vicinity (10-20 microns) of the current-carrying wires. One of the most interesting results shows a periodic motion of erythrocytes between the two conducting contours, whose frequency is controlled by an electric circuit. The obtained results demonstrate the feasibility of non-destructive cell manipulation by magnetic nanoparticles with micrometer-scale precision.

  3. Self-assembled nanoparticles based on amphiphilic chitosan derivative and arginine for oral curcumin delivery

    PubMed Central

    Raja, Mazhar Ali; Zeenat, Shah; Arif, Muhammad; Liu, Chenguang

    2016-01-01

    Curcumin (Cur) is a striking anticancer agent, but its low aqueous solubility, poor absorption, hasty metabolism, and elimination limit its oral bioavailability and consequently hinder its development as a drug. To redress these limitations, amphiphilic chitosan (CS) conjugate with improved mucoadhesion and solubility over a wider pH range was developed by modification with hydrophobic acrylonitrile (AN) and hydrophilic arginine (Arg); the synthesized conjugate (AN–CS–Arg), which was well characterized by Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy. Results of critical aggregation concentration revealed that the AN–CS–Arg conjugate had low critical aggregation concentration and was prone to form self-assembled nanoparticles (NPs) in aqueous medium. Cur-encapsulated AN–CS–Arg NPs (AN–CS–Arg/Cur NPs) were developed by a simple sonication method and characterized for the physicochemical parameters such as zeta potential, particle size, and drug encapsulation. The results showed that zeta potential of the prepared NPs was 40.1±2.81 mV and the average size was ~218 nm. A considerable improvement in the aqueous solubility of Cur was observed after encapsulation into AN–CS–Arg/Cur NPs. With the increase in Cur concentration, loading efficiency increased but encapsulation efficiency decreased. The in vitro release profile exhibited sustained release pattern from the AN–CS–Arg/Cur NPs in typical biological buffers. The ex vivo mucoadhesion study revealed that AN–CS–Arg/Cur NPs had greater mucoadhesion than the control CS NPs. Compared with free Cur solution, AN–CS–Arg/Cur NPs showed stronger dose-dependent cytotoxicity against HT-29 cells. In addition, it was observed that cell uptake of AN–CS–Arg/Cur NPs was much higher compared with free Cur. Furthermore, the in vivo pharmacokinetic results in rats demonstrated that the AN–CS–Arg/Cur NPs could remarkably improve the oral bioavailability of Cur

  4. Self-assembled nanoparticles based on amphiphilic chitosan derivative and arginine for oral curcumin delivery

    PubMed Central

    Raja, Mazhar Ali; Zeenat, Shah; Arif, Muhammad; Liu, Chenguang

    2016-01-01

    Curcumin (Cur) is a striking anticancer agent, but its low aqueous solubility, poor absorption, hasty metabolism, and elimination limit its oral bioavailability and consequently hinder its development as a drug. To redress these limitations, amphiphilic chitosan (CS) conjugate with improved mucoadhesion and solubility over a wider pH range was developed by modification with hydrophobic acrylonitrile (AN) and hydrophilic arginine (Arg); the synthesized conjugate (AN–CS–Arg), which was well characterized by Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy. Results of critical aggregation concentration revealed that the AN–CS–Arg conjugate had low critical aggregation concentration and was prone to form self-assembled nanoparticles (NPs) in aqueous medium. Cur-encapsulated AN–CS–Arg NPs (AN–CS–Arg/Cur NPs) were developed by a simple sonication method and characterized for the physicochemical parameters such as zeta potential, particle size, and drug encapsulation. The results showed that zeta potential of the prepared NPs was 40.1±2.81 mV and the average size was ~218 nm. A considerable improvement in the aqueous solubility of Cur was observed after encapsulation into AN–CS–Arg/Cur NPs. With the increase in Cur concentration, loading efficiency increased but encapsulation efficiency decreased. The in vitro release profile exhibited sustained release pattern from the AN–CS–Arg/Cur NPs in typical biological buffers. The ex vivo mucoadhesion study revealed that AN–CS–Arg/Cur NPs had greater mucoadhesion than the control CS NPs. Compared with free Cur solution, AN–CS–Arg/Cur NPs showed stronger dose-dependent cytotoxicity against HT-29 cells. In addition, it was observed that cell uptake of AN–CS–Arg/Cur NPs was much higher compared with free Cur. Furthermore, the in vivo pharmacokinetic results in rats demonstrated that the AN–CS–Arg/Cur NPs could remarkably improve the oral bioavailability of Cur

  5. Preparation, statistical optimization, and in vitro characterization of insulin nanoparticles composed of quaternized aromatic derivatives of chitosan.

    PubMed

    Mahjub, Reza; Dorkoosh, Farid Abedin; Amini, Mohsen; Khoshayand, Mohammad Reza; Rafiee-Tehrani, Morteza

    2011-12-01

    The aim of this study was the preparation, optimization, and in vitro characterization of insulin nanoparticles composed of methylated N-(4-N,N-dimethylaminobenzyl), methylated N-(4-pyridinyl), and methylated N-(benzyl) chitosan. Three types of derivatives were synthesized by the Schiff base reaction followed by quaternization. Nanoparticles were prepared by the polyelectrolyte complexation method. Experimental design D-optimal response surface methodology was used for the optimization of the nanoparticles. Independent variables were pH of polymer solution, concentration ratio of polymer/insulin, and also polymer type. Dependent variables include size, zeta potential, polydispersity index (PdI), and entrapment efficiency (EE%). Optimized nanoparticles were studied morphologically by transmission electron microscopy (TEM), and in vitro release of insulin from nanoparticles were determined under phosphate buffer (pH = 6.8) condition. Although a quadratic model has been chosen to fit the responses for size, PdI, and EE%, the zeta potential of the particles has been best fitted to 2-FI model. The optimized nanoparticles were characterized. The size of the particles were found to be 346, 318, and 289 nm; zeta potentials were 28.5, 27.7, and 22.2 mV; PdI of particles were 0.305, 0.333, and 0.437; and calculated EE% were 70.3%, 84.5%, and 69.2%, for methylated (aminobenzyl), methylated (pyridinyl), and methylated (benzyl) chitosan nanoparticles, respectively. TEM images show separated and non-aggregated nanoparticles with sub-spherical shapes and smooth surfaces. An in vitro release study of the prepared nanoparticles showed that the cumulative percentage of insulin released from the nanoparticles were 47.1%, 38%, and 68.7% for (aminobenzyl), (pyridinyl), and (benzyl) chitosan, respectively, within 300 min.

  6. A simple method to fabricate a chitosan-gold nanoparticles film and its application in glucose biosensor.

    PubMed

    Du, Ying; Luo, Xi-Liang; Xu, Jing-Juan; Chen, Hong-Yuan

    2007-05-01

    A novel film of chitosan-gold nanoparticles is fabricated by a direct and facile electrochemical deposition method and its application in glucose biosensor is investigated. HAuCl(4) solution is mixed with chitosan and electrochemically reduced to gold nanoparticles, which can be stabilized by chitosan and electrodeposited onto glassy carbon electrode surfaces along with the electrodeposition of chitosan. Then a model enzyme, glucose oxidase (GOD) is immobilized onto the resulting film to construct a glucose biosensor through self-assembly. The resulting modified electrode surfaces are characterized with both AFM and cyclic voltammetry. Effects of chitosan and HAuCl(4) concentration in the mixture together with the deposition time and the applied voltage on the amperometric response of the biosensor are also investigated. The linear range of the glucose biosensor is from 5.0 x 10(-5) approximately 1.30 x 10(-3) M with a Michaelis-Menten constant of 3.5 mM and a detection limit of about 13 microM. PMID:16793348

  7. Hydrocaffeic acid-chitosan nanoparticles with enhanced stability, mucoadhesion and permeation properties.

    PubMed

    Soliman, Ghareb M; Zhang, Yu Ling; Merle, Geraldine; Cerruti, Marta; Barralet, Jake

    2014-11-01

    Catechol-containing molecules, such as hydrocaffeic acid (HCA) have been shown to increase the mucoadhesion of several polymers. We report here a simple and bioinspired approach to enhance chitosan (CS) mucoadhesion and stabilize it in nanoparticulate form by preparing HCA-CS conjugates. HCA-CS conjugates containing 6 and 15mol% HCA were synthesized and characterized by FT-IR, (1)H NMR and UV-vis spectrophotometry. HCA-CS nanoparticles prepared by ionic gelation with sodium tripolyphosphate (TPP) ranged in size between 100 and 250nm depending on the polymer and TPP/CS weight ratio. In contrast to CS nanoparticles, which aggregate at pH>6.5, HCA-CS nanoparticles did not show any sign of aggregation or precipitation over the 4-10 pH range and maintain their size. Unexpectedly, HCA-CS nanoparticles also maintained their size and polydispersity index at pH 7.4 and NaCl concentrations of up to 500mM. Partial oxidation of HCA resulted in nanoparticle cross-linking and improved stability at pH<4. HCA-CS mucoadhesion to rabbit small intestine was 6 times higher than unmodified CS. CS and HCA-CS nanoparticles were able to induce reversible tight junction opening in Caco-2 cell monolayers. Tight junction opening facilitated the permeability of a model hydrophilic molecule, fluorescein isothiocyanate-labeled dextran (FD4) and was 3 times higher in the cells treated with HCA-CS 15% nanoparticles compared to control groups. HCA-CS conjugates were found to be excellent candidates for stable nanodelivery systems with enhanced oral absorption of hydrophilic molecules.

  8. A comparative study of neurotoxic potential of synthesized polysaccharide-coated and native ferritin-based magnetic nanoparticles

    PubMed Central

    Borysov, Arseniy; Krisanova, Natalia; Chunihin, Olexander; Ostapchenko, Ludmila; Pozdnyakova, Nataliya; Borisova, Тatiana

    2014-01-01

    Aim To analyze the neurotoxic potential of synthesized magnetite nanoparticles coated by dextran, hydroxyethyl starch, oxidized hydroxyethyl starch, and chitosan, and magnetic nanoparticles combined with ferritin as a native protein. Methods The size of nanoparticles was analyzed using photon correlation spectroscopy, their effects on the conductance of planar lipid membrane by planar lipid bilayer technique, membrane potential and acidification of synaptic vesicles by spectrofluorimetry, and glutamate uptake and ambient level of glutamate in isolated rat brain nerve terminals (synaptosomes) by radiolabeled assay. Results Uncoated synthesized magnetite nanoparticles and nanoparticles coated by different polysaccharides had no significant effect on synaptic vesicle acidification, the initial velocity of L-[14C]glutamate uptake, ambient level of L-[14C]glutamate and the potential of the plasma membrane of synaptosomes, and conductance of planar lipid membrane. Native ferritin-based magnetic nanoparticles had no effect on the membrane potential but significantly reduced L-[14C]glutamate transport in synaptosomes and acidification of synaptic vesicles. Conclusions Our study indicates that synthesized magnetite nanoparticles in contrast to ferritin have no effects on the functional state and glutamate transport of nerve terminals, and so ferritin cannot be used as a prototype, analogue, or model of polysaccharide-coated magnetic nanoparticle in toxicity risk assessment and manipulation of nerve terminals by external magnetic fields. Still, the ability of ferritin to change the functional state of nerve terminals in combination with its magnetic properties suggests its biotechnological potential. PMID:24891278

  9. Effect of magnetic field in malaria diagnosis using magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Quan; Yuen, Clement

    2011-07-01

    The current gold standard method of Malaria diagnosis relies on the blood smears examination. The method is laborintensive, time consuming and requires the expertise for data interpretation. In contrast, Raman scattering from a metabolic byproduct of the malaria parasite (Hemozoin) shows the possibility of rapid and objective diagnosis of malaria. However, hemozoin concentration is usually extremely low especially at the early stage of malaria infection, rendering weak Raman signal. In this work, we propose the sensitive detection of enriched β-hematin, whose spectroscopic properties are equivalent to hemozoin, based on surface enhanced Raman spectroscopy (SERS) by using magnetic nanoparticles. A few orders of magnitude enhancement in the Raman signal of β-hematin can be achieved using magnetic nanoparticles. Furthermore, the effect of magnetic field on SERS enhancement is investigated. Our result demonstrates the potential of SERS using magnetic nanoparticles in the effective detection of hemozoin for malaria diagnosis.

  10. Functionalized magnetic nanoparticles: A novel heterogeneous catalyst support

    EPA Science Inventory

    Functionalized magnetic nanoparticles have emerged as viable alternatives to conventional materials, as robust, high-surface-area heterogeneous catalyst supports. Post-synthetic surface modification protocol for magnetic nanoparticles has been developed that imparts desirable che...

  11. Multidentate zwitterionic chitosan oligosaccharide modified gold nanoparticles: stability, biocompatibility and cell interactions

    NASA Astrophysics Data System (ADS)

    Liu, Xiangsheng; Huang, Haoyuan; Liu, Gongyan; Zhou, Wenbo; Chen, Yangjun; Jin, Qiao; Ji, Jian

    2013-04-01

    Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt conditions, wide pH range and serum or plasma containing media. The AuNPs also show strong resistance to competition from dithiothreitol (as high as 1.5 M). Moreover, the modified AuNPs demonstrate low cytotoxicity investigated by both MTT and LDH assays, and good hemocompatibility evaluated by hemolysis of human red blood cells. In addition, the intracellular fate of AuNPs was investigated by ICP-MS and TEM. It showed that the AuNPs are uptaken by cells in a concentration dependent manner, and they can escape from endosomes/lysosomes to cytosol and tend to accumulate around the nucleus after 24 h incubation but few of them are excreted out of the cells. Gold nanorods are also stabilized by this ligand, which demonstrates robust dispersion stability and excellent hemocompatibility. This kind of multidentate zwitterionic chitosan derivative could be widely used for stabilizing other inorganic nanoparticles, which will greatly improve their performance in a variety of bio-related applications.Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt

  12. Tuning the Magnetic Properties of Nanoparticles

    PubMed Central

    Kolhatkar, Arati G.; Jamison, Andrew C.; Litvinov, Dmitri; Willson, Richard C.; Lee, T. Randall

    2013-01-01

    The tremendous interest in magnetic nanoparticles (MNPs) is reflected in published research that ranges from novel methods of synthesis of unique nanoparticle shapes and composite structures to a large number of MNP characterization techniques, and finally to their use in many biomedical and nanotechnology-based applications. The knowledge gained from this vast body of research can be made more useful if we organize the associated results to correlate key magnetic properties with the parameters that influence them. Tuning these properties of MNPs will allow us to tailor nanoparticles for specific applications, thus increasing their effectiveness. The complex magnetic behavior exhibited by MNPs is governed by many factors; these factors can either improve or adversely affect the desired magnetic properties. In this report, we have outlined a matrix of parameters that can be varied to tune the magnetic properties of nanoparticles. For practical utility, this review focuses on the effect of size, shape, composition, and shell-core structure on saturation magnetization, coercivity, blocking temperature, and relaxation time. PMID:23912237

  13. Anti-biofilm activity of chitosan gels formulated with silver nanoparticles and their cytotoxic effect on human fibroblasts.

    PubMed

    Pérez-Díaz, M; Alvarado-Gomez, E; Magaña-Aquino, M; Sánchez-Sánchez, R; Velasquillo, C; Gonzalez, C; Ganem-Rondero, A; Martínez-Castañon, G; Zavala-Alonso, N; Martinez-Gutierrez, F

    2016-03-01

    The development of multi-species biofilms in chronic wounds is a serious health problem that primarily generates strong resistance mechanisms to antimicrobial therapy. The use of silver nanoparticles (AgNPs) as a broad-spectrum antimicrobial agent has been studied previously. However, their cytotoxic effects limit its use within the medical area. The purpose of this study was to evaluate the anti-biofilm capacity of chitosan gel formulations loaded with AgNPs, using silver sulfadiazine (SSD) as a standard treatment, on strains of clinical isolates, as well as their cytotoxic effect on human primary fibroblasts. Multi-species biofilm of Staphylococcus aureus oxacillin resistant (MRSA) and Pseudomonas aeruginosa obtained from a patient with chronic wound infection were carried out using a standard Drip Flow Reactor (DFR) under conditions that mimic the flow of nutrients in the human skin. Anti-biofilm activity of chitosan gels and SSD showed a log-reduction of 6.0 for MRSA when chitosan gel with AgNPs at a concentration of 100 ppm was used, however it was necessary to increase the concentration of the chitosan gel with AgNPs to 1000 ppm to get a log-reduction of 3.3, while the SSD showed a total reduction of both bacteria in comparison with the negative control. The biocompatibility evaluation on primary fibroblasts showed better results when the chitosan gels with AgNPs were tested even in the high concentration, in contrast with SSD, which killed all the primary fibroblasts. In conclusion, chitosan gel formulations loaded with AgNPs effectively prevent the formation of biofilm and kill bacteria in established biofilm, which suggest that chitosan gels with AgNPs could be used for prevention and treatment of infections in chronic wounds. The statistic significance of the biocompatibility of chitosan gel formulations loaded with AgNPs represents an advance; however further research and development are necessary to translate this technology into therapeutic and

  14. Microfluidic Biosensing Systems Using Magnetic Nanoparticles

    PubMed Central

    Giouroudi, Ioanna; Keplinger, Franz

    2013-01-01

    In recent years, there has been rapidly growing interest in developing hand held, sensitive and cost-effective on-chip biosensing systems that directly translate the presence of certain bioanalytes (e.g., biomolecules, cells and viruses) into an electronic signal. The impressive and rapid progress in micro- and nanotechnology as well as in biotechnology enables the integration of a variety of analytical functions in a single chip. All necessary sample handling and analysis steps are then performed within the chip. Microfluidic systems for biomedical analysis usually consist of a set of units, which guarantees the manipulation, detection and recognition of bioanalytes in a reliable and flexible manner. Additionally, the use of magnetic fields for performing the aforementioned tasks has been steadily gaining interest. This is because magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the biosensing system. In combination with these applied magnetic fields, magnetic nanoparticles are utilized. Some of the merits of magnetic nanoparticles are the possibility of manipulating them inside microfluidic channels by utilizing high gradient magnetic fields, their detection by integrated magnetic microsensors, and their flexibility due to functionalization by means of surface modification and specific binding. Their multi-functionality is what makes them ideal candidates as the active component in miniaturized on-chip biosensing systems. In this review, focus will be given to the type of biosening systems that use microfluidics in combination with magnetoresistive sensors and detect the presence of bioanalyte tagged with magnetic nanoparticles. PMID:24022689

  15. Simulations of magnetic nanoparticle Brownian motion

    NASA Astrophysics Data System (ADS)

    Reeves, Daniel B.; Weaver, John B.

    2012-12-01

    Magnetic nanoparticles are useful in many medical applications because they interact with biology on a cellular level thus allowing microenvironmental investigation. An enhanced understanding of the dynamics of magnetic particles may lead to advances in imaging directly in magnetic particle imaging or through enhanced MRI contrast and is essential for nanoparticle sensing as in magnetic spectroscopy of Brownian motion. Moreover, therapeutic techniques like hyperthermia require information about particle dynamics for effective, safe, and reliable use in the clinic. To that end, we have developed and validated a stochastic dynamical model of rotating Brownian nanoparticles from a Langevin equation approach. With no field, the relaxation time toward equilibrium matches Einstein's model of Brownian motion. In a static field, the equilibrium magnetization agrees with the Langevin function. For high frequency or low amplitude driving fields, behavior characteristic of the linearized Debye approximation is reproduced. In a higher field regime where magnetic saturation occurs, the magnetization and its harmonics compare well with the effective field model. On another level, the model has been benchmarked against experimental results, successfully demonstrating that harmonics of the magnetization carry enough information to infer environmental parameters like viscosity and temperature.

  16. Design and evaluation of an intravesical delivery system for superficial bladder cancer: preparation of gemcitabine HCl-loaded chitosan-thioglycolic acid nanoparticles and comparison of chitosan/poloxamer gels as carriers.

    PubMed

    Şenyiğit, Zeynep Ay; Karavana, Sinem Yaprak; İlem-Özdemir, Derya; Çalışkan, Çağrı; Waldner, Claudia; Şen, Sait; Bernkop-Schnürch, Andreas; Baloğlu, Esra

    2015-01-01

    This study aimed to develop an intravesical delivery system of gemcitabine HCl for superficial bladder cancer in order to provide a controlled release profile, to prolong the residence time, and to avoid drug elimination via urination. For this aim, bioadhesive nanoparticles were prepared with thiolated chitosan (chitosan-thioglycolic acid conjugate) and were dispersed in bioadhesive chitosan gel or in an in situ gelling poloxamer formulation in order to improve intravesical residence time. In addition, nanoparticle-loaded gels were diluted with artificial urine to mimic in vivo conditions in the bladder and were characterized regarding changes in gel structure. The obtained results showed that chitosanthioglycolic acid nanoparticles with a mean diameter of 174.5±3.762 nm and zeta potential of 32.100±0.575 mV were successfully developed via ionotropic gelation and that the encapsulation efficiency of gemcitabine HCl was nearly 20%. In vitro/ex vivo characterization studies demonstrated that both nanoparticles and nanoparticle-loaded chitosan and poloxamer gels might be alternative carriers for intravesical administration of gemcitabine HCl, prolonging its residence time in the bladder and hence improving treatment efficacy. However, when the gel formulations were diluted with artificial urine, poloxamer gels lost their in situ gelling properties at body temperature, which is in conflict with the aimed formulation property. Therefore, 2% chitosan gel formulation was found to be a more promising carrier system for intravesical administration of nanoparticles.

  17. Structure and properties of solid polymer electrolyte based on chitosan and ZrO2 nanoparticle for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Sudaryanto, Yulianti, Evi; Patimatuzzohrah

    2016-02-01

    In order to develop all solid lithium ion battery, study on the structure and properties of solid polymer electrolytes (SPE) based on chitosan has been done. The SPE were prepared by adding Zirconia (ZrO2) nanoparticle and LiClO4 as lithium salt into the chitosan solution followed by casting method. Effect of the ZrO2 and salt concentration to the structure and properties of SPE were elaborated using several methods. The structure of the SPE cast film, were characterized mainly by using X-ray diffractometer (XRD). While the electrical properties of SPE were studied by electrochemical impedance spectrometer (EIS) and ion transference number measurement. XRD profiles show that the addition of ZrO2 and LiClO4 disrupts the crystality of chitosan. The decrease in sample crytalinity with the nanoparticle and salt addition may increase the molecular mobility result in the increasing sample conductivity and cathionic transference number as determined by EIS and ion transference number measurement, respectively. The highest ionic conductivity (3.58×10-4 S cm-1) was obtained when 4 wt% of ZrO2 nanoparticle and 40 wt% of LiClO4 salt were added to the chitosan. The ion transference number with that composition was 0.55. It is high enough to be used as SPE for lithium ion battery.

  18. A Novel Chitosan-Hydrogel-Based Nanoparticle Delivery System for Local Inner Ear Application

    PubMed Central

    Lajud, Shayanne A.; Nagda, Danish A.; Qiao, Peter; Tanaka, Nobuaki; Civantos, Alyssa; Gu, Rende; Cheng, Zhiliang; Tsourkas, Andrew; O’Malley, Bert W.; Li, Daqing

    2014-01-01

    Hypothesis A chitosan-hydrogel-based nanoparticle (nanohydrogel) delivery system can be used to deliver therapeutic biomaterials across the round window membrane (RWM) into the inner ear in a mouse model. Background Delivering therapies to the inner ear has always been a challenge for the Otolaryngologist. Advances in biomedical nanotechnology, increased understanding of the RWM diffusion properties, and discovery of novel therapeutic targets and agents, have all sparked interest in the controlled local delivery of drugs and biomaterials to the inner ear using nanoparticles (NPs). Methods Fluorescently-labeled liposomal NPs were constructed and loaded into a chitosan-based hydrogel to form a nanohydrogel, and in vitro studies were performed to evaluate its properties and release kinetics. Furthermore, the nanohydrogel was applied to the RWM of mice, and perilymph and morphologic analysis were performed to assess the NP delivery and distribution within the inner ear. Results NPs with an average diameter of 160nm were obtained. In vitro experiments showed that liposomal NPs can persist under physiologic conditions for at least two weeks without significant degradation, and that the nanohydrogel can carry and release these NPs in a controlled and sustained manner. In vivo findings demonstrated that the nanohydrogel can deliver intact nanoparticles into the perilymphatic system and reach cellular structures in the scala media of the inner ear of our mouse model. Conclusion Our study suggests that the nanohydrogel system has great potential to deliver therapeutics in a controlled and sustained manner from the middle ear to the inner ear without altering inner ear structures. PMID:25587675

  19. Preparation of mono-dispersed silver nanoparticles assisted by chitosan-g-poly(ɛ-caprolactone) micelles and their antimicrobial application

    NASA Astrophysics Data System (ADS)

    Gu, Chunhua; Zhang, Huan; Lang, Meidong

    2014-05-01

    Amphiphilic chitosan-graft-poly(ɛ-caprolactone) (CS-g-PCLs) copolymers were synthesized by a homogeneous coupling method and characterized by 1H NMR, FTIR and ninhydrin assay. The graft copolymers were subsequently self-assembled into micelles, which were measured by DLS and TEM. The particle size of the micelles decreased as the segment grafting fraction was increased. Thereafter, silver nanoparticles were prepared in the presence of chitosan-based micelles under UV irradiation. The molar ratio and radiation time of silver to micelles were optimized with process monitored via UV-vis spectrophotometer. DLS and TEM were used to illustrate the particle structure and size while XRD patterns were applied to characterize the crystal structures of polymer-assisted silver nanoparticles. Films impregnated with silver nanoparticles were conducted with results of strong antimicrobial activities against Escherichia coli and Staphylococcus aureus as model Gram-negative and positive bacteria.

  20. Tailored super magnetic nanoparticles synthesized via template free hydrothermal technique

    NASA Astrophysics Data System (ADS)

    Attallah, Olivia A.; Girgis, E.; Abdel-Mottaleb, Mohamed M. S. A.

    2016-01-01

    Magnetite nanoparticles of controlled shape and dimensions were synthesized using a modified hydrothermal technique. The influence of different synthesis conditions on the shape, size (length and diameter), structure and magnetic properties of the prepared nanoparticles is presented. The mineral phases, the morphologies, size distribution of the resulting magnetic nanoparticles and their magnetic properties were characterized using different characterization methods. We designed magnetite nanoparticles with different morphologies (nanospheres, nanorods, nanocubes and hexagons) and with improved saturation magnetization reaching 90 emu/g.

  1. Monodisperse Magnetic Nanoparticles for Theranostic Applications

    PubMed Central

    Ho, Don; Sun, Xiaolian; Sun, Shouheng

    2011-01-01

    Conspectus The development of highly effective medicine requires the on-time monitoring of the medical treatment process. This combination of monitoring and therapeutics allows a large degree of control on the treatment efficacy and is now commonly referred to as “theranostics”. Magnetic nanoparticles (NPs) provide a unique nano-platform for theranostic applications due to their comparable sizes with various functional biomolecules, their biocompatibility and their responses to the external magnetic field. Recent efforts in studying magnetic NPs for both imaging and therapeutic applications have led to great advances in NP fabrication with controls in dimension, surface functionalization and magnetic property. These magnetic NPs have been proven to be robust agents that can be target-specific for enhancing magnetic resonance imaging sensitivity and magnetic heating efficiency. These, plus the deep tissue penetration of magnetic field, make magnetic NPs the most promising candidates for successful theranostics in the future. In this Account, we review the recent advances in the synthesis of magnetic NPs of iron oxide, Fe, as well as FePt and FeCo NPs for imaging and therapeutic applications. We will first introduce briefly nanomagnetism, magnetic resonance imaging (MRI), and magnetic fluid hyperthermia (MFH). We will then focus on chemical synthesis of monodisperse magnetic NPs with controlled sizes, morphologies, and magnetic properties. Typical examples in using monodisperse magnetic NPs for MRI and MFH are highlighted. PMID:21661754

  2. In vivo uptake and acute immune response to orally administered chitosan and PEG coated PLGA nanoparticles

    SciTech Connect

    Semete, B.; Booysen, L.I.J.; Kalombo, L.; Venter, J.D.; Katata, L.; Ramalapa, B.; Verschoor, J.A.; Swai, H.

    2010-12-01

    Nanoparticulate drug delivery systems offer great promise in addressing challenges of drug toxicity, poor bioavailability and non-specificity for a number of drugs. Much progress has been reported for nano drug delivery systems for intravenous administration, however very little is known about the effects of orally administered nanoparticles. Furthermore, the development of nanoparticulate systems necessitates a thorough understanding of the biological response post exposure. This study aimed to elucidate the in vivo uptake of chitosan and polyethylene glycol (PEG) coated Poly, DL, lactic-co-glycolic Acid (PLGA) nanoparticles and the immunological response within 24 h of oral and peritoneal administration. These PLGA nanoparticles were administered orally and peritoneally to female Balb/C mice, they were taken up by macrophages of the peritoneum. When these particles were fluorescently labelled, intracellular localisation was observed. The expression of pro-inflammatory cytokines IL-2, IL-6, IL-12p70 and TNF-{alpha} in plasma and peritoneal lavage was found to remain at low concentration in PLGA nanoparticles treated mice as well as ZnO nanoparticles during the 24 hour period. However, these were significantly increased in lipopolysaccharide (LPS) treated mice. Of these pro-inflammatory cytokines, IL-6 and IL-12p70 were produced at the highest concentration in the positive control group. The anti-inflammatory cytokines IL-10 and chemokines INF-{gamma}, IL-4, IL-5 remained at normal levels in PLGA treated mice. IL-10 and INF-{gamma} were significantly increased in LPS treated mice. MCP-1 was found to be significantly produced in all groups in the first hours, except the saline treated mice. These results provide the first report to detail the induction of cytokine production by PLGA nanoparticles engineered for oral applications.

  3. Magnetic properties of ZnO nanoparticles.

    PubMed

    Garcia, M A; Merino, J M; Fernández Pinel, E; Quesada, A; de la Venta, J; Ruíz González, M L; Castro, G R; Crespo, P; Llopis, J; González-Calbet, J M; Hernando, A

    2007-06-01

    We experimentally show that it is possible to induce room-temperature ferromagnetic-like behavior in ZnO nanoparticles without doping with magnetic impurities but simply inducing an alteration of their electronic configuration. Capping ZnO nanoparticles ( approximately 10 nm size) with different organic molecules produces an alteration of their electronic configuration that depends on the particular molecule, as evidenced by photoluminescence and X-ray absorption spectroscopies and altering their magnetic properties that varies from diamagnetic to ferromagnetic-like behavior.

  4. Tuning the magnetism of ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Viñas, S. Liébana; Simeonidis, K.; Li, Z.-A.; Ma, Z.; Myrovali, E.; Makridis, A.; Sakellari, D.; Angelakeris, M.; Wiedwald, U.; Spasova, M.; Farle, M.

    2016-10-01

    The importance of magnetic interactions within an individual nanoparticle or between adjacent ones is crucial not only for the macroscopic collective magnetic behavior but for the AC magnetic heating efficiency as well. On this concept, single-(MFe2O4 where M=Fe, Co, Mn) and core-shell ferrite nanoparticles consisting of a magnetically softer (MnFe2O4) or magnetically harder (CoFe2O4) core and a magnetite (Fe3O4) shell with an overall size in the 10 nm range were synthesized and studied for their magnetic particle hyperthermia efficiency. Magnetic measurements indicate that the coating of the hard magnetic phase (CoFe2O4) by Fe3O4 provides a significant enhancement of hysteresis losses over the corresponding single-phase counterpart response, and thus results in a multiplication of the magnetic hyperthermia efficiency opening a novel pathway for high-performance, magnetic hyperthermia agents. At the same time, the existence of a biocompatible Fe3O4 outer shell, toxicologically renders these systems similar to iron-oxide ones with significantly milder side-effects.

  5. Triggered self-assembly of magnetic nanoparticles

    PubMed Central

    Ye, L.; Pearson, T.; Cordeau, Y.; Mefford, O. T.; Crawford, T. M.

    2016-01-01

    Colloidal magnetic nanoparticles are candidates for application in biology, medicine and nanomanufac-turing. Understanding how these particles interact collectively in fluids, especially how they assemble and aggregate under external magnetic fields, is critical for high quality, safe, and reliable deployment of these particles. Here, by applying magnetic forces that vary strongly over the same length scale as the colloidal stabilizing force and then varying this colloidal repulsion, we can trigger self-assembly of these nanoparticles into parallel line patterns on the surface of a disk drive medium. Localized within nanometers of the medium surface, this effect is strongly dependent on the ionic properties of the colloidal fluid but at a level too small to cause bulk colloidal aggregation. We use real-time optical diffraction to monitor the dynamics of self-assembly, detecting local colloidal changes with greatly enhanced sensitivity compared with conventional light scattering. Simulations predict the triggering but not the dynamics, especially at short measurement times. Beyond using spatially-varying magnetic forces to balance interactions and drive assembly in magnetic nanoparticles, future measurements leveraging the sensitivity of this approach could identify novel colloidal effects that impact real-world applications of these nanoparticles. PMID:26975332

  6. Triggered self-assembly of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Ye, L.; Pearson, T.; Cordeau, Y.; Mefford, O. T.; Crawford, T. M.

    2016-03-01

    Colloidal magnetic nanoparticles are candidates for application in biology, medicine and nanomanufac-turing. Understanding how these particles interact collectively in fluids, especially how they assemble and aggregate under external magnetic fields, is critical for high quality, safe, and reliable deployment of these particles. Here, by applying magnetic forces that vary strongly over the same length scale as the colloidal stabilizing force and then varying this colloidal repulsion, we can trigger self-assembly of these nanoparticles into parallel line patterns on the surface of a disk drive medium. Localized within nanometers of the medium surface, this effect is strongly dependent on the ionic properties of the colloidal fluid but at a level too small to cause bulk colloidal aggregation. We use real-time optical diffraction to monitor the dynamics of self-assembly, detecting local colloidal changes with greatly enhanced sensitivity compared with conventional light scattering. Simulations predict the triggering but not the dynamics, especially at short measurement times. Beyond using spatially-varying magnetic forces to balance interactions and drive assembly in magnetic nanoparticles, future measurements leveraging the sensitivity of this approach could identify novel colloidal effects that impact real-world applications of these nanoparticles.

  7. Functionalized magnetic nanoparticle analyte sensor

    DOEpatents

    Yantasee, Wassana; Warner, Maryin G; Warner, Cynthia L; Addleman, Raymond S; Fryxell, Glen E; Timchalk, Charles; Toloczko, Mychailo B

    2014-03-25

    A method and system for simply and efficiently determining quantities of a preselected material in a particular solution by the placement of at least one superparamagnetic nanoparticle having a specified functionalized organic material connected thereto into a particular sample solution, wherein preselected analytes attach to the functionalized organic groups, these superparamagnetic nanoparticles are then collected at a collection site and analyzed for the presence of a particular analyte.

  8. Preparation and optimization of N-trimethyl-O-carboxymethyl chitosan nanoparticles for delivery of low-molecular-weight heparin.

    PubMed

    Mahjub, Reza; Heidari Shayesteh, Tavakol; Radmehr, Moojan; Vafaei, Seyed Yaser; Amini, Mohsen; Dinarvand, Rasoul; Dorkoosh, Farid Abedin

    2016-01-01

    The aim of this study was preparation, optimization and in vitro characterization of nanoparticles composed of 6-[O-carboxymethyl]-[N,N,N-trimethyl] (TMCMC) for oral delivery of low-molecular-weight heparin. The chitosan derivative was synthesized. Nanoparticles were prepared using the polyelectrolyte complexation method. Box-Behnken response surface experimental design methodology was used for optimization of nanoparticles. The morphology of nanoparticles was studied using transmission electron microscopy. In vitro release of enoxaparin from nanoparticles was determined under simulated intestinal fluid. The cytotoxicity of nanoparticles on a Caco-2 cell line was determined, and finally the transport of prepared nanoparticles across Caco-2 cell monolayer was defined. Optimized nanoparticles with proper physico-chemical properties were obtained. The size, zeta potential, poly-dispersity index, entrapment efficiency and loading efficiency of nanoparticles were reported as 235 ± 24.3 nm, +18.6 ± 2.57 mV, 0.230 ± 0.03, 76.4 ± 5.43% and 12.6 ± 1.37%, respectively. Morphological studies revealed spherical nanoparticles with no sign of aggregation. In vitro release studies demonstrated that 93.6 ± 1.17% of enoxaparin released from nanoparticles after 600 min of incubation. MTT cell cytotoxicity studies showed no cytotoxicity at 3 h post-incubation, while the study demonstrated concentration-dependent cytotoxicity after 24 h of exposure. The obtained data had shown that the nanoparticles prepared from trimethylcarboxymethyl chitosan may be considered as a good candidate for oral delivery of enoxaparin.

  9. Design and evaluation of novel pH-sensitive ureido-conjugated chitosan/TPP nanoparticles targeted to Helicobacter pylori.

    PubMed

    Jing, Zi-Wei; Jia, Yi-Yang; Wan, Ning; Luo, Min; Huan, Meng-Lei; Kang, Tai-Bin; Zhou, Si-Yuan; Zhang, Bang-Le

    2016-04-01

    The covalently modified ureido-conjugated chitosan/TPP multifunctional nanoparticles have been developed as targeted nanomedicine delivery system for eradication of Helicobacter pylori. H. pylori can specifically express the urea transport protein on its membrane to transport urea into cytoplasm for urease to produce ammonia, which protects the bacterium in the acid milieu of stomach. The clinical applicability of topical antimicrobial agent is needed to eradicate H. pylori in the infected fundal area. In this study, we designed and synthesized two ureido-conjugated chitosan derivatives UCCs-1 and UCCs-2 for preparation of multifunctional nanoparticles. The process was optimized in order to prepare UCCs/TPP nanoparticles for encapsulation of amoxicillin. The results showed that the amoxicillin-UCCs/TPP nanoparticles exhibited favorable pH-sensitive characteristics, which could procrastinate the release of amoxicillin at gastric acids and enable the drug to deliver and target to H. pylori at its survival region effectively. Compared with unmodified amoxicillin-chitosan/TPP nanoparticles, a more specific and effective H. pylori growth inhibition was observed for amoxicillin-UCCs/TPP nanoparticles. Drug uptake analysis tested by flow cytometry and confocal laser scanning microscopy verified that the uptake of FITC-UCCs-2/TPP nanoparticles was associated with urea transport protein on the membrane of H. pylori and reduced with the addition of urea as competitive transport substrate. These findings suggest that the multifunctional amoxicillin-loaded nanoparticles have great potential for effective therapy of H. pylori infection. They may also serve as pharmacologically effective nanocarriers for oral targeted delivery of other therapeutic drugs to treat H. pylori.

  10. Preparation of polyelectrolyte complex nanoparticles of chitosan and poly(2-acry1amido-2-methylpropanesulfonic acid) for doxorubicin release.

    PubMed

    Zhang, Liping; Wang, Jie; Ni, Caihua; Zhang, Yanan; Shi, Gang

    2016-01-01

    A new kind of polyelectrolyte complex (PEC) based on cationic chitosan (CS) and anionic poly(2-acry1amido-2-methylpropanesulfonic acid) (PAMPS) was prepared using a polymer-monomer pair reaction system. Chitosan was mixed with 2-acry1amido-2-methylpropanesulfonic acid) (AMPS) in an aqueous solution, followed by polymerization of AMPS. The complex was formed by electrostatic interaction of NH3(+) groups of CS and SO3(-) groups of AMPS, leading to a formation of complex nanoparticles of CS-PAMPS. A series of nanoparticles were obtained by changing the weight ratio of CS to AMPS, the structure and properties of nanoparticles were investigated. It was observed that the nanoparticles possessed spherical morphologies with average diameters from 255 nm to 390 nm varied with compositions of the nanoparticles. The nanoparticles were used as drug vehicles for doxorubicin, displaying relative high drug loading rate and encapsulation rate. The vitro release profiles revealed that the drug release could be controlled by adjusting pH of the release media. The nanoparticles demonstrated apparent advantages such as simple preparation process, free of organic solvents, size controllable, good biodegradability and biocompatibility, and they could be potentially used in drug controlled release field.

  11. Preparation of polyelectrolyte complex nanoparticles of chitosan and poly(2-acry1amido-2-methylpropanesulfonic acid) for doxorubicin release.

    PubMed

    Zhang, Liping; Wang, Jie; Ni, Caihua; Zhang, Yanan; Shi, Gang

    2016-01-01

    A new kind of polyelectrolyte complex (PEC) based on cationic chitosan (CS) and anionic poly(2-acry1amido-2-methylpropanesulfonic acid) (PAMPS) was prepared using a polymer-monomer pair reaction system. Chitosan was mixed with 2-acry1amido-2-methylpropanesulfonic acid) (AMPS) in an aqueous solution, followed by polymerization of AMPS. The complex was formed by electrostatic interaction of NH3(+) groups of CS and SO3(-) groups of AMPS, leading to a formation of complex nanoparticles of CS-PAMPS. A series of nanoparticles were obtained by changing the weight ratio of CS to AMPS, the structure and properties of nanoparticles were investigated. It was observed that the nanoparticles possessed spherical morphologies with average diameters from 255 nm to 390 nm varied with compositions of the nanoparticles. The nanoparticles were used as drug vehicles for doxorubicin, displaying relative high drug loading rate and encapsulation rate. The vitro release profiles revealed that the drug release could be controlled by adjusting pH of the release media. The nanoparticles demonstrated apparent advantages such as simple preparation process, free of organic solvents, size controllable, good biodegradability and biocompatibility, and they could be potentially used in drug controlled release field. PMID:26478364

  12. Development of bioactive fish gelatin/chitosan nanoparticles composite films with antimicrobial properties.

    PubMed

    Hosseini, Seyed Fakhreddin; Rezaei, Masoud; Zandi, Mojgan; Farahmandghavi, Farhid

    2016-03-01

    The objective of this work was to develop active bio-based nanocomposite films from fish gelatin (FG) and chitosan nanoparticles (CSNPs) incorporated with Origanum vulgare L. essential oil (OEO). CSNPs were obtained by ionic gelation of chitosan with sodium tripolyphosphate, which presented a spherical morphology with size range of 40-80nm. Remarkable differences in the surface morphology were observed between the control and bioactive nanocomposite films as revealed by SEM and AFM images. FTIR results confirmed that an interaction between polymer matrix and essential oil had occurred, as shown by an increase in the amplitude of peaks at wavenumbers 1242cm(-1) and 1451cm(-1). Meanwhile, XRD peaks of OEO-containing films were more intense, indicating that the introduction of essential oil into the film matrix induces an increase in crystallinity. TGA analysis demonstrated that the addition of OEO had no impact on thermal stability of the films. Inclusion of OEO in the film matrix resulted in less resistant and more flexible films, with a decrease in water vapor permeability (WVP). The FG/CSNPs bioactive films exhibited distinctive antimicrobial activity against four test food pathogens, namely Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritidis and Escherichia coli.

  13. Effect of silver nanoparticles on the DC conductivity in chitosan-silver triflate polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Aziz, Shujahadeen B.; Abidin, Z. H. Z.; Arof, A. K.

    2010-11-01

    A solid polymer electrolyte composed of chitosan and silver triflate (AgCF 3SO 3) has been prepared by the solution cast technique. The formation of polymer-salt complex has been confirmed by X-ray diffraction. The DC electrical conductivity of chitosan-silver triflate electrolyte has been investigated between 303 and 423 K, using electrochemical impedance spectroscopy over the frequency range from 50 Hz to 1000 kHz. The conductivity was found to increase with increase in AgCF 3SO 3 concentration at room temperature. The DC conductivity obeys Arrhenius relationship up to a particular temperature and decreases at higher temperatures due to decrease in silver ions as a result of the formation of silver nanoparticles. The presence of an additional semicircular arc in the Cole-Cole plot obtained above 328 K indicates the existence of grain boundaries, which can be attributed to the silver particles. The presence of silver particles also have been proven by XRD after heating at 333, 363, and 393 K where the (1 1 1) peak of Ag is observed to increase with temperature. The silver particles were shown to be of nanosize using transmission electron microscopy (TEM).

  14. Chitosan based nanoparticles functionalized with peptidomimetic derivatives for oral drug delivery.

    PubMed

    Chronopoulou, Laura; Nocca, Giuseppina; Castagnola, Massimo; Paludetti, Gaetano; Ortaggi, Giancarlo; Sciubba, Fabio; Bevilacqua, Melania; Lupi, Alessandro; Gambarini, Gianluca; Palocci, Cleofe

    2016-01-25

    The goal of this study was to develop an optimized drug delivery carrier for oral mucosa applications able to release in situ bioactive molecules by using biopolymeric materials. Among them chitosan and poly(lactic-co-glycolic acid) (PLGA) have gained considerable attention as biocompatible carriers able to improve the delivery of active agents. The formulation of such vehicles in the form of nanoparticles (NPs) could permit to exploit the peculiar properties of nanomaterials in order to enhance the efficacy of active agents. Chitosan (CS) and PLGA chlorexidine dihydrochloride (CHX)-loaded NPs were synthesized by ionotropic gelation and osmosis based methodology respectively. In order to facilitate NPs adhesion on human dental surfaces, two different strategies were employed: PLGA particles with an external shell of CS to produce a positive surface charge allowing CHX loaded PLGA NPs to interact with the negative charged dental surfaces, while CS particles were functionalized with peptidomimetic derivative glutathione (GSH). The morphology was investigated by scanning electron microscopy. A sustained release profile of CHX from CS NPs was achieved. CS-based NPs adhered on human tooth surfaces in a simulated brushing and rinsing process and their in vitro toxicity evaluation on Human Gingival Fibroblasts (HGFs) was between 20 and 60% in all experimental conditions. Thanks to their adhesion properties and low cytotoxicity, the synthesized CS-based formulations may be efficiently exploited for therapy purposes or to enhance in vivo dental care (i.e. preparation of toothpastes or other cosmetics for daily oral care). PMID:26257139

  15. Development of bioactive fish gelatin/chitosan nanoparticles composite films with antimicrobial properties.

    PubMed

    Hosseini, Seyed Fakhreddin; Rezaei, Masoud; Zandi, Mojgan; Farahmandghavi, Farhid

    2016-03-01

    The objective of this work was to develop active bio-based nanocomposite films from fish gelatin (FG) and chitosan nanoparticles (CSNPs) incorporated with Origanum vulgare L. essential oil (OEO). CSNPs were obtained by ionic gelation of chitosan with sodium tripolyphosphate, which presented a spherical morphology with size range of 40-80nm. Remarkable differences in the surface morphology were observed between the control and bioactive nanocomposite films as revealed by SEM and AFM images. FTIR results confirmed that an interaction between polymer matrix and essential oil had occurred, as shown by an increase in the amplitude of peaks at wavenumbers 1242cm(-1) and 1451cm(-1). Meanwhile, XRD peaks of OEO-containing films were more intense, indicating that the introduction of essential oil into the film matrix induces an increase in crystallinity. TGA analysis demonstrated that the addition of OEO had no impact on thermal stability of the films. Inclusion of OEO in the film matrix resulted in less resistant and more flexible films, with a decrease in water vapor permeability (WVP). The FG/CSNPs bioactive films exhibited distinctive antimicrobial activity against four test food pathogens, namely Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritidis and Escherichia coli. PMID:26471681

  16. Corrosion resistance of Ti modified by chitosan-gold nanoparticles for orthopedic implantation.

    PubMed

    Farghali, R A; Fekry, A M; Ahmed, Rasha A; Elhakim, H K A

    2015-08-01

    Highly uniform bionanocomposite film composed of chitosan (CS) and gold nanoparticles (AuNPs) was synthesized successfully by electrodeposition method. The influence of AuNPs/CS bionanocomposite film on corrosion resistance of Ti was investigated. Surface morphology and compositional properties of the bionanocomposite were analyzed by scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Moreover, cyclic voltammetry (CV), open-circuit potential measurements (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (Rp) were used to examine the corrosion behavior in Hanks' solution. In comparison with Ti, Nyquist and Bode plots displayed higher impedance values and phase angles for AuNPs/CS biocomposite denoting a more protective passive film on Ti with inhibition efficiency (IE%) of 98%. An electric equivalent circuit with three time constants was modeled for the bionanocomposite. In addition, the antibacterial effect revealed the high efficiencies of the bionanocomposite film for inhibiting bacterial growth. The combination of the high biocompatibility of chitosan and strong adsorption ability of AuNPs make AuNPs/CS bionanocomposite promising candidate for modifying biomaterial surfaces for medical implantation applications.

  17. Silver nanoparticles impregnated alginate-chitosan-blended nanocarrier induces apoptosis in human glioblastoma cells.

    PubMed

    Sharma, Shilpa; Chockalingam, S; Sanpui, Pallab; Chattopadhyay, Arun; Ghosh, Siddhartha Sankar

    2014-01-01

    Herein, a green method for the development of a novel biodegradable silver nanoparticles (NPs) impregnated alginate-chitosan-blended nanocarrier (Ag NPs-Alg-Chi NC) is reported. The synthesis of Ag NPs-Alg-Chi NC is based on the polyelectrolyte complex formation between alginate and chitosan. The composite NC is characterized by ultraviolet-visible spectroscopy, transmission electron microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X-ray diffraction. The Ag NPs in the NC are found to elicit anticell proliferative effect on refractory U87MG (human glioblastoma) cells at IC50 of 2.4 μg mL(-1) for Ag NPs. The cell cycle analysis shows extensive DNA damage. Elevation in reactive oxygen species level indicates induction of oxidative stress in treated cells. Mitochondrial dysfunction in cell death is evident from the depolarization of mitochondrial membrane potential (ΔΨm ). Fluorescence and SEM images of the treated cells reveal nuclear and morphological changes characteristic of apoptosis, which is further confirmed by TUNEL assay. The induction of apoptosis at low concentration of Ag NPs present in Ag NPs-Alg-Chi NC in comparison with free Ag NPs makes it a promising tool for cancer therapy.

  18. Crosslinked chitosan-dextran sulfate nanoparticle for improved topical ocular drug delivery

    PubMed Central

    Chaiyasan, Wanachat; Srinivas, Sangly P.

    2015-01-01

    Purpose To examine the benefits of chitosan-dextran sulfate nanoparticles (CDNs) as a topical ocular delivery system with lutein as a model drug. Methods CDNs were developed by polyelectrolyte complexation of positively charged chitosan (CS) and negatively charged dextran sulfate (DS). 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and polyethylene glycol 400 (PEG400) were used as co-crosslinking and stabilizing agents, respectively. The influence of these on the properties of CDNs, including drug release and mucoadhesiveness, was examined. The chemical stability of lutein in CDNs (LCDNs) was also examined. Results Typically, LCDNs showed a spherical shape, possessing a mean size of ~400 nm with a narrow size distribution. The entrapment efficiency of lutein was in the range of 60%–76%. LCDNs possessing a positive surface charge (+46 mV) were found to be mucoadhesive. The release profile of LCDNs followed Higuchi’s square root model, suggesting drug release by diffusion from the polymer matrix. Lutein in LCDNs showed increased chemical stability during storage compared to its solution form. Conclusions These characteristics of CDNs make them suitable for drug delivery to the ocular surface. PMID:26604662

  19. Development of oral sustained release rifampicin loaded chitosan nanoparticles by design of experiment.

    PubMed

    Patel, Bhavin K; Parikh, Rajesh H; Aboti, Pooja S

    2013-01-01

    Objective. The main objective of the present investigation was to develop and optimize oral sustained release Chitosan nanoparticles (CNs) of rifampicin by design of experiment (DOE). Methodology. CNs were prepared by modified emulsion ionic gelation technique. Here, inclusion of hydrophobic drug moiety in the hydrophilic matrix of polymer is applied for rifampicin delivery using CN. The 2(3) full-factorial design was employed by selecting the independent variables such as Chitosan concentration (X 1), concentration of tripolyphosphate (X 2), and homogenization speed (X 3) in order to achieve desired particle size with maximum percent entrapment efficiency and drug loading. The design was validated by checkpoint analysis, and formulation was optimized using the desirability function. Results. Particle size, drug entrapment efficiency, and drug loading for the optimized batch were found to be 221.9 nm, 44.17 ± 1.98% W/W, and 42.96 ± 2.91% W/W, respectively. In vitro release data of optimized formulation showed an initial burst followed by slow sustained drug release. Kinetic drug release from CNs was best fitted to Higuchi model. Conclusion. Design of Experiment is an important tool for obtaining desired characteristics of rifampicin loaded CNs. In vitro study suggests that oral sustained release CNs might be an effective drug delivery system for tuberculosis.

  20. Chitosan/interfering RNA nanoparticle mediated gene silencing in disease vector mosquito larvae.

    PubMed

    Zhang, Xin; Mysore, Keshava; Flannery, Ellen; Michel, Kristin; Severson, David W; Zhu, Kun Yan; Duman-Scheel, Molly

    2015-03-25

    Vector mosquitoes inflict more human suffering than any other organism-and kill more than one million people each year. The mosquito genome projects facilitated research in new facets of mosquito biology, including functional genetic studies in the primary African malaria vector Anopheles gambiae and the dengue and yellow fever vector Aedes aegypti. RNA interference- (RNAi-) mediated gene silencing has been used to target genes of interest in both of these disease vector mosquito species. Here, we describe a procedure for preparation of chitosan/interfering RNA nanoparticles that are combined with food and ingested by larvae. This technically straightforward, high-throughput, and relatively inexpensive methodology, which is compatible with long double stranded RNA (dsRNA) or small interfering RNA (siRNA) molecules, has been used for the successful knockdown of a number of different genes in A. gambiae and A. aegypti larvae. Following larval feedings, knockdown, which is verified through qRT-PCR or in situ hybridization, can persist at least through the late pupal stage. This methodology may be applicable to a wide variety of mosquito and other insect species, including agricultural pests, as well as other non-model organisms. In addition to its utility in the research laboratory, in the future, chitosan, an inexpensive, non-toxic and biodegradable polymer, could potentially be utilized in the field.

  1. EDITORIAL: Biomedical applications of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    O'Grady, K.

    2002-07-01

    Magnetic materials have been used with grain sizes down to the nanoscale for longer than any other type of material. This is because of a fundamental change in the magnetic structure of ferro- and ferrimagnetic materials when grain sizes are reduced. In these circumstances, the normal macroscopic domain structure transforms into a single domain state at a critical size which typically lies below 100 nm. Once this transformation occurs the mechanism of magnetisation reversal can only be via the rotation of the magnetisation vector from one magnetic easy axis to another via a magnetically hard direction. This change of reversal mechanism has led to a new class of magnetic materials whose properties and the basic underlying physical mechanism governing them were defined in a seminal work first published by E C Stoner and E P Wolhfarth in 1949. As a consequence of this rotation mechanism, magnetic nanoparticles exist having coercivities which are highly controllable and lie between soft materials and normal permanent magnet materials. This ability to control coercivity in such particles has led to a number of significant technological advances, particularly in the field of information storage. The high value of information storage technology has meant that since the 1950s an enormous research and development effort has gone into techniques for the preparation of magnetic particles and thin films having well defined properties. Hence, certainly since the 1960s, a wide range of techniques to produce both metallic and oxide magnetic nanoparticles with sizes ranging from 4-100 nm has been developed. The availability of this wide range of materials led to speculation from the 1960s onwards that they may have applications in biology and medicine. The fact that a magnetic field gradient can be used to either remotely position or selectively filter biological materials leads to a number of obvious applications. These applications fall broadly into two categories: those

  2. Nonlinear energy dissipation of magnetic nanoparticles in oscillating magnetic fields

    NASA Astrophysics Data System (ADS)

    Soto-Aquino, D.; Rinaldi, C.

    2015-11-01

    The heating of magnetic nanoparticle suspensions subjected to alternating magnetic fields enables a variety of emerging applications such as magnetic fluid hyperthermia and triggered drug release. Rosensweig (2002) [25] obtained a model for the heat dissipation rate of a collection of non-interacting particles. However, the assumptions made in this analysis make it rigorously valid only in the limit of small applied magnetic field amplitude and frequency (i.e., values of the Langevin parameter that are much less than unity and frequencies below the inverse relaxation time). In this contribution we approach the problem from an alternative point of view by solving the phenomenological magnetization relaxation equation exactly for the case of arbitrary magnetic field amplitude and frequency and by solving a more accurate magnetization relaxation equation numerically. We also use rotational Brownian dynamics simulations of non-interacting magnetic nanoparticles subjected to an alternating magnetic field to estimate the rate of energy dissipation and compare the results of the phenomenological theories to the particle-scale simulations. The results are summarized in terms of a normalized energy dissipation rate and show that Rosensweig's expression provides an upper bound on the energy dissipation rate achieved at high field frequency and amplitude. Estimates of the predicted dependence of energy dissipation rate, quantified as specific absorption rate (SAR), on magnetic field amplitude and frequency, and particle core and hydrodynamic diameter, are also given.

  3. Improvements of physical, mechanical and biodegradation properties of polybutadiene rubber insulators by chitosan and silica nanoparticles.

    PubMed

    Saboktakin, Amin; Saboktakin, Mohammadreza

    2016-10-01

    1,4-cis-Polybutadiene rubber(1,4-cis pBR) as an insulation material is developing that will provide superior thermal insulation properties, flexibility, toughness by natural polymers such as chitosan(CS) and silica nanoparticles. This material is widely used in the insulation industries specially architecture. This research concerns physical, mechanical properties and also biodegradation of 1,4-cis pBR, which to be composed with the natural polymers such as CS. Silica nanoparticles were used as filler to improve the physical and mechanical properties of 1,4-cis pBR. To evaluating its physical and mechanical properties, stretching and bending and impact tests were used and the results show some improvement in these properties. Our observations show that temperature plays an important role as main factor in order to improve the mechanical properties of nanocomposites. Similar improvements in tensile modulus and strength have been observed for 1,4-cis pBR/CS-silica nanoparticles.

  4. Chitosan/tripolyphosphate nanoparticles loaded with paraquat herbicide: an environmentally safer alternative for weed control.

    PubMed

    Grillo, Renato; Pereira, Anderson E S; Nishisaka, Caroline S; de Lima, Renata; Oehlke, Kathleen; Greiner, Ralf; Fraceto, Leonardo F

    2014-08-15

    Paraquat is a fast acting nonselective contact herbicide that is extensively used worldwide. However, the aqueous solubility and soil sorption of this compound can cause problems of toxicity in nontarget organisms. This work investigates the preparation and characterization of nanoparticles composed of chitosan and sodium tripolyphosphate (TPP) to produce an efficient herbicidal formulation that was less toxic and could be used for safer control of weeds in agriculture. The toxicities of the formulations were evaluated using cell culture viability assays and the Allium cepa chromosome aberration test. The herbicidal activity was investigated in cultivations of maize (Zea mays) and mustard (Brassica sp.), and soil sorption of the nanoencapsulated herbicide was measured. The efficiency association of paraquat with the nanoparticles was 62.6 ± 0.7%. Encapsulation of the herbicide resulted in changes in its diffusion and release as well as its sorption by soil. Cytotoxicity and genotoxicity assays showed that the nanoencapsulated herbicide was less toxic than the pure compound, indicating its potential to control weeds while at the same time reducing environmental impacts. Measurements of herbicidal activity showed that the effectiveness of paraquat was preserved after encapsulation. It was concluded that the encapsulation of paraquat in nanoparticles can provide a useful means of reducing adverse impacts on human health and the environment, and that the formulation therefore has potential for use in agriculture. PMID:24968252

  5. Curcumin encapsulated in chitosan nanoparticles: a novel strategy for the treatment of arsenic toxicity.

    PubMed

    Yadav, Abhishek; Lomash, Vinay; Samim, M; Flora, Swaran J S

    2012-07-30

    Water-soluble nanoparticles of curcumin were synthesized, characterized and applied as a stable detoxifying agent for arsenic poisoning. Chitosan nanoparticles of less than 50 nm in diameter containing curcumin were prepared. The particles were characterized by TEM, DLS and FT-IR. The therapeutic efficacy of the encapsulated curcumin nanoparticles (ECNPs) against arsenic-induced toxicity in rats was investigated. Sodium arsenite (2mg/kg) and ECNPs (1.5 or 15 mg/kg) were orally administered to male Wistar rats for 4 weeks to evaluate the therapeutic potential of ECNPs in blood and soft tissues. Arsenic significantly decreased blood δ-aminolevulinic acid dehydratase (δ-ALAD) activity, reduced glutathione (GSH) and increased blood reactive oxygen species (ROS). These changes were accompanied by increases in hepatic total ROS, oxidized glutathione, and thiobarbituric acid-reactive substance levels. By contrast, hepatic GSH, superoxide dismutase and catalase activities significantly decreased on arsenic exposure, indicative of oxidative stress. Brain biogenic amines (dopamine, norepinephrine and 5-hydroxytryptamine) levels also showed significant changes on arsenic exposure. Co-administration of ECNPs provided pronounced beneficial effects on the adverse changes in oxidative stress parameters induced by arsenic. The results indicate that ECNPs have better antioxidant and chelating potential (even at the lower dose of 1.5 mg/kg) compared to free curcumin at 15 mg/kg. The significant neurochemical and immunohistochemical protection afforded by ECNPs indicates their neuroprotective efficacy. The formulation provides a novel therapeutic regime for preventing arsenic toxicity.

  6. Mono-lithocholated exendin-4-loaded glycol chitosan nanoparticles with prolonged antidiabetic effects.

    PubMed

    Son, Sohee; Lim, Sung Mook; Chae, Su Young; Kim, Kwangmeyung; Park, Eun Ji; Lee, Kang Choon; Na, Dong Hee

    2015-11-10

    Hydrophobically modified glycol chitosan (HGC) nanoparticles loaded with mono-lithocholic acid-conjugated exendin-4 at the Lys(27) residue (LAM1-Ex4) were prepared and characterized by particle size measurement, proteolytic stability, in vitro drug-release profile, and in vivo antidiabetic effects in a db/db diabetic mouse model. Compared with Ex-4-loaded HGC nanoparticles (Ex4/HGC NPs) prepared as a control, LAM1-Ex4-loaded HGC nanoparticles (LAM1-Ex4/HGC NPs) showed improved drug-loading efficiency, small particle size, enhanced resistance against proteolytic digestion, and an extended in vitro drug release profile. These findings may be attributable to the strong hydrophobic interaction between LAM1-Ex4 and the inner core of HGC. Furthermore, LAM1-Ex4/HGC NPs showed prolonged hypoglycemic efficacy in db/db mice, lasting 1 week after a single subcutaneous administration. The present study demonstrated that LAM1-Ex4/HGC NPs have considerable potential as a long-acting sustained-release antidiabetic system for type 2 diabetes.

  7. Improvements of physical, mechanical and biodegradation properties of polybutadiene rubber insulators by chitosan and silica nanoparticles.

    PubMed

    Saboktakin, Amin; Saboktakin, Mohammadreza

    2016-10-01

    1,4-cis-Polybutadiene rubber(1,4-cis pBR) as an insulation material is developing that will provide superior thermal insulation properties, flexibility, toughness by natural polymers such as chitosan(CS) and silica nanoparticles. This material is widely used in the insulation industries specially architecture. This research concerns physical, mechanical properties and also biodegradation of 1,4-cis pBR, which to be composed with the natural polymers such as CS. Silica nanoparticles were used as filler to improve the physical and mechanical properties of 1,4-cis pBR. To evaluating its physical and mechanical properties, stretching and bending and impact tests were used and the results show some improvement in these properties. Our observations show that temperature plays an important role as main factor in order to improve the mechanical properties of nanocomposites. Similar improvements in tensile modulus and strength have been observed for 1,4-cis pBR/CS-silica nanoparticles. PMID:27353394

  8. New core-shell hyperbranched chitosan-based nanoparticles as optical sensor for ammonia detection.

    PubMed

    El-Sherbiny, Ibrahim M; Hefnawy, Amr; Salih, Ehab

    2016-05-01

    In this paper, preparation of new core-shell amino-terminated hyperbranched chitosan nanoparticles (HBCs-NH2) NPs is described. The synthesized nanoparticles were characterized using ninhydrin assay, FTIR, TGA, and FESEM. The newly prepared (HBCs-NH2) NPs were then used as a platform for facile and controlled synthesis of silver nanoparticles (AgNPs) which was confirmed using FTIR, UV-vis spectrometry, X-ray diffraction, SEM and HRTEM. Formation of the AgNPs was also noted upon changing the color of (HBCs-NH2) NPs suspension from colorless into yellow as well as through the appearance of surface plasmon resonance (SPR) peak at 400 nm. HRTEM showed a uniform and spherical morphology of the resulting HBCs-NH2 NPs with average size 400 nm, and the AgNPs were formed mainly on their surface with average size of 20-50 nm. The newly developed (HBCs-NH2) NPs-AgNPs showed a great potential as optical sensor for efficient detection of the ammonia concentration in solutions based on the change in the SPR. PMID:26851206

  9. Chitosan-based nanoparticles as a sustained protein release carrier for tissue engineering applications.

    PubMed

    Hou, Yaping; Hu, Junli; Park, Hyejin; Lee, Min

    2012-04-01

    Chitosan/tripolyphosphate/chondroitin sulfate (Chi/TPP/CS) nanoparticles were prepared by an ionic gelation method to obtain a controlled release of proteins. Using Nel-like molecule-1 (Nell-1), a novel osteogenic protein, as a model protein, it was demonstrated that adjusting the composition of the particles modulated the protein association and release kinetics of incorporated proteins. Increasing the amounts of Chi crosslinking agents, TPP and CS, in the particles achieved sustained protein release. An increase in crosslinking density decreased degradation rates of the particles. Furthermore, the bioactivity of the protein was preserved during the encapsulating procedure into the particles. To demonstrate the feasibility of Chi/TPP/CS nanoparticles as sustained release carriers for tissue engineering scaffold applications, protein-loaded nanoparticles were successfully incorporated into collagen hydrogels or prefabricated porous poly(lactide-co-glycolide) (PLGA) scaffolds without obstructing the integrity of the hydrogels or porous structure of the scaffolds. Thus, we expect that these particles have a potential for efficient protein carriers in tissue engineering applications, and will be further evaluated in vivo. PMID:22275184

  10. Effect of preparation parameters on ultra low molecular weight chitosan/hyaluronic acid nanoparticles.

    PubMed

    Nazeri, Niloofar; Avadi, Mohammad Reza; Faramarzi, Mohammad Ali; Safarian, Shahrokh; Tavoosidana, Gholamreza; Khoshayand, Mohammad Reza; Amani, Amir

    2013-11-01

    Nanoparticles of ultra low molecular weight chitosan (ULMWCS)/hyaluronic acid (HA) were prepared by ion gelation. Three independent variables, namely, ratio of concentration of ULMWCS to HA (CS/HA), pH of solution and stirring time were studied to identify their effects on size, polydispersity and zeta potential of prepared nanoparticles using a Box-Behnken design. Results showed that pH and CS/HA have a direct effect on size, while increase of stirring time decreases the size of nanoparticles. Additionally, it was shown that all the independent parameters have direct effects on zeta potential. Also, the minimum polydispersity index was observed at lowest values of CS/HA. The model also predicted that the optimum values are 4.15, 4.14 and 180 (min) for the CS/HA, solution pH and stirring time, respectively. The obtained preparation had a size of 200 nm, polydispersity index of 0.37, and zeta potential of 13.0 mV.

  11. Preparation of self-assembled nanoparticles of chitosan oligosaccharide-graft-polycaprolactone as a carrier of bovine serum albumin drug.

    PubMed

    Li, Fenghong; Zhang, Xinrui; Li, Hongyi; Xiang, Liying; Chen, Yanming

    2014-01-01

    Chitosan oligosaccharides graft polycaprolactone copolymer (PHCSO-g-PCL) has been synthesized via initiating the polymerization of e-caprolactone (CL) monomer through an amino group protection route using phthaloyl chitosan oligosaccharide (PHCSO) as intermediate. The grafting reaction was carried out in Pyridine at 120 °C with the hydroxyl group of the chitosan oligosaccharide (CSO) as initiator and the tin 2-ethylhexanoate (Sn (Oct)2) as catalyst. The PHCSO-g-PCL nanoparticles with and without bovine serum albumin (BSA) drug were prepared through the self-assembled approach in Dimethylformamide (DMF) organic solvents. PHCSO-PCL copolymer was investigated by Fourier transform infrared spectroscopy (FTIR), 1H NMR spectrum and scanning electron microscopy (SEM). The physicochemical properties of the hydrophobized PHCSO-g-PCL nanoparticles were characterized by fluorescence spectroscopy and dynamic light scattering (DLS). The results of DLS showed that the hydrodynamic diameters and particle size distribution with various concentrations of PHCSO-g-PCL nanoparticles were from 69.82 nm to 195.9 nm with a narrow polydispersity factor of 0.212 to 0.172. The results of DLS also showed that the hydrodynamic diameters and particle size distribution of PHCSO-g-PCL (5 mg/ml) nanoparticles without and with BSA drug (0.4 mg/ml) were from 168.44 nm to 200.7 nm. The polydispersity factor was from 0.119 to 0.159. PMID:25226900

  12. Development and evaluation of porous chitosan nanoparticles for treatment of enterotoxigenic Escherichia coil infection.

    PubMed

    Khan, Mohammed S; Vishakante, Gowda D

    2013-01-01

    Enterotoxigenic Escherichia coil (ETEC) infections result in large mortality rate and usually a frequent cause of diarrhea in infants and a major cause of economic losses in the swine industry. To prevent enterotoxigenic Escherichia coli infections animal needs an active mucosal immunity at the moment of weaning. In the present study, F4 loaded porous chitosan nanoparticles were prepared by spray drying method for oral vaccination. In order to prevent the release the antigen in upper GI tract and to release it at target site nanoparticles were coated with Eudragit L100 which protect the antigen against the detrimental effects in the gastro-intestinal tract. Average size of prepared nanoparticles varied between 548 +/- 2.3 to 98 +/- 1.1 nm with a polydispersity index ranging from 0.767 +/- 0.023 to 0.209 +/- 0.021. Zeta potential for prepared nanoparticles was found to be in range from +18.3 +/- 2.5 to +29.5 +/- 2.8 mV. SEM studies completely revealed that the drug loaded nanoparticles were found to be distinct, spherical in shape with pores formed. Practicability of NPs was compared to vaccination with F4 fimbriae in solution. Mucosal immune response study revealed that, immune response were elicited in solution was well as in NPs group but colonization of the small intestine by F4+ ETEC upon oral solution challenge could not be prevented. However animals vaccinated with porous NPs group reveal a significant reduction in excretion of F4+ E. coli. Studies indicate that a solid vaccine formulation will be more efficient as compared to oral solutions. These systems can contribute to the development of oral vaccines in veterinary as well as in human medicines. PMID:23627073

  13. Development and evaluation of porous chitosan nanoparticles for treatment of enterotoxigenic Escherichia coil infection.

    PubMed

    Khan, Mohammed S; Vishakante, Gowda D

    2013-01-01

    Enterotoxigenic Escherichia coil (ETEC) infections result in large mortality rate and usually a frequent cause of diarrhea in infants and a major cause of economic losses in the swine industry. To prevent enterotoxigenic Escherichia coli infections animal needs an active mucosal immunity at the moment of weaning. In the present study, F4 loaded porous chitosan nanoparticles were prepared by spray drying method for oral vaccination. In order to prevent the release the antigen in upper GI tract and to release it at target site nanoparticles were coated with Eudragit L100 which protect the antigen against the detrimental effects in the gastro-intestinal tract. Average size of prepared nanoparticles varied between 548 +/- 2.3 to 98 +/- 1.1 nm with a polydispersity index ranging from 0.767 +/- 0.023 to 0.209 +/- 0.021. Zeta potential for prepared nanoparticles was found to be in range from +18.3 +/- 2.5 to +29.5 +/- 2.8 mV. SEM studies completely revealed that the drug loaded nanoparticles were found to be distinct, spherical in shape with pores formed. Practicability of NPs was compared to vaccination with F4 fimbriae in solution. Mucosal immune response study revealed that, immune response were elicited in solution was well as in NPs group but colonization of the small intestine by F4+ ETEC upon oral solution challenge could not be prevented. However animals vaccinated with porous NPs group reveal a significant reduction in excretion of F4+ E. coli. Studies indicate that a solid vaccine formulation will be more efficient as compared to oral solutions. These systems can contribute to the development of oral vaccines in veterinary as well as in human medicines.

  14. Barium Titanate Nanoparticles: Highly Cytocompatible Dispersions in Glycol-chitosan and Doxorubicin Complexes for Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Ciofani, Gianni; Danti, Serena; D'Alessandro, Delfo; Moscato, Stefania; Petrini, Mario; Menciassi, Arianna

    2010-07-01

    In the latest years, innovative nanomaterials have attracted a dramatic and exponentially increasing interest, in particular for their potential applications in the biomedical field. In this paper, we reported our findings on the cytocompatibility of barium titanate nanoparticles (BTNPs), an extremely interesting ceramic material. A rational and systematic study of BTNP cytocompatibility was performed, using a dispersion method based on a non-covalent binding to glycol-chitosan, which demonstrated the optimal cytocompatibility of this nanomaterial even at high concentration (100 μg/ml). Moreover, we showed that the efficiency of doxorubicin, a widely used chemotherapy drug, is highly enhanced following the complexation with BTNPs. Our results suggest that innovative ceramic nanomaterials such as BTNPs can be realistically exploited as alternative cellular nanovectors.

  15. Chitosan as a potential stabilizing agent for titania nanoparticle dispersions for preparation of multifunctional cotton fabric.

    PubMed

    Goyal, Nidhi; Rastogi, Deepali; Jassal, Manjeet; Agrawal, Ashwini K

    2016-12-10

    Titania (TiO2) nanoparticle dispersions in water were prepared using chitosan (CS) as the stabilizing agent. The dispersion stability was evaluated with respect to storage time, hydrodynamic particle size, and zeta potential. The effect of the molecular weight of CS and presence of non-ionic polymers (poly(vinyl alcohol) and poly(ethylene glycol)) as co-dispersants was investigated. Despite the increase in size of dispersed particles, the long-term storage stability of the dispersions improved with increasing concentration and molecular weight of CS. The TiO2/CS dispersions were applied on cotton fabric and characterized. The presence of CS did not seriously affect the photocatalytic self-cleaning activity (SCA) of TiO2; with CS, a SCA of 89% was achieved compared with a value of 96% without CS. In addition, the TiO2/CS-treated cotton fabrics provided UV protection and significant antimicrobial activity. PMID:27577907

  16. Preparation of curcumin-loaded pluronic F127/chitosan nanoparticles for cancer therapy

    NASA Astrophysics Data System (ADS)

    Phuc Le, Thi Minh; Phuc Pham, Van; Lua Dang, Thi Minh; Huyen La, Thi; Hanh Le, Thi; Huan Le, Quang

    2013-06-01

    Nanoparticles (NPs) have been proven to be an effective delivery system with few side effects for anticancer drugs. In this study, curcumin-loaded NPs have been prepared by an ionic gelation method using chitosan (Chi) and pluronic®F-127 (PF) as carriers to deliver curcumin to the target cancer cells. Prepared NPs were characterized using Zetasizer, fluorescence microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Our results showed that the encapsulation efficiency of curcumin was approximately 50%. The average size of curcumin-loaded PF/Chi NPs was 150.9 nm, while the zeta potential was 5.09 mV. Cellular uptake of curcumin-loaded NPs into HEK293 cells was confirmed by fluorescence microscopy.

  17. Alginate coated chitosan core shell nanoparticles for oral delivery of enoxaparin: in vitro and in vivo assessment.

    PubMed

    Bagre, Archana Pataskar; Jain, Keerti; Jain, Narendra K

    2013-11-01

    The objective of present research work was to develop alginate coated chitosan core shell nanoparticles (Alg-CS-NPs) for oral delivery of low molecular weight heparin, enoxaparin. Chitosan nanoparticles (CS-NPs) were synthesized by ionic gelation of chitosan using sodium tripolyphosphate. Core shell nanoparticles were prepared by coating CS-NPs with alginate solution under mild agitation. The Alg-CS-NPs were characterized for surface morphology, surface coating, particle size, polydispersity index, zeta potential, drug loading and entrapment efficiency using SEM, Zeta-sizer, FTIR and DSC techniques. Alginate coating increased the size of optimized chitosan nanoparticles from around 213 nm to about 335 nm as measured by dynamic light scattering in zeta sizer and further confirmed by SEM analysis. The performance of optimized enoxaparin loaded Alg-CS-NPs was evaluated by in vitro drug release studies, in vitro permeation study across intestinal epithelium, in vivo venous thrombosis model, particulate uptake by intestinal epithelium using fluorescence microscopy and pharmacokinetic studies in rats. Coating of alginate over the CS-NPs improved the release profile of enoxaparin from the nanoparticles for successful oral delivery. In vitro permeation studies elucidated that more than 75% enoxaparin permeated across the intestinal epithelium with Alg-CS-NPs. The Alg-CS-NPs significantly increased (p<0.05) the oral bioavailability of enoxaparin in comparison to plain enoxaparin solution as revealed by threefold increase in AUC of plasma drug concentration time curve and around 60% reduction in thrombus formation in rat venous thrombosis model. The core shell Alg-CS-NPs showed promising potential for oral delivery and significantly enhanced the in vivo oral absorption of enoxaparin. PMID:23994363

  18. Alginate coated chitosan core shell nanoparticles for oral delivery of enoxaparin: in vitro and in vivo assessment.

    PubMed

    Bagre, Archana Pataskar; Jain, Keerti; Jain, Narendra K

    2013-11-01

    The objective of present research work was to develop alginate coated chitosan core shell nanoparticles (Alg-CS-NPs) for oral delivery of low molecular weight heparin, enoxaparin. Chitosan nanoparticles (CS-NPs) were synthesized by ionic gelation of chitosan using sodium tripolyphosphate. Core shell nanoparticles were prepared by coating CS-NPs with alginate solution under mild agitation. The Alg-CS-NPs were characterized for surface morphology, surface coating, particle size, polydispersity index, zeta potential, drug loading and entrapment efficiency using SEM, Zeta-sizer, FTIR and DSC techniques. Alginate coating increased the size of optimized chitosan nanoparticles from around 213 nm to about 335 nm as measured by dynamic light scattering in zeta sizer and further confirmed by SEM analysis. The performance of optimized enoxaparin loaded Alg-CS-NPs was evaluated by in vitro drug release studies, in vitro permeation study across intestinal epithelium, in vivo venous thrombosis model, particulate uptake by intestinal epithelium using fluorescence microscopy and pharmacokinetic studies in rats. Coating of alginate over the CS-NPs improved the release profile of enoxaparin from the nanoparticles for successful oral delivery. In vitro permeation studies elucidated that more than 75% enoxaparin permeated across the intestinal epithelium with Alg-CS-NPs. The Alg-CS-NPs significantly increased (p<0.05) the oral bioavailability of enoxaparin in comparison to plain enoxaparin solution as revealed by threefold increase in AUC of plasma drug concentration time curve and around 60% reduction in thrombus formation in rat venous thrombosis model. The core shell Alg-CS-NPs showed promising potential for oral delivery and significantly enhanced the in vivo oral absorption of enoxaparin.

  19. pACC1 peptide loaded chitosan nanoparticles induces apoptosis via reduced fatty acid synthesis in MDA-MB-231 cells

    NASA Astrophysics Data System (ADS)

    Kaliaperumal, Jagatheesh; Hari, Natarajan; Pavankumar, Padarthi; Elangovan, Namasivayam

    2016-06-01

    The development of formulations with therapeutic peptides has been restricted to poor cell penetration and in this attempt; we developed pACC1 peptide loaded chitosan nanoparticles. The prepared nanoparticles were characterized with FT-IR, XRD, SEM and TEM. In addition, the suitable formulation was evaluated for hemocompatibility, plasma stability and embryo toxicity using Danio rerio embryo model. The results showed that pACC1 peptide loaded chitosan nanoparticles were compatible with plasma. They possess sustained release pattern and also found to be safe up to 300 mg/L in embryo toxicity tests. Cytotoxicity assays with MDA-MB-231 cell lines suggested that, pACC1 peptide loaded chitosan nanoparticles were capable of enhanced cellular penetration and reduced palmitic acid content, which was confirmed by H1 NMR. Hence, these nanoparticles could be employed as excellent adjuvant therapeutics while treating solid tumors with multi-drug resistance.

  20. Electroactive chitosan nanoparticles for the detection of single-nucleotide polymorphisms using peptide nucleic acids.

    PubMed

    Kerman, Kagan; Saito, Masato; Tamiya, Eiichi

    2008-08-01

    Here we report an electrochemical biosensor that would allow for simple and rapid analysis of nucleic acids in combination with nuclease activity on nucleic acids and electroactive bionanoparticles. The detection of single-nucleotide polymorphisms (SNPs) using PNA probes takes advantage of the significant structural and physicochemical differences between the full hybrids and SNPs in PNA/DNA and DNA/DNA duplexes. Ferrocene-conjugated chitosan nanoparticles (Chi-Fc) were used as the electroactive indicator of hybridization. Chi-Fc had no affinity towards the neutral PNA probe immobilized on a gold electrode (AuE) surface. When the PNA probe on the electrode surface hybridized with a full-complementary target DNA, Chi-Fc electrostatically attached to the negatively-charged phosphate backbone of DNA on the surface and gave rise to a high electrochemical oxidation signal from ferrocene at approximately 0.30 V. Exposing the surface to a single-stranded DNA specific nuclease, Nuclease S1, was found to be very effective for removing the nonspecifically adsorbed SNP DNA. An SNP in the target DNA to PNA made it susceptible to the enzymatic digestion. After the enzymatic digestion and subsequent exposure to Chi-Fc, the presence of SNPs was determined by monitoring the changes in the electrical current response of Chi-Fc. The method provided a detection limit of 1 fM (S/N = 3) for the target DNA oligonucleotide. Additionally, asymmetric PCR was employed to detect the presence of genetically modified organism (GMO) in standard Roundup Ready soybean samples. PNA-mediated PCR amplification of real DNA samples was performed to detect SNPs related to alcohol dehydrogenase (ALDH). Chitosan nanoparticles are promising biomaterials for various analytical and pharmaceutical applications.

  1. Catechol-functionalized chitosan/iron oxide nanoparticle composite inspired by mussel thread coating and squid beak interfacial chemistry.

    PubMed

    Zvarec, Ondrej; Purushotham, Sreekanth; Masic, Admir; Ramanujan, Raju V; Miserez, Ali

    2013-08-27

    Biological materials offer a wide range of multifunctional and structural properties that are currently not achieved in synthetic materials. Herein we report on the synthesis and preparation of bioinspired organic/inorganic composites that mimic the key physicochemical features associated with the mechanical strengthening of both squid beaks and mussel thread coatings using chitosan as an initial template. While chitosan is a well-known biocompatible material, it suffers from key drawbacks that have limited its usage in a wider range of structural biomedical applications. First, its load-bearing capability in hydrated conditions remains poor, and second it completely dissolves at pH < 6, preventing its use in mild acidic microenvironments. In order to overcome these intrinsic limitations, a chitosan-based organic/inorganic biocomposite is prepared that mimics the interfacial chemistry of squid beaks and mussel thread coating. Chitosan was functionalized with catechol moieties in a highly controlled fashion and combined with superparamagnetic iron oxide (γ-Fe2O3) nanoparticles to give composites that represent a significant improvement in functionality of chitosan-based biomaterials. The inorganic/organic (γ-Fe2O3/catechol) interfaces are stabilized and strengthened by coordination bonding, resulting in hybrid composites with improved stability at high temperatures, physiological pH conditions, and acid/base conditions. The inclusion of superparamagnetic particles also makes the composites stimuli-responsive. PMID:23865752

  2. Stearyl methacrylate-grafted-chitosan nanoparticle as a nanofiller for PLA: Radiation-induced grafting and characterization

    NASA Astrophysics Data System (ADS)

    Rattanawongwiboon, Thitirat; Haema, Kamonwon; Pasanphan, Wanvimol

    2014-01-01

    This paper reports a one-pot synthesis using radiation-induced grafting technique to modify biopolymer-based chitosan nanoparticles as a nanofiller for blending with poly(lactic acid) (PLA). Hydrophobic stearyl methacrylate (SMA) was grafted onto non-irradiated chitosan (CS0) and pre-irradiated chitosan with a γ-ray dose of 40 kGy (CS40) to obtain stearyl methacrylate-grafted-chitosan nanoparticles (SMA-g-CSNPs).The effects of the pre-irradiated CS, grafting doses and SMA concentrations on degree of grafting (DG) and particle formation were studied. FT-IR and XRD were used to characterize the chemical and packing structure of SMA-g-CSNPs. The particle formulation and size of SMA-g-CSNPs were observed by TEM and AFM. The spherical core-shell SMA-g-CSNPs with the size ranging from 50 to 140 nm were successfully prepared. The SMA-g-CSNPs from CS40 has higher DG and smaller particle size when compared with CS0. The SMA-g-CSNPs are able to improve the compatibility between CS and PLA.

  3. Multi-vortex states in magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Gan, W. L.; Chandra Sekhar, M.; Wong, D. W.; Purnama, I.; Chiam, S. Y.; Wong, L. M.; Lew, W. S.

    2014-10-01

    We demonstrate a fabrication technique to create cylindrical NiFe magnetic nanoparticles (MNPs) with controlled dimensions and composition. MNPs thicker than 200 nm can form a double vortex configuration, which consists of a pair of vortices with opposite chirality. When MNPs thicker than 300 nm are relaxed after saturation, it forms a frustrated triple vortex state which produces a higher net magnetization as verified by light transmissivity measurements. Therefore, a greater magnetic torque can be actuated on a MNP in the triple vortex state.

  4. Nonlinear simulations to optimize magnetic nanoparticle hyperthermia

    SciTech Connect

    Reeves, Daniel B. Weaver, John B.

    2014-03-10

    Magnetic nanoparticle hyperthermia is an attractive emerging cancer treatment, but the acting microscopic energy deposition mechanisms are not well understood and optimization suffers. We describe several approximate forms for the characteristic time of Néel rotations with varying properties and external influences. We then present stochastic simulations that show agreement between the approximate expressions and the micromagnetic model. The simulations show nonlinear imaginary responses and associated relaxational hysteresis due to the field and frequency dependencies of the magnetization. This suggests that efficient heating is possible by matching fields to particles instead of resorting to maximizing the power of the applied magnetic fields.

  5. Arranging matter by magnetic nanoparticle assemblers

    PubMed Central

    Yellen, Benjamin B.; Hovorka, Ondrej; Friedman, Gary

    2005-01-01

    We introduce a method for transporting colloidal particles, large molecules, cells, and other materials across surfaces and for assembling them into highly regular patterns. In this method, nonmagnetic materials are manipulated by a fluid dispersion of magnetic nanoparticles. Manipulation of materials is guided by a program of magnetic information stored in a substrate. Dynamic control over the motion of nonmagnetic particles can be achieved by reprogramming the substrate magnetization on the fly. The unexpectedly large degree of control over particle motion can be used to manipulate large ensembles of particles in parallel, potentially with local control over particle trajectory. PMID:15956215

  6. Synthesis and characterization of amphiphilic glycidol-chitosan-deoxycholic acid nanoparticles as a drug carrier for doxorubicin.

    PubMed

    Zhou, Huofei; Yu, Weiting; Guo, Xin; Liu, Xiudong; Li, Nan; Zhang, Ying; Ma, Xiaojun

    2010-12-13

    Novel amphiphilic chitosan derivatives (glycidol-chitosan-deoxycholic acid, G-CS-DCA) were synthesized by grafting hydrophobic moieties, deoxycholic acid (DCA), and hydrophilic moieties, glycidol, with the purpose of preparing carriers for poorly soluble drugs. Based on self-assembly, G-CS-DCA can form nanoparticles with size ranging from 160 to 210 nm, and G-CS-DCA nanoparticles maintained stable structure for about 3 months when stored in PBS (pH 7.4) at room temperature. The critical aggregation concentration decreased from 0.043 mg/mL to 0.013 mg/mL with the increase of degree of substitution (DS) of DCA. Doxorubicin (DOX) could be easily encapsulated into G-CS-DCA nanoparticles and keep a sustained release manner without burst release when exposed to PBS (pH 7.4) at 37 °C. Antitumor efficacy results showed that DOX-G-CS-DCA have significant antitumor activity when MCF-7 cells were incubated with different concentration of DOX-G-CS-DCA nanoparticles. The fluorescence imaging results indicated DOX-G-CS-DCA nanoparticles could easily be uptaken by MCF-7 cells. These results suggested that G-CS-DCA nanoparticles may be a promising carrier for DOX delivery in cancer therapy.

  7. Multifunctional Magnetic Nanoparticles for Medical Imaging Applications

    PubMed Central

    Fang, Chen; Zhang, Miqin

    2010-01-01

    Magnetic nanoparticles (MNPs) have attracted enormous research attention due to their unique magnetic properties that enable the detection by the non-invasive medical imaging modality—magnetic resonance imaging (MRI). By incorporating advanced features, such as specific targeting, multimodality, therapeutic delivery, the detectability and applicability of MNPs have been dramatically expanded. A delicate design on structure, composition and surface chemistry is essential to achieving desired properties in MNP systems, such as high imaging contrast and chemical stability, non-fouling surface, target specificity and/or multimodality. This article presents the design fundamentals on the development of MNP systems, from discussion of material selection for nanoparticle cores and coatings, strategies for chemical synthesis and surface modification and their merits and limitations, to conjugation of special biomolecules for intended functions, and reviews the recent advances in the field. PMID:20593005

  8. Efficient pH Dependent Drug Delivery to Target Cancer Cells by Gold Nanoparticles Capped with Carboxymethyl Chitosan

    PubMed Central

    Madhusudhan, Alle; Reddy, Gangapuram Bhagavanth; Venkatesham, Maragoni; Veerabhadram, Guttena; Kumar, Dudde Anil; Natarajan, Sumathi; Yang, Ming-Yeh; Hu, Anren; Singh, Surya S.

    2014-01-01

    Doxorubicin (DOX) was immobilized on gold nanoparticles (AuNPs) capped with carboxymethyl chitosan (CMC) for effective delivery to cancer cells. The carboxylic group of carboxymethyl chitosan interacts with the amino group of the doxorubicin (DOX) forming stable, non-covalent interactions on the surface of AuNPs. The carboxylic group ionizes at acidic pH, thereby releasing the drug effectively at acidic pH suitable to target cancer cells. The DOX loaded gold nanoparticles were effectively absorbed by cervical cancer cells compared to free DOX and their uptake was further increased at acidic conditions induced by nigericin, an ionophore that causes intracellular acidification. These results suggest that DOX loaded AuNPs with pH-triggered drug releasing properties is a novel nanotheraputic approach to overcome drug resistance in cancer. PMID:24821542

  9. Development and Characterization of VEGF165-Chitosan Nanoparticles for the Treatment of Radiation-Induced Skin Injury in Rats

    PubMed Central

    Yu, Daojiang; Li, Shan; Wang, Shuai; Li, Xiujie; Zhu, Minsheng; Huang, Shai; Sun, Li; Zhang, Yongsheng; Liu, Yanli; Wang, Shouli

    2016-01-01

    Radiation-induced skin injury, which remains a serious concern in radiation therapy, is currently believed to be the result of vascular endothelial cell injury and apoptosis. Here, we established a model of acute radiation-induced skin injury and compared the effect of different vascular growth factors on skin healing by observing the changes of microcirculation and cell apoptosis. Vascular endothelial growth factor (VEGF) was more effective at inhibiting apoptosis and preventing injury progression than other factors. A new strategy for improving the bioavailability of vascular growth factors was developed by loading VEGF with chitosan nanoparticles. The VEGF-chitosan nanoparticles showed a protective effect on vascular endothelial cells, improved the local microcirculation, and delayed the development of radioactive skin damage. PMID:27727163

  10. Tailoring magnetic nanoparticle for transformers application.

    PubMed

    Morais, P C; Silva, A S; Leite, E S; Garg, V K; Oliveira, A C; Viali, W R; Sartoratto, P P C

    2010-02-01

    In this study photoacoustic spectroscopy was used to investigate the effect of dilution of an oil-based magnetic fluid sample on the magnetic nanoparticle surface-coating. Changes of the photoacoustic signal intensity on the band-L region (640 to 830 nm) upon dilution of the stock magnetic fluid sample were discussed in terms of molecular surface desorption. The model proposed here assumes that the driving force taking the molecules out from the nanoparticle surface into the bulk solvent is the gradient of osmotic pressure. This gradient of osmotic pressure is established between the nanoparticle surface and the bulk suspension. It is further assumed that the photoacoustic signal intensity (area under the photoacoustic spectra) scales linearly with the number of coating molecules (surface grafting) at the nanoparticle surface. This model picture provides a non-linear analytical description for the reduction of the surface grafting coefficient upon dilution, which was successfully-used to curve-fit the photoacoustic experimental data. PMID:20352784

  11. Tracking stem cells using magnetic nanoparticles

    PubMed Central

    Cromer Berman, Stacey M.; Walczak, Piotr; Bulte, Jeff W.M.

    2011-01-01

    Stem cell therapies offer great promise for many diseases, especially those without current effective treatments. It is believed that noninvasive imaging techniques, which offer the ability to track the status of cells after transplantation, will expedite progress in this field and help to achieve maximized therapeutic effect. Today’s biomedical imaging technology allows for real-time, noninvasive monitoring of grafted stem cells including their biodistribution, migration, survival, and differentiation, with magnetic resonance imaging (MRI) of nanoparticle-labeled cells being one of the most commonly used techniques. Among the advantages of MR cell tracking are its high spatial resolution, no exposure to ionizing radiation, and clinical applicability. In order to track cells by MRI, the cells need to be labeled with magnetic nanoparticles, for which many types exist. There are several cellular labeling techniques available, including simple incubation, use of transfection agents, magnetoelectroporation, and magnetosonoporation. In this overview article, we will review the use of different magnetic nanoparticles and discuss how these particles can be used to track the distribution of transplanted cells in different organ systems. Caveats and limitations inherent to the tracking of nanoparticle-labeled stem cells are also discussed. PMID:21472999

  12. Gamma aminobutyric acid B and 5-hydroxy tryptamine 2A receptors functional regulation during enhanced liver cell proliferation by GABA and 5-HT chitosan nanoparticles treatment.

    PubMed

    Shilpa, Joy; Pretty, Mary Abraham; Anitha, Malat; Paulose, Cheramadathikudyil Skaria

    2013-09-01

    Liver is one of the major organs in vertebrates and hepatocytes are damaged by many factors. The liver cell maintenance and multiplication after injury and treatment gained immense interest. The present study investigated the role of Gamma aminobutyric acid (GABA) and serotonin or 5-hydroxytryptamine (5-HT) coupled with chitosan nanoparticles in the functional regulation of Gamma aminobutyric acid B and 5-hydroxy tryptamine 2A receptors mediated cell signaling mechanisms, extend of DNA methylation and superoxide dismutase activity during enhanced liver cell proliferation. Liver injury was achieved by partial hepatectomy of male Wistar rats and the GABA and 5-HT chitosan nanoparticles treatments were given intraperitoneally. The experimental groups were sham operated control (C), partially hepatectomised rats with no treatment (PHNT), partially hepatectomised rats with GABA chitosan nanoparticle (GCNP), 5-HT chitosan nanoparticle (SCNP) and a combination of GABA and 5-HT chitosan nanoparticle (GSCNP) treatments. In GABA and 5-HT chitosan nanoparticle treated group there was a significant decrease (P<0.001) in the receptor expression of Gamma aminobutyric acid B and a significant increase (P<0.001) in the receptor expression of 5-hydroxy tryptamine 2A when compared to PHNT. The cyclic adenosine monophosphate content and its regulatory protein, presence of methylated DNA and superoxide dismutase activity were decreased in GCNP, SCNP and GSCNP when compared to PHNT. The Gamma aminobutyric acid B and 5-hydroxy tryptamine 2A receptors coupled signaling elements played an important role in GABA and 5-HT chitosan nanoparticles induced liver cell proliferation which has therapeutic significance in liver disease management.

  13. [Preparation of magnetic quaternary chitosan salt and its adsorption of methyl orange from water].

    PubMed

    Zhang, Cong-lu; Hu, Xiao-min; Ying, Shi-ying; Wang, Fang

    2013-05-01

    First, quaternary chitosan salts with different substitution degrees were prepared in glycine hydrochloride ([Gly]Cl) ionic liquid. Nano-sized Fe3O4 powder was obtained through chemical co-precipitation method. And then, magnetic quaternary chitosan particles were prepared through inverse suspension cross-linking using Fe3O4 was the nucleus and glutaraldehyde as the cross-linking agent. The influence of different reaction conditions on adsorption was discussed. Adsorption of methyl orange (MO) by magnetic quaternary chitosan particles was studied through the static adsorption method. The results showed that at pH 3.0 and 25 degrees C the adsorption capacity varied from 37.45 mg x g(-1) to 277.5 mg x g(-1) with the MO concentration ranging from 20 mg x L(-1) to 150 mg x L(-1). The adsorption isotherm was fitted to the Freundlich model and the adsorption kinetics was fitted to the pseudo-second order kinetic isotherms capacity experiment. It was found that after the adsorbent was used for four times, its removal rate still exceeded 90%. PMID:23914533

  14. Ex vivo permeation of tamoxifen and its 4-OH metabolite through rat intestine from lecithin/chitosan nanoparticles.

    PubMed

    Barbieri, S; Buttini, F; Rossi, A; Bettini, R; Colombo, P; Ponchel, G; Sonvico, F; Colombo, G

    2015-08-01

    Tamoxifen citrate is an anticancer drug slightly soluble in water. Administered orally, it shows great intra- and inter-patient variations in bioavailability. We developed a nanoformulation based on phospholipid and chitosan able to efficiently load tamoxifen and showing an enzyme triggered release. In this work the permeation of tamoxifen released from lecithin/chitosan nanoparticles across excised rat intestinal wall mounted in an Ussing chamber was investigated. Compared to tamoxifen citrate suspension, the amount of the drug permeated using the nanoformulation was increased from 1.5 to 90 times, in absence or in presence of pancreatin or lipase, respectively. It was also evidenced the formation of an active metabolite of tamoxifen, 4-hydroxy tamoxifen, however, the amount of metabolite permeated remained roughly constant in all experiments. The effect of enzymes on intestinal permeation of tamoxifen was shown only when tamoxifen-loaded nanoparticles were in intimate contact with the mucosal surface. The encapsulation of tamoxifen in lecithin/chitosan nanoparticles improved the non-metabolized drug passing through the rat intestinal tissue via paracellular transport. PMID:26095916

  15. Use of carboxylated cellulose nanofibrils-filled magnetic chitosan hydrogel beads as adsorbents for Pb(II).

    PubMed

    Zhou, Yiming; Fu, Shiyu; Zhang, Liangliang; Zhan, Huaiyu; Levit, Mikhail V

    2014-01-30

    Novel magnetic hydrogel beads (m-CS/PVA/CCNFs), consisting of carboxylated cellulose nanofibrils (CCNFs), amine-functionalized magnetite nanoparticles and poly(vinyl alcohol) (PVA) blended chitosan (CS), were prepared by an instantaneous gelation method. SEM, XRD, and TGA techniques were applied to investigate the structure of the hydrogel materials. The magnetic hydrogels were employed as absorbents for removal of Pb(II) ions from aqueous solutions and the fundamental adsorption behavior was studied. Experimental results revealed that the m-CS/PVA/CCNFs hydrogels exhibit higher adsorption capacity with the value of 171.0mg/g, and the carboxylate groups on the CCNFs surface play an important role in Pb(II) adsorption. Moreover, adsorption isotherm data were reliably described by the Langmuir model and the adsorption kinetics closely followed pseudo-second order model. Additionally, the Pb(II)-loaded m-CS/PVA/CCNFs hydrogels could be easily regenerated in weak acid solution and the adsorption effectiveness of 90% can be maintained after the 4 cycles.

  16. Stochastic magnetization dynamics of biochemically bound magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Reeves, Daniel; Weaver, John

    2015-03-01

    Understanding the dynamics of magnetic nanoparticles in applied magnetic fields is critical for biosensing and therapeutic applications. In biological environments, the nanoparticles may clump together and the resultant dynamics are interesting and important. We show simulation schemes using stochastic Langevin equations that describe the particle rotations in various conditions and suggest ways to improve the applications. Biochemical binding is described in terms of changes of the size distribution from network theory perspective. Also, using log-normally size distributed particles, a master variable is derived that contains all the significant variables. This compacts the parameter space, quickens simulation, and improves intuition. An approximate closed form solution to the magnetization harmonics in an oscillating field is given in terms of this variable using the Langevin function.

  17. Thermoresponsive magnetic nanoparticles for seawater desalination.

    PubMed

    Zhao, Qipeng; Chen, Ningping; Zhao, Dieling; Lu, Xianmao

    2013-11-13

    Thermoresponsive magnetic nanoparticles (MNPs) as a class of smart materials that respond to a change in temperature may by used as a draw solute to extract water from brackish or seawater by forward osmosis (FO). A distinct advantage is the efficient regeneration of the draw solute and the recovery of water via heat-facilitated magnetic separation. However, the osmotic pressure attained by this type of draw solution is too low to counteract that of seawater. In this work, we have designed a FO draw solution based on multifunctional Fe3O4 nanoparticles grafted with copolymer poly(sodium styrene-4-sulfonate)-co-poly(N-isopropylacrylamide) (PSSS-PNIPAM). The resulting regenerable draw solution shows high osmotic pressure for seawater desalination. This is enabled by three essential functional components integrated within the nanostructure: (i) a Fe3O4 core that allows magnetic separation of the nanoparticles from the solvent, (ii) a thermoresponsive polymer, PNIPAM, that enables reversible clustering of the particles for further improved magnetic capturing at a temperature above its low critical solution temperature (LCST), and (iii) a polyelectrolyte, PSSS, that provides an osmotic pressure that is well above that of seawater.

  18. Thermoresponsive magnetic nanoparticles for seawater desalination.

    PubMed

    Zhao, Qipeng; Chen, Ningping; Zhao, Dieling; Lu, Xianmao

    2013-11-13

    Thermoresponsive magnetic nanoparticles (MNPs) as a class of smart materials that respond to a change in temperature may by used as a draw solute to extract water from brackish or seawater by forward osmosis (FO). A distinct advantage is the efficient regeneration of the draw solute and the recovery of water via heat-facilitated magnetic separation. However, the osmotic pressure attained by this type of draw solution is too low to counteract that of seawater. In this work, we have designed a FO draw solution based on multifunctional Fe3O4 nanoparticles grafted with copolymer poly(sodium styrene-4-sulfonate)-co-poly(N-isopropylacrylamide) (PSSS-PNIPAM). The resulting regenerable draw solution shows high osmotic pressure for seawater desalination. This is enabled by three essential functional components integrated within the nanostructure: (i) a Fe3O4 core that allows magnetic separation of the nanoparticles from the solvent, (ii) a thermoresponsive polymer, PNIPAM, that enables reversible clustering of the particles for further improved magnetic capturing at a temperature above its low critical solution temperature (LCST), and (iii) a polyelectrolyte, PSSS, that provides an osmotic pressure that is well above that of seawater. PMID:24134565

  19. Sorption of carbamazepine from water by magnetic molecularly imprinted polymers based on chitosan-Fe₃O₄.

    PubMed

    Zhang, Ya-Lei; Zhang, Juan; Dai, Chao-Meng; Zhou, Xue-Fei; Liu, Shu-Guang

    2013-09-12

    A novel magnetic-molecularly imprinted polymer (MMIP) based on chitosan-Fe₃O₄ has been synthesized for fast separation of carbamazepine (CBZ) from water. During polymerization, the modified chitosan-Fe₃O₄ was used not only as supporter but also as functional monomer. The properties of obtained MMIP were characterized by scanning electron and transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectra, thermo-gravimetric analysis and so on. The sorption equilibrium data was well described by Freundlich isotherm model and the increase in the temperature generated an increase in the sorption amount, indicating endothermic nature of adsorption process. Sorption kinetics followed the pseudo-second-order model. The feasibility of selective sorption of CBZ from real water by the MMIP was analyzed by using spiked real water samples. The result showed that the sorption capacity of MMIP has no obvious decrease in different water samples whereas there was obvious decline in the sorption amount of the MNIP.

  20. Antibacterial electrospun chitosan-polyethylene oxide nanocomposite mats containing bioactive silver nanoparticles.

    PubMed

    Kohsari, Iraj; Shariatinia, Zahra; Pourmortazavi, Seied Mahdi

    2016-04-20

    The antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofibrous mats were developed by electrospinning technique for wound dressing applications. Indeed, a green route was introduced for fabrication of antibacterial mats loaded with 0.25% and 0.50% (w/w) of bioactive silver nanoparticles (Ag NPs, ∼70nm diameter) reduced by Falcaria vulgaris herbal extract. The mats were characterized by FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. All of the nanofibers had an average ∼200nm diameter. Interestingly, both of the CS-PEO mats containing 0.25% and 0.50% bioactive F. vulgaris-Ag NPs revealed 100% bactericidal activities against both Staphylococcus aureus and Escherichia coli bacteria. The silver release from nanofiber mats was sharply increased within first eight hours for both CS-PEO mats including 0.25% and 0.50% F. vulgaris-Ag NPs but after that the Ag nanoparticles were released very slowly (almost constant). The improved hydrophilicity, higher tensile strength and much greater silver release for CS-PEO-0.50% F. vulgaris-Ag NPs relative to those of the CS-PEO 0.25% F. vulgaris-Ag NPs suggested that the former was superior for biomedical applications. PMID:26876856

  1. Chitosan-Poly (I:C)-PADRE Based Nanoparticles as Delivery Vehicles for Synthetic Peptide Vaccines.

    PubMed

    Correia-Pinto, Jorge F; Csaba, Noemi; Schiller, John T; Alonso, Maria J

    2015-01-01

    The safety and precision of peptide antigens has prompted the search for adjuvants capable of increasing the immune response against these intrinsically poorly immunogenic antigens. The integration of both immunostimulants and peptide antigens within nanometric delivery systems for their co-delivery to immune cells is a promising vaccination strategy. With this in mind, the potential synergistic effect of the immunostimulant poly (I:C) (pIC) and a T-Helper peptide (PADRE), integrated into a chitosan (CS) based nanostructure, was explored. The value of this nanostructured combination of materials was assessed for a peptide antigen (1338aa) derived from the HPV-16 L2 protein. These nanoparticles, produced by ionic gelation technique, exhibited a nanometric size (<300 nm), a high positive surface charge (>40 mV) and high pIC association efficiency (>96%). They also showed capacity for the association of both the 1338aa and PADRE peptides. The influence of the presence of pIC and PADRE in the nanocomposition, as well as that of the peptide presentation form (encapsulated versus surface adsorbed) on the antibody induction was evaluated in a preliminary in vivo study. The data obtained highlights the possibility to engineer nanoparticles through the rational combination of a number of adjuvant molecules together with the antigen.

  2. Trans-resveratrol loaded chitosan nanoparticles modified with biotin and avidin to target hepatic carcinoma.

    PubMed

    Bu, Le; Gan, Liang-Chun; Guo, Xiao-Qiang; Chen, Feng-Zheng; Song, Qin; Qi-Zhao; Gou, Xiao-Jun; Hou, Shi-Xiang; Yao, Qian

    2013-08-16

    Conventional liver targeted system focuses on delivering drugs to liver, bringing toxicity on hepatic normal tissues. The purpose of this study is to construct a new system capable of specially targeting to hepatic carcinoma instead of the whole liver. Based on the fact that nanoparticles (NPs) bound with either biotin or avidin tend to accumulate in tumors and avidin-attached reagents were quickly eliminated from blood circulation and assembled in liver, trans-resveratrol loaded chitosan nanoparticles (CS-NPs), CS-NPs with the surface modified either by biotin (B-CS-NPs) or by both biotin and avidin (A-B-CS-NPs) were prepared and their physiochemical properties were investigated. The in vitro release profiles of the three NPs all conformed to bioexponential equation. Pharmacokinetic experiment indicated that A-B-CS-NPs rapidly assembled in liver after injection, with the highest liver targeting index of 2.70, while the modification of biotin attenuated the liver targeting ability of NPs. Inhibitory study on HepG2 cells declared that compared to trans-resveratrol solution and CS-NPs, both B-CS-NPs and A-B-CS-NPs significantly improved the anticancer activity. When incubated with HepG2 cells at high concentration for longer time, A-B-CS-NPs exhibited superior cytotoxicity than B-CS-NPs. This study exclaims that A-B-CS-NPs may be a potent drug delivery vector specially targeting to hepatic carcinoma.