			Home About us Contact

Chitosan Nanoparticles (chitosan + nanoparticle)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Life Sciences	18%

Selected Abstracts

Transmission electron microscopy and electron diffraction study of BSA-loaded quaternized chitosan nanoparticles

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008
A-jun Wan
Abstract Chitosan nanoparticles, O -(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O -HTCC) nanoparticles and bovine serum albumin (BSA) loaded chitosan and O -HTCC nanoparticles of a size (about 200,600 nm) were obtained through the process of ionic gelation between chitosan or O -HTCC and sodium tripolyphosphate (TPP). The physicochemical properties of nanoparticles made from chitosan, O -HTCC, BSA loaded chitosan, and BSA loaded O -HTCC were determined by transmission electron microscopy (TEM), polarized optical microscopy (POM), photon correlation spectroscopy (PCS), and X-ray diffraction (XRD) pattern. Zeta potential was also performed to understand the surface properties of nanoparticles and their ability to bind negatively charged BSA. TEM, POM, and XRD suggested that ionic-gelation process significantly influenced the crystallinity of BSA, and greater chain realignment in the BSA-loaded chitosan and O -HTCC nanoparticles. PCS revealed that BSA-loaded chitosan nanoparticles were bigger than chitosan nanoparticles in size and BSA-loaded O -HTCC nanoparticles were smaller than O-HTCC nanoparticles in size. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source]

Chitosan nanoparticles encapsulated vesicular systems for oral immunization: preparation, in-vitro and in-vivo characterization

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2006
Sanyog Jain
BSA-loaded chitosan nanoparticles were prepared and encapsulated in vesicles (liposomes and nio-somes) to make them acid resistant upon oral administration. Prepared systems were characterized in-vitro for shape, size, entrapment efficiency and stability in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.5). The immune stimulating activity was studied by measuring serum IgG titre and secretory IgA (sIgA) levels in mucosal secretions following oral administration of various formulations in albino rats. Significantly higher (P < 0.05) serum IgG titres were achieved following oral administration of novel nanoparticulate vesicular formulations as compared with unmodified chitosan nanoparticles. Further, high sIgA levels in mucosal secretions advocated a possible application of chitosan nanoparticle encapsulated in vesicles as an oral vaccine delivery carrier-adjuvant system. [source]

Preparation and properties of ionically cross-linked chitosan nanoparticles

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 7 2009
Hui Liu
Abstract Chitosan nanoparticles were fabricated by a method of tripolyphosphate (TPP) cross-linking. The influence of fabrication conditions on the physical properties and drug loading and release properties was investigated by transmission electron microscopy (TEM), dynamic light scattering (DLS), and UV,vis spectroscopy. The nanoparticles could be prepared only within a zone of appropriate chitosan and TPP concentrations. The particle size and surface zeta potential can be manipulated by variation of the fabrication conditions such as chitosan/TPP ratio and concentration, solution pH and salt addition. TEM observation revealed a core,shell structure for the as-prepared nanoparticles, but a filled structure for the ciprofloxacin (CH) loaded particles. Results show that the chitosan nanoparticles were rather stable and no cytotoxicity of the chitosan nanoparticles was found in an in vitro cell culture experiment. Loading and release of CH can be modulated by the environmental factors such as solution pH and medium quality. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Chitosan nanoparticles encapsulated vesicular systems for oral immunization: preparation, in-vitro and in-vivo characterization

Enhancement of immunity and resistance in mice by pig IL-6 gene and CpG motifs encapsulated in chitosan nanoparticle

BIOTECHNOLOGY JOURNAL, Issue 2 2008
Qian Chen
Abstract This study was conducted to explore the synergetic effect of a novel plasmid containing a porcine IL-6 gene and CpG motifs on immunity of mice in order to develop an effective adjuvant to boost resistance against infection. The synthetic oligodeoxynucleotide containing 11 CpG motifs was inserted into the reconstructed VR1020 plasmid containing the pig IL-6 gene (VRPIL6), designated VRIL6C, and then encapsulated in chitosan nanoparticles (CNP) prepared by ionic cross linkage, designated VRIL6C-CNP. The 3-week old mice were injected, respectively, with VRIL6C-CNP, VRIL6-CNP, CpG-CNP and VR1020-CNP to detect the changes of immunity. At 28 days post inoculation, the mice were challenged with virulent hemolytic serotype 2 Streptococcus to test their resistance against infection. The results showed that there was a significant increase in immunoglobulins and interleukins in mice receiving VRIL6C-CNP compared with the control groups, as well as an increase in the lymphocytes and monocytes in the inoculated mice, so that the immunity was remarkably improved in the VRIL6C-CNP group. The challenge provoked stronger immunity and protection against infection in the VRIL6C-CNP group than in the control mice that manifested severe symptoms and lesions. This suggests that VRIL6C-CNP could remarkably enhance the nonspecific immunity of mice, and facilitate the development of an effective immunopotentiator to promote the resistance of the animals against infection. [source]

Controlled size chitosan nanoparticles as an efficient, biocompatible oligonucleotides delivery system

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010
Romila Manchanda
Abstract Polymeric nanoparticles of chitosan crosslinked with glutaraldehyde have been prepared using reverse micellar system. An optically clear solution was obtained on redispersing these nanoparticles in aqueous buffer. The nanoparticles were characterized for their size and surface morphology employing dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The TEM images showed spherical particles with smooth surface and narrow size distribution of about 90 nm, which was also supported by DLS data. Size and morphology of the particles remains the same on redispersing the lyophilized powder of these nanoparticles in aqueous buffer. Further, these nanoparticles were loaded with different synthetic oligonucleotides (ODNs). In vitro pH dependent release of the adsorbed oligonucleotides from these nanoparticles was also studied. At basic pH the release of oligonucleotides was found higher as compared with neutral and acidic medium. Cytotoxicity studies done on HEK 293 cells reveals that oligonucleotide loaded nanoparticles have high cell viability of nearly 76,88% whereas those of lipofectamine was about 35%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Physicochemical characterization and antioxidant activity of quercetin-loaded chitosan nanoparticles

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008
Yuying Zhang
Abstract Quercetin is an abundant flavonoid in food plants with numerous biological activities and widely used as a potent antioxidant. Being sparingly soluble in water and subject to degradation in aqueous intestinal fluids, the absorption of quercetin is limited upon oral administration. In the present study, chitosan nanoparticles and quercetin-loaded nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. The encapsulation of quercetin in the chitosan nanoparticles were confirmed by differential scanning calorimetry, X-ray powder diffractometry, Fourier transformed infrared spectroscopy, ultraviolet-visible spectrum, and fluorescence spectrum. The morphology of the nanoparticles was characterized by atomic force microscopy. The antioxidant activity of the quercetin-nanoparticles was also evaluated in vitro by two different methods (free radical scavenging activity test and reducing power test), which indicates that inclusion of quercetin in chitosan nanopaticles may be useful in improving the bioavailabilty of quercetin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source]

Comparison of ciprofloxacin hydrochloride-loaded protein, lipid, and chitosan nanoparticles for drug delivery

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008
Dharmendra Jain
Abstract The aim of the present study was to develop single dose delivery systems based on nanotechnology for prolonged antibiotic release in a controlled manner. Five different drug,carrier ratios of ciprofloxacin hydrochloride-loaded nanoparticles of albumin, gelatin, chitosan (CS), and lipid [solid lipid nanoparticles (SLNs)] were prepared and characterized. Average particle size was found to be in the range of 73 ± 2 to 98 ± 44 nm for SLNs, 140 ± 7 to 175 ± 24 nm for albumin nanoparticles, 143 ± 18 to 184 ± 27 nm for gelatin nanoparticles, and 247 ± 48 to 322 ± 52 nm for CS nanoparticles. A drug-to-carrier ratio of 0.5:1 was preferred for CS nanoparticles having zeta potential of >20 mV and drug encapsulation of 35.01% ± 2.66%. Similarly, 0.6:1 ratio was preferred for albumin nanoparticles with zeta potential >16 mV and drug encapsulation 48.20% ± 3.01%. Zeta potentials of gelatin nanoparticles loaded with ciprofloxacin suggested that they were unstable and prone to flocculation. SLN with 0.25:1 drug carrier ratio showed 38.71% ± 2.38% drug entrapment and ,28 ± 1 mV surface charge. All the nanoparticles showed sustained drug release avoiding "burst effect" of the free drugs for up to 120 h for albumin nanoparticles, 96 h for CS and gelatin nanoparticles, and 80 h for SLNs. The drug release profiles followed Higuchi model. Results suggest that CS nanoparticles and SLNs can act as promising carriers for sustained ciprofloxacin release in infective conditions. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source]

Transmission electron microscopy and electron diffraction study of BSA-loaded quaternized chitosan nanoparticles

Role of M2, M3, and M4 muscarinic receptor subtypes in the spinal cholinergic control of nociception revealed using siRNA in rats

JOURNAL OF NEUROCHEMISTRY, Issue 4 2009
You-Qing Cai
Abstract Muscarinic acetylcholine receptors (mAChRs) are involved in the control of nociception in the spinal cord. The M2, M3, and M4 mAChR subtypes are present in the spinal dorsal horn. However, the role of the individual subtypes in the anti-nociceptive effect produced by mAChR agonists is uncertain. Here, we determined the contribution of M2, M3, and M4 subtypes to spinal muscarinic analgesia by using small-interference RNA (siRNA) targeting specific mAChR subtypes in rats. The neuronal uptake and distribution of a chitosan-siRNA conjugated fluorescent dye in the spinal cord and dorsal root ganglion were confirmed after intrathecal injection. The control and gene-specific siRNA-chitosan complexes were injected intrathecally for three consecutive days. Quantitative reverse-transcription polymerase chain reaction analysis showed that treatment with siRNA targeting M2, M3, or M4 subtype produced a large reduction in the corresponding mRNA levels in the dorsal root ganglion and dorsal spinal cord. Also, the protein levels of the mAChR subtypes in the spinal cord were significantly down-regulated by siRNA treatment, as determined by the immunoprecipitation and receptor-binding assay. Treatment with the M2 -siRNA caused a large reduction in the inhibitory effect of muscarine on the nociceptive withdrawal threshold. Furthermore, M4 knockdown at the spinal level significantly reduced the anti-nociceptive effect of muscarine. However, the anti-nociceptive effect of muscarine was not significantly changed by the M3 -specific siRNA. Our study suggests that chitosan nanoparticles can be used for efficient delivery of siRNA into the neuronal tissues in vivo. Our findings also provide important functional evidence that M2 and M4, but not M3, contribute to nociceptive regulation by mAChRs at the spinal level. [source]

Formulation pH modulates the interaction of insulin with chitosan nanoparticles

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2002
Zengshuan Ma
Abstract Previous studies on chitosan-insulin nanoparticles have reported diverse encapsulation efficiency and insulin release profiles despite similar formulation and preparation procedures. This study examined the efficiency and mechanism of association of insulin with chitosan nanoparticles in the pH range of 2.3 to 6.3. Nanoparticles of 237 to 235 nm were prepared by ionotropic gelation of chitosan with tripolyphosphate counterions. Insulin was quantified by an RP-HPLC method. The insulin association efficiency (AE) spanned a broad range from 2 to 85%, and was highly sensitive to formulation pH. Highest AE was measured at insulin loading concentrations,,,4.28 U/mL and pH 6.1, close to the pI of native insulin and the pKa of chitosan. This association, attributed to physical adsorption of insulin through hydrophobic interactions with chitosan, was labile, and the associated insulin rapidly and completely released by dilution of the nanoparticles in aqueous media of pH 2 to 7.4. AE obtained at pH 5.3 was less than half that measured at pH 6.1 at corresponding insulin concentration, but the association at pH 5.3 appeared to be based on stronger interactions, because the release of insulin was pH-dependent and recovery was less than 25% even upon disintegration of the chitosan matrix. Interaction of insulin with the chitosan nanoparticles rendered the protein more susceptible to acid and enzymatic hydrolyses, the effects being more predominant in nanoparticles prepared at pH 5.3 than at pH 6.1. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:1396,1404, 2002 [source]

Cancer, chitosan nanoparticles and catalytic nucleic acids

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 1 2009
Mei Lin Tan
Abstract Objectives The aim of this review was to examine gene therapy involving DNAzyme and siRNA encapsulation into chitosan nanoparticles, discussing the current and future status of this drug delivery system in enhancing drug delivery and cancer therapy. Key findings Cancer is a disease state in which the cells in our body undergo mutations at the genetic level and are transformed, acquiring the ability to replicate limitlessly. Conventional cancer treatment involves the use of surgery and cytotoxic chemotherapy and/or radiotherapy, which have the potential of harming normal, otherwise healthy, non-neoplastic cells. Newer forms of therapy such as immunotherapy and gene therapy have shown initial promise, but still require better ways to limit exposure to cancerous lesions in the body. As a result drug delivery systems have been developed in attempts to deliver therapeutics specifically to the target lesion site. One recent drug delivery system has revolved around the use of chitosan nanoparticle technology, where therapeutics are encapsulated into nanoparticles and targeted to tumours. Summary Though few, attempts at encapsulating therapeutics such as deoxyribozymes and small or short interfering RNA have been optimistic and encouraging. [source]

Chitosan nanoparticles encapsulated vesicular systems for oral immunization: preparation, in-vitro and in-vivo characterization

Preparation and properties of ionically cross-linked chitosan nanoparticles

Enhancement of immunity and resistance in mice by pig IL-6 gene and CpG motifs encapsulated in chitosan nanoparticle

Biocompatible nanoparticles trigger rapid bacteria clustering

BIOTECHNOLOGY PROGRESS, Issue 4 2009
Mona Utne Larsen
Abstract This study reveals an exciting phenomenon of stimulated bacteria clustering. Rapid aggregation and microbial arrest are shown to occur in Escherichia coli solutions of neutral pH when chitosan nanoparticles with positive zeta potential are added. Because chitosan nanoparticles can easily be dispersed in aqueous buffers, the rapid clustering phenomenon requires only minuscule nanoparticle concentrations and will be critical in developing new methods for extricating bacterial pathogens. This work establishes the dominant role of electrostatic attraction in bacteria-nanoparticle interactions by varying the nanoparticle zeta potential from highly positive to strongly negative values, and by exploring concentration effects. For strongly negative nanoparticles, no clusters form, while aggregates are small and loose at intermediate conditions. In addition, optical density measurements indicate that over 90% of the suspended bacteria flocculate within seconds of being mixed with chitosan nanoparticles of a highly positive surface charge. Finally, the nanoparticles are significantly more efficient as a clustering agent compared to an equal mass of molecular chitosan in solution, as the bacteria-nanoparticle clusters formed are substantially larger. The bacteria-nanoparticle aggregation effect demonstrated here promises a rapid separation method for aiding pathogen detection and for flocculation of bacteria in fermentation processes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]