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1.
Liposomes have been identified as effective immunological adjuvants and have potential for the intranasal and oral delivery of protein antigen. Anionic MLV liposomes were prepared by dehydration–rehydration method. For coating, liposomes were incubated in chitosan solution. Efficiency of coating was confirmed by the evaluation of FITC-labelled chitosan-coated liposomes using a fluorescent microscope. Liposomes morphology and size were studied by optical microscope and size analyzer. Mucoadhesion potential of liposomes was evaluated in human nose by gamma-scintigraphy using 99mTc-labelled liposomes. Rabbits (4 animals per group) were nasally immunized in weeks 0, 2 and 4 by liposomes encapsulated with 40 Lf TT. Bleedings and lavage collections were taken place in weeks 3 and 6, and IgG and sIgA titers were measured by ELISA method.Liposomes had a mean diameter of 2.38 μm. Loading of TT was 58.7 ± 12.4%. The mucoadhesion (clearance rate from nose) of both coated and non-coated liposomes was similar (P > 0.05). Among the immunized animals, the highest nasal lavage sIgA titers were seen in non-coated liposomes followed by coated ones. The serum IgG titers (2nd bleeding) in animals immunized by both kinds of liposome were similar (P > 0.05), and were lower than the TT solution group (P < 0.05). Immunization by i.m. injection of TT solution resulted in the lowest sIgA and highest IgG titers (P < 0.05) compared with liposomal groups.The results were indicative of good potential of negatively charged liposomes in the induction of mucosal immunity. Coating of liposomes by chitosan, failed to increase both the residence time of liposomes in nasal cavity and systemic responses. Conversely, coated liposomes could not induce the mucosal responses as efficiently as non-coated liposomes. It seems that the coating of liposomes affected their interaction potential with nasal associated lymphoid tissue cells.  相似文献   

2.
Oral delivery of proteins and peptides is one of the main challenges in pharmaceutical drug development. Microdevices have the possibility to protect the therapeutics until release is desired, avoiding losses by degradation. One type of microdevice is polymeric microcontainers. In this study, lysozyme is chosen as model protein and loaded into microcontainers with the permeation enhancer sodium decanoate (C10). The loaded microcontainers are sealed and functionalized by applying polymeric lids onto the cavity of the devices. The first lid is poly(lactic‐co‐glycolic) acid (PLGA) and on top of this either polyethylene glycol (PEG) or chitosan is applied (PLGA+PEG or PLGA+chitosan, respectively). The functionalization is evaluated in vitro for morphology, drug release, and mucoadhesive properties. These are coupled with in vitro and ex vivo studies using Caco‐2 cells, Caco‐2/HT29‐MTX‐E12 co‐cultures, and porcine intestinal tissue. PLGA+chitosan shows slower release compared to PLGA+PEG or only PLGA in buffer and the transport of lysozyme across cell cultures is not enhanced compared to the bulk powder. Microcontainers coated with chitosan or PEG demonstrate a three times stronger adhesion during ex vivo mucoadhesion studies compared to samples without coatings. Altogether, functionalized microcontainers with mucoadhesive properties and tunable release for oral protein delivery are developed and characterized.  相似文献   

3.
Chito-oligosaccharides (COSs) were encapsulated by the film-ultrasonic method into three nano-liposomes, which were uncoated liposomes (COSs-Lip), chitosan-coated liposomes (CH-COSs-Lip), and sodium alginate (SA)/chitosan (CH)-coated liposomes (SA/CH-COSs-Lip). The physicochemical and structural properties, as well as the stability and digestive characteristics, of all three nano-liposomes were assessed in the current study. Thereafter, the characteristics of intestinal absorption and transport of nano-liposomes were investigated by the Caco-2 cell monolayer. All nano-liposomes showed a smaller-sized distribution with a higher encapsulation efficiency. The ζ-potential, Z-average diameter (Dz), and polydispersity index (PDI) demonstrated that the stability of the SA/CH-COSs-Lip had much better stability than COSs-Lip and CH-COSs-Lip. In addition, the transport of the nano-liposomes via the Caco-2 cell monolayer indicated a higher transmembrane transport capacity. In summary, the chitosan and sodium alginate could serve as potential delivery systems for COSs to fortify functional foods and medicines.  相似文献   

4.
The present study aimed to develop n-propyl gallate (PG)-encapsulated liposomes through a novel direct pouring method using the quality-by-design (QbD) approach. A further aim was to coat liposomes with hyaluronic acid (HA) to improve the stability of the formulation in nasal mucosa. The QbD method was used for the determination of critical quality attributes in the formulation of PG-loaded liposomes coated with HA. The optimized formulation was determined by applying the Box–Behnken design to investigate the effect of composition and process variables on particle size, polydispersity index (PDI), and zeta potential. Physiochemical characterization, in vitro release, and permeability tests, as well as accelerated stability studies, were performed with the optimized liposomal formulation. The optimized formulation resulted in 90 ± 3.6% encapsulation efficiency, 167.9 ± 3.5 nm average hydrodynamic diameter, 0.129 ± 0.002 PDI, and −33.9 ± 4.5 zeta potential. Coated liposomes showed significantly improved properties in 24 h in an in vitro release test (>60%), in vitro permeability measurement (420 μg/cm2) within 60 min, and also in accelerated stability studies compared to uncoated liposomes. A hydrogen-peroxide-scavenging assay showed improved stability of PG-containing liposomes. It can be concluded that the optimization of PG-encapsulated liposomes coated with HA has great potential for targeting several brain diseases.  相似文献   

5.
The surfaces of poly(l-lactide) (PLLA) microspheres were modified by chitosan via a method of hydrolysis and grafting-coating to improve their compatibility to chondrocytes. The PLLA microspheres with a diameter of 74-150mum were fabricated by an oil/water emulsion solvent evaporation method, followed by hydrolysis in alkaline solution to produce a larger number of carboxyl groups. Using water-soluble carbodiimide as a coupling reagent, chitosan was covalently grafted onto the microspheres. Due to the physical entanglement and insolubility at neutral pH, unbonded chitosan molecules were stably remained to yield a large amount of coated chitosan. Biological performance of the control PLLA and the chitosan-coated PLLA microspheres were assessed by in vitro culture of rabbit auricular chondrocytes. After 24h and 7d culture, the chitosan-coated PLLA microspheres, especially the ones with larger chitosan amount, exhibited stronger ability to promote cell attachment and proliferation, and maintain the secretion function of the chondrocytes. Therefore, the chitosan-coated PLLA microspheres can be potentially used as the injectable cell microcarriers for chondrogenesis in cartilage tissue engineering.  相似文献   

6.
The present study was aimed to formulate and evaluate in situ thermoreversible intranasal gel of an antimigraine drug rizatriptan benzoate. The poloxamer 407 and carbopol 934 were used as thermoreversible and mucoadhesive polymers respectively. The gels were prepared with cold method. The phase transition temperature was determined with visual method. The gels were evaluated for their pH, mucoadhesive strength, in vitro release and ex vivo drug permeation through goat nasal mucosa. The histopathological study of the nasal mucosa was carried out to check for its damage during drug permeation. The 18 % w/v poloxamer solution was found to be showing phase transition at physiologic conditions (34–35 °C). As the percentage of carbopol 934 was increased from 0.1 to 0.5 % w/v the gelling temperature was found to be decreased. All formulations were showing mucoadhesive strength above 4,000 dynes/cm2. Drug permeation studies have indicated that the drug permeation rate can be increased by using carbopol 934 above 0.3 % w/v concentration. The histopathological evaluation of nasal mucosa after drug permeation study has not shown any evidence of damage. Thus in situ thermoreversible mucoadhesive gel of rizatriptan benzoate can be a promising approach to treat migraine.  相似文献   

7.
A water-soluble chitosan-coated oxidized regenerated cellulose (ORC) gauze was prepared by the oxidation of a viscose gauze with NO2/CCl4 and subsequent treatment with a solution of chitosan in aqueous acetic acid and finally neutralization with NaOH/C2H5OH solution. A series of C6 ORC samples with different –COOH content were prepared and coated by chitosans (CTS) with different molecular weight (Mw) of 2,000, 50,000, 100,000 (denoted as CTS1, CTS2, CTS3). FT-IR and TG suggested the formation of the amide bond between the carboxyl group of ORC and the amino group of CTS. Kjeldahl nitrogen analysis of ORC gauze treated with CTS (CTS-ORC) showed that the percentage of chitosan with the lowest Mw of 2,000 introduced on ORC surface was highest and increased with oxidation time, while chitosans with medium and high Mw showed that the maximum percentage of chitosan introduced on ORC surface occurred at the oxidation time of 8 h. The neutralized chitosan-coated ORC gauze could still maintain its original morphological form and was water-soluble, and could form a transparent gel quickly for 5 s in water. The prepared water-soluble gauze could be anticipated to possess the improved hemostatic and antibacterial properties.  相似文献   

8.
Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S. marianum were exploited for their in vitro potential to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension cultures were maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 ± 1.7 g/L fresh weight (FW) and 17.7 ± 0.5 g/L dry weight (DW) productions. All chitosan treatments resulted in an overall increase in the accumulation of total flavonoids (5.0 ± 0.1 mg/g DW for 5.0 mg/L chitosan), total phenolic compounds (11.0 ± 0.2 mg/g DW for 0.5 mg/L chitosan) and silymarin (9.9 ± 0.5 mg/g DW for 0.5 mg/L chitosan). In particular, higher accumulation levels of silybin B (6.3 ± 0.2 mg/g DW), silybin A (1.2 ± 0.1 mg/g DW) and silydianin (1.0 ± 0.0 mg/g DW) were recorded for 0.5 mg/L chitosan. The corresponding extracts displayed enhanced antioxidant and anti-inflammatory capacities: in particular, high ABTS antioxidant activity (741.5 ± 4.4 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan, whereas highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 ± 1.3 %), secretory phospholipase A2 (sPLA2, 33.9 ± 1.3 %) and 15-lipoxygenase (15-LOX-2, 31.6 ± 1.2 %) enzymes involved in inflammation process were measured in extracts obtained in the presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation in the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.  相似文献   

9.
High-pressure carbon dioxide in contact with water dissolves to form carbonic acid, causing a decrease in pH. By use of these characteristics of a CO2/H2O biphasic system, chitosan-coated cationic liposomes of l-alpha-dipalmitoylphosphatidylcholine were successfully prepared by an improved supercritical reverse-phase evaporation (ISCRPE) method. Liposome-chitosan complexes carrying a positive charge were prepared in a single-step procedure without the use of acid or organic solvent, including ethanol. The maximum trapping efficiency of liposomes prepared by the ISCRPE method was 17%, with or without the addition of chitosan, compared to only 2% for liposomes prepared by the Bangham method. Furthermore, the liposomal dispersion was stable at room temperature in a sealed tube for over 30 days.  相似文献   

10.
New mucoadhesive formulations were designed and studied in order to improve local vaginal therapy by increasing formulation retention prolonging thus drug-mucosa contact time. Some gels were prepared using hydroxyethylcellulose (HEC) alone or mixed with chitosan (CS) or its derivative 5-methyl-pyrrolidinone-chitosan (MPCS) and were loaded with the antibacterial metronidazole (MET) (0.75%). All formulations showed pseudoplastic flow and viscosity increase was observed proportionally to chitosan content (CS>MPCS). Prepared gels showed better extrusion properties (yield stress) than market formulation Zidoval. Mucoadhesion force studies permitted to point out that: (i) CS decreases mucoadhesion force; (ii) MPCS addition increases the mucoadhesion force at high percentage; (iii) all gels containing chitosan showed better mucoadhesive performances than Zidoval. Gels containing MPCS showed higher and faster drug release than those containing CS. All the preparations were able to release higher drug amounts if compared to market formulation. In conclusion MPCS improved gel characteristics in terms of mucoadhesion force, rheological behaviour and drug release pointing out that this modified chitosan is very suitable to obtain manageable and more acceptable vaginal formulation.  相似文献   

11.
Vitamin C nanoliposomes were prepared by combining a conventional method (film evaporation) with dynamic high pressure microfluidization. Their physicochemical characterizations (antioxidant activity, particle size, entrapment efficiency, morphology, in vitro drug release, and storage stability) and skin permeation behavior were investigated. The results showed that vitamin C nanoliposomes, having equivalent DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging capacity of pure vitamin C solution without loss of their biological activity, exhibited better storage stability at 37°C for 24 hours and at 4°C for 60 days, a more excellent sustained drug release as well as higher skin penetration rate than vitamin C liposomes.  相似文献   

12.
The skin permeation of bacitracin zinc in liposomes and niosomes after topical application were elucidated in the present study with the to increase its penetration capacity and, hence, efficiency. The formulations of bacitracin zinc were prepared by film hydration method and characterized for vesicle shape, size, entrapment efficiency, and drug permeation across rat skin and also evaluated for their stability. Formulation with niosomes demonstrated a better skin permeation potential, sustained release characteristic, and higher stability as compared to liposomes. The ability of liposomes and niosomes to modulate drug delivery makes the two vesicles useful to formulate topical bacitracin zinc.  相似文献   

13.
《先进技术聚合物》2018,29(6):1815-1825
Ricinoleic acid (RA) has potential to promote wound healing because of its analgesic and anti‐inflammatory properties. This study investigates the synthesis and characterization of RA liposomes infused in a hydrogel for topical application. Lecithin liposomes containing RA were prepared and incorporated into a chitosan solution and were subsequently cross‐linked with di‐aldehyde β‐cyclodextrin (Di‐β‐CD). Chitosan/Di‐β‐CD concentrations and reaction temperatures were varied to alter gelation time, water content, and mechanical properties of the hydrogel in an effort to obtain a wide range of RA release profiles. Hydrogel cross‐linking was confirmed by spectroscopy, and liposome and carrier hydrogel morphology via microscopy. Chitosan, Di‐β‐CD, and liposome concentrations within the formulation affected the extent of matrix swelling, mechanical strength, and pore and overall morphology. Higher cross‐linking density of the hydrogel led to lower water uptake and slower release rate of RA. Optimized formulations resulted in a burst release of RA followed by a steady release pattern accounting for 80% of the encapsulated RA over a period of 48 hours. However, RA concentrations above 0.1 mg/mL were found to be cytotoxic to fibroblast cultures in vitro because of the oily nature of RA. These formulations promoted wound healing when used to treat full thickness skin wounds (2 cm2) in Wister male rats. The wound contraction rates were significantly higher compared to a commercially available topical cream after a time period of 21 days. Histopathological analysis of the RA‐liposomal chitosan hydrogel group showed that the epidermis, dermis, and subcutaneous skin layers displayed an accelerated yet normal healing compared to control group.  相似文献   

14.
The present study investigated the surface coating of charged liposomes by three different types of pectin (LM, HM and amidated pectin) by particle size determinations and zeta potential measurements. The pectins and the pectin coated liposomes were visualized by atomic force microscopy. The adsorption of pectin onto positive liposomes yielded a reproducible increase in particle size and a shift of the zeta potential from positive to negative side for all three pectin types, whereas the adsorption of pectin onto negative liposomes did not render any significant changes probably due to electrostatic repulsion. The positive liposomes coated with HM-pectin gave the largest pectin coated particles with the least negative zeta potential, while the opposite was observed for the LM-pectin coated positive liposomes. Furthermore, results from dynamic light scattering revealed narrow size distributions, indicating that the degree of aggregation was low for the pectin coated liposomes. As liposomes are able to encapsulate drugs and pectin has been found to be mucoadhesive, these pectin coated liposomes may be potential drug delivery systems.  相似文献   

15.
Nanoliposomes are important carriers capable of packaging drugs for various delivery applications through passive targeting tumor sites by enhancing permeability and retention effect. Radiolabeled liposomes have potential applications in radiotherapy and diagnostic imaging. However, the physico-chemical instability of liposomes during manufacturing and storage limits their extensive application. Therefore, considerable numbers of studies have been made on the stability of liposomes over the last few years in order to overcome this problem. In this study, we attempted to prepare polymer-coated liposomes using water-soluble chitosan in order to enhance the stability of rhenium(III) chloride-incorporated liposomes. They were characterized by an electrophoretic light-scattering spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), UV–Vis spectrometer, and phase-contrast microscopy. The chitosan-coated liposomes are spherical and the particle size is about 800–850 nm. Incorporation of chitosan into the liposome bilayer decreased rhenium(III) chloride release from the liposome due to an increased rigidity of the liposome membrane structure. Chitosan-coated liposomes showed a higher stability compared with the stability of non-coated liposomes. The release characteristics of rhenium(III) chloride encapsulated in the liposome were taken as a measure of stability of the liposome membrane.  相似文献   

16.
Polycaprolactone (PCL) nanoparticles decorated with a mucoadhesive polysaccharide chitosan (CS) containing curcumin were developed aiming the buccal delivery of this drug. These nanoparticles were prepared by the nanoprecipitation method using different molar masses and concentrations of chitosan and concentrations of triblock surfactant poloxamer (PEO-PPO-PEO), in order to optimize the preparation conditions. Chitosan-coated nanoparticles showed positive surface charge and a mean particle radius ranging between 114 and 125 nm, confirming the decoration of the nanoparticles with the mucoadhesive polymer, through hydrogen bonds between ether and amino groups from PEO and CS, respectively. Dynamic Light Scattering (DLS) studies at different scattering angles and concentrations have shown that the nanoparticles are monodisperse (polydispersity indices were lower than 0.3). The nanoparticle systems were also examined with Nanoparticle Tracking Analysis (NTA), and the results were in good agreement with those obtained by DLS. Colloidal systems showed mean drug content about 460 μg/mL and encapsulation efficiency higher than 99%. Finally, when coated with chitosan, these nanoparticles show a great ability to interact with mucin indicating also their suitability for mucoadhesive applications.  相似文献   

17.
In the present study, RGD peptide was coupled with ferulic acid (FA) liposomes for binding to monocytes and neutrophils in peripheral blood for brain targeting in response to leukocyte recruitment. Cholesterol (Ch) was esterified with succinic anhydride to introduce a carboxylic end group (Ch-COOH). Soybean phosphatidylcholine, cholesterol and Ch-COOH were in a molar ratio of 1 : 0.23 : 0.05. FA was loaded into liposomes with 80.2+/-5.2% entrapment efficiency (EE) using a calcium acetate gradient method since it was difficult to load FA by other methods. RGD peptide was a novel compound coupled with Ch-COOH via carbodiimide and N-hydroxysulfosuccinimide. The results of the in vitro flow cytometric study showed that RGD conjugation liposomes (RGD-liposomes) could bind to monocytes/neutrophils efficiently. The rats were subjected to intrastriatal microinjections of 100 microl of human recombinant IL-1beta to produce brain inflammation and subsequently sacrificed after 15, 30, 60 and 120 min of administration of three formulations (FA solution, FA liposome, RGD-coated FA liposome). The body distribution results showed that RGD-liposomes could be directed to the target site, i.e. the brain, by cell selectivity in case of an inflammatory response. For RGD coated liposomes, the concentration of FA in brain was 6-fold higher than that of FA solution and 3-fold higher than that of uncoated liposomes. MTT assay and flow cytometry were used in the pharmacodynamic studies where it was found that FA liposomes exhibited greater antioxidant activity to FA solution on U937 cell.  相似文献   

18.
The conjugation of biomolecules to magnetic nanoparticles has emerged as promising approach in biomedicine as the treatment of several diseases, such as cancer. In this study, conjugation of bioactive peptide fractions from germinated soybeans to magnetite nanoparticles was achieved. Different fractions of germinated soybean peptides (>10 kDa and 5–10 kDa) were for the first time conjugated to previously coated magnetite nanoparticles (with 3-aminopropyltriethoxysilane (APTES) and sodium citrate) by the Ugi four-component reaction. The crystallinity of the nanoparticles was corroborated by X-ray diffraction, while the particle size was determined by scanning transmission electron microscopy. The analyses were carried out using infrared and ultraviolet–visible spectroscopy, dynamic light scattering, and thermogravimetry, which confirmed the coating and functionalization of the magnetite nanoparticles and conjugation of different peptide fractions on their surfaces. The antioxidant activity of the conjugates was determined by the reducing power and hydroxyl radical scavenging activity. The nanoparticles synthesized represent promising materials, as they have found applications in bionanotechnology for enhanced treatment of diseases, such as cancer, due to a higher antioxidant capacity than that of fractions without conjugation. The highest antioxidant capacity was observed for a >10 kDa peptide fraction conjugated to the magnetite nanoparticles coated with APTES.  相似文献   

19.
In order to determine the effect of quaternary ammonium groups and carboxymethyl groups of chitosan on antioxidant activity, nine quaternized carboxymethyl chitosan oligosaccharides (QCMCOs) were prepared from chitosan with chloroacetic acid and 2,3-epoxypropyltrimethyl ammoniumchloride as the modifying agent under microwave irradiation. The structures of QCMCOs were characterized by FT-IR, NMR, XRD and their Mw were detected by gel permeation chromatography (GPC). The thermal stability was evaluated by thermal gravimetric analysis (TGA), and their antioxidant activities were investigated including scavenging activity of superoxide and hydroxyl radical, reducing power and metal chelating ability. The results revealed that the introduction of quaternary ammonium groups and carboxymethyl groups decreased the crystallinity and the thermal stability of chitosan oligosaccharide (COS), and their antioxidant activities were closely related to the degree of substitution of quaternary ammonium groups and the carboxymethyl groups. This study provides important guidelines for developing new antioxidant agents.  相似文献   

20.
Using a solution technique, chitosan-based polyelectrolyte complexes (PECs) were developed as pervaporation membranes by incorporating phosphotungstic acid (PTA). The resulting membranes were characterized by Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Membranes were tested for their ability to separate water–isopropanol mixtures by pervaporation in the temperature range of 30–50 °C. The experimental results demonstrated that both flux and selectivity were increased simultaneously with increasing PTA content in the membrane. The permeation flux of pure chitosan membrane was increased dramatically from 4.13 to 11.70 × 10−2 kg/m2 h and correspondingly its separation factor was increased from 4490 to 11,241 and then decreased to 7490 at 30 °C for 10 mass% of water in the feed. The total flux and flux of water were found to be almost overlapping particularly for PECs membranes, suggesting that these could be used effectively to break the azeotropic point of water–isopropanol mixtures. From the temperature dependency of diffusion and permeation values, the Arrhenius activation parameters were estimated and discussed in the context of membranes efficiency. The pure chitosan and a small amount of PTA-incorporated PECs membranes exhibited positive heat of sorption while other PECs membranes exhibited negative heat of sorption, giving exothermic contribution.  相似文献   

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