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1.
The mucosal barrier remains a major barrier in the pulmonary drug delivery system, as mucociliary clearance in the airway accelerates the removal of inhaled nanoparticles (NPs). Herein, we designed and developed the inhalable Pluronic F127-modified silk fibroin NPs loading with quercetin (marked as QR-SF (PF127) NPs), aiming to solve the airway mucus barrier and improve the cancer therapeutic effect of QR. The PF127 coating on the SF NPs could attenuate the interaction between NPs and mucin proteins, thus facilitating the diffusion of SF(PF127) NPs in the mucus layer. The QR-SF (PF127) NPs had particle sizes of approximately 200 nm with negatively charged surfaces and showed constant drug release properties. Fluorescence recovery after photobleaching (FRAP) assay and transepithelial transport test showed that QR-SF (PF127) NPs exhibited superior mucus-penetrating ability in artificial mucus and monolayer Calu-3 cell model. Notably, a large amount of QR-SF (PF127) NPs distributed uniformly in the mice airway section, indicating the good retention of NPs in the respiratory tract. The mice melanoma lung metastasis model was established, and the therapeutic effect of QR-SF (PF127) NPs was significantly improved in vivo. PF127-modified SF NPs may be a promising strategy to attenuate the interaction with mucin proteins and enhance mucus penetration efficiency in the pulmonary drug delivery system.  相似文献   

2.
Introduction: Vaginal infection is widespread and > 80% of females encounter such infections during their lives. Topical treatment and prevention of vaginal infection allows direct therapeutic action, reduced drug doses and adverse effects, convenient administration and improved compliance. The advent of nanotechnology results in the use of nanoparticulate vehicle to control drug release, to enhance dosage form mucoadhesive properties and vaginal retention, and to promote mucus and epithelium permeation for both extracellular and intracellular drug delivery.

Areas covered: This review discusses the conflicting formulation requirements on polymeric nanoparticles in order to have them mucoadhesive and retentive in vaginal tract, while able to penetrate through mucus to reach adherent mucus layer or epithelium surfaces to prolong extracellular drug release, or facilitate mucosal permeation and intracellular drug delivery.

Expert opinion: Nanoscale systems are potentially useful in topical vaginal drug delivery. A thorough understanding of their mucus penetration and retention behavior as a function of their formulation, size and surface properties, biorecognition, pH, temperature or other stimuli responsiveness is essential for design of therapeutically effective nanomatrices.  相似文献   

3.
Oral delivery is the most common method for drug administration. However, poor solubility, stability, and bioavailability of many drugs make achieving therapeutic levels via the gastrointestinal (GI) tract challenging. Drug delivery must overcome numerous hurdles, including the acidic gastric environment and the continuous secretion of mucus that protects the GI tract. Nanoparticle drug carriers that can shield drugs from degradation and deliver them to intended sites within the GI tract may enable more efficient and sustained drug delivery. However, the rapid secretion and shedding of GI tract mucus can significantly limit the effectiveness of nanoparticle drug delivery systems. Many types of nanoparticles are efficiently trapped in and rapidly removed by mucus, making controlled release in the GI tract difficult. This review addresses the protective barrier properties of mucus secretions, how mucus affects the fate of orally administered nanoparticles, and recent developments in nanoparticles engineered to penetrate the mucus barrier.  相似文献   

4.
Mucoadhesive polymers have recently gained interest among pharmaceutical scientists as a means of improving drug delivery by promoting the residence time and contact time of the dosage form with the mucous membranes. Mucoadhesion is the process whereby synthetic and natural polymers adhere to mucosal surfaces in the body. If these materials are then incorporated into pharmaceutical formulations, drug absorption by mucosal cells may be enhanced or the drug will be released at the site for an extended period of time. Microspheres, in general, have the potential to be used for targeted and controlled release drug delivery; however, coupling of mucoadhesive properties to microspheres has additional advantages like, a much more intimate contact with the mucus layer, efficient absorption and enhanced bioavailability of the drugs due to a high surface to volume ratio. The present review describes the potential applications of mucoadhesive microspheres as a novel carrier system to improve drug delivery by various routes of administration like buccal, oral, nasal, ocular, vaginal and rectal, either for systemic or for local effects. The mucoadhesive polymers, methods of preparation of microspheres and their in vitro and in vivo evaluation are also described.  相似文献   

5.
It was the aim of the present study to evaluate and compare the distribution of thiolated mucoadhesive anionic poly(acrylic acid) (PAA) and cationic chitosan (CS) nanoparticles on intestinal mucosa. Modifications of these polymers were achieved by conjugation with cysteine (PAA-Cys) and 2-iminothiolane (CS-TBA). Nanoparticles (NP) were prepared by ionic gelation and labelled with the strong hydrophilic fluorescent dye Alexa Fluor 488 (AF 488) and hydrophobic fluorescein diacetate (FDA). Unmodified and modified CS and PAA NP were examined in vitro in terms of their mucoadhesive and mucus penetrating properties on the mucosa of rat small intestine. To investigate the transport of NP across the mucus layer, their diffusion behaviour through natural porcine intestinal mucus was studied through a new diffusion method developed by our group. Lyophilised particles displayed 526 μmol/g (CS) and 513 μmol/g (PAA) of free thiol groups and a zeta potential of 20 mV (CS) and -14 mV for PAA NP. Nanoparticle distribution on rat intestine suggested that mucoadhesion of thiolated NP is higher than the diffusion into the intestinal mucosa. Modified particles displayed more than a 6-fold increase in mucoadhesion compared to unmodified ones. The rank order with regard to mucoadhesion of all particles was: CS-TBA>PAA-Cys>CS>PAA, whereas CS-TBA showed 2-fold higher mucoadhesive properties compared to PAA-Cys NP. Diffusion through intestinal mucus was much higher for unmodified than for thiolated as well as for anionic compared to cationic particles. Overall, it was shown that thiolated particles of both anionic and cationic polymers have improved mucoadhesive properties and could be promising carriers for mucosal drug delivery.  相似文献   

6.
Introduction: Therapeutic proteins have become a highly attractive drug of choice due to minimal toxicity, high activity and exquisite specificity. Oral delivery of protein drugs is a very interesting area for research, and, naturally, numerous technologies are required to improve the oral bioavailability of therapeutic proteins.

Areas covered: This review article systemically generalized the major physiological barriers facing oral macromolecule delivery as well as the current approaches and novel developments in the field, including permeation enhancers, enzyme inhibitors, particulate drug delivery system, ligand delivery system, mucoadhesive delivery system, mucus penetration delivery system and other strategies.

Expert opinion: The development of composite formulation methods need to meet regulatory requirements for reproducibility, manufacturing cost, and bioavailability. So far, oral delivery of protein and peptide drugs is still facing immense challenges despite of the fact that some clinical studies are undergoing. The most advanced clinical strategies for therapeutic proteins are co-administration of absorption enhancers or protease inhibitors. Besides, rising new technologies in the field also provides a growing opportunity, such as nanotechnology, mucoadhesive and mucus penetration particulate delivery system.  相似文献   


7.
Improving peroral delivery efficiency is always a persistent goal for both small-molecule and macromolecular drug development. However, intestinal mucus barrier which greatly impedes drug-loaded nanoparticles penetration is commonly overlooked. Therefore, in this study, taking fluorescent labeled PLGA (poly (lactic-co-glycolic acid)) nanoparticles as a tool, the influence of anionic and nonionic surfactants on mucus penetration ability of nanoparticles and their mucus barrier regulating ability were studied. The movement of PLGA nanoparticles in mucus was tracked by multiple particles tracking method (MPT). Alteration of mucus properties by addition of surfactants was evaluated by rheology and morphology study. Rat intestinal villus penetration study was used to further evaluate penetration enhancement of nanoparticles. The effective diffusivities of the nanoparticles in surfactants pretreated mucus were increased by 2–3 times and the mucus barrier regulating capacity was also surfactant type dependent. Sodium dodecyl sulfate (SDS) increased the complex viscosity and viscoelastic properties of mucus, but poloxamer presented a decreased trend. Tween 80 maintained the rheological property of the mucus. With the mucus barrier regulated by surfactants, the penetration of nanoparticles in intestinal villus was obviously increased. In summary, the mucus penetration ability of nanoparticles could be enhanced by altering mucus microenvironment with surfactants. Tween 80 which largely retains the original mucus rheology and morphology properties may be a promising candidate for facilitating nanoparticle penetration through the mucus barrier with good safety profile.  相似文献   

8.
The aim of the present investigation was to evaluate the potential use of mucoadhesive microspheres for gastroretentive delivery of acyclovir. Chitosan, thiolated chitosan, Carbopol 71G and Methocel K15M were used as mucoadhesive polymers. Microsphere formulations were prepared using emulsion-chemical crosslinking technique and evaluated in vitro, ex-vivo and in-vivo. Gelatin capsules containing drug powder showed complete dissolution (90.5 +/- 3.6%) in 1 h. The release of drug was prolonged to 12 h (78.8 +/- 3.9) when incorporated into mucoadhesive microspheres. The poor bioavailability of acyclovir is attributed to short retention of its dosage form at the absorption sites (in upper gastrointestinal tract to duodenum and jejunum). The results of mucoadhesion study showed better retention of thiolated chitosan microspheres (8.0 +/- 0.8 h) in duodenal and jejunum regions of intestine. The results of qualitative and quantitative GI distribution study also showed significant higher retention of mucoadhesive microspheres in upper GI tract. Pharmacokinetic study revealed that administration of mucoadhesive microspheres could maintain measurable plasma concentration of acyclovir through 24 h, as compared to 5 h after its administration in solution form. Thiolated chitosan microsphere showed superiority over the other formulations as observed with nearly 4.0-fold higher AUC(0-24) value (1,090 +/- 51 ng h/ml) in comparison to drug solution (281 +/- 28 ng h/ml). Overall, the result indicated prolonged delivery with significant improvement in oral bioavailability of acyclovir from mucoadhesive microspheres due to enhanced retention in the upper GI tract.  相似文献   

9.
A new strategy to deliver antibiotics to the Cryptosporidium-infected gastrointestinal tract is presented. In an effort to augment the anticryptosporidial effect of clinically used drugs, mucoadhesive nanosuspensions were prepared. They have the ability to reside in the gastrointestinal tract for an extended period. The hydrogel contained bupravaquone nanosuspensions and an adhesive polymer (chitosan) powder dispersed in water. By the development of mucoadhesive nanosuspensions, a potential drug delivery system for poorly soluble drugs has been investigated to overcome bioavailability problems caused by the pathophysiological diarrhoeic situation in patients suffering from cryptosporidiosis. Adapting drug delivery systems to the situation of Cryptosporidium parvum infections in man allows increased retention times with a prolonged action at reduced elimination in the gastrointestinal tract. In this communication, in vivo data are presented to document the efficiency of bupravaquone formulated as mucoadhesive polymers to improve its activity against C. parvum.  相似文献   

10.
Abstract

Oral delivery is the most common method of drug administration with high safety and good compliance for patients. However, delivering therapeutic proteins to the target site via oral route involves tremendous challenge due to unfavourable conditions like biochemical barrier, mucus barrier and epithelial barriers. According to the functional differences of various protein drug delivery systems, the recent advances in pH responsive polymer-based drug delivery system, mucoadhesive polymer-based drug delivery system, absorption enhancers-based drug delivery system and composite polymer-based delivery system all were briefly summarised in this review, which not only clarified the clinic potential of these novel drug delivery systems, but also described the way for increasing oral bioavailability of therapeutic protein.  相似文献   

11.
Over the past few years, nasal drug delivery has attracted more and more attentions, and been recognized as the most promising alternative route for the systemic medication of drugs limited to intravenous administration. Many experiments in animal models have shown that nanoscale carriers have the ability to enhance the nasal delivery of peptide/protein drugs and vaccines compared to the conventional drug solution formulations. However, the rapid mucociliary clearance of the drug-loaded nanoparticles can cause a reduction in bioavailability percentage after intranasal administration. Thus, research efforts have considerably been directed towards the development of hydrogel nanosystems which have mucoadhesive properties in order to maximize the residence time, and hence increase the period of contact with the nasal mucosa and enhance the drug absorption. It is most certain that the high viscosity of hydrogel-based nanosystems can efficiently offer this mucoadhesive property. This update review discusses the possible benefits of using hydrogel polymer-based nanoparticles and hydrogel nanocomposites for drug/vaccine delivery through the intranasal administration.  相似文献   

12.
To design an effective particulate drug delivery system having mucoadhesive function, several mucoadhesion tests for polymers and the resultant particulate systems were developed. Mucin particle method is a simple mucoadhesion test for polymers, in which the commercial mucin particles are used. By measuring the change in particle size or zeta potential of the mucin particle in a certain concentration of polymer solution, we could estimate the extent of their mucoadhesive property. BIACORE method is also a novel mucoadhesion test for polymers. On passing through the mucin suspension on the polymer-immobilized chip of BIACORE instrument, the interaction was quantitatively evaluated with the change in its response diagram. By using these mucoadhesion tests, we detected a strong mucoadhesive property of several types of chitosan and Carbopol. Evaluation of mucoadhesive property of polymer-coated particulate systems was demonstrated with the particle counting method developed by us. To detect the mucoadhesive phenomena in the intestinal tract, we observed the rat intestine with the confocal laser scanning microscope (CLSM) after oral administration of the particulate systems. The resultant photographs clearly showed a longer retention of submicron-sized chitosan-coated liposomes (ssCS-Lip) in the intestinal tract than other liposomal particles tested such as non-coated liposomes and chitosan-coated multilamellar one. These observations explained well the superiority of the ssCS-Lip as drug carrier in oral administration of calcitonin in rats than other liposomal particles.  相似文献   

13.

Purpose

Pulmonary antibiotic delivery is recommended as maintenance therapy for cystic fibrosis (CF) patients who experience chronic infections. However, abnormally thick and sticky mucus present in the respiratory tract of CF patients impairs mucus penetration and limits the efficacy of inhaled antibiotics. To overcome the obstacles of pulmonary antibiotic delivery, we have developed nanocomposite microparticles (nCmP) for the inhalation application of antibiotics in the form of dry powder aerosols.

Methods

Azithromycin-loaded and rapamycin-loaded polymeric nanoparticles (NP) were prepared via nanoprecipitation and nCmP were prepared by spray drying and the physicochemical characteristics were evaluated.

Results

The nanoparticles were 200 nm in diameter both before loading into and after redispersion from nCmP. The NP exhibited smooth, spherical morphology and the nCmP were corrugated spheres about 1 μm in diameter. Both drugs were successfully encapsulated into the NP and were released in a sustained manner. The NP were successfully loaded into nCmP with favorable encapsulation efficacy. All materials were stable at manufacturing and storage conditions and nCmP were in an amorphous state after spray drying. nCmP demonstrated desirable aerosol dispersion characteristics, allowing them to deposit into the deep lung regions for effective drug delivery.

Conclusions

The described nCmP have the potential to overcome mucus-limited pulmonary delivery of antibiotics.
  相似文献   

14.
The objectives of this study were to investigate the effects of mucoadhesive excipients on systemic bioavailability of an inhaled drug and to evaluate the feasibility of using the pulmonary route for non-invasive systemic delivery of scutellarin, a poorly orally absorbed flavonoid glucuronide. Following intratracheal spray of the scutellarin solution, the bioavailability was found to be approximately 77% in rats, which was >30-fold higher than that via the peroral route. In addition, the pulmonary absorption of scutellarin appeared to avoid the intestinal first-pass metabolism accompanied by peroral administration. Spray-dried scutellarin particles with the presence of mucoadhesive excipients were found to affect the corresponding mucociliary transport rate (MTR) as evaluated by a frog palate model. The pharmacokinetic results indicated that the magnitude of AUC0–480 of intrapulmonary delivered drug particles was not correlated to the fine particle fraction (FPF) but inversely related to the MTR. Incorporating mucoadhesive polymeric mixtures into the scutellarin particles, the MTR decreased by sixfold, and the absolute bioavailability of the drug was found to increase from 70.1% to 97.9% despite a decrease in the FPF. Moreover, in vitro results evaluated using Calu-3 and A549 cell lines showed that scutellarin and spray-dried particles with or without the presence of mucoadhesives exhibited no local cell cytotoxic effects in the tested concentration range. In conclusion, the conducting airway is well permeable to scutellarin, and scutellarin may be effectively delivered systemically through inhalation of respirable droplets or particles.  相似文献   

15.
The present paper focuses on the development and characterization of silica nanoparticles (SiNP) coated with hydrophilic polymers as mucoadhesive carriers for oral administration of insulin. SiNP were prepared by sol–gel technology under mild conditions and coated with different hydrophilic polymers, namely, chitosan, sodium alginate or poly(ethylene glycol) (PEG) with low and high molecular weight (PEG 6000 and PEG 20000) to increase the residence time at intestinal mucosa. The mean size and size distribution, association efficiency, insulin structure and insulin thermal denaturation have been determined. The mean nanoparticle diameter ranged from 289 nm to 625 nm with a PI between 0.251 and 0.580. The insulin association efficiency in SiNP was recorded above 70%. After coating, the association efficiency of insulin increased up to 90%, showing the high affinity of the protein to the hydrophilic polymer chains. Circular dichroism (CD) indicated that no conformation changes of insulin structure occurred after loading the peptide into SiNP. Nano-differential scanning calorimetry (nDSC) showed that SiNP shifted the insulin endothermic peak to higher temperatures. The influence of coating on the interaction of nanoparticles with dipalmitoylphosphatidylcholine (DPPC) biomembrane models was also evaluated by nDSC. The increase of ΔH values suggested a strong association of non-coated SiNP and those PEGylated nanoparticles coated with DPPC polar heads by forming hydrogen bonds and/or by electrostatic interaction. The mucoadhesive properties of nanoparticles were examined by studying the interaction with mucin in aqueous solution. SiNP coated with alginate or chitosan showed high contact with mucin. On the other hand, non-coated SiNP and PEGylated SiNP showed lower interaction with mucin, indicating that these nanoparticles can interdiffuse across mucus network. The results of the present work provide valuable data in assessing the in vitro performance of insulin-loaded SiNP coated with mucoadhesive polymers.  相似文献   

16.
药物微粒载体在黏膜给药中的黏液屏障与传递策略   总被引:1,自引:0,他引:1  
黏液是一种黏弹性和可黏着的凝胶,用来保护呼吸道、胃肠道、生殖道、眼睛和其他黏膜表面免受外来微粒及病原体等有害物质的侵入,同时也能阻碍和限制药物微粒载体在其中的有效扩散及吸收,因此,黏膜给药的生物利用度往往较低。本文简述了黏液的生理学特性和阻滞微粒渗透的机制,介绍了一种新型的黏膜药物载体——穿透黏液粒子(MPP),以及纳米粒子在黏液等复杂的生物屏障中传递方式及扩散速率的定量方法——多粒子追踪(MPT)技术。  相似文献   

17.
BACKGROUND AND THE PURPOSE OF THE STUDY: The poor bioavailability and therapeutic response exhibited by the conventional ophthalmic solutions due to precorneal elimination of the drug may be overcome by the use of mucoadhesive in situ gel forming systems that are instilled as drops into the eye and undergo a sol-gel transition in the cul-de-sac and have good mucoadhesion with ocular mucus layers. The objective of this study was to formulate ophthalmic mucoadhesive system of gatifloxacin (GTN) and to evaluate its in vitro antibacterial potential against, Staphylococcus aureus and Escherichia coli. METHODS: : Mucoadhesive systems were prepared using gellan combined with sodium carboxymethylcellulose (NaCMC) or sodium alginate to enhance the gel bioadhesion properties. The prepared formulations were evaluated for their gelation, and rheological behaviors, mucoadhesion force, in vitro drug release, and antibacterial activity. RESULTS: All formulations in non-physiological or physiological conditions showed pseudoplastic behaviors. Increase in the concentration of mucoadhesive agent enhanced the mucoadhesive force significantly. In vitro release of gatifloxacin from the mucoadhesive system in simulated tear fluid (STF, pH of 7.4) was influenced significantly by the properties and concentration of gellan, sodium carboxymethyl cellulose and sodium alginate. Significant reduction in the total bacterial count was observed between drug solution (control) and mucoadhesive batches against both tested organisms. MAJOR CONCLUSION: The developed mucoadhesive system is a viable alternative to conventional eye drops of GTN due to its ability to enhance bioavailability through its longer precorneal residence time and ability to sustain the release of the drug.  相似文献   

18.
The aim of present study was to investigate a pH-responsive and mucoadhesive nanoparticle system for oral bioavailability enhancement of low-molecular weight heparin (LMWH). The thioglycolic acid (TGA) was first covalently attached to chitosan (CS) with 396.97?±?54.54?μmol thiol groups per gram of polymer and then the nanoparticles were prepared with thiolated chitosan (TCS) and pH-sensitive polymer hydroxypropyl methylcellulose phthalate (HPMCP) by ionic cross-linking method. The obtained nanoparticles were characterized for the shape, particle size, zeta potential, drug entrapment efficiency and loading capacity. In vitro results revealed the acid stability of pH-responsive nanoparticles, which had a significant control over LMWH release and could effectively protect entrapped drugs in simulated gastric conditions. By the attachment of the thiol ligand, an improvement of permeation-enhancing effect on freshly excised carp intestine (1.86-fold improvement) could be found. The mucoadhesive properties were evaluated using fluorescently labeled TCS or CS nanoparticles. As compared with the controls, a significant improvement of mucoadhesion on rat intestinal mucosa was observed in TCS/HPMCP nanoparticles via confocal laser scanning microscopy. The activated partial thromboplastin time (APTT) was significantly prolonged and an increase in the oral bioavailability of LMWH was turned out to be pronounced after oral delivered LMWH-loaded TCS/HPMCP nanoparticles in rats, which suggested enhanced anticoagulant effects and improved absorption of LMWH. In conclusion, pH-responsive TCS/HPMCP nanoparticles hold promise for oral delivery of LMWH.  相似文献   

19.
The goal of this critical review is to provide a critical analysis of the chain dynamics responsible for the action of micro- and nanoparticles of mucoadhesive biomaterials. The objective of using bioadhesive controlled drug delivery devices is to prolong their residence at a specific site of delivery, thus enhancing the drug absorption process. These mucoadhesive devices can protect the drug during the absorption process in addition to protecting it on its route to the delivery site. The major emphasis of recent research on mucoadhesive biomaterials has been on the use of adhesion promoters, which would enhance the adhesion between synthetic polymers and mucus. The use of adhesion promoters such as linear or tethered polymer chains is a natural result of the diffusional characteristics of adhesion. Mucoadhesion depends largely on the structure of the synthetic polymer gels used in controlled release applications.  相似文献   

20.
Self-nanoemulsifying systems (SNEs) have excellent ability to improve the solubility of poorly water-soluble drugs (PWSD). However, SNEs are likely to be degraded in gastrointestinal (GIT) when their surface is recognized by lipase/co-lipase enzyme complex, resulting in rapid release and precipitation of encapsulated drugs. The precipitates are then captured and removed by intestinal mucus, reducing the delivery efficacy of SNEs. Herein, the amphiphilic polymer Pluronic® F127 was incorporated into long and short-chain triglycerides (LCT, SCT) based SNEs to diminish the recognition and therefore minimized their degradation by enzymes and clearance by mucus. The SNEs were characterized in terms of particle size, zeta potential and stability. Ex vivo multiple particles tracking studies were performed by adding particle solution into fresh rat mucus. Cellular uptake of SNEs were conducted by using E12 cells, the absorption and distribution in small intestine were also studied after oral administration in male Sprague-Dawley (SD) rats. The in vitro digestion rate of SNEs were found to be in following order SCT-SNE > SCT-F127-SNE > LCT-SNE > LCT-F127-SNE. Moreover, the LCT-F127-SNE was found to be most effective in enhancing cellular uptake, resulting in 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE and SCT-F127-SNE, respectively. After incubating the SNE with E12 cells, the LCT-F127-SNE exhibited the highest amount regarding both mucus penetration and cellular uptake, with an uptake amount number (via bicinchoninic acid (BCA) analysis) of 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE and SCT-F127-SNE, respectively. The in vivo results revealed that orally administered LCT-F127-SNE could significantly increase the bioavailability of Cyclosporine A (CsA), which was approximately 2.43-fold, 1.33-fold and 1.80-fold higher than that of SCT-SNE, SCT-F127-SNE and LCT-SNE, respectively. We address in this work that F127-modified SNEs have potentials to improve oral drug absorption by significantly reducing gastrointestinal enzymatic degradation and simultaneously enhancing mucus penetration.  相似文献   

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