Aminoclay Nanoparticles Induce Anti-Inflammatory Dendritic Cells to Attenuate LPS-Elicited Pro-Inflammatory Immune Responses.

Although 3-aminopropyl functionalized magnesium phyllosilicate nanoparticles (hereafter aminoclay nanoparticles, ACNs) are well-known nanomaterials employed as drug carriers, their effects on immune cells remain unclear. To address this issue, we explored murine dendritic cells (DCs) as these cells belong to the innate arm of the immune system and function as antigen-presenting cells to elicit adaptive immune responses. We examined the in vitro effects of ACNs on DCs isolated from B6 mice. ACN treatment significantly down-regulated the expression of inflammasome-related markers, including NLRP3, caspase-1, and IL1ß. The ACNs-induced anti-inflammatory DC phenotype was further confirmed by down-regulation of the AKT/mTOR/HIF1α signaling pathway. Such anti-inflammatory effects of ACNs on DCs occurred independently of DC subtypes. To document the effects of ACNs on DCs more clearly, we examined their anti-inflammatory effects on lipopolysaccharide (LPS)-activated DCs. As expected, excessive inflammatory responses (increased mitochondrial ROS and Th1-type cytokines such as IL12 and IL1ß) of LPS-activated DCs were dramatically attenuated by ACN treatment. Furthermore, ACNs down-regulated IFNγ production by antigen-specific CD4+ T cells, which is consistent with a reduced inflammatory phenotype of DCs. Overall, our results provide support for employing ACNs as drug delivery materials with therapeutic potential to control inflammatory disorders.

Ternary nanocomposite carriers based on organic clay-lipid vesicles as an effective colon-targeted drug delivery system: preparation and in vitro/in vivo characterization.

This study aimed to develop a new colon-targeted drug delivery system via the preparation of ternary nanocomposite carriers based on organic polymer, aminoclay and lipid vesicles. Budesonide (Bud), an anti-inflammatory drug was chosen as a model drug and encapsulated into three different formulations: liposome (Bud-Lip), aminoclay-coated liposome (AC-Bud-Lip), and Eudragit® S100-aminoclay double coated liposome (EAC-Bud-Lip). The formation of the aminoclay-lipid vesicle nanocomposite was confirmed by energy dispersive X-ray spectrum, transmission electron microscopy, and Fourier-transform infrared spectroscopy. All formulations were produced with a high encapsulation efficiency in a narrow size distribution. Drug release from EAC-Bud-Lip was approximately 10% for 2-h incubation at pH 1.2, implying the minimal drug release in acidic gastric condition. At pH 7.4, EAC-Bud-Lip underwent significant size reduction and exhibited drug release profiles similar to that from AC-Bud-Lip, implying the pH-dependent removal of the outer coating layer. Compared to free Bud solution, EAC-Bud-Lip achieved a higher drug uptake in Caco-2 cells and exhibited a stronger inhibition of TNF-α and IL-6 secretion in LPS-stimulated Raw264.7 cells. Furthermore, a bio-distribution study in mice demonstrated that Eudragit® S100-aminoclay dual coating led to a higher colonic distribution with a longer residence time, which correlated well with the delayed systemic drug exposure in rats. Taken together, the present study suggests that the ternary nanocomposite carrier consisting of Eudragit® S100, aminoclay, and lipid vesicle might be useful as an effective colon-targeted drug delivery system.

Nanocomposites-based targeted oral drug delivery systems with infliximab in a murine colitis model.

BACKGROUND: Infliximab (IFX), a TNF-α blocking chimeric monoclonal antibody, induces clinical response and mucosal healing in patients with inflammatory bowel disease (IBD). However, systemic administration of this agent causes unwanted side effects. Oral delivery of antibody therapeutics might be an effective treatment strategy for IBD compared to intravenous administration. RESULTS: All three carriers had a high encapsulation efficiency, narrow size distribution, and minimal systemic exposure. There was a higher interaction between nanocomposite carriers and monocytes compared to lymphocytes in the PBMC of IBD patients. Orally administered nanocomposite carriers targeted to inflamed colitis minimized systemic exposure. All IFX delivery formulations with nanocomposite carriers had a significantly less colitis-induced body weight loss, colon shortening and histomorphological score, compared to the DSS-treated group. AC-IFX-L and EAC-IFX-L groups showed significantly higher improvement of the disease activity index, compared to the DSS-treated group. In addition, AC-IFX-L and EAC-IFX-L alleviated pro-inflammatory cytokine expressions (Tnfa, Il1b, and Il17). CONCLUSION: We present orally administered antibody delivery systems which improved efficacy in murine colitis while reducing systemic exposure. These oral delivery systems suggest a promising therapeutic approach for treating IBD.

Hymenobacter segetis sp. nov., isolated from soil.

A polyphasic taxonomic study was performed on a novel strain designated as S7-3-11T, which was isolated from soil of the Gyeongsangnam-do province in Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain S7-3-11T belongs to the genus Hymenobacter and is most closely related to Hymenobacter ruber PB156T (97.9%), Hymenobacter daeguensis 16F3Y-2T (97.8%), Hymenobacter glaciei VUG-A130T (97.7%), Hymenobacter soli PB17T (97.5%), Hymenobacter terrae DG7AT (97.5%), and Hymenobacter antarcticus VUG-A42aaT (97.3%). However, DNA-DNA hybridization results showed less than 50% relatedness with respect to the type strains of the six most closely related species. The DNA G + C content of strain S7-3-11T was 60.2 mol%. MK-7 was identified as the predominant respiratory quinone, and summed feature 3 (C16:1 ω7c/C16:1 ω6c; 21.5%), C15:0 iso (16.8%), C15:0 anteiso (16.2%), and C15:1 iso G (10.8%) were the major fatty acids. Phosphatidylethanolamine, an unidentified aminolipid, and an unidentified aminophospholipid were detected as major polar lipids. On the basis of the polyphasic evidence presented, strain S7-3-11T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter segetis sp. nov. is proposed. The type strain is S7-3-11T (= KCTC 52732T = JCM 32197T).

Hymenobacter pedocola sp. nov., a novel bacterium isolated from soil.

Strain S12-2-1T was isolated from a soil sample collected in the Gyeongsangnam-do province of the Republic of Korea. The isolate is a Gram-stain-negative, aerobic, short, rod-shaped bacterium, and its colonies are red to pink in colour. Analysis of the 16S rRNA gene identified strain S12-2-1T as a member of the genus Hymenobacter in the family Cytophagaceae, with high levels of 16S rRNA gene sequence similarity to Hymenobacter arizonensis OR362-8T (97.7 %), Hymenobacter sedentarius DG5BT (97.4 %) and Hymenobacter humi DG31AT (97.2 %). The isolate was positive for catalase and oxidase, but negative for acid production from glucose. The growth of strain S12-2-1T was supported at 4-30 °C, pH 7-10 and in the presence of 0-0.5 % NaCl. Strain S12-2-1T contained menaquinone-7 as the predominant respiratory quinone, sym-homospermidine as the major polyamine and iso-C15 : 0, anteiso-C15 : 0 and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) as the major fatty acids. Phosphatidylethanolamine was the major polar lipid. The genomic DNA G+C content was 58.7 mol%. Phenotypic and chemotaxonomic data supported the assignment of the isolate to the genus Hymenobacter. However, strain S12-2-1T exhibited a relatively low level of DNA-DNA relatedness with H. humi (31.7 %), H. arizonensis (24.4 %) and H. sedentarius (21.3 %). Based on its phenotypic and genotypic properties, along with its phylogenetic distinctiveness, strain S12-2-1T should be considered a novel species in the genus Hymenobacter, for which the name Hymenobacter pedocola sp. nov. is proposed. The type strain is S12-2-1T (=KCTC 52730T=JCM 32198T).

Novel piroxicam-loaded nanospheres generated by the electrospraying technique: physicochemical characterisation and oral bioavailability evaluation.

To determine if a novel electrospraying technique could be applied to an oral drug delivery system for improving the solubility and oral bioavailability of poorly water-soluble piroxicam; the nanospheres were generated with drug and polyvinylpyrrolidone (PVP) using electrospraying technique; and their physicochemical properties, solubility, release and pharmacokinetics were evaluated in comparison with piroxicam powder. All nanospheres had significantly increased drug solubility and dissolution rates in comparison with the drug powder. In particular, the nanosphere composed of piroxicam and PVP at a weight ratio of 2:8 gave about 600-fold higher solubility, 15-fold higher release rate and 3-fold higher AUC in comparison to piroxicam powder, leading to significantly enhanced oral bioavailability in rats, due to the mingled effect of nanonisation along with transformation to the amorphous state. Thus, this electrospraying technique can be utilised to produce a novel oral nanosphere delivery system with enhanced solubility and oral bioavailability for poorly water-soluble piroxicam.

Fluorescent iodized emulsion for pre- and intraoperative sentinel lymph node imaging: validation in a preclinical model.

PURPOSE: To validate the usefulness of a newly developed tracer for preoperative gastric sentinel lymph node (LN) (SLN) mapping and intraoperative navigation after a single preoperative submucosal injection in rat and beagle models. MATERIALS AND METHODS: This study was approved by the Experimental Animal Ethical Committee of Yonsei University College of Medicine according to the eighth edition of the Guide for the Care and Use of Laboratory Animals published in 2011. An emulsion was developed that contained indocyanine green in iodized oil, which can be visualized with both computed tomography (CT) and near-infrared (NIR) optical imaging and has the property of delayed washout. This emulsion was injected into the footpad of rats (n = 6) and the gastric submucosa of beagles (n = 8). CT lymphography was performed. The degree of enhancement of popliteal LNs was measured in rats, and the enhancing LNs were identified and the degree of enhancement of the enhancing LNs was measured in beagles. Next, NIR imaging was performed in beagles during open, laparoscopic, and robotic surgery to identify LNs containing the fluorescent signals of indocyanine green. The enhanced LNs detected with CT lymphography and NIR imaging were matched to see if they corresponded. RESULTS: Preoperative CT lymphography facilitated SLN mapping, and 26 SLNs were identified in eight beagles. NIR imaging enabled high-spatial-resolution visualization of both SLNs and the intervening lymphatic vessels and was useful for intraoperative SLN navigation. CONCLUSION: SLN mapping with fluorescent iodized oil emulsion is effective and feasible for both CT and NIR imaging.

Solid self-nanoemulsifying drug delivery system (SNEDDS) for enhanced oral bioavailability of poorly water-soluble tacrolimus: physicochemical characterisation and pharmacokinetics.

To develop a novel self-nanoemulsifying drug delivery system (solid SNEDDS) with better oral bioavailability of tacrolimus, the solid SNEDDS was obtained by spray-drying the solutions containing the liquid SNEDDS and colloidal silica. Its reconstitution properties were determined and correlated to solid state characterisation of the powder. Moreover, the dissolution and pharmacokinetics in rats was done in comparison to the commercial product. Among the liquid SNEDDS formulations tested, the liquid SNEDDS comprised of Capryol PGMC, Transcutol HP and Labrasol (10:15:75, v/v/v) presented the highest dissolution rate. In the solid SNEDDS, this liquid SNEDDS was absorbed in the pores and attached onto the surface of the colloidal silica. Drug was present in the amorphous state in it. The solid SNEDDS with 5% w/v tacrolimus produced the nanoemulsions and improved the oral bioavailability of tacrolimus in rats. Therefore, this solid SNEDDS would be a potential candidate for enhancing the oral bioavailability of tacrolimus.

Computed tomography-guided screening of surfactant effect on blood circulation time of emulsions: application to the design of an emulsion formulation for paclitaxel.

PURPOSE: In an effort to apply the imaging techniques currently used in disease diagnosis for monitoring the pharmacokinetics and biodisposition of particulate drug carriers, we sought to use computed tomography (CT) scanning methodology to investigate the impact of surfactant on the blood residence time of emulsions. METHODS: We prepared the iodinated oil Lipiodol emulsions with different compositions of surfactants and investigated the impact of surfactant on the blood residence time of emulsions by CT scanning. RESULTS: The blood circulation time of emulsions was prolonged by including Tween 80 or DSPE-PEG (polyethylene glycol 2000) in emulsions. Tween 80 was less effective than DSPE-PEG in terms of prolongation effect, but the blood circulating time of emulsions was prolonged in a Tween 80 content-dependent manner. As a proof-of-concept demonstration of the usefulness of CT-guided screening in the process of formulating drugs that need to be loaded in emulsions, paclitaxel was loaded in emulsions prepared with 87 or 65% Tween 80-containing surfactant mixtures. A pharmacokinetics study showed that paclitaxel loaded in 87% Tween 80 emulsions circulated longer in the bloodstream compared to those in 65% Tween 80 emulsions, as predicted by CT imaging. CONCLUSIONS: CT-visible, Lipiodol emulsions enabled the simple evaluation of surfactant composition effects on the biodisposition of emulsions.

Pre-mixing of omega-3 fatty acid-containing liposomes enhances the drug release rate and therapeutic efficacy of anticancer drugs loaded in liposomes.

The therapeutic efficacy of anticancer drugs loaded in liposomes composed of rigid phosphatidylcholine (PC) is hindered by the limited release of these drugs at the tumor site, which in turn hampers delivery of the drug to its intracellular target. In an attempt to improve the therapeutic efficacy of liposomal anticancer drugs, we here explored the use of empty liposomes as "trigger" vehicles to induce drug release from drug-loaded liposomes through liposome-liposome interactions. Empty liposomes containing PC in which omega-3 fatty acids comprised both fatty acid strands (Omega-L) showed a triggering effect on drug release from doxorubicin (DOX)-loaded liposomes (Caelyx). The effectiveness of this triggered-release effect was dependent on the Omega-L composition as well as the mixing ratio of Omega-L to Caelyx. Cryo-TEM and differential calorimetry studies revealed that the Omega-L effect was associated with liposome-liposome interactions that led to loosened membrane packing and increased fluidity of Caelyx. In cultured cells, the intracellular/intranuclear DOX uptake and anticancer efficacy of Caelyx was greatly improved by Omega-L pre-mixing. Intravenous injection of rats with Caelyx, premixed with Omega-L, decreased the area under the plasma concentration-time curve from time zero to time infinity and increased clearance without significantly changing the mean residence time or terminal half-life of DOX compared with Caelyx alone. Ex vivo bioimaging showed that DOX fluorescence in tumors, but not in other organs, was significantly increased by Omega-L premixing. In the mouse xenograft model, premixing of Omega-L with Caelyx suppressed tumor growth 2.5-fold compared with Caelyx. Collectively, the data provide preliminary evidence that the Omega-L-triggered drug release that occurs before and after dosing, particularly at tumor site, improved the therapeutic efficacy of Caelyx. The simple approach described here could enhance the therapeutic value of Caelyx and other anticancer drug-loaded liposomes.

Establishment of nanoparticle screening technique: A pivotal role of sodium carboxymethylcellulose in enhancing oral bioavailability of poorly water-soluble aceclofenac.

A novel nanoparticle screening technique was established to mostly enhance the aqueous solubility and oral bioavailability of aceclofenac using nanoparticle systems. Among the polymers investigated, sodium carboxymethylcellulose (Na-CMC) showed the greatest increase in drug solubility. Utilizing spray-drying technique, the solvent-evaporated solid dispersion (SESD), surface-attached solid dispersion (SASD), and solvent-wetted solid dispersion (SWSD) were prepared using aceclofenac and Na-CMC at a weight ratio of 1:1 in 50 % ethanol, distilled water, and ethanol, respectively. Using Na-CMC as a solid carrier, an aceclofenac-loaded liquid self-emulsifying drug delivery system was spray-dried and fluid-bed granulated together with microcrystalline cellulose, producing a solid self-nanoemulsifying drug delivery system (SNEDDS) and solid self-nanoemulsifying granule system (SNEGS), respectively. Their physicochemical properties and preclinical assessments in rats were performed. All nanoparticles exhibited very different properties, including morphology, crystallinity, and size. As a result, they significantly enhanced the solubility, dissolution, and oral bioavailability in the following order: SNEDDS ≥ SNEGS > SESD ≥ SASD ≥ SWSD. Based on our screening technique, the SNEDDS was selected as the optimal nanoparticle with the highest bioavailability of aceclofenac. Thus, our nanoparticle screening technique should be an excellent guideline for solubilization research to improve the solubility and bioavailability of many poorly water-soluble bioactive materials.

Cellular uptake and antitumour activity of paclitaxel incorporated into trilaurin-based solid lipid nanoparticles in ovarian cancer.

Trilaurin-based solid lipid nanoparticles (TL-SLNs) containing paclitaxel (PTX) were prepared by hot-melt high-pressure homogenisation and subsequent freezing and thawing. PTX-containing TL-SLNs showed 160.0 ± 15.8 nm of mean particle size and -43.9 mV of zeta potential. Scanning electron microscopy also revealed the spherical shape and submicron-size of the TL-SLNs. Differential scanning calorimetry measurement presented melting transition peak of TL in SLNs indicating the solidified state of the core lipid. The prepared TL-SLNs were physically stable without significant particle size changes at 4 °C for 2 months. The amounts of uptake into the human ovarian cancer cells, SKOV-3, were similar between PTX delivered in Cremophor EL-based formulation and TL-SLNs. In vitro and in vivo antitumour activity of PTX in TL-SLNs was comparable to the commercial Cremophor EL-based formulation in SKOV-3. These results suggest that PTX-loaded TL-SLNs have promising potential as an alternative parenteral formulation for PTX.

Impact of carrier hydrophilicity on solid self nano-emulsifying drug delivery system and self nano-emulsifying granule system.

The purpose of this study was to investigate the impact of carrier hydrophilicity on solid self nano-emulsifying drug delivery system (SNEDDS) and self nano-emulsifying granule system (SEGS). The mesoporous calcium silicate (Ca-silicate) and hydroxypropyl-ß-cyclodextrin (HP-ß-CD) were utilised as hydrophobic carrier and hydrophilic carrier, respectively. The liquid SNEDDS formulation, composed of Tween80/Kollipohr EL/corn oil (35/50/15%) with 31% (w/w) dexibuprofen, was spray-dried and fluid-bed granulated together with Avicel using Ca-silicate or HP- ß-CD as a solid carrier, producing four different solid SNEDDS and SEGS formulations. Unlike the Ca-silicate-based systems, spherical shape and aggregated particles were shown in HP-ß-CD-based solid SNEDDS and SEGS, respectively. Molecular interaction was detected between Ca-silicate and the drug; though, none was shown between HP-ß-CD and the drug. Each system prepared with either carrier gave no significant differences in micromeritic properties, crystallinity, droplet morphology, size, dissolution and oral bioavailability in rats. However, the HP-ß-CD-based system more significantly improved the drug solubility than did the Ca-silicate-based system. Therefore, both carriers hardly affected the properties of both solid SNEDDS and SEGS; though, there were differences in the aspect of appearance, molecular interaction and solubility.

Comparison of three tocopherol analogs as an inhibitor of production of proinflammatory mediators in macrophages.

Anti-inflammatory effects of tocopherol (TOL) analogs have been attributed to their potent antioxidant activities. However, we and others have separately reported that γTOL or α-tocopheryl succinate (αTOS), despite their lower antioxidant activities, inhibit lipopolysaccharide (LPS)-induced production of prostaglandin E(2) (PGE(2)) in macrophages and lung epithelial cells more effectively than αTOL. In the present study, we sought to directly analyze the effect of three TOL analogs (αTOL, αTOS, and γTOL) on LPS-induced production of pro-inflammatory mediators in macrophages. Our data demonstrated that the inhibitory effects of all three TOL analogs on nitric oxide production were very limited. In contrast, αTOS dose-dependently and significantly inhibited LPS-induced PGE(2) production in both RAW264.7 cells and peritoneal macrophages, whereas αTOL and γTOL were much less effective. Although αTOS had no effect on LPS-induced cyclooxygenase-2 expression, it did inhibit COX activity in intact cells. αTOS in combination with sulforaphane, a compound that blocked LPS-induced COX-2 expression, cooperatively and more significantly inhibited PGE(2) production. These findings suggest that αTOS is a more potent inhibitor of the pro-inflammatory mediator PGE(2). The inclusion of αTOS in vitamin supplements may further enhance the effectiveness of strategies for preventing diseases associated with inflammation.

Nanoscale iodized oil emulsion: a useful tracer for pretreatment sentinel node detection using CT lymphography in a normal canine gastric model.

BACKGROUND: Pretreatment identification of the sentinel lymph nodes (SLNs) in gastric cancer patients may have great advantages for minimally invasive treatment. No reliable method for the detection of SLNs during the pretreatment period in gastric cancer has been established. The aim of this study was to determine whether computed tomographic (CT) lymphography using nanoscale iodized oil emulsion via endoscopic submucosal injection can visualize LNs. METHODS: Five dogs underwent CT lymphography after endoscopic submucosal injection of 2 ml of a nanoscale iodized oil emulsion. CT images were taken before and 30, 90, and 210 min after contrast injection. Intraoperative SLN detection was performed using endoscopically injected indocyanine green lymphography for comparison. RESULTS: Computed tomographic lymphography with nanoscale iodized oil emulsion enabled the visualization of 19 enhanced LNs (mean = 3.8/dog, range = 3-6) with a 100% SLN detection rate. The locations of the SLNs were the lesser curvature (n = 7), greater curvature (n = 1), infrapyloric (n = 3), and left gastric (n = 8) areas. Contrast enhancement of SLNs continuously increased and peaked after 210 min at 142.4 ± 42.3 HU. No green LNs were visualized in the three locations that were detected by CT lymphography. However, no additional LNs were visualized using the dye method. The concordance rate based on the LNs between the SLNs on CT lymphography and the green LNs using the ICG method was 84% (16/19), whereas the concordance rate of the stations identified by CT lymphography and the dye method was 78.6% (11/14). CONCLUSIONS: Computed tomographic lymphography using nanoscale iodized oil emulsion is a promising tool for preoperative SLN detection for early gastric cancer if the biological safety of the nanoscale iodized oil emulsion can be established.

Hydroxypropyl-ß-cyclodextrin-based solid dispersed granules: A prospective alternative to conventional solid dispersion.

The purpose of the present study was to develop hydroxypropyl-ß-cyclodextrin (HP-ß-CD)-based solid dispersed granules as a superior system to solid dispersion. The solid dispersed granules and solid dispersion were compared in terms of powder property improvement, solubility increment and oral bioavailability enhancement of poorly water-soluble dexibuprofen. Solid dispersion (drug/HP-ß-CD/Tween80 = 1:7:0.1, weight ratio) and solid dispersed granules (drug/HP-ß-CD/Tween80/Microcrystalline cellulose = 1:7:0.1:4) were fabricated using a spray-dryer and fluid bed granulator, respectively. The HP-ß-CD-based solid dispersed granules significantly improved solubility, dissolution profile and oral bioavailability of dexibuprofen compared to pure drug powder. Moreover, the solid dispersed granules maximised the oral bioavailability of dexibuprofen to the same extent as the solid dispersion. However, considerable improvements of powder and tablet properties were observed in solid dispersed granules as compared with solid dispersion. Therefore, HP-ß-CD-based solid dispersed granules would be a prospective alternative to solid dispersion.

Preparation and in vitro evaluation of anti-VCAM-1-Fab'-conjugated liposomes for the targeted delivery of the poorly water-soluble drug celecoxib.

When an inflammatory stimulus is given, vascular endothelial cells express various cell adhesion molecules including the vascular cell adhesion molecule (VCAM)-1. In this study, the possibility of specifically delivering anti-inflammatory drugs to activated endothelial cells by utilizing VCAM-1 as a target receptor was explored by loading celecoxib, a selective cyclooxygenase-2 inhibitor, into liposomes coupled to the Fab' fragment against VCAM-1. Anti-VCAM-1-Fab'-conjugated liposomes were prepared by forming an amide linkage between amino groups of Fab' and the carboxylic group of glutaryl-N-phosphatidylethanolamine in liposomes using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as a cross-linker in the presence of sulpho-N-hydroxysuccinimide. The coupling of Fab' to phospholipids constituting liposomes was confirmed by SDS-PAGE analysis. Under our optimized conjugation conditions, 130.0 µg Fab' was coupled to 1 µmol liposomes. Immunoblotting analysis showed that VCAM-1 protein expression could be induced by incubating human umbilical vein endothelial cells (HUVEC) with TNF-α. Confocal laser microsopy analysis revealed that Fab' conjugation to liposomes selectively increased liposomal uptake in TNF-α-pre-stimulated (VCAM-1-expressed) HUVECs, but not in cells without VCAM-1 expression. The concentration of celecoxib loaded in Fab'-conjugated liposomes was 281.1 ± 29 µg/mL, suggesting that liposomal loading also helped to overcome the limitations in celecoxib administration caused by its poor water solubility. Celecoxib loaded in Fab'-conjugated liposomes inhibited prostaglandin E2 (PGE2) production induced by TNF-α-pre-stimulation more efficiently than when loaded in conventional liposomes. Therefore, Fab'-conjugated liposomes served as a drug delivery system with dual functions: targeted delivery and solubilizing capacity.

Enhanced Stability of Indocyanine Green by Encapsulation in Zein-Phosphatidylcholine Hybrid Nanoparticles for Use in the Phototherapy of Cancer.

Indocyanine green (ICG) is a clinically approved near-infrared dye that has shown promise as a photosensitizer for the phototherapy of cancer. However, its chemical instability in an aqueous solution has limited its clinical application. Encapsulating ICG in liposomes, phosphatidylcholine nanoparticles (PC-NP), has shown partial effectiveness in stabilizing it. Prompted by our recent finding that the zein-phosphatidylcholine hybrid nanoparticles (Z/PC-NP) provide an advanced drug carrier compared to PC-NP, we herein investigated the potential of Z/PC-NP as an improved ICG formulation. Dynamic light scattering analysis, transmission electron microscopy, and Fourier-transform infrared spectroscopy studies showed that ICG was encapsulated in Z/PC-NP without hampering the high colloidal stability of the Z/PC-NP. During storage, the Z/PC-NP almost completely inhibited the ICG aggregation, whereas the PC-NP did so partially. The Z/PC-NP also more effectively blocked the ICG degradation compared to the PC-NP. The phototoxicity of ICG encapsulated in Z/PC-NP on cancer cells was twofold higher than that in the PC-NP. The ICG encapsulated in Z/PC-NP, but not in PC-NP, maintained its photocytotoxicity after four-day storage. These findings highlight the promising potential of Z/PC-NP as an ICG formulation that provides a higher stabilization effect than PC-NP.

The Effect of a TLR4 Agonist/Cationic Liposome Adjuvant on Varicella-Zoster Virus Glycoprotein E Vaccine Efficacy: Antigen Presentation, Uptake, and Delivery to Lymph Nodes.

Adjuvant CIA09, composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)-based cationic liposomes and the toll-like receptor 4 agonist de-O-acylated lipooligosaccharide (dLOS), has been shown to enhance antibody and cellular immune responses to varicella-zoster virus (VZV) glycoprotein E (gE), recombinant tuberculosis vaccine antigen, and inactivated Japanese encephalitis vaccine. In this study, we investigated its modes of action using VZV gE as a model antigen. Liposomes adsorbed gE and cooperatively with dLOS promoted endocytosis-mediated cellular uptake of gE by mouse dendritic cells in vitro. CIA09 increased the stability and cellular uptake of the antigen at the muscle site of injection, and induced immune cell recruitment and cytokine and chemokine production, which led to efficient antigen delivery to draining lymph nodes. Mouse bone marrow-derived dendritic cells, pulsed with CIA09-adjuvanted gE, efficiently presented gE to antigen-specific T cells, inducing Th1-type biased immunity, as shown by high IFN-γ production. The data indicate that liposomes and dLOS cooperate in the adjuvant activity of CIA09 by promoting antigen uptake and delivery to lymph nodes as well as antigen presentation to T cells.

New potential application of hydroxypropyl-ß-cyclodextrin in solid self-nanoemulsifying drug delivery system and solid dispersion.

The purpose of this study was to use hydroxypropyl-ß-cyclodextrin (HP-ß-CD) as a novel carrier in solid SNEDDS and solid dispersions to enhance the solubility and oral bioavailability of poorly water-soluble dexibuprofen. The novel dexibuprofen-loaded solid SNEDDS was composed of dexibuprofen, corn oil, polysorbate 80, Cremophor® EL, and HP-ß-CD at a weight ratio of 45/35/50/15/100. This solid SNEDDS spontaneously formed a nano-emulsion with a size of approximately 120 nm. Unlike the conventional solid SNEDDS prepared with colloidal silica as a carrier, this dexibuprofen-loaded solid SNEDDS exhibited a spherical structure. Similar to the dexibuprofen-loaded solid dispersion prepared with HP-ß-CD, the transformation of the crystalline drug to an amorphous state with no molecular interactions were observed in the solid SNEDDS. Compared to the solid dispersion and dexibuprofen powder, solid SNEDDS significantly enhanced drug solubility and AUC. Therefore, HP-ß-CD is a novel potential carrier in SNEDDS for improving the oral bioavailability of dexibuprofen.