Determination of Nonspherical Morphology of Doxorubicin-Loaded Liposomes by Atomic Force Microscopy

The 3-D morphology of doxorubicin (DOX)–loaded liposomes with a size of circa 100 nm was characterized by atomic force microscopy in an aqueous environment. Prolate liposomes appear in accordance with linear expansion of DOX fiber bundles precipitated inside liposomes. Oblate and concave liposomes were simultaneously observed with increased DOX concentrations; however, their morphologies were not readily determined by 2-D cryo-TEM imaging. Precise data analysis of the 3-D parameters of each liposome allowed semiquantitative evaluation of the transformation of spherical liposomes into nonspherical—prolate, oblate, and concave liposomes. In addition, nonspherical liposomes became spherical on the replacement of the liposomal outer phase consisting of a sucrose solution, with water and subsequent water influx. All spherical liposomes transformed into oblate and concave liposomes with a return to hyperosmotic conditions, when transferred from water to sucrose solution. Furthermore, the concave liposomes did not appear under DOX incubation conditions (65°C), which could be due to the amorphous and supersaturated DOX inside the liposomes that restrained liposomal shrinkage. As atomic force microscopy has improved our ability to image 3-D morphologies of liposomes in various conditions, it is an alternative analytical tool to cryo-TEM and may have future applications in regulatory tests for quality control and assurance.     

Dehydropropylpantothenamide isolated by a co-culture of Nocardia tenerifensis IFM 10554T in the presence of animal cells

Journal of Natural Medicines - A new amide, named dehydropropylpantothenamide (1), was obtained by a co-culture of Nocardia tenerifensis IFM 10554T in the presence of the mouse macrophage-like cell...     

L-PGDS-derived PGD2 attenuates acute lung injury by enhancing endothelial barrier formation

Acute lung injury (ALI) is caused by various stimuli such as acid aspiration and infection, resulting in severe clinical outcomes with high mortality. Prostaglandin D₂ (PGD₂) is a lipid mediator produced in the lungs of patients with ALI. There are two prostaglandin D synthases (PGDS), namely, lipocalin-type PGDS (L-PGDS) and hematopoietic PGDS (H-PGDS). We previously reported the anti-inflammatory role of H-PGDS-derived PGD₂ in an endotoxin-induced murine ALI model. Therefore, in this study, we investigated the role of L-PGDS-derived PGD₂ in ALI in comparison to H-PGDS-derived PGD₂. Intratracheal administration of HCl caused lung inflammation accompanied by tissue edema and neutrophil accumulation in mouse lungs. The deficiency of both L-PGDS and H-PGDS exacerbated HCl-induced lung dysfunction to a similar extent. Furthermore, a detailed investigation revealed that L-PGDS-derived PGD₂ inhibited lung edema, while H-PGDS-derived PGD₂ inhibited neutrophil infiltration. Immunostaining showed that inflamed endothelial/epithelial cells express L-PGDS, while macrophages and neutrophils express H-PGDS. Hematopoietic reconstitution with WT bone marrow did not rescue the exacerbated lung edema in L-PGDS deficient mice, indicating the importance of nonhematopoietic endothelial/epithelial cell-expressing L-PGDS for protection against ALI. A modified Miles assay showed that L-PGDS deficiency accelerated vascular hyper-permeability in the inflamed lung, which was suppressed by the stimulation of D prostanoid (DP) receptor, a PGD₂ receptor. In vitro, DP agonism enhanced the barrier function of endothelial cells but not epithelial cells. Taken together, our results suggest that in the HCl-induced murine ALI model PGD₂ was produced locally by inflamed endothelial and epithelial L-PGDS and this enhanced the endothelial barrier through the DP receptor. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Malt1 inactivation attenuates experimental colitis through the regulation of Th17 and Th1/17 cells

Inflammation Research - Protease activity of MALT lymphoma-translocation protein 1 (Malt1) plays an important role in the development of colitis, but the detailed mechanism has not been fully...     

The influence of medial implant location in three-unit posterior cantilever fixed partial dentures on stress distribution in surrounding mandibular bone

This study examined the influence of medial implant location in three-unit posterior cantilever fixed partial dentures (FPDs) on stress distribution in mandibular bone surrounding two implants. A three-dimensional finite element model that included three-unit FPD and two cylindrical-type implants (4 mm in diameter and 10 mm in length) osseointegrated in the posterior mandible, was digitized. Five different models were created according to the medial implant location between the missing second premolar and the first molar location. The distal implant was fixed at the missing second molar location. Oblique bite force of 100 N at 30 degrees buccal to the vertical direction was directed on each of three artificial teeth, respectively and simultaneously, while the lower surface of the mandible was fixed. The maximum equivalent stress in the cortical and the trabecular bone generally increased as the medial implant shifted to a distal position. Under the simultaneous bite force, relatively low maximum stresses within the cortical bone: between 55 MPa and 57 MPa, were shown in the models with the medial implant placed within the range of one implant diameter from the most medial position, while higher maximum stresses: between 64 MPa and 73 MPa, were demonstrated with more distally placed medial implants. The results suggest that reasonably low mechanical stress in the surrounding bone may be assured when the medial implant is placed in the range between the missing second premolar position and one implant diameter distal from that location.     

Helicobacter pylori and Campylobacter rectus share a common antigen

AIM: The aim of this study was to investigate the presence of antigens with immunological cross-reactivity in periodontopathogenic bacteria and Helicobacter pylori, the pathogen associated with gastritis and peptic ulcers in human. MATERIALS AND METHODS/RESULTS: Among the putative periodontopathogens tested (Actinobacillus actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola), cross-reactive bands were only detected in C. rectus by SDS-PAGE/Western immunoblotting analysis using a polyclonal antibody directed to H. pylori cells. One of these cross-reactive antigens, a 64-kDa band antigen, also reacted with a monoclonal antibody directed to the human heat shock protein (HSP) 60. The N-terminal amino acid sequence of this C. rectus protein revealed a high degree of homology with corresponding regions of other HSPs belonging to the HSP60 family, indicating that the 64-kDa antigen was a GroEL protein. The nucleotide sequence of the C. rectus GroEL protein coded for a 547 amino acid protein with a predicted size of 57.8 kDa. Comparison of the alignment of the deduced amino acid sequence of the GroEL protein of C. rectus with that of H. pylori showed a high degree of similarity throughout its length (76.8%). GroEL protein from C. rectus possessed the ability to stimulate production of IL-6 by a confluent monolayer of human gingival epithelial cells and was cytotoxic when used at a high concentration. CONCLUSIONS: This study reveals an immunological relationship between H. pylori and C. rectus, and clearly indicates that one of the shared antigens is a GroEL protein possessing a biological activity that might play a role in the initiation and progression of periodontal disease.     

Effect of rinsing alginate impressions using acidic electrolyzed water on dimensional change and deformation of stone models

This study investigated the effect of rinsing alginate impressions using acidic electrolyzed water on the dimensional change and deformation of stone models. Two brands of alginate impression materials were used. The impressions were rinsed using tap water or acidic electrolyzed water with a pH of 2.3, an oxidation-reduction potential of 1,230 mV, and a residual chlorine concentration of 45.0 ppm for 30 sec or 3 min. The sectional profiles of the stone models obtained from them were measured using a three-dimensional coordinate measuring system. For the same rinsing time, there was no significant difference in dimensional change between the two types of rinsing water. The change in shape from the master die was approximately the same for the stone models obtained from rinsed impressions using either water. The results suggest that the use of acidic electrolyzed water rather than tap water for rinsing is an acceptable treatment for alginate impressions.     

Possible involvement of extracellular signal-regulated kinases 1/2 in mitogenic response of periodontal ligament cells to enamel matrix derivative

The efficacy of enamel matrix derivative (EMD) as an adjunct to periodontal regenerative therapy has been demonstrated in recent clinical studies, however, little is known about its molecular mechanism (s). We examined the mitogenic response of cultured periodontal ligament (PDL) cells to EMD and characterized associated changes in proliferation-related intracellular signaling molecules, including mitogen-activated protein kinases (MAPK) and Akt kinases/protein kinase B (Akt/PKB) kinases. The DNA synthesis of PDL cells increased following treatment with EMD at concentrations higher than 1 microg ml(-1). This mitogenic response to EMD was associated with the selective activation of extracellular signal-regulated kinase (ERK) 1/2. No other MAPKs, or Akt/PKB kinases, responded to EMD stimulation. The EMD induction of DNA synthesis and activation of ERK 1/2 were diminished by pretreatment with suramin, an inhibitor of receptor tyrosine kinases (RTK). The signaling pathway induced by EMD from RTK to ERK 1/2 was similar to that activated by epidermal growth factor (EGF), although the specific binding of 125I-EGF to PDL cells was not affected by pretreatment or concomitant treatment with EMD. These findings suggest that EMD elicits its mitogenic signal through an EMD-specific RTK towards ERK 1/2.     

Local ofloxacin delivery using a controlled-release insert (PT-01) in the human periodontal pocket

PT-01, a controlled-release insert, was developed for topical chemotherapy in periodontal disease. It is a soluble insert that consists of fast-release and sustained-release parts containing ofloxacin (OFLX) as an antibacterial agent. In this study, the release profile of OFLX from PT-01 was investigated in vitro. Twelve adult volunteers were administered OFLX as PT-01 or as an aqueous solution into their periodontal pockets, OFLX concentrations in gingival crevicular fluid (GCF) were evaluated from the viewpoint of pharmacokinetics. The in vitro release profile of OFLX from PT-01 showed a biphasic pattern. The release rate of OFLX was relatively rapid in the early phase and slow thereafter. When OFLX aqueous solution was administered into periodontal pockets, the OFLX level in GCF rapidly decreased to be about 1/100 after 30 minutes. When PT-01 was inserted into the pockets, the OFLX level in GCF immediately reached a peak (about 12 mg/ml), and gradually decreased until the 3rd day, and maintained a constant level above 2 micrograms/ml, the effective minimum antibacterial concentration for periodontopathic microorganisms, from the 3rd to 7th day after insertion. No side-effects were observed in the volunteers who received the PT-01 insert. The above results suggest that PT-01 is a suitable pharmaceutical preparation for periodontal chemotherapy.