Preparation of Degradable and Transformable Core–Corona-Type Particles that Control Cellular Uptake by Thermal Shape Change

Particle–cell interactions, such as cellular uptake, vary depending on the particle size, shape, and surface properties. By dynamic control of the physical properties of particles, microparticle–cell interactions can intentionally be altered. Particle degradability is also necessary for their application in the body. In this study, we aimed to prepare degradable core–corona-type particles that are deformed near the body temperature and investigated particle shape-dependent cellular uptake. Degradable and transformable particles consisting of poly(2-methylene-1,3-dioxepane)-co-poly(ethylene glycol) with three-armed poly(ε-caprolactone) (PCL) were prepared. The particle melting point was controlled by the chain length of the three-armed PCL. Particle degradation occurred under both acidic and alkaline conditions via ester group hydrolysis in the polymer backbones. The rod-shaped microparticles prepared by uniaxial stretching at a temperature above the melting point of the core showed less uptake into macrophages than did the spherical microparticles. Therefore, the degradable transformable particles enable macrophage interaction control via stimuli-regulated particle shapes and are expected to be applied as drug delivery carriers that can be decomposed and excreted from the body

A unique increase in prefrontal gray matter volume in hoarding disorder compared to obsessive-compulsive disorder

<div><p>Background</p><p>Hoarding disorder (HD) is a disease concept newly presented in DSM-5. As far as we know, no studies have examined the structural changes relevant to hoarding by applying the diagnostic criteria of HD in DSM-5. In the present study, we aimed to find abnormalities in gray matter (GM) structures of patients with HD.</p><p>Methods</p><p>Seventeen patients who met the DSM-5 criteria for HD, 17 obsessive-compulsive disorder (OCD) patients, and 17 healthy controls (HCs) participated in this study. All participants underwent MRI scanning of the brain by a 3.0-Tesla MRI scanner. In a voxel-based morphometric procedure, preprocessed GM structural images were used to compare the three groups. Thereafter we investigated the correlation between the clinical data (age of onset, symptomatic severity) and GM volume.</p><p>Results</p><p>The HD group showed a significantly increased GM volume compared to the OCD and healthy control groups (p<0.05) in both Brodmann area (BA)10 and BA11. There was no significant difference between OCD and healthy control groups. No significant correlation between the clinical data including age of onset, symptom severity score, and GM volume was observed in HD and OCD groups.</p><p>Conclusions</p><p>The results might help to explain the inconsistency of previous studies. As with OCD, HD is considered to have cognitive dysfunction as its basis. This result is convincing after considering the clinical features of HD and suggested that structural abnormalities in the prefrontal regions might relate to the pathophysiology of HD.</p></div

The results of ROI analysis.

<p>In the comparison of the three groups based on the gray matter volume obtained by ROI analysis, the HD group showed significantly increased GM volumes compared to the OCD group and the healthy control group (p<0.05) in both BA10 and BA11.</p

Demographic and clinical characteristics of all subjects.

<p>Demographic and clinical characteristics of all subjects.</p

The results of correlation analysis.

<p>No significant correlation between the DY-BOCS dimensional score (HD: hoarding score, OCD: contamination/washing score) and GM volume was observed in either the HD or OCD group.</p

Differences in GM volumes among three groups (HD, OCD, and HCs).

<p>Differences in GM volumes among three groups (HD, OCD, and HCs).</p

The results of VBM analyses.

<p>In voxel-based analysis of variance (ANOVA), three groups (HD, OCD, and HCs) exhibited the presence of significant regional GM volume differences in the right prefrontal regions. The initial voxel threshold was set to 0.001 uncorrected. Clusters were considered as significant when falling below a cluster-corrected p (FWE) = 0.05. The cluster size was 1228 voxels, and the p value was 0.004. Peak coordinates (Montreal Neurological Institute) were x = 20, y = 64, z = -18.</p

Cytotoxic effects of K-7174 on bortezomib-resistant MM cells.

<p>We established wild-type (WT) and mutant (mutant) sublines from RPMI8226 by transducing with wild-type and mutated <i>PSMB5</i> cDNA, respectively, and analyzed the expression of VENUS by flow cytometry (A) and proteasome ß5 subunit by immunoblotting (B). The signal intensities of ß5 subunit (PSMB5) were quantified, normalized to those of the corresponding GAPDH, and shown as relative values in the panel B. C. Cell proliferation was measured by MTT assays after culturing each subline with either K-7174 or bortezomib at the indicated doses for 72 hours. Results are represented as relative absorbance with untreated control set at 100%. The means ± S.D. (bars) of three independent experiments are shown. <i>P</i>-values were calculated by one-way ANOVA with the Student-Newman-Keuls multiple comparisons test. Asterisks indicate p<0.01 against the WT subline. D. Each subline was cultured with either K-7174 or bortezomib (Bort) at the indicated doses for 48 hours. Whole cell lysates were subjected to immunoblotting for cellular protein ubiquitination, proteasome ß5 subunit (PSMB5) and GAPDH (internal control).</p

Statistics of crystallographic analysis.

a<p>Completeness and <i>R-</i>merge, are given for overall data and for the highest resolution shell.</p><p>The highest resolution shells for the dataset were 2.54–2.50 Å.</p>b<p><i>R</i>merge = ∑ | <i>I_i</i> – <<i>I</i>> |/∑|<i>I_i</i>|; where <i>I_i</i> is intensity of an observation and <<i>I</i>> is the mean value of that reflection and the summations are over all equivalents.</p>c<p><i>R-work</i> = ∑<i>_h</i> || <i>Fo(h)</i> | – | <i>Fc(h)</i> ||/∑<i>_hFo(h)</i>; where <i>Fo</i> and <i>Fc</i> are the observed and calculated structure factor amplitudes, respectively. The <i>R-free</i> was calculated with 5% of the data excluded from the refinement.</p

Comparison of K-7174 and bortezomib in cytotoxic activity and proteasome binding.

<p>A. Cell proliferation was measured by MTT assays after culturing with serially diluted K-7174, K-10487 and bortezomib for 72 hours. Absorbance at 450 nm was analyzed with a microplate reader, and expressed as a percentage of the value of corresponding untreated cells. The IC₅₀ value was defined as the concentration of each drug that produces 50% inhibition of cell growth. The means ± S.D. (bars) of three independent experiments are shown. Asterisks indicate “not determined”. B. Overall crystallographic structures showing the folds of ß1 to ß7 subunits in the proteasome bound with K-7174 (left panel) and bortezomib (right panel). Mutation sites observed in bortezomib-resistant cells are circled. C. Structure of the proteasome in complex with bortezomib (PDB cord 2F16) overlapped that with K-7174 described here. Only the protein atoms of the bortezomib-bound form are shown. Bortezomib-resistant mutant residues (Ala49, Thr21, Cys52 and Met45) are colored red and shown as a space-filling diagram.</p