Injectable and Thermosensitive Soluble Extracellular Matrix and Methylcellulose Hydrogels for Stem Cell Delivery in Skin Wounds

Extracellular matrix (ECM) provides structural support and biochemical cues for tissue development and regeneration. Here we report a thermosensitive hydrogel composed of soluble ECM (sECM) and methylcellulose (MC) for injectable stem cell delivery. The sECM was prepared by denaturing solid ECM extracted from human adipose tissue and then blended with a MC solution. At low temperatures, the sECM-MC solution displayed a viscous solution state in which the loss modulus (<i>G</i>″) was predominant over the storage modulus (<i>G</i>′). With increasing temperature, <i>G</i>′ increased dramatically and eventually exceeded <i>G</i>″ around 34 °C, characteristic of the transition from a liquid-like state to an elastic gel-like state. After a single injection of the stem cell-embedded hydrogel in full thickness cutaneous wound, the wound healed rapidly through re-epithelialization and neovascularization with minimum scar formation. The overall results suggest that in-situ-forming sECM-MC hydrogels are a promising injectable vehicle for stem cell delivery and tissue regeneration

Table_1_One-year prevalence and clinical characteristics in chronic dizziness: The 2019–2020 Korean National Health and Nutrition Examination Survey.docx

IntroductionIn this cross-sectional study, we investigated the 1-year prevalence and related factors in the general population with an experience of chronic dizziness.MethodsThis study analyzed persons (n = 5,163) who respond to dizziness and nutrition questionnaire from participant of Korean National Health and Nutrition Examination Survey (KNHANES, 2019-2020).ResultsOf individuals over 40 years, 25.3% of the general population (61.6% females) reported either dizziness or imbalance for the past year. Moreover, 4.8% of the patients reported they suffered from chronic dizziness or imbalance for more than 3 months. In multiple regression analysis, patients with chronic dizziness were older, females, had lower body mass index (BMI), had stress awareness, and had a history of tinnitus within 1 year (>5 min per episode). Relative to normal body weight, both overweight and mild obesity (obesity stages 1 and 2) were associated with a significantly lower risk of chronic dizziness. Overweight, obesity stage 1, and obesity stage 2 had odds ratios of 0.549 [95% confidence interval (CI), 0.332–0.910], 0.445 (95% CI, 0.273–0.727), and 0.234 (95% CI, 0.070–0.779), respectively.ConclusionsIn this study, the prevalence of chronic dizziness in the general population was 4.8%. Our study demonstrated that overweight and mild obesity were independently associated with a lower risk of chronic dizziness in adults for the past year. Therefore, the optimal BMI for patients with dizziness should be defined and managed according to an integrated care pathway.</p

Foamy histiocyte with intracellular fatty lobules and neo-vascularization in the injected sECM/MC hydrogels.

<p>(A) Focal capillary ingrowths (arrowhead) into the injection site. Cell aggregations with intracellular fatty lobules in the injection area (asterisk). (B) RAM 11 positive cells (dark brown) are foamy histiocytes, which increased as a function of time.</p

Laryngoscopic images after injection laryngoplasty of sECM/MC hydrogels into the left paralyzed vocal fold.

<p>The sECM/MC hydrogel injection group exhibited a straight and medialized vocal fold (white arrowhead) while the control group had a curved and lateralized vocal fold (black arrowhead), which is likely due to denervation of the recurrent laryngeal nerve.</p

Shape-Controlled Anisotropic Block Copolymer Particles via Interfacial Engineering of Multiple-Phase Emulsions

Block copolymers (BCPs) confined within nonspherical emulsion droplets can assemble into anisotropic particles with tunable shapes and internal structures. Here, we present a versatile strategy for producing anisotropic BCP particles by incorporating a nonsolvent into evaporative emulsion droplets. The immiscibility between the BCP-rich phase and the nonsolvent induces liquid–liquid phase separation to yield a double emulsion, providing a nonspherical compartment for the confined self-assembly of BCPs. The configuration of the double emulsion can be effectively controlled from Janus to core–shell by using either silicone oil or hexadecane as the nonsolvent. Furthermore, the choice of surfactants used for stabilizing the Janus emulsion is critical in determining the final structure of the particles. Mushroom-shaped particles, featuring a hyperbolic protrusion and a hemisphere, are produced from a confined assembly of BCPs in a Janus emulsion under asymmetric wetting conditions. On the other hand, a kidney bean-shaped particle, featuring an ellipsoid with a dimple on the low-curvature interface, is generated under neutral wetting conditions. Detailed analysis of the structural features of each particle reveals that (i) the asymmetric wetting condition from BCP/water and BCP/nonsolvent interface and (ii) the weak interfacial selectivity at BCP/nonsolvent interface play important roles in determining the particle shape. Furthermore, we demonstrate that the shape anisotropy of both mushroom-shaped and kidney bean-shaped particles can be finely tuned by varying the volume fraction of the nonsolvent

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold - Fig 2

<p><b>Representative serial images of high-speed camera recording at 8 weeks (A), the asymmetric index using videokymograms (B) and the results of asymmetry index for vocal functional analysis (C)</b>. (A) Normal and symmetrical vocal contacts showed no change in the vibration of vocal mucosa in sECM/MC groups relative to the control group. (B) The maximum distance in the left denervated vocal fold (<i>a</i>) was compared to the right vocal fold (<i>b</i>) using a videokymogram to generate an asymmetry index. The asymmetry index was calculated as follows: Asymmetry index = <i>a</i> / <i>b</i>. (C) The mean asymmetry index of the sECM/MC hydrogel group (1.020 ± 0.069) and the control group (0.787 ± 0.102) are shown (<i>p</i> = 0.047 using a Mann-Whitney U test). In diseased conditions, the index deviates from the value of 1.0</p

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold - Fig 3

Standard hematoxylin and eosin (H&E) staining of rabbit larynx after injection laryngoplasty into the left paralyzed vocal fold (A) and the quantitative analysis of remaining volume of sECM/MC hydrogels (B). (A) Histological examination of the injected biomaterials at 8 weeks post procedure. Area of the laryngeal intrinsic muscle was smaller on the denervated side in the control group (green dotted line) than on the contralateral normal side. In the sECM/MC group, the laryngeal muscle area was compensated for by the injected sECM/MC hydrogel (brown dotted line). The injected sECM/MC hydrogel (arrowhead) induced no significant inflammatory response including neutrophils or lymphocytes aggregation in the surrounding muscle (*), lamina propria (†), or epithelium (‡). (B) Quantitative analysis of remaining sECM/MC hydrogel volume (p = 0.501 using Kruskal-Wallis test).</p

Effect of SmoA1 and Gα₁₃QL on 3T3-L1 adipogenic differentiation.

3T3-L1 fibroblasts were transduced with recombinant adenoviruses encoding with LacZ, SmoA1, or Gα13QL (MOI of 10), or no virus, in the presence of DEAE-dextran (10 μg/ml). The medium was replaced, and the cells were induced to differentiate with a combination of IBMX (0.5 mM), dexamethasone (0.25 μM), rosiglitazone (2 μM), and insulin (1 μg/ml) as described in ‘Materials and Methods’. The cells were fixed at 2 weeks, and triglyceride accumulation was evaluated with Oil Red O. The data shown are from one experiment representative of three total, each carried out in triplicate, ± SEM; **, p 490 for SmoA1 and Gα13QL relative to that for untransformed differentiated cells, subtracting the absorbance for undifferentiated cells, was 0.1 ± 0.07 for both SmoA1 and Gα13QL (p < 0.05).</p

Hypoxia Antagonizes Glucose Deprivation on Interleukin 6 Expression in an Akt Dependent, but HIF-1/2α Independent Manner

<div><p>Although both glucose deprivation and hypoxia have been reported to promote cascades of biological alterations that lead to induction of inflammatory mediators, we hypothesized that glucose deprivation and hypoxia might show neutral, synergistic or antagonistic effects to each other on gene expression of inflammatory mediators depending on the regulatory components in their promoters. Gene expression of interleukin 6 (IL-6) was analyzed by real-time PCR, ELISA, or Western blot. Effects of glucose deprivation and/or hypoxia on activation of signaling pathways were analyzed by time-dependent phosphorylation patterns of signaling molecules. We demonstrate that hypoxia antagonized the effects of glucose deprivation on induction of IL-6 gene expression in microglia, macrophages, and monocytes. Hypoxia also antagonized thapsigargin-induced IL-6 gene expression. Hypoxia enhanced phosphorylation of Akt, and inhibition of Akt was able to reverse the effects of hypoxia on IL-6 gene expression. However, inhibition of HIF-1/2α did not reverse the effects of hypoxia on IL-6 gene expression. In addition, phosphorylation of p38, but not JNK, was responsible for the effects of glucose deprivation on IL-6 gene expression.</p> </div

Stress fiber formation in response to SmoA1 and Gα₁₃QL.

<p>C3H10T1/2 cells grown on coverslips were serum-starved for 12 h then incubated with recombinant adenoviruses encoding LacZ, SmoA1, or Gα₁₃QL (MOI = 10) in the presence of DEAE-Dextran (10 μg/ml). They were serum-starved an additional 18 h and fixed with paraformaldehyde. F-actin was stained with FITC-Phalloidin, and nuclei were counterstained with DAPI. ‘Merge’ is pseudocolored. Shown is one experiment representative of three total. Few or no stress fibers were identified in the absence of transduction (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0197442#pone.0197442.s002" target="_blank">S2 Fig</a>).</p