Effect of fiber surface treatment on mechanical, interfacial, and moisture absorption properties of cattail fiber-reinforced composites

AUTHORS

Md Shadhin, Raghavan Jayaraman, Mashiur Rahman, Danny Mann

ABSTRACT

Surface treatment of cattail, a lignocellulosic renewable fiber, was investigated to determine the conditions that would reduce moisture absorption while maximizing the properties of cattail fiber-reinforced unsaturated polyester composites. Surface modification of cattail fiber was studied by treating them with 2.5, 5, and 10% of 1,6-diisocyanatohexane (DIH) and 2-hydroxyethyl acrylate (HEA) for three different immersion times (10, 20, and 30 min). DIH-HEA treated fibers were preformed into a non-woven mat and impregnated with unsaturated polyester resin to manufacture composite. The existence of covalent bonds on the treated fibers via NH and CN groups was confirmed by FTIR spectroscopy. The 10% DIH-HEA resulted in the best results; while the mean diameter of the treated fiber decreased by ~37%, the modulus and the strength of it increased by ~267 and ~151%, respectively. Equilibrium moisture regain of the treated fibers and their composites decreased by ~43% and ~40%, respectively. The tensile modulus of the composites increased by ~171%. Enhancement in tensile strength is observed but could not be quantified due to the difference in Vf and scatter in the data. SEM examination confirmed the enhancement in fiber–matrix bonding due to surface treatment.

FKBP5 drives bone marrow stem cells senescence and suppresses osteogenic differentiation via canonical WNT/β-catenin signaling pathway

AUTHORS

Bin Zhu, Bowen Cai, Kaixiao Xue, Guoyong Yin, Shumin Zhou, Jiahu Fang

ABSTRACT

Senile osteoporosis and associated fractures significantly increase the morbidity and mortality of older people, thus increasing the cost of public health. Further investigations are required to explore the molecular causes of senile osteoporosis. In this study, FKBP5 expression in bone marrow mesenchymal stem cells (BMSCs) increased with age, and the degree of expression was inversely related to the patient's bone mineral density or CT values. Functional studies have validated the regulatory function of FKBP5 in BMSCs osteogenesis differentiation through the canonical WNT/β-catenin signaling pathway by binding to β-catenin and promoting its ubiquitination and degradation. Administration of SAFit2, a selective inhibitor of FKBP5, enhanced bone density in an animal model of senile osteoporosis. These findings suggest that FKBP5 may be a novel target and offer a new perspective on osteoporosis treatment.

The synergistic treatment of cyclolinopeptide J and calcium carbonate nanoparticles for osteoporosis via BMP/Wnt signaling: In vivo and in vitro

AUTHORS

Jiazi Chen, Wen Li, Yee-Ying Lee, Zizhe Cai, Jing Chen, Yong Wang

ABSTRACT

This research focuses on the investigation of cyclolinopeptide J (CLJ), a bioactive peptide naturally present in flaxseed, which loaded in porous calcium carbonate (CA) nanoparticles (JCA) to augment the effectiveness of CLJ on osteogenesis. The JCA was successfully synthesized with a high loading capacity (47.8 %) and encapsulation efficiency (95.6 %). Results showed that CLJ exerted an excellent osteogenic effect at 10 µM in MC3T3-E1 cells. CLJ and CA have been shown to activate osteogenic factors by modulating the Wnt/β-catenin and BMP/Smad signaling pathways. Furthermore, JCA treatment exhibited a remarkable ability to restore the intricate trabecular characteristics of bone in OVX-induced mice. The trabecular bone architecture observed in JCA-treated mice closely resembled that of healthy controls, indicating a substantial amelioration of osteoporotic bone loss. Our findings highlight the synergistic treatment of CLJ and CA in restoring bone integrity and structure and provide compelling evidence for the effectiveness of this novel functional supplement.

Sympathetic Overdrive and Unrestrained Adipose Lipolysis Drive Alcohol-Induced Hepatic Steatosis in Rodents

AUTHORS

Chunxue Zhou 1, Henry H. Ruiz, Li Ling, Giulia Maurizi, Kenichi Sakamoto, Claudia Liberini, Ling Wang, Adrien Stanley, Hale E. Egritag, Sofia M. Sanz, Claudia Lindtner, Mary A. Butera, Christoph Buettner

ABSTRACT

Objective

Hepatic steatosis is a key initiating event in the pathogenesis of alcohol-associated liver disease (ALD), the most detrimental organ damage resulting from alcohol use disorder. However, the mechanisms by which alcohol induces steatosis remain incompletely understood. We have previously found that alcohol binging impairs brain insulin action, resulting in increased adipose tissue lipolysis by unrestraining sympathetic nervous system (SNS) outflow. Here, we examined whether an impaired brain-SNS-adipose tissue axis drives hepatic steatosis through unrestrained adipose tissue lipolysis and increased lipid flux to the liver.

Methods

We examined the role of lipolysis, and the brain-SNS-adipose tissue axis and stress in alcohol induced hepatic triglyceride accumulation in a series of rodent models: pharmacological inhibition of the negative regulator of insulin signaling protein-tyrosine phosphatase 1β (PTP1b) in the rat brain, tyrosine hydroxylase (TH) knockout mice as a pharmacogenetic model of sympathectomy, adipocyte specific adipose triglyceride lipase (ATGL) knockout mice, wildtype (WT) mice treated with β3 adrenergic agonist or undergoing restraint stress.

Results

Intracerebral administration of a PTP1b inhibitor, inhibition of adipose tissue lipolysis and reduction of sympathetic outflow ameliorated alcohol induced steatosis. Conversely, induction of adipose tissue lipolysis through β3 adrenergic agonism or by restraint stress worsened alcohol induced steatosis.

Conclusions

Brain insulin resistance through upregulation of PTP1b, increased sympathetic activity, and unrestrained adipose tissue lipolysis are key drivers of alcoholic steatosis. Targeting these drivers of steatosis may provide effective therapeutic strategies to ameliorate ALD.

Loss of Notch signaling in skeletal stem cells enhances bone formation with aging

AUTHORS

Lindsey H. Remark, Kevin Leclerc, Malissa Ramsukh, Ziyan Lin, Sooyeon Lee, Backialakshmi Dharmalingam, Lauren Gillinov, Vasudev V. Nayak, Paulo El Parente, Margaux Sambon, Pablo J. Atria, Mohamed A. E. Ali, Lukasz Witek, Alesha B. Castillo, Christopher Y, Park, Ralf H. Adams, Aristotelis Tsirigos, Sophie M. Morgani & Philipp Leucht

ABSTRACT

Skeletal stem and progenitor cells (SSPCs) perform bone maintenance and repair. With age, they produce fewer osteoblasts and more adipocytes leading to a loss of skeletal integrity. The molecular mechanisms that underlie this detrimental transformation are largely unknown. Single-cell RNA sequencing revealed that Notch signaling becomes elevated in SSPCs during aging. To examine the role of increased Notch activity, we deleted Nicastrin, an essential Notch pathway component, in SSPCs in vivo. Middle-aged conditional knockout mice displayed elevated SSPC osteo-lineage gene expression, increased trabecular bone mass, reduced bone marrow adiposity, and enhanced bone repair. Thus, Notch regulates SSPC cell fate decisions, and moderating Notch signaling ameliorates the skeletal aging phenotype, increasing bone mass even beyond that of young mice. Finally, we identified the transcription factor Ebf3 as a downstream mediator of Notch signaling in SSPCs that is dysregulated with aging, highlighting it as a promising therapeutic target to rejuvenate the aged skeleton.

Histological Compatibility in Distal Neurotizations: A Systematic Review

AUTHORS

Cristina Schmitt Cavalheiro, João Carlos Nakamoto, Teng Hsiang Wei, Luiz Sorrenti, Erick Yoshio Wataya

ABSTRACT

Considering the importance of defining the minimum number of axons between recipient and donor branches, that is, the definition of histological compatibility in distal neurotizations for the success of the procedure and the surgeon's freedom to choose individualized strategies for each patient, this systematic review was conducted to find out the most recent studies on the subject. The objective of this systematic review was to determine the importance of the number of axons and the relationship between axon counts in the donor and recipient nerves in the success of nerve transfer. A literature review was performed on five international databases: Web of Science, Scopus, Wiley (Cochrane Database), Embase, and PubMed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed (2020 version), a guide designed to guide the elaboration of systematic literature reviews. One hundred and fifty-seven studies were found, and 23 were selected based on the eligibility criteria. The articles presented were conclusive in determining the importance of the number of axons in the success of nerve transfer. Still, the relationship between the number of axons in the donor and recipient nerves seems more relevant in the success of transfers and is not always explored by the authors. The review of the articles has provided compelling evidence that the number of axons is a critical determinant of the success of nerve transfer procedures. However, the relationship between the number of axons in the donor nerve and that in the recipient nerve appears to be even more crucial for successful transfers, a factor that is not always adequately explored by authors in the existing literature.