Contractile myocytes provide a test of the hypothesis that cells sense their mechanical as well as molecular microenvironment, altering expression, organization, and/or morphology accordingly. Here, myoblasts were cultured on collagen strips attached to glass or polymer gels of varied elasticity. Subsequent fusion into myotubes occurs independent of substrate flexibility. However, myosin/actin striations emerge later only on gels with stiffness typical of normal muscle (passive Young's modulus, E approximately 12 kPa). On glass and much softer or stiffer gels, including gels emulating stiff dystrophic muscle, cells do not striate. In addition, myotubes grown on top of a compliant bottom layer of glass-attached myotubes (but not softer fibroblasts) will striate, whereas the bottom cells will only assemble stress fibers and vinculin-rich adhesions. Unlike sarcomere formation, adhesion strength increases monotonically versus substrate stiffness with strongest adhesion on glass. These findings have major implications for in vivo introduction of stem cells into diseased or damaged striated muscle of altered mechanical composition.

/pdf/myotubes-differentiate-optimally-on-substrates-with-tissue-2s499cqco3.pdf

Myotubes differentiate optimally on substrates with tissue-like stiffness: pathological implications for soft or stiff microenvironments

https://nanomechanics.mit.edu/sites/default/files/documents/2007_Acta_Bio_Cancer_S.Suresh.pdf

Biomechanics and biophysics of cancer cells.

https://faculty.washington.edu/nsniadec/ME599/S09/private/8Solon.pdf

Fibroblast Adaptation and Stiffness Matching to Soft Elastic Substrates

AFM indentation study of breast cancer cells.

http://www.medic.ula.ve/histologia/anexos/microscopweb/MONOWEB/anexos/atomicforce.pdf

Atomic force microscopy probing of cell elasticity.

https://home.uni-leipzig.de/pwm/web/download/Mahaffy2004.pdf

Quantitative analysis of the viscoelastic properties of thin regions of fibroblasts using atomic force microscopy.

Cell motility and local viscoelasticity of fibroblasts.

Alzheimer’s disease (AD) is an irreversible and progressive neurodegenerative disorder. Most existing treatments only provide symptomatic solutions. Here, we introduce currently available commercial drugs and new therapeutics, including repositioned drugs, to treat AD. Despite tremendous efforts, treatments targeting the hallmarks of AD show limited efficacy. Challenges in treating AD are partly caused by difficulties in penetrating the blood–brain barrier (BBB). Recently, nanoparticle (NP)-based systems have shown promising potential as precision medicines that can effectively penetrate the BBB and enhance the targeting ability of numerous drugs. Here, we describe how NPs enter the brain by crossing, avoiding, or disrupting the BBB. In addition, we provide an overview of the action of NPs in the microenvironment of the brain for the treatment of AD. Diverse systems, including liposomes, micelles, polymeric NPs, solid-lipid NPs, and inorganic NPs, have been investigated for NP drug loading to relieve AD symptoms, target AD hallmarks, and target moieties to diagnose AD. We also highlight NP-based immunotherapy, which has recently gained special attention as a potential treatment option to disrupt AD progression. Overall, this review focuses on recently investigated NP systems that represent innovative strategies to understand AD pathogenesis and suggests treatment and diagnostic modalities to cure AD.

/pdf/recent-advances-in-the-treatment-of-alzheimers-disease-using-2n3g0ur1.pdf

Soyeun Park

Papers

Quantitative analysis of the viscoelastic properties of thin regions of fibroblasts using atomic force microscopy.

Cell motility and local viscoelasticity of fibroblasts.

Recent Advances in the Treatment of Alzheimer’s Disease Using Nanoparticle-Based Drug Delivery Systems

Mechanical characterization of multi-layered lipid nanoparticles using high-resolution AFM force spectroscopy

A nanomechanical strategy involving focal adhesion kinase for overcoming drug resistance in breast cancer.