Non pharmacological high-intensity ultrasound treatment of human dermal fibroblasts to accelerate wound healing

Designed Nanodrugs for Ultrasonic Removal of Toxic Polyglutamine Aggregates from Neuron Cells

Clearing of toxic polyglutamine aggregates from neuronal cells is crucial for ameliorating Huntington's disease. However, such clearance is challenging, requiring the targeting of affected neuron cells in the brain, followed by the removal of polyglutamine from cells. Here we report a designed nanodrug that can be used for the ultrasound-based removal of toxic polyglutamine aggregates from neuron cells. The nanodrug is composed of a sonosensitizer molecule, chlorin e6- or protoporphyrin IX-loaded polymer micelle of 20-30 nm in size that rapidly delivers the sonosensitizer into the cell nucleus. Ultrasound exposure of these cells generates singlet oxygen in the nucleus/perinuclear region that induces strong autophagic flux and clears toxic polyglutamine aggregates from cells. It has been demonstrated that the nanodrug and ultrasound treatment can enhance the cell survival against polyglutamine aggregates by 4 times. This result suggests that the nanodrug can be designed for focused ultrasound-based wireless treatment of various neurodegenerative diseases.

Effect of Therapeutic Ultrasound on the Mechanical and Biological Properties of Fibroblasts

Purpose

This paper explores the effect of therapeutic ultrasound on the mechanical and biological properties of ligament fibroblasts.

Methods and Results

We assessed pulsed ultrasound doses of 1.0 and 2.0 W/cm2 at 1 MHz frequency for five days on ligament fibroblasts using a multidisciplinary approach. Atomic force microscopy showed a decrease in cell elastic modulus for both doses, but the treated cells were still viable based on flow cytometry. Finite element method analysis exhibited visible cytoskeleton displacements and decreased harmonics in treated cells. Colorimetric assay revealed increased cell proliferation, while scratch assay showed increased migration at a low dose. Enzyme-linked immunoassay detected increased collagen and fibronectin at a high dose, and immunofluorescence imaging technique visualized β-actin expression for both treatments.

Conclusion

Both doses of ultrasound altered the fibroblast mechanical properties due to cytoskeletal reorganization and enhanced the regenerative and remodeling stages of cell repair.

Lay Summary

Knee ligament injuries are a lesion of the musculoskeletal system frequently diagnosed in active and sedentary lifestyles in young and older populations. Therapeutic ultrasound is a rehabilitation strategy that may lead to the regenerative and remodeling of ligament wound healing. This research demonstrated that pulsed therapeutic ultrasound applied for 5 days reorganized the ligament fibroblasts structure to increase the cell proliferation and migration at a low dose and to increase the releasing proteins that give the stiffness of the healed ligament at a high dose.

Future Works

Future research should further develop and confirm that therapeutic ultrasound may improve the regenerative and remodeling stages of the ligament healing process applied in clinical trials in active and sedentary lifestyles in young and older populations.

Graphical abstract

K. PK, Han KH, Um W, Lee J, Lee JA, Jung JM, Kang H, Park JH. Self-immolative nanosensitizer for glutathione depletion- assisted sonodynamic therapy

Background: Despite remarkable advances in sonodynamic therapy (SDT) of cancer, the low reactive oxygen species (ROS) quantum yield of the sonosensitizer remains a critical concern in glutathione (GSH)-overexpressing cancer cells. Methods: For enhanced SDT, we report hydrophilized self-immolative polymer (SIP)-decorated TiO2 nanoparticles (HSIPT-NPs) to achieve on-demand GSH depletion and ROS generation. Results: Upon intracellular delivery of HSIPT-NPs into hydrogen peroxide-rich cancer cells, SIP is degraded through electron transfer to produce GSH-depleting quinone methide, reprogramming GSH high cancer cells into GSH low phenotype. In the presence of ultrasound, compared to conventional TiO2 NPs, HSIPT-NPs induce significantly higher oxidative stress to cancer cells by incapacitating their antioxidant effects. SDT with HSIPT-NPs effectively inhibit tumor growth in mice via the synergistic effects of GSH depletion and ROS generation. Conclusion: On the basis of their ability to reprogram cancer cells, HSIPT-NPs offer considerable potential as a nanosensitizer for enhanced SDT.

Adipose-derived stem cells-derived exosomes facilitate cutaneous wound healing by delivering XIST and restoring discoidin domain receptor 2

BACKGROUND

Adipose-derived stem cells (ADSCs) and their derived exosomes (ADSC-Exos) have shown potential functions in tissue repair. This study focuses on the effects of ADSCs-Exos on cutaneous wound healing and the potential involvement of the long non-coding RNA (lncRNA) XIST/microRNA-96-5p (miR-96-5p)/discoidin domain receptor 2 (DDR2) axis.

METHODS

Exos were isolated from the ADSCs and identified. A mouse model of full-thickness skin wounds was established. The mice were treated with ADSC-Exos to evaluate the function of ADSC-Exos in wound healing. Mouse dermal fibroblasts (MDFs) were co-cultured with the ADSC-Exos for in vitro experiments. The most differentially expressed lncRNAs in mouse skin tissues after ADSC-Exo treatment were screened by microarray analysis. The downstream molecules were analyzed by bioinformatics tools. Gain- and loss-of-function studies were performed to examine the functions of the XIST/miR-96-5p/DDR2 axis in wound healing.

RESULTS

ADSC-Exos facilitated wound healing in mice, reduced inflammatory infiltration, and increased collagen deposition in the wound skin tissues. In vitro, the ADSC-Exos promoted proliferation, migration of the MDFs. XIST was the most upregulated lncRNA in MDFs after ADSC-Exo treatment. Downregulation of XIST suppressed the promoting role of ADSC-Exos in wound healing. XIST bound to miR-96-5p to restore the expression of DDR2 mRNA. Either silencing of miR-96-5p or overexpression of DDR2 restored the promoting functions of ADSC-Exos in proliferation and migration of MDFs.

CONCLUSION

This study demonstrates that ADSC-Exos-carried XIST accelerates cutaneous wound healing through suppressing miR-96-5p and restoring the DDR2 expression.