Category Archives: Medical electronics

Accelerated Wound Healing on Skin by Electrical Stimulation with a Bioelectric Plaster

Journal: Advanced Healthcare Materials

Author: Hiroyuki Kai and Matsuhiko Nishizawa et al.

Affiliation: Tohoku University, Japan

Publication date: 2017.09.20

Summarized by Inyeol Yun

 

– Bioelectric Plaster (Fig. 1)
v. Wound healing on skin involves cell migration and proliferation in response to endogenous electric current.
v. External electrical stimulation is used to promote these biological processes for the treatment of chronic wounds.
v. An enzymatic biofuel cell (EBFC) that generates ionic current along the surface of the skin by enzymatic electrochemical reactions for more than 12h. (Fig. 2)

fig1

Fig. 1

fig2.png

Fig. 2

 

– Materials
v. Cathode : carbon fiber fabric coated with carbon nanotubes, on which reducing enzyme bilirubin oxidase
v. Anode : carbon fiber fabric coated with carbon nanotubes, on which oxidizing enzyme fructose dehydrogenase
v. Hydrogel : citrate buffer solutions with different concentrations of fructose.
v. Stretchable resistor : PEDOT/PU film

 

– Result
v. Time-dependent current changes of the bioelectric plaster with different external resistances and citrate buffer solutions with different concentrations. (Fig. 3)
v. Changes of wound width and height of Group A (gray), Group B (red), and Group C (blue) (Fig. 4)
v. Microscopy images of skin sections at the wound at day 7: a) the boundary between normal tissue and healed tissue, b) the area of normal tissue, c) the area of healed tissue, d) dermis, e) fat tissue (Fig. 5)  Group C > Group A on scar after healing, wound closure speed.

fig3

Fig. 3

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Fig. 4

fig5.png

Fig. 5

 

– Reference
v. https://en.wikipedia.org/wiki/Enzymatic_biofuel_cell (accessed September 26, 2017)

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Top Down Fabrication Meets Bottom-up Synthesis for Nanoelectronic Barcoding of Micro Particles

Journal: Lab on a chip

Publication date: 2017. 06

Summarized by Jinpyeo Jeung

 

– Nanoelectrically barcoded micro particles (Fig. 1)

v. Could be used in biomarker based diagnostics

v. Allows miniaturization of the readout instrument thus suitable for wearable device

v. Structure similar to Janus microparticles (JPs)

v. Polystyrene bead (3μm diameter), gold (20nm), Aluminium oxide (5nm, 20nm)

v. Due to difference in capacitance of bead, shows different frequency response (Fig. 2)

fig1.png

Fig. 1

fig2.png

Fig. 2

 

– Fabrication (Fig. 3)

v. Polystyrene microsphere self assembled onto a glass substrate using drop-casting

v. Wafer heated to evaporate liquid

v. Using electron beam evaporation, deposited gold layer

v. Using ALD, deposited an insulative layer

v. Particles lifted off from the film using ultrasonification

fig3.png

Fig. 3

 

– Result (Fig. 4)

v. 4 different bead could be distinguished by frequency response data

v. successful barcoding of micro particles

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Fig. 4