Transcript Document

The plasma needle: A non-thermal atmospheric plasma for treatment of
biological tissue
Ingrid Kieft, Raymond Sladek, Eva Stoffels
Department of Biomedical Engineering, Eindhoven University of Technology
P.O.Box 513, 5600 MB Eindhoven, The Netherlands
E-mail: [email protected]
Introduction
Cells and tissues (Ingrid Kieft)
Dental cavities (Raymond Sladek)
-Hand-operated tool
- Use of cultured fibroblast cells as model system [2]
-Atmospheric glow discharge
- Cell detachment observed within 30 s
- Temperature measurements inside pulp chamber
Plasma can be safely applied for 60s:
T < 2.2 oC [3]
Temperature increases after plasma off
-Effects studied in biomedical field [1]
 cells and tissues
 dental cavities
1
-No thermal damage
3
2
4
-Research divided in 2 parts:
Detached cells followed
in time. 1) control
sample,
2) 15 min. after
treatment, 3) 1 hour after
treatment, 4) 4 hours
after
treatment
-1. Cells and tissues: understanding of cell reactions and tissue
damage
- Radicals are expected to play major role in process:
Detected with fluorescent probe CM-H2DCFDA
-2. Dental cavities: Investigation of non-destructive and less painful tool
Concentration
in
µM
range
~
fysiological
concentration
to clean cavities
- Air admixture to helium <1%
Cells:
-lipids
-proteins
-DNA
Teeth:
-Bacteria
-Heat and pain for
pulp chamber
-First experiments on tissue engineered skin (by D. Bronneberg)
vacuole formation and detachment
Cross section of tissue
engineered skin.
Control sample (left) and
sample treated for 5 min
(right)
Plasma needle
Plasma parameters
•Plasma power
•Voltage peak to peak
•Helium flow
•frequency
< 100 mW
~600 V
2 l/min
13.56 MHz
(Raman scattering)
[1] Stoffels,E., Kieft, I.E., Sladek, R.E.J., “Superficial treatment of mammalian cells using
plasma needle”, J.Phys.D: Appl. Phys. 36 (2003) 2908-2913
[2] Kieft, I.E., Broers, J.L.V., Caubet-Hilloutou, V., Slaaf, D.W., Ramaekers, F.C.S.,
Stoffels, E., “Electric discharge plasmas influence attachment of cultured CHO K1 cells”,
accepted for publication in Bioelectromagnetics
[3] Zach, L. and Cohen, G., “Pulp response to externally applied heat”, Oral Surgery, Oral
Medicine, Oral Pathology, 19, no. 4, (1965) 515-530
- Bacterial cleaning: no need for 100 % decontamination
- Decontamination efficiency tested on E. coli
Colony forming units of
E. coli
- After plasma treatment bacteria are plated on Agar culture dishes,
colony forming units are counted
Colony forming units of E.
coli as function of time of
treatment by He plasma
Conclusions
- Time to kill 90 % of bacteria is about 40s.
• Cells detach after plasma treatment, and remain alive. They are
capable of reattachment and cytokinesis.
Conclusions
•Radicals reach the liquid in fysiological concentrations.
References:
Temperature recorded by a PT-100
inserted in the root channel.
From bottom to top:
setting at 200, 230, 270, 300,340 mV
Plasma switched off at t=60 s
•More molecules in plasma leads to less radicals.
• The high precision plasma treatment can have applications in
wound healing and cancer treatment.
•Little temperature increase (1-5 oC) in the gas
•Even less in dental tissue
•Teeth can be safely exposed to the plasma
•No pain is experienced
•Plasma treatment is a promising technique in dental care