EFFECTS OF MULTI-WALLED CARBON NANOTUBES ON MURINE TM4 CELLS

Ciarán MullanImmunology and Toxicology

WHAT ARE NANO-PARTICLES 1-100nm

Unique Properties Sun-screens Baby powders Food packaging

High surface area to volume ratio

CARBON NANOPARTICLES Fullerines

Ultra-fine Carbon Black

Carbon Nanotubes

CARBON NANOTUBES Cylindrical mesh structure

Single and Multi-walled

Surface impurities

Diameter in nano-range

PRODUCTION OF CNTS Laser Ablation

Arc Deposition

Catalytic Methods

APPLICATIONS Electronics

CT/MRI imaging

Construction

Biomedical

NANOTUBE TOXICITY Structural Differences

Madani et al. – high aspect ratio = more toxic

Bottini et al. – functionalised = less toxic

Koyama et al. – metal impurities = more toxic

SERTOLI CELL “Nurse Cells”

Phagocytic Role

Role in Blood:Testis Barrier Maintenance

Separates developing sperm from immune system

RELEVANCE Declining Sperm Quality

Carlsen et al. – 50% decrease in 50 years 1940-1990

Many believe trend due to environmental toxicants

(Evidence is however somwhat disputed)

AIMS Develop the TM4 cell model

“To investigate the toxicty of various forms of multi-walled CNTs on murine Sertoli cells”

SO, WHAT DID I DO? Cultured primary TM4 cell line

Seeded 96 well plates

Treated with MWCNT

Conducted WST-1/Alamar Blue viability assay

RESULTS

SPL Plate

TPP Plate

0 0.125 1.25 12.5 25 50 100 2000

20

40

60

80

100

120

Coiled Vs Straight CNT Relat-ive % Viability

Coiled % viability Straight % viability

THE STATS

No significance for coiled CNTs P=0.382

Straight CNTs significant at 200µg/ml P=0.033

0 0.125 1.25 12.5 25 50 100 200020406080

100120140160

CNTs +/- Iron % Viability

Without Iron % viabilityWith Iron % viability

THE STATS No iron resulted in p=0.011

Due to high error, 200 sig from 1.25 and 50

Iron resulted in p=0.259 Standard Deviation as high as 75%

SO, WHAT DOES THIS SHOW Straight MWCNT more toxic than Coiled

Yuan et al. showed physical piercing with straight CNTs

Coiled CNTs may behave like larger particles Auffan et al. showed this effect

SO, WHAT DOES THIS SHOW With/Without iron CNTs had large amounts

of error Issues with suspension

No level showed toxicity of NanoAmor CNTs Aspect ratio less than 3:1

Greater toxicity found without iron CNTs with iron rose to highest level above 100%

FUTURE STUDIES Sertoli and Leydig Co-culture

Sertoli/Leydig co-culture shows increased cell activity

Animal model Ability of CNTs to cross into testis Accumulation Toxic effects Sperm quality Investigate effect of site of exposure Generational study

Thank You