Evaluation of size-dependent uptake, transport and cytotoxicity of polystyrene microplastic in a blood-brain barrier...

Area of Science:

• Environmental Science
• Toxicology
• Neuroscience

Background:

• Microplastics enter the human body via ingestion, inhalation, and dermal contact.
• Emerging evidence suggests microplastics may impact the central nervous system (CNS) by breaching the blood-brain barrier (BBB).
• Mechanisms of microplastic transport, uptake, and toxicity at the BBB are not fully understood.

Purpose of the Study:

• To investigate the size-dependent uptake and cytotoxicity of polystyrene microparticles at an engineered BBB model.
• To elucidate the impact of microplastic size on BBB permeability and cellular integrity.
• To assess the influence of inflammatory stimuli (TNF-α) on microplastic BBB interactions.

Main Methods:

• Utilized an engineered blood-brain barrier (BBB) model to assess polystyrene microparticle uptake and transport.
• Compared the effects of 0.2 μm and 1.0 μm polystyrene microparticles on BBB permeability and cell viability.
• Evaluated microplastic effects under both basal and TNF-α stimulated conditions.
• Compared toxicity in 2D cell cultures versus 3D BBB models.

Main Results:

• 0.2 μm microparticles demonstrated significantly higher uptake and transendothelial transport than 1.0 μm particles.
• Microplastic exposure led to dose- and size-dependent increases in BBB permeability.
• After 72h, 0.2 μm particles increased permeability 27.3-fold, while 1.0 μm particles increased it 4.5-fold.
• TNF-α stimulation enhanced microplastic absorption and BBB damage.
• Size-dependent toxicity varied between 2D and 3D BBB models.

Conclusions:

• Microplastic size is a critical factor influencing BBB penetration and associated neurotoxicity.
• Engineered BBB models, particularly 3D models, are essential for accurately assessing environmental toxicity.
• Inflammatory conditions may exacerbate the risks posed by microplastic exposure to the CNS.