Study of particle deposition in the Nano Aerosol Chamber In-Vitro Toxicity (NACIVT) System for determination of deposited doses onto cell cultures

Abstract

Inhalation of engineered nanoparticles that are handled as powders or sprays in
consumer products poses a potential health risk. To investigate the effects of
nanoparticles on human health, the Nano Aerosol Chamber for In-Vitro Toxicity
(NACIVT) system has been designed for controlled deposition of aerosol particles
onto cell cultures. The objective of this study was to estimate the deposited dose
onto the exposure areas and to investigate if the deposition varies between the
different exposure wells using particles generated from both a solution of
fluorescein salt and ZnO nanoparticles.
Aerosolized particles were generated through an atomizer and deposited into the
NACIVT chamber. The particle size distributions were measured with an SMPS and
APS. Four experiments were conducted with fluorescein sodium salt of 10 µg/ml,
and two different suspension of ZnO NPs were included. A spectrophotometer was
employed to quantify the experimental deposited dose of fluorescein salt particles,
whereas ICP-MS was utilized to obtain the experimental deposited dose of ZnO
NPs. Both concentrations were compared to theoretically obtained doses using the
size distributions from the SMPS and APS.
Among the experiments with fluorescein salt, the deposited amount was estimated
to be between 0.005 µg/ml and 0.011 µg/ml. In contrast, the doses obtained from
the number concentration data were higher than the experimental values, ranging
from 0.082 µg/ml to 0.140 µg/ml. One of the experiments showed higher, mass
concentration, calculated number dose, and the surface area dose compared to other
experiments. A similar pattern was observed in those doses when generating
particles from the diluted suspension of ZnO NPs. The experimental deposition
resulted in almost the same level on average (0.026 µg/ml) from the two suspensions
of ZnO after collecting the particles from the NACIVT chamber. In contrast, the
theoretically obtained doses accounted for around 6 µg/ml and 11.5 µg/ml with the
atomizers’ suspensions of ZnO containing 88 µg/ml and 58 µg/ml, respectively. A
little fluctuation was observed within the wells from the deposited salt particle in all
the experiments; however, quite inconsistent mass concentrations were obtained
from the wells exposed to ZnO NPs. The outcomes of the study demonstrate further
optimization to minimize the variation between the experimental and theoretical
doses as well as the variation within the wells.

Popular Abstract

Studies of nanoparticles (diameter 1 to 100 nm) are frequently conducted in recent times due to their
potential toxic effects. Exposure systems to deliver these nanoparticles to cells in lab environment have
become a fundamental tool for evaluating health hazards. The Nano Aerosol Chamber for In-Vitro
Toxicity Testing (NACIVT) is a system that provides a controlled environment for those experiments. In
the exposure system, accurate determination of particle deposition is an important aspect. This study
focused on characterizing and quantifying the delivered dose of aerosolized particles of Fluorescein
Sodium Salt and Zinc Oxide Nanoparticles deposited into the NACIVT system.
Aerosolized particles are first generated from a solution or suspension using pressurized air. To
characterize the generated aerosol particles entering the NACIVT chamber and to quantify the accurate
deposited dose, two complementary particle sizing instruments were incorporated: the Scanning Mobility
Particle Sizer (SMPS) and the Aerodynamic Particle Sizer (APS). The SMPS was used to measure the
number concentration (number of particles per cubic centimeter of air) and size distribution of particles in
the nanometer scale, typically from 10 nm to 500 nm. The APS measured the larger particles from
approximately 500 nm to 20 µm based on their aerodynamic behavior. These instruments provided a
comprehensive particle size distribution and number concentration of the aerosol stream. The data
obtained from SMPS and APS were used along with the known airflow directed toward the chamber to
estimate the mass or number of particles deposited into the wells inside the NACIVT system. Among
three different concentrations, one salt solution was chosen to be deposited into the NACIVT system.
Four experiments were carried out using the specific salt solution, and the deposited doses were obtained
theoretically and experimentally. The experimental values were lower than the theoretical calculations.
For zinc oxide nanoparticles, two different concentrations were used. Similar to salt solutions, the
experimentally measured deposited doses of nanoparticles were lower than the theoretical values.
However, some variation from experimentally obtained doses was observed among the samples in both
salt solution and zinc oxide suspension.

• author: Imtiaz, Rashed
• supervisor: Julia Linell
• organization: Ergonomics and Aerosol Technology
• course: MAMM25 20251
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• language: English
• id: 9201086
• date added to LUP: 2025-06-17 11:11:31
• date last changed: 2025-06-17 11:11:31