Table 2 Characteristics of air-liquid interface exposure chambers for in vitro cell cultures

What level of throughput can be achieved?

VITROCELL^® 6/6

VITROCELL^® Cloud 6

Cultex^® RFS

NACIVT

• 6-well inserts (can use adaptors to adapt to 12 or 24-well-sized)

• 6-well inserts

• 6, 12, or 24-well inserts

• 6-well inserts

• compartments for exposing 6 cell culture inserts

• compartments for exposing 6 cell culture inserts: 6 inserts at one exposure; no clean air control

• compartments for exposing 3 cell culture inserts - all exposed to the same substance

• compartments for exposing 24 cell culture inserts – allexposed to the same substance.

• allows for separate clean air exposure in one module:

• 1 well can be used for the (optional) microbalance.

• would have to purchase 2 modules for clean air control

• would have to purchase 2 modules for clean air control

o 3 replicates clean air control

o 3 replicates of one dose (or 2 replicates plus optional 1 well for microbalance)

VITROCELL^® 12/12

VITROCELL^® Cloud 12

Cultex^® RFS Compact

• 12-well inserts (can use adaptors to adapt to 24-well-sized)

• 12-well inserts

• 12 or 24-well inserts

• compartments for exposing 12 cell culture inserts

• compartments for exposing 12 cell culture inserts

• compartments for exposing 6 cell culture inserts

• allows for separate clean air exposure in one module:

• allows for separate clean air exposure in one module:

• allows for separate clean air exposure in one module

o 3 replicates clean air control

o 3 replicates for clean air control

o 3 dose dilutions with 3 replicates per dilution (or 2 replicates plus optional 1 well for microbalance)

o 9 inserts at one exposure (1 well can be used for the optional microbalance)

VITROCELL^® 24/24

VITROCELL^® Cloud 24

• 24-well inserts

• 24-well inserts

• compartments for exposing 24 cell culture inserts

• compartments for exposing 24 cell culture inserts; 24 inserts at one exposure (1 well can be used for the optional microbalance)

• allows for separate clean air exposure in one module:

• would have to purchase 2 modules for clean air control

o 4 replicates clean air control

o 5 dose dilutions with 4 replicates per dilution (or 3 replicates plus optional 1 well for microbalance)

Commercially available?

Yes

Yes

Yes

No

Deposited-dose determination

• The microbalance is capable of measuring the deposition in the module at a resolution of 10 ng/cm².

1 well can be used for the microbalance (optional).

Gravimetric methods, using the precision balance.

One of the wells is designed to carry a transmission electron microscope (TEM) grid to monitor exposure. Also has an electrometer.

• For the 6/6 and 12/12, a built-in microbalance option is available. A microbalance sensor would occupy one compartment; therefore, the module should have at least 4 compartments in order to allow 3 replicates for exposure.

• For the 24/24, the purchase of a separate, standalone 12/1 CF module to use a microbalance would be needed.

Exposure Method

The VITROCELL^® 6/6 is compatible with electrostatic deposition.

Not compatible with electrostatic deposition, but due to high deposition efficiency of NMs in the Cloud, electrostatic deposition is not needed (Cloud is equipped with a nebulizer that generates liquid aerosols).

Compatible with electrostatic deposition (both RFS and RFS compact).

Compatible with electrostatic deposition.

The 12/12 and 24/24 are not, but in those cases, the VITROCELL^® 6/6 modules can be used with adaptors for 12 or 24-well inserts.

Exposure time duration

Maximum 6 h possible

Approximately 3–4 min

Up to 1 h reported

Up to 2 h reported

Ability to utilize multiple aerosol generating techniques?

May be used with a wide range of aerosol generators.

Compatible only with the aerosol generator, which is part of the delivery (vibrating mesh type for liquid aerosols).

May be used with a wide range of aerosol generators; One option is the Cultex^® dust generator, which is a Mitchell or screw mill type.

May be used with a wide range of aerosol generators; Can be placed close to the workplace or aside a busy street.