TY  - JOUR
AB  - We describe the engineering design, computational modeling, and empirical performance of a moving air-liquid interface (MALI) bioreactor for the study of aerosol deposition on cells cultured on an elastic, porous membrane which mimics both air-liquid interface exposure conditions and mechanoelastic motion of lung tissue during breathing. The device consists of two chambers separated by a cell layer cultured on a porous, flexible membrane. The lower (basolateral) chamber is perfused with cell culture medium simulating blood circulation. The upper (apical) chamber representing the air compartment of the lung is interfaced to an aerosol generator and a pressure actuation system. By cycling the pressure in the apical chamber between 0 and 7 kPa, the membrane can mimic the periodic mechanical strain of the alveolar wall. Focusing on the engineering aspects of the system, we show that membrane strain can be monitored by measuring changes in pressure resulting from the movement of media in the basolateral chamber. Moreover, liquid aerosol deposition at a high dose delivery rate (>1 mu l cm(-2) min(-1)) is highly efficient (ca. 51.5%) and can be accurately modeled using finite element methods. Finally, we show that lung epithelial cells can be mechanically stimulated under air-liquid interface and stretch-conditions without loss of viability. The MALI bioreactor could be used to study the effects of aerosol on alveolar cells cultured at the air-liquid interface in a biodynamic environment or for toxicological or therapeutic applications.
AU  - Cei, D.*
AU  - Doryab, A.
AU  - Lenz, A.-G.
AU  - Schröppel, A.
AU  - Mayer, P.
AU  - Burgstaller, G.
AU  - Nossa, R.*
AU  - Ahluwalia, A.*
AU  - Schmid, O.
C1  - 60560
C2  - 49420
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
SP  - 690-702
TI  - Development of a dynamic in vitro stretch model of the alveolar interface with aerosol delivery.
JO  - Biotechnol. Bioeng.
VL  - 118
IS  - 2
PB  - Wiley
PY  - 2021
SN  - 0006-3592
ER  - 

TY  - JOUR
AB  - The success of in situ bioremediation is often limited by the inability to bring bacteria in contact with the pollutant, which they will degrade. A bench-scale model aquifer was used to evaluate the impact of chemotaxis on the migration of bacteria toward the source of a chemical pollutant. The model was packed with sand and aqueous media was pumped across horizontally, simulating groundwater flow in a homogenous aquifer. A vertical gradient in chemoattractant was created by either a continuous injection of sodium benzoate or a pulse injection of sodium acetate. A pulse of chemotactic Pseudomonas putida F1 or a non-chemotactic mutant of the same species was injected below the attractant. The eluent was sampled at the microcosm outlet to generate vertical concentration profiles of the bacteria and chemoattractant. Moment analysis was used to determine the center and variance of the bacterial profiles. The center of the chemotactic bacterial population was located at an average of 0.74 ± 0.07 cm closer to the level at which the chemoattractant was injected than its non-chemotactic mutant in benzoate experiments (P < 0.015) and 0.4 ± 0.2 cm closer in acetate experiments (P < 0.05). The transverse dispersivity of the chemotactic bacteria was 4 ± 1 × 10(-3) cm higher in benzoate experiments than the transverse dispersivity of the non-chemotactic mutant and 1 ± 2 × 10(-3) cm higher in acetate experiments. These results underscore the contribution of chemotaxis to improve transport of bacteria to contaminant sources, potentially enhancing the effectiveness of in situ bioremediation.
AU  - Strobel, K.L.*
AU  - McGowan, S.*
AU  - Bauer, R.D.
AU  - Griebler, C.
AU  - Liu, J.*
AU  - Ford, R.M.*
C1  - 6605
C2  - 28972
CY  - New York, NJ
SP  - 2070-2077
TI  - Chemotaxis increases vertical migration and apparent transverse dispersion of bacteria in a bench-scale microcosm.
JO  - Biotechnol. Bioeng.
VL  - 108
IS  - 9
PB  - Wiley-Blackwell
PY  - 2011
SN  - 0006-3592
ER  -