Here, we describe a biomimetic microsystem that reconstitutes the critical functional alveolar-capillary interface of the human lung. This bioinspired microdevice reproduces complex integrated organ-level responses to bacteria and inflammatory cytokines introduced into the alveolar space. In nanotoxicology studies, this lung mimic revealed that cyclic mechanical strain accentuates toxic and inflammatory responses of the lung to silica nanoparticles. Mechanical strain also enhances epithelial and endothelial uptake of nanoparticulates and stimulates their transport into the underlying microvascular channel. Similar effects of physiological breathing on nanoparticle absorption are observed in whole mouse lung. Mechanically active "organ-on-a-chip" microdevices that reconstitute tissue-tissue interfaces critical to organ function may therefore expand the capabilities of cell culture models and provide low-cost alternatives to animal and clinical studies for drug screening and toxicology applications.

IR and Raman spectra are reported for 1,1-difluorocyclopropane-d0, -d2, and -d4, and complete assignments of vibrational fundamentals are given for these species. These assignments are consistent with predictions of frequencies, intensities, and Raman depolarization ratios computed with the B3LYP/cc-pVTZ quantum chemical (QC) model. Ground state rotational constants for five 13C and deuterium isotopomers, obtained from published microwave spectra, were "corrected" into equilibrium rotational constants. The needed vibration-rotation interaction constants were computed with QC models after scaling the force constants. A semi-experimental equilibrium structure, fitted to the equilibrium moments of inertia, is rC1C = 1.470(1) A, rCC = 1.546(1) A, rCF = 1.343(1) A, rCH = 1.078(1) A, alphaFCF = 109.5(1), alphaFCC = 119.4(1) degrees, alphaHCH = 116.7(1) degrees, alphaC1CH = 117.4(1) degrees, and alphaCCH = 117.1(1) degrees. This structure agrees within the indicated uncertainties with the ab initio structure obtained from an extrapolated set of CCSD(T)/aug-cc-pVnZ calculations except for rCC = 1.548 A. The F2C-CH2 bonds are significantly shortened and strengthened; the H2C-CH2 bond is significantly lengthened and weakened.