Current perspectives in pulmonary surfactant--inhibition, enhancement and evaluation.

Perspective on lung injury and recruitment: a skeptical look at the opening and collapse story.

The biomechanical properties of connective tissues play fundamental roles in how mechanical interactions of the body with its environment produce physical forces at the cellular level. It is now recognized that mechanical interactions between cells and the extracellular matrix (ECM) have major regulatory effects on cellular physiology and cell-cycle kinetics that can lead to the reorganization and remodeling of the ECM. The connective tissues are composed of cells and the ECM, which includes water and a variety of biological macromolecules. The macromolecules that are most important in determining the mechanical properties of these tissues are collagen, elastin, and proteoglycans. Among these macromolecules, the most abundant and perhaps most critical for structural integrity is collagen. In this review, we examine how mechanical forces affect the physiological functioning of the lung parenchyma, with special emphasis on the role of collagen. First, we overview the composition of the connective tissue of the lung and their complex structural organization. We then describe how mechanical properties of the parenchyma arise from its composition as well as from the architectural organization of the connective tissue. We argue that, because collagen is the most important load-bearing component of the parenchymal connective tissue, it is also critical in determining the homeostasis and cellular responses to injury. Finally, we overview the interactions between the parenchymal collagen network and cellular remodeling and speculate how mechanotransduction might contribute to disease propagation and the development of small- and large-scale heterogeneities with implications to impaired lung function in emphysema.

https://www.physiology.org/doi/pdf/10.1152/japplphysiol.01087.2004

Biomechanics of the lung parenchyma : critical roles of collagen and mechanical forces

Preface 1. Introduction 2. Cellular biomechanics 3. Hemodynamics 4. The circulatory system 5. The interstitium 6. Ocular biomechanics 7. The respiratory system 8. Muscles and movement 9. Skeletal biomechanics 10. Terrestrial locomotion Appendix A. The electrocardiogram Index.

Introductory Biomechanics: From Cells to Organisms

To test the hypotheses that during small tidal volume ventilation (5 mL/kg) deliberate volume recruitment maneuvers allow expansion of atelectatic lung units and that a high positive end-expiratory pressure (PEEP) above the lower inflection point of the pressure/volume (PV) curve is not necessarily required to maintain recruited lung volume in acute lung injury.

J Hildebrandt

Papers

Pressure-volume curves of air- and liquid-filled excised lungs-surface tension in situ.