Lung

Pagina 1

1 WHOLE LUNG Tissue Engineering Petersen et al. [“Tissue-Engineered Lungs for in Vivo Implantation”, 2010] decellularized murine lungs and then recellularized them with epithelial cells and micro-vascular lung endothelial cells from neonatal rat lungs. Suppose to design a specific bioreactor to mimic certain features of the human adult lung environment, including vascular perfusion (red arrows) , which delivers oxygenated and glucose- rich medium to the lungs, and cyclic inflation -deflation of the alveoli with a liquid medium, mimicking ventilation (green arrows). Bioreactor sketch Exemplification of lung structure at alveolar level A) Knowing that the vascular medium flow rate Q m is equal to 5 l/min, the arterial concentration c1 of glucose is 4.86 mM [P. Pezzati, M. Tronchin, G. Messeri. Biochimica clinica, 2004, vol. 28, n. 5-6] and the venous concentration c2 is 5% lower, assess the total consumption of glucose. Determine the total consumption of oxygen knowing tha t the difference of oxygen concentration between arterial and venous blood is 2 mM. Consider that the alveolo - capillary oxygen transfer is 310 ml/min and the molar volume of oxygen is equal to 17.36 ∗ 10−3 𝑚𝑚3/𝑚𝑚𝑚𝑚𝑚𝑚. DATA: Qm=5 l/min c1glu= 4.86 mM [1M=1mol/l] c2glu= c1glu-5% c1glu O2Transf=310 ml/min=310 cm3/min (where O2Transf is the alveolo -capillary oxygen transfer) c1o2-c2o2= 2mM O2 molar volume=17.36 ∗ 10−3 𝑚𝑚3/𝑚𝑚𝑚𝑚𝑚𝑚 Compartmental model: Vol ∙ ∂c ∂t = Q1 ∙ c1 − Q2 ∙ c2 + P − V c1 c2 2 SOLUTION: To study the consumption of glucose, consider a simple compartmental model applied to the sole vascular perfusion: 𝜕𝜕𝜕𝜕 𝜕𝜕𝜕𝜕𝑉𝑉𝑚𝑚𝑚𝑚= 𝑄𝑄𝑚𝑚𝜕𝜕1𝑔𝑔𝑙𝑙𝑙𝑙− 𝑄𝑄𝑚𝑚𝜕𝜕2𝑔𝑔𝑙𝑙𝑙𝑙+ 𝑃𝑃𝑔𝑔𝑙𝑙𝑙𝑙− 𝑉𝑉𝑔𝑔𝑙𝑙𝑙𝑙 Since there is no accumulation 𝜕𝜕𝜕𝜕 𝜕𝜕𝜕𝜕= 0, and since we have no production of glucose within the tissue Pglu=0. The…