1. Chapter 10. Mass Transport and Biochemical Interactions
BMOLE Biomolecular Engineering Engineering in the Life Sciences Era
BMOLE – Transport
Chapter 10. Mass Transport and Biochemical Interactions
Text Book: Transport Phenomena in Biological Systems
Authors: Truskey, Yuan, Katz
Focus on what is presented in class and problems…
Dr. Corey J. Bishop Assistant Professor of Biomedical Engineering Principal Investigator of the Pharmacoengineering Laboratory: pharmacoengineering.com Dwight Look College of Engineering Texas A&M University Emerging Technologies Building Room 5016 College Station, TX
Francis Crick and neuroscience? Why is E = mc2 and not ½ mc^2… Name all of the energy equations you know? Integral => 1/2
© Prof. Anthony Guiseppi-Elie; T: F:

2. Problems 10.5, 10.7, 10.8, 10.16 and a reaction scheme with Laplace PK and PD

6. Problem 10.7

7. Problem 10.7
Since the lethal dose is much smaller than Km, it is likely
that toxin levels within the blood are less than the lethal dose.

8. Problem 10.7
Since the lethal dose is much smaller than Km, it is likely
that toxin levels within the blood are less than the lethal dose.
The reaction can be assumed to be first order.

9. Problem 10.7
Since the lethal dose is much smaller than Km, it is likely
that toxin levels within the blood are less than the lethal dose.
The reaction can be assumed to be first order.
Thiele modulus=> φ2 = diffusion time (L2/Deff)/reaction time (1/k)
Reaction limited
η= effectiveness factor
Diffusion
limited

10. Problem 10.7
Since the lethal dose is much smaller than Km, it is likely
that toxin levels within the blood are less than the lethal dose.
The reaction can be assumed to be first order.
Thiele modulus=> φ2 = diffusion time (L2/Deff)/reaction time (1/k)
Reaction limited
η= effectiveness factor
Rmax/Km
Diffusion
limited
L=Radius/e

11. Other questions about the above problem:
Why do you want it reaction-limited and not diffusion-limited?
If Km increases, does this tend to be more reaction- or diffusion-limited?

12. Problem 10.8

13. Problem 10.8 BBB Blood brain barrier:
Active drug vs pro-drug’s active metabolite or function as a reagent + X =>active agent
Pro-drug might be permeable to BBB whereas the active agent might not be…

14. Problem 10.8
i.e., NuvaRing
Patrick Kiser
Anti-HIV and Contraceptive

15. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
Anti-HIV and Contraceptive

16. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
Anti-HIV and Contraceptive

17. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
1st order rate constant means what?
Anti-HIV and Contraceptive

18. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
1st order rate constant means what?
Is this diffusion-limited?
Anti-HIV and Contraceptive

19. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
1st order rate constant means what?
Is this diffusion-limited? What would that mean?
Anti-HIV and Contraceptive

20. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
1st order rate constant means what?
Is this diffusion-limited? What would that mean?
Is being diffusion-limited desirable in this application?
Anti-HIV and Contraceptive

21. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
1st order rate constant means what?
Is this diffusion-limited? What would that mean?
Is being diffusion-limited desirable in this application?
Do you want what to be delivered to be controlled by diffusion or control diffusion by your
drug delivery system?
Anti-HIV and Contraceptive

22. Problem 10.8 “Long” means don’t worry about the ends R Λ L
Dissolution Rate = Ro
Ke = rate of metabolism (km would be more conventional)
1st order rate constant means what?
Is this diffusion-limited? What would that mean?
Is being diffusion-limited desirable in this application?
What happens in time? Will this always be reaction-limited in time?
Anti-HIV and Contraceptive
Anti-cancer: Nerve growth factor: 14.92
Anti-cancer: Nerve growth factor: 0.067
ɸ>3 =diffusion-limited (may see diff. values in lit.)

23. 10.8 Deff=5e-6; Radius = 0.1; L = 1; Lambda = 1;
Dist = (L+Lambda/3)/3;
k = 2.8e-4;
phi = Dist*sqrt(k/Deff)
effectiveness = tanh(phi)/phi

28. There is one other… invL(1/[(s-a)(s-b)])= eat-ebt ------------------
a-b