This two-year proposal describes the development of functional lymphatic networks and their integration into artificial dermal constructs in vitro. While many methods have been developed to form microvascular networks suitable for perfusion of engineered tissues, much less is known about how to form structures that can drain these same tissues of excess interstitial fluid and proteins. To promote lymphatic function in engineered vascular constructs, we propose to use microfluidic collagen gels as scaffolds and to manipulate the microenvironmental conditions to mimic native lymphatic drainage conditions in vivo. Specifically, in Aim 1, we intend to examine how transmural pressure and shear stress - two factors that are extremely small in the lymphatic circulation - affect functional maturation in vitro. We will then use an optimized set of these stresses to form hybrid constructs that contain both blood and lymphatic microvessels, in which the former exhibits a tight barrier while the latter is leaky.
In Aim 2, we will integrate these design parameters to form lymphatic networks suitable for draining a 1 cm2 area of dermal tissue. These networks will be formed by a lithographic method, and the conditions obtained in Aim 1 will serve as a starting point for the development of lymphatic function in entire networks. These constructs will contain an independent vascular network for perfusion. We will determine how the geometry of the lymphatic network promotes its ability to maintain a non-edematous state, both under basal and hyper-filtration conditions. We expect the proposed work to provide underlying principles that govern the rational design and function of engineered lymphatic networks. This work will serve as a first step towards the systematic synthesis of dermal tissue that integrates functional blood and lymphatic vascular systems. This work will study how to build lymphatic vessels - the vessels that drain organs of their excess fluids. We intend to incorporate these vessels into an artificial skin (dermis) and to show that they function as lymphatics do in intact, native skin. We anticipate that this work will provide a first step towards engineered organs that can drain properly when implanted into a patient.

Public Health Relevance

This work will study how to build lymphatic vessels?the vessels that drain organs of their excess fluids. We intend to incorporate these vessels into an artificial skin (dermis) and to show that they function as lymphatics do in intact, native skin. We anticipate that this work will provide a first step towards engineered organs that can drain properly when implanted into a patient.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21HL092335-02
Application #
7844942
Study Section
Biomaterials and Biointerfaces Study Section (BMBI)
Program Officer
Lundberg, Martha
Project Start
2009-07-01
Project End
2012-12-31
Budget Start
2010-07-01
Budget End
2012-12-31
Support Year
2
Fiscal Year
2010
Total Cost
$203,125
Indirect Cost
Name
Boston University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
049435266
City
Boston
State
MA
Country
United States
Zip Code
02215
Thompson, Rebecca L; Margolis, Emily A; Ryan, Tyler J et al. (2018) Design principles for lymphatic drainage of fluid and solutes from collagen scaffolds. J Biomed Mater Res A 106:106-114
Chan, Kelvin L S; Khankhel, Aimal H; Thompson, Rebecca L et al. (2014) Crosslinking of collagen scaffolds promotes blood and lymphatic vascular stability. J Biomed Mater Res A 102:3186-3195
Wong, Keith H K; Truslow, James G; Khankhel, Aimal H et al. (2013) Artificial lymphatic drainage systems for vascularized microfluidic scaffolds. J Biomed Mater Res A 101:2181-90
Truslow, James G; Tien, Joe (2013) Determination of vascular permeability coefficients under slow luminal filling. Microvasc Res 90:117-20
Wong, Keith H K; Chan, Juliana M; Kamm, Roger D et al. (2012) Microfluidic models of vascular functions. Annu Rev Biomed Eng 14:205-30
Price, Gavrielle M; Wong, Keith H K; Truslow, James G et al. (2010) Effect of mechanical factors on the function of engineered human blood microvessels in microfluidic collagen gels. Biomaterials 31:6182-9