Project IV

Jiro Nagatomi

Mechanically Guided Urological Tissue Regeneration in Vitro

Target Investigator
Dr. Jiro Nagatomi
Associate Professor of Bioengineering
Clemson University

Approximately 400 million people suffer from bladder diseases world-wide and many of them require partial or total organ reconstruction. Despite the recent clinical success in bladder tissue engineering as a new alternative for tissue reconstruction, there remain several unresolved issues. For example, use of PLGA, a rigid polymer, for scaffold does not permit proper distension and contraction of the smooth muscle tissue. Seeding and culturing of smooth muscle cells on these scaffolds with random pore architecture does not allow organizing cells into the highly oriented 3D (three dimensional) architecture of the native bladder which governs its mechanical function. Moreover, prolonged in vitro cultures of smooth muscle cells often result in dedifferentiation and loss of contractile phenotype of these cells. Thus, development of both a biomaterial that matches the native tissue mechanical properties and an approach to guide smooth muscle cell growth into organized 3D bundle structures is necessary for enhancement of bladder tissue engineering.

Our group previously demonstrated that 3D cultures of bladder smooth muscle cells in collagen gel subjected to sustained tension exhibited cell orientation along the direction of the applied stimulus and significantly greater levels of contractile phenotype markers compared to the no-tension control (Roby et al, 2008). Moreover, in collaboration with Dr. Ken Webb, we are currently developing a novel hydrogel formulation containing Tetronic (PEO-PPO), type I collagen, and hyaluronic acid (HA), which exhibits high compliance and superior mechanical strength to collagen gels. We are combining our strength in tissue biomechanics and mechanobiology with the existing biomaterials technologies of the Clemson Bioengineering program to demonstrate a novel enabling technology for tissue engineering by building 3D urinary bladder constructs.

We hypothesize that continuous exposure of 3D culture of bladder smooth muscle cells to appropriate mechanical stimuli leads to guided directional cell growth and retention of contractile smooth muscle phenotype. The main goal of the proposed pilot study is to create and characterize viable, 3D tissue constructs that closely resemble the morphology and contractile function of the native bladder.

Specific aims are:

  • To generate 3D tissues from stacks of Tetronic-collagen-HA encapsulated smooth muscle cell bundles and urothelial cells in vitro.
  • To develop an experimental platform for mechanical Stimulation of 3D bladder tissue constructs.
  • To characterize 3D bladder tissue construct response to mechanical stimuli in vitro.

Upon completion of this preliminary project we will then scale it up to the size and more complex geometries of small and large animals for in vivo studies.

Please click here for more information about Dr. Nagatomi's laboratory.