Apr 23, 2009
Nanotexture promotes bladder tissue regeneration
Nanotechnology is contributing greatly to regenerative medicine, particularly by creating nanometer pores and associated nanometer surface features to improve bladder tissue growth while inhibiting bladder calcium stone formation, which is a common disease affecting 5.2% of adults in the US with a high rate of recurrence.
The need for bladder regeneration materials arises for a number of reasons including bladder cancer, which is diagnosed in 38,000 men and 15,000 women each year in the US. Nanotechnology offers the opportunity to design artificial bladder scaffolds that mimic natural tissue more accurately than today's materials, which helps to promote tissue growth at a quicker rate while also prohibiting bladder stone formation.
Nanoscale roughness and nanometer topography have been shown to enhance cell functions that are pertinent for numerous tissue engineering uses including bone, cartilage, vascular, nervous system, skin and cardiac applications. The roughness and topographical features that nanotechnology can create match those of natural tissue and possess special surface properties (such as energy) that are important for promoting cell functions.
Nanoscale features can be created easily using chemical or physical techniques. For example, polymers can be soaked in chemical agents, such as an acid for a basic polymeric chemistry or a base for an acidic polymeric chemistry, or by using physical processes such as electron beam evaporation. These processes will change the surface roughness and consequently the energy of biomaterials to influence initial protein interactions, including adsorption and bioactivity, to promote cell functions such as adhesion, proliferation and extracellular matrix synthesis.
In recent months, researchers at Brown University (who are creating improved bladder polymer scaffolds through the use of nanotechnology and understanding the relationship between bladder tissue formation and biomaterial surface properties) confirmed that changes in nano-roughness on poly (lactic-co-glycolic acid) (PLGA) and poly urethane (PU) promote bladder urothelial cell (the innermost cells of bladder tissue that are involved in cancer mutation) growth compared with a conventional polymer with no roughness at the nanometer level; similar results have also been measured for bladder smooth muscle cells (the cells that reside in the bladder wall).
The group has also implemented nano-rough topographies on PLGA and PU to prevent the formation of calcium stones. Once calcium oxalate stones form in the bladder or urethra through the increased concentration of each compound (calcium and oxalate) they are not easily removed. Such calcium oxalate stones cause blood in the urine, abdominal pain and urinary tract infections. The study revealed that calcium crystal formation decreased by 50% on nanometer rough polymers compared with conventional polymer surfaces that have no nanometer roughness.
The researchers presented their work in Nanotechnology.
About the author
Associate professor Thomas Webster led the bladder project with assistance from research professor Karen Haberstroh. Prof. Webster's research addresses the design, synthesis and evaluation of nanophase (that is, materials with fundamental length scales less than 100 nm) materials as more effective biomedical implants. Prof. Webster is the current director of the Nanomedicine Laboratories. To date, his lab group has generated five textbooks, 37 book chapters, 186 invited presentations, 283 peer-reviewed literature articles and/or conference proceedings, 435 conference presentations and 17 provisional or full patents. This research was financially supported by the Coulter and Hermann Foundations. Young Wook Chun who is a PhD candidate and Dongwoo Khang, a postdoctoral researcher, performed the work.