"Novel Multi-functional Dendrimers for Drug Delivery, Gene Therapy and

Tissue Engineering"

 

Inventors:  T.L. Lowe, Y.S. Kim

PSU Inv. Disc. No. 2003-2783

Licensing Contact:  Matthew D. Smith

 

 

Technology Summary

 

Dendrimers have become increasingly important in controlled drug delivery due to their high degree of molecular uniformity, narrow molecular weight distribution, specific size and intriguing structural properties such as internal voids and cavities, and a highly functional terminal surface.  They hold promise in targeted delivery of anticancer agents, and can enhance accumulation within the tumor microvasculature, increase extravasation into tumor tissue and exhibit low systemic toxicity.  In addition, dendrimers are also nanoparticles. In vitro and in vivo experiments have shown that nanoparticles might have long blood circulation times and a low reticuloendothelial system (RES) uptake. They were able to strongly interact with the brain blood vessel endothelial cells of mice, and then be taken up by these cells by endocytosis. Bound drugs, such as nerve growth factor (NGF), as intact molecules were then released and exhibited their pharmacological action on the central nervous system (CNS).  Others’ attempt in synthesizing biodegradable dendrons have resulted in polymers that are neither thermo-responsive nor bona fide dendrimers.  In fact, the most common methods of encapsulating and delivering NGF under development involve the use of organic solvents, which have adverse effects on the NGF.

 

Penn State researchers have developed a novel synthesis process and compositions of several patent pending “Intelligent Polymers” which are both biodegradable and thermal-responsive.  The Intelligent Polymers are comprised of poly (N-isopropylacrylamid) (“PNIPAAM”) as the thermal-responsive unit, poly (L-lactic acid) (“PLLA”) as the biodegradable hydrophobic unit, and a pH-sensitive poly(L-lysine) (“PLL”) dendron domain.  Penn State’s Intelligent Polymers have been tested in preliminary studies to be effective multi-stimuli-responsive biodegradable polymeric materials. 

 

Acute thermal-responsiveness

Complete biodegradation

Controlled and sustained release of growth factor

3-dimensional scaffolding and proper microenvironment fostering cell growth

 

Commercial Applications

 

Penn State’s patent pending Intelligent Polymers, and their synthesis processes, can be manipulated and adapted to suit a variety of clinical needs.  They can serve as a targeted, sustained and controlled drug delivery system, dispensing proteins, genes and/or small molecule therapeutics.  Their acute bio-responsiveness allows for fewer administration and maintenance of drug levels, and eliminates potential for under- or overdosing.  Intelligent Polymers can also serve as biocompatible polymer for cell scaffolding packed with drugs or growth factors needed to enhance tissue or organ repair.  Complete biodegradability eliminates unnecessary secondary surgical procedures and adverse physical reactions to un-degraded by-products.