New Biodegradable Biocompatible Citric Acid Nano Polymers for Cell Culture Growth & Implantation Engineered by Northwestern University Scientists

FIG. 1 is a schematic representation of the synthesis of poly (1,8-octanediol-co-citric acid) (POC) engineered at Northwestern University as depicted in U.S. Patent Application 20090325859. 

A Northwestern University (Evanston, IL) research team of Professor Guillermo Ameer,  Jian Yang and Ryan Hoshi  has created nano citric acid polymers for use as biocompatible scaffolds on which to culture a variety of cells.   

Northwestern University’s U.S. Patent Application 20090325859  describes a series of  elastomeric citric acid nano-polymers and methods of making and using these polymers as a biologically active molecule delivery platform. The patent application also details a novel biphasic scaffold design for blood vessel tissue engineering and nanoporous citrate polymer. 

A crosslinked polymer network using biodegradable poly(1,8 octanediol-co-citric acid) (POC) polymer in conjunction with a nonreactive porogen, polyethylene glycol dimethyl ether (PEGDM) can be used for drug delivery.  Due to the unique properties of nanoscale systems, such as a relatively large surface area to volume ratio, the nanoporous POC can be used as a material to encapsulate and deliver bioactive molecules, protein based drug therapies such as enzymes, and growth factors and other therapeutic agents under very mild and physiologically relevant conditions. 

The polymers can adsorb biologically active molecules. The polymers contain pores that are between about 7 and 15 nanometers in diameter. In other embodiments, the polymer comprises poly(1,8 octanediol-co-ctric acid). In certain embodiments, the polymers are made by employing polyethylene glycol dimethyl ether (PEGDM), according to Ameer, Yang and Hoshi. 

Biodegradable citric acid polymers can be used as scaffolds for the growth of cells and culturing cells of the tissue on the scaffold. The polymer poly 1,8-octanediol-co-citric acid, or a derivative are particularly useful as scaffold material.  The cells selected for growth can be endothelial cells, ligament tissue, muscle cells, bone cells, cartilage cells. The tissue engineering method comprises growing the cells on the scaffold in a bioreactor. 

 FIG. 11 is a photomicrograph (.times.100) (A, B, C, and D) and SEM pictures (E and F) of human aortic endothelial cells on POC at different culture times: A) 1 hour; B) 24 hours: C) 4 days; D) 6 days; E) and F) 6 days

FIG. 13 is a photograph depicting porous and non-porous tube scaffold and sponge scaffold made by POC.

FIG. 16 shows SEM pictures of A) a cross section of a POC biphasic scaffold; B) the pore structure of the porous phase; C) human aortic smooth muscles cells on the porous phase of co-cultured biphasic scaffold; D) human aortic endothelial cells on the lumen of co-cultured biphasic scaffold.

 FIG. 20. SEM images of a) Control non leached 50% wt. PEGDM to cross-linked POC polymer and b) same sample that was leached in acetone and critically point dried.

Other organs for which tissue implantation patches may be generated include, but are not limited to skin tissue for skin grafts, myocardial tissue, bone tissue for bone regeneration, testicular tissue, endothelial cells, blood vessels, and any other cells from which a tissue patch may be generated.  It should be understood that cells from any organ may be seeded onto the biocompatible polymers to produce useful tissue for implantation and/or study.

P2i Targets $3 billion Global Hearing Aid Market for Lqiuid Repellant Nano-Scale Polymer Coating

Materials science innovator P2i has created Aridion™, a revolutionary liquid-repellent nano-coating technology that protects consumer electronics devices against damage from water and sweat, to improve their performance in challenging applications. P2i's multi-patented liquid repellent technology employs a special pulsed ionized gas (plasma), created within a vacuum chamber, to attach a nanometer-thin polymer layer over the entire surface of a product. 

On surfaces protected with Aridion™ , a nano-scale polymer coating one thousand times thinner than a human hair -- water forms beads and simply roll off. Thanks to this, Aridion™ can transform the reliability of consumer electronics devices containing delicate, expensive components at high risk of liquid damage.  

Although Aridion™ has the potential to protect all kinds of consumer electronics devices, it is initially being targeted at manufacturers in the $3 billion global hearing aid market. Thanks to the protection Aridion™ provides, manufacturers will be able to improve profitability through reduced repair and replacement costs, will increase user confidence through improved reliability, and will deliver clear product benefits that support premium pricing. All of these factors combine to enhance brand image, sharpen competitive edge and increase market share.  

Stephen Coulson, Chief Technology Officer of P2i, comments: “We’re excited to have developed Aridion™ as a unique protective nano-coating technology concept for consumer electronics, and delighted that we have found such a ready market for our benefits, within the world’s fast growing hearing aid business. We are already achieving excellent results with two of the world’s largest hearing aid manufacturers, who have recognized how our revolutionary technology will increase reliability and improve the user experience with their products.” 

Aridion™ can be cost-effectively applied to finished products using compact, high-throughput P2i processing machines. These integrate seamlessly and effortlessly with existing assembly lines, are easy to scale-up, and can be operated by ordinary workers at the touch of a single button. In a typical production environment, one P2i machine can treat a hearing aid in less than ten seconds.

Although the Aridion™ coating is imperceptible to users and does not affect hearing aid acoustic properties, it physically bonds to the product surface at a nanoscopic level and thus is as durable as the material it protects. Plus, because Aridion™ effectively coats every aspect of a finished product, it protects much more thoroughly than alternative approaches where individual product components are treated prior to manufacture.

Superior protection is particularly important to hearing aid manufacturers marketing the latest receiver-in-canal (RIC) behind-the-ear (BTE) hearing instruments to new generations of users. Market share of these instruments, with their discreet appearance and comfortable open-ear fitting, rose from 26.4% in 2004 to 43.8% in 2006 (source: Hearing Aid Market: Low Penetration Offers Development Opportunities, Koncept Analytics 2008). 

However, younger users have high expectations of reliable, extended performance as part of an active outdoor lifestyle, bringing an increased risk of warranty failures and inadvertent accidental liquid damage. Because RIC/BTE devices are delicate and contain expensive digital electronics, repair costs (to manufacturers via warranty failure, or users via accidental damage) are potentially very high, especially given the current trend towards wearing binaural devices; one for each ear. 

Aridion™ helps minimize these costs by providing „one-shot‟ protection against steam and humidity as well as sweat. The superior protection afforded by Aridion™ includes improved battery life (by avoiding moisture short circuits), and preventing component failure due to saline corrosion (sweat).

 Aridion™ also helps reduce the risk of inconvenience due to component failure, which is a significant user-acceptance issue. In a survey reported by Koncept Analytics, 56% of users rated “fewer breakdowns” as highly desirable. Plus, thanks to its superior protection, Aridion could also benefit hearing aids aimed at children, people suffering cognitive disorders and people working in hazardous environments, due to the higher risks of damage in each case.