A novel procedure for nanostructuring of polymer surfaces for medical implants to resist bacterial adhesion and biofilm formation
Institute Reference: INV-14027
So far in the medical device community, several techniques have been used to improve the cytocompatibility of polymer surfaces by chemical or physical techniques for tissue engineering applications. Nanostructuring of polymer surfaces can improve cell adhesion and proliferation. Methods of nanostructuring polymer surfaces include etching, electron beam lithography, mechanical brushing, nanopatterning the surface of a metal mold, ion beam etching, reactive ion etching, plasma etching, and plasma assisted chemical vapor deposition.
Medical devices that are surgically implanted are subject to bacterial growth and biofilm formation on their outer surfaces, which often results in serious infections and the need to surgically remove or replace the device. Previous efforts to inhibit the growth of bacteria on such surfaces include chemical modification of the polymer surface and the application of coatings containing antimicrobial materials such as silver. However, such methods remain subject to variability, poor durability, and potential toxicity.
Thus, there remains a need to develop new methods of nanostructuring polymer surfaces used in implantable medical devices and developing surfaces that resist bacterial adhesion and biofilm formation.
The presented Northeastern University invention provides methods for creating nanostructured surface features on polymers and polymer composites using low pressure (i.e., vacuum). The methods of the invention create nanostructured surface features on polymers and polymer composites using low pressure conditions. Specifically, by allowing polymers to cure (solidify) under low pressure, distinct polymer nano features can be created which significantly alter cellular functions (such as decreasing bacterial growth). This is because nanostructured surface features alter surface energetics to control initial protein adsorption events important for altering cellular functions. This technology can be used while a polymer is being extruded, cast-mold, or after production in which small amounts of a solvent are added to the polymer as long as pressure is being applied.
The procedure:
• Is simple and inexpensive
• Enables creation of distinct polymer nano features that are capable of altering key cellular functions without using pharmaceutical agents
• Is effectively used while a polymer is being extruded, cast molded, or produced
• Effectively changes the surface energy of a medical device, which in turn changes surface protein adsorption events
• Is capable of decreasing the bacterial functions by altering nano scale surface roughness alone
• Is free from potential side effects as associated with use of other therapeutic agents such as drugs
• Is effectively used during medical device or post medical device production, significantly enhancing its lifetime