Scalable Fabrication of Low Elastic Modulus Polymeric Nanocarriers With Controlled Shapes for Diagnostics and Drug Delivery

Abstract

A new process, decoupled functional imprint lithography (DFIL), is presented for fabricating low elastic modulus polymeric nanocarriers possessing Young's modulus of bulk material as low as sub1 MPa. This method is employed to fabricate sub50 nm diameter cylinders with >3:1 aspect ratio and other challenging shapes from low elastic modulus polymers such as Nisopropylacrylamide (NIPAM) and poly(ethylene glycol) diacrylate (PEGDA), possessing Young's modulus of bulk material <10 MPa which is cannot otherwise be imprinted in similar size and pitch using existing imprint techniques. Standard imprint lithography polymers have Young's modulus >1 GPa, and so these polymers used in nanocarrier fabrication in comparison have very low elastic modulus. Monodispersed, shapeand sizespecific nanocarriers composed of NIPAM with material elastic modulus of <1 MPa have been fabricated and show thermal responsive behavior at the lower critical solubility temperature (LCST) of ∼32 آ°C. In addition, reentrant shaped nanocarriers composed of PEGDA with elastic modulus <10 MPa are also fabricated. Nanocarriers fabricated from PEGDA are shown with model imaging agent and anticancer drug (Doxorubicin) encapsulated in as small as 50 nm cylindrical nanocarriers.