Transfer molding processes for nanoscale patterning of poly-L-lactic acid (PLLA) films

Abstract

Nanoscale patterned structures composed of biomaterials exhibit great potential for the fabrication of functional biostructures. In this paper, we report cost-effective, rapid, and highly reproducible soft lithographic transfer-molding techniques for creating periodic micro-and nano-scale textures on poly (L-lactic acid) (PLLA) surface. These artificial textures can increase the overall surface area and change the release dynamics of the therapeutic agents coated on it. Specifically, we use the double replication technique in which the master pattern is first transferred to the PDMS mold and the pattern on PDMS is then transferred to the PLLA films through drop-casting as well as nano-imprinting. The ensuing comparison studies reveal that the drop-cast PLLA allows pattern transfer at higher levels of fidelity, enabling the realization of nano-hole and nano-cone arrays with pitch down to ~700 nm. The nano-patterned PLLA film was then coated with rapamycin to make it drug-eluting.

Array of Nanopore Sensors Detect Nanoscale Biomolecules by Nucleic Acid Analysis

“…Usually, the PLLA nanopore substrate is fabricated using the micro-transfer molding and double replication techniques. [66] A nanoporous PET membrane was fabricated for sensing applications. [104] Under 80 MeV krypton irritation, a 12 um PET membrane was introduced with structure defects with a track density of 5 × 10 7 cm À 2 .…”

“…Poly‐L‐lactic acid (PLLA) is a synthetic, biocompatible, biodegradable polymer [66] which has been available in Europe since 1999 and safely used in an array of clinical applications for over 30 years, [67] including tissue engineering, dissolvable sutures and controlled drug release devices. Usually, the PLLA nanopore substrate is fabricated using the micro‐transfer molding and double replication techniques [66] …”