A systemic approach toward optimization of the hot embossing of poly-L-lactic acid for biomedical applications

Poly L-lactic acid (PLLA) is a popular biodegradable polymer that is used extensively for many biological applications. A limitation of using PLLA is the difficulty in forming the polymer in complex shapes and forms for applications that include drug delivery and tissue engineering. This study focuses on PLLA replication using hot embossing technology. In this study hot embossing process parameters were identified, replication quality was examined, and crystallinity of PLLA was analyzed. The replication quality of micropillars and microreservoirs was examined using optical microscopy and scanning electron microscopy, with good replication obtained using a hot embossing pressure of 18 MPa at a temperature of 85°C and holding time of 120 s. The material properties were examined using differential scanning calorimetry and infrared spectroscopy that indicated no substantial crystallinity or structural changes during hot embossing of PLLA. The study presented in this article concludes with the assessment that hot embossing technology could be used as a viable micromanufacturing process for the fabrication of inexpensive PLLA-based microdevices, with possible applications to controlled drug delivery, growth factors pathways, or other therapeutic applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008