Yuki Nakamura, Shunpu Horiuchi, Eiki Koshinuma, Satomitsu Imai, and Yasushiro Nishioka^*

Department of Precision Machinery Engineering, College of Science and Technology, Nihon University, Funabashi, Chiba 274-8501, Japan

Tel & Fax: + 81 – 47 – 469 - 6482

*e-mail: nishioka.yasushiro@nihon-u.ac.jp

In regenerative medicine field of nervous system, a technique to fabricate microstructure of neurons on flexible and biodegradable substrates has attracted attention [1]. On the other hand, we have focused on poly lactic-co-glycolic acid (PLGA) as a candidate for the substrate material. The degradation products of PLGA have been reported to be non-cytotoxic and safely removed from host system via normal metabolic activity. Furthermore, it has also been reported that the hydrolysis reaction speed can be modified through controlling the ratio of lactide to glycolide [2]. The characteristics of degradation and removal in vivoare advantageous for regenerative medicine. Neural cell culture on micropatterns of polylysine containing laminin layer has been reported as a technique enabling selective axonal outgrowth of neurons [3]. In this research, biodegradable neuron culture thin films that enable selective axonal outgrowth of neurons were fabricated using PLGA thin films with micro lactic patterns of polylysine with laminin on them. Micro lactic patterns of polylysine with laminin as narrow as 20 μm in width ware defined by using the micromolding in capillaries (MIMIC) technique. Polydimethylsiloxane (PDMS) channel molds used for MIMIC and stencil sheets used for the microstencil method were fabricated by curing a polyether ether ketone mold, which was fabricated by nanoimprinting. The 100µm thick PLGA thin film was fabricated by diluting the PLGA into acetone (5w/w%), packing the solution into a PDMS mold, drawing a vacuum, baking and then cooling it down to cure. The selective growth of neurons on the culture sheet with the micropatterns were confirmed.

References

[1] Y. Inada, et al. "Surgical relief of causalgia with an artificial nerve guide tube: Successful surgical treatment of causalgia (Complex Regional Pain Syndrome Type II) by in situ tissue engineering with a polyglycolic acid-collagen tube." Pain 117.3: 251-258, (2005).

[2] H. K. Makadia, et al. "Poly Lactic-co-Glycolic Acid (PLGA) as Biodegradable Controlled Drug Delivery Carrier" Polymers 2011, 3: 1377-1397, (2011).

[3] L. Kam, et al. "Axonal outgrowth of hippocampal neurons on micro-scale networks of polylysine-conjugated laminin." Biomaterials 22.10: 1049-1054, (2001).