The present study conducted to determine the in vivo immune response to biologically active, bioabsorbable, polymer-based nerve conduits that were manufactured using ink-jet microdispensing technology and to see whether or not these conduits will produce a significant inflammatory reaction. All polymer formulations employed either poly(L-lactide) (PLL) and poly(lactic-co-glycolide) (PLG) dissolved in a solvent casting and extrusion technique. Surgeries were performed on 17, male Harlan Sprague-Dawley rats. Small 2 cm incisions were made in the lateral thigh muscles of the rat and small intramuscular pouches were created in which the implants were placed. The polymer implants were harvested at two and four weeks post implantation. Staining was performed with a standard Harris hematoxylin and eosin (H&E) protocol. Qualitative analysis using brightlight microscopy was performed by the pathology department to analyze signs of inflammatory reaction. Inflammation scale was given to assess results. The scale was (0) for no significant inflammation, (1) and (1+) for mild and moderate inflammatory reaction. Fragmentation of the conduits was also observed in 4 specimens. . Group 1 (n=8, 2 weeks harvest) Group 2 (n=9, 4 weeks harvest) Inflammation scale (0) 5 4 Inflammation scale (1) 2 2 Inflammation scale (1+) 1 3 Fragmentation 2 2

Although the inflammatory reaction was slightly more evident in group (2) the majority of the specimens showed no or mild inflammatory reactions. This in vivo analysis of these printable nerve conduits demonstrate their potential use as nerve guide for tissue engineered constructs.