Overlaying Therapy Using Collagen Spin-coated Plla Nanosheet for Fixation of Polypropylene Mesh

Keiichi Fujino, MD PhD, Manabu Kinoshita, MD PhD, Hiroki Haniuda, Hidekazu Yano, MD, Akihiro Saitoh, PhD, Toshinori Fujie, PhD, Kahoko Nishikawa, PhD, Keiichi Iwaya, MD PhD, Shinji Takeoka, PhD, Daizoh Saitoh, MD PhD, Yuji Tanaka, MD PhD. Department of General Medicine, National Defense Medical College

Introduction  We have recently developed a biocompatible poly L-lactic acid (PLLA) nanosheet and demonstrated its anti-adhesive properties in intraperitoneal polypropylene mesh (PPM).We herein investigated the fixative effect of collagen spin-coated on a PLLA nanosheet (Col-Spin-PLLA) on a rabbit model.

Materials & Methods  We prepared a hetero-functional freestanding PLLA nanosheet with a spin-coated collagen side and an uncoated side (J Biomater Appl; 2011, DOI: 10.1177/0885328210394470). Nanosheet was scooped up with wire frame and held in air. Expt. 1: Two pieces of mesh were implanted on each side of injured peritoneal side apart from the midline incision. The mesh was overlaid with PLLA (n=12) or Col-Spin-PLLA (n=14) without a fixed suture. Expt. 2: Two pieces of mesh were implanted into each side of extraperitoneal spaces (TAPP model). The insertion region was overlaid with PLLA (n=6) or Col-Spin-PLLA (n=14) without a fixed suture. After 3 weeks, the degree of adhesion tenacity and the fixation rate were assessed histologically.

Results  Nanosheet scooped up with wire frame was good handling. Expt. 1: The fixation rate was higher in the Col-Spin-PLLA group than in the PLLA group (64% vs. 33%). Expt. 2: The insertion regions showed good wound healing in the Col-Spin-PLLA group. The numbers of neovascularity and fibroblast proliferation were significantly larger in the Col-Spin-PLLA group than in the PLLA group. The adhesion rate was rarely.

Conclusion  We have succeeded in developing a hetero-functional nanosheet comprising a collagen modified side. PLLA side acts as an adhesion barrier. Collagen-coated side acts as a scaffold and thereby may enhance mesh fixation. 

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