Development of Hybrid Porous Scaffold for Bone Regeneration

Enhanced Osteoinductivity through Mimicking the in vivo Nano- and Micro-environment

2012.06.06
(2012.07.12 Update)

National Institute for Materials Science
RIKEN
National Center for Child Health and Development

Tissue Regeneration Materials Unit of the NIMS International Center for Materials Nanoarchitectonics (MANA), in joint research with RIKEN and the National Center for Child Health and Development, succeeded in developing a hybrid porous scaffold which promotes bone regeneration.

Abstract

  1. A hybrid porous scaffold with enhanced osteoinductivity has been successfully developed by a collaboration team from Tissue Regeneration Materials Unit (Unit Director: Guoping Chen), International Center for Materials Nanoarchitectonics (MANA; Director-General: Masakazu Aono), National Institute for Materials Science (President: Sukekatsu Ushioda), Nano Medical Engineering Laboratory (Chief Scientist: Yoshihiro Ito), Advanced Science Institute (Director: Kohei Tamao) of RIKEN (President: Ryoji Noyori) and Department of Reproductive Biology (Department Head and Chairman: Akihiro Umezawa) of National Center for Child Health and Development (President: Michiya Natori).
  2. As there are limitations to the intrinsic regeneration/restoration capacity of bone tissue, when a large defect occurs in bone due to injury or disease, regenerative medicine using porous scaffolds is considered to be a promising method for bone regeneration. However, it is difficult to prepare polymeric porous scaffolds with both high biocompatibility and mechanical strength from a single material. In order to solve this problem, the researchers previously developed a porous scaffold by hybridizing a naturally derived polymer and a biodegradable synthetic polymer such as poly (lactic-co-glycolic acid) (PLGA), and have applied the hybrid scaffold for tissue regeneration. To further improve its bioactivity, incorporation of bioactive factors has been desirable.
  3. In the present research, a bioactive factor called BMP4, which promotes bone formation, was incorporated in the previously developed hybrid scaffold, and a 3-component hybrid porous scaffold material consisting of BMP4, collagen sponge, and PLGA mesh was successfully developed. The BMP4 was immobilized in the hybrid scaffold through a fusion protein of BMP4 with an amino acid sequence that enables bonding with collagen molecules. The fusion protein was prepared by genetic engineering technique so that the bioactivity of BMP4 not be lost after hybridization. The 3-component hybrid porous scaffold mimics the nano- and micro-environment surrounding cells in vivo. The scaffold showed enhanced bioactivity to promote bone tissue formation after subcutaneous implantation in mice.
  4. The collagen/PLGA/BMP4 hybrid porous scaffold will be useful for bone tissue regeneration to treat large bone defect. As it is also possible to hybridize the scaffold with other types of bioactive proteins fused with collagen-binding domain, the new scaffold has the potential for regeneration of various other types of tissues such as cartilage and skin.
  5. The results have been recently published in the Biomaterials journal.