Synthesis and characterization of UPPE-PLGA-rhBMP2 scaffolds for bone regeneration

J Huazhong Univ Sci Technolog Med Sci. 2012 Aug;32(4):563-570. doi: 10.1007/s11596-012-0097-4. Epub 2012 Aug 11.

Abstract

A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Morphogenetic Protein 2 / chemistry*
  • Bone Morphogenetic Protein 2 / pharmacology*
  • Bone Regeneration / drug effects*
  • Humans
  • Lactic Acid / chemistry*
  • Lactic Acid / pharmacology*
  • Phosphatidylinositol Phosphates / chemistry*
  • Phosphatidylinositol Phosphates / pharmacology*
  • Polyglycolic Acid / chemistry*
  • Polyglycolic Acid / pharmacology*
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Tissue Scaffolds

Substances

  • BMP2 protein, human
  • Bone Morphogenetic Protein 2
  • Phosphatidylinositol Phosphates
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid