Toward accelerated bone regeneration by altering poly(D,L-lactic-co-glycolic) acid porogen content in calcium phosphate cement

J Biomed Mater Res A. 2016 Feb;104(2):483-92. doi: 10.1002/jbm.a.35584. Epub 2015 Oct 29.

Abstract

This work aimed to compare in vitro degradation of dense PLGA microspheres and milled PLGA particles as porogens within CPC, considering that the manufacturing of milled PLGA is more cost-effective when compared with PLGA microspheres. Additionally, we aimed to examine the effect of porogen amount within CPC/PLGA on degradation and bone formation. Our in vitro results showed no differences between both forms of PLGA particles (as porogens in CPC; spherical for microspheres, irregular for milled) regarding morphology, porosity, and degradation. Using milled PLGA as porogens within CPC/PLGA, we evaluated the effect of porogen amount on degradation and bone forming capacity in vivo. Titanium landmarks surrounded by CPC/PLGA with 30 and 50 wt % PLGA, were implanted in forty femoral bone defects of twenty male Wistar rats. Histomorphometrical results showed a significant temporal decrease in the amount of CPC, for both formulas, and confirmed that 50 wt % PLGA degrades faster than 30 wt%, and allows for a 1.5-fold higher amount of newly formed bone. Taken together, this study demonstrated that (i) milled PLGA particles perform equal to PLGA microspheres, and (ii) tuning of the PLGA content in CPC/PLGA is a feasible approach to leverage material degradation and bone formation.

Keywords: bone regeneration; bone substitute; calcium phosphate cement; material degradation; poly(d,l-lactic-co-glycolic) acid.

MeSH terms

  • Animals
  • Bone Cements* / chemistry
  • Bone Cements* / pharmacology
  • Bone Regeneration / drug effects*
  • Calcium Phosphates* / chemistry
  • Calcium Phosphates* / pharmacology
  • Femur / injuries*
  • Femur / metabolism*
  • Femur / pathology
  • Lactic Acid* / chemistry
  • Lactic Acid* / pharmacology
  • Male
  • Osteogenesis / drug effects
  • Polyglycolic Acid* / chemistry
  • Polyglycolic Acid* / pharmacology
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Porosity
  • Rats
  • Rats, Wistar

Substances

  • Bone Cements
  • Calcium Phosphates
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • calcium phosphate