Aligned PLGA/HA nanofibrous nanocomposite scaffolds for bone tissue engineering

Acta Biomater. 2009 Jan;5(1):305-15. doi: 10.1016/j.actbio.2008.07.019. Epub 2008 Jul 31.

Abstract

Aligned nanofibrous scaffolds based on poly(d,l-lactide-co-glycolide) (PLGA) and nano-hydroxyapatite (nano-HA) were synthesized by electrospinning for bone tissue engineering. Morphological characterization using scanning electron microscopy showed that the addition of different amounts of nano-HA (1, 5, 10 and 20wt.%) increased the average fiber diameter from 300nm (neat PLGA) to 700nm (20% nano-HA). At higher concentrations (>or=10%), agglomeration of HA was observed and this had a marked effect at 20% concentration whereby the presence of nano-HA resulted in fiber breaking. Thermal characterization showed that the fast processing of electrospinning locked in the amorphous character of PLGA; this resulted in a decrease in the glass transition temperature of the scaffolds. Furthermore, an increase in the glass transition temperature was observed with increasing nano-HA concentration. The dynamic mechanical behavior of the scaffolds reflected the morphological observation, whereby nano-HA acted as reinforcements at lower concentrations (1% and 5%) but acted as defects at higher concentrations (10% and 20%). The storage modulus value of the scaffolds increased from 441MPa for neat PLGA to 724MPa for 5% nano-HA; however, further increasing the concentration leads to a decrease in storage modulus, to 371MPa for 20% nano-HA. Degradation characteristics showed that hydrophilic nano-HA influenced phosphate-buffered saline uptake and mass loss. The mechanical behavior showed a sinusoidal trend with a slight decrease in modulus by week 1 due to the plasticizing effect of the medium followed by an increase due to shrinkage, and a subsequent drop by week 6 due to degradation.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biocompatible Materials / chemistry*
  • Bone Substitutes / chemistry*
  • Calorimetry, Differential Scanning / methods
  • Durapatite / chemistry*
  • Electrochemistry / methods
  • Lactic Acid / chemistry*
  • Nanocomposites / chemistry*
  • Phosphates / chemistry
  • Polyglycolic Acid / chemistry*
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Porosity
  • Pressure
  • Spectrophotometry, Infrared / methods
  • Spectroscopy, Fourier Transform Infrared
  • Stress, Mechanical
  • Tissue Engineering / methods*

Substances

  • Biocompatible Materials
  • Bone Substitutes
  • Phosphates
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • Durapatite