Aligned PLGA/HA nanofibrous nanocomposite scaffolds for bone tissue engineering

• Published in: Acta biomaterialia 2009, Vol.5 (1), p.305-315
• Main Authors: Jose, Moncy V., Thomas, Vinoy, Johnson, Kalonda T., Dean, Derrick R., Nyairo, Elijah
• Format: Article
• Language: English
• Subjects: Biocompatible Materials - chemistry; Bone Substitutes - chemistry; Calorimetry, Differential Scanning - methods; Durapatite - chemistry; Electrochemistry - methods; Electrospinning; Lactic Acid - chemistry; Nano-hydroxyapatite; Nanocomposite; Nanocomposites - chemistry; Phosphates - chemistry; Poly ( d, l-lactide-co-glycolide); Polyglycolic Acid - chemistry; Porosity; Pressure; Spectrophotometry, Infrared - methods; Spectroscopy, Fourier Transform Infrared; Stress, Mechanical; Tissue Engineering - methods
• ISSN: 1742-7061; 1878-7568
• DOI: 10.1016/j.actbio.2008.07.019

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 20 wt.%) increased the average fiber diameter from 300 nm (neat PLGA) to 700 nm (20% nano-HA). At higher concentrations (⩾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 441 MPa for neat PLGA to 724 MPa for 5% nano-HA; however, further increasing the concentration leads to a decrease in storage modulus, to 371 MPa 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.