Load-bearing biodegradable PCL-PGA-beta TCP scaffolds for bone tissue regeneration

J Biomed Mater Res B Appl Biomater. 2021 Feb;109(2):193-200. doi: 10.1002/jbm.b.34691. Epub 2020 Aug 4.

Abstract

A biocompatible and biodegradable scaffold with load-bearing ability is required to enhance the repair of bone defects by facilitating the attachment, and proliferation of cells, and vascularization during new bone formation. However, it is challenging to maintain the porosity and biodegradability, as well as mechanical properties (especially compressive strength), at the same time. Therefore, in the present work, a biodegradable composite structure of poly(caprolactone) (PCL) was designed using compression molding with varying amounts of poly(glycolic acid) (PGA) (25, 50, 75 wt%) and fixed amount (20 wt%) of beta tricalcium phosphate (beta TCP). It was hypothesized that the fabricated composite structure will develop porosity during the degradation of the PGA and that the corresponding decrease in mechanical properties will be compensated by new bone formation and ingrowth, in vivo. Accordingly, we have systematically studied the effects of sample composition on time-dependent dissolution and mechanical properties of the PGA/beta TCP scaffolds. The compressive strength increased up to ~92 MPa at 50% compression of the designed PCL-PGA samples. Furthermore, the dissolution rate, as well as weight loss, was observed to increase with an increase in the PGA amount in PCL. Based on the mechanical properties and dissolution data, it is concluded that the PCL-PGA scaffolds with beta TCP can be suitable candidates for bone tissue engineering applications, specifically for the reconstruction of bone defects, where strength and biodegradation are both important characteristics.

Keywords: PCL; PGA; TCP; bone; mechanical properties.

Publication types

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

MeSH terms

  • Absorbable Implants*
  • Bone Substitutes / chemistry*
  • Calcium Phosphates / chemistry*
  • Compressive Strength
  • Polyesters / chemistry*
  • Polyglycolic Acid / chemistry*
  • Weight-Bearing

Substances

  • Bone Substitutes
  • Calcium Phosphates
  • Polyesters
  • beta-tricalcium phosphate
  • polycaprolactone
  • Polyglycolic Acid