The Effect of Branching (Star Architecture) on Poly(d,l-lactide) (PDLLA) Degradation and Drug Delivery

Biomacromolecules. 2017 Mar 13;18(3):728-739. doi: 10.1021/acs.biomac.6b01524. Epub 2017 Feb 16.

Abstract

This study focuses on the comparative evaluation of star (branched) and linear poly(l,d-lactic acid) (PDLLA) as degradable materials employed in controlled release. The polymers were prepared via ring-opening polymerization initiated by decanol (linear), pentaerythritol (4-armed star) and dipentaerythritol (6-armed star), and processed both in the form of films and nanoparticles. Independent of the length or number of their arms, star polymers degrade slower than linear polymers, possibly through a surface (vs bulk) mechanism. Further, the release of a model drug (atorvastatin) followed zero-order-like kinetics for the branched polymers, and first-order kinetics for linear PDLLA. Using NHOst osteoblastic cells, both linear and star polymers were devoid of any significant toxicity and released atorvastatin in a bioavailable form; cell adhesion was considerably lower on star polymer films, and the slower release from their nanoparticles appeared to be beneficial to avoid atorvastatin overdosing.

MeSH terms

  • Atorvastatin / pharmacology
  • Biological Availability
  • Cells, Cultured
  • Chemical Phenomena
  • Drug Delivery Systems*
  • Drug Liberation
  • Humans
  • Magnetic Resonance Spectroscopy
  • Microscopy, Atomic Force
  • Molecular Weight
  • Nanoparticles / chemistry*
  • Osteoblasts / drug effects
  • Polyesters / chemistry*
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Polyesters
  • poly(lactide)
  • Atorvastatin