Poly(caprolactone)-Based Coatings on 3D-Printed Biodegradable Implants: A Novel Strategy to Prolong Delivery of Hydrophilic Drugs

Sarah Stewart, Juan Dominguez-Robles, Victoria McIlorum, Zoilo Gonzalez, Emilia Utomo, Elena Mancuso, Dimitrios Lamprou, Ryan F Donnelly, Eneko Larraneta

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48 Citations (Scopus)
51 Downloads (Pure)


Implantable devices are versatile and promising drug delivery systems, and their advantages are well established. Of these advantages, long-acting drug delivery is perhaps the most valuable. Hydrophilic compounds are particularly difficult to deliver for prolonged times. This work investigates the use of poly(caprolactone) (PCL)-based implant coatings as a novel strategy to prolong the delivery of hydrophilic compounds from implantable devices that have been prepared by additive manufacturing (AM). Hollow implants were prepared from poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) using fused filament fabrication (FFF) AM and subsequently coated in a PCL-based coating. Coatings were prepared by solution-casting mixtures of differing molecular weights of PCL and poly(ethylene glycol) (PEG). Increasing the proportion of low-molecular-weight PCL up to 60% in the formulations decreased the crystallinity by over 20%, melting temperature by over 4 °C, and water contact angle by over 40°, resulting in an increased degradation rate when compared to pure high-molecular-weight PCL. Addition of 30% PEG to the formulation increased the porosity of the formulation by over 50% when compared to an equivalent PCL-only formulation. These implants demonstrated in vitro release rates for hydrophilic model compounds (methylene blue and ibuprofen sodium) ranging from 0.01 to 34.09 mg/day, depending on the drug used. The versatility of the devices produced in this work and the range of release rates achievable show great potential. Implants could be specifically developed in order to match the specific release rate required for a number of drugs for a wide range of conditions.
Original languageEnglish
Pages (from-to)3487-3500
Number of pages14
JournalMolecular Pharmaceutics
Issue number9
Early online date16 Jul 2020
Publication statusPublished (in print/issue) - 8 Sept 2020

Bibliographical note

Funding Information:
This work was financially supported by the Wellcome Trust (UNS40040 and WT094085MA). S.A.S. is a Ph.D. candidate funded by a Department for the Economy (Northern Ireland) studentship.

Publisher Copyright:
Copyright © 2020 American Chemical Society.

Copyright 2020 Elsevier B.V., All rights reserved.


  • poly(caprolactone) coatings
  • Poly(ethylene glycol)
  • implantable drug delivery
  • hydrophilic drugs
  • additive manufacturing
  • 3d printing


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