Selenium-Substituted Hydroxyapatite/Biodegradable Polymer/Pamidronate Combined Scaffold for the Therapy of Bone Tumour.

Ewa Oledzka,Marcin Sobczak,Grzegorz Nalecz-Jawecki,Joanna Kolmas

doi:10.3390/ijms160922205

Ewa Oledzka, Marcin Sobczak + Show 2 more

Open Access

https://doi.org/10.3390/ijms160922205

Copy DOI

Abstract

The present study evaluated a new concept of combined scaffolds as a promising bone replacement material for patients with a bone tumour or bone metastasis. The scaffolds were composed of hydroxyapatite doped with selenium ions and a biodegradable polymer (linear or branched), and contained an active substance—bisphosphonate. For this purpose, a series of biodegradable polyesters were synthesized through a ring-opening polymerization of ε-caprolactone or d,l-lactide in the presence of 2-hydroxyethyl methacrylate (HEMA) or hyperbranched 2,2-bis(hydroxymethyl)propionic acid polyester-16-hydroxyl (bis-MPA) initiators, substances often used in the synthesis of medical materials. The polymers were obtained with a high yield and a number-average molecular weight up to 45,300 (g/mol). The combined scaffolds were then manufactured by a direct compression of pre-synthesized hydroxyapatite doped with selenite or selenate ions, obtained polymer and pamidronate as a model drug. It was found that the kinetic release of the drug from the scaffolds tested in vitro under physiological conditions is strongly dependent on the physicochemical properties and average molecular weight of the polymers. Furthermore, there was good correlation with the hydrolytic biodegradation results of the scaffolds fabricated without drug. The preliminary findings suggest that the fabricated combined scaffolds could be effectively used for the sustained delivery of bioactive molecules at bone defect sites.

Highlights

In recent years, the trend for the development of biomaterials for implantology indicates the growing importance of composite materials based on polymers [1,2]
We presented the preparation and characterization of the combined scaffolds composed of hydroxyapatite doped with selenium ions and a biodegradable polyester, and containing an active substance—pamidronate for potential application as a bone replacement material for patients with a bone tumour or bone metastasis
The combined scaffolds, composed of the synthesized hydroxyapatite doped with selenium ions, biodegradable polyester and containing PAM as a model drug, were successfully developed as an excellent drug delivery platform for use as a bone replacement material

Summary

Introduction

The trend for the development of biomaterials for implantology indicates the growing importance of composite materials based on polymers [1,2]. The inimical mechanical properties of the polymeric materials, such as their mechanical strength, Young’s modulus and fracture toughness have limited their application as implants. It is possible to improve these properties and create composite materials when a modifying phase (e.g., hydroxyapatite (HA)) is applied to impart appropriate mechanical and biological properties. The application of the modifying phase provides the possibility of improving the poor mechanical properties of polymers (e.g., increasing the strength and fracture toughness while maintaining the Young’s modulus level at the module level of the bone tissue). The idea of strengthening bioactive polymer composites by ceramic particles was introduced by Bonfield et al [3], resulting in the mechanical similarity of these materials to a natural bone. The HA composite based on polyethylene (PE) was the first bioactive polymer-ceramic composite, applied for the production of a middle ear implant [4]

Methods

Results

Conclusion