Poly(L-Lactic Acid) Composite with Surface-Modified Magnesium Hydroxide Nanoparticles by Biodegradable Oligomer for Augmented Mechanical and Biological Properties.

Seung-Woon Baek,Chun Gwon Park,Dong Keun Han,Da-Seul Kim,Yun Heo,Ho In Lee,Jun Hyuk Kim,Duck Hyun Song

doi:10.3390/ma14195869

Seung-Woon Baek, Chun Gwon Park + Show 6 more

Open Access

https://doi.org/10.3390/ma14195869

Copy DOI

Abstract

Poly(L-lactic acid) (PLLA) has attracted a great deal of attention for its use in biomedical materials such as biodegradable vascular scaffolds due to its high biocompatibility. However, its inherent brittleness and inflammatory responses by acidic by-products of PLLA limit its application in biomedical materials. Magnesium hydroxide (MH) has drawn attention as a potential additive since it has a neutralizing effect. Despite the advantages of MH, the MH can be easily agglomerated, resulting in poor dispersion in the polymer matrix. To overcome this problem, oligo-L-lactide-ε-caprolactone (OLCL) as a flexible character was grafted onto the surface of MH nanoparticles due to its acid-neutralizing effect and was added to the PLLA to obtain PLLA/MH composites. The pH neutralization effect of MH was maintained after surface modification. In an in vitro cell experiment, the PLLA/MH composites including OLCL-grafted MH exhibited lower platelet adhesion, cytotoxicity, and inflammatory responses better than those of the control group. Taken together, these results prove that PLLA/MH composites including OLCL-grafted MH show excellent augmented mechanical and biological properties. This technology can be applied to biomedical materials for vascular devices such as biodegradable vascular scaffolds.

Highlights

Biodegradable polymers like polyglycolide, poly(L-lactic acid) (PLLA), and polycaprolactone are widely used in materials for biomedical applications
Hydrophobic-oligomer-modified Magnesium hydroxide (MH) nanoparticles were contained in the PLLA matrix to inhibit inflammatory reactions caused by acidic degradation products of PLLA
Hydrophobic oligomers were successfully modified on the MH surface through a nucleophilic addition reaction

Summary

Introduction

Biodegradable polymers like polyglycolide, poly(L-lactic acid) (PLLA), and polycaprolactone are widely used in materials for biomedical applications. PLLA has attracted a great deal of attention for its use in biomedical materials such as biodegradable vascular scaffold (BVS) due to its high biocompatibility. Thermal processing such as extrusion and injection molding is utilized to produce implant devices using PLLA [1,2]. Thermal degradation of PLLA occurs via inter- or intramolecular transesterification reactions and hydrolysis while thermal processing decreases the mechanical properties and molecular weight of the products and increases the biodegradation rate. Overcoming the inflammatory problem of PLLA is important in the application to medical devices

Objectives

Methods

Results

Conclusion