Morphology andIn VitroBehavior of Electrospun Fibrous Poly(D,L-lactic acid) for Biomedical Applications

Toshihiro Inami,Yo Shibata,Masayuki Ueda,Kazutaka Kasai,Satoshi Hirayama,Masaru Yamaguchi,Yasuhiro Tanimoto

doi:10.1155/2013/140643

Abstract

This work describes the fabrication, optimization, and characterization of electrospun fibrous poly(D,L-lactic acid) (PDLLA) for biomedical applications. The influences of the polymer concentration of the electrospinning solution (5, 10, or 15 wt%) and the solution flow rate (0.1, 0.5, 1.0, or 2.0 mL/h) on the morphology of the obtained fibrous PDLLA were evaluated. Thein vitrobiocompatibility of two types of PDLLA, ester terminated PDLLA (PDLLA-R) and carboxyl terminated PDLLA (PDLLA-COOH), was evaluated by monitoring apatite formation on samples immersed in Hanks’ balanced salt (HBS) solution. 15 wt% polymer solution was the most beneficial for preparing a fibrous PDLLA structure. Meanwhile, no differences in morphology were observed for PDLLA prepared at various flow rates. Apatite precipitate is formed on both types of PDLLA only 1 day after immersion in HBS solution. After 7 days of immersion, PDLLA-COOH showed greater apatite formation ability compared with that of PDLLA-R, as measured by thin-film X-ray diffraction. The results indicated that the carboxyl group is effective for apatite precipitation in the body environment.

Highlights

Owing to its biodegradability and biocompatibility, poly(lactic acid) (PLA) has been demonstrated to be a suitable biodegradable polymer to produce carriers for drug delivery systems, scaffolds for tissue engineering, and implanted medical devices [1,2,3]
Electrospinning is a versatile polymer processing technique in which a stream of polymer solution or melt is subjected to a high electric field, resulting in formation of a fibrous structure
Fibrous structures were observed for both PDLLA-R and PDLLA-COOH at a concentration of 15 wt%, and the beads completely disappeared

Summary

Introduction

Owing to its biodegradability and biocompatibility, poly(lactic acid) (PLA) has been demonstrated to be a suitable biodegradable polymer to produce carriers for drug delivery systems, scaffolds for tissue engineering, and implanted medical devices [1,2,3]. The fibrous form of PLA is more preferable than the bulk material for bone tissue engineering, because its high porosity encourages the migration and adhesion of osteoblast-like cells [4]. Electrospinning is a simple and effective method for the production of fibrous structures from polymer solutions [5,6,7]. The advantage of electrospinning method is that it can be used to produce fibrous structures having fiber diameters ranging from a few micrometers to a few hundred nanometers, with large specific surface areas. There are basically three components required for the process: a high voltage supply, a capillary tube with a pipette or needle of small diameter, and a metallic collecting screen. The polymer solution is delivered through a needle and a high voltage is applied to induce charges in the fluid. Between the needle tip and the collector, the jet is highly stretched, dried, and deposited as Polymer solution

Methods

Results

Conclusion