Coaxial Electrospinning as a Process to Engineer Biodegradable Polymeric Scaffolds as Drug Delivery Systems for Anti-Inflammatory and Anti- Thrombotic Pharmaceutical Agents

Alexandros Repanas,Willem F Wolkers

doi:10.4172/2161-1459.1000192

Alexandros Repanas, Willem F Wolkers

Open Access

https://doi.org/10.4172/2161-1459.1000192

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Abstract

Abstract Objective: Blend electrospinning has been acknowledged as a cost-effective technique for the production of fibrous scaffolds, suitable for various biomedical applications. Coaxial electrospinning is a method variant that results in core-shell structures with advantages, such as delayed diffusion and protection of sensitive biomolecules. The aim of this work was to evaluate how different process and solution parameters affect the structural, mechanical and physical properties of the fibers, created by polycaprolactone (PCL). In addition, acetylsalicylic acid (ASA) that was used as a model anti-inflammatory and anti-thrombotic agent, was loaded within the fiber meshes in order to compare release kinetics between fibers produced by conventional blend and coaxial electrospinning. Methods: Scanning electron microscopy (SEM) was used to investigate the structural and morphological characteristics of the fibers. The fibers’ hydrophilicity was investigated using contact angle measurements while the electrical conductivity of the polymeric solutions and the thermal properties of the fibers were also evaluated. Differential scanning calorimetry (DSC) was used to determine the fibers’ melting point and mechanical tensile tests were performed in order to study the mechanical properties of the fibers. Moreover, UV-vis spectroscopy was used to determine the release kinetics of ASA. Results: The results indicated that increasing the concentration of PCL led to thicker and less aligned fibers. Furthermore, the physicochemical characterization did not reveal significant changes during the process. Coaxially electrospun fibers that were loaded with ASA exhibited a slower and sustained, biphasic release profile compared to blend electrospun fibers with 34% of ASA released during the first 8h and 97% in total after 3 months. Conclusion: Taken together, fibrous meshes created by coaxial electrospinning using PCL, can be tailor-made by a careful optimization of all the process and solution parameters, in order to fit the scope of specific applications in the fields of biomedical engineering and drug delivery.

Highlights

During the past two decades electrospinning has received increased attention as a technology for applications in the biomedical field
Taken together, fibrous meshes created by coaxial electrospinning using PCL, can be tailor-made by a careful optimization of all the process and solution parameters, in order to fit the scope of specific applications in the fields of biomedical engineering and drug delivery
In Figure.1A, Scanning electron microscopy (SEM) pictures depict the differences between the electrospun fibers for different solution flow rate, applied voltage and PCL concentration

Summary

Introduction

During the past two decades electrospinning has received increased attention as a technology for applications in the biomedical field. Various solution parameters (concentration of polymers, choice of solvents, solution viscosity and surface tension) and process parameters (spinning distance, applied voltage and solution flow rate) affect the structural, physicochemical and mechanical properties of the fibers [5,6]. In contrast to blend electrospinning, coaxial electrospinning involves two concentrically arranged nozzles that are connected to the power source This can be used to create fibers with a core-shell morphology that can have various applications in the fields of drug delivery, tissue engineering and wound healing [8,9,10,11]. Polycaprolactone (PCL) is a hydrophobic, semicrystalline polymer, approved from the Food and Drug Administration (FDA) in the United States of America, whose crystallinity depends on its molecular weight It is soluble in most organic solvents, has a low melting point (59-64oC) and very good blend compatibility [15]. The Received: August 25, 2015; Accepted: September 21, 2015; Published: September 28, 2015

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