Preparation and Characterization of Poly (ε-caprolactone) PCL Scaffolds for Tissue Engineering Applications

Abstract

The field of Tissue Engineering has developed in response to the shortcomings associated to the replacement of tissues lost to disease or trauma: donor tissue rejection, chronic inflammation, and donor tissue shortages. The driving force behind Tissue Engineering is to avoid these problems by creating biological substitutes capable of replacing the damaged tissue. This is done by combining scaffolds, cells and signals in order to create living, physiological, three-dimensional tissues. Scaffolds are porous biodegradable structures that are meant to be colonized by cells and degrade in time with tissue generation. Scaffold design and development is mainly an engineering challenge, and is the goal of this thesis. The main aim of this thesis is to develop and characterize scaffolds for Tissue Engineering applications. Specifically, its objectives are:
 To study scaffold processing method: Phase Separation. This is done by experiment design analysis.
 To characterize the behavior of the scaffolds produced.
The scaffolds are prepared using a biodegradable polymer polycaprolactone by thermally induced phase separation technique using solid-liquid phase separation. The porosity, crystallinity and pore size was characterized using scanning electron microscopy (SEM), differential scanning calorimeter (DSC), Mercury porosimeter, and X-ray diffraction (XRD). The parameters that found to influence the architecture of the scaffolds were freezing temperature, freezing medium and polymer concentration. The freezing temperature was found to have a profound effect on the pore size and final morphology of the porous structures. The degree of crystallinity determined using XRD was comparable with that of the as received PCL. The porosity of the structures was found to be 90-97%. The porosity of the PCL structures can be controlled by the concentration of the polymer solution used. Micrographs of the samples from the SEM revealed that the pore size was smaller when the polymer solution was quenched to lower temperatures (-200C). Mercury porosimeter resulted in a pore size distribution from 50-100μm which makes them suitable for tissue engineering applications. PCL scaffolds therefore may have considerable potential as scaffold for tissue engineering.