Poly (ε-caprolactone)-based electrospun nano-featured substrate for tissue engineering applications: a review

Abstract

The restoration of normal functioning of damaged body tissues is one of the major objectives of tissue engineering. Scaffolds are generally used as artificial supports and as substrates for regenerating new tissues and should closely mimic natural extracellular matrix (ECM). The materials used for fabricating scaffolds must be biocompatible, non-cytotoxic and bioabsorbable/biodegradable. For this application, specifically biopolymers such as PLA, PGA, PTMC, PCL etc. satisfying the above criteria are promising materials. Poly(ε-caprolactone) (PCL) is one such potential candidate which can be blended with other materials forming blends, copolymers and composites with the essential physiochemical and mechanical properties as per the requirement. Nanofibrous scaffolds are fabricated by various techniques such as template synthesis, fiber drawing, phase separation, self-assembly, electrospinning etc. Among which electrospinning is the most popular and versatile technique. It is a clean, simple, tunable and viable technique for fabrication of polymer-based nanofibrous scaffolds. The design and fabrication of electrospun nanofibrous scaffolds are of intense research interest over the recent years. These scaffolds offer a unique architecture at nano-scale with desired porosity for selective movement of small molecules and form a suitable three-dimensional matrix similar to ECM. This review focuses on PCL synthesis, modifications, properties and scaffold fabrication techniques aiming at the targeted tissue engineering applications.

Keywords: Biocompatible; Electrospinning; Nanofibrous substrate; Poly(ε-caprolactone); Scaffolds; Tissue engineering.

Fig. 1

Application of electrospun scaffolds for tissue regeneration at various parts of human body. With permission Wang et al. (2013)

Fig. 2

Different synthesis routes of PCL

Fig. 3

PCL/gelatin scaffolds showing L929 fibroblast cell seeding after 24 h (a), (b) and (c) at  × 500,  × 2500 and  × 5000 magnification. With permission Gautam et al. (2014)

Fig. 4

Various stages involved in scaffold assisted TE approach ( Source: Asadian et al. (2020))

Fig. 5

TEM images of a PCL scaffold and b Core–shell structure of PGS/PCL scaffold. With permission Silva et al. (2020)

Fig. 6

SEM micrographs comparing cell morphology on PCL-based scaffolds with and without phytochemicals. With permission Venugopal et al. (2019)

Fig. 7

SEM images showing random and aligned PCL/gelatin nanofibers of 70/30 composition. With permission Ghasemi-Mobarakeh et al. (2008a, b)

Fig. 8

EESEM images of PCL/gelatin/graphene oxide scaffolds showing a Adherence of PC12 cells after 2 days and b Adherence of PC12 cells after 7 days. With permission Heidari et al. (2019)

Fig. 9

Schematic representation showing the tri-leaflet structured heart valve made out of PCL/PLLA. With permission Hasan et al. (2018)