Single-step, acid-based fabrication of homogeneous gelatin-polycaprolactone fibrillar scaffolds intended for skin tissue engineering

Gina Prado-Prone,Jorge A García-Macedo,Javier Perez-Orive,Clemente Ibarra,Cristina Velasquillo,Maria Letizia Focarete,Phaedra Silva-Bermudez,Masoomeh Bazzar

doi:10.1088/1748-605x/ab673b

Abstract

Blends of natural and synthetic polymers have recently attracted great attention as scaffolds for tissue engineering applications due to their favorable biological and mechanical properties. Nevertheless, phase-separation of blend components is an important challenge facing the development of electrospun homogeneous fibrillar natural-synthetic polymers scaffolds; phase-separation can produce significant detrimental effects for scaffolds fabricated by electrospinning. In the present study, blends of gelatin (Gel; natural polymer) and polycaprolactone (PCL; synthetic polymer), containing 30 and 45 wt% Gel, were prepared using acetic acid as a ‘green’ sole solvent to straightforwardly produce appropriate single-step Gel-PCL solutions for electrospinning. Miscibility of Gel and PCL in the scaffolds was assessed and the morphology, chemical composition and structural and solid-state properties of the scaffolds were thoroughly investigated. Results showed that the two polymers proved miscible under the single-step solution process used and that the electrospun scaffolds presented suitable properties for potential skin tissue engineering applications. Viability, metabolic activity and protein expression of human fibroblasts cultured on the Gel-PCL scaffolds were evaluated using LIVE/DEAD (calcein/ethidium homodimer), MTT-Formazan and immunocytochemistry assays, respectively. In vitro results showed that the electrospun Gel-PCL scaffolds enhanced cell viability and proliferation in comparison to PCL scaffolds. Furthermore, scaffolds allowed fibroblasts expression of extracellular matrix proteins, tropoelastin and collagen Type I, in a similar way to positive controls. Results indicated the feasibility of the single-step solution process used herein to obtain homogeneous electrospun Gel-PCL scaffolds with Gel content ≥30 wt% and potential properties to be used as scaffolds for skin tissue engineering applications for wound healing.

Highlights

Blends of natural and synthetic polymers have gained increasing importance as biomaterials10 because they combine the properties of their constituents to result in materials with improved characteristics
Viscosity of solutions significantly decreased with the addition of Gel to the solutions and it significantly decreased with the increment of Gel concentration in the Gel-PCL blend solutions
The conductivity of the solutions significantly increased with the increment of Gel concentration in the electrospinning solutions

Summary

Introduction

Blends of natural and synthetic polymers have gained increasing importance as biomaterials10 because they combine the properties of their constituents to result in materials with improved characteristics. Flexible scaffolds resembling the morphology and functionality of the extracellular matrix (ECM) constitute interesting materials that can provide support for cell adhesion, proliferation and differentiation, as well as wound cover [5,6,7,8]. Polycaprolactone (PCL) is a biocompatible, 32 biodegradable, synthetic polymer approved by the U.S Food and Drug Administration (FDA) for different medical applications [16]. It has adequate structural and mechanical stability for soft-tissue engineering applications; its hydrophobic character limits its ability to promote cell adhesion and proliferation [17,18].

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Discussion

Conclusion