Oxygen Plasma Treated-Electrospun Polyhydroxyalkanoate Scaffolds for Hydrophilicity Improvement and Cell Adhesion.

Asiyah Esmail,Maria A M Reis,Ugur Deneb Menda,Filomena Freitas,Célia Henriques,Abel Oliva,Christian Grandfils,Sara Silvestre,João R Pereira,Elvira Fortunato,Patrícia Zoio,Chantal Sevrin

doi:10.3390/polym13071056

Abstract

Poly(hydroxyalkanoates) (PHAs) with differing material properties, namely, the homopolymer poly(3-hydroxybutyrate), P(3HB), the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), P(3HB-co-3HV), with a 3HV content of 25 wt.% and a medium chain length PHA, and mcl-PHA, mainly composed of 3-hydroxydecanoate, were studied as scaffolding material for cell culture. P(3HB) and P(3HB-co-3HV) were individually spun into fibers, as well as blends of the mcl-PHA with each of the scl-PHAs. An overall biopolymer concentration of 4 wt.% was used to prepare the electrospinning solutions, using chloroform as the solvent. A stable electrospinning process and good quality fibers were obtained for a solution flow rate of 0.5 mL h−1, a needle tip collector distance of 20 cm and a voltage of 12 kV for P(3HB) and P(3HB-co-3HV) solutions, while for the mcl-PHA the distance was increased to 25 cm and the voltage to 15 kV. The scaffolds’ hydrophilicity was significantly increased under exposure to oxygen plasma as a surface treatment. Complete wetting was obtained for the oxygen plasma treated scaffolds and the water uptake degree increased in all treated scaffolds. The biopolymers crystallinity was not affected by the electrospinning process, while their treatment with oxygen plasma decreased their crystalline fraction. Human dermal fibroblasts were able to adhere and proliferate within the electrospun PHA-based scaffolds. The P(3HB-co-3HV): mcl-PHA oxygen plasma treated scaffold highlighted the most promising results with a cell adhesion rate of 40 ± 8%, compared to 14 ± 4% for the commercial oxygen plasma treated polystyrene scaffold AlvetexTM. Scaffolds based on P(3HB-co-3HV): mcl-PHA blends produced by electrospinning and submitted to oxygen plasma exposure are therefore promising biomaterials for the development of scaffolds for tissue engineering.

Highlights

A scaffold is a 3D structure made of synthetic, natural or mixed components that serves as support for cellular proliferation and differentiation, in view to mimic the microstructure, mechanical properties and biochemical functionality of living tissues [1,2,3]
The copolymer’s Tm and thermal degradation (Tdeg) values were similar (171 and 292 ◦C, respectively) to those found for the homopolymer
P(3HB) melting enthalpy and crystallinity (76.6 J g−1 and 52.4%, respectively) were lower than those of P(3HB-co-3HV) (34.5 J g−1 and 23.6 %, respectively), which could be assigned to its 3HV content (25 wt.%)

Summary

Introduction

A scaffold is a 3D structure made of synthetic, natural or mixed components that serves as support for cellular proliferation and differentiation, in view to mimic the microstructure, mechanical properties and biochemical functionality of living tissues [1,2,3]. This material should fulfil to several specifications before considering its medical application. Amongst other, it should be a biocompatible and non-immunogenic and should present an interconnected open-pore geometry with pore size allowing cell colonization, adhesion, growth and reorganization [1,4]. Some of them have been able to generate in vitro different biological tissue-like structures (blood vessels [6], skin [7], bone [8] and gut [9]) with potential applications in translational research, drug discovery and clinical transplantation or [3,10]

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