A Novel Bilayer Polycaprolactone Membrane for Guided Bone Regeneration: Combining Electrospinning and Emulsion Templating

Abstract

Guided bone regeneration is a common dental implant treatment where a barrier membrane (BM) is used between epithelial tissue and bone or bone graft to prevent the invasion of the fast-proliferating epithelial cells into the defect site to be able to preserve a space for infiltration of slower-growing bone cells into the periodontal defect site. In this study, a bilayer polycaprolactone (PCL) BM was developed by combining electrospinning and emulsion templating techniques. First, a 250 µm thick polymerised high internal phase emulsion (polyHIPE) made of photocurable PCL was manufactured and treated with air plasma, which was shown to enhance the cellular infiltration. Then, four solvent compositions were investigated to find the best composition for electrospinning a nanofibrous PCL barrier layer on PCL polyHIPE. The biocompatibility and the barrier properties of the electrospun layer were demonstrated over four weeks in vitro by histological staining. Following in vitro assessment of cell viability and cell migration, cell infiltration and the potential of PCL polyHIPE for supporting blood vessel ingrowth were further investigated using an ex-ovo chick chorioallantoic membrane assay. Our results demonstrated that the nanofibrous PCL electrospun layer was capable of limiting cell infiltration for at least four weeks, while PCL polyHIPE supported cell infiltration, calcium and mineral deposition of bone cells, and blood vessel ingrowth through pores.

Basic Principles of Emulsion Templating and Its Use as an Emerging Manufacturing Method of Tissue Engineering Scaffolds

“…We showed that murine longbone osteocytes (MLO-A5s) attached, proliferated and infiltrated throughout the interconnects of the PCL PolyHIPE scaffolds. Suitability of the pores for blood vessel ingrowth was also shown using chick chorioallantoic membrane (CAM) assay (Figures 13L-O; Aldemir Dikici et al, 2019a, 2020.…”

“…In the photoinitiator selection process, the critical parameter is that the absorption band of the photoinitiator should overlap with the emission spectrum of the light source ( Eibel et al, 2018 ). 2,4,6-Trimethylbenzoyl phosphine oxide/2-hydroxy-2-methyl propiophenone blend ( Johnson et al, 2015 ; Sherborne et al, 2018 ; Aldemir Dikici et al, 2019a , b ) and phenyl bis(2,4,6−trimethyl benzoyl)−phosphine oxide (BAPO) ( Sears et al, 2016 ) are widely used photoinitiators in photo-polymerisation of HIPEs. Photoinitiators are mostly used in the HIPE composition at a concentration range of 0.2–10% (w/w) of the polymer.…”

“…To date, various scaffold manufacturing techniques such as gas foaming ( Salerno et al, 2009 ; Bak et al, 2014 ), porogen leaching ( Reignier and Huneault, 2006 ; Bak et al, 2014 ), electrospinning ( Aldemir Dikici et al, 2019a ; Mangir et al, 2019a ; Dikici et al, 2020b , c ), and additive manufacturing (AM) ( Elomaa et al, 2011 ; Aldemir Dikici et al, 2017 ) have been widely used to introduce porosity into TE scaffolds. Recently, emulsion templating has gained particular attention as a scaffold fabrication technique due to its three main advantages; providing (i) high porosity[(up to 99%) ( Richez et al, 2005 )], (ii) high interconnectivity ( Figure 1C ), and (iii) high tunability.…”

“…( Christenson et al, 2007 ), k. ( Padbury, 2019 ), l. ( Moglia et al, 2011 ), m. ( Johnson et al, 2013 ; Sušec et al, 2013 ), n. ( Hu et al, 2014a ), o. ( Aldemir Dikici et al, 2019b ), p. ( Aldemir Dikici et al, 2019a )].…”

Evaluation of 1-Ethyl-3-(3-Dimethylaminopropyl) Carbodiimide Cross-Linked Collagen Membranes for Guided Bone Regeneration in Beagle Dogs

“…Collagen membranes derived from animal species are commonly used as resorbable membranes [ 19 ]. Collagen is a major structural protein of extracellular matrix and supports the growth of various tissues, and also has the advantages of inducing little inflammation and of being noncytotoxic [ 20 , 21 ].…”