Osteosarcoma growth on trabecular bone mimicking structures manufactured via laser direct write

Abstract

This paper describes the direct laser write of a photocurable acrylate-based PolyHIPE (High Internal Phase Emulsion) to produce scaffolds with both macro-and microporosity, and the use of these scaffolds in osteosarcoma-based 3D cell culture. The macroporosity was introduced via the application of stereolithography to produce a classical "woodpile" structure with struts having an approximate diameter of 200 μm and pores were typically around 500 μm in diameter. The PolyHIPE retained its microporosity after stereolithographic manufacture, with a range of pore sizes typically between 10 and 60 μm (with most pores between 20 and 30 μm). The resulting scaffolds were suitable substrates for further modification using acrylic acid plasma polymerisation. This scaffold was used as a structural mimic of the trabecular bone and in vitro determination of biocompatibility using cultured bone cells (MG63) demonstrated that cells were able to colonise all materials tested, with evidence that acrylic acid plasma polymerisation improved biocompatibility in the long term. The osteosarcoma cell culture on the 3D printed scaffold exhibits different growth behaviour than observed on tissue culture plastic or a flat disk of the porous material; tumour spheroids are observed on parts of the scaffolds. The growth of these spheroids indicates that the osteosarcoma behave more akin to in vivo in this 3D mimic of trabecular bone. It was concluded that PolyHIPEs represent versatile biomaterial systems with considerable potential for the manufacture of complex devices or scaffolds for regenerative medicine. In particular, the possibility to readily mimic the hierarchical structure of native tissue enables opportunities to build in vitro models closely resembling tumour tissue.

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

“…Exactly on the same date, Sušec et al (2013) reported the development of stable photocurable thiolene HIPEs that can be used to produce PolyHIPEs using stereolithography. Fabrication of EHA:IBOA PolyHIPEs via stereolithography in wood-pile structure has been reported many times for various TE applications (Figure 10Bb; Malayeri et al, 2016;Owen et al, 2016;Wang et al, 2016). However, manufacturing of EHA:IBOA PolyHIPEs using stereolithography cause the formation of surface skin that is characterised with the closed pore at the surface.…”

“…Nalawade et al verified this finding on hydrogel-based HIPEs ( Nalawade et al, 2016 ). Trimethylolpropane triacrylate (TMPTA) is also widely used crosslinker for EHA and isobornyl acrylate (IBOA) PolyHIPEs ( Malayeri et al, 2016 ; Owen et al, 2016 ).…”

Additive Manufacturing for Guided Bone Regeneration: A Perspective for Alveolar Ridge Augmentation

“…A. Malayeri et al developed a hierarchically porous polymer scaffold, known as a polyHIPE due to its synthesis using high internal phase emulsions (HIPEs), using 2-ethylhexyl acrylates (EHA) and isobornyl acrylate (IBOA) [ 55 ]. PolyHIPEs are a class of material where porosity is created via a phase-separation process, caused by mixing two immiscible liquids in the presence of an emulsifier [ 56 ].…”

Porous microspheres support mesenchymal progenitor cell ingrowth and stimulate angiogenesis

“…29,57 Therefore, in preparation for cell culture, the surface chemistry of the polyHIPE microspheres was modified by inductively coupled plasma polymerisation of acrylic acid. The plasma polymerisation was carried out in a custom-made apparatus consisting of a cylindrical borosilicate glass chamber with stainless steel endplates connected to the vacuum pump (RV8, Edwards).…”