Hierarchically Porous Microspheres by Thiol-ene Photopolymerization of High Internal Phase Emulsions-in-Water Colloidal Systems

Abstract

A facile method for the preparation of hierarchically porous spherical particles using high internal phase water-in-oil-in-water (w/o/w) double emulsions via the photopolymerization of the water-in-oil high internal phase emulsion (w/o HIPE) was developed. Visible-light photopolymerization was used for the synthesis of microspherical particles. The HIP emulsion had an internal phase volume of 80% and an oil phase containing either thiol pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) or trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) and acrylate trimethylolpropane triacrylate (TMPTA). This enabled the preparation of microspheres with an open porous morphology, on both the surface and within the microsphere, with high yields in a batch manner. The effect of the thiol-to-acrylate ratio on the microsphere diameter, pore and window diameter, and degradation was investigated. It is shown that thiol has a minor effect on the microsphere and pore diameter, while the acrylate ratio affects the degradation speed, which decreases with increasing acrylate content. The possibility of free thiol group functionalization was demonstrated by a reaction with allylamine, while the microsphere adsorption capabilities were tested by the adsorption of methylene blue.

Aminopoly(carboxylic acid)-Functionalized PolyHIPE Beads toward Eliminating Trace Heavy Metal Ions from Water

“…Compared to blocky polyHIPE materials, polyHIPE beads are easier to achieve uniform modification of the void surface and subsequent metal ion adsorption. 47,49,58,59 The preparation of uniform hydrophilic polyHIPE beads by thermal sedimentation polymerization of HIPE droplets in oil has been reported widely. 45,50,60 However, a large quantity of organic solvent was involved in those methods, which has high impact on the environment and cost.…”

“…Compared to blocky polyHIPE materials, polyHIPE beads are easier to achieve uniform modification of the void surface and subsequent metal ion adsorption. ,,, The preparation of uniform hydrophilic polyHIPE beads by thermal sedimentation polymerization of HIPE droplets in oil has been reported widely. ,, However, a large quantity of organic solvent was involved in those methods, which has high impact on the environment and cost . Herein, to make the fabrication process environmentally friendly and avoid the use of organic solvents, a suspension polymerization of a water-in-monomer-in-water (w/o/w) system was designed to prepare poly­(St- co -GMA- co -EGDMA) (PSGE) polyHIPE beads.…”

Elastomeric Porous Poly(glycerol sebacate) Methacrylate (PGSm) Microspheres as 3D Scaffolds for Chondrocyte Culture and Cartilage Tissue Engineering

“…Costatini et al highlighted the use of monodisperse alginate/chitosan microspheres [ 34 ] for 3D culture of hMSCs. Additionally, the production of thiol-ene microspheres for biological applications has been reported by Kramer et al [ 38 ], whereby these polydisperse microspheres were produced via a CSTR process. The same group also highlighted the use of macroscopic disk thiol-ene polyHIPE scaffolds as potential scaffolds for cartilage repair [ 39 ] since they showed good chondrocyte ingrowth and cartilage production in in vitro studies.…”

Synthetic Polypeptide–Polyester PolyHIPEs Prepared by Thiol–Ene Photopolymerization

“…BLG NCA was prepared according to the procedure described previously. 37 1 H and 13 C NMR spectra are shown in Figure S1. BLG NCA (1.5 g, 5.7 mmol) was dissolved in anhydrous DMF (15 mL).…”

“…Morphology is a feature that affects both the mechanical and biological efficiency of scaffolds as a highly interconnective porous architecture is required to allow cell infiltration, nutrient flux, and integration of the material into the host tissue. , Such specific morphological features, as well as mechanical properties, can be conveniently tuned by high internal phase emulsion (HIPE) templating . Polymerized HIPEs (polyHIPEs) based on biodegradable materials have already been used as scaffolds for tissue engineering. , Recently, there has been considerable interest in the development of polyHIPEs prepared from a variety of biocompatible and biodegradable polymers using fast-curing thiol–ene step-growth photopolymerization. − …”