Piezoelectric Ink‐Jet Printing of Horseradish Peroxidase: Effect of Ink Viscosity Modifiers on Activity

Abstract

In this study a bioink containing the horseradish peroxidase (HRP) enzyme was formulated and jetted with a piezoelectric‐based ink‐jet deposition system. A number of polymers with different molecular weights, functional groups and electric charge were tested as viscosity modifiers. The impact of viscosity modifiers on HRP activity was systematically studied. It was found that viscosity modifiers typically used in commercial ink formulations significantly impaired HRP activity possibly due to limitations in diffusion. In contrast, carboxymethyl cellulose increased viscosity to the desired range for piezoelectric jetting without negatively affecting the HRP activity. Good jettability was obtained for the HRP bioink by adding a suitable surfactant, a viscosity modifier and a humectant.magnified image

Orodispersible films: Towards drug delivery in special populations

“…viscosity modifiers, co-solvents etc.) can improve the specific printability parameters of drug-containing ink solutions such as surface tension and viscosity as well as final properties of the printed dosage forms (drug distribution and stability) (Di Risio and Yan, 2007;Genina et al, 2012;Wickström et al, 2015). For sufficient loading of poorly soluble drugs, the ink formulations needs to be modified accordingly (non-aqueous solutions, nano-suspensions, lipidic formulations) (Williams et al, 2013).…”

Inkjet‐Printed TiO2 Nanoparticles from Aqueous Solutions for Dye‐Sensitized Solar Cells (DSSCs)

“…[1] Viscosities can be increased with the addition of polymeric additives such as glycerol, ethylene glycol, or ethyl cellulose. [2] However, high-temperature curing in the range of 450-500 8C is required to completely remove these large amounts of material from the printed layers. [3] Screenprinted pastes can sometimes result in significant cracking and peeling of layers from the substrate.…”

“…The current-voltage (I-V) characteristics were measured under one sun (air mass 1.5, 100 mW cm À2 ) using a source meter (Model 2400, Keithley Instrument, Inc.), and the active area of the cell was 0.25 cm 2 . The inkjet-printed TiO 2 photoanode produced a device with a short-circuit current (I sc ) of 9.42 mA cm…”

Inkjet printing for pharmaceutics – A review of research and manufacturing

“…Pure water at room temperature has a viscosity of 1 mPa s and thus aqueous inks are usually of too low a viscosity and require additional modifying ingredients. Typical modifiers in standard inkjet printing and bioprinting techniques include polyhydric alcohols such as glycols, glycerol and diols (Di Risio and Yan 2007). The surface tension needs to be relatively low and so aqueous inks often require surfactants to reach a level of the order of 30 mN m -1 , pure water having a surface tension of 72 mN m -1 , but these must be carefully monitored due to potential effect on the API and especially denaturing of some molecules in biopharmaceuticals.…”