The effect of continuous long-term illumination with visible light in different spectral ranges on mammalian cells.

One of the biggest challenges in tissue engineering and regenerative medicine is to ensure oxygen supply of cells in the (temporary) absence of vasculature. With the vision to exploit photosynthetic oxygen production by microalgae, co-cultivated in close vicinity to oxygen-consuming mammalian cells, we are searching for culture conditions that are compatible for both sides. Herein, we investigated the impact of long-term illumination on mammalian cells which is essential to enable photosynthesis by microalgae: four different cell types-primary human fibroblasts, dental pulp stem cells, and osteoblasts as well as the murine beta-cell line INS-1-were continuously exposed to warm white light, red or blue light over seven days.

Assessing non-synthetic crosslinkers in biomaterial inks based on polymers of marine origin to increase the shape fidelity in 3D extrusion printing.

In the past decade, there has been significant progress in 3D printing research for tissue engineering (TE) using biomaterial inks made from natural and synthetic compounds. These constructs can aid in the regeneration process after tissue loss or injury, but achieving high shape fidelity is a challenge as it affects the construct's physical and biological performance with cells. In parallel with the growth of 3D bioprinting approaches, some marine-origin polymers have been studied due to their biocompatibility, biodegradability, low immunogenicity, and similarities to human extracellular matrix components, making them an excellent alternative to land mammal-origin polymers with reduced disease transmission risk and ethical concerns.

Selection of a suitable photosynthetically active microalgae strain for the co-cultivation with mammalian cells.

Preventing hypoxic zones in 3D bioprinted mammalian cell-laden constructs using an internal oxygen supply could enable a more successful cultivation both and . In this study, the suitability of green microalgae as photosynthetic oxygen generators within bioprinted constructs was evaluated by defining and investigating important parameters for a successful co-culture. First, we assessed the impact of light-necessary for photosynthesis-on two non-light adapted mammalian cell types and defined red-light illumination and a temperature of 37°C as essential factors in a co-culture.

Think outside the box: 3D bioprinting concepts for biotechnological applications - recent developments and future perspectives.

3D bioprinting - the fabrication of geometrically complex 3D structures from biocompatible materials containing living cells using additive manufacturing technologies - is a rapidly developing research field with a broad range of potential applications in fundamental research, regenerative medicine and industry. Currently, research into 3D bioprinting is mostly focused on new therapeutic concepts for the treatment of injured or degenerative tissue by fabrication of functional tissue equivalents or disease models, utilizing mammalian cells. However, 3D bioprinting also has an enormous potential in biotechnology.

Homogeneous and Reproducible Mixing of Highly Viscous Biomaterial Inks and Cell Suspensions to Create Bioinks.

Highly viscous bioinks offer great advantages for the three-dimensional fabrication of cell-laden constructs by microextrusion printing. However, no standardised method of mixing a high viscosity biomaterial ink and a cell suspension has been established so far, leading to non-reproducible printing results. A novel method for the homogeneous and reproducible mixing of the two components using a mixing unit connecting two syringes is developed and investigated.