Biology subjects

Butelmann, T.

Publications and source records attributed to Butelmann, T..

4 recordsLinked to original sources

bioRxiv2026

Bespoke sustainable 3D-printed labware for enhanced handling and standardization of tumor spheroid migration and invasion assays

Three-dimensional (3D) cell culture models, particularly multicellular tumor spheroids, have become essential tools for studying cancer biology, drug screening, and preclinical testing due to their ability to mimic physiological tumor microenvironments. However, traditional invasion assays, such as Boyden-chamber- or Transwell-based systems, often suffer from variability introduced by spheroid handling and transfer, compromising data reproducibility. Here, we present a novel, 3D-printed migration and invasion platform --the MQm-sert-- designed to standardize and streamline spheroid-based invasion assays while maintaining spheroid integrity. Fabricated via fused filament fabrication using biobased polylactic acid, the MQm-sert integrates a hanging-drop spheroid culture system (MQm-sert) with a membrane-based invasion chamber (M-sert), eliminating the need for disruptive spheroid transfer steps. Using synthetic tumor environment mimics (STEMs) composed of breast cancer cells (MDA-MB-231 and MCF7), mesenchymal stromal cells (MSCs), and human pulmonary microvascular endothelial cells (HPMECs), we quantified invasion dynamics and cellular interactions. This innovation significantly reduces experimental variability, as demonstrated by lower variance in invasive cell mass dimensions and cell density compared to conventional workflows. Beyond biological insights, the platform aligns with sustainability goals by leveraging cost-effective, open-source 3D printing, reducing reliance on commercial labware, and addressing key challenges in 3D cell culture standardization.

bioengineering↗

bioRxiv2026

Engineering Stable Hydrogels with Polydisperse Yeast Exopolysaccharides for Embedding Cancer Spheroids

Polysaccharides are often used to mimic physiological environments such as for cancer research models. However, established polysaccharides can display limited long-term stability and high batch-to-batch variability. To overcome this, biomanufactured polysaccharides are increasingly utilized in biomaterials. Here, we produced and characterized Rhodotorula toruloides yeast exopolysaccharides (EPS) and used it to engineer hydrogel for culturing cancer cells. Yeast fermentation of glucose, mannose, and xylose yielded varying EPS amounts (1.68, 1.44, and 0.48 g/L, respectively) with similar compositions, suggesting a common biosynthetic pathway. The glucose-derived EPS characterization identified multiple linkage types and three molecular weight fractions (1.75, 30.0, and 1000 kDa), and its solutions exhibited Newtonian behavior, indicating minimal chain-chain interactions. Solubilizing this polydisperse EPS with polyethylene glycol diacrylate and UV-crosslinking it enabled the engineering of semi-interpenetrating polymer network hydrogel that efficiently embedded cancer spheroids. Our study introduces an integrated biomanufacturing strategy to generate stable and consistent biomaterials, applicable for tissue engineering. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/703759v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@110d079org.highwire.dtl.DTLVardef@e6e390org.highwire.dtl.DTLVardef@662540org.highwire.dtl.DTLVardef@17afd5_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2021

Metabolism Control in 3D Printed Living Materials

The three-dimensional printing of cells offers an attractive opportunity to design and develop innovative biotechnological applications, such as the fabrication of biosensors or modular bioreactors. Living materials (LMs) are cross-linked polymeric hydrogel matrices containing cells, and recently, one of the most deployed LMs consists of F127-bis-urethane methacrylate (F127-BUM). The material properties of F127-BUM allow reproducible 3D printing and stability of LMs in physiological environments. These materials are permissible for small molecules like glucose and ethanol. However, no information is available for oxygen, which is essential-- for example, towards the development of aerobic bioprocesses using microbial cell factories. To address this challenge, we investigated the role of oxygen as a terminal electron acceptor in the budding yeasts respiratory chain and determined its permissibility in LMs. We quantified the ability of cell-retaining LMs to utilize oxygen and compared it with cells in suspension culture. We found that the cells ability to consume oxygen was heavily impaired inside LMs, indicating that the metabolism mostly relied on fermentation instead of respiration. To demonstrate an application of these 3D printed LMs, we evaluated a comparative brewing process. The analysis showed a significantly higher (3.7%) ethanol production using 3D printed LMs than traditional brewing, indicating an efficient control of the metabolism. Towards molecular and systems biology studies using LMs, we developed a highly reliable method to isolate cells from LMs for flow cytometry and further purified macromolecules (proteins, RNA, and DNA). Our results show the application of F127-BUM-based LMs for microaerobic processes and envision the development of diverse bioprocesses using versatile LMs in the future.

bioengineering↗

bioRxiv2020

Physical confinement impacts cellular phenotype within living materials

Additive manufacturing allows three-dimensional printing of polymeric materials together with cells, creating living materials for applications in biomedical research and biotechnology. However, understanding the cellular phenotype within living materials is lacking and a key limitation for their wider application. Herein, we present an approach to characterize the cellular phenotype within living materials. We immobilized the budding yeast Saccharomyces cerevisiae in three different photocross-linkable triblock polymeric hydrogels containing F127-bis-urethane methacrylate, F127-dimethacrylate, or poly(alkyl glycidyl ether)-dimethacrylate. Using optical and scanning electron microscopy, we showed that hydrogels based on these polymers were stable under physiological conditions, but yeast colonies showed differences in the interaction within the living materials. We found that the physical confinement, imparted by compositional and structural properties of the hydrogels, impacted the cellular phenotype by reducing the size of cells in living materials compared with suspension cells. These properties also contributed to the differences in immobilization patterns, growth of colonies, and colony coatings. We observed that a composition-dependent degradation of polymers was likely possible by cells residing in the living materials. In conclusion, our investigation highlights the need for a holistic understanding of the cellular response within hydrogels to facilitate the synthesis of application-specific polymers and the design of advanced living materials in the future.

bioengineering↗