biomaterials

Multifunctional Microstructured Surfaces by Microcontact Printing of Reactive Microgels

Engineering surfaces with precisely controlled chemical and structural properties is essential for developing advanced biomaterials, tissue engineering platforms, and biofunctional interfaces. In this article, Inga Litzen, Alexander Töpel, Martin Zenke, Antonio Sechi, and Andrij Pich present a versatile strategy for fabricating multifunctional microstructured surfaces by combining microcontact printing with reactive microgel technology.
The authors synthesized poly(N-vinylcaprolactam-co-glycidyl methacrylate) (p(VCL-co-GMA)) microgels that serve as functional colloidal inks for microcontact printing onto glass substrates. This approach enabled the fabrication of stable microgel arrays with well-defined geometries and allowed subsequent post-modification with functional molecules, including fluorescent dyes and cell-adhesive peptide sequences. By further introducing controlled surface-chemical gradients through dip-coating, the researchers demonstrated precise spatial control over surface functionality. Cell culture experiments using NIH-3T3 fibroblasts confirmed that peptide-functionalized microgel patterns significantly influenced cell adhesion and migration, highlighting the potential of this platform for bioengineering and regenerative medicine.
Atomic force microscopy (AFM) was employed to characterize the morphology and surface structure of the synthesized microgels after deposition. High-resolution AFM imaging was performed in tapping mode using a NanoWorld PointProbe® NCH AFM probe. The silicon AFM probe, featuring a resonance frequency of approximately 320 kHz and a spring constant of 42 N/m, enabled detailed visualization of the microgel topography and provided valuable information on particle morphology and surface organization at the nanoscale.
AFM characterization complemented dynamic light scattering and zeta potential measurements by providing direct nanoscale imaging of the surface-coated microgels. The high spatial resolution of the NanoWorld PointProbe® NCH AFM probe allowed the authors to verify the successful formation of uniform microgel structures, supporting the optimization of the microcontact printing process and the subsequent surface functionalization steps.

This article demonstrates how NanoWorld AFM probes contribute to the characterization of advanced polymeric microgel systems used for surface engineering. By combining high-resolution AFM imaging with microcontact printing and post-functionalization strategies, the study provides new opportunities for designing multifunctional surfaces for biomedical, biotechnology, and materials science applications.

Figure 3
Imaging of surfaces structured with p(VCL-co-10mol%GMA-shell) microgels via microcontact printing. a,b,e-j) Light microscopy images and c,k-m) AFM images were recorded. Additionally, d) shows a height profile generated from the AFM image b). The ideal dimensions of resulting patterns are given in the schemes above. Dark grey areas in light microscopy images represent microgel stripes, lighter areas represent the bare glass. Scale bars in light microscopy images: 100 µm.

Full citation:
Litzen, I.; Töpel, A.; Zenke, M.; Sechi, A.; Pich, A.
Multifunctional Microstructured Surfaces by Microcontact Printing of Reactive Microgels.
Advanced Functional Materials 36(15), e16135 (2026).
https://doi.org/10.1002/adfm.202516135

Creative Commons license: CC BY 4.0

The Capacities of the Probiotic Strains L. helveticus MIMLh5 and L. acidophilus NCFM to Induce Th1-Stimulating Cytokines in Dendritic Cells Are Inversely Correlated with the Thickness of Their S-Layers

The surface layer (S-layer) of probiotic bacteria plays an important role in their interaction with the host immune system. In this article, Valentina Taverniti , Paolo D’Incecco , Stefano Farris , Peter Riber Jonsen , Helene Skovsted Eld , Juliane Sørensen, Laura Brunelli, Giacomo Mantegazza, Stefania Arioli and Hanne Frøkiær, investigated how the thickness of the S-layer influences the ability of Lactobacillus helveticus MIMLh5 and Lactobacillus acidophilus NCFM to stimulate Th1-related cytokine production in dendritic cells.

The results revealed an inverse correlation between S-layer thickness and the induction of interleukin-12, indicating that thinner S-layers are associated with a stronger immune-stimulating response. These findings provide new insights into the structure–function relationship of bacterial surface layers and their role in probiotic–host interactions.

Atomic force microscopy (AFM) was used for nanomechanical and morphological characterization of bacterial cells. Measurements were performed using a commercially available AFM instrument operated in contact resonance amplitude imaging (CRAI) mode. A NanoWorld Arrow-FMR force modulation AFM probe was used. This silicon AFM probe features a rectangular beam with a triangular free end and a tetrahedral tip (tip radius ~10 nm, tip height 10–15 μm), a spring constant of 2.8 N/m and a resonance frequency of 75 kHz. Images of 10 × 10 μm² and force–distance curves were recorded at multiple locations on the bacterial surface. Nanomechanical properties, including the elastic (Young’s) modulus, were determined by fitting approach curves to the Hertzian model with an indentation depth set to 2 nm.

Figure S1: Schematic representation of the 4-step procedure for the AFM analysis of the bacteria surface: scanning of the surface in contact resonance amplitude (CRAI) mode (a); creation of the 10-point map of the nanomechanical test (b); generation of the force-distance curves (c); and fitting procedure for the extrapolation of the elastic modulus (d).

Taverniti, V.; D’Incecco, P.; Farris, S.; Jonsen, P. R.; Eld, H. S.; Sørensen, J.; Brunelli, L.; Mantegazza, G.; Arioli, S.; Mora, D.; Guglielmetti, S.; Frøkiær, H.
The Capacities of the Probiotic Strains L. helveticus MIMLh5 and L. acidophilus NCFM to Induce Th1-Stimulating Cytokines in Dendritic Cells Are Inversely Correlated with the Thickness of Their S-Layers.
Biomolecules 2025, 15(7), 1012.
https://doi.org/10.3390/biom15071012

The article: The Capacities of the Probiotic Strains L. helveticus MIMLh5 and L. acidophilus NCFM to Induce Th1-Stimulating Cytokines in Dendritic Cells Are Inversely Correlated with the Thickness of Their S-Layers, is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

NanoWorld at MRS Fall Meeting & Exhibit 2024 this week

NanoWorld CEO Manfred Detterbeck is in Boston for the MRS Fall 2024 Meeting & Exhibit this week.
You’ll meet him at some of the sessions or at NanoAndMore USA booth no. 402.

If you’re there too feel free to say hi and have a chat about #AFMprobes with him.

Happy to be at MRS Fall 2024. Hope to see many of you here.