Inge Herrmann

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Herrmann

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Inge

ORCID

0000-0002-3018-6796

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Publications1 - 10 of 47

Nanoparticle Metal Mass Uptake Correlates with Radiosensitizing Efficacy across 2D, 3D, and In Vivo Models
Gerken, Lukas R.H.; Schaller, Laurin G.S.; Dok, Rüveyda; et al. (2026)
ACS Applied Bio Materials
Despite extensive efforts to develop nanoparticle-based radioenhancers, clinical translation remains limited, partly due to the lack of physiologically relevant preclinical models. To address this gap, we developed a 3D spheroid model of head and neck cancer using FaDu cells and compared it directly to a corresponding in vivo model in a radiotherapy setting. The spheroids exhibited key tumor-like features, including the formation of a hypoxic core and growth kinetics similar to those of in vivo tumors. Importantly, the model allowed for long-term monitoring of tumor growth and radiation response. Upon X-ray irradiation, the dose-response behavior in spheroids mirrored that observed in vivo. Furthermore, TiO2, HfO2, and Au nanoparticles demonstrated consistent radiosensitization effects in both systems when matched for the uptake mass. In contrast, conventional 2D clonogenic assays failed to align with in vivo performance, likely due to their lower radioresistance and unrealistic nanoparticle exposure conditions. This study introduces a robust, scalable, and clinically compatible 3D in vitro platform for the preclinical screening of nanoparticle radioenhancers. The system may offer streamlining of development pipelines and support the 3R principles of reduction, replacement, and refinement in radiation oncology research.
Reversible Mechanical Contraception and Endometriosis Treatment Using Stimuli-Responsive Hydrogels
Anthis, Alexandre H.C.; Kilchenmann, Samuel; Murdeu, Manon; et al. (2024)
Advanced Materials
Female sterilization via fallopian tube ligation is a common procedure; However, after the operation, over 10% of women seek re-fertilization, which is frequently unsuccessful. In addition, there is evidence that fallopian tubes contribute to the spread of endometriotic tissue as they serve as channels for proinflammatory media entering the abdominal cavity via retrograde menstruation. Here, stimuli-degradable hydrogel implants are presented for the functional, biocompatible, and reversible occlusion of fallopian tubes. The hydrogel implants, designed with customized swelling properties, mechanically occlude fallopian tubes in a high-performance manner with burst pressures reaching 255-558 mmHg, exceeding normal abdominal pressures (95 mmHg). Their damage-free removal can be achieved within 30 min using near-visible UV light or a glutathione solution, employing a method akin to standard fallopian tube perfusion diagnostics. Ultrasound-guided implant placement is demonstrated using a clinical hysteroscope in a human-scale uterus model and biocompatibility in a porcine in vivo model. Importantly, the prevention of live sperm as well as endometrial cell passage through blocked fallopian tubes is demonstrated. Overall, a multifunctional system is presented that constitutes a possible means of on-demand, reversible contraception along with the first-ever mechanical approach to abdominal endometriosis prevention and treatment.
Inducing in-plane uniaxial magnetic anisotropies in amorphous CoFeB thin films
Scheibler, Subas; Yildirim, Oguz; Herrmann, Inge; et al. (2023)
Journal of Magnetism and Magnetic Materials
Controlling the magnetic anisotropy of thin magnetic films with in-plane magnetization is of highest relevance particularly for magnetic field sensors. Here, the origin and magnitude of the in-plane magnetic anisotropies of ferromagnetic Co20Fe60B20 films with obliquely sputter-deposited Ta-seed layers are investigated. Uniaxial in-plane anisotropy constants in the range of a few kJ/m³ up to about 25 kJ/m³ become accessible. We find that the anisotropy is predominantly determined by an surface rather than the bulk term. However, the magnetostatic effects arising from the measured directional roughness of the Ta seed cannot fully account for the observed anisotropy, indicating the existence of an additional origin of the anisotropy arising from the oblique sputtering. Further, we find that the anisotropies of films deposited with normal incidence in an applied magnetic field are about an order of magnitude weaker. Overall, this work shows that oblique sputtering offers a strategy to induce in plane anisotropies of up to 25 kJ/m³ in CoFeB, however, at the expense of larger Ta seed thickness.
Inorganic nanohybrids combat antibiotic-resistant bacteria hiding within human macrophages
Matter, Martin T.; Doppegieter, Meagan; Gogos, Alexander; et al. (2021)
Nanoscale
Bacterial infections are one of the main health concerns humanity faces today and bacterial resistances and protection mechanisms are set to aggravate the issue in the coming years. An increasing number of bacterial strains evades antibiotic treatment by hiding inside cells. Conventional antimicrobial agents are unable to penetrate or be retained in the infected mammalian cells. Recent approaches to overcome these limitations have focused on load-carrier systems, requiring a triggered discharge leading to complex release kinetics. The unison of potent antimicrobial activity with high mammalian cell compatibility is a prerequisite for intracellular activity, which is not well-met by otherwise well-established inorganic systems, such as silver-based nanoparticles. In this work, load and carrier are combined into one functional inorganic nanoparticle system, which unites antimicrobial activity with mammalian cell compatibility. These multicomponent nanohybrids based on cerium oxide are produced in one step, yet unite complex materials. The nanoparticles form suprastructures of similar size and surface charge as bacteria, therefore facilitating the uptake into the same subcellular compartments, where they unleash their antibacterial effect. Such intrinsically antibacterial nanohybrids significantly reduce bacterial survival inside macrophages without harming the latter. Furthermore, blocking of nanoparticle endocytosis and subcellular electron microscopy elucidate the mechanism of action. Taken together, this work presents the first demonstration of antibacterial activity of ceria-based nanoparticles inside of mammalian cells and offers a route to straightforward and robust intracellular antibacterial agents that do not depend on payload delivery or biological constituents.
Sutureless gastrointestinal anastomoses
Anthis, Alexandre H.C.; Schlegel, Andrea A.; Hartel, Mark; et al. (2022)
Nature Biomedical Engineering
An adhesive hydrogel patch made from off-the-shelf materials seals and aids the healing of gastrointestinal-tissue defects without the need for sutures, as shown with the repair of gastrointestinal leaks in live rats and pigs.
Smart sealants for prevention and monitoring of gastrointestinal anastomotic leaks using portable smartphone-controlled ultrasound transducers
Anthis, Alexandre H.C.; Abundo, Maria Paulene; Neuer, Anna L.; et al. (2022)
bioRxiv
Millions of patients every year undergo gastrointestinal surgery. While often lifesaving, sutured and stapled reconnections leak in around 10% of the cases. Penetration of digestive fluids into the peritoneal cavity may lead to dreadful complications, including sepsis and premature death. Modern suture supports and tissue adhesives only insufficiently address the issue. Due to the scarcity of alternatives, surgeons rely on monitoring surrogate markers and clinical symptoms, which oftentimes lack sensitivity and specificity, hence only offering late-stage detection of already fully developed leaks. Here, a first-of-its-kind, modular, intelligent suture support patch capable of sealing and monitoring leaks under harsh gastrointestinal conditions is presented. The smart adhesive layered hydrogel patch provides, in addition to unprecedented tissue sealing under most demanding conditions, unique leak-detection capabilities based on pH and/or enzyme-responsive sensing elements, which can be read out by non-invasive point-of-need ultrasound imaging. Reliable detection of the breaching of sutures in as little as 3 hours in intestinal leak and 15 minutes in gastric leak conditions, and before an actual leak develops, is demonstrated. This technology paves the way for next-generation suture support materials that offer disambiguation in cases of anastomotic leaks based on point-of-need monitoring, without reliance on complex electronics or bulky (bio)electronic implantables.
Protein Aggregation on Metal Oxides Governs Catalytic Activity and Cellular Uptake
Nissler, Robert; Dennebouy, Lena; Gogos, Alexander; et al. (2024)
Small
Engineering of catalytically active inorganic nanomaterials holds promising prospects for biomedicine. Catalytically active metal oxides show applications in enhancing wound healing but have also been employed to induce cell death in photodynamic or radiation therapy. Upon introduction into a biological system, nanomaterials are exposed to complex fluids, causing interaction and adsorption of ions and proteins. While protein corona formation on nanomaterials is acknowledged, its modulation of nanomaterial catalytic efficacy is less understood. In this study, proteomic analyses and nano-analytic methodologies quantify and characterize adsorbed proteins, correlating this protein layer with metal oxide catalytic activity in vitro and in vivo. The protein corona comprises up to 280 different proteins, constituting up to 38% by weight. Enhanced complement factors and other opsonins on nanocatalyst surfaces lead to their uptake into macrophages when applied topically, localizing >99% of the nanomaterials in tissue-resident macrophages. Initially, the formation of the protein corona significantly reduces the nanocatalysts' activity, but this activity can be partially recovered in endosomal conditions due to the proteolytic degradation of the corona. Overall, the research reveals the complex relationship between physisorbed proteins and the catalytic characteristics of specific metal oxide nanoparticles, providing design parameters for optimizing nanocatalysts in complex biological environments.
An Augmented Reality Visor for Intraoperative Visualization, Guidance, and Temperature Monitoring Using Fluorescence
Cipolato, Oscar; Fauconneau, Matthias; LeValley, Paige J.; et al. (2025)
Journal of Biophotonics
Fluorescence-guided surgeries, including tumor resection and tissue soldering, are advancing the frontiers of surgical precision by offering enhanced control that minimizes tissue damage, improving recovery and outcomes. However, integrating fluorescence visualization with real-time temperature monitoring remains a challenge, limiting broader clinical use. We address this issue with an augmented reality (AR) visor that combines nanomaterial excitation, fluorescence detection, and temperature monitoring. Using advanced fluorescent nanoparticles like indocyanine green-doped particles and carbon nanotubes, the visor provides a comprehensive view of both the surgical field and sub-surface conditions invisible to the naked eye. This integration improves the safety and efficacy of fluorescence-guided surgeries, including laser tissue soldering, by ensuring optimal temperatures and laser guidance in real time. The presented technology enhances existing surgical techniques and supports the development of new strategies and sensing technologies in areas where traditional methods fall short, marking significant progress in precision surgery and potentially improving patient care.
Scalable Synthesis of Ultrasmall Metal Oxide Radio-Enhancers Outperforming Gold
Gerken, Lukas R.H.; Neuer, Anna L.; Gschwend, Pascal; et al. (2021)
Chemistry of Materials
Nanoparticle-based radio-enhancement has the potential to improve cancer cell eradication by augmenting the photoelectric cross-section of targeted cancer cells relative to the healthy surroundings. Encouraging results have been reported for various nanomaterials, including gold and hafnia. However, the lack of scalable synthesis methods and comparative studies is prohibitive to rationalized material design and hampers translation of this promising cancer management strategy. Here, we present a scalable (>100 g day–1) and sterile alternative to conventional batch synthesis of group IV metal oxides (TiO2, ZrO2, and HfO2), which yields near-monodisperse ultrasmall metal oxide nanoparticles with radio-enhancement properties. Access to group IV oxide nanoparticles, which solely differ in atomic number but otherwise exhibit comparable morphologies, sizes, and surface chemistries, enables the direct comparison of their radio-enhancement properties to rationally guide material selection for optimal radio-enhancement performance. We show that the metal oxide nanoparticles exhibit atomic-number-dependent radio-enhancement in cancer cells (HT1080 and HeLa), which is attenuated to baseline levels in normal fibroblasts (normal human dermal fibroblasts). The observed radio-enhancement effects show excellent agreement with physical dose enhancement and nanoparticle dosimetry calculations. Direct benchmarking against gold nanoparticles, the current gold standard in the field, rationalizes the use of hafnia nanoparticles based on their radio-enhancement performance, which is superior to equi-sized gold nanoparticles. Taken together, the competitive radio-enhancement properties for near-monodisperse nanoparticles produced by scalable and sterile flame spray synthesis offer a route to overcoming key roadblocks in the translation of nanoparticle-based radio-enhancers.
Nanoanalytical Insights into the Stability, Intracellular Fate, and Biotransformation of Metal-Organic Frameworks
Neuer, Anna Lena; Geck, Deborah; Gogos, Alexander; et al. (2023)
ACS Applied Materials & Interfaces
Metal-organic frameworks (MOFs) have found increasingapplicationsin the biomedical field due to their unique properties and high modularity.Although the limited stability of MOFs in biological environmentsis increasingly recognized, analytical techniques have not yet beenharnessed to their full potential to assess the biological fate ofMOFs. Here, we investigate the environment-dependent biochemical transformationsof widely researched nanosized MOFs (nMOFs) under conditions relevantto their medical application. We assess the chemical stability ofantimicrobial zinc-based drug delivery nMOFs (Zn-ZIF-8 and Zn-ZIF-8:Ce)and radio-enhancer candidate nMOFs (Hf-DBA, Ti-MIL-125, and TiZr-PCN-415)containing biologically nonessential group IV metal ions. We revealthat even a moderate decrease in pH to values encountered in lysosomes(pH 4.5-5) leads to significant dissolution of ZIF-8 and partialdissolution of Ti-MIL-125, whereas no substantial dissolution wasobserved for TiZr-PCN-415 and Hf-DBA nMOFs. Exposure to phosphate-richbuffers led to phosphate incorporation in all nMOFs, resulting inamorphization and morphological changes. Interestingly, long-termcell culture studies revealed that nMOF (bio)transformations of, e.g.,Ti-MIL-125 were cellular compartment-dependent and that the phosphatecontent in the nMOF varied significantly between nMOFs localized inlysosomes and those in the cytoplasm. These results illustrate thedelicate nature and environment-dependent properties of nMOFs acrossall stages of their life cycle, including storage, formulation, andapplication, and the need for in-depth analyses of biotransformationsfor an improved understanding of structure-function relationships.The findings encourage the considerate choice of suspension buffersfor MOFs because these media may lead to significant material alterationsprior to application.

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Inge Herrmann

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