Biology subjects

Nissler, R.

Publications and source records attributed to Nissler, R..

3 recordsLinked to original sources

bioRxiv2024

An Augmented Reality Visor for Intraoperative Visualization, Guidance and Temperature Monitoring using Fluorescence

Fluorescence-guided surgical techniques, including tumor resection and tissue soldering, are advancing the frontiers of surgical precision by offering enhanced control that minimizes tissue damage and improves recovery as well as outcomes. However, integrating the visualization of the fluorescent signal and temperature monitoring seamlessly into surgical workflows has not been fully realized and remains a challenge, thus limiting their effectiveness and wide-spread clinical adoption. To address this issue, we introduce an augmented reality (AR) visor designed to unite nanomaterial excitation along with fluorescence detection, and temperature monitoring during surgical procedures. The AR visor was evaluated using advanced fluorescent nanoparticles, such as indocyanine green-doped particles and singlewalled carbon nanotubes. By consolidating fluorescence visualization, excitation monitoring, and precise temperature control into a single AR platform, we equip surgeons with a comprehensive view of both the surgical field and sub-surface conditions invisible to the naked eye. This integration notably improves the safety and efficacy of fluorescence-guided surgeries, as well as emerging technologies including laser tissue soldering, by ensuring the soldering temperature stays within therapeutic thresholds and the laser is accurately guided by real-time fluorescence signals. The presented technology not only enhances existing surgical techniques but also supports the development of new strategies and sensing technologies in areas where traditional methods fall short, marking significant progress in precision surgery, which could ultimately improve patient care.

bioengineering↗

bioRxiv2019

Programmed transport and release of nanoscale cargo by immune cells

Transport and delivery of (nanoscale) materials are crucial for many applications in biomedicine. However, controlled uptake, transport and triggered release of such cargo remains challenging. In this study, we use human immune cells (neutrophilic granulocytes, neutrophils) and program them to perform these tasks in vitro. For this purpose, we let neutrophils phagocytose a nanoscale cargo. As an example, we used DNA-functionalized single-walled carbon nanotubes (SWCNT) that fluoresce in the near infrared (980 nm) and serve as sensors for small molecules. Cells still migrate, follow chemical gradients and respond to inflammatory signals after uptake of the cargo. To program release, we make use of neutrophil extracellular trap formation (NETosis), a novel cell death mechanism that leads to chromatin swelling and subsequent rupture of the cellular membrane and release of the cells whole content. By using the process of NETosis we can program the time point of cargo release via the initial concentration of stimuli such as phorbol 12-myristate-13-acetate (PMA) or lipopolysaccharide (LPS). At intermediate stimulation with LPS (100 g/ml), cells continue to migrate, follow gradients and surface cues for around 30 minutes and up to several hundred micrometers until they stop and release their cargo. The transported and released SWCNT sensor cargo is still functional as shown by subsequent detection of the neurotransmitter dopamine and reactive oxygen species (H2O2). In summary, we hijack a biological process (NETosis) and demonstrate how neutrophils can be used for programmed transport and delivery of functional nanomaterials.

biophysics↗

bioRxiv2019

Exfoliated near infrared fluorescent CaCuSi4O10 nanosheets with ultra-high photostability and brightness for biological imaging

Imaging of complex (biological) samples in the near infrared (nIR) range of the spectrum is beneficial due to reduced light scattering, absorption, phototoxicity and autofluorescence. However, there are only few near infrared fluorescent materials known and suitable for biomedical applications. Here, we exfoliate the layered pigment CaCuSi4O10 (known as Egyptian Blue, EB) via facile tip sonication into nanosheets (EB-NS) with ultra-high nIR fluorescence stability and brightness. The size of EB-NS can be tailored by tip sonication to diameters < 20 nm and heights down to 1 nm. EB-NS fluoresce at 910 nm and the total fluorescence intensity scales with the number of Cu2+ ions that serve as luminescent centers. Furthermore, EB-NS display no bleaching and ultra-high brightness compared to other nIR fluorophores. The versatility of EB-NS is demonstrated by in vivo single-particle tracking and microrheology measurements in developing Drosophila embryos. Additionally, we show that EB-NS can be uptaken by plants and remotely detected in a low cost stand-off detection setup despite strong plant background fluorescence. In summary, EB-NS are a highly versatile, bright, photostable and biocompatible nIR fluorescent material that has the potential for a wide range of bioimaging applications both in animal and plant systems.

biophysics↗