Research Focus: Cell-Nanoparticle-Interactions

The Achazi Group investigates how negatively charged macromolecules interact with biological systems and how these interactions shape cellular function and host–pathogen processes. Naturally occurring glycosaminoglycans (GAGs) on cell surfaces and in the extracellular matrix influence tissue mechanics, cell–cell contacts and migration, and the binding and mobilization of signaling molecules. Soluble GAGs such as heparin additionally display anticoagulant, anti‑inflammatory and antimicrobial properties. Inspired by these natural polyanions, the lab develops and tests synthetic charged macromolecules and nanomaterials (nanoparticles, nanogels, polymers) as tailored nano‑therapeutics, drug carriers and imaging probes. We focus on the biological characterization of these materials—their binding to pathogens and proteins, cellular uptake, intracellular distribution, binding specificity and biocompatibility—with the aim of improving efficacy for intended applications and deepening mechanistic understanding. High‑resolution optical microscopy, in particular live‑cell confocal laser‑scanning microscopy that the lab has established and continues to advance, is a central tool. Our work is highly interdisciplinary and builds on close collaborations with chemists, physicists and engineers. Current projects investigate uptake mechanisms, intracellular localization and functional effects of synthetic polyanions and polycations with varied architectures and functionalizations designed to be anti‑inflammatory or to inactivate pathogens, with potential applications from therapeutics to water and blood purification. The SupraFAB research building, with its S2 biology and advanced microscopy facilities, provides the Achazi Group with new opportunities to advance this research.

Selected recent publications

• Achazi K., Haag R., Ballauff M., Dernedde J., Kizhakkedathu J. N., Maysinger D., Multhaup G. Understanding the Interaction of Polyelectrolyte Architectures with Proteins and Biosystems. Angew Chem Int Ed Engl 2021, 8, 3882–3904.
  (Comprehensive review on how polyelectrolyte structure governs interactions with proteins and cells.)
• Ahmadi V., Nie C., Mohammadifar E., Achazi K., Wedepohl S., Kerkhoff Y., Block S., Osterrieder K., Haag R. One‑pot gram‑scale synthesis of virucidal heparin‑mimicking polymers as HSV‑1 inhibitors. Chem Commun (Camb) 2021, 90, 11948–11951.
  (Scalable synthesis of heparin‑mimics with demonstrable antiviral activity.)
• Pouyan P., Nie C., Bhatia S., Wedepohl S., Achazi K., Osterrieder N., Haag R. Inhibition of Herpes Simplex Virus Type 1 Attachment and Infection by Sulfated Polyglycerols with Different Architectures. Biomacromolecules 2021, 4, 1545–1554.
  (Architecture‑dependent antiviral effects of sulfated polyglycerols.)
• Donskyi I. S., Nie C., Ludwig K., Trimpert J., Ahmed R., Quaas E., Achazi K., Radnik J., Adeli M., Haag R., Osterrieder K. Graphene Sheets with Defined Dual Functionalities for the Strong SARS‑CoV‑2 Interactions. Small 2021, 11, e2007091.
  (Design of multifunctional graphene surfaces to probe virus–material interactions.)
• Cherri M., Ferraro M., Mohammadifar E., Quaas E., Achazi K., Ludwig K., Grotzinger C., Schirner M., Haag R. Biodegradable Dendritic Polyglycerol Sulfate for the Delivery and Tumor Accumulation of Cytostatic Anticancer Drugs. ACS Biomater Sci Eng 2021, 6, 2569–2579.
  (Biodegradable sulfated nanocarriers for targeted drug delivery.)
• Kepsutlu B., Wycisk V., Achazi K., et al. Cells Undergo Major Changes in the Quantity of Cytoplasmic Organelles after Uptake of Gold Nanoparticles with Biologically Relevant Surface Coatings. ACS Nano 2020, 2, 2248–2264.
  (Microscopy‑based study linking nanoparticle surface chemistry to cellular organelle responses.)
• Donskyi I. S., Chen Y., Nickl P., Guday G., Qiao H., Achazi K., et al. Self‑degrading graphene sheets for tumor therapy. Nanoscale 2020, 26, 14222–14229.
  (Stimuli‑responsive graphene materials designed for therapeutic applications.)