Biomedical Photonics for Regeneration Studies


Our research group aims to understand and model regeneration by combining new approaches and technologies from optics and photonics with specific biological models. Firstly, this includes regeneration in single cells, for instance, after laser based ablation of subcellular organelles or cell membrane laser optoporation. Secondly, we aim to achieve a translation of currently established laser imaging and manipulation techniques to an in vivo setting to understand micro regeneration in REBIRTH related organ systems by manipulation of low number of cells.

Research Focus

Fig. 1: Nanosurgery in the sarcomere of human embryonic stem cell derived cardiomyocytes: We evaluate the regeneration upon ablation of Z-disc elements to relate this to cardiac disease models.

We combine several single and multi-cell laser-based manipulation techniques to achieve cell surgery, ablation or stimulation in cells, tissue, or in in vivo model systems.

Single and Multi-Cell Manipulation
We have established several techniques to achieve laser manipulation with simultaneous and continuous imaging of single or multiple cells in cooperation with REBIRTH Unit 7.6 “LASER MANIPULATION AND CELLULAR ENGINEERING” by Prof. Heisterkamp and with the Laser Zentrum Hannover e.V. by Dr. Heiko Meyer. Single cells can be targeted by ultrashort laser pulses during simultaneous multiphoton microscopy. This enables penetration depths down to 300 µm in most tissues. Due to thermal and thermo-elastic confinement and a precise deposition of the laser energy, it is possible to manipulate on scales down to the size of small cell organelles, like cytoskeletal elements. To achieve multi-cell targeting, we can combine these approaches with gold nanoparticles, which can exemplarily adhere to the cell membrane. These are irradiated by weakly focused laser pulses thereby enabling multi-cell targeting. Localized effects at the nanoparticle (heating and bubble formation) lead, for instance, to a permeabilization of the cell membrane such that molecules from the surrounding can flow into the cell.

Cell Surgery and Ablation
We address regeneration in single cells by femtosecond laser based surgery and ablation. As an example, we aim to study the cytoskeleton in muscle cells like cardiomyocytes after laser based surgery in stress fibers or in the sarcomere (see Figure 1). We employ different microscopy techniques to follow cell reaction. On a larger scale, in more complex tissue or 3D cultures, we are interested in cell rearrangement and regeneration after ablation of single cells. How are surrounding cells affected, how is the tissue affected, and how does it regenerate? We are planning to extend this microregeneration approach to in vivo settings with simultaneous multiphoton microscopy.


Cell Transfection
Laser targeting of the membrane with a focused laser beam or gold nanoparticle mediated laser transfection enable a transient cell permeabilization and molecules from the surrounding space can flow into the cells. We are applying these techniques for targeted genetic modification of cells, either on a single cell or multi cell stage. The methods have been in particular proven successful for delivery of dyes, proteins or small antisense molecules.

Cell Stimulation
The laser irradiation can induce different responses of the cell, for instance, if membrane permeabilization occurs, this also results in ion exchange with the surrounding. We have used this exchange and direct triggering for a stimulation of cardiomyocytes. Alternatively, it might be possible to indirectly stimulate cells via laser irradiation by heat, membrane permeabilization, or stress responses via appropriate promoter systems.


  • Prof. A Heisterkamp, REBIRTH Unit Laser Manipulation and Cellular Engineering, Institute of Quantum Optics, Leibniz Universität Hannover
  • Dr. T. Ripken, Dr. D. Heinemann, Dr. H. Meyer, Department of Biomedical Optics, Laser Zentrum Hannover e.V.
  • Dr. R. Zweigerdt, REBIRTH Unit Mass Production of Pluripotent Stem Cells, Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School
  • Prof. R. Förster, Institute of Immunology, Hannover Medical School
  • PD Dr. Hugo Murua Escobar, Department of Medicine, Clinic III - Hematology/Oncology/Palliative Care, Rostock University
  • Prof. A. Bleich, Zentrales Tierlabor und Institut für Versuchstierkunde, Hannover Medical School
  • Dr. U. Böer, AG Böer/Wilhelmi - Laboratory For Tissue Engineering, Hannover Medical School
  • Prof. A. Ngezahayo, Institute of Biophysics, Leibniz University Hannover
  • Prof. Chris B. Schaffer, Meinig School of Biomedical Engineering, Cornell University
  • Prof. F. Gunn Moore, Prof. K. Dholakia, St. Andrews University, United Kingdom


  • 09/2015-01/2016 Fulbright Scholarship to S. Kalies, Research stay at Cornell University, Ithaca (US).
  • 2015 Second prize to S. Kalies: Best Student Paper Award, Conference Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XV, Photonics West
  • 2015 Newport Travel Award to S. Kalies, Photonics West 2015


2013 - ongoing


Hagenah D, Heisterkamp A, Kalies S. Effects of cell state and staining on femtosecond laser nanosurgery. J Biophotonics. 2018.


Saklayen N, Kalies S, Madrid M, Nuzzo V, Huber M, Shen W, Sinanan-Singh J, Heinemann D, Heisterkamp A, Mazur E. Analysis of poration-induced changes in cells from laser-activated plasmonic substrates. Biomed Opt Express. 2017/10/31 ed2017. p. 4756-71.

Gentemann L, Kalies S, Coffee M, Meyer H, Ripken T, Heisterkamp A, Zweigerdt R, Heinemann D. Modulation of cardiomyocyte activity using pulsed laser irradiated gold nanoparticles. Biomed Opt Express. 2017/01/20 ed2017. p. 177-92


Schomaker M, Killian D, Willenbrock S, Heinemann D, Kalies S, Ngezahayo A, Nolte I, Ripken T, Junghanss C, Meyer H, Escobar HM, Heisterkamp A. Biophysical Effects in Off-Resonant Gold Nanoparticle Mediated (Gnome) Laser Transfection of Cell Lines, Primary- and Stem Cells Using Fs Laser Pulses. Journal of Biophotonics. 2015;8(8):646-58.

Kalies S, Keil S, Sender S, Hammer SC, Antonopoulos GC, Schomaker M, Ripken T, Escobar HM, Meyer H, Heinemann D. Characterization of the Cellular Response Triggered by Gold Nanoparticle-Mediated Laser Manipulation. Journal of Biomedical Optics. 2015;20(11).

Kalies S, Antonopoulos GC, Rakoski MS, Heinemann D, Schomaker M, Ripken T, Meyer H. Investigation of Biophysical Mechanisms in Gold Nanoparticle Mediated Laser Manipulation of Cells Using a Multimodal Holographic and Fluorescence Imaging Setup. PLoS One. 2015;10(4).


Kalies S, Gentemann L, Schomaker M, Heinemann D, Ripken T, Meyer H. Surface Modification of Silica Particles with Gold Nanoparticles as an Augmentation of Gold Nanoparticle Mediated Laser Perforation. Biomedical Optics Express. 2014;5(8):2686-96.

Heinemann D, Kalies S, Schomaker M, Ertmer W, Escobar HM, Meyer H, Ripken T. Delivery of Proteins to Mammalian Cells Via Gold Nanoparticle Mediated Laser Transfection. Nanotechnology. 2014;25(24).


Mitchell CA, Kalies S, Cizmar T, Heisterkamp A, Torrance L, Roberts AG, Gunn-Moore FJ, Dholakia K. Femtosecond Optoinjection of Intact Tobacco by-2 Cells Using a Reconfigurable Photoporation Platform. PLoS One. 2013;8(11).

2006 - 2012

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