Lauren Cooper

All Publications

• Acoustic printing of conductive polymers. Proceedings of the National Academy of Sciences of the United States of America Trepka, E., Cooper, L., Brinson, K., Thompson, S., Malinao, M. G., Rommelfanger, N. J., Fordyce, P., Hong, G. 2025; 122 (48): e2509652122

  Abstract

  Fabricating materials within optically opaque structures, such as biological tissue, is a considerable challenge. Recently, ultrasound-based printing ("sonoprinting") approaches have emerged as a promising strategy to address this challenge. However, an approach to sonoprint conductive materials has yet to be realized, limiting potential bioelectronic applications. Here, we extend sonoprinting to conductive materials by designing temperature-based and pressure-based methods to polymerize conductive polymers with focused ultrasound (FUS). Our temperature-based approach relies on the acoustic attenuation of the surrounding medium to generate heat under FUS, whereas our pressure-based approach leverages the acoustic vaporization of perfluorohexane double emulsions to trigger polymerization. We demonstrate that both approaches can be used to print the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) through optically opaque hydrogels and biological tissue with high spatial resolution. Taken together, our results establish complementary temperature- and pressure-based methods for sonoprinting conductive polymers, paving the way for future efforts to fabricate bioelectronic interfaces in tissue.

  View details for DOI 10.1073/pnas.2509652122

  View details for PubMedID 41284884

• Color-neutral and reversible tissue transparency enables longitudinal deep-tissue imaging in live mice. Proceedings of the National Academy of Sciences of the United States of America Keck, C. H., Schmidt, E. L., Roth, R. H., Floyd, B. M., Tsai, A. P., Garcia, H. B., Cui, M., Chen, X., Wang, C., Park, A., Zhao, S., Liao, P. A., Casey, K. M., Reineking, W., Cai, S., Zhang, L. Y., Yang, Q., Yuan, L., Baghdasaryan, A., Lopez, E. R., Cooper, L., Cui, H., Esquivel, D., Brinson, K., Chen, X., Wyss-Coray, T., Coleman, T. P., Brongersma, M. L., Bertozzi, C. R., Wang, G. X., Ding, J. B., Hong, G. 2025; 122 (35): e2504264122

  Abstract

  Light scattering in biological tissue presents a significant challenge for deep in vivo imaging. Our previous work demonstrated the ability to achieve optical transparency in live mice using intensely absorbing dye molecules, which created transparency in the red spectrum while blocking shorter-wavelength photons. In this paper, we extend this capability to achieve optical transparency across the entire visible spectrum by employing molecules with strong absorption in the ultraviolet spectrum and sharp absorption edges that rapidly decline upon entering the visible spectrum. This color-neutral and reversible tissue transparency method enables optical transparency for imaging commonly used fluorophores in the green and yellow spectra. Notably, this approach facilitates tissue transparency for structural and functional imaging of the live mouse brain labeled with yellow fluorescent protein and GCaMP through the scalp and skull. We show that this method enables longitudinal imaging of the same brain regions in awake mice over multiple days during development. Histological analyses of the skin and systemic toxicology studies indicate minimal acute or chronic damage to the skin or body using this approach. This color-neutral and reversible tissue transparency technique opens opportunities for noninvasive deep-tissue optical imaging, enabling long-term visualization of cellular structures and dynamic activity with high spatiotemporal resolution and chronic tracking capabilities.

  View details for DOI 10.1073/pnas.2504264122

  View details for PubMedID 40857313

• Force-Based Neuromodulation. Accounts of chemical research Cooper, L., Malinao, M. G., Hong, G. 2024

  Abstract

  ConspectusTechnologies for neuromodulation have rapidly developed in the past decade with a particular emphasis on creating noninvasive tools with high spatial and temporal precision. The existence of such tools is critical in the advancement of our understanding of neural circuitry and its influence on behavior and neurological disease. Existing technologies have employed various modalities, such as light, electrical, and magnetic fields, to interface with neural activity. While each method offers unique advantages, many struggle with modulating activity with high spatiotemporal precision without the need for invasive tools. One modality of interest for neuromodulation has been the use of mechanical force. Mechanical force encapsulates a broad range of techniques, ranging from mechanical waves delivered via focused ultrasound (FUS) to torque applied to the cell membrane.Mechanical force can be delivered to the tissue in two forms. The first form is the delivery of a mechanical force through focused ultrasound. Energy delivery facilitated by FUS has been the foundation for many neuromodulation techniques, owing to its precision and penetration depth. FUS possesses the potential to penetrate deeply (∼centimeters) into tissue while maintaining relatively precise spatial resolution, although there exists a trade-off between the penetration depth and spatial resolution. FUS may work synergistically with ultrasound-responsive nanotransducers or devices to produce a secondary energy, such as light, heat, or an electric field, in the target region. This layered technology, first enabled by noninvasive FUS, overcomes the need for bulky invasive implants and also often improves the spatiotemporal precision of light, heat, electrical fields, or other techniques alone. Conversely, the second form of mechanical force modulation is the generation of mechanical force from other modalities, such as light or magnetic fields, for neuromodulation via mechanosensitive proteins. This approach localizes the mechanical force at the cellular level, enhancing the precision of the original energy delivery. Direct interaction of mechanical force with tissue presents translational potential in its ability to interface with endogenous mechanosensitive proteins without the need for transgenes.In this Account, we categorize force-mediated neuromodulation into two categories: 1) methods where mechanical force is the primary stimulus and 2) methods where mechanical force is generated as a secondary stimulus in response to other modalities. We summarize the general design principles and current progress of each respective approach. We identify the key advantages of the limitations of each technology, particularly noting features in spatiotemporal precision, the need for transgene delivery, and the potential outlook. Finally, we highlight recent technologies that leverage mechanical force for enhanced spatiotemporal precision and advanced applications.

  View details for DOI 10.1021/acs.accounts.4c00074

  View details for PubMedID 38657038