Biology subjects

Yun, S.-H.

Publications and source records attributed to Yun, S.-H..

5 recordsLinked to original sources

bioRxiv2024

Wideband Tuning and Deep-Tissue Spectral Detection of Indium Phosphide Nano-Laser Particles

Laser particles (LPs) emitting narrowband spectra across wide spectral ranges are highly promising for high-multiplex optical barcoding. Here, we present LPs based on indium phosphide (InP) nanodisks, operating in the near-infrared wavelength range of 740-970 nm. Utilizing low-order whispering gallery resonance modes in size-tuned nanodisks, we achieved an ultrawide color palette with 27% bandwidth utilization and nanometer-scale linewidth. The minimum laser size was 430 nm in air and 560 nm within the cytoplasm, operating at mode order 4 or 5. We further demonstrated spectral detection of laser peaks with high signal-to-background ratios in highly-scattering media, including 1-cm-thick chicken breast tissue and blood vessels in live mice.

bioengineering↗

bioRxiv2024

Antimicrobial blue light-bathing therapy for wound infection control

The prevalence of antibiotic resistance and tolerance in wound infection management poses a serious and growing health threat, necessitating the exploration of alternative approaches. Antimicrobial blue light therapy offers an appealing, non-pharmacological solution. However, its practical application has been hindered by the requirement for high irradiance levels, which particularly raises safety concerns. Here, we introduce a light-bathing strategy that employs prolonged, continuous exposure to blue light at an irradiance range lower by more than an order of magnitude (5 mW/cm2). This method consistently applies bacteriostatic pressure, keeping wound bioburden low, all while minimizing photothermal risks. Leveraging tailor-made, wearable light-emitting patches, we conducted preclinical trials on rat models of wound infection, demonstrating its safety and efficacy for suppressing infections induced by methicillin- resistant S. aureus and multidrug-resistant P. aeruginosa. Our results pave a new way for the application of blue light therapy in wound care.

bioengineering↗

bioRxiv2022

Highly efficient, all-organic bioluminescence-photosensitizer conjugate eradicates early-stagetumors and prevents metastasis in mice

Photodynamic therapy (PDT) is an established treatment modality using light-activatable drugs. Despite its unique cytotoxic mechanism, the shallow penetration of light has been a serious drawback limiting the applications of PDT. Here, we report bioluminescence-activated PDT (BL-PDT) using efficient bioluminescence resonance energy transfer (BRET) conjugates of clinically approved photosensitizers, Ce6, and luciferase proteins. A high photon-to-Ce6 conversion efficiency (80%), along with intracellular delivery by membrane-fusion liposomes, enabled effective cancer cell killing in vitro. In a syngeneic mouse model of aggressive 4T1 triple-negative breast cancer, as well as a xenograft model of MDA-MB-231 tumors, BL-PDT resulted in complete tumor remission and prevention of metastasis, as well as neo-adjuvant effects. Our result shows the promise of molecularly activable, clinically viable, depth-unlimited phototherapy.

cancer biology↗

bioRxiv2022

Single-cell transcriptomics of dynamic cell behaviors

Despite advances in spatial transcriptomics, the molecular profiling of dynamic behaviors of cells in their native environment remains a major challenge. We present a method, termed behavioral transcriptomics, that allows us to couple physiological behaviors of single cells in an intact tissue to deep molecular profiling of individual cells. This method enabled us to establish a novel molecular signature for a striking migratory cellular behavior following tissue injury.

cell biology↗

bioRxiv2018

Wavelength-encoded laser particles for massively-multiplexed cell tagging

Large-scale single-cell analyses have become increasingly important given the role of cellular heterogeneity in complex biological systems. However, no current techniques enable optical imaging of uniquely-tagged individual cells. Fluorescence-based approaches can only distinguish a handful of distinct cells or cell groups at a time because of spectral crosstalk between conventional fluorophores. Here we show a novel class of imaging probes emitting coherent laser light, called laser particles. Made of silica-coated semiconductor microcavities, these laser particles have single-mode emission over a broad range from 1170 to 1580 nm with sub-nm linewidths, enabling massive spectral multiplexing. We demonstrate the stability and biocompatibility of these probes in vitro and their utility for wavelength-multiplexed cell tagging and imaging. We demonstrate real-time tracking of thousands of individual cells in a 3D tumor model for several days showing different behavioral phenotypes. We expect laser particles will enable new approaches for single-cell analyses.

biophysics↗