Optical coherence tomography (OCT) is capable of high-resolution cross-sectional imaging of retinal tissue and is typically paired with near-infrared (NIR) wavelengths due to its ability to penetrate deeper into tissue compared to visible wavelengths. This imaging modality has helped ophthalmologists diagnose and learn more about the structural changes found in retinal diseases. To help further the effectiveness and versatility of this imaging modality, broadband visible wavelengths were incorporated into the system to enable detection of spectroscopic signals. Wavelengths centered at 580 nm will provide valuable molecular information that was not provided with just NIR wavelengths. Here we demonstrated the use of visible wavelengths and introduced a novel spectroscopic analysis technique in a visible OCT system, which was then characterized and tested.

Optical coherence tomography (OCT) is a high resolution, minimally invasive imaging technique, which can produce depth-resolved cross-sectional images. OCT was used to detect changes in the optical properties of cortical tissue during the induction of global (pentylenetetrazol) and focal (4-aminopyridine) seizures. To utilize the spatiotemporal resolution provided by OCT, we developed an analytical method, creating fOCT volumes, to display statically significant changes in the cortical tissue’s attenuation coefficients while maintaining spatial specificity. We were able to visualize depth-resolved changes in attenuation during seizures as well as track focal seizure propagation with high spatiotemporal resolution. The results from this study demonstrate the potential utility of OCT as a minimally-invasive tool for studying seizure onset and propagation with high spatiotemporal resolution.

Molecular dynamics (MD) is a simulation technique that has been utilized to analyze biomolecular systems. Classical MD simulations and constant pH MD simulations have been applied to observe the behavior of components involved in two biomolecular systems of interest, the complement system and CRISPR-Cas9. The complement system is a defense mechanism part of the innate immune system. Complement associated diseases, such as paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome, are treated with complement inhibitors. Monoclonal antibody, eculizumab, is used as treatment for these diseases and functions as an inhibitor of complement component 5 (C5). A next generation version of eculizumab has also been developed known as ravulizumab, resulting from mutations within the heavy chain of eculizumab. MD simulations elucidated key residues involved in intermolecular interactions between complement inhibitors, eculizumab and ravulizumab, and C5. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 is part of the bacterial adaptive immune system that functions as a genome editing tool. The HNH domain of CRISPR-Cas9 is involved in DNA cleavage. Through classical MD simulations, residues near the catalytic center of the HNH domain were observed. Mutations were applied to several residues within the HNH domain. The wild type structure was compared to different mutated structures to analyze the effect of the mutations. Distances between residues and RMSD were calculated. Constant pH MD simulations determined pKa values for histidine for the wild type and mutated structures. Taken together, our simulations clarified mechanisms and function of the complement and CRISPR-Cas systems, helping fundamental understanding and engineering.