This PDF file contains the front matter associated with SPIE Proceedings Volume 12821, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Pancreatic ductal adenocarcinoma continues to be one of the most lethal cancers today with an abysmal ~8% 5-year survival rate that has remained relatively constant over time. This is thought to be largely due the desmoplastic stroma in the extracellular matrix of these tumor types, inhibiting both the penetration as well as target engagement of treatments. Here we present a methodology for evaluating a monoclonal antibody’s drug target engagement in the presence of an extracellular matrix remodeling drug using paired-agent imaging principles and a subcutaneous tumor mouse model.

Trans-energy imaging modalities have been significantly explored to overcome existing problems in conventional imaging modalities with respect to spatial/temporal resolutions, penetration depth, signal-to-noise ratio, contrast, and so on. Among them, photoacoustic imaging, an emerging hybrid modality that can provide strong endogenous and exogenous optical absorption contrasts with high ultrasonic spatial resolution, has overcome the fundamental depth limitation while keeping the spatial resolution. The image resolution, as well as the maximum imaging depth, is scalable with ultrasonic frequency within the reach of diffuse photons. In this presentation, the following topics will be discussed; (1) multiscale and multiparametric trans-energy imaging systems, (2) various preclinical applications particularly for image guided drug delivery and molecular imaging, (3) recent clinical study results in pathology, endocrinology, oncology, cardiology, dermatology, and radiology, and (4) efforts to commercialization.

Personalized medicine is one of the main directions in current cancer care. Patients can be pre-screened for different treatments based on genetic profiling and the treatments can be adjusted to each patient accordingly. In photoimmunotherapy the treatment monitoring can be done optically in real-time and adjusting the treatment based on the retrieved data for each patient. To answer this need, Modulight has implemented a minimally invasive real-time optical treatment monitoring unit into medical laser platform ML7710. It has been designed to illuminate and retrieve spectral data from the tumor tissue simultaneously from up to eight different locations. The device can be tailored for several different multi-wavelength illumination and measurement configurations. The automatic drug detection feature in the ML7710 platform is designed to enhance clinicians' decision-making capabilities. By intelligently prioritizing measurement locations based on the presence of fluorescence, this feature serves to minimize unnecessary measurements, consequently reducing both treatment duration and associated risks. In addition to its hardware capabilities, the platform is integrated with a cloud-connected analytics server, which ensures the immediate transfer and real-time processing of all diagnostic and treatment data. This data-driven approach allows for quick adjustments to treatment protocols and sets the stage for improved patient outcomes, contributing to more effective, personalized therapeutic strategies.

Emergent breast tumor resistance and tumor microenvironment (TME) heterogeneity can lead to decreased drug delivery efficacy, resulting in therapeutic failure. Preclinical molecular imaging is a crucial tool in the advancement of targeted therapeutics for supporting the development of new drugs but also to elucidate factors hampering optimal drug delivery. However, noninvasive tumor imaging modalities that can quantify drug-target engagement, which is critical for therapeutic actuation, are still lacking. We have demonstrated the utility of macroscopic fluorescence lifetime Forster’s Resonance Energy Transfer (MFLI FRET)-based optical imaging to measure labeled trastuzumab (TZM)-human epidermal growth factor receptor (HER2) binding in human HER2+ cell lines and breast tumor xenograft mice models. We have established a clinically relevant TZM antibody drug containing the Meditope (MDT) peptide conjugated to near-infrared (NIR) dyelabeled FRET pairs, that retain full HER2 binding capability. Herein, we demonstrate FRET measurements using MFLI in vivo imaging platform to measure the ability of MDT-TZM to bind HER2 in living breast tumor xenografts. HER2+ AU565 breast tumor xenografts bearing nude mice were injected retro-orbitally with TZM (NHS-conjugated) or MDTTZM labeled with AlexaFluor700 (donor) and AlexaFluor750 (acceptor) and MFLIFRET imaging was performed 24 h and 48 h post-injection. Preliminary data suggest that MDT-TZM shows higher uniform and consistent FRET signal compared to TZM, suggesting increased efficacy of TZM-MDT-HER2 binding. Also staggered injections of donor and acceptor MDT-TZM may be optimal for quantifying MDT-TZM using MFLIFRET compared to single injections.

Traditional drug sensitivity assay confirms the cell death by time-consuming fixation and labeling. This snapshot evaluation overlooks the valuable time-course pharmacodynamics that could offer new insights for accurate drug screening. In this study, we have developed a label-free method to promptly detect cell senescence using endogenous lipofuscin-like autofluorescence. Following drug treatment, we observed that damaged mitochondria release molecules emitting lipofuscin-like red autofluorescence. This corresponding fluorescence intensity significantly increases in apoptotic and necrotic cells. Such innovative approach enables the real-time observation of treatment outcomes in 3D tumor organoids and has the potential to determine drug sensitivity earlier than the Annexin V/PI assay. This metabolic fluorescence signature could substantially enhance the efficiency of drug sensitivity testing.

Recent advances in label-free chemical imaging approaches have yielded new methods for measuring drug distribution in biological tissues. Such techniques include Raman spectroscopy and multiphoton microscopies, in addition to a suite of powerful mass spectrometry imaging methods. These techniques offer complementary information, with different strengths and limitations. By combining several of these datasets using image registration, powerful visualization can be achieved, combining high chemical specificity and sensitivity with sub-micron spatial resolution. Here we present a correlative imaging example that combines nonlinear optical spectroscopies and secondary ion mass spectroscopy imaging, applied to the same skin sample, for label-free visualization of the tissue structure and the distribution of an applied model compound.

Accurate characterization of tissue biodistribution (BD) is essential for the development of new drug and imaging agents. Recently, a novel method to quantify tissue-specific BD of fluorescent imaging agent has been developed and characterized. A subsequent tissue BD study, using this method, was performed in mice with subcutaneous tumor xenograft of head and neck squamous cell carcinoma (NHSCC). Here we utilized the same method to characterize tissue BD of two imaging agents, ABY-029 and IRDye 680LT in mouse orthotopic HNSCC tumor model. Tissue-specific fluorescence intensities were measured 5h after imaging agent administration. The two imaging agents shared similar trends of relative fluorescence intensities across ten types of tissue. Highest tissue-specific fluorescence values were observed in kidney and liver for both imaging agents while brain and muscle showed the lowest distribution for both agents.

Chemotherapy is one of the treatment methods aimed at killing cancer cells and hindering their metastasis. However, chemotherapy is known to induce multiple adverse side-effects. One of them is peripheral neuropathy, which causes significant discomfort to the cancer patient. It is hypothesized that neuropathy is directly linked to peripheral nerve damage or elasticity change. In this study we have attempted to use Brillouin spectroscopy to evaluate nerve elasticity changes and correlate them to the effects of chemotherapy.

The delivery of genetic payloads to cells using genetic medicines is challenging to predict and the existing tools to assess delivery in animal models, although critical for discovering and advancing these drugs to the clinic, do not readily facilitate assessments of functional delivery throughout the entire body. To complement these existing techniques, our lab has used whole-body 3-D hyperspectral fluorescence cryo-imaging for the evaluation of functional delivery in whole animal specimens at high resolution. This instrument acquires hyperspectral fluorescence images of whole animal specimen while they are sectioned at micron-level resolution. In this study, mice were administered AAV9, a common adeno-associated viral delivery vehicle to express and image a fluorescent reporter. As the specimen is sectioned the acquisition can be paused to collect whole-body tissue samples which are then stained for immunofluorescence (IF) analysis. Herein, we describe a technique to reconstruct IF images into a single whole-body tissue specimen to be assessed alongside the co-registered cryo-images.