Craniofacial bone defects, particularly alveolar clefts, pose significant clinical challenges in pediatric patients due to complex anatomy and the limitations of current grafting options. Although autologous bone grafts remain the clinical gold standard, their use is restricted by donor-site morbidity, limited tissue availability, high cost, and risks such as infection, chronic pain, and functional impairment. Decellularized and demineralized bone matrix (DDBM) offers an attractive alternative but lacks controlled drug-release capability and cannot be monitored in real time in patients. To address these limitations, we developed indocyanine green–encapsulated bone-derived nanoparticles (ICG/BPs) from porcine DDBM, combining the intrinsic osteoinductive and osteoconductive properties of DDBM with near-infrared (NIR) imaging functionality. In this study, we fabricated two ICG/BP formulations , crosslinked (X-ICG/BP) and uncrosslinked (UnX-ICG/BP), and compared their in vitro degradation, release profiles, and in vivo performance in a rat model of cavity-type alveolar defects. Crosslinking improved particle stability and prolonged ICG release, and NIR imaging enabled real-time, non-invasive monitoring of particle degradation and retention within the defect. Additionally, both ICG/BP formulations supported bone regeneration, with X-ICG/BPs demonstrating greater regeneration, tissue organization, and vascularization. Overall, these findings highlight the tunability and theranostic potential of ICG/BPs and support their continued development as an image-guided functional biomaterial for craniofacial bone repair.

Craniofacial bone defects, particularly alveolar clefts, pose significant clinical challenges in pediatric patients due to complex anatomy and the limitations of current grafting options. Although autologous bone grafts remain the clinical gold standard, their use is restricted by donor-site morbidity, limited tissue availability, high cost, and risks such as infection, chronic pain, and functional impairment. Decellularized and demineralized bone matrix (DDBM) offers an attractive alternative but lacks controlled drug-release capability and cannot be monitored in real time in patients. To address these limitations, we developed indocyanine green-encapsulated bone-derived nanoparticles (ICG/BPs) from porcine DDBM, combining the intrinsic osteoinductive and osteoconductive properties of DDBM with near-infrared (NIR) imaging functionality. In this study, we fabricated two ICG/BP formulations , crosslinked (X-ICG/BP) and uncrosslinked (UnX-ICG/BP), and compared their in vitro degradation, release profiles, and in vivo performance in a rat model of cavity-type alveolar defects. Crosslinking improved particle stability and prolonged ICG release, and NIR imaging enabled real-time, non-invasive monitoring of particle degradation and retention within the defect. Additionally, both ICG/BP formulations supported bone regeneration, with X-ICG/BPs demonstrating greater regeneration, tissue organization, and vascularization. Overall, these findings highlight the tunability and theranostic potential of ICG/BPs and support their continued development as an image-guided functional biomaterial for craniofacial bone repair.

IL-12 is a potent cytokine with promising pre-clinical efficacy in solid tumors, including triple-negative breast cancer (TNBC), by enhancing anti-tumor immunity through Treg reprogramming and boosting CD8+ T cell function. However, its clinical use is limited by systemic toxicity and challenges in targeted tumor delivery. Combining IL-12 with photodynamic therapy (PDT) represents a potential solution to these issues, optimizing therapeutic outcomes. Concept & Novelty: We developed a cationic tetra-lipid organic nanoparticle to co-encapsulate IL-12 and HPPH (a photosensitizer; λmax = 658 nm). Efficient IL-12 encapsulation has been challenging due to steric hindrance and hydrophilic nature. To overcome this, we employed a bipolar solvent system (CHCl3:CH3OH, 2:1), achieving 98% IL-12 loading. The self-assembly of IL-12 in methanol enables its complexation with chloroform, forming hydrogen-bonding through synergistic solvation that enhances encapsulation efficiency. (a) Liposomal nanoparticle (LNP) Synthesis: The cationic core lumen for IL-12 encapsulation in LNP was achieved by dissolving DPPC, cholesterol, and DOTAP in a 13:5:1 molar ratio in CHCl3. IL-12 (2 mg/mL in CH3OH) was added and stirred for 1 hour. Subsequently, DSPE-PEG-2000-NH2 conjugated with HPPH and DiR in CHCl3 added dropwise and stirred under inert conditions. Solvent removed to form lipid cake (15 mg/L total lipid concentration), and hydrated with PBS. LNP achieved with sonication and multiple freeze/thaw cycles. Purified with centrifugation-dialysis. (b) In-Vivo: 4T1 murine model of breast cancer was developed with 20 Balb/c mice. Double-blind segregation in 5 groups (1 test + 4 control) was done. The test group received intravenous (i.v.) injections of IL-12 and HPPH-loaded LNP (IL-12@LNP-DiR@HPPH) and treated with laser. The control groups received either/or free IL-12/IL-12@LNP-DiR/LNP/No treatment. The biodistribution of LNP was monitored through time-dependent IVIS imaging. & Discussion: We synthesized 92 nm IL-12@LNP-DiR@HPPH nanoparticles with surface charge of 0-0.4 mV, indicating stability for biological use. After intravenous injection, maximum DiR fluorescence was observed at tumor site at 6 hours. At this time point, photodynamic therapy with IL-12@LNP-DiR@HPPH resulted in 80-94% tumor volume regression and increased cytolytic T cell presence in the tumor, compared to controls. No toxicity, ulceration, or metastasis was observed in the treatment group during the therapeutic window. We present a novel platform that addresses the challenge of multiple drug loading including efficient loading of IL-12 and successful delivery to the tumor site. A crosstalk between IL-12-mediated immune response and photo-triggered ROS generation promises a potential therapeutic strategy for TNBC with interventions. Sayantan Sinha, Dhruv Bhatnagar, Anne Frei, Heather Himburg, Amit Joshi. Multimodal liposomal organic nanoparticle for immunomodulation and photodynamic combinatorial therapy for triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4469.

Fluorescence Image Guided Surgery utilizes continuous wave epi-fluorescence measurements on the tissue surface to locate targets such as tumors or lymph nodes, but precise 3D localization of deep targets remains intractable due to the illposedness of the associated inverse problem. We propose a Fluorescence Diffuse Optical Tomography scheme which leverages the different contrast agent kinetics in malignant vs normal tissue and reconstructs the 3D tumor location from a time series of epi-fluorescence measurements. We conduct sequential synthetic experiments, which mimic the differential up-take and release profile of fluorescent dye ICG in tumors vs normal tissue and demonstrate for the first time that the proposed method can robustly recover targets up to 1cm deep and in the presence of realistic tumor-to-background ratios.

Purpose: Dr. Richard Hill performed pioneering work in the field of radiation-induced normal tissue injury to the lung including noninvasive imaging studies aimed at identifying imaging biomarkers of radiation-induced lung injury (RILI). RILI is a life-threatening toxicity of radiation exposure relevant to both cancer patients undergoing thoracic radiation therapy (RT) and victims of accidental radiation exposure. The ability to detect RILI noninvasively has the potential to guide treatment planning for RT and, in the case of victims of acute radiation exposures, inform the decision to start mitigative therapies. As part of this special issue of IJRB honoring Dr. Hill's many contributions to the field of radiation biology, this article reviews current advances in noninvasive imaging of RILI including computed tomography (CT), magnetic resonance (MR), hyperpolarized MR, nuclear medicine (PET and SPECT), and optical imaging with near-infrared (NIR) probes. Conclusion: The imaging modalities reviewed have potential to not only provide early identification of RILI but may also provide mechanistic insights into the progression of RILI via noninvasive detection of characteristic RILI mechanisms including: inflammation, vascular damage, cell death, oxidative stress, and fibrosis.

Hydroxyapatite (HA)-binding peptides hold strong potential for bone-targeted therapies due to their high affinity for mineralized tissues. However, most existing studies have primarily focused on in vitro binding characterization, offering limited insight into their in vivo biodistribution and bone-binding performance. In this study, we evaluated the in vivo behavior of four HA-binding peptides, including D8, E8, YD8, and YE8, using fluorescence imaging to assess biodistribution in both healthy and pathological bone environments. In healthy animals, D8 showed the strongest bone-binding capacity, with prominent localization in the skull, femur, and tibia, while YD8 exhibited moderate binding. E8 and YE8 showed more limited localization, influenced by peptide dosage and binding kinetics. In pathological models, including tibial defects and osteogenesis imperfecta (OIM) mice, D8 and YD8 preferentially accumulated in compromised bone regions, highlighting their potential utility in targeting diseased bone microenvironments. Fluorescence imaging combined with spectral unmixing algorithms enabled effective visualization and quantification of peptide localization and distribution. These findings emphasize the value of in vivo studies for advancing the therapeutic and diagnostic applications of HA-binding peptides. The results provide a foundation for optimizing peptide design to improve specificity and efficacy in bone repair and regeneration. Translational Impact Statement: This study advances the development of bone-targeted therapeutics by identifying HA-binding peptides, particularly D8 and YD8, with strong affinity for both normal and diseased bone tissue. Through fluorescent imaging, we demonstrate their selective accumulation in pathological bone, highlighting their potential for targeted drug delivery and diagnostics. These findings support the clinical translation of peptide-based strategies to enhance precision in treating skeletal disorders, offering a foundation for improved therapies in conditions such as osteoporosis, bone metastases, and radiation-induced bone damage.

This study developed a new type of bone-based nanoparticle (BPs) directly from the entire decellularized porcine bone, additionally encapsulating indocyanine green dye (ICG) for an in vivo monitoring capability.

Hydroxyapatite (HA)-binding peptides are emerging as promising candidates for bone-targeted therapies due to their strong affinity for mineralized tissues and biocompatibility. However, most studies to date have focused on in vitro characterization, providing limited insight into their in vivo performance. This study bridges that gap by evaluating the in vivo behavior of HA-binding peptides D8, E8, YD8, and YE8 using fluorescence imaging to assess their biodistribution in healthy and pathological bone environments. In healthy animal models, D8 demonstrated the strongest binding across mineralized tissues, including the skull, femur, and tibia, while YD8 showed moderate binding. In contrast, E8 and YE8 exhibited limited localization influenced by peptide dosage and binding kinetics. Pathological models, including defective tibia and osteogenesis imperfecta (OIM) mice, revealed preferential accumulation of D8 and YD8 in structurally compromised regions, underscoring their potential for targeting diseased bone microenvironments. Fluorescence imaging, enhanced by spectral unmixing algorithms, proved effective for assessing peptide localization and distribution. These findings highlight the utility of HA-binding peptides for bone-targeted therapies and emphasize the importance of in vivo studies in advancing their therapeutic and diagnostic applications. This work provides a foundation for optimizing peptide designs to improve specificity and efficacy in bone repair and regeneration. ### Competing Interest Statement The authors have declared no competing interest.

Ischemia-reperfusion injury (IRI) is an intrinsic risk associated with liver transplantation. Ex vivo hepatic machine perfusion (MP) is an emerging organ preservation technique that can mitigate IRI, especially in livers subjected to prolonged warm ischemia time (WIT). However, a method to quantify the biological response to WIT during MP has not been established. Previous studies used physiologically based pharmacokinetic (PBPK) modeling to demonstrate that a decrease in hepatic transport and biliary excretion of the tracer molecule sodium fluorescein (SF) could correlate with increasing WIT in situ. Furthermore, these studies proposed intracellular sequestration of the hepatocyte canalicular membrane transporter multidrug resistance-associated protein 2 (MRP2) leading to decreased MRP2 activity (maximal transport velocity; V-max) as the potential mechanism for decreased biliary SF excretion. We adapted an extant PBPK model to account for ex vivo hepatic MP and fit a six-parameter version of this model to control time-course measurements of SF in MP perfusate and bile. We then identified parameters whose values were likely insensitive to changes in WIT and fixed them to generate a reduced model with only three unknown parameters. Finally, we fit the reduced model to each individual biological replicate SF time course with differing WIT, found the mean estimated value for each parameter, and compared them using a one-way ANOVA. We demonstrated that there was a significant decrease in the estimated value of V-max for MRP2 at the 30-min WIT. These studies provide the foundation for future studies investigating real-time assessment of liver viability during ex vivo MP. NEW & NOTEWORTHY We developed a computational model of sodium fluorescein (SF) biliary excretion in ex vivo machine perfusion and used this model to assess changes in model parameters associated with the activity of MRP2, a hepatocyte membrane transporter, in response to increasing warm ischemia time. We found a significant decrease in the parameter value describing MRP2 activity, consistent with a role of decreased MRP2 function in ischemia-reperfusion injury leading to decreased secretion of SF into bile.

Rationale: Ischemia-reperfusion injury (IRI) is inevitable in liver transplantation (LT) which can be mitigated by normothermic machine perfusion (NMP) before LT. The current NMP liver viability criteria for LT mainly rely on bile production and perfusate lactate levels, factors that can also be affected by external variables such as NMP conditions and perfusate additives. Incorporating mitochondrial bioenergetic data could improve the predictive value of current NMP viability criteria for LT. Thus, the goal of this study was to evaluate mitochondrial oxygen consumption rate (OCR), membrane potential (Δψ), and H2O2 oxidant emission in control livers and in livers with IRI and to explore underlying mechanisms responsible for any observed differences. Methods: Healthy control livers and livers exposed to 60 minutes warm ischemia time (WIT) through in situ clamping of the portal vein and hepatic artery followed by 60 minutes reperfusion (IRI) were harvested from adult male Sprague-Dawley rats. Mitochondria from control and IRI livers were isolated using established protocols and assessed for their bioenergetics responses. Three different substrate combinations, namely, pyruvate+malate (PM), glutamate+malate (GM), and succinate were used, followed by addition(s) of ADP and the uncoupler FCCP. Two different ADP addition protocols were designed to determine how different substrates influence mitochondrial OCR, Δψ, and H2O2 emission during oxidative phosphorylation (OxPhos) between control and IRI conditions. In one protocol, a single saturated dose of ADP addition, and in the other, sequentially increasing doses of ADP additions were made following substrate addition. The OCR and Δψ were measured simultaneously using a dual chamber Oroboros Oxygraph-2k Instrument coupled to a fluorometer using the TMRM dye. The H2O2 emission was measured spectrofluorometrically using the amplex red and horseradish peroxidase assay. Results: The measured data show that the kinetics and effciency of OxPhos defining mitochondrial OCR and Δψ responses in the liver are negatively affected by IRI, characterized by enhanced H2O2 emission, in a substrate-dependent manner. Interestingly, the respiratory rates are higher when GM and succinate are utilized as substrates, whereas the use of PM shows comparatively lower respiration in both conditions. Control mitochondria exhibited higher respiratory rates than IRI mitochondria irrespective of the substrate utilized. The ADP-induced state 3 OCR in IRI mitochondria was 50% lower than that in control mitochondria resulting in doubling the duration of state 3 OCR. Similar differences were observed in Δψ for both ADP addition protocols. Compromised mitochondrial bioenergetics during IRI was observed using both single and sequentially increasing doses of ADP and was concomitant with a higher rate of H2O2 emission. Conclusion: This study provided novel quantitative data demonstrating the substrate specific changes in mitochondrial bioenergetics in hepatic IRI, which can be used to improve the NMP viability criteria for LT. The obtained bioenergetics and H2O2 emission data indicate that, during IRI, mitochondrial function is highly affected which may critically impact energy dependent metabolism and lactate/pyruvate ratio. NIH R01-HL151587. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

ObjectivesWe report the in vivo biodistribution and ototoxicity of cationic liposomal-ceftriaxone (CFX) delivered via ear drop formulation in adult chinchilla.MethodsCFX was encapsulated in liposomes with size of ∼100 nm and surface charge of +20 mV. 100 μl liposomes or free drug was applied twice daily in both external ear canals of adult chinchillas for either 3 or 10 days. Study groups included free ceftriaxone (CFX, Day 3: n = 4, Day 10: n = 8), liposomal ceftriaxone (CFX-Lipo, Day 3: n = 4, Day 10: n = 8), and a systemic control group (Day 3: n = 4, Day 10: n = 4). Ceftriaxone delivery to the middle ear and systemic circulation was quantified by HPLC assays. Liposome transport was visualized via confocal microscopy. Auditory brainstem response (ABR) tests and cochlear histology were used to assess ototoxicity.ResultsLiposomal ceftriaxone (CFX-Lipo) displayed a ∼658-fold increase in drug delivery efficiency in the middle ear relative to the free CFX (8.548 ± 0.4638% vs. 0.013 ± 0.0009%, %Injected dose, Mean ± SEM). CFX measured in blood serum (48.2 ± 7.78 ng/ml) following CFX-Lipo treatment in ear was 41-fold lower compared to systemic free-CFX treatment (1990.7 ± 617.34 ng/ml). ABR tests and histological analysis indicated no ototoxicity due to the treatment.ConclusionCationic liposomal encapsulation results in potent drug delivery across the tympanic membrane to the middle ear with minimal systemic exposure and no ototoxicity.

Significance: Although the lymphatic system is the second largest circulatory system in the body, there are limited techniques available for characterizing lymphatic vessel function. We report shortwave-infrared (SWIR) imaging for minimally invasive in vivo quantification of lymphatic circulation with superior contrast and resolution compared with near-infrared first window imaging. Aim: We aim to study the lymphatic structure and function in vivo via SWIR fluorescence imaging. Approach: We evaluated subsurface lymphatic circulation in healthy, adult immunocompromised salt-sensitive Sprague-Dawley rats using two fluorescence imaging modalities: near-infrared first window (NIR-I, 700 to 900 nm) and SWIR (900 to 1800 nm) imaging. We also compared two fluorescent imaging probes: indocyanine green (ICG) and silver sulfide quantum dots (QDs) as SWIR lymphatic contrast agents following intradermal footpad delivery in these rats. Results: SWIR imaging exhibits reduced scattering and autofluorescence background relative to NIR-I imaging. SWIR imaging with ICG provides 1.7 times better resolution and sensitivity than NIR-I, and SWIR imaging with QDs provides nearly two times better resolution and sensitivity with enhanced vessel distinguishability. SWIR images thus provide a more accurate estimation of in vivo vessel size than conventional NIR-I images. Conclusions: SWIR imaging of silver sulfide QDs into the intradermal footpad injection provides superior image resolution compared with conventional imaging techniques using NIR-I imaging with ICG dye.

BACKGROUND:Head and neck squamous cell carcinoma (HNSCC) presents significant treatment challenges, particularly in cases unrelated to human papillomavirus (HPV). The chemokine receptor CXCR4, interacting with its ligand CXCL12, plays a crucial role in tumor proliferation, metastasis, and treatment resistance. This study explores the therapeutic potential of engineered monomeric and dimerized CXCL12 variants (CXCL121 and CXCL122, respectively) in HNSCC and evaluates potential additive effects when combined with radiation therapy. METHODS:Clinical HNSCC biopsies were evaluated for CXCR4 expression in both previously untreated and radiorecurrent disease. HNSCC cell lines were then treated with combinations of CXCL12 variants and radiotherapy and interrogated for proliferation, gene expression change, and underlying molecular mechanisms. In vivo studies evaluated the biodistribution of engineered CXCL12 and tested these treatments in humanized cell line-derived xenograft (CDX) models. RESULTS:CXCL122 significantly reduced HNSCC cell proliferation and enhanced the effects of radiotherapy, likely through biased agonism at the CXCR4 receptor and upregulation of the KISS1R pathway. In vivo, CXCL122 localized to tumor sites and augmented the effects of radiation to inhibit tumor growth. CONCLUSIONS:CXCL122, in combination with radiation, demonstrates potent anti-tumor effects in HNSCC. These findings support further clinical investigation of CXCL122 to enhance the effects of radiotherapy.

'Shared-service contracts' provided by Original Equipment Manufacturers (OEMs) are a standard feature of capital-intensive, long-life products. In such contracts, OEMs assume a predetermined portion of the products' long-term failure opportunity costs by conducting routine and breakdown maintenance tasks for their customers. Recently, OEMs have been utilizing predictive technology to improve service productivity. It enables OEMs to reduce failure opportunity costs mentioned while using the data generated to develop products at lower costs. We extend the adverse selection framework to model the market segmentation of products offered with shared-service contracts and predictive technology. Our model includes: (i) the cost of product development and operation, (ii) the failure opportunity cost driven by long-term product failures, (iii) the cost of designing product reliability, and (iv) the cost of incorporating predictive technology, which reduces the first two cost components. Here, the OEM targets a basic and a premium offering at their respective customer types. We find that using predictive technology improves the quality and price of OEM products, thereby increasing their profitability. However, predictive technology enables the OEM to design a product line with lower reliability. In addition, the OEM is more likely to choose a 'premium-only' strategy when predictive technology is present.

IntroductionRadiation therapy for head and neck squamous cell carcinoma is constrained by radiotoxicity to normal tissue. We demonstrate 100 nm theranostic nanoparticles for image-guided radiation therapy planning and enhancement in rat head and neck squamous cell carcinoma models. MethodsPEG conjugated theranostic nanoparticles comprising of Au nanorods coated with Gadolinium oxide layers were tested for radiation therapy enhancement in 2D cultures of OSC-19-GFP-luc cells, and orthotopic tongue xenografts in male immunocompromised Salt sensitive or SS rats via both intratumoral and intravenous delivery. The radiation therapy enhancement mechanism was investigated. ResultsTheranostic nanoparticles demonstrated both X-ray/magnetic resonance contrast in a dose-dependent manner. Magnetic resonance images depicted optimal tumor-to-background uptake at 4 h post injection. Theranostic nanoparticle + Radiation treated rats experienced reduced tumor growth compared to controls, and reduction in lung metastasis. ConclusionsTheranostic nanoparticles enable preprocedure radiotherapy planning, as well as enhance radiation treatment efficacy for head and neck tumors.

Vascular endothelium plays a central role in the pathogenesis of acute and chronic radiation injuries, yet the mechanisms which promote sustained endothelial dysfunction and contribute to late responding organ failure are unclear. We employed 2nd window (> 1100 nm emission) Near-Infrared (NIR) imaging using indocyanine green (ICG) to track and define the role of the notch ligand Delta-like ligand 4 (Dll4) in mediating vascular injury in two late-responding radiosensitive organs: the lung and kidney. Consomic strains of female Salt Sensitive or SS (Dll4-high) and SS with 3rd chromosome inherited from Brown Norway, SS.BN3 (Dll4-low) rats at ages 11–12 weeks were used to demonstrate the impact of reduced Dll4 expression on long-term vascular integrity, renal function, and survival following high-dose 13 Gy partial body irradiation at 42- and 90 days post-radiation. 2nd window dynamic NIR fluorescence imaging with ICG was analyzed with physiology-based pharmacokinetic modeling and confirmed with assays of endothelial Dll4 expression to assess the role of endogenous Dll4 expression on radiation injury protection. We show that SS.BN3 (Dll4-low) rats are relatively protected from vascular permeability disruption compared to the SS (Dll4-high) strain. We further demonstrated that SS.BN3 (Dll4-low) rats have reduced radiation induced loss of CD31+ vascular endothelial cells, and increased Dll4 vascular expression is correlated with vascular dysfunction. Together, these data suggest Dll4 plays a key role in pathogenesis of radiation-induced vascular injury to the lung and kidney.

Efficient algorithms for solving inverse optical tomography problems with noisy and sparse measurements are a major challenge for near-infrared fluorescence guided surgery. To address that challenge, we propose an Incremental Fluorescent Target Reconstruction scheme based on the recent advances in convex optimization and sparse regularization. We demonstrate the efficacy of the proposed scheme on continuous wave reflectance mode boundary measurements of emission fluence from a 3D fluorophore target immersed in a tissue like media and acquired by an inexpensive consumer-grade camera.

Objectives: Human Papillomavirus (HPV)-negative head and neck cancer (HNC) is an aggressive malignancy with a poor prognosis. To improve outcomes, we developed a novel liposomal targeting system embedded with 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH), a chlorin-based photosensitizer. Upon exposure to 660 nm light, HPPH phototriggering generates reactive oxygen species. The objective of this study was to evaluate biodistribution and test efficacy of HPPH-liposomal therapy in a patient-derived xenograft (PDX) model of chemoradioresistant HNC.Materials and Methods: PDX models were developed from two surgically resected HNCs (P033 and P038) recurrent after chemoradiation. HPPH-liposomes were created including trace amounts of DiR (Ex/Em 785/830 nm), a near infrared lipid probe. Liposomes were injected via tail vein into PDX models. Biodistribution was assessed at serial timepoints in tumor and end-organs through in vivo DiR fluorescence. To evaluate efficacy, tumors were treated with a cw-diode 660 nm laser (90 mW/cm2, 5 min). This experimental arm was compared to appropriate controls, including HPPH-liposomes without laser or vehicle with laser alone.Results: HPPH-liposomes delivered via tail vein exhibited selective tumor penetration, with a peak concentration at 4 h. No systemic toxicity was observed. Treatment with combined HPPH-liposomes and laser resulted in improved tumor control relative to either vehicle or laser alone. Histologically, this manifested as both increased cellular necrosis and decreased Ki-67 staining in the tumors treated with combined therapy.Conclusions: These data demonstrate tumor-specific anti-neoplastic efficacy of HPPH-liposomal treatment for HNC. Importantly, this platform can be leveraged in future studies for targeted delivery of immunotherapies which can be packaged within HPPH-liposomes.

Delta like canonical notch ligand 4 (Dll4) expression levels in tumors are known to affect the efficacy of cancer therapies. This study aimed to develop a model to predict Dll4 expression levels in tumors using dynamic enhanced near-infrared (NIR) imaging with indocyanine green (ICG). Two rat-based consomic xenograft (CXM) strains of breast cancer with different Dll4 expression levels and eight congenic xenograft strains were studied. Principal component analysis (PCA) was used to visualize and segment tumors, and modified PCA techniques identified and analyzed tumor and normal regions of interest (ROIs). The average NIR intensity for each ROI was calculated from pixel brightness at each time interval, yielding easily interpretable features including the slope of initial ICG uptake, time to peak perfusion, and rate of ICG intensity change after reaching half-maximum intensity. Machine learning algorithms were applied to select discriminative features for classification, and model performance was evaluated with a confusion matrix, receiver operating characteristic curve, and area under the curve. The selected machine learning methods accurately identified host Dll4 expression alterations with sensitivity and specificity above 90%. This may enable stratification of patients for Dll4 targeted therapies. NIR imaging with ICG can noninvasively assess Dll4 expression levels in tumors and aid in effective decision making for cancer therapy.