Intraoperative Imaging in Hepatopancreatobiliary Surgery.

Hepatopancreatobiliary surgery belongs to one of the most complex fields of general surgery. An intricate and vital anatomy is accompanied by difficult distinctions of tumors from fibrosis and inflammation; the identification of precise tumor margins; or small, even disappearing, lesions on currently available imaging. The routine implementation of ultrasound use shifted the possibilities in the operating room, yet more precision is necessary to achieve negative resection margins. Modalities utilizing fluorescent-compatible dyes have proven their role in hepatopancreatobiliary surgery, although this is not yet a routine practice, as there are many limitations. Modalities, such as photoacoustic imaging or 3D holograms, are emerging but are mostly limited to preclinical settings. There is a need to identify and develop an ideal contrast agent capable of differentiating between malignant and benign tissue and to report on the prognostic benefits of implemented intraoperative imaging in order to navigate clinical translation. This review focuses on existing and developing imaging modalities for intraoperative use, tailored to the needs of hepatopancreatobiliary cancers. We will also cover the application of these imaging techniques to theranostics to achieve combined diagnostic and therapeutic potential.

Simultaneous Detection of Multiple Tumor-targeted Gold Nanoparticles in HER2-Positive Breast Tumors Using Optoacoustic Imaging.

Purpose To develop optoacoustic, spectrally distinct, actively targeted gold nanoparticle-based near-infrared probes (trastuzumab [TRA], TRA-Aurelia-1, and TRA-Aurelia-2) that can be individually identifiable at multispectral optoacoustic tomography (MSOT) of human epidermal growth factor receptor 2 (HER2)-positive breast tumors. Materials and Methods Gold nanoparticle-based near-infrared probes (Aurelia-1 and 2) that are optoacoustically active and spectrally distinct for simultaneous MSOT imaging were synthesized and conjugated to TRA to produce TRA-Aurelia-1 and 2. Freshly resected human HER2-positive (n = 6) and HER2-negative (n = 6) triple-negative breast cancer tumors were treated with TRA-Aurelia-1 and TRA-Aurelia-2 for 2 hours and imaged with MSOT. HER2-expressing DY36T2Q cells and HER2-negative MDA-MB-231 cells were implanted orthotopically into mice (n = 5). MSOT imaging was performed 6 hours following the injection, and the Friedman test was used for analysis. Results TRA-Aurelia-1 (absorption peak, 780 nm) and TRA-Aurelia-2 (absorption peak, 720 nm) were spectrally distinct. HER2-positive human breast tumors exhibited a significant increase in optoacoustic signal following TRA-Aurelia-1 (28.8-fold) or 2 (29.5-fold) (P = .002) treatment relative to HER2-negative tumors. Treatment with TRA-Aurelia-1 and 2 increased optoacoustic signals in DY36T2Q tumors relative to those in MDA-MB-231 controls (14.8-fold, P < .001; 20.8-fold, P < .001, respectively). Conclusion The study demonstrates that TRA-Aurelia 1 and 2 nanoparticles operate as a spectrally distinct HER2 breast tumor-targeted in vivo optoacoustic agent. Keywords: Molecular Imaging, Nanoparticles, Photoacoustic Imaging, Breast Cancer Supplemental material is available for this article. © RSNA, 2023.

Active Targeting Significantly Outperforms Nanoparticle Size in Facilitating Tumor-Specific Uptake in Orthotopic Pancreatic Cancer.

Nanoparticles are widely studied as theranostic vehicles for cancer; however, clinical translation has been limited due to poor tumor specificity. Features that maximize tumor uptake remain controversial, particularly when using clinically relevant models. We report a systematic study that assesses two major features for the impact on tumor specificity, i.e., active vs passive targeting and nanoparticle size, to evaluate relative influences in vivo. Active targeting via the V7 peptide is superior to passive targeting for uptake by pancreatic tumors, irrespective of nanoparticle size, observed through in vivo imaging. Size has a secondary effect on uptake for actively targeted nanoparticles in which 26 nm nanoparticles outperform larger 45 and 73 nm nanoparticles. Nanoparticle size had no significant effect on uptake for passively targeted nanoparticles. Results highlight the superiority of active targeting over nanoparticle size for tumor uptake. These findings suggest a framework for optimizing similar nonaggregate nanoparticles for theranostic treatment of recalcitrant cancers.

Diabetes, Obesity, and Inflammation: Impact on Clinical and Radiographic Features of Breast Cancer.

Obesity, diabetes, and inflammation increase the risk of breast cancer, the most common malignancy in women. One of the mainstays of breast cancer treatment and improving outcomes is early detection through imaging-based screening. There may be a role for individualized imaging strategies for patients with certain co-morbidities. Herein, we review the literature regarding the accuracy of conventional imaging modalities in obese and diabetic women, the potential role of anti-inflammatory agents to improve detection, and the novel molecular imaging techniques that may have a role for breast cancer screening in these patients. We demonstrate that with conventional imaging modalities, increased sensitivity often comes with a loss of specificity, resulting in unnecessary biopsies and overtreatment. Obese women have body size limitations that impair image quality, and diabetes increases the risk for dense breast tis-sue. Increased density is known to obscure the diagnosis of cancer on routine screening mammography. Novel molecu-lar imaging agents with targets such as estrogen receptor, human epidermal growth factor receptor 2 (HER2), pyrimi-dine analogues, and ligand-targeted receptor probes, among others, have potential to reduce false positive results. They can also improve detection rates with increased resolution and inform therapeutic decision making. These emerg-ing imaging techniques promise to improve breast cancer diagnosis in obese patients with diabetes who have dense breasts, but more work is needed to validate their clinical application.

Mesoporous Silica Nanoparticles: Properties and Strategies for Enhancing Clinical Effect.

Due to the theragnostic potential of mesoporous silica nanoparticles (MSNs), these were extensively investigated as a novel approach to improve clinical outcomes. Boasting an impressive array of formulations and modifications, MSNs demonstrate significant in vivo efficacy when used to identify or treat myriad malignant diseases in preclinical models. As MSNs continue transitioning into clinical trials, a thorough understanding of the characteristics of effective MSNs is necessary. This review highlights recent discoveries and advances in MSN understanding and technology. Specific focus is given to cancer theragnostic approaches using MSNs. Characteristics of MSNs such as size, shape, and surface properties are discussed in relation to effective nanomedicine practice and projected clinical efficacy. Additionally, tumor-targeting options used with MSNs are presented with extensive discussion on active-targeting molecules. Methods for decreasing MSN toxicity, improving site-specific delivery, and controlling release of loaded molecules are further explained. Challenges facing the field and translation to clinical environments are presented alongside potential avenues for continuing investigations.

Molecular Imaging of Inflammatory Disease.

Inflammatory diseases include a wide variety of highly prevalent conditions with high mortality rates in severe cases ranging from cardiovascular disease, to rheumatoid arthritis, to chronic obstructive pulmonary disease, to graft vs. host disease, to a number of gastrointestinal disorders. Many diseases that are not considered inflammatory per se are associated with varying levels of inflammation. Imaging of the immune system and inflammatory response is of interest as it can give insight into disease progression and severity. Clinical imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI) are traditionally limited to the visualization of anatomical information; then, the presence or absence of an inflammatory state must be inferred from the structural abnormalities. Improvement in available contrast agents has made it possible to obtain functional information as well as anatomical. In vivo imaging of inflammation ultimately facilitates an improved accuracy of diagnostics and monitoring of patients to allow for better patient care. Highly specific molecular imaging of inflammatory biomarkers allows for earlier diagnosis to prevent irreversible damage. Advancements in imaging instruments, targeted tracers, and contrast agents represent a rapidly growing area of preclinical research with the hopes of quick translation to the clinic.

The neutral red assay can be used to evaluate cell viability during autophagy or in an acidic microenvironment in vitro.

Harsh conditions within the tumor microenvironment, such as hypoxia and extracellular acidic pH (pHe), inactivate some chemotherapies, which results in limited or no cytotoxicity. Standard MTT, ATPlite and protease assays that are used to determine the potency of newly developed drugs often give erroneous results when applied under hypoxic or acidic conditions. Therefore, development of a cytotoxicity assay that does not yield false positive or false negative results under circumstances of both hypoxia and acidic pHe is needed. We evaluated currently used cell viability assays as well as neutral red staining to assess viability of ovarian and pancreatic cancer cells grown in an acidic pHe microenvironment after treatment with carboplatin, gemcitabine or chloroquine. We validated cell viability using western blotting of pro-caspase-9 and cleaved-caspase-9, and LC3-I and - II. Standard cell viability assays indicated cell viability accurately at pHe 7.4, but was not correlated with induction of apoptosis or autophagy at acidic pHe. By contrast, our modified neutral red assay detected cell viability accurately over a range of pHe as demonstrated by its correlation with induction of apoptosis and autophagy. Neutral red staining is effective for evaluating the effect of chemotherapeutic agents on cell viability under acidic pHe or hypoxic conditions.

Actively Targeted Nanodelivery of Echinomycin Induces Autophagy-Mediated Death in Chemoresistant Pancreatic Cancer In Vivo.

Pancreatic cancer remains a recalcitrant neoplasm associated with chemoresistance and high fatality. Because it is frequently resistant to apoptosis, exploiting autophagic cell death could offer a new treatment approach. We repurpose echinomycin, an antibiotic encapsulated within a syndecan-1 actively targeted nanoparticle, for treatment of pancreatic cancer. Tumor-specific uptake, biodistribution, efficacy of nanodelivered echinomycin, and mechanism of cell death were assessed in aggressive, metastatic models of pancreatic cancer. In these autophagic-dependent pancreatic cancer models, echinomycin treatment resulted in autophagic cell death noted by high levels of LC3 among other autophagy markers, but without hallmarks of apoptosis, e.g., caspase activation and chromatin fragmentation, or necrosis, e.g., plasma membrane degradation and chromatin condensation/degrading. In vivo, biodistribution of syndecan-1-targeted nanoparticles indicated preferential S2VP10 or S2CP9 tumor uptake compared to the liver and kidney (S2VP10 p = 0.0016, p = 0.00004 and S2CP9 p = 0.0009, p = 0.0001). Actively targeted nanodelivered echinomycin resulted in significant survival increases compared to Gemzar (S2VP10 p = 0.0003, S2CP9 p = 0.0017) or echinomycin only (S2VP10 p = 0.0096, S2CP9 p = 0.0073). We demonstrate that actively targeted nanodelivery of echinomycin results in autophagic cell death in pancreatic and potentially other high-autophagy, apoptosis-resistant tumors. Collectively, these findings support syndecan-1-targeted delivery of echinomycin and dysregulation of autophagy to induce cell death in pancreatic cancer.

Engagement in Early Intervention Services Among Mothers in Recovery From Opioid Use Disorders.

BACKGROUND AND OBJECTIVES: Opioid-exposed infants frequently qualify for early intervention (EI). However, many eligible families choose not to enroll in this voluntary service. This study aims to understand the perceptions and experiences that may impact engagement with, and the potential benefits of, EI services among mothers in recovery from opioid use disorders (OUDs). METHODS: We conducted semistructured qualitative interviews (n = 22) and 1 focus group (n = 6) with mothers in recovery from OUDs in western Massachusetts. Transcripts were coded and analyzed by using a descriptive approach. RESULTS: The mean participant age was 32 years, and 13 had a high school degree or less. Five major themes emerged revealing mothers' development through stages of engagement in EI services: (1) fear, guilt, and shame related to drug use (emotions acting as barriers to enrollment); (2) the question of whether it is "needed" (deciding whether there is value in EI for opioid-exposed infants); (3) starting with "judgment" (baseline level of perceived stigma that parents in recovery associate with EI); (4) breaking down the "wall" (how parents overcome the fear and perceived judgment to build partnerships with providers); and (5) "above and beyond" (need for a personal connection with mothers and concrete supports through EI in addition to the child-focused services provided). CONCLUSIONS: Barriers to engagement in EI among mothers in recovery from OUDs include a range of emotions, perceived stigma, and ambivalence. An effort to purposefully listen to and care for mothers through a strengths-based, bigenerational approach may help establish greater connections and foster stronger EI engagement among families affected by OUDs.

Optoacoustic imaging identifies ovarian cancer using a microenvironment targeted theranostic wormhole mesoporous silica nanoparticle.

At the intersection of the newly emerging fields of optoacoustic imaging and theranostic nanomedicine, promising clinical progress can be made in dismal prognosis of ovarian cancer. An acidic pH targeted wormhole mesoporous silica nanoparticle (V7-RUBY) was developed to serve as a novel tumor specific theranostic nanoparticle detectable using multispectral optoacoustic tomographic (MSOT) imaging. We report the synthesis of a small, < 40 nm, biocompatible asymmetric wormhole pore mesoporous silica core particle that has both large loading capacity and favorable release kinetics combined with tumor-specific targeting and gatekeeping. V7-RUBY exploits the acidic tumor microenvironment for tumor-specific targeting and tumor-specific release. In vitro, treatment with V7-RUBY containing either paclitaxel or carboplatin resulted in increased cell death at pH 6.6 in comparison to drug alone (p < 0.0001). In orthotopic ovarian xenograft mouse models, V7-RUBY containing IR780 was specifically detected within the tumor 7X and 4X higher than the liver and >10X higher than in the kidney using both multispectral optoacoustic tomography (MSOT) imaging with secondary confirmation using near infrared fluorescence imaging (p < 0.0004). The V7-RUBY system carrying a cargo of either contrast agent or an anti-neoplastic drug has the potential to become a theranostic nanoparticle which can improve both diagnosis and treatment of ovarian cancer.

Identification of pancreatic tumors in vivo with ligand-targeted, pH responsive mesoporous silica nanoparticles by multispectral optoacoustic tomography.

Despite significant efforts to translate nanotechnology for cancer application, lack of identification of biodistribution/accumulation of these nanovehicles in vivo remains a substantial barrier for successful implementation of theranostic nanoparticles in the clinic. The purpose of the study was to develop a tumor-targeted theranostic nanovehicle for pancreatic cancer detectable by multispectral optoacoustic tomography (MSOT). To improve the tumor specificity of our mesoporous silica nanoparticle (MSN), we utilized a dual targeting strategy: 1) an elevated tumor receptor, urokinase plasminogen activator receptor (UPAR), and 2) the acidic tumor microenvironment. The tumor specificity of the MSN particle was improved with the addition of both chitosan, targeting acidic pH, and urokinase plasminogen activator (UPA), targeting UPAR. Drug release assays confirmed pH responsive release of gemcitabine in vitro. The UPAR specific binding of MSN-UPA nanoparticles was confirmed by reduction in fluorescence signal following MSN-UPA nanoparticle treatment in UPAR positive cells blocked with a UPAR-blocking antibody. Based upon Indocyanine Green encapsulation within the nanoparticles, UPA ligand targeted MSNs demonstrated increased intensity compared to untargeted MSNs at both pH7.4 (7×) and 6.5 (20×); however the signal was much more pronounced at a pH of 6.5 using tissue phantoms (p<0.05). In vivo, MSN-UPA particles demonstrated orthotopic pancreatic tumor specific accumulation compared to liver or kidney as identified using multispectral optoacoustic tomography (p<0.05) and confirmed by ex vivo analysis. By tracking in vivo nanoparticle biodistribution with MSOT, it was shown that pH responsive, ligand targeted MSNs preferentially bind to pancreatic tumors for payload delivery.