Integrated nanotechnology platform for tumor-targeted multimodal imaging and therapeutic cargo release

A major challenge of targeted molecular imaging and drug delivery in cancer is establishing a functional combination of ligand-directed cargo with a triggered release system. Here we develop a hydrogel-based nanotechnology platform that integrates tumor targeting, photon-to-heat conversion, and triggered drug delivery within a single nanostructure to enable multimodal imaging and controlled release of therapeutic cargo. In proof-of-concept experiments, we show a broad range of ligand peptide-based applications with phage particles, heat-sensitive liposomes, or mesoporous silica nanoparticles that self-assemble into a hydrogel for tumor-targeted drug delivery. Because nanoparticles pack densely within the nanocarrier, their surface plasmon resonance shifts to near-infrared, thereby enabling a laser-mediated photothermal mechanism of cargo release. We demonstrate both noninvasive imaging and targeted drug delivery in preclinical mouse models of breast and prostate cancer. Finally, we applied mathematical modeling to predict and confirm tumor targeting and drug delivery. These results are meaningful steps toward the design and initial translation of an enabling nanotechnology platform with potential for broad clinical applications.A long-term goal in contemporary cancer nanomedicine has been to design and generate drug delivery systems that improve the narrow therapeutic window associated with conventional chemotherapeutics (1, 2). Conceptually, several nanotechnology-based entity candidates, including protocells (3), biosynthetic nanoparticles (NPs), viruses, and liposome-based nanoparticles, could be targeted for active delivery through a defined cell surface ligand receptor system and/or physically triggered for finely tuned cargo release (2, 4, 5).Numerous efforts have been made to functionalize NPs by combining them with antibodies, aptamers, peptides, vitamins, or carbohydrates (6–8), but the majority of studies involve untargeted nanoplatforms (4, 9). In practice, targeting NPs is far from trivial, and ongoing challenges include synthesis and purification, selection of an appropriate ligand receptor, and specific composition for NP conjugation. Even the conjugation reaction itself may alter the binding of the tumor-targeting moiety to its receptor through conformational changes, steric freedom restriction, or orientation distortion (10, 11). Unfortunately, the cost-to-benefit ratio of these modifications often elevate the complexity of the NP synthesis, complicating regulatory hurdles because of formulations that are heterogeneous or difficult to reproduce (10, 12, 13).To minimize such drawbacks, NPs can be functionalized via virus-based nanoplatforms as an alternative for targeted cargo delivery (14–16). In particular, filamentous bacteriophage (phage)—a prokaryotic virus—is an attractive candidate to develop a bionanomedicine for cancer therapeutics because phage particles are cost-effectively produced with biological uniformity, as well as being physically robust and stable under harsh conditions (17). Notably, phage-based nanoplatforms are biocompatible and nonpathogenic with eukaryotic organisms and are able to preserve the desired cell targeting and internalization (18). Moreover, phage particles are ideal for incorporating other NPs, which can be released after reaching the tumor site. An admixture of colloidal gold NP (AuNP) with phage particles spontaneously organizes into hydrogel network-like fractal structures (19, 20). These hydrogel networks offer convenient multifunctional integration within a single entity for tumor targeting, enhanced fluorescence and dark-field microscopy, near-infrared (NIR) photon-to-heat conversion, and surface-enhanced Raman scattering (SERS)-based detection (20, 21).In the present work, we developed a tumor targeting theranostic (meaning a combination of therapeutics and diagnostics) hydrogel-based nanoplatform that enables ligand-directed tumor targeting, multimodal imaging capability, and triggered therapeutic cargo release. Our data suggest that targeted hydrogel photothermal therapy represents a functional theranostic approach (fostering “see and treat, treat and see”) in the diagnosis and management of tumors.     

Successful laparoscopic extirpation of a large omental lipoblastoma in a child

Omental lipoblastoma is extremely rare among benign tumors. We herein report the case of a child who underwent laparoscopic extirpation of a large omental lipoblastoma. A 4‐year‐old girl was diagnosed with an intra‐abdominal solid tumor. Abdominal imaging revealed a fat density mass that was well encapsulated and measured 18 × 15 × 7.5 cm in size. Considering the MRI findings and movability of the tumor, we strongly suspected that the lesion was an omental lipoblastoma. We initially decided to perform laparoscopic exploration and, if possible, extirpation of the solid tumor sequentially. A total of five trocars were used, and the tumor was found to originate from the omentum. We successfully performed complete resection of the tumor laparoscopically. A histological examination revealed lipoblastoma. For large abdominal tumors in children, the laparoscopic approach is recommended as the first procedure when the tumor is preoperatively considered to be benign and resectable.     

Sparing Native Upper Lobes in Living‐Donor Lobar Lung Transplantation: Five Cases From a Single Center

Living‐donor lobar lung transplantation (LDLLT) is indicated for rapidly deteriorating patients, and the total volume of two lower lobe grafts must be sufficient for the recipient. To rescue patients with small lobar grafts, we performed five LDLLTs sparing native upper lobes. This strategy was used when upper lobes or segments were preoperatively less impaired. There were no hospital deaths. Extracorporeal circulation time and operative time were similar to those of conventional LDLLTs. The length of intensive care unit stay was also similar. Late complications attributed to the spared lungs were airway infection in one recipient and pneumothorax in two but they were successfully managed. All recipients were discharged without supplemental oxygen. The spared lung volumes measured by volumetry did not change after LDLLT. Lung perfusion scintigraphy performed at 1 year showed remaining perfusion in the spared lungs, although much less than in the grafts. These results suggested that the spared lobes kept adequate space in the thoracic cavity and kept functioning to a limited extent. The new lobar‐sparing strategy appears feasible and effective in LDLLT using small grafts for selected patients when the upper lobes or segments are less impaired.     

Assessment of regional wall motion using strain Doppler imaging during right ventricular bifocal pacing in a patient with severe congestive heart failure: a case report

A 79-year-old man presented with dilated cardiomyopathy and chronic atrial fibrillation. A DDD pacemaker was implanted due to sick sinus syndrome. His left ventricular ejection fraction was 23%. He was repeatedly admitted with congestive heart failure. Although cardiac resynchronization therapy was attempted, insertion of a pacing lead into the coronary sinus failed. Right ventricular bifocal pacing was done. The QRS width was shortened to 155 msec during bifocal pacing and 157 msec during right ventricular outflow pacing from 221 msec during right ventricular apical pacing. Heart failure was improved from New York Heart Association class III to II. Regional wall motion was assessed by strain of the myocardium. Bifocal pacing increased stroke volume due to improvement of longitudinal dyssynchrony of the septal and lateral walls. Bifocal pacing is effective for patients with severe congestive heart failure in whom biventricular pacing therapy has failed. Strain Doppler imaging is useful for the assessment of regional wall motion during cardiac pacing.     

Surgery for hepatocellular carcinoma with tumor thrombus extending into the right atrium: report of a successful resection without the use of cardiopulmonary bypass

Hepatocellular carcinomas, of which the tumor thrombus extends into the right atrium via the inferior vena cava, may soon cause fatal complications. Only surgery can be an effective treatment. This procedure usually needs the aid of cardiopulmonary bypass. We recently experienced a successful surgery to remove thrombus combined with hepatectomy. Reporting the detailed technique, both associated diagnosis and intraoperative management are discussed herein. We were able to perform hepatectomy of tumor thrombus in the right atrium without the use of cardiopulmonary bypass or veno-venous bypass. The tumor thrombus was removed from the right atrium into the suprahepatic inferior vena cava by reducing the liver on the tail side. And after total hepatic vascular exclusion was achieved, the intracaval tumor thrombus and the right lobe of the liver were removed en bloc. The operation took 545 minutes and the total hepatic vascular exclusion period was 32 minutes. The postoperative course was uneventful. There are some key points for this procedure. Preoperative or intraoperative US is essential in judging whether tumor thrombus can be removed from the right atrium into the inferior vena cava by reducing the liver or not. Test clamping of the inferior vena cava prior to total hepatic vascular exclusion will enable us to judge whether veno-venous bypass during total hepatic vascular exclusion is needed or not. Surgery without the use of cardiopulmonary bypass is safe and can be minimally invasive when it is performed with a reliable diagnosis and technique.     

Induction of cyclooxygenase protein and stimulation of prostaglandin E2 release by epidermal growth factor in cultured guinea pig gastric mucous cells

The present study was undertaken to investigate whether epidermal growth factor (EGF) could stimulate prostaglandin E₂ release, and if so, by what mechanism EGF would exert such an effect in gastric mucosal cells. In cultured guinea pig gastric mucous cells, EGF dosedependently stimulated prostaglandin E₂ release, with maximal stimulation observed at 10 ng/ml. EGF stimulated an increase in cyclooxygenase activity, which was reduced by protein synthesis inhibitor, actinomycin D, and cycloheximide. EGF also stimulated the enzyme protein synthesis estimated by Western blot analysis, whereas EGF did not stimulate phospholipase A₂ activity. These results suggest that such an effect of EGF onde novo synthesis of cyclooxygenase protein and prostaglandin E₂ release may be involved at least in part in the mechanism of EGF-induced local regulation of gastric mucosal integrity.