NIRF Imaging Research Articles

Rapid Target Binding and Cargo Release of Activatable Liposomes Bearing HER2 and FAP Single-Chain Antibody Fragments Reveal Potentials for Image-Guided Delivery to Tumors.

Liposomes represent suitable tools for the diagnosis and treatment of a variety of diseases, including cancers. To study the role of the human epidermal growth factor receptor 2 (HER2) as target in cancer imaging and image-guided deliveries, liposomes were encapsulated with an intrinsically quenched concentration of a near-infrared fluorescent dye in their aqueous interior. This resulted in quenched liposomes (termed LipQ), that were fluorescent exclusively upon degradation, dye release, and activation. The liposomes carried an always-on green fluorescent phospholipid in the lipid layer to enable tracking of intact liposomes. Additionally, they were functionalized with single-chain antibody fragments directed to fibroblast activation protein (FAP), a marker of stromal fibroblasts of most epithelial cancers, and to HER2, whose overexpression in 20–30% of all breast cancers and many other cancer types is associated with a poor treatment outcome and relapse. We show that both monospecific (HER2-IL) and bispecific (Bi-FAP/HER2-IL) formulations are quenched and undergo HER2-dependent rapid uptake and cargo release in cultured target cells and tumor models in mice. Thereby, tumor fluorescence was retained in whole-body NIRF imaging for 32–48 h post-injection. Opposed to cell culture studies, Bi-FAP/HER2-IL-based live confocal microscopy of a high HER2-expressing tumor revealed nuclear delivery of the encapsulated dye. Thus, the liposomes have potentials for image-guided nuclear delivery of therapeutics, and also for intraoperative delineation of tumors, metastasis, and tumor margins.

Cell-Penetrating Peptide-Conjugated BF2 -Oxasmaragdyrins as NIRF Imaging and Photothermal Agents.

Cell-penetrating peptides (CPPs) are excellent cell internalizing agents for hydrophobic drug/dye moieties. We exploited this property of CPPs for the cell internalization of BF2 -oxasmaragdyrin by constructing covalent conjugates of BF2 -oxasmaragdyrin with CPPs (CRGDK and polyarginine (R9 )) using a solid-phase peptide synthesis (SPPS) methodology. The CPP-conjugated BF2 -oxasmaragdyrins were purified by reversed-phase HPLC and characterized by mass spectrometry. The CPP-conjugated BF2 -oxasmaragdyrins were found to be photostable, absorb in the visible-NIR region (400-700 nm), emit in the NIR-I region (∼715-720 nm) with moderate quantum yields, and be biocompatible, with excellent cellular imaging potential in breast cancer cells (MDA-MB-231). The R9 conjugate, being the first water-soluble BF2 -oxasmaragdyrin, also possesses excellent photothermal transduction efficacy with 750 nm laser irradiation and is a potential theranostic agent.

Targeted NIRF/MR dual-mode imaging of breast cancer brain metastasis using BRBP1-functionalized ultra-small iron oxide nanoparticles.

Tumor metastasis to brain is the main clinical manifestation of patients with advanced breast cancer, leading to poor survival prognosis. In order to detect the early incidence of brain metastasis, it is urgent to develop hypersensitive contrast agents for multimode imaging. In this study, PEG-phospholipids coated, a phage play derived peptide, BRBP1 peptide modified ultra-small iron oxide nanoparticles were prepared for targeted NIRF and MR imaging of breast cancer brain metastasis. The nanoparticles showed 10nm core-shell, high relaxivity values and photon emission efficiency in vitro. The nanoparticles offered a T2 contrast imaging effect and near-infrared fluorescent signal enhancement. Compared with control peptide modified nanoparticles, the MR/NIRF imaging signal of BRBP1-modified nanoparticles in tumor tissue was significantly enhanced, which should be induced by the targeting ability of BRBP1 peptide. These results indicated that BRBP1-SPIO@mPEG (DiR) nanoparticles could be applied as an effective targeted delivery system for diagnosis of breast cancer brain metastasis.

Lipid-mimicking peptide decorates erythrocyte membrane for active delivery to engrafted MDA-MB-231 breast tumour

Decorating the membrane surface of vesicle carriers with proteins for targeted delivery has been achieved mainly by chemical methods. In this study, we report the rational design of a lipid-mimicking peptide for biomembrane decoration without chemical conjugation. A peptide Pm45 consisting of a hydrophobic helical tail and an anionic headgroup linked with an integrin-targeting RGD moiety was manually designed. Pm45 was synthesized and characterized, which confirmed an alpha-helix at the C-terminal. Pm45 spontaneously intercalated into the lipid bilayer as illustrated by quartz crystal of microbalance with dissipation (QCM-D), a calcein leakage assay, and TEM. The intercalation was accomplished within 10 min, and the ITC results indicated that the affinity of Pm45 binding with lipids was ~100-fold greater than that of the naturally occurring cell-penetrating peptide Ib-AMP4. In vitro cellular experiments indicated that the Pm45-decorated erythrocyte vesicles specifically bound and killed integrin αvβ3-expressing MDA-MB-231 breast cancer cells. The targeting potential of Pm45-decorated erythrocyte vesicles was further evaluated in an MDA-MB-231 xenograft nude mouse model. The in vivo therapeutic effects indicated that the targeting vesicles significantly improved the therapeutic effect of encapsulated doxorubicin (DOX) compared with that of DOX or non-targeting vesicles. NIRF imaging implied that the targeting vesicles improved the pharmacokinetics of DOX in vivo and concentrated DOX in the tumour tissue at levels >50% higher than those achieved by non-targeting liposomes. This study reports a new method for liposome decoration as an alternative to chemical conjugation.

Fluorescence-guided surgery using indocyanine green in dogs with superficial solid tumours

BackgroundNear-infrared fluorescence (NIRF) imaging is a relatively novel technique that can aid surgeons during intraoperative tumour identification.MethodsNine canine oncology patients (five mammary gland tumours, three mast cell tumours and one...

Challenges in Tracking of Fluorochrome-Labelled Nanoparticles in Mice via Whole Body NIRF Imaging.

Fluorochrome-labelled iron oxide magnetic nanoparticles (MNP) have been of great help in elucidating biological processes. Here, we used dually-fluorochrome-labelled MNP and studied to what extent fluorescence detection could reflect their fate in living animals. One day after application in mice (200 µmol Fe/kg body weight), the fluorescence of the dye attached to the core (DY-730) was very prominent and in agreement with the increase of iron in the liver and spleen of mice, but inconspicuous at time points thereafter. We attribute this fluorescence behavior to early degradation processes of the MNP´s core in the cellular lysosomal compartment. In contrast, the fluorescence of the dye DY-555 stuck to the PEG coating was not detectable in vivo. In summary, labelling of MNP with dyes at their metallic core could be of help when detecting first incidences of MNP biodegradation in vivo, as opposed to dyes attached to the MNP coating.

In vivo pharmacodynamic evaluation of antidepressants based on flux mitochondrial Cys in living mice via near infrared fluorescence imaging.

The establishment of an objective and effective approach is imperative for depression diagnosis and anti-depressant efficacy evaluation, which might eliminate the drawbacks of current clinical diagnoses that rest on subjective scales. Oxidative stress may lead to depression with an excess of oxidants, but correspondingly, reductants play essential roles in retaining redox homeostasis, one of which is mitochondrial cysteine (Cys). Therefore, real-time and in situ monitoring of mitochondrial Cys fluctuations in the mouse brain is expected to achieve effective diagnosis and pharmacodynamic evaluation of depression. Herein, we developed a near-infrared fluorescence imaging probe (CSS) for the detection of mitochondrial Cys in the mouse brain. CSS is responsive to changes in the level of Cys at 705 nm and has high sensitivity, selectivity, temporal-spatial resolution and deep tissue penetration. Utilizing the probe, we revealed that the concentration of mitochondrial Cys decreased in the brains of mice with depression. Importantly, in the brains of depressed mice with three antidepressants, varying levels of Cys were observed, indicating different antidepressant efficacies. Altogether, this work affords a convincing strategy for the precise diagnosis of depression and pharmacodynamic evaluation of antidepressants.

A multifunctional theranostic contrast agent for ultrasound/near infrared fluorescence imaging-based tumor diagnosis and ultrasound-triggered combined photothermal and gene therapy

PurposeEncapsulated microbubbles (MBs) have been reported as new theranostic carriers for simultaneous imaging and ultrasound (US)-triggered therapy. Here, we designed a dual-modality US/NIRF contrast agent and extended its applications from image contrast enhancement to combined diagnosis and therapy with US-directed and site-specific targeting. MethodsGold nanorods (AuNRs) resonant at 880 nm together with the NIR797 dye were first encapsulated in lipid-shelled MBs to construct fluorescent gold microbubbles (NIR797/AuMBs) via thin film hydration and mechanical shaking in the presence of sulfur hexafluoride (SF6) gas. Then, polyethylenimine (PEI)-DNA complexes were electrostatically conjugated onto the surface of the NIR797/AuMBs, forming theranostic encapsulated MBs (PEI-DNA/NIR797/AuMBs). The potential of the PEI-DNA/NIR797/AuMBs for use as a dual-modality contrast enhancement agent was evaluated in vitro and in vivo. The antitumor effect of US/NIR laser irradiation mediating double-fusion suicide gene and photothermal therapy was also investigated using Bel-7402 cells and xenografts. ResultsThe developed theranostic AuMB complexes could not only provide excellent US and NIRF imaging to detect tumors but also serve as an efficient US-triggered carrier for gene delivery and photothermal ablation of tumors in xenografted nude mice. And US + laser exposure group showed a much higher rate of cell inhibition, apoptosis and necrosis as well as a higher Bel-7402 xenograft inhibition rate than the single gene therapy or single exposure (US or laser) group. ConclusionsPEI-DNA/NIR797/AuMBs would be of great value for providing more comprehensive diagnostic information and to guide more accurate and effective synergistic cancer therapy. Statement of SignificanceThis is an original paper focusing on developing a dual-modality US/NIRF contrast agent and extended its applications from image contrast enhancement to combined diagnosis and therapy with US-directed and site-specific targeting. The developed theranostic AuMB complexes could not only provide excellent US and NIRF imaging to detect tumors but also serve as an efficient US-triggered carrier for gene delivery and photothermal ablation of tumors in xenografted nude mice. PEI-DNA/NIR797/AuMBs would be of great value for providing more comprehensive diagnostic information and to guide more accurate and effective synergistic cancer therapy.

Dual-functional red-emitting fluorescent probes for imaging beta-amyloid plaques and viscosity

A series of dual-functional red-emitting fluorescent probes were rationally designed, synthesized and evaluated through the introduction of amine chains based on a neutral merocyanine dye (MC-1) for in vivo imaging of beta-amyloid plaques as well as viscosity at cellular level. After optimization, the MC-N derivatives with higher fluorescence quantum yield and rational Log P showed high sensitivity to the surrounding environment and Aβ aggregates. Besides, the MC-N derivatives can distinguish Aβ plaques and viscosity changes through differences in the emission wavelengths in different environments. In vivo NIRF imaging demonstrated that the probe MC-N-2 was capable of readily penetrating the blood-brain barrier and efficiently made a distinction between transgenic and wild type mice at a low injection dosage (0.1 mg/kg).

Abstract 1956: ICG pHLIP: A novel agent for fluorescence-guided surgery

Abstract Introduction: Fluorescence imaging has applications in medicine for many image-guided procedures such as mapping and visualization of lymph nodes, targeting and marking cancerous lesions and assessment of tumor margins. Several fluorescent molecules are approved for clinical use including the ICG (indocyanine green) near infrared (NIR) fluorescent dye. We conjugated ICG to a pH Low Insertion Peptide (pHLIP®), which senses and targets the acidity at the surfaces of cancer cells, and evaluated ICG pHLIP® as a targeted imaging agent for tumor visualization. Our construct is progressing toward clinical trials. Experimental Procedures: ICG pHLIP® was manufactured for proof-of-concept tumor-targeting imaging studies in mice, and toxicity evaluation in mice, dogs and rats. Tumor targeting was assessed in various human and murine tumor models. Biodistribution was evaluated at different time points from 5 min to 48 hours after a single intravenous administration of 0.5 mg/kg of ICG pHLIP®. The distribution of the agent within tumors was evaluated in tumor sections. Results: The fluorescence of ICG is enhanced about 15 times when pHLIP® tethers it to a cell membrane, significantly improving the contrast index. No toxicity is seen at 25-30x of the proposed human dose, evaluated in mice and dogs. ICG pHLIP® demonstrates excellent tumor targeting, including targeting of 1-3 mm sized tumors in breast. About 10-15% ID/g was observed within tumors at 4 hours p.i., and the signal persists for up to 24 hours with a slight decline at 48 hours. The background signal in major organs decayed after agent administration. The highest uptake, of about 50% ID/g, was observed in liver at 4 hrs p.i. and decayed after that. An excellent correlation was established between ICG pHLIP® NIRF imaging and H&E histopathology at the indicated tumor location. Conclusions: ICG pHLIP® is a promising new imaging agent for fluorescence-guided surgical applications. It is on the path to clinical translation for accurate resection of breast tumors. Since pHLIP® targeting of tumors is based on the general principle of cancer cell surface acidity, ICG pHLIP® is an agent that may be used in a range of fluorescence-guided surgical interventions. Citation Format: Troy Crawford, Anna Moshnikova, Sean Roles, Lukas M. Carter, Jason S. Lewis, Donald M. Engelman, Oleg A. Andreev, Yana K. Reshetnyak. ICG pHLIP: A novel agent for fluorescence-guided surgery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1956.

Multifunctional A7R Peptide-Modified Hollow Mesoporous Silica@Ag₂S Nanotheranostics for Photoacoustic/Near-Infrared Fluorescence Imaging-Guided Tumor-Targeted Chemo-Photothermal Therapy.

The fabrication of theranostic nanoplatforms which combine diagnostic and therapeutic functions have become an emerging approach for personal nanomedicine. Herein, a multifunctional nanoplatform consisting of A7R peptide (ATWLPPR) conjugated hollow mesoporous silica nanoparticles decorated with Ag₂S nanodots (Ag₂S@HMSs-A7R) has been developed as an efficient theranostic agent for simultaneous photoacoustic (PA) imaging and near-infrared fluorescence imaging (NIRF)-guided targeted chemotherapy and photothermal therapy against human breast cancer MDA-MB-231 cells. The design of Ag₂S doped HMSs by in situ controlled growth of ultrasmall Ag₂S nanodots in the mesopores of HMSs. The synthesized multifunctional nanoplatform exhibits high doxorubicin (DOX) loading capability (451 mg/g) and can be precisely controlled by glutathione (GSH), acidic environment and external laser irradiation. Thanks to the strong tunable NIR absorbance of Ag₂S, the nanoplatform produce effective photoacoustic capacity and superb photothermal conversion under light irradiation, thereby exhibiting sufficient in vivo fluorescence and photoacoustic signals as well as desirable photothermal therapeutic performance. Importantly, A7R peptide can selectively bind the Neuropilin-1 (NRP-1) receptor which overexpressed by the MDA-MB-231 cells. The achieved Ag₂S@HMSs-A7R possess ideal imaging capability for both PA and NIRF imaging in vivo, and the anti-tumor effect of Ag₂S@HMSs(DOX)-A7R was studied in vitro and in vivo, showing remarkable synergistic chemo-photothermal effect (combination index, CI < 1). Over all, the strategy of utilizing triple-responsive nanocarriers presents a highly promising potential as an efficient method for cancer theranostics.

Multifunctional Theranostic Contrast Agent for US/NIRF-Based Tumor Diagnosis and US-Triggered Combined Photothermal and Gene Therapy

Purpose: Encapsulated microbubbles (MBs) have been reported asnew theranostic carriers for simultaneous imaging and ultrasound (US)-triggered therapy. Here, we designed a dual-modality US/NIRF contrastagent and extended its applications from image contrast enhancement tocombined diagnosis and therapy with US-directed and site-specifictargeting. Methods: Gold nanorods (AuNRs) resonant at 880 nm together with theNIR797 dye were first encapsulated in lipid-shelled MBs to constructfluorescent gold microbubbles (NIR797/AuMBs) via thin film hydration andmechanical shaking in the presence of sulfur hexafluoride (SF6) gas.Then, polyethylenimine (PEI)-DNA complexes were electrostaticallyconjugated onto the surface of the NIR797/AuMBs, forming theranosticencapsulated MBs (PEI-DNA/NIR797/AuMBs). The potential of the PEIDNA/NIR797/AuMBs for use as a dual-modality contrast enhancement agentwas evaluated in vitro and in vivo. The antitumor effect of US/NIR laserirradiation mediating double-fusion suicide gene and photothermal therapywas also investigated using Bel-7402 cells and xenografts. Results: The developed theranostic AuMB complexes could not only provideexcellent US and NIRF imaging to detect tumors but also serve as anefficient US-triggered carrier for gene delivery and photothermalablation of tumors in xenografted nude mice. And US + laser exposuregroup showed a much higher rate of cell inhibition, apoptosis andnecrosis as well as a higher Bel-7402 xenograft inhibition rate than thesingle gene therapy or single exposure (US or laser) group. Conclusions: PEI-DNA/NIR797/AuMBs would be of great value for providingmore comprehensive diagnostic information and to guide more accurate andeffective synergistic cancer therapy.

In Vivo Near-Infrared Fluorescence Imaging of Atherosclerosis Using Local Delivery of Novel Targeted Molecular Probes

This study aimed to evaluate the feasibility and accuracy of a technique for atherosclerosis imaging using local delivery of relatively small quantities (0.04–0.4 mg/kg) of labeled-specific imaging tracers targeting ICAM-1 and unpolymerized type I collagen or negative controls in 13 rabbits with atheroma induced by balloon injury in the abdominal aorta and a 12-week high-cholesterol diet. Immediately after local infusion, in vivo intravascular ultrasonography (IVUS)-NIRF imaging was performed at different time-points over a 40-minute period. The in vivo peak NIRF signal was significantly higher in the molecular tracer-injected rabbits than in the control-injected animals (P < 0.05). Ex vivo peak NIRF signal was significantly higher in the ICAM-1 probe-injected rabbits than in controls (P = 0.04), but not in the collagen probe-injected group (P = 0.29). NIRF signal discrimination following dual-probe delivery was also shown to be feasible in a single animal and thus offers the possibility of combining several distinct biological imaging agents in future studies. This innovative imaging strategy using in vivo local delivery of low concentrations of labeled molecular tracers followed by IVUS-NIRF catheter-based imaging holds potential for detection of vulnerable human coronary artery plaques.

Near Infrared Fluorescence Imaging to Assess Breast Flap Perfusion and Prevention of Ischemia: Case Report

Introduction: Breast skin flap ischemia and necrosis is a serious consequence of breast reconstruction with reported incidence of 10% to 15%. Current clinical method of assessing breast skin flap perfusion includes combination of skin color, temperature, dermal edge bleeding, and capillary refill. Given the high incidence of ischemia and the presence of certain cohort of patient with greater risk, there is a need for an objective method of assessing the skin flap perfusion. Near infrared fluorescence imaging using indocyanine green is a new technique of assessing skin flap perfusion. We present a first reported case where breast skin flap ischemia was objectively identified intraoperatively by NIRF imaging, and this ischemia was reversed through active intra- and postoperative measures, which was objectively again identified by NIRF imaging. Case presentation: A 36-year-old female patient underwent bilateral nipple sparing mastectomies with immediate reconstruction using tissue expanders. Clinical assessment of the breast skin flap was equivocal. NIRF imaging using SPY imaging system (Novadaq Technologies Inc, Toronto, ON, Canada) showed poor perfusion in the periareolar region. As a result, it was decided to completely deflate the expander, actively warm the skin flap and encourage cutaneous perfusion through use of topical glycerin trinitrate patch. A repeat NIRF imaging 48 hours showed 10-fold increase in perfusion in the skin flap. Conclusion: NIRF imaging is a useful tool in assessing breast skin perfusion and to predict potential ischemia, which can aid in surgeon's management of patient.

Development of an orthotopic canine prostate cancer model expressing human GRPr.

Ace-1 canine prostate cancer cells grow orthotopically in cyclosporine immunosuppressed laboratory beagles. We previously transfected (human Gastrin-Releasing Peptide Receptor, huGRPr) into Ace-1 cells and demonstrated receptor-targeted NIRF imaging with IR800-G-Abz4-t-BBN, an agonist to huGRPr. Herein, we used the new cell line to develop the first canine prostate cancer model expressing a human growth factor receptor. Dogs were immunosuppressed with cyclosporine, azathioprine, prednisolone, and methylprednisolone. Their prostate glands were implanted with Ace-1huGRPr cells. The implantation wounds were sealed with a cyanoacrylic adhesive to prevent extraprostatic tumor growth. Intraprostatic tumors grew in 4-5 week. A lobar prostatic artery was then catheterized via the carotid artery and 25-100 nmol IR800-Abz4-t-BBN was infused in 2 mL followed by euthanasia in dogs 1-2, and recovery for 24 h before euthanasia in dogs 3-6. Excised tissues were imaged optically imaged, and histopathology performed. Dog1 grew no tumors with cyclosporine alone. Using the four drug protocol, Dogs 2-6 grew abundant 1-2 mm intracapsular and 1-2 cm intraglandular tumors. Tumors grew >5 cm when the prostate cancer cells became extracapsular. Dogs 4-6 with sealed prostatic capsule implantation sites had growth of intracapsular and intraglandular tumors and LN metastases at 5 weeks. High tumor to background BPH signal in the NIRF images of sectioned prostate glands resulted from the 100 nmol dose (∼8 nmol/kg) in dogs 2-4 and 50 nmol dose in dog 5, but not from the 25 nmol dose in Dog 6. Imaging of mouse Ace-1huGRPr tumors required an intravenous dose of 500 nmol/kg body wt. A lymph node that drained the prostate gland was detectable in Dog 4. Histologic findings confirmed the imaging data. Ace-1huGRPr cells created viable, huGRPr-expressing tumors when implanted orthotopically into immune-suppressed dogs. Local delivery of an imaging agent through the prostatic artery allowed a very low imaging dose, suggesting that therapeutic agents could be used safely for treatment of early localized intraglandular prostate cancer as adjuvant therapy for active surveillance or focal ablation therapies, or for treating multifocal intraglandular disease where focal ablation therapies are not indicated or ineffective.

Optimizing the image of fluorescence cholangiography using ICG: a systematic review and ex vivo experiments

BackgroundThough often only briefly described in the literature, there are clearly factors that have an influence on the fluorescence intensity, and thereby the usefulness of the technique. This article aims to provide an overview of the factors influencing the fluorescence intensity of fluorescence imaging with Indocyanine green, primarily focussed on NIRF guided cholangiography.MethodsA systematic search was conducted to gain an overview of currently used methods in NIRF imaging in laparoscopic cholecystectomies. Relevant literature was searched to gain advice on what methods to use. Ex vivo experiments were performed to assess various factors that influence fluorescence intensity and whether the found clinical advices can be confirmed.ResultsICG is currently the most widely applied fluorescent dye. Optimal ICG concentration lies between 0.00195 and 0.025 mg/ml, and this dose should be given as early as achievable—but maximum 24 h—before surgery. When holding the laparoscope closer and perpendicular to the dye, the signal is most intense. In patients with a higher BMI and/or cholecystitis, fluorescence intensity is lower, but NIRF seems to be more helpful. There are differences between various marketed fluorescence systems. Also, no uniform method to assess fluorescence intensity is available yet.ConclusionsThis study identified and discussed several factors that influence the signal of fluorescence cholangiography. These factors should be taken into account when using NIRF cholangiography. Also, surgeons should be aware of new dyes and clinical systems, in order to benefit most from the potential of NIRF imaging.

(290) - A novel targeted local analgesia platform to mitigate neuroinflammation and promote neuroregeneration

The management of acute neuropathic pain (ANP) remains a significant therapeutic challenge. Drug delivery targeted directly to the area of neuroinflammation in ANP could allow timely, site-specific therapeutic interventions with minimized systemic and off-target side effects. Our goal was the design, development, in vitro validation and pilot in vivo assessment of a new Theranostic Analgesic Regenerative Gel-Emulsion Technology (TARGET) platform for local anti-inflammatory drug delivery. The TARGET platform is biocompatible, thermoresponsive nanoemulgel laden with NIRF labelled theranostic nanoemulsions designed for macrophage targeted drug delivery of COX-2 inhibitors. Given their established pathogenic role in neuroinflammation, macrophages are critical cellular targets for therapy in both acute and chronic pain. Furthermore, modulation of macrophage behaviour with intracellular delivery of a COX-2 inhibitor in the context of neuronal injury can enhance neuroregeneration through stimulation of the M2 phenotype. Integration of dual therapeutic and diagnostic functions in a single local delivery platform provides an imaging signature of the underlying pathology, delivers a therapeutic agent (COX-2 inhibitor), and allows for monitoring drug delivery and therapeutic efficacy by live NIRF imaging. The TARGET platform represents a theranostic nanoemulgel which incorporates a triphasic perfluoropolyether (PFPE) nanoemulsion into a thermoresponsive hydrogel matrix. The nanoemulgel material is designed to flow at temperatures up to 90°F while gelling at body temperature to facilitate extended drug release for up to 30 days. Nanoemulsions incorporated into the hydrogel retain their size, shape and drug loading/release properties. We present in vitro characterization, product quality assessment and pharmacological validation and demonstrate in vivo efficacy in pilot testing in rat models of neuronal injury supported by behaviour assays and NIRF imaging. To the best of our knowledge, the TARGET platform represents the first paradigm of site specific analgesia with COX-2 inhibitors designed to augment neuroregeneration and suppress neuroinflammation in cell targeted manner.

Constructing reduction-sensitive PEGylated NIRF mesoporous silica nanoparticles via a one-pot Passerini reaction for photothermal/chemo-therapy.

In this work, we decorated the surface of MSNs by a one-pot Passerini reaction using near-infrared fluorescence BODIPY and poly(ethylene glycol) with an aldehyde group (PEG-CHO) for the first time. Doxorubicin (Dox) was loaded to demonstrate the reduction response. The formed MSNs neatly integrate chemotherapy, photothermal therapy and near-infrared fluorescence (NIRF) imaging.

Recombinant nanocomposites by the clinical drugs of Abraxane® and Herceptin® as sequentially dual-targeting therapeutics for breast cancer.

Breast cancer greatly threatens the health of women all over the word despite of several effective drugs. Targeted therapy for breast cancer is limited to human epidermal growth factor receptor 2 (HER2). Herceptin®, monoclonal antibody against HER2, is now widely used in HER2(+) breast cancer. Abraxane®, the current gold standard for paclitaxel (PTX) delivery, has shown superiority in breast cancer based on nanoparticle albumin bound technology. Despite these advances, further novel targeted therapy with more improved anti-tumor efficacy for breast cancer is still urgently needed. Here, we report the recombinant nanocomposites (NPs) composed of the above two clinical drugs of Abraxane® and Herceptin® (Abra/anti-HER2), which at first migrates to the tumor region through the unique targeting mechanism of human serum albumin (HSA) of Abraxane®, and sequentially further precisely recognize the HER2(+) breast cancer cells due to Herceptin®. The Abra/anti-HER2 NPs were fabricated by a “one-step” synthesis using EDC/NHS. In vitro analysis of cell viability, apoptosis and cell cycle revealed that Abra/anti-HER2 NPs showed more anti-tumor efficacy against HER2(+) SK-BR-3 cells than Abraxane® at equivalent PTX concentration. In addition, in HER2(+) breast cancer xenograft model, Abra/anti-HER2 NPs significantly inhibited tumor growth with less side effects. Moreover, the properties of more precise target and delayed release of PTX were proved by NIRF imaging. Thus, our results indicate that Abra/anti-HER2 NPs could represent a next-generation sequentially dual-targeting therapeutic agent for HER2(+) breast cancer.

Antibody-nanoparticle conjugate constructed with trastuzumab and nab-paclitaxel for the targeted therapy of positive human epidermal growth factor receptor 2 gastric cancer.

e15506 Background: Gastric cancer is the most lethal malignancies in the digestive system. This study was to investigate antibody-nanoparticle conjugate (ANC) constructed with Herceptin® and Abraxane® (Herceptin®/Abraxane®) as a novel strategy of targeted therapy for human epidermal growth factor receptor 2 (HER2) positive gastric cancer. Methods: Firstly, we fabricated the ANC with Herceptin and Abraxane by a “one-step” synthesis using EDC/NHS. In vitro study, the cell viability, apoptosis and cell cycle of the positive HER2 gastric cancer NCI-N87 cells were measured and compared in four groups of PBS, paclitaxel (Taxol), nano- paclitaxel (Abraxane) and ANC (Herceptin/ Abraxane). In addition, we constructed gastric cancer xenograft model in nude mice to evaluate the targeted antitumor effect in vivo. Furthermore, we chose the NIR797 to locate on the ANC and use the NIR imaging to demonstrate that the ANC could more precise target and delayed release of paclitaxel. Results: ANC of Herceptin/Abraxane was spherical in shape and in a suitable size (289.18 nm±102.6 nm). In vitro, the half-maximal inhibitory concentration (IC50), defined as the concentration of Taxol equivalent needed to kill 50% of cells, was found to be 0.24, 0.13 and 0.048 μg/ml for Taxol , Abraxane and ANC of Herceptin/Abraxane respectively for NCI-N87 cells with an excellent dose-effect relationship. Compared with Taxol and Abraxane, ANC of Herceptin/Abraxane could induce significant G2/M arrest. In vivo, at 4 weeks after treatment, mice treated by ANC of Herceptin/Abraxane had a mean tumor volume of 233±24 mm3, Abraxane of 559±97 mm3, Taxol of 871±94 mm3 and PBS as control of 1576±190 mm3. Obviously, the ANC could surpasses Abraxane and Taxol in reducing tumor volume with lesser side effects. Furthermore, NIRF imaging indicated a better targeting and sustained release of paclitaxel with ANC than that with Abraxane and Taxol. Conclusions: Antibody-nanoparticle conjugate of Herceptin/Abraxane could mediate targeted therapy and enhance antitumor activity, which could represent a novel targeted therapeutic agent for positive HER2 gastric cancer.