Development of an Easily Bioconjugatable Water-Soluble Single-Photon Emission-Computed Tomography/Optical Imaging Bimodal Imaging Probe Based on the aza-BODIPY Fluorophore

A water-soluble fluorescent aza-BODIPY platform (Wazaby) was prepared and functionalized by a polyazamacrocycle agent and a bioconjugable arm. The resulting fluorescent derivative was characterized and bioconjugated onto a trastuzumab monoclonal antibody as a vector. After bioconjugation, the imaging agent appeared to be stable in serum (>72 h at 37 °C) and specifically labeled HER-2-positive breast tumors slices. The bioconjugate was radiolabeled with [¹¹¹In] indium and studied in vivo. The developed monomolecular multimodal imaging probe (MOMIP) is water-soluble and chemically and photochemically stable, emits in the near infrared (NIR) region (734 nm in aqueous media), and displays a good quantum yield of fluorescence (around 15%). Single-photon emission-computed tomography and fluorescence imaging have been performed in nude mice bearing HER2-overexpressing HCC1954 human breast cancer xenografts and have evidenced the good tumor targeting of the [¹¹¹In] In bimodal agent. Finally, the proof of concept of using it as a new tool for fluorescence-guided surgery has been shown.

Positron Emission Tomography Imaging of Neurotensin Receptor-Positive Tumors with 68Ga-Labeled Antagonists: The Chelate Makes the Difference Again

Neurotensin receptor 1 (NTS₁) is involved in the development and progression of numerous cancers, which makes it an interesting target for the development of diagnostic and therapeutic agents. A small molecule NTS₁ antagonist, named [¹⁷⁷Lu]Lu-IPN01087, is currently evaluated in phase I/II clinical trials for the targeted therapy of neurotensin receptor-positive cancers. In this study, we synthesized seven compounds based on the structure of NTS₁ antagonists, bearing different chelating agents, and radiolabeled them with gallium-68 for PET imaging. These compounds were evaluated in vitro and in vivo in mice bearing a HT-29 xenograft. The compound [⁶⁸Ga]Ga-bisNODAGA-16 showed a promising biodistribution profile with mainly signal in tumor (4.917 ± 0.776%ID/g, 2 h post-injection). Its rapid clearance from healthy tissues led to high tumor-to-organ ratios, resulting in highly contrasted PET images. These results were confirmed on subcutaneous xenografts of AsPC-1 tumor cells, a model of NTS₁-positive human pancreatic adenocarcinoma.

Risk factors for imminent fractures: a substudy of the FRISBEE cohort

Multiple factors increase the risk of an imminent fracture, including a recent fracture, older age, osteoporosis, comorbidities, and the fracture site. These findings could be a first step in the development of a model to predict an imminent fracture and select patients most at need of immediate treatment.

INTRODUCTION

The risk of a recurrent fragility fracture is maximal during the first 2 years following an incident fracture. In this prospective cohort study, we looked at the incidence of recurrent fractures within 2 years after a first incident fracture and we assessed independent clinical risk factors (CRFs) increasing this imminent fracture risk.

METHODS

A total of 3560 postmenopausal women recruited from 2007 to 2013 were surveyed yearly for the occurrence of fragility fractures. We identified patients who sustained a fracture during the first 2 years following a first incident fragility fracture. We quantified the risk of a new fracture and assessed independent CRFs, associated with an imminent fracture at various sites.

RESULTS

A recent fracture was a significant CRF for an imminent fracture (OR (95% CI): 3.7 (2.4-5.7) [p < 0.0001]). The incidence of an imminent fracture was higher in subjects above 80 years (p < 0.001). Other CRFs highly predictive in a multivariate analysis were osteoporosis diagnosis (p < 0.01), a central fracture as the index fracture (p < 0.01), and the presence of comorbidities (p < 0.05), with likelihood ratios of 1.9, 1.9, and 2.2, respectively. An imminent fracture was better predicted by a central fracture (p < 0.01) than by a major osteoporotic fracture. The hazard ratio was the highest for a central fracture.

CONCLUSION

In patients with a recent fracture, older age, osteoporosis, comorbidities, and fracture site were associated with an imminent fracture risk. These findings could be a first step in the development of a model to predict an imminent fracture and select patients most at need of immediate and most appropriate treatment.

Nanofitins targeting heat shock protein 110: An innovative immunotherapeutic modality in cancer

The presence of an inactivating heat shock protein 110 (HSP110) mutation in colorectal cancers has been correlated with an excellent prognosis and with the ability of HSP110 to favor the formation of tolerogenic (M2-like) macrophages. These clinical and experimental results suggest a potentially powerful new strategy against colorectal cancer: the inhibition of HSP110. In this work, as an alternative to neutralizing antibodies, Nanofitins (scaffold ~7 kDa proteins) targeting HSP110 were isolated from the screening of a synthetic Nanofitin library, and their capacity to bind (immunoprecipitation, biolayer interferometry) and to inhibit HSP110 was analyzed in vitro and in vivo. Three Nanofitins were found to inhibit HSP110 chaperone activity. Interestingly, they share a high degree of homology in their variable domain and target the peptide-binding domain of HSP110. In vitro, they inhibited the ability of HSP110 to favor M2-like macrophages. The Nanofitin with the highest affinity, A-C2, was studied in the CT26 colorectal cancer mice model. Our PET/scan experiments demonstrate that A-C2 may be localized within the tumor area, in accordance with the reported HSP110 abundance in the tumor microenvironment. A-C2 treatment reduced tumor growth and was associated with an increase in immune cells infiltrating the tumor and particularly cytotoxic macrophages. These results were confirmed in a chicken chorioallantoic membrane tumor model. Finally, we showed the complementarity between A-C2 and an anti-PD-L1 strategy in the in vivo and in ovo tumor models. Overall, Nanofitins appear to be promising new immunotherapeutic lead compounds.

[18F]FMISO PET/CT imaging of hypoxia as a non-invasive biomarker of disease progression and therapy efficacy in a preclinical model of pulmonary fibrosis: comparison with the [18F]FDG PET/CT approach

Purpose

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor outcome and limited therapeutic options. Imaging of IPF is limited to high-resolution computed tomography (HRCT) which is often not sufficient for a definite diagnosis and has a limited impact on therapeutic decision and patient management. Hypoxia of the lung is a significant feature of IPF but its role on disease progression remains elusive. Thus, the aim of our study was to evaluate hypoxia imaging with [¹⁸F]FMISO as a predictive biomarker of disease progression and therapy efficacy in preclinical models of lung fibrosis in comparison with [¹⁸F]FDG.

Methods

Eight-week-old C57/BL6 mice received an intratracheal administration of bleomycin (BLM) at day (D) 0 to initiate lung fibrosis. Mice received pirfenidone (300 mg/kg) or nintedanib (60 mg/kg) by daily gavage from D9 to D23. Mice underwent successive PET/CT imaging at several stages of the disease (baseline, D8/D9, D15/D16, D22/D23) with [¹⁸F]FDG and [¹⁸F]FMISO. Histological determination of the lung expression of HIF-1α and GLUT-1 was performed at D23.

Results

We demonstrate that mean lung density on CT as well as [¹⁸F]FDG and [¹⁸F]FMISO uptakes are upregulated in established lung fibrosis (1.4-, 2.6- and 3.2-fold increase respectively). At early stages, lung areas with [¹⁸F]FMISO uptake are still appearing normal on CT scans and correspond to areas which will deteriorate towards fibrotic lesions at later timepoints. Nintedanib and pirfenidone dramatically and rapidly decreased mean lung density on CT as well as [¹⁸F]FDG and [¹⁸F]FMISO lung uptakes (pirfenidone: 1.2-, 2.9- and 2.6-fold decrease; nintedanib: 1.2-, 2.3- and 2.5-fold decrease respectively). Early [¹⁸F]FMISO lung uptake was correlated with aggressive disease progression and better nintedanib efficacy.

Conclusion

[¹⁸F]FMISO PET imaging is a promising tool to early detect and monitor lung fibrosis progression and therapy efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05209-2.

Discriminating value of HR-pQCT for fractures in women with similar FRAX scores: A substudy of the FRISBEE cohort

Areal bone mineral density (aBMD) has a low sensitivity to identify women at high fracture risk. The FRAX algorithm, by combining several clinical risk factors, might improve fracture prediction compared to aBMD alone. Several micro-architectural and biomechanical parameters which can be measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) are associated with fracture risk. HR-pQCT in combination or not with finite element analysis (FEA) may be used to improve bone strength prediction. Our aim was to assess whether HR-pQCT measurements (densities, cortical and trabecular microarchitecture, biomechanical proprieties assessed by FEA) had an added value in predicting fractures in a subgroup of women belonging to the Belgian FRISBEE cohort. One hundred nineteen women who sustained a fracture (aged 60 to 85 years) during the initial follow-up of our cohort had a radius and tibia examination by HR-pQCT and were compared with controls matched for their FRAX score at baseline. We found that low distal radius total (OR = 1.41 [1.07-1.86] per SD, p < 0.05) and trabecular densities (OR = 1.45 [1.10-1.90], p < 0.01), trabecular number (OR = 1.32 [1.01-1.72], p < 0.05), intra individual distribution of separation (OR = 0.73 [0.54-0.99], p < 0.05) as several FEA parameters were significantly associated with fractures. At the distal tibia, impaired cortical density (OR = 1.32 [1.03-1.70] per SD, p < 0.05) and thickness (OR = 1.29 [1.01-1.63], p < 0.05) and apparent modulus (OR = 1.30 [1.01-1.66], p < 0.05) were significantly correlated with fractures. A low ultra distal radial aBMD (UDR) measured at the time of HR-pQCT was significantly associated with fractures (OR = 1.67 [1.22-2.28], p < 0.01). Women from both groups were followed further after the realization of the HR-pQCT and 46 new fractures were registered. In this second part of the study, low UDR aBMD (OR = 1.66 [1.18-2.35], p < 0.01), total (OR = 1.48 [1.08-2.03], p < 0.05), cortical (OR = 1.40 [1.04-1.87], p < 0.05) and trabecular (OR = 1.37 [1.01-1.85], p < 0.05) densities or apparent modulus (OR = 1.49 [1.07-2.05], p < 0.05) at the radius were associated with a significant increase of fracture risk. At the tibia, only the cortical density was significantly associated with the fracture risk (OR = 1.34 [1.02-2.76], p < 0.05). These results confirm the interest of HR-pQCT measurements for the evaluation of fracture risk, also in women matched for their baseline FRAX score. They also highlight that UDR aBMD contains pertinent information.

Lipoproteins LDL versus HDL as nanocarriers to target either cancer cells or macrophages

In this work, we have explored natural unmodified low- and high-density lipoproteins (LDL and HDL, respectively) as selective delivery vectors in colorectal cancer therapy. We show in vitro in cultured cells and in vivo (NanoSPECT/CT) in the CT-26 mice colorectal cancer model that LDLs are mainly taken up by cancer cells, while HDLs are preferentially taken up by macrophages. We loaded LDLs with cisplatin and HDLs with the heat shock protein-70 inhibitor AC1LINNC, turning them into a pair of “Trojan horses” delivering drugs selectively to their target cells as demonstrated in vitro in human colorectal cancer cells and macrophages, and in vivo. Coupling of the drugs to lipoproteins and stability was assessed by mass spectometry and raman spectrometry analysis. Cisplatin vectorized in LDLs led to better tumor growth suppression with strongly reduced adverse effects such as renal or liver toxicity. AC1LINNC vectorized into HDLs induced a strong oxidative burst in macrophages and innate anticancer immune response. Cumulative antitumor effect was observed for both drug-loaded lipoproteins. Altogether, our data show that lipoproteins from patient blood can be used as natural nanocarriers allowing cell-specific targeting, paving the way toward more efficient, safer, and personalized use of chemotherapeutic and immunotherapeutic drugs in cancer.

Osteoporosis treatment gap in a prospective cohort of volunteer women

Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture. The high treatment gap in our cohort consisted of unselected volunteer patients highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.

INTRODUCTION

Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture, with a treatment gap around 80%. This can have dramatic consequences for patients and the healthcare systems.

METHODS

In this study based on longitudinal data from the FRISBEE (Fracture RIsk Brussels Epidemiological Enquiry) cohort of 3560 volunteer women aged 60 to 85 years, we evaluated the 1-year treatment gap after a first major incident fragility fracture.

RESULTS

There were 386 first validated fragility fractures, 285 major osteoporotic fractures (MOF) and 101 "other major" fractures. The rate of untreated patients was 85.0% (82.8% for MOF versus 91.0 % for "other major" fracture sites) (p = 0.04), with a lower rate for spine (70.5%) and hip (72.5%) versus shoulder (91.6%) and wrist (94.1%) (p < 0.0001). More specifically, the treatment gap for patients with osteoporosis, defined by a T-score < - 2.5 SD was 74.6% versus 76.5% for patients with osteoporosis defined by the presence of hip, shoulder, or spine fractures, independently of DXA results. When considering age groups, the rate of untreated women was 87.9% for women 60-70 years old, 88.2% between 70 and 80 years and 77.8% above 80 years (p = 0.03), with a greater difference between women who were younger or older than 80 years at inclusion: 88.1% versus 77.8% (p = 0.009). A diagnosis of osteoporosis (p = 0.01) and age (p = 0.03) were the only clinical risk factors (CRFs) significantly associated with treatment initiation.

CONCLUSIONS

This study highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.

What is the validity of self-reported fractures?

We assessed the validity of self-reported fractures, over a median follow-up period of 6.2 years, in a well characterized population-based cohort of 3560 postmenopausal women, aged 60-85 years, from the Fracture Risk Brussels Epidemiological Enquiry (FRISBEE) study. Incident low-traumatic (falls from a standing height or less) or non-traumatic fractures, including peripheral fractures, were registered during each annual follow-up telephone interview. A self-reported fracture was considered as a true positive if it was validated by written reliable medical reports (radiographs, CT scans or surgical report). False positives fractures were considered to be those for which the radiology report indicated that there was no fracture at the reported site. Among self-reported fractures, false positive rates were 14.4% for all fractures. The rate of false positives of 11.2% (n = 48/429) was not negligible for the four classical major osteoporotic fractures (MOFs: hip, clinical spine, forearm or shoulder fractures). In terms of fracture site, we found the lowest false positive rate (4.4%) at the hip, and the highest (16.8%) at the spine, with the proximal humerus and the wrist in between, at about 10% each. The global rates of false positives were 12.5% (n = 22/176) for other major fractures and 22.3% (n = 49/220) for minor fractures. Younger subjects, individuals with fractures at sites other than the hip, with a lower education level, or with a higher BMI were more likely to report false positive fractures. Our data indicate that the inaccuracy of self-reported fractures is clinically relevant for several major fractures, which could influence any fracture risk prediction model.

Pore selectivity and electron transfers in HZSM-5 single crystals: a Raman microspectroscopy mapping and confocal fluorescence imaging combined study

Electron transfers at the single particle level in HZSM-5 zeolite are followed by combining Raman microspectroscopy mapping and confocal fluorescence imaging. The effects of pore accessibility and guest diffusion on reactivity are investigated.

A radical approach to achieve complete cytoreductive surgery improve survival of patients with advanced ovarian cancer

INTRODUCTION

Cytoreductive surgery of locally advanced ovarian cancer has evolved in the last few years from surgery to remove macroscopic residual disease (<1cm; R2b) to macroscopic complete cytoreductive surgery with no gross residual disease (R1). The aim of this study was to evaluate the impact of the adoption of a maximalist surgical approach on postoperative complications, disease recurrence and survival.

MATERIALS AND METHODS

This was a retrospective study using prospectively collected data on patients who received either conservative approach (CA) or radical approach (RA) surgical treatment for primary ovarian cancer stage IIIc/IVa/IVb between June 2006 and June 2013.

RESULTS

Data for 114 patients were included, 33 patients in the CA group and 68 patients in the RA group were consequently analysed. In the RA group, operative time was longer, in relation to more complex surgical procedures; with more blood losses and a higher rate of compete macroscopic resection. Totally, 77% of the patients had postoperative complications, with more grade I/II complications in the RA group but the same rates of grade III/IV complications in the both groups (P=0.14). For all patient study population, the overall and disease-free survivals were improved in case of no macroscopic residual disease. Overall survival was improved in the RA group (P=0.05), with no difference in terms of disease-free survival (P=0.29) CONCLUSION: A radical approach in advanced ovarian cancer allows a higher rate of complete cytoreductive surgery impacting overall survival. However, a non-significant trend for increased mild complications (grade I/II) rate is observed in this group.

Titanate Nanotubes Engineered with Gold Nanoparticles and Docetaxel to Enhance Radiotherapy on Xenografted Prostate Tumors

Nanohybrids based on titanate nanotubes (TiONts) were developed to fight prostate cancer by intratumoral (IT) injection, and particular attention was paid to their step-by-step synthesis. TiONts were synthesized by a hydrothermal process. To develop the custom-engineered nanohybrids, the surface of TiONts was coated beforehand with a siloxane (APTES), and coupled with both dithiolated diethylenetriaminepentaacetic acid-modified gold nanoparticles (Au@DTDTPA NPs) and a heterobifunctional polymer (PEG₃₀₀₀) to significantly improve suspension stability and biocompatibility of TiONts for targeted biomedical applications. The pre-functionalized surface of this scaffold had reactive sites to graft therapeutic agents, such as docetaxel (DTX). This novel combination, aimed at retaining the AuNPs inside the tumor via TiONts, was able to enhance the radiation effect. Nanohybrids have been extensively characterized and were detectable by SPECT/CT imaging through grafted Au@DTDTPA NPs, radiolabeled with ¹¹¹In. In vitro results showed that TiONts-AuNPs-PEG₃₀₀₀-DTX had a substantial cytotoxic activity on human PC-3 prostate adenocarcinoma cells, unlike initial nanohybrids without DTX (Au@DTDTPA NPs and TiONts-AuNPs-PEG₃₀₀₀). Biodistribution studies demonstrated that these novel nanocarriers, consisting of AuNP- and DTX-grafted TiONts, were retained within the tumor for at least 20 days on mice PC-3 xenografted tumors after IT injection, delaying tumor growth upon irradiation.

Does the Prediction Accuracy of Osteoporotic Fractures by BMD and Clinical Risk Factors Vary With Fracture Site?

Several clinical risk factors (CRFs) have been shown to predict the risk of fragility fractures independently of BMD, but their accuracy in the prediction of a particular fracture site has not been extensively studied. In this study based on longitudinal data from the FRISBEE cohort (Fracture Risk Brussels Epidemiological Enquiry), we evaluated if CRFs are specific for sites of incident osteoporotic fractures during follow‐up. We recruited 3560 postmenopausal women, aged 60 to 85 years, from 2007 to 2013, and surveyed yearly for the occurrence of fragility fractures during 6.2 years (median). We analyzed the association between CRFs included in the FRAX (fracture risk assessment tool) model or additional CRFs (falls, sedentary lifestyle, early untreated menopause, diabetes, use of selective serotonin reuptake inhibitors or proton pump inhibitors) and the first incident validated major osteoporotic fracture (MOF; n = 362; vertebra, hip, shoulder, and wrist) or other major fractures (n = 74; ankle, pelvis/sacrum, elbow, knee, long bones). Uni‐ and multivariate analyses using the Cox proportional hazards model were used. For MOFs considered together, the risk of fracture was highly associated in uni‐ and multivariate analyses (p<0.01) with osteoporosis (T‐score < −2.5), prior fracture, age, BMD (assessed by DXA), and fall history (HR 2.34, 1.82,1.71, 1.38, and 1.32, respectively). For each site analyzed separately, prior OF, age, smoking, and total hip BMD remained independent predictors for hip fractures (HR 5.72, 3.98, 3.10, 2.32, and 1.92, respectively); osteoporosis, age, prior OF, glucocorticoids, and spine BMD for vertebral fracture (HR 2.08, 1.87, 1.78, 1.76, and 1.45, respectively); osteoporosis, prior OF, and femoral neck BMD (HR 1.83, 1.60, and 1.56, respectively) for wrist fracture; osteoporosis, prior OF, and spine BMD (HR 2.48, 1.78, and 1.31, respectively) for shoulder fracture; prior OF and diabetes (HR 2.62 and 2.03) for other major fractures. Thus, a prior fracture and BMD were the best predictors of fracture risk at any site. Other CRFs have a weaker predictive value, which is a function of the site of a future fracture. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.