Radiolabeled PET/MRI Nanoparticles for Tumor Imaging

The development of integrated positron emission tomography (PET)/ magnetic resonance imaging (MRI) scanners opened a new scenario for cancer diagnosis, treatment, and follow-up. Multimodal imaging combines functional and morphological information from different modalities, which, singularly, cannot provide a comprehensive pathophysiological overview. Molecular imaging exploits multimodal imaging in order to obtain information at a biological and cellular level; in this way, it is possible to track biological pathways and discover many typical tumoral features. In this context, nanoparticle-based contrast agents (CAs) can improve probe biocompatibility and biodistribution, prolonging blood half-life to achieve specific target accumulation and non-toxicity. In addition, CAs can be simultaneously delivered with drugs or, in general, therapeutic agents gathering a dual diagnostic and therapeutic effect in order to perform cancer diagnosis and treatment simultaneous. The way for personalized medicine is not so far. Herein, we report principles, characteristics, applications, and concerns of nanoparticle (NP)-based PET/MRI CAs

Theranostic design of angiopep‐2 conjugated hyaluronic acid nanoparticles (Thera‐ang‐chanps) for dual targeting a

Glioblastoma multiforme (GBM) has a mean survival of only 15 months. Tumour heterogeneity and blood‐brain barrier (BBB) mainly hinder the transport of active agents, leading to late diagnosis, ineffective therapy and inaccurate follow‐up. The use of hydrogel nanoparticles, particularly hyaluronic acid as naturally occurring polymer of the extracellular matrix (ECM), has great potential in improving the transport of drug molecules and, furthermore, in facilitatating the early diagnosis by the effect of hydrodenticity enabling the T1 boosting of Gadolinium chelates for MRI. Here, crosslinked hyaluronic acid nanoparticles encapsulating gadolinium-diethylenetriamine pentaacetic acid (Gd‐DTPA) and the chemotherapeutic agent irinotecan (Thera-cHANPs) are proposed as theranostic nanovectors, with improved MRI capacities. Irinotecan was selected since currently repurposed as an alternative compound to the poorly effective temozolomide (TMZ), generally approved as the gold standard in GBM clinical care. Also, active crossing and targeting are achieved by theranostic cHANPs decorated with angiopep‐2 (Thera‐ ANG‐cHANPs), a dual‐targeting peptide interacting with low density lipoprotein receptor related protein‐1(LRP‐1) receptors overexpressed by both endothelial cells of the BBB and glioma cells. Results showed preserving the hydrodenticity effect in the advanced formulation and internalization by the active peptide‐mediated uptake of Thera‐cHANPs in U87 and GS‐102 cells. Moreover, Thera‐ANG‐cHANPs proved to reduce ironotecan time response, showing a significant cytotoxic effect in 24 h instead of 48 h

Theranostic Design of Angiopep-2 Conjugated Hyaluronic Acid Nanoparticles (Thera-ANG-cHANPs) for Dual Targeting and Boosted Imaging of Glioma Cells

Glioblastoma multiforme (GBM) has a mean survival of only 15 months. Tumour heterogeneity and blood-brain barrier (BBB) mainly hinder the transport of active agents, leading to late diagnosis, ineffective therapy and inaccurate follow-up. The use of hydrogel nanoparticles, particularly hyaluronic acid as naturally occurring polymer of the extracellular matrix (ECM), has great potential in improving the transport of drug molecules and, furthermore, in facilitatating the early diagnosis by the effect of hydrodenticity enabling the T1 boosting of Gadolinium chelates for MRI. Here, crosslinked hyaluronic acid nanoparticles encapsulating gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and the chemotherapeutic agent irinotecan (Thera-cHANPs) are proposed as theranostic nanovectors, with improved MRI capacities. Irinotecan was selected since currently repurposed as an alternative compound to the poorly effective temozolomide (TMZ), generally approved as the gold standard in GBM clinical care. Also, active crossing and targeting are achieved by theranostic cHANPs decorated with angiopep-2 (Thera-ANG-cHANPs), a dual-targeting peptide interacting with low density lipoprotein receptor related protein-1(LRP-1) receptors overexpressed by both endothelial cells of the BBB and glioma cells. Results showed preserving the hydrodenticity effect in the advanced formulation and internalization by the active peptide-mediated uptake of Thera-cHANPs in U87 and GS-102 cells. Moreover, Thera-ANG-cHANPs proved to reduce ironotecan time response, showing a significant cytotoxic effect in 24 h instead of 48 h

Understanding the mechanisms of crossing delivery and targeting of nanostructures for brain theranostics

The review of the state of the art in the study of nano-bio-interactions reveals that the scientific community is still in an embryonal stage of comprehension of the mechanisms involved in the interaction of nanomaterial with the biological environment at all different levels, with most of the studies involving scarcely reliable NPs and biological models. This translates directly in the development of poorly effective nanoformulations and consequently in their poor clinical translation. In this framework, my thesis work aimed to the study, characterization, and deep understanding of the connection existing between the synthetic and biological identity of Hyaluronic Acid (HA) - based NPs, as a clinically relevant NP model. Starting from a patented, microfluidic-based nanoprecipitation process to produce crosslinked Hyaluronic Acid Nanoparticles (cHANPs), a library of HA-based nanovectors with different synthetic identities was produced with tight control over production process leading to highly homogeneous population of NPs with well-defined features. The choice of HA at different MW, the introduction of another polymer (polyethylene glycol – PEG) and the encapsulation of different active agents allowed to characterize the impact that these variables have on the thermodynamic of the processes of nucleation and growth, the crosslinking of the hydrogel matrix and encapsulation efficiencies, as presented in our work “A Microfluidic Platform to design Multimodal PEG - crosslinked Hyaluronic Acid Nanoparticles (PEG-cHANPs) for diagnostic applications” 51. Secondly, the biological identity of these nanovectors was investigated in different biological sera assessing their colloidal stability, their antifouling ability and changes in surface properties due to protein absorption, as well as the impact that these changes have on the uptake and the uptake kinetic of NPs by cells. Moving further, Glioblastoma Multiforme was chosen as a case study to identify disease-specific biological barriers and investigate the potentialities of theranostic cHANPs (Thera-cHANPs) as well as specifically engineered theranostic cHANPs (Thera-ANG-cHANPs) to overcome these biological barriers, preserving the Hydrodenticity effect and keeping unmodified their functionality, validating their efficacy against tumor cells, as presented in our publication “Theranostic design of Angiopep-2 conjugated Hyaluronic Acid Nanoparticles (Thera-ANG-cHANPs) for dual targeting and boosted imaging of glioma cells”. In addition, the ability of cHANPs of preserving structural stability was confirmed in an extremely complex biological environment, such as human atherosclerotic plaques (AP). After a specific surface functionalization (Ab-cHANPs), the ability of Ab-cHANPs in preserving the Hydrodenticity effect upon injection in this human complex tissue was assessed in a clinical 1.5 T MRI as described in our work “Targeting Nanostrategies for Imaging of Atherosclerosis”

Boosted transport of Theranostic Angiopep-2 engineered crosslinked Hyaluronic Acid NanoParticles (Thera-ANG-cHANPs) in glioblastoma cells

Angiopep-2 is a 19 amino acid synthetic peptide that demonstrated the ability to shuttle active agents across the BBB in clinics by the interaction with LRP-1 receptors. The combination of such peptide with properly designed drug delivery systems can strongly improve the outcome of patients with brain tumours, a pathology in which the standard of care is scarcely effective because of poor transport and resistance. In this work, we engineered theranostic crosslinked hyaluronic acid nanoparticles (Thera-cHANPs), co-encapsulating Gd-DTPA with boosted relaxivity and the chemotherapeutic drug Irinotecan (CPT-11), with Angiopep-2, to produce Thera-ANG-cHANPs. Thera-ANG-cHANPs demonstrated stability in the biological environment, boosted uptake by patient derived Glioblastoma cells and, as consequence of improved transport, a boosted therapeutic effect exerted with a lower dose of drug in a reduced time window.</p

Insulin Activation Mediated by Uptake Mechanisms: A Comparison of the Behavior between Polymer Nanoparticles and Extracellular Vesicles in 3D Liver Tissues

In this work, we compare the role of two different uptake mechanisms in the effectiveness of a nanoformulated drug, specifically insulin. Insulin is activated by interacting with insulin receptors exposed on the liver cell membrane that triggers the uptake and storage of glucose. To prove that the uptake mechanism of a delivery system can interfere directly with the effectiveness of the delivered drug, two extremely different delivery systems are tested. In detail, hydrogel-based NPs (cHANPs) and natural lipid vesicles (EVs) encapsulating insulin are used to trigger the activation of this hormone in 3D liver microtissues (μTs) based on their different uptake mechanisms. Results demonstrated that the fusion mechanism of Ins-EVs mediates faster and more pronounced insulin activation with respect to the endocytic mechanism of Ins-cHANPs. Indeed, the fusion causes an increased reduction in glucose concentration in the culture medium EV-treated l-μTs with respect to free insulin-treated tissues. The same effect is not observed for Ins-cHANPs that, taken up by endocytosis, can only equal the reduction in glucose concentration produced by free insulin in 48 h. Overall, these results demonstrate that the effectiveness of nanoformulated drugs depends on the identity they acquire in the biological context (biological identity). Indeed, the nanoparticle (NP) biological identity, such as the uptake mechanism, triggers a unique set of nano-bio-interactions that is ultimately responsible for their fate both in the extracellular and intracellular compartments

Targeting Nanostrategies for Imaging of Atherosclerosis

Despite the progress in cardiovascular research, atherosclerosis still represents the main cause of death worldwide. Clinically, the diagnosis of Atherosclerotic Cardiovascular Disease (ASCVD) relies on imaging methodologies including X-ray angiography and computed tomography (CT), which however still fails in the identification of patients at high risk of plaque rupture, the main cause of severe clinical events as stroke and heart attack. Magnetic resonance imaging, which is characterized by very high spatial resolution, could provide a better characterization of atherosclerotic plaque (AP) anatomy and composition, aiding in the identification of “vulnerable” plaques. In this context, hydrogel matrices, which have been demonstrated able to boost relaxometric properties of Gd-based contrast agents (CAs) by the effect of Hydrodenticity, represent a valuable tool towards the precision imaging of ASCVD improving the performance of this class of CAs while reducing systemic toxicity. In particular, hydrogel nanoparticles encapsulating Gd-DTPA can further contribute to providing CA-specific accumulation in the AP by nanoparticle surface decoration triggering an active targeting of the AP with the overall effect of allowing an earlier and more accurate diagnosis. In this work, we tested crosslinked Hyaluronic Acid Nanoparticles (cHANPs) in the complex environment of human atherosclerotic plaque. In addition, the surface of cHANPs was decorated with the antibody anti-CD36 (Ab36-cHANPs) for the active targeting of AP-associated macrophages. Results demonstrate that the Hydrodenticity of cHANPs and Ab36-cHANPs is preserved in this complex system and, preliminarily, that interaction of these probes with the AP is present

Effects on the incidence of cardiovascular events of the addition of pioglitazone versus sulfonylureas in patients with type 2 diabetes inadequately controlled with metformin (TOSCA.IT): a randomised, multicentre trial

Background The best treatment option for patients with type 2 diabetes in whom treatment with metformin alone fails to achieve adequate glycaemic control is debated. We aimed to compare the long-term effects of pioglitazone versus sulfonylureas, given in addition to metformin, on cardiovascular events in patients with type 2 diabetes. Methods TOSCA.IT was a multicentre, randomised, pragmatic clinical trial, in which patients aged 50\ue2\u80\u9375 years with type 2 diabetes inadequately controlled with metformin monotherapy (2\ue2\u80\u933 g per day) were recruited from 57 diabetes clinics in Italy. Patients were randomly assigned (1:1), by permuted blocks randomisation (block size 10), stratified by site and previous cardiovascular events, to add-on pioglitazone (15\ue2\u80\u9345 mg) or a sulfonylurea (5\ue2\u80\u9315 mg glibenclamide, 2\ue2\u80\u936 mg glimepiride, or 30\ue2\u80\u93120 mg gliclazide, in accordance with local practice). The trial was unblinded, but event adjudicators were unaware of treatment assignment. The primary outcome, assessed with a Cox proportional-hazards model, was a composite of first occurrence of all-cause death, non-fatal myocardial infarction, non-fatal stroke, or urgent coronary revascularisation, assessed in the modified intention-to-treat population (all randomly assigned participants with baseline data available and without any protocol violations in relation to inclusion or exclusion criteria). This study is registered with ClinicalTrials.gov, number NCT00700856. Findings Between Sept 18, 2008, and Jan 15, 2014, 3028 patients were randomly assigned and included in the analyses. 1535 were assigned to pioglitazone and 1493 to sulfonylureas (glibenclamide 24 [2%], glimepiride 723 [48%], gliclazide 745 [50%]). At baseline, 335 (11%) participants had a previous cardiovascular event. The study was stopped early on the basis of a futility analysis after a median follow-up of 57\uc2\ub73 months. The primary outcome occurred in 105 patients (1\uc2\ub75 per 100 person-years) who were given pioglitazone and 108 (1\uc2\ub75 per 100 person-years) who were given sulfonylureas (hazard ratio 0\uc2\ub796, 95% CI 0\uc2\ub774\ue2\u80\u931\uc2\ub726, p=0\uc2\ub779). Fewer patients had hypoglycaemias in the pioglitazone group than in the sulfonylureas group (148 [10%] vs 508 [34%], p&lt;0\uc2\ub70001). Moderate weight gain (less than 2 kg, on average) occurred in both groups. Rates of heart failure, bladder cancer, and fractures were not significantly different between treatment groups. Interpretation In this long-term, pragmatic trial, incidence of cardiovascular events was similar with sulfonylureas (mostly glimepiride and gliclazide) and pioglitazone as add-on treatments to metformin. Both of these widely available and affordable treatments are suitable options with respect to efficacy and adverse events, although pioglitazone was associated with fewer hypoglycaemia events. Funding Italian Medicines Agency, Diabete Ricerca, and Italian Diabetes Society