HIGH INTENSITY FOCUSED ULTRASOUND AND OXYGEN LOAD NANOBUBBLES: TWO DIFFERENT APPROCHES FOR CANCER TREATMENT

The study of applications based on the use of ultrasound in medicine and biology for therapeutic purposes is under strong development at international level and joins the notoriously well-established and widespread use of diagnostic applications [1]. In the past few years, High Intensity Focused Ultrasound (HIFU) has developed from a scientific curiosity to an accepted therapeutic modality. HIFU is a non invasive technique for the treatment of various types of cancer, as well as non-malignant pathologies, by inducing localized hyperthermia that causes necrosis of the tissue. Beside HIFU technology, other innovative therapeutic modalities to treat cancer are emerging. Among them, an extremely innovative technique is represented by oxygen loaded nanobubbles (OLNs): gas cavities confined by an appropriately functionalized coating. This is an oxygenating drugs aimed at re-oxygenation of cancerous tissue. Oxygen deficiency, in fact, is the main hallmark of cancerous solid tumors and a major factor limiting the effectiveness of radiotherapy. In this work, these two approaches to treat tumours are under study from a metrological point of view. In particular, a complete characterization of an HIFU fields regarding power, pressure and temperature is provided while oxygen load nanobubbles are synthesized, characterized and applied in in vitro and in vivo experiments

Oxygen-loaded nanodroplets effectively abrogate hypoxia dysregulating effects on secretion of MMP-9 and TIMP-1 by human monocytes

Monocytes play a key role in the inflammatory stage of the healing process. To allow monocyte migration to injured tissues, the balances between secreted matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) must be finely modulated. However, a reduction of blood supply and local oxygen tension can modify the phenotype of immune cells. Intriguingly, hypoxia might be targeted by new effective oxygenating devices such as 2H,3H-decafluoropentane- (DFP-) based oxygen-loaded nanodroplets (OLNs). Here, hypoxia effects on gelatinase/TIMP release from human peripheral monocytes were investigated, and the therapeutic potential of dextran-shelled OLNs was evaluated. Normoxic monocytes constitutively released ~500 ng/mL MMP-9, ~1.3 ng/mL TIMP-1, and ~0.6 ng/mL TIMP-2 proteins. MMP-2 was not detected. After 24 hours, hypoxia significantly altered MMP-9/TIMP-1 balance by reducing MMP-9 and increasing TIMP-1, without affecting TIMP-2 secretion. Interestingly OLNs, not displaying toxicity to human monocytes after cell internalization, effectively counteracted hypoxia, restoring a normoxia-like MMP-9/TIMP-1 ratio. The action of OLNs was specifically dependent on time-sustained oxygen diffusion up to 24 h from their DFP-based core. Therefore, OLNs appear as innovative, nonconventional, cost-effective, and nontoxic therapeutic tools, to be potentially employed to restore the physiological invasive phenotype of immune cells in hypoxia-associated inflammation

2H,3H-decafluoropentane-based nanodroplets: New perspectives for oxygen delivery to hypoxic cutaneous tissues

Perfluoropentane (PFP)-based oxygen-loaded nanobubbles (OLNBs) were previously proposed as adjuvant therapeutic tools for pathologies of different etiology sharing hypoxia as a common feature, including cancer, infection, and autoimmunity. Here we introduce a new platform of oxygen nanocarriers, based on 2H,3H-decafluoropentane (DFP) as core fluorocarbon. These new nanocarriers have been named oxygen-loaded nanodroplets (OLNDs) since DFP is liquid at body temperature, unlike gaseous PFP. Dextran-shelled OLNDs, available either in liquid or gel formulations, display spherical morphology, ~600 nm diameters, anionic charge, good oxygen carrying capacity, and no toxic effects on human keratinocytes after cell internalization. In vitro OLNDs result more effective in releasing oxygen to hypoxic environments than former OLNBs, as demonstrated by analysis through oxymetry. In vivo, OLNDs effectively enhance oxy-hemoglobin levels, as emerged from investigation by photoacoustic imaging. Interestingly, ultrasound (US) treatment further improves transdermal oxygen release from OLNDs. Taken together, these data suggest that US-activated, DFP-based OLNDs might be innovative, suitable and cost-effective devices to topically treat hypoxia-associated pathologies of the cutaneous tissues

Oxygen-Loaded Nanodroplets Effectively Abrogate Hypoxia Dysregulating Effects on Secretion of MMP-9 and TIMP-1 by Human Monocytes

Monocytes play a key role in the inflammatory stage of the healing process. To allow monocyte migration to injured tissues, the balances between secreted matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) must be finely modulated. However, a reduction of blood supply and local oxygen tension can modify the phenotype of immune cells. Intriguingly, hypoxia might be targeted by new effective oxygenating devices such as 2H,3H-decafluoropentane- (DFP-) based oxygen-loaded nanodroplets (OLNs). Here, hypoxia effects on gelatinase/TIMP release from human peripheral monocytes were investigated, and the therapeutic potential of dextran-shelled OLNs was evaluated. Normoxic monocytes constitutively released ~500 ng/mL MMP-9, ~1.3 ng/mL TIMP-1, and ~0.6 ng/mL TIMP-2 proteins. MMP-2 was not detected. After 24 hours, hypoxia significantly altered MMP-9/TIMP-1 balance by reducing MMP-9 and increasing TIMP-1, without affecting TIMP-2 secretion. Interestingly OLNs, not displaying toxicity to human monocytes after cell internalization, effectively counteracted hypoxia, restoring a normoxia-like MMP-9/TIMP-1 ratio. The action of OLNs was specifically dependent on time-sustained oxygen diffusion up to 24 h from their DFP-based core. Therefore, OLNs appear as innovative, nonconventional, cost-effective, and nontoxic therapeutic tools, to be potentially employed to restore the physiological invasive phenotype of immune cells in hypoxia-associated inflammation

HIFU e nanobolle di ossigeno: due differenti approcci per il trattamento del cancro - HIFU and oxygen load nanobubbles:two different approches for cancer treatment

L’utilizzo di ultrasuoni focalizzati ad alta intensità (HIFU) ha ottenuto un rapido consenso in ambito clinico come strumento chirurgico non invasivo per l’ablazione di cellule tumorali. L’impiego di tale tecnologia, applicata simultaneamente a nano-bolle riempite di ossigeno (OLN), realizzate e caratterizzate presso l’INRiM e volte a trattare patologie associate all’ipossia (come i tumori), costituiscono un innovativo strumento terapeutico per la cura del cancro proposto in questo lavoro. ---------- Use of high intensity focused ultrasound (HIFU) beam has gained rapid agreement in clinical environment as a tool for non-invasive surgical ablation of tumor cells. This technology, applied simultaneously to nano-bubbles filled with oxygen (OLN), realized and characterized at INRiM with the purpose of treating diseases associated to hypoxia (such as tumors), constitute an innovative therapeutic tool for cancer treatment proposed in this article

Measurements of temperature increase induced on a tissue-mimicking material by a clinical US-guided HIFU system

A framework for the evaluation of temperature increase in a tissue-mimicking material (TMM) induced by a clinical Ultrasound-guided High Intensity Focused Ultrasound (US-guided HIFU) system was developed. HIFU procedures are minimally invasive treatments that achieve deep tumor ablation, with the sparing of normal tissues, through thermal or mechanical effects induced by a HIFU beam generated with a focused transducer. Temperature evaluation is therefore crucial for the assurance of patient safety and treatment effectiveness. Nevertheless, it is a very difficult task on the US-guided systems, where high-pressure fields are involved. As far as we know, this study is the first attempt of temperature evaluation on a clinical US-guided HIFU system. Temperature evaluation was performed at typical clinical settings (between 80 W and 400 W, for 3s sonications) by the use of needle thermocouples connected to a voltmeter and inserted in a polyacrylamide gel phantom, prepared in-house to reproduce soft tissue behavior. Data sampling was performed with the use of acquisition software developed with LabView, while US-imaging was used to verify the position of the thermocouple. Typical rising curves of temperature were recovered, and rapid decrease was found when the HIFU field turned off. The highest temperature increases were concentrated inside the geometrical focus and were higher than 55 Celsius degrees at all power outputs. Repetition of measurements was not possible after sonications at the highest power outputs (400W). The absolute temperature of 98 Celsius degrees was never exceeded