Publications by authors named "Frochot C"

Photodynamic therapy is an accepted therapy cancer treatment. Its advantages encourage researchers to delve deeper. The use of nanoparticles in PDT has several advantages including the passive targeting of cancer cells.

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Ovarian cancer (OC) is one of the most lethal cancers among women. Frequent recurrence in the peritoneum due to the presence of microscopic tumor residues justifies the development of new therapies. Indeed, our main objective is to develop a targeted photodynamic therapy (PDT) treatment of peritoneal carcinomatosis from OC to improve the life expectancy of cancer patients.

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The antitumoral activity of hydroxymethylene bisphosphonates (HMBP) such as alendronate or zoledronate is hampered by their exceptional bone-binding properties and their short plasmatic half-life which preclude their accumulation in non-skeletal tumors. In this context, the use of lipophilic prodrugs represents a simple and straightforward strategy to enhance the biodistribution of bisphosphonates in these tissues. We describe in this article the synthesis of light-responsive prodrugs of HMBP alendronate.

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Despite advances achieved in the health field over the last decade, infections caused by resistant bacterial strains are an increasingly important societal issue that needs to be addressed. New approaches have already been developed to overcome this problem. Photodynamic antimicrobial chemotherapy (PACT) could provide a promising alternative method to eradicate microbes.

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Background: Recent COVID crisis has demonstrated that modern society urgently needs an accessible protection against mass infections, especially viruses, as the new strains are appearing at an ever-increasing pace and cause severe harm to the population and the world economy.

Methods: We have developed an efficient phthalocyanine photosensitizer LASU, that is suitable for dyeing textiles and allows to prepare reusable self-disinfecting fabrics with strong antiviral properties. The safety profile of LASU was evaluated in accredited laboratories by several in vitro assays according to the OECD-guidelines.

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Photodynamic therapy (PDT) is a medical technique for the treatment of cancer. It is based on the use of non-toxic molecules, called photosensitizers (PSs), that become toxic when irradiated with light and produce reactive oxygen specious (ROS) such as singlet oxygen (O). This light-induced toxicity is rather selective since the physician only targets a specific area of the body, leading to minimal side effects.

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Lack of selectivity is one of the main issues with currently used chemotherapies, causing damage not only to altered cells but also to healthy cells. Over the last decades, photodynamic therapy (PDT) has increased as a promising therapeutic tool due to its potential to treat diseases like cancer or bacterial infections with a high spatiotemporal control. Ruthenium(II) polypyridyl compounds are gaining attention for their application as photosensitizers (PSs) since they are generally nontoxic in dark conditions, while they show remarkable toxicity after light irradiation.

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Light-activated treatments, such as photodynamic therapy (PDT), provide temporal and spatial control over a specific cytotoxic response by exploiting toxicity differences between irradiated and dark conditions. In this work, a novel strategy for developing near infrared (NIR)-activatable Ru(II) polypyridyl-based photosensitizers (PSs) was successfully developed through the incorporation of symmetric heptamethine cyanine dyes in the metal complex via a phenanthrimidazole ligand. Owing to their strong absorption in the NIR region, the PSs could be efficiently photoactivated with highly penetrating NIR light (770 nm), leading to high photocytotoxicities towards several cancer cell lines under both normoxic and hypoxic conditions.

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Neuropilin 1 (NRP1), a cell-surface co-receptor of a number of growth factors and other signaling molecules, has long been the focus of attention due to its association with the development and the progression of several types of cancer. For example, the KDKPPR peptide has recently been combined with a photosensitizer and a contrast agent to bind NRP1 for the detection and treatment by photodynamic therapy of glioblastoma, an aggressive brain cancer. The main therapeutic target is a pocket of the fragment b1 of NRP1 (NRP1-b1), in which vascular endothelial growth factors (VEGFs) bind.

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Photodynamic therapy (PDT) has shown improvements in cancer treatment and in the induction of a proper anti-tumor immune response. However, current photosensitizers (PS) lack tumor specificity, resulting in reduced efficacy and side effects in patients with intraperitoneal ovarian cancer (OC). In order to target peritoneal metastases of OC, which overexpress folate receptor (FRα) in 80% of cases, we proposed a targeted PDT using a PS coupled with folic acid.

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A novel Ru(II) cyclometalated photosensitizer (PS), Ru-NH , for photodynamic therapy (PDT) of formula [Ru(appy)(bphen) ]PF (where appy=4-amino-2-phenylpyridine and bphen=bathophenanthroline) and its cetuximab (CTX) bioconjugates, Ru-Mal-CTX and Ru-BAA-CTX (where Mal=maleimide and BAA=benzoylacrylic acid) were synthesised and characterised. The photophysical properties of Ru-NH revealed absorption maxima around 580 nm with an absorption up to 725 nm. The generation of singlet oxygen ( O ) upon light irradiation was confirmed with a O quantum yield of 0.

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Glioblastoma (GBM) is the most difficult brain cancer to treat, and photodynamic therapy (PDT) is emerging as a complementary approach to improve tumor eradication. Neuropilin-1 (NRP-1) protein expression plays a critical role in GBM progression and immune response. Moreover, various clinical databases highlight a relationship between NRP-1 and M2 macrophage infiltration.

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A novel symmetric -imidazolium--heterocycle, called C7, was designed and synthesized in a quick two-step pathway, with the objective to synthesize biologically active supramolecular assembly. The synthesized compound was then analyzed for its photophysical properties, for a potential application in theragnostic (fluorescence) or phototherapy (photodynamic therapy, with the production of reactive oxygen species, such as singlet oxygen O). C7 was thus screened for its biological activity, in particular against important human pathogens of viral origin (respiratory viruses such as adenovirus type 2 and human coronavirus 229E) and of fungal and bacterial origin.

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Rationale & Objective: Infections are an important cause of mortality among patients receiving maintenance hemodialysis. Staphylococcus aureus is a frequent etiological agent, and previous nasal colonization is a risk factor for infection. Repeated antimicrobial decolonization reduces infection in this population but can induce antibiotic resistance.

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Targeting vascular endothelial growth factor receptor (VEFGR) and its co-receptor neuropilin-1 (NRP-1) is an interesting vascular strategy. tLyp-1 is a tumor-homing and penetrating peptide of 7 amino acids (CGNKRTR). It is a truncated form of Lyp-1 (CGNKRTRGC), which is known to target NRP-1 receptor, with high affinity and specificity.

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Rose Bengal (RB) is a photosensitizer (PS) used in anti-cancer and anti-bacterial photodynamic therapy (PDT). The specific excitation of this PS allows the production of singlet oxygen and oxygen reactive species that kill bacteria and tumor cells. In this review, we summarize the history of the use of RB as a PS coupled by chemical or physical means to nanoparticles (NPs).

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Despite conventional treatment combining complete macroscopic cytoreductive surgery (CRS) and systemic chemotherapy, residual microscopic peritoneal metastases (mPM) may persist as the cause of peritoneal recurrence in 60% of patients. Therefore, there is a real need to specifically target these mPM to definitively eradicate any traces of the disease and improve patient survival. Therapeutic targeting method, such as photodynamic therapy, would be a promising method for such a purpose.

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Photodynamic therapy (PDT) is a method of treating precancerous diseases and malignant neoplasms. The efficacy of PDT depends on different parameters such as light dosimetry, oxygen availability, and photophysical and physical-chemical properties of the photosensitizer. In PDT, a photosensitizer is activated using light to promote oxygen photosensitization and cellular transport plays a key role in the reach of it to the desired tissue.

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Photodynamic therapy (PDT) is a promising technique to treat different kinds of disease especially cancer. PDT requires three elements: molecular oxygen, a photoactivatable molecule called the photosensitizer (PS), and appropriate light. Under illumination, the PSs generate, in the presence of oxygen, the formation of reactive oxygen species including singlet oxygen, toxic, which then destroys the surrounding tissues.

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Article Synopsis
  • Secondary brain tumors present significant challenges in oncology due to their poor prognosis and high fatality rates, complicating early diagnosis with current imaging tools.
  • Molecular imaging techniques, like Positron Emission Tomography (PET), show potential but face limitations due to their reliance on existing radiotracers, particularly for detecting cerebral metastases.
  • A new gallium-68 radiolabeled peptide targeting the NRP-1 receptor has been developed, demonstrating in vitro stability and effective imaging capabilities with promising in vivo results that distinguish healthy brain tissue from metastatic tumors.
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The combination of photodynamic therapy and chemotherapy is a promising strategy to enhance cancer therapeutic efficacy and reduce drug resistance. In this study two zinc(II) phthalocyanine-tin(IV) conjugates linked by a triethylene glycol chain were synthesized and characterized. In these complexes, the zinc(II) phthalocyanine was used as a potential photosensitizer for PDT and the tin complex was selected as cytostatic moiety.

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X-ray-induced photodynamic therapy is based on the energy transfer from a nanoscintillator to a photosensitizer molecule, whose activation leads to singlet oxygen and radical species generation, triggering cancer cells to cell death. Herein, we synthesized ultra-small nanoparticle chelated with Terbium (Tb) as a nanoscintillator and 5-(4-carboxyphenyl succinimide ester)-10,15,20-triphenyl porphyrin (P1) as a photosensitizer (AGuIX@Tb-P1). The synthesis was based on the AGuIX@ platform design.

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Self-aggregation of Curcumin (Cur) in aqueous biological environment decreases its bioavailability and in vivo therapeutic efficacy, which hampers its clinical use as candidate for reducing risk of neurodegenerative diseases. Here, we focused on the design of new Cur- β-Cyclodextrin nanoconjugates to improve the solubility and reduce cell toxicity of Cur. In this study, we described the synthesis, structural characterization, photophysical properties and neuron cell toxicity of two new water soluble β-CD/Cur nanoconjugates as new strategy for reducing risks of neurodegenerative diseases.

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Despite advances achieved over the last decade, infections caused by multi-drug-resistant bacterial strains are increasingly becoming important societal issues that need to be addressed. New approaches have already been developed in order to overcome this problem. Photodynamic antimicrobial chemotherapy (PACT) could provide an alternative to fight infectious bacteria.

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