Doxorubicin Intracellular Release External UV Irradiation of Dextran--poly(-nitrobenzyl acrylate) Photosensitive Nanoparticles.

In the present study, innovative doxorubicin-loaded nanoparticles (NPs) made of a photosensitive poly(-nitrobenzyl acrylate) (PNBA) hydrophobic matrix and an hydrophilic dextran (Dex) shell were first formulated by the emulsion-solvent evaporation process. Doxorubicin (DOX), a very well-known anticancer drug, was herein chosen as the model. DOX-loaded NPs were successfully produced by covering the hydrophobic PNBA core with Dex chains either physically adsorbed or covalently linked by changing process parameters as the presence of a catalyst (CuBr or CuSO/ascorbic acid).

Inclusion complex vs. conjugation of hydrophobic photosensitizers with β-cyclodextrin: Improved disaggregation and photodynamic therapy efficacy against glioblastoma cells.

Self-aggregation of hydrophobic porphyrin-based photosensitizers (PSs) in aqueous biological environment decreases their bioavailability and in vivo therapeutic efficacy, which hampers their clinical use in photodynamic therapy (PDT). In the current study, we explore three new supramolecular systems based of hydrophobic PSs (i.e.

New Targeted Gold Nanorods for the Treatment of Glioblastoma by Photodynamic Therapy.

This study describes the employment of gold nanorods (AuNRs), known for their good reputation in hyperthermia-based cancer therapy, in a hybrid combination of photosensitizers (PS) and peptides (PP). We report here, the design and the synthesis of this nanosystem and its application as a vehicle for the selective drug delivery and the efficient photodynamic therapy (PDT). AuNRs were functionalized by polyethylene glycol, phototoxic pyropheophorbide-a (Pyro) PS, and a "KDKPPR" peptide moiety to target neuropilin-1 receptor (NRP-1).

Fighting Hypoxia to Improve PDT.

Photodynamic therapy (PDT) has drawn great interest in recent years mainly due to its low side effects and few drug resistances. Nevertheless, one of the issues of PDT is the need for oxygen to induce a photodynamic effect. Tumours often have low oxygen concentrations, related to the abnormal structure of the microvessels leading to an ineffective blood distribution.

Light-sensitive dextran-covered PNBA nanoparticles to continuously or discontinuously improve the drug release.

In this work, photo-sensitive core/shell nanoparticles (NPs) based on biocompatible dextran-g-poly(o-nitrobenzyl acrylate) copolymers (Dex-g-PNBA), containing dextran as hydrophilic backbone and PNBA as photosensitive grafts, were formulated using two processes. In the first process (nanoprecipitation), NPs were prepared using preformed Dex-g-PNBA copolymers. Using the second process (emulsion/organic solvent evaporation), "clicked" or "unclicked" NPs were obtained carrying out (or not) an interfacial in situ click chemistry, respectively.

Use of Cyclodextrins in Anticancer Photodynamic Therapy Treatment.

Photodynamic therapy (PDT) is mainly used to destroy cancerous cells; it combines the action of three components: a photoactivatable molecule or photosensitizer (PS), the light of an appropriate wavelength, and naturally occurring molecular oxygen. After light excitation of the PS, the excited PS then reacts with molecular oxygen to produce reactive oxygen species (ROS), leading to cellular damage. One of the drawbacks of PSs is their lack of solubility in water and body tissue fluids, thereby causing low bioavailability, drug-delivery efficiency, therapeutic efficacy, and ROS production.

Lysine Analogue of Polymyxin B as a Significant Opportunity for Photodynamic Antimicrobial Chemotherapy.

In order to highlight the potential of photodynamic antimicrobial chemotherapy in case of infections by antibiotic resistant-strains, a new antimicrobial peptide conjugate has been synthesized, consisting of a derivative of polymyxin B and a cationic porphyrin covalently attached together to a spacer. A polymyxin-derived moiety was subjected to a primary structural modification in the replacement of four diaminobutyrate residues with lysine ones. This modification was done in order to strongly reduce bactericidal activity, with the aim to eliminate the potential rise of polymyxin-resistant strains.

New photodynamic molecular beacons (PMB) as potential cancer-targeted agents in PDT.

Further improvements in Photodynamic therapy (PDT) necessitate that the dye targets more selectively tumour tissues or neovascularization than healthy cells. Different enzymes such as matrix metalloproteinases (MMPs) are overexpressed in tumour areas. Among these MMPs, gelatinases (MMP-2 and MMP-9) and its activator MMP-14 are known to play a key role in tumour angiogenesis and the growth of many cancers such as glioblastoma multiforme (GBM), an aggressive malignant tumour of the brain.

Light-sensitive dextran-covered PNBA nanoparticles as triggered drug delivery systems: Formulation, characteristics and cytotoxicity.

Hypothesis: For some years, smart nano-objects are one of the main focuses of current research. In the framework of polymeric nanomedicine, o-nitrobenzyl alcohol derivatives lead to light-responsive polymeric materials. At this day, nanomedicine based on polysaccharide/poly(o-nitrobenzyl acrylate) (PNBA) copolymers have never been reported.

The application of titanium dioxide, zinc oxide, fullerene, and graphene nanoparticles in photodynamic therapy.

Nanoparticles (NPs) have been shown to have good ability to improve the targeting and delivery of therapeutics. In the field of photodynamic therapy (PDT), this targeting advantage of NPs could help ensure drug delivery at specific sites. Among the commonly reported NPs for PDT applications, NPs from zinc oxide, titanium dioxide, and fullerene are commonly reported.

Ultrasmall AGuIX theranostic nanoparticles for vascular-targeted interstitial photodynamic therapy of glioblastoma.

Despite combined treatments, glioblastoma outcome remains poor with frequent local recurrences, indicating that a more efficient and local therapy is needed. In this way, vascular-targeted photodynamic therapy (VTP) could help tumor eradication by destroying its neovessels. In this study, we designed a polysiloxane-based nanoparticle (NP) combining a magnetic resonance imaging (MRI) contrast agent, a photosensitizer (PS) and a new ligand peptide motif (KDKPPR) targeting neuropilin-1 (NRP-1), a receptor overexpressed by angiogenic endothelial cells of the tumor vasculature.

A Photosensitizer Lanthanide Nanoparticle Formulation that Induces Singlet Oxygen with Direct Light Excitation, But Not By Photon or X-ray Energy Transfer.

We report the design and synthesis of europium-doped gadolinium oxysulfide nanoscintillators Gd O S:Eu conjugated with two different photosensitizers (PSs): a zinc chlorin (ZnTPC) and a zinc phtalocyanine (ZnPc) by covalent bonding through a layer of N-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA). These conjugates were designed to be activated under X-ray excitation to allow a photodynamic effect, although this desired outcome was not achieved in this study. The monodispersed nanoparticles of ∼70 nm diameter were pegylated to be stabilized in aqueous suspension.

Extraction, Identification and Photo-Physical Characterization of Persimmon (Diospyros kaki L.) Carotenoids.

Carotenoid pigments were extracted and purified from persimmon fruits using accelerated solvent extraction (ASE). Eleven pigments were isolated and five of them were clearly identified as all--violaxanthine, all--lutein, all--zeaxanthin all--cryptoxanthin and all--β-carotene. Absorption and fluorescence spectra were recorded.

Folic acid conjugates with photosensitizers for cancer targeting in photodynamic therapy: Synthesis and photophysical properties.

Recent researches in photodynamic therapy have focused on novel techniques to enhance tumour targeting of anticancer drugs and photosensitizers. Coupling a photosensitizer with folic acid could allow more effective targeting of folate receptors which are over-expressed on the surface of many tumour cells. In this study, different folic acid-OEG-conjugated photosensitizers were synthesized, characterized and their photophysical properties were evaluated.

Stability of folic acid under several parameters.

Folic acid is a small molecule, also known as vitamin B9. It is an essential compound involved in important biochemical processes. It is widely used as a vector for targeted treatment and diagnosis especially in cancer therapeutics.

Response surface methodology applied to Supercritical Fluid Extraction (SFE) of carotenoids from Persimmon (Diospyros kaki L.).

Supercritical carbon dioxide with ethanol as co-solvent was used to extract carotenoids from persimmon fruits (Diospyros kaki L.). Based on a response surface methodology (RSM), a predicting model describing the effects of CO2 temperature, pressure, flow rate, ethanol percentage and extraction time was set up for each of the four carotenoids of interest.

Molecular modelling, synthesis and biological evaluation of peptide inhibitors as anti-angiogenic agent targeting neuropilin-1 for anticancer application.

Vascular endothelial growth factor (VEGF) and its co-receptor neuropilin-1 (NRP-1) are important targets of many pro-angiogenic factors. In this study, nine peptides were synthesized and evaluated for their molecular interaction with NRP-1 and compared to our previous peptide ATWLPPR. Docking study showed that the investigated peptides shared the same binding region as shown by tuftsin known to bind selectively to NRP-1.

Inorganic Nanoparticles for Photodynamic Therapy.

Photodynamic therapy (PDT) is a well-established technique employed to treat aged macular degeneration and certain types of cancer, or to kill microbes by using a photoactivatable molecule (a photosensitizer, PS) combined with light of an appropriate wavelength and oxygen. Many PSs are used against cancer but none of them are highly specific. Moreover, most are hydrophobic, so are poorly soluble in aqueous media.

New Peptide-Conjugated Chlorin-Type Photosensitizer Targeting Neuropilin-1 for Anti-Vascular Targeted Photodynamic Therapy.

Photodynamic therapy (PDT) is a cancer treatment modality that requires three components, namely light, dioxygen and a photosensitizing agent. After light excitation, the photosensitizer (PS) in its excited state transfers its energy to oxygen, which leads to photooxidation reactions. In order to improve the selectivity of the treatment, research has focused on the design of PS covalently attached to a tumor-targeting moiety.

Synthesis of Porphyrin, Chlorin and Phthalocyanine Derivatives by Azide-Alkyne Click Chemistry.

The aim of this review is to provide a summary of the use of copper-catalyzed azide-alkyne cycloaddition (CuAAC) in the synthesis of porphyrin, chlorin and phthalocyanine derivatives for different types of therapeutic applications. The click reaction is a powerful and versatile tool for scientists working on the synthesis of various symmetrically and asymmetrically substituted tetrapyrrolic derivatives. For example, click chemistry is widely used for the elaboration of photosensitizer conjugates for photodynamic therapy applications.

Synthesis and photophysical properties of the photoactivatable cationic porphyrin 5-(4-N-dodecylpyridyl)-10,15,20-tri(4-N-methylpyridyl)-21H,23H-porphyrin tetraiodide for anti-malaria PDT.

This article describes a new synthetic method for obtaining three water soluble porphyrins. The more sophisticated porphyrin [5-(4-N-dodecylpyridyl)-10,15,20-tri(4-N-methylpyridyl)-21H,23H-porphyrin tetraiodide], also named C12 porphyrin, was obtained through a three step methodology. The improvements, compared to syntheses described in the literature, mostly concern the purification procedures.

Accelerated solvent extraction of carotenoids from: Tunisian Kaki (Diospyros kaki L.), peach (Prunus persica L.) and apricot (Prunus armeniaca L.).

Extraction of carotenoids from biological matrices and quantifications remains a difficult task. Accelerated solvent extraction was used as an efficient extraction process for carotenoids extraction from three fruits cultivated in Tunisia: kaki (Diospyros kaki L.), peach (Prunus persica L.

Multifunctional ultrasmall nanoplatforms for vascular-targeted interstitial photodynamic therapy of brain tumors guided by real-time MRI.

Photodynamic therapy (PDT) for brain tumors appears to be complementary to conventional treatments. A number of studies show the major role of the vascular effect in the tumor eradication by PDT. For interstitial PDT (iPDT) of brain tumors guided by real-time imaging, multifunctional nanoparticles consisting of a surface-localized tumor vasculature targeting neuropilin-1 (NRP-1) peptide and encapsulated photosensitizer and magnetic resonance imaging (MRI) contrast agents, have been designed.

Preparation and characterization of mTHPC-loaded solid lipid nanoparticles for photodynamic therapy.

Among various attempts to enhance the therapeutic efficacy of photodynamic therapy (PDT), the specific delivery of photosensitizer (PS) in the tumor tissue is expected to improve its clinical applications. The aim of this study was to engineer lipid nanoparticles (LNP) with different sizes and various PS contents, using simple solvent-free and easily scale up manufacturing processes. Meso-(tetrahydroxyphenyl) chlorin (mTHPC) is one of the most potent photoactive compounds for clinical use.

Polysaccharide-covered nanoparticles with improved shell stability using click-chemistry strategies.

Dextran-covered PLA nanoparticles have been formulated by two strategies. On one hand, dextran-g-PLA copolymers have been synthesized by click-chemistry between azide-multifunctionalized dextran (DexN3) and alkyne end-functionalized PLA chains (α-alkyne PLA); then nanoprecipitated without any additional surfactants. On the other hand, DexN3 exhibiting surfactant properties have been emulsified with unfunctionalized or α-alkyne PLA, which are dissolved in organic phase with or without CuBr.