Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites.

Multidrug-resistant bacteria represent a global health and economic burden that urgently calls for new technologies to combat bacterial antimicrobial resistance. Here, we developed novel nanocomposites (NCPs) based on chitosan that display different degrees of acetylation (DAs), and conjugated polymer cyano-substituted poly(-phenylene vinylene) (CNPPV) as an alternative approach to inactivate Gram-negative () and Gram-positive () bacteria. Chitosan's structure was confirmed through FT-Raman spectroscopy.

Mitochondrial Targeting and Imaging with Small Organic Conjugated Fluorophores: A Review.

The last decade has seen an increasingly large number of studies reporting on the development of novel small organic conjugated systems for mitochondrial imaging exploiting optical signal transduction pathways. Mitochondria are known to play a critical role in a number of key biological processes, including cellular metabolism. Importantly, irregularities on their working function are nowadays understood to be intimately linked to a range of clinical conditions, highlighting the importance of targeting mitochondria for therapeutic benefits.

Photosensitized and Photothermal Stimulation of Cellular Membranes by Organic Thin Films and Nanoparticles.

Conjugated polymers are increasingly exploited for biomedical applications. In this work, we explored the optical characteristics of conjugated polymers of variable chemical structures at multiple levels relevant to biological interfacing, from fluorescence yield to their influence on cellular membrane potential. We systematically compared the performance of conjugated polymer as cast thin films and as nanoparticles stabilized with amphiphilic polyethylene glycol-poly lactic acid-co-glycolic acid (PEG-PLGA).

Synthesis of micellar-like terpolymer nanoparticles with reductively-cleavable cross-links and evaluation of efficacy in 2D and 3D models of triple negative breast cancer.

Triple negative or basal-like breast cancer (TNBC) is characterised by aggressive progression, lack of standard therapies and poorer overall survival rates for patients. The bad prognosis, high rate of relapse and resistance against anticancer drugs have been associated with a highly abnormal loss of redox control in TNBC cells. Here, we developed docetaxel (DTX)-loaded micellar-like nanoparticles (MLNPs), designed to address the aberrant TNBC biology through the placement of redox responsive cross-links designed into a terpolymer.

Development of a Neutral Diketopyrrolopyrrole Phosphine Oxide for the Selective Bioimaging of Mitochondria at the Nanomolar Level.

Development of novel bioimaging materials that exhibit organelle specific accumulation continues to be at the forefront of research interests and efforts. Among the various subcellular organelles, mitochondria, which are found in the cytoplasm of eukaryotic cells, are of particular interest in relation to their vital function. To date, most molecular probes that target mitochondria utilise delocalised lipophilic cations such as triphenylphosphonium and pyridinium.

Conjugated polymers as nanoparticle probes for fluorescence and photoacoustic imaging.

Bioimaging enables the visualisation of biological processes at the microscopic and macroscopic levels, finding applications from cellular tracking to whole body scanning for diagnosis purposes. The different techniques developed to acquire images make use of most radiation types of the electromagnetic spectrum. Recently, there has been interest in non-ionising radiation imaging techniques that can offer improved detection or additional information about biological processes, and fluorescence and photoacoustic imaging have become an eminent field.

Enhancing doxorubicin anticancer activity with a novel polymeric platform photoreleasing nitric oxide.

Combinations of conventional chemotherapeutics with unconventional anticancer agents such as reactive oxygen and nitrogen species may offer treatment benefits for cancer therapies. Here we report a novel polymeric platform combining the delivery of Doxorubicin (DOXO) with the light-regulated release of nitric oxide (NO). An amphiphilic block-copolymer (P1) was designed and synthesized as the drug carrier, with pendant amine groups to attach DOXO via a urea linkage and a NO photodonor (NOPD) activable by visible light.

Low molecular weight PEG-PLGA polymers provide a superior matrix for conjugated polymer nanoparticles in terms of physicochemical properties, biocompatibility and optical/photoacoustic performance.

The near-infrared absorbing conjugated polymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) has been investigated as a contrast agent for optical and photoacoustic imaging. Lipophilic π-conjugated polymers can be efficiently encapsulated within self-assembling diblock copolymer poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG-PLGA) nanoparticles, although the effect of variations in PEG and PLGA chain lengths on nanoparticle properties, performance and biocompatibility have not yet been investigated. In this study, PEG-PLGA with different block lengths (PEG-PLGA, PEG-PLGA and PEG-PLGA) were used to encapsulate PCPDTBT.

Amphiphilic tri- and tetra-block co-polymers combining versatile functionality with facile assembly into cytocompatible nanoparticles.

In order for synthetic polymers to find widespread practical application as biomaterials, their syntheses must be easy to perform, utilising freely available building blocks, and should generate products which have no adverse effects on cells or tissue. In addition, it is highly desirable that the synthesis platform for the biomaterials can be adapted to generate polymers with a range of physical properties and macromolecular architectures, and with multiple functional handles to allow derivatisation with 'actives' for sensing or therapy. Here we describe the syntheses of amphiphilic tri- and tetra-block copolymers, using diazabicyclo[5.

Influence of the Surfactant Structure on Photoluminescent π-Conjugated Polymer Nanoparticles: Interfacial Properties and Protein Binding.

π-Conjugated polymer nanoparticles (CPNs) are under investigation as photoluminescent agents for diagnostics and bioimaging. To determine whether the choice of surfactant can improve CPN properties and prevent protein adsorption, five nonionic polyethylene glycol alkyl ether surfactants were used to produce CPNs from three representative π-conjugated polymers. The surfactant structure did not influence size or yield, which was dependent on the nature of the conjugated polymer.

Interactions of stealth conjugated polymer nanoparticles with human whole blood.

Photoluminescent conjugated polymeric nanoparticles (CPNs) exhibit favourable properties as fluorescent probes due to their brightness, high photostability, tunable emission spectra and ease of surface modification. Potential cellular and clinical applications of these new diagnostic agents are easily envisioned, providing a rationale to study CPN biocompatibility. Here, stealth formulations of poly phenylene vinylene (PPV) and poly phenylene ethinylene (PPE) were manufactured and their interactions with human blood components assessed.

Surface chemistry of photoluminescent F8BT conjugated polymer nanoparticles determines protein corona formation and internalization by phagocytic cells.

Conjugated polymer nanoparticles are being developed for a variety of diagnostic and theranostic applications. The conjugated polymer, F8BT, a polyfluorene derivative, was used as a model system to examine the biological behavior of conjugated polymer nanoparticle formulations stabilized with ionic (sodium dodecyl sulfate; F8BT-SDS; ∼207 nm; -31 mV) and nonionic (pegylated 12-hydroxystearate; F8BT-PEG; ∼175 nm; -5 mV) surfactants, and compared with polystyrene nanoparticles of a similar size (PS200; ∼217 nm; -40 mV). F8BT nanoparticles were as hydrophobic as PS200 (hydrophobic interaction chromatography index value: 0.

Delivery systems and local administration routes for therapeutic siRNA.

With the increasing number of studies proposing new and optimal delivery strategies for the efficacious silencing of gene-related diseases by the local administration of siRNAs, the present review aims to provide a broad overview of the most important and latest developments of non-viral siRNA delivery systems for local administration. Moreover, the main disease targets for the local delivery of siRNA to specific tissues or organs, including the skin, the lung, the eye, the nervous system, the digestive system and the vagina, were explored.