Organic semiconducting polymers are a powerful platform for the design of next-generation technologies due to their excellent optoelectronic properties and solution processability, allowing access to low-cost and scalable manufacturing techniques...
Phosphate remediation from wastewater is rapidly becoming an ever more attractive process due to a combination of both the economic pressure of increasing phosphate scarcity and the environmental damage caused by untreated agricultural runoff. Ideally, remediated phosphate will be recoverable and would be able to be reused as fertilizer. Many different resins have been investigated, but due to the scale of the challenge, any feasible solution will involve the use of very inexpensive waste products as the solid support. Sawdust, functionalized with iron-binding ligands, is such a potential resin. Sawdust alone binds 0.3 g/kg of phosphate which is insufficient. Iron has a strong affinity for phosphate, making the formation of iron-phosphate bonds a promising avenue for the development of recyclable resins. Previously prepared iron-chitosan complexes bound 8.2 g/kg. However, as the price of chitosan has rapidly increased, alternatives are required. In this current study, the covalent modification of the sawdust using either carboxymethylcellulosesupported ligands, or direct functionalization of the sawdust can increase this to 40 g/kg using ethylene diamine as the iron-binding ligand. Binding decreases over repeated cycles of phosphate exposure and elution, but can be fully restored through regeneration using iron salts. The simple green synthesis of this material, and the iron-binding capability of the investigated ligands is discussed. These sawdust-based resins show promise as potential candidates for industrial-scale phosphate recovery efforts in the future.
Glioblastoma is one of the most aggressive types of cancer with success of therapy being hampered by the existence of treatment resistant populations of stem-like Tumour Initiating Cells (TICs) and poor blood–brain barrier drug penetration. Therapies capable of effectively targeting the TIC population are in high demand. Here, we synthesize spherical diketopyrrolopyrrole-based Conjugated Polymer Nanoparticles (CPNs) with an average diameter of 109 nm. CPNs were designed to include fluorescein-conjugated Hyaluronic Acid (HA), a ligand for the CD44 receptor present on one population of TICs. We demonstrate blood–brain barrier permeability of this system and concentration and cell cycle phase-dependent selective uptake of HA-CPNs in CD44 positive GBM-patient derived cultures. Interestingly, we found that uptake alone regulated the levels and signaling activity of the CD44 receptor, decreasing stemness, invasive properties and proliferation of the CD44-TIC populations in vitro and in a patient-derived xenograft zebrafish model. This work proposes a novel, CPN- based, and surface moiety-driven selective way of targeting of TIC populations in brain cancer.
Microplastic
(MP) pollution is a global challenge that requires
immediate mitigation practices. Monitoring is crucial for quantifying
MPs, but their mitigation remains very challenging due to several
factors, including the lack of selective materials to specific polymers,
and the low sensitivity of the current detection techniques. In this
work, we introduce a novel design for the selective detection of MPs
through fluorescence spectroscopy by exploiting conjugated polymer
nanoparticles (CPNs). Fluorescent diketopyrrolopyrrole nanoparticles
were prepared by nanoprecipitation to incorporate peripheral hyaluronic
acid to increase their affinity for various plastics. The affinity
of the new ligand for various types of MPs was examined through several
characterization techniques, including fluorescence spectroscopy and
microscopy, nanoparticle tracking analysis and computational studies.
The new CPN were shown to be highly fluorescent in the presence of
typically abundant MPs, achieving very strong binding constants in
the picomolar range. This very strong affinity for a broad family
of plastics was found to be the results of cooperative supramolecular
effects and topographical affinity, as probed by advanced microscopy
and in silico studies. Furthermore, the new affinity probes were shown
to be highly selective for MPs, allowing for their detection in heterogeneous
samples, including soil debris and other organic contaminants. The
new materials design introduced in this work constitute a promising
platform for the development of novel MP detection devices directly
useable at the point of collection. Moreover, it opens new avenue
for the mitigation of this environmental hazard through tailorable
materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.