Enhancement of cellular uptake by increasing the number of encapsulated gold nanoparticles in polymeric micelles

We apply a combination of polycaprolactone (PCL)-thiol ligand functionalization with flow-controlled microfluidic block copolymer self-assembly to produce biocompatible gold nanoparticle (GNP)-loaded micellar polymer nanoparticles (GNP-PNPs) in which GNPs are encapsulated within PCL cores surrounded by an external layer of poly(ethylene glycol) (PEG). By varying both the relative amount of block copolymer and the microfluidic flow rate, a series of GNP-PNPs are produced in which the mean number of GNPs per PNP in the < 50-nm fraction (Zave,d< 50 nm) varies between 0.1 and 1.9 while the external PEG surface is constant. Zave,d< 50 nm values are determined by statistical analysis of TEM images and compared with the results of cell uptake experiments on MDA-MB-231 cancer cells. For Zave,d< 50 nm ≤ 1 (including a control sample of individual GNPs also with a PEG surface layer), cell uptake is relatively constant, but increases sharply for Zave,d< 50 nm > 1, with a factor of 7 enhancement as Zave,d< 50 nm increases from 1 to ∼2. Enabled by the shear processing control provided by the microfluidic chip, these results provide the first evidence that cellular uptake can be enhanced specifically by increasing the number of GNPs per vector, with other parameters, including polymeric material, internal structure, and external surface chemistry, held constant. They also demonstrate a versatile platform for packaging GNPs in biocompatible polymeric carriers with flow-controlled formulation optimization for various therapeutic and diagnostic applications.

Liquid Crystalline Nanoparticles via Polymerization-Induced Self-Assembly: Morphology Evolution and Function Regulation

Liquid crystalline nanoparticles (LC NPs) are a kind of polymer NPs with LC mesogens, which can form special anisotropic morphologies due to the influence of LC ordering. Owing to the stimuli-responsiveness of the LC blocks, LC NPs show abundant morphology evolution behaviors in response to external regulation. LC NPs have great application potential in nano-devices, drug delivery, special fibers and other fields. Polymerization-induced self-assembly (PISA) method can synthesize LC NPs at high solid content, reducing the harsh demand for reaction solvent of the LC polymers, being a better choice for large-scale production. In this review, we introduced recent research progress of PISA-LC NPs by dividing them into several parts according to the LC mesogen, and discussed the improvement of experimental conditions and the potential application of these polymers.

Nanomedicine and versatile therapies for cancer treatment

The higher prevalence of cancer is related to high rates of mortality and morbidity worldwide. By virtue of the properties of matter at the nanoscale, nanomedicine is proven to be a powerful tool to develop innovative drug carriers with greater efficacies and fewer side effects than conventional therapies. In this review, different nanocarriers for controlled drug release and their routes of administration have been discussed in detail, especially for cancer treatment. Special emphasis has been given on the design of drug delivery vehicles for sustained release and specific application methods for targeted delivery to the affected areas. Different polymeric vehicles designed for the delivery of chemotherapeutics have been discussed, including graft copolymers, liposomes, hydrogels, dendrimers, micelles, and nanoparticles. Furthermore, the effect of dimensional properties on chemotherapy is vividly described. Another integral section of the review focuses on the modes of administration of nanomedicines and emerging therapies, such as photothermal, photodynamic, immunotherapy, chemodynamic, and gas therapy, for cancer treatment. The properties, therapeutic value, advantages, and limitations of these nanomedicines are highlighted, with a focus on their increased performance versus conventional molecular anticancer therapies.

Metal-Coordinated Supramolecular Self-Assemblies for Cancer Theranostics

Metal-coordinated supramolecular nanoassemblies have recently attracted extensive attention as materials for cancer theranostics. Owing to their unique physicochemical properties, metal-coordinated supramolecular self-assemblies can bridge the boundary between traditional inorganic and organic materials. By tailoring the structural components of the metal ions and binding ligands, numerous multifunctional theranostic nanomedicines can be constructed. Metal-coordinated supramolecular nanoassemblies can modulate the tumor microenvironment (TME), thus facilitating the development of TME-responsive nanomedicines. More importantly, TME-responsive organic-inorganic hybrid nanomaterials can be constructed in vivo by exploiting the metal-coordinated self-assembly of a variety of functional ligands, which is a promising strategy for enhancing the tumor accumulation of theranostic molecules. In this review, recent advancements in the design and fabrication of metal-coordinated supramolecular nanomedicines for cancer theranostics are highlighted. These supramolecular compounds are classified according to the order in which the coordinated metal ions appear in the periodic table. Furthermore, the prospects and challenges of metal-coordinated supramolecular self-assemblies for both technical advances and clinical translation are discussed. In particular, the superiority of TME-responsive nanomedicines for in vivo coordinated self-assembly is elaborated, with an emphasis on strategies that enhance the accumulation of functional components in tumors for an ideal theranostic outcome.

Molecular engineering of stimuli-responsive, functional, side-chain liquid crystalline copolymers: synthesis, properties and applications

This review describes recent progress made in designing stimuli-responsive, functional, side-chain, end-on mesogen attached liquid crystalline polymers (LCPs).

One-Pot Synthesis of Thermoresponsive Amyloidogenic Peptide-Polymer Conjugates via Thio-Bromo "Click" Reaction of RAFT Polymers

A synthetic strategy to efficiently prepare main-chain peptide-polymer conjugates probing their aggregation in solution is described. An in situ tandem reaction based on aminolysis/thio-bromo "click" reaction is performed to tether an amyloidogenic peptide fragment amyloid-β_17-20 (Leu-Val-Phe-Phe (LVFF)) to the ω-chain end of poly(diethylene glycol methyl ether acrylate) (PDEGA), prepared via reversible addition fragmentation chain transfer polymerization. Structural confirmation of the constructed conjugates PDEGA-LVFF (M_n,SEC = 5600, Ð = 1.21), (M_n,SEC = 7600, Ð = 1.16), and (M_n,SEC = 8900, Ð = 1.15) is successfully made by combined studies of ¹ H NMR, size-exclusion chromatography, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, and electrospray ionization time-of-flight (ESI-TOF) mass spectrometry. The effect of the peptidic constituent on the thermoresponsive behavior of the polymer is examined by UV-vis spectroscopy, and the self-assembly behavior of the amphiphilic conjugate is further exploited, exhibiting micellar morphology in aqueous solution.

Luminescent supramolecular hydrogels from a tripeptide and nitrogen-doped carbon nanodots

The combination of different components such as carbon nanostructures and organic gelators into composite nanostructured hydrogels is attracting wide interest for a variety of applications, including sensing and biomaterials. In particular, both supramolecular hydrogels that are formed from unprotected D,L-tripeptides bearing the Phe-Phe motif and nitrogen-doped carbon nanodots (NCNDs) are promising materials for biological use. In this work, they were combined to obtain luminescent, supramolecular hydrogels at physiological conditions. The self-assembly of a tripeptide upon application of a pH trigger was studied in the presence of NCNDs to evaluate effects at the supramolecular level. Luminescent hydrogels were obtained whereby NCND addition allowed the rheological properties to be fine-tuned and led to an overall more homogeneous system composed of thinner fibrils with narrower diameter distribution.

Amphiphilic Polymers Containing Cholesterol for Drug Delivery Systems

The interaction of binary copolymers poly(maleic anhydride-co-poly(ethylene glycol) methyl ether methacrylate) with cholesterol results in formation of cholesterol containing polymers, which contain from 4.6 to 46.0 mol % monocholesteryl maleic links. Their structure was confirmed using functional analysis and IR spectroscopy. Acidic and anhydride links of these copolymers form polymeric salts if react with alkali. These salts are surfactants which in aqueous medium form a hierarchy micelles and micellar aggregates depending on the copolymer concentration. Using conductometry it was found that preferably monomolecular micelles are formed in dilute solutions, and micellar aggregates begin to form at higher concentrations. In aqueous media polymeric salts are able to solubilize such lipophilic substances as Sudan III dye and anticancer drug curcumin. Efficiency of solubilization towards Sudan III grows if the content of monocholesteryl maleic fragment in surfactant increases.

A library of AuNPs modified by RAFT polymers of different charge and chain length: high throughput synthesis and synchrotron XFM imaging using a zebrafish larvae model

A PAuNPs library was constructed via high throughput methods and PAuNPs were visualized in PAuNPs injected zebrafish larvae by synchrotron XFM.

DNA templated self-assembly of gold nanoparticle clusters in the colorimetric detection of plant viral DNA using a gold nanoparticle conjugated bifunctional oligonucleotide probe

The DNA templated self-assembly of gold nanoparticles clustered in different configurations (nn = 2–∞) was investigated in the colorimetric detection of ToLCNDV DNA using a gold nanoparticle conjugated bifunctional oligonucleotide probe.

Construction of PEG-based amphiphilic brush polymers bearing hydrophobic poly(lactic acid) side chains via successive RAFT polymerization and ROP

This article reports the synthesis of PEG-b-(PAA-g-PLA) amphiphilic brush polymers by the combination of RAFT polymerization and organocatalytic ROP, which could self-assemble into spheres for sustained release of doxorubicin.

Fluorescent carbon dot-molecular salt hydrogels

We report the incorporation of functionalised carbon nanodots within a low molecular weight salt hydrogel enhancing the gelation and fluorescence properties of both the gel and carbon nanomaterial.

The incorporation of functionalised carbon nanodots within a novel low molecular weight salt hydrogel derived from 5-aminosalicylic acid is reported. The carbon dots result in markedly enhanced gelation properties, while inclusion within the hydrophobic gel results in a dramatic fluorescence enhancement for the carbon nanomaterials. The resulting hybrid CD gels exhibit a useful sensor response for heavy metal ions, particularly Pb²⁺.

Redox-sensitive nanoparticles from amphiphilic cholesterol-based block copolymers for enhanced tumor intracellular release of doxorubicin

A novel amphiphilic cholesterol-based block copolymer comprised of a polymethacrylate bearing cholesterol block and a polyethylene glycol block with reducible disulfide bonds (PC5MA-SS-PEO) was synthesized and evaluated as a redox-sensitive nanoparticulate delivery system. The self-assembled PC5MA-SS-PEO nanoparticles (SS-NPs) encapsulated the anticancer drug doxorubicin (DOX) with high drug loading (18.2% w/w) and high encapsulation efficiency (94.9%). DOX-encapsulated PC5MA-SS-PEO self-assembled nanoparticles (DOX-encapsulated SS-NPs) showed excellent stability and exhibited a rapid DOX release in response to dithiothreitol reductive condition. Importantly, following internalization by lung cancer cells, the reducible DOX-encapsulated SS-NPs achieved higher cytotoxicity than the non-reducible thioester NPs whereas blank nanoparticles were non-cytotoxic. Furthermore, in vivo imaging studies in tumor-bearing severe combined immunodeficiency (SCID) mice showed that the nanoparticles preferentially accumulated in tumor tissue with remarkably reduced accumulation in the healthy non-target organs. The results indicated that the SS-NPs may be a promising platform for cancer-cell specific delivery of hydrophobic anticancer drugs.

FROM THE CLINICAL EDITOR

The use of nanocarriers for drug delivery against tumors has been under intense research. One problem of using carrier system is the drug release kinetics at tumor site. In this article, the authors continued their previous study in the development of an amphiphilic cholesterol-based block copolymer with redox-sensitive modification, so that the payload drug could be released in response to the microenvironment. The interesting results should provide a new direction for designing future novel nanocarrier systems.

Biomacrocyclic side-chain liquid crystalline polymers bearing cholesterol mesogens: facile synthesis and topological effect study

Biomacrocyclic side-chain liquid crystalline polymers bearing cholesterol mesogens with three different length methylene spacers were prepared. Meanwhile, the liquid crystalline phase behaviors were investigated systematically.

Well-defined diblock brush polymer–drug conjugates for sustained delivery of paclitaxel

The synthesis, characterization and property studies of paclitaxel (PTXL)-containing brush polymer–drug conjugates (BPDCs) are presented and the influence of grafting structures of BPDCs on their assembly behaviour, drug release profile and therapeutic effects is discussed in this article.

Nanocomposite hydrogels based on liquid crystalline brush-like block copolymer–Au nanorods and their application in H2O2 detection

The nanocomposite hydrogel from liquid crystalline brush-like block copolymers and gold nanorods is developed, which is used to develop a simple and reproducible method to detect H₂O₂.