Enhancing Oil Recovery in Low-Permeability Reservoirs Using a Low-Molecular Weight Amphiphilic Polymer

Polymer flooding has achieved considerable success in medium-high permeability reservoirs. However, when it comes to low-permeability reservoirs, polymer flooding suffers from poor injectivity due to the large molecular size of the commonly used high-molecular-weight (high-MW) partially hydrolyzed polyacrylamides (HPAM). Herein, an amphiphilic polymer (LMWAP) with a low MW (3.9 × 106 g/mol) was synthesized by introducing an amphiphilic monomer (Allyl-OP-10) and a chain transfer agent into the polymerization reaction. Despite the low MW, LMWAP exhibited better thickening capability in brine than its counterparts HPAM-1800 (MW = 1.8 × 107 g/mol) and HPAM-800 (MW = 8 × 106 g/mol) due to the intermolecular hydrophobic association. LMWAP also exhibited more significant shear-thinning behavior and stronger elasticity than the two counterparts. Furthermore, LMWAP possesses favorable oil-water interfacial activity due to its amphiphilicity. The oil-water interfacial tension (IFT) could be reduced to 0.88 mN/m and oil-in-water (O/W) emulsions could be formed under the effect of LMWAP. In addition, the reversible hydrophobic association endows the molecular chains of LMWAP with dynamic association-disassociation transition ability. Therefore, despite the similar hydrodynamic sizes in brine, LMWAP exhibited favorable injectivity under low-permeability conditions, while the counterpart HPAM-1800 led to fatal plugging. Furthermore, LMWAP could enhance oil recovery up to 21.5%, while the counterpart HPAM-800 could only enhance oil recovery by up to 11.5%, which could be attributed to the favorable interfacial activity of LMWAP.

Exosome Isolation Using Chitosan Oligosaccharide Lactate-1-Pyrenecarboxylic Acid-Based Self-Assembled Magnetic Nanoclusters

Exosomes are small extracellular vesicles that play a crucial role in intercellular communication and offer significant potential for a wide range of biomedical applications. However, conventional methods for exosome isolation have limitations in terms of purity, scalability, and preservation of exosome structural integrity. To address these challenges, an exosome isolation platform using chitosan oligosaccharide lactate conjugated 1-pyrenecarboxylic acid (COL-Py) based self-assembled magnetic nanoclusters (CMNCs), is presented. CMNCs are characterized to optimize their size, stability, and interaction dynamics with exosomes. The efficiency of CMNCs in isolating exosomes is systematically evaluated using various analytical methods to demonstrate their ability to capture exosomes based on amphiphilic lipid bilayers. CMNC-based exosome isolation consistently yields exosomes with structural integrity and purity similar to those obtained using traditional methods. The reusability of CMNCs over multiple exosome isolation cycles underscores their scalability and offers an efficient solution for biomedical applications. These results are supported by western blot analysis, which demonstrated the superiority of CMNC-based isolation in terms of purity compared to conventional methods. By providing a scalable and efficient exosome isolation process that preserves both structural integrity and purity, CMNCs can constitute a new platform that can contribute to the field of exosome studies.

Preparation and Performance Evaluation of Amphiphilic Polymers for Enhanced Heavy Oil Recovery

The continuous growth in global energy and chemical raw material demand has drawn significant attention to the development of heavy oil resources. A primary challenge in heavy oil extraction lies in reducing crude oil viscosity. Alkali-surfactant-polymer (ASP) flooding technology has emerged as an effective method for enhancing heavy oil recovery. However, the chromatographic separation of chemical agents presents a formidable obstacle in heavy oil extraction. To address this challenge, we utilized a free radical polymerization method, employing acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, lauryl acrylate, and benzyl acrylate as raw materials. This approach led to the synthesis of a multifunctional amphiphilic polymer known as PAALB, which we applied to the extraction of heavy oil. The structure of PAALB was meticulously characterized using techniques such as infrared spectroscopy and Nuclear Magnetic Resonance Spectroscopy. To assess the effectiveness of PAALB in reducing heavy oil viscosity and enhancing oil recovery, we conducted a series of tests, including contact angle measurements, interfacial tension assessments, self-emulsification experiments, critical association concentration tests, and sand-packed tube flooding experiments. The research findings indicate that PAALB can reduce oil-water displacement, reduce heavy oil viscosity, and improve swept volume upon injection into the formation. A solution of 5000 mg/L PAALB reduced the contact angle of water droplets on the core surface from 106.55° to 34.95°, shifting the core surface from oil-wet to water-wet, thereby enabling oil-water displacement. Moreover, A solution of 10,000 mg/L PAALB reduced the oil-water interfacial tension to 3.32 × 10-4 mN/m, reaching an ultra-low interfacial tension level, thereby inducing spontaneous emulsification of heavy oil within the formation. Under the condition of an oil-water ratio of 7:3, a solution of 10,000 mg/L PAALB can reduce the viscosity of heavy oil from 14,315 mPa·s to 201 mPa·s via the glass bottle inversion method, with a viscosity reduction rate of 98.60%. In sand-packed tube flooding experiments, under the injection volume of 1.5 PV, PAALB increased the recovery rate by 25.63% compared to traditional hydrolyzed polyacrylamide (HPAM) polymer. The insights derived from this research on amphiphilic polymers hold significant reference value for the development and optimization of chemical flooding strategies aimed at enhancing heavy oil recovery.

Amphiphilic Fluorinated Unimer Micelles as Nanocarriers of Fluorescent Probes for Bioimaging

The unique self-assembly properties of unimer micelles are exploited for the preparation of fluorescent nanocarriers embedding hydrophobic fluorophores. Unimer micelles are constituted by a (meth)acrylate copolymer with oligoethyleneglycol and perflurohexylethyl side chains (PEGMA90-co-FA10) in which the hydrophilic and hydrophobic comonomers are statistically distributed along the polymeric backbone. Thanks to hydrophobic interactions in water, the amphiphilic copolymer forms small nanoparticles (<10 nm), with tunable properties and functionality. An easy procedure for the encapsulation of a small hydrophobic molecule (C153 fluorophore) within unimer micelles is presented. UV-vis, fluorescence, and fluorescence anisotropy spectroscopic experimental data demonstrate that the fluorophore is effectively embedded in the nanocarriers. Moreover, the nanocarrier positively contributes to preserve the good emissive properties of the fluorophore in water. The efficacy of the dye-loaded nanocarrier as a fluorescent probe is tested in two-photon imaging of thick ex vivo porcine scleral tissue.

Cellular Internalization and Exiting Behavior of Zwitterionic 4-Armed Star-Shaped Polymers

The zwitterionic phospholipid polymer poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) is amphiphilic copolymer, and it has been reported to directly penetrate cell membranes and have good cytocompatibility. Conventional PMBs are linear-type random copolymers that are polymerized by a free radical polymerization technique. In contrast, star-shaped polymers, or simple branched-type polymers, have unique properties compared to the linear types, for example, a viscosity based on the effect of the excluded volume. In this study, a branched architecture was introduced into a PMB molecular structure, and a 4-armed star-shaped PMB (4armPMB) was synthesized by an atom transfer radical polymerization (ATRP) technique known as living radical polymerization. Linear-type PMB was also synthesized using ATRP. The effects of the polymer architecture on cytotoxicity and cellular uptake were investigated. Both 4armPMB and LinearPMB were successfully synthesized, and these polymers were verified to be water soluble. Pyrene fluorescence in the polymer solution indicated that the architecture had no effect on the behavior of the polymer aggregates. In addition, these polymers caused no cytotoxicity or cell membrane damage. The 4armPMB and LinearPMB penetrated into the cells after a short incubation period, with similar rates. In contrast, the 4armPMB showed a quicker back-diffusion from the cells than that of LinearPMB. The 4armPMB showed fast cellular internalization and exiting behaviors.

Consequences of poly(ethylene oxide) and poloxamer P188 on transcription in healthy and stressed myoblasts

Poly(ethylene oxide) (PEO) and poloxamers, a class of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, have many personal and medical care applications, including the stabilization of stressed cellular membranes. Despite the widespread use, the cellular transcriptional response to these molecules is relatively unknown. C2C12 myoblasts, a model muscle cell, were subjected to short-term Poloxamer 188 (P188) and PEO181 (8,000 g/mol) treatment in culture. RNA was extracted and sequenced to quantify transcriptomic impact. The addition of moderate concentrations (14 µM) of either polymer to unstressed cells caused substantial differential gene expression, including at least twofold modulation of 357 and 588 genes, respectively. In addition, evaluation of the transcriptome response to osmotic stress without polymer treatment revealed dramatic change in RNA expression. Interestingly, the addition of polymer to stressed cells-at concentrations that provide physiological protection-did not yield a significant difference in expression of any gene relative to stress alone. Genome-scale expression analysis was corroborated by single-gene quantitative real-time PCR. Changes in protein expression were measured via western blot, which revealed partial alignment with the RNA results. Collectively, the significant changes to expression of multiple genes and resultant protein translation demonstrates an unexpectedly broad biochemical response to these polymers in healthy myoblasts in vitro. Meanwhile, the lack of substantial transcriptional response to polymer treatment in stressed cells highlights the physical nature of that protective mechanism.

Inhibition of the Fibrillation of Amyloid Aβ1-40 by Hybrid-Lipid-Polymer Vesicles

The transformation of functional proteins into amyloidic plaques is responsible for the impairment of neurological functions in patients fallen victim to debilitating neurological conditions like Alzheimer's, Parkinson's, and Huntington's diseases. The nucleating role of amyloid beta (Aβ_1-40 ) peptide into amyloids is well established. Herein, lipid hybrid-vesicles are generated with glycerol/cholesterol-bearing polymers aiming to alter the nucleation process and modulate the early phases of Aβ_1-40 fibrillation. Hybrid-vesicles (±100 nm) are prepared by incorporating variable amounts of cholesterol-/glycerol-conjugated poly(di(ethylene glycol)_m acrylates)_n polymers into 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) membranes. The in vitro fibrillation kinetics coupled to transmission electron microscopy (TEM) is employed to investigate the role of hybrid-vesicles on Aβ_1-40 fibrillation without destroying the vesicular membrane. Both polymers, when embedded in hybrid-vesicles (up to 20%) significantly prolonged the fibrillation lag phase (t_lag ) compared to a small acceleration in the presence of DOPC vesicles, irrespective of the amount of polymers inside the hybrid-vesicles. Along with this notable retardation effect, a morphological transformation of the amyloid's secondary structures to amorphous aggregates or the absence of fibrillar structures when interacting with the hybrid-vesicles is confirmed by TEM and circular dichroism (CD) spectroscopy.

Amphiphilic Grafted Polymers Based on Citric Acid and Aniline Used to Enhance the Antifouling and Permeability Properties of PES Membranes

Water treatment technology based on ultrafiltration (UF) faces the problem of severe membrane fouling due to its inherent hydrophobicity. The use of amphiphilic polymers that possess both hydrophobic and hydrophilic chain segments can be advantageous for the hydrophilic modification of UF membranes due to their excellent combination in the membrane matrix. In the present study, we examined a novel amphiphilic CA-g-AN material, constructed by grafting citric acid (CA) to aniline (AN), as a modified material to improve the hydrophilicity of a PES membrane. This material was more compatible with the polymer membrane matrix than a pure hydrophilic modified material. The polyethersulfone (PES) membranes modified by amphiphilic CA-g-AN demonstrated a higher water flux (290.13 L·m^-2·h^-1), which was more than eight times higher than that of the pure PES membrane. Furthermore, the flux recovery ratio (FRR) of the modified membrane could reach 83.24% and the value of the water contact angle (WCA) was 76.43°, demonstrating the enhanced hydrophilicity and antifouling ability of the modified membranes. With this study, we aimed to develop a new amphiphilic polymer to improve the antifouling property and permeability of polymer-based UF membranes to remove organic pollutants from water.

Potential Hemostatic and Wound Healing Effects of Thermoresponsive Wound Dressing Gel Loaded with Lignosus rhinocerotis and Punica granatum Extracts

Biologically active compounds in Lignosus rhinocerotis and Punica granatum are found to facilitate wound healing and exhibit hemostatic activity, making them a good combination as bioactives for wound dressings. This study, therefore, aimed to evaluate the potential of thermoresponsive gels loaded with L. rhinocerotis (HLRE) and P. granatum (PPE) extracts as dressings for wound treatment. The gels were prepared using Pluronic PF127 polymer and mixed with PEG 400 and/or starch prior to incorporation with both extracts (0.06 to 1 mg/mL). The gelation temperature (Tgel) at the skin temperature was achieved when Pluronic PF127 was mixed with 22% w/v PEG 400 and reduced to 25.7 ± 0.3-26.7 ± 1.2 °C after adding HLRE and PPE. The gels exhibited satisfactory hardness (2.02 ± 0.19-6.45 ± 0.53 N), cohesiveness (0.9 ± 0.07-2.28 ± 0.4 mJ), adhesiveness (5.07 ± 2.41-19.6 ± 1.1 mJ), and viscosity (0.15 ± 0.04-0.95 ± 0.03 Pa.s), suitable for wound dressings. The optimized gels displayed high thrombin activity and cell migration rate (wound closure of 74% ± 12-89% ± 2 within 24 h), demonstrating hemostatic and healing effects. The thermoresponsive gels demonstrated advantages to be used as dressings for treating acute and open wounds.

Nanocapsules: An Emerging Drug Delivery System

BACKGROUND

Controlled drug release and site-specific delivery of drugs make nanocapsules the most approbative drug delivery system for various kinds of drugs, bioactive, protein, and peptide compounds. Nanocapsules (NCs) are spherical shape microscopic shells consisting of a core (solid or liquid) in which the drug is positioned in a cavity enclosed by a distinctive polymeric membrane.

OBJECTIVES

The main objective of the present patent study is to elaborate on various formulation techniques and methods of nanocapsules (NCs). The review also spotlights various biomedical applications as well as on the patents of NCs to date.

METHODS

The review was extracted from the searches performed using various search engines such as PubMed, Google Patents, Medline, Google Scholars, etc. In order to emphasize the importance of NCs, some published patents of NCs have also been reported in the review.

RESULTS

NCs are tiny magical shells having incredible reproducibility. Various techniques can be used to formulate NCs. The pharmaceutical performance of the formulated NCs can be judged by evaluating their shape, size, entrapment efficiency, loading capacity, etc., using different analytical techniques. Their main applications are found in the field of agrochemicals, genetic manipulation, cosmetics, hygiene items, strategic distribution of drugs to tumors, nanocapsule bandages to combat infection, and radiotherapy.

CONCLUSION

In the present review, our team made a deliberate effort to summarize the recent advances in the field of NCs and focus on new patents related to the implementation of NCs delivery systems in the area of some life-threatening disorders like diabetes, cancer, and cardiovascular diseases.

Testing an Iron Oxide Nanoparticle-Based Method for Magnetic Separation of Nanoplastics and Microplastics from Water

Nanoplastic pollution is increasing worldwide and poses a threat to humans, animals, and ecological systems. High-throughput, reliable methods for the isolation and separation of NMPs from drinking water, wastewater, or environmental bodies of water are of interest. We investigated iron oxide nanoparticles (IONPs) with hydrophobic coatings to magnetize plastic particulate waste for removal. We produced and tested IONPs synthesized using air-free conditions and in atmospheric air, coated with several polydimethylsiloxane (PDMS)-based hydrophobic coatings. Particles were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) magnetometry, dynamic light scattering (DLS), X-ray diffraction (XRD) and zeta potential. The IONPs synthesized in air contained a higher percentage of the magnetic spinel phase and stronger magnetization. Binding and recovery of NMPs from both salt and freshwater samples was demonstrated. Specifically, we were able to remove 100% of particles in a range of sizes, from 2-5 mm, and nearly 90% of nanoplastic particles with a size range from 100 nm to 1000 nm using a simple 2-inch permanent NdFeB magnet. Magnetization of NMPs using IONPs is a viable method for separation from water samples for quantification, characterization, and purification and remediation of water.

"Brush-like" Amphiphilic Polymer for Environmental Adaptive Coating

Multiple functional coating is urgently needed in complex service surroundings to meet various requirements. In this work, a brush-like amphiphilic copolymer of poly methacryloxyethyl dimethyl butyl ammonium bromide-polydimethylsiloxane (pMDBAB-PDMS) was synthesized to construct an environment-adaptive multifunctional coating based on the copolymer via the UV-curing method. The special molecule chains of the copolymer assembled predominately on the coating surface in different surroundings, which rendered the surface with various functions. In water-rich surroundings, the hydrophilic quaternary ammonium groups in the coating endow the coating surface with antifogging, oleophobicity underwater, self-cleaning, antibacteria, triboelectric resistance, and super lubrication properties. In dry air surroundings, the long, flexible, low surface energy molecular PDMS chains tend to distribute on the top of the coating surface, which gives a low friction coefficient and antioil properties. This work presents a strategy to construct environmental adaptive coating that has an important application prospect in the field of optical lens.

Self-Assembled Amphiphilic Fluorinated Random Copolymers for the Encapsulation and Release of the Hydrophobic Combretastatin A-4 Drug

Water-soluble amphiphilic random copolymers composed of tri(ethylene glycol) methacrylate (TEGMA) or poly(ethylene glycol) methyl ether methacrylate (PEGMA) and perfluorohexylethyl acrylate (FA) were synthesized by ARGET-ATRP, and their self-assembling and thermoresponsive behavior in water was studied by dynamic light scattering (DLS) and UV-vis spectroscopy. The copolymer ability to self-fold in single-chain nano-sized structures (unimer micelles) in aqueous solutions was exploited to encapsulate Combretastatin A-4 (CA-4), which is a very hydrophobic anticancer drug. The cloud point temperature (T_cp) was found to linearly decrease with increasing drug concentration in the drug/copolymer system. Moreover, while CA-4 was preferentially incorporated into the unimer micelles of TEGMA-ran-FA, the drug was found to induce multi-chain, submicro-sized aggregation of PEGMA-ran-FA. Anyway, the encapsulation efficiency was very high (≥81%) for both copolymers. The drug release was evaluated in PBS aqueous solutions both below and above T_cp for TEGMA-ran-FA copolymer and below T_cp, but at two different drug loadings, for PEGMA-ran-FA copolymer. In any case, the release kinetics presented similar profiles, characterized by linear trends up to ≈10–13 h and ≈7 h for TEGMA-ran-FA and PEGMA-ran-FA, respectively. Then, the release rate decreased, reaching a plateau. The release from TEGMA-ran-FA was moderately faster above T_cp than below T_cp, suggesting that copolymer thermoresponsiveness increased the release rate, which occurred anyway by diffusion below T_cp. Cytotoxicity tests were carried out on copolymer solutions in a wide concentration range (5–60 mg/mL) at 37 °C by using Balb/3T3 clone A31 cells. Interestingly, it was found that the concentration-dependent micro-sized aggregation of the amphiphilic random copolymers above T_cp caused a sort of “cellular asphyxiation” with a loss of cell viability clearly visible for TEGMA-ran-FA solutions (T_cp below 37 °C) with higher copolymer concentrations. On the other hand, cells in contact with the analogous PEGMA-ran-FA (T_cp above 37 °C) presented a very good viability (≥75%) with respect to the control at any given concentration.

Computational Reverse Engineering Analysis for Scattering Experiments (CREASE) on Vesicles Assembled from Amphiphilic Macromolecular Solutions

In this paper we present the development and validation of the "Computational Reverse-Engineering Analysis for Scattering Experiments" (CREASE) method for analyzing scattering results from vesicle structures that are commonly found upon assembly of synthetic, biomimetic, or bioderived amphiphilic copolymers in solution. The two-step CREASE method takes the amphiphilic polymer chemistry and small-angle scattering intensity profile, I exp(q), as input and determines the vesicles' structural features on multiple length scales ranging from assembled vesicle wall's individual layer thicknesses to the monomer-level packing and distribution of polymer conformations. In the first step of CREASE, a genetic algorithm (GA) is used to determine the relevant vesicle dimensions from the input macromolecular solution information and I exp(q) by identifying the structure whose computed scattering profile best matches the input I exp(q). Then in the second step, the GA-determined dimensions are used for molecular reconstruction of the vesicle structure. To validate CREASE for vesicles, we test CREASE on input scattering intensity profiles generated mathematically (termed as in silico I exp(q) vs q) from a variety of vesicle sizes with known dimensions. We also test CREASE on in silico I exp(q) vs q generated from vesicles with dispersity in all relevant dimensions, resembling real experiments. After successful validation of CREASE, we compare the CREASE-determined dimensions against those obtained from the traditional approach of fitting the scattering intensity profile to relevant analytical model in SASVIEW package. We show that CREASE performs better than or as well as the core-multishell analytical model's fitting in SASVIEW in determining vesicle dimensions with dispersity. We also show that CREASE provides structural information beyond those possible from traditional scattering analysis using the core-multishell model, such as the distribution of solvophilic monomers between the vesicle wall's inner and outer layers in the vesicle wall and the chain-level packing within each vesicle layer.

Amphiphilic Polyphosphonate Copolymers as New Additives for PDMS-Based Antifouling Coatings

Poly(ethyl ethylene phosphonate)-based methacrylic copolymers containing polysiloxane methacrylate (SiMA) co-units are proposed as surface-active additives as alternative solutions to the more investigated polyzwitterionic and polyethylene glycol counterparts for the fabrication of novel PDMS-based coatings for marine antifouling applications. In particular, the same hydrophobic SiMA macromonomer was copolymerized with a methacrylate carrying a poly(ethyl ethylene phosphonate) (PEtEPMA), a phosphorylcholine (MPC), and a poly(ethylene glycol) (PEGMA) side chain to obtain non-water soluble copolymers with similar mole content of the different hydrophilic units. The hydrolysis of poly(ethyl ethylene phosphonate)-based polymers was also studied in conditions similar to those of the marine environment to investigate their potential as erodible films. Copolymers of the three classes were blended into a condensation cure PDMS matrix in two different loadings (10 and 20 wt%) to prepare the top-coat of three-layer films to be subjected to wettability analysis and bioassays with marine model organisms. Water contact angle measurements showed that all of the films underwent surface reconstruction upon prolonged immersion in water, becoming much more hydrophilic. Interestingly, the extent of surface modification appeared to be affected by the type of hydrophilic units, showing a tendency to increase according to the order PEGMA < MPC < PEtEPMA. Biological tests showed that Ficopomatus enigmaticus release was maximized on the most hydrophilic film containing 10 wt% of the PEtEP-based copolymer. Moreover, coatings with a 10 wt% loading of the copolymer performed better than those containing 20 wt% for the removal of both Ficopomatus and Navicula, independent from the copolymer nature.

Improving and evaluating the adhesion and stability of make-up by enhancing the affinity between skin/make-up layer

PURPOSE

upMake-up clumps, bumps and collapses are the three factors that determine how well make-up has been performed. The purpose of this study is to reduce the three factors mentioned above by using amphiphilic substances to increase the affinity between the skin and the make-up layer. In addition, it aims to evaluate the improvement of the make-up layer by developing an objective make-up layer evaluation method.

METHODS

Experiments were performed in an attempt to increase the affinity between the skin and the make-up layer by minimizing the difference in surface energy between the two. Multiple types of artificial skin (leather and bio-skin) were used and treated to form the liquid foundation layer. Qualitative evaluation of the make-up layer was conducted by analyzing the surface, cross-section, and fracture area of the make-up layer, using the evaluation method proposed in this study.

RESULTS

After applying this method and taking measurements by 3D surface analysis, the surface roughness of the make-up layer reduced by 46%, and the maximum thickness of the make-up layer reduced by about 50% in comparison with the control group (method not applied). In the case of the make-up layer to which this method was applied, two-dimensional cross-sectional Scanning Electron Microscope (SEM) image analysis confirmed that agglomeration was reduced, and the thickness of the make-up layer was also reduced by an average of 54%. According to this result, the technique of increasing the affinity between the skin and the make-up layer reduces the level of aggregation of make-up and encourages the formation of a uniform and thin make-up layer. Also, the fracture area after motion simulation was reduced by 33%. These results indicate that the method of increasing the affinity between skin/make-up membranes positively affects the formation of a uniform make-up layer.

CONCLUSION

Increasing the affinity by reducing the surface energy between the skin and the make-up layer plays an important role in forming a thin and uniform make-up layer by improving the problems of lifting, agglomeration, and collapse of the make-up. In addition, it has been confirmed that through this method, the quality of consumer experience related to make-up satisfaction can be improved. The results show that objective analyses of make-up help the understanding of the quality of consumer experience on make-up.

Polymeric micelles as drug-delivery systems in cancer: challenges and opportunities

Tweetable abstract Micelles are nanocarriers for hydrophobic chemotherapeutic drugs. This editorial discusses the current status of preclinical micellar research and sheds light on the possibility of their clinical translation.

Impact of Tuning the Surface Charge Distribution on Colloidal Iron Oxide Nanoparticle Toxicity Investigated in Caenorhabditis elegans

Assessing the toxic effect in living organisms remains a major issue for the development of safe nanomedicines and exposure of researchers involved in the synthesis, handling and manipulation of nanoparticles. In this study, we demonstrate that Caenorhabditis elegans could represent an in vivo model alternative to superior mammalians for the collection of several physiological functionality parameters associated to both short-term and long-term effects of colloidally stable nanoparticles even in absence of microbial feeding, usually reported to be necessary to ensure appropriate intake. Contextually, we investigated the impact of surface charge on toxicity of superparamagnetic iron oxide coated with a wrapping polymeric envelop that confers them optimal colloidal stability. By finely tuning the functional group composition of this shallow polymer–obtaining totally anionic, partially pegylated, partially anionic and partially cationic, respectively–we showed that the ideal surface charge organization to optimize safety of colloidal nanoparticles is the one containing both cationic and anionic groups. Our results are in accordance with previous evidence that zwitterionic nanoparticles allow long circulation, favorable distribution in the tumor area and optimal tumor penetration and thus support the hypothesis that zwitterionic iron oxide nanoparticles could be an excellent solution for diagnostic imaging and therapeutic applications in nanooncology.

Amphiphilic Comb Polymers as New Additives in Bicontinuous Microemulsions

It has been shown that the thermodynamics of bicontinuous microemulsions can be tailored via the addition of various different amphiphilic polymers. In this manuscript, we now focus on comb-type polymers consisting of hydrophobic backbones and hydrophilic side chains. The distinct philicity of the backbone and side chains leads to a well-defined segregation into the oil and water domains respectively, as confirmed by contrast variation small-angle neutron scattering experiments. This polymer-microemulsion structure leads to well-described conformational entropies of the polymer fragments (backbone and side chains) that exert pressure on the membrane, which influences the thermodynamics of the overall microemulsion. In the context of the different polymer architectures that have been studied by our group with regards to their phase diagrams and small-angle neutron scattering, the microemulsion thermodynamics of comb polymers can be described in terms of a superposition of the backbone and side chain fragments. The denser or longer the side chain, the stronger the grafting and the more visible the brush effect of the side chains becomes. Possible applications of the comb polymers as switchable additives are discussed. Finally, a balanced philicity of polymers also motivates transmembrane migration in biological systems of the polymers themselves or of polymer-DNA complexes.

Electrospinning/Electrospray of Ferrocene Containing Copolymers to Fabricate ROS-Responsive Particles and Fibers

We demonstrate an electrospray/electrospinning process to fabricate stimuli-responsive nanofibers or particles that can be utilized as stimuli-responsive drug-loaded materials. A series of random copolymers consisting of hydrophobic ferrocene monomers and hydrophilic carboxyl groups, namely poly(ferrocenylmethyl methacrylate-r-methacrylic acid) [poly(FMMA-r-MA)] with varied composition, was synthesized with free radical copolymerization. The morphologies of the resulting objects created by electrospray/electrospinning of the poly(FMMA-r-MA) solutions were effectively varied from particulate to fibrous structures by control of the composition, suggesting that the morphology of electrosprayed/electrospun copolymer objects was governed by its composition and hence, interaction with the solvent, highlighting the significance of the balance of hydrophilicity/hydrophobicity of the copolymer chain to the assembled structure. Resulting particles and nanofibers exhibited largely preserved responsiveness to reactive oxygen species (ROS) during the deposition process, opening up the potential to fabricate ROS-sensitive material with various desirable structures toward different applications.

Stealth and Bright Monomolecular Fluorescent Organic Nanoparticles Based on Folded Amphiphilic Polymer

Fluorescent nanoparticles (NPs), owing to their superior brightness, are an attractive alternative to organic dyes. However, their cellular applications remain limited because of their large size, poor homogeneity, and nonspecific interactions in biological media. Herein, we propose a concept of monomolecular fluorescent organic nanoparticles of high brightness and very small size (10-14 nm) built of a single amphiphilic polymer bearing specially designed fluorescent dyes. We found that high PEGylation of poly(maleic anhydride-alt-1-octadecene (PMAO) favors a single-chain polymer folding into monomolecular stealth NPs with highly reduced nonspecific interactions with proteins and live cells. To ensure high stability of our NPs, the fluorophores (BODIPYs) are covalently linked to the polymer through an optimized linker. Among tested linkers of different lengths and polarity, a short medium-polar linker favoring location of the dyes at NPs interface ensures good fluorescence quantum yield and small particle size. The fluorescence brightness of these NPs has been dramatically enhanced by increasing the bulkiness of the BODIPY dyes that prevents their H-aggregation, reaching 2500000 M^-1 cm^-1 (extinction coefficient × quantum yield). Fluorescence microscopy revealed that the single-particle brightness of these NPs is ∼5-fold higher than that of QDot-585 using the same excitation wavelength (532 nm). Finally, when microinjected inside cells, these small and stealth NPs (10 nm diameter) distribute more evenly than 20 nm QDots inside the cytosol, showing similar spreading as a fluorescent protein. Thus, the developed monomolecular NPs, owing to their small size and stealth properties, are artificial analogues of fluorescent proteins, surpassing the latter >50-fold in terms of brightness.

Assessment of Amphiphilic Poly-N-vinylpyrrolidone Nanoparticles' Biocompatibility with Endothelial Cells in Vitro and Delivery of an Anti-Inflammatory Drug

Nanoparticles (NPs) produced from amphiphilic derivatives of poly-N-vinylpyrrolidone (Amph-PVP), composed of various molecular weight polymeric hydrophilic fragments linked into hydrophobic n-alkyl chains of varying lengths, were previously shown to exert excellent biocompatibility. Although routes of administration can be different, finally, most nanosystems enter the blood circulation or lymphatic vessels, and by this, they establish direct contact with endothelial cells. In this study, Amph-PVP NPs and fluorescently labeled Amph-PVP-based NPs, namely "PVP" NPs (Amph-PVP-NPs (6000 Da) unloaded) and "F"-NPs (Amph-PVP-NPs (6000 Da) loaded with fluorescent FITC), were synthesized to study Amph-PVP NPs interactions with HMEC-1 endothelial cells. PVP NPs were readily uptaken by HMEC-1 cells in a concentration-dependent manner, as demonstrated by immunofluorescence imaging. Upon uptake, the FITC dye was localized to the perinuclear region and cytoplasm of treated cells. The generation of lipopolysaccharide (LPS)-induced activated endothelium model revealed an increased uptake of PVPNPs, as shown by confocal microscopy. Both unloaded PVP NPs and F-NPs did not affect EC viability in the 0.01 to 0.066 mg/mL range. Furthermore, we focused on the potential immunological activation of HMEC-1 endothelial cells upon PVPNPs treatment by assessing the expression of their E-Selectin, ICAM-1, and VCAM-1 adhesion receptors. None of the adhesion molecules were affected by NP treatments of both activated by LPS and nonactivated HMEC-1 cells, at the utilized concentrations (p = NS). In this study, PVP (6000 Da) NPs were used to encapsulate indomethacin, a widely used anti-inflammatory drug. The synthesized drug carrier complex did not affect HMEC-1 cell growth and expression of E-selectin, ICAM-1, and VCAM-1 adhesion receptors. In summary, PVP-based NPs are safe for use on both basal and activated endothelium, which more accurately mimics pathological conditions. Amph-PVP NPs are a promising drug delivery system.

Tuning the Encapsulation of Simple Fragrances with an Amphiphilic Graft Copolymer

The encapsulation of poorly water-soluble compounds such as perfumes, flavors, and bioactive molecules is a key step in the formulation of a large variety of consumer products in the fields of household care and personal care. We study the encapsulation ability of an amphiphilic poly(ethylene glycol)-graft-poly(vinyl acetate) (PEG-g-PVAc) graft copolymer, extending the focus to the entire phase diagram of polymer/perfume/water systems with three common natural fragrances. The three perfume molecules (2-phenyl ethanol, L-carvone, and α-pinene) possess different water affinities, as expressed by their octanol/water partition coefficients. The investigation of the polymorphism of PEG-g-PVAc in these systems is carried out by means of dynamic light scattering, small-angle X-ray scattering, NMR spectroscopy, and confocal laser scanning microscopy. The results presented here demonstrate that the choice of fragrance can dramatically affect the supramolecular structures formed by the polymer in aqueous solution, with important consequences on formulations of industrial interest such as the demixing of complex perfume blends when one or more of the components have no chemical affinity for any of the polymer blocks.

The Effect of Poly(ethylene glycol) (PEG) Length on the Wettability and Surface Chemistry of PEG-Fluoroalkyl-Modified Polystyrene Diblock Copolymers and Their Two-Layer Films with Elastomer Matrix

Diblock copolymers composed of a polystyrene first block and a PEG-fluoroalkyl chain-modified polystyrene second block were synthesized by controlled atom transfer radical polymerization (ATRP), starting from the same polystyrene macroinitiator. The wettability of the polymer film surfaces was investigated by measurements of static and dynamic contact angles. An increase in advancing water contact angle was evident for all the films after immersion in water for short times (10 and 1000 s), consistent with an unusual contraphilic switch of the PEG-fluoroalkyl side chains. Such a contraphilic response also accounted for the retained wettability of the polymer films upon prolonged contact with water, without an anticipated increase in the hydrophilic character. The copolymers were then used as surface-active modifiers of elastomer poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)-based two-layer films. The elastomeric behavior of the films was varied by using SEBS matrices with different amounts of polystyrene. Whereas the mechanical properties strictly resembled those of the nature of the SEBS matrix, the surface properties were imposed by the additive. The contraphilic switch of the PEG-fluoroalkyl side chains resulted in an exceptionally high enrichment in fluorine of the film surface after immersion in water for seven days.

Preparation and Properties of Stereocomplex of Poly(lactic acid) and Its Amphiphilic Copolymers Containing Glucose Groups

The stereocomplex of poly(lactic acid) containing glucose groups (sc-PLAG) was prepared by solution blending from equal amounts of poly(l-lactic acid) (PLLA) and poly(d-lactic acid-co-glucose) (PDLAG), which were synthesized from l- and d-lactic acid and glucose by melt polycondensation. The methods, including 1H nuclear magnetic resonance spectroscopy (1H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), polarizing microscope (POM), scanning electron microscope (SEM), transmission electron microscope (TEM), and contact angle were used to determine the effects of the stereocomplexation of enantiomeric poly(lactic acid) (PLA) units, the amphiphilicity due to glucose residues and lactic acid units, and the interaction of glucose residues with lactic units on the crystallization performance, hydrophilicity, thermal stability, and morphology of samples. The results showed PDLAG was multi-armed, and partial OH groups of glucose residues in PDLAG might remain unreacted. The molecular weight (Mw), dispersity (Ɖ), and glucose proportion in the chain of PDLAG thereby had significant effects on sc-PLAG. There were the stereocomplexation of enantiomeric lactic units and the amphiphilic self-assembly of PDLAG in sc-PLAG, which resulted in glucose groups mainly in the surface phase and lactic units in the bulk phase. The sc-PLAG only possessed the stereocomplex crystal owing to the interaction between nearly equimolar of l-lactic units of PLLA and d-lactic units of PDLAG, and had no homo-crystallites of l- or d-lactic units, which improved the melting temperature (Tm) of sc-PLAG about 50 °C higher than that of PLLA. Glucose groups in sc-PLAG played an important role by forming heterogeneous nucleation, promoting amphiphilic self-assembly, and affecting the ordered arrangement of lactic units. The glass transition temperature (Tg), the melting temperature (Tm), crystallinity, crystallization rate, and water absorption of sc-PLAG showed similar changes with the increased glucose content in feeding. All these parameters increased at first, and the maximum appeared as glucose content in feeding about 2%, such as the maximum crystallinity of 48.8% and the maximum water absorption ratio being 11.7%. When glucose content in feeding continued increasing, all these performances showed a downward trend due to the decrease of arrangement regularity of lactic acid chains caused by glucose groups. Moreover, the contact angle of sc-PLAG decreased gradually with the increased glucose content in feeding to obtain the minimum 77.5° as the glucose content in feeding being 5%, while that of PLLA was 85.0°. The sc-PLAG possessed a regular microsphere structure, and its microspheres with a diameter of about 200 nm could be observed. In conclusion, sc-PLAG containing proper glucose amount could effectively enhance the crystallinity, hydrophilicity, and thermal stability of PLA material, which is useful for drug delivery, a scaffold for tissue engineering, and other applications of biomedicine.

Amphiphilic Polymer-Mediated Aggregation-Induced Emission Nanoparticles for Highly Sensitive Organophosphorus Pesticide Biosensing

Biosensing applications require signal reporters to be sufficiently stable and biosafe as well as highly efficient. Aggregation-induced emission (AIE) nanoparticles have proven to be capable of cell-imaging and cancer therapy; however, realizing sensitive detection of biomolecules remains a great challenge because of their instability, biotoxicity, and lack of modifiable functional groups. Herein, we report a self-assembling strategy to fabricate AIE nanoparticles (PTDNPs) through the dispersion of amphiphilic polymers (PTDs) in phosphate-buffered saline. The PTDs were prepared through radical copolymerization of N-(1,2,2-triphenylvinyl)-4-acetylaniline and dimethyl diallyl ammonium chloride. We found that the particle size, morphology, functional groups, and fluorescence property of PTDNPs can be fine-tuned. Further, PTDNPs-0.10 were chosen as signal reporters to detect organophosphorus pesticides (OPs) with the aid of gold nanoparticles. Their sensing performance on OPs is superior to that using C-dot/quantum dot/rhodamine B as the signal reporter. This study not only provides new possibilities to fabricate novel AIE nanoparticles with exceptional properties, but also facilitates the AIE nanoparticle's application for target analyte biosensing.

Selenol-Based Nucleophilic Reaction for the Preparation of Reactive Oxygen Species-Responsive Amphiphilic Diblock Copolymers

Selenide-containing amphiphilic copolymers have shown significant potential for application in drug release systems. Herein, we present a methodology for the design of a reactive oxygen species-responsive amphiphilic diblock selenide-labeled copolymer. This copolymer with controlled molecular weight and narrow molecular weight distribution was prepared by sequential organoselenium-mediated reversible addition fragmentation chain transfer (Se-RAFT) polymerization and selenol-based nucleophilic reaction. Nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionization time-to-flight (MALDI-TOF) techniques were used to characterize its structure. Its corresponding nanomicelles successfully formed through self-assembly from the copolymer itself. Such nanomicelles could rapidly disassemble under oxidative conditions due to the fragmentation of the Se-C bond. Therefore, this type of nanomicelle based on selenide-labeled amphiphilic copolymers potentially provides a new platform for drug delivery.

Naturally-Derived Amphiphilic Polystyrenes Prepared by Aqueous Controlled/Living Cationic Polymerization and Copolymerization of Vinylguaiacol with R⁻OH/BF₃·OEt₂

In this study, we investigated direct-controlled/living cationic polymerization and copolymerization of 4-vinylguaiacol (4VG), i.e., 4-hydroxy-3-methoxystyrene, which can be derived from naturally-occurring ferulic acid, to develop novel bio-based amphiphilic polystyrenes with phenol functions. The controlled/living cationic polymerization of 4VG was achieved using the R⁻OH/BF₃·OEt₂ initiating system, which is effective for the controlled/living polymerization of petroleum-derived 4-vinylphenol in the presence of a large amount of water via reversible activation of terminal C⁻OH bond catalyzed by BF₃·OEt₂, to result in the polymers with controlled molecular weights and narrow molecular weight distributions. The random or block copolymerization of 4VG was also examined using p-methoxystyrene (pMOS) as a comonomer with an aqueous initiating system to tune the amphiphilic nature of the 4VG-derived phenolic polymers. The obtained polymer can be expected not only to be used as a novel styrenic bio-based polymer but also as a material with amphiphilic nature for some applications.

Preliminary Studies of Mucoadhesion and Cell Interaction Properties

Most of the methods of poly-lactic-glycolic acid (PLGA) preparation involve the passage through the emulsification of a PLGA organic solution in water followed by solvent evaporation or extraction. The choice of the droplet stabilizer during the emulsion step is critical for the dimensions and the surface characteristics of the nanoparticles (NPs). In the present work, a recently described ionic amphiphilic chitosan derivative, chitosan oleate salt (CS-OA), was proposed for the first time to prepare PLGA NPs. A full factorial design was used to understand the effect of some formulation and preparation parameters on the NP dimensions and on encapsulation efficiency (EE%) of Nile red, used as a tracer. On the basis of the DoE study, curcumin loaded NPs were prepared, having 329 ± 42 nm dimensions and 68.75% EE%. The presence of a chitosan coating at the surface was confirmed by positive zeta potential and resulted in mucoadhesion behavior. The expected improvement of the interaction of the chitosan surface modified nanoparticles with cell membrane surface was confirmed in Caco-2 cell culture by the internalization of the loaded curcumin.

Amphiphilic Polymeric Micelles Based on Deoxycholic Acid and Folic Acid Modified Chitosan for the Delivery of Paclitaxel

The present investigation aimed to develop a tumor-targeting drug delivery system for paclitaxel (PTX). The hydrophobic deoxycholic acid (DA) and active targeting ligand folic acid (FA) were used to modify water-soluble chitosan (CS). As an amphiphilic polymer, the conjugate FA-CS-DA was synthesized and characterized by Proton nuclear magnetic resonance (¹H-NMR) and Fourier-transform infrared spectroscopy (FTIR) analysis. The degree of substitutions of DA and FA were calculated as 15.8% and 8.0%, respectively. In aqueous medium, the conjugate could self-assemble into micelles with the critical micelle concentration of 6.6 × 10⁻³ mg/mL. Under a transmission electron microscope (TEM), the PTX-loaded micelles exhibited a spherical shape. The particle size determined by dynamic light scattering was 126 nm, and the zeta potential was +19.3 mV. The drug loading efficiency and entrapment efficiency were 9.1% and 81.2%, respectively. X-Ray Diffraction (XRD) analysis showed that the PTX was encapsulated in the micelles in a molecular or amorphous state. In vitro and in vivo antitumor evaluations demonstrated the excellent antitumor activity of PTX-loaded micelles. It was suggested that FA-CS-DA was a safe and effective carrier for the intravenous delivery of paclitaxel.

Polymeric Micelles Based on Modified Glycol Chitosan for Paclitaxel Delivery: Preparation, Characterization and Evaluation

Amphiphilic polymer of α-tocopherol succinate modified glycol chitosan (TS-GC) was successfully constructed by conjugating α-tocopherol succinate to the skeleton of glycol chitosan and characterized by Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). In aqueous milieu, the conjugates self-assembled to micelles with the critical aggregation concentration of 7.2 × 10⁻³ mg/mL. Transmission electron microscope (TEM) observation and dynamic light scattering (DLS) measurements were carried out to determine the physicochemical properties of the micelles. The results revealed that paclitaxel (PTX)-loaded TS-GC micelles were spherical in shape. Moreover, the PTX-loaded micelles showed increased particle sizes (35 nm vs. 142 nm) and a little reduced zeta potential (+19 mV vs. +16 mV) compared with blank micelles. The X-ray diffraction (XRD) spectra demonstrated that PTX existed inside the micelles in amorphous or molecular state. In vitro and in vivo tests showed that the PTX-loaded TS-GC micelles had advantages over the Cremophor EL-based formulation in terms of low toxicity level and increased dose, which suggested the potential of the polymer as carriers for PTX to improve their delivery properties.

Sorting of Semiconducting Single-Walled Carbon Nanotubes in Polar Solvents with an Amphiphilic Conjugated Polymer Provides General Guidelines for Enrichment

Conjugated polymer extraction (CPE) has been shown to be a highly effective method to isolate high-purity semiconducting single-walled carbon nanotubes (sc-SWCNTs). In both literature reports and industrial manufacturing, this method has enabled enrichment of sc-SWCNTs with high purity (≥99.9%). High selectivity is typically obtained in nonpolar aromatic solvents, yet polar solvents may provide process improvements in terms of yield, purity and efficiency. Using an amphiphilic fluorene-alt-pyridine conjugated copolymer with hydrophilic side chains, we have investigated the enrichment of sc-SWCNTs in polar solvents. Various conditions such as polymer/SWCNT ratio, solvent polarity, solvent dielectric constant as well as polymer solubility and SWCNT dispersibility were explored in order to optimize the purity and yield of the enriched product. Herein, we provide insights on CPE by demonstrating that a conjugated polymer having a hydrophobic backbone and hydrophilic oligo(ethylene oxide) side chains provides near full recovery (95%) of sc-SWCNTs using a multiextraction protocol. High purity is also obtained, and differences in chiral selectivity compared to analogous hydrophobic systems were confirmed by optical absorption and Raman spectroscopy as well as photoluminescence excitation mapping. Taking into consideration the solvent dielectric constant, polarity index as well as polymer solubility and SWCNT dispersibility provides a better understanding of structure-property effects on sc-SWCNT enrichment. The resulting hydrophilic SWCNT dispersions demonstrate long-term colloidal stability, making them suitable for ink formulation and high-performance thin-film transistors fabrication.

Nanoparticles Embedded in Amphiphilic Membranes for Carbon Dioxide Separation and Dehumidification

Polymers containing ethylene oxide (EO) groups have gained significant interest as the EO groups have favorable interactions with polar molecules such as H₂ O, quadrupolar molecules such as CO₂ , and metal ions. However, the main challenges of poly(ethylene oxide) (PEO) membranes are their weak mechanical properties and high crystallinity nature. The amphiphilic copolymer made from PEO terephthalate and poly(butylene terephthalate) (PEOT/PBT) comprises both hydrophilic and hydrophobic segments. The hydrophilic PEOT segment is thermosensitive, which facilities gas transports whereas the hydrophobic PBT segment is rigid, which provides mechanical robustness. This work demonstrates a new strategy to design amphiphilic mixed matrix membranes (MMMs) by incorporating zeolitic imidazolate framework, ZIF-71, into the PEOT/PBT copolymer. The resultant membrane shows an enhanced CO₂ permeability with an ideal CO₂ /N₂ selectivity surpassing the original PEOT/PBT and Robeson's Upper bound line. The nanoparticles-embedded amphiphilic membranes exhibit characteristics of high transparency and mechanical robustness. Mechanically strong composite hollow fiber membranes consisting of PEOT/PBT/ZIF-71 as the selective layer were also prepared. The resultant hollow fibers possess an excellent CO₂ permeance of 131 GPU (gas permeation units), CO₂ /N₂ selectivity of 52.6, H₂ O permeance of 9300 GPU and H₂ O/N₂ selectivity of 3700, showing great potential for industrial CO₂ capture and dehumidification.

Parallel comparative studies on toxicity of quantum dots synthesized and surface engineered with different methods in vitro and in vivo

Quantum dots (QDs) have been considered to be promising probes for biosensing, bioimaging, and diagnosis. However, their toxicity issues caused by heavy metals in QDs remain to be addressed, in particular for their in vivo biomedical applications. In this study, a parallel comparative investigation in vitro and in vivo is presented to disclose the impact of synthetic methods and their following surface modifications on the toxicity of QDs. Cellular assays after exposure to QDs were conducted including cell viability assessment, DNA breakage study in a single cellular level, intracellular reactive oxygen species (ROS) receptor measurement, and transmission electron microscopy to evaluate their toxicity in vitro. Mice experiments after QD administration, including analysis of hemobiological indices, pharmacokinetics, histological examination, and body weight, were further carried out to evaluate their systematic toxicity in vivo. Results show that QDs fabricated by the thermal decomposition approach in organic phase and encapsulated by an amphiphilic polymer (denoted as QDs-1) present the least toxicity in acute damage, compared with those of QDs surface engineered by glutathione-mediated ligand exchange (denoted as QDs-2), and the ones prepared by coprecipitation approach in aqueous phase with mercaptopropionic acid capped (denoted as QDs-3). With the extension of the investigation time of mice respectively injected with QDs, we found that the damage caused by QDs to the organs can be gradually recovered. This parallel comparative investigation suggests that synthetic methods and their resulting surface microenvironment play vital roles in the acute toxicity profiles of QDs. The present study provides updated insights into the fabrication and surface engineering of QDs for their translational applications in theranostics.

Rational Design of Branched Nanoporous Gold Nanoshells with Enhanced Physico-Optical Properties for Optical Imaging and Cancer Therapy

Reported procedures on the synthesis of gold nanoshells with smooth surfaces have merely demonstrated efficient control of shell thickness and particle size, yet no branch and nanoporous features on the nanoshell have been implemented to date. Herein, we demonstrate the ability to control the roughness and nanoscale porosity of gold nanoshells by using redox-active polymer poly(vinylphenol)-b-(styrene) nanoparticles as reducing agent and template. The porosity and size of the branches on this branched nanoporous gold nanoshell (BAuNSP) material can be facilely adjusted by control of the reaction speed or the reaction time between the redox-active polymer nanoparticles and gold ions (Au³⁺). Due to the strong reduction ability of the redox-active polymer, the yield of BAuNSP was virtually 100%. By taking advantage of the sharp branches and nanoporous features, BAuNSP exhibited greatly enhanced physico-optical properties, including photothermal effect, surface-enhanced Raman scattering (SERS), and photoacoustic (PA) signals. The photothermal conversion efficiency can reach as high as 75.5%, which is greater than most gold nanocrystals. Furthermore, the nanoporous nature of the shells allows for effective drug loading and controlled drug release. The thermoresponsive polymer coated on the BAuNSP surface serves as a gate keeper, governing the drug release behavior through photothermal heating. Positron emission tomography imaging demonstrated a high passive tumor accumulation of ⁶⁴Cu-labeled BAuNSP. The strong SERS signal generated by the SERS-active BAuNSP in vivo, accompanied by enhanced PA signals in the tumor region, provide significant tumor information, including size, morphology, position, and boundaries between tumor and healthy tissues. In vivo tumor therapy experiments demonstrated a highly synergistic chemo-photothermal therapy effect of drug-loaded BAuNSPs, guided by three modes of optical imaging.

Supramolecularly Engineered Amphiphilic Macromolecules: Molecular Interaction Overrules Packing Parameters

We report molecular interaction-driven self-assembly of supramolecularly engineered amphiphilic macromolecules (SEAM) containing a single supramolecular structure-directing unit (SSDU) consisting of an H-bonding group connected to a naphthalene diimide chromophore. Two such SEAMs, P1-50 and P2-50, having the identical chemical structure and hydrophobic/hydrophilic balance, exhibit distinct self-assembled structures (polymersome and cylindrical micelle, respectively) due to a difference in the H-bonding group (hydrazide or amide, respectively) of the single SSDU. When mixed together, P1-50 and P2-50 adopted self-sorted assembly. For either series of polymers, variation in the hydrophobic/hydrophilic balance does not alter the morphology reconfirming that self-assembly is primarily driven by directional molecular interaction which is capable of overruling the existing norms in packing parameter-dependent morphology control in an immiscibility-driven block copolymer assembly.

Study on physisorption between G-actin and amphiphilic polymer-coated gold nanoparticles

Physisorptions occurs everywhere and constantly in living organisms and between nanomaterials and biomolecules. In this study, one of the most important proteins, G-actin, was selected to investigate its bio-nano physisorption with a model nanoparticle coated with a amphiphilic polymer. Using a photoluminescence quenching method, both the binding constant and the Hill constant were determined as 1.79 × 10⁷  M^-1 and 0.84, respectively. Thermodynamic calculations proved that such a physisorption was a spontaneous procedure. The physisorption-mediated protein-nanoparticle conjugates were robust enough to resist gel electrophoresis, and protein conformation was kept intact, as revealed using circular dichroism. This conjugate might be a promising candidate for nanofabrication or could play a significant role in actin-related bioactivities.

Synthesis of Amphiphilic Poly(β-amino ester) for Efficiently Minicircle DNA Delivery in Vivo

Minicircle DNA (mcDNA) is a kind of enhanced nonviral DNA vector with excellent profiles in biosafety and transgene expression. Herein, we reported a novel amphiphilic polymer comprising polyethylenimine(PEI) modified Poly(β-amino ester) PEI-PBAE(C16) for efficient mcDNA delivery in vivo. The synthesized polymer could condense mcDNA into nanoscaled structure and exhibited efficient gene transfection ability without detectable cytotoxicity. Importantly, when injected into mouse intraperitoneally, these PEI-PBAE(C16) nanocomplexes were able to result in high level of trangene expression which lasted at least 72 h. Overall, these results demonstrated the PEI-PBAE(C16) can mediate effective and safe gene delivery in vivo with clinical application potential.

Relationship between Surface Properties and In Vitro Drug Release from a Compressed Matrix Containing an Amphiphilic Polymer Material

The performance of compressed tablet drug delivery systems made using polymeric materials depend on multiple factors, such as surface properties like contact angle, surface free energy and water absorption rate, besides the release mechanisms driven by the kind of polymer used. Hence, it should be possible to establish a relationship between the surface properties and the drug release kinetics. Compressed tablets with different proportions of poly(maleic acid-alt-octadecene) potassium salt (0%, 10%, 20%, 30% and 40%) were prepared. Blends of a model drug (ampicillin trihydrate) and the polymer material were analyzed by DSC. The surface properties of the tablets were determined by the sessile drop method, while the surface energy was determined using the semi-empirical Young-Dupre, Neumann and OWRK models. The release profiles were determined simulating in vitro conditions (buffer solutions pH 1.2 and pH 7.4 with ionic strength of 1.5 M at 37 °C (310.15 K)). A kinetic analysis of the dissolution profiles using different models (zero order, first order, Higuchi and Korsmeyer-Peppas) was realized. The results showed a significant effect of the proportion of polymer in both the surface properties of the tablets and the dissolution release, indicating a relationship between the kinetic and thermodynamic properties.

[Interfacial Property of Amphiphilic Copolymer Blending PVDF UF Membrane and Protein Anti-fouling]

The phase transformation kinetic process of amphiphilic copolymer polyoxyethylene/polyoxypropylene/polyoxyethylene[PEO-PPO-PEO(F127)] blending polyvinylidene fluoride (PVDF) casting solution in an aqueous gel bath was investigated. The influences of F127 content on the PEO enrichment rate of PVDF membrane surface, membrane morphology and structural parameters were investigated by a total reflection fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), atomic force microscopy (AFM) and other analytical techniques. F127/PVDF blending membrane fouling behavior of bovine serum albumin (BSA) was evaluated by the static adsorption capacity, normalized filtration decay rate and membrane fouling resistance model. The results showed that the membrane delayed phase separation process increased, the membrane surface, internal pore size and porosity increased and the surface roughness increased with increasing F127 addition, and the increment of PEO enrichment rate on the membrane surface became stable when the F127 content reached 15%. F127 blending membranes with F127 contents ranging from 15% to 25% had a higher flux and BSA rejection, lower static adsorption capacity, slower flux decay rate, lower irreversible fouling index and smaller pore blocking resistance and cake layer resistance distribution coefficient, which showed a good anti-fouling property.

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules

The topic of stimuli-responsive nanocarriers for loading guest molecules is dynamic. It has been widely studied in applications including drug controlled release, smart sensing, catalysis, and modeling. In this paper, a graft copolymer (hyperbranched polystyrene)-g-poly[2-(dimethylamino)ethyl methacrylate] (HBPS-g-PDMAEMA) was synthesized and characterized by (1)H NMR and GPC. It was observed that the star-like HBPS-g-PDMAEMA formed aggregates in aqueous solution. The influence of polymer concentration, ionic strength and pH value on the aggregates in aqueous solution was investigated by using UV-vis spectroscopy and DLS analysis. The results showed that size of aggregates was affected by a corresponding stimulus. In addition, the loading ability of HBPS-g-PDMAEMA aggregates was investigated by using pyrene or Nile red as the model guest molecules by using UV-vis and fluorescence spectroscopy. The results showed that HBPS-g-PDMAEMA aggregates were capable to encapsulate small hydrophobic molecules. These newly prepared HBPS-g-PDMAEMA nanocarriers might be used in, e.g., medicine or catalysis.

Understanding the Robust Physisorption between Bovine Serum Albumin and Amphiphilic Polymer Coated Nanoparticles

The robust physisorption between nanoparticles (NPs) and proteins has attracted increasing attention due to the significance for both conjugation techniques and protein's corona formation at the bionano interface. In the present study, we first explored the possible binding sites of the bovine serum albumin (BSA) on amphiphilic polymer coated gold nanoparticles (AP-AuNPs). By using mass spectrometry, a 105-amino-acid peptide (12.2 kDa) is discovered as the possible "epitope" responsible for the robust physisorption between BSA and AP-AuNPs. Second, with the help of nanometal surface energy transfer (NSET) theory, we further found that the epitope peptide could insert at least 2.9 nm into the organic molecular layers of AP-AuNPs when the robust conjugates formed, which indicates how such a long epitope peptide can be accommodated by AP-AuNPs and resist protease's digestion. These findings might shed light on a new strategy for studying interactions between proteins and NPs, and further guide the rational design of NPs for safe and effective biomedical applications.

Physical characterization and in vivo pharmacokinetic study of self-assembling amphotericin B-loaded lecithin-based mixed polymeric micelles

To alleviate the inherent problems of amphotericin B (AmB), such as poor water solubility and nephrotoxicity, a novel self-assembling mixed polymeric micelle delivery system based on lecithin and combined with amphiphilic polymers, Pluronic^®, Kolliphor^®, d-alpha tocopheryl polyethylene glycol succinate, and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy(poly(ethylene glycol)-2000 (DSPE-PEG2K) was developed. An optimal formulation (Ambicelles) composed of AmB:lecithin:DSPE-PEG2K in a 1:1:10 weight ratio was obtained. The particle size, polydispersion index, drug encapsulation efficiency, and drug loading were 187.20±10.55 nm, 0.51±0.017, 90.14%, and 7.51%, respectively, and the solubility was increased from 0.001 to 5 mg/mL. Compared with that of Fungizone^®, the bioavailability of Ambicelles administered intravenously and orally increased 2.18- and 1.50-fold, respectively. Regarding the in vitro cytotoxicity, Ambicelles had a higher cell viability than free AmB solution or Fungizone^® did. With pretreatment of 50 μg/mL ethanolic extract of Taiwanofungus camphoratus followed by AmB to HT29 colon cancer cells, the 50% inhibitory concentration of AmB solution was 12 μg/mL, whereas that of Ambicelles was 1 μg/mL, indicating that Ambicelles exerted a greater synergistic anticancer effect.

Novel Redox-Responsive Amphiphilic Copolymer Micelles for Drug Delivery: Synthesis and Characterization

A novel redox-responsive amphiphilic polymer was synthesized with bioreductive trimethyl-locked quinone propionic acid for a potential triggered drug delivery application. The aim of this study was to synthesize and characterize the redox-responsive amphiphilic block copolymer micelles containing pendant bioreductive quinone propionic acid (QPA) switches. The redox-responsive hydrophobic block (polyQPA), synthesized from QPA-serinol and adipoyl chloride, was end-capped with methoxy poly(ethylene glycol) of molecular weight 750 (mPEG750) to achieve a redox-responsive amphiphilic block copolymer, polyQPA-mPEG750. PolyQPA-mPEG750 was able to self-assemble as micelles to show a critical micelle concentration (CMC) of 0.039% w/v (0.39 mg/ml, 0.107 mM) determined by a dye solubilization method using 1,6-diphenyl-1,3,5-hexatriene (DPH) in phosphate-buffered saline (PBS). The mean diameter of polymeric micelles was found to be 27.50 nm (PI = 0.064) by dynamic light scattering. Furthermore, redox-triggered destabilization of the polymeric micelles was confirmed by (1)H-NMR spectroscopy and particle size measurements in a simulated redox state. PolyQPA-mPEG750 underwent triggered reduction to shed pendant redox-responsive QPA groups and its polymeric micelles were swollen to be dissembled in the presence of a reducing agent, thereby enabling the release of loaded model drug, paclitaxel. The redox-responsive polyQPA-mPEG750 polymer micelles would be useful as a drug delivery system allowing triggered drug release in an altered redox state such as tumor microenvironments with an altered redox potential and/or redox enzyme upregulation.

Photopolymerized Network Polysiloxane Films with Dangling Hydrophilic/Hydrophobic Chains for the Biofouling Release of Invasive Marine Serpulid Ficopomatus enigmaticus

Novel photopolymerized network films based on a polysiloxane matrix containing varied amounts of polyoxyethylene (P3) or perfluorohexylethyl (F) dangling side chains were investigated. For films containing less than 10 wt % P3 and F, the wettability and elastic modulus were similar to those of the photopolymerized network matrix. However, angle-resolved X-ray photoelectron spectroscopy measurements proved that the surface of films with F dangling chains was highly enriched in fluorine depending on both the amount of P3 and F and their relative ratio in the films. The biological performance of the films was evaluated against a new widespread and invasive marine biofoulant, the serpulid Ficopomatus enigmaticus. The diatom Navicula salinicola was also assayed as a conventional model organism for comparison. Films richer in P3 better resisted the settlement and promoted the release of calcified tubeworms of F. enigmaticus.

Templated repair of long bone defects in rats with bioactive spiral-wrapped electrospun amphiphilic polymer/hydroxyapatite scaffolds

Effective repair of critical-size long bone defects presents a significant clinical challenge. Electrospun scaffolds can be exploited to deliver protein therapeutics and progenitor cells, but their standalone application for long bone repair has not been explored. We have previously shown that electrospun composites of amphiphilic poly(d,l-lactic acid)-co-poly(ethylene glycol)-co-poly(d,l-lactic acid) (PELA) and hydroxyapatite (HA) guide the osteogenic differentiation of bone marrow stromal cells (MSCs), making these scaffolds uniquely suited for evaluating cell-based bone regeneration approaches. Here we examine whether the in vitro bioactivity of these electrospun scaffolds can be exploited for long bone defect repair, either through the participation of exogenous MSCs or through the activation of endogenous cells by a low dose of recombinant human bone morphogenetic protein-2 (rhBMP-2). In critical-size rat femoral segmental defects, spiral-wrapped electrospun HA-PELA with preseeded MSCs resulted in laminated endochondral ossification templated by the scaffold across the longitudinal span of the defect. Using GFP labeling, we confirmed that the exogenous MSCs adhered to HA-PELA survived at least 7 days postimplantation, suggesting direct participation of these exogenous cells in templated bone formation. When loaded with 500 ng of rhBMP-2, HA-PELA spirals led to more robust but less clearly templated bone formation than MSC-bearing scaffolds. Both treatment groups resulted in new bone bridging over the majority of the defect by 12 weeks. This study is the first demonstration of a standalone bioactive electrospun scaffold for templated bone formation in critical-size long bone defects.

Air-liquid interfacial self-assembly of conjugated block copolymers into ordered nanowire arrays

The ability to control the molecular packing and nanoscale morphology of conjugated polymers is important for many of their applications. Here, we report the fabrication of well-ordered nanoarrays of conjugated polymers, based on the self-assembly of conjugated block copolymers at the air-liquid interface. We demonstrate that the self-assembly of poly(3-hexylthiophene)-block-poly(ethylene glycol) (P3HT-b-PEG) at the air-water interface leads to large-area free-standing films of well-aligned P3HT nanowires. Block copolymers with high P3HT contents (82-91%) formed well-ordered nanoarrays at the interface. The fluidic nature of the interface, block copolymer architecture, and rigid nature of P3HT were necessary for the formation of well-ordered nanostructures. The free-standing films formed at the interface can be readily transferred to arbitrary solid substrates. The P3HT-b-PEG films are integrated in field-effect transistors and show orders of magnitude higher charge carrier mobility than spin-cast films, demonstrating that the air-liquid interfacial self-assembly is an effective thin film fabrication tool for conjugated block copolymers.

Preparation and characterization of self-assembled nanoparticles based on low-molecular-weight heparin and stearylamine conjugates for controlled delivery of docetaxel

Low-molecular-weight heparin (LMWH)–stearylamine (SA) conjugates (LHSA)-based self-assembled nanoparticles were prepared for intravenous delivery of docetaxel (DCT). 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide were used as coupling agents for synthesis of LHSA conjugates. The physicochemical properties, in vitro antitumor efficacy, in vitro cellular uptake efficiency, in vivo antitumor efficacy, and in vivo pharmacokinetics of LHSA nanoparticles were investigated. The LHSA nanoparticles exhibited a spherical shape with a mean diameter of 140–180 nm and a negative surface charge. According to in vitro release and in vivo pharmacokinetic test results, the docetaxel-loaded LHSA5 (LMWH:SA =1:5) nanoparticles exhibited sustained drug release profiles. The blank LHSA nanoparticles demonstrated only an insignificant cytotoxicity in MCF-7 and MDAMB 231 human breast cancer cells; additionally, higher cellular uptake of coumarin 6 (C6) in MCF-7 and MDAMB 231 cells was observed in the LHSA5 nanoparticles group than that in the C6 solution group. The in vivo tumor growth inhibition efficacy of docetaxel-loaded LHSA5 nanoparticles was also significantly higher than the Taxotere^®-treated group in the MDAMB 231 tumor-xenografted mouse model. These results indicated that the LHSA5-based nanoparticles could be a promising anticancer drug delivery system.

Amphiphilic polymer-mediated formation of laponite-based nanohybrids with robust stability and pH sensitivity for anticancer drug delivery

The development of pH-sensitive drug delivery nanosystems that present a low drug release at the physiological pH and are able to increase the extent of the release at a lower pH value (like those existent in the interstitial space of solid tumors (pH 6.5) and in the intracellular endolysosomal compartments (pH 5.0)) is very important for an efficient and safe cancer therapy. Laponite (LP) is a synthetic silicate nanoparticle with a nanodisk structure (25 nm in diameter and 0.92 nm in thickness) and negative-charged surface, which can be used for the encapsulation of doxorubicin (DOX, a cationic drug) through electrostatic interactions and exhibit good pH sensitivity in drug delivery. However, the colloidal instability of LP still limits its potential clinical applications. In this study, we demonstrate an elegant strategy to develop stable Laponite-based nanohybrids through the functionalization of its surface with an amphiphile PEG-PLA copolymer by a self-assembly process. The hydrophobic block of PEG-PLA acts as an anchor that binds to the surface of drug-loaded LP nanodisks, maintaining the core structure, whereas the hydrophilic PEG part serves as a protective stealth shell that improves the whole stability of the nanohybrids under physiological conditions. The resulting nanocarriers can effectively load the DOX drug (the encapsulation efficiency is 85%), and display a pH-enhanced drug release behavior in a sustained way. In vitro biological evaluation indicated that the DOX-loaded nanocarriers can be effectively internalized by CAL-72 cells (an osteosarcoma cell line), and exhibit a remarkable higher anticancer cytotoxicity than free DOX. The merits of Laponite/PEG-PLA nanohybrids, such as good cytocompatibility, excellent physiological stability, sustained pH-responsive release properties, and improved anticancer activity, make them a promising platform for the delivery of other therapeutic agents beyond DOX.

Amphiphilic polymer promoted assembly of macroporous graphene/SnO2 frameworks with tunable porosity for high-performance lithium storage

3D macroporous graphene/SnO2 frameworks (MGTFs) are fabricated by amphiphilic polymer-promoted assembly method, which exhibit controllable macroporous structure and outstanding lithium storage performance.