Glycol Units Research Articles

Exactly defined molecular weight poly(ethylene glycol) allows for facile identification of PEGylation sites on proteins.

PEGylation (the covalent attachment of one or more poly(ethylene glycol) (PEG) units to a therapeutic) is a well-established technique in the pharmaceutical industry to increase blood-residence time and decrease immunogenicity. A challenging aspect of PEGylation is the dispersity of PEGylation agents, which results in batch-to-batch variations and analytical limitations. Herein, we present an approach to overcome these limitations by manufacturing a defined molecular weight (dispersity-free) PEGylation agent. We synthesise a defined molecular weight (Mw), linear 5 kDa methoxy-PEG (mPEG) active ester in an efficient and scalable manner using an iterative liquid-phase approach based on Nanostar Sieving. We then perform a comparative study on the random PEGylation and subsequent characterisation of the protein bovine serum albumin (BSA), using both the defined Mw, dispersity-free mPEG active ester, and a commercially available disperse 5 kDa mPEG active ester. We demonstrate that the defined Mw PEG both allows for facile monitoring of chemical modification reactions during the synthesis of the PEGylation agents, and facilitates straightforward identification of the PEGylated fragments within a PEGylated protein via a simple peptide mapping approach using UPLC-MS.

Evaluation of the electrochemical response of aromatic peptides for biodetection of dopamine

Biologically inspired aromatic peptide-based materials are gaining increasing interest as novel charge transport materials for bioelectronics due to their remarkable electrical response and inherent biocompatibility. In this work, the electrochemical response of ten aromatic amino acids and eleven aromatic peptides has been evaluated to assess the potential of incorporating peptides into electrochemical sensors not as biorecognition elements but as biocompatible electronic materials. While the electrochemical response of amino acids is null in all cases, the hexapeptide of phenylalanine (Phe) capped with eight polyethylene glycol units at the N-terminus and, especially, the cyclic dipeptide formed by two dehydro-phenylalanine residues (cyclo(ΔPhe2)), which organize in fibrillary self-assembled structures of nano- and submicrometric size, respectively, are the most electroactive peptides. Electrodes to electrochemically detect the oxidation of dopamine have been prepared using a plasma-activated polyethylene terephthalate glycol substrate covered with a poly(3,4-ethylenedioxythiophene) layer and a peptide coating deposited at the surface. The highest analytical sensitivity and the lowest limits of detection and quantifications have been obtained for the electrode coated with cyclo(ΔPhe2), which shows much better results than that without peptide. These results, on the one hand, confirm the significant role of electron transport through π-stacking interactions in the electrochemical response of peptides and, on the other hand, demonstrate that peptides can be directly used as electronic materials rather than as simple recognition elements in electrochemical biosensors.

Ion‐Pairing Chromonic Liquid Crystals via Alternately Stacked Assembly of Amphiphilic Charged π‐Electronic Systems

In this study, a new assembly strategy for lyotropic chromonic liquid crystals (LCLCs) is proposed using iπ–iπ interactions, mainly comprising electrostatic and dispersion forces, between charged π‐electronic systems to form stacking structures supported by the hydration of triethylene glycol (TEG) units. Meso‐TEG‐aryl‐substituted porphyrin AuIII complex, an amphiphilic π‐electronic cation, showed diverse states and assembly modes in ion pairs depending on the coexisting counteranions. The PCCp– ion pair formed a hexagonal columnar (Colh) LC phase based on a charge‐by‐charge assembly, suggesting the formation of an ordered arrangement of charged p‐electronic systems through iπ–iπ interactions, with reduced interactions between the TEG chains. Furthermore, in the presence of water, LCLC behaviors in the Colh and nematic columnar phases according to the amount of water were observed for the PCCp– ion pair via iπ–iπ interactions. Magnetic‐field‐induced orientation of the charge‐by‐charge columnar structures upon dehydration was observed. Furthermore, single‐stranded charge‐by‐charge columnar structures, as components of the LCLCs, were observed using transmission electron microscopy (TEM).

Structure-activity relationships study of N-ethylene glycol-comprising alkyl heterocyclic carboxamides against A549 lung cancer cells.

Aim: Certain cancer cells depend on oxidative phosphorylation for survival; thus, inhibiting this process may be a promising treatment strategy. This study explored the structure-activity relationships of the mitochondrial inhibitor N-ethylene glycol-comprising alkyl thiophene-3-carboxamide 3.Methods & results: We synthesized and evaluated 13 analogs (5a-m) with different ethylene glycol units, heterocyclesand connecting groups for their growth-inhibitory effects on A549 non-small cell lung cancer cells. We found that increasing the number of ethylene glycol units significantly enhanced inhibitory activity. Some analogs activated adenosine monophosphate-activated protein kinase, similar to 3. Notably, analog 5e, which contains tetraethylene glycol units, significantly inhibited tumor growth in vivo.Conclusion: Analog 5 may be a potential therapeutic agent for non-small cell lung cancer treatment.

Poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) copolyesters with good degradation and barrier properties

In this work, poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) (PBTFGA) copolyesters were synthesized from 2,5-thiophenedicarboxylic acid, 1,4-butanediol and glycolic acid. The influence of the glycolic acid content on thermal properties, mechanical properties and degradation capacity of copolyesters was systematically investigated. The glass transition temperature of copolyesters closely matched that of poly(butylene 2,5-thiophenedicarboxylate) (PBTF). While also demonstrating good thermal stability. When the glycolic acid content was low, the copolyesters exhibited some crystallization capability, but they gradually became fully amorphous as the glycolic acid content increased. The tensile tests revealed that the young's modulus of the PBTFGA copolyesters ranged from 69.2 MPa to 221.4 MPa. With elongation at break exceeding 659%, outperforming most biodegradable packaging materials. Copolyesters exhibited excellent gas barrier properties to both oxygen (PO2 = 0.024 barrer) and carbon dioxide (PCO2 = 0.029 barrer), both of which are superior to poly(butylene 2,5-thiophenedicarboxylate). The incorporation of glycolic acid significantly reduced the crystalline content of the copolyesters, facilitating the interaction of water molecules with ester bonds in the polymer backbone. The weight of poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) was decreased significantly during enzymatic hydrolysis, indicating excellent degradation performance

Confocal microscopic oxygen imaging of xenograft tumors using Ir(III) complexes as in vivo intravascular and intracellular probes

Hypoxia is an important feature of the tumor microenvironment (TME) of most solid tumors, and it is closely linked to cancer cell proliferation, therapy resistance, and the tumor immune response. Herein, we describe a method for hypoxia-induced heterogeneous oxygen distribution in xenograft tumors based on phosphorescence imaging microscopy (PLIM) using intravascular and intracellular oxygen probes. We synthesized Ir(III) complexes with polyethylene glycol (PEG) units of different molecular weights into the ligand as intravascular oxygen probes, BTP-PEGm (m = 2000, 5000, 10000, 20000). BTP-PEGm showed red emission with relatively high emission quantum yield and high oxygen sensitivity in saline. Cellular and in vivo experiments using these complexes revealed that BTP-PEG10000 was the most suitable probe in terms of blood retention and ease of intravenous administration in mice. PLIM measurements of xenograft tumors in mice treated with BTP-PEG10000 allowed simultaneous imaging of the tumor microvasculature and quantification of oxygen partial pressures. From lifetime images using the red-emitting intracellular oxygen probe BTPDM1 and the green-emitting intravascular fluorescent probe FITC-dextran, we demonstrated hypoxic heterogeneity in the TME with a sparse vascular network and showed that the oxygen levels of tumor cells gradually decreased with vascular distance.

Influence of Solvophobicity of Biphenol-Derived Small Surface Ligands on the Formation of Size-Controllable Gold Nanoparticle Vesicles.

The self-assembly of gold nanoparticles (GNPs) into gold nanoparticle vesicles (GNVs) has been a topic of significant interest in recent years. However, the formation mechanism of GNVs is still not fully understood. In this article, we report that the new oligo(ethylene glycol)-terminated biphenol ligands (OBLs) show different solubility in tetrahydrofuran (THF) depending upon the number of terminal ethylene glycol units, resulting in a differential solvophobicity. The fluorine-free OBLs have the ability to self-assemble with GNPs into GNVs driven by the solvophobic feature of the ligands. The size of GNVs can be precisely controlled by tuning the interparticle attraction through changes in the unit number of terminal ethylene glycol or the water content in THF. Time-dependent studies revealed that the vesicle formation process consists of two stages: the rapid generation of vesicles, followed by their fusion to form thermodynamically stable GNVs with a saturated size. These two rapid processes are primarily influenced by the pronounced solvophobic attraction exerted by the surface ligands.

Shaping the structure and properties of HyTemp using polyethylene glycol diglycidyl ether cross‐linkers

AbstractNovel elastomers are made by reaction of hydroxyl‐terminated polyacrylic ester (HyTemp) with polyethylene glycol (PEG, number of ethylene glycol units 1, 3, 6, 9) based cross‐linkers. The influence of the cross‐linker length, the HyTemp/cross‐linker (w/w) ratio and the cross‐linking accelerator trifluoromethanesulfonate scandium salt (ScTFMS) on the structure and the properties of the materials are studied. The cross‐linker length has not influence on the glass transition (Tg) of the products because of the presence of the flexible PEG units that cancels out the cross‐linking effect associated to a shift to higher Tg. A two‐domain structure is seen by the presence of a dual Tg in samples cured with ScTFMS. Mathematical analysis of the modulated differential scanning calorimetry curves offers for the first time the possibility to identify/confirm structural differences in complex three‐dimensional polymeric structures. Scanning electron microscopy and swelling experiments in ethyl acetate respectively reveal an increase in the pore size (1.13 to 5.48 nm) and in the absorption ability of the elastomers cured with different types and quantities of PEG cross‐linker. The new elastomeric materials are exhibiting a rubbery state over a wide temperature range and absorptivity for the potential recovery of pollutants in soil and/or water.

Controlled Amphiphilicity and Thermo-Responsiveness of Functional Copolymers Based on Oligo(Ethylene Glycol) Methyl Ether Methacrylates.

In this work, comb homopolymers as well as comb-type copolymers of thermo-responsive oligo(ethylene glycol methyl ether methacrylate)s, OEGMAs, with various chain lengths (DEGMA, PEGMA500, and PEGMA950 containing 2, 9, or 19 repeating ethylene glycol units, respectively) were synthesized through free radical (co)polymerization. For the copolymers, either the functional hydrophobic glycidyl methacrylate (GMA) or the inert hydrophilic N,N-dimethylacrylamide (DMAM) were selected as comonomers. The self-assembly and thermo-responsive behavior of the products was investigated through Nile Red fluorescence probing, turbidimetry, and dynamic light scattering (DLS). Interestingly, it was found that all OEGMA-based homopolymers exhibit a tendency to self-organize in aqueous media, in addition to thermo-responsiveness. The critical aggregation concentration (CAC) increases with the number of repeating ethylene oxide units in the OEGMA macromonomers (CAC was found to be 0.003, 0.01, and 0.03% w/v for the homopolymers PDEGMA, PPEGMA500, and PPEGMA950, respectively). Moreover, the CAC of the copolymers in aqueous media is highly affected by the incorporation of hydrophobic GMA or hydrophilic DMAM units, leading to lower or higher values, respectively. Thus, the CAC decreases down to 0.003% w/v for the GMA-richest copolymer of PEGMA950, whereas CAC increases up to 0.01% w/v for the DMAM-richest copolymer of DEGMA. Turbidimetry and DLS studies proved that the thermo-sensitivity of the polymers is governed by several parameters such as the number of repeating ethylene glycol groups in the side chains of the OEGMAs, the molar percentage of the hydrophobic or hydrophilic comonomers, along with the addition of salts in the aqueous polymer solutions. Thus, the cloud point of the homopolymer PDEGMA was found at 23 °C and it increases to 33.5 °C for the DMAM-richest copolymer of DEGMA. Lastly, the formation of a hydrogel upon heating aqueous mixtures of the GMA-comprising copolymers with silica nanoparticles overnight is strong evidence of the functional character of these polymers.

Stimuli-responsive azo-functionalized non-ionic amphiphiles for controlled drug delivery applications

A series of stimuli-responsive non-ionic amphiphiles have been synthesized consisting of n-alkyl/fluoroalkyl chain to impart lipophilicity, and lactose/polyethylene glycol units which confers hydrophilicity. To execute the release of encapsulated guest in a controlled manner, the azo and ester functionalities were incorporated in the synthesized amphiphiles. The ability of the azo unit to undergo trans–cis-trans spatiotemporal isomerization under UV irradiation with subsequent release of the encapsulated guest has been studied in the aqueous solution of amphiphiles at 365 and 254 nm. Furthermore, an immobilized enzyme Candida antarctica lipase (Novozym 435), a hydrolase, was observed to facilitate the cleavage of the ester moiety of the synthesized amphiphiles resulting in the gradual collapse of the nano-aggregates and subsequent release of encapsulated guest. The aggregation and guest encapsulation behaviour of synthesized azo-functionalized amphiphiles were studied by dynamic light scattering (DLS), critical micelle concentration (CMC), and transmission electron microscopy, fluorescence and UV–Vis spectroscopy. Entrapment of hydrophobic drug/dye i.e. curcumin/Nile red in the lipophilic core, their cellular uptake, and consequently the stimuli responsive release of payload demonstrated the potential of these nanostructures in controlled drug delivery applications.

Phase Morphology Dependence of Ionic Conductivity and Oxidative Stability in Fluorinated Ether Solid-State Electrolytes.

Solid-state polymer electrolytes can enable the safe operation of high energy density lithium metal batteries; unfortunately, they have low ionic conductivity and poor redox stability at electrode interfaces. Fluorinated ether polymer electrolytes are a promising approach because the ether units can solvate and conduct ions, while the fluorinated moieties can increase oxidative stability. However, current perfluoropolyether (PFPE) electrolytes exhibit deficient lithium-ion coordination and ion transport. Here, we incorporate cross-linked poly(ethylene glycol) (PEG) units within the PFPE matrix and increase the polymer blend electrolyte conductivity by 6 orders of magnitude as compared to pure PFPE at 60 °C from 1.55 × 10-11 to 2.26 × 10-5 S/cm. Blending varying ratios of PEG and PFPE induces microscale phase separation, and we show the impact of morphology on ion solvation and dynamics in the electrolyte. Spectroscopy and simulations show weak ion-PFPE interactions, which promote salt phase segregation into-and ion transport within-the PEG domain. These polymer electrolytes show promise for use in high-voltage lithium metal batteries with improved Li|Li cycling due to enhanced mechanical properties and high-voltage stability beyond 6 V versus Li/Li+. Our work provides insights into transport and stability in fluorinated polymer electrolytes for next-generation batteries.

Full valorisation of waste PET into dimethyl terephthalate and cyclic arylboronic esters

Developing efficient and cost-effective methodologies for high value-added conversion of waste plastic delivers substantial environmental and economic benefits. Herein, we develop a novel approach utilizing boric acid in the methanolysis of waste polyethylene terephthalate (PET) to derive pure dimethyl terephthalate (DMT) and boronic acid esters through in-situ capture of ethylene glycol (EG). It not only upcycles waste PET but also eliminates intricate EG purification processes. Catalyzed by magnalium-aluminum-layered double oxides (Mg4Al1-LDO), this method achieved 100 % conversions of PET with 96 % and 99 % yields of arylboronic esters and DMT, respectively. Kinetic studies and in-situ Fourier-transform infrared spectroscopy (FT-IR) demonstrated the pivotal role of the monodentate methoxy species, generated through the interaction of medium basic Mg–O ion pairs and methanol. This method demonstrates applicability for the upcycling of assorted discarded PET wastes, polyesters, and polycarbonates with EG units, highlighting its potential as a comprehensive solution for waste plastic management.

Perfluorinated Single-Ion Li+ Conducting Polymer Electrolyte for Lithium-Metal Batteries

Single-ion (Li+) conducting electrolytes with a high Li+ conductivity and transference number (LTN) are promising electrolyte candidates for eliminating the concentration polarization and inhibiting the growth of lithium dendrites in lithium-metal batteries at high power and energy densities. This study presents the synthesis and electrochemical characterization of an AB-type single-ion Li+ conducting polymer consisting of a perfluorinated lithium-salt monomer (A) covalently bonded to a polyethylene glycol monomer (B). An investigation into several plasticizers reveals that ether-based solvents with moderate dielectric constants significantly enhance the Li+ conductivity of single-ion (Li+) conducting gel polymer electrolytes (SIC-GPE) while also maintaining the mechanical integrity of SIC-GPE. The perfluorinated lithium-salt units with weakly coordinating anions provide the advantage of high Li+ conductivity (1.1 × 10–4 S cm–2) and transference number (0.92), while polyethylene glycol units contribute to high flexibility and enhance plasticizer wettability in the SIC-GPE. The interfacial stability and electrochemical performance of SIC-GPE are demonstrated in lithium-metal symmetric cells (maintaining stability for >1300 h at 1 mAh cm–2) and lithium-metal batteries (retaining 98% capacity after 200 cycles).

In situ EPR spin-trapping tracking of macroradical formation and the role of a hindered phenol anti-oxidant in reducing thermo-oxidative phenomena of poly(ethylene terephthalate)

One of the major issues concerning poly(ethylene terephthalate) (PET) produced with titanium-based catalysts is its sensitivity to high-temperature oxidation, which results in performance loss and discoloration. Here, the thermo-oxidative phenomena of titanium-catalyst-produced PET during its synthesis and post-processing in the presence of hindered phenol anti-oxidant Irganox 1425 has been investigated by a spin-trapping technique. Three types of spin adducts have been determined and quantified; –O−•CH− is the dominant radical intermediate, while •CH2− and –O−•CH− are mainly produced by the decomposition of diethylene glycol (DEG) units. An excessively high DEG content leads to instability of PET chains at high temperatures and so is not conducive to suppressing oxidation. An anti-oxidant can effectively eliminate radicals induced by thermo-oxidative reactions and improve the thermal stability of PET, especially in the post-processing stage. A comprehensive thermal oxidation mechanism is proposed, in which PET thermolysis starts with hydrogen abstraction to produce –O−•CH−, and then auto-oxidation ensues by radical intermediates attacking other PET chains. The cyclic reaction is reasonably terminated by the anti-oxidant serving as a hydrogen donor to quench radical intermediates.

Impact of hydrophilic side chains on the thin film transistor performance of a benzothieno-benzothiophene derivative.

Side-chain engineering in molecular semiconductors provides a versatile toolbox for precisely manipulating the material's processability, crystallographic properties, as well as electronic and optoelectronic characteristics. This study explores the impact of integrating hydrophilic side chains, specifically oligoethylene glycol (OEG) units, into the molecular structure of the small molecule semiconductor, 2,7-bis(2(2-methoxy ethoxy)ethoxy) benzo[b]benzo[4,5] thieno[2,3-d] thiophene (OEG-BTBT). The investigation includes a comprehensive analysis of thin film morphology and crystallographic properties, along with the optimization of deposition parameters for improving the device performance. Despite the anticipated benefits, such as enhanced processability, our investigation into OEG-BTBT-based organic field-effect transistors (OFETs) reveals suboptimal performance marked by a low effective charge carrier mobility, a low on/off ratio, and a high threshold voltage. The study unveils bias stress effects and device degradation attributed to the high ionization energy of OEG-BTBT alongside the hydrophilic nature of the ethylene-glycol moieties, which lead to charge trapping at the dielectric interface. Our findings underscore the need for a meticulous balance between electronic properties and chemical functionalities in molecular semiconductors to achieve stable and efficient performance in organic electronic devices.

Distinguishing anti-PEG antibodies by specificity for the PEG terminus using nanoarchitectonics-based antibiofouling cello-oligosaccharide platforms.

The conjugation of poly(ethylene glycol) (PEG) to therapeutic proteins or nanoparticles is a widely used pharmaceutical strategy to improve their therapeutic efficacy. However, conjugation can make PEG immunogenic and induce the production of anti-PEG antibodies, which decreases both the therapeutic efficacy after repeated dosing and clinical safety. To address these concerns, it is essential to analyze the binding characteristics of anti-PEG antibodies to PEG. However, distinguishing anti-PEG antibodies is still a difficult task. Herein, we demonstrate the use of antibiofouling cello-oligosaccharide assemblies tethering one-terminal methoxy oligo(ethylene glycol) (OEG) ligands for distinguishing anti-PEG antibodies in a simple manner. The OEG ligand-tethering two-dimensional crystalline cello-oligosaccharide assemblies were stably dispersed in a buffer solution and had antibiofouling properties against nonspecific protein adsorption. These characteristics allowed enzyme-linked immunosorbent assays (ELISAs) to be simply performed by cycles of centrifugation/redispersion of aqueous dispersions of the assemblies. The simple assays revealed that the specific OEG ligand-tethering assemblies could distinguish anti-PEG antibodies to detect a specific antibody that preferentially binds to the methoxy terminus of the PEG chain with 3 repeating ethylene glycol units. Furthermore, quantitative detection of the antibodies was successfully performed with high sensitivity even in the presence of serum. The detectable and quantifiable range of antibody concentrations covered those required clinically. Our findings open a new avenue for analyzing the binding characteristics of anti-PEG antibodies in biological samples.

Tetracene cyclophanes showing controlled intramolecular singlet fission by through-space orientations.

Tetracene cyclophanes: a series of cyclic tetracene dimers bridged by two flexible ethylene glycol units demonstrated enhanced intramolecular singlet fission through through-space orientations by suppressing the H-type excited complex.

Tunable electrochemiluminescence of TADF luminophores: manipulating efficiency and unveiling water-soluble emitters.

Thermally Activated Delayed Fluorescent (TADF) luminophores offer the potential to achieve 100% Internal Quantum Efficiency (IQE) by harvesting both singlet and triplet excitons via reverse intersystem crossing from T1 to S1. This class of molecules has therefore been embraced in the pursuit of cheaper and more efficient electrochemiluminescent (ECL) labels. The present study explores how tuning the electron-donating (D) and -accepting (A) strengths of peripheral substituents affects the ECL emission of mono- and dicyanoarene-based TADF dyes. To this end, we synthesized two series of TADF compounds, independently manipulating electron donors and acceptors by (i) halogenating electron-rich diphenylamine moieties, or (ii) mono- or di-substituting the electron-poor cyanoarene core with either fluorine or imidazole. Through a comparative analysis, we elucidate the role of each substituent in shaping the photophysics of the investigated luminophores. Despite only achieving a relative Φ ECL as high as 1.27%, this framework identifies several molecular features that boost the ECL efficiency to pave the way for designing highly efficient TADF-based ECL emitters. Ultimately, imidazole substituents are exploited as a platform for functionalization with triethylene glycol units. The resulting water-soluble TADF luminophores are characterized under conditions usual to commercial ECL bioanalysis, proving their potential as a cost-effective alternative replacement to [Ru(bpy)3]2+ in clinical diagnostic.

Aziridine-derived poly(sulfonamide thioether)s: Synthesis and the self-healing elastomeric properties

We introduce a straightforward polymerization methodology for synthesizing poly(sulfonamide thioether)s by the step-growth polyaddition of dithiols to chiral bis(2-monosubstituted N-sulfonyl aziridine)s. Undesired cross-linking reactions do not occur when employing the nucleophilic catalyst tributylphosphine. The resulting polymers exhibit both optical activity and impressive thermal stability, with a decomposition temperature (Td,5%) up to 328.1 °C. Moreover, one of the synthesized polymers, incorporating the diethylene glycol unit, demonstrates remarkable mechanical properties, presenting a tensile strength exceeding 2.0 MPa and an extraordinary strain tensile rate exceeding 2,000%. Most notably, this elastomer exhibits rapid self-healing capabilities at room temperature without external stimuli. These findings not only contribute to the synthetic methods for aziridine-derived polymeric materials but also offer promising avenues for developing advanced elastomers with exceptional mechanical and self-healing attributes.

Statically Very Hydrophilic but Dynamically Hydrophobic Surfaces Showing Surprising Water Sliding Performance

AbstractIt is generally believed that water droplets on (super)hydrophilic surfaces is spread and strongly pin to the surface. The surface chemistry that achieves the paradoxical surface properties of being statically very hydrophilic, but exhibiting outstanding water sliding properties, has not yet established. Here, a facile approach to prepare such unusual surfaces based on a combination of a sol–gel process using an organosilane containing polyethylene glycol units and tetraethoxysilane, and subsequent alkali‐treatment is reported. The resulting sol–gel thin films are smooth, transparent, hydrophilic (static contact angle (CA) (θS) of ≈37°) and show a liquid‐like nature with both low CA hysteresis (≈4°) and sliding angle (α) for 10 µL water droplets (≈10°). Surprisingly, after alkali‐treatment for sufficient time, the surface becomes very hydrophilic (θS of ≈14°) while improving its dynamic wetting behaviors (CA hysteresis of ≈3° and α for 10 µL water droplet of ≈4°), such that even a mere 0.5 µL water drop can slide down smoothly without pinning and/or tailing.