Hydrophilic Poly Ethylene Glycol Research Articles

Ultrasensitive Detection of Chemokines in Clinical Samples with Graphene-Based Field-Effect Transistors.

Due to their ultra-high sensitivity, solution-gated graphene-based field-effect transistors (SG-GFET) have been proposed for applications in bio-sensing. However, challenges regarding the functionalization of GFETs have prevented their applications in clinical diagnostics so far. Here GFET sensors based on van der Waals (vdW) heterostructures of single-layer graphene layered with a molecular ≈1nm thick carbon nanomembrane (CNM) are presented. The CNM acts as an ultrathin molecular interposer between the graphene channel and the analyte and allows bio-functionalization without impairing the graphene properties including its charge carrier mobility. To achieve specificity and reliability in the detection of biomarkers in real patient samples, the functionalization incorporates biostable aptamers in the non-natural l-configuration and hydrophilic polyethylene glycol for avoiding non-specific adsorption. A rapid (≈5min) detection of the clinically relevant inflammatory mediator CXCL8/IL-8 within the concentration range of 0.5 - 500 pM (5 - 5000 pgml-1) is demonstrated in nasal swab samples collected from patients with respiratory tract infections. This detection range may aid in diagnostics of early-stage infectious diseases making the reported approach promising for the development of future medical tools.

Ultra-Slippery Hydrophilic Surfaces by Hybrid Monolayers.

Slippery solid surfaces with low droplet contact angle hysteresis (CAH) are crucial for applications in thermal management, energy harvesting, and environmental remediation. Traditionally, reducing CAH has been achieved by enhancing surface homogeneity. This work challenges this conventional approach by developing slippery yet hydrophilic surfaces through hybrid monolayers composed of hydrophilic polyethylene glycol (PEG)-silane and hydrophobic alkyl-silane molecules. These hybrid surfaces exhibited exceptionally low CAH (<2°), outperforming well-established homogeneous slippery surfaces. Molecular structural analyses suggested that the remarkable slipperiness is due to a unique spatially staggered molecular configuration, where longer PEG chains shield shorter alkyl chains, thus creating additional free volume while ensuring surface coverage. This was supported by the observation of decreased CAH with increasing temperature, highlighting the role of grafted chain mobility in enhancing slipperiness by self-smoothing and fluid-like behaviors. Furthermore, condensation experiments demonstrated the exceptional performance of the hydrophilic slippery surfaces in dew harvesting due to superior condensation nucleation, droplet coalescence, and self-sweeping efficiency. These findings offer a novel paradigm for designing advanced slippery surfaces and provide valuable insights into the molecular mechanisms governing dynamic wetting.

Surface modification and patterning of polymer thin films by plasma and adsorption behavior of proteins

The surface wettability property of hydrophobic polystyrene (PS) and hydrophilic polyethylene glycol (PEG) thin films subjected to modification by direct current plasma glow discharge is studied. The polymer films exhibited change of surface wettability on exposure to air, nitrogen, oxygen or argon plasmas. In PS films a swift modification to hydrophilic surface and subsequent steady recovery following first order kinetics are observed. The rate of modification and recovery are adjustable by adjusting the plasma ambient and parameters, and additional wet-chemical treatment using ionic solutions. In PEG films the hydrophobic wettability evolve with ageing following the first order kinetics, and is stable for long period on exposure to air ambient. Moreover, a vapor deposition like process is possible using the PEG films as source to deposit self-assembled molecular layers with hydrophobic wettability on other surfaces. Using surface modification or molecular deposition processes, the fabrication of wettability patterns in the surface of PS and PEG films, and on other surfaces by vapor transport using PEG films, and also the possibility to produce gradient wettability patterns are demonstrated. Moreover, the adsorption behavior of immuno-specific system of proteins on surface modified hydrophilic PS films is studied.

Controllable Contact-Destructive Hydrogel Actuators.

Constructing hydrogels with spatially heterogeneous structures are crucial for unlocking novel applications. To this end, selectively removing a specific portion of hydrogels by facile and intricate destructive strategies is worth exploring. Herein, a "contact-destructive" hydrogel actuator is presented, composed of a dynamic hydrogel network doped with hydrophilic polyethylene glycol (PEG). The destructive behavior of the hydrogel actuator is attributed to the surface tension-induced spreading effect and the enhanced water absorption due to the additive PEG. Parameters that act on these mechanisms are used to control the destruction of the hydrogel. During the destructive process, the hydrogel actuator exhibits locomotion routes predetermined by the graphic pattern with the aid of 3D printing. Additionally, such self-destructive behavior can be terminated by UV light irradiation when PEG is replaced with poly(ethylene glycol) diacrylate (PEGDA). Significantly, diverse applications including controllable 3D structures collapse, self-erasing, and on-demand cell release, are realized with such self-destructive hydrogel. These results demonstrate that the present hydrogel has great values in soft robotics, anti-counterfeiting, controlled drug delivery, and other related fields.

Efficient synthesis of the undiluted vegetable juice-compatible hydrophilic quantum dot-labeled fluorescent molecularly imprinted polymer microspheres via facile one-pot surface-initiated ARGET ATRP

The development of fluorescent molecularly imprinted polymers (MIPs) applicable for herbicide optosensing in the undiluted vegetable juices is highly important for food safety control, but still remains a challenging task. Herein, we report on a facile and efficient new strategy for the synthesis of hydrophilic quantum dot (QD)-labeled fluorescent MIP microspheres capable of directly and selectively optosensing a widely used herbicide (i.e., 2,4-dichlorophenoxyacetic acid, 2,4-D) in the undiluted vegetable juices. Such fluorescent MIP particles were readily prepared through one-step grafting of a red CdTe QD-labeled 2,4-D-MIP layer with hydrophilic polyethylene glycol brushes onto the preformed uniform “living” polymer microspheres (with surface-bound alkyl halide groups) via one-pot surface-initiated activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) (SI-ARGET ATRP). They proved to be a highly useful optosensor with high 2,4-D selectivity and sensitivity (the limit of detection ≤ 0.14 μM) in the undiluted Chinese cabbage and cucumber juices. They also showed excellent photostability and reusability and could be directly utilized for 2,4-D detection with high recoveries (98.2 %-102.4 %) and accuracy (RSD≤3.8 %) in the undiluted Chinese cabbage and cucumber juices at three spiking levels of both 2,4-D and its mixtures with several analogues. The use of SI-ARGET ATRP significantly reduced the applied copper catalyst concentration (about 5 μM), which greatly alleviated the quenching effect of the copper catalyst on the fluorescence of the QD-labeled MIP (usually observed for those prepared via normal ATRPs that typically use several hundreds of μM of copper catalysts), thus making this facile new strategy highly efficient for developing advanced fluorescent MIPs that hold much promise in various bioanalytical and diagnostic applications.

Synthetic Chemicals as Potential Tracers of Impacts of Fracturing Fluids on Groundwater

Application of hydraulic fracturing to produce “unconventional” oil and gas from shale formations and other low-permeability geological units has raised concerns about the potential environmental impacts, including potential adverse effects of fracturing fluids (FF) on groundwater. In this study, laboratory batch test experiments and new analytical methods were developed to analyze FF chemicals as potential indicators (tracers) to detect impacts of fracturing fluids on groundwater. The tests, conducted over 101–196 days, included FF with synthetic chemicals (~40,000–4,000,000 µg/L), placed in batches with groundwater and sediment at 5° and 25 °C, along with sterile controls. Using the new methods, measurable concentrations of the FF chemicals were many orders in magnitude lower (~3000 to 3,000,000 X) compared to their concentrations in synthetic fracturing fluids, indicating that these chemicals are excellent candidates as indicators of FF contamination in groundwater, if they are relatively persistent, and not prone to extensive loss by sorption during migration in the subsurface. Variable sorption and degradation of the chemicals was observed in both batch and column tests. Sorption was negligible (sorption coefficient, Kd~0.0) for some synthetic chemicals (polyethylene glycol, ethanolamines, isopropanol, and ethyl hexanol) in some tests. At the other extreme, strong sorption was observed for some of the higher molecular weight cocamido propyl betaine (max Kd = 1.17) and polyethylene glycol (max Kd = 1.12) components, and triethanolamine (max Kd = 0.47) in other tests. Apparent loss by degradation was observed for each chemical in some tests, but negligible in others. The shortest apparent half-lives were for isopropanol and ethyl hexanol at 25 °C (t½ &lt; 11 days), and the most persistent synthetic chemicals were polyethylene glycols (t½ ≥ 182 d) and the ethanolamines (t½ ≥ 212 d). Of the potentially diagnostic FF chemicals investigated, the relatively hydrophilic and persistent lower molecular weight polyethylene glycols are some of the most promising as potential indicators of contamination of groundwater by FF.

Optimizing release properties of tablets from Spondias mombin spray-dried leaves extract using dry and melt granulation

This study aimed to investigate the efficacy of conventional dry granulation (slugging) and twin-screw melt granulation (TSMG) as downstream processing methods to enhance the technological properties, such as flowability and tabletability, of spray-dried plant extracts (SDE). A hydrophilic (Polyethylene glycol 6000-PEG) and a lipophilic binder (glyceryl dibehenate-GBE) were explored for the melt granulation process. Compression behavior and powder rheological properties of SDE and its granules were investigated. Compression analysis by in-die Heckel analysis explained the SDE's poor mechanical properties resulting in poor compact integrity in addition to the poor flow properties of the SDE. Despite the success of granulation strategies to improve the material's flowability and tabletability, the TSMG granules exhibited better performance than slugged granules. Regarding formulation, the lipophilic binder facilitated greater plastic deformation than the hydrophilic binder, enhancing the release of formulations across different profiles from controlled release, adjusting the granules quantity, to immediate-release tablets containing either brittle or plastic fillers. In conclusion, TSMG combined with a lipophilic melt binder emerged as a promising technology for overcoming the challenges of poor tabletability and modifying the release profile of ellagitannin from SDE.

Nanoparticles (NPs)-mediated lncMALAT1 silencing to reverse cisplatin resistance for effective hepatocellular carcinoma therapy.

Platinum-based chemotherapy has been widely used for clinical cancer treatment, but drug resistance is the main barrier to induce the poor prognosis of cancer patients. Long non-coding RNAs (lncRNAs) have been recognized as a type of new cancer therapeutic targets due to their important role in regulating cancer progression such as drug resistance. However, it is still challenged to effectively intervene the expression of lncRNAs as they are usually located at various subcellular organelles (e.g., nucleus, mitochondrion, and endoplasmic reticulum). We herein developed an endosomal pH-responsive nanoparticle (NP) platform for small interfering RNA (siRNA) and cisplatin prodrug co-delivery and effective cisplatin-resistant hepatocellular carcinoma (HCC) therapy. This co-delivery nanoplatform is comprised of a hydrophilic polyethylene glycol (PEG) shell and a hydrophobic poly (2-(diisopropylamino)ethyl methacrylate) (PDPA) core, in which cisplatin prodrug and electrostatic complexes of nucleus-targeting amphiphilic peptide (NTPA) and siRNA are encapsulated. After intravenous injection and then uptake by tumor cells, the endosomal pH could trigger the dissociation of nanoplatform and enhance the endosomal escape of loaded cisplatin prodrug and NTPA/siRNA complexes via the "proton sponge" effect. Subsequently, the NTPA/siRNA complexes could specifically transport siRNA into the nucleus and efficiently reverse cisplatin resistance via silencing the expression of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (lncMALAT1) mainly localized in the nucleus, ultimately inhibiting the growth of cisplatin-resistant HCC tumor.

Enhancing camptothecin loading and release control through physical surface modification of organosilica nanoparticles with polyethylene glycol

The surface modification of nanoparticles holds the potential to enhance the loading capacity of drug molecules and regulate their release, making it possible to exploit the differences between tumor and normal cells. To this end, the surfaces of tetrasulfide-based phenylene-containing biodegradable periodic mesoporous organosilica (BPMO) nanoparticles (designated P4S) are modified herein with a hydrophilic and biocompatible polyethylene glycol (PEG) polymer. The PEG coating is optimized by adjusting the PEG concentration during synthesis, thus resulting in a significant increase in the nanoparticle stability. Furthermore, PEG modification enhances the nanoparticles' camptothecin (CPT) loading capacity. Drug release assessments under physical and acidic pH conditions demonstrate the pH-responsive properties of the P4S nanoparticles upon PEG functionalization, which results in increased drug release at low pH, along with enhanced cellular uptake potential. Notably, the cytotoxicity of CPT against HepG2 cancer cells is significantly improved when loaded into the P4S-PEG nanoparticles. These findings reveal the efficacy of PEG surface modification of the drug-delivery material in augmenting the activity of CPT, with promising prospects for clinical applications.

PEG-functionalized aliphatic polycarbonate brushes with self-polishing dynamic antifouling properties

Hydrophilic antifouling polymers provide excellent antifouling effects under usual short-term use conditions, but the long-term accumulation of contaminants causes them to lose their antifouling properties. To overcome this drawback, surface-initiated ring-opening graft polymerization (SI-ROP) was performed on the surface of the material by applying the cyclic carbide monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC), which contains a sulfonylfluoride group on the side chain, followed by a “sulfur(IV)-fluorine exchange” (SuFEx) post click modification reaction to link the hydrophilic polyethylene glycol (PEG) to the polyFMC (PFMC) brush, and a novel antifouling strategy for self-polishing dynamic antifouling surfaces was developed. The experimental results showed that the antifouling surface could effectively prevent the adsorption of proteins such as bovine serum albumin (BSA, ∼96.4%), fibrinogen (Fg, ∼87.8%) and lysozyme (Lyz ∼69.4%) as well as the adhesion of microorganisms such as the bacteria Staphylococcus aureus (S. aureus) (∼87.5%) and HeLa cells (∼67.2%). Moreover, the enzymatically self-polished surface still has excellent antifouling properties. Therefore, this modification method has potential applications in the field of biosensors and novel antifouling materials.

Fine-Tuning the Amphiphilic Properties of Carbosilane Dendritic Networks towards High-Swelling Thermogels.

Dendritic hydrogels based on carbosilane crosslinkers are promising drug delivery systems, as their amphiphilic nature improves the compatibility with poorly water-soluble drugs. In this work, we explored the impact of the complementary polymer on the amphiphilic properties of the dendritic network. Different polymers were selected as precursors, from the highly lipophilic propylene glycol (PPG) to the hydrophilic polyethylene glycol (PEG), including amphiphilic Pluronics L31, L35 and L61. The dithiol polymers reacted with carbosilane crosslinkers through UV-initiated thiol-ene coupling (TEC), and the resultant materials were classified as non-swelling networks (for PPG, PLUL31 and PLUL61) and high-swelling hydrogels (for PEG and PLUL35). The hydrogels exhibited thermo-responsive properties, shrinking at higher temperatures, and exhibited an intriguing drug release pattern due to internal nanostructuring. Furthermore, we fine-tuned the dendritic crosslinker, including hydroxyl and azide pendant groups in the focal point, generating functional networks that can be modified through degradable (ester) and non-degradable (triazol) bonds. Overall, this work highlighted the crucial role of the amphiphilic balance in the design of dendritic hydrogels with thermo-responsive behavior and confirmed their potential as functional networks for biomedical applications.

Abstract 6581: DX126-262 combined with chemotherapy (Cisplatin and 5-Fu) demonstrates promising antitumor efficacy in HER2-positive gastric cancer

Abstract Gastric cancer is a common malignant tumor of the digestive system, and its morbidity and mortality rank among the top five in the world. Although significant progress has been made in cytotoxic chemotherapy, immunotherapy and targeted therapy in recent years, the long-term prognosis of patients with advanced or metastatic gastric cancer is still poor. Trastuzumab combined with chemotherapy is the first-line standard of care (SOC) for HER2-positive advanced or metastatic gastric cancer. Two ADC drugs targeting HER2, DS-8201 and RC-48, have also been approved for the treatment of gastric cancer. However, their limited clinical benefits and occurrence of adverse events still present a significant challenge. Therefore, minimizing the off-target toxicity and collateral damage while achieving significant chemotherapy efficacy has become the focus of gastric cancer treatment. DX126-262 is a novel HER2-targeting antibody-drug conjugate (ADC), generated by conjugating a Tubulysin B analogue to a recombinant humanized anti-HER2 monoclonal antibody through a linker containing branched hydrophilic polyethylene glycol, using thiol-maleimide chemistry to achieve drug antibody ratio (DAR) of 3.8. Previous studies have confirmed that DX126-262 monotherapy showed excellent efficacy in HER2-positive gastric cancer NCI-N87 cells in vitro and in vivo. And the efficacy has also been demonstrated in clinical trials (now in phase II, CTR20211871). Based on above results, we intended to further explore whether combination therapy of DX126-262 with Cisplatin and 5-FU can improve the anti-tumor efficacy compared with SOC (Herceptin plus Cisplatin and 5-FU) or DS-8201 monotherapy. The triple-drug combination therapy demonstrated much better therapeutic efficacy than single drug (DX126-262, Cisplatin, 5-FU, Herceptin, or DS-8201) or double-drug combination (Cisplatin plus 5-FU) or SOC (Herceptin plus Cisplatin and 5-FU) on human gastric cancer cells in vitro and in vivo. Meanwhile, triple-drug combination therapy did not exhibit superimposed toxicity, judging by the body weight of mice and hemal biochemistry assays. These results suggested that DX126-262 plus Cisplatin and 5-FU might be a promising strategy for treatment of HER2-positive advanced or metastatic gastric cancer in clinic. Citation Format: Xiaobo Cai, Min Cao, Huihui Guo, Qingliang Yang, Xiangfei Kong, Yong Du, Zhicang Ye, Zhixiang Guo, Lingli Zhang, Lu Bai, Junxiang Jia, Yunxia Zheng, Yongxiang Chen, Miaomiao Chen, Wei Zheng, Jun Zheng, Wenjun Li, Yuanyuan Huang, Mengmeng Liu, Zhongliang Fan, Hangbo Ye, Yifang Xu, Binbin Chen, Meng Dai, Robert Y. Zhao. DX126-262 combined with chemotherapy (Cisplatin and 5-Fu) demonstrates promising antitumor efficacy in HER2-positive gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6581.

Piezo-photodynamic therapy of Au@PEG-ZnO nanostructures enabled with a battery-free wireless cancer therapeutic dot

Cancer remains a global health concern, necessitating advanced therapeutic strategies to address its fatal challenges. Conventional treatments, such as radiotherapy and chemotherapy, often lack tumor specificity and may induce systemic toxicity. Photodynamic therapy (PDT) and sonodynamic therapy (SDT) have emerged as promising alternatives, demonstrating high specificity and minimal side effects. In this study, we propose a novel piezo-photodynamic therapy (PPDT) enabled with battery-free wireless cancer therapeutic dot, in which the nanocomposites of gold nanoparticles (Au NPs), zinc oxide nanorods (ZnO NRs) and hydrophilic polyethylene glycol (PEG) can enhance reactive oxygen species (ROS) generation and effectively inhibit tumor growth. The therapeutic dot is implanted directly inside the tissue around the tumor and wirelessly controlled by ultrasound (US), allowing dual activation of electron-hole pairs from the nanocomposites via US and ultraviolet light (UV). The internally generated piezoelectric field minimizes electron-hole recombination, maximizing ROS induction within tumor cells. This PPDT approach surpasses the efficacy of conventional PDT and SDT, showcasing a synergistic therapeutic effect. The study further elucidates the detailed mechanism of Au@PEG-ZnO NRs catalysts, providing insights into their piezoelectric-photocatalytic action. The battery-free wireless control and minimally invasive implantation of the therapeutic dot with inorganic piezo-photocatalyst open new perspectives in cancer therapy.

Development of Injectable Thermosensitive Nanocomposite Hydrogel for Ratiometric Drug Delivery to Treat Drug Resistant Chondrosarcoma In Vivo.

Chondrosarcoma(CS), a prevalent primary malignant bone tumor, frequently exhibits chemotherapy resistance attributed to upregulated anti-apoptosis pathways such as the Bcl-2 family. In this manuscript, a new strategy is presented to augment chemosensitivity and mitigate systemic toxicity by harnessing a nano-enabled drug delivery hydrogel platform. The platform utilizes "PLGA-PEG-PLGA", an amphiphilic triblock copolymer combining hydrophilic polyethylene glycol (PEG) and hydrophobic polylactide glycolide (PLGA) blocks, renowned for its properties conducive to crafting a biodegradable, temperature-sensitive hydrogel. This platform is tailored to encapsulate a ratiometrically designed dual-loaded liposomes containing a first-line chemo option for CS, Doxorubicin (Dox), plus a calculated amount of small molecule inhibitor for anti-apoptotic Bcl-2 pathway, ABT-737. In vitro and in vivo evaluations demonstrate successful Bcl-2 suppression, resulting in the restoration of Dox sensitivity, evident through impeded tumor growth and amplified necrosis rates at the tumor site. This delivery system showcases remarkable thermal responsiveness, injectability, and biodegradability, all finely aligned with the clinical demands of CS treatment. Collectively, this study introduces a transformative avenue for tackling drug resistance in CS chemotherapy, offering significant clinical potential.

Significant reduction of activity retention in the kidneys via optimized linker sequences in radiohybrid-based minigastrin analogs

BackgroundWe recently introduced radiohybrid (rh)-based minigastrin analogs e.g., DOTA-rhCCK-18 (DOTA-D-Dap(p-SiFA)-(D-γ-Glu)8-Ala-Tyr-Gly-Trp-Nle-Asp-Phe-NH2), that revealed substantially increased activity retention in the tumor. However, one major drawback of these first generation rh-based cholecystokinin-2 receptor (CCK-2R) ligands is their elevated activity levels in the kidneys, especially at later time points (24 h p.i.). Therefore, this study aimed to reduce kidney retention with regard to a therapeutic use via substitution of negatively charged D-glutamic acid moieties by hydrophilic uncharged polyethylene glycol (PEG) linkers of various length ((PEG)4 to (PEG)11). Furthermore, the influence of differently charged silicon-based fluoride acceptor (SiFA)-moieties (p-SiFA: neutral, SiFA-ipa: negatively charged, and SiFAlin: positively charged) on in vitro properties of minigastrin analogs was evaluated. Out of all compounds evaluated in vitro, the two most promising minigastrin analogs were further investigated in vivo.ResultsCCK-2R affinity of most compounds evaluated was found to be in a range of 8–20 nM (by means of apparent IC50), while ligands containing a SiFA-ipa moiety displayed elevated IC50 values. Lipophilicity was noticeably lower for compounds containing a D-γ-glutamate (D-γ-Glu) moiety next to the D-Dap(SiFA) unit as compared to their counterparts lacking the additional negative charge. Within this study, combining the most favorable CCK-2R affinity and lipophilicity, [177/natLu]Lu-DOTA-rhCCK-70 (DOTA-D-Dap(p-SiFA)-D-γ-Glu-(PEG)7-D-γ-Glu-(PEG)3-Trp-(N-Me)Nle-Asp-1-Nal-NH2; IC50: 12.6 ± 2.0 nM; logD7.4: − 1.67 ± 0.08) and [177/natLu]Lu-DOTA-rhCCK-91 (DOTA-D-Dap(SiFAlin)-D-γ-Glu-(PEG)4-D-γ-Glu-(PEG)3-Trp-(N-Me)Nle-Asp-1-Nal-NH2; IC50: 8.6 ± 0.7 nM; logD7.4 = − 1.66 ± 0.07) were further evaluated in vivo. Biodistribution data of both compounds revealed significantly reduced (p < 0.0001) activity accumulation in the kidneys compared to [177Lu]Lu-DOTA-rhCCK-18 at 24 h p.i., leading to enhanced tumor-to-kidney ratios despite lower tumor uptake. However, overall tumor-to-background ratios of the novel compounds were lower than those of [177Lu]Lu-DOTA-rhCCK-18.ConclusionWe could show that the reduction of negative charges within the linker section of radiohybrid-based minigastrin analogs led to decreased activity levels in the kidneys at 24 h p.i., while maintaining a good tumor uptake. Thus, favorable tumor-to-kidney ratios were accomplished in vivo. However, further optimization has to be done in order to improve tumor retention and general biodistribution profile.Graphical abstract

PEGylated AIEgens for dual sensing of ATP and H2S and cancer cells photodynamic therapy

Fluorescent sensors have been widely applied for biosensing, but probes for both multiple analytes sensing and photodynamic therapy (PDT) effect are less reported. In this article, we reported three AIE-based probes anchored with different mass-weight polyethylene glycol (PEG) tails, i.e., TPE-PEG160, TPE-PEG350, and TPE-PEG750, for both adenosine-5′-triphosphate (ATP) and hydrogen sulfide (H2S) detection and also cancer cells photodynamic therapy. TPE-PEGns (n = 160, 350 and 750) contain the tetraphenylethylene-based fluorophore core, the pyridinium and amide anion binding sites, the H2S cleavable disulfide bond, and the hydrophilic PEG chain. They exhibit a good amphiphilic property and can self-assemble nona-aggregation with a moderated red emission in an aqueous solution. Importantly, the size of aggregation, photophysical property, sensing ability and photosensitivity of these amphiphilic probes can be controlled by tuning the PEG chain length. Moreover, the selected probe TPE-PEG160 has been successfully used to detect environmental H2S and image ATP levels in living cells, and TPE-PEG750 has been used for photodynamic therapy of tumor cells under light irradiation.

Preparation and characterization of ultrafiltration membranes derived from recycled Polyethylene terephthalate (PET) bottles

The pressing need for sustainable practices and eco-friendly materials in the face of escalating environmental concerns has led to exploring the transformation of discarded polyethylene terephthalate (PET) bottles into functional ultrafiltration membranes. This research prepares and characterizes ultrafiltration membranes derived from PET bottle waste. The study involves collecting PET waste material and fabrication processes to develop asymmetric flat sheet membranes blended with varying proportions of hydrophilic polyethylene glycol (PEG) using phase inversion techniques. Rigorous characterization employing SEM, EDS analysis, and water vapor permeability (WVP) assessments examine these membranes' structural, morphological, and performance attributes. The surface analysis elucidates a notable correlation between increased PEG content and larger pore sizes, consistent with prior studies involving PEG in membrane modifications. Additionally, incorporating PEG in the casting solution elevates water vapor permeability. Ultrafiltration experiments reveal differing rejection rates, with membrane M2 exhibiting enhanced anti-fouling properties despite reduced flux compared to M3 and M4. This research lays the groundwork for repurposing PET waste into selective membrane materials, emphasizing optimization strategies to enhance membrane quality and performance for diverse operational settings.

Enhancing protein dynamics analysis with hydrophilic polyethylene glycol cross-linkers.

Cross-linkers play a critical role in capturing protein dynamics in chemical cross-linking mass spectrometry techniques. Various types of cross-linkers with different backbone features are widely used in the study of proteins. However, it is still not clear how the cross-linkers' backbone affect their own structure and their interactions with proteins. In this study, we systematically characterized and compared methylene backbone and polyethylene glycol (PEG) backbone cross-linkers in terms of capturing protein structure and dynamics. The results indicate the cross-linker with PEG backbone have a better ability to capture the inter-domain dynamics of calmodulin, adenylate kinase, maltodextrin binding protein and dual-specificity protein phosphatase. We further conducted quantum chemical calculations and all-atom molecular dynamics simulations to analyze thermodynamic and kinetic properties of PEG backbone and methylene backbone cross-linkers. Solution nuclear magnetic resonance was employed to validate the interaction interface between proteins and cross-linkers. Our findings suggest that the polarity distribution of PEG backbone enhances the accessibility of the cross-linker to the protein surface, facilitating the capture of sites located in dynamic regions. By comprehensively benchmarking with disuccinimidyl suberate (DSS)/bis-sulfosuccinimidyl-suberate(BS3), bis-succinimidyl-(PEG)2 revealed superior advantages in protein dynamic conformation analysis in vitro and in vivo, enabling the capture of a greater number of cross-linking sites and better modeling of protein dynamics. Furthermore, our study provides valuable guidance for the development and application of PEG backbone cross-linkers.

Elution-free hollow-fiber membranes of block copolymers for hemodialysis balancing protein retaining and toxin clearance

Hemodialysis has been used as the primary treatment for patients with end-stage renal disease, however, the current hemodialysis membranes still need complicated modifications to enhance the hemocompatibility and overcome the additive leaching issue. Herein, we prepare hemodialysis hollow-fiber membranes (HFMs) via the melt spinning and selective swelling of the block copolymers of polysulfone (PSF) and polyethylene glycol (PEG), PSF-b-PEG. PSF-b-PEG is first melt-extruded to form dense hollow fibers, and then soaked in selective solvents to transform the PEG microdomains into nanopores following the mechanism of selective swelling-induced pore generation, thus producing HFMs with three dimensionally interconnected porosities. As neither additives nor involatile solvents are involved in the manufacturing process of the HFMs, no elution of any organic matters could be detected for the HFMs during hemodialysis. The HFMs possess a symmetrical structure ensuring tight selectivity, and hydrophilic PEG chains are enriched on the pore surfaces, thus endowing the membranes with enhanced hydrophilicity and durable biocompatibility. We systematically investigate the effect of PEG contents and swelling conditions on pore sizes, porosities, surface properties, and consequently the hemodialysis performance. The optimized HFMs reject >99 % serum albumin while clear ∼70 % middle molecular toxins such as lysozyme and 93–95 % small molecular toxins including urea, phosphate and creatinine. This work provides a strategy to prepare elution-free hemodialysis membranes by taking advantage of selective swelling of block copolymers to balance high protein retaining and high clearance of middle and small molecular toxins, and demonstrates their superiority in hemodialysis performance and safety than conventional membranes.

Design of novel poly(L-lactide)-based shape memory multiblock copolymers for biodegradable esophageal stent application

Esophageal cancer is a globally prevalent malignancy known for its extremely aggressive nature and high fatality rates. However, the conventional stents used in its treatment pose limitations including rigidity, non-degradability, and a lack of anti-inflammatory action. Shape memory multiblock copolymer stents (SMBS) have attracted considerable attention because of their distinctive characteristics. Nonetheless, achieving a variety of key functionalities, such as biocompatibility, biodegradability, thermoresponsiveness (body temperature, 37 °C), water responsiveness (biofluid), flexibility, and robustness, in a simple polymer system for practical applications still presents a significant problem. Herein, a versatile SMBS that is capable of delivering all the aforementioned key functionalities is proposed. This SMBS can efficiently be prepared via a rapid two-step strategy, leveraging the shape memory effect (SME) of a poly(L-lactide) (PLA)-based physical crosslinking network programmed into specific shapes. The proposed stent design incorporates bio-based PLA with flexible and hydrophilic polyethylene glycol (PEG), resulting in PEG-PLA multiblock copolymers with tunable transition temperatures (31.90–54.60 °C), effectively covering the body temperature (37 °C). Additionally, PEG-PLA exhibited a wide range of water uptake ratio of 41 % to 328 % and satisfactory elongation at break (142.8 % to 1920.6 %), and desired pH-dependent and simulated gastrointestinal biodegradability. Specifically, PEG4000PLA1500 displayed excellent body temperature-triggered (with a recovery rate of 99.5 %) and water-triggered dual SME, which allowed it to potentially be fabricated into on-demand synchronous shape memory and drug-release functional SMBS for esophageal stenosis therapy. The results of this study indicate that the proposed SMBS holds substantial potential for biomedical applications.