PEG Molecular Weight Research Articles

Shape Memory Performance and Microstructural Evolution in PLA/PEG Blends: Role of Plasticizer Content and Molecular Weight

Poly(lactic acid) (PLA) exhibits excellent shape memory properties but suffers from brittleness and a high glass transition temperature (Tg), limiting its utility in flexible and durable applications. This study explored the modification of PLA properties through the incorporation of poly(ethylene glycol) (PEG), varying in both content (5–20 wt%) and molecular weight (4000–12,000 g/mol), to enhance its suitability for specific applications, such as medical splints. The PLA/PEG blend, containing 15 wt% PEG and with a molecular weight of 12,000 g/mol, exhibited superior shape fixity (99.27%) and recovery (95.77%) in shape memory tests conducted at a programming temperature (Tp) of 45 °C and a recovery temperature (Tr) of 60 °C. Differential scanning calorimetry (DSC) analysis provided insights into the thermal mechanisms driving shape memory behavior of the PLA/PEG blend. The addition of PEG to the PLA blend resulted in a reduction in Tg and an increase in crystallinity, thereby facilitating enhanced chain mobility and structural reorganization. These thermal changes enhanced the shape fixity and recovery of the PLA/PEG blend. Synchrotron wide-angle X-ray scattering (WAXS) was further employed to elucidate the microstructural evolution of PLA/PEG blends during the shape memory process. Upon stretching, the PLA/PEG chains aligned predominantly along the tensile direction, reflecting strain-induced orientation. During recovery, the PLA/PEG chains underwent isotropic relaxation, reorganizing into their original configurations. This structural reorganization highlighted the critical role of chain mobility and alignment in driving the shape memory behavior of PLA/PEG blends, enabling them to effectively return to their initial shape. Mechanical testing confirmed that increasing PEG content and molecular weight enhanced elongation at break and impact strength, balancing flexibility and strength. These findings demonstrated that PLA/PEG blends, especially with 15 wt% PEG at 12,000 g/mol, offer an optimal combination of shape memory performance and mechanical properties, positioning them as promising candidates for customizable and biodegradable medical applications.

Effect of Mild Conditions on PVA-Based Theta Gel Preparation: Thermal and Rheological Characterization.

Polyvinyl alcohol (PVA), possessing a strong ability to form hydrogels, has been widely used for various pharmaceutical and biomedical applications. In particular, the use of PVA-PEG in the form of theta gels for altered cartilage treatment has attracted an enormous amount of attention in the last 20 years. In this paper, we prepared 42 PVA-PEG in the form of theta gels at room temperature in an aqueous environment, testing the crystallization occurrence at basic pH (10 or 12). Using a statistical approach, the effect of PEG molecular weight, PVA molecular weight and alkaline pH values on water content and mechanical performance was evaluated. The used procedure permitted the theta gels to maintain swelling properties comparable to those of human cartilage, from 60% to 85%, with both polymers having the same influence. PEG MW mainly affected the hydrophilic properties, whereas the thermal properties were mostly influenced by the PVA. The shear and compression mechanical behavior of the produced materials were affected by both the polymers' MWs. The sample obtained using PVA 125 kDa with PEG 20 kDa as a porogen appeared to be the most suitable one for cartilage disease treatment, as it had an equilibrium shear modulus in the range of 50-250 kPa, close to that of native articular cartilage, as well as optimal mechanical response under compression along the entire analyzed frequency range with a mean value of 0.12 MPa and a coefficient of friction (COF) which remained under 0.10 for all the tested sliding speeds (mm/s).

Synthesis of Stearyl Alcohol/Polyethylene Glycol Hybrids as Water-Repellent Finishes for Cotton/Polyester Blended Fabric

Nowadays, developing and innovation of new finishing agents that are cost effective, efficient, durable, and safe for the consumer as well as the environment are greatly required by the textile manufactures. In that concern, new stearyl alcohol/polyethylene glycol (SA/PEG) hybrids were synthesized, characterized, and applied as textile finishes to impart cotton/polyester fabric with water repellency. Such hybrids were synthesized by reaction of SA with PEG of molecular weight 1000 or 4000 Da in the presence of ammonium persulfate (APS) as initiator. The optimum conditions of the synthesis reaction are: APS/PEG, 20%; PEG/SA, 15%; reaction temperature, 80 °C and reaction time, 45 min. The synthesized hybrids are self-water dispersible that form oil-in-water stable emulsions. The results indicated that treating cotton/polyester fabric with easy-care finishing formulation containing 60 g/L of dimethyloldihydroxyethylene urea as a cross-linker, and 60 g/L of any of such hybrids emulsions imparts the treated fabric with water repellency, softness, and stiffness properties. Moreover, increasing the PEG molecular weight from 1000 to 4000 Da leads to a reduction in extents of softness and contact angle along with an enhancement in stiffness of treated fabric. Furthermore, the prepared hybrids emulsions-treated fabric samples are durable up to five washing cycles. The FTIR analysis confirmed the chemical structure of the synthesized SA/PEG1000 hybrid. The transmission electron microscope (TEM) revealed that the particles size of SA/PEG4000 hybrid emulsion is in the range of 34–70 nm and reaches to 185 nm in case of the SA/PEG4000 hybrid emulsion. The surface of SA/PEG1000 hybrid emulsion-treated fabric was characterized via scanning electron microscope (SEM).

Evolution of [formula omitted]-spacing in clay with PEG bulk volume fraction and molecular weight: Theoretical and experimental study

In the pursuit of ensuring the sustainability of the construction sector and fortifying its resilience against climate change, scientists have dedicated significant efforts to explore new classes of innovative, affordable, and technologically advanced materials that exhibit high efficiency, thereby securing the future for generations to come. In this context, we have opted to produce clay-polymer ecosystems through the direct insertion process. The PEG2000/clay and PEG6000/clay composites underwent analysis using X-ray diffraction (XRD) techniques, revealing the evolution of dhklconcerning the PEG bulk volume fraction. The results indicate the presence of two adsorption cycles, each comprising three stages (dilute, two-dimensional semi-dilute, and plateau). Each cycle delineates the incorporation of a polymer layer into the interlayer spaces of clay minerals. To elucidate this adsorption process, we have proposed a model depicting PEG chain conformation in confined spaces, represented as both monolayer and bilayer configurations. The influence of PEG molecular weight is distinctly evident in the dhklevolution across various clay categories. Ultimately, the application of scaling theory to model the experimental results proves to be robust, offering a precise description of the three discussed regimes.

Cytocompatible Hyperbranched Polyesters Capable of Altering the Ca2+ Signaling in Neuronal Cells In Vitro.

Synthetic hyperbranched polyesters with potential therapeutic properties were synthesized using the bifunctional polyethylene glycol or PEG with different molecular weights, ca., 4000, 6000, and 20,000 g/mol, and the trifunctional trans-aconitic acid or TAA. During polycondensation, a fixed amount of PEG was allowed to react with varying amounts of TAA (1:1 and 1:3) to control the branching extents. It was found that the synthetic polyesters had a considerable yield and were highly water soluble. Spectroscopic data (Fourier transform infrared and 1H NMR) confirmed the polyester formation; the branching percentages were determined from 1H NMR spectroscopy which varied from 73% to 22% among the synthesized samples. As the molecular weight of PEG was increased, the branching percentage drastically dropped. All polyesters were found to be negatively charged due to the ionization of unreacted -COOH in the branched ends at the working pH (7.4). Both the hydrodynamic size and intrinsic viscosity were found to reduce as the branching extent increased. Among the sets of polyesters, the one with the highest branching percentage (73%) showed the core-shell morphology (evident from field emission scanning electron microscopy and transmission electron microscopy studies). It also exhibited the highest efficiency toward Ca2+ influx in neuronal cells due to the unique morphology and the negatively charged surface. Nevertheless, this particular grade of polyester along with all the other grades was cytocompatible and induced reactive oxygen species generation. Since the maximally branched grade was highly efficient in altering the Ca2+ signaling through stronger influx, it may well be tested for treating neuronal disorders in vivo in future.

Shape-stable composite of synthetic phase change materials from balsa wood by epoxy/PEG through alkaline method

Phase change materials have excellent thermal energy storage capacity, making them an appealing option for energy management applications. Stabilizing the form of phase change materials enhances their practical effectiveness. This research focuses on sustaining the shape of low molecular weight PEG phase change materials in wood structures made from natural balsa wood. The alkalization process is used to modify the wood, after which the PEG/epoxy polymers are infused into the wood structure to form a synthetic phase change material. The process of treating wood with alkali involves partially removing lignin from the wood, creating specific spaces. Results from optical transmittance analysis demonstrate that wood treated with alkali and wood infused with phase change polymer exhibit high optical transmittance. SEM images also illustrate the presence of spaces in delignified wood treated with Epoxy/PEG 400 and Epoxy/PEG 600. The synthetic phase change material remains stable at temperatures below 310°C and possesses a ∆Hc of 170.1J/g to 162.8 J/g. The phase transition temperatures during heating are 56.4°C and 57.2°C, cooling is 25.7°C and 30.1°C.

A novel magnetorheological-polyethylene glycol shear thickening gel based on enhanced gel matrix

A novel magnetorheological-polyethylene glycol (PEG) shear thickening gel (MR-PSTG) with both shear thickening and magnetorheological effect is prepared based on polyethylene glycol shear thickening gel (PSTG) matrix possessing higher relative shear thickening effect (RSTE). Firstly, a new shear thickening mechanism is revealed through Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis. Then, the orthogonal experiment is conducted to analyze the impact of factors on MR-PSTG and obtain the optimal factor combinations of the RSTE and relative magnetorheological effect (RMRE). Finally, the composite relative effect (CRE) is proposed to represent the comprehensive performance of MR-PSTG. Experiment results show that the RSTE increases with the increase of PEG molecular weight, and the maximum RSTE increases by 2.37 times. B atoms from the B-O-C structure in new molecular chains can share electrons with O atoms in the Si-O-Si structure to form B-O cross-linking bonds, which is responsible for the increase in RSTE. The orthogonal experiment indicates that the maximum RSTE and RMRE of MR-PSTG can reach 1024286% and 3839%, respectively. Results also show that the CIP mass fraction has the greatest impact on the RSTE, RMRE, and CRE of MR-PSTG, while the PEG mass has the smallest impact.

Study on extraction desulfurization of road-paving asphalt by deep eutectic solvents

During the hot mixing process of road-paving asphalt, odorous substances are released, primarily consisting of sulfur-containing compounds that are regarded as atmospheric pollutants, negatively impacting both human quality of life and the eco-environment. In the paper, a kind of simulated asphalt solution was designed with two sulfur-containing compounds, dibenzothiophene (DBT) and benzothiophene (BT), as well as n-eicosane dissolved in cyclohexane. DBT and BT were extracted with deep eutectic solvent (DES) of tetrabutylammonium bromide and polyethylene glycol (TBAB/PEG). The effects of different molecular weight of PEG as donor on desulfurization efficiency were investigated. The effects of DES donor/receptor ratio, extraction temperature and time, solvent oil ratio, mixing speed, recycling performance of DES on desulfurization efficiency were also studied and optimized. The results indicated that the maximum desulfurization efficiency of BT reached 89.40 % at room temperature with a ratio of agent to oil of 2:1, reaction time of 30 min, and mixing speed of 600 rpm. Similarly, the desulfurization efficiency of DBT achieved 95.54 % when the ratio of agent to oil was 3.5:1, with reaction time of 30 min and mixing speed of 600 rpm. After being recycled eight times, the extraction efficiencies of DBT and BT remained at 85.3 % and 65.2 %, respectively. Under optimized conditions, the extraction efficiency of petroleum asphalt exceeded 23 %. Fourier Transform Infrared (FTIR) analysis indicated that the sulfur-containing compounds found in the saturates and aromatics of road-paving asphalt were extracted by DESs, which are generally more volatile than those found in asphaltenes during hot-mixing. Additionally, minimal changes were observed in the structural composition of the four fractions of desulfurized asphalt.

Effect of Viscosity and Air Gap within the Spinneret on the Morphology and Mechanical Properties of Hollow-Fiber Polymer Membranes for Separation Performance.

Hollow-fiber membranes for nanofiltration were prepared from the blending of Poly (ethylene glycol) (PEG) with Poly (vinyl chloride) (PVC) with different PEG molecular weights (400 and 4000 g/mol) and PVC via a dry/wet spinning process. In the spinning process, the effects of air gap, wind-up speed, dope extrusion rate, and bore extrusion rate were examined. In addition, the different lengths of the center tube, which acted as the inner-side fiber diameter during the preparation of hollow-fiber membranes, were studied. This research was investigated in order to observe the morphological, dielectric, and dynamic mechanical thermal properties to identify a suitable preparation of a hollow-fiber membrane for feasible applications. The morphology of the PVC-580 blended PEG-400 5 weight percent hollow-fiber membrane was seen to have a dense skin on both the inner and outer fiber surface, along with a suitable dope viscosity. Moreover, it offered finger-like substructures that could provide a high applicable feed-stream permeability and selectivity. Finger-like substructures were present on the near inner fiber surface at the controlled center-tube length of 0.3 cm, more so than at the center tube of 1 cm. This was because the solvent and non-solvent in the lumen tube exchanged more quickly than they did in the coagulant bath. The effect of the wind-up speed during the spinning process was significantly influenced by an affordable hollow fiber that can be indicated by the drawing ratio (λ). It was found that the drawing ratio of 3.3 showed a thickness thinner than 2.6 and 2.0, respectively. In summary, a controlled wind-up speed, an acceptable dope viscosity, and-most importantly-an agglomerated time resulted in membrane preparation.

Purification of secretory IgA monoclonal antibodies enriched fraction directly from cell culture medium using aqueous two-phase systems

Secretory immunoglobulin A [sIgA] is a promising candidate for enteric therapeutics applications, and several sIgA-based constructs are currently being developed by groups utilizing clarified Chinese hamster ovary [CHO] cell culture supernatants. To the monoclonal antibody downstream processing typically entails chromatography-based purification processes beginning with Protein A chromatography. In this paper, aqueous two-phase systems [ATPS] were employed for the preliminary purification of secretory immunoglobulin A [sIgA] monoclonal antibody [mAb] from clarified CHO-cell culture supernatants. A 24 full factorial design was utilized. The influence of various process parameters such as pH, PEG molecular weight [MPEG], PEG concentration [CPEG], and phosphate salt concentration [CPHO], on the sIgA partition coefficient [K sIgA] and the recovery index [Y] in the PEG phase were evaluated. The Elisa assay revealed that, in the ATPS conditions tested, sIgA mAb was mostly detected in PEG upper phase. Run 14 with the highest sIgA activity exhibited the following conditions: MPEG 8.000 g/mol, CPEG 12,5 %, pH 7,0 and CPHO 10 %, and a sIgA K of 94.50 and a recovery index [Y] of 33.52 %. The proposed platform provides straightforward implementation, yields comparable results, and offers significantly improved economics for manufacturing sIgA mAb biotherapeutics.

Reversing the Trend: Deciphering Self-Assembly of Unconventional Amphiphiles Having Both Alkyl-Chain and PEG.

In the field of molecular self-assembly, the core of an assembly is always made up of hydrophobic moiety like a long alkyl chain, whereas the outer part has always been a hydrophilic moiety such as poly(ethylene glycol) (PEG), or charged species. Hence, reversing the trend to manifest self-assembled structures with a PEG core and a surface consisting of alkyl chains in aqueous system is incredibly challenging. Herein, we architected a unique class of cationic bolaamphiphiles containing low molecular weight PEG and alkyl chains of different lengths. The bolaamphiphiles spontaneously form vesicles without external stimuli. These vesicles are unprecedented because PEG makes up the vesicle core, while the alkyl chains appear on the vesicles' exterior. Hence, this particular design reverses the usual trend of self-assembly formation. The vesicle size increases with the increase in alkyl chain-length. To our great surprise, we obtained large micelles for longest alkyl-chain amphiphile, which in turn act as a gemini amphiphile. The shift from a particular bolaamphiphile to gemini amphiphile with the variation of alkyl chain is also unexplored. Therefore, this specific class of self-assembled structure would compound a new paradigm in molecular self-assembly and supramolecular chemistry.

Crystallization-Induced Self-Assembly of Poly(ethylene glycol) Side Chains in Dithiol-yne-Based Comb Polymers: Side Chain Spacing and Molecular Weight Effects.

The chain architecture and topology of macromolecules impact their physical properties and final performance, including their crystallization process. In this work, comb polymers constituted by poly(ethylene glycol), PEG, side chains, and a dithiol-yne-based ring polymer backbone have been studied, focusing on the micro- and nanostructures of the system, thermal behavior, and crystallization kinetics. The designed comb system allows us to investigate the role of a ring backbone, the impact of varying the distance between two neighboring side chains, and the effect of the molecular weight of the side chain. The results reflect that the governing factor in the crystalline properties is the molar mass of the side chains and that the tethering of PEG chains to the ring backbone brings important constraints to the crystallization process, reducing the crystallinity degree and slowing down the crystallization kinetics in comparison to analogue PEG homopolymers. We demonstrate that the effect of spatial hindrance in the comb-like PEG polymers drives the morphology toward highly ordered, self-assembled, semicrystalline superstructures with either extended interdigitated chain crystals or novel (for comb polymers) interdigitated folded chain lamellar crystals. These structures depend on PEG molecular weight, the distance between neighboring tethered PEG chains, and the crystallization conditions (nonisothermal versus isothermal). This work sheds light on the role of chain architecture and topology in the structure of comb-like semicrystalline polymers.

Simple and Rapid Method of Microwell Array Fabrication for Drug Testing on 3D Cancer Spheroids.

Three-dimensional (3D) cell culture systems are becoming increasingly popular due to their ability to mimic the complex process of angiogenesis in cancer, providing more accurate and physiologically relevant data than traditional two-dimensional (2D) cell culture systems. Microwell systems are particularly useful in this context as they provide a microenvironment that more closely resembles the in vivo environment than traditional microwells. Poly(ethylene glycol) (PEG) microwells are particularly advantageous due to their bio-inertness and the ability to tailor their material characteristics depending on the PEG molecular weight. Although there are several methods available for microwell fabrication, most of them are time-consuming and expensive. The current study utilizes a low-cost laser etching technique on poly(methyl methacrylate) materials followed by molding with PDMS to produce microwells. The optimal conditions for making concave microwells are an engraving parameter speed of 600 mm/s, power of 20%, and a design diameter of the microwell of 0.4 mm. The artificial tumor achieved its full size after 7 days of cell growth in a microwell system, and the cells developed drugs through a live/dead assay test. The results of the drug testing revealed that the IC50 value of zerumbone-loaded liposomes in HepG2 was 4.53 pM, which is greater than the IC50 value of zerumbone. The HepG2 cancer sphere's 3D platform for medication testing revealed that zerumbone-loaded liposomes were very effective at high doses. These findings generally imply that zerumbone-loaded liposomes have the capacity to target the liver and maintain medication delivery.

Mesoscale mechanics investigation of multi-component solid propellant systems

Abstract To enhance the mechanical properties of the Nitrate Ester Plasticized Polyether solid propellant matrix, the uniaxial tension of multi-component systems is simulated and the factors influencing the mechanical properties of the propellant matrix are investigated. First, mesoscale models of five types of systems include poly alpha olefin (PAO(3)), polyethylene glycol (PEG200, PEG400, PEG600), and 1,4-butanediol (BDO) are established, followed by uniaxial tensile simulations. The results show PEG600, PEG400, PEG200, BDO, and PAO(3) in order of enhancing the mechanical performance of the matrix. Second, the diffusion behavior of nitroglycerin (NG) and butanetriol trinitrate (BTTN) in various systems is investigated. The results show that NG exhibits higher diffusion capacity than BTTN, and the diffusion coefficient increases with an increment in the molecular weight of PEG. Additionally, the influence of different plasticizer ratios (2.8–3.0), curing parameters (1.58–1.62), and chain extension parameters (0.08–0.10) on the mechanical properties of the PEG600 system are investigated. The results demonstrate that as the plasticizer ratio increases, there is a gradual decrease in the modulus of the matrix. Additionally, an increase in the curing parameter leads to a substantial enhancement in the tensile strength of the matrix, while increasing the chain extension parameter significantly expands the maximum tensile length of the matrix. Finally, employing the Slip-Spring model, the effects of the physical and chemical cross-linked network of the propellant are simulated. The result shows that increasing the content of a chemical cross-linked network significantly improves the tensile strength of the matrix.

Synthesis, physicochemical characterization, and investigation of anti-inflammatory activity of water-soluble PEGylated 1,2,4-Triazoles

A series of water-soluble PEGylated 1,2,4-triazoles 5–8 were successfully synthesized from methyl 5-(chloromethyl)-1-aryl-1H-1,2,4-triazole-3-carboxylates 1. All of the water-soluble PEGylated 1,2,4-triazoles were characterized by FT-IR and 1H NMR spectroscopy. The solubility, in vitro plasma stability, and anti-inflammatory activity were also determined and compared to original methyl 5-(halomethyl)-1-aryl-1H-1,2,4-triazole-3-carboxylates. For SAR study, all PEGylated 1,2,4-triazoles 5–8 performed potential anti-inflammatory activity on LPS-induced RAW 264.7 cells (IC50 = 3.42–7.81 μM). Moreover, the western blot result showed PEGylated 1,2,4-triazole 7d performed 5.43 and 2.37 folds inhibitory activity over iNOS and COX-2 expressions. On the other hand, the cell viability study revealed PEGylated 1,2,4-triazoles 7 and 8 with PEG molecular weight more than 600 presented better cell safety (cell viability > 95 %). Through the solubility and in vitro plasma stability studies, PEGylated 1,2,4-triazoles 7a–d exhibited higher hydrophilicity and prolonged 2.01 folds of half-life in compound 7d. Furthermore, the in vivo anti-inflammatory and gastric safety results indicated PEGylated 1,2,4-triazole 7d more effectively decreased the inflammatory response in edema and COX-2 expression and exhibited higher gastric safety than Indomethacin. Following the in vitro and in vivo study results, PEGylated 1,2,4-triazole 7d possessed favorable solubility, plasma stability features, safety, and significant anti-inflammatory activity to become the potential water-soluble anti-inflammatory candidate.

Sodium alginate/polyvinyl alcohol semi-interpenetrating hydrogels reinforced with PEG-grafted-graphene oxide

Semi-interpenetrating polymer network (SIPN) hydrogels composed of sodium alginate/poly (vinyl alcohol), reinforced by PEG-grafted-graphene oxide (GO-g-PEG) were prepared by ionic crosslinking of sodium alginate. The impact of grafted PEG molecular weight with two molecular weights, i.e. 400 and 2000 g/mol, and component composition were studied on the morphology, swelling behavior, mechanical and dynamic properties. SEM observation showed fine dispersion and distribution of GO-g-PEG throughout the hydrogel indicating a good interaction of particles with the components. Our results revealed that although incorporating GO-g-PEG increases the water content, it significantly enhances the mechanical properties, i.e. tensile modulus, elongation at break, and fracture toughness with a more pronounced impact at higher PEG molecular weight. As a result, the tensile modulus and the elongation at break increased by 270 % and 28 %, respectively. The SA/PVA SIPN hydrogels reinforced with the GO-g-PEG exhibit a non-linear elastic behavior with a toe at low strains. This behavior is attributed to the unique structural features of SIPN hydrogels and the orientation of GO-g-PEG particles with proper interaction with the components. The small amplitude oscillatory shear was also performed to further study the impact of SA, PVA, and GO-g-PEG compositions on the microstructure of hydrogels.

Low-Molecular-Weight PEGs for Cryopreservation of Stem Cell Spheroids

Stem cell spheroids (SCSs) are a valuable tool in stem cell research and regenerative medicine. SCSs provide a platform for stem cell behavior in a more biologically relevant context with enhanced cell–cell communications. In this study, we investigated the recovery of SCSs after cryopreservation at –196 °C for 7 days. Prior to cryopreservation, the SCSs were preincubated for 0 h (no preincubation), 2 h, 4 h, and 6 h at 37 °C in the presence of low-molecular-weight poly(ethylene glycol) (PEG) with molecular weights of 200, 400, and 600 Da. The recovery rate of SCSs was markedly affected by both the PEG molecular weight and the preincubation time. Specifically, when SCSs were preincubated with a PEG200 solution for 2 to 6 h, it significantly enhanced the recovery rate of the SCSs. Internalization of PEG200 through simple diffusion into the SCSs may be the cryoprotective mechanism. The PEG200 diffuses into the SCSs, which not only suppresses osmotic pressure development inside the cell but also inhibits ice formation. The recovered SCSs demonstrated both fusibility and capabilities for proliferation and differentiation comparable to SCSs recovered after dimethyl sulfoxide 10% cryopreservation. This study indicates that PEG200 serves as an effective cryoprotectant for SCSs. A simple preincubation procedure in the presence of the polymer greatly improves the recovery rate of SCSs from cryopreservation.

AIE/AEE tripodal PEGyl-melphalan supramolecules and detection of trinitrophenol in water.

Herein, the design of a novel aggregation-induced emission (AIE) supramolecular fluorescence sensor (TA-PEGn) based on a tridentate melphalan derivative and three different molecular weight PEGs is presented. The three TA-PEGn sensors could self-assemble into a supramolecular system in water and show sensitive and selective responses toward trinitrophenol.

Functional nanochaperones for PEGylated insulin delivery in long-term glycemic control.

PEGylation is a promising strategy for modulating the physicochemical properties and improving the therapeutic efficacy of protein drugs. However, the application of multi-PEGylation frequently results in diminished protein activity. A single low molecular weight PEG (5 kDa) modified at the amino terminus of the B chain preserves the biological activity of insulin and moderately improves its pharmacokinetics. Nonetheless, this modification offers limited protein stabilization. Furthermore, overdoses still carry the risk of hypoglycemia, posing challenges for the clinical application of PEGylated insulin. Here, we constructed multifunctional nanochaperones featuring phenylboronic acid (PBA) modified hydrophobic microdomains and nitrilotriacetic acid (NTA)-based coordination domains (PN-nChaps) for PEGylated insulin delivery. This delivery strategy effectively overcomes the limitations associated with PEGylation by enhancing the stability and reducing the immunogenicity of PEGylated insulin, while enabling glucose-responsive controlled release. PEGylated insulin with nanochaperone carrier demonstrates a prolonged half-life (t1/2 = 18.66 h), facilitates on-demand release, and minimizes the risk of hypoglycemia. This approach provides a safe and effective strategy for long-term glycemic management in diabetic patients.

Evaluation of solubility parameters and relative energy difference (RED) on the preparation of polysulfone/polyethylene glycol membrane: A study on the casting solution and coagulation bath

Solubility parameters are effective factors for controlling membrane preparation based on hydrophilic/hydrophobic polymers. Hansen solubility parameters (HSPs) of a polysulfone/polyethylene glycol (PSU/PEG) in increasing PEG molecular weights and binary coagulation bath of solvent/non-solvent mixtures are investigated. The results revealed that with increased PEG molecular weight in the casting solution, the relative energy difference (RED) of the solution increases, and subsequently its instability increases too. On the other hand, by increasing the solvent in the coagulation bath, RED decreases. Findings demonstrated that by increasing PEG molecular weight to 15,000 g/mol and increasing solvent to 60 wt% in the coagulation bath, an interconnected sponge-like structure with maximum mean pore size (120 nm) was achieved. With increased PEG molecular weight, membrane morphology tended toward to a sponge-like structure due to delayed demixing in the phase inversion stage. Furthermore, pure water permeability and rejection capability of membranes exhibited that with increasing RED of casting solution and reducing RED of coagulation bath, the highest permeability (2199 L/m2h and the lowest rejection capability (33%) of the membrane were attained. This study confirmed that, for the PSU/PEG system, by controlling the solubility parameters, RED value of casting solution and coagulation bath, membrane characteristics can be controlled.