Poly(ethylene Glycol) Diacrylate Research Articles

Improving the 3D Printability and Mechanical Performance of Biorenewable Soybean Oil-Based Photocurable Resins.

The general requirement of replacing petroleum-derived plastics with renewable resources is particularly challenging for new technologies such as the additive manufacturing of photocurable resins. In this work, the influence of mono- and bifunctional reactive diluents on the printability and performance of resins based on acrylated epoxidized soybean oil (AESO) was explored. Polyethylene glycol di(meth)acrylates of different molecular weights were selected as diluents based on the viscosity and mechanical properties of their binary mixtures with AESO. Ternary mixtures containing 60% AESO, polyethylene glycol diacrylate (PEGDA) and polyethyleneglycol dimethacrylate (PEG200DMA) further improved the mechanical properties, water resistance and printability of the resin. Specifically, the terpolymer AESO/PEG575/PEG200DMA 60/20/20 (wt.%) improved the modulus (16% increase), tensile strength (63% increase) and %deformation at the break (21% increase), with respect to pure AESO. The enhancement of the printability provided by the reactive diluents was proven by Jacobs working curves and the improved accuracy of printed patterns. The proposed formulation, with a biorenewable carbon content of 67%, can be used as the matrix of innovative resins with unrestricted applicability in the electronics and biomedical fields. However, much effort must be done to increase the array of bio-based raw materials.

Vat photopolymerization of dual-scale porosity alumina honeycombs using phase-separable camphene porogen dissolved in binary photopolymer blends

Dual-scale porosity ceramics comprised of macro-scale pore networks surrounded by porous frameworks manufactured by additive manufacturing (AM) can offer significantly enhanced functions compared to conventional porous ceramics. However, exploring new ways of more tightly controlling micro-scale porous structures for AM still remains challenging. Here, we propose a novel type of vat photopolymerization using camphene as a phase-separable porogen dissolved in binary photopolymer blends for manufacturing dual-scale porosity alumina honeycombs. More specifically, solid camphene with various contents (40 vol%, 50 vol%, and 60 vol%) could be completely dissolved in blends of triethylene glycol dimethacrylate (TEGDMA) and polyethylene glycol diacrylate (PEGDA) used as solvent and anti-solvent, respectively, at room temperature and then crystallize dendritically at ∼ 5 °C via phase separation. After which, thin layers of phase-separated alumina suspensions could be selectively photopolymerized by a digital light processing (DLP) engine to construct 3-dimensionally interconnected macro-scale pore channels. In addition, micro-scale pores could be created in alumina frameworks by removing camphene-rich crystals by freeze-drying. This new approach enabled manufacturing of well-defined macro-scale honeycomb structures with tailored micro-scale porosities. As the camphene content increased from 40 vol% to 60 vol%, micro-scale porosity increased from 39.1 ± 0.5 vol% to 57.5 ± 0.6 vol%, and thus the overall porosity increased from 58.5 ± 0.1 vol% to 68.8 ± 0.3 vol%, while the compressive strength decreased from 355.6 ± 67.1 MPa to 97.6 ± 10.2 MPa.

Li6.28La3Zr2Al0.24O12-reinforced Single-ion Conducting Composite Polymer Electrolyte for Room-Temperature Li-Metal Batteries

Composite polymer electrolytes composed of inorganic fillers and organic polymers are promising electrolyte candidates for Li metal batteries, with benefits of improved safety and suppressed lithium dendrite growth. However, a severe concentration polarization effect often occurs when using conventional dual-ion electrolytes, and the increase in internal impedance during cycling results in decreased lifespan of the battery. To address this challenge, a plasticized single-ion conducting composite polymer electrolyte (SICE) was designed and fabricated by polymerizing the monomers of lithium (4-styrenesulfonyl) (trifluoromethanesulfonyl) imide (LiSTFSI) and poly(ethylene glycol) methyl ether acrylate (PEGMEA), crosslinker poly(ethylene glycol) diacrylate (PEGDA), silane-modified Li6.28La3Al0.24Zr2O12 nanofibers (s@LLAZO NFs), along with a PEG-based plasticizer tetraethylene glycol dimethyl ether (TEGDME), by heat-initiation. The anions were restrained and delocalized so that only Li cation migration occurred during the charging/discharging process, leading to a superior lithium-ion transference number. The s@LLAZO NFs enabled direct monomer grafting with the polymer matrix, resulting in controlled formation of an organic-inorganic network with increased filler content and improved filler distribution in the SICE system. The SICE membrane exhibited high ionic conductivity at room temperature, reduced activation energy and excellent oxidation stability. Most importantly, the all-solid-state Li-metal batteries assembled with the fabricated SICE demonstrated stable long-term cycling performance and remarkable rate capability at room temperature.

Hydrogels based on crosslinked polyethylene glycol diacrylate and fish skin gelatin

The aim of this work was to develop hydrogels based on poly(ethylene glycol diacrylate) (PEGDA) and fish gelatin for potential biomedical applications such as wound healing, drug delivery and biosensors. The hydrogels were prepared via in situ Michael addition of ammonia crosslinker to PEGDA in the presence of cold-water fish skin gelatin that was used as an additive. The fabrication conditions and properties of the hydrogels were examined using various amounts of fish gelatin to evaluate the influence of its concentration on gelation time, crosslinking density and swelling behavior of the hydrogels. FTIR spectra confirmed the formation of the crosslinked hydrogels and the degree of conversion (DC) of the double bonds for the hydrogels containing 5, 7.5 and 10 % w/v of gelatin was between 72 and 80 %. Fish skin gelatin had a strong effect on the dimentional stability and water absorbing properties of the hydrogels and the system containing 7.5 % w/v gelatin exhibited the longest swelling time of 18 h. The hydrophobicity of the hydrogels was achieved by covalent grafting of the residual double bonds with thiol-containing small hydrocarbon molecules using thiol-ene click chemistry reaction conditions, leading to the increase of the water contact angle from 0° to 60-73°.

3D cross-linked POSS-containing borate single ion conductor organic-inorganic hybrid gel electrolytes for dendrite-free lithium metal batteries

At present, lithium (Li) metal has become the most promising anode for the next generation of batteries due to its excellent theoretical capacity and low electrochemical potential. Nevertheless, low lithium-ion transference numbers and poor stability between conventional electrolytes and electrodes limit its development. In this work, a novel three-dimensional cross-linked hybrid borate single ion conductor polymer electrolyte (POSS-BSICP) was constructed by coupling of novel synthesized lithium bis-allylmalonate borate (LiBAMB), poly (ethylene glycol) diacrylate (PEGDA) and vinyl-containing caged poly(sesquisiloxane) (MAPOSS) in the presence of pentaerythritol tetrakis(mercaptoacetate) (PETMP) as cross-linker and PVDF-HFP as support materials through UV-thermal Dual-Curing procedures. As expected, the lithium-ion transference number and electrochemical stability of the hybrid electrolyte membranes improve with the incorporation of MAPOSS. The tLi+ is up to 0.82 and the electrochemical window reaches 5.50 V. The Li/Li cell assembled with the POSS-containing single ion conductor gel polymer electrolytes can be subjected to stripping/plating cycles without short circuit over 2700 h at 0.1 mA cm−2, the peak of the SiO bond at 102.3 eV in the Si 2p spectrum confirms that the POSS participate in the formation of SEI, indicating that the incorporation of MAPOSS could increase the compatibility between the electrolytes and electrode. The Li|POSS-BSICP|LiFePO4 cell exhibits excellent cycle performance with a capacity retention over 90 % after 170 cycles and 82.0 % after 290 cycles at 0.1 C.

Regulating and understanding the compatibility of sulfide composite solid-state electrolyte in nickel-rich lithium metal batteries

In the pursuit of high-energy-density lithium batteries, composite solid-state electrolytes are highly favored due to the combination of flexibility and acceptable ionic conductivity. However, challenges such as unpredictable lithium dendrite growth, cathode material structural instability, and oxidative resistance at high voltages pose significant hurdles for solid-state batteries. To investigate the synergistic interactions of polymers and sulfides, a hybrid poly (1,3-dioxolane) and poly (polyethylene glycol diacrylate) blend was designed through in-situ polymerization, allowing LiFePO4//Li batteries to achieve an average coulombic efficiency exceeding 99% at 0.5C and stable cycling for at least 1000 h in lithium symmetric cells. Computational analysis and component detection demonstrate the stability of the components and the formation of a LiF-stabilized anode from lithium salt decomposition. Similarly, on the cathode side, when Li3PO4-coated LiNi0.6Co0.2Mn0.2O2 is used as the cathode material, a more stable interface suppresses cathode particles' collapse and harmful electrolytes’ decomposition. In ambient environments, after 200 cycles at 0.5C, the capacity retention remains as high as 90.48%. Impedance changes by in-situ methods and component composition were further analyzed. This work integrates multiple methods and stabilizes and validates the anode and cathode interface, providing a promising approach and strategy for designing high-performance sulfide composite solid-state batteries.

Ultrafast Sunlight-Induced Polymerization: Unveiling 2-Phenylnaphtho[2,3-d]Thiazole-4,9-dione as a Unique Scaffold for High-Speed and Precision 3D Printing.

A series of 15 dyes based on the 2-phenylnaphtho[2,3-d]thiazole-4,9-dione scaffold and 1 compound based on the 2,3-diphenyl-1,2,3,4-tetrahydrobenzo[g]quinoxaline-5,10-dione scaffold are studied as photoinitiators. These compounds are used in two- and three-component high-performance photoinitiating systems for the free radical polymerization of trimethylolpropane triacrylate (TMPTA) and polyethylene glycol diacrylate (PEGDA) under sunlight. Remarkably, the conversion of TMPTA can reach ≈60% within 20s, while PEGDA attains a 96% conversion within 90s. To delve into the intricate chemical mechanisms governing the polymerization, an array of analytical techniques is employed. Specifically, UV-vis absorption and fluorescence spectroscopy, steady-state photolysis, stability experiments, fluorescence quenching experiments, cyclic voltammetry, and electron spin resonance spin trapping (ESR-ST) experiments, collectively contribute to a comprehensive understanding of the photochemical mechanisms. Photoinitiation capacities of these systems are determined using real-time Fourier transformed infrared spectroscopy (RT-FTIR). Of particular interest is the revelation that, owing to the superior initiation ability of these dyes, high-resolution 3D patterns can be manufactured by direct laser write (DLW) technology and 3D printing. This underscores the efficient initiation of free radical polymerization processes by the newly developed dyes under both artificial and natural light sources, presenting an avenue for energy-saving, and environmentally friendly polymerization conditions.

Superlubricity Achieved by a Transparent Poly(vinylpyrrolidone) Composite Hydrogel with Glycerol Ethoxylate in Ocular Conditions.

Efficient and stable ocular lubrication is pivotal in safeguarding eye tissues from wear, especially under repetitive strain due to frequent blinking. Hydrogels have been reported to possess adjustable mechanical properties, biocompatibility, durability, and elevated water content and extensive utilization in medical fields. In this work, a kind of visible photo-cross-linking poly(vinylpyrrolidone) (PVP) hydrogel was designed and synthesized using 1-vinyl-2-pyrrolidone (NVP) and poly(ethylene glycol) diacrylate (PEGDA). To optimize the structure and improve the lubrication performance of hydrogels, we prepared and investigated glycerol ethoxylate (GE)-introduced composite hydrogels (GE/PVP). The results show that the addition of 3 wt % GE helped the hydrogel to form a uniform and dense porous matrix and reduce the frictional coefficient (COF) by over 50%, achieving superlubricity (COF ≈ 0.005). However, with the excessive increase of GE (6 wt %), the structure of the hydrogel is destroyed, inducing pore walls to thin and expand. After that, a lubrication mechanism of the GE/PVP composite hydrogel was proposed, in which the addition of GE reduced the surface tension of the hydrogel, enhanced the hydration ability of the hydrogel, and thus decreased the friction between sliding surfaces. Besides, the cytotoxicity tests show that the composite hydrogels possess good biocompatibility. Overall, the as-synthesized hydrogels hold great potential as lubricating medium for use in ocular applications.

Fabrication and Characterization of Quad-Component Bioinspired Hydrogels to Model Elevated Fibrin Levels in Central Nervous Tissue Scaffolds.

Multicomponent interpenetrating polymer network (mIPN) hydrogels are promising tissue-engineering scaffolds that could closely resemble key characteristics of native tissues. The mechanical and biochemical properties of mIPNs can be finely controlled to mimic key features of target cellular microenvironments, regulating cell-matrix interactions. In this work, we fabricated hydrogels made of collagen type I (Col I), fibrin, hyaluronic acid (HA), and poly (ethylene glycol) diacrylate (PEGDA) using a network-by-network fabrication approach. With these mIPNs, we aimed to develop a biomaterial platform that supports the in vitro culture of human astrocytes and potentially serves to assess the effects of the abnormal deposition of fibrin in cortex tissue and simulate key aspects in the progression of neuroinflammation typically found in human pathologies such as Alzheimer's disease (AD), Parkinson's disease (PD), and tissue trauma. Our resulting hydrogels closely resembled the complex modulus of AD human brain cortex tissue (~7.35 kPa), promoting cell spreading while allowing for the modulation of fibrin and hyaluronic acid levels. The individual networks and their microarchitecture were evaluated using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Human astrocytes were encapsulated in mIPNs, and negligible cytotoxicity was observed 24 h after the cell encapsulation.

Remodeling Microenvironment for Implant-Associated Osteomyelitis by Dual Metal Peroxide.

Implant-associated osteomyelitis (IAOM) is characterized by bone infection and destruction; current therapy of antibiotic treatment and surgical debridement often results in drug resistance and bone defect. It is challenging to develop an antibiotic-free bactericidal and osteogenic-enhanced strategy for IAOM. Herein, an IAOM-tailored antibacterial and osteoinductive composite of copper (Cu)-strontium (Sr) peroxide nanoparticles (CSp NPs), encapsulated in polyethylene glycol diacrylate (PEGDA) (CSp@PEGDA), is designed. The dual functional CSp NPs display hydrogen peroxide (H2O2) self-supplying and Fenton catalytic Cu2+ ions' release, generating plenty of hydroxyl radical (•OH) in a pH-responsive manner for bacterial killing, while the released Sr2+ promotes the in vitro osteogenicity regarding cell proliferation, alkaline phosphatase activity, extracellular matrix calcification, and osteo-associated genes expression. The integration of Cu2+ and Sr2+ in CSp NPs together with the coated PEGDA hydrogel ensures the stable and sustainable ion release during short- and long-term periods. Benefitted from the injectablity and photo-crosslink ability, CSp@PEGDA is able to thoroughly fill the infectious site and gelate in situ for bacterial elimination and bone regeneration, which is verified through in vivo evaluation using a clinical-simulating IAOM mouse model. These favorable abilities of CSp@PEGDA precisely meet the multiple therapeutic needs and pave a promising way for implant-associated osteomyelitis treatment.

Gelatin methacrylate based liquid dressing with antibacterial and hemostasis properties

For incompressible and irregularly shaped wounds, developing a novel dressing based on photo-crosslinked hydrogel that has both hemostasis and antibacterial functions is highly desirable. In this study, photoreactive substrate gelatin methacrylate (GelMA) and Poly (ethylene glycol) diacrylate (PEGDA) were combined with water-soluble quaternary ammonium antibacterial monomers (DMC). Interestingly, they can quickly change from liquid to hydrogel under visible light at 405 nm within 1 min, which is suitable for small incompressible wounds. Regarding the biosafety of the dressing, cell viability and blood viability test indicated that the GelMA/PEGDA/DMC3 dressing has no cytotoxicity toward L929 cells and red blood cells. The antibacterial performance test proved that the addition of DMC significantly improved the antibacterial performance of the dressing. Moreover, the GelMA/PEGDA/DMC3 dressing showed rapid hemostasis ability in tail clipping hemostasis test and liver hemostasis test. Taken together, this new type of convenient hydrogel dressing exhibits great potential as a quick hemostasis and antibacterial wound dressing candidate for small bleeding wounds.

Adipose-derived stem cells loaded photocurable and bioprintable bioinks composed of GelMA, HAMA and PEGDA crosslinker to differentiate into smooth muscle phenotype

Developing a polymer-based photocrosslinked 3D printable scaffolds comprised of gelatin methacryloyl (G) and hyaluronic acid methacryloyl (H) incorporated with two molecular weights of polyethylene glycol diacrylate (P) of various concentrations that enables rabbit adipose-derived stem cells (rADSCs) to survive, grow, and differentiate into smooth muscle cells (SMCs). Then, the chemical modification and physicochemical properties of the PGH bioinks were evaluated. The cell viability was assessed via MTT, CCK-8 assay and visualized employing Live/Dead assay. In addition, the morphology and nucleus count of differentiated SMCs were investigated by adopting TRAP (tartrate-resistant acid phosphatase) staining, and quantitative RT-PCR analysis was applied to detect gene expression using two different SMC-specific gene markers α-SMA and SM-MHC. The SMC-specific protein markers namely α-SMA and SM-MHC were applied to investigate SMC differentiation ability by implementing Immunocytofluorescence staining (ICC) and western blotting. Moreover, the disk, square, and tubular cellular models of PGH7 (GelMA/HAMA=2/1) + PEGDA-8000 Da, 3% w/v) hybrid bioink were printed using an extrusion bioprinting and cell viability of rADSCs was also analysed within 3D printed square construct practising Live/Dead assay. The results elicited the overall viability of SMCs, conserving its phenotype in biocompatible PGH7 hybrid bioink revealing its great potential to regenerate SMCs associated organs repair.

3D printing of melatonin-loaded esophageal stents for treatment of corrosive esophagitis

Corrosive esophagitis (CE) is a severe disease caused by accidental or suicidal ingestion of corrosive chemical agents, leading to serious esophageal stenosis or fibrosis. However, the effective and safe treatment of CE is lacking. Here, a melatonin esophagus stent (MES) was prepared using the stereolithography three-dimensional (3D) printing technology with melatonin, polyethylene glycol diacrylate (PEGDA), polyethylene glycol (PEG) 400, and other additives. The MESs with the Roman columns, caduceus, Pagoda, and mace morphologies were designed and printed, respectively. Pagoda MESs exhibited good mechanical properties, retained in the esophagus for more than 24 h, and showed rapid melatonin release. MESs had high in vitro and in vivo safety. More importantly, the implanted MES was broken down into fragments in the gastrointestinal tract and then completely evacuated from the rat body. The CE rat model was established by injecting a strong alkaline solution into the esophagus. The Pagoda MES was conveniently implanted at the injury position, which remarkably alleviated the CE symptoms, reduced inflammation, and prevented esophagus stenosis and fibrosis. 3D-printed Pagoda MESs hold promise for the treatment of CE.

The role of pores in structure of polyethylenglycol diacrylate based‐inverse opal photonic crystal in binding protein applicable to optical biosensor

AbstractHere, the role of pores in the structure of inverse opal photonic crystals (IOPC) in binding proteins in comparison with their parent photonic crystal (PC) templates has been investigated. For this purpose, polyethyleneglycol diacrylate (PEGDA) coated with SiO2‐based PC (PEGDA/SiO2‐based PC) and PEGDA‐based IOPC were attached with fluorophore Alexa 488, which is a polyclonal secondary antibody, to investigate their fluorescence emission. Scanning electron microscopy (SEM) images showed face centered cubic (fcc) packing of the PEGDA/SiO2‐based PC. And it remained after the formation of PEGDA‐based IOPC. The presence of 3‐aminopropyl triethoxysilane (APTES) and Alexa 488 that immobilized the PEGDA‐based PC and PEGDA‐based IOPC was recognized by the appearance of bands at 850, 1175, and a dominant increase in the band at 1750 cm−1. Those were attributed to (N─H) wagging, (C─N) stretching, and (C═O) stretching vibrations, respectively. Reflectance spectra showed a blue shift of the Bragg photonic band gap of the PEGDA‐based IOPC in comparison with that of the PEGDA/SiO2‐based PC. The fluorescence images showed a significant increase in the fluorescence intensity of PEGDA‐based IOPC owing to the resonance effect. These obtained results indicated the role of pores in structure of PEGDA‐based IOPC in improvement of the attachment of Alexa 488 protein.

Imiquimod nanocrystal-loaded dissolving microneedles prepared by DLP printing.

The utilization of 3D printing- digital light processing (DLP) technique, for the direct fabrication of microneedles encounters the problem of drug solubility in printing resin, especially if it is predominantly composed of water. The possible solution how to ensure ideal belonging of drug and water-based printing resin is its pre-formulation in nanosuspension such as nanocrystals. This study investigates the feasibility of this approach on a resin containing nanocrystals of imiquimod (IMQ), an active used in (pre)cancerous skin conditions, well known for its problematic solubility and bioavailability. The resin blend of polyethylene glycol diacrylate and N-vinylpyrrolidone, and lithium phenyl-2,4,6-trimethylbenzoylphosphinate as a photoinitiator, was used, mixed with IMQ nanocrystals in water. The final microneedle-patches had 36 cylindrical microneedles arranged in a square grid, measuring approximately 600μm in height and 500μm in diameter. They contained 5wt% IMQ, which is equivalent to a commercially available cream. The homogeneity of IMQ distribution in the matrix was higher for nanocrystals compared to usual crystalline form. The release of IMQ from the patches was determined ex vivo in natural skin and revealed a 48% increase in efficacy for nanocrystal formulations compared to the crystalline form of IMQ.

The effect of triglycerol diacrylate on the printability and properties of UV curable, bio-based nanohydroxyapatite composites

3D printable biopolymer nanocomposites composed of hydroxyapatite nanoparticles and functionalized plant-based monomers demonstrate potential as sustainable and structural biomaterials. To increase this potential, their printability and performance must be improved. For extrusion-based 3D printing, such as Direct Ink Writing (DIW), printability is important for print fidelity. In this work, triglycerol diacrylate (TGDA) was added to an acrylated epoxidized soybean oil:polyethylene glycol diacrylate resin to increase hydrogen bonding. Greater hydrogen bonding was hypothesized to improve printability by increasing the ink's shear yield strength, and therefore shape holding after deposition. The effects of this additive on material and mechanical properties were quantified. Increased hydrogen bonding due to TGDA content increased the ink's shear yield stress and viscosity by 916% and 27.6%, respectively. This resulted in improved printability, with best performance at 3 vol% TGDA. This composition achieved an ultimate tensile strength (UTS) of 32.4 ± 2.1 MPa and elastic modulus of 1.15 ± 0.21 GPa. These were increased from the 0 vol% TGDA composite, which had an UTS of 24.8 ± 1.8 MPa and a modulus of 0.88 ± 0.06 GPa. This study demonstrates the development of bio-based additive manufacturing feedstocks for potential uses in sustainable manufacturing, rapid prototyping, and biomaterial applications.

Clay Sculpture-Inspired 3D Printed Microcage Module Using Bioadhesion Assembly for Specific-Shaped Tissue Vascularization and Regeneration.

3D bioprinting techniques have enabled the fabrication of irregular large-sized tissue engineering scaffolds. However, complicated customized designs increase the medical burden. Meanwhile, the integrated printing process hinders the cellular uniform distribution and local angiogenesis. A novel approach is introduced to the construction of sizable tissue engineering grafts by employing hydrogel 3D printing for modular bioadhesion assembly, and a poly (ethylene glycol) diacrylate (PEGDA)-gelatin-dopamine (PGD) hydrogel, photosensitive and adhesive, enabling fine microcage module fabrication via DLP 3D printing is developed. The PGD hydrogel printed micocages are flexible, allowing various shapes and cell/tissue fillings for repairing diverse irregular tissue defects. In vivo experiments demonstrate robust vascularization and superior graft survival in nude mice. This assembly strategy based on scalable 3D printed hydrogel microcage module could simplify the construction of tissue with large volume and complex components, offering promise for diverse large tissue defect repairs.

Poly(ethylene glycol)(PEG)-cryogels: A novel platform towards enzymatic electrochemiluminescence (ECL)-based sensor applications

Enzymes-based electrochemical biosensors require the immobilisation of the enzymes on the electrode surfaces as well as their storage in aqueous environments to maintain the enzymatic activity. Herein, we described an enzyme-based electrochemiluminescence biosensor fabricated by incorporating oxidase enzymes (horseradish peroxidase, HRP; glucose, GOx, lactate, LOx, and cholesterol oxidases, ChOx) within poly(ethylene glycol)diacrylate (PEGDA) cryogels, which retain their activity when stored in dry conditions. The redox reactions between the oxidase enzymes and their corresponding substrates produce hydrogen peroxide that can be detected in the presence of a layer of polyluminol deposited on the electrode surface. These oxidases PEG-based cryogels were characterized using cyclic voltammetry and electrochemiluminescence (ECL) to assess the redox reactions between the enzymes and the corresponding substrates. The proposed biosensors were characterised by good stability and repeatability with a calculated limit of detections (LODs) in the micromolar concentration range. The performances of PEG cryogels over the time evidenced the stability of the as-prepared materials up to 30 days in dry conditions, confirming good retention of the encapsulated enzymes. Furthermore, the biosensors were tested in the presence of interferent species showing good selectivity. Finally, these oxidases-PEG cryogels were tested in real samples (commercial contact lenses, artificial sweat and commercial milk) confirming the suitability of such material for the detection of hydrogen peroxide with calculated LoDs as 10.37 ± 0.4 µM for HRP/contact lenses liquid; 3.87 ± 0.3 µM for GOx/artificial sweat; 1.09 ± 0.6 µM for LOx/artificial sweat; and 6.59 ± 0.5 for ChOx/milk.

Transport of carboxylate salts of varying chain lengths in crosslinked polyether membranes

Carboxylate anions of various chain lengths are important molecules for many applications such as CO2 reduction, membrane-based bioreactors, etc. Also, carboxylate anions are ubiquitous in biological molecules such as amino acids, fatty acids, etc. Therefore, understanding the transport behavior of carboxylates of different chain lengths in polymer materials is important both as a fundamental phenomenon but also for designing materials for applications. Here, we characterized transport behavior by measuring the permeability (P), and total partition coefficient (K) for a series of polymer membranes for four model carboxylate salts—sodium salts of formate (NaOFm), acetate (NaOAc), propionate (NaOPr), and butanoate (NaOBu)—at varied upstream salt concentrations (0.1–1 M) or a series of polyethylene glycol diacrylate (PEGDA)-based membranes with 1) varying pre-polymerization water content; 2) varying uncharged side chain comonomer (polyethylene glycol methacrylate, PEGMA), and 3) varying charged comonomer)2-acrylamido-2-methyl-1-propanesulfonic acid, AMPS). Also, diffusivity values of the four salts through the membranes have been calculated based on the solution diffusion model equation (PK × D), experimentally obtained permeability, and total partition coefficients. For a majority of these membranes, NaOFm's permeability is much higher than the other three carboxylate salts (NaOAc, NaOPr, and NaOBu) seemingly due to the lower chain length and thereby smaller hydrated diameter. In terms of total partition coefficient, a size-based trend is not observed. For example, NaOBu's total partition coefficient (K) is generally the largest among the four, and at higher upstream salt concentrations (1 M), the values of the total partition coefficients of the four salts converge. From this we conclude that the carboxylate salt transport through these PEGDA-based non-porous dense membranes to be primarily driven by kinetics and not sorption.

Construction of a PEGDA/chitosan hydrogel incorporating mineralized copper-doped mesoporous silica nanospheres for accelerated bone regeneration

Hydrogels, integrating diverse biocompatible materials, have emerged as promising candidates for bone repair applications. This study presents a double network hydrogel designed for bone tissue engineering, combining poly(ethylene glycol) diacrylate (PEGDA) and chitosan (CS) crosslinked through UV polymerization and ionic crosslinking. Concurrently, copper-doped mesoporous silica nanospheres (Cu-MSNs) were synthesized using a one-pot method. Cu-MSNs underwent additional modification through in-situ biomineralization, resulting in the formation of an apatite layer. Polydopamine was employed to facilitate the deposition of Calcium (Ca) and Phosphate (P) ions on the surface of Cu-MSNs (Cu-MSNs/PDA@CaP). Composite hydrogels were created by integrating varied concentrations of Cu-MSNs/PDA@CaP (25, 50, 100, 150, 200 μg/mL). Characterization unveiled distinctive interconnected porous structures within the composite hydrogel, showcasing a notable 169.6 % enhancement in compressive stress (elevating from 89.01 to 240.19 kPa) compared to pure PEGDA. In vitro biocompatibility experiments illustrated that the composite hydrogel maintained elevated cell viability (up to 106.6 %) and facilitated rapid cell proliferation over 7 days. The hydrogel demonstrated a substantial 57.58 % rise in ALP expression and a surprising 235.27 % increase in ARS staining. Moreover, it significantly enhanced the expression of crucial osteogenic genes, such as run-related transcription factors 2 (RUNX2), collagen 1a1 (Col1a1), and secreted phosphoprotein 1 (Spp1), establishing it as a promising scaffold for bone regeneration. This study shows how Cu-MSNs/PDA@CaP were successfully integrated into a double network hydrogel, resulting in a composite material with good biological responses. Due to its improved characteristics, this composite hydrogel holds the potential for advancing bone regeneration procedures.