Diphenylphosphine Oxide Research Articles

One‐Pot Transformation Strategy of o‐Hydroxyphenyl Propargylamines for Modular Access to 3‐Functionalized Benzofurans

AbstractA one‐pot strategy to C3‐functioanlized benzofurans is achieved from o‐hydroxyphenyl propargylamines (o‐HPPAs). 3‐Aminobenzofurans were obtained in 64–96% yields through the cascade alkyne‐allene tautomerization and 5‐exo‐dig annulation of o‐HPPAs in the presence of KOH/NaOtBu as the fruitful base combination. Moreover, with benzenesulfinates and diphenylphosphine oxide as nucleophiles, a one‐pot protocol towards these derivatives was also demonstrated through a cascade 1,4‐conjugate addition/5‐exo‐dig annulation/aromatization process. Additionally, a gram‐scale synthesis and further transformation into other valuable functionalized benzofurans were conducted to show the potential in organic synthesis of these developed synthetic approaches.

Diphenylphosphine oxide derivative with a symmetrical structure as an efficient flame retardant for application in epoxy resin

AbstractA fresh phosphorus‐containing fireproofing agent (oxybis(4,1‐phenylene))bis((2,5‐dihydroxyphenyl)(phenyl)phosphine oxide) (ODDPO‐HQ) was synthesized by a simple two‐step reaction. The effect of ODDPO‐HQ on the glass transition temperature (Tg), crosslinking density, thermal stability, fire resistance, dielectric performances, hydrophobicity, and water absorption of epoxy resin (EP) was studied. EP/ODDPO‐HQ containing 1.2 wt% phosphorus not only achieved the vertical burning V‐0 grade with a limited oxygen index of 28.9% but also maintained good thermal stability. Compared to unmodified EP, its Tg value has only decreased by 7.2°C. Detailed studies revealed that the excellent flame resistance of ODDPO‐HQ for epoxies was ascribed to the flame suppression both in the gaseous phase and condensed phase, especially the obvious barrier effect. Although the water uptake of the modified epoxies slightly rose with the content of ODDPO‐HQ caused by the reduction of the crosslinking density within the matrix, it did not adversely affect the properties of the polymer. The modified epoxies showed reduced dielectric constant and dielectric loss values, and the contact angle of EP/ODDPO‐HQ samples increased as the flame retardant content rose, which might be due to the symmetrical structure of ODDPO‐HQ reducing the polarity. Our study presents an easy approach for producing high‐performance epoxies.

Dimesitylborane as Electron Accepting Unit in High Performance Yellow Single-Layer Phosphorescent Organic Light Emitting Diode.

A new host material for Single-Layer Phosphorescent Organic Light-Emitting Diodes (SL-PhOLED) is reported, namely SPA-2-FDMB, using the dimesitylborane (DMB) fragment as an acceptor unit. The molecular design is constructed on the general donor-spiro-acceptor architecture, which consists of connecting, via a spiro bridge, a donor and an acceptor units in order to avoid strong interaction between them. The DMB fragment is known for many electronic applications (notably Aggregation-Induced Emission) but has not been used yet for SL-PhOLED applications. This appears particularly interesting, as the development of this simplified technology has shown that only a few electron-accepting fragments such as diphenylphosphine oxide can provide high-performance devices. Herein, the yellow-emitting SL-PhOLED using SPA-2-FDMB as host presents an External Quantum Efficiency of 8.1% (Current Efficiency of 24.9cd.A-1) with a low threshold voltage of 2.6V. As SPA-2-FDMB presents a sharp HOMO/LUMO difference, the good matching of HOMO and LUMO energy levels with the Fermi level of the electrodes is responsible for these performances. The low LUMO level of -2.61eV also appears particularly important. These performances are, to date, the highest reported for a yellow/orange-emitting SL-PhOLED and show the potential of DMB unit in the single-layer technology.

Functional Ligand‐Modified Perovskite Quantum Dots for Stable Full‐Color Microarrays via Photopolymerization

AbstractIntegration of lead‐halide perovskite quantum dots (PQDs) into full‐color microarrays presents numerous advantages for full‐color micro‐LED displays. There is an urgent requirement for a new design approach that simplifies the creation of durable PQD/polymer composites to produce stable PQD microarrays. Here, mono‐2‐(methacryloyloxy)ethyl succinate (MMeS) is utilized as a functional ligand to synthesize green MMeS‐modified CsPbBr3 PQDs (M‐CPB PQDs). The subsequent photopolymerization of M‐CPB PQDs with 1,6‐hexanediol diacrylate (HDDA) forms a CsPbBr3 PQD/polymer composite. This composite exhibits a solid‐state photoluminescence quantum yield of 73.1%, and the photoluminescence intensity retains 72% of its original value after 17 days of continuous immersion in water. Stable green PQD/polymer microarrays can be printed using an ink containing M‐CPB PQDs, HDDA, diphenyl (2,4,6‐trimethylbenzoyl) phosphine oxide, and n‐dodecane via electrohydrodynamic jet printing and in situ polymerization under UV light irradiation. Full‐color patterns can also be generated with MMeS‐modified red, green, and blue PQDs. These findings highlight the critical role of functionalizing the surface ligands of PQDs to improve their processability, thereby facilitating the development of stable PQD/polymer microarrays.

Customized bioresin formulation for stereolithography in tissue engineering

Recently, advancements in fabrication technology have brought a new aspect to the field of tissue engineering. By utilizing advanced techniques in 3D manufacturing and biomaterials, scientists have successfully created tissue engineering scaffolds with complex three-dimensional structures and customized chemical compositions that closely mimic the natural environment of living tissues. These methodologies show potential not only for developing therapies that restore lost tissue function but also for creating in vitro models that replicate living tissue. The current investigation involved the synthesis of methacrylated polycaprolactone (PCLMA) by incorporating methacryloyl chloride (Meth-Cl) into polycaprolactone (PCL) with a molecular weight of 80,000 Da. Afterwards, PCLMA was subjected to crosslinking with glycerol acrylate (GA) and, by utilizing Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator, achieved the three-dimensional (3D) printing of tissue materials using Stereolithography (SLA). Analytical techniques included nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cell viability was investigated using Human Osteoblast (HOB) cells. The biocompatibility of glycerol acrylate (GA) crosslinked polymethacrylated polycaprolactone (PCLMA) was confirmed using cell viability experiments. Overall, the GA-crosslinked PCLMA bioresin, particularly PCLMA-8, shows promise for further use in tissue engineering applications.

Acyl Iodide Synthesis from Carboxylic Acids Using a Novel Ph2P(O)H‐I2 Binary System and Its Application to Facile Preparation of Amides, Esters, and Thioesters

AbstractAcyl iodides are expected to be excellent acylating agents due to the low bond dissociation energy of the carbon–iodine bond and the high capability of iodine as a leaving group. Unfortunately, the preparative methods for acyl iodides directly from carboxylic acids are rather limited. In this work, we found that a novel binary system combining I2 and diphenylphosphine oxide (Ph2P(O)H) provides a simple method for the preparation of acyl iodides from carboxylic acids. Furthermore, the subsequent one‐pot reaction with appropriate nucleophiles, such as amines, alcohols, and thiols, afforded the corresponding amides, esters, and thioesters, respectively, in good to excellent yields.

Comparison of composite resins containing UV light-sensitive chitosan derivatives in stereolithography (SLA)-3D printers.

This study produced composite resins by combining acrylate, chitosan (CH), carboxymethyl chitosan (CMCH), hydroxypropyl chitosan (HPCH), and hydroxyethyl chitosan (HECH) to create materials suitable for use in 3D stereolithography (SLA) printers. Tripropylene glycol diacrylate (TPGDA), urethane acrylate (UA), and photoinitiator (Diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO)) were mixed. CH and its derivatives were added separately to the resin to obtain composite resins. The mechanical test results are clear; the optimum TPGDA: UA ratio was 1:1, the cure time was 60s, and the TPO ratio was 1%. The optimum viscosity of the resin is 340-350cP. Hydrophobic/hydrophilic properties of cured composite resins were examined. The addition of CH and its derivatives to the resin caused a decrease in compressive strength. Adding up to 2.5% CH, CMCH, and HECH to the resin significantly increased the tensile strength of the resin, giving it flexibility. The gel content of cured composite resins was between 97.72% and 96.11%. The cured composite resins demonstrated high chemical and solvent resistance to HCl, NaOH, and HF but exhibited limited resistance to toluene and chloroform. The accelerated UV aging test results show that adding CH derivatives to the resin makes the composite resin more prone to photooxidative aging.

Selective Synthesis of Mono- and Bis-Phosphorylated (Dihydro)pyrans via TMSCl-Mediated Cascade Phosphorylation Cycloisomerization of Enynones.

A chlorotrimethylsilane (TMSCl)-mediated cascade phosphorylation and cycloisomerization of enynones with diphenylphosphine oxides is presented. This methodology enables the highly selective synthesis of monophosphorylated 2H-pyrans and bisphosphorylated dihydropyrans through precise solvent-reagent stoichiometry control. The strategy demonstrated excellent functional group compatibility and high yields (up to 96%), providing facile access to structurally diverse phosphorylated heterocycles with potential applications in medicinal chemistry and materials science.

In Situ Ligand-Transformation-Assisted Assembly of a Polyoxometalate and Silver-Phosphine Oxide Cluster for Colorimetric Detection of Phenol Contaminants.

In situ ligand transformation strategies represent an efficient pathway for constructing function-oriented polyoxometalate (POM)-based crystalline materials. Herein, three POM-based hybrid networks were synthesized through in situ transformation of the phosphine ligand, formulated as [Ag(dppeo)6][H2PMo12O40]·5H2O (1), [Ag(dedpo)]4[SiW12O40]·6H2O (2), and [Ag(dppeo)]3[PW12O40]·3H2O (3) (dedpo = (2-(diphenylphosphaneyl)ethyl)diphenylphosphine oxide; dppeo = ethane-1,2-diylbis(diphenylphosphine oxide)). During the synthesis of these compounds, the 1,2-diphenylphosphine ethane molecule underwent in situ oxidation, transforming into dppeo and dedpo ligands, respectively. Compound 1 features a supramolecular architecture assembled from [Ag(dppeo)3]+/[Ag2(dppeo)6]2+ cationic clusters with disordered Ag centers and protonated [H2PMo12O40]- anions. Compound 2 presents a 3-D POM-supported metal-organic framework consisting of binuclear [Ag(dedpo)]22+ units, {-dedpo-Ag-dedpo-} chains, and [SiW12O40]4- polyoxoanions. Compound 3 displays a 2-D layered structure formed by {-dppeo-Ag3-dppeo-} chains and [PW12O40]3- clusters. Pronounced argentophilic interactions are observed in compounds 1 and 3. The three compounds demonstrate satisfactory heterogeneous catalytic activity in the colorimetric detection reactions toward phenol pollutants with detection limits of 1.73, 1.92, and 4.6 μM, respectively. Additionally, compounds 1-3 show high anti-interference capabilities and high sensitivity in differentiating phenol from its halogenated derivatives. This work presents some guidance for designing specific function-oriented POM-based materials via an in situ ligand transformation strategy.

Luminescent Platinum(II) Complexes with Stimuli-Responsive Flexible Lewis Pair Ligands: Spectroscopic and Computational Studies.

A series of new luminescent bimetallic platinum(II) complexes with stimuli-responsive flexible Lewis pair (FlexLP) ligands are described. The FlexLP ligands consist of a dimesitylboron Lewis acid and diphenylphosphine oxide Lewis base which are in equilibrium between the unbound open form and the Lewis adduct, controlled by the hydrogen bond donating strength of the solvent. Spectroscopic techniques and density functional theory (DFT) calculations were used to interpret the photophysics of the platinum(II) complexes. All complexes exhibit tunable absorption in the region of 300-500 nm and green to orange photoluminescence, depending on the ratio of weak (THF) to strong (MeOH) hydrogen bond donating solvent employed. Spectroscopic and computational data shows that phosphine and peripheral acetylide ligands on the platinum(II) centers have limited influence on the emission energy, indicating the emission originates from the FlexLP-dominated fluorescence. Using time-resolved transient absorption spectroscopy it is shown that the complexes undergo intersystem crossing (ISC) to the triplet excited state upon photoexcitation, and the ISC efficiency is affected by the peripheral acetylide ligands. The triplet excited state lifetime can also be manipulated by the state of the FlexLP ligand, with the closed form complexes having longer lifetimes than the open form complexes.

Facile and convenient electrochemical syntheses of novel multifunctional (catalytic, antioxidant and in vivo antimicrobial) phosphorylated chitosan derivatives

The electrochemical coupling of N-protected chitosan with diphenylphosphine oxide was recognized as new facile, fast, and convenient route to phosphorylated chitosans. The reaction affords low substituted (capable of self-assembling into nanoparticles), moderately substituted (water soluble) or highly substituted (soluble in both water and toluene) polymeric chitosan phosphonates. The degree of substitution can be adjusted by simply increasing the triphenylphosphine oxide/chitosan ratio. Highly substituted polymers (CH-P0.70) are efficient homogeneous catalysts towards the model reaction of monoglyceride synthesis (ca. 100% yield in 3 h). The phosphorylated chitosans are also efficient antioxidants. Their antioxidant effect increases with an increase in their degree of substitution. CH-P0.70 exhibits an antioxidant activity comparable to that of the natural antioxidant ascorbic acid. Remarkably, the highly substituted species is characterized by a strong in vivo antibacterial effect which is even more pronounced than that of the commercial antibiotics ampicillin and gentamicin. Moreover, the obtained phosphorylated chitosan CH-P0.70 demonstrates neither acute nor subacute in vivo toxicity.

Preparation and characterization of UV-curable composite containing nano silica for glass-to-glass bonding

Glass is a transparent and geometrically ordered element in architecture. Glass bonding can be classified into adhesive, layered, and mechanical categories. One of the best bonding materials for glass applications is adhesive. The preparation and investigation of Ultraviolet (UV)-curable composites for glass-to-glass bonding is the goal of this research. The investigation focused on the effect of raw material type and weight percentage on mechanical properties. Epoxy acrylate resin was employed as an oligomer in this study. Trimethylolpropane triacrylate (TMPTA), tripropyleneglycol triacrylate (TPGDA), and pentaerythritol tetraacrylate (PETA) were used as monomers. As photoinitiators, were used bis (2,4,6 trimethylbenzoyl)-phenylphosphine oxide, hydroxycyclohexyl phenylketone, and 2,4,6-trimethylbenzoyl diphenyl phosphineoxide. Benzophenone, acrylic acid, nano silica, and trimethoxysilylpropyl methacrylate (TMSPMA) were used as the additives. The mechanical properties of the samples were studied using compressive and shear tests. The degree of conversion (DC) was obtained using Fourier transform infrared spectroscopy (FTIR). The mechanical behavior of the samples were measured as a function of temperature using dynamic mechanical thermal analysis (DMTA); and the distribution of nanoparticles was examined using scanning electron microscopy (SEM). The results showed that the sample containing 4 wt% nano silica, which also contained 24 wt% PETA and 7 wt% TMSPMA, has the best mechanical properties with 0.42 and 0.63 MPa compressive and shear strength, respectively. In the FTIR, was observed an increase of nano silica from the lowest (1 wt%) to the highest amount (5 wt%), the DC current decreased by 11 %. In the DMTA analysis, it was observed that an increase of nano silica from 1 to 5 wt%, the storage modulus increased by 41 %. The highest loss modulus and loss temperature were related to the samples containing 1 and 2 wt% nano silica with 221 MPa and 113.8 °C. Finally, the best distribution of nanoparticles was observed in the sample containing 1 wt% nano silica. In the SEM images, agglomeration of nanoparticles was seen in the sample containing 5 wt% nano silica.

Parylene C Coating Efficacy Studies: Enhancing Biocompatibility of 3D Printed Polyurethane Parts for Biopharmaceutical and CGT Applications.

Additive manufacturing, particularly Vat photopolymerization, presents a promising technique for producing complex, tailor-made structures, making it an attractive option for generating single-use components used in biopharmaceutical manufacturing equipment or cell culture devices. However, the potential leaching of cytotoxic compounds from Vat photopolymer resins poses a significant concern, especially regarding cell growth and viability in cell culture applications. This study explores the potential of parylene C coating to enhance the inertness of a polyurethane-based photopolymer resin, aiming to prevent cytotoxicity and improve biocompatibility. The study includes an analysis of extractables from the resin and photoinitiator to evaluate the resin's composition and to define selected marker compounds for investigating the coating efficiency. The time-dependent accumulation of relevant extractable compounds over a 70-day period are assessed to address the long-term use of the coated components. The impact of irradiation on the material and the coating was evaluated, along with an accelerated aging study to address the long-term performance of the coating. Biocompatibility in terms of in vitro cell growth studies is evaluated using Chinese hamster ovary cells, a standard cell line in biopharmaceutical manufacturing. Results demonstrate that parylene C coating significantly reduces the release of cytotoxic compounds, such as the photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO). Although accelerated aging indicates a reduction in the barrier properties of the coating over time, the parylene C coating still effectively slows the release of extractables and significantly improves cell compatibility of the 3D printed parts. The findings suggest that parylene C-coated components can be safely integrated into biopharmaceutical manufacturing processes, with recommendations to minimize storage times between coating application and use to ensure optimal performance.

Harnessing the Reactivity of ortho-Alkynylaldehydes: Silver Triflate Catalyzed Regioselective Synthesis of Phosphonylated Fluorescent Molecules

AbstractAn efficient approach for the facile synthesis of phosphonylated 1,3-dihydrofuro[3,4-b]quinolines and dihydrofuro[3,4-b]pyridines is developed. Reaction proceeds by the formation of new C–P and C–O bonds affording Z-selective phosphonylated products at room temperature. Diphenylphosphine oxides and dialkyl phosphites are explicitly incorporated into the carbonyl carbon of o-alkynylaldehydes in good to excellent yields. The reaction exhibits mild conditions, broad substrate scope, and the formation of three new bonds in the presence of a silver catalyst. The mechanistic studies revealed that the reaction proceeded via an ionic pathway in a 5-exo-dig manner to give Z-selective products, which was validated by X-ray crystallographic studies. Photophysical studies of selected compounds revealed the emission maxima in the range of 455 nm.

Synthesis, crystal structure and cytotoxic activity of 2,2′-bipyridine / 1,10-Phenanthroline based Copper(II) complexes with diphenylphosphinic acid

Mixed-ligand 2,2′-bipyridine, 1,10-phenanthroline based copper(II) complexes are often considered as potential antitumor agents. This research was aimed at synthesis and finding the cytotoxic potential of copper(II) complexes with diphenylphosphinic acid (HL) and 2,2′-bipyridine, 1,10-phenanthroline derivatives – [Cu(phen)(H2O)L2]·H2O (1), [Cu(dmphen)(H2O)L2] (2), [Cu(Cl-phen)(H2O)2L]L·EtOH (3), [Cu(bipy)(H2O)L2] (4) and Cu(dmbipy)(H2O)L2 (5) (phen – 1,10-phenanthroline, dmphen – 4,7-dimethyl-1,10-phenanthroline, Cl-phen – 5-chloro-1,10-phenanthroline, bipy – 2,2′-bipyridine, dmbipy – 4,4′-dimethyl-2,2′-bipyridine). Obtained mononuclear compounds have been characterized by EPR and IR-spectroscopy, elemental, thermogravimetric, single-crystal and powder X-ray diffraction analyses. According to single-crystal X-ray diffraction data, complexes possess distorted trigonal bipyramidal or square pyramidal geometry. 2,2′-Bipyridine and 1,10-phenanthroline derivatives have been shown to be chelating agents in these complexes, while anion of diphenylphosphinic acid acts as a monodentate ligand. Complexes 1–5 have been monitored for their solution stability using UV–vis spectroscopy. In the present study, cytotoxic activity of the complexes has been investigated on 2D human cell culture models (larynx carcinoma Hep2, hepatocellular carcinoma HepG2, breast carcinoma MCF-7 and non-tumor lung fibroblasts MRC5) and 3D HepG2 human cell model. 1,10-Phenanthroline based complexes have demonstrated the highest cytotoxicity superior to the reference drug cisplatin. The level of reactive oxygen species generation in Hep2 cells has been shown to increase after incubation with complexes.

Understanding the Adsorption Mechanism of BTPA, DEPA, and DPPA in the Separation of Malachite from Calcite and Quartz: DFT and Experimental Studies

The relationship between the structure of bis (2,4,4-trimethylpentyl) phosphinic acid (BTPA), diethyl phosphinic acid (DEPA), and diphenyl phosphinic acid (DPPA) on the flotation performance of malachite was investigated. Through a series of flotation experiments, density functional theory (DFT) calculations, and surface analysis methods, we aimed to deeply understand the microscopic mechanism of the interactions between these collectors and the malachite surface. The experimental results showed that BTPA exhibited excellent selectivity and flotation performance for malachite in the pH range of 5.0–11.0, significantly better than DEPA and DPPA. Surface analysis evidence from X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) further confirmed the chemical adsorption characteristics of BTPA on the malachite surface. DFT calculations revealed that the adsorption capacity of BTPA on the malachite surface exceeds that of DEPA and DPPA. Electron transfer analysis, especially through frontier molecular orbital theory, differential charge density, PDOS, and COHP analysis, indicated that the charge transfer process from the s orbitals of oxygen atoms in the collectors to the d orbitals of copper atoms on the mineral surface is the decisive factor for the adsorption strength.

A diphenylphosphine oxide decorated multi-resonance TADF emitter for narrowband green electroluminescence with an EQE of 32.4.

A new narrowband thermally activated delayed fluorescence emitter, PhCzBN-PO, was developed by incorporating the diphenylphosphine oxide (DPPO) group into a multi-resonance core. The unique properties of DPPO enabled PhCzBN-PO to achieve pure green emission and a nonplanar structure. The resulting electroluminescent devices achieved high external quantum efficiencies up to 32.4% with extremely low efficiency roll-off and pure-green emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.24, 0.67).

Developing flame retardant solutions for partially aromatic polyamide with phosphine oxides

Partially aromatic polyamides owing to their excellent thermal stability are widely used in high temperature applications, however, like their aliphatic counterparts, they are readily flammable and more challenging to process. In this work, several organophosphorus flame retardants were synthesized and compounded with partially aromatic polyamide and evaluated for their processability, thermal, and fire behaviour. The compounds containing a commercial flame retardant, Exolit® OP 1230 (EX), and two new flame retardants, namely 1,4-phenylenebis(diphenylphosphine oxide) (MP) and (1,1′-biphenyl]-4,4′-diylbis(diphenylphosphine oxide) (BP), showed self-extinguishing capability (i.e., UL94 V0 class) with 4 wt% phosphorus (P) loading, together with a substantial reduction in the pHRR (up to 47 %), with respect to the pristine PAP. Rheological measurements on extended timescales were used to assess the melt stability of partially aromatic polyamide compounds. The presence of MP and BP in the polymer matrix did not trigger any excessive degradation phenomena such as chain scission, branching, or crosslinking reactions, thus, allowing a stable processability similar to a pristine partially aromatic polyamide sample. Finally, analysis of evolved gases during thermal decomposition revealed that MP and BP mainly exert a flame inhibition effect quite early in the decomposition process.

Chemo-, regio-, and stereoselective catalyst-free addition of diphenylphosphine oxide to acetylenic amino ketones. Synthesis of Z-diphenylphosphoryl(organylamino)alkenones

Chemo-, regio-, and stereoselective catalyst-free addition of diphenylphosphine oxide to acetylenic amino ketones. Synthesis of Z-diphenylphosphoryl(organylamino)alkenones

Development of novel 3D printable inks for protein delivery

The application of 3D printing technology in the delivery of macromolecules, such as proteins and enzymes, is limited by the lack of suitable inks. In this study, we report the development of novel inks for 3D printing of constructs containing proteins while maintaining the activity of the proteins during and after printing. Different ink formulations containing Pluronic F-127 (20–35 %, w/v), trehalose (2–10 %, w/v) or mannitol, poly (ethylene glycol) diacrylate (PEGDA) (0 or 10 %, w/w), and diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO, 0 or 0.2 mg/mL) were prepared for 3D-microextrusion printing. The F2 formulation that contained β-galactosidase (β-gal) as a model enzyme, Pluronic F-127 (30 %), and trehalose (10 %) demonstrated the desired viscosity, printability, and dose flexibility. The shear-thinning property of the F2 formulation enabled the printing of β-gal containing constructs with a good peak force during extrusion. After 3D printing, the enzymatic activity of the β-gal in the constructs was maintained for an extended period, depending on the construct design and storage conditions. For instance, there was a 50 % reduction in β-gal activity in the two-layer constructs, but only a 20 % reduction in the four-layer construct (i.e., 54.5 ± 1.2 % and 82.7 ± 9.9 %, respectively), after 4 days of storage. The β-gal activity in constructs printed from the F2 formulation was maintained for up to 20 days when stored in sealed bags at room temperatures (21 ± 2 °C), but not when stored unsealed in the same conditions (e.g., ∼60 % activity loss within 7 days). The β-gal from constructs printed from F2 started to release within 5 min and reached 100 % after 20 min. With the design flexibility offered by the 3D printing, the β-gal release from the constructs was delayed to 3 h by printing a backing layer of β-gal-free F5 ink on the constructs printed from the F2 ink. Finally, ovalbumin as an alternative protein was also incorporated in similar ink compositions. Ovalbumin exhibited a release profile like that of the β-gal, and the release can also be modified with different shape design and/or ink composition. In conclusion, ink formulations that possess desirable properties for 3D printing of protein-containing constructs while maintaining the protein activity during and after printing were developed.