Photo Cross-linking Research Articles

A dual crosslinking strategy to tailor rheological properties of gelatin methacryloyl

3D bioprinting is an emerging technology that enables the fabrication of three-dimensional organised cellular constructs. One of the major challenges in 3D bioprinting is to develop a material to meet the harsh requirements (cell-compatibility, printability, structural stability post-printing and bio-functionality to regulate cell behaviours) suitable for printing. Gelatin methacryloyl (GelMA) has recently emerged as an attractive biomaterial in tissue engineering because it satisfies the requirements of bio-functionality and mechanical tunability. However, poor rheological property such as low viscosity at body temperature inhibits its application in 3D bioprinting. In this work, an enzymatic crosslinking method triggered by Ca2+-independent microbial transglutaminase (MTGase) was introduced to catalyse isopeptide bonds formation between chains of GelMA, which could improve its rheological behaviours, specifically its viscosity. By combining enzymatic crosslinking and photo crosslinking, it is possible to tune the solution viscosity and quickly stabilize the gelatin macromolecules at the same time. The results showed that the enzymatic crosslinking can increase the solution viscosity. Subsequent photo crosslinking could aid in fast stabilization of the structure and make handling easy.

Single-electron transfer between sulfonium and tryptophan enables site-selective photo crosslinking of methyllysine reader proteins.

The identification of readers, an important class of proteins that recognize modified residues at specific sites, is essential to uncover the biological roles of post-translational modifications. Photoreactive crosslinkers are powerful tools for investigating readers. However, existing methods usually employ synthetically challenging photoreactive warheads, and their high-energy intermediates generated upon irradiation, such as nitrene and carbene, may cause substantial non-specific crosslinking. Here we report dimethylsulfonium as a methyllysine mimic that binds to specific readers and subsequently crosslinks to a conserved tryptophan inside the binding pocket through single-electron transfer under ultraviolet irradiation. The crosslinking relies on a protein-templated σ-π electron donor-acceptor interaction between sulfonium and indole, ensuring excellent site selectivity for tryptophan in the active site and orthogonality to other methyllysine readers. This method could escalate the discovery of methyllysine readers from complex cell samples. Furthermore, this photo crosslinking strategy could be extended to develop other types of microenvironment-dependent conjugations to site-specific tryptophan.

A larger TatBC complex associates with TatA clusters for transport of folded proteins across the bacterial cytoplasmic membrane

The twin-arginine translocation (Tat) system transports folded proteins across energized biological membranes in bacteria, plastids, and plant mitochondria. In Escherichia coli, the three membrane proteins TatA, TatB and TatC associate to enable Tat transport. While TatB and TatC together form complexes that bind Tat-dependently transported proteins, the TatA component is responsible for the permeabilization of the membrane during transport. With wild type Tat systems, the TatB- and TatC-containing Tat complexes TC1 and TC2 can be differentiated. Their TatA content has not been resolved, nor could they be assigned to any step of the translocation mechanism. It is therefore a key question of current Tat research to understand how TatA associates with Tat systems during transport. By analyzing affinity-purified Tat complexes with mutations in TatC that selectively enrich either TC1 or TC2, we now for the first time demonstrate that both Tat complexes associate with TatA, but the larger TC2 recruits significantly more TatA than the smaller TC1. Most TatA co-purified as multimeric clusters. Using site-specific photo cross-linking, we could detect TatA–TatC interactions only near TatC transmembrane helices 5 and 6. Substrate-binding did not change the interacting positions but affected the stability of the interaction, pointing to a substrate-induced conformational transition. Together, our findings indicate that TatA clusters associate with TatBC without being integrated into the complex by major rearrangements. The increased TatA affinity of the larger Tat complex TC2 suggests that functional assembly is advanced in this complex.

Elucidation of Saccharomyces cerevisiae Msh2-Msh6 and Holliday junction binding interactions via UV photo crosslinking

Elucidation of Saccharomyces cerevisiae Msh2-Msh6 and Holliday junction binding interactions via UV photo crosslinking

3D printing of recombinant collagen/chitosan methacrylate/nanoclay hydrogels loaded with Kartogenin nanoparticles for cartilage regeneration.

Cartilage defects are frequently caused by trauma, illness and degradation of the cartilage. If these defects are not sufficiently treated, the joints will degrade irreversibly, possibly resulting in disability. Articular cartilage lacks blood vessels and nerves and is unable to regenerate itself, so the repair of cartilage defects is extremely challenging in clinical treatment. Tissue engineering technology is an emerging technology in cartilage repair and cartilage regeneration. 3D-printed hydrogels show great potential in cartilage tissue engineering for the fabrication of 3D cell culture scaffolds to mimic extracellular matrix. In this study, we construct a 3D-printed hydrogel loaded with nanoparticles by electrostatic interaction and photo cross-linking for the regeneration of cartilage, which has adaptable and drug-continuous release behavior. A photopolymerizable bioink was prepared using recombinant collagen, chitosan, nanoclay Laponite-XLG and nanoparticles loaded with Kartogenin (KGN). This bioink was added with KGN, a small molecule drug that promotes cartilage differentiation, and as a result, the 3D-printed CF/CM/3%LAP/KGN scaffolds obtained by extrusion printing is expected to be used for cartilage repair. It was shown that the 3D-printed scaffolds had good cytocompatibility for human bone marrow mesenchymal stem cells (hBMSCs) and exhibited excellent antimicrobial properties, the continuous release of KGN in the scaffold induced the hBMSCs differentiation into chondrocytes, which significantly enhanced the expression of collagen II and glycosaminoglycan. In vivo studies have shown that implantation of KGN-loaded scaffolds into cartilage-injured tissues promoted cartilage tissue regeneration. This study demonstrated that 3D-printed CF/CM/3%LAP/KGN scaffolds can be used for cartilage repair, which is expected to lead to new healing opportunities for cartilage injury-based diseases.

Strong and Tough Biofibers Designed by Dual Crosslinking for Sutures

AbstractHigh‐performance bio‐based fibers have unique advantages in biocompatibility for biomedical applications, such as sutures, hernia patches, and blood vessels. Herein, strong and tough biofibers based on regenerated silk fibroins (RSFs) are designed by a dual‐crosslinking strategy and prepared continuously in situ via a single‐channel microfluidic device. During the wet spinning process, covalent bonds between tyrosines are introduced by photo crosslinking and coordination interactions of Zn2+ ions with serines are built between RSFs, forming a dual‐crosslinked, and inter‐connected network and effectively improving the mechanical performances of RSF fibers. By optimizing the wet spinning parameters and applying an optimal post‐stretching treatment, dual‐crosslinked RSF fibers exhibit an excellent tensile strength of 891 MPa, a remarkable Young's modulus of 15.0 GPa, a large tensile strain of 20.1%, and an outstanding toughness of 114 MJ m−3, which are superior to other regenerated biofibers. In addition to the outstanding mechanical performances, dual‐crosslinked RSF fibers also possess excellent temperature adaptability, fatigue resistance, biocompatibility, and biodegradability, making them ideal candidates for biomedical applications. In vivo tests of dual‐crosslinked RSF fibers as sutures demonstrate a good wound healing performance with smaller scar and lower inflammation.

Gel Polymer Electrolytes for Lithium-Ion Batteries Enabled by Photo Crosslinked Polymer Network.

We demonstrate a gel polymer electrolyte (GPE) featuring a crosslinked polymer matrix formed by poly(ethylene glycol) diacrylate (PEGDA) and dipentaerythritol hexaacrylate (DPHA) using the radical photo initiator via ultraviolet (UV) photopolymerization for lithium-ion batteries. The two monomers with acrylate functional groups undergo chemical crosslinking, resulting in a three-dimensional structure capable of absorbing liquid electrolytes to form a gel. The GPE system was strategically designed by varying the ratios between the main polymer backbone (PEGDA) and the crosslinker (DPHA) to achieve an optimal gel polymer electrolyte network. The resulting GPE exhibited enhanced thermal stability compared to conventional liquid electrolytes (LE) and demonstrated high ionic conductivity (1.40 mS/cm) with a high lithium transference number of 0.65. Moreover, the obtained GPE displayed exceptional cycle performance, maintaining a higher capacity retention (85.2%) comparable to the cell with LE (79.3%) after 200 cycles.

Hypoxia and Matrix Metalloproteinase 13-Responsive Hydrogel Microspheres Alleviate Osteoarthritis Progression In Vivo.

The occurrence of osteoarthritis (OA) is highly associated with the inflammatory hypoxic microenvironment. Yet currently no attention has been paid to fabricating hypoxia-responsive platforms for OA treatment. Herein, an injectable hydrogel microsphere system (HAM-SA@HCQ) focusing on the hypoxic inflamed joint is prepared with methacrylate-modified sulfonated azocalix[4]arene (SAC4A-MA), methacrylated hyaluronic acid (HA-MA), and dithiol-terminated matrix metalloproteinase 13 (MMP-13) sensitive peptide via a microfluidic device and photo crosslinking technique, followed by encapsulation of the anti-inflammatory drug hydroxychloroquine (HCQ) through host-guest interaction. Owing to the hydrophobic deep cavity, phenolic units, and azo bonds of SAC4A-MA, the hydrogel microspheres show strong drug loading capacity, prominent reactive oxygen species (ROS) scavenging capability, and specific hypoxia-responsive drug release ability. In the OA tissue microenvironment, the hydrogel microspheres undergo degradation by excessive MMP-13 and release HCQ under the hypoxia condition, which synergizes with the ROS-scavenging calixarene to inhibit the inflammatory response of macrophages. After being injected into the OA-inflamed joint, the HAM-SA@HCQ can significantly attenuate the oxidative stress, downregulate the expression of hypoxia-induced factor-1α and inflammatory cytokines, and prevent the cartilage from being destroyed.

Large-scale preparation of UV photo-crosslinked composite membrane with high pervaporation desalination properties and excellent fouling resistance

In this study, we developed a high-performance composite membrane with rapid cross-linking and large-scale technology for PV desalination. Some strategies were adopted to achieve this purpose. First, photo cross-linking was used to shorten the cross-linking time of PVA within 60 s. Second, a PTFE microfiltration membrane was utilized as the substrate that mitigated the transport resistance of the supporting layer. Third, an large-scale spray-coating device was built-up which completed the amplification preparation of composite PV membrane. Finally, ZIF-8 nano-particle was introduced into the PVA layer that increased the free volume and amorphous region of PVA, enhancing the water flux of membrane. When desalted a 3.5 wt% NaCl solution at 80 °C, a water flux of 307.58 ± 15.09 kg/m2·h was achieved for the PVA/ZIF-8/PTFE composite membrane. To better reflect the membrane performance, the permeance of PVA/ZIF-8/PTFE membrane was also calculated, which was reached to 674.37 kg/m2 h bar, exceeding 18.4% than the highest reported property of PVA/PAN nanofiber membrane (569.55 kg/m2 h bar). In addition, the composite membrane showed stable water flux and salt rejection when treating highly concentrated brine solution containing organic pollutant. When desalinated a 10 wt% NaCl solution with 1 wt% HA at 80 °C, the PVA/ZIF-8/PTFE membrane produced water with low conductivity of 15.78 μs/cm and a high water flux of 129.95 kg/m2·h in a period of 180 min.

Microparticles comprising cinnamoyl cellulose and cinnamoyl gelatin prepared by emulsion method and their pH and electric field-responsive release property

pH- and electric field-responsive microparticles were prepared by photo cross-linking cinnamoyl gelatin (CinGel) and cinnamoyl cellulose nanocrystal (CinCNC) contained in the water droplet of W/O emulsion. Cinnamoyl chloride (CC) was covalently attached to Gel and CNC through a condensation reaction to obtain CinGel and CinCNC, confirmed by 1H NMR and FT-IR spectroscopy. Using a colorimetric method, the cinnamoyl group (CG) content of CinGel was determined to be 1.6 % and that of CinCNC to be 3–15.3 %, depending on the CC/CNC ratio in the reaction mixture. The maximum photo-dimerization degree of CG of CinGel obtained under UV irradiation was about 33 % and that of CinCNC was 4.4–7.5 %. Microparticles were prepared by cross-linking CinGel and CinCNC contained in the water droplet of the emulsion using UV irradiation. Sphere-like particles and irregularly shaped ones were found on the SEM photo of CinGel/CinCNC microparticles and the mean dimeters were determined to be 11.6–17.1 µm. CinGel/CinCNC ratio in the emulsion little affected the shape and size of the resulting microparticles. An energy dispersive spectroscopy revealed that the microparticle composition was reflecting CinGel/CinCNC ratio in the emulsion. The release of a payload (i.e. amaranth) markedly promoted as the medium pH value increased from 3 to 8, possibly due to the decomplexation of CinGel/CinCNC electrostatic complex and/or the electrostatic expulsion of the payload from CinGel. The release was expedited as the applied voltage increased up to 4.5 V, probably due to the shear stress-induced deformation of the microparticle matrix and/or the forced electrostatic expulsion of the payload.

Double Cross-Linked Chitosan/Bacterial Cellulose Dressing with Self-Healable Ability.

Self-healing hydrogel products have attracted a great deal of interest in wound healing due to their ability to repair their own structural damage. Herein, an all-natural self-healing hydrogel based on methacrylated chitosan (CSMA) and dialdehyde bacterial cellulose (DABC) is developed. MA is used to modify CS and obtain water-soluble biomaterial-based CSMA with photo crosslinking effects. BC is modified through a simple oxidation method to gain dialdehyde on the polymer chain. The success of the modification is confirmed via FTIR. Hydrogels are formed within 11 min through the establishment of a Schiff base between the amino of CSMA and the aldehyde of DABC. A dynamically reversible Schiff base bond endows hydrogel with good self-healing properties through macroscopic and microscopic observations. We observe the uniform and porous structure in the hydrogel using SEM images, and DABC nanofibers are found to be well distributed in the hydrogel. The compressive strength of the hydrogel is more than 20 kPa and the swelling rate sees over a 10-fold increase. In addition, the CSMA/DABC hydrogel has good cytocompatibility, with cell viability exceeding 90%. These results indicate that the all-natural self-healable CSMA/DABC hydrogel demonstrates strong application potential in wound healing and tissue repair.

Silk fibroin hydrogel membranes prepared by a sequential cross-linking strategy for guided bone regeneration

Silk fibroin hydrogel is a widely used material for tissue engineering. However, its mechanical properties are the main obstacle to its application to medical bone regeneration barrier membranes. Here, we developed a new hydrogel membrane for guided bone regeneration (GBR). In this study, a sequential crosslinking strategy including photo crosslinking and organic solvent (ethanol) treatment was used to obtain silk fibroin hydrogel membrane (EA-SF). The mechanical properties of EA-SF were significantly enhanced compared to the hydrogel prepared only by photocrosslinking (E-SF). The compressive and tensile strengths of the hydrogel film treated with 75% ethanol for 6 h were 1.18 ± 0.36 MPa and 0.43 ± 0.03 MPa, respectively. In vitro cell culture results showed that EA-SF has good biocompatibility and can effectively shield fibroblasts (L929). EA-SF also has excellent in vitro protein hydrolysis stability. In vivo experiments (subcutaneous implantation and calvarial defect experiment) confirmed the stability and barrier functionality of EA-SF. In conclusion, this study demonstrated that ethanol could improve the mechanical properties of silk fibroin hydrogel and extend the scope of their application, making silk fibroin hydrogel a promising GBR material.

Generation of cell-laden GelMA microspheres using microfluidic chip and its cryopreservation method

Gelatin methacrylate (GelMA) hydrogels have been widely used in tissue engineering because of their excellent biological and physical properties. Here, we used a microfluidic flow-focusing chip based on polymethyl methacrylate to fabricate cell-laden GelMA hydrogel microspheres. Structures of the throat region and photo crosslinking region on the chip, flow rate ratio of GelMA and oil phase, and GelMA concentration were optimized to obtain the stable and suitable size of microspheres. Cell-laden GelMA microspheres can be cryopreserved by slow freezing and rapid freezing. The survival rate of encapsulated cells after rapid freezing was significantly higher than that of unencapsulated cells. There was no significant difference between the results of the rapid freezing of encapsulated cells with 5% DMSO and the traditional slow freezing of suspended cells with 10% DMSO. It demonstrates the possibility that GelMA hydrogel itself can replace some of the cryoprotective agents and has some protective effect on cells. Our study provides new ideas to optimize GelMA hydrogels for cell cryopreservation, facilitating the off-the-shelf availability of tissue-engineered constructs.

Reversible bond formation via sulfur free reversible addition fragmentation in photo-3D printing

An addition-fragmentation monomer (AFM) has been used as a crosslinker in photopolymerization-based 3D printer resins in order to try and reduce shrinkage due to polymerisation. This results in reversible network formation via photo crosslinking with reversible covalent bond formation to effect mechanical performance. The 3D printing conditions were optimized with regards to print quality, print speed, etc. The AFM was synthesized via catalytic chain transfer polymerization (CCTP) and characterized using NMR and size exclusion chromatography (SEC). The incorporation of the AFM as a crosslinker allows for rapid reversible covalent bond formation during network formation in 3D photopolymerization printing resulting in a reduction in both polymerisation shrinkage and stress higher molecular weight crosslinkers lead to less shrinkage and reversible bond formation to less stress build up. Curing was monitored via photo-rheology and Fourier Transform Infrared Spectroscopy (FT-IR). At lower contents of AFM, the mechanical properties (strength and Young’s modulus) are improved without compromising material properties, printing conditions and curing time. At higher AFM content, the kinetic analysis of the photopolymerization reaction shows a reduced final conversion of the vinylic bonds along with a delay of the gel point. The thermal and mechanical properties were evaluated with incorporation of different concentrations of AFM added to the resin formulations.

Tuning the Porosity of Dextran Microgels with Supramacromolecular Nanogels as Soft Sacrificial Templates.

Hydrogels, as well as colloidal hydrogels (microgels), are important materials for a large variety of applications in the biomedical field. Microgels with a controlled pore size (meso- and macropores) are required for efficient nutrient support, modulation of cell adhesion, removal of metabolic products in cell cultures, and probiotic loading. Common microgel fabrication techniques do not provide sufficient control over pore sizes and geometry. In this work, the natural polysaccharide dextran modified with methacrylate groups is used to synthesize highly monodisperse meso- and macroporous microgels in a size range of100-150µm via photo cross-linking in microfluidic droplets. The size of mesopores is varied by the concentration of dextran methacrylate chains in the droplets (50-200gL-1 ) and the size of macropores is regulated by the integration of pH-degradable supramacromolecular nanogels with diameters of 300 and 700nm as sacrificial templates. Using permeability assays combined with confocal laser scanning microscopy, it is demonstrated that functional dextran-based microgels with uniform and defined pores could be obtained.

Architecting oxidized alginate methacrylate hydrogels with tunable characteristics by altering the sequence of the cross-linking steps, methacrylation reaction time, and polymer concentration.

In this study, biodegradable oxidized methacrylated alginate (OMA) hydrogels with controllable mechanical properties were engineered. An ionic and photo cross-linking combination was employed to fabricate dual cross-linked hydrogels. By altering the degree of methacrylation and polymer concentration, hydrogels with an elastic modulus of 4.85 ± 0.13 to 21.02 ± 0.91kPa, controllable swelling, and degradation kinetics, and cross-link density in the range of 1.0 × 10-5 to 6.5 × 10-5mol/cm3 were obtained. Moreover, evaluating the effect of cross-linking sequence on the hydrogels' mechanical properties demonstrated that in comparison to the hydrogels fabricated by ionic cross-linking followed by photo-polymerization, hydrogels produced by photo-polymerization followed by ionic cross-linking retain a stiffer gel network with more compact structure. Cytocompatibility examination was performed via MTT assay against L929 fibroblasts, and all the hydrogel samples demonstrated high cell viability (>80%). The findings demonstrate the significant effect of the sequence of cross-linking as a novel tool to tune the OMA hydrogel's final properties which can serve as a useful platform for tissue engineering applications.

Construction of a bioactive copper-based metal organic framework-embedded dual-crosslinked alginate hydrogel for antimicrobial applications

Metal-organic frameworks (MOFs) containing bioactive metals have the potential to exhibit antimicrobial activity by releasing metal ions or ligands through the cleavage of metal-ligand bonds. Recently, copper-based MOFs (Cu-MOFs) with sustained release capability, porosity, and structural flexibility have shown promising antimicrobial properties. However, for clinical use, the controlled release of Cu2+ over an extended time period is crucial to prevent toxicity. In this study, we developed an alginate-based antimicrobial scaffold and encapsulated MOFs within a dual-crosslinked alginate polymer network. We synthesized Cu-MOFs containing glutarate (Glu) and 4,4′-azopyridine (AZPY) (Cu(AZPY)-MOF) and encapsulated them in an alginate-based hydrogel through a combination of visible light-induced photo and calcium ion-induced chemical crosslinking processes. We confirmed Cu(AZPY)-MOF synthesis using scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, and thermogravimetric analysis. This antimicrobial hydrogel demonstrated excellent antibacterial and antifungal properties against two bacterial strains (MRSA and S. mutans, with >99.9 % antibacterial rate) and one fungal strain (C. albicans, with >78.7 % antifungal rate) as well as negligible cytotoxicity towards mouse embryonic fibroblasts, making it a promising candidate for various tissue engineering applications in biomedical fields.

Influence of PEGDA Molecular Weight and Concentration on the In Vitro Release of the Model Protein BSA-FITC from Photo Crosslinked Systems.

Novel 3D printing techniques enable the development of medical devices with drug delivery systems that are tailored to the patient in terms of scaffold shape and the desired pharmaceutically active substance release. Gentle curing methods such as photopolymerization are also relevant for the incorporation of potent and sensitive drugs including proteins. However, retaining the pharmaceutical functions of proteins remains challenging due to the possible crosslinking between the functional groups of proteins, and the used photopolymers such as acrylates. In this work, the in vitro release of the model protein drug, albumin-fluorescein isothiocyanate conjugate (BSA-FITC) from differently composed, photopolymerized poly(ethylene) glycol diacrylate (PEGDA), an often employed, nontoxic, easily curable resin, was investigated. Different PEGDA concentrations in water (20, 30, and 40 wt %) and their different molecular masses (4000, 10,000, and 20,000 g/mol) were used to prepare a protein carrier with photopolymerization and molding. The viscosity measurements of photomonomer solutions revealed exponentially increasing values with increasing PEGDA concentration and molecular mass. Polymerized samples showed increasing medium uptake with an increasing molecular mass and decreasing uptake with increasing PEGDA content. Therefore, the modification of the inner network resulted in the most swollen samples (20 wt %) also releasing the highest amount of incorporated BSA-FITC for all PEGDA molecular masses.

Nucleotide-amino acid π-stacking interactions initiate photo cross-linking in RNA-protein complexes

Photo-induced cross-linking is a mainstay technique to characterize RNA-protein interactions. However, UV-induced cross-linking between RNA and proteins at “zero-distance” is poorly understood. Here, we investigate cross-linking of the RBFOX alternative splicing factor with its hepta-ribonucleotide binding element as a model system. We examine the influence of nucleobase, nucleotide position and amino acid composition using CLIR-MS technology (crosslinking-of-isotope-labelled-RNA-and-tandem-mass-spectrometry), that locates cross-links on RNA and protein with site-specific resolution. Surprisingly, cross-linking occurs only at nucleotides that are π-stacked to phenylalanines. Notably, this π-stacking interaction is also necessary for the amino-acids flanking phenylalanines to partake in UV-cross-linking. We confirmed these observations in several published datasets where cross-linking sites could be mapped to a high resolution structure. We hypothesize that π-stacking to aromatic amino acids activates cross-linking in RNA-protein complexes, whereafter nucleotide and peptide radicals recombine. These findings will facilitate interpretation of cross-linking data from structural studies and from genome-wide datasets generated using CLIP (cross-linking-and-immunoprecipitation) methods.

Water soluble photocurable carboxymethyl cellulose‐based bioactive hydrogels for digital light processing

AbstractThe development of light‐based three‐dimensional (3D) printing has changed the manufacturing processes from various materials. The advantages of printing using customized materials are gradually highlighted due to excellent and reliable precision, high repeatability, and wide range of build materials, which enable customized materials to be use in aerospace, biomedical, engineering, and other fields. Due to the existence of acrylate group or epoxy group, most of the commonly used photoactive macromolecules have the main limitations of poor water solubility and/or high biological stimulation, severely constraining the widespread application of these materials in biomanufacturing. To overcome these challenges, a natural hydrogel was modified in this study to achieve a new photocurable material with good biocompatibility and photocrosslinking activity. In particular, methacrylate‐carboxymethyl cellulose (Me‐CMC) was esterified by hydroxyl groups on the long chains of CMC, and hydroxyethyl methacrylate (HEMA)/acrylamide (Am) was added as the crosslinking reaction point between the long molecular chains. Thus, networked structures of this biocompatible material can be formed by photo crosslinking in digital light processing (DLP). The developed composite hydrogel can facilitate the rapid prototyping and high precision manufacturing. The mechanical toughness, swelling property, and microstructures of the composite hydrogel were tunable by changing HEMA/Am content. In addition, it was found that cell survival rate of this photocurable composite hydrogel was good by culturing bone marrow stromal cells (BMSCs) with the material and, cells proliferated significantly in a short time (7 days), which proved the biocompatibility of the proposed material.