Calcium Alginate Hydrogel Research Articles

Exploiting the role of nanoparticle shape in enhancing hydrogel adhesive and mechanical properties

The ability to control nanostructure shape and dimensions presents opportunities to design materials in which their macroscopic properties are dependent upon the nature of the nanoparticle. Although particle morphology has been recognized as a crucial parameter, the exploitation of the potential shape-dependent properties has, to date, been limited. Herein, we demonstrate that nanoparticle shape is a critical consideration in the determination of nanocomposite hydrogel properties. Using translationally relevant calcium-alginate hydrogels, we show that the use of poly(L-lactide)-based nanoparticles with platelet morphology as an adhesive results in a significant enhancement of adhesion over nanoparticle glues comprised of spherical or cylindrical micelles. Furthermore, gel nanocomposites containing platelets showed an enhanced resistance to breaking under strain compared to their spherical and cylindrical counterparts. This study opens the doors to a change in direction in the field of gel nanocomposites, where nanoparticle shape plays an important role in tuning mechanical properties.

Magnetic/pH-sensitive double-layer microrobots for drug delivery and sustained release

Remarkable evolution of drug-loaded microrobots has aroused growing interest in targeted therapy. However, existing microrobots encounter a number of challenges including maneuverability, biodegradability, and drug sustained release capabilities in medical applications. Designed double-layer drug-loaded microrobots (TDMs) were made of outer layer calcium alginate hydrogel and inner layer magnetic chitosan microspheres (mCSs). TDMs precisely deliver drug-loaded mCSs following the expected route towards the predefined destinations under a vision-guided magnetic driving system. In acidic conditions the outer layer of TDMs can protect mCSs, while in alkaline conditions calcium alginate hydrogel dissolves at an appropriate rate to render mCSs be continuously released. The mCSs fulfill drug sustained release tasks in vitro. The new designed low-cost microrobots will be competent for intestinal cancer targeted therapy after oral administration and bridge the gap between scientific research and market demand.

Dielectric Analysis of Microcapsule-Immobilized Composite Capsules Suspension: Substances Release.

Dielectric spectroscopy has unique advantages in monitoring drug release. In this work, a dielectric measurement was carried out on the release of the substances of microcapsule-immobilized composite capsules, which were fabricated by encapsulating the Perinereis aibuhitensis extract-loaded gum Arabic/gelatin microcapsules (PaE: GA/GE-MCs) in calcium alginate hydrogel (PaE: CA/GA/GE-CCs). We established the dielectric model of PaE: CA/GA/GE-CCs and got in-depth information on the systems. There are two relaxations in the dielectric spectroscopy, both of which are caused by interfacial polarization. The relaxation mechanisms correspond to the interfacial polarization of the PaE-loading core/calcium alginate shell interface and the calcium alginate shell/solution interface, respectively. Besides, the swelling of composite capsules and substance migration in the composite capsules were observed by analyzing phase parameters. Finally, the characteristic release of calcium alginate composite capsules was confirmed, and the substance release mechanism of composite capsules, namely, the swelling-diffusion mechanism, was obtained.

Utilizing Calcium Alginate for the Assessment of Bone Morphogenetic Protein 15 Induction Effect on the Differentiation of Mesenchymal Stem Cell Derived from Human Follicular Fluid to Oocyte-Like Structure.

Background:Follicular fluid (FF)-derived mesenchymal stem cells (MSCs) are possible new source of cells in the study of oogenesis and regenerative medicine. Several biomaterials have been used as scaffolds to mimic ovarian tissue stroma. Using good matrix is essential for increasing the cell survival rate, proliferation, and differentiation. However, no study has been performed to investigate the effects of BMP15 and calcium alginate hydrogel on the differentiation potential of FF-derived MSCs to oocyte-like structures (OLSs).Materials and Methods:In this work, FF MSCs, which were collected from women in routine in vitro fertilization procedure, were capsulated with 0.5% calcium alginate, and then the encapsulated cells were cultured in medium containing BMP15 for 2 weeks. Trypan blue staining was carried out to determine cell viability. Real-time polymerase chain reaction (PCR) and immunofluorescence (ICC) staining method were performed to characterize the expression of OCT4, Nanog, ZP2, and ZP3 genes and protein. The encapsulation process did not change the morphology and viability of the encapsulated cells.Results:Reverse-transcription-PCR and ICC showed that MSCs expressed germ line stem cell markers such as OCT4 and Nanog. After 4 days of culture, OLSs formed and expressed zona pellucida markers. OLSs at least reached 180–230 μm in diameter in the control and BMP15-treated groups. Finally, a reduction in the expression pattern of pluripotency and ZP markers was detected in the encapsulated cells cultured in the BMP15-supplemented medium.Conclusion:The three-dimensional alginate culture system seems to be a promising method of getting in vitro differentiation and development of ovarian cells, which could mimic the native ovarian condition.

Chemotropism among populations of yeast cells with spatiotemporal resolution in a biofabricated microfluidic platform.

Chemotropism is an essential response of organisms to external chemical gradients that direct the growth of cells toward the gradient source. Chemotropic responses between single cells have been studied using in vitro gradients of synthetically derived signaling molecules and helped to develop a better understanding of chemotropism in multiple organisms. However, dynamic changes including spatial changes to the gradient as well as fluctuations in levels of cell generated signaling molecules can result in the redirection of chemotropic responses, which can be difficult to model with synthetic peptides and single cells. An experimental system that brings together populations of cells to monitor the population-scale chemotropic responses yet retain single cell spatiotemporal resolution would be useful to further inform on models of chemotropism. Here, we describe a microfluidic platform that can measure the chemotropic response between populations of mating yeast A- and α-cells with spatiotemporal programmability and sensitivity by positioning cell populations side by side in calcium alginate hydrogels along semipermeable membranes with micrometer spatial control. The mating phenotypes of the yeast populations were clearly observed over hours. Three distinct responses were observed depending on the distance between the A- and α-cell populations: the cells either continued to divide, arrest, and develop a stereotypical polarized projection termed a "shmoo" toward the cells of opposite mating type or formed shmoos in random directions. The results from our studies of yeast mating suggest that the biofabricated microfluidic platform can be adopted to study population-scale, spatial-sensitive cell-cell signaling behaviors that would be challenging using conventional approaches.

Selective Adsorption Capacity of Grape Marc Hydrogel for Adsorption of Binary Mixtures of Dyes

In this work, an aqueous solution containing industrial dyes consisting of methylene blue (MB), and methyl red (MR) was treated with bio-oxidize grape marc entrapped or not in calcium alginate hydrogels. Experiments were carried out in batch, a room temperature using different concentration of adsorbents and dyes. When dyes were evaluated separately, non-immobilized grape marc hydrogel was unable to remove any MR, whereas when the bioadsorbent was immobilized in calcium alginate beads the removal of MR was around 88%. Contrarily, 98% of MB was removed with both, non-entrapped or entrapped grape marc. Regarding binary mixtures, it was observed that the adsorption of MR was not affected by the presence of MB, whereas the adsorption of MB decreased in high extend on non-entrapped grape marc when MR was present. Adsorption conditions were optimized for binary mixtures using a Box-Behnken factorial design, obtaining theoretical equations that allowed to calculate the removal percentage and capacity of calcium alginate-grape marc hydrogel depending on the concentration of dyes (40–100 mg/L), ratio between bioadsorbent and water stream (0.6–1.2) and adsorption time (10–60 min). The equations obtained revealed that grape marc hydrogel is able to remove 100.0–93.3% of MB and 78.72–57.80% of MR in 10 min in the range of dye and bioadsorbent stablished in the experimental design, being the extraction time the less significant variable. Additionally, the kinetic study showed that pseudo-second-order was the model that better explained the bioadsorption process for both dyes in binary mixtures onto grape marc hydrogel.

Amino-carbamate moiety grafted calcium alginate hydrogel beads for effective biosorption of Ag(I) from aqueous solution: Economically-competitive recovery

In present study, pure and amino-carbamate moiety grafted calcium alginate hydrogel beads (CA, PSC-CA) were prepared for their biosorption performance in the recovery of silver ions. The produced sorbents were characterized using FTIR, SEM, EDX and TGA. FTIR and SEM-EDX confirmed the successful modification and loading of silver ions onto hydrogel beads. When compared with CA, PSC-CA showed enhanced sorption but comparable kinetics. Equilibrium sorption studies showed that pH, sorbent dose, contact time and adsorbate concentration influenced the sorption capacity. The uptake kinetic data was well demonstrated by pseudo second order rate equation (PSORE). Elovich equation and the resistance to intra-particle diffusion model (RID) suggested that there were two phases of sorption, first one was rapid followed by relatively slow uptake step. Equilibrium isothermal sorption data was well fitted by Langmuir and Sips models. The separation factor RL was found as 0 < RL < 1 which indicated favourable sorption. The maximum monolayer sorption capacity was computed as 210 mg/g at 298 K. Thermodynamic studies revealed the sorption process to be spontaneous and exothermic. PSC-CA hydrogel beads were found as cost-effective and efficient sorbent for economically-competitive recovery of Ag(I).

Zn2+-loaded TOBC nanofiber-reinforced biomimetic calcium alginate hydrogel for antibacterial wound dressing

Calcium alginate hydrogel dressing is an excellent hydrogel dressing because of its excellent absorption characteristics and tear-free pain. However, its application is limited by its poor mechanical properties and non-bacterial properties. Here, we reported a new biomimetic hydrogel dressing with good mechanical properties and antibacterial properties by 2,2,6,6-tetramethylpiperidine-1-oxyl oxidized bacterial cellulose (TOBC) intensified and a simple method for loading Zn2+. The results indicated that the mechanical properties were obviously improved by adding 20 wt% TOBC due to the formation of conjoined-network structure. When the concentration of Zn2+ is controlled at about 0.0001 wt%, the hydrogel has good antimicrobial and biological properties. This study provides a simple and sufficient method to prepare new biomimetic antimicrobial hydrogel dressings with good properties.

Method and device with catalyst storage and delivery capsule for converting biomass into solid and gaseous components

We have designed microcapsules-immobilized composite capsules and evaluated the oral delivery efficacy. The composite capsules were developed by encapsulating Perinereis aibuhitensis extract (PaE), a model substance possessing antioxidant activity, loaded gum Arabic/gelatin microcapsules in calcium alginate (CA) hydrogel (PaE:CA/GA/GE-CCs). In vitro antioxidant assay showed the obtained composite capsules were able to protect PaE from gastric acid, since O2− scavenging rate of encapsulated PaE was about 1.8 folds as that of free PaE after 5 h incubation in simulated gastrointestinal fluid. Moreover, in vivo study showed that after the treatment of oral administration for 30 days, the mice of PaE:CA/GA/GE-CCs group suffered significantly lower oxidative stress level than those of other groups, illustrated as higher SOD and catalase activity, as well as lower malondialdehyde content in liver cells. The results demonstrated the composite capsules could concentrate PaE in small intestine, and enhance the absorption efficiency and in vivo efficacy.

Bioelectrical Analysis of Various Cancer Cell Types Immobilized in 3D Matrix and Cultured in 3D-Printed Well.

Cancer cell lines are important tools for anticancer drug research and assessment. Impedance measurements can provide valuable information about cell viability in real time. This work presents the proof-of-concept development of a bioelectrical, impedance-based analysis technique applied to four adherent mammalian cancer cells lines immobilized in a three-dimensional (3D) calcium alginate hydrogel matrix, thus mimicking in vivo tissue conditions. Cells were treated with cytostatic agent5-fluoruracil (5-FU). The cell lines used in this study were SK-N-SH, HEK293, HeLa, and MCF-7. For each cell culture, three cell population densities were chosen (50,000, 100,000, and 200,000 cells/100 μL). The aim of this study was the extraction of mean impedance values at various frequencies for the assessment of the different behavior of various cancer cells when 5-FU was applied. For comparison purposes, impedance measurements were implemented on untreated immobilized cell lines. The results demonstrated not only the dependence of each cell line impedance value on the frequency, but also the relation of the impedance level to the cell population density for every individual cell line. By establishing a cell line-specific bioelectrical behavior, it is possible to obtain a unique fingerprint for each cancer cell line reaction to a selected anticancer agent.

Entrapment of AlCrFeMn based high entropy alloys in calcium alginate hydrogel balls for decolorization of azo dyes

In the past ten years, high-entropy alloys (HEAs) have attracted wide attention due to their unique structure and remarkable properties. In order to understand their functional properties in depth, the treatment of azo dyes wastewater by HEAs were studied by us. We found that ball milled (BM) AlCrFeMn (S0), AlCrFeMnMg (SMg) and AlCrFeMnS (SS) HEAs powders showed promient performance for decolorization of azo dye Direct Blue 6 (DB6). The efficiencies of the BM S0, SMg, and SS decolorizing DB6 were 3, 6.3 and 90.6 times faster than that of BM MgZn-based amorphous alloy, respectively. MgZn-based amorphous alloy is the best alloy material reported so far. However, since the HEAs powder reacts too fast with DB6, it is difficult to control, resulting in a large loss rate of HEAs powders, which is not conducive to recycling. We found that if the powders were entrapped in calcium alginate hydrogel spheres (CAHBs), these problems could be effectively solved. The BM S0, SMg and SS HEAs powder entrapped in CAHBs by a combination of electrostatic spray and microfluidic are reported in this work for the first time. To compare the SS HEA-CAHBs with the bare SS HEA powder, we found that the reaction of the SS HEA-CAHBs with DB6 was easier to control and more stable for 4 cycles of the reaction. Moreover, the SS HEA-CAHBs could be separated from the solution by simple filtering, and the loss rate of the SS powder decreased from 45 % to 7 %, indicating that entrapment of the CAHBs could greatly reduce the powder loss. The research in this work is of great significance for wastewater treatment.

An Acoustic Droplet-Induced Enzyme Responsive Platform for the Capture and On-Demand Release of Single Circulating Tumor Cells.

The recovery of rare single circulating tumor cells (CTCs) from patients has great potential to facilitate the study of cell heterogeneity and cancer metastasis, which may promote the development of individualized cancer immunotherapy. Herein, a versatile single-cell recovery approach that utilizes an acoustic droplet-induced enzyme responsive platform for the capture and on-demand release of single CTCs is proposed. The platform combines a multifunctional enzyme-responsive gelatin nanoparticle (GNP)-decorated substrate (GNP-chip) for specific capture with an acoustic droplet positioning technique to realize on-demand release of single CTCs. The acoustic droplet dispenser is employed to generate oxidized alginate microdroplets containing the MMP-9 enzyme (OA-MMP-9) with controllable size and precise positioning upon the cell-attached GNP-chip, allowing controlled cell-surface biodegradation under enzymatic reactions followed by calcium chloride (CaCl2) solution treatment to form single-cell encapsulated calcium alginate hydrogels. Benefitting from the existence of hydrogels, the released cells could be efficiently recovered by microcapillary. Results demonstrate that the encapsulated cells maintain good cell morphology in the hydrogels, which allow further single-cell nucleic acid analysis. As a proof-of-concept platform, this approach enables reliable and efficient retrieval of single CTCs and holds the potential for versatility in single-cell analysis systems.

Cold-Responsive Nanocapsules Enable the Sole-Cryoprotectant-Trehalose Cryopreservation of β Cell-Laden Hydrogels for Diabetes Treatment.

Islet transplantation has been one promising strategy in diabetes treatment, which can maintain patient's insulin level long-term and avoid periodical insulin injections. However, donor shortage and temporal mismatch between donors and recipients has limited its widespread use. Therefore, searching for islet substitutes and developing efficient cryopreservation technology (providing potential islet bank for transplantation on demand) is in great need. Herein, a novel cryopreservation method is developed for islet β cells by combining microfluidic encapsulation and cold-responsive nanocapsules (CR-NCs). The cryopreserved cell-laden hydrogels (calcium alginate hydrogel, CAH) can be transplanted for diabetes treatment. During the freezing process, trehalose is released inside β cells through the CR-NCs and serves as the sole cryoprotectant (CPA). Additionally, CAH helps cells to survive the freeze-thaw process and provide cells with a natural immune barrier in vivo. Different from traditional cryopreservation methods, this method combining the CR-NCs and hydrogel encapsulation replaces the toxic CPAs with natural trehalose. Great preservation results are obtained and transplantation experiments of diabetic rats further prove the excellent glucose regulation ability of such β cell-laden hydrogels post cryopreservation. This novel cryopreservation method helps to establish a reliable and ready-to-use bank of biological samples for transplantation therapy and other biomedical applications.

Rubidium-Containing Calcium Alginate Hydrogel for Antibacterial and Diabetic Skin Wound Healing Applications.

Rubidium (Rb) is an important microelement for the human body, which can kill and inhibit bacteria. Rubidium-containing polyhydrated ionogens have been applied to treat refractory wounds. In this work, for the first time, Rb was added into calcium alginate hydrogel (Rb-CA gel) and then made into a dressing by freeze-drying. The addition of Rb to CA maintained a well-ordered porous structure with only slightly reduced swelling and storage modulus and increased roughness and in vitro degradation rate. Experiments in vitro demonstrated that Rb-CA gels could not only inhibit the growth of Staphylococcus aureus and Pseudomonas aeruginosa ubiquitous but were nontoxic and even conducive to human umbilical vein endothelial cells (HUVECs), fibroblasts, and keratinocytes. HUVECs exposed to Rb-CA gels exhibited enhanced migration and tubule formation ability, increased vascular endothelial growth factor secretion, and improved activation of the nuclear factor (erythroid-derived 2)-like 2 (NRF2)/heme-oxygenase-1 (HO-1) signaling pathway. Rb-CA gels also promoted the migration of fibroblasts and keratinocytes. In vivo, in a type II diabetic male Sprague-Dawley rat wound model, neovascularization, re-epithelialization, and collagen deposition were all improved greatly by the Rb-CA gel, with the upregulation of NRF2 and HO-1 protein secretion that inhibited the oxidative stress reaction in the wound sites. Moreover, the Rb-CA gel exhibited a strong anti-inflammatory effect on the wound. In summary, the application of Rb-CA gel dressings to diabetic wounds could produce various synergetic enhancements in terms of angiogenesis, re-epithelialization, and collagen deposition. Hence, Rb-CA gels can be used as a novel therapeutic strategy to promote the healing of diabetic wounds.

Effective biosorption of U(VI) from aqueous solution using calcium alginate hydrogel beads grafted with amino-carbamate moieties

Novel amino-carbamate moiety grafted calcium alginate hydrogel beads (CA-1) were synthesized by reacting sodium alginate with 4-phenylsemicarbazide followed by ionotropic crosslinking with Ca(II) ions. As compared to pure calcium alginate hydrogel beads (CA), CA-1 exhibited fast kinetics and enhanced sorption capacity towards U(VI) ions, from mild acidic conditions. The sorption kinetic could be described by pseudo-second order equation, with the chemisorption as the rate-controlling step. The sorption isotherm were fitted well by Langmuir (qm = 233.2 mg/g at 298 K). CA-1 hydrogel beads exhibited fast kinetic, high sorption capacity and excellent selectivity for U(VI) sorption, thus it could be potentially used for the removal/recovery of U(VI) ions from wastewater.

Plant-mediated biosynthesis of iron nanoparticles-calcium alginate hydrogel membrane and its eminent performance in removal of Cr(VI)

Iron nanoparticles (FeNPs)-calcium alginate (CaAlg) hydrogel membrane was biosynthesized using green tea extract. Characterization of ultraviolet and visible (UV–Vis) spectra, Scanning Electronic Microscopy (SEM) and Transmission Electron Microscope (TEM) of FeNPs and FeNPs-CaAlg hydrogel membrane confirmed that the FeNPs-CaAlg hydrogel membrane is covered by FeNPs and the FeNPs are spherical in shape and the average particle size is 4.96 ± 2.03 nm. The composite membrane shows a eminent performance in removing chromium Cr(VI) from wastewater. The FeNPs-CaAlg hydrogel membrane (0.6 g) can remove as high as 99.5% of 1 mg/L (50 mL) Cr(VI) at room temperature (23 °C) and original pH (5.41) within 10 min. It is confirmed that the combination of biosynthesized FeNPs and CaAlg hydrogel membrane show synergistic effect on removal of Cr(VI). Furthermore, the superiority and complementary mechanism of the composite membrane were proposed with the aid of X-ray photoelectron spectroscopy (XPS).

Enhanced performance and functionality of active edible films by incorporating tea polyphenols into thin calcium alginate hydrogels

Active edible films were prepared consisting of tea polyphenols incorporated within thin calcium alginate gels. These films were prepared by plating an alginate solution, air drying (50 °C), and then cross-linking with calcium. In this study, the effects of tea polyphenol incorporation (1–5% w/w) on the physicochemical, morphological, and antioxidant properties of the films were evaluated. The tensile strength, breaking strain, and water vapor permeability of the films increased as the tea polyphenol level increased, whereas the optical transmittance as measured by UV–visible spectrometer decreased. Fourier transform infrared spectroscopy indicated that various types of intermolecular interactions occurred between the alginate and tea polyphenols. Scanning electron microscopy showed that the films had smooth surfaces with dense internal structures. The antioxidant capacity of the films, as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiozoline-6)-sulphonic acid (ABTS) radical analysis, and the anti-inflammatory properties were enhanced by incorporating tea polyphenols into them. Overall, this study showed that the functional properties of active edible films can be enhanced by introducing tea polyphenols, which may lead to new applications of these films for food packaging applications.

A green strategy for preparing durable underwater superoleophobic calcium alginate hydrogel coated-meshes for oil/water separation

Superhydrophilic and underwater superoleophobic calcium alginate (CA) hydrogel-coated meshes (CAHMs) were prepared via a green dip-coating and self-assembly method without adding any toxic or expensive modifying agents. Since meshes possess intrinsic chemical inert characterisitics, the first CA layer was employed as a precoating and then continually facilitated deposition of CA hydrogel via coordination bonding to form extraordinary underwater superoleophobicity. All results proved that CA was introduced to generate both hydrophilic chemical compositions and rough structures onto resultant mesh surfaces. The obtained meshes, which possessed a underwater oil contact angle (UOCA) of ~154.3° and low oil sliding angle (OSA) of ~7°, could separate various oil/water mixtures with efficiency above 99% and maximum water flux up to 28,108.9 L·m−2·h−1. This separation process was spontaneous and only driven by gravity. Furthermore, as-prepared meshes still maintained high stability under corrosive organic solvents. These outstanding performances made it a promise for oil/water separation in the future.

Synthesis of nonembryonic synseeds in Hemidesmus indicus R. Br.: short term conservation, evaluation of phytochemicals and genetic fidelity of the regenerants

Non-embryogenic, synthetic seeds were formed by encapsulating the nodal segments (NS) of Hemidesmus indicus R. Br. in calcium alginate hydrogel comprising of MS basal medium for short-term conservation. A 3% sodium aliginate (SA) with 100 mM CaCl2 was found most suitable for the preparation of isodiametrical beads. Highest shoot regrowth (84.50 ± 0.35%) was recorded when the gelling matrix, i.e. 3% SA in Murashige and Skoog (MS) basal medium was supplemented with 5.0 µM 6-benzyladenine (BA) + 0.5 µM indole-3-butyric acid (IBA) and inoculated onto the nutrient medium comprised of MS + 5.0 µM BA gave 5.53 ± 0.096 shoots/encapsulated NS. Rooting in microshoots was obtained on the half strength liquid MS + 0.1 µM IBA. Plantlets achieved from preserved synthetic seeds were acclimatized and relocated in the natural condition successfully with the immortality rate of 89.3%. During the days of acclimatization, the obtained plants were subjected for the assessment of their pigment content and biochemical assay. The results obtained clearly exhibited the enhancement in the pigment content as the acclimatization period increases. A significant rise and fall in Superoxide dismutase (SOD), Catalase (CAT), Glutathione reductase (GR) and Ascorbate peroxidase (APX) were evident, suggesting their preventive role against the several environmental stresses during the acclimatization of the plant. Further gas chromatography–mass spectrometry (GC–MS) analysis of both mother and in vitro raised plants showed the occurrence of more than 60 diverse phyto-chemicals in the methanolic root extract. HPLC analysis of the root extract revealed the presence of 2-hydroxy-4-methoxybenzaldehyde (2H4MB), a potential phytoactive compound and flavouring agent. 2H4MB content quantified by high-performance liquid chromatography (HPLC) in methanol extract was 17.94 μg/ml. The genetic stability of the regenerated plantlets with mother plant was confirmed by the presence of monomorphic bands generated through inter simple sequence repeat (ISSR) markers. A protocol with improved results has been developed for synthetic seed production and regeneration in H. indicus using nodal explants.

Continuous fabrication of near-infrared light responsive bilayer hydrogel fibers based on microfluidic spinning

AbstractHydrogel microfibers with inhomogenous structure can achieve some complex motions such as bending, folding and twisting. So it can be applied to soft actuators, soft robots and micropumps. In this paper, continuous bilayer hydrogel fibers in which one layer is calcium alginate hydrogel and the other is linear poly(N-isopropylacrylamide) (PNIPAM)/calcium alginate/graphene oxide (GO) semi-interpenetrating hydrogel were prepared based on microfluidic spinning method. The results show that the bilayer hydrogel fibers have particular porous internal structures of semi-IPN hydrogels and the pore size becomes smaller with the increase of GO content. Besides, the bilayer hydrogel fibers can bend response to the temperature and near-infrared (NIR) light. The diameter of the hydrogel fibers can be tuned by changing the flow rate of spinning fluid and the take-up velocity of winding device.