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Glioma is the most common malignant tumor in the brain, accounting for over 80% of all primary intracranial tumors. The current clinical treatment has shown certain limitations. Although M1 type microglia can secrete various pro-inflammatory cytokines and are expected to be used for glioma treatment, direct use of microglia may lead to overactivation and trigger immune storms. Therefore, we first found that serum starvation can stimulate the transformation of microglia into M1 type. Subsequently, we found through comparative experiments that the inhibitory effect of microglial cell lysis medium on glioma cells was stronger than that of microglial cell culture medium. Finally, we successfully prepared sodium alginate hydrogel loaded with microglia lysis solution to achieve sustained inhibitory effect on the growth of glioma and avoid its proliferation. [ABSTRACT FROM AUTHOR]

A novel composite hydrogel was prepared by combining polyvinyl alcohol (PVA) and sodium alginate (SA) in a specific proportion to serve as a drug carrier, and then loading the extract of Thesium chinense (TCE) onto the drug carrier for use in the trauma treatment. The morphology, structure and biological activity of PVA hydrogel, PVA/SA hydrogel and PVA/SA-TCE hydrogel were characterized, and their wound healing effects on SD rats were investigated. The results show that at a PVA content of 5 wt% and a SA content of 0.6 wt%, the swelling rate of PVA/SA-TCE hydrogel reached 1351 ± 32.0%, indicating excellent liquid absorption and permeation capabilities. When loaded with 2 mg/mL of TCE, PVA/SA-TCE hydrogel exhibited no cytotoxicity and achieved a drug release rate of over 50% at 24 h in buffer solutions with different pH values. Additionally, PVA/SA-TCE hydrogel demonstrated superior anti-inflammatory, antioxidant and antibacterial properties compared to PVA and PVA/SA hydrogels. It effectively prevented the infiltration of Escherichia coli and Staphylococcus aureus, reducing the risk of bacterial infection. In SD rats with full cortical incision, the application of PVA/SA-TCE hydrogel was found to promote wound healing significantly. The wound healing rate on the 20th day reached 99.7%, which was notably higher than that of the control group. [ABSTRACT FROM AUTHOR]

Based on the previous research, this work aimed to reveal the effect of sweet potato protein hydrolysates (SPPHs) with different molecular weights (1000, 3000, and 8000 Da) at 0.5 % on the gelation behavior of calcium-induced sodium alginate (SA), and the encapsulation efficiency and storage stability of purple sweet potato anthocyanins (PSPA) in calcium-induced alginate gel beads was determined. Results indicated that SPPHs with a molecular weight of 8000 Da formed hydrogen bonds and other interactions with SA, which strengthened the internal network connections of the gel, significantly enhanced the gel and effectively filled its pores. The highest encapsulation efficiency was achieved at 87.27 %, compared to 61.73 % without SPPHs. Additionally, stored at 37 °C for 21 days after commercial sterilization, the residual concentration of PSPA with SPPHs was 2.50 times higher than that without SPPHs. SPPHs can enhance the encapsulation efficiency of PSPA and retard their release in gel beads.

Introduction: Osteochondral repair poses a significant challenge due to its unique pathological mechanisms and complex repair processes, particularly in bacterial tissue conditions resulting from open injuries, infections, and surgical contamination. This study introduces a biomimetic honeycomb-like scaffold (Zn-AlgMA@Mg) designed for osteochondral repair. The scaffold consists of a dicalcium phosphate dihydrate (DCPD)-coated porous magnesium scaffold (DCPD Mg) embedded within a dual crosslinked sodium alginate hydrogel (Zn-AlgMA). This combination aims to synergistically exert antibacterial and osteochondral integrated repair properties.Methods: The Zn-AlgMA@Mg scaffold was fabricated by coating porous magnesium scaffolds with DCPD and embedding them within a dual crosslinked sodium alginate hydrogel. The structural and mechanical properties of the DCPD Mg scaffold were characterized using scanning electron microscopy (SEM) and mechanical testing. The microstructural features and hydrophilicity of Zn-AlgMA were assessed. In vitro studies were conducted to evaluate the controlled release of magnesium and zinc ions, as well as the scaffold’s osteogenic, chondrogenic, and antibacterial properties. Proteomic analysis was performed to elucidate the mechanism of osteochondral integrated repair. In vivo efficacy was evaluated using a rabbit full-thickness osteochondral defect model, with micro-CT evaluation, quantitative analysis, and histological staining (hematoxylin-eosin, Safranin-O, and Masson’s trichrome).Results: The DCPD Mg scaffold exhibited a uniform porous structure and superior mechanical properties. The Zn-AlgMA hydrogel displayed consistent microstructural features and enhanced hydrophilicity. The Zn-AlgMA@Mg scaffold provided controlled release of magnesium and zinc ions, promoting cell proliferation and vitality. In vitro studies demonstrated significant osteogenic and chondrogenic properties, as well as antibacterial efficacy. Proteomic analysis revealed the underlying mechanism of osteochondral integrated repair facilitated by the scaffold. Micro-CT evaluation and histological analysis confirmed successful osteochondral integration in the rabbit model.Discussion: The biomimetic honeycomb-like scaffold (Zn-AlgMA@Mg) demonstrated promising results for osteochondral repair, effectively addressing the challenges posed by bacterial tissue conditions. The scaffold’s ability to release magnesium and zinc ions in a controlled manner contributed to its significant osteogenic, chondrogenic, and antibacterial properties. Proteomic analysis provided insights into the scaffold’s mechanism of action, supporting its potential for integrated osteochondral regeneration. The successful in vivo results highlight the scaffold’s efficacy, making it a promising biomaterial for future applications in osteochondral repair.

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sectors. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes with antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings, such as poor water solubility, poor chemical stability, and fast metabolic rate, limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to their biomimetic structure, soft porous microarchitecture, and favorable biomechanical properties. The drug loading/releasing efficiencies can also be controlled via using highly crystalline and porous metal-organic frameworks (MOFs). Herein, a flexible hydrogel composed of a sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to comply with human skin mechanically. The as-prepared hydrogel could capture efficient CCM for slow drug release and effectively kill bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings. [ABSTRACT FROM AUTHOR]

Dye-related water pollution is a worldwide problem. This work describes a facile fabrication of the super-absorbent sodium alginate hydrogel (SA-Ca hydrogel) with improved chemical stability and biocompatibility. By combining the freeze–thaw process with calcium crosslinking, hydrogel with nanopores ranging from 10 to 200 nm was prepared. The SA-Ca hydrogel presents a swelling ratio of 90.6 g·g−1. The effects of pH, initial concentration of the methylene blue (MB) concentration, amounts of absorbents, and temperature on adsorption capacity are investigated. At optimized conditions, the maximum adsorption capacity can reach 2986 mg·g−1. The adsorption kinetics are analyzed using different models, and the pseudo-second-order model can be used to describe the kinetic profile. According to the thermodynamic parameters, the MB adsorption processes using SA-Ca hydrogel are favorable, spontaneous, and endothermic. The proposed SA-Ca hydrogel is expected to be an effective absorbent for water treatment without extra pollution. [ABSTRACT FROM AUTHOR]

Tin-based anode materials are important components of lithium-ion batteries (LIBs) owing to their larger theoretical capacitance and lower working potential. However, the synthesis of tin-based anode materials is very complex, impeding their industrialization. In this work, tin dioxide nanoparticles were synthesized using sodium alginate hydrogel as a chelating agent for the ion-exchange reaction with tin tetrachloride. The resulting nano-tin dioxide was uniformly distributed with a porous structure morphology. The addition of sodium alginate at 0.1 g yielded a sample (SA-0.1) with a high reversible specific capacity, excellent multiplicative properties, and good cycling stability. After 702 cycles, the capacity of reversible discharge of the SA-0.1 maintained 621.1 mAh g−1 at the current density of 0.5A g−1, which cooperates with the facile synthesis method making the composite promising for commercialization. [ABSTRACT FROM AUTHOR]

Infertility and intestinal blockage are just two examples of the postoperative consequences that can arise from peritoneal damage, which can also result in severe peritoneal fibrosis and peritoneal adhesions. Peritoneal adhesions are still not effectively treated, and both pharmaceutical therapy and biomaterial barriers have only had modest preventative effects. In this work, we looked into the effectiveness of in-place injectable sodium alginate hydrogel for peritoneal adhesion prevention. The findings demonstrated that sodium alginate hydrogel promoted human peritoneal mesothelial cell proliferation and migration, prevented peritoneal fibrosis by suppressing the production of transforming growth factor-β1, and, most importantly, promoted mesothelium self-repair. These findings imply that this brand-new sodium alginate hydrogel is a good candidate material for peritoneal adhesion prevention. [ABSTRACT FROM AUTHOR]

Metal–organic framework materials(ZIF-9) were loaded on Sodium alginate/polyvinyl(PVA/SA) hydrogel by in situ growth method for adsorption of heavy metal Cu (II). The structure of hydrogels composited with MOFs and polymers was designed to improve the poor mechanical properties of natural polymer gel materials and the inconvenience of powdered MOFs materials in practical applications. The adsorption results showed that the optimum adsorption process of Cu (II) pH was 5.0. The adsorption kinetics and isotherm suggest that the adsorption process follows the Freundlich isotherm and the pseudo-second-order models. The experimental maximum adsorption capacity was 98.98 mg/g, 2.6 times and 1.5 times higher than ordinary SA and PVA/SA hydrogel spheres. Synthesized hydrogel spheres were characterized by FT-IR, SEM, XRD, and XPS, which confirmed that MOF materials have grown in situ on PVA/SA hydrogel spheres. More importantly, PVA/SA@ZIF-9 exhibited exceptional mechanical stability and showed excellent recycling capability in the cyclic adsorption process. [ABSTRACT FROM AUTHOR]

The current research studies the synergistic effect of Cydonia oblonga and its extracted nano bio‑silver as a natural and eco-friendly agent for the improvement of three-dimensional (3D)-printed alginate wound dressings. Therefore, Cydonia oblonga extract was first prepared and silver nanoparticles were extracted from it through a green and simple method. The Cydonia oblonga and its extracted bio-based nanoparticles were then added to 3D printing alginate-based ink. Subsequently, a 3D structural extrusion printer was employed to create the porous hydrogel-based wound dressings. The morphological investigation demonstrated that using the extraction method the bio-based silver nanoparticles were successfully prepared, having an average size of 17.95 ± 4.50 nm. The Cydonia oblonga extract showed comparable antioxidant activity to the commercial antioxidant and an excellent total phenol content. In addition, the results showed the combination of Cydonia oblonga extracts/silver nanoparticles significantly improved the antibacterial performance of alginate-based bioinks. In vivo , and in vitro studies confirmed their biocompatibility and significant efficacy in the treatment of burn wounds. • Cydonia oblonga extract and bio-based silver nanoparticles were synthesized. • Cydonia oblonga extract had significant antioxidant activity. • The extract and nanosilver in the bioink showed a high antibacterial performance. • The prepared alginate-based bioink showed a high capability of 3D printing. • The 3D-printed bioink showed a promising wound-healing performance. [ABSTRACT FROM AUTHOR]

Burn injuries are the fourth most prevalent devastating form of trauma worldwide. Among the most extensively explored materials, composite dressings with alginate loaded with herbal extract can be mentioned. This research aimed to develop a sodium alginate (SA)-based hydrogel encapsulated with Mentha aquatica (MA) methanol extract and investigate its therapeutic efficacy in the infected burn mouse model. SEM, FTIR, in vitro extract release, HPLC, mechanical test, contact angle, swelling, degradability, and temperature response properties were used to analyze the hydrogel scaffold's physicochemical structure. Additionally, the antibacterial activity and MIC level of the extract, cell cytotoxicity, and macroscopic and microscopic analysis of the wound healing process were done using Masson's trichrome and hematoxylin-eosin staining. The physicochemical properties of the SA hydrogel encapsulated with MA extract were verified. The lowest inhibitory dose of the extract was determined to be 12.5 mg/ml. Application of SA/MA hydrogel to localized wounds of deep third-degree burns demonstrated faster tissue regeneration, collagen recovery, and eradication of bacterial infection. This research focused on the design and the preparation of a novel and effective biomaterials-based medical product, which has the potential to rehabilitate infected and injured skin tissue; therefore, it can be a promising candidate for wound dressing applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this manuscript., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Based on the previous research, this work aimed to reveal the effect of sweet potato protein hydrolysates (SPPHs) with different molecular weights (1000, 3000, and 8000 Da) at 0.5 % on the gelation behavior of calcium-induced sodium alginate (SA), and the encapsulation efficiency and storage stability of purple sweet potato anthocyanins (PSPA) in calcium-induced alginate gel beads was determined. Results indicated that SPPHs with a molecular weight of 8000 Da formed hydrogen bonds and other interactions with SA, which strengthened the internal network connections of the gel, significantly enhanced the gel and effectively filled its pores. The highest encapsulation efficiency was achieved at 87.27 %, compared to 61.73 % without SPPHs. Additionally, stored at 37 °C for 21 days after commercial sterilization, the residual concentration of PSPA with SPPHs was 2.50 times higher than that without SPPHs. SPPHs can enhance the encapsulation efficiency of PSPA and retard their release in gel beads., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sectors. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes with antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings, such as poor water solubility, poor chemical stability, and fast metabolic rate, limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to their biomimetic structure, soft porous microarchitecture, and favorable biomechanical properties. The drug loading/releasing efficiencies can also be controlled via using highly crystalline and porous metal-organic frameworks (MOFs). Herein, a flexible hydrogel composed of a sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to comply with human skin mechanically. The as-prepared hydrogel could capture efficient CCM for slow drug release and effectively kill bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.

Gene therapy is one of the most promising approaches in regenerative medicine to restore damaged tissues of various types. However, the ability to control the dose of bioactive molecules in the injection site can be challenging. The combination of genetic constructs, bioresorbable material, and the 3D printing technique can help to overcome these difficulties and not only serve as a microenvironment for cell infiltration but also provide localized gene release in a more sustainable way to induce effective cell differentiation. Herein, the cell transfection with plasmid DNA directly incorporated into sodium alginate prior to 3D printing was investigated both in vitro and in vivo. The 3D cryoprinting ensures pDNA structure integrity and safety. 3D printed gene-activated scaffolds (GAS) mediated HEK293 transfection in vitro and effective synthesis of model EGFP protein in vivo, thereby allowing the implementation of the developed GAS in future tissue engineering applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: Numerous studies have reported that transforming growth factor beta 3 combined with alginate and mesenchymal stem cells can repair cartilage defects in animal experiments. However, there is little research about the effect of transforming growth factor beta 3 and sodium alginate hydrogel combined with mesenchymal stem cells on repairing cartilage injury. OBJECTIVE: To compare effects of sodium alginate hydrogel and sodium alginate hydrogel loaded with transforming growth factor beta 3 on bone defect with bone marrow mesenchymal stem cells. METHODS: Rabbit bone marrow mesenchymal stem cells were isolated and cultured in vitro. A suitable amount of transforming growth factor beta 3 was added into sodium alginate solution. Before transplantation, bone marrow mesenchymal stem cell suspension was mixed with the hydrogel in equal volumes. Totally 48 New Zealand white rabbits were used to prepare unilateral articular cartilage defects and randomly divided into three groups. The injury group did not take any treatment; the control group was implanted with alginate hydrogel and bone marrow mesenchymal stem cell suspension; and the observation group was implanted with transforming growth factor beta 3-sodium alginate hydrogel complex and bone marrow mesenchymal stem cell suspension. At 12 weeks after operation, the samples were taken for gross and histological observation and type II collagen immunohistochemical staining and RT-PCR. RESULTS AND CONCLUSION: (1) General observation: At 12 weeks, the defect site of the injury group was filled with a large number of granulation tissue; the control group was filled with translucent cartilage like tissue; and the observation group was filled with new tissue. (2) Histological observation: At 12 weeks after operation, hematoxylin-eosin staining and safranin O staining showed that the defect site in the injury group was filled with more fibrous tissue, and there was a large gap in the central part. In the control group, there were more cartilage like tissue and fibroblast tissue; the surface was irregular; most of the material was degraded; and the material was surrounded by a large number of bone trabeculae. In the observation group, there was a large number of cartilage like tissue, with smooth surface and dense structure, similar to the surrounding normal cartilage tissue. (3) Immunohistochemical staining of type II collagen: only very weak positive staining was found in the injury group, while positive staining was found in the control group and the observation group, and the degree of positive staining in the observation group was significantly stronger than that in the control group. (4) RT-PCR detection: mRNA expression of type II collagen, Sox9 and glycosaminoglycan in the regenerated cartilage of the control group was lower than that of the observation group (P < 0.05). (5) The results suggest that transforming growth factor beta 3-sodium alginate hydrogel complex with bone marrow mesenchymal stem cells can promote the repair of articular cartilage defects and enhance the expression of articular cartilage genes. [ABSTRACT FROM AUTHOR]

Minimally invasive, efficient, and satisfactory treatment for irregular and lacunar bone defects is still a challenge. Alginate hydrogels serve as promising stem cell (SC) delivery systems for bone regeneration but are limited by low cellular viability, poor osteogenic differentiation, and insufficient mechanical support. Herein, we developed a BMSCs-laden mechanically reinforced bioactive sodium alginate composite hydrogel microspheres (BCHMs) system via a microfluidic method that possesses 1) a uniform size and good injectability to meet clinical bone defects with complex shapes, 2) high cellular viability maintenance and further osteogenic induction capacity, and 3) improved mechanical properties. As the main matrix, the sodium alginate hydrogel maintains the high viability of encapsulated BMSCs and efficient substance exchange. Enhanced mechanical properties and osteogenic differentiation of the BCHMs in vitro were observed with xonotlite (Ca 6 Si 6 O 17 (OH) 2 , CSH) nanowires incorporated. Furthermore, BCHMs with 12.5 % CSH were injected into rat femoral bone defects, and satisfactory in situ regeneration outcomes were observed. Overall, it is believed that BCHMs expand the application of polysaccharide science and provide a promising injectable bone substitute for minimally invasive bone repair. [ABSTRACT FROM AUTHOR]

Promoting blood–spinal cord barrier (BSCB) repair at the early stage plays a crucial role in treatment of spinal cord injury (SCI). Excessive activation of autophagy can prevent recovery of BSCB after SCI. Basic fibroblast growth factor (bFGF) has been shown to promote BSCB repair and locomotor function recovery in SCI. However, the therapeutic effect of bFGF via direct administration on SCI is limited because of its rapid degradation and dilution at injury site. Based on these considerations, controlled release of bFGF in the lesion area is becoming an attractive strategy for SCI repair. At present, we have designed a sustained-release system of bFGF (called ALG-bFGF) using sodium alginate hydrogel, which is able to load large amounts of bFGF and suitable for in situ administration of bFGF in vivo. Here, traumatic SCI mice models and oxygen glucose deprivation (OGD)–stimulated human brain microvascular endothelial cells were performed to explore the effects and the underlying mechanisms of ALG-bFGF in promoting SCI repair. After a single in situ injection of ALG-bFGF hydrogel into the injured spinal cord, sustained release of bFGF from ALG hydrogel distinctly prevented BSCB destruction and improved motor functional recovery in mice after SCI, which showed better therapeutic effect than those in mice treated with bFGF solution or ALG. Evidences have demonstrated that autophagy is involved in maintaining BSCB integrity and functional restoration in animals after SCI. In this study, SCI/OGD exposure–induced significant upregulations of autophagy activation-related proteins (Beclin1, ATG5, LC3II/I) were distinctly decreased by ALG-bFGF hydrogel near the baseline and not less than it both in vivo and in vitro , and this inhibitory effect contributed to prevent BSCB destruction. Finally, PI3K inhibitor LY294002 and KLF4 inhibitor NSC-664704 were applied to further explore the underlying mechanism by which ALG-bFGF attenuated autophagy activation to alleviate BSCB destruction after SCI. The results further indicated that ALG-bFGF hydrogel maintaining BSCB integrity by inhibiting autophagy activation was regulated by PI3K/Akt/FOXO1/KLF4 pathway. In summary, our current study revealed a novel mechanism by which ALG-bFGF hydrogel improves BSCB and motor function recovery after SCI, providing an effective therapeutic strategy for SCI repair. [ABSTRACT FROM AUTHOR]

Promoting blood–spinal cord barrier (BSCB) repair at the early stage plays a crucial role in treatment of spinal cord injury (SCI). Excessive activation of autophagy can prevent recovery of BSCB after SCI. Basic fibroblast growth factor (bFGF) has been shown to promote BSCB repair and locomotor function recovery in SCI. However, the therapeutic effect of bFGF via direct administration on SCI is limited because of its rapid degradation and dilution at injury site. Based on these considerations, controlled release of bFGF in the lesion area is becoming an attractive strategy for SCI repair. At present, we have designed a sustained-release system of bFGF (called ALG-bFGF) using sodium alginate hydrogel, which is able to load large amounts of bFGF and suitable for in situ administration of bFGF in vivo. Here, traumatic SCI mice models and oxygen glucose deprivation (OGD)–stimulated human brain microvascular endothelial cells were performed to explore the effects and the underlying mechanisms of ALG-bFGF in promoting SCI repair. After a single in situ injection of ALG-bFGF hydrogel into the injured spinal cord, sustained release of bFGF from ALG hydrogel distinctly prevented BSCB destruction and improved motor functional recovery in mice after SCI, which showed better therapeutic effect than those in mice treated with bFGF solution or ALG. Evidences have demonstrated that autophagy is involved in maintaining BSCB integrity and functional restoration in animals after SCI. In this study, SCI/OGD exposure–induced significant upregulations of autophagy activation-related proteins (Beclin1, ATG5, LC3II/I) were distinctly decreased by ALG-bFGF hydrogel near the baseline and not less than it both in vivo and in vitro, and this inhibitory effect contributed to prevent BSCB destruction. Finally, PI3K inhibitor LY294002 and KLF4 inhibitor NSC-664704 were applied to further explore the underlying mechanism by which ALG-bFGF attenuated autophagy activation to alleviate BSCB destruction after SCI. The results further indicated that ALG-bFGF hydrogel maintaining BSCB integrity by inhibiting autophagy activation was regulated by PI3K/Akt/FOXO1/KLF4 pathway. In summary, our current study revealed a novel mechanism by which ALG-bFGF hydrogel improves BSCB and motor function recovery after SCI, providing an effective therapeutic strategy for SCI repair.

Introduction: Osteochondral repair poses a significant challenge due to its unique pathological mechanisms and complex repair processes, particularly in bacterial tissue conditions resulting from open injuries, infections, and surgical contamination. This study introduces a biomimetic honeycomb-like scaffold (Zn-AlgMA@Mg) designed for osteochondral repair. The scaffold consists of a dicalcium phosphate dihydrate (DCPD)-coated porous magnesium scaffold (DCPD Mg) embedded within a dual crosslinked sodium alginate hydrogel (Zn-AlgMA). This combination aims to synergistically exert antibacterial and osteochondral integrated repair properties. Methods: The Zn-AlgMA@Mg scaffold was fabricated by coating porous magnesium scaffolds with DCPD and embedding them within a dual crosslinked sodium alginate hydrogel. The structural and mechanical properties of the DCPD Mg scaffold were characterized using scanning electron microscopy (SEM) and mechanical testing. The microstructural features and hydrophilicity of Zn-AlgMA were assessed. In vitro studies were conducted to evaluate the controlled release of magnesium and zinc ions, as well as the scaffold's osteogenic, chondrogenic, and antibacterial properties. Proteomic analysis was performed to elucidate the mechanism of osteochondral integrated repair. In vivo efficacy was evaluated using a rabbit full-thickness osteochondral defect model, with micro-CT evaluation, quantitative analysis, and histological staining (hematoxylin-eosin, Safranin-O, and Masson's trichrome). Results: The DCPD Mg scaffold exhibited a uniform porous structure and superior mechanical properties. The Zn-AlgMA hydrogel displayed consistent microstructural features and enhanced hydrophilicity. The Zn-AlgMA@Mg scaffold provided controlled release of magnesium and zinc ions, promoting cell proliferation and vitality. In vitro studies demonstrated significant osteogenic and chondrogenic properties, as well as antibacterial efficacy. Proteomic analysis revealed the underlying mechanism of osteochondral integrated repair facilitated by the scaffold. Micro-CT evaluation and histological analysis confirmed successful osteochondral integration in the rabbit model. Discussion: The biomimetic honeycomb-like scaffold (Zn-AlgMA@Mg) demonstrated promising results for osteochondral repair, effectively addressing the challenges posed by bacterial tissue conditions. The scaffold's ability to release magnesium and zinc ions in a controlled manner contributed to its significant osteogenic, chondrogenic, and antibacterial properties. Proteomic analysis provided insights into the scaffold's mechanism of action, supporting its potential for integrated osteochondral regeneration. The successful in vivo results highlight the scaffold's efficacy, making it a promising biomaterial for future applications in osteochondral repair., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhang, Dong, Zhao, Sun, Lin, Zhang, Wang, Yang, Jiang, Li, Cao, Cai, Liu, Zhang, Bai and Yao.)

Intrauterine adhesion (IUA) stands as a prevalent medical condition characterized by endometrial fibrosis and scar tissue formation within the uterine cavity, resulting in infertility and, in severe cases, recurrent miscarriages. Cell therapy, especially with stem cells, offers an alternative to surgery, but concerns about uncontrolled differentiation and tumorigenicity limit its use. Exosomes, more stable and immunogenicity-reduced than parent cells, have emerged as a promising avenue for IUA treatment. In this study, a novel approach has been proposed wherein exosomes originating from decidual stromal cells (DSCs) are encapsulated within sodium alginate hydrogel (SAH) scaffolds to repair endometrial damage and restore fertility in a mouse IUA model. Current results demonstrate that in situ injection of DSC-derived exosomes (DSC-exos)/SAH into the uterine cavity has the capability to induce uterine angiogenesis, initiate mesenchymal-to-epithelial transformation (MET), facilitate collagen fiber remodeling and dissolution, promote endometrial regeneration, enhance endometrial receptivity, and contribute to the recovery of fertility. RNA sequencing and advanced bioinformatics analysis reveal miRNA enrichment in exosomes, potentially supporting endometrial repair. This finding elucidates how DSC-exos/SAH mechanistically fosters collagen ablation, endometrium regeneration, and fertility recovery, holding the potential to introduce a novel IUA treatment and offering invaluable insights into the realm of regenerative medicine., (© 2024 Wiley‐VCH GmbH.)

Gene therapy is one of the most promising approaches in regenerative medicine to restore damaged tissues of various types. However, the ability to control the dose of bioactive molecules in the injection site can be challenging. The combination of genetic constructs, bioresorbable material, and the 3D printing technique can help to overcome these difficulties and not only serve as a microenvironment for cell infiltration but also provide localized gene release in a more sustainable way to induce effective cell differentiation. Herein, the cell transfection with plasmid DNA directly incorporated into sodium alginate prior to 3D printing was investigated both in vitro and in vivo. The 3D cryoprinting ensures pDNA structure integrity and safety. 3D printed gene-activated scaffolds (GAS) mediated HEK293 transfection in vitro and effective synthesis of model EGFP protein in vivo, thereby allowing the implementation of the developed GAS in future tissue engineering applications.

CuS/ZnS/sodium alginate/reduced graphene oxide nanocomposites (CZSrG) were prepared by physical crosslinking followed by one-step reduction and were justified as green binder-free hydrogel high-capacitance electrodes. The physical crosslinking was realized simply through the hydrogen-bond interaction between sodium alginate (SA) and graphene oxide (GO), avoiding the usage of traditional Ca2+ crosslinking agent. The hydrogel structure made of CZSrG possessed the most beneficial effect of avoiding large volume change and increasing cycle stability for supercapacitors. When used as electrode, the specific capacitance of CZSrG was 992 F·g−1 (10 mV·s−1) in a three-electrode system. Furthermore, the fabricated supercapacitors had a specific capacitance of 252.1 F·g−1 (5 mV·s−1), and a power density of 1800 Wh·kg−1 at the energy density of 2.05 Wh·kg−1. Thus, the CZSrG has a favorable electrochemical performance and wide application prospects in supercapacitors. Unlabelled Image • The CZSrG nanocomposites were designed by physical crosslinking and one-step reduction. • The physical crosslinking was binder-free and achieved by hydrogen-bonds. • The hydrogel structure replaced the traditional organic binder PTFE. • The CZSrG had excellent capacitance compared with other CuS electrodes. [ABSTRACT FROM AUTHOR]

Heart failure (HF) is a common and serious manifestation after myocardial infarction (MI). Despite their clinical importance, current treatments for MI still have several limitations. Revascularization has been proven to have positive effects on MI-induced damage. Currently biomaterial-based angiogenesis strategies represent potential candidates for MI treatment. Bioglass (BG) is a commercially available family of bioactive glasses. BG has angiogenic properties and thus might be an attractive alternative for MI treatments. Here, we loaded BG in sodium alginate (BGSA), locally injected it into peri-infarct myocardial tissue and examined its suitability for inducing cardiac angiogenesis and eventually improving cardiac function following MI. Cardiac function was evaluated via echocardiography. Infarct morphometry, angiogenesis, apoptosis and angiogenic protein expression were all analysed 4 weeks after BGSA injection. Compared with the control treatment, BGSA was sufficient to prompt angiogenesis, suppress apoptosis, up-regulate the expression of angiogenic proteins, attenuate infarct size, preserve wall thickness and eventually improve cardiac function. Our results demonstrate the feasibility and effectiveness of BGSA in myocardial regeneration via angiogenesis, suggesting that BGSA is a potential therapeutic strategy for post-infarct myocardial regeneration.

In this work, a new strategy of dual-reaction triggered sensitivity amplification for ultrasensitive electrochemical detection of matrix metalloproteinase-7 (MMP-7) was developed. The sensitivity of amperometric biosensor relies on the current signal differences (ΔI) caused by per unit concentration target. Benefited from dual-reaction catalytic activities of Pd nanoparticles, dual catalytic reactions were implemented in the biosensor to amplify the ΔI: (1) Fenton-like reaction was triggered by the probes to degrade redox species methylene blue; (2) catalytic precipitation reaction was followed subsequently to generate insoluble precipitation by 4-chloro-1-naphthol oxidation. Dual-enhancement of ΔI triggered by Pd nanoparticle-based catalytic probes significantly improved the detection performance of the biosensor. The peptide-cleavage based biosensor integrated Pd nanoparticle-based catalytic probes with reduced graphene oxide-Au/methylene blue-sodium alginate hydrogel (Au-rGO/MB-SA) nanocomposites substrate for ultrasensitive detection of MMP-7. Under optimal conditions, the proposed biosensor exhibited a wide linear range from 10 fg mL −1 to 10 ng mL −1 with an ultralow detection limit of 3.1 fg mL −1 . This strategy successfully combines the multiple catalytic reactions triggered by nanomaterials with peptide-cleavage pattern in electrochemical biosensor, providing a promising method for detection of other proteases. [ABSTRACT FROM AUTHOR]

We prepared shape-controllable, sodium alginate-based hydrogels containing various particles inside the hydrogels. Centrifugal injection method was employed to obtain smaller sized gels, compared to that fabricated by conventional method. A conventionally-fabricated gel beads were spherically-shaped, in which the shape was determined by the droplets of sodium alginate solution from syringe needle. The shape of the gels was easily manipulated to obtain hollow-cylindrical gels by simple use of embedding particles and by changing the concentration of sodium alginate, calcium chloride, and the embedding components. As a result, the hollow-centered gels with the unique shape were obtained. [ABSTRACT FROM AUTHOR]

In this paper, an environmentally friendly, visible and easy-to-recycle spherical adsorbent (SA@PEI-CDs, SA: sodium alginate, PEI: polyethyleneimine, CDs: carbon dots) has been prepared from functionalized positively charged biomass carbons dots (PEI-CDs) and anionic polyelectrolyte sodium alginate (SA) through electrostatic self-assembly. SA@PEI-CDs can efficiently and preferentially adsorb Pb2+. Compared to bare SA, the adsorption capacity of SA@PEI-CDs increased from 206.93 mg/g to 380.39 mg/g (at pH=4), which enhanced 83.82%. It can still maintain 85.67% of the original adsorption capacity after five cycles. The quenching of the blue fluorescence of the adsorbent derived from carbon dots indicates that the adsorption process has reached saturation. The investigation about the adsorption isotherm models, kinetics and thermodynamic parameters reveals that the adsorption process follows Freundlich isotherm model based on chemical adsorption, which is an endothermic spontaneous reaction with an increase in entropy. The possible adsorption mechanism is electrostatic attraction, ion exchange, and together with the coordination of -NH 2 , -OH, -COOH with Pb2+. In addition, the extremely easy-to-recycle spherical adsorbent is also used in the multi-layer adsorption and separation of simulated sewage samples in the water purifier model. For simulated water samples whose concentration of five/three types of heavy metal ions exceeds 100 times the standard, after using adsorbent SA@PEI-CDs for two or three consecutive adsorptions, the content of heavy metals decreases rapidly, which is far below the limit value of high-quality water. The Pb2+ ion concentration decreased from 1.0 mg/L to 0.002540 mg/L and 0.003611 mg/L, respectively. [Display omitted] ● SA@PEI-CDs is derived from functional biomass CDs and sodium alginate hydrogel. ● SA@PEI-CDs can preferentially and selectively adsorb heavy metal Pb2+. ● The blue fluorescence of PEI-CDs can indicate the progress of adsorption. ● SA@PEI-CDs is easy to separate and will not cause secondary pollution. ● The process is chemical adsorption, assisted by intra-particle diffusion. [ABSTRACT FROM AUTHOR]

Reverse osmosis (RO) is widely used in water purification process. However, most commercial RO membranes have low water permeance, and encounter a "trade-off" effect between permeance and rejection. In this work, a kind of RO membrane with an in-situ formed film of sodium alginate (SA) hydrogel as an interlayer on the surface of a polysulfone (PSf) substrate has been extensively investigated. The SA hydrogel interlayer significantly controls and reduces the diffusion rate of the aqueous monomer, m-phenylenediamine (MPD) during the interfacial polymerization (IP), leading to the formation of a relatively smooth (−58 nm) polyamide (PA) separation skin layer with more unreacted acryl chloride groups remaining thereon, which makes it more hydrophilic after the hydrolysis of these groups. Under the optimal fabrication conditions, the water permeance achieves 27.8 L m−2 h−1 MPa−1 with a salt rejection maintaining at 99.2 % for 2000 mg L−1 NaCl solution, indicating that the prepared RO membrane has a broad prospect for the application in brackish water desalination, which is beneficial for the future development of RO membranes with high performance. [Display omitted] • A SA hydrogel interlayer was formed by crosslinking on PSf substrate surface. • Hydrogel interlayer effectively manipulated the interfacial polymerization process. • Greatly improved water permeance of RO membrane with high rejection maintained. [ABSTRACT FROM AUTHOR]

With the development of technology, adjuvant immunotherapy has become a promising strategy for prevention of postoperative tumor regression and metastasis by stimulating the host immune response. However, the therapeutic effects are still unsatisfactory due to the lack of synergy between different methods. In this study, an efficient synergistic immunotherapy system based on injectable sodium alginate hydrogels was designed to inhibit in situ recurrence and metastasis at the same time. On the one hand, an injectable sodium alginate (SA) hydrogel microsystem loaded with toll-like receptor (TLR) agonists (CpG ODNs) was synthesized for inhibiting in situ recurrence, and then carcinoembryonic antigen (CEA) probe was also added to detect CEA based on fluorescence resonance energy transfer (FRET) technology to monitor the occurrence and development of tumor recurrence. On the other hand, an anti-programmed cell death 1 ligand 1 antibody (anti-PD-L1)-modified SA nanogel loaded with indocyanine green (ICG@SA-anti-PD-L1 nanogel) was prepared for diagnosing and inhibiting lung metastasis by assisting orthotopic tumor therapy. In vitro and in vivo results demonstrated that this SA micro/nanosystem could monitor and inhibit postoperative recurrence and metastasis. We hope that this micro/nano-synergistic system will become an effective strategy for postoperative adjuvant immunotherapy.

Heart failure (HF) is a common and serious manifestation after myocardial infarction (MI). Despite their clinical importance, current treatments for MI still have several limitations. Revascularization has been proven to have positive effects on MI-induced damage. Currently biomaterial-based angiogenesis strategies represent potential candidates for MI treatment. Bioglass (BG) is a commercially available family of bioactive glasses. BG has angiogenic properties and thus might be an attractive alternative for MI treatments. Here, we loaded BG in sodium alginate (BG SA), locally injected it into peri-infarct myocardial tissue and examined its suitability for inducing cardiac angiogenesis and eventually improving cardiac function following MI. Cardiac function was evaluated via echocardiography. Infarct morphometry, angiogenesis, apoptosis and angiogenic protein expression were all analysed 4 weeks after BG SA injection. Compared with the control treatment, BG SA was sufficient to prompt angiogenesis, suppress apoptosis, up-regulate the expression of angiogenic proteins, attenuate infarct size, preserve wall thickness and eventually improve cardiac function. Our results demonstrate the feasibility and effectiveness of BG SA in myocardial regeneration via angiogenesis, suggesting that BG SA is a potential therapeutic strategy for post-infarct myocardial regeneration. [ABSTRACT FROM AUTHOR]

A "signal-on" chemiluminescence biosensor was established for detecting thrombin. The thrombin aptamer1-functionalized magnetic sodium alginate (Malg-Apt1) hydrogel was synthesized by physical interaction between sodium alginate and Ca2+, and it was used in the biosensor for separating and enriching thrombin. Ethylenediamine tetraacetic acid (EDTA) was used to chelate with Ca2+ to dissolve the hydrogel and release thrombin. A metalloporphyrinic metal-organic framework nanosheet, named as Cu-TCPP(Co) MOFs, was prepared as signal amplification strategy. Cu-TCPP(Co) MOFs/Au-ssDNA (ssDNA: single-strand DNA) was synthesized for controllable further amplification of chemiluminescent signal. The thrombin aptamer2-functionalized magnetic carbon nanotubes (MCNTs-Apt2) were used as a matrix, and Cu-TCPP(Co) MOFs/Au-ssDNA was adsorbed on the MCNTs by the complementary pairing of the partial bases between ssDNA and Apt2. Compared with ssDNA, Apt2 has a stronger interaction with thrombin. Therefore, thrombin can trigger the release of Cu-TCPP(Co) MOFs/Au-ssDNA to achieve signal amplification. Under the optimal conditions, the biosensor could detect thrombin as low as 2.178 × 10−13 mol/L with the range from 8.934 × 10−13 to 5.956 × 10−10 mol/L and exhibited excellent selectively. Moreover, the "signal-on" chemiluminescence biosensor showed potential application for the detection of thrombin in body fluids. Image 1 • Malg-Apt1 was prepared to separate and enrich thrombin, and the selectivity of the CL biosensor was improved. • Cu-TCPP(Co) MOFs nanosheets was prepared to provide more active sites and catalyze the reaction between luminol and H 2 O 2. • The synthesized Cu-TCPP(Co) MOFs/Au-ssDNA as a catalyst significantly improved the sensitivity of CL biosensor. [ABSTRACT FROM AUTHOR]

Herein, a bilayer cylindrical conduit (P-CA) is presented consisting of electrospun polycaprolactone (PCL) nanofibers and sodium alginate hydrogel covalently cross-linked with N,N'-disuccinimidyl carbonate (DSC). The bilayer P-CA conduit is developed by combining the electrospinning and outer-inner layer methods. Using DSC, as a covalent crosslinker, increases the degradation time of the sodium alginate hydrogel up to 2 months. The swelling ratio of the hydrogel is also 503% during the first 8 h. The DSC cross-linked sodium alginate in the inner layer of the conduit promotes the adhesion and proliferation of nerve cells, while the electrospun PCL nanofibers in the outer layer provide maximum tensile strength of the conduit during surgery. P-CA conduit promotes the migration of Schwann cells along the axon in a rat model based on functional and histological evidences. In conclusion, P-CA conduit will be a promising construct for repairing sciatic nerves in a rat model., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Bone marrow derived mesenchymal stromal cells (BMSCs) migration to injury site is a prevalent event in tissue repair process after damage occurrence. The migration process is always accompanied with matrix stiffness change. In this study, sodium alginate hydrogels with different stiffness and Transwell chambers with gradient chemical factors were employed to mimic tissue repair in vivo. In this work, in the stiffness range of 1–20 kPa, BMSCs in stiffer matrix showed higher migration speed compared to those in softer matrix. Moreover, stiffer matrix decreased the nuclear stiffness of BMSCs and reduced the expression of lamin A/C, which playing a main role in the regulation of nuclear stiffness. Furthermore, it was found that BMSCs fitted environment by selecting migration strategy. This study provides a novel platform for the investigation of BMSCs migration to mimic the natural tissue repair process. [ABSTRACT FROM AUTHOR]