Intrauterine injection of bioengineered hydrogel loaded exosomes derived from HUCM stem cells and spermidine prominently augments the pregnancy rate in thin endometrium rats

The endometrium is essential to the development of embryos and pregnancy. Human umbilical cord mesenchymal stem cells (HUCMSCs) are promising stem cell sources. HUCMSCs self-renew quickly and are painless to collect. Spermidine is an inherent polyamine needed for cellular and molecular processes that regulate physiology and function. HUCMSCs and spermidine (SN) may heal intrauterine adhesions. HUCMSCs were investigated for endometrial repair in rats. Composite hydrogels are used for medical exosome implantation, including their materials, properties, and embedding procedures. This study examined whether bioengineered hydrogel-loaded exosomes from HUCMSCs and spermidine prenatally improved conception rates in mice with poor endometrial lining. The data show that HUCMSC and SN provide a good experimental base for HUCMSC safety and intrauterine treatment in rats. Western blots, exosome structural analysis, pregnancy outcomes, flow cytometry, H&E staining, immunohistochemistry, and immunofluorescence labelling found and recovered the aberrant area. HUCM-derived stem cells and spermidine-derived exosomes biophysically match. These traits strengthen and prolong endometrial function. Pregnant rats with HUCMSC and SN had thinner endometrium. Hydrogel-incorporated HEHUCMSC and SN exosomes may improve IUI in rats with thin endometrium.

Advancing burn wound treatment: exploring hydrogel as a transdermal drug delivery system

Burn injuries are prevalent and life-threatening forms that contribute significantly to mortality rates due to associated wound infections. The management of burn wounds presents substantial challenges. Hydrogel exhibits tremendous potential as an ideal alternative to traditional wound dressings such as gauze. This is primarily attributed to its three-dimensional (3D) crosslinked polymer network, which possesses a high water content, fostering a moist environment that supports effective burn wound healing. Additionally, hydrogel facilitates the penetration of loaded therapeutic agents throughout the wound surface, combating burn wound pathogens through the hydration effect and thereby enhancing the healing process. However, the presence of eschar formation on burn wounds obstructs the passive diffusion of therapeutics, impairing the efficacy of hydrogel as a wound dressing, particularly in cases of severe burns involving deeper tissue damage. This review focuses on exploring the potential of hydrogel as a carrier for transdermal drug delivery in burn wound treatment. Furthermore, strategies aimed at enhancing the transdermal delivery of therapeutic agents from hydrogel to optimize burn wound healing are also discussed.

Nanosponge hydrogel of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate of Alcaligenes faecalis

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate (ODHP) was extracted in a previous study from the culture broth of soil isolate Alcaligenes faecalis MT332429 and showed a promising antimycotic activity. This study was aimed to formulate ODHP loaded β-cyclodextrins (CD) nanosponge (NS) hydrogel (HG) to control skin fungal ailments since nanosponges augment the retention of tested agents in the skin. Box-Behnken design was used to produce the optimized NS formulation, where entrapment efficiency percent (EE%), polydispersity index (PDI), and particle size (PS) were assigned as dependent parameters, while the independent process parameters were polyvinyl alcohol % (w/v %), polymer-linker ratio, homogenization time, and speed. The carbopol 940 hydrogel was then created by incorporating the nanosponges. The hydrogel fit Higuchi's kinetic release model the best, according to in vitro drug release. Stability and photodegradation studies revealed that the NS-HG remained stable under tested conditions. The formulation also showed higher in vitro antifungal activity against Candida albicans compared to the control fluconazole. In vivo study showed that ODHP-NS-HG increased survival rates, wound contraction, and healing of wound gap and inhibited the inflammation process compared to the other control groups. The histopathological examinations and Masson's trichrome staining showed improved healing and higher records of collagen deposition. Moreover, the permeability of ODHP-NS-HG was higher through rats' skin by 1.5-folds compared to the control isoconazole 1%. Therefore, based on these results, NS-HG formulation is a potential carrier for enhanced and improved topical delivery of ODHP. Our study is a pioneering research on the development of a formulation for ODHP produced naturally from soil bacteria. KEY POINTS: • Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate was successfully formulated as a nanosponge hydrogel and statistically optimized. • The new formula exhibited in vitro good stability, drug release, and higher antifungal activity against C. albicans as compared to the fluconazole. • Ex vivo showed enhanced skin permeability, and in vivo analysis showed high antifungal activity as evidenced by measurement of various biochemical parameters and histopathological examination.

Casein-based hydrogels: Advances and prospects

Casein-based hydrogels (Casein Gels) possess advantageous properties, including mechanical strength, stability, biocompatibility, and even adhesion, conductivity, sensing capabilities, as well as controlled-releasing behavior of drugs. These features are attributed to their gelation methods and functionalization with various polymers. Casein Gels is an important protein-based material in the food industry, in terms of dairy and functional foods, biological and medicine, in terms of carrier for bioactive and sensitive drugs, wound healing, and flexible sensors and wearable devices. Herein, this review aims to highlight the importance of the features mentioned above via a comprehensive investigation of Casein Gels through multiple directions and dimensional applications. Firstly, the composition, structure, and properties of casein, along with the gelation methods employed to create Casein Gels are elaborated, which serves as a foundation for further exploration. Then, the application progresses of Casein Gels in dairy products, functional foods, medicine, flexible sensors and wearable devices, are thoroughly discussed to provide insights into the diverse fields where Casein Gels have shown promise and utility. Lastly, the existing challenges and future research trends are highlighted from an interdisciplinary perspective. We present the latest research advances of Casein Gels and provide references for the development of multifunctional biomass-based hydrogels.

Fluorescent carbon dots in situ polymerized biodegradable semi-interpenetrating tough hydrogel films with antioxidant and antibacterial activity for applications in food industry

A flexible, antioxidant, biodegradable, and UV-resistant polymeric nanocomposite hydrogel with heteroatom-doped carbon dots (CDs) has been fabricated using a simple one-step in situ free radical gelation process. The hydrogel formation and their physico-mehcanical characteristics have been assessed by rheology, uniaxial tensile and compression testing. The water uptake behaviour of the hydrogels is controlled by the CDs by manipulating their internal morphology and porosity. The porous nature of the hydrogels has been found from their scanning electron microscopic images which are also supported by their anomalous diffusion-based transport mechanism. The rheological signatures of the hydrogels show delayed network rupturing due to the secondary physical crosslinking alleviated by CDs. Moreover, CDs are directly influencing the permeabilites (oxygen and moisture) by lowering the values compared to their neat hydrogel films which are essential for a packing material. The biodegradability of the hydrogel films showed gradual weight loss (<75 %) within 3 weeks. The hydrogel films also have been qualified to be acted as antibacterial and antioxidant material. The shelf-life and non-leaching of CDs from gel matrices are also performed which shows its excellent capability to be used as a potential antibacterial, biodegradable, antioxidant alternative packaging material in food sectors.

Modulus-tunable multifunctional hydrogel ink with nanofillers for 3D-Printed soft electronics

Seamless integration and conformal contact of soft electronics with tissue surfaces have emerged as major challenges in realizing accurate monitoring of biological signals. However, the mechanical mismatch between the electronics and biological tissues impedes the conformal interfacing between them. Attempts have been made to utilize soft hydrogels as the bioelectronic materials to realize tissue-comfortable bioelectronics. However, hydrogels have several limitations in terms of their electrical and mechanical properties. In this study, we present the development of a 3D-printable modulus-tunable hydrogel with multiple functionalities. The hydrogel has a cross-linked double network, which greatly improves its mechanical properties. Functional fillers such as XLG or functionalized carbon nanotubes (fCNT) can be incorporated into the hydrogel to provide tunable mechanics (Young's modulus of 10-300 kPa) and electrical conductivity (electrical conductivity of ∼20 S/m). The developed hydrogel exhibits stretchability (∼1000% strain), self-healing ability (within 5 min), toughness (400-731 kJ/m3) viscoelasticity, tissue conformability, and biocompatibility. Upon examining the rheological properties in the modulated region, hydrogels can be 3D printed to customize the shape and design of the bioelectronics. These hydrogels can be fabricated into ring-shaped strain sensors for wearable sensor applications.

Tough, conductive hydrogels based on gelatin and oxidized sodium carboxymethyl cellulose as flexible sensors

Natural polymer-based hydrogels have been wildly used in electronic skin, health monitoring and human motion sensing. However, the construction of hydrogel with excellent mechanical strength and electrical conductivity totally using natural polymers still faces many challenges. In this paper, gelatin and oxidized sodium carboxymethylcellulose were used to synthesize a double-network hydrogel through the dynamic Schiff base bonds. Then, the mechanical strength of the hydrogel was further enhanced by immersing it in an ammonium sulfate solution based on the Hofmeister effect between gelatin and salt. Finally, the gelatin/oxidized sodium carboxymethylcellulose hydrogel exhibited high tensile properties (614 %), tensile fracture strength (2.6 MPa), excellent compressive fracture strength (64 MPa), and compressive toughness (4.28 MJ/m3). Also, the electrical conductivity reached 3.94 S/m. The hydrogel after salt soaked was fabricated as strain sensors, which could accurately monitor the movement of many joints in the human body, such as fingers, wrists, elbows, neck, and throat. Therefore, the designed hydrogel fully originated from natural polymers and has great application potential in motion detection and information recording.

Drug delivery using reduction-responsive hydrogel based on carboxyethyl-succinoglycan with highly improved rheological, antibacterial, and antioxidant properties

The development of exopolysaccharide-based polymers is gaining increasing attention in various industrial biotechnology fields for materials such as thickeners, texture modifiers, anti-freeze agents, antioxidants, and antibacterial agents. High-viscosity carboxyethyl-succinoglycan (CE-SG) was directly synthesized from succinoglycan (SG) isolated from Sinorhizobium meliloti Rm 1021, and its structural, rheological, and physiological properties were investigated. The viscosity of CE-SG gradually increased in proportion to the degree of carboxyethylation substitution. In particular, when the molar ratio of SG and 3-chloropropionic acid was 1:100, the viscosity was significantly improved by 21.18 times at a shear rate of 10 s-1. Increased carboxyethylation of SG also improved the thermal stability of CE-SG. Furthermore, the CE-SG solution showed 90.18 and 91.78 % antibacterial effects against Escherichia coli and Staphylococcus aureus and effective antioxidant activity against DPPH and hydroxyl radicals. In particular, CE-SG hydrogels coordinated with Fe3+ ions, which improved both viscosity and rheological properties, while also exhibiting reduction-responsive drug release through 1,4-dithiothreitol. The results of this study suggest that SG derivatives, such as CE-SG, can be used as functional biomaterials in various fields such as food, cosmetics, and pharmaceutical industries.

Recent updates on guar gum derivatives in colon specific drug delivery

Colon specific delivery of therapeutics have gained much attention of pharmaceutical researchers in the recent past. Colonic specific targeting of drugs is used not only for facilitating absorption of protein or peptide drugs, but also localization of therapeutic agents in colon to treat several colonic disorders. Among various biopolymers, guar gum (GG) exhibits pH dependent swelling, which allows colon specific release of drug. GG also shows microbial degradation in the colonic environment which makes it a suitable excipient for developing colon specific drug delivery systems. The uncontrolled swelling and hydration of GG can be controlled by structural modification or by grafting with another polymeric moiety. Several graft copolymerized guar gum derivatives are investigated for colon targeting of drugs. The efficacy of various guar gum derivatives are evaluated for colon specific delivery of drugs. The reviewed literature evidenced the potentiality of guar gum in localizing drugs in the colonic environment. This review focuses on the synthesis of several guar gum derivatives and their application in developing various colon specific drug delivery systems including matrix tablets, coated formulations, nano or microparticulate delivery systems and hydrogels.

Highly elastic, fatigue-resistant, antibacterial, conductive, and nanocellulose-enhanced hydrogels with selenium nanoparticles loading as strain sensors

The fabrication of highly elastic, fatigue-resistant and conductive hydrogels with antibacterial properties is highly desirable in the field of wearable devices. However, it remains challenging to simultaneously realize the above properties within one hydrogel without compromising excellent sensing ability. Herein, we fabricated a highly elastic, fatigue-resistant, conductive, antibacterial and cellulose nanocrystal (CNC) enhanced hydrogel as a sensitive strain sensor by the synergistic effect of biosynthesized selenium nanoparticles (BioSeNPs), MXene and nanocellulose. The structure and potential mechanism to generate biologically synthesized SeNPs (BioSeNPs) were systematically investigated, and the role of protease A (PrA) in enhancing the adsorption between proteins and SeNPs was demonstrated. Additionally, owing to the incorporation of BioSeNPs, CNC and MXene, the synthesized hydrogels showed high elasticity, excellent fatigue resistance and antibacterial properties. More importantly, the sensitivity of hydrogels determined by the gauge factor was as high as 6.24 when a high strain was applied (400-700 %). This study provides a new horizon to synthesize high-performance antibacterial and conductive hydrogels for soft electronics applications.

Bioinspired engineering ADSC nanovesicles thermosensitive hydrogel enhance autophagy of dermal papilla cells for androgenetic alopecia treatment

Androgenic alopecia (AGA) is a highly prevalent form of non-scarring alopecia but lacks effective treatments. Stem cell exosomes have similar repair effects to stem cells, suffer from the drawbacks of high cost and low yield yet. Cell-derived nanovesicles acquired through mechanical extrusion exhibit favorable biomimetic properties similar to exosomes, enabling them to efficiently encapsulate substantial quantities of therapeutic proteins. In this study, we observed that JAM-A, an adhesion protein, resulted in a significantly increased the adhesion and resilience of dermal papilla cells to form snap structures against damage caused by dihydrotestosterone and macrophages, thereby facilitating the process of hair regrowth in cases of AGA. Consequently, adipose-derived stem cells were modified to overexpress JAM-A to produce engineered JAM-A overexpressing nanovesicles (JAM-AOE@NV). The incorporation of JAM-AOE@NV into a thermosensitive hydrogel matrix (JAM-AOE@NV Gel) to effectively addresses the limitations associated with the short half-life of JAM-AOE@NV, and resulted in the achievement of a sustained-release profile for JAM-AOE@NV. The physicochemical characteristics of the JAM-AOE@NV Gel were analyzed and assessed for its efficacy in promoting hair regrowth in vivo and vitro. The JAM-AOE@NV Gel, thus, presents a novel therapeutic approach and theoretical framework for promoting the treatment of low cell adhesion diseases similar to AGA.

The orchestration of sustained drug delivery by bacterial cellulose/gelatin nanocomposites reinforced with carboxylic carbon nanotubes

Recently, modifying bacterial cellulose (BC) by compositing it with other nano-biomaterials has become inevitable to achieve its desired properties in drug delivery. To address this, our study endeavors to utilize an in-situ fabrication method for the creation of a multifunctional BC/gelatin (BC/Gel) platform reinforced with carboxylic multi-walled carbon nanotubes (cMWCNTs) as a sustainable delivery model of biomolecules. Incipiently, cMWCNTs were loaded with human serum albumin (HSA) as a drug model, with an optimized nanoparticle-to-protein ratio of 1:5 and loading efficiency of 90.0 ± 1.0 % before incorporation into BC/Gel hydrogels. By comparison, nanocomposition improved the surface area and overall porosity of BC/Gel up to 58.0 ± 1.3 m2/g and 85.5 ± 1.1 %, respectively. Likewise, significant wettability of 44.0 ± 0.1° and dramatic biodegradation rate of 36.9 ± 1.2 % were other exceptionally gained attributes. Meanwhile, with a Zero-order kinetic mechanism, CNT-HSA integration facilitated the controlled release of 56.0 ± 0.9 % HSA over 7 days. Drug-loaded nanocomposites showcased >70 % viability during in vitro cellular trials using Human Foreskin Fibroblasts (HFF). Overall, BC/Gel/CNT-HSA nanocomposite exhibited favorable cell behavior, devoid of cytotoxic manifestations. Consequently, this BC-based nanocomposite scaffold implicates the premiere capability in the sustained delivery of an extended range of protein biomolecules, offering a promising therapeutic avenue for bolstering tissue regeneration.

Development of a microfluidic-assisted open-source 3D bioprinting system (MOS3S) for the engineering of hierarchical tissues

The engineering of new 3D bioprinting approaches has shown great promise in the field of tissue engineering and disease modelling. However, the high cost of commercial 3D bioprinters has limited their accessibility, especially to those laboratories in resource-limited settings. Moreover, the need for a 3D bioprinting system capable of dispensing multiple materials is growing apace. Therefore, the development of a Microfluidic-assisted Open Source 3D bioprinting System (MOS3S) for the engineering of hierarchical tissues is needed to progress in fabricating functional tissues, but with a technology accessible to a wider range of researchers. The MOS3S platform is designed to allow the deposition of biomaterial inks using microfluidic printheads or coaxial nozzles for the in-situ crosslinking and scaffolds fabrication. The coupling of 3D printed syringe pumps with the motion control system is used for driving the tunable extrusion of inks for the fabrication of centimeter scale hierarchical lattice constructs for tissue engineering purposes. MOS3S performance have been validated to fabricate high-resolution structures with coaxial microfluidic technology, opening to new frontiers for seminal studies in pre-clinical disease modelling and tissue regeneration.

One-step construction of multiplexed enzymatic biosensors using light-addressable electrochemistry on a single silicon photoelectrode

The multiplexed detection of metabolites in parallel within a single biosensor plate is sufficiently valuable but also challenging. Herein, we combine the inherent light addressability of silicon with the high selectivity of enzymes, for the construction of multiplexed photoelectrochemical enzymatic biosensors. To conduct a stable electrochemistry and reagentless biosensing on silicon, a new strategy involving the immobilization of both redox mediators and enzymes using an amide bond-based hydrogel membrane was proposed. The membrane characterization results demonstrated a covalent coupling of ferrocene mediator to hydrogel, in which the mediator acted as not only a signal generator but also a renewable sacrifice agent. By adding corresponding enzymes on different spots of hydrogel membrane modified silicon and recording local photocurrents with a moveable light pointer, this biosensor setup was used successfully to detect multiple metabolites, such as lactate, glucose, and sarcosine, with good analytical performances. The limits of detection of glucose, sarcosine and lactate were found to be 179 μM, 16 μM, and 780 μM with the linear ranges of 0.5-2.5 mM, 0.3-1.5 mM, and 1.0-3.0 mM, respectively. We believe this proof-of-concept study provides a simple and rapid one-step immobilization approach for the fabrication of reagentless enzymatic assays with silicon-based light-addressable electrochemistry.

Viscoelastic polyacrylamide MR elastography phantoms with tunable damping ratio independent of shear stiffness

Physiologically modeled test samples with known properties and characteristics, or phantoms, are essential for developing sensitive, repeatable, and accurate quantitative MRI techniques. Magnetic resonance elastography (MRE) is one such technique used to estimate tissue mechanical properties, and it is advantageous to use phantoms with independently tunable mechanical properties to benchmark the accuracy of MRE methods. Phantoms with tunable shear stiffness are commonly used for MRE, but tuning the viscosity or damping ratio has proven to be difficult. A promising candidate for MRE phantoms with tunable damping ratio is polyacrylamide (PAA). While pure PAA has very low attenuation, viscoelastic hydrogels have been made by entrapping linear polyacrylamide strands (LPAA) within the PAA network. In this study, we evaluate the use of LPAA/PAA gels as physiologically accurate phantoms with tunable damping ratio, independent of shear stiffness, via MRE. Phantoms were made with 15.3 wt% PAA while the LPAA concentration ranged from 4.5 wt% to 8.0 wt%. MRE was performed at 9.4 T with 400 Hz vibration on all phantoms revealing a strong, positive correlation between damping ratio and LPAA content (p < 0.001). There was no significant correlation between shear stiffness and LPAA content, confirming a constant PAA concentration yielded constant shear stiffness. Rheometry at 10 Hz was performed to verify the damping ratio of the phantoms. Nearly identical slopes for damping ratio versus LPAA content were found from both MRE and rheometry (0.0073 and 0.0075 respectively). Ultimately, this study validates the adaptation of polyacrylamide gels into physiologically-relevant MRE phantoms to enable testing of MRE estimates of damping ratio.

Nanocellulose-mediated conductive hydrogels with NIR photoresponse and fatigue resistance for multifunctional wearable sensors

The rapid development of hydrogels has garnered significant attention in health monitoring and human motion sensing. However, the synthesis of multifunctional conductive hydrogels with excellent strain/pressure sensing and photoresponsiveness remains a challenge. Herein, the conductive hydrogels (BPTP) with excellent mechanical properties, fatigue resistance and photoresponsive behavior composed of polyacrylamide (PAM) matrix, 2,2,6,6-tetramethylpiperidin-1-yloxy-oxidized cellulose nanofibers (TOCNs) reinforcement and polydopamine-modified black phosphorus (BP@PDA) photosensitizer are prepared through a facile free-radical polymerization approach. The PDA adhered to the BP surface by π-π stacking promotes the optical properties of BP while also preventing BP oxidation from water. Through hydrogen bonding interactions, TOCNs improve the homogeneous dispersion of BP@PDA nanosheets and the mechanical toughness of BPTP. Benefiting from the synergistic effect of PDA and TOCNs, the conductive BPTP integrates superior mechanical performances, excellent photoelectric response and photothermal conversion capability. The BPTP-based sensor with high cycling stability demonstrates superior strain sensitivity (GF = 6.0) and pressure sensing capability (S = 0.13 kPa-1) to monitor various human activities. Therefore, this work delivers an alternative construction strategy for generating high-performance conductive hydrogels as multifunctional wearable sensors.

Bioengineering approaches for the endometrial research and application

The endometrium undergoes a series of precise monthly changes under the regulation of dynamic levels of ovarian hormones that are characterized by repeated shedding and subsequent regeneration without scarring. This provides the potential for wound healing during endometrial injuries. Bioengineering materials highlight the faithful replication of constitutive cells and the extracellular matrix that simulates the physical and biomechanical properties of the endometrium to a larger extent. Significant progress has been made in this field, and functional endometrial tissue bioengineering allows an in-depth investigation of regulatory factors for endometrial and myometrial defects in vitro and provides highly therapeutic methods to alleviate obstetric and gynecological complications. However, much remains to be learned about the latest progress in the application of bioengineering technologies to the human endometrium. Here, we summarize the existing developments in biomaterials and bioengineering models for endometrial regeneration and improving the female reproductive potential.

Design, characterization and digestibility of β-carotene-loaded emulsion system stabilized by whey protein with chitosan and potato starch addition

The physicochemical properties and gastrointestinal fate of β-carotene-loaded emulsions and emulsion gels were examined. The emulsion was emulsified by whey protein isolate and incorporated with chitosan, then the emulsion gels were produced by gelatinizing potato starch in the aqueous phase. The rheology properties, water distribution, and microstructure of emulsions and emulsion gels were modulated by chitosan combination. A standardized INFOGEST method was employed to track the gastrointestinal fate of emulsion systems. Significant changes in droplet size, zeta-potential, and aggregation state were detected during in vitro digestion, including simulated oral, stomach, and small intestine phases. The presence of chitosan led to a significantly reduced free fatty acids release in emulsion, whereas a slightly increasing released amount in the emulsion gel. β-carotene bioaccessibility was significantly improved by hydrogel formation and chitosan addition. These results could be used to formulate advanced emulsion systems to improve the gastrointestinal fate of hydrophobic nutraceuticals.

Multifunctional polysaccharide/metal/polyphenol double-crosslinked hydrogel for infected wound

Bacterial-infected wounds present a significant challenge in the medical field, posing a severe threat to public health. Traditional wound dressings have limited efficacy in treating bacterial-infected wounds, and antibiotics suffer from cytotoxicity and drug resistance. Consequently, an urgent requirement exists for developing multifunctional wound dressings capable of providing superior antimicrobial activity and expediting wound repair. In recent years, chitosan-based natural polysaccharide hydrogels have garnered attention for their biocompatibility, antimicrobial properties, and ability to aid in hemostasis. This study presents the development of a multi-functional, bi-dynamic network hydrogel for the treatment of wounds infected with bacteria. The hydrogel consists of a backbone of chitosan grafted with chlorogenic acid (CA-ECS), oxidized pullulan polysaccharides (OP), and zinc ions (Zn2+). The CA-ECS/OP/Zn2+ hydrogel displayed strong adhesion, good injectability, and high mechanical strength and was biodegradable and biocompatible. Furthermore, adding Zn2+ and CA enhanced the hydrogel's mechanical properties and antioxidant and antimicrobial activities. In a rat model of full-thickness skin wounds infected with S. aureus, the CA-ECS/OP/Zn2+ hydrogel demonstrated great anti-inflammatory, angiogenic, and folliculogenic properties, resulting in accelerated wound healing. The CA-ECS/OP/Zn2+ hydrogel has great potential for treating bacterial-infected wounds.

A stimuli-responsive hydrogel for reversible information storage, encryption and decryption

Smart hydrogel materials, known for their sensitivity to external stimuli, exhibit a reversible dynamic response and find applications in diverse fields, particularly in information storage. Despite significant efforts in this domain, developing a hydrogel with high-resolution, repeatable recording, and robust information encryption/decryption capabilities still remains a challenge. In this study, we synthesized a polymer hydrogel, namely polyvinyl alcohol-n-isopropylacrylamide-octadecyl polyoxyethylene ether acrylate hydrogel (PPNS), which features multiple hydrogen bonds through copolymerization, by using N-isopropylacrylamide, polyvinyl alcohol, and octadecyl polyoxyethylene ether acrylate (SGA15) as raw materials. The PPNS hydrogel demonstrated outstanding high-resolution, repeatable recording capabilities, enabling reversible recording, encryption, and decryption of information using anhydrous ethanol as the inducer. Varying the SGA15 monomer concentration revealed that the PPNS-2% hydrogel, prepared with 2% SGA15, outperformed the other hydrogels in terms of information recording and encryption/decryption when immersed in anhydrous ethanol and deionized water. Furthermore, the PPNS-2% hydrogel exhibited the ability to undergo multiple information cycles while maintaining excellent mechanical properties even after 25 cycles. Notably, ethanol served as a specialized ink for inscribing different patterns on the hydrogel surface for information recording. The recorded information could be erased through water wiping or ethanol volatilization, enabling reversible information recording, encryption, and decryption. Due to their responsive and dynamic nature of PPNS hydrogels are positions them as promising candidates for use as innovative information storage platforms.

Contaminated soil remediation with nano-FeS loaded lignin hydrogel: A novel strategy to produce safe rice grains while reducing cadmium in paddy field

Cadmium (Cd) contamination in agricultural soil has been an elevated concern due to the high health risks associated with the transfer through the soil-food chain, particularly in the case of rice. Recently, there has numerous researches on the use of nanoparticle-loaded materials for heavy metal-polluted soil remediation, resulting in favorable outcomes. However, there has been limited research focus on the field-scale application and recovery. This study was aimed to validate the Cd reduction effect of the nano-FeS loaded lignin hydrogel composites (FHC) in mildly polluted paddies, and to propose a field-scale application method. Hence, a multi-site field experiment was conducted in southern China. After the application for 94-103 days, the FHC exhibited a high integrity and elasticity, with a recovery rate of 91.90%. The single-round remediation led to decreases of 0.42-31.72% in soil Cd content and 1.52-49.11% in grain Cd content. Additionally, this remediation technique did not adversely impact rice production. Consequently, applying FHC in the field was demonstrated to be an innovative, efficient, and promising remediation technology. Simultaneously, a strategy was proposed for reducing Cd levels while cultivating rice in mildly polluted fields using the FHC.

Silver oxide doped iron oxide/alginate nanocomposite coated cotton cloth for selective catalytic reduction of potassium ferricyanide

Silver oxide doped iron oxide (Ag2O-Fe2O3) nanocatalyst was prepared and coated on cotton cloth (CC) as well as wrapped in sodium alginate (Alg) hydrogel. Ag2O-Fe2O3 coated CC (Ag2O-Fe2O3/CC) and Ag2O-Fe2O3 wrapped Alg (Ag2O-Fe2O3/Alg) were utilized as catalysts in reduction reaction of 4-nitrophenol (4-NP), congo red (CR), methylene blue (MB) and potassium ferricyanide (K3[Fe(CN)6]). Ag2O-Fe2O3/CC and Ag2O-Fe2O3/Alg were found to be effective and selective catalyst for the reaction of K3[Fe(CN)6]. Further amount of catalyst, K3[Fe(CN)6] quantity, amount of NaBH4, stability of catalyst and recyclability were optimized for the reaction of K3[Fe(CN)6] reduction. Ag2O-Fe2O3/Alg and Ag2O-Fe2O3/CC were appeared to be the stable catalysts by maintaining high activity during recyclability tests showing highest reaction rate constants (kapp) of 0.3472 and 0.5629 min-1, correspondingly. However, Ag2O-Fe2O3/CC can be easily recovered as compared to Ag2O-Fe2O3/Alg by simply removing from the reaction which is the main advantage of Ag2O-Fe2O3/CC. Moreover, Ag2O-Fe2O3/Alg and Ag2O-Fe2O3/CC were also examined in real samples and found useful for K3[Fe(CN)6] reduction involving real samples. The Ag2O-Fe2O3/CC nanocatalyst is a cost and time saving material for economical reduction of K3[Fe(CN)6] and environmental safety.

Cellulose nanocrystal-based polymer hydrogel embedded with iron oxide nanorods for efficient arsenic removal

A cellulose nanocrystal (CNC) polymer hydrogel containing magnetic iron oxide nanorods (Fe3O4NRs) was prepared for As(III) removal in water. Systematic studies on the performance of these prepared CNC-based composite hydrogels for the removal of As(III) have been undertaken. The maximum adsorption capacity of the CNC-g-PAA/qP4VP (CPqP) hydrogel was 241.3 mg/g. After introduction of Fe3O4NRs in the hydrogel, the maximum adsorption capacity of the resulting Fe3O4NRs@CNC-g-PAA/qP4VP (FN@CPqP) hydrogel was further improved to 263.0 mg/g. The high adsorption performance can be attributed to the facts that the 3D interconnected porous network of the hydrogel allows As species to easily enter into the hydrogel, the quaternized P4VP chains provides more adsorption sites, Fe3O4NRs uniformly distributed in the internal cavity of the hydrogel significantly reduces the nanoparticle aggregation. The adsorption kinetics indicated that the adsorption of arsenic by the hydrogel was mainly chemisorption. The isotherm analysis revealed that the adsorption of arsenic by the hydrogel was principally monolayer adsorption on a homogeneous surface. Moreover, the as-prepared CNC-based polymer hydrogels exhibited good stability and reusability with negligible performance loss after five adsorption-desorption cycles. The novel FN@CPqP hydrogel demonstrates great potential as a cost-effective adsorbent for the removal of arsenic contaminants from wastewater.

Cubic liquid crystals containing propolis flavonoids as in situ thermo-sensitive hydrogel depots for periodontitis treatment: Preparation, pharmacodynamics and therapeutic mechanisms

Propolis has a long ethnopharmacological history for oral periodontal diseases treatment. Propolis flavonoids are main active components for anti-inflammation and tissue protection. However, the intractable dissolution properties of propolis flavonoids and complex oral environment pose great challenges for periodontal delivery. In addition, the therapeutic mechanism as well as the therapeutic correlation of inflammation resolution and tissue regeneration remain unclear for propolis flavonoids. In this study, we constructed an in situ thermosensitive depot systems using total flavonoids from propolis-loaded cubic liquid crystals (TFP-CLC) hydrogel for periodontal delivery. TFP-CLC inhibited inflammatory cell infiltration, reactive oxygen species and the expression of inflammatory cytokines of NF-κB and IL-1β. In addition, alveolar bone and collagen were significantly regenerated after TFP-CLC administration according to micro-CT and immunohistochemistry. Mechanism studies suggested that TFP-CLC alleviated inflammation and promoted alveolar bone repair via regulating TLR4/MyD88/NF-κB p65 and RANK/NF-κB signaling pathways, respectively. Correlation analysis further confirmed that the inflammatory resolution produced by TFP-CLC could accelerate periodontal tissue regeneration. In summary, TFP-CLC is a promising multifunctional in situ thermo-sensitive hydrogel depots for periodontitis treatment.

Preparation of carboxymethyl chitosan/double-formaldehyde cellulose based hydrogel loaded with ginger essential oil nanoemulsion for meat preservation

An antibacterial nano-hydrogel (ginger essential oil nanoemulsion hydrogel, GEONH) based on Schiff base reaction was prepared using double-formaldehyde micro fibrillated cellulose (DAMFC) and carboxymethyl chitosan (CMCS) loaded with ginger essential oil nanoemulsion (GEON). It was found that when the mass ratio of DAMFC/CMCS/GEON was 1/9/270, the gel time, the water absorbency, gel strength, and morphology were the best. The results of X-ray diffraction and FT-IR confirmed that the aldehyde group on the DAMFC molecular chain formed a stable chemical crosslinking with the amino group on the CMCS molecular chain, resulting in a change in the crystal structure. GEONH showed excellent bactericidal activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Simultaneously, the prepared GEONH decreased the total viable count, Malondialdehyde, and total sulfhydryl content and improved the taste in the storage of boiled salted duck. Therefore, GEONH film is a promising fresh-keeping packaging for storing meat products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01437-4.

Reversing cancer immunoediting phases with a tumor-activated and optically reinforced immunoscaffold

In situ vaccine (ISV) is a promising immunotherapeutic tactic due to its complete tumoral antigenic repertoire. However, its efficiency is limited by extrinsic inevitable immunosuppression and intrinsic immunogenicity scarcity. To break this plight, a tumor-activated and optically reinforced immunoscaffold (TURN) is exploited to trigger cancer immunoediting phases regression, thus levering potent systemic antitumor immune responses. Upon response to tumoral reactive oxygen species, TURN will first release RGX-104 to attenuate excessive immunosuppressive cells and cytokines, and thus immunosuppression falls and immunogenicity rises. Subsequently, intermittent laser irradiation-activated photothermal agents (PL) trigger abundant tumor antigens exposure, which causes immunogenicity springs and preliminary infiltration of T cells. Finally, CD137 agonists from TURN further promotes the proliferation, function, and survival of T cells for durable antitumor effects. Therefore, cancer immunoediting phases reverse and systemic antitumor immune responses occur. TURN achieves over 90 % tumor growth inhibition in both primary and secondary tumor lesions, induces potent systemic immune responses, and triggers superior long-term immune memory in vivo. Taken together, TURN provides a prospective sight for ISV from the perspective of immunoediting phases.

Preparation of Decellularized Tissue as Dual Cell Carrier Systems: A Step Towards Facilitating Re-epithelization and Cell Encapsulation for Tracheal Reconstruction

Surgical treatment of tracheal diseases, trauma, and congenital stenosis has shown success through tracheal reconstruction coupled with palliative care. However, challenges in surgical-based tracheal repairs have prompted the exploration of alternative approaches for tracheal replacement. Tissue-based treatments, involving the cultivation of patient cells on a network of extracellular matrix (ECM) from donor tissue, hold promise for restoring tracheal structure and function without eliciting an immune reaction. In this study, we utilized decellularized canine tracheas as tissue models to develop two types of cell carriers: a decellularized scaffold and a hydrogel. Our hypothesis posits that both carriers, containing essential biochemical niches provided by ECM components, facilitate cell attachment without inducing cytotoxicity. Canine tracheas underwent vacuum-assisted decellularization (VAD), and the ECM-rich hydrogel was prepared through peptic digestion of the decellularized trachea. The decellularized canine trachea exhibited a significant reduction in DNA content and major histocompatibility complex class II, while preserving crucial ECM components such as collagen, glycosaminoglycan, laminin, and fibronectin. Scanning electron microscope and fluorescent microscope images revealed a fibrous ECM network on the luminal side of the cell-free trachea, supporting epithelial cell attachment. Moreover, the ECM-rich hydrogel exhibited excellent viability for human mesenchymal stem cells encapsulated for 3 days, indicating the potential of cell-laden hydrogel in promoting the development of cartilage rings of the trachea. This study underscores the versatility of the trachea in producing two distinct cell carriers-decellularized scaffold and hydrogel-both containing the native biochemical niche essential for tracheal tissue engineering applications.

A nanoenzyme-modified hydrogel targets macrophage reprogramming-angiogenesis crosstalk to boost diabetic wound repair

Diabetic wounds has a gradually increasing incidence and morbidity. Excessive inflammation due to immune imbalance leads to delayed wound healing. Here, we reveal the interconnection between activation of the NLRP3 inflammatory pathway in endotheliocyte and polarization of macrophages via the cGAS-STING pathway in the oxidative microenvironment. To enhance the immune-regulation based on repairing mitochondrial oxidative damage, a zeolitic imidazolate framework-8 coated with cerium dioxide that carries Rhoassociated protein kinase inhibition Y-27632 (CeO2-Y@ZIF-8) is developed. It is encapsulated in a photocross-linkable hydrogel (GelMA) with cationic quaternary ammonium salt groups modified to endow the antibacterial properties (CeO2-Y@ZIF-8@Gel). CeO2 with superoxide dismutase and catalase activities can remove excess reactive oxygen species to limit mitochondrial damage and Y-27632 can repair damaged mitochondrial DNA, thus improving the proliferation of endotheliocyte. After endotheliocyte uptakes CeO2-Y@ZIF-8 NPs to degrade peroxides into water and oxygen in cells and mitochondria, NLRP3 inflammatory pathway is inhibited and the leakage of oxidatively damaged mitochondrial DNA (Ox-mtDNA, a damage-associated molecular pattern) through mPTP decreases. Futhermore, as the cGAS-STING pathway activated by Ox-mtDNA down-regulated, the M2 phenotype polarization and anti-inflammatory factors increase. Collectively, CeO2-Y@ZIF-8@Gel, through remodulating the crosstalk between macrophage reprogramming and angiogenesis to alleviate inflammation in the microenvironment and accelerates wound healing.

An Injectable silk-based hydrogel as a novel biomineralization seedbed for critical-sized bone defect regeneration

The healing process of critical-sized bone defects urges for a suitable biomineralization environment. However, the unsatisfying repair outcome usually results from a disturbed intricate milieu and the lack of in situ mineralization resources. In this work, we have developed a composite hydrogel that mimics the natural bone healing processes and serves as a seedbed for bone regeneration. The oxidized silk fibroin and fibrin are incorporated as rigid geogrids, and amorphous calcium phosphate (ACP) and platelet-rich plasma serve as the fertilizers and loam, respectively. Encouragingly, the seedbed hydrogel demonstrates excellent mechanical and biomineralization properties as a stable scaffold and promotes vascularized bone regeneration in vivo. Additionally, the seedbed serves a succinate-like function via the PI3K-Akt signaling pathway and subsequently orchestrates the mitochondrial calcium uptake, further converting the exogenous ACP into endogenous ACP. Additionally, the seedbed hydrogel realizes the succession of calcium resources and promotes the evolution of the biotemplate from fibrin to collagen. Therefore, our work has established a novel silk-based hydrogel that functions as an in-situ biomineralization seedbed, providing a new insight for critical-sized bone defect regeneration.

Superabsorbent carboxymethyl cellulose-based hydrogel fabricated by liquid-metal-induced double crosslinking polymerisation

Herein, we introduced a liquid-metal/polymerisable deep eutectic solvent (LM/PDES) system to the carboxymethyl cellulose (CMC) and acrylic acid solution to prepare a double-cross-linked CMC-polyacrylic acid (PAA)-LM/PDES superabsorbent hydrogel via graft crosslinking polymerisation for 5 min. FTIR and XRD provided evidence for the coordinate crosslinking between Ga3+ and carboxy groups in the CMC-PAA-LM/PDES gel structure and chemical crosslinking between CMC and PAA components. The pore size of the obtained hydrogels gradually decreases with the increase of LM-AA/PDES content. The rigid CMC polysaccharide chains increased the distance between the ionic groups on the flexible PAA molecular chains, resulting in high osmotic pressure. In addition, the synergistic effects of hydrophilic groups, electrostatic repulsion, macroporous structures and double crosslinking on the CMC and PAA structures provided a driving force and space for the gel to absorb electrolyte containing liquid. The absorption capacity of the CMC-PAA-LM/PDES gel for physiological saline reached 97 g/g, which exceeded that of a single cross-linked CMC-PAA gel and a reported superabsorbent material (71 g/g). This work solved the problem of long heating times and insufficient mechanical properties for the preparation of superabsorbent gels, providing a theoretical reference for improving the absorption capacity of superabsorbent materials for electrolyte-containing aqueous solutions.

Therapeutic delivery systems for rheumatoid arthritis based on hydrogel carriers

Rheumatoid arthritis (RA) is an autoimmune disease suffered by millions of people worldwide. It can significantly affect the patient's quality of life by damaging not only the joints but also organs such as the lungs and the heart. RA is normally treated using nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, disease-modifying antirheumatic drugs (DMARDs), and biologics. These active agents often cause side effects and offer low efficacy due to their lack of specificity and limited retention time. In an attempt to improve RA treatments, hydrogel-based systems have been proposed as drug delivery carriers. Due to their exceptional adaptability and biocompatibility, hydrogels have the potential of enhancing the delivery of RA therapy through different administration routes in an efficient and effective manner. In this review, we explore the application of hydrogel systems as potential carriers in RA treatment. Additionally, we discuss recent work in the field and highlight the required hydrogel properties, depending on the administration route. The outstanding potential of hydrogel systems as carriers for RA was demonstrated; however, there is extensive research yet to be done to improve available treatments for RA.

A hydrogel-based ratiometric fluorescent sensor relying on rhodamine B labelled AIE-featured hyperbranched poly(amido amine) for heparin detection

The fluorescent flexible sensor for point-of-care quantification of clinical anticoagulant drug, Heparin (Hep), is still an urgent need of breakthrough. In this research, a hyperbranched poly(amido amine) (HPA) was decorated with tetraphenylethene (TPE) and Rhodamine B (RhB), constructing a ratiometric fluorescent sensor (TR-HPA) for Hep. When the sensor was exposed to Hep, the TPE units within the probe skeleton would aggregate, resulting in an increasing fluorescent emission at 483 nm. The 580 nm of fluorescence came from RhB enhance, simultaneously, due to the fluorescence resonance energy transfer. As a result, there are two good linear correlation between the fluorescence emission ratio (E483/E580) of TR-HPA and the Hep concentration over a range of 0-1.0 μM, with a low limit of detection of 3.0 nM. Furthermore, we incorporate the TR-HPA probe into a polyvinyl alcohol (PVA) hydrogel matrix to create a flexible fluorescent sensing system platform, denoted as TR-HPA/PVA. This approach offers a straightforward visual detection method by causing a fluorescence color change from pink to blue when trace amounts of Hep are present. The hydrogel-based fluorescent sensor streamlines the detection procedures for Hep in biomedical applications. It shows great potential in rapid and point-of-care human blood clotting condition monitoring, making it suitable for next-generation wearable medical devices.

Studying removal of anionic dye by prepared highly adsorbent surface hydrogel nanocomposite as an applicable for aqueous solution

In this study, a Sodium alginate-g-poly (acrylamide-clay)/TiO2 hydrogel nanocomposite [SA-g-p(AM-Bn)/TiO2] was synthesized using the biopolymer sodium alginate (SA), acrylamide (AM), and bentonite clay (Bn) as hybrid materials embedded with titanium dioxide nanoparticles (TiO2NPs) for the removal of toxic Congo Red (CR) dye from an aqueous solution. The [SA-g-p(AM-Bn)/TiO2] nanocomposite has been described on the basis of thermal stability, morphological analysis, estimation of functional group, and crystalline/amorphous character by TGA, EFSEM/EDX, TEM, FT-IR, and XRD analysis, respectively. The effects of operational parameters toward the CR dye adsorption on [SA-g-p(AM-Bn)/TiO2], including contact time, adsorbent dosage, initial concentration, initial pH, and temperature were investigated. The maximum adsorption efficiency was found to be 185.12 mg/g for [SA-g-p(AM-Bn)/TiO2] in 100 mg/L of solution CR at pH 6.0 within 1 h. The equilibrium isotherms, kinetics, and thermodynamics parameters of adsorption were examined, and results showed that the isotherm fitted the Freundlich model and the kinetics adsorption model of CR followed pseudo-first-order, thus indicating physisorption of anionic-CR onto the sorbent due to the development of an electrostatic attraction bond. Thermodynamic parameters for [SA-g-p(AM-Bn)/TiO2] have values (ΔG and ΔH) reflecting the spontaneous and endothermic nature of the adsorption processes. Moreover, [SA-g-p(AM-Bn)/TiO2] presented outstanding excellent reusability and recyclability with a relatively best removal percentage as compared to [SA-g-p(AM-Bn)] and suggested their applicability towards the textile industry and water purification purposes.

Local thiamet-G delivery by a thermosensitive hydrogel confers ischemic cardiac repair via myeloid M2-like activation in a STAT6 O-GlcNAcylation-dependent manner

Infarct healing requires a dynamic and orchestrated inflammatory reaction following myocardial infarction (MI). While an uncontrolled excessive inflammatory response exaggerates ischemic injury post-MI, M2-like reparative macrophages may facilitate inflammation regression and promote myocardial healing. However, how protein post-translational modification regulates post-MI cardiac repair and dynamic myeloid activation remains unknown. Here we show that M2-like reparative, but not M1-like inflammatory activation, is enhanced by pharmacologically-induced hyper-O-GlcNAcylation. Mechanistically, myeloid knockdown of O-GlcNAc hydrolase O-GlcNAcase (Oga), which also results in hyper-O-GlcNAcylation, positively regulates M2-like activation in a STAT6-dependent fashion, which is controlled by O-GlcNAcylation of STAT6. Of note, both systemic and local supplementation of thiamet-G (TMG), an Oga inhibitor, effectively facilitates cardiac recovery in mice by elevating the accumulation of M2-like macrophages in infarcted hearts. Our study provides a novel clue for monocyte/macrophage modulating therapies aimed at reducing post-MI hyperinflammation in ischemic myocardium.

Cyclodextrin 'Chaperones' Enable Quasi-Ideal Supramolecular Network Formation and Enhanced Photodimerization of Hydrophobic, Red-shifted Photoswitches in Water

Precision-engineered light-triggered hydrogels are important for a diversity of applications. However, fields such as biomaterials require wavelength outside the harsh UV regime to prevent photodamage, typically requiring chromophores with extended p-conjugation that suffer from poor water solubility. Herein, we demonstrate how cyclodextrins can be used as auxiliary agents to not only solubilize such chromophores, but even to preorganize them in a 2:2 host-guest inclusion complex to facilitate photodimerization. We apply our concept to styrylpyrene-end-functionalized star-shaped polyethylene glycols (sPEGs). We initially unravel details of the host-guest inclusion complex using spectroscopy and mass spectrometry to give clear evidence of a 2:2 complex formation. Subsequently, we show that the resultant supramolecularly linked hydrogels conform to theories of supramolecular quasi-ideal model networks, and derive details on their association dynamics using in-depth rheological measurements and kinetic models. By comparing sPEGs of different arm length, we further elucidate the model network topology and the accessible mechanical property space. The photo-mediated dimerization proceeds smoothly, allowing to transform the supramolecular model networks into covalent ones. We believe that our strategy opens new avenues for executing hydrophobic photochemistry in aqueous environments with enhanced control over reactivity, hydrogel topology or programmable mechanical properties.

Hydrogels containing KYNA promote angiogenesis and inhibit inflammation to improve the survival rate of multi-territory perforator flaps

BACKGROUND

A new spray adhesive (KYNA-PF127) was established through the combination of thermosensitive hydrogel (Pluronic F127) and KYNA, aimed to investigate the effect of KYNA-PF127 on multi-territory perforator flaps and its possible molecular mechanism.

MATERIALS AND METHODS

36 SD male rats with 250-300 g were randomly divided into 3 groups (n = 12): control group, blank glue group and KYNA-PF127 group. KYNA-PF127 hydrogel was prepared and characterized for its morphology and properties using scanning electron microscopy. CCK-8 assay, scratch wound assay, transwell assay, tube formation assay and Ki67 staining were used to study the effect of KYNA-PF127 on the proliferation, migration, and tube formation of HUVECs. VEGF and FGF2 were measured by qPCR to evaluate the angiogenesis capacity of HUVECs in vitro. In vivo, the effect of each group on the survival area of the cross-zone perforator flap was evaluated, and angiogenesis was evaluated by HE and immunofluorescence (CD31 and MMP-9). The effect of inflammation on skin collagen fibers was assessed by Masson. Immunohistochemistry (SOD1, IL-1β, TNF-α) was used to evaluate the effects of oxidative stress and inflammatory factors on multi-territory flaps.

RESULTS

KYNA-PF127 has good sustained release and biocompatibility at 25% concentration. KYNA-PF127 promoted the proliferation, migration, and angiogenesis of HUVECs in vitro. In vivo, the survival area of multi-territory perforator flaps and angiogenic capability have increased after KYNA-PF127 intervention. KYNA-PF127 could effectively reduce the oxidative stress and inflammation of multi-territory perforator flaps.

CONCLUSION

KYNA-PF127 promotes angiogenesis through its antioxidant stress and anti-inflammatory effects, and shows potential clinical value in promoting the survival viability and drug delivery of multi-territory perforator flaps.

Luteolin-incorporated fish collagen hydrogel scaffold: An effective drug delivery strategy for wound healing

In clinical practice, wound care has always been challenging. Hydrogels play a key role in facilitating active wound recovery by absorbing exudates, maintaining moisture, and alleviating pain through cooling. In this study, type I collagen was isolated from the skin of crucian carp (Carassius carassius) and verified by amino acid analysis, FTIR, and SDS-PAGE. By adopting a new approach, luteolin was added to collagen hydrogels in situ after being dissolved in an alkaline solution. XRD and SEM confirmed the luteolin was incorporated and entirely distributed throughout the hydrogel. The plastic compression improved the young's modulus of hydrogel to 15.24 ± 0.59 kPa, which is adequate for wound protection. The drug loading efficiency was 98 ± 1.47 % in the selected formulation. The luteolin-incorporated hydrogel enabled regulated drug release. We assessed the cytotoxicity using MTT and live-dead assays, as well as examined the hemocompatibility to determine the biocompatibility of the hydrogel. In vivo experiments showed that the hydrogel with luteolin had the highest wound closure rate (94.01 ± 2.1 %) and improved wound healing with granular tissue formation, collagen deposition, and re-epithelialization. These findings indicate that this efficient drug delivery technology can accelerate the process of wound healing.

Swim bladder-derived biomaterials: structures, compositions, properties, modifications, and biomedical applications

Animal-derived biomaterials have been extensively employed in clinical practice owing to their compositional and structural similarities with those of human tissues and organs, exhibiting good mechanical properties and biocompatibility, and extensive sources. However, there is an associated risk of infection with pathogenic microorganisms after the implantation of tissues from pigs, cattle, and other mammals in humans. Therefore, researchers have begun to explore the development of non-mammalian regenerative biomaterials. Among these is the swim bladder, a fish-derived biomaterial that is rapidly used in various fields of biomedicine because of its high collagen, elastin, and polysaccharide content. However, relevant reviews on the biomedical applications of swim bladders as effective biomaterials are lacking. Therefore, based on our previous research and in-depth understanding of this field, this review describes the structures and compositions, properties, and modifications of the swim bladder, with their direct (including soft tissue repair, dural repair, cardiovascular repair, and edible and pharmaceutical fish maw) and indirect applications (including extracted collagen peptides with smaller molecular weights, and collagen or gelatin with higher molecular weights used for hydrogels, and biological adhesives or glues) in the field of biomedicine in recent years. This review provides insights into the use of swim bladders as source of biomaterial; hence, it can aid biomedicine scholars by providing directions for advancements in this field.

Rapid formed temperature-sensitive hydrogel for the multi-effective wound healing of deep second-degree burn with shikonin based scar prevention

Burns are a significant public health issue worldwide, resulting in prolonged hospitalization, disfigurement, disability and, in severe cases, death. Among them, deep second-degree burns are often accompanied by bacterial infections, insufficient blood flow, excessive skin fibroblasts proliferation and collagen deposition, all of which contribute to poor wound healing and scarring following recovery. In this study, SNP/MCNs-SKN-chitosan-β-glycerophosphate hydrogel (MSSH), a hydrogel composed of a temperature-sensitive chitosan-β-glycerophosphate hydrogel matrix (CGH), mesoporous carbon nanospheres (MCNs), nitric oxide (NO) donor sodium nitroprusside (SNP) and anti-scarring substance shikonin (SKN), is intended for use as a biomedical material. In vitro tests have revealed that MSSH has broad-spectrum antibacterial abilities and releases NO in response to near-infrared (NIR) laser to promote angiogenesis. Notably, MSSH can inhibit excessive proliferation of fibroblasts and effectively reduce scarring caused by deep second-degree burns, as demonstrated by in vitro and in vivo tests.

Highly efficient and reusable CuAu nanoparticles supported on crosslinked chitosan hydrogels as a plasmonic catalyst for nitroarene reduction

The synthesis of CuAu-based monometallic (MNPs) and bimetallic nanoparticles (BNPs) supported on chitosan-based hydrogels for their application as catalysts is presented. The hydrogels consisted of chitosan chains cross-linked with tripolyphosphate (TPP) in the form of beads with an approximate average diameter of 1.81 mm. The MNPs and BNPs were obtained by the adsorption of metallic ions and their subsequent reduction with hydrazine, achieving a metallic loading of 0.297 mmol per gram of dry sample, with average nanoparticle sizes that were found between 2.6 and 4.4 nm. Both processes, metal adsorption and the stabilization of the nanoparticles, are mainly attributed to the participation of chitosan hydroxyl, amine and amide functional groups. The materials revealed important absorption bands in the visible region of the light spectra, specifically between 520 and 590 nm, mainly attributed to LSPR given the nature of the MNPs and BNPs inside the hydrogels. Subsequently, the hydrogels were evaluated as catalysts against the reduction of 4-nitrophenol (4NP) into 4-aminophenol (4AP), followed by UV-visible spectroscopy. The kinetic advance of the reaction revealed important improvements in the catalytic activity of the materials by synergistic effect of BNPs and plasmonic enhancement under visible light irradiation, given the combination of metals and the light harvesting properties of the nanocomposites. Finally, the catalytic performance of hydrogels containing BNPs CuAu 3:1 showed an important selectivity, recyclability and reusability performance, due to the relevant interaction of the BNPs with the chitosan matrix, highlighting the potential of this nanocomposite as an effective catalyst, with a potential environmental application.

Effects of charge state of nano-chitin on the properties of polyvinyl alcohol composite hydrogel

The present work investigates the effects of nano-chitin with different charge, obtained by acid hydrolysis and TEMPO oxidation, on the structure and properties of borax crosslinked polyvinyl alcohol (PVA) hydrogels. In detail, nano-chitin prepared by acid hydrolysis (ACh) is positively charged (+28.8 mV). The electrostatic attraction between ACh and borax ions leads to a maximum tensile stress of composite hydrogel (ACh/PB), 54.25 KPa, 17 times of the borax crosslinked PVA (PB). In contrast, nano-chitin prepared by TEMPO-oxidation (TCh) shows negative charge (-59.0 mV). Due to the electrostatic repulsion with borax ions, the maximum tensile stress of composite hydrogel (TCh/PB) is only 9.25 KPa, a very limit reinforcing effect. However, TCh/PB showed better self-healing efficiency (96.0 %) as well as ionic conductivity (1.25 × 10-5 S/m). The present work shows that the charge state of the nano-chitin exerts great influence on the interaction with the crosslinking agent borax, therefore, affects the structure and properties of the final PVA composite hydrogels. The results could provide important information about making full use of nano-chitin as a reinforcement by adjusting its surface charge state.

Anisotropic materials based on carbohydrate polymers: A review of fabrication strategies, properties, and applications

Anisotropic structures exist in almost all living organisms to endow them with superior properties and physiological functionalities. However, conventional artificial materials possess unordered isotropic structures, resulting in limited functions and applications. The development of anisotropic structures on carbohydrates is reported to have an impact on their properties and applications. In this review, various alignment strategies for carbohydrates (i.e., cellulose, chitin and alginate) from bottom-up to top-down strategies are discussed, including the rapidly developed innovative technologies such as shear-induced orientation through extrusion-based 3D/4D printing, magnetic-assisted alignment, and electric-induced alignment. The unique properties and wide applications of anisotropic carbohydrate materials across different fields, from biomedical, biosensors, smart actuators, soft conductive materials, to thermal management are also summarized. Finally, recommendations on the selection of fabrication strategies are given. The major challenge lies in the construction of long-range hierarchical alignment with high orientation degree and precise control over complicated architectures. With the future development of hierarchical alignment strategies, alignment control techniques, and alignment mechanism elucidation, the potential of anisotropic carbohydrate materials for scalable manufacture and clinical applications will be fully realized.

Integrating DFT and machine learning for the design and optimization of sodium alginate-based hydrogel adsorbents: Efficient removal of pollutants from wastewater

This study presents a novel approach to design and optimize a sodium alginate-based hydrogel (SAH) for efficient adsorption of the model water pollutant methylene blue (MB) dye. Utilizing density functional theory (DFT) calculations, sodium alginate-g-poly (acrylamide-co-itaconic acid) was identified with the lowest adsorption energy (Eads) for MB dye among 14 different clusters. SAHs were prepared using selected monomers and sodium alginate combinations through graft co-polymerization, and swelling studies were conducted to optimize grafting conditions. Advanced characterization techniques, including FTIR, XRD, XPS, SEM, EDS, and TGA, were employed, and the process was optimized using statistical and machine learning tools. Screening tests demonstrated that Eads serves as an effective predicting indicator for adsorption capacity (qe) and MB removal efficiency (RRMB,%), with reasonable agreement between Eads and both responses under given conditions. Process modeling and optimization revealed that 5 mg of selected SAH achieves a maximum qe of 3244 mg g-1 at 84.4% RRMB under pH 8.05, 98.8 min, and MB concentration of 383.3 mg L-1, as identified by the desirability function approach. Moreover, SAH effectively eliminated various contaminants from aqueous solutions, including sulfasalazine (SFZ) and dibenzothiophene (DBT). MB adsorption onto selected SAH was exothermic, spontaneous, and followed the pseudo-first-order and Langmuir-Freundlich isotherm models. The remarkable ability of SAH to adsorb MB is attributed to its well-designed structure predicted through DFT and optimal operational conditions achieved by AI-based parametric optimization. By integrating DFT-based computations and machine-learning tools, this study contributes to the efficient design of adsorbent materials and optimization of adsorption processes, also showcasing the potential of SAH as an efficient adsorbent for the abatement of aqueous pollution.

Assessment of energy cane bagasse-derived cellulosic microfiber hydrogels on the growth of potted chili peppers

Energy cane (Saccharum spp.) bagasse, a type of biomass waste, is often underutilized, burned, or left to dispose of itself. This research aimed to evaluate the potential of converting this bagasse into high-value cellulosic microfiber hydrogels (CMH) for water conservation and potted chili (Capsicum annuum) plant growth. CMH offers a biodegradable alternative to synthetic polyacrylamide (PA) hydrogels and provides the dual benefit of improved water use efficiency and reduced environmental impact due to their ability to naturally break down in the soil. In this study, CMH and PA hydrogels were compared for water retention value (WRV), and reswelling kinetics (RK), as well as their effects on plant height, leaf count, root-to-shoot ratios (R:S ratio), and soil moisture retention. Two versions of CMH, CMH65 and CMH60, were prepared with varying cellulose-chitosan ratios: 65:35 and 60:40, respectively. The hydrogels were tested at four concentrations (0, 0.5, 1.0, and 2.0% w/w) by being mixed in Promix® soil. Observations were recorded over a 16-day period without additional water. Also, the WRV of hydrogels at 240 min and RK (10-180 min) were compared over three swelling-deswelling cycles. The PA hydrogel exhibited higher WRV (exceeding 450%) compared to CMH (45%). However, PA led to reduced plant height, leaf count, and R:S ratio when compared to higher concentrations of CMH65 and CMH60. In general, CMH60 (0.5% and 2%) exhibited superior plant growth. All hydrogels exhibited a significant decrease (p < 0.05) in WRV across successive cycles. Notably, during cycle 2, both CMH65 and CMH60 peaked in WRV at 10 and 20 min, respectively, compared to cycle 1. This study demonstrates the potential of bagasse-derived hydrogels as a value-added product for water conservation and crop growth.

Developing hydrogels for gene therapy and tissue engineering

Hydrogels are a class of highly absorbent and easily modified polymer materials suitable for use as slow-release carriers for drugs. Gene therapy is highly specific and can overcome the limitations of traditional tissue engineering techniques and has significant advantages in tissue repair. However, therapeutic genes are often affected by cellular barriers and enzyme sensitivity, and carrier loading of therapeutic genes is essential. Therapeutic gene hydrogels can well overcome these difficulties. Moreover, gene-therapeutic hydrogels have made considerable progress. This review summarizes the recent research on carrier gene hydrogels for the treatment of tissue damage through a summary of the most current research frontiers. We initially introduce the classification of hydrogels and their cross-linking methods, followed by a detailed overview of the types and modifications of therapeutic genes, a detailed discussion on the loading of therapeutic genes in hydrogels and their characterization features, a summary of the design of hydrogels for therapeutic gene release, and an overview of their applications in tissue engineering. Finally, we provide comments and look forward to the shortcomings and future directions of hydrogels for gene therapy. We hope that this article will provide researchers in related fields with more comprehensive and systematic strategies for tissue engineering repair and further promote the development of the field of hydrogels for gene therapy.

A self-assembling hydrogel nanocomposite based on xanthan gum modified with SiO2 NPs and HPAM for improved adsorption of crystal violet cationic dye from aqueous solution

This paper presents the rational design and novel synthesis of multifunctional nanocomposite hydrogel derived from xanthan gum (XG) modified with silica nanoparticles and partially hydrolyzed polyacrylamide (HPAM) via H-bonding interactions (self-assembly) through the "green" gelation process in water. Different techniques have been employed to characterize HPAM/SiO2@XG, including FT-IR, FE-SEM, XRD, TEM, BET, and TG/DTG as well as swelling kinetics. Crystal violet (CV)'s adsorption performance was investigated using batch experiments by varying various variables involving adsorbent composition, pH, adsorbent quantity, contact time, CV concentration, ionic strength, and temperature. A well-fitting Langmuir isotherm was found for the adsorption data at 30 °C and pH 7.0, yielding 342.19 mg CV/g as the equilibrium state's maximum adsorption (qm). CV adsorption data agreed better with the pseudo-second-order model than other kinetic models. Furthermore, the HPAM/SiO2@XG nanocomposite hydrogel showed a significant increase in adsorption capacity over the SiO2@XG hydrogel precursor. According to thermodynamic analysis, CV adsorbs to HPAM/XG@SiO2 spontaneously and exothermically. Our results showed that the nanocomposite hydrogel's functional groups interact with CV predominantly through electrostatic interactions, coupled with H-bonding. Nanocomposite hydrogel has been regenerated using a five-cycle adsorption-desorption process, and the efficiency of CV removal has remained a satisfactory level of removal efficiency (94.5 % to 71.5 %).

Effect of incorporating modified pinhão starch in alginate-based hydrogel beads for encapsulation of bioactive compounds by hydrodynamic electrospray ionization jetting

Known for its antioxidant properties, Araucaria angustifolia bracts extract was encapsulated using hydrodynamic electrospray ionization jetting within calcium alginate cross-linked hydrogel beads with varying contents of modified pinhão starch. The rheological properties of the dispersions and analysis of the physicochemical and digestive properties of encapsulated beads were studied. The results demonstrated that dispersions containing starch exhibited higher viscosity and reduced compliance values, indicating samples with stronger, more compact, and stable structures that are less susceptible to deformation. This was confirmed by the beads rupture strength test. The ATR-FTIR analysis suggest that no new chemical bonds were formed, with encapsulation being responsible only for physical interactions between the functional groups of the polymers used and the active groups of the compounds present in the extract. The thermal stability of starch-containing beads was higher. Total tannins were higher in beads containing starch, with 53.61 %, 56.83 %, and 66.99 % encapsulation yield for samples with 2 %, 4 %, and 6 % starch, respectively, and the remaining antioxidant activity ranged from 96.04 % to 81.08 %. In vitro gastrointestinal digestion simulation indicated that the highest releases occurred in the intestinal phase, ranging from 60.72 % to 63.50 % for the release of total phenolic compounds.

MG53/GMs/HA-Dex neural scaffold promotes the functional recovery of spinal cord injury by alleviating neuroinflammation

The adverse microenvironment, including neuroinflammation, hinders the recovery of spinal cord injury (SCI). Regulating microglial polarization to alleviate neuroinflammation at the injury site is an effective strategy for SCI recovery. MG53 protein exerts obvious repair ability on multiple tissues damage, but with short half-life. In this study, we composited an innovative MG53/GMs/HA-Dex neural scaffold using gelatin microspheres (GMs), hyaluronic acid (HA), and dextran (Dex) loaded with MG53 protein. This novel neural scaffold could respond to MMP-2/9 protein and stably release MG53 protein with good physicochemical properties and biocompatibility. In addition, it significantly improved the motor function of SCI mice, suppressed M1 polarization of microglia and neuroinflammation, and promoted neurogenesis and axon regeneration. Further mechanistic experiments demonstrated that MG53/GMs/HA-Dex hydrogel inhibited the JAK2/STAT3 signaling pathway. Thus, this MG53/GMs/HA-Dex neural scaffold promotes the functional recovery of SCI mice by alleviating neuroinflammation, which provides a new intervention strategy for the neural regeneration and functional repair of SCI.

Therapeutic effect of ZnO NPs-polyhexanide-hydrogel on Staphylococcus aureus-induced skin wound infection in mice

Nanometer zinc oxide (ZnONPs) offers strong antibacterial, wound healing, hemostatic benefits, and UV protection. Additionally, poly(hexamethylene biguanide)hydrochloride (PHMB) is an environmentally friendly polymer with strong bactericidal properties. However, the synergistic effect of the combination of ZnONPs and PHMB has not been previously explored. The purpose of this study is to explore the synergies of ZnONPs and PHMB and the healing efficacy of ZnO NPs-PHMB-hydrogel on skin wounds in mice infected with Staphylococcus aureus. Therefore, the mice were subjected to skin trauma to create a wound model and were subsequently infected with S. aureus, and then divided into various experimental groups. The repair effect was evaluated by assessing the healing rate, as well as measuring the levels of TNF-α, IL-2, EGF, and TGF-β1 contents in the tissue. On the 4th and 9th days post-modeling, the Z-P group exhibited notably higher healing rates compared to the control group. However, on the 15th day, both the Z-P and AC groups achieved healing rates exceeding 99%. ZnO NPs-PHMB-hydrogel promoted the formation of a fully restored epithelium, increased new hair follicles and sebaceous glands beneath the epidermis, and markedly reduced inflammatory cell infiltration, which was markedly distinct from the control group. On the 7th day, the Z-P group exhibited significantly higher levels of EGF and TGF-β1, along with a considerable reduction in the TNF-α levels as compared with the control group. These results affirmed that ZnO NPs-PHMB-hydrogel effectively inhibits S. aureus infection and accelerates skin wound healing.

Self-assembly of a AuNPs/Ti3C2 MXene hydrogel for cascade amplification of microRNA-122 biosensing

A three-dimensional (3D) self-assembled AuNPs/Ti3C2 MXene hydrogel (AuNPs/Ti3C2 MXH) nanocomposite was prepared for the fabrication of a novel microRNA-122 electrochemical biosensor. The 3D hydrogel structure was gelated from two-dimensional MXene nanosheets with the assistance of graphite oxide and ethylenediamine. MXene hydrogels supported the in situ formation of Au nanoparticles (AuNPs) that predominantly exploring the (111) facet, and these AuNPs are utilized as carriers for hairpin DNA (hpDNA) probes, facilitating DNA hybridization. MXene acted as both a reductant and stabilizer, significantly improving the electrochemical signal. In addition, the conjugation of PAMAM dendrimer-encapsulated AuNPs and H-DNA worked as an ideal bridge to connect targets and efficient electrochemical tags, providing a high amplification efficiency for the sensing of microRNA-122. A linear relationship between the peak currents and the logarithm of the concentrations of microRNA-122 from 1.0 × 10-2 to 1.0 × 102 fM (I = 1.642 + 0.312 lgc, R2 = 0.9891), is obtained. The detection limit is  0.8 × 10-2 fM (S/N = 3). The average recovery for human serum detection ranged from 97.32 to 101.4% (RSD < 5%).