Search Results (607)

Cell therapies for gastric disorders lack minimally invasive delivery platforms that preserve cell viability during storage and enable effective tissue penetration, owing to the high toughness and harsh environment of the gastric wall. Herein, we developed a mechanically reinforced, porous silk-based cryogenic microneedle (silk-cryoMN) platform for in situ cell delivery to the gastric wall. The optimized 1.5% (w/v) silk scaffolds exhibited interconnected pores (24.4 ± 7.9 μm, ~81% porosity), a compressive strength (422.8 ± 73.4 MPa), and a 3.4-fold increase in β-sheet content. The silk-cryoMNs showed greater thermal stability than H₂O-cryoMNs, maintaining structural integrity for over 60 s at room temperature. With a cryopreservation medium containing 100 mM sucrose and 2% DMSO, post-thaw cell viability exceeded 80% after 11 days of freezing, and most cells were released within 1 h. Furthermore, ex vivo studies confirmed penetration of porcine gastric tissue to depths of 422–448 μm within 30 s. These results suggest that the platform may address several translational barriers, including tissue penetration, handling stability, and cell viability preservation. Further in vivo studies and long-term safety evaluations are needed before clinical translation can be considered. Full article

Transbronchial lung cryobiopsy (TBLC) is increasingly used as a minimally invasive approach for tissue acquisition in the evaluation of interstitial lung disease (ILD), serving as an alternative to surgical lung biopsy (SLB) within multidisciplinary diagnostic pathways. Despite its growing adoption, variability in diagnostic yield and complication rates highlight the importance of procedural technique, probe selection, and freezing parameters. This narrative review summarizes the current landscape of TBLC, with emphasis on factors that influence diagnostic performance and safety, including procedural considerations involving endobronchial balloon blockade (EBB), radial probe endobronchial ultrasound (RP-EBUS), and cone-beam computed tomography (CBCT) for biopsy localization and airway management. Much of the existing experience is based on conventional cryoprobes, including 2.4 mm and 1.9 mm devices, typically used with freezing times of several seconds. While these approaches have defined the current role of TBLC in ILD, outcomes remain variable across centers, prompting continued refinement of procedural strategies to improve consistency. More recently, attention has expanded to include a broader range of smaller cryoprobe sizes—1.7 mm and 1.1 mm. Overall, this review provides a framework for understanding contemporary TBLC practice and highlights key areas where further study is needed to better define optimal technique and improve consistency in clinical outcomes. Full article

Self-healing biomaterials have attracted significant attention due to their ability to restore structural integrity, extend material lifetime, and reduce maintenance costs without external intervention. In this study, Polyvinyl Alcohol/Graphene Oxide/Eggshell Particle (PVA/GO/ESP) composite hydrogels were synthesized via a freeze–thawing method and characterized using XRD, SEM/EDS, and FTIR analyses. The effect of ESP incorporation on the self-healing and mechanical properties of the hydrogels was systematically investigated. Tensile test results demonstrated that incorporation of 1 wt% ESP improved the tensile strength up to 0.326 MPa while maintaining high strain capacity. Healing efficiency values calculated from recovered tensile strength showed approximately 69%, 47%, and 67% recovery for PVA/GO, PVA/GO/ESP (0.5%), and PVA/GO/ESP (1%) hydrogels, respectively. The developed hydrogels demonstrated rapid self-healing behavior at room temperature without external stimuli. These findings suggest that ESP-reinforced PVA/GO hydrogels may serve as promising candidates for future biomaterial and soft tissue engineering studies. The developed hydrogels demonstrated enhanced tensile strength, rapid self-healing behavior, and promising swelling properties, indicating their potential use in soft tissue engineering and biomaterial applications. Full article

Rapid rewarming is the most conventional and primary treatment for frostbite, yet effective adjunctive strategies remain absent. Conventional wound dressings, such as therapeutic hydrogels, tend to freeze and lack the necessary rewarming ability, rendering them unsuitable for direct application. Herein, we engineered an environmentally tolerant photothermal hydrogel, named 5A-Gel, featuring anti-swelling, anti-pressure, antioxidant, anti-freezing, and anti-drying capacities, for the treatment of frostbite. 5A-Gel was formed via dynamic crosslinking between gelatin and tea polyphenols in a glycerol/water solvent system. The incorporation of glycerol endowed the hydrogel with superior anti-swelling, anti-freezing, and anti-drying performance (remaining flexible at −20 °C and 37 °C for at least 60 days), along with concentration-dependent antioxidant activity due to tea polyphenols. Furthermore, 5A-Gel exhibited excellent photothermal effects, maintaining stable temperature and softness under 808 nm laser irradiation with robust cyclic durability. In addition, 5A-Gel showed slow degradability, excellent hemocompatibility, and favorable in vivo biosafety. Functionally, in a mouse frostbite wound model, photothermal rewarming therapy using 5A-Gel markedly expedited frostbite healing, promoting re-epithelialization, enhancing collagen deposition, alleviating inflammatory response, and stimulating neovascularization. Therefore, the as-prepared 5A-Gel serves as a competent therapeutic platform for in situ frostbite treatment and offers innovative principles for the rational engineering of high-performance hydrogel systems targeting frostbite tissue injuries. Full article

Freezing stress is one of the major abiotic factors limiting plant growth and productivity. This study evaluates the effects of diatomite (DTM) as a natural silicon-rich amendment on growth performance, physiological responses, and cold stress tolerance in barley (Hordeum vulgare L.). Seed priming and substrate application of DTM at different concentrations (5–20%) were used to assess morphological, biochemical, and ultrastructural changes under normal and low-temperature conditions. Results showed that DTM significantly enhanced root growth and biomass accumulation, with the most pronounced effect at 10% concentration. Treated plants exhibited improved survival under freezing stress, along with better preservation of leaf cellular structure and photosynthetic pigments. Biochemical analyses revealed reduced proline accumulation and decreased activity of key antioxidant enzymes, indicating alleviation of oxidative stress and improved redox balance. Electron microscopy confirmed the integration of diatomite particles into seed and tissue structures, providing physical reinforcement and thermal protection. Overall, diatomite acts as a multifunctional, environmentally safe soil amendment that enhances plant growth and improves tolerance to cold stress through combined physical and physiological mechanisms. Full article

Scaffolds designed for mechanically demanding soft tissue engineering applications should integrate mechanical support, efficient mass transfer, and good cellular compatibility. This work presents a one-pot method based on “radical-free click chemistry + carbodiimide coupling” to produce a double-network (DN) PEG–alginate cryogel. The PEG network is formed by a Michael addition reaction between thiol-based crosslinker and 8-arm PEG-acrylate. The second network is covalently crosslinked through EDC/NHS-mediated coupling of carboxyl groups in alginate and adipic acid dihydrazide (AAD). The subsequent freezing and gelation of the gel precursor at sub-zero temperatures results in an ice templated cryogel with an interconnected macroporous network. These cryogels demonstrate high elasticity, compressive modulus and rapid swelling equilibrium in aqueous environments, as well as controlled degradation under physiological conditions. Compared to the classical Ca²⁺ ion crosslinking systems, the covalent linking of the alginate in the double-network cryogel shows advantages in mechanical and structural stability. In addition, it is cell-compatible and allows culture of mesenchymal stem cells (MSCs) with homogeneous infiltration. Furthermore, the double-network cryogels supports chondrogenic differentiation of MSCs upon treatment with chondrogenic media or macrophage-conditioned media for a short period of time. These results indicate that crosslinking chemistry and polymer composition can be used to modulate the balance between mechanical performance and degradation behavior, while maintaining cytocompatibility and an interconnected macroporous network, thereby providing a scaffold design strategy for applications that require coordinated mechanical support and mass transfer, such as cartilage-related tissue engineering. Full article

Three-dimensional (3D) cardiac models, including spheroids, organoids, and organ-on-chips, are advanced systems for studying human physiology, disease, and drug responses with greater biological relevance than 2D models. As their use expands in biomedical research, tissue engineering, and regenerative medicine, reliable preservation methods are needed. However, cryopreservation often fails to protect 3D systems due to limited cryoprotectant penetration, ice formation, and mechanical stress during freezing and thawing. Room-temperature (RT) preservation has emerged as a promising alternative for short-term transport. This study evaluated a RT-based transport medium (CellShip^®) for preserving cardiac organoids for up to seven days, compared with conventional cryopreservation using slow-freezing in Cryostor^®CS10. Viability and functionality were assessed using apoptosis, ATP levels, beating activity, proliferation, and size. During maturation, organoids showed increased size, ATP levels, and beating capacity. Cryopreservation reduced size, proliferation, ATP levels, and altered beating, while increasing apoptosis. In contrast, RT preservation maintained stable viability and functionality after recovery. These findings demonstrate that RT preservation effectively maintains cardiac organoid integrity and function, offering a promising alternative for short-term storage and transport, with potential terrestrial and nonterrestrial applications. Full article

Ovarian tissue cryopreservation (OTC) has emerged as the only viable fertility preservation strategy for prepubertal girls and adolescent cancer patients facing gonadotoxic treatments. While OTC has transitioned from an experimental procedure to an established clinical practice, the functional longevity of transplanted grafts remains limited by massive follicle depletion. This review synthesizes recent technological advances in OTC for female children, with a particular focus on the underlying molecular mechanisms and innovative protective strategies. We systematically evaluate pre-cryopreservation assessments, surgical harvesting techniques such as medulla-sparing biopsies, and the comparative efficacy of slow freezing versus vitrification in preserving stromal and follicular integrity. Central to this discussion are the molecular drivers of post-transplantation injury, including ischemia–reperfusion-induced oxidative stress and the iatrogenic over-activation of the PI3K/Akt/mTOR signaling pathway, which leads to follicular “burnout.” Furthermore, we explore targeted pharmacological interventions, such as the dual-drug application of VEGFA and rapamycin, alongside emerging bioengineering frontiers including decellularized extracellular matrix scaffolds and 3D-printed bioprosthetic ovaries. Clinical outcomes are also summarized, highlighting high rates of endocrine recovery (~95%) and promising live birth rates (~28%), predominantly through natural conception. By integrating deep molecular insights with advanced tissue engineering, this review provides a comprehensive framework for optimizing long-term fertility restoration and improving the quality of survivorship for young female cancer survivors. Full article

Articular cartilage has attracted significant attention for its essential roles in joint lubrication and stress buffering. However, its inherent self-repair capacity is limited. Addressing inflammatory damage to this tissue, therefore, presents a major clinical challenge in orthopedics. Poly(vinyl alcohol) (PVA)-based hydrogels have emerged as promising repair materials due to their high water content, which mimics the properties of natural cartilage, as well as their tunable mechanical properties and favorable biocompatibility. This review comprehensively examines PVA-based hydrogels, beginning with an overview of their network formation. It then systematically summarizes the main methods and principles for constructing their networks, including physical crosslinking (e.g., cyclic freezing-thawing), chemical crosslinking, and radiation crosslinking, as well as targeted strategies to enhance performance and modify functionality. Particular emphasis is placed on their diverse clinical applications in treating osteoarthritis, primarily including their use as surgical adjuncts, such as injectable gels and anti-adhesion membranes, as long-term or biodegradable cartilage replacement implants, and their potential in partial joint surface resurfacing and reconstruction. Finally, prospects for the application of PVA-based hydrogels in osteoarthritis therapy are considered. Overall, as versatile platform materials, PVA-based hydrogels demonstrate significant potential for clinical translation in cartilage repair. Full article

Background/Objectives: Intraoperative margin assessments of oral squamous cell carcinoma (SCC) are fundamentally limited by sampling errors and freezing artifacts inherent to standard frozen section analysis. We developed a mobile, multi-scale, wide field-of-view (FOV) swept-source optical coherence tomography/microscopy (SS-OCT/OCM) system operating in the Near-Infrared-II (NIR-II) window (1.68 μm) to provide a rapid, non-destructive, volumetric evaluation of excised oral mucosal tissues. Methods: To correlate optical images with histopathology, we engineered a custom 3D-printed tissue cassette that physically mitigates macroscopic shrinkage during scanning and subsequent tissue fixation. A three-axis motorized assembly extends the effective imaging FOV without compromising resolution, while a custom 3D multi-resolution pyramid stitching algorithm synthesizes wide-FOV mosaics. Results: The customized cassette enabled precise, one-to-one spatial correlation between optical volumes and histopathology sections. Crucially, a 3 × 3 mosaic scan acquired with a 10× objective balanced imaging resolution and acquisition time, providing sufficient structural clarity to visualize basement membrane loss—a hallmark of SCC invasion. Conclusions: This 1.68 μm, fully automatic, multiscale SS-OCT/OCM platform demonstrates the feasibility of serving as a rapid, three-dimensional imaging tool for potential future use as an adjunct to conventional frozen sections. Full article

Athetis lepigone (Möschler) is an important pest of maize in North China, whose larvae feed mainly on maize leaves, stems, and roots during the seedling stage, with conventional maize lacking effective resistance to it. In recent years, transgenic Bt maize expressing Cry1Ab and Vip3Aa proteins has been commercialized in China; however, its resistance against A. lepigone has not yet been systematically evaluated. In this study, three Bt maize events, DBN3601T expressing Cry1Ab and Vip3Aa, DBN9936 expressing Cry1Ab, and DBN9501 expressing Vip3Aa, were used to comprehensively assess resistance against the pest based on Bt protein expression levels in different maize tissues, larval susceptibility across instars, and larval feeding behavior under controlled laboratory conditions. The results showed that Bt protein expression varied significantly among maize tissues commonly fed upon by the insect, following the general pattern: seedling leaf > stem > root. Bioassays using artificial diets incorporated with freeze-dried maize leaf powder indicated that larvae were significantly more susceptible to Cry1Ab than to Vip3Aa, with LC₅₀ values of 1.05 and 2.65 μg·g⁻¹, respectively. Maize co-expressing both proteins exhibited high insecticidal activity. First-instar larvae displayed feeding avoidance of Bt maize tissues, and early instars were more sensitive than later instars; however, stems and roots showed stronger toxicity to older larvae. In simulated field infestation assays, the control efficacies of DBN3601T, DBN9936, and DBN9501 reached 94.35%, 88.79%, and 10.56%, respectively, at five days post-infestation. Overall, DBN3601T maize exhibited a strong resistance performance against A. lepigone, indicating strong potential for pest management applications. Full article

Injectable hydrogels have attracted substantial and rapidly growing interest due to their ability to be administered into cavities of any shape and provide local therapeutic treatment. This study reports the synthesis and characterization of thermosensitive microgels and hydrogels obtained via photoinitiated copolymerization of methacrylated gelatin (GN-MA) and N-isopropylacrylamide (NIPAM) in the absence and presence of N,N′-methylenebisacrylamide (MBA). The effects of monomer concentration, crosslinker content (MBA), and irradiation time on product yield, grafted chain length, and material properties were systematically investigated. Depending on the polymerization conditions, microgel samples exhibited hydrodynamic diameters in the range of 354–1022 nm at 20 °C, which decreased to 183–308 nm upon heating to 40 °C. Freeze-drying of the microgel dispersions resulted in the formation of a porous sponge-like structure with pore sizes of 50–90 µm. Rheological studies of the hydrogel properties demonstrated evident thermoresponsive behavior, with storage moduli (G′) ranging from 20 to 600 Pa, matching the mechanics of certain soft tissues. The hydrogels showed high equilibrium swelling capacity at 20 °C, which was reduced at 40 °C, as well as temperature-dependent moxifloxacin release (38–88% over 6 days) and excellent biocompatibility (>85% cell viability) with human skin fibroblasts. These findings make them promising for biomedical applications such as postoperative cavity filling and local drug delivery. Full article

Freezing effectively extends the shelf life of food and maintains product quality by inhibiting microorganisms, enzyme activity, and chemical reactions. However, issues such as ice crystal formation, protein denaturation, lipid oxidation, and the low-temperature adaptability of psychrophilic microorganisms during the freezing process can directly affect the final quality of frozen foods. Among these, the size and distribution of ice crystals are key factors determining the extent of tissue damage. Therefore, this review aims to identify innovative and optimized freezing and frozen storage strategies. In order to save energy and improve product quality, various new technologies have emerged in recent years, such as ultrasonic-assisted freezing, high-pressure freezing, and magnetic-field-assisted freezing. This study systematically discusses the principles, applications, and impact mechanisms of these technologies on frozen foods. Furthermore, this study proposes the future development trends of frozen foods, filling the gap in the current food industry where there is a lack of systematic discussion and evaluation of frozen foods. It provides technical support and research directions for continuous development and innovation in the field of frozen foods. Full article

Acrylated epoxidized soybean oil (AESO) is a bio-based, biocompatible, and biodegradable photopolymerizable resin that exhibits shape-memory behavior, making it attractive for a wide range of biomaterial applications. Despite various strategies to fabricate porous AESO scaffolds for tissue regeneration, achieving high pore interconnectivity remains challenging. Herein, we demonstrate the utility and versatility of thermoreversible terpenes as porogens in AESO to enable the formation of highly aligned and interconnected pore architectures. More specifically, a blend of 90 wt% camphene and 10 wt% camphor was employed as the terpene system, since it could be completely melted at 70 °C, uniformly mixed with liquid AESO, and subsequently crystallized at −20 °C. This process generated a bicontinuous network comprising terpene crystals and liquid AESO, thereby enabling efficient UV photopolymerization of AESO. Following terpene removal via freeze-drying, highly aligned pore networks with excellent pore interconnectivity were obtained, which are hardly achievable using conventional liquid or solid porogens. The porosity and mechanical properties of the AESO scaffolds were tuned by adjusting terpene content. Porosity increased from 61.5 to 81.5% as terpene content rose from 60 to 80 vol%. As a result, tensile strength decreased from 0.29 ± 0.045 to 0.17 ± 0.017 MPa, while elongation at break increased from 20.2 ± 4.9 to 35.5 ± 1.34%. Furthermore, this approach is compatible with vat photopolymerization (VP), a 3D printing technique. As a proof of concept, dual-scale porous AESO scaffolds, composed of unidirectional channels surrounded by highly aligned porous frameworks, were successfully fabricated. These results indicate that a variety of dual-scale porous AESO scaffolds, with greatly enhanced mechanical properties at given porosities coupled with outstanding tissue regeneration, can be produced through VP using terpene porogens, in contrast to conventional porous scaffolds comprising uniform porous frameworks. Full article

In this study, a streptomycin sulfate-loaded bioactive glass/chitosan (STRS–BG/CH) composite scaffold was fabricated via an improved unidirectional freeze-drying method, with drug loadings of 20–40%. The scaffolds were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray analysis before and after in vitro testing. Antibacterial efficacy was evaluated against Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Klebsiella pneumoniae, Escherichia coli) microorganisms via the agar diffusion method. The STRS–BG/CH scaffolds exhibited highly interconnected porous structures, prolonged antibacterial activity, and enhanced apatite-forming ability in vitro. Compared with bead-based carriers, scaffold-based systems provide enhanced structural integrity and interconnected porosity, which are advantageous for sustained drug release, apatite formation, and tissue integration. Accordingly, these multifunctional scaffolds may simultaneously provide localized antibacterial activity and potential relevance to bone tissue engineering applications. The prepared STRS–BG/CH scaffolds functioned as controlled release carriers for streptomycin sulfate while simultaneously maintaining antibacterial efficacy and bioactive performance. These results illustrate the importance of STRS–BG/CH scaffolds as a promising antibacterial bioactive scaffold system, warranting further biological investigation. Full article