Search Results (596)

Background: Conventional transdermal drug delivery systems are often limited by poor skin permeability and low drug loading efficiency, necessitating the development of advanced delivery platforms. Objectives: This study aimed to develop and optimize photopolymerizable bioinks (PBs) for liquid crystal display (LCD)-based 3D printing of crosslinked hydrogel microneedles (cHMNs) to enhance transdermal delivery of estradiol valerate (E2V). Methods: A Box–Behnken design (BBD) was used to optimize the effects of Gantrez™ S-97, Jurymer™, and polyvinyl alcohol (PVA) on viscosity, exposure time, hardness, and elasticity, with strong predictive performance (R² = 0.9702–0.9907). Results: Estradiol valerate-loaded nanoparticles (E2V-NPs) were prepared via ionotropic gelation, exhibiting a particle size of 698.33 (0.78) nm, PDI of 0.50 (0.06), zeta potential of −39.09 (7.32) mV, and high encapsulation efficiency (86.87 (0.78)%). The optimized PBs enabled fabrication of uniform cHMNs (~800 µm height) with adequate mechanical strength (hardness 20.45 (1.23) N; elasticity 2.97 (0.49) MPa) and effective insertion capability. The E2V-NPs-loaded cHMNs exhibited sustained drug release over 12 days (~56.92 (4.27)%). Skin permeation studies showed a significantly enhanced flux (10.81 (4.55) µg/cm²/h) and cumulative permeation (12.94 (2.06) µg/cm²) compared to topical E2V-NPs and suspension, along with increased skin accumulation (38.55 (0.10) µg). Cytotoxicity studies confirmed that E2V and E2V-NPs were biocompatible (>80% viability), while PBs showed concentration-dependent cytotoxicity. Conclusions: Overall, this integrated platform combining design of experiment, nanoparticles, microneedles, and LCD 3D printing offered a promising strategy for enhancing transdermal drug delivery efficiency and reproducibility. Full article

Size-exclusion chromatography (SEC) or gel-permeation chromatography (GPC) is an essential tool for determining the molecular weight and polydispersity of water-soluble polymers, including biopolymers used in hydrogels, sealants, bioinks, and other biomedical materials. However, aqueous SEC of polyelectrolytes, i.e., charged polymers, is often complicated by non-size interactions among polymer chains, porous column beads, pore surfaces, frits, tubing, and mobile phase. Salt addition to eluent is commonly used to screen these interactions, but the minimum salt concentration required to restore reliable SEC behavior remains poorly defined, and excessive salt may introduce tailing, refractive-index artifacts, deposits, or instrument concerns. In this study, aqueous SEC with refractive index (RI) and right-angle light scattering (RALS) detection was used to evaluate the effect of salt ($\mathrm{N}{\mathrm{a}}_2\mathrm{S}{\mathrm{O}}_4$) concentration on poly(ethylene oxide) (PEO), a nominally neutral reference standard polymer, and sodium alginate as a model anionic biopolymer. PEO retained a single bell-shaped peak across the tested salt range, but its elution volume and SEC/RALS-derived molecular weights varied slightly with salt concentration, showing that even a nominally neutral reference polymer is affected by mobile-phase conditions. Alginate showed much stronger salt dependence: eluent at very low salt concentration produced broad, noisy, and convoluted chromatograms, whereas increasing salt concentration progressively narrowed the main peak. The first condition that produced a clear, approximately symmetric RI/RALS main peak was $6.25\times {10}^{-3} \mathrm{M}$ $\mathrm{N}{\mathrm{a}}_2\mathrm{S}{\mathrm{O}}_4$, identifying it as the minimum effective salt concentration for this alginate/column/instrument system. To rigorously validate these observations, we propose a set of both qualitative and quantitative peak analyses that objectively confirm the optimal mobile-phase conditions. Ultimately, these results provide a practical workflow for identifying the minimum effective salt concentration required for reliable SEC analysis of water-soluble polymers. Full article

The extracellular matrix (ECM) provides a dynamic microenvironment that regulates cell proliferation, migration, and tissue remodeling during wound healing. However, replicating the structural and functional complexity and ECM heterogeneity of native skin ECM remains challenging with conventional single-material hydrogels. Recent advances in multimaterial 3D bioprinting have enabled the spatial integration of diverse biomaterials within a single construct. Lignocellulose has attracted increasing attention as a promising biomaterial for recreating key structural features of the native ECM because of its fibrous architecture, mechanical strength, and biocompatibility. This review offers a comprehensive and integrated perspective on the use of lignocellulose-based multimaterial printing to recreate ECM-mimicking architectures, an underexplored area at the intersection of biomaterials and biofabrication. The roles of cellulose, hemicellulose, and lignin in printability, scaffold stability, porosity, bioactivity, and wound-healing performance are discussed. Representative studies have demonstrated that lignocellulose-based multimaterial bioinks provide porous architectures that support cell adhesion, proliferation, and tissue regeneration. These benefits are accompanied by improved mechanical performance, as cellulose nanofibers exhibit elastic moduli exceeding 100 GPa, and lignin-containing hydrogels have achieved compressive moduli of up to 135 kPa. Such mechanical advantages make lignocellulosic materials particularly attractive for fabricating ECM-mimicking scaffolds that require long-term structural integrity. Finally, key design considerations and current limitations associated with lignocellulose-based multimaterial bioprinting are critically discussed. A framework for the rational design of lignocellulose-based multimaterial bioinks is presented, together with future directions toward gradient and adaptive scaffolds, smart wound dressings, and advanced wound-healing applications. Full article

Gelatin is a valuable hydrocolloid produced by partial hydrolysis of collagen from mainly mammalian and fish sources. The rheological properties of fish gelatin differ from those of mammalian species in terms of gel strength, viscosity, and other rheological characteristics, even from different fish species and parts of the fish with different properties. Fish gelatin is sustainable for the environment and easy for people to accept for cultural reasons. Owing to these properties, gelatin is used across food, biomedical, pharmaceutical, and health sectors, where 3D printing enables customization and functional performance. Key determinants of print fidelity include gelatin concentration, rheological properties, temperature, gelling behavior, water content, and printing parameters. Suitability for 3D printing is typically assessed via physicochemical characterization, particularly rheology and gelling mechanisms/kinetics. Gelatin-based 3D printing systems offer various advantages due to their biocompatibility, low cost, and controllable rheological properties, and they have potential applications in the food, healthcare, biomedical, tissue engineering, and drug delivery system areas. Using gelatin in combination with other additives can improve printing accuracy and mechanical strength parameters, overcome the limitations of gelatin’s inherent mechanical strength, and develop higher printing accuracy and performance systems. This allows for the development of functional, innovative, and high-value-added products while ensuring safe use. Full article

Organic memristive devices are promising components for neuromorphic systems. Although based on solution-processable materials, their fabrication often involves complex, resource-intensive processes. Here, we report the fabrication of organic memristive devices using aerosol jet printing to deposit both the active channel based on proprietary polyaniline-based bioink and PEDOT:PSS electrodes. Polymers printing has been carried out both on rigid and flexible substrates, the latter with the aim of demonstrating a flexible device not subjected to films delamination upon bending. By optimizing printing parameters, we achieved devices exhibiting high ON/OFF current ratios exceeding 100 and rapid switching dynamics, with performance comparable on glass and Kapton supports. Morphological and electrical characterizations revealed that channel thickness and uniformity critically influence resistive switching behavior. These findings demonstrate that aerosol jet printing enables scalable, low-material-consumption production of flexible organic memristive devices suitable for neuromorphic applications, potentially facilitating their integration into complex, energy-efficient bio-inspired circuits. Full article

Three-dimensional (3D) cell culture models more faithfully reproduce native tissue organization and function than conventional two-dimensional systems, yet many existing bioprinting methods depend on scaffolds, complex instrumentation, or limited control over cell positioning. This review examines magnetic bioinks as a versatile platform for contactless 3D cell manipulation and biofabrication. It first outlines the fundamentals of magnetophoresis and defines magnetic bioinks as combinations of magnetic agents, including magnetic nanoparticles or paramagnetic salts, with biological components such as cells, proteins, or fluids. The review then compares label-based strategies, in which cells are magnetized and guided by positive magnetophoresis, with label-free approaches that exploit magnetic susceptibility differences to position diamagnetic cells through negative magnetophoresis. Across these methods, magnetic bioinks have enabled single-cell sorting, spatial patterning, spheroid and co-culture assembly, multilayer tissue formation, and hydrogel-integrated printing. These capabilities support applications in disease modeling, drug screening, biosensing, regenerative medicine, and emerging biofabrication under microgravity conditions. The paper also highlights key limitations, including nanoparticle biocompatibility, paramagnetic salt toxicity, osmotic stress, and the need for better assay standardization and translational validation. Overall, magnetic bioinks represent a promising scaffold-free approach for rapidly producing physiologically relevant 3D biological constructs for research and clinical innovation. Full article

Corneal blindness remains a major clinical challenge, yet donor grafts are scarce. Bioprinting has emerged in recent decades to potentially overcome donor shortage. In bioprinting, collagen is a common biomaterial. However, one alternative biomaterial, which has shown promising results in corneal tissue engineering, is keratin. Therefore, human hair keratin was investigated in this study as a bioink component for stroma bioprinting. Two keratin preparations, an aqueous extraction and an alkaline extraction, were incorporated into a methacrylated hyaluronic acid bioink and compared with a collagen methacrylated hyaluronic acid bioink. Corneal stroma-like constructs were printed by extrusion bioprinting and evaluated for optical transmission, biomechanical properties, cell compatibility and protein expression of collagen type I and alpha-smooth muscle actin over a four-week period. Two different cell types, immortalized corneal keratocytes and human corneal fibroblasts, were used. The alkaline keratin dialysate-supplemented bioink showed similar optical transparency and biomechanical properties to the collagen-supplemented bioink. Cell viability was high in all formulations. Protein expression of collagen type I and α-smooth muscle actin remained low in all bioinks. Human corneal fibroblasts appeared to be in a quiescent state and were unable to produce large amounts of collagen. This comparative study between collagen and keratin is a first step towards establishing keratins in bioprinting, leading to more complex bioinks. Full article

Since current therapies cannot regenerate lost myocardium or reverse adverse ventricular remodeling—major contributors to worldwide cardiovascular mortality—advanced biomaterials, particularly hydrogels, have emerged as promising therapeutic platforms. Among these, bacterial nanocellulose (BNC) has gained increasing attention due to its hydrated nanofibrillar architecture, high crystallinity, robust mechanical performance, and excellent water-retention capacity, features that closely resemble key aspects of the native extracellular matrix. These properties provide a favorable microenvironment for cell adhesion, survival, and tissue organization in cardiovascular applications. Preclinical evidence suggests that BNC-based cardiac constructs, including acellular patches and cell-laden systems, may reduce post-infarction ventricular dilation, promote angiogenesis, and improve cellular engraftment. In vascular tissue engineering, BNC has also been explored in small-diameter grafts, anisotropic hydrogel systems, and shape-memory conduits with encouraging hemocompatibility and functional durability. Functional modifications—including gelatin incorporation, oxidative surface treatments, peptide grafting, conductive polymers, and structural alignment strategies—further expand the biological and mechanical versatility of BNC-based systems. In addition, BNC-containing bioinks have demonstrated promising rheological behavior, printability, and cell compatibility for 3D bioprinting applications. Despite these advances, important challenges remain, including optimization of material functionalization, host integration, degradation control, vascularization, scalable manufacturing, and regulatory translation toward clinical application. Full article

Incorporation of extracellular matrix (ECM) components into bioinks can enhance biological functionality but often compromises print fidelity and structural stability. This study developed a dual-stage calcium chloride (CaCl₂) crosslinking strategy to incorporate Wharton’s jelly-derived ECM (WJ-ECM) into a gelatin-alginate bioink for bioprinted scaffold fabrication. A baseline formulation (BGA) and a WJ-ECM-supplemented formulation (BGAE, 1 mg/mL) were pre-crosslinked with 14 mM CaCl₂ prior to extrusion, followed by secondary crosslinking in 0.5 M CaCl₂ post-printing. Both formulations exhibited comparable viscosity (20–180 kcP) and high print fidelity (Pr = 0.99 ± 0.01 for BGA; 0.95 ± 0.01 for BGAE), with scaffolds displaying well-defined architecture and over 84% of pores within the target range (160–270 µm). FTIR analysis confirmed WJ-ECM incorporation without detectable alteration of the primary matrix structure. Both scaffolds were non-cytotoxic and supported fibroblast viability; BGAE constructs showed greater cell coverage over 14 days when surface-seeded and more stable fluorescence intensity through 28 days when encapsulated. In a murine thermal burn model, BGAE-treated wounds demonstrated more advanced re-epithelialization and more continuous epidermal coverage at day 14 compared to controls. These findings indicate that dual-stage crosslinking enables WJ-ECM integration while preserving printability, offering a practical platform for bioactive skin tissue engineering applications. Full article

Traumatic injuries often result in nerve tissue damage and functional deficits due to limited regeneration. Silk fibroin, a biopolymer with inherent biocompatibility and tunable properties, is a promising material for 3D-bioprinted neural tissue scaffolds. This review highlights recent advancements in silk-derived composite scaffolds, often incorporating additional materials like collagen or conductive polymers to enhance their performance. This review examines how material composition, scaffold architecture, and fabrication strategy influence biological response and functional recovery. This comprehensive review follows PRISMA guidelines and uses comprehensive searches of PubMed, MEDLINE, Embase, Web of Science, Cochrane Central, and ClinicalTrials.gov for studies published through 2025. Studies were screened for eligibility based on substance type, mechanical properties, production methods, and outcomes. Findings were synthesized qualitatively. Twelve studies were included, comprising rat (50%), canine (8.3%), and in vitro (41.7%) models. Analysis reveals that silk fibroin acts as a highly adaptable mechanical backbone. It can consistently integrate with bioactive additives (collagen, dECM) or conductive polymers (Polypyrrole, MXene) to meet specific therapeutic demands. For spinal cord injuries, composites reached a compressive modulus capable of resisting physiological pressures and preventing scaffold collapse. In soft tissue applications, silk–hydrogel blends provided localized release of exosomes and small molecules during the acute injury phase, reducing neuroinflammatory markers. Additionally, adding conductive materials allowed the scaffolds to bridge electrical gaps and promote Schwann cell proliferation and neuronal differentiation. Furthermore, 3D bioprinting enabled the creation of defined microchannels that replicate native fascicular architecture. In vivo outcomes consistently showed superior axonal regeneration, myelination, and synaptic reconnection compared to controls, correlating with significant improvements in electrophysiological and motor function. This review highlights the clinical potential of silk fibroin-based 3D-printed biomaterials for nerve regeneration, including neural repair and neural tissue engineering. More recent studies place greater emphasis on integrating mechanical, architectural, and biological considerations into scaffold design, resulting in increasingly multifunctional scaffold systems. Despite promising efficacy, the heterogeneity of fabrication methods and the predominance of rodent models highlight the need for standardized protocols and evaluations in relevant models to facilitate clinical translation. Full article

Three-dimensional (3D) bioprinting has rapidly evolved into a controlling platform for the fabrication of patient-specific biomedical implants, with growing importance in advanced drug delivery systems. Beyond structural tissue engineering, bioprinted constructs now function as programmable therapeutic depots capable of localized, sustained, and stimuli-responsive drug release. This review focuses on recent biomaterial design strategies that enable precise control over drug encapsulation, retention, and release kinetics within 3D bioprinted architectures. The physicochemical and mechanical properties of bioinks, including crosslinking density, porosity, degradation behavior, viscoelasticity, and swelling characteristics, directly influence drug loading efficiency and release dynamics under physiological conditions. The rational tuning of these parameters allows the development of constructs that provide spatially controlled and temporally regulated therapeutic delivery. Recent advances in predictive modeling, such as finite element modeling (FEM), data-driven machine learning approaches, and ML, have significantly improved the ability to correlate material composition, printing parameters, and structural geometry with drug diffusion and degradation-mediated release mechanisms. These tools facilitate the optimization of printing variables including extrusion pressure, nozzle diameter, and layer resolution to ensure structural fidelity while maintaining therapeutic functionality. Emerging strategies incorporating multi-material printing, gradient architectures, and stimuli-responsive biomaterials have expanded the potential of 3D bioprinting for combination therapies and personalized medicine. This review discusses key challenges in translating bioprinted drug delivery systems into clinical applications, including the standardization of drug release characterization methods, and long-term stability assessment. Full article

This study investigated the effects of curdlan (CUR) on the structural stability and thermal processing properties of Pleurotus eryngii mycelium–soy protein isolate–cassava starch gels used as bio-ink scaffolds for 4D-printed meat analogs. Bio-inks containing different CUR concentrations (0–5%, w/w) were prepared, and their rheological properties, 3D printability, microstructure, and water distribution were systematically evaluated. The fermented meat analogs were then subjected to steaming and baking to assess cooking loss, dimensional shrinkage, and textural properties. The results showed that CUR significantly increased the yield stress and structural recovery of the bio-inks while maintaining high height retention (>87%), thereby providing a favorable scaffold for mycelial growth and subsequent product formation. During thermal processing, CUR effectively mitigated structural collapse, which may be attributed to its heat-induced thermally irreversible gelation and the formation of an internal supporting network that resisted matrix contraction and dehydration. In particular, the addition of 5% CUR reduced cooking loss from 12.83% to 7.35% during steaming and from 42.52% to 38.59% during baking, while reducing shrinkage to 9.29% and 18.00%, respectively. In addition, hardness, springiness, and chewiness were significantly improved after cooking. Overall, CUR functioned not only as a rheological modifier for extrusion printing but also as a heat-activated internal supporting network during cooking, owing to its thermally irreversible gelation. Full article

3D bioprinting technology has made great strides in the field of bone tissue engineering. It has been able to create personalized biological structures on a macroscopic scale. In terms of microstructure bionics, 3D printing technology has also made some progress in recent years. The use of nanotechnology and drug delivery technology has provided a microenvironment that is more compatible with cell growth. Finally, it is possible to bridge the gap between engineered organizational structures and natural tissues. In this work, we summarize the widely used 3D bioprinting methods and the preparation of bioinks. Next, the classification of bone tissue engineering scaffold materials and nanomaterials for loading is briefly introduced. Then the technical shortcomings of current nanotechnology-based 3D bioprinting are described, along with the corresponding improvements. Finally, we summarize the prospects of nano-based 3D bioprinting technology in bone tissue engineering. Full article

The development of biomimetic and mechanically functional constructs remains a major challenge in skeletal muscle tissue engineering. In this study, we present a multi-component 3D bioprinted platform integrating a polycaprolactone (PCL) support for mechanical stimulation, a sacrificial gelatin (GE) matrix for controlled bioink deposition, and collagen-based bioinks laden with Rattus norvegicus L6 skeletal muscle cells. The influence of PCL architecture, GE concentration (0.75, 1.5 and 3 wt%), and bioink composition—collagen (C), collagen–Matrigel (CM), and extracellular matrix-based (ECM)—was systematically evaluated. Rheological characterization demonstrated that all bioinks exhibited shear-thinning behavior and suitable viscoelastic properties for extrusion-based bioprinting, with sufficient mechanical stability to withstand dynamic bioreactor conditions. Microstructural analysis revealed highly interconnected porous networks, particularly in ECM-based scaffolds. While no statistically significant differences were observed, the ECM-based bioinks showed the highest cell viability and improved structural organization. Overall, this work demonstrates a versatile bioprinting strategy that combines mechanical support and biomimetic environments, highlighting the potential of ECM-based bioinks for the fabrication of functional skeletal muscle constructs. Full article