Search Results (1,112)

Osteochondral defects, involving both articular cartilage and subchondral bone, can lead to joint degeneration and osteoarthritis. Recent advances in 3D-printed biphasic scaffolds offer promising opportunities to recreate physiological microenvironments for tissue regeneration. In tissue engineering, these scaffolds can be mechanically stimulated to promote targeted cartilage and bone formation. While computational models have been widely used to study mechanically induced cellular responses in monophasic scaffolds, time-dependent modelling of biphasic osteochondral systems remains relatively scarce. In this study, a fluid–structure interaction (FSI) framework coupled with a mechanoregulatory algorithm was developed to predict mechanically induced early-stage mesenchymal stem cell (MSC) differentiation in biphasic open-porous osteochondral scaffolds comprising chondral and bone layers designed for direct ink writing (DIW). In a second model, an interfacial barrier layer representing the native osteochondral interface was integrated. Dynamic compressive loading (1 Hz, $2.5\%$ strain) was applied. The simulations predicted region-specific differentiation patterns in both the chondral and subchondral bone regions. In the scaffold without a barrier layer, approximately $68.9\%$ of MSCs in the chondral layer and $93.4\%$ of MSCs in the bone layer underwent chondrogenic and osteogenic differentiation, respectively. Incorporation of the barrier layer caused only minor changes, reducing predicted cartilage and bone differentiation by approximately $1.5\%$ and $3.9\%$, respectively. Overall, this study highlights the capability of computational modelling to predict mechanobiological responses in complex osteochondral systems and support scaffold design and effective mechanical stimulation protocols. Full article

For critical-sized bone defects, bioactive implants are indispensable. Although advanced three-dimensional (3D) printing technology enables the precise manufacturing of customized bone scaffolds, implant-associated infections (IAIs) remain a significant clinical challenge. Moreover, traditional passive antibacterial coatings often face problems such as uncontrolled release of antibacterial agents and insufficient long-term antibacterial efficacy. This review elaborates on the transformation of antibacterial strategies in the field of bone tissue engineering (BTE) from “passive” to “smart responsive” modes. We summarize the endogenous (such as pH, temperature, reactive oxygen species (ROS), and enzyme) and exogenous (such as light, microwave, and ultrasound) response systems. Notably, the ultrasound-driven strategy is highly emphasized due to its outstanding deep tissue penetrability and dual functional characteristics: it can not only eliminate stubborn biofilms through the sonodynamic effect by generating ROS, but also promote osteogenesis through the piezoelectric effect. Additionally, we also discuss the recent progress of artificial intelligence (AI) in the field of bone scaffold manufacturing. AI-driven algorithms help to rapidly optimize complex scaffold structures and accurately predict their mechanical properties, thereby effectively avoiding the inefficiencies brought about by the traditional “trial and error” method. In conclusion, combining AI-assisted manufacturing technology with smart responsive antibacterial strategies opens up a highly promising frontier field for the development of personalized and infection-free bone implants. Full article

The meniscus is a fibrocartilaginous tissue essential for load transmission, shock absorption, joint stability, and cartilage protection in the knee. However, its intrinsic healing capacity is severely limited, particularly in the avascular region and in complex defects, often resulting in persistent symptoms, functional impairment, and progressive joint degeneration. Although current clinical interventions, including meniscal repair, partial meniscectomy, allograft transplantation, and scaffold-assisted meniscal substitution, can provide symptomatic and functional improvement in selected patients, durable structural and functional restoration remains difficult to achieve. Meniscus tissue engineering has therefore emerged as a potential strategy for tissue preservation and functional reconstruction. This review synthesizes recent advances in meniscus tissue-engineered scaffolds, focusing on biomaterial systems, biofabrication strategies, and translational progress. Natural polymers, decellularized extracellular matrix, synthetic polymers, and composite materials are discussed according to their respective roles in biological regulation, mechanical support, structural organization, and clinical feasibility. Emerging biofabrication strategies are further analyzed with respect to geometric reconstruction, zonal organization, fibrous anisotropy, and their implications for scaffold evaluation. Finally, current in vitro, preclinical, and clinical evidence is critically examined to identify the key barriers that still limit long-term regeneration and clinical translation. Full article

This study reports the fabrication of curcuminoid-loaded nanofibrillated cellulose (NFC)–alginate scaffolds via extrusion-based 3D printing, integrating supercritical CO₂ extraction with biofabrication. NFC–alginate inks were pre-crosslinked with CaCl₂ (1 to 10 mM) to tune structure and properties. Rheological analysis confirmed shear-thinning behavior suitable for extrusion printing. Mechanical testing revealed a non-linear dependence on crosslinking: optimal performance was achieved by Ink 2 (1 mM CaCl₂ with curcuminoid extract), with tensile strength increasing from ~0.60 to ~0.80 MPa and Young’s modulus from ~1.5 to ~3.0 MPa relative (Ink 1, 10 mM CaCl₂, without extract), reflecting the combined effect of extract incorporation and ionic pre-crosslinking rather than crosslinker concentration alone; higher crosslinking reduced stiffness (~1.15 MPa). SEM revealed porous architectures (Ink 1: 542 ± 63 μm; Ink 4: 398 ± 71 μm) with increasing structural heterogeneity upon curcuminoid incorporation. In vitro release exhibited biphasic, diffusion-dominated behavior, reaching ~50 to 60% in ethanol-containing media; PBS inclusion as a physiological reference confirmed minimal release (<5%), consistent with the known hydrophobicity and pH-dependent instability of curcuminoids and defining the physicochemical delivery boundaries of the system. The highest release (~372 ng/mL) was achieved at intermediate loading (10×). Kinetic modeling confirmed Higuchi-type diffusion as the dominant mechanism (R² ≈ 0.90 to 0.99). These results establish a clear structure–property–release relationship and position the scaffolds as a tunable, diffusion-controlled delivery platform for hydrophobic bioactives in topical or formulation-assisted applications employing co-solvents or solubilizing excipients. Full article

Focal articular cartilage defects retain limited intrinsic repair capacity owing to the avascular, alymphatic and aneural nature of hyaline cartilage. Marrow-stimulation procedures often generate mechanically inferior fibrocartilage with declining benefit within 2–5 years in larger or high-demand lesions, while matrix-induced autologous chondrocyte implantation (MACI) achieves durable 10-year benefit but remains constrained by two-stage logistics, in vitro dedifferentiation and cost. This review integrates the cellular, biomaterial, biochemical and immunological dimensions of articular cartilage tissue engineering with quantitative benchmarks and a critical reading of failure modes, scalability and regulatory standing. We benchmark MACI against single-stage chondron- and progenitor-based therapies; examine mesenchymal stromal cells (MSCs) from bone marrow, adipose, synovium and the infrapatellar fat pad with a mechanistic dissection of the Wnt/β-catenin, IHH–PTHrP, RUNX2/MEF2C and HIF-1α inputs driving hypertrophic drift; reframe scaffolds as bioinstructive environments delivering mechanical, biochemical and tribological cues, including stimuli-responsive and 4D-printed systems and low-intensity pulsed ultrasound (LIPUS) as a non-invasive adjunct; develop the immunological dialogue between altered native cartilage, the infrapatellar fat pad–synovium unit and engineered constructs; and appraise CRISPR-based cell engineering and artificial-intelligence applications in biofabrication. We classify the principal approaches into four explicit translational tiers so that the evidentiary standing of each strategy is transparent. Translation will be paced by standardised potency assays, immune-aware construct design and robust long-term in vivo evidence. Full article

Porous silicate scaffolds represent a promising class of grafting materials for hard tissue engineering due to their superior bioactivity, adjustable degradation rates, and ability to stimulate both osteogenesis and angiogenesis. In this work, scaffolds based on an akermanite-targeted (Ca₂MgSi₂O₇) starting composition, including copper-doped variants, were synthesized using sol–gel and combustion routes, followed by 3D printing to achieve porous architectures with controlled pore size and interconnectivity. The powders were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermal analysis to evaluate their morphology, composition, and crystalline phases. The scaffolds were further assessed in terms of bioactivity by immersion in simulated body fluid (SBF), antibacterial activity, and in vitro cellular response. The results confirmed that copper doping enhanced antibacterial properties, while maintaining favorable biological behavior. Comparative analysis revealed differences between the two synthesis methods, with sol–gel providing more homogeneous structures and combustion leading to highly porous morphologies. These findings highlight copper-doped silicate scaffolds as promising candidates for bone tissue regeneration, combining architectural integrity with biological functionality. Full article

Magnesium alloys are considered to be the third generation of biomaterials used in biomedical applications to promote bone tissue regeneration. Due to their Young’s modulus being similar to that of human bone and their release of magnesium ions that are antimicrobial and osteoinductive, these biomaterials not only promote bone regeneration, minimize the effects of stress shielding and reduce the risk of infection, but also their exceptional biocompatibility and bioresorbability eliminate the need for a second surgery to remove the implant. However, because magnesium has poor corrosion resistance, without different coatings and surface treatments, the implant can be compromised before the bone is fully healed. With additive manufacturing (AM) as a revolutionary technology, the one-size-fits-all approach can be replaced by fully personalized medicine, in which complex shapes can be created, designed, and processed with unique parameters for each patient. However, 3D printing of Mg-based devices remains particularly challenging due to magnesium’s high chemical reactivity, combustion risk, and low vaporization temperature, challenges that are further compounded when alloying elements are introduced. This review addresses this gap by critically examining the properties, corrosion behavior, and bio-medical performance of Mg and its alloys, with a focused analysis of selective laser melting (SLM) and wire arc additive manufacturing (WAAM) as key fabrication methods. The influence of processing parameters, microstructural defects, and alloy composition on the final properties of AM-fabricated Mg components is systematically discussed, alongside current limitations and prospective strategies toward their clinical translation. Full article

The increasing demand for materials with enhanced properties and high-performance devices has driven substantial research into nanomanufacturing, particularly using carbon nanotubes (CNTs), because of their exceptional properties and high sensitivity to chemical doping. In this way, this work summarizes nanomanufacturing methods for CNT-based devices developed in Brazil, covering the complete cycle from nanocomposite production to functional device assembly across cellulosic, polymeric, and metallic matrix systems. For cellulosic matrices, vacuum filtration enables the production of buckypaper, which is subsequently assembled into chemiresistive, thermoresistive, and thermoelectric devices. For polymeric matrices, 3D printing combined with surface functionalization techniques (spray coating, inverted immersion, and direct immersion) produces piezoresistive robotic sensors, metal-free thermal sensors, and biomedical scaffolds for tissue engineering. For metallic matrices, electrodeposition can produce Cu-CNT-coated aluminum comparable to traditional copper power transmission cables, while arc welding produces stainless steel composites with properties comparable to commercial high-grade steels. These devices have commercial and industrial applications, with low-cost and scalable production methods in comparison with conventional materials. Characterization results demonstrate that CNT integration into diverse matrices successfully bridges nanoscale properties to macroscopic functional devices. Current challenges include uniform CNT dispersion and structural defect control, laboratory to industry scale transition, and long-term device stability under environmental conditions. Future perspectives encompass lab-on-chip systems, wearable devices, 3D-printed smart structures, Internet of Things integration, and machine learning-enhanced analytics. Full article

3D-printed hydrogel scaffolds have emerged as important platforms in tissue engineering and regenerative medicine owing to their extracellular matrix-like three-dimensional hydrated networks, tunable physicochemical properties, and ability to spatially organize cells, bioactive factors, and scaffold architectures. Early studies mainly focused on the printability, shape fidelity, and biocompatibility of hydrogel inks, whereas current research has gradually shifted toward the construction of bioactive scaffolds with tissue-specific functions. Because different tissues exhibit distinct requirements in terms of mechanical properties, cellular microenvironment, vascularization, innervation, degradation behavior, and functional maturation, the design of 3D-printed hydrogel scaffolds should comprehensively consider material composition, printing strategy, biofactor delivery, and tissue-specific functional demands. In this review, we focus on the transition from printability to biofunctionality and systematically summarize recent advances in 3D-printed hydrogel scaffolds for multi-tissue engineering. Particular emphasis is placed on regenerative applications of 3D-printed hydrogel scaffolds in bone, cartilage, vascular, neural, and skin tissue engineering. Finally, we discuss the major challenges associated with 3D-printed hydrogel scaffolds and further highlight future directions. This review aims to provide a systematic reference for the functional design and application of 3D-printed hydrogel scaffolds in multi-tissue engineering. Full article

Traumatic Brain Injuries (TBIs) frequently require cranioplasty procedures to restore skull integrity and protect underlying brain. Conventional cranial implants are often limited by inadequate osteointegration, risk of inflammation, infection, or the need for secondary surgical interventions. In this study, a multifunctional strategy for cranial reconstruction is proposed, combining additive manufacturing, bioactive surface functionalization, and local drug delivery. Porous polylactic acid (PLA) scaffolds were fabricated by Fused Deposition Modelling (FDM) to obtain lightweight structures with controlled porosity. The scaffolds were subsequently functionalized with hydroxyapatite coatings, deposited through sol–gel, to provide osteointegrative properties. To locally modulate post-implant inflammatory responses, a drug delivery system based on polycaprolactone (PCL) microparticles loaded with dexamethasone was developed and entrapped within hydroxyapatite-coated PLA structures. The produced systems were extensively characterized in terms of morphology, mechanical and thermal behavior, structural properties, biological response, and drug release behavior. Results demonstrated that the 3D-printed scaffolds exhibited homogeneous hydroxyapatite coatings, whose continuity and retention were enhanced by NaOH surface pre-treatment. Biological assays demonstrated that HAp coating significantly improved cell viability and osteogenic differentiation, confirming the osteoconductive potential of the scaffolds for craniofacial bone regeneration applications. Dexamethasone-loaded PCL microparticles were successfully integrated into the coated scaffolds, exhibiting controlled drug release, absence of cytotoxicity, and homogeneous distribution within the porous architecture, thereby demonstrating the feasibility of a multifunctional platform combining bone-regenerative and therapeutic delivery functionalities. Overall, the proposed multifunctional scaffolds represent a promising, low-cost and customizable approach for advanced cranioplasty applications, integrating structural support, osteointegration and local anti-inflammatory therapy within a single system. Full article

The regeneration of the dentin-pulp complex remains a significant challenge in regenerative endodontics. While conventional therapeutic approaches are effective in eliminating infection and preserving dental structure, they fail to restore the biological functionality of the pulp tissue. In recent years, three-dimensional (3D) printing and biopolymer-based bioprinting have opened unprecedented opportunities in dental tissue engineering, enabling the fabrication of biomimetic scaffolds with precisely controlled structural and bioactive properties. This review synthesizes current advances in bioprinting technologies, the diversity of biomaterials and bioinks employed, and the various stem cell sources utilized in pulp regeneration. It further examines how the three-dimensional microenvironment modulates cell viability, odontogenic differentiation, and the promotion of angiogenesis and neurogenesis, emphasizing the role of scaffold composition, mechanical properties, and internal architecture in influencing regenerative outcomes. Additionally, persistent challenges are discussed, including the optimization of bioink formulations, the achievement of functional vascular integration, and long-term validation of regenerated tissues, underscoring the need for multidisciplinary strategies to facilitate clinical translation. By integrating recent evidence, this review establishes a conceptual framework for the development of personalized and predictable approaches to dentin-pulp complex reconstruction. Full article

Lightweight resin lattice structures are prone to instability and failure under compressive loading, which leads to limited load bearing capacity and energy absorption performance. In this study, tough resin triply periodic minimal surface (TPMS) lattice scaffolds were fabricated using stereolithography-based 3D printing, and polyurethane foam (PUF) was subsequently infiltrated into three representative topologies, namely Schwarz Primitive (P), I-Wrapped Package (IWP), and Gyroid (G), to form interpenetrating phase composites (IPC). Quasi-static compression results show that PUF infiltration significantly improves the compressive response of all IPC architectures. The stress level in the plateau region is increased, while the magnitude of local stress drops is reduced, leading to a more stable progressive compression behavior. By comparing the stress–strain responses of IPC with the linear superposition of the pure resin scaffold and PUF phases, it is found that the actual energy absorption of IPC exceeds the predicted additive response, indicating a pronounced synergistic effect between the two phases. Among them, the IWP-based IPC achieves a specific energy absorption of 11.72 J/g. These results demonstrate that interpenetrating phase architectures can maintain lightweight characteristics while enhancing load bearing stability and energy absorption efficiency, providing useful guidance for topology selection and lightweight design of TPMS-based energy absorbing composite structures. Full article

Bone defects from trauma, tumour resection, infection, and degenerative disease remain a major clinical burden, and autografts face limitations of supply and donor-site morbidity. Three-dimensional (3D) printing offers a route to patient-specific, architecturally defined bone scaffolds, while biopolymers from natural sources provide biodegradability, biocompatibility, and extracellular matrix-mimicking cues consistent with sustainable, green biomaterials science. This review synthesises recent progress in 3D printing of biopolymer-based scaffolds for bone tissue engineering. We first examine the principal feedstocks—alginate, gelatin and gelatin methacryloyl, collagen, chitosan, silk fibroin, cellulose, and microbial polyesters—and their preparation, crosslinking chemistry, and printability. We then compare extrusion, light-based, and indirect printing technologies and the process–property relationships governing resolution, mechanical competence, and cell viability. Composite and functionalisation strategies, including biopolymer–bioceramic hybrids and controlled delivery of growth factors and antimicrobial agents, are analysed as routes to osteoinduction, vascularisation, and infection control. Finally, we evaluate translational performance in preclinical models and outline central challenges of vascularisation, mechanical–degradation matching, scalability, and regulatory standardisation. Biopolymer 3D printing is positioned as a ve rsatile, sustainable platform whose clinical maturation depends on integrated material, structural, and biological design. 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