Search Results (515)

Biotissues represent a new technology in tissue regeneration in otolaryngology. Various biomaterials functioning in different combinations are used as bioinks for 3D bioprinting of tissues/tissue fragments. The scaffolds can be populated with several cell categories, each offering distinct advantages and disadvantages, depending on the targeted pathology. Results from in vitro and in vivo studies on animal models are promising, with superior therapeutic potential. The combination of these elements provides promising results, enabling their potential application in personalized medicine. Based on these findings, their application in ENT (ear, nose, and throat) pathology is starting to gain traction. Despite being an emerging field, 3D/4D bioprinting in otolaryngology is rapidly evolving, increasingly replacing conventional inert materials with more sophisticated, bio-integrated alternatives. These alternatives are based on novel bioink formulation involving cells capable of proliferating and integrating the new neo-fragment organ into the host’s endogenous tissues. In this context, this review outlines novel applications that could enhance traditional procedures in ENT reconstructive medicine. Furthermore, biomimetic scaffolds for otolaryngology can be tailored to address factors influencing implant fate during the procedure and in the early and late postoperative periods. Full article

Dental tissue regeneration, particularly alveolar bone and gingival repair, remains a major challenge in regenerative medicine. 3D bioprinting offers patient-specific and anatomically precise constructs, representing an advanced alternative to conventional grafting. In this study, nanohydroxyapatite (nHA), chitosan (CS), and collagen (CoL) were combined to fabricate and characterize 3D bioprinted dental grafts. SEM revealed a highly porous, interconnected architecture favorable for cell infiltration and nutrient exchange. EDS confirmed Ca/P ratios of 2.06 for nHA/CoL and 1.83 for nHA/CS/CoL, both of which are above the stoichiometric 1.67, indicating the presence of additional mineral phases and ion substitutions. FTIR and XRD verified characteristic functional groups and crystalline phases, including B-type HA with carbonate substitution. Mechanical testing showed that pure nHA exhibited the lowest compressive strength, whereas CoL incorporation improved stiffness. The nHA/CS/CoL composite achieved the highest compressive strength, elastic modulus, and toughness, demonstrating superior mechanical resilience. DSC analysis indicated endothermic peaks at 106.49 °C and 351.91 °C, with enthalpy values (264.91 J/g and 15.09 J/g) surpassing those of nHA alone. TGA revealed ~28.8% weight loss across three degradation stages, confirming enhanced thermal stability. In vitro cytocompatibility testing using L929 fibroblasts validated the biocompatibility of the composites. Collectively, the synergy between bioceramics and biopolymers markedly improved both mechanical and thermal performance. These findings position the nHA/CS/CoL scaffold as a promising candidate for clinical applications in dental tissue regeneration. Unlike conventional grafting materials, this study introduces a synergistically optimized nHA/CS/CoL bio-ink formulation specifically designed for extrusion-based 3D bioprinting of patient-specific dental constructs. The core innovation lies in the precise integration of nHA within a dual-polymer matrix (CS/CoL), which bridges the gap between mechanical resilience and biological signaling, achieving a compressive strength that mimics native alveolar bone while maintaining high cytocompatibility. Full article

In regenerative medicine, three-dimensional (3D) printing provides precise spatial control over the fabrication of complex, biomimetic tissue constructs, enabling the production of architecturally defined and functionally tailored scaffolds. By enabling precise layer-by-layer deposition of cells, biomaterials, and bioactive compounds, 3D printing overcomes many limitations associated with conventional scaffold fabrication methods. This approach facilitates the development of tailored structures that mimic the mechanical, biological, and structural characteristics of native tissues, thereby enhancing cellular organization, proliferation, and differentiation. Extensive research in tissue engineering has led to the development of 3D-printed scaffolds for the regeneration of vascular, skin, bone, cartilage, and soft tissues. Advances in bioink formulations—including growth factor-loaded systems, decellularized extracellular matrix components, and natural and synthetic polymers—have further improved tissue-specific functionality. Moreover, multimaterial and multiscale printing strategies enable the fabrication of heterogeneous constructs with controlled porosity, mechanical gradients, and spatially regulated biological cues. Although vascularized tissue constructs remain a major challenge for clinical translation, recent bioprinting advancements have significantly accelerated progress in this area. Integration of computer-aided design with patient-specific imaging data has further strengthened the potential of 3D printing for personalized regenerative therapies. Despite these advances, challenges related to scalability, regulatory approval, and long-term functionality persist. Nevertheless, continued progress in printing technologies, biomaterials, and regulatory and standards frameworks is expected to drive the clinical adoption of 3D printing. Ultimately, 3D printing represents a transformative approach in tissue engineering, redefining strategies for functional tissue regeneration and translational regenerative medicine. Full article

Marine algae, microalgae, and Cyanophyceae emerge as sustainable and versatile sources of biomacromolecules for the fabrication of hydrogels with broad biomedical potential. Their phycocolloids, such as alginate, agar, carrageenan, ulvan, and extracellular polysaccharides (EPS), exhibit intrinsic biocompatibility, tunable gelation behavior, and bioactive sulfated structures that support cell viability, tissue regeneration, and therapeutic delivery. This review provides a comprehensive overview of hydrogel fabrication strategies, including physical, chemical, and hybrid crosslinking approaches, and highlights recent advances in composite systems incorporating proteins, glycosaminoglycans, and functional nanomaterials. Applications in skin repair, cartilage and bone regeneration, neural and cardiovascular engineering, and controlled drug delivery are examined, alongside the expanding role of marine-derived hydrogels as bioinks for 3D and 4D bioprinting. Despite their promise, challenges remain related to extract variability, purification complexity, mechanical limitations, and the need for standardized characterization. Future perspectives emphasize genetic engineering of algae and cyanobacteria, development of multifunctional hybrid hydrogels, sustainable large-scale production, and pathways toward clinical translation. Together, these insights position marine-derived hydrogels as next-generation biomaterials with significant potential for regenerative medicine and therapeutic innovation. Full article

Bone tissue is among the most commonly transplanted tissues worldwide. The treatment of critical-sized bone defects remains a significant challenge, as there is currently no universally accepted experimental model or therapeutic standard. Recent advances in fundamental cell biology are driving a paradigm shift in approaches to bone regeneration, highlighting the transformative potential of biofabrication technologies that integrate tissue engineering with personalized regenerative strategies. Three-dimensional (3D) bioprinting technology enables precise control over the architecture and spatial distribution of cellular and biologically active components, facilitating the creation of complex, personalized bone constructs. Central to this process are bioinks and biomaterials that mimic the extracellular matrix (ECM) and provide an optimal microenvironment for cellular function. Despite the substantial body of accumulated data, a comprehensive theoretical framework for functional bone biofabrication has not yet been fully established, emphasizing both the challenges and the innovative potential of the field. This integrative review synthesizes current knowledge on bone biology—from embryogenesis and cell–matrix interactions to molecular and neural regulation—and links it to the opportunities offered by biofabrication. Particular attention is given to bioinks as mediators between cell biology and engineering sciences, as well as to strategies for creating biomimetic ECM, optimizing scaffold design, and guiding future research toward clinically translatable bone regeneration. Full article

Current in vitro tissue models struggle to recapitulate the structural, vascular, and mechanical complexity of human tissues, limiting their physiological relevance for disease modelling and preclinical testing. Self-organising three-dimensional cultures such as spheroids and organoids capture key aspects of cellular organisation and differentiation, but they commonly lack controlled geometry, perfusable vasculature, and reproducible mechanical microenvironments. Conversely, biofabrication strategies, such as three-dimensional (3D) bioprinting and organ-on-chip (OoC) microfluidic devices, offer spatial control, integrated perfusion, and dynamic mechanical stimulation, yet often fall short in recapitulating the full cellular diversity and self-organisation of native tissues. Notably, emerging hybrid approaches that embed self-organising biological units (e.g., organoids and spheroids) into engineered scaffolds or microfluidic platforms combine biological relevance, architectural fidelity, and functional control. Advances in bioink chemistry, sacrificial-printing vascularisation, and chip–organoid interfaces now enable perfusable, multicompartment tissues suitable for disease modelling and preclinical testing. This review highlights the most recent (2020–2025) progress in organoid vascularisation, bioprinting strategies for prevascularised constructs, and OoC integration, outlining remaining challenges and emphasising priorities for next-generation hybrid cellular and tissue models. Full article

Three-dimensional (3D) bioprinting is an advanced additive manufacturing technology that utilizes bioinks composed of living cells and biomaterials to construct tissue-like structures for a wide range of medical applications. This paper reviews key applications, including tissue engineering, organ modeling and printing, drug testing and development, disease modeling, cosmetics and chemical testing, regenerative medicine, and personalized medicine. In parallel, biomimicry of natural plant architectures offers powerful opportunities for innovation in biomedical material design. Among these, the rose stands out for its intricate hierarchical geometry, which provides not only aesthetic appeal but also exceptional mechanical resilience. Incorporating rose-inspired structural elements into 3D-bioprinted medical constructs can significantly enhance mechanical strength, flexibility, and surface adaptability. This review also highlights plant- and rose-inspired approaches in medical applications and outlines the potential of rose-inspired 3D bioprinting to advance the design of functional and biomimetic tissue models. Nature provides a rich source of inspiration for biomimetic design, and translating biological principles into engineering solutions can contribute to sustainable technological development aligned with the Sustainable Development Goals (SDGs). In this regard, roses and other plant systems offer valuable structural and functional inspiration for advancing 3D bioprinting in medical applications. Full article

Background and Objectives: Hypocalcemia due to hypoparathyroidism (HypoPTH) is the most common complication following thyroid surgery, typically resulting from iatrogenic removal, tissue damage, or compromised vascularization of the parathyroid glands. Patients with persistent HypoPTH are at risk for long-term complications such as osteoporosis, cardiac dysfunction, and renal impairment. Lifelong regulation of calcium levels is therefore essential to prevent morbidity and mortality associated with these complications. In this study, we aimed to evaluate the functional engraftment efficacy of 3D bioprinted human parathyroid tissue constructs in a xenograft model in vivo. Materials and Methods: Primary cells obtained from freshly excised human parathyroid tissue specimens were isolated and 3D bioprinted using alginate-based bioink. The bioprinted tissue constructs were implanted into CD1 athymic mice. Histopathological evaluation of the grafted constructs was performed at different time points. In addition, surface calcium-sensing receptor (CaSR) expression was assessed by immunofluorescence as an indicator of functional parathyroid tissue engraftment. Results: The presence of CaSR on parathyroid cells within the 3D-printed scaffolds confirmed the persistence of functional parathyroid cells following implantation. In tissue samples obtained during the first, second, and third weeks after implantation, CaSR positivity was consistently observed in the parathyroid cells. However, at the three-month follow-up, the pores within the scaffolds were found to be filled with calcified material and replaced by fibrotic tissue. At this stage, the absence of parathyroid hormone (PTH) expression indicated a loss of functional activity in the grafted biomaterial. Conclusions: Human primary parathyroid cells were successfully isolated, and a functional, hormone-active parathyroid tissue substitute was developed ex vivo using 3D-bioprinted hydrogel scaffolds combined with autologous cells. Although short-term functional engraftment was achieved, long-term graft viability and hormonal activity were limited due to scaffold degradation and fibrosis. These findings indicate the necessity for further improvement in scaffold biocompatibility to enhance the therapeutic potential of 3D-bioprinted parathyroid tissue constructs for in vivo applications. Full article

In this work, we report the synthesis and evaluation of a bioink based on marine collagen, chitosan, and silica-doped hydroxyapatite (HA–SiO₂) for extrusion-based 3D bioprinting. FTIR spectroscopy confirmed amide (I–III) and phosphate/siloxane signals, TGA showed initial dehydration and degradation stages compatible with the process’s thermal handling, and SEM revealed an interconnected porous microstructure. Rheologically, the ink exhibited elastic dominance (G′ > G″) within the linear range and pseudoplastic, shear-thinning behavior—consistent with pneumatic extrusion. Process evaluation on a BIO X printer (14 G nozzle, low print speeds, moderate pressure, cartridge at 37 °C to 45 °C, and a cooled build platform) enabled deposition of strands with local shape retention. However, filament continuity was limited and line width varied, indicating only preliminary printability and a narrow operating window. Overall, physicochemical, microstructural, and rheological evidence supports the formulation’s viability as a starting point for scaffold fabrication. Full article

Three-dimensional (3D) bioprinting has rapidly emerged as a transformative technology at the interface of biomedical engineering and regenerative medicine. By enabling the spatially controlled deposition of living cells, biomaterials, and bioactive molecules, it offers an unprecedented potential to fabricate functional tissues and potentially whole organs in the future. This review explores recent advances in bioprinting materials, processes, and applications, emphasizing the integration of bioinks, printing methods, and mechanical design principles that underpin tissue functionality. Natural and synthetic biomaterials such as hydrogels (e.g., collagen, alginate), polyethylene glycol (PEG), and polyesters like PLGA are evaluated in terms of biocompatibility, printability, and degradation behavior. Key bioprinting modalities, including extrusion, inkjet, and laser-assisted bioprinting, are compared based on printing resolution, cell viability, and scalability. Structural considerations such as scaffold architecture, mechanical stability, and biomimetic design are discussed in relation to native tissue mechanics and requirements. The review also surveys emerging applications in tissue engineering (e.g., bone, cartilage, skin replacements), organ-on-a-chip systems for drug testing, and patient-specific implants, while addressing persistent challenges such as standardization of biofabrication, regulatory and ethical considerations, and manufacturing scale-up. Finally, future trends, including the integration of artificial intelligence (AI) and robotic automation, multi-material and four-dimensional (4D) bioprinting, and the maturation of personalized bioprinting strategies, are highlighted as pathways toward more autonomous and clinically relevant bioprinting systems. Collectively, these developments signify a paradigm shift in how biological constructs are designed and manufactured, bridging the gap between laboratory research and clinical translation. Full article

Extrusion-based 3D bioprinting enables the fabrication of complex tissue structures, yet achieving both high structural fidelity and cell viability remains challenging due to complex bioink rheology and parameter interplay. This review presents a quantitative framework linking hydrogel properties to printing outcomes. Key rheological features—shear-thinning, yield stress, reversible gel-sol transition, self-healing, and creep resistance—are examined for their roles in extrusion and shape retention. We also evaluate printing accuracy using metrics such as filament uniformity and multilayer stability. Advanced models, including Herschel-Bulkley and extrusion pressure models, correlate material parameters with flow dynamics and predict critical factors like wall shear stress. Finally, we propose an integrated assessment system combining material properties, process parameters, and structural fidelity to guide bioink design and printing optimization, advancing the field of hydrogel bioprinting. Full article

Decellularization removes immunogenic intracellular components of fish tissues while keeping the extracellular matrix (dECM) structure, mechanical integrity, and bioactivity. Fish-derived dECM retains native bioactive components, exhibiting high biocompatibility, low immunogenicity, and biodegradability, while supporting cell adhesion, proliferation, and tissue regeneration. Due to its abundance, minimal ethical concerns, and low zoonotic risks, fish wastes are emerging as sustainable sources of dECM, offering an eco-friendly alternative to mammalian biomaterials. This review highlights advances in decellularizing fish wastes such as skin, scales, bones, viscera, and swim bladders from species including tilapia, tuna, milkfish, carp, goldfish, and sturgeon. Physical, chemical, biological, and hybrid decellularization methods are assessed for cell removal, ECM preservation, and mechanical performance. Recent advances in polymer-dECM composites, crosslinking, and 3D bioprinting have significantly improved scaffold performance, making fish-derived dECM applicable for healing of wounds, regeneration of bone and cartilage, and repair of soft tissues. Despite its potential, challenges remain in optimizing perfusion rates, temperature variations, and tissue-specific protocols, as well as developing eco-friendly decellularization techniques using biodegradable reagents. Future perspectives include expanding decellularized fish tissue sources, innovating bio-inks for 3D bioprinting, and refining tissue-specific processing methods to maximize the potential of fish-derived dECM in regenerative medicine and tissue engineering. Full article

Autologous adipose tissue (AT) grafting is often compromised by insufficient early vascularization, leading to ischemia, fibrosis, and inconsistent long-term volume retention. Incorporating platelet-rich plasma (PRP) into AT bioinks offers a clinically accessible means to enhance vascular recruitment, but the in vivo impact of PRP dosage remains unclear. Here, we investigated how PRP concentration, uniformly integrated into a previously reported clinically relevant AT bioink, regulates vascular infiltration, tissue remodeling, and overall graft survival. High-dose PRP markedly improved graft performance, including an 8-fold increase in highly perfused regions, a 3.8-fold enhancement in adipocyte survival, a 1.67-fold reduction in fibrosis, and a 2.51-fold increase in collagen III deposition compared with PRP-free AT grafts. Histological analysis further demonstrated that PRP mitigates the adverse effects of poor perfusion, reducing regional disparities in survival and extracellular matrix (ECM) remodeling. High-dose PRP also maximized graft retention, preserving 103% of graft mass relative to 50.6% in native AT. Together, these results establish a clear in vivo dose–response relationship for PRP-enhanced AT grafts and highlight platelet concentration as a key design parameter for soft-tissue reconstruction. This work provides a translational framework for optimizing PRP-functionalized bioinks to improve clinical outcomes in reconstructive surgery. Full article

Three-dimensional bioprinting revolutionized tissue and organ replacement by enabling the precise deposition of living cells and biomaterials, making it ideal for biomedical applications. Natural polymers are commonly used as bioink for their biocompatibility and bioactivity. Among them, type I collagen, the most abundant protein of extracellular matrix, is commonly used as bioink. However, mammalian-derived collagens raise concerns related to zoonotic disease transmission, religious restrictions, and immunogenicity. Fish-derived collagen represents a safer and more sustainable alternative, although its rapid degradation and limited mechanical properties remain significant challenges. In this study, the printability of a novel fish collagen ink was assessed for micropatterned scaffolding by extrusion. In order to overcome material-related challenges, the effect of UV-induced crosslinking was investigated. Morphological, rheological, and physicochemical characterizations—including thermal behavior, degradation resistance, exposed chemical groups, and roughness—were performed before and after UV treatment. Results demonstrated that UV crosslinking significantly improved the structural integrity and stability of the printed scaffolds. These findings support the potential of UV-crosslinked fish collagen as biomaterial ink for regenerative medicine and tissue engineering applications. Full article

Extrusion-based bioprinting is widely used for fabricating cell-laden constructs; however, its success is highly dependent on the rheological and biological performance of the bioink. Natural polysaccharide gums have emerged as promising bioink components due to their biocompatibility and tunable properties. Among them, tragacanth gum (TG), a complex anionic heteropolysaccharide composed of tragacanthin and bassorin fractions, has gained increasing attention for extrusion bioprinting applications. TG exhibits pronounced shear-thinning behavior, high water uptake, and spontaneous gel-forming ability, which collectively enhance the printability, shape fidelity, and structural stability of bioinks. This review critically summarizes recent advances in TG-based hydrogels and bioinks, with emphasis on their molecular characteristics, rheological and physicochemical properties, and biological performance in extrusion bioprinting systems. The role of TG as a functional component in composite bioinks, particularly in improving mechanical integrity, extrusion consistency, and cytocompatibility, is discussed. Finally, current challenges and future research directions are highlighted to support the development and clinical translation of TG-based bioinks for tissue engineering applications. Full article