Search Results (875)

A biomimetic cartilage scaffold featuring a continuous hydroxyapatite (HA) concentration gradient and a spatially curved architecture was developed using a dual-channel mixing extrusion-based 3D printing approach. By dynamically regulating the feeding rates of two bioinks during printing, a continuous HA gradient decreasing from the bottom to the top of the scaffold was precisely achieved, mimicking the compositional transition from the calcified to the non-calcified cartilage region in native articular cartilage. The integration of gradient material deposition with synchronized multi-axis motion enabled accurate fabrication of curved geometries with high structural fidelity. The printed scaffolds exhibited stable swelling and degradation behavior and showed improved compressive performance compared with step-gradient counterparts. Rheological analysis confirmed that the bioinks possessed suitable shear-thinning and recovery properties, ensuring printability and shape stability during extrusion. In vitro evaluations demonstrated good cytocompatibility, supporting bone marrow mesenchymal stem cell (BMSC) adhesion and proliferation. Chondrogenic assessment based on scaffold extracts indicated that the incorporation of HA and its gradient distribution did not inhibit cartilage-related extracellular matrix synthesis, confirming the biosafety of the composite hydrogel system. Overall, this study presents a controllable and versatile fabrication strategy for constructing curved, compositionally graded cartilage scaffolds, providing a promising platform for the development of biomimetic cartilage tissue engineering constructs. Full article

Spinal cord injury (SCI) remains one of the most formidable challenges in regenerative medicine, often resulting in permanent loss of motor, sensory, and autonomic function. Cell-based therapies offer a promising path toward repair by providing donor neurons and glia capable of integrating into host circuits, modulating the injury environment, and restoring function. Early studies employing fetal neural tissue and neural progenitor cells (NPCs) have demonstrated proof-of-principle for survival, differentiation, and synaptic integration. More recently, pluripotent stem cell (PSC)-derived donor populations and engineered constructs have expanded the therapeutic repertoire, enabling precise specification of interneuron subtypes, astrocytes, and oligodendrocytes tailored to the injured spinal cord. Advances in genetic engineering, including CRISPR-based editing, trophic factor overexpression, and immune-evasive modifications, are giving rise to next-generation donor cells with enhanced survival and controllable integration. At the same time, biomaterials, pharmacological agents, activity-based therapies, and neuromodulation strategies are being combined with transplantation to overcome barriers and promote long-term recovery. In this review, we summarize progress in designing and engineering donor cells and tissues for SCI repair, highlight how combination strategies are reshaping the therapeutic landscape, and outline opportunities for next-generation approaches. Together, these advances point toward a future in which tailored, multimodal cell-based therapies achieve consistent and durable restoration of spinal cord function. Full article

Nanoparticle-mediated photothermal conversion exploits the unique light-to-heat transduction properties of engineered nanomaterials to address challenges in energy, water, and healthcare. This review first examines fundamental mechanisms—localized surface plasmon resonance (LSPR) in plasmonic metals and broadband interband transitions in semiconductors—demonstrating how tailored nanoparticle compositions can achieve >96% absorption across 250–2500 nm and photothermal efficiencies exceeding 98% under one-sun illumination (1000 W·m⁻², AM 1.5G). Next, we highlight advances in solar steam generation and desalination: floating photothermal receivers on carbonized wood or hydrogels reach >95% efficiency in solar-to-vapor conversion and >2 kg·m⁻²·h⁻¹ evaporation rates; three-dimensional architectures recapture diffuse flux and ambient heat; and full-spectrum nanofluids (LaB₆, Au colloids) extend photothermal harvesting into portable, scalable designs. We then survey photothermal-enhanced thermal energy storage: metal-oxide–paraffin composites, core–shell phase-change material (PCM) nanocapsules, and MXene– polyethylene glycol—PEG—aerogels deliver >85% solar charging efficiencies, reduce supercooling, and improve thermal conductivity. In biomedicine, gold nanoshells, nanorods, and transition-metal dichalcogenide (TMDC) nanosheets enable deep-tissue photothermal therapy (PTT) with imaging guidance, achieving >94% tumor ablation in preclinical and pilot clinical studies. Multifunctional constructs combine PTT with chemotherapy, immunotherapy, or gene regulation, yielding synergistic tumor eradication and durable immune responses. Finally, we explore emerging opto-thermal nanobiosystems—light-triggered gene silencing in microalgae and poly(N-isopropylacrylamide) (PNIPAM)–gold nanoparticle (AuNP) membranes for microfluidic photothermal filtration and control—demonstrating how nanoscale heating enables remote, reversible biological and fluidic functions. We conclude by discussing challenges in scalable nanoparticle synthesis, stability, and integration, and outline future directions: multicomponent high-entropy alloys, modular photothermal–PCM devices, and opto-thermal control in synthetic biology. These interdisciplinary innovations promise sustainable solutions for global energy, water, and healthcare demands. Full article

Ultra-short peptides (USPs; ≤7–8 amino acids) emerge as minimal self-assembling building blocks for hydrogel-based biomaterials. Their intrinsic biocompatibility, straightforward synthesis, and ease of tunability make them particularly attractive candidates for potential use in bioprinting. This review provides an overview of the properties of USPs along with their applications in three-dimensional (3D) bioprinting. We first discuss how peptide sequence, terminal and side-chain modifications, and environmental triggers govern USPs’ self-assembly into nanofibers and 3D networks and how these supramolecular features translate into key rheological properties such as shear-thinning, rapid gelation, and mechanical tunability. We then survey reported applications in tissue engineering, wound healing, and organotypic models, as well as emerging ultra-short peptide-based systems for drug delivery, biosensing, and imaging, highlighting examples where printed constructs support cell viability, differentiation, and matrix deposition. Attention is given to hybrid and multi-material formulations in which USPs provide bioactivity while complementary components contribute structural robustness or additional functionality. Finally, this review outlines the main challenges that currently limit widespread adoption, including achieving high print fidelity with cytocompatible crosslinking, controlling batch-to-batch variability, and addressing the scalability, cost, and sustainability of peptide manufacturing. We conclude by discussing future opportunities such as AI-assisted peptide design, adaptive and multi-material bioprinting workflows, and greener synthetic routes, which together may accelerate the translation of ultra-short peptide-based bioinks from proof-of-concept studies to clinically and industrially relevant platforms. Full article

Tissue engineering is entering a new era, one defined not by passive scaffolds but by smart, adaptive biomaterials that can sense, think, and respond to their surroundings. These next-generation materials go beyond simply providing structure; they interact with cells and tissues in real time. Recent advances in mechanically responsive hydrogels and dynamic crosslinking have demonstrated how materials can adjust their stiffness, repair themselves, and transmit mechanical cues that directly influence cell behavior and tissue growth. Meanwhile, in vivo studies are demonstrating how engineered materials can harness the body’s own mechanical forces to activate natural repair programs without relying on growth factors or additional ligands, paving the way for minimally invasive, force-based therapies. The emergence of electroactive and conductive biomaterials has further expanded these capabilities, enabling two-way electrical communication with excitable tissues such as the heart and nerves, supporting more coordinated and mature tissue growth. Meanwhile, programmable bioinks and advanced bioprinting technologies now allow for precise spatial patterning of multiple materials and living cells. These printed constructs can adapt and regenerate after implantation, combining architectural stability with flexibility to respond to biological changes. This review brings together these cross-cutting advances, dynamic chemical design, mechanobiology-guided engineering, bioelectronic integration, and precision bio-fabrication to provide a comprehensive view of the path forward in this field. We discuss key challenges, including scalability, safety compliance, and real-time sensing validation, alongside emerging opportunities such as in situ stimulation, personalized electromechanical sites, and closed loop “living” implants. Taken together, these adaptive biomaterials represent a transformative step toward information-rich, self-aware scaffolds capable of guiding regeneration in patient-specific pathways, blurring the boundary between living tissue and engineered material. Full article

Background/Objectives: Boron-dipyrromethene (BODIPY) derivatives are a superior class of fluorophores prized for their exceptional photostability and tunable photophysical properties. While ideal for imaging, their translation to photodynamic therapy (PDT) has been hampered by excitation in the visible range, leading to poor tissue penetration. To overcome this, intense research has focused on developing near-infrared (NIR)-absorbing BODIPY photosensitizers (PS). This review aims to systematically summarize the hierarchical design strategies, from molecular engineering to advanced nanoplatform construction, that underpin the recent progress of NIR-BODIPY PS in therapeutic applications. Methods: We conducted a comprehensive literature review using PubMed, Scopus, and Web of Science databases. The search focused on keywords such as “BODIPY”, “aza-BODIPY”, “near-infrared”, “photodynamic therapy”, “photothermal therapy”, “nanocarriers”, “hypoxia”, “immuno-phototherapy”, and “antibacterial.” This review analyzes key studies describing molecular design, chemical modification strategies (e.g., heavy-atom effect, π-extension), nanoplatform formulation, and therapeutic applications in vitro and in vivo. Results: Our analysis reveals a clear progression in design complexity. At the molecular level, we summarize strategies to enhance selectivity, including active targeting, designing “smart” PS responsive to the tumor microenvironment (TME) (e.g., hypoxia or low pH), and precise subcellular localization (e.g., mitochondria, lysosomes). We then detail the core chemical strategies for achieving NIR absorption and high singlet oxygen yield, including π-extension, the internal heavy-atom effect, and heavy-atom-free mechanisms (e.g., dimerization). The main body of the review categorizes the evolution of advanced theranostic nanoplatforms, including targeted systems, stimuli-responsive ‘smart’ systems, photo-immunotherapy (PIT) platforms inducing immunogenic cell death (ICD), hypoxia-overcoming systems, and synergistic chemo-phototherapy carriers. Finally, we highlight emerging applications beyond oncology, focusing on the use of NIR-BODIPY PS for antibacterial therapy and biofilm eradication. Conclusions: NIR-BODIPY photosensitizers are a highly versatile and powerful class of theranostic agents. The field is rapidly moving from simple molecules to sophisticated, multifunctional nanoplatforms designed to overcome key clinical hurdles like hypoxia, poor selectivity, and drug resistance. While challenges in scalability and clinical translation remain, the rational design strategies and expanding applications, including in infectious diseases, confirm that NIR-BODIPY derivatives will be foundational to the next generation of precision photomedicine. Full article

Bombyx mori silk fibroin (BMSF) has developed from a textile fibre into a mature biomaterial with broad utility in regenerative medicine, owing to its unique hierarchical molecular structure. Its excellent biocompatibility, tuneable mechanical properties, optical property, and controllable biodegradability arise from its protein conformation, which can be precisely regulated through processing and fabrication strategies. Recent advances in bioengineering have further expanded the capabilities of BMSF, enabling the development of biomaterials with engineered architectures, tailored microtopographies, and enhanced bioactivity. These technological developments have facilitated the design of scaffolds that more effectively guide tissue regeneration and enhance functional outcomes. Such constructs have demonstrated promising outcomes in the regeneration of bone, cartilage, vascular, neural, corneal, and skin tissues. This review summarises current progress while emphasising emerging trends that couple BMSF’s unique molecular features with immune-responsive design, instructive microarchitectures that guide cell behaviour, composite scaffold design, and functionalisation with bioactive molecules. BMSF has been positioned as a structurally adaptable and biologically instructive platform whose continued progression will depend on integrating advanced fabrication, mechanistic understanding, and translational standardisation. Full article

Objective: This study aims to engineer a novel nanoparticle formulation for combined tumor therapy, designated as PDA@Mn-siSur-c-NPs, which comprises a polydopamine/manganese dioxide (PDA@MnO₂) core alongside survivin-targeting siRNA and cyclo(RGD-DPhe-K)-targeting moiety. Methods: The PDA@Mn-siSur-c-NPs were constructed and subjected to detailed characterization. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was employed to quantify manganese content. To assess siRNA stability within the system, samples were incubated with 50% fetal bovine serum (FBS) before agarose gel electrophoresis analysis. Additionally, cellular internalization by 4T1 cells and in vitro photothermal conversion efficiency of the formulation were evaluated. ICP-OES was further utilized to investigate the in vivo pharmacokinetics and tissue distribution of manganese. Animal model studies were conducted to assess the anti-breast cancer efficacy of PDA@Mn-siSur-c-NPs in combination with infrared irradiation. Results: The newly developed PDA@Mn-siSur-c-NPs demonstrated superior siRNA protection, reduced toxicity, and high photothermal conversion capacity. When combined with photothermal therapy (PTT), these nanoparticles exerted enhanced synergistic anti-tumor effects. Delivery of survivin siRNA resulted in a significant downregulation of survivin protein expression in tumor tissues. Moreover, magnetic resonance imaging (MRI) confirmed that the nanoparticles possess favorable imaging properties. Conclusions: This research demonstrates that the integration of PDA@Mn-siSur-c-NPs with PTT holds considerable therapeutic promise for improved breast cancer treatment. Full article

Biomimetic scaffolds are required in tissue engineering to provide structural support as well as promote cell adhesion, proliferation, and differentiation. Fibrous scaffolds composed of micro- and nanofibers replicate the architecture of the native extracellular matrix. Electrospinning is widely used for fabricating nanofibers; however, constructing fibrous scaffolds that integrate multiple fiber scales into a single structure is difficult. We addressed this issue by developing a fiber-spinning device using two pairs of counter-facing syringes that simultaneously produce micro- and nanofibers under different processing conditions. Poly(ε-caprolactone) solutions are ejected through needle-type nozzles via centrifugal force, and fiber diameter is controlled by adjusting the polymer concentration and nozzle diameter. We fabricated scaffolds with the proposed device, which exhibited a random three-dimensional fibrous network in which microfibers and nanofibers were homogeneously integrated. C2C12 myoblasts cultured on the composite scaffolds strongly adhered to the fibrous network, remained viable, and extended along the fibers to form multinucleated cells within the structure. The developed system produced composite micro/nanofiber scaffolds with tunable morphology and biocompatibility, providing a platform for fibrous tissue engineering applications. Full article

In this study, an innovative bioreactor, named BioAxFlow, particularly suitable for tissue engineering applications, is tested. Unlike traditional bioreactors, it does not rely on mechanical components to agitate the culture medium, but on the unique fluid-dynamics behaviour induced by the geometry of the culture chamber, which ensures continuous movement of the medium, promoting the constant exposure of the cells to nutrients and growth factors. Using the human osteosarcoma cell line SAOS-2, the bioreactor’s ability to enhance cell adhesion and proliferation on polylactic acid (PLA) scaffolds, mimicking bone matrix architecture, is investigated. Cells cultured in the bioreactor showed significant improvement in cell growth and adhesion, compared to static cultures, and a more homogeneous cell distribution upon the scaffold surfaces, which is crucial for the development of functional tissue constructs. The bioreactor also preserves the osteogenic potential of SAOS-2 cells as assessed by the expression of key osteogenic markers. Additionally, it retains the tumorigenic characteristics of SAOS-2 cells, including the expression of pro-angiogenic factors and apoptosis-related genes. These results indicate that the BioAxFlow bioreactor could be an effective platform for tissue engineering and cancer research, offering a promising tool for both regenerative medicine applications and drug testing. Full article

The development of implantable neural interfaces is essential for enabling bidirectional communication between the nervous system and prosthetic devices, yet their evaluation still relies primarily on in vivo models which are costly, variable, and ethically constrained. Here, we report a bio-inspired artificial nerve simulator engineered as a reproducible ex vivo platform for pre-implantation testing of plug-type electrodes. The simulator is fabricated from a conductive hydrogel composite based on reduced graphene oxide (rGO), polyaniline (PANI), agarose, sucrose, and sodium chloride, with embedded conductive channels that replicate the fascicular organization and conductivity of peripheral nerves. The resulting construct exhibits impedance values of ~2.4–2.9 kΩ between electrode needles at 1 kHz, closely matching in vivo measurements (~2 kΩ) obtained in Sus scrofa domesticus nerve tissue. Its structural and electrical fidelity enables systematic evaluation of electrode–nerve contact properties, signal transmission, and insertion behavior under controlled conditions, while reducing reliance on animal experiments. This bio-inspired simulator offers a scalable and physiologically relevant testbed that bridges materials engineering and translational neuroprosthetics, accelerating the development of next-generation implantable neural interfaces. Full article

Achilles tendon injuries are among the most frequent and debilitating musculoskeletal conditions, often resulting in incomplete healing and functional deficits. Conventional repair techniques primarily restore structural continuity but rarely achieve full biomechanical or histological regeneration. Recent advances in tissue engineering have introduced innovative strategies combining biomimetic scaffolds, cellular therapy, growth factors, and mechanical loading to promote regenerative rather than fibrotic repair. This review summarises the current understanding of Achilles tendon biology and healing mechanisms, with a focus on the integration of stem cell technologies, scaffold design, and mechanobiological conditioning. Various scaffold systems, including natural, synthetic, hybrid, and hydrogel-based constructs, are evaluated for their biocompatibility, mechanical performance, and tenoinductive potential. Preclinical studies demonstrate that mesenchymal stem cell (MSC)-loaded scaffolds exhibit significantly enhanced biomechanical outcomes in tendon defect models, including improved tensile strength, organized collagen I deposition and aligned fibre architecture in repaired constructs. While preclinical results are promising, clinical translation remains limited by regulatory, economic, and methodological challenges. Future research should prioritise standardised protocols, long-term functional outcomes, and interdisciplinary collaboration. Full article

The rapid development of 3D bioprinting technology has not been critically evaluated for its potential clinical applications… The ability of 3D manufacturing to create organ-like structures obscures the fact that the formed grafts are not physiologically relevant. We hypothesize that researchers do not use techniques that allow for the evaluation of the micro-architectonics of formed implants and mainly focus on biocompatibility and commonly observed immunological responses. This study aims to investigate the morphological landscape of the basics of 3D bioprinting through a systematic review of the outcomes of the experimental implantation of bioprinted constructs. A systematic search was conducted in the PubMed database using the following query: (bioprinting OR printing OR bioprinted OR printed OR bioinks) AND (cell OR cells) AND (implantation OR implanted OR in vivo) AND (goat OR porcine OR pig OR swine OR dog OR rabbit OR sheep) NOT (human OR humans). This systematic review evaluated the preformed studies of the in vivo assessment the 3D-bioprinted constructs, and 41 articles meeting the inclusion criteria were selected. We concluded that 3D bioprinting has limited applications for forming living tissue for orthotopic implantation. Additionally, quantitative methods for evaluating the properties and morphological quality of implanted bioprinted constructs have not been developed for tissue engineering applications. Full article

The expanding application of three-dimensional matrices with complex surface topographies in regenerative medicine requires new methods to visualize and analyze the evolving elastic properties of tissue-engineered constructs (TECs) during maturation. In this study, scanning impulse acoustic microscopy (SIAM) was employed for the non-invasive investigation of non-woven matrices based on PLLA and its composites with chitosan. This technique was used to determine the speed of sound, integral attenuation, and spectral characteristics within the samples. The data obtained through acoustic microscopy were compared with the results from tensile testing, gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, and CCK-8 assays. The findings demonstrate that SIAM exhibits high sensitivity to alterations in the TEC’s composition, including the presence of functionalizing additives, embedded cells, and the subsequent processes of cell proliferation and extracellular matrix synthesis, as well as to changes in its geometric structure. Consequently, this methodology can be recommended as a powerful and non-destructive tool for the comprehensive monitoring of TECs throughout their in vitro maturation period. Full article

Tissue engineering approaches for cartilage tissue regeneration are expanding to include the complex features of the tissue, such as the biological and mechanical gradients. Many of these approaches are, however, based on the use of multiple biomaterials or concentrations, and crosslinking methods that make it difficult to integrate and control the properties of the resulting scaffolds. In this study, a 3D bioprinted scaffold with a stiffness gradient was fabricated by using a single biomaterial type and concentration combined with a directional ionic crosslinking method. The scaffolds revealed a gradient in stiffness from 39.8 ± 6.6 kPa at the top to 60.6 ± 10.9 kPa at the bottom of the scaffolds. Live/dead analysis of human chondrocytes embedded in the scaffolds showed no negative effects of the stiffness gradient on cell viability over 28 days. The induced stiffness gradient led to a gradient in cell density and sulfated glycosaminoglycan deposition in the bioprinted tissue constructs with enhanced values in the softer top region of the scaffolds as compared to the stiffer bottom part. This study showed a novel method to generate scaffolds with stiffness gradients from a single biomaterial and indicates that such scaffolds could be used to spatially regulate the behavior of chondrocytes and the associated deposition of the cartilage matrix. Full article