Search Results (39)

Flexible and biocompatible sensors are vital for a wide range of biomedical applications, including real-time health monitoring, intracranial pressure monitoring, knee replacement surgeries, wearables, and smart prosthetics. While various highly sensitive and stable pressure sensors have been demonstrated, they often lack the conformability and biocompatibility crucial for their wider application in various bio-integrated electronic systems. Herein, a piezoelectric pressure sensor is proposed using a hybrid polymer composite by leveraging the unique properties of Chitosan and Parylene C. Various material characterisations, such as XRD and FTIR, were performed to reveal structural and chemical characteristics of the novel composite material. Next, electromechanical characterisations of the pressure sensor were performed to reveal its dynamic sensing properties. The pressure sensor exhibits excellent sensitivity for both pressure and frequency, as well as cyclic stability (10³ cycles), wide pressure range (20–70 kPa), and biocompatibility. Full article

Metallic implants used in orthopedics, such as titanium alloys, possess excellent mechanical strength but suffer from corrosion and poor bio-integration, often necessitating revision surgeries. Bioactive coatings, particularly hydroxyapatite, can enhance implant osteoconductivity, but high-purity synthetic hydroxyapatite is costly. This study investigates the development and characterization of a low-cost, biocompatible coating using hydroxyapatite derived from an unconventional natural source dromedary bone applied onto a titanium substrate via plasma spraying. Hydroxyapatite powder was synthesized from dromedary femurs through a thermal treatment process at 1000 °C. The resulting powder was then deposited onto a sandblasted titanium dioxide substrate using an atmospheric plasma spray technique. The physicochemical, structural, and morphological properties of both the source powder and the final coating were comprehensively analyzed using Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-ray Diffraction, and Fourier-Transform Infrared Spectroscopy. Characterization of the powder confirmed the successful synthesis of pure, crystalline hydroxyapatite, with Fourier-Transform Infrared Spectroscopy analysis verifying the complete removal of organic matter. The plasma-sprayed coating exhibited good adhesion and a homogenous, lamellar microstructure typical of thermal spray processes, with an average thickness of approximately 95 μm. X-ray Diffraction analysis of the coating revealed that while hydroxyapatite remained the primary phase, partial decomposition occurred during spraying, leading to the formation of secondary phases, including tricalcium phosphate and calcium oxide. Scanning Electron Microscopy imaging showed a porous surface composed of fully and partially melted particles, a feature potentially beneficial for bone integration. The findings demonstrate that dromedary bone is a viable and low-cost precursor for producing bioactive hydroxyapatite coatings for orthopedic implants. The plasma spray method successfully creates a well-adhered, porous coating, though process-induced phase changes must be considered for biomedical applications. Full article

Polymeric semiconductors have rapidly evolved from early conductive polymers, such as polyacetylene, to high-performance donor–acceptor copolymers, offering a unique combination of mechanical flexibility, solution processability, and tunable optoelectronic properties. These advancements have positioned polymeric semiconductors as versatile materials for next-generation electronics, including wearable, stretchable, and bio-integrated devices, IoT systems, and soft robotics. In this review, we systematically present the fundamental principles of polymeric semiconductors, including electronic structure, charge transport mechanisms, molecular packing, and solid-state morphology, and elucidate how these factors collectively govern device performance. We further discuss recent advances in synthesis strategies, thin-film processing techniques, molecular doping, and interface engineering, emphasizing their critical roles in improving operational stability, charge-carrier mobility, and energy efficiency. Key applications—such as organic photovoltaics, field-effect transistors, neuromorphic devices, and memristors—are analyzed, with a focus on the intricate structure–property–performance relationships that dictate functionality. Finally, we highlight emerging directions and scientific innovations, including sustainable and degradable polymers, hybrid and two-dimensional polymer systems, and novel strategies to enhance device stability and performance. By integrating fundamental polymer science with device engineering, this review provides a comprehensive, structured, and forward-looking perspective, identifying knowledge gaps and offering insights to guide future breakthroughs and the rational design of high-performance, multifunctional, and environmentally responsible polymeric electronic devices. Full article

Thin films have become indispensable in shaping the landscape of modern and future technologies, offering versatile platforms where properties can be engineered at the atomic to microscale to deliver performance unattainable with bulk materials. Historically evolving from protective coatings and optical layers, the field has advanced into a highly interdisciplinary domain that underpins innovations in microelectronics, energy harvesting, optoelectronics, sensing, and biomedical devices. In this review, a structured approach has been adopted to consolidate the fundamentals of thin film growth and the governing principles of nucleation, surface dynamics, and interface interactions, followed by an in-depth comparison of deposition strategies such as physical vapor deposition, chemical vapor deposition, atomic layer deposition (ALD), and novel solution-based techniques, highlighting their scalability, precision, and application relevance. By critically evaluating experimental studies and technological implementations, this review identifies key findings linking microstructural evolution to device performance, while also addressing the pressing challenges of stability, degradation pathways, and reliability under operational stresses. The synthesis of evidence points to the transformative role of advanced deposition controls, in situ monitoring, and emerging AI-driven optimization in overcoming current bottlenecks. Ultimately, this work concludes that thin film technologies are poised to drive the next generation of sustainable, intelligent, and multifunctional devices, with emerging frontiers such as hybrid heterostructures, quantum materials, and bio-integrated systems charting the future roadmap. Full article

This work describes the preparation and characterization of chitosan-based biopolymer coatings containing silver, zinc, and hydroxyapatite nanoparticles deposited on the Ti13Zr13Nb alloy by the EPD method. It was intended to evaluate the influence of surface pretreatments and deposition parameters on the structural, electrochemical, and biological properties of coatings. The morphology and composition were characterized by means of SEM/EDS, AFM, XRD, and FTIR analysis. The obtained results indicated uniform continuous layers with homogeneously distributed nanoparticles and the presence of characteristic functional groups originating from chitosan and hydroxyapatite. Corrosion investigations performed in SBF solution revealed a significant enhancement in corrosion resistance for chitosan/nanoAg/nanoZn/nanoHAp coatings, reflected in a drastic decrease in corrosion current density compared with uncoated Ti13Zr13Nb alloy. The contact angle measurements confirmed their hydrophilic nature, which favors better biointegration ability. Biological tests (MTT and LDH) performed on human osteoblasts (hFOB 1.19) confirmed high biocompatibility (>85% cell viability) in the case of all coatings with the addition of hydroxyapatite, whereas in the case of coatings without HAp, cytotoxicity was observed, probably due to the uncontrolled release of metallic nanoparticles. These findings suggest that the presence of hydroxyapatite in chitosan-based coatings efficiently enhances corrosion protection and cytocompatibility, showing very good prospects for biomedical applications such as the surface modification of titanium implants. Full article

Background/Objectives: A comparative study of silver (Ag), titanium nitride (TiN), zirconium nitride (ZrN), and copper (Cu) coatings on titanium (Ti) disks, considering the specifications of a microporous skin- and bone-integrated titanium pylon (SBIP), was performed to assess their biocompatibility, osseointegration, and mechanical properties. Methods: To assess cytotoxicity and biocompatibility, Ti disks with various metal coatings were co-cultured with FetMSCs and MG-63 cells for 1, 3, 7, and 14 days and subsequently evaluated using a cell viability assay, as supported by SEM and confocal microscopy studies. The antimicrobial activity of the selected four materials coating the implants was tested against S. aureus by mounting Ti disks onto the surface of LB agar dishes spread with a bacterial suspension and measuring the diameter of the growth inhibition zones. Quantitative Real-Time Polymerase Chain Reaction (RT-PCR) analysis of the relative gene expression of biomarkers that are associated with extracellular matrix components (fibronectin, vitronectin, type I collagen) and cell adhesion (α2, α5, αV integrins), as well as of osteogenic markers (osteopontin, osteonectin, TGF-β1, SMAD), was performed during the 14-day follow-up period. Additionally, the activity of matrix metalloproteinases (MMP-1, -2, -8, -9) was assessed. Results: All samples with metal coatings, except the copper coating, demonstrated a good cytotoxicity profile, as evidenced by the presence of a cellular monolayer on the sample surface on the 14th day of the follow-up period (as shown by SEM and inverted confocal microscopy). All metal coatings enhanced MMP activity, as well as cellular adhesion and osteogenic marker expression; however, TiN showed the highest values of these parameters. Significant inhibition of bacterial growth was observed only in the Ag-coated Ti disks, and it persisted for over 35 days. Conclusions: The silver-based coating, due to its high antibacterial activity, low cytotoxicity, and biointegrative capacity, can be recommended as the coating of choice for microporous titanium implants for further preclinical studies. Full article

Poly(methyl methacrylate) (PMMA)-based bone cements are widely used in orthopaedic surgery, yet their inherent brittleness, lack of bioactivity, and exothermic polymerization remain critical limitations. Recent strategies have focused on modifying PMMA with functional additives to improve not only mechanical performance but also thermal behaviour and biological interactions. This study investigates the mechanical properties of two commercial PMMA cements—Palamed^® (antibiotic-free) and Refobacin Plus G (gentamicin-loaded)—reinforced with glassy carbon (GC) particles of two different grain sizes (0.4–1.2 µm and 20–50 µm) and various concentrations. The results demonstrate that coarse GC particles (20–50 µm) significantly reduced compressive strength, particularly in the antibiotic-loaded cement. In contrast, the incorporation of fine GC particles (0.4–1.2 µm) did not markedly impair mechanical performance in Palamed^®, suggesting better compatibility with the PMMA matrix. In addition to mechanical enhancement, the structural and chemical stability of glassy carbon may contribute to improved biological response and reduced polymerization heat. These findings highlight the potential of glassy carbon as a functional additive for designing PMMA-based biomaterials that combine improved mechanical properties with favourable characteristics for long-term implant integration. Full article

Cartilage tissue engineering (CTE) is an advancing field focused on developing biomimetic scaffolds to overcome cartilage’s inherently limited self-repair capacity. Smart hydrogels (SHs) have gained prominence among the various scaffold materials due to their ability to modulate cellular behavior through tunable mechanical and biochemical properties. These hydrogels respond dynamically to external stimuli, offering precise control over biological processes and facilitating targeted tissue regeneration. Recent advances in fabrication technologies have enabled the design of SHs with sophisticated architecture, improved mechanical strength, and enhanced biointegration. Key features such as injectability, controlled biodegradability, and stimulus-dependent release of biomolecules make them particularly suitable for regenerative applications. The incorporation of nanoparticles further improves mechanical performance and delivery capability. In addition, shape memory and self-healing properties contribute to the scaffolds’ resilience and adaptability in dynamic physiological environments. An emerging innovation in this area is integrating artificial intelligence (AI) and omics-based approaches that enable high-resolution profiling of cellular responses to engineered hydrogels. These data-driven tools support the rational design and optimization of hydrogel systems and allow the development of more effective and personalized scaffolds. The convergence of smart hydrogel technologies with omics insights represents a transformative step in regenerative medicine and offers promising strategies for restoring cartilage function. Full article

Organic semiconductors hold immense promise in the field of optoelectronic synapses due to their tunable optoelectronic properties, mechanical flexibility, and biocompatibility. This review article provides a comprehensive overview of recent advancements in organic optoelectronic synaptic devices. We delve into the fundamental concepts and classifications of these devices, examine their roles and operational mechanisms, and explore their diverse application scenarios. Additionally, we highlight the current challenges and emerging opportunities in this field, outlining a forward-looking path for the future development and application of these materials and devices in next-generation artificial intelligence (AI). We emphasize the potential of further optimizing organic materials and devices, which could significantly enhance the integration of organic synapses into biointegrated electronics and human–computer interfaces. By addressing key challenges such as material stability, device performance, and scalability, we aim to accelerate the transition from laboratory research to practical applications, paving the way for innovative AI systems that mimic biological neural networks. Full article

This review examines the distinct advantages of organic semiconductors over conventional insulating polymers as optically active materials in photonic applications. We analyze the fundamental principles governing their unique optical and electronic properties, from basic conjugated polymer systems to advanced molecular architectures. The review systematically explores key material classes, including polyfluorenes, polyphenylene vinylenes, and polythiophenes, highlighting their dual electrical–optical functionality unavailable in passive polymer systems. Particular attention is given to polymer blends, composites, and hybrid organic–inorganic systems, demonstrating how semiconductor properties enable enhanced performance through materials engineering. We contrast passive components with active photonic devices, illustrating how the semiconductor nature of these polymers facilitates novel functionalities beyond simple light guiding. The review explores emerging applications in neuromorphic photonics, quantum systems, and bio-integrated devices, where the combined electronic–optical properties of organic semiconductors create unique capabilities impossible with insulating polymers. Finally, we discuss design strategies for optimizing these distinctive properties and present perspectives on future developments. This review establishes organic semiconductors as transformative materials for advancing photonic technologies through their combined electronic–optical functionality. Full article

3D-printed microporous titanium scaffolds enjoy good biointegration with the residuum’s soft and bone tissues, and they promote excellent biomechanical properties in attached prostheses. Implant-associated infection, however, remains a major clinical challenge. Silver-based implant coatings can potentially reduce bacterial growth and inhibit biofilm formation, thereby reducing the risk of periprosthetic infections. In the current study, a 1-µm thick silver coating was prepared on the surface of a 3D-printed microporous titanium alloy with physical vapor deposition (PVD), with a final silver content of 1.00 ± 02 mg/cm². Cell viability was evaluated with an MTT assay of MC3T3-E1 osteoblasts and human dermal fibroblasts cultured on the surface of the implants, and showed low cytotoxicity for cells during the 14-day follow-up period. Quantitative real-time polymerase chain reaction (RT-PCR) analysis of the relative gene expression of the extracellular matrix components (fibronectin, vitronectin, type I collagen) and cell adhesion markers (α2, α5, αV, β1 integrins) in dermal fibroblasts showed that cell adhesion was not reduced by the silver coating of the microporous implants. An RT-PCR analysis of gene expression related to osteogenic differentiation, including TGF-β1, SMAD4, osteocalcin, osteopontin, and osteonectin in MC3T3-E1 osteoblasts, demonstrated that silver coating did not reduce the osteogenic activity of cells and, to the contrary, enhanced the activity of the TGF-β signaling pathway. For representative sample S5 on day 14, the gene expression levels were 7.15 ± 0.29 (osteonectin), 6.08 ± 0.12 (osteocalcin), and 11.19 ± 0.77 (osteopontin). In conclusion, the data indicate that the silver coating of the microporous titanium implants did not reduce the biointegrative or osteoinductive properties of the titanium scaffold, a finding that argues in favor of applying this coating in designing personalized osseointegrated implants. Full article

Percutaneous implants osseointegrated into the residuum of a person with limb amputation need to provide mechanical stability and protection against infections. Although significant progress has been made in the biointegration of percutaneous implants, the problem of forming a reliable natural barrier at the level of the surface of the implant and the skin and bone tissues remains unresolved. The use of a microporous implant structure incorporated into the Skin and Bone Integrated Pylon (SBIP) should address the issue by allowing soft and bone tissues to grow directly into the implant structure itself, which, in turn, should form a reliable barrier to infections and support strong osseointegration. To evaluate biological interactions between dermal fibroblasts and MC3T3-E1 osteoblasts in vitro, small titanium discs (with varying pore sizes and volume fractions to achieve deep porosity) were fabricated via 3D printing and sintering. The cell viability MTT assay demonstrated low cytotoxicity for cells co-cultured in the pores of the 3D-printed and sintered Ti samples during the 14-day follow-up period. A subsequent Quantitative Real-Time Polymerase Chain Reaction (RT-PCR) analysis of the relative gene expression of biomarkers that are associated with cell adhesion (α2, α5, αV, and β1 integrins) and extracellular matrix components (fibronectin, vitronectin, type I collagen) demonstrated that micropore sizes ranging from 200 to 500 µm of the 3D printed and sintered Ti discs were favorable for dermal fibroblast adhesion. For example, for representative 3D-printed Ti sample S6 at 72 h the values were 4.71 ± 0.08 (α2 integrin), 4.96 ± 0.08 (α5 integrin), 4.71 ± 0.08 (αV integrin), and 1.87 ± 0.12 (β1 integrin). In contrast, Ti discs with pore sizes ranging from 400 to 800 µm demonstrated the best results (in terms of marker expression related to osteogenic differentiation, including osteopontin, osteonectin, osteocalcin, TGF-β1, and SMAD4) for MC3T3-E1 cells. For example, for the representative 3D sample S4 on day 14, the marker levels were 11.19 ± 0.77 (osteopontin), 7.15 ± 0.29 (osteonectin), and 6.08 ± 0.12 (osteocalcin), while for sintered samples the levels of markers constituted 5.85 ± 0.4 (osteopontin), 4.45 ± 0.36 (osteonectin), and 4.46 ± 0.3 (osteocalcin). In conclusion, the data obtained show the high biointegrative properties of porous titanium structures, while the ability to implement several pore options in one structure using 3D printing makes it possible to create personalized implants for the best one-time integration with both skin and bone tissues. Full article

This paper reviews different approaches to obtain biomaterials with tailored functionalities and explains their significant characteristics that influence their bioactivity. The main goal of this discussion underscores the significance of surface properties in materials, with a particular emphasis on their role in facilitating cell adhesion in order to obtain good biocompatibility and biointegration, while preventing adverse effects, such as bacterial contamination and inflammation processes. Consequently, it is essential to design strategies and interventions that avoid bacterial infections, reducing inflammation and enhancing compatibility systems. Within this review, we elucidate the most prevalent techniques employed for surface modification, notably emphasizing surface chemical composition and coatings. In the case of surface chemical composition, we delve into four commonly applied approaches: hydrolysis, aminolysis, oxidation, and plasma treatment. On the other hand, coatings can be categorized based on their material composition, encompassing ceramic-based and polymer-based coatings. Both types of coatings have demonstrated efficacy in preventing bacterial contamination, promoting cell adhesion and improving biological properties of the surface. Furthermore, the addition of biological agents such as drugs, proteins, peptides, metallic ions plays a pivotal role in manifesting the prevention of bacterial infection, inflammatory responses, and coagulation mechanism. Full article

The use of natural polymers such as sericin (SS) and chitosan (Ch) for developing biomaterials has increased in tissue engineering. To ensure adequate biointegration with the biological environment, the method used to obtain the biomaterial plays an important role, which is why the electrospinning technique has been employed due to its versatility with regard to emulating the native extracellular matrix. The present study evaluated the influence of electrospinning parameters on the morphological, chemical, and thermal properties of polycaprolactone (PCL), Ch, and SS composite membranes. To achieve this, experiments were designed with varying manufacturing parameters and SS concentrations. The membranes were then characterized by scanning electron microscopy (SEM), Fourier transforms spectrophotometry (FTIR), and thermogravimetric analysis (TGA). SEM images showed that the electrospinning conditions and SS concentrations allow the development of electrospun membranes with high fibrillar density randomly oriented and fiber diameters below 100 nm. Likewise, the spectra and thermograms of the composite membranes show the possible chemical interactions and thermal behavior, demonstrating the homogeneity and stability of the fibrillar structure. Full article

Development of an ideal biomaterial for clinical use is one of the main objectives of current research in tissue engineering. Marine-origin polysaccharides, in particular agaroses, have been widely explored as scaffolds for tissue engineering. We previously developed a biomaterial based on a combination of agarose with fibrin, that was successfully translated to clinical practice. However, in search of novel biomaterials with improved physical and biological properties, we have now generated new fibrin-agarose (FA) biomaterials using 5 different types of agaroses at 4 different concentrations. First, we evaluated the cytotoxic effects and the biomechanical properties of these biomaterials. Then, each bioartificial tissue was grafted in vivo and histological, histochemical and immunohistochemical analyses were performed after 30 days. Ex vivo evaluation showed high biocompatibility and differences in their biomechanical properties. In vivo, FA tissues were biocompatible at the systemic and local levels, and histological analyses showed that biointegration was associated to a pro-regenerative process with M2-type CD206-positive macrophages. These results confirm the biocompatibility of FA biomaterials and support their clinical use for the generation of human tissues by tissue engineering, with the possibility of selecting specific agarose types and concentrations for applications requiring precise biomechanical properties and in vivo reabsorption times. Full article