Search Results (178)

Polyetheretherketone (PEEK) is increasingly attractive for patient-specific maxillofacial reconstruction because its elastic modulus approximates cortical bone, it is fully radiolucent, and it is compatible with additive manufacturing; its principal limitation is bioinertness, as the hydrophobic surface does not support protein adsorption or direct bone apposition. This study aimed to functionalize the surface of fused-deposition-modeling (FDM)-printed, medical-grade PEEK to increase its potential for bioactivity while preserving these bulk advantages. To this end, 3D-printed specimens of implant-grade PEEK were activated by CO₂ plasma and coated with gelatin methacryloyl (GelMA) via EDC/NHS coupling followed by UV photocrosslinking. Surfaces were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, sessile-drop water contact angle measurement, gravimetric analysis, and scanning electron microscopy (SEM). Plasma treatment introduced oxygen-containing functional groups and reduced the water contact angle from 78.3° to 6.6°. GelMA deposition following EDC/NHS coupling, consistent with covalent immobilization, was supported by characteristic amide bands and was most pronounced for the 50 mg/mL formulation, corresponding to a deposited mass of 11.81 ± 0.47 μg/mm²; SEM revealed a relatively uniform protein film along the printed filaments. These results establish a surface-functionalization route and provide preliminary physicochemical indicators of potential bioactivity for patient-specific PEEK implants, to be confirmed through in vitro and in vivo biological validation. Full article

Long-term implantable neural electrodes underpin brain–machine interfaces, deep brain stimulation, epilepsy monitoring, and closed-loop neuromodulation. Following chronic implantation, however, the foreign body response (FBR) at the electrode–tissue interface remains a major constraint on long-term performance, as reflected by increased interfacial impedance, lower signal-to-noise ratios, fewer resolvable units, and higher stimulation thresholds. This deterioration arises from interrelated events that include implantation injury, protein adsorption, blood–brain barrier disruption, complement activation, glial reactivity, oxidative stress, glial scar formation, and neuronal loss. It cannot be attributed solely to material ageing or encapsulation failure. This review examines the molecular mechanisms of neural-electrode FBR and relates them to surface-biofunctionalization strategies, including antifouling coatings, bioactive ligands, immobilized neurotrophic factors, drug-eluting electrodes, and emerging immunomodulatory interfaces. Establishing mechanistic links among molecular events, material interfaces, and functionalization strategies may guide the rational design of durable neural electrodes. Full article

Magnesium alloys are used or considered for lightweight structures and biodegradable implants, but high electrochemical activity, limited wear resistance, and localized corrosion still limit their service reliability. Plasma electrolytic oxidation (PEO), also called micro-arc oxidation (MAO), forms an adherent ceramic scaffold. Discharge channels, interconnected pores, thermal cracks, and a mechanically weak outer layer mean that the as-formed coating is rarely a complete protective system. This review examines advanced PEO/MAO-based composite coatings through a process–structure–function lens and develops an application-oriented design framework. The discussion covers PEO/MAO process-window control, electrolyte and particle engineering, sol–gel and polymer sealing, layered double hydroxide/inhibitor systems, self-healing reservoirs, superhydrophobic and slippery interfaces, Ca-P/hydroxyapatite and polymer biofunctionalization, and duplex coatings for wear, electrical, and thermal functions. Emphasis is placed on how these modules regulate defect connectivity, mass transport, interfacial stability, damage response, tribocorrosion, and biodegradation, as well as on the evidence needed to support each claimed function. The analysis indicates that coating performance is governed not by multilayer complexity alone, but by the compatibility among the ceramic scaffold, functional module, dominant failure mode, and service-specific validation protocol. Chloride-exposed structures require durable pore sealing and active inhibition; wear-critical components require coupled corrosion–wear assessment; and biodegradable implants require a degradation window that balances corrosion moderation, cytocompatibility, biofunctionality, and residual mechanical integrity. Remaining challenges include interfacial durability, finite inhibitor reservoirs, wetting-state instability, process reproducibility, scale-up, and life-cycle impacts. The proposed process maps and validation criteria are intended to support modular, testable, and application-specific PEO/MAO surface systems for magnesium alloys. Full article

Polyetheretherketone (PEEK) has emerged as a promising biomaterial for orthopedic and craniofacial implants due to its favorable mechanical properties and fatigue resistance; however, its inherent chemical inertness limits effective osseointegration. In this study, femtosecond laser surface modification is explored as a strategy to enhance the bioactivity of PEEK. Based on a previously performed parametric study, controlled micro- and nanoscale surface textures were fabricated using femtosecond laser processing, enabling precise tuning of surface roughness and wettability without the need for additional chemical treatment. The modified surfaces were systematically characterized in terms of morphology, composition, and topography using scanning electron microscopy (SEM), 3D profilometry, and water contact angle measurements. Four optimized femtosecond laser-generated surface architectures were selected for the present investigation and comprehensively characterized, followed by in vitro evaluation of dental pulp stem cell adhesion, morphology, and proliferation. The results indicate that laser-induced micro/nanostructuring enhances the surface properties of PEEK, while supporting cellular attachment and favorable cell–surface interaction. Differences in the biological response were observed among the optimized laser-textured surfaces. These findings highlight the feasibility of femtosecond laser texturing as a clean, reproducible, and scalable approach for the development of next-generation, personalized orthopedic implants. Full article

Metal alloys in arthroplasty face limitations including aseptic loosening, material failure, and allergic reactions. High-performance oxide ceramics (HPOCs) represent an alternative but are bioinert, restricting osseointegration and osteoconduction. The aim of this study was to convert bioinert HPOC surfaces into bioactive osteogenic microenvironments through stable peptide-biofunctionalization with cyclic-arginylglycylaspartic acid (cRGD) or modified-hepatocyte growth factor (mod-HGF). In a rabbit femoral defect model, cylindrical ATZ implants were press-fitted into 4.5 × 8 mm defects and examined after 18 weeks. Three groups were compared: uncoated ATZ, cRGD-coated, and mod-HGF-coated implants (n = 8 each). Histomorphometry (Movat Pentachrome, H&E, Alcian Blue), scanning electron microscopy, and energy-dispersive X-ray spectroscopy were performed. Both cRGD- and mod-HGF-coated implants significantly increased bone formation and bone–implant contact relative to controls. Reduced fibrotic encapsulation and enhanced vascularization were observed in both groups, with the strongest effects in the mod-HGF group. Microscopy and spectroscopy confirmed greater mineralization and continuous bone–implant interfaces in coated implants. These results demonstrate that biologically functionalizing ATZ with cRGD or mod-HGF effectively enhances bone formation and implant integration in vivo while reducing fibrotic responses. We proved through the in vivo experiments that bioinert HPOCs obtain osseointegrative behavior due to the hydrolytically stable organo-chemical surface functionalization. Full article

Titanium-based dental implants have evolved significantly, with the development of binary alloys like Ti-15Zr (Roxolid™) representing a pivotal advancement in mechanical performance. Current research focuses on biomimetic surface engineering to further accelerate osseointegration and optimize bone regeneration, particularly in clinically compromised sites. This review constitutes a narrative synthesis of how these strategies replicate the bone extracellular matrix (ECM) through a holistic framework of architectural, mechanical, and biochemical integration. A structured literature search across PubMed, Scopus, and Web of Science (2010–2026) identified relevant studies focusing on the synergy between Ti-15Zr substrates and surface modifications. Evidence confirms that the high fatigue strength of Roxolid™ alloys provides an ideal foundation for advanced, hierarchical surface engineering without compromising structural integrity. This strategy utilizes macro-topography for primary stability, nano-topography for protein adsorption, and bio-functionalization (e.g., RGD peptides and osteogenic ions) to direct mesenchymal stem cell (MSC) differentiation. This synergy accelerates the transition from passive to active osseointegration, effectively bridging the “biological gap” during early healing. Biomimetic engineering transforms implants into instructive biological platforms, improving outcomes for patients with compromised bone quality and facilitating predictable immediate loading protocols. Full article

Gold nanoparticles (AuNPs) have emerged as versatile antiviral nanoplatforms because their size, morphology, plasmonic properties, and surface chemistry can be precisely engineered. In this review, we summarize the core design principles of antiviral AuNPs from a structure–function–mechanism perspective. We first outline representative synthetic and interface-programming routes for AuNP preparation, including citrate reduction, Brust–Schiffrin synthesis, seed-mediated growth, green synthesis, direct thiol-conjugation, and mixed-ligand shell strategies, emphasizing how these approaches define particle size, morphology, surface accessibility, interfacial composition, and downstream biofunctionalization potential. We then discuss major surface engineering strategies, including polyethylene glycol, nucleic acids, antibodies and nanobodies, peptides, glycans, antiviral drugs, and biomimetic coatings, with particular attention to how ligand density, orientation, flexibility, and interfacial stability determine biological performance. Next, we examine how functionalized AuNPs inhibit different stages of the viral life cycle, including viral attachment and entry, intracellular replication, assembly and egress, photothermal inactivation, and immune modulation or vaccine delivery. Finally, we highlight current challenges, including incomplete structure–activity relationships, dynamic nano–bio interactions under physiological conditions, limited standardization across studies, and translational barriers related to safety, reproducibility, and scale-up. This review provides a conceptual framework for the rational development of next-generation AuNP-based antiviral nanotherapeutics. Full article

This study presents a novel approach for the development of biofunctional and skin-comfortable cotton textiles through the integration of blackcurrant water/ethanol pomace extract into polysaccharide-based fabric coating. Extraction of bioactive compounds from blackcurrant pomace was optimized using response surface methodology, yielding a total phenolic content of 36.04 mg GAE/g DW, along with significant contents of flavonoids (5.28 mg QE/g DW) and anthocyanins (5.18 mg/g DW). The cotton fabric was biofunctionalized using the layer-by-layer (LbL) deposition technique, incorporating blackcurrant pomace extract within four, eight, or twelve chitosan/pectin bilayers. The biofunctionalized fabrics exhibited no cytotoxic effect and demonstrated nearly 100% antioxidant and antibacterial activity against E. coli and S. aureus. Additionally, the LbL coating enabled tunable extract adsorption (0.09–2.70%) and stabilization of bioactive compounds on the cotton surface, resulting in adjustable fabric coloration and moisture management properties (assessed using the Moisture Management Tester). Molecular docking analysis provided insight into the interactions between HPLC-detected anthocyanins (cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, delphinidin-3-O-glucoside, and delphinidin-3-O-rutinoside) and polysaccharides, revealing an increase in binding affinity from cellulose to chitosan and pectin. The transition from comfort-oriented fabric to a material featuring integrated moisture management and enhanced biofunctionality, achieved by coating cotton with eight chitosan/pectin bilayers incorporating blackcurrant pomace extract, renders the textile suited for medical, protective, and high-comfort applications. Full article

Metal accumulation in cacao (Theobroma cacao L.) cultivation represents an important agronomic and food-safety concern, particularly in acidic tropical soils where cadmium (Cd) and other trace metals can become bioavailable and translocate to plant tissues. Green magnetic nanomaterials offer a potential strategy for reducing metal mobility in agricultural substrates, but their performance depends on surface chemistry, dose, and plant genotype. In this study, we synthesized and evaluated MCRES, defined here as a maghemite–Citrus reticulata extract system, a biofunctionalized γ-Fe₂O₃-based nanosystem prepared by coupling iron oxide nanoparticles (NPs) with a 3% (w/v) Citrus reticulata peel extract. The objective was to determine whether citrus-mediated biofunctionalization could produce a scalable magnetic nanoamendment capable of modifying Cd and naturally occurring Ni partitioning in cacao seedlings. MCRES was recovered magnetically and dried, yielding 8.44 g of product from 10 g of precursor. Rietveld analysis performed in X ray diffractograms confirmed phase-pure cubic γ-Fe₂O₃ with a lattice parameter of 0.8332 nm, a crystallite size of 11.3(1) nm, and satisfactory refinement quality (χ² ≈ 1.34). Transmission electron microscope images showed quasi-spherical NPs with a log-normal size distribution centered at 7.5 nm. Magnetic measurements showed superparamagnetic-like behavior at 300 K, high saturation magnetization values of 62 emu g⁻¹ at 300 K and 71 emu g⁻¹ at 5 K, and elevated effective anisotropy values obtained from the Law of Approach to Saturation fitting. MCRES was applied at 0, 1, 2, 4, and 6 g pot⁻¹ to cacao seedlings containing Cd-amended Ultisol with naturally occurring Ni. Plant responses were genotype and dose dependent: TSH-1188 genotype showed limited dose sensitivity for most biometric variables, whereas ICS-95 genotype showed significant dose effects, with maximum growth at the 2 g pot⁻¹ treatment. Metal-partitioning results indicated that Cd remained comparatively mobile toward shoots, whereas Ni was preferentially retained in roots. In TSH-1188 genotype, the Ni translocation factor decreased from 3.07 in the control to 0.85–1.00 at higher MCRES doses. Compared with previous work on non-biofunctionalized nanomaghemite, these results suggest that citrus-mediated biofunctionalization produces a distinct Cd/Ni partitioning response. Overall, MCRES is recommended as a promising nursery-scale green nanoamendment for reducing metal mobility in cacao cultivation, but its agronomic use should be optimized according to genotype and dose. Future work should include side-by-side comparisons with unfunctionalized γ-Fe₂O₃, Citrus reticulata extract alone, and non-contaminated controls under field conditions to validate its long-term effectiveness and environmental safety. Full article

CD4⁺ T lymphocytes are important regulators of immune homeostasis, and their dysregulation is closely linked to a wide range of diseases. For this reason, their reliable detection remains a major challenge. Despite the fact that current methods are analytically robust, they rely mainly on laboratory infrastructure, limiting their flexibility and wider applicability. The present review analyzes established and emerging approaches for CD4⁺ T-cell detection, with a focus on their practical limitations regarding portability, flexibility and applicability. To the best of our knowledge, for the first time, the authors are examining the possibility of exploring marine magnetotactic bacteria (MTBs) as active biological elements in immune cell detection due to their intrinsic magnetic properties, biological organization, and surface biofunctionalization potential. Rather than offering an immediate technological solution, the use of MTBs serves as a challenging biological framework that could provide more adaptable and sensitive detection strategies. At the same time, the limitations of this concept are acknowledged, emphasizing the need for further experimental validation, considering that this strategy, although promising, remains an exploratory concept. Full article

Silver nanoparticles (AgNPs) have attracted substantial scientific interest in biomedical research owing to their unique physicochemical characteristics, broad-spectrum antimicrobial activity, plasmonic properties, and therapeutic versatility. Although conventional physicochemical synthesis methods enable controlled NPs fabrication, their dependence on hazardous reagents, elevated energy input, and environmentally detrimental processing conditions has stimulated the development of sustainable biogenic alternatives. Biological synthesis utilizing plants, microorganisms, fungi, algae, and purified biomolecules has emerged as an eco-friendly and bio-compatible strategy for AgNP fabrication, enabling simultaneous reduction, stabilization, and intrinsic biofunctionalization of NPs. However, traditional biogenic synthesis remains constrained by limited mechanistic understanding, poor batch reproducibility, inadequate control over physicochemical properties, and challenges in large-scale manufacturing. Recent advances in bioengineering have transformed this field through the integration of metabolic engineering, synthetic biology, microfluidic-assisted synthesis, artificial intelligence-guided process optimization, and continuous-flow biomanufacturing, collectively enabling precision fabrication of biogenic AgNPs with enhanced uniformity, scalability, and functional tunability. Furthermore, strategic surface engineering and functionalization have expanded the applicability of biogenic AgNPs across targeted anticancer therapy, antimicrobial intervention, wound healing, regenerative medicine, drug delivery, and theranostic imaging. Despite these advancements, critical challenges remain regarding nano–bio interactions, toxicological safety, regulatory compliance, and translational scalability. Unlike conventional reviews focused primarily on green synthesis approaches, this review critically highlights emerging bioengineering paradigms that enable programmable, scalable, and precision-controlled biogenic AgNP fabrication. This review comprehensively examines next-generation paradigms and strategies for AgNPs biosynthesis, elucidates the molecular mechanisms governing their formation, highlights emerging functionalization and biomedical application paradigms, and discusses current translational barriers. Forming biogenic composites of AgNPs and heteroatom doped carbon nanodots needs intense research in near future. Full article

Background: Osteoinduction and bone regeneration are fundamental biological mechanisms enabling osseointegration and long-term durability of endosseous dental implants. In clinical practice, poor bone conditions, aesthetic demands, and peri-implant soft tissue problems commonly need the utilization of regenerative techniques targeted at optimizing both hard and soft tissue results. The purpose of this narrative review was to examine osteo-inductive and regenerative strategies currently employed in implant dentistry, with particular emphasis on the mechanobiological integration of hard–soft tissue regeneration and its implications for peri-implant tissue stability, osseointegration, and clinical predictability. Methods: A narrative literature review was done using PubMed and Scopus databases. Based on predetermined inclusion and exclusion criteria, studies published in English during the previous five years were reviewed. The core narrative analysis comprised a selection of physiologically relevant research that addressed osteo-inductive techniques, bone regeneration, osseointegration, and peri-implant soft tissue outcomes, as well as clinical studies, randomized controlled trials, systematic reviews, and narrative reviews. A narrative synthesis was carried out because of methodological variability. Special emphasis was placed on evidence addressing the biological and clinical interaction between hard- and soft-tissue regenerative strategies, reflecting the specific conceptual focus of the review. Results: The evidence presented suggests that implant surface biofunctionalization, biologically active grafting materials, guided bone regeneration, and supplementary biological treatments may have a favorable impact on implant stability and peri-implant bone healing. Several investigations also underlined the biological dependency between peri-implant bone regeneration and soft tissue architecture, stressing the significance of soft tissue thickness, keratinized mucosa, and emergence profile stability. Even in inflammatory environments, bioactive titanium surface changes showed osteogenic potential, indicating a supporting function in early osseointegration. Conclusions: By promoting osseointegration and improving peri-implant tissue outcomes, osteo-inductive and regenerative techniques are essential to modern implant dentistry; however, their greatest potential may lie in integrated hard–soft tissue regenerative approaches aimed at improving long-term clinical predictability. To further understand the clinical efficacy of combination hard–soft tissue regeneration methods, future well-designed clinical trials with standardized outcome measures are needed. Future research should further clarify the mechanobiological principles underlying these integrated regenerative approaches. Full article

Poor bone quality in osteoporotic patients remains a major challenge for achieving predictable osseointegration. This study serves as a mechanistic complement to previously reported structural data, aiming to investigate the molecular pathways underlying the synergy between nanostructured surfaces and autologous blood concentrates in compromised bone. Ninety-six Wistar rats were divided into healthy (SHAM) and osteoporotic (OVX) groups. Implants with nanostructured hydroxyapatite (NanoHA) or dual acid-etched (DAE) surfaces were installed in the tibiae, associated or not with leukocyte- and platelet-rich fibrin (L-PRF). Gene expression (RT-qPCR) for Runx2, Alpl, Bglap, Spp1, Tnfrsf11, and Tnfrsf11b was assessed at 7 and 30 days. In compromised systemic conditions (OVX), the NanoHA + L-PRF association promoted a robust “molecular rescue” of bone metabolism. At 30 days, this synergistic group exhibited a significant upregulation of Alpl (mean: 11.69 ± 1.65) and Runx2 (mean: 4.49 ± 0.82) compared to DAE controls (p < 0.05). Crucially, the therapy orchestrated a protective remodeling environment by significantly inducing Tnfrsf11b expression (5.50 ± 0.88), effectively balancing the Tnfrsf11/Tnfrsf11b ratio. Late-stage maturation markers (Bglap and Spp1) were also significantly elevated, effectively mimicking healthy physiological levels observed in the SHAM group. NanoHA biofunctionalization, synergistically with L-PRF, triggers a transcriptional reprogramming of the peri-implant microenvironment, mitigating the catabolic effects of estrogen deficiency. These findings provide a biological foundation for enhanced clinical predictability in high-risk patients, suggesting that local interfacial modifications can overcome systemic bone compromise. Full article

A semi-distributed interferometer is a low-reflectivity device with refractive index sensing capability, exploiting the random reflectivity of a nanoparticle-doped fiber to form a weak distributed cavity. In this work, we extend this concept to an extrinsic semi-distributed interferometer (ESDI), using an overlay made of polydimethylsiloxane (PDMS) around the fiber tip; this structure can then be surface-modified using a thin metallic film or a nanoparticle coating. We report gold-sputtered and gold-nanoparticle-coated ESDI structures for refractive index sensing capability, with the latter achieving superior performances with an average sensitivity of 62.8 dB/RIU (refractive index units) with resolution of 3.9 × 10⁻⁵ RIU over the range of 1.34790–1.35981. We also report a possible biological application using a biofunctionalized version of this probe for the detection of VEGF (vascular endothelial growth factor); the gold-sputtered probe achieves the highest sensitivity, 0.0565 dB for each 10× concentration increase, with 355 fM detection limit. Full article

The development of reliable electrochemical interfaces for biosensor applications requires materials that combine high conductivity, large effective surface area, and suitable platforms for biomolecule immobilization. In this work, a hybrid electrochemical platform based on screen-printed carbon electrodes (SPCEs) modified with electropolymerized polypyrrole (PPy) and electrodeposited silver particles (AgPs) is presented for the subsequent immobilization of Ki-67 antibodies. PPy films were synthesized under optimized electrochemical conditions, producing homogeneous, porous, and electrochemically stable coatings that significantly enhanced the doping/undoping processes from 0.3280 C/0.3284 C to 0.3281 C/0.3284 C for SPCE and SPCE-PPy, respectively. Subsequently, silver particles were deposited onto the PPy matrix, resulting in a well-dispersed and uniform distribution of AgPs, promoted by the interaction between Ag⁰ and the nitrogen groups in the polymer backbone. The synergistic combination of PPy and AgPs resulted in improved charge-transfer properties and enhanced electrochemical reversibility, thereby decreasing the peak-to-peak separation of the ferricyanide/ferrocyanide redox couple used as a probe by 40%. Immobilization of Ki-67 antibodies was achieved via direct interaction with AgPs, resulting in a marked passivation effect, as evidenced by the suppression of redox probe signals, confirming successful biofunctionalization. The proposed SPCE-PPy-AgP architecture provides a robust, reproducible, and versatile platform for antibody immobilization, as demonstrated by oxidation and reduction peaks with relative standard deviations (RSDs) of 3.18% and 4.43%, respectively, highlighting its potential for developing label-free electrochemical immunosensors for clinically relevant proliferation biomarkers. Full article