Journal of biomedical materials research. Part B, Applied biomaterials最新文献

Spinal cord injury (SCI) causes permanent loss of motor and sensory functions, which is primarily caused by restricted regenerative capacity and inhibitory post-injury environment. Maintenance of extracellular matrix (ECM) architecture is essential to sustain endogenous repair processes. This study aims to prepare perfusion-decellularized goat spinal cord scaffold (dGSC) and assess its therapeutic potential, biocompatibility, and structural integrity in fostering neuroregeneration and functional recovery in complete SCI rat model. This study employed agitation and perfusion method to goat spinal cord (GSC) with several detergents, including sodium deoxycholate (SDC), Triton X-100, Tween 20 (T20), Tween 80, sodium dodecyl sulfate, and their combinations. Among all the combinations, the SDC + T20 perfusion method showed less DNA content, and protein retention thus validating its biocompatibility and ECM integrity. This optimized scaffold was used for transplantion in complete thoracic SCI to investigate its ability to promote neural regeneration. Functional recovery was evaluated based on BBB scores, actophotometer measurements, MRI, electrophysiology, histology, immunohistochemistry, tract tracing, and analysis of gene expression after 4 weeks. The perfusion-decellularized scaffold had significantly less DNA (< 50 ng/mg; p < 0.01), retained ECM ultrastructure, and had favorable mechanical characteristics. Animals that had scaffolds implanted in them had greatly improved motor function (p < 0.001), less glial scarring (GFAP, p < 0.01), neuronal survival (NeuN+, p < 0.05), and angiogenic (CD31, VEGF; p < 0.05) response. Retrograde tract tracing confirmed that axons bridge the lesion. These findings suggest that the perfusion-decellularized goat spinal cord scaffold has great promise for clinical translation use as a biological bridge to facilitate neuroregeneration and functional recovery post SCI.

Repairing critical-sized bone defects remains a clinical challenge. Nano-hydroxyapatite/polyamide 66 (n-HA/PA66) offers excellent biocompatibility and mechanics but limited bioactivity. This study aims to develop a multifunctional composite scaffold to overcome this limitation. A platelet-rich plasma (PRP)-loaded polydopamine/chitosan (PDA/CS) hydrogel was integrated with a 3D-printed porous n-HA/PA66 scaffold (PRP-PDA/CS-n-HA/PA66). Hydrogel's cytoprotective, immunomodulatory, and osteogenic effects were assessed in vitro using human osteoblasts, macrophages, and bone marrow mesenchymal stem cells (BMSCs) under hydrogen peroxide (H₂O₂)-induced oxidative stress or lipopolysaccharide (LPS)-induced inflammatory conditions. The osteogenic efficacy of the PRP-PDA/CS-n-HA/PA66 composite scaffold was further validated in a rabbit femoral condyle critical-sized defect model, assessed by micro-computed tomography, histological staining, and immunohistochemistry. The PRP-PDA/CS hydrogel demonstrated potent antioxidant activity, protected osteoblasts and BMSCs from H₂O₂-induced apoptosis and functional impairment, and promoted macrophage polarization toward the pro-healing M2 phenotype. It significantly enhanced BMSCs' proliferation, osteogenic differentiation, and mineralization. These effects were associated with the upregulation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 antioxidant pathway and suppression of the nuclear factor kappa-B inflammatory pathway. In vivo, the PRP-PDA/CS-n-HA/PA66 composite scaffold markedly accelerated new bone formation, improved bone microarchitecture, including bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and bone mineral density (BMD), upregulated osteogenic marker expression, and concurrently reduced local M1 macrophages, oxidative DNA damage, and pro-inflammatory cytokines. In conclusion, the PRP-PDA/CS-n-HA/PA66 composite scaffold synergizes structural support with multifaceted bioactivity, effectively promoting bone regeneration by mitigating oxidative stress, modulating immune responses, and enhancing osteogenesis, demonstrating significant translational potential.

To develop a novel enhancement medium using polyethylene glycol (PEG)-conjugated gold nanoparticles (AuNPs) for improved detection of clinically significant alloantibodies in antibody screening tests (AST), addressing the limitations of low ionic strength solution (LISS). PEG AuNPs were synthesized through a one-step method and characterized using UV–Visible spectroscopy, EFTEM, FESEM, particle size analysis, zeta potential measurement, and FT-IR spectroscopy. The PEG AuNPs' performance was evaluated against LISS in 120 plasma samples (both antibody-positive and negative) by scoring RBC agglutination reactions. Synthesized PEG AuNPs showed a ruby red color with a single absorption peak at 529 nm, confirming AuNP surface plasmon resonance. Spherical colloids averaged 152.73 ± 19.59 nm, with stability indicated by a zeta potential of −6.24 ± 0.57 mV. Significantly higher RBC agglutination scores were observed with PEG AuNPs during the anti-human globulin (AHG) phase (p = 0.010), especially for anti-D and anti-Le^a/anti-Le^b antibodies (p = 0.007 and 0.036, respectively). PEGylated AuNPs significantly enhanced RBC agglutination reactions compared to LISS, particularly for anti-D and combined anti-Le^a/anti-Le^b antibodies, presenting a promising alternative for AST.

Transcatheter cardiovascular devices require high-purity Nitinol materials with exceptional fatigue resistance to meet stringent Class III regulatory durability requirements. Ultra-clean VAR/EBR (Vacuum Arc Remelt/Electron Beam Remelt) Nitinol represents a metallurgical advancement that achieves unprecedented control over inclusion size and distribution. This study characterizes the fatigue behavior of VAR/EBR Nitinol with nominal inclusion sizes below 10 μm under conditions representative of transcatheter mitral valve replacement (TMVR) applications, using the HighLife Mitral Valve Replacement system as a clinical case study. Diamond-shaped fatigue specimens were manufactured from ultra-clean VAR/EBR Nitinol tubing used in the HighLife Mitral Valve Replacement system and tested under physiologically relevant conditions to 10⁷, 10⁸, and 4 × 10⁸ cycles. Testing included multiple combinations of mean strains (1.5%–9%) and strain amplitudes (0.50%–2.50%) to simulate the multi-strain operating environments encountered in TMVR devices. VAR/EBR Nitinol demonstrated a conservative 130% improvement in 4 × 10⁸-cycle Fatigue Strain Limit (FSL) compared to conventional VAR Nitinol at mean strains between 3% and 5%. The FSL behavior revealed two distinct strain regimes correlating with stress-induced martensitic transformation. Fractographic analysis confirmed elimination of inclusion-initiated fatigue failure, with crack initiation occurring independently of microstructural defects. The ultra-clean microstructure of VAR/EBR Nitinol enables a fundamental shift from flaw-dominated to stress-dominated fatigue behavior, providing unprecedented safety margins for complex transcatheter devices operating across diverse mechanical conditions. This material advancement has broad implications for Class III cardiovascular device design, enabling devices like the HighLife system and other TMVR platforms to meet stringent regulatory durability requirements while maintaining safety across complex multi-strain operating environments.

The use of biodegradable alternatives to conventional metallic orthopedic devices addresses several inherent limitations of permanent implants by providing temporary mechanical support, obviating the need for secondary removal surgeries, and potentially lowering overall healthcare costs. This review summarizes the principal classes of biodegradable materials—metals (e.g., magnesium, zinc), polymers (e.g., PLGA, PLLA), and bioceramics—and their applications across diverse device types, including screws, nails/rods, plates, and scaffolds. Drawing upon evidence from clinical and preclinical studies, we evaluate the material-specific advantages within each device category and critically examine their associated challenges, such as rapid degradation leading to fixation loss, gas evolution resulting in tissue disruption, and mechanical mismatch contributing to stress shielding. Cost-effectiveness is emphasized through the potential reduction in reoperation rates. Moreover, we highlight integrative technological advances (including surface modification, additive manufacturing, and drug-eluting designs) that are shaping the next generation of biodegradable implants. As clinical evidence continues to accumulate, the future success of these devices will depend on achieving an optimal balance between degradation kinetics and bone healing, conducting large-scale multicenter trials, and leveraging modern bioengineering and computational tools.

Developing innovative wound dressing biomaterials is vital for proper wound care management. The synergy of medicinal plant secondary metabolites and nanotechnology presents a promising approach to promoting wound healing by facilitating a quicker and more effective healing progression. In this study, polycaprolactone (PCL) in combination with gelatin (Gel) nanofibrous membranes containing 7-hydroxy-4-methyl coumarin (coumarin)-loaded layered double hydroxide (LDH) nanohybrids were fabricated via electrospinning. LDH/coumarin nanohybrids were prepared using the coprecipitation method. LDH/coumarin was added to the PCL-Gel solution at different concentrations. Scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX) were used to characterize the nanofibers. The nanofibers were evaluated for their mechanical, cytocompatibility, and in vivo properties. The results demonstrated that LDH improved the mechanical properties of PCL-Gel nanofibers, and the highest tensile strength was achieved in PCL-Gel containing 1 wt% LDH (3.12 MPa). Moreover, the nanofibers exhibited no cytotoxicity against the L-929 mouse fibroblast cell line (viability was greater than or equal to 70%). The animal study results revealed that the rate of wound healing was faster in nanofibers containing LDH/coumarin, covering 77.5% of the wound area, and the quality of wound healing was significantly increased in guinea pigs' skin wound closure. The synergistic effect of PCL-Gel-LDH/coumarin (1%) could provide valuable insights and implications for promoting its application in wound dressings.

Considering the scarcity of medications with a wide range of therapeutic effects for the endodontic treatment, this study aimed to synthesize two morin (Mo) derivatives and test their cytotoxicity and effect on multispecies biofilm, in solution and loaded in nanoemulsions (NE). Minimum inhibitory and bactericidal concentration (MIC/MBC) of Mo, penta-acetylated Mo (Ac-Mo), Mo complexed with strontium (Sr-Mo) and control chlorhexidine digluconate (CHX) were determined against Enteroccocus faecalis, Actinomyces israelii, Streptococcus mutans, Lactobacillus casei, Fusobacterium nucleatum. NE were physiochemically characterized by analysis of droplet size and polydispersity index using dynamic light scattering, by determination of zeta potential, by Nanoparticle Tracking Analysis, and by Fourier Transform Infrared Spectroscopy analysis. NE containing Mo, its derivatives (at 2 mg/mL), and CHX (at 0.5 mg/mL) were evaluated against multispecies biofilms by bacterial counts, scanning electron microscopy, and confocal microscopy. The cytotoxicity of the compounds and NE was also determined in fibroblasts (L929) using resazurin assays. The data were statistically evaluated (p < 0.05). All compounds were considered potentially bactericidal against the bacteria tested. The values of MBC ranged from 0.25 to 1 mg/mL. Metabolic activity of fibroblasts was higher than 70% after treatment with compounds up to 0.25 mg/mL. Data from physiochemical characterization confirmed the successful formation of stable, uniformly dispersed nanoemulsion suitable for drug delivery applications. The highest bacterial reduction in multispecies biofilms was observed in NE + Ac-Mo, followed by NE + Mo, CHX, and NE + Sr-Mo groups. All NE diluted at 12.5% did not affect fibroblast metabolism after 24 h of treatment. Although in different concentrations, morin and its derivatives, either alone or loaded in nanoemulsions, were bactericidal (up to 1 mg/mL) and demonstrated antibiofilm effect (at 2 mg/mL). They also were cytocompatible at lower concentrations (0.25 mg/mL). Nanoemulsion containing penta-acetylated morin could be an alternative intracanal medication for reducing residual bacteria between short-term clinical appointments in endodontic approaches.

Tissue-engineering scaffolds require interconnected porous networks to support cell infiltration, nutrient diffusion, and waste removal. Conventional methods to introduce porosity—such as particulate leaching, gas foaming, and freeze-drying—can leave cytotoxic residues. We propose a scalable, cytocompatible approach to tune hydrogel porosity using lipid-shelled gas microbubbles as a transient porogen. In this study, we demonstrate that lipid-shelled microbubbles can be incorporated into alginate, poly(ethylene glycol) diacrylate (PEGDA), or gelatin methacrylate (GelMA) precursors, and subsequently expanded post-gelation with mild heat or vacuum to yield controlled porosity. In alginate fibers, the vacuum expansion of embedded microbubbles increased the swelling capacity by approximately 74% relative to nonporous control, without reducing compressive strength. Porous PEGDA hydrogels showed faster degradation (approximately 40% reduction in degradation time) and a lower compressive modulus compared to the dense PEGDA control, reflecting a tunable trade-off between porosity and stiffness. Unlike traditional porogen-based or 3D-printing techniques, this microbubble method requires no toxic additives or specialized equipment and is compatible with both ionic (alginate) and photo-crosslinked (PEGDA, GelMA) systems. We further demonstrate integration of this approach with a microfluidic fiber production platform. We validate that porosity modulation via microbubbles does not adversely affect the viability of mesenchymal stem cells on GelMA hydrogels. Overall, this work establishes a broadly applicable and easily scaled strategy in which porosity can be tuned post-gelation with simple triggers (heat or vacuum), enabling application-specific control of nutrient transport, degradation, and mechanics across multiple biomaterials.