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Direct Metal Printing (DMP) three-dimensional (3D) printing technology, also known as direct laser sintering of metal powders, enables the production of metal components with complex geometries that are not achievable with traditional casting methods or subtractive techniques. The DMP method enables the production of metal objects with high precision. One of the important applications of additive manufacturing is the production of medical implants. A significant challenge in the production of medical devices using DMP technology is the so-called post-processing. An improperly performed postproduction cleaning process may lead to the presence of metal powder particles that were not bound during laser melting. Their presence in the friction pair after implantation, and/or their release into surrounding tissues, may cause accelerated wear and induce inflammatory reactions. The most common drawbacks of widely available and commonly used post-processing methods include their limited effectiveness in removing surface powder residues and a significant loss in volume and mass of the prints. In the second case, the result is a reduction in the mechanical strength of the implant (e.g., with electrochemical methods), and in the first case, there is a risk of inducing an immune response in the body. According to literature reports, regardless of size, at high concentrations in the body (1 × 106 particles/mL), unbound powder particles induce an immune response already at an early stage. Electrochemical methods effectively remove unbound particles, but at the same time cause significant losses in the volume and mass of prints, which affects their strength. This study aimed to improve the quality of 3D-printed implants by cleaning their surfaces of unbound metal particles (post-processing). Comparing the results reported in the literature for various surface treatment methods (chemical, electrochemical, mechanical, plasma), plasma treatment was identified as the most promising solution. Oxygen and argon plasma cleaning was performed at different time periods (1, 2, and 4 h) on sandblasted substrates after production and without this treatment. The study aimed to verify the effectiveness of the plasma cleaning process in removing particles from metallic 3D-printed components and to assess the impact of surface treatments on biological response using an osteoblast cell model.
Retrieved hip implant components experience a range of corrosion types and severity, often on small surface areas of the taper region. Tribocorrosion-related damage within modular taper regions and resulting changes of the oxide-covered surface can alter the local impedance of the interface. We hypothesize that near-field electrochemical impedance spectroscopy (nfEIS), where local area impedance measurements can be made, can serve as an excellent method to distinguish different forms and severity of tribocorrosion degradation in localized regions of the implant surface. Impedance measurements can also help determine subsequent corrosion susceptibility. Recent studies have shown that EIS on a localized, or global basis, is a useful tool to ascertain the corrosion resistance and extent of oxide alteration in retrieved hip implant components. Hence, the goal of this study was to systematically assess different types of corrosion modes found on the modular taper surfaces of retrieved acetabular liners using nfEIS and to correlate the resulting local impedance response with visually identified different corrosion modes. Utilizing an easy-to-manufacture microelectrode on wrought CoCrMo liners, we found that local impedance measurements are a good indicator of differences it forms of corrosion-related damage. nfEIS measurements captured damage-specific differences in the impedance response that were unique to specific types and severity of corrosion. We could describe the surfaces in terms of equivalent circuit models consisting of resistive and capacitive (or constant phase) elements. Intergranular corrosion (IGC) and oxide deposits were found to match a coated model behavior, with a characteristic double-hump phase angle response. Phase boundary corrosion (PBC) and control (polished CoCrMo disk) were found to match a constant-phase-element Randle's circuit model with a mostly intact surface and minimal to no material loss. We found that polarization resistance, where higher Rp indicates greater corrosion resistance, correlated with the intactness of the surface: greater material loss on the surface translated to lower Rp values (IGC sample Rp = 8.46E6 Ω/cm2 compared to PBC sample Rp = 5.79E7 Ω/cm2). Our findings demonstrate the versatility of this technique to analyze different types of retrieved device surfaces to make objective determinations in terms of the nature of the corrosion damage and the surface's continued corrosion susceptibility. Further developing this technique and testing it on a variety of tribocorrosion features and different biomedical alloys will help ascertain its applications in retrieval analysis and may assist in determining the extent of device damage at revision surgery.
In this study, we introduce a hybrid approach for fabricating multifunctional coatings composed of chitosan and copper nanoparticles (CuNPs) on NiTi substrates. The fabrication process combines the immersion technique for chitosan layer deposition with inert gas condensation (IGC) based on magnetron sputtering for the generation of CuNPs. This method enables precise control over nanoparticle size and concentration, allowing for their uniform incorporation into a biopolymer matrix. The resulting CS/CuNPs/CS multilayers exhibit excellent surface coverage, nanoscale roughness (Ra of 30-65 nm), and moderately hydrophilic character (contact angle of 30°-35°), which collectively support cell adhesion and proliferation. Surface characterization confirmed the stability and durability of the coatings, which can be attributed to prior substrate activation using Piranha solution and plasma treatment. Electrochemical tests demonstrated enhanced corrosion resistance of the CS/CuNPs/CS layers, with a reduced current density (4.10 × 10-4 mA/cm2) and good temporal stability. In vitro studies using the MG-63 osteoblast-like cell line indicated non-cytotoxicity response of the coatings, confirming their plausible applicability in tissue engineering. Antibacterial assays revealed effective inhibition of Staphylococcus aureus growth and complete elimination of Escherichia coli, highlighting the strong bactericidal potential of the developed system. Moreover, Cu ion release within the surface layer profiles obtained in Ringer's solution over a 7-day period showed a predominantly linear release of copper ions, indicating a controlled and sustained antimicrobial effect. The ability to modulate chitosan layer thickness and nanoparticle loading during sequential deposition steps enables the customization of the coating properties to meet specific therapeutic requirements while minimizing nanoparticle usage. This strategy offers a promising platform for developing safe, effective, and tunable antibacterial coatings for biomedical implants.
Epilepsy is the second most prevalent neurological disorder worldwide. It is mostly identified by abnormal electrical activity in multiple brain regions. The massive influx of Ca2+ into neurons is the main neurotoxic mechanism that leads to cell death and eventually neurodegeneration. Despite the abundance of antiseizure medications, many patients with refractory epilepsy do not benefit from the treatment. Nanomedicine is a viable alternative for boosting the central nervous system's bioavailability of anti-seizure medications. This study examined the anti-epileptic effects of CuNPs@Boswellia thurifera in Swiss albino mice using experimental epilepsy models. Advanced methods like fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) were used to examine the material's structural properties. The 6-Hz-induced seizure model was first used to assess the effectiveness of CuNPs@B. thurifera. Using an actophotometer, the strong CuNPs@B. thurifera were tested for their ability to reduce locomotor activity. The effectiveness of the CuNPs@B. thurifera on the GABA levels in the brain was also examined in order to investigate their potential method of action. The effectiveness of the nanoparticles in producing maximal electroshock (MES) and convulsions induced by pentylenetetrazole (PTZ) was next assessed. CuNPs@B. thurifera at either of the 100 or 200 μg/kg doses demonstrated a notable rise in brain gamma-aminobutyric acid (GABA) levels but no influence on locomotor activity. Notably, a higher dosage of the nanocomposite and diazepam successfully prevented convulsions in all anticonvulsant studies. It should be mentioned that CuNPs@B. thurifera has demonstrated remarkable protection against seizures caused by PTZ and MES, with the level of protection varying across doses. Building on these findings, the CuNPs@B. thurifera was subsequently examined in MES and PTZ models. The CuNPs@B. thurifera at doses of 100 and 200 μg/kg showed a significant decrease in 6-Hz-induced seizures. These results suggest that CuNPs@B. thurifera has potent anticonvulsant effects, possibly due to its capacity to increase GABA levels in the brain.
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.
The work is devoted to research on the influence of β-cyclodextrin/eugenol complex (CP-EU) on the properties of methacrylic bone cement. Eugenol (4-allyl-2-methoxyphenol) is an essential oil that exhibits antimicrobial properties against pathogenic bacteria, and these properties are desirable in bone cements. This may allow the replacement of antibiotics currently used in bone cements. However, since eugenol causes a decrease in the polymerization rate, it was decided to modify it with sulfobutylether-β-cyclodextrin (Captisol). The use of CP-EU complex in the amount of 0.5 wt% (calculated on EU amount) eliminated this unfavorable effect of eugenol on the polymerization process and influenced its release from bone cement. Properties of modified bone cements were examined, including doughing time, maximum temperature (Tmax), setting temperature (Tset), setting time (tset), compressive strength, and antibacterial properties. The CP-EU complex does not affect the maximum curing temperature of bone cement, which remained within the clinically acceptable range (58.7°C-69.8°C), and all formulations meet ISO 5833:2002 standards. Importantly, it causes an increase in compressive strength of up to 33.5% and Young's modulus of up to 454.1%, demonstrating a beneficial enhancement in the mechanical performance of the tested materials. The release of eugenol was very high, ranging from 84.5% to 86.9%. Furthermore, antibacterial studies show that the tested materials, the CP-EU complex and modified bone cements, have antibacterial properties for Escherichia coli strains. The cell viability in the presence of the CP-EU complex was 39.9% after 72 h of incubation. Cytotoxicity assays conducted on osteoblasts demonstrated that free eugenol induces both acute and persistent cytotoxic effects, whereas its complexation with Captisol restores biocompatibility and enhances osteoblast viability. Consequently, Captisol serves as an effective carrier for modulating eugenol release and improving the biological performance of modified acrylic cements. In summary, the modified bone cements meet all standard requirements and are characterized by good mechanical properties, high eugenol release, and antibacterial properties. Thus, the incorporation of eugenol into β-cyclodextrin allowed obtaining a CP-EU complex for bone cement modification, exhibiting the desired properties.
Rare-earth element (REE)-doped hydroxyapatite nanoparticles (HAp-NPs) have emerged as multifunctional bioceramics with significant potential across diverse biomedical fields, owing to their excellent biocompatibility, bioactivity, and tunable physicochemical properties. Recent advances in the doping of HAp-NPs with lanthanide ions have expanded their functionality, enabling innovative applications in bone tissue engineering, targeted drug delivery, cancer therapy, dentistry, and biomedical imaging. This review provides a comprehensive assessment of the synthesis strategies and surface modification techniques, utilizing both natural and synthetic precursors, for REE-doped HAp-NPs. Particular attention is given to the role of individual REE dopants (e.g., La3+, Ce3+, Pr3+, Eu3+, Gd3+, Er3+, Sm3+, Nd3+, Dy3+, Tb3+, Yb3+, and Y3+) in modulating the luminescent, antibacterial, osteoconductive, and drug-delivery properties of HAp-NPs. Furthermore, the theranostic potential of these nanomaterials is examined, emphasizing their low cytotoxicity, high loading capacity, efficient cellular uptake, and advanced imaging capabilities. Collectively, REE-doped HAp-NPs represent a versatile and promising platform for the development of next-generation nanomedicines, with broad implications for precision therapy and regenerative medicine.
Polycaprolactone (PCL) electrospun nanofiber dressings loaded with lipophosphonoxin (LPPO) have shown antibacterial activity and pro-healing potential. To optimize dressing thickness for partial-thickness skin wounds and evaluate translational relevance. We compared PCL dressings with areal weights of 10, 20, and 30 g/m2 (with or without 7 wt.% LPPO) in a porcine model using partial-thickness wounds. Standard comparators were Aquacel Ag+ (antibacterial control) and Jelonet (standard control). Healing was assessed macroscopically and histologically (hematoxylin and eosin, keratins-10 and -14 immunohistochemistry). Systemic LPPO exposure was measured by LC-MS/MS in plasma and liver. A clinical case (STSG donor site) used a 15 g/m2 NANO dressing. Thinner dressings (10 and 20 g/m2), whether unloaded (NANO) or LPPO-loaded (NANO-LPPO), supported rapid re-epithelialization from wound edges and hair follicles and yielded complete closure in wounds, comparable to controls. The 30 g/m2 variants of both NANO and NANO-LPPO were associated with persistent inflammation and delayed re-epithelialization. LC-MS/MS showed plasma concentrations of LPPO below the quantification limit and very low liver levels. The clinical case mirrored the porcine findings: timely re-epithelialization of the STSG donor site with 15 g/m2 NANO was comparable to Jelonet. Dressing thickness influenced healing quality in the porcine model. Partial-thickness wounds treated with 10-20 g/m2 NANO dressings showed superior outcomes compared with 30 g/m2, with negligible systemic LPPO exposure. In the clinical case, a 15 g/m2 NANO dressing supported timely re-epithelialization of the STSG donor site, comparable to standard care. These findings justify further clinical development of PCL NANO-LPPO dressings.
Today, tissue engineering and nanotechnology researchers are looking to design a bone scaffold that can mimic bone extracellular matrix and stimulate bone regeneration by regulating cell activity and differentiation. The scaffold must be biocompatible and bioactive and can provide a suitable porous physical structure for the growth and adhesion of cells and then undergo biological degradation. Finding an effective active ingredient with an optimal dose that can increase bone regeneration is also important. In this study, polycaprolactone (PCL)/carboxymethyl chitosan (CMC)-bioglass nanoparticles (BGNP) scaffolds incorporating varying concentrations of cerivastatin (Ceriv) were fabricated and subjected to comprehensive in vivo and in vitro characterization to assess their impact on bone healing. Scaffolds with varying cerivastatin concentrations (0.01, 0.1, and 1 wt%) were fabricated via freeze-casting and subsequently examined using scanning electron microscopy (SEM). In vitro evaluations included tests of the material's physical properties, cytotoxicity, blood compatibility, pH levels, blood coagulation index, release profile, and Alizarin staining. In vivo evaluations involved the implantation of scaffolds into rat calvarial defects distributed across six groups, each comprising six subjects, over a period of 12 weeks. Histological analysis utilizing hematoxylin-eosin and trichrome-Mason staining assessed the formation of bone and fibrous tissue, along with the quantities of osteons, osteoblasts, and fibroblasts. In vitro studies demonstrated that the scaffold was biocompatible and exhibited optimal physical properties. Histological analysis revealed a significant increase in bone formation and osteon quantity with 0.1% cerivastatin (p < 0.05). Higher amounts of cerivastatin (1%) led to less bone formation and more fibrous tissue. This increase was linked to a higher blood coagulation index and acidity caused by scaffold degradation (p < 0.05). In summary, all scaffolds, except those with 1 wt% cerivastatin, promoted bone regeneration. The PCL/CMC-BGNP-Ceriv 0.1% concentration produced the best results, which means it works well to help bones heal.
The immunotoxicological evaluation of collagen-based medical devices typically relies on wild-type rodent models, but interspecies differences may cause biases in immune response. To address this, we developed a human Type III collagen transgenic mouse model. In accordance with ISO/TS 10993-20 guidelines, we assessed the immunotoxicity of human collagen and recombinant/cell-engineered collagens (CCs) using this model, alongside wild-type controls. The full-length human COL3A1 gene was integrated into C57BL/6J mice, with expression confirmed through mRNA and peptide analysis. Mice were injected with human placental stromal protein (positive control), two recombinant humanized collagens (RC-1, RC-2), and CC. The experimental design adhered to GB/T 16886.20 (ISO 10993-20) and YY/T 1465 standards, with assessments including serum antibody detection at multiple timepoints (0-90 days) and terminal analyses at 30 and 90 days, focusing on splenic lymphocyte subsets and local tissue reactions. Results showed that transgenic mice had lower antibody levels compared to wild-type controls, with wild-type mice displaying significantly higher antibody responses at 60 days. These findings suggest altered immune recognition patterns in transgenic mice. The study also indicated that recombinant/CCs triggered only transient immune responses, with no sustained activation. This model provides new insights for refining immunoevaluation strategies for collagen-based materials.
Large-area bone loss from disease, trauma, or congenital defects requires surgical procedures and bone grafting. Alveolar bone loss from severe periodontal disease and non-unions often demands immediate grafting. Treating large alveolar bone defects using grafts and substitutes is challenging due to the complex oral environment, infection risks, and unstable graft properties, which may compromise strength and bioactivity. Successful grafts must promote vasculature development and osteogenesis while maintaining mechanical stability at the graft site. Current bone graft substitutes are inadequate for optimal alveolar bone healing. New biomaterial technologies including additive manufacturing techniques enhance repair processes by developing anatomically equivalent implants that integrates better with host tissues, provide mechanical stability and activate innate healing mechanisms. Smart stimuli-responsive materials (SSMs), combined with exogenous physical stimulation, further advance this by triggering cell regulatory pathways, promoting bone mineralization, blood vessel development, and mechanical integrity. Electrical, magnetic, mechanical, ultrasound, and shockwave stimulations activate Ras, p38 kinase, PI3K/Akt, JNK, NF-κB, MAPK/ERK, Wnt, BMP, and VEGF pathways, enhancing osteogenic genes like Runx2, YAP, osteopontin, and osteocalcin to promote osteoinduction and osteogenesis. This article provides an in-depth literature analysis of smart biomaterials and stimuli-mediated alveolar bone repair and regeneration mechanisms. It also highlights the unmet needs of innovative biomaterials such as SSMs and explores strategies to manage the bone microenvironment, aiming to enhance clinical translation for large-area bone defects regeneration.
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.
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.
Electrospun nanofiber scaffolds met a pressing need for degradable matrices that matched the architecture and mechanics of soft tissues, yet neat poly(ε-caprolactone) (PCL) fibers often exhibited low surface energy, modest stiffness, and a loss of strength after sterilization and hydration. Graphene additives were expected to provide interfacial reinforcement and wettability improvements, but the effects of specific functional groups at low loading and under clinically relevant conditioning conditions had not been clarified. This study aimed to engineer sterilization-resistant, water-stable PCL scaffolds by comparing carboxyl- and hydroxyl-functionalized graphene (CFG and HFG) and defining an operating window via response surface methodology. PCL was electrospun with 0.5-2.0 wt% CFG or HFG while varying voltage; dispersion and chemistry were verified by FTIR and Raman mapping, thermal behavior by DSC/TGA, mechanics by tensile and DMA including cyclic loading, stability by EtO and γ sterilization with wet testing, surface energetics by contact angles and Owens-Wendt analysis, protein adsorption by BSA/fibronectin assays, cytocompatibility by human dermal fibroblasts, and aging by PBS degradation with GPC. The 1 wt% composites increased ultimate tensile strength by ~45%-55% and modulus by ~40%-55% relative to neat PCL, with modest reductions in elongation; storage modulus increased across -20°C to 60°C, and the composite retained ~98% stiffness after 50 cycles compared with ~90% for PCL. After γ-sterilization, strength retention was ~90%-92% for composites versus ~80% for PCL; wet-state modulus retention approached ~95%. Tc shifted upward by 2°C-3°C and crystallinity increase by ~5%-8%, while TGA showed a ~10°C onset increase; Raman maps confirmed uniform dispersion with I D / I G $$ {I}_{\mathrm{D}}/{I}_{\mathrm{G}} $$  ≈ 1.1 (CFG) and ≈1.0 (HFG). Contact angle fell from ~130° (PCL) to ~90°-95°, fibronectin adsorption increased and correlated with Day-7 viability (R ≈ 0.95), hemolysis stayed near 1%-2%, and bacterial attachment decreased to ~70%-80% of PCL. Response-surface analysis identified a practical region around 1.2-1.3 wt% graphene and 16-18 kV that balanced strength and sterilization retention. These findings supported use in soft-tissue scaffolds requiring robust handling and rapid cell coverage, and suggested extension to scale-up studies and in vivo validation, including sterilization dose mapping and sustained-release add-ons.
Transverse femoral fractures heal through a complex secondary healing process, often stabilized using locking compression plates (LCPs) that maintain compression across an interfragmentary gap. Conventional LCPs made of non-biodegradable Ti-alloys provide adequate mechanical support but can induce stress-shielding in newly formed callus and bone, necessitating revision surgeries. To address this, Mg-based biodegradable LCPs have been actively investigated. However, their clinical translation and commercial adoption remain limited, primarily due to concerns regarding their lower mechanical strength and fixation stability compared to Ti-alloys. Embossed structure-based LCP (ELCP) was designed previously to enhance its mechanical performance. However, its biomechanical feasibility under physiological loading across different fracture healing phases has not yet been systematically evaluated. In the present study, fractured femur models for two fixation strategies, a conventional LCP (M2) and the ELCP (M3), were developed. These strategies were tested using three candidate biomaterials (one non-biodegradable material, Ti-alloy, and two biodegradable materials, Mg-alloy and PLA/50% Mg composite). Three physiological loading conditions corresponding to the healing and early repair phases were applied. The results showed that although Ti-alloy-based conventional LCPs provided superior fixation strength, Mg-alloy-based ELCPs also performed substantially better than conventional LCPs, as reflected by high safety factors ranging from 1.81 to 3.42, unlike composite-based plates. Moreover, Mg-alloy-based ELCPs exhibited higher interfragmentary strain (within or above the ideal strain range) in the callus compared to Ti-alloy-based LCPs, which might promote faster callus strengthening. Thus, Mg-alloy-based ELCPs could represent a viable alternative to conventional LCPs by offering adequate fixation strength while potentially reducing stress-shielding.
Approximately 50% of patients that undergo surgical reconstruction to repair the congenital heart defect tetralogy of Fallot (ToF) experience adverse effects by the age of 50. These effects can be linked to the poor healing response elicited by the synthetic materials in the commonly used cardiovascular patches. Extracellular matrix (ECM) biomaterial-based therapies, on the other hand, have been shown to elicit positive healing responses in various tissues and pathologies, including those in the heart. Few studies, however, have been directed towards the development of an ECM-based cardiovascular patch that can realistically fill the voids in tissue present in ToF patients. Furthermore, cardiac ECM is typically derived from adult sources, despite knowledge that only fetal and neonatal rodents can fully regenerate functional cardiac tissue. Here, we demonstrate the widening of the RVOT in young porcine with a novel cardiovascular patch fabricated from fetal cardiac ECM and silk fibroin (cECM-silk). Histological analyses show our fetal cECM-silk patches improve patch-tissue integration and patch degradation compared to a clinical-standard GORE ACUSEAL cardiovascular patch, as a representative of expanded polytetrafluoroethylene (ePTFE)-based material. Our fetal cardiac ECM-silk patches also improve vascularization in and around the patch and reduce the detrimental fibrotic response typically seen with the GORE ACUSEAL patches. Finally, the culture of activated cardiac fibroblasts in vitro showed analogous reduction in fibroblast activation when treated with solubilized fetal cECM. Our results suggest that fetal cECM is a potential alternative cardiovascular patch material that enables improved healing responses over synthetic materials post-surgical repair of ToF and other CHDs.
This research focuses on creating innovative biogenic cerium oxide nanoparticles with multifunctional capabilities to improve treatment strategies for myocardial infarction and enhance cardiac care. The study specifically examined how curcumin-capped silver nanoparticles (Cur@CeO2NPs) influence oxidative stress resulting from isoproterenol (ISO)-induced myocardial injury. A range of sophisticated characterization methods, such as UV-vis spectroscopy, FTIR, TEM, and XRD, verified that the environmentally produced Cur@CeO2NPs had a cubic structure and demonstrated significant interactions with curcumin compounds. In this investigation, adult male Wistar rats were used and divided into three groups: a control group, one subjected to ISO injections, and a third group treated with Cur@CeO2NPs. After the completion of the experiments, the levels of enzymes CK-MB and LDH were measured, and the expression of inflammatory markers HIF1α, TNF-α, and IL-6 was assessed through quantitative reverse transcription PCR (qRT-PCR). Histological changes in heart tissues resulting from ISO exposure were also evaluated using Hematoxylin and Eosin (H&E) staining. The results revealed a significant reduction in the inflammatory markers TNF-α and IL-6 in the Cur@CeO2NPs treated group. This outcome validated the anti-inflammatory and antioxidant effects of Cur@CeO2NPs, suggesting their protective role against cardiac injury. The study concludes that Cur@CeO2NPs help restore redox balance and reduce inflammation, suggesting their potential protective properties. Nonetheless, further investigations are warranted to clarify their effects on inflammatory responses related to myocardial infarction.
Aseptic osteolysis induced by ultra-high-molecular-weight polyethylene (UHMWPE) wear debris has historically been a major cause of late failure in total hip arthroplasty, highlighting the need for more robust methods to isolate and identify wear particles in complex biological matrices. To validate an optimized protocol for the isolation and identification of UHMWPE wear debris from hip simulator lubricant serum by combining lyophilization, alkaline digestion, and chemometric analysis based on principal component analysis (PCA) applied to energy-dispersive x-ray spectroscopy (EDS) data. Wear tests were performed in a hip simulator in accordance with ABNT NBR ISO 14242-1, using metal-on-UHMWPE and ceramic-on-UHMWPE bearing couples lubricated with 25% fetal bovine serum. Three isolation procedures were compared: direct liquid digestion and two protocols based on lyophilization followed by alkaline digestion with 6 mol/L KOH. Particles retained on polyethersulfone (PES) membranes were characterized by scanning electron microscopy (SEM; ASTM F1877) and EDS. Weight percentages of C, O, Na, K, Ca, Cl, S, and Au were subjected to PCA after autoscaling. Lyophilization increased filtration efficiency from 17% (0.2 g) to 25% (~4 g) and markedly reduced sample storage volume. SEM micrographs revealed typical fibrillar and globular UHMWPE particles ranging from 0.1 to 20 μm. PCA explained 67.4% of the total variance in the first three components and generated a distinct cluster of carbon-rich regions, clearly separated from areas dominated by salts and membrane background. The combination of lyophilization, alkaline digestion, and PCA-assisted EDS analysis improves recovery efficiency, preserves particle morphology, and supports the discrimination of UHMWPE wear debris in complex serum matrices, providing a practical and transferable approach for preclinical wear testing.
This study developed and evaluated a novel composite electrospun nanofiber wound dressing co-loaded with propolis (PP) and PP-functionalized silver nanoparticles (PP-AgNPs) in a polycaprolactone (PCL) matrix for accelerated wound healing. Three types of mats-neat PCL, PCL/PP (10 wt.%), and PCL/PP-AgNPs (10 wt.%)-were fabricated. Incorporation of PP-AgNPs significantly altered the solution properties, increasing conductivity to 891.0 ± 3.9 μS and reducing the mean fiber diameter to 256 ± 63 nm, compared to 693 ± 245 nm for neat PCL. In vivo assessment using a full-thickness rat wound model over 14 days demonstrated that the PCL/PP-AgNPs composite dressing (Group 6) superiorly promoted healing. It achieved near-complete wound closure (99.8%), significantly enhanced wound contraction rates, and improved histological outcomes, including complete re-epithelialization and dense, organized collagen deposition. Biochemical analyses revealed that the PCL/PP-AgNPs dressing effectively modulated the wound microenvironment by reducing oxidative stress (increased SOD, decreased MDA) and suppressing pro-inflammatory cytokines (IL-6, TNF-α). Furthermore, it exhibited protective effects on liver (ALT, AST) and kidney (Urea, Creatinine) functions. The synergistic combination of PP's antioxidant and anti-inflammatory properties with the antimicrobial and bioactive effects of AgNPs, delivered via a nanostructured PCL fiber matrix, validates this composite as a highly effective and multifunctional dressing for faster, more complete wound repair.