Journal of Functional Biomaterials最新文献

Bone tissue engineering has seen significant advancements with innovative scaffold fabrication techniques such as 3D printing. This review focuses on enhancing polycaprolactone (PCL) scaffold properties through structural modifications, including surface treatments, pore architecture adjustments, and the incorporation of biomaterials like hydroxyapatite (HA). These modifications aim to improve scaffold conformation, cellular behavior, and mechanical performance, with particular emphasis on the role of mesenchymal stem cells (MSCs) in bone regeneration. The review also explores the potential of integrating nanomaterials and graphene oxide (GO) to further enhance the mechanical and biological properties of PCL scaffolds. Future directions involve optimizing scaffold structures and compositions for improved bone tissue regeneration outcomes.

Poly (N-vinylcaprolactam) (PNVCL) and poly (N-isopropylacrylamide) (PNIPAm) are two popular negatively temperature-responsive hydrogels, due to their biocompatibility, softness, hydrophilicity, superabsorbency, viscoelasticity, and near-physiological lower critical solution temperature (LCST). These characteristics make them ideal for biomedical applications. When combined with other materials, hydrogel expansion induces the morphing of the assembly due to internal stress differences. Our recent developments in NVCL hydrogel, enhanced by nanoclay incorporation, have driven us to the creation of a bilayer structure to study its shapeshifting response across various temperatures. This study focused on the bending behaviour of bilayer samples composed of an active hydrogel layer and a passive non-swellable layer. Using photopolymerisation, circular discs and rectangular bilayer samples of varying sizes were fabricated. Homogeneous circular samples demonstrated that hydrogel density increased proportionally with temperature, with the swelling ratio exhibiting two distinct rates of change below and above its LCST. In bilayer samples, the volume of the passive layer influenced bending, and its optimal volume was identified. The investigation revealed that geometry affected the overall bending effect due to changes in the passive layer stiffness. Lastly, a temperature-responsive gripper capable of picking up objects several times its own weight was demonstrated, highlighting the potential of NVCL hydrogels as bioactuators for minimally invasive surgery.

Hydroxyapatite (HAp) is a widely used biocompatible material in orthopedic composite preparations. However, HAp composites that exhibit both anticancer and antibacterial activities through bioactive coordination complexes are relatively rare. To explore orthopedic applications, we blended several silver camphorimine compounds with HAp to create [Ag(I)] composites. All compounds [Ag(NO₃)(L)_n] (n = 1,2) based on camphorimine (L^A), camphor sulfonimine (L^B) or imine bi-camphor (L^C) ligands demonstrated significant cytotoxic activity (IC₅₀ = 0.30-2.6 μg_Ag/mL) against osteosarcoma cancer cells (HOS). Based on their structural and electronic characteristics, four complexes (1-4) were selected for antibacterial evaluation against Escherichia coli, Burkholderia contaminans, Pseudomonas aeruginosa, and Staphylococcus aureus. All complexes (1-4) revealed combined anticancer and antibacterial activities; therefore, they were used to prepare [Ag(I)]:HAp composites of 50:50% and 20:80% weight compositions and the activities of the composites were assessed. Results showed that they retain the dual anticancer and antibacterial characteristics of their precursor complexes. To replicate the clinical context of bone-filling applications, hand-pressed surfaces (pellets) were prepared. It is worth highlighting that no agglutination agent was necessary for the pellet's consistency. The biological properties of the so-prepared pellets were assessed, and the HOS cells and bacteria spreading on the pellet's surface were analyzed by SEM. Notably, composite 4B, derived from the bicamphor (L^C) complex [Ag(NO₃)(OC₁₀H₁₄N(C₆H₄)₂NC₁₀H₁₄O)], exhibited significant anticancer activity against HOS cells and antibacterial activity against P. aeruginosa, fostering potential clinical applications on post-surgical OS treatment.

The rising demand for effective bone regeneration has underscored the limitations of traditional methods like autografts and allografts, including donor site morbidity and insufficient biological signaling. This review examines nanoparticles (NPs) in tissue engineering (TE) to address these challenges, evaluating polymers, metals, ceramics, and composites for their potential to enhance osteogenesis and angiogenesis by mimicking the extracellular matrix (ECM) nanostructure. The methods involved synthesizing and characterizing nanoparticle-based scaffoldsand integrating hydroxyapatite (HAp) with polymers to enhance mechanical properties and osteogenic potential. The results showed that these NPs significantly promote cell growth, differentiation, and bone formation, with carbon-based NPs like graphene and carbon nanotubes showing promise. NPs offer versatile, biocompatible, and customizable scaffolds that enhance drug delivery and support bone repair. Despite promising results, challenges with cytotoxicity, biodistribution, and immune responses remain. Addressing these issues through surface modifications and biocompatible molecules can improve the biocompatibility and efficacy of nanomaterials. Future research should focus on long-term in vivo studies to assess the safety and efficacy of NP-based scaffolds and explore synergistic effects with other bioactive molecules or growth factors. This review underscores the transformative potential of NPs in advancing BTE and calls for further research to optimize these technologies for clinical applications.

Bone cortical tissues reorganize and remodel in response to tensile forces acting on them, while compressive forces cause atrophy. However, implants support most of the payload. Bones do not regenerate, and stress shielding occurs. The aim is to analyze the biomechanical behavior of a lumbar cage to study the implant's stress shielding. The ASTM E-9 standard was used with the necessary adjustments to perform compression tests on lumbar and thoracic porcine spinal vertebrae. Twelve cases were analyzed: six with the metal prosthesis and six with the PEEK implant. A mathematical model based on the Hertz contact theory is proposed to assess the stress shielding for endoprosthesis used in spine pathologies. The lumbar spacer (screw) helps to reduce the stress shielding effect due to the ACME thread. The best interspinous spacer is the PEEK screw. It does not embed in bone. The deformation capability increases by 11.5% and supports 78.6 kg more than a system without any interspinous spacer.

(1) Background: OD burs are used in two different modes: (i) CW and (ii) CCW. The purpose of the study was to evaluate the ΔT during the preparation of implant osteotomies in a four-way interaction. (2) Methods: Three hundred and sixty osteotomies were prepared at 12 mm depth in human cadaver tibiae. The ΔT values were calculated similarly to the method used in two previous studies carried out by our group. Four different variables were evaluated for their effect on ΔT. (3) Results: A four-way interaction was observed in the CCW mode, allowing for 1000 RPM to have the least effect in both modes. However, in the CCW mode the use of 3.0 and 4.0 burs after 23 osteotomies showed a statistically significant increase in ΔT, and significant chatter, compared to the CW mode. In the CCW mode, the ΔT was increased significantly as the diameter of the burs increased in 800 and 1200 RPM. (4) Conclusions: The synergistic effect of drills' diameter, CCW mode, 800 and 1200 RPM, and bur usage (over 23 times) had a significant effect on ΔT, which exceeded 47 °C. One thousand (1000) RPM had the least effect in both modes. The 3.0 and 4.0 burs in the CCW mode drastically increased the temperature and produced significant chatter.

Understanding bone surface curvatures is crucial for the advancement of bone material design, as these curvatures play a significant role in the mechanical behavior and functionality of bone structures. Previous studies have demonstrated that bone surface curvature distributions could be used to characterize bone geometry and have been proposed as key parameters for biomimetic microstructure design and optimization. However, understanding of how bone surface curvature distributions correlate with bone microstructure and mechanical properties remains limited. This study hypothesized that bone surface curvature distributions could be used to predict the microstructure as well as mechanical properties of trabecular bone. To test the hypothesis, a convolutional neural network (CNN) model was trained and validated to predict the histomorphometric parameters (e.g., BV/TV, BS, Tb.Th, DA, Conn.D, and SMI), geometric parameters (e.g., plate area PA, plate thickness PT, rod length RL, rod diameter RD, plate-to-plate nearest neighbor distance NND_PP, rod-to-rod nearest neighbor distance NND_RR, plate number PN, and rod number RN), as well as the apparent stiffness tensor of trabecular bone using various bone surface curvature distributions, including maximum principal curvature distribution, minimum principal curvature distribution, Gaussian curvature distribution, and mean curvature distribution. The results showed that the surface curvature distribution-based deep learning model achieved high fidelity in predicting the major histomorphometric parameters and geometric parameters as well as the stiffness tenor of trabecular bone, thus supporting the hypothesis of this study. The findings of this study underscore the importance of incorporating bone surface curvature analysis in the design of synthetic bone materials and implants.

Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs), a biologically active compound derived from selenium polysaccharides, have demonstrated potential in addressing obesity. However, the mechanism through which LCS-SeNPs alleviate high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) remains unclear. Our results elucidated that LCS-SeNPs significantly inhibited fat accumulation and markedly improved the intestinal barrier by increasing mucus secretion from goblet cells. Moreover, LCS-SeNPs reshaped intestinal flora composition by increasing the abundance of mucus-associated microbiota (Bifidobacterium, Akkermansia, and Muribaculaceae_unclassified) and decreasing the abundance of obesity-contributed bacterium (Anaerotruncus, Lachnoclostridium, and Proteus). The modulation of intestinal microbiota by LCS-SeNPs influenced several metabolic pathways, including bile acid secretion, purine metabolites, and tryptophan derivation. Meanwhile, glycocholic acid and tauro-beta-muricholic acid were significantly reduced in the LCS-SeNP group. Our study suggests the crucial role of intestinal microbiota composition and metabolism, providing a new theoretical foundation for utilizing selenium polysaccharides in the intervention of HFD-induced NAFLD.

Background: Removable prostheses have seen a fundamental change recently because of advances in polymer materials, allowing improved durability and performance. Despite these advancements, notable differences still occur amongst various polymer materials and processing technologies, requiring a thorough grasp of their mechanical, physical, and therapeutic implications. The compressive strength of dentures manufactured using various technologies will be investigated.

Methods: Traditional, injection molding, and additive and subtractive CAD/CAM processing techniques, all utilizing Polymethyl methacrylate (PMMA) as the main material, were used to construct complete dentures. The specimens underwent a compressive mechanical test, which reveals the differences in compressive strength.

Results: All the specimens broke under the influence of a certain force, rather than yielding through flow, as is characteristic for plastic materials. For each specimen, the maximum force (N) was recorded, as well as the breaking energy. The mean force required to break the dentures for each processing technology is as follows: 4.54 kN for traditional packing-press technique, 17.92 kN for the injection molding technique, 1.51 kN for the additive CAD/CAM dentures, and 5.9 kN for the subtractive CAD/CAM dentures.

Conclusions: The best results were obtained in the case of the thermoplastic injection system and the worst results were recorded in the case of 3D printed samples. Another important aspect depicted is the standard deviation for each group, which reveal a relatively unstable property for the thermoplastic injected dentures. Good results here in terms of absolute property and stability of the property can be conferred to CAD/CAM milled group.

Lymphedema presents significant challenges to patients' quality of life, prompting the exploration of innovative treatments, such as collagen scaffolds, aimed at treating and reducing the risk of lymphedema. We aimed to evaluate the preventive and therapeutic efficacy and the lymphangiogenic potential of implanted aligned nanofibrillar collagen scaffolds (BioBridge^TM) following the induction of secondary lymphedema in a rabbit model. Thirty rabbits were divided into treatment (G1), prevention (G2), and control (G3) groups. Secondary lymphedema was induced in all groups. BioBridge^TM implantation was performed in G2 and G1 on days 0 and 60, respectively. Follow-ups included hindlimb circumference measurements and indocyanine green lymphography at 0, 60, and 90 days. None of the study rabbits exhibited dermal backflow on day 0 before surgery. At 60 days, the incidence rates of dermal backflow in G1, G2, and G3 were 100%, 44.4%, and 90%, respectively. Furthermore, at 90 days, the incidence rates were 22.2%, 44.4%, and 90%, respectively. New linear lymphatic observation was seen in rabbits with resolved dermal backflow. The findings of this study demonstrated the capacity of BioBridge^TM scaffolds to induce new lymphatic vessel formation and reduce dermal backflow in secondary lymphedema in a rabbit model.