Attapulgite-enhanced ε-poly-l-lysine for heightened antibacterial efficiency against Pseudomonas syringae pv. Tomato.

ε-Poly-l-lysine (ε-PL) is an effective antimicrobial peptide for controlling fungal plant diseases, exhibiting significant antifungal activity and safety. Despite its known efficacy, the potential of ε-PL in combating plant bacterial diseases remains underexplored. This study evaluated the effectiveness of ε-PL and its nanomaterial derivative in managing tomato bacterial spot disease caused by Pseudomonas syringae pv. tomato. Results indicated that ε-PL substantially inhibited the growth of Pseudomonas syringae pv. tomato. Additionally, when ε-PL was loaded onto attapulgite (encoded as ATT@PL), its antibacterial effect was significantly enhanced. Notably, the antibacterial efficiency of ATT@PL containing 18.80 µg/mL ε-PL was even close to that of 100 µg/mL pure ε-PL. Further molecular study results showed that, ATT@PL stimulated the antioxidant system and the salicylic acid signaling pathway in tomatoes, bolstering the plants disease resistance. Importantly, the nanocomposite demonstrated no negative effects on both seed germination and plant growth, indicating its safety and aligning with sustainable agricultural practices. This study not only confirmed the effectiveness of ε-PL in controlling tomato bacterial spot disease, but also introduced an innovative high antibacterial efficiency ε-PL composite with good bio-safety. This strategy we believe can also be used in improving other bio-pesticides, and has high applicability in agriculture practice.

Fabrication and characterization of sodium alginate-silicon nitride-PVA composite biomaterials with damping properties.

Silicon nitride is utilized clinically as a bioceramic for spinal fusion cages, owing to its high strength, osteoconductivity, and antibacterial effects. Nevertheless, silicon nitride exhibits suboptimal damping properties, a critical factor in mitigating traumatic bone injuries and fractures. In fact, there is a scarcity of spinal implants that simultaneously demonstrate proficient damping performance and support osteogenesis. In our study, we fabricated a novel sodium alginate-silicon nitride/poly(vinyl alcohol) (SA-SiN/PVA) composite scaffold, enabling enhanced energy absorption and rapid elastic recovery under quasi-static and impact loading scenarios. Furthermore, the study demonstrated that the incorporation of physical and chemical cross-linking significantly improved stiffness and recoverable energy dissipation. Concerning the interaction between cells and materials, our findings suggest that the addition of silicon nitride stimulated osteogenic differentiation while inhibiting Staphylococcus aureus growth. Collectively, the amalgamation of ceramics and tough hydrogels facilitates the development of advanced composites for spinal implants, manifesting superior damping, osteogenic potential, and antibacterial properties. This approach holds broader implications for applications in bone tissue engineering.

Investigation on the Osteogenic and Antibacterial Properties of Silicon Nitride-Coated Titanium Dental Implants.

The silicon nitride (Si3N4) coating exhibits promising potential in oral applications due to its excellent osteogenic and antibacterial properties. However, a comprehensive investigation of Si3N4 coatings in the context of dental implants is still lacking, especially regarding their corrosion resistance and in vivo performance. In this study, Si3N4 coatings were prepared on a titanium surface using the nonequilibrium magnetron sputtering method. A systematic comparison among the titanium group (Ti), Si3N4 coating group (Si3N4-Ti), and sandblasted and acid-etched-treated titanium group (SLA-Ti) has been conducted in vitro and in vivo. The results showed that the Si3N4-Ti group had the best corrosion resistance and antibacterial properties, which were mainly attributed to the dense structure and chemical activity of Si-O and Si-N bonds on the surface. Furthermore, the Si3N4-Ti group exhibited superior cellular responses in vitro and new bone regeneration and osseointegration in vivo, respectively. In this sense, silicon nitride coating shows promising prospects in the field of dental implantology.

Virological evaluation of natural and modified attapulgite against porcine epidemic diarrhoea virus.

BACKGROUND: The Porcine Epidemic Diarrhea Virus (PEDV) has caused significant economic losses in the global swine industry. As a potential drug for treating diarrhea, the antiviral properties of attapulgite deserve further study. METHODS: In this study, various methods such as RT-qPCR, Western blot, viral titer assay, Cytopathic Effect, immunofluorescence analysis and transmission electron microscopy were used to detect the antiviral activity of attapulgite and to assess its inhibitory effect on PEDV. RESULTS: When exposed to the same amount of virus, there was a significant decrease in the expression of the S protein, resulting in a viral titer reduction from 10-5.613 TCID50/mL to 10-2.90 TCID50/mL, which represents a decrease of approximately 102.6 folds. Results of cytopathic effect and indirect immunofluorescence also indicate a notable decrease in viral infectivity after attapulgite treatment. Additionally, it was observed that modified materials after acidification had weaker antiviral efficacy compared to powdered samples that underwent ultrasonic disintegration, which showed the strongest antiviral effects. CONCLUSION: As a result, Attapulgite powders can trap and adsorb viruses to inhibit PEDV in vitro, leading to loss of viral infectivity. This study provides new materials for the development of novel disinfectants and antiviral additives.

Instantaneous Inactivation of Herpes Simplex Virus by Silicon Nitride Bioceramics.

Hydrolytic reactions taking place at the surface of a silicon nitride (Si3N4) bioceramic were found to induce instantaneous inactivation of Human herpesvirus 1 (HHV-1, also known as Herpes simplex virus 1 or HSV-1). Si3N4 is a non-oxide ceramic compound with strong antibacterial and antiviral properties that has been proven safe for human cells. HSV-1 is a double-stranded DNA virus that infects a variety of host tissues through a lytic and latent cycle. Real-time reverse transcription (RT)-polymerase chain reaction (PCR) tests of HSV-1 DNA after instantaneous contact with Si3N4 showed that ammonia and its nitrogen radical byproducts, produced upon Si3N4 hydrolysis, directly reacted with viral proteins and fragmented the virus DNA, irreversibly damaging its structure. A comparison carried out upon testing HSV-1 against ZrO2 particles under identical experimental conditions showed a significantly weaker (but not null) antiviral effect, which was attributed to oxygen radical influence. The results of this study extend the effectiveness of Si3N4's antiviral properties beyond their previously proven efficacy against a large variety of single-stranded enveloped and non-enveloped RNA viruses. Possible applications include the development of antiviral creams or gels and oral rinses to exploit an extremely efficient, localized, and instantaneous viral reduction by means of a safe and more effective alternative to conventional antiviral creams. Upon incorporating a minor fraction of micrometric Si3N4 particles into polymeric matrices, antiherpetic devices could be fabricated, which would effectively impede viral reactivation and enable high local effectiveness for extended periods of time.

Alkylated chitosan-attapulgite composite sponge for rapid hemostasis.

This study reported the development of a composite sponge (ACATS) based on alkylated chitosan (AC) and attapulgite (AT) for rapid hemostasis. The well-designed ACATS, with an optimal AC N-alkylation of 5.9 % and an optimal AC/AT mass ratio of 3:1, exhibited a hierarchical porous structure with a favorable biocompatibility. The ACATS can effectively and rapidly stop the uncontrolled bleeding in 235 ± 64 s with a total blood loss of 8.4 ± 4.0 g in comparison with those of Celox as a positive control (602 ± 101 s and 22.3 ± 2.4 g, respectively) using rabbit carotid artery injury model in vivo. ACATS could rapidly interact with blood and its components, including platelets (PLs), red blood cells (RBCs), and coagulation factors, resulting in these blood components rapidly accumulation and the following thrombus formation and coagulation factors activation.

Silicon Nitride as a Biomedical Material: An Overview.

Silicon nitride possesses a variety of excellent properties that can be specifically designed and manufactured for different medical applications. On the one hand, silicon nitride is known to have good mechanical properties, such as high strength and fracture toughness. On the other hand, the uniqueness of the osteogenic/antibacterial dualism of silicon nitride makes it a favorable bioceramic for implants. The surface of silicon nitride can simultaneously inhibit the proliferation of bacteria while supporting the physiological activities of eukaryotic cells and promoting the healing of bone tissue. There are hardly any biomaterials that possess all these properties concurrently. Although silicon nitride has been intensively studied as a biomedical material for years, there is a paucity of comprehensive data on its properties and medical applications. To provide a comprehensive understanding of this potential cornerstone material of the medical field, this review presents scientific and technical data on silicon nitride, including its mechanical properties, osteogenic behavior, and antibacterial capabilities. In addition, this paper highlights the current and potential medical use of silicon nitride and explains the bottlenecks that need to be addressed, as well as possible solutions.

Naringin: antitumor potential in silico and in vitro on bladder cancer cells

Introduction: Urothelial carcinoma is a significant public health problem. Transitional cell carcinoma (TCC) is the most common subtype, accounting for approximately 90 % of all bladder cancers. Chemotherapeutic protocols have been studied, but some present high toxicity and low tolerability. Naringin is a polyphenolic compound found mainly in citrus fruits, which antitumor activity has been studied in several types of cancer. However, there is little information about naringin effects on bladder cancer. This study aimed to evaluate the antitumor potential of naringin in silico and in vitro using two bladder cancer cell lines. Method: In silico analysis was carried out by PASS Online software. In vitro , the effects of naringin treatment (12.5 - 400 µM) were evaluated regarding its cytotoxicity, clonogenic survival, morphological alterations, cell cycle progression, migration, and mutagenicity Results: In silico analyses predicted antitumor activity through several mechanisms of action. In vitro results showed naringin presented cytotoxic effects, reduced the number of colonies, inhibited cell migration, and changed the morphology and cell cycle progression of the two cell lines evaluated. However, naringin did not present mutagenic effects. Conclusions: Naringin has antiproliferative activity and is a promising candidate for bladder cancer treatment.(AU)

Introducción: El carcinoma urotelial es un problema de salud pública importante. El carcinoma de células de transición es el subtipo más común y representa aproximadamente el 90 % de todos los cánceres de vejiga. Se han estudiado protocolos quimioterapéuticos, pero algunos presentan alta toxicidad y baja tolerabilidad. La naringina es un compuesto polifenólico que se encuentra principalmente en los cítricos, cuya actividad antitumoral se ha estudiado en varios tipos de cáncer. Sin embargo, hay poca información sobre los efectos de la naringina en el cáncer de vejiga. Este estudio tuvo como objetivo evaluar el potencial antitumoral de la naringina in silico e in vitro utilizando dos líneas celulares de cáncer de vejiga. Método: El análisis in silico se llevó a cabo mediante el software PASS Online. In vitro, se evaluaron los efectos del tratamiento con naringina (12,5 - 400 µM) en cuanto a su citotoxicidad, supervivencia clonogénica, alteraciones morfológicas, progresión del ciclo celular, migración y mutagenicidad. Resultados: los análisis in silico predijeron la actividad antitumoral a través de varios mecanismos de acción. Los resultados in vitro mostraron que la naringina presentó efectos citotóxicos, redujo el número de colonias, inhibió la migración celular y cambió la morfología y la progresión del ciclo celular de las dos líneas celulares evaluadas. Sin embargo, la naringina no presentó efectos mutagénicos. Conclusiones: la naringina tiene actividad antiproliferativa y es un candidato prometedor para el tratamiento del cáncer de vejiga.(AU)

Multifunctional Ca-Zn-Si-based micro-nano spheres with anti-infective, anti-inflammatory, and dentin regenerative properties for pulp capping application.

While pulp capping using a variety of materials has been applied clinically to preserve the health and vitality of the dental pulp and induce dentin repair no material meets all the anti-infection, anti-inflammation, and promoting pulp tissue regeneration criteria. Micro-nano materials of bioactive glasses (BG) with the biocompatibility and osteogenesis-promoting properties were developed for this study using Zn-doped bioactive glass (BGz) micro-nano spheres for dental pulp capping to control infection and inflammation and promote tissue regeneration. Of three key findings, the co-culture of Porphyromonas gingivalis showed that the BGz had an excellent antibacterial effect, and after being stimulated with BGz in vitro, macrophages showed a significant decrease of pro-inflammatory M1 markers compared with the undoped BG group. It is also noted that the conditioned medium derived from BGz-stimulated macrophages could significantly promote mineralized dentin formation of dental pulp cells (DPCs). In rats, acute pulp restoration experiments proved that BGz used as a pulp capping agent had excellent dentin regenerative properties. This work may provide a novel strategy to promote osteo/dentinogenic differentiation through regulating early inflammation, with potential applications in pulp capping.

Development of hydrofluoric acid-cleaned silicon nitride implants for periprosthetic infection eradication and bone regeneration enhancement.

Orthopedic implant is commonly associated with occurrence or relapse of osteomyelitis. This study developed a hydrofluoric acid (HF) cleaned silicon nitride (Si3N4) implant Si3N4_AC for osteomyelitis control and established a rat tibial osteomyelitis model to evaluate its efficacy on eradicating periprosthetic infection and enhancing bone regeneration. In vitro studies revealed Si3N4_AC had improved biocompatibility and inhibited Staphylococcus aureus adhesion. A custom-made Si3N4_AC implant was prepared and inserted into the rat tibia longitudinal cavity inoculated with Staphylococcus aureus. The in vivo bacteriostatic and osteogenic efficacies of Si3N4_AC implant were evaluated by histological, microbiological and Micro-CT analyses and compared with implants of pure Ti and Si3N4 . Si3N4_AC implant group revealed 99.5% inhibition of periprosthetic Staphylococcus aureus compared to the osteomyelitis group after 14 days post-operation. Implant-adhering bacteria density of Si3N4_AC was also much lower than pure Ti and Si3N4. In addition, micro-CT evaluation of peri-implant bone formation under the condition of periprosthetic osteomyelitis after 30 days post-surgery confirmed the osteogenic ability of Si3N4_AC. Taken together, Si3N4_AC can be an effective orthopedic biomaterial to eradicate periprosthetic infection and enhance bone regeneration.

Photothermal treatment of oropharyngeal cancer with carbon-defective silicon carbide.

Oral squamous carcinoma (OSCC) is a clinical common tumor with high recurrence rate and low 5 year survival rate. In this work, photothermal antitumor treatment has been performed to treat OSCC by taking anti-wound infection into consideration. By introducing C defects, we have successfully converted the semi-conductive SiC into metallic carbon-defective silicon carbide (SiC1-x), and endowed it with the near infrared absorption property for photothermal therapy (PTT). The results revealed that SiC1-x mediated PTT treatment could remove solid OSCC tumor in a biosafe way, showing low hematotoxicity, cytotoxicity and tissue toxicity. Moreover, the low invasion of PTT treatment could not only prevent the invasion of bacteria, but also realize an antibacterial effect on the wound, both of which are important for oral surgery. SiC1-x could be excreted from the body post treatment, which thus reduces the long-term potential toxicity. On the whole, this study provided a promising way to treat OSCC in an effective and safe way.

Bone screws of porous silicon carbide coated with tantalum improve osseointegration and osteogenesis in goat femoral neck fractures.

Traditional metal materials, such as stainless steel and titanium (Ti) alloys, are still the gold standards for fracture fixation. However, the elastic moduli of these materials differ from that of human cortical bone, and the stress shielding effect affects fracture healing, leading to secondary fractures. Herein, a new porous Ta coated SiC (pTa-SiC) scaffold using in internal fixation devices with good mechanical and biological properties was prepared based on porous silicon carbide (SiC) scaffold and tantalum (Ta) metal. The osteogenic and osseointegration properties of the pTa-SiC scaffold were investigated by bothin vitroandin vivotests. The results showed that compared with porous titanium (pTi), the pTa-SiC promoted the proliferation, migration, and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells. Moreover, the internal fixation tests were carried out in a goat load-bearing femoral neck fracture model. Histological results showed good osseointegration around the pTa-SiC screws. And the acid etching results showed that bone cells grew tightly on the pTa-SiC throughout bone canaliculi, and the growth mode was contact osteogenesis, which indicated good biological fixation effects. Therefore, it is reasonable to be expected that the new pTa-SiC scaffold with excellent mechanical and biological properties could be a promising candidate for bone implant field.

Reinforced Supramolecular Hydrogels from Attapulgite and Cyclodextrin Pseudopolyrotaxane for Sustained Intra-Articular Drug Delivery.

Injectable hydrogels for nonsteroidal anti-inflammatory drugs' (NSAIDs) delivery to minimize the side effects of NSAIDs and achieve long-term sustained release at the targeted site of synovial joint are attractive for osteoarthritis therapy, but how to improve its mechanical strength remains a challenge. In this work, a kind of 1D natural clay mineral material, attapulgite (ATP), is introduced to a classical cyclodextrin pseudopolyrotaxane (PPR) system to form a reinforced supramolecular hydrogel for sustained release of diclofenac sodium (DS) due to its rigid, rod-like morphology, and unique structure, which has great potential in tissue regeneration, repair, and engineering. Investigation on the interior morphology and rheological property of the obtained hydrogel points out that the ATP distributed in PPR hydrogel plays a role similar to the "reinforcement in concrete" and exhibits a positive effect on improving the mechanical properties of PPR hydrogel by regulating their interior morphology from a randomly distributed style to the well-ordered porous frame structure. The hybrid hydrogels demonstrate good shear-thinning and thixotropic properties, excellent biocompability, and sustained release behavior both in vitro and in vivo. Furthermore, preliminary in vivo treatment in an acute inflammatory rat model reveals that the ATP hybrid hydrogels present sustained anti-inflammatory effect.

An upgraded and universal strategy to reinforce chitosan/polyvinylpyrrolidone film by incorporating active silica nanorods derived from natural palygorskite.

Active silica nanorod (OPal) was prepared from natural palygorskite (RPal) using an updated acid leaching route, and then the effect of RPal and OPal as nano-filler on the network structure, mechanical, thermal and anti-aging properties of chitosan/polyvinylpyrrolidone (CS/PVP) films was studied comparatively. It was revealed that OPal had a better dispersibility than RPal in CS/PVP substrate, and its incorporation improved the mechanical properties and thermal stability of the films significantly. The optimal composite film containing OPal shows the maximum tensile strength of 27.53 MPa (only 14.87 MPa and 22.47 MPa for CS/PVP and CS/PVP/RPal films, respectively), resulting from the more uniform dispersion of OPal in polymer substrate and its stronger interaction with 3D polymer network. By a controllable acid-leaching process, the metal ions in octahedral sheets of RPal were dissolved out continuously, which is favorable to alleviate the adverse effects of variable metal ions on the film under UV light irradiation, and thus improve the aging-resistant ability of films. This study provides new ideas for improving the reinforcing ability of natural clay minerals towards biopolymer-based material, finds a new way to resolve the aging problem of polymer composites caused by incorporation of natural clay minerals.

Surface functionalization of PEEK with silicon nitride.

Surface roughness, bioactivity, and antibacterial properties are desirable in skeletal implants. We hot-pressed a mix of particulate sodium chloride (NaCl) salt and silicon nitride (ß-Si3N4) onto the surface of bulk PEEK. NaCl grains were removed by leaching in water, resulting in a porous PEEK surface embedded with sim15 vol% ß-Si3N4particles. This functionalized surface showed the osteogenic and antibacterial properties previously reported in bulk silicon nitride implants. Surface enhancement of PEEK with ß-Si3N4could improve the performance of spinal fusion cages, by facilitating arthrodesis and resisting bacteria.

Effect of Attapulgite-Doped Electrospun Fibrous PLGA Scaffold on Pro-Osteogenesis and Barrier Function in the Application of Guided Bone Regeneration.

PURPOSE: Guided bone regeneration (GBR) therapy, which is a widely used technique in clinical practice and is effective in improving the repair of alveolar bone defects or bone mass deficiency regeneration, requires the use of membrane materials with good biocompatibility, barrier function, rigidity matching the space maintenance ability, economic benefits and excellent clinical applicability. The aim of this study was to develop an electrospun attapulgite (ATT)-doped poly (lactic-co-glycolic acid) (PLGA) scaffold (PLGA/ATT scaffold) as a novel material for GBR applications. METHODS AND RESULTS: Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to determine the morphology and the crystalline structure of the PLGA/ATT scaffolds, respectively. Porosity and contact-angle measurements were also carried out to further characterize the physical properties of the PLGA/ATT scaffolds. The results of in vitro studies showed that bone marrow mesenchymal stem cells (BMSCs) attached more readily to and spread better over the PLGA/ATT scaffolds than the Bio-Gide membrane. Furthermore, in the in vitro osteoinductive experiments with BMSCs, the PLGA/ATT scaffolds were found to enhance the activity of alkaline phosphatase (ALP), promote the formation of mineralized bone nodules, and up-regulate the expression of several osteogenic markers-namely, runt-related transcription factor 2, alkaline phosphatase, osteopontin, and osteocalcin-which are similar to the effects of the Bio-Gide membrane. Further, in in vivo studies, the results of sequential fluorescent labeling, micro-computed tomography, and histological analysis suggest that using the PLGA/ATT scaffolds for repairing V-shaped buccal dehiscence on a dog's tooth root improved bone regeneration, which is not only similar to the result obtained using the Bio-Gide membrane but also much better than that obtained using PLGA scaffolds and the negative control. CONCLUSION: To achieve satisfactory therapeutic results and to lower the cost of GBR treatment, this study provided a promising alternative material of bio-degradable membrane in clinical treatment.

Protein adsorption and in vitro behavior of additively manufactured 3D-silicon nitride scaffolds intended for bone tissue engineering.

Highly porous scaffolds of Si3N4 are fabricated by direct ink writing method (Robocasting) with a pattern of macroporous cavities of 650-700µm. Two different Si3N4 ink compositions regarding the oxide sintering aids (namely, Y2O3, Al2O3, and SiO2) are tried. Both inks reach solid volume fractions of ~0.40 with about 10-12wt% of polymeric additive content that imparts the necessary pseudoplastic characteristics. The printed structures are sintered under controlled N2 atmosphere either in a conventional graphite furnace or by the spark plasma sintering technique. Skeleton of the scaffolds reaches densities above 95% of the theoretical value with ≈18-24% of linear shrinkage. Analysis of the crystalline phases, microstructure and mechanical properties are comparatively done for both compositions. The bioactivity of these structures is addressed by evaluating the ion release rate in simulated body fluid. In parallel, atomic force microscopy is used to determine the effect of the filaments surface roughness on protein adsorption (Bovine Serum Albumin) for assessing the potential application of 3D-Si3N4 scaffolds in bone regeneration.

Injectable gellan gum/lignocellulose nanofibrils hydrogels enriched with melatonin loaded forsterite nanoparticles for cartilage tissue engineering: Fabrication, characterization and cell culture studies.

Injectable hydrogels based on natural polysaccharides have attracted considerable attention in cartilage tissue engineering, especially those reinforced with mineral nanofilers carrying drug molecules. Here, a novel injectable hydrogel based on gellan gum (GG)/lignocellulose nanofibrils (LGNF) composite enriched with melatonin (MEL) loaded forsterite (FS) nanoparticles (FS-MEL) was developed to yield enhanced mechanical and biological properties of the hydrogels. Gelation time and temperature were determined for different hydrogel formulation containing 1-5 w/v% LGNF and 0.1-0.3 w/v% FS-MEL. The injectability test proved the ease of injection of the developed hydrogels. Degradation rate and swelling degree of developed hydrogel were evaluated to determine the effect of LGNF and FS on hydrogel behaviour. Results of mechanical characterization showed that the compressive modulus and strength of GG hydrogels were improved by incorporation of LGNF and FS. The results of MEL release study in PBS revealed that MEL showed more sustained release from the hydrogel compared to FS nanoparticles. Cell-hydrogels interaction was evaluated by culturing chondrocyte cells. Results exhibited higher cell adhesion, proliferation and gene expression on GG/LGNF/FS-MEL hydrogel compared to GG/LGNF and GG/LGNF/FS, which can be attributed to the synergic effect of FS and MEL. Overall results demonstrated that the developed GG/LGNF/FS-MEL hydrogels can be offered as promising materials for cartilage regeneration applications.

The role of nitrogen off-stoichiometry in the osteogenic behavior of silicon nitride bioceramics.

The surface chemistry of silicon nitride plays an important role in stimulating osteoblasts to proliferate and produce bone tissue with improved efficiency. This property, which is advantageous in spinal fusion surgery has a chemical origin and is a direct consequence of the cleavage of covalent SN bonds in an aqueous environment. Building upon a wealth of published research on the stimulation of osteoblastic activity by silicon, the aim of this paper is to explore the role of nitrogen and, more specifically, the N/Si atomic ratio on the osteogenic response of Si3N4. The surface stoichiometry of Si3N4 was gradually altered toward a silicon-rich composition by systematically treating the Si3N4 surface with a high-power pulsed laser in an Ar gas atmosphere (i.e., operated at different pulse times, spot sizes, and voltages). Different analytical probes were used to characterize the surface including X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and energy dispersive X-ray spectroscopy (EDS). Osteoconductivity was tested in vitro using SaOS-2 osteosarcoma cells, and samples with different surface stoichiometry were compared for their osteogenic response. These experiments clearly indicated a fundamental role for nitrogen off-stoichiometry in osteogenesis, and showed that both cell proliferation and growth of bone tissue diminished with decreasing nitrogen content.

Biocompatibility between Silicon or Silicon Carbide surface and Neural Stem Cells.

Silicon has been widely used as a material for microelectronic for more than 60 years, attracting considerable scientific interest as a promising tool for the manufacture of implantable medical devices in the context of neurodegenerative diseases. However, the use of such material involves responsibilities due to its toxicity, and researchers are pushing towards the generation of new classes of composite semiconductors, including the Silicon Carbide (3C-SiC). In the present work, we tested the biocompatibility of Silicon and 3C-SiC using an in vitro model of human neuronal stem cells derived from dental pulp (DP-NSCs) and mouse Olfactory Ensheathing Cells (OECs), a particular glial cell type showing stem cell characteristics. Specifically, we investigated the effects of 3C-SiC on neural cell morphology, viability and mitochondrial membrane potential. Data showed that both DP-NSCs and OECs, cultured on 3C-SiC, did not undergo consistent oxidative stress events and did not exhibit morphological modifications or adverse reactions in mitochondrial membrane potential. Our findings highlight the possibility to use Neural Stem Cells plated on 3C-SiC substrate as clinical tool for lesioned neural areas, paving the way for future perspectives in novel cell therapies for neuro-degenerated patients.