Birmingham hip resurfacing (BHR) is an alternative to bone-sparing total hip arthroplasty; however, failures may be associated with the cementing technique. This study aimed to evaluate the characteristics of the cement layer and potential failure mechanisms. BHR explants were analyzed using radiographic evaluation, stereomicroscopy, scanning electron microscopy (SEM), and histopathology. The cement layer was nonuniform, with excessive thickness in the dome regions and insufficient lateral coverage. Increased cement penetration values exceeded recommended thresholds. SEM analysis revealed inhomogeneous cement with cracks, air inclusions, and loosening at the cement-prosthesis interface. BHR failure may be associated with a complex interplay between cementation parameters, cement mantle morphology, and the biological response at the bone-cement interface, as well as interactions at the cement-prosthesis interface. Microscopic evaluation may provide valuable insights into the mechanisms potentially contributing to BHR prosthesis failure.

Objectives: In dental implantology, the priorities in scientific research are to identify solutions that guarantee a beneficial biomaterial-tissue interaction, both in terms of implant biointegration and protection against infections. The experimental approach consisted of chemical deposition of silver (Ag), silver and hydroxyapatite (HAP) on a TiZr metallic support. The aim of the research is to study the influence of hydroxyapatite on the possible adverse effects produced by silver in antibacterial coatings. Methods: The characterization of the coating was performed by scanning electron microscopy (SEM) and EDS spectroscopy, XRD diffraction and FT-IR infrared analysis. In vitro cell viability and adhesion testing was performed by quantitative (MTT) and qualitative fluorescence-based assays on samples (without deposition and with chemical deposition), in the presence of human fetal osteoblasts (hFOB cell line) after 8 days of incubation. Results: The findings of the study indicate an increase in cell viability by combining silver with hydroxyapatite. Preliminary data indicated a cell viability of 20% when the metal support is coated exclusively with silver and 60% in the presence of hydroxyapatite in the silver coating. Conclusions: The experimental study offers insights into the potential cytotoxic effects of silver in antibacterial coatings. Co-deposition with hydroxyapatite improved osteoblast viability compared to surfaces coated with silver alone, indicating that it may have a beneficial effect in Ag-based surface functionalization. The underlying mechanism (e.g., modulation of silver species/ion release) was not directly quantified in this work and should be addressed in future studies.

Background/Objectives: The clinical application of CAD/CAM restorative materials continues to evolve due to increasing demand for aesthetic, durable, and minimally invasive indirect restorations. Hybrid nanoceramics, such as Grandio disc (VOCO GmbH, Cuxhaven, Germany), are increasingly used in indirect restorative dentistry due to their favourable combination of mechanical strength, polishability, wear resistance, and bonding potential. One challenge associated with adhesive protocols for CAD/CAM materials lies in achieving durable bonds with resin cements. Extensive post-polymerization during fabrication reduces the number of unreacted monomers available for chemical interaction, thereby limiting the effectiveness of traditional adhesive strategies and necessitating specific surface conditioning approaches. This study aimed to evaluate, in a preliminary, non-inferential manner, the influence of several combined conditioning protocols on surface micromorphology, elemental composition, and descriptive SBS trends of a CAD/CAM hybrid nanoceramic. This work was designed as a preliminary pilot feasibility study. Due to the limited number of specimens (two discs per protocol, each providing two independent enamel bonding measurements), all bond strength outcomes were interpreted descriptively, without inferential statistical testing. This in vitro study investigated the effects of various surface conditioning protocols on the adhesive performance of CAD/CAM hybrid nanoceramics (Grandio disc, VOCO GmbH, Cuxhaven, Germany) to dental enamel. Hydrofluoric acid (HF) etching was performed to improve adhesion to indirect resin-based materials using two commercially available gels: 9.5% Porcelain Etchant (Bisco, Inc., Schaumburg, IL, USA) and 4.5% IPS Ceramic Etching Gel (Ivoclar Vivadent, Schaan, Liechtenstein), in combination with airborne-particle abrasion (APA), silanization, and universal adhesive application. HF may selectively dissolve the inorganic phase, while APA increases surface texture and micromechanical retention. However, existing literature reports inconsistent results regarding the optimal conditioning method for hybrid composites and nanoceramics, and the relationship between micromorphology, elemental surface changes, and adhesion remains insufficiently clarified. Methods: A total of ten composite specimens were subjected to five conditioning protocols combining airborne-particle abrasion with varying hydrofluoric acid (HF) concentrations and etching times. Bonding was performed using a dual-cure resin cement (BiFix QM) and evaluated by shear bond strength (SBS) testing. Surface morphology was examined through environmental scanning electron microscopy (ESEM), and elemental composition was analyzed via energy-dispersive X-ray spectroscopy (EDS). Results: indicated that dual treatment with HF and sandblasting showed descriptively higher SBS, with values ranging from 5.01 to 6.14 MPa, compared to 1.85 MPa in the sandblasting-only group. ESEM revealed that higher HF concentrations (10%) created more porous and irregular surfaces, while EDS indicated an increased fluorine presence trend and silicon reduction, indicating deeper chemical activation. However, extending HF exposure beyond 20 s did not further improve bonding, suggesting the importance of protocol optimization. Conclusions: The preliminary observations suggest a synergistic effect of mechanical and chemical conditioning on hybrid ceramic adhesion, but values should be interpreted qualitatively due to the pilot nature of the study. Manufacturer-recommended air abrasion alone may provide limited adhesion under high-stress conditions, although this requires confirmation in studies with larger sample sizes and ageing simulations. Future studies should address long-term durability and extend the comparison to other hybrid CAD/CAM materials and to other etching protocols.

Background/Objectives: The main objective of optimizing the composition of dental implants is to improve tissue compatibility for enhanced biological/biochemical performance. In this context, research on the development of new titanium alloys in dental implantology considers the careful selection of alloying elements, both in terms of biocompatibility (their lack of toxicity) and their potential to improve the metallurgical processing capacity (thermal and/or thermomechanical), which through controlled microstructural changes lead to the optimal combination of properties for functionality and durability of the implant. The purpose of the research is to study the influence of alloying elements on the phase composition and physical-mechanical properties of experimental titanium alloys. Methods: Four alloys with original chemical compositions were developed, coded in the experiments as follows: Ti1, Ti2, Ti3, Ti4. The characterization of the alloys was carried out by detailed analysis of the chemical composition, phase structure and by testing the physico-mechanical properties (HV hardness, tensile strength, yield strength, elongation, modulus of elasticity), by standardized modern methods. Characterization methods, such as optical microscopy, SEM, EDS and XRD were performed, followed by tensile tests based on ASTM EB/EBM-22 and EN ISO 6892-1-2009 standards. Results: The research results provide information regarding the relationship between the composition and the physico-mechanical properties (Rm, Rp, HV, A, G, E) of the experimental alloys (Ti1-Ti4). Depending on the value level of the properties, these have been highlighted: compositions in which the alloy can be indicated for conditions of intense stress (Ti3), compositions that describe highly ductile alloys, easy to process and adapt to clinical requirements (Ti4), but also alloys compositions characterized by a balanced combination of strength, plasticity/ductility (Ti1, Ti2). Conclusions: Research for the development of new titanium alloys through the optimization of chemical composition has taken into account the requirements regarding the biological/biomechanical compatibility of biomaterials. Analyzed in comparison with Cp-Ti grade 4 and Ti6A4V, the experimental alloys (Ti1-Ti4) can be characterized as follows: The mechanical strength properties (Rm and Rp) are higher than those of pure commercial titanium (Cp-Ti grade 4) for all compositions Ti1-Ti4, but slightly lower than those of alloy Ti6Al4V. The plasticity-ductility properties have values comparable to those of Cp-Ti grade 4 (Ti4 and Ti2 compositions) and Ti6Al4V (Ti1 composition), with one exception, the Ti3 alloy. All four experimental alloys have a lower modulus of elasticity than Cp-Ti grade 4 (102-104 GPa) and Ti6Al4V (113 GPa), commonly used in dental implants. An in-depth analysis, which will also consider information on corrosion behavior and cellular testing, may support the selection of some of the four experimental alloys studied. The research aims to continue the progress to a higher level of testing, through the realization of dental implants (e.g., fatigue, wear, osteointegration capacity, etc.).

In this study, biocomposite filaments based on alginic acid (sodium salt) reinforced with cotton fibres (length of 2 ± 0.5 mm) were developed. The polymeric matrix was prepared using alginic acid at a concentration of 1%, while cotton fibres were incorporated at concentrations of 0.5%, 1%, and 1.5%. The synthesis of biocomposite filaments was carried out using the wet spinning technique employing a mechanically actuated syringe, followed by crosslinking using a 1% calcium chloride solution. The obtained filaments were initially characterised from morphological and chemical perspectives using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and Fourier Transform Infrared Spectroscopy (FT-IR). The SEM results demonstrated that the obtained alginate filament has a dense, homogeneous structure with certain folds resulting from the wet-spinning process. Additionally, the reinforcement with cotton fibres forms a 3D network within the matrix and significantly modifies the porosity of the alginate filaments. Regarding the chemical composition of the filaments, the EDS analysis revealed that the predominant elements are carbon and oxygen, thus indicating the organic nature of both the alginate matrix and the reinforcing agent. FTIR analysis enabled the identification of the main functional groups corresponding to characteristic absorption bands from the fingerprint region of each precursor material, for all composite materials. Afterwards, the absorption capacity of all filaments, with/without cotton fibres, was tested in physiological serum. The results revealed statistically significant differences as a function of the cotton fibres incorporation ratio, highlighting the impact of composition on the hydrophilic behaviour of the filaments. The development of composite filaments based on alginic acid is a crucial aspect in obtaining innovative hybrid materials characterised by low cost, biocompatibility, and biodegradability. These structures can be effectively implemented in various biomedical applications, including controlled and targeted drug delivery, soft tissue engineering, and the development of advanced dressings for wound treatment.

Long‐term antibiotic‐loaded products are the cornerstone in developing targeted bone regeneration therapies. Here, the fabrication of new antibacterial composite products, by a two‐step homogenization process, is governed by the isolation of an antibiotic with thermal stability at the processing temperature (200°C). Based on preliminary thermogravimetric assessment, only rifampicin (RIF) responds positively. The composites’ synthesis involves, for the first time, the concomitant modulation of RIF (1–5 wt.%), bovine bone‐derived hydroxyapatite (HA) (0–30 wt.%), and graphene nanoplatelets (0–3 wt.%) into the poly(lactic acid) matrix. The conjoined incorporation of all materials evolved into superimposed strong molecular cross‐links, without any structural alteration during preparation. The microporous morphology of the HA particles facilitates the adhesion to the polymeric matrix and the entrapment/attachment of the RIF particles, contributing to a prolonged drug release and effect during the patient's recovery. The ascending trend of RIF release over 24 h corroborates the strong antibacterial activity of the products against Staphylococcus aureus (the principal bacteria responsible for the occurrence of osteomyelitis) and a medium‐low response against Escherichia coli , providing evidence that the antimicrobial properties were preserved during composite manufacturing at a maximum temperature of 200°C. The degradation process is indicative of the fragmentation of the ceramic particles, leading to the formation of new nucleation sites required for the growth of new bone in the long term. Overall, the results pinpointed the desired features for novel antibacterial composite materials compatible for future filament extrusion and 3D printing of implantable products for bone applications.

In the continuous development of additive technologies and light-sensitive resins, the biological performance of 3D-printed resins is strongly dependent on photopolymerization efficiency and post-processing conditions. This study evaluated the effect of post-curing duration on the cellular response to two denture base resins using direct contact and indirect eluate-based pathways. Human gingival fibroblasts were assessed through viability, membrane integrity, nitric oxide production, fluorescence live/dead staining, and caspase-3/7 activity. As a result of contact between the cells and the surface interface of the specimen disks, reduced metabolic activity was noticed compared with the control under direct exposure, indicating cellular stress. Extended polymerization has been demonstrated to improve metabolic activity and reduce apoptotic signals for the V-Print dentbase resin, whereas FotoDent Denture presented a less uniform response under the same parameters. Therefore, for evaluating the cytotoxicity of light-sensitive resins, it is not sufficient to assess only the saliva-soluble substances released from the resin, such as residual monomers, but also the 3D printing parameters.

This research aims to study the antibacterial coatings of invasive surgical medical devices, including dental implants, to reduce superficial and deep local infections over the long term. To obtain the coating without altering the initial properties of the substrate (dental implant made of TiZr bioalloy), simple, cost-effective, and efficient methods were employed, such as chemical deposition of silver (Ag). The deposition characteristics were analyzed using scanning electron microscopy (SEM), EDX analysis, and FT-IR infrared analysis. The in vitro testing of antimicrobial activity was conducted using the diffusion method by cultivating the bacterial strains Escherichia coli (E. coli) ATCC25922 and Staphylococcus aureus (S. aureus) ATCC25923 and measuring the diameter of the bacterial inhibition zone. Investigations and biocompatibility evaluations were performed on both uncoated and silver-coated (Ag) samples by analyzing cell viability and morphology in the presence of human fetal osteoblasts (hFOB cell line) and human gingival fibroblasts (HFIB-G cells) after 8 days of incubation. The research results confirm the biocompatibility of the coating, demonstrated by the lack of significant differences in cell density between the Ag-coated samples and the control group, as well as by the fact that the silver-coated surface effectively supports actin cytoskeleton organization, adhesion, and migration of both human osteoblasts and gingival fibroblasts. The results regarding the antibacterial efficiency of the silver implant coating indicated that the E. coli bacterial strain is more resistant than S. aureus. The resistance difference between the two bacterial strains was attributed to differences in the structure of their cell envelopes.

This study investigates the biocompatibility and regenerative potential of collagen-based scaffolds enriched with keratin and hydroxyapatite in a rat bilateral hydroxyapatite, and collagen-hydroxyapatite-keratin) were evaluated using FTIR spectroscopy, radiological imaging, and high-resolution micro-CT analysis. The keratin-enriched scaffold showed enhanced bone regeneration, with improved trabecular architecture and mineralization compared to controls. Strong correlations between conventional radiography and micro-CT parameters validated grayscale analysis as a complementary tool for assessing bone regeneration, offering a practical and accessible method to approximate microstructural changes in preclinical studies. These findings highlight the potential of keratin-functionalized biomaterials in osteochondral repair strategies.

This in vitro study aimed to compare the effects of various surface treatments and hydrothermal aging on the phase composition, microstructure, and compressive strength of dental zirconia (ZrO2). Forty-eight zirconia cubes (8 × 8 × 8 mm) were fabricated using CAD/CAM from two materials: infrastructure zirconia (Group S1) and super-translucent multilayered monolithic zirconia (Group S2). Four samples of each material were analyzed in their pre-sintered state (S1-0, S2-0). The remaining specimens were sintered and assigned to sub-groups based on surface treatment: untreated, sandblasted with 30 µm or 50 µm Al2O3, polished, or polished and glazed. Characterization was performed using EDX, SEM, XRD with Rietveld refinement, Raman spectroscopy, and compressive testing before and after accelerated hydrothermal aging, according to EN ISO 13356:2015. EDX revealed a higher yttria content in monolithic zirconia (10.57 wt%) than in infrastructure zirconia (6.51 wt%). SEM images showed minimal changes in polished samples but clear surface damage after sandblasting, which was more pronounced with larger abrasive particles. XRD and Raman confirmed that sandblasting promoted the tetragonal (t-ZrO2) to monoclinic (m-ZrO2) phase transformation (t→m), amplified further by hydrothermal aging. The polished groups showed greater phase stability post-aging. Compressive strength decreased in all treated and aged samples, with monolithic zirconia being more affected. Polished samples displayed the best surface quality and structural resilience across both materials. These findings underline the impact of clinical surface treatments on zirconia’s long-term mechanical and structural behavior.

Biodegradable templates are sought for targeted antibiotic administration/delivery in bone infections to avoid detrimental reactions during bone regeneration. We investigated two key-aspects in this direction: 1) the optimal antibiotic delineation, with thermal stability equivalent to the temperature involved for templates preparation and 2) the antibacterial templates development by a two-step homogenization process. The selected antibiotic - ampicillin (AMP) was mechanically and then thermally mixed with the prime materials: poly(lactic acid) (PLA) - the polymeric matrix, biogenic bovine bone-derived hydroxyapatite (HA, particles <40 mu m), and graphene nanoplatelets (GnP, micrometric range). For the first time, all materials were used in simultaneous modulated ratios for the synthesis of PLA/AMP (1-5 wt.%)/HA (0-30 wt.%)/GnP (0-3 wt.%) composites. The influence of the concomitant materials modulation was surveyed through several assays. The FTIR-ATR spectroscopy depicted a three-level model of overlapping structures asserting the solid molecular cross-linking between all materials, without structural alterations induced to any material (XRD analysis). The addition of AMP to the PLA matrix caused a slight particle conglomeration, alleviated through GnP addition. The microporous HA particles supported the adhesion to the PLA matrix and promoted the AMP particles' entrapment/attachment. Linked to the enhanced wettability of the composite materials, the phosphate buffered saline solution (PBS) degradation profiles revealed a pronounced burst during the first 14-28 days of incubation and a long-term, low-level process hereafter. Thus, the formation of pores and cavities were signalled along with the HA particles' fragmentation. The released AMP (percentage) pictured an ascending trendline during the 24 h of analysis, at all targeted ratios. The preservation of AMP features at 200 degrees C was endorsed by the strong antibacterial activity of composite materials against Staphylococcus aureus (S. Aureus) growth and the medium response against Escherichia coli (E. Coli) - the higher the drug release, the higher the inhibitory effect on bacteria evolution.

This study explores a novel approach to enhance the surface properties of Ti-Al alloys for biomedical applications by creating a compositional gradient layer through aluminum deposition using Electrical Discharge Machining (EDM). The primary goal was to develop a metallurgically bonded intermetallic zone that supports strong adhesion and improved compatibility for subsequent hydroxyapatite (HA) deposition. Aluminum was deposited onto a Ti6Al4V substrate via EDM under controlled conditions, followed by thermal and thermochemical treatments to induce diffusion and intermetallic phase formation. Comprehensive analyses using optical and electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) revealed the formation of well-adhered layers composed of complex Ti-Al intermetallics such as TiAl2 and TiAl3, along with oxide phases including TiO2 and Al2O3. Thermal and thermochemical treatments further improved surface hardness, reaching up to 1057 HV, and influenced the diffusion behavior of aluminum, titanium, and vanadium. Adhesion tests confirmed that the untreated and thermochemically treated layers exhibited superior mechanical stability, while thermal treatment alone led to brittleness and delamination. These findings demonstrate that a properly engineered intermediate aluminide layer can significantly improve the performance of bioceramic coatings, particularly HA, by providing enhanced structural integrity and biocompatibility.

Background/Objectives: The purpose of this study was to assess the in vitro biocompatibility and corrosion resistance of five titanium alloys that have been recently developed for dental implant applications, whose compositions were designed to align with current approaches in the development of novel biomaterials. Priority was given to limiting the harmfulness associated with specific chemical elements present in common conventional alloys and increasing corrosion resistance to improve the biomaterial–tissue cellular interaction. Methods: For this purpose, five types of titanium alloys with original chemical compositions (Ti1–Ti5) were developed. The electrochemical behavior of the alloys was analyzed by evaluating the corrosion resistance in environments that simulate the oral environment, as well as the cellular behavior, by evaluating the viability, growth, and proliferation of human cells on osteoblasts and gingival fibroblasts. Detailed analysis of the chemical composition by scanning electron microscope (SEM/EDS) methods was used. The corrosion rate of the alloys in artificial saliva was tested using the polarization resistance technique (Tafel). Human osteoblasts (hFOB cell line) and human gingival fibroblasts (hFIB-G cell line) were used to measure biocompatibility in vitro. Results: The Ti5 alloy demonstrated the highest cell viability and the lowest corrosion rate (0.114 μm/year) among all tested compositions, with the Ti3 alloy containing Mo and Zr following closely behind. The Ti2 alloy exhibited reduced biocompatibility because of the inclusion of Ni and Fe in its composition. Conclusions: Taken together, the results of this study provide useful information on the basic characteristics of titanium alloys with original chemical compositions. The titanium alloys were analyzed in comparison with common conventional alloys (Cp–Ti and Ti6Al4V) as well as alloys such as Ti–Zr, Ti–Nb, and Ti–Nb–Zr–Ta, which are considered to be viable alternatives to conventional materials for making dental implants.

The proposed strategy for the extrusion of printable composite filaments follows the favourable association of biogenic hydroxyapatite (HA) and graphene nanoplatelets (GNP) as reinforcement materials for a poly(lactic acid) (PLA) matrix. HA particles were chosen in the <40 μm range, while GNP were selected in the micrometric range. During the melt–mixing incorporation into the PLA matrix, both reinforcement ratios were simultaneously modulated for the first time at different increments. Cylindrical composite pellets/test samples were obtained only for the mechanical and wettability behaviour evaluation. The Fourier-transformed infrared spectroscopy depicted two levels of overlapping structures due to the solid molecular bond between all materials. Scanning electron microscopy and surface wettability and mechanical evaluations vouched for the (1) uniform/homogenous dispersion/embedding of HA particles up to the highest HA/GNP ratio, (2) physical adhesion at the HA-PLA interface due to the HA particles’ porosity, (3) HA-GNP bonding, and (4) PLA-GNP synergy based on GNP complete exfoliation and dispersion into the matrix.

This study follows the process for the development of an innovative biomimetic composite derived from bovine collagen with keratin, with hydroxyapatite being hybridized into its architecture, and it builds a comprehensive evaluation of the composite’s characteristics. The novel biomimetic materials are tailored with special traits to be achieved for the repair of osteochondral defects (OCDs). The purpose of the present research is to create a reliable effective alternative to existing bone graft materials while leveraging the intrinsic properties of the components for enhanced osteoinduction and integration. The composites were characterized based on their morphological properties, including water absorption, through scanning electron microscopy (SEM), and their structural properties were characterized by Fourier-Transform Infrared Spectroscopy (FTIR). Biological performance was assessed in vitro using human bone marrow mesenchymal stem cells (BMSCs), focusing on cytotoxicity, cell viability, and the ability to support cell colonization with forthcoming results. This in vivo study illustrates the real potential that this class of novel composites exhibits in regard to bone and cartilage tissue engineering and encourages further exploration and development for future clinical applications.

Solid oxide fuel cells (SOFC) are electrochemical conversion devices that produces electricity directly from oxidizing a fuel and their development became of high importance to drastically reduce the greenhouse emission. Rare earth elements (REEs) are widely used as materials and dopants in controlling the ionic conductivity of solid electrolytes for SOFCs. Their criticality and high costs for separation to individual REEs lead to first studies aiming to search possible use of mixed REEs with natural occurrence as extracted from concentrates. This paper focused on obtaining sintered pellets based on zirconia doped with natural mixture of REEs extracted from monazite and study their microstructure, impedance spectra and dielectric properties vs. operating temperatures to assess their potential applications as solid electrolyte. ZrO2 doped powders with 8% natural mixture of REEs (8ZrMZ) were synthesized by hydrothermal process. ZrO2 doped with 4% Y2O3 (4ZrY) and 8%Y2O3 (8ZrY) were also obtained by the same route and used as standard materials already used in commercial SOFCs. All powders were uniaxially pressed and sintered in air, with highest densities obtained for 1400 °C. The Niquist diagrams for 8ZrMZ samples show significantly lower ionic conductivity compared to standards 4ZrY and 8 ZrY. This may be attributed to the presence of detrimental Fe and Si impurities following the mixed REE after Th and U removal from monazite concentrates and the ratio of REEs in the dopant composition affecting the ionic conductivity due to possible association of structural defects. Research works are further needed to improve the receipt for using naturally mixed REEs and asses their possible use as a competitive dopant for solid electrolytes.

This study aims to evaluate the osteoconductive and osteoinductive potential of novel composite collagenous sponges enriched with keratin (K), hydroxyapatite (HA), and their combination (K+HA) for osteochondral regeneration in rat knee models. By examining cell proliferation, mineralization, and vascularization, we aim to determine the regenerative effectiveness of these materials in promoting osteochondral repair, particularly in load-bearing joints like the knee. Addressing the problem of osteochondral defects (OCD), which lead to osteoarthritis-a condition characterized by pain and functional impairment-the hereby research evaluates these biomaterials for their potential to foster bone and cartilage repair, especially in load-bearing joints as the knee. By leveraging an experimental living rat knee model, the effectiveness of these bio-composites is tasted through detailed morphological, biomechanical, and histological analyses. We have employed a rigorous methodology encompassing the selection of biomaterials based on their osteoconductive and osteoinductive traits, their intraosseous application in Wistar rats, and ulterior comprehensive and minutely monitoring. The comparison covers aspects such as cell growth, mean pixel intensity, and other key morphological properties, offering good insights into each material's regenerative capacity. Furthermore, in the present study we have highlighted the fabrication processes of the sponges, including lyophilization and crosslinking, underlining the importance of the biomaterials' physical characteristics in achieving targeted and optimal regenerative outcomes. Preliminary results obtained illustrate the biocompatibility and potential efficacy of these collagen-based composites in promoting bone healing and regeneration, with particular attention being given to the synergistic effects observed in the K+HA combination. This research will contribute to the understanding of material-based regeneration of osteochondral units but also might open avenues for future investigations into the optimization of such therapies for further clinical application. Through a detailed examination of the materials' integration with the test animal bone and cartilaginous tissues and their impact on bone and cartilage healing, this study sets the stage for the advancement of regenerative medicine solutions for OCD and the array of related conditions, offering hope for patients suffering from joint degeneration and injury.

The successful regeneration of large-size bone defects remains one of the most critical challenges faced in orthopaedics. Recently, 3D printing technology has been widely used to fabricate reliable, reproducible and economically affordable scaffolds with specifically designed shapes and porosity, capable of providing sufficient biomimetic cues for a desired cellular behaviour. Natural or synthetic polymers reinforced with active bioceramics and/or graphene derivatives have demonstrated adequate mechanical properties and a proper cellular response, attracting the attention of researchers in the bone regeneration field. In the present work, 3D-printed graphene nanoplatelet (GNP)-reinforced polylactic acid (PLA)/hydroxyapatite (HA) composite scaffolds were fabricated using the fused deposition modelling (FDM) technique. The in vitro response of the MC3T3-E1 pre-osteoblasts and RAW 264.7 macrophages revealed that these newly designed scaffolds exhibited various survival rates and a sustained proliferation. Moreover, as expected, the addition of HA into the PLA matrix contributed to mimicking a bone extracellular matrix, leading to positive effects on the pre-osteoblast osteogenic differentiation. In addition, a limited inflammatory response was also observed. Overall, the results suggest the great potential of the newly developed 3D-printed composite materials as suitable candidates for bone tissue engineering applications.

Alloys with superior properties represent the main topic of recent studies due to their effectiveness in reducing the cost of equipment maintenance and enhancing usage time, in addition to other benefits in domains such as geothermal, marine, and airspace. Al0.5CrFeNiTi was produced by solid state processing in a planetary ball mill, with the objective of obtaining a high alloying degree and a homogenous composition that could be further processed by pressing and sintering. The metallic powder was technologically characterized, indicating a particle size reduction following mechanical alloying processing when compared to the elemental raw powder materials. The microstructural analysis presented the evolution of the alloying degree during milling but also a compact structure with no major defects in the pressed and sintered bulk samples. The X-ray diffraction results confirmed the presence of face-centered cubic (FCC) and body-centered cubic (BCC) phases, predicted by the theoretical calculations, along with a hexagonal close-packed (HCP) phase, where the Al, Cr, Fe, Ni, and Ti phase was identified in both the alloyed powder material and sintered sample.

Novel biomaterials with promising bone regeneration potential, derived from rich, renewable, and cheap sources, are reported. Thus, thin films were synthesized from marine-derived (i.e., from fish bones and seashells) hydroxyapatite (MdHA) by pulsed laser deposition (PLD) technique. Besides the physical–chemical and mechanical investigations, the deposited thin films were also evaluated in vitro using dedicated cytocompatibility and antimicrobial assays. The morphological examination of MdHA films revealed the fabrication of rough surfaces, which were shown to favor good cell adhesion, and furthermore could foster the in-situ anchorage of implants. The strong hydrophilic behavior of the thin films was evidenced by contact angle (CA) measurements, with values in the range of 15–18°. The inferred bonding strength adherence values were superior (i.e., ~49 MPa) to the threshold established by ISO regulation for high-load implant coatings. After immersion in biological fluids, the growth of an apatite-based layer was noted, which indicated the good mineralization capacity of the MdHA films. All PLD films exhibited low cytotoxicity on osteoblast, fibroblast, and epithelial cells. Moreover, a persistent protective effect against bacterial and fungal colonization (i.e., 1- to 3-log reduction of E. coli, E. faecalis, and C. albicans growth) was demonstrated after 48 h of incubation, with respect to the Ti control. The good cytocompatibility and effective antimicrobial activity, along with the reduced fabrication costs from sustainable sources (available in large quantities), should, therefore, recommend the MdHA materials proposed herein as innovative and viable solutions for the development of novel coatings for metallic dental implants.