Search Results (64)

One-dimensional fibrous scaffolds with tunable bioactivity offer promise for bone tissue regeneration, yet optimal calcium phosphate phases for enhancing osteogenic performance remain underexplored. This study aimed to evaluate the impact of monetite-, brushite-, and cerium-doped phosphate deposition on electrospun nylon nanofibres functionalised via matrix-assisted pulsed laser evaporation (MAPLE). Five nylon fibre compositions were synthesised, coated with three calcium phosphate phases, and calcined at varying temperatures (500–800 °C) before laser deposition. Physicochemical properties were assessed using energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and fibre diameter measurements, averaging $62.1\pm 23.8$ nm. Biocompatibility assays following MC3T3 preosteoblast seeding and incubation evaluated biological performance. EDX confirmed homogeneous phase deposition; SEM showed phase- and temperature-dependent morphology, with monetite yielding uniform granular structures and cerium-doped phosphate at 800 °C forming dense aggregates. Brushite-coated fibres exhibited superior preosteoblast metabolic activity, reaching $178\pm 2\%$ after 48 h (p < 0.001), indicating phase-specific stimulation of bone cell growth. These phosphate-functionalised nylon fibres retain structural integrity, hierarchical porosity, and enhanced bioactivity, providing a versatile electrospinning-MAPLE platform for customisable bone grafts with clinical potential. Full article

In this study, salmon fish bone waste from the fish processing industry was converted into an inorganic ash filler by calcination and incorporated into an SLA-compatible photopolymer resin at 4, 8, and 12 wt.%. To compensate for filler-induced optical scattering and rheological changes, the printing parameters were systematically optimized, and the optimum conditions were identified as a layer thickness of 30 µm and an exposure time of 12 s. Tensile tests performed in accordance with ASTM D638 Type IV showed that fish bone ash significantly enhanced the tensile strength of the photopolymer matrix, increasing it from 24.8 MPa for the neat resin to 37.95 MPa at 12 wt.% filler loading. In contrast, increasing filler content reduced elongation at break and promoted a more brittle fracture response. Statistical evaluation using Welch ANOVA and Games–Howell post hoc analysis confirmed that filler loading had a statistically significant effect on tensile strength (p < 0.05). FTIR analysis revealed that the filler remained chemically stable within the matrix and that the interfacial interactions were predominantly physical rather than covalent. SEM observations indicated that low and medium filler loadings improved crack deflection and energy dissipation, whereas particle agglomeration at higher loading increased the tendency for brittle fracture. These findings demonstrate that fish bone ash can be used as a sustainable bio-waste-derived reinforcement to improve the mechanical performance of SLA photopolymer composites. Full article

Sunscreens are essential for photoprotection, but conventional inorganic UV filters raise concerns regarding marine toxicity. This study investigated hydroxyapatite (HAp) derived from skipjack, tongol, and salmon bone waste as a potential synergistic booster for Tinosorb^® S (TS). HAp powders were prepared via alkaline treatment and calcination at 900 °C. XRD and XRF results confirmed highly crystalline HAp as the dominant phase. While 10% HAp alone provided negligible UV protection, a pronounced synergistic effect was observed in 1:1 hybrid formulations (5% HAp:5% TS), significantly enhancing Sun Protection Factor (SPF) and Ultraviolet A Protection Factor (UVAPF). Notably, particle-size refinement of salmon-derived HAp (SM–HAp) yielded an SPF of approximately 35, comparable to a commercial HAp counterpart. This improvement was suggested to be associated with enhanced dispersion, film uniformity, and particle–matrix interactions, which might contribute to achieving PA++++ protection. All formulations complied with microbiological and heavy metal safety standards. These results indicated that fish bone-derived HAp could potentially serve as a viable and sustainable functional additive derived from marine biowaste for the development of high-performance hybrid sunscreens, promoting biomaterial valorization in the cosmetic industry. Full article

The development of effective bone substitutes remains a central goal in regenerative medicine. In this study, lithium-modified bioglass-ceramics based on the 47.5S5 silicate oxide system were synthesized using the sol–gel method, followed by calcination and axial pressing to form cylindrical samples. These materials were sintered at 700 and 800 °C and subsequently examined to evaluate their structural, mechanical, and biological performance. Structural and microstructural analyses confirmed the presence of crystalline phases such as combeite (Na₆Ca₃Si₆O₁₈), NaLiSiO₄, Li₂SiO₃, and calcium silicates, indicating the successful incorporation of lithium within the glass-ceramic network. The bioceramics exhibited improved densification, deformability, and compressive strength with increasing sintering temperature. In vitro degradation in simulated body fluid revealed a consistent increase in mass loss with higher lithium content, suggesting enhanced resorbability linked to lithium oxide. Antibacterial testing indicated moderate antimicrobial activity, with slightly better results observed at higher sintering temperatures. Cell viability assays further supported the materials cytocompatibility. Taken together, these findings suggest that lithium substitution contributes positively to both mechanical robustness and biological behaviour, positioning these ceramics as promising bioresorbable bone substitutes with controlled degradation, suitable for bone tissue engineering where durability, bioactivity, and antimicrobial function are required. Full article

In this research, aluminium-doped biphasic calcium phosphate (Al-BCP) was synthesized by co-precipitation and formulated with hydrolyzed collagen and acetylsalicylic acid (ASA) to yield composites designed as a new class of bone-regenerative biomaterials with enhanced biological performance. Undoped and Al-modified powders (5/10 wt% Al precursor) were prepared at 40 °C (pH ~ 11) and calcined at 700 °C, and composites were produced at a 1:1:0.1 mass ratio (ceramic–collagen–ASA). Structure and chemistry were assessed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman spectroscopies, and X-ray photoelectron spectroscopy (XPS). Morphology and elemental distribution were examined by scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX). Biological performance was preliminarily evaluated using HaCaT (immortalized human keratinocytes) viability and antibacterial assays against Staphylococcus aureus and Escherichia coli. XRD confirmed a biphasic hydroxyapatite/β-tricalcium phosphate system and showed that Al incorporation shifted the phase balance toward hydroxyapatite (HAp fraction 54.8% in BCP vs. ~68.6–68.7% in Al-doped samples). FTIR/Raman preserved BCP vibrational signatures and revealed collagen/ASA bands in the composites. XPS/EDX verified the expected composition, including surface N 1s from organics and Al at ~2–5 at% for doped samples, with surface Ca/P ≈ 1.15–1.16. SEM revealed multigranular microstructures with homogeneous Al distribution. All composites were non-cytotoxic (≥70% viability); M_Al10_Col_ASA exceeded 90% viability at 12.5% dilution. Preliminary antibacterial assays against Gram-positive and Gram-negative strains showed modest, time-dependent reductions in CFU relative to controls. These results corroborate the compositional/structural profile and preliminary biological performance of Al-BCP–collagen–ASA composites as multifunctional bone tissue engineering materials that foster a bone-friendly microenvironment, warranting further evaluation for bone regeneration. Full article

The transesterification process of vegetable oil applied in biodiesel synthesis is catalytic. Industrial production uses chemical catalysts that are difficult to separate from the product, regenerate, and reuse, which is why there is a search for new catalysts that are of natural origin or obtained from various types of waste. Calcium oxide is widely used as a heterogeneous catalyst, and can be obtained from calcium carbonate. The article reviews the possibilities of using eggshells as a catalyst for biodiesel synthesis: the optimal calcination conditions, the efficiency of the obtained catalyst, the optimal transesterification conditions, and the influence of various factors on biodiesel yield. It also discusses the possibilities and conditions for regenerating the catalyst and reusing it. Another food industry waste containing calcium compounds is animal bones, from which an effective biodiesel synthesis catalyst can be obtained. Before use, the bones are also crushed and calcined. The article presents the conditions for catalyst preparation and catalytic activity, and the possibilities for its enhancement by incorporating other elements, as well as the dependence of ester yields on transesterification conditions. The process of catalyst regeneration and reuse is discussed. Full article

The chemical and structural similarity of calcium orthophosphates to hard tissues in the human body makes them suitable as biomaterials for bone implants, cements, injection systems, etc., for bone regeneration and reconstruction. Tetracalcium phosphate (Ca₄(PO₄)₂O, TTCP) is a promising component for such biomaterials due to its high calcium content and alkaline nature. The former makes it suitable for promoting mineralization, while the latter supports neutralization of the acidic environment, helping to prevent inflammation and improve the biocompatibility of the materials. However, it is the least used calcium orthophosphate due to the difficulties in its synthesis. This study examines the effect of high-energy mechanochemical activation on the phase evolution, particle morphology, and thermal behaviour of equimolar mixtures of Ca(OH)₂ and CaHPO₄, with the aim of optimizing precursor conditions for the synthesis of (TTCP)-rich ceramic materials. The results demonstrate that mechanochemical activation effectively induces structural disorder, promotes the formation of amorphous and nanocrystalline phases, and facilitates subsequent phase transitions upon calcination. The combined use of solid-state NMR, XRD, TEM, and thermal analysis provides a comprehensive understanding of the transformation pathways. Ultimately, 24 h of activation under the experimental conditions was identified as optimal for producing a precursor with a favorable phase composition for obtaining TTCP-rich ceramic materials after calcination at 1350 °C. Full article

The increasing demand for novel tissue engineering (TE) applications in bone tissue regeneration underscores the importance of exploring advanced manufacturing techniques and biomaterials for personalised treatment approaches. Three-dimensional printing (3DP) technology facilitates the development of implantable devices with intricate geometries, enabling patient-specific therapeutic solutions. Although Fused Filament Fabrication (FFF) and Direct Ink Writing (DIW) are widely utilised for fabricating bone-like implants, the need for multiple processing steps often prolongs the overall production time. In this study, a single-step melt-extrusion 3DP technique was performed to develop multi-material scaffolds including bioceramics, hydroxyapatite (HA), and β-tricalcium phosphate (TCP) in both their bioactive and calcined forms at 10% and 20% w/w, within polycaprolactone (PCL) matrices. Printing parameters were optimised, and physicochemical properties of all biomaterials and final forms were evaluated. Thermal degradation and surface morphology analyses assessed the consistency and distribution of the ceramics across the different formulations. The tensile testing of the scaffolds defined the impact of each ceramic type and wt% on scaffold flexibility performance, while in vitro cell studies determined the cytocompatibility efficiency. Hence, all 3D-printed PCL–ceramic composite scaffolds achieved structural integrity and physicochemical and thermal stability. The mechanical profile of extruded samples was relevant to the ceramic consistency, providing valuable insights for further mechanotransduction investigations. Notably, all materials showed high cell viability and proliferation, indicating strong biocompatibility. Therefore, this additive manufacturing (AM) process is a precise and fast approach for developing biomaterial-based scaffolds, with potential applications in surgical restoration and support of segmental bone defects. Full article

Aim: Despite a persistent presence in periodontitis, calculus remains a paradox. This narrative review reevaluates the role of calculus in periodontitis based on in situ, ex vivo, and in vitro studies published over the last two decades. Review: Results from multiple studies argue for the reconsideration of calculus as an independent risk factor in periodontitis. The results of a human study suggest that calculus contributes more to inflammation than simply serving as a substrate for biofilm accumulation. Ultrastructure studies have revealed residual calculus embedded in cementum following scaling and root planing (SRP). In vitro studies show that calculus particles can stimulate IL-1β secretion via the NLRP3 inflammasome in human and mouse phagocytes, and the crystalline structure is partially responsible for the activation. Other studies indicate that calculus particles may promote bone resorption via IL-1β induction in patients with periodontitis. Further, heat-treated calculus particles and hydroxyapatite crystals induce cell death in epithelial cell lines, suggesting that calculus plays a role in the breakdown of pocket epithelial integrity. Conclusions: Studies have shown that particles of microscopic calculus persist following traditional SRP. In vitro studies report that sterile and calcined calculus particles free of proteinaceous material are cytotoxic to cultured oral epithelial cells. Collectively, these studies suggest that residual microscopic calculus may be a potential risk factor for the failure of periodontal therapy. Full article

Strontium-added bioactive glass (SBG) has been widely used in bone tissue engineering. SBG can be prepared by conventional high-temperature melt-quenching or calcining sol-gelled powder at 700 °C or above. In the present study, the effects of calcination temperature (400–650 °C) and the amount of strontium addition (0–7 mol.%) were investigated simultaneously. The sol-gel process and post-calcination were used to prepare the Sr-added 58S bioactive glass (SBG) powders. The bioactivity of the SBG powder was assessed by immersing it in simulated body fluid, while biocompatibility and cytotoxicity were evaluated using L929 and MG63 cells, and a zebrafish animal model. The calcination temperatures were determined by thermogravimetric analysis based on the weight loss at various stages. X-ray diffraction was used to reveal the crystalline structure of calcined or SBF-immersed SBG powders. Meanwhile, the texture characteristics of SBG powders were examined by the BET method. Fourier-transformed infrared spectroscopy and scanning electron microscopy were used to investigate the absorption bands and powder morphology of SBG powders before and after SBF immersion. The experimental results showed that all SBG powders were mesoporous with a high specific surface area larger than 200 m²/g. SBG powder calcined at 650 °C with 5% Sr addition possessed a major Ca_14.92(PO₄)_2.35(SiO₄)_5.65 phase, the smallest pore size of 5.86 nm, and the largest specific surface area of 233 m²/g. It was noncytotoxic and exhibited good bioactivity and biocompatibility. Full article

The expansion of fisheries and aquaculture in recent decades has led to a substantial increase in fish by-products. This study investigates the extraction and characterization of calcium phosphates from the by-products of representative species in these industries, aiming to identify potential sources for biotechnological and pharmaceutical applications. Clean bones obtained by enzyme hydrolysis from the heads, central skeletons, and/or tails of Atlantic horse mackerel, blue whiting, hake, mackerel, and farmed turbot were subjected to calcination to obtain calcium phosphates. The clean bone content in terms of nitrogen, lipids, organic matter, total protein, and amino acids was evaluated together with the chemical bonds, structures, and elemental composition of calcium phosphates. Results indicated a significantly higher yield of wet bone recovery (23%, p < 0.05) for the central skeleton of Atlantic horse mackerel and the highest mineral fraction for the heads of Atlantic horse mackerel (73.2%), followed by that of blue whiting (72.6%). Hake and turbot presented the lowest mineral fractions and, therefore, the highest protein content (27–31%, p < 0.05), with significant levels of collagen-related amino acids (p < 0.05). X-ray diffraction (XRD) and Fourier-transform Raman spectroscopy (FT-Raman) confirmed the biphasic calcium phosphate composition for most samples based on hydroxyapatite with contributions of whitlockite/β-tricalcium phosphate. The highest contribution to the non-apatite phase was made by the central skeletons of both mackerel and Atlantic horse mackerel. Full article

This study addresses the dual challenges of water pollution and waste management by exploring the valorization of chicken bone biomass in native (NBio) and calcined (CBio) forms as biosorbents for dye removal. Basic fuchsine (BF) and methylene blue (MB) were selected as model pollutants, and adsorption was assessed under varying operational conditions. Characterization using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) showed that calcination improved crystallinity, eliminated organic impurities, and increased surface area (247 m²/g for NBio vs. 370 m²/g for CBio). Adsorption tests revealed higher performance for CBio, with maximum adsorption capacities of 100 mg/g (BF) and 142.85 mg/g (MB) based on the Langmuir isotherm, while NBio with maximum adsorption capacities of 111 mg/g (BF) and 111.11 mg/g (MB) followed the Freundlich model. Adsorption kinetics indicated pseudo-second-order behavior, suggesting chemisorption. The possible interactions between dyes and the biosorbent are hydrogen bonding, electrostatic interactions, and Lewis acid–base interactions. Thermodynamic analysis highlighted exothermic behavior for NBio and endothermic, entropy-driven adsorption for CBio, with both processes being spontaneous. A decision tree with Least Squares Boosting (DT_LSBOOST) provided accurate predictions (R² = 0.9999, RMSE < 0.003) by integrating key parameters. These findings promote chicken bone biomass as a cost-effective, sustainable biosorbent, offering promising potential in wastewater treatment and environmental remediation. Full article

The Comarca Lagunera is one of Mexico’s most important productive areas. Its main economic activities are livestock, agriculture, and the processing industry. A wide variety of industries emit wastes that are considered highly toxic environmental pollutants, which have strong negative impacts on public health. The objective of this work was to determine the lead concentrations present in tissues of pigeons (Columba livia) belonging to the urban area of the Comarca Lagunera, Mexico. Specimens were collected from the localities that comprise the region and the tissue extracted; the organs were dried, calcined, and diluted in an acidic HCl solution. Lead concentrations were obtained by atomic absorption spectrometry using the graphite furnace technique. The results demonstrate the presence of lead in all the tissues analyzed, with maximum concentrations of 191.14 mg/kg and minimum concentrations of 0.86 mg/kg, the area with the highest average concentration being Torreón, Coahuila (p = 0.030). The organ with the highest concentration was the bone (p = 0.000). Evidence of lead poisoning is presented in Columba livia tissues in the Comarca Lagunera, thus demonstrating the presence of this contaminant and the ability of these pigeons to function as bioindicators of environmental contamination. Full article

The global tuna canning industry generates substantial volumes of by-products, comprising 50% to 70% of the total processed material. Traditionally, these by-products have been utilized in low-value products such as fish oils and fishmeal. However, there is significant potential to extract high-value compounds from these by-products, such as calcium phosphates (CaP), which can have pharmaceutical, agricultural and biotechnological applications. This work explores the potential of tuna canning by-products, particularly mineral-rich fractions (central skeleton, head and fish bones) as sources of calcium phosphates (CaP), offering a sustainable alternative to conventional synthetic derivatives within a circular bioeconomy framework. By-products from two of the most exploited species (yellowfin and skipjack) were subjected to enzymatic hydrolysis and chemical extraction, followed by controlled calcination to obtain CaP. The content of organic matter, nitrogen, total proteins, lipids and amino acids in the cleaned bones, as well as the main chemical bonds, structure and elemental composition (FT-Raman, XRD, XRF) were evaluated. Results indicated that the highest recovery yield of wet bones was achieved using the chemical method, particularly from the dorsal and caudal fins of yellowfin tuna. The proximal composition, with ash content ranging from 52% to 66% and protein content varying between 30% and 53%, highlights the potential of tuna skeleton substrates for plant growth formulations. Furthermore, variations in crystalline structures of the substrates revealed significant differences depending on the by-product source and species. XRD and Raman results confirmed a monophase calcium phosphate composition in most samples from both species, primarily based on hydroxyapatite (central skeleton, caudal and dorsal fin) or whitlockite/β-tricalcium phosphate (viscera), whereas the heads exhibited a biphasic composition. Comparing the species, yellowfin tuna (YF) exhibited a hydroxyapatite structure in the branchial arch and scales, while skipjack (SKJ) had a biphasic composition in these same regions. Full article

This work presents the successful production of highly porous 3D nanofibrous hybrid scaffolds of polylactic acid (PLA)/polyethylene glycol (PEG) blends with the incorporation of calcium phosphate (CaP) bioceramics by a facile two-step process using the solution blow spinning (SBS) technique. CaP nanofibers were obtained at two calcium/phosphorus (Ca/P) ratios, 1.67 and 1.1, by SBS and calcination at 1000 °C. They were incorporated in PLA/PEG blends by SBS at 10 and 20 wt% to form 3D hybrid cotton-wool-like scaffolds. Morphological analysis showed that the fibrous scaffolds obtained had a randomly interconnected and highly porous structure. Also, the mean fiber diameter ranged from 408 ± 141 nm to 893 ± 496 nm. Apatite deposited considerably within 14 days in a simulated body fluid (SBF) test for hybrid scaffolds containing a mix of hydroxyapatite (HAp) and tri-calcium phosphate-β (β-TCP) phases. The scaffolds with 20 wt% CaP and a Ca/P ration of 1.1 showed better in vitro bioactivity to induce calcium mineralization for bone regeneration. Cellular tests evidenced that the developed scaffolds can support the osteogenic differentiation and proliferation of pre-osteoblastic MC3T3-E1 cells into mature osteoblasts. The results showed that the developed 3D scaffolds have potential applications for bone tissue engineering. Full article