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Objective: This study aimed to evaluate the effectiveness of biomaterials in bone healing of critical bone defects created by piezoelectric surgery in rat calvaria. Method and materials: Histomorphologic analysis was performed to assess bone regeneration and tissue response. Fifty animals were randomized into five groups with one of the following treatments: Control group (n = 10), spontaneous blood clot formation with no bone fill; BO group (Bio-Oss, Geistlich Pharma; n = 10), defects were filled with bovine medullary bone substitute; BF group (Bonefill, Bionnovation; n = 10), defects were filled with bovine cortical bone substitute; hydroxyapatite group (n = 10), defects were filled with hydroxyapatite; calcium sulfate group (n = 10), defects were filled with calcium sulfate. Five animals from each group were euthanized at 30 and 45 days. The histomorphometry calculated the percentage of the new bone formation in the bone defect. Results: All data obtained were evaluated statistically considering P < .05 as statistically significant. The results demonstrated the potential of all biomaterials for enhancing bone regeneration. The findings showed no statistical differences between all the biomaterials at 30 and 45 days including the control group without bone grafting. Conclusion: In conclusion, the tested biomaterials presented an estimated capacity of osteoconduction, statistically nonsignificant between them. In addition, the selection of biomaterial should consider the specific clinical aspect, resorption rates, size of the particle, and desired bone healing responses. It is important to emphasize that in some cases, using no bone filler might provide comparable results with reduced cost and possible complications questioning the very frequent use of ridge presentation procedures. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the available evidence and assess the effect of different implant coatings on healing outcomes. Materials and Methods: Using the PICOS strategy, a structured question was formed. A protocol was agreed upon and registered with PROSPERO (no. CRD42022321926). The MEDLINE, Embase, Cochrane Database of Systematic Reviews, Scopus, Web of Science, Pubmed, and ScienceDirect databases were searched using a structured strategy. Study selection was independently carried out in duplicate, first by title and abstract, then by full-text assessment. Quality and risk of bias were independently assessed in duplicate using AMSTAR 2 and ROBIS. Data extraction was independently undertaken in duplicate using a predefined extraction form. Results: The search yielded 11 systematic reviews for inclusion. The most commonly assessed coatings were based on calcium phosphate--including hydroxyapatite (HA), brushite, and bioabsorbable nano-HA--followed by bisphosphonate, then bioactive glass coatings. Included reviews most frequently assessed marginal bone loss (MBL), bone-to-implant contact (BIC), and survival/success rates. There was considerable heterogeneity and small sample sizes. The quality assessment suggested low confidence in the reviews and high risk of bias. Conclusions: The included reviews provide weak evidence that implant coatings improve osseointegration and reduce MBL following implant placement. There was weak evidence for progressive complications for calcium phosphate coatings. Further research and long-term multicenter controlled clinical trials with improved standardization and control of bias are required to better understand the effects of coating implants. [ABSTRACT FROM AUTHOR]

This study clinically and histologically evaluated the outcome of a porcineapatite xenograft used to elevate the maxillary sinus floor in a severely atrophic ridge. A two-stage crestal window sinus elevation protocol was conducted in 24 patients with crestal bone ≤ 2 mm. Highly porous porcine carbonate apatite moistened with saline solution was placed in the elevated sinus cavity as the sole grafting material. Bone core biopsy samples were taken at 6, 9, and 12 months after sinus augmentation surgery (at implant placement). Treatment outcomes were assessed using microCT (μCT) and histologic analysis. Statistical analysis was performed using nonparametric Kruskal-Wallis test, followed by post-hoc Dunn multiple comparison test. At 6 months after implant placement, all implants achieved good primary stability (insertion torque ≥ 30 Ncm) and successfully osseointegrated. The residual graft amount (mean ± SE) was low (11.91% ± 1.99%) at 6 months and further decreased (6.11% ± 2.64%) by 12 months. On the contrary, the amount of new bone detected was 18.94% ± 4.08% at 6 months and was significantly (P < .05) increased (40.16% ± 5.27%) at 12 months. Histologic assessment revealed osteoclasts actively resorbing the graft as well as osteoblasts actively forming new bone. In the severely atrophic maxilla, the porcine-apatite xenograft promotes new bone formation while being slowly absorbed. Within the limited sample size, the porcine-apatite xenograft seems to be a good graft material for crestal window sinus augmentation. [ABSTRACT FROM AUTHOR]

Purpose: To compare bone substitutes composed of glycated collagen with synthetic micro-sized (1 to 10 µm) hydroxyapatite (OB) vs non-cross-linked collagen matrix with large-particle (250 to 1,000 µm) bovine-derived hydroxyapatite (BOC). Materials and Methods: The P1 to P4 premolars were bilaterally extracted from the mandibles of 19 Beagle dogs. After 21 days, osteotomies were created in each dog that received OB or BOC and were covered with a collagen membrane or were left untreated. The animals were randomly divided into three groups based on sacrifice time (4, 12, or 24 weeks). The right and left hemimandibles were trimmed to facilitate imaging and histology, and all tissues were placed in 10% neutral-buffered formalin. Microcomputed tomography (MicroCT 40 Scanner, Scanco) was used to analyze bone sections. Bone volume, residual material volume, and bone mineral density were determined for each treatment site (OB and BOC) based on a volume of interest that encompassed the original defect. Additionally, blinded histopathologic assessment (based on the ISO 10993-6 scoring system) and histomorphometry were performed on sections ground to < 100 µm thick and stained with Stevenel's blue. Results: No clinical side effects were noted. No statistical differences were observed for OB vs BOC regarding the mineral volume percentage. Compared to OB, BOC had significantly higher mean mineralization densities at 12 weeks (P < .01), but this difference did not extend to 24 weeks. For residual grafting material, bone maturation, alveolar ridge restoration, and inflammatory response, OB showed a residual amount of bone graft and no statistical differences compared to BOC. Conclusion: Both OB and BOC represent valid treatment options for critically sized bone defects. Both bone fillers outperformed the sham-operated, ungrafted (empty) control, demonstrating statistically improved bone growth and ridge restoration. [ABSTRACT FROM AUTHOR]

Over the last decade, bioactive silicates have gained significant interest as bone graft substitutes due to their excellent ability to repair, replace, and regenerate damaged tissue in injured bone. In this work, a sol–gel combustion route was used to synthesize nanostructured barium-doped diopside (Ca1-XBaXMgSi2O6) using stoichiometric amounts of calcium nitrate, magnesium nitrate, and barium nitrate as oxidizers, and tartaric acid as a fuel. The resultant powder was examined by powder XRD to confirm the phase purity. Pure phase of diopside was achieved at 850 °C without any secondary phase. For functional group analysis, FT-IR was employed, and microscopic imaging (SEM/EDAX) was used to study morphological changes. Due to barium doping in the diopside matrix, the crystallite size was reduced, and the mechanical and degradation properties of the prepared pellets was enhanced after immersion in SBF medium over a period of time. The results show compressive strength of the doped diopside was found to be 169 MPa, closer to cortical bone strength and similar to previous findings. It can be concluded that barium can be considered as a dopant to improve bioactivity of Ca-Mg silicate for hard tissue application. [ABSTRACT FROM AUTHOR]

Template residues during the preparation of hydroxyapatite (HA) microspheres with hollow structures limit their biological applications to some extent. In this study, the nanosheet-assembled porous-wall hollow HA microspheres were successfully synthesized by a template-free hydrothermal method. SEM and TEM observations revealed that the prepared hollow HA microspheres were about 3–7 μm in diameter and were composed of an interior cavity and a porous shell assembled by nanosheets (consisting of radial nanorods arranged side-by-side). A possible mechanism for the formation of the hollow HA microspheres was proposed based on the time-gradient experiments. Furthermore, the hollow HA microspheres exhibited excellent vancomycin loading capacity (101.3 mg/g) and pH-responsive release properties. This study provides new inspiration for the design and various applications of hollow materials. [ABSTRACT FROM AUTHOR]

Calcium phosphate cement (CPC), composed of silica-modified hydroxyapatite (HA-SiO 2), cerium oxide (CeO 2), and silica (SiO 2), was developed as an osteoporosis bone filler. The effect of CeO 2 and SiO 2 content on the CPC's properties, such as crystal parameters, surface properties, antibacterial activity, and toxicity properties, were studied. HA-SiO 2 was prepared using the sol-gel method, while CeO 2 was prepared using the precipitation method. HA in HA-SiO 2 has crystal properties similar to pure HA. Synthesized CeO 2 contains Ce3+ and Ce4+ ions with Ce3+/Ce4+ = 0.34. Computational calculation predicted that the CeO 2 (111) surface and glycine molecule interaction was categorized as chemisorption. Moreover, CeO 2 has antibacterial activity toward Escherichia coli and Staphylococcus aureus. Combining HA-SiO 2 and CeO 2 did not change the adsorption-desorption isotherm curve type, but slightly decreased the surface area, total pore volume, and average pore. Increasing the percentage of CeO 2 and adding 10 % SiO 2 (w/w) affected the particle's size and CeO 2 distribution. However, CPC lost antibacterial activity toward Staphylococcus aureus but adding 10 % SiO 2 (w/w) increases the bacterial activity toward Escherichia coli close to that of pure CeO 2. The MTT assay using pre-osteoblast MC3T3E1 cells showed that the CPC has IC 50 = 4227 μg/ml or is nontoxic. [Display omitted] [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) or bioceramic-based coatings on stainless steel (SS) 316L significantly enhance the biofunctionality of the base material's surface. However, HA's low thermal conductivity and brittleness limit its effectiveness as a coating material. This study investigates HA coating on SS 316L using electric discharge machining (EDM) with varying discharge energies and powder concentrations. Surface morphology, elemental composition, and phase analysis of untreated and coated samples were characterised using field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). The results demonstrate that the HA-assisted EDM process creates a coating comprising biocompatible oxides, phosphates, carbides, and intermetallic compounds. The coating exhibits a thin resolidified layer of 10.74 μm, characterised by redeposited spherical debris, shallow cavities, and a surface texture of 2.688 μm. The layer's hydrophilic nature is confirmed by a minimum contact angle of 47.68°. Taguchi analysis indicates that the machining rate is optimised at an HA powder concentration of 16 g/l, with peak current and HA powder concentration being the most influential parameters affecting resolidified layer thickness, surface texture, and wetting angle. The research intends to motivate SS 316L medical device manufacturers to implement the HA-assisted EDM process for bioimplant's dual machining and coating. [ABSTRACT FROM AUTHOR]

The coalescence of nanocrystals that occurs during low-temperature thermal treatments during the purification of hydroxyapatite from pigs has not yet been studied in the context of low-temperature environmentally friendly purification. To preserve the nature of hydroxyapatite, two extraction methods were investigated: Route 1 (autoclave and Soxhlet) and Route 2 (calcination at low temperatures with different times). The focus is on observing the effectiveness of removing fats and proteins while maintaining crystallite size and morphology. DSC showed that coalescence of crystallites occurred at 452, 566, 648, and 704 °C. Raw has a higher IR FWHM (phosphate band) due to the organic material; R1 had a lower FWHM (partial removal of lipids and proteins). Increasing the calcination temperature decreases the FWHM, indicating a shift in vibrational states from surface to bulk, leading to an increase in apparent crystallite size due to coalescence. For 20–80 h at quasi-stable temperatures of 400 and 500 °C, no significant changes occur in the IR spectrum. X-ray diffraction indicates the removal of organic material during calcination, as the peaks become clearer with increasing temperature. The crystallite size is not affected and remains in similar ranges. Purification with hydroxide shows an increase in both lattice parameters, in addition to the fluctuations that occur due to the ionic substitutions that naturally occur in biogenic HAp. And the TEM study confirms that the changes in apparent size from 2D to 3D are the result of the phenomenon of interplanar coalescence at low temperatures that occurs in sintering processes. [ABSTRACT FROM AUTHOR]

Biomedical coatings were elaborated by pulsed electrodeposition with hydrogen peroxide (H 2 O 2) into electrolytes on Ti 6 Al 4 V substrates, and the effect of H 2 O 2 concentration on the electrolyte and the heat treatment was studied. The experimental procedures employed in this study produce a consistent hydroxyapatite coating. This coating is well-suited for use in bio-implants, as it enhances the integration of the implant with surrounding bone tissue and improves the mechanical performance. The coatings' surface morphology and chemical composition were assessed using scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray spectroscopy (EDXS) for x-ray microanalysis. X-ray diffraction (XRD) was also utilized to identify the phases and composition of the coatings. Nanoindentation and scratch tests were conducted to analyze the nanomechanical properties and adhesion behavior. Potentiodynamic polarization was employed in the Ringer solution to evaluate the corrosion resistance and replicate the conditions of the human body environment. The results of our thorough investigation revealed that employing pulsed electrodeposition with 9 % H 2 O 2 in the electrolyte, combined with subsequent heat treatment, facilitated the creation of coatings comprising two distinct phases: stoichiometric hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP). Our meticulous research underscores the significance of this process in achieving these specific coating compositions. Under these tests listed above, this composite demonstrated favorable mechanical properties (E = 30.45 GPa and H = 72.2 MPa). It also exhibited superior scratch adhesion and a critical load of 23 MPa and 12 N, respectively. Additionally, an improvement in tribological comportment was observed, and the wear volume decreased from 4.15 106 μm3 to 2.44 106 μm3. The HAP coating heat treated with 9 % H 2 O 2 exhibited the highest corrosion resistance, with E corr at −0.189 V/SCE and i corr at −1.11 μA cm−2 [ABSTRACT FROM AUTHOR]

[Display omitted] Stone-built cultural heritage faces threats from natural forces and anthropogenic pollutants, including local climate, acid rain, and outdoor conditions like temperature fluctuations and wind exposure, all of which impact their structural integrity and lead to their degradation. The development of a water-based, environmentally-friendly protective coatings that meet a combination of requirements posed by the diversity of the substrates, different environmental conditions, and structures with complex geometries remains a formidable challenge, given the numerous obstacles faced by current conservation strategies. Here we report the structural, electrical, and mechanical characterization, along with performance testing, of a nanostructured hydrophilic and self-healing hybrid coating based on hydroxyapatite (HAp) nanocrystals and polyelectrolyte multilayers (PEM), formed in-situ on Greek marble through a simple spray layer-by-layer surface functionalization technique. The polyelectrolyte-hydroxyapatite multilayer (PHM) structure resembled the design of naturally forming trabecular bone, attained at a short procedural time. It exhibited chemical affinity, aesthetical compatibility and resistance to weathering while offering reversibility. The proposed method is able to generate micron-sized coatings with controlled properties, such as adhesion and self-healing, leading to less weathered surfaces. Our results show that the PHM is a highly effective protective material that can be applied for stone protection and other similar applications. [ABSTRACT FROM AUTHOR]

Polymer technology has rapidly advanced across diverse domains, particularly in biomedical applications. Among various polymers, polyurethane (PU) hold great potential in developing biomaterials such as biomedical scaffold and drug delivery. In this study, we have innovatively engineered eco‐friendly polyurethane using lignin, a sustainable bio‐polyol derived from oil palm empty fruit bunches. To enhance the physicochemical properties of the PU, we have incorporated hydroxyapatite (HA) into the composites. The inclusion of HA has led to notable improvements in crucial properties such as density, porosity, and water absorption, making these composites ideal candidates for tissue regeneration scaffolds. Furthermore, to assess their biomedical applicability in drug delivery and cell scaffolding, we have employed the quercetin drug model. The results revealed a sustained kinetic release behavior within the polyurethane/hydroxyapatite (PU/HA) composites, showcasing their potential for controlled drug delivery applications. Moreover, cytotoxicity assays conducted using neuro‐2a cell models demonstrated the non‐cytotoxic nature of both PU and PU/HA composites. This finding holds significant implications for biomedical applications, indicating that these composites offer biocompatible platforms for tissue engineering and regenerative medicine endeavors. The ability of these composites to support cell viability underscores their potential for a wide range of biomedical applications, including neural tissue engineering and drug delivery systems targeting brain diseases. These findings pave the way for the development of innovative and sustainable biomaterials with diverse biomedical applications. Highlights: An eco‐friendly polyurethane has been engineered by harnessing liginin‐derived oil palm empty fruit bunches.Incorporation of hydroxyapaptite enhance the physical properties of polyurethane.Controlled kinetic drug release is one of polyurethane/hydroxyapatite (PU/HA) composites features.The PU/HA composites has low cytotoxicity against neuro‐2a cells. [ABSTRACT FROM AUTHOR]

Ti-6Al-4V metal is widely used as an implantable material due to its biocompatibility and corrosion resistance; however, it has low bioactive properties. The formation of nanotubes and a hydroxyapatite-polyvinyl alcohol-collagen composite coating on Ti-6Al-4V metal aims to enhance its biocompatibility and bioactivity. The nanotube oxide layer Ti-6Al-4V was formed by the anodization method. The composite’s infrared spectrum showed characteristic absorption bands from Hydroxyapatite (HAp), polyvinyl alcohol, and collagen. The composite-coated Ti-6Al-4V metal, both non-nanotube, and nanotube, showed a typical diffraction pattern of HAp and titanium element. The electron microscope image showed the uniform granular form of HAp. The corrosion test results showed that composite-coated nanotube Ti-6Al-4V metal could not improve corrosion resistance. It is also relevant to the in vitro test in a lactate ringer solution that showed the higher Ca2+ ion of nanotube Ti-6Al-4V metal than that of non-nanotube Ti-6Al-4V metal. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) bioceramics are widely used materials for orthopaedic applications, offering enhanced cellular adhesion and differentiation. However, the lack of antibacterial features makes the HA biomaterials prone to bacterial infections in in-vivo conditions. The osteomyelitis-like conditions are often treated with prolonged doses of antibiotics and may require surgical removal. Such problems can be tackled by inducing the antibacterial characteristics in the biomaterials which prevent such infections. Various research studies have been conducted to improve the mechanical and antibacterial characteristics of biomaterials like HA through doping. The present study focuses on the synthesis, characterization, and antibacterial study of Zn and Fe doped HA (ZFHAp) for application in the treatment of osteomyelitis. Response Surface Methodology (RSM) based Central Composite Design (CCD) approach was used to optimize the process parameters using the Design Expert software. The analyses indicated the presence of Calcium Iron Hydrogen Phosphate (CIHP) and Parascholzite (PS) as major phases. The optimized experimental conditions were estimated as 0.09 M Zn and 0.04 M Fe at 65 °C, corresponding to 71.29 % and 28.71 % of the CIHP and PS phases, respectively. The synthesized nanopowder showed mixed morphology comprising spherical and rod-shaped particles due to biphasic composition. The ZFHAp sample showed a broad-spectrum antibacterial activity, with IC 50 values of 4.02 mg/ml and 4.79 mg/ml against E. coli and S. aureus , respectively. The optimized sample showed excellent biocompatibility with the osteoblast-like cells (MG-63) with improved biomineralization properties. The antibacterial and osteoinductive characteristics of the synthesized biphasic Fe and Zn doped HA suggest its potential application against osteomyelitis-related conditions. • Biphasic composite was prepared with Fe containing CIHP and Zn containing PS phases. • RSM-CCD optimization process suggested conditions as 0.09 M Zn and 0.04 M Fe at 65 °C. • Excellent alkaline phosphatase activity with increased cell proliferation. • Broad spectrum antibacterial activities with IC 50 values less than 5 mg/ml. • Decreased surface energy of ZHHAp than HA indicating increased surface hydrophobicity. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF) is one of ideal reinforcements to hydroxyapatite (HA) owing to its unique structure, excellent biocompatibility and high mechanical properties. However, the mechanical property of CF reinforced HA (CF/HA) composites cannot be effectively improved due to the mismatch in surface properties and thermal expansion coefficients between CF and HA. In order to solve the problems, nano-hydroxyapatite (nHA) coating with different thickness was fabricated on the CF surface. The effect of the coating thickness on mechanical property of nHA-coated CF/HA composites was studied by finite element analysis. The CF with proper nHA coating thickness was subsequently used to reinforce HA. The compressive strength of nHA-coated CF/HA composites was approximately 97.3 % and 164.6 % higher than those of the uncoated CF/HA composites and pure HA ceramics, respectively. The interface properties and crack propagation were analyzed by cohesive element in the finite element analysis. The toughening mechanism of the composites included interfacial debonding, crack deflection, crack branching, and crack bridging. The mechanical properties of nHA-coated CF/HA composites were enhanced due to the strong interfacial bonding strength and reducing cracking in HA matrix. The prepared nHA-coated CF/HA composites satisfy the requirement of the mechanical properties of human load-bearing bone. It can be used to prepare cages, plates, screws, pins and other compact bone substitute parts in bone grafting. The study provided a method for construction of nHA-coated CF/HA composites with the designed properties by adjusting the nHA coating on the fiber and can be used to design other fibers reinforced ceramic matrix composites. [Display omitted] [ABSTRACT FROM AUTHOR]

The study proposes the utilization of microwave-assisted methods for converting neutralization slag (NS) into hydroxyapatite (HAP), offering an alternative to the conventional hydrothermal method. The microwave-assisted approach addresses the challenges encountered in hydrothermal reactions, such as particle agglomeration, reduced specific surface area, prolonged reaction time, high temperature requirements, and inadequate saturation adsorption capacity. By employing the response surface methodology with a Box-Behnken design, the study found that the microwave-assisted method significantly reduced the synthesis time from 90 to 25 min and the temperature from 120 °C to 56 °C. Furthermore, the microwave method consumed only 1/43 of the energy utilized in hydrothermal synthesis. To assess the performance of the synthesized HAP, various detection methods were utilized, including XRD, SEM-EDS, FTIR, Zeta potential, and ICP, which analyzed the crystal structure, crystallinity, morphology, chemical composition, and surface charge of HAP. The BET method was used to measure the specific surface area, further confirming the successful synthesis of HAP. The HAP synthesized through this microwave-assisted method exhibited a saturation adsorption capacity of up to 98.4 mg/g of fluoride ions from vanadium industrial raffinate. This study demonstrates that the microwave-assisted method provides a viable solution for reducing energy consumption and enhancing HAP synthesis efficiency for wastewater treatment in the vanadium industry. [Display omitted] [ABSTRACT FROM AUTHOR]

Doping silicon wafers without using highly toxic or corrosive chemical substances has become a critical issue for semiconductor device manufacturing. In this work, ultra‐thin films of hydroxyapatite (Ca5(PO4)3OH) are prepared by tethering by aggregation and growth (T‐BAG), and further processed by spike annealing. Via in situ infrared (IR), the decomposition of hydroxyapatite and intermixing with the native silicon oxide is observed already at temperatures as low as 200 °C. Phosphate transport through the native silicon oxide is driven by a phase transformation into a more stable thermal oxide. At 700 °C, diffusion of phosphorus into the sub‐surface region of oxide‐free silicon is observed. In situ IR combined with electrical impedance spectroscopy (EIS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), and X‐ray photoelectron spectroscopy (XPS) measurements allows to conclude that the phosphorus is: i) transported through the silicon oxide barrier, ii)) diffused inside the oxide‐free silicon, and iii) finally modified the electrical activity of the silicon wafer. To further explain the experimental findings, density‐functional theory (DFT) is used to demonstrate the extent of the effect of phosphorus doping on the electronic nature of silicon surfaces, showing that even small amounts of doping can have a measurable effect on the electrical performance of semiconductor wafers. [ABSTRACT FROM AUTHOR]

Dental implants fabricated from titanium have several limitations and therefore, alternative materials that fulfil the criteria of successful dental implant (bioactivity and anti-bacterial activity) need to be considered. Polyether ether ketone (PEEK) has been suggested to replace titanium implants. However, this material needs surface modification to meet the appropriate criteria. A nano-sized zirconium phosphate/GO (nZrP/GO) composite coating was prepared to improve PEEK's biological qualities. Polished and cleaned PEEK discs were coated with the composite of nZrP doped with 1.25 wt% GO by the soft-template method. To analyze the composite coating, X-ray, atomic force microscopy, and field emission scanning electron microscopy-energy dispersive spectroscopy were used. The adhesion of the coating to PEEK was measured by adhesive tape test. By measuring the optical contact angle, the coated and non-coated samples' differences in wettability were evaluated. Antimicrobial activity was evaluated against S. aureus and E. coli and cytotoxicity tested employing gingival fibroblasts and osteoblast-like cells. The nZrP/GO composite coating was 23.45 µm thick, was irregular and attached strongly to the PEEK surface. Following coating, the water contact angle dropped to 34° and surface roughness to 13 nm. The coating reduced the count of bacteria two-fold and was non-cytotoxic to mammalian osteoblast-like cells and fibroblasts. A precipitation of nano-calcium-deficient apatite was observed on the surface of the nZrP/GO coating following a 28-day immersion in SBF. PEEK-coated with nZr/GO coating is a good candidate as dental implant. • nZrP/GO converts PEEK surface from bionert to a bioactive surface. • Addition of GO into nZrP potentiates its anti-bacterial activity. • PEEK implant coated with nZrP/GO is not cytotoxic to mammalian cells. • nZrP/GO increases surface wettability of PEEK implant. • Addition of GO has no effect on adhesion of nZrP coating to PEEK surface. [ABSTRACT FROM AUTHOR]

BACKGROUND: A growing population of patients is seeking treatments that not only affect their overlying features but also restore a more biologically youthful structure and function to the underlying tissue. These strategies are part of what is known as regenerative aesthetics (RA). As an emergent field, clarity regarding the precise definitions and aims of RA and methods to measure the regenerative capacity of RA treatments are lacking. METHODS: A panel of 6 multidisciplinary experts discussed the foundational aspects of RA. Consensus statements covered aspects of RA including terminology, goals of treatment, treatment strategies, and biological benchmarks indicating regeneration. Consensus on a statement was defined as $75% agreement. Results: Panelists emphasized the importance of natural, youthful tissue architecture and function including cellular and extracellular components. Replacement of a single biological component was not considered sufficient for an aesthetic treatment to be described as regenerative. Rather, the relative amounts, ratios, types, and organization are important to determine regenerative potential. Calcium hydroxylapatite is an example of an aesthetic injectable with evidence of regenerative capacity, as demonstrated by its ability to improve collagen type I/III ratios as well as induce the production of elastin and proteoglycans, which ultimately improve measures of skin quality. [ABSTRACT FROM AUTHOR]

BACKGROUND: Injectable biostimulators are widely used to improve facial aging signs. This study was performed to compare the genetic pathways affected by 2 different injectable biostimulators. METHODS: Randomized 13-week study (n = 21) comparing gene expression after poly L-lactic acid (PLLA-SCA) and calcium hydroxylapatite (CaHA-R) injections (baseline [BL] and Day 28) as treatment of nasolabial fold wrinkles. Punch biopsy was performed at BL and day 90; RNA was isolated, gene expression was analyzed, and bulk RNA sequencing performed. Data from both pathways were studied using the Search Tool for Retrieval of Interacting Genes/Proteins and Reactome databases. RESULTS: Analysis at Day 0 and Day 90 showed differing gene regulation for PLLA-SCA and CaHA-R (after accounting for minor differences at BL, p, .05 at Day 90 for 9-12 genes). PLLA-SCA uniquely correlates with genes involved in adipocyte regeneration, while CaHA-R did not affect these genes. Clinically, this could translate to healthy fat replacement with an enhanced effect beyond the improvement of the collagen structure and a longer-lasting effect with PLLA-SCA. Furthermore, the adipokines that appear to be upregulated are regenerative with a positive impact on skin health. CONCLUSION: PLLA-SCA has a novel and unique signature, which supports a potential regenerative mechanism of action through its role in the modulation of adipocyte function. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAP) is a well-established material in biomedical applications, especially for bone tissue regeneration, dental implants, and drug delivery systems. Recent research emphasizes enhancing the biocompatibility and osteoconductivity of orthopedic implants using HAP. This study explores the potential of combining HAP with a lipid matrix to improve the surface properties and biocompatibility of poly(lactic acid) (PLA)-based, 3D-printed, resorbable bone implants. We utilized the Langmuir–Blodgett method to deposit HAP within a dihexadecyl phosphate (DHP) matrix onto PLA substrates. This study demonstrates that DHP and HAP form stable monolayers at the air/water interface with HAP particles distributed within a homogeneous lipid matrix. The presence of HAP and the resulting changes in surface free energy (SFE) are hypothesized to enhance the biocompatibility of PLA implants. Our findings indicate that films composed of DHP + HAP 5:1 are particularly effective in altering PLA surface characteristics, potentially improving osteointegration, and reducing microbial adherence. Overall, this work highlights that surface modification of PLA with HAP and lipid matrices is the first step towards new, promising, and cost-effective strategies for developing advanced biomaterials for bone regeneration. [ABSTRACT FROM AUTHOR]

Before employing a biomedical material in medical applications, a researcher must possess comprehensive knowledge regarding its chemical, physical, biological, structural, and mechanical properties. Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) is a vital constituent of the calcium orthophosphate group. The material exhibits good dielectric and biological compatibility, diamagnetic behavior, thermal stability, osteoconductivity, and bioactivity. Additionally, it has a Ca:P molar ratio of 1.67. Because HAp has a chemical composition that is quite similar to normal bone and teeth, it has the potential to be used as a material for implant implantation in fractured portions of the human skeletal system. Many ways for generating HAp nanoparticles have been found as a result of the increasing usage of HAp in medicine. The conditions under which HAp is generated determine its physical and chemical properties, crystalline structure, and form. This study provides detailed information on the HAp's characteristics and manufacturing procedures, as well as revealing the structure and its properties. [ABSTRACT FROM AUTHOR]

Polysulfone (Psf) ultrafiltration flat-sheet membranes were modified with hydroxyapatite (HA) powder during preparation using the wet-phase inversion method. HA was incorporated to enhance the protein separation capabilities. The asymmetric Psf membranes were synthesized using NMP as the solvent. Through Scanning Electron Microscopy (SEM) analysis, it was revealed that HA was distributed across the membrane. Incorporating HA led to higher flux, the improved rejection of protein, and enhanced surface hydrophilicity. The permeability flux increased with HA concentration, peaking at 0.3 wt.%, resulting in a 38% improvement to 65 LMH/bar. Whey protein separation was evaluated using the model proteins BSA and lysozyme, representing α-Lactalbumin. The results of protein rejection for the blend membranes indicated that the rejection rates for BSA and lysozyme increased to 97.2% and 73%, respectively. Both the native and blend membranes showed similar BSA rejection rates; however, the blend membranes demonstrated better performance in lysozyme separation, indicating superior selectivity compared to native membranes. The modified membranes exhibited improved hydrophilicity, with water contact angles decreasing from 66° to 53°, alongside improved antifouling properties, indicated by a lower flux decline ratio value. This simple and economical modification method enhances permeability without sacrificing separation efficiency, hence facilitating the scalability of membrane production in the whey protein separation industry. [ABSTRACT FROM AUTHOR]

The process of osteointegration depends significantly on the surface roughness, structure, chemical composition, and mechanical characteristics of the coating. In this regard, an important direction in the development of medical materials is the development of new techniques of surface modification and the creation of bioactive ceramic coatings. Calcium-phosphate materials based on hydroxyapatite have been proposed as bioactive ceramic coatings on titanium implants for the effective acceleration of bone tissue healing. To obtain bioactive ceramic coatings, pulse power sources are best suited, namely detonation spraying, in which the energy of the explosion of gas mixtures is used as a source of pulse action. The pulse mode of operation in the detonation spraying method is preferable for the formation of bioactive ceramic coatings. It provides a high velocity of hydroxyapatite particles, which promotes their effective fixation on the titanium substrate, while minimizing the heating of the material. This approach preserves the substrate structure and improves the coating adhesion. Four different types of coatings with varying O2/C2H2 molar ratios, ranging from 2.6 to 3.7, were obtained using detonation spraying. Powders and obtained coatings of hydroxyapatite were studied by Raman spectroscopy and XRD structural analysis. The results of XRD phase analysis showed the partial conversion of the hydroxyapatite phase to the α-tricalcium phosphate (α-TCP) phase during the detonation spraying process. The results obtained by Raman spectroscopy indicate that hydroxyapatite is the main phase in coatings. All hydroxyapatite-based coatings exhibited hydrophobic properties, which was confirmed by contact-angle values above 90° in wettability tests, characteristic of hydrophobic surfaces. The adhesive strength of the coatings was measured by the scratch test method. Tribological tests were conducted using the ball-on-disk method under both dry conditions and in Ringer's solution. This approach enabled the evaluation of wear resistance and friction coefficient of the coatings in different environments, simulating both lubrication-free conditions and those resembling physiological environments. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp) and hydroxyapatite-based materials show promising potential in the healthcare sector due to their distinctive properties such as biocompatibility, antimicrobial efficacy, non-toxicity, and robust mechanical characteristics. This makes HAp materials play an important role in hindering infection spreading in healthcare provider institutions. This study assesses the antimicrobial efficacy of the developed hydroxyapatite-based composites incorporating copper, zinc, and silver nanoparticles. The synthesized HAp and its modified composite variants (Cu/HAp, Zn/HAp, and Ag/HAp) with varying ratios ranging from 0 to 15% (wt) were characterized using XRD, XPS, SEM, and TEM analyses. Furthermore, the antibacterial and antifungal properties of the synthesized HAp and HAp-based composites were evaluated. The antibacterial effectiveness of the HAp and its composites was evaluated using a modified disc diffusion test, where the resulting inhibition zones on the agar surface were observed. All the HAp and HAp-based composites (HAp, Cu/HAp, Zn/HAp, and Ag/HAp materials) elicited in the formation of inhibitory zones. The most substantial inhibition values were observed for the 5% Ag/HAp formulation, with values of 19.7 and 13.8, against E. coli and S. aureus, respectively. The 5% Ag/HAp concentration may strike an ideal balance, providing high antimicrobial activity without adverse effects on biocompatibility or material stability. These findings underscore the recommendation of the proposed HAp-based composites for infection control measures through their application on medical instruments, textiles, healthcare personnel attire, and patient garments. [ABSTRACT FROM AUTHOR]

Ru/HAP catalyst with high-dispersion is prepared by a novel homogeneous deposition precipitation method (DPU). As compared to the conventional impregnation method (IM), the catalytic oxidation performance for toluene and DCM are much higher for DPU-sample with higher activity and good stability in humid air. Characterizations reveal that DPU-sample has a larger surface area with mesoporous structure, keeping smaller Ru particle size and uniform distribution on HAP, which is favorable for the exposure of active sites. The preparation and reaction conditions were also systematically studied, showing that 0.5 Ru/HAP(500)-DPU sample is a promising catalyst for VOC and CVOC removal. The Ru/HAP (DPU) is a promising broad-spectrum catalyst for VOC and CVOC removal. [ABSTRACT FROM AUTHOR]

Ammonia borane (AB, NH3BH3) is a promising candidate for a hydrogen-storage material because of its high stability as a solid state at room temperature under atmospheric pressure. This study demonstrated a novel catalyst design for highly efficient hydrolysis of AB by hybridizing Pt catalyst with hydroxyapatite (HAp, Ca10(PO4)6(OH)2) as an "active support", possessing Lewis-acidic Ca2+ sites in the a-plane and Lewis-basic PO43- sites in the c-plane. Facet-engineered HAp particles were synthesized via the microwave-assisted hydrothermal reaction using Ca-EDTA chelates. Varying the Ca/P ratio of HAp precursor (from 1.5 to 1.8) affected the particle morphology, exposed facet ratio of {300} to {002}, and the percentage of phosphate anion species (PO43- and HPO42-). The rod-like HAp sole catalysts performed approximately 2-fold higher activity for the hydrolysis of AB, compared with spherical HAp with low crystallinity. Moreover, the Pt/rod-like HAp co-catalyst demonstrated superior catalytic performance with a turnover frequency (TOF) of 623 molH2 molPt-1 min-1 than the Pt/spherical HAp (<232 molH2 molPt-1 min-1). We proposed a possible mechanism of a synergistic effect in the significant enhancement of the hydrogen release rate from AB. Lewis basic PO43- and Lewis acidic Ca2+ sites on HAp would affect preferential adsorption of electron-deficient BH3 and electron-rich NH3 groups in AB, catalyzing cleavage of B-N bonds. Besides, PO43- sites play a critical role in anchoring Pt particles towards electron transfer from Pt to PO43-, resulting in considerable enhancement of catalytic performance in dissociative adsorption of water molecules, which is a rate-determining step in the hydrolysis. [ABSTRACT FROM AUTHOR]

The objective of this work is to review the literature on the use of three-dimensional scaffolds obtained by printing for the regeneration of bone defects in the maxillofacial area. The research question asked was: what clinical experiences exist on the use of bone biomaterials manufactured by CAD/CAM in the maxillofacial area? Prospective and retrospective studies and randomized clinical trials in humans with reconstruction area in the maxillofacial and intraoral area were included. The articles had to obtain scaffolds for bone reconstruction that were designed by computer processing and printed in different materials. Clinical cases, case series, in vitro studies and those that were not performed in humans were excluded. Six clinical studies were selected that met the established inclusion criteria. The selected studies showed heterogeneity in their objectives, materials used and types of regenerated bone defects. A high survival rate was found for dental implants placed on 3D-printed scaffolds, with rates ranging from 94.3% to 98%. The materials used included polycaprolactone, coral-derived hydroxyapatite, biphasic calcium phosphate (BCP) and bioceramics. The use of CAD/CAM technology is seen as key for satisfying variations in the shapes and requirements of different fabrics and size variations between different individuals. Furthermore, the possibility of using the patient's own stem cells could revolutionize the way bone defects are currently treated in oral surgery. The results indicate a high survival rate of dental implants placed on 3D-printed scaffolds, suggesting the potential of this technology for bone regeneration in the maxillofacial mass. [ABSTRACT FROM AUTHOR]

Calcium phosphate hydroxyapatite (HA) was successfully incorporated into poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/gelatin (PHBV/GEL) nanofibers through an electrospinning process in a hexafluoroisopropanol solvent (HFIP). The PHBV/GEL was electrospun and collected using a rotating metallic network to develop highly ordered nonwoven mats. The effects of HA addition on the morphologies of the obtained fibers were investigated using SEM. The average diameter of the fibers ranged around 700–900 nm, depending on the HA content. From a mechanical perspective, the addition of HA nanoparticles showed variations in tensile strength and elastic modulus values. The lowest tensile strength measured for neat PHBV/GEL was 0.37 ± 0.08 MPa with an elastic modulus of 9.45 ± 0.65 MPa, whereas the highest tensile strength reported for 5% HA‐loaded PHBV/GEL mats was 1.1 ± 0.4 MPa with an elastic modulus of 16.9 ± 0.39 MPa. In addition, cell viability, and mineral deposition were also studied using MC3T3‐E1 pre‐osteoblasts. The in vitro experiment results showed that the HA loaded‐PHBV/GEL mats provide optimal conditions for cell growth and osteogenic differentiation of MC3T3‐E1 cells. This study reveals the potential of PHBV/GEL/HA matrices in the development of novel guided bone‐regeneration (GBR) membranes for orthopedic and craniomaxillofacial surgery, by providing favorable structural features for attachment, growth, and differentiation of osteoblast cells. Highlights: Simple and cheap electrospinning strategy toward network‐like fibrous mats.Microstructure, mechanical, and biological features were evaluated.Electrospun PHBV/GEL/HA promoted calcium phosphate deposition by MC3T3‐E1 cells. [ABSTRACT FROM AUTHOR]

Polymethylmethacrylate (PMMA) and hydroxyapatite (HAp) are the two most promising biocompatible materials used in biomedical applications. The current research performs the wettability and tribological characterization of the novel hybrid biocomposite of PMMA reinforced with eggshell-derived, silver-doped hydroxyapatite (HAPAg). Varying wt% of HAPAg in PMMA were analyzed using a ball-on-disk tribometer. The coefficient of friction shows an increasing trend with an increase in normal load for all the compositions while, with reinforcement of HAPAg, it increases till 5 wt% and then shows a sudden decrement at PHA7.5 due to the formation of flattened asperities at the contact surface. However, the progressive increase in hardness with the inclusion of HAPAg in PMMA correlates with the reduction in the wear rate of the composite samples. The highest wear rate was observed for PHA0 (i.e. 862.42 × 10−5 mm3/m) at 60 N. As observed, the hydrophilicity increases (contact angle changed from 96.30° ± 2.11° [PHA0] to 81.70° ± 1.01° [PHA7.5]), and the porosity decreases (≈2.86%) with the reinforcement of HAPAg in PMMA which further improves the cohesion strength and microhardness of the composite material. The X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis confirms the uniform reinforcement of HAPAg, and the worn surface behavior was inspected using scanning electron microscopy, Stereo zoom microscope, and three-dimensional surface profilometer. The low-specific wear characteristic at higher loads ensures the application of developed biocomposite material in dental and orthopedic applications. [ABSTRACT FROM AUTHOR]

In this experimental study, the initial phase involved preparing composite structures with various mix ratios using the Ti‐6Al‐4V alloy, widely used in clinical applications, in conjunction with ZrO2 and hydroxyapatite (HA) synthesized via the precipitation method, employing powder metallurgy techniques. Subsequently, the microstructures of the resultant hybrid composite materials were imaged, and x‐ray diffraction (XRD) phase analyses were conducted. In the final phase of the experimental work, tests were performed to determine the biocompatibility properties of the hybrid composites. For this purpose, cytotoxicity and genotoxicity assays were carried out. The tests and examinations revealed that structures compatible both morphologically and elementally were obtained with no phase transformations that could disrupt the structure. The incorporation of ZrO2 into the Ti‐6Al‐4V alloy was observed to enhance cell viability values. The value of 98.25 ± 0.42 obtained by adding 20% ZrO2 gave the highest cell viability result. The addition of HA into the hybrid structures further increased the cell viability values by approximately 10%. All viability values for both HA‐added and HA‐free groups were obtained above the 70% viability level defined in the standard. According to the genotoxicity test results, the highest cytokinesis‐block proliferation index values were obtained as 1.666 and 0.620 in structures containing 20% ZrO2 and 10% ZrO2 + 10% HA, respectively. Remarkably, all fabricated composite and hybrid composite materials surpassed established biocompatibility standards and exhibited nontoxic and nongenotoxic properties. This comprehensive study contributes vital insights for future biomechanical and other in vitro and in vivo experiments, as it meticulously addresses fundamental characterization parameters crucial for medical device development. Research Highlights: Support of optimum doping rates ions on hybrid composites and concentrations.Development of uniform surface appearance and distributions/orientations of microcrystals on ceramic compoundsImprovement of cell viability and desired increase in biocompatibility with the doping of HA. [ABSTRACT FROM AUTHOR]

The study investigates the impact of powder metallurgical factors on the corrosion rate (CR) of biodegradable zinc (Zn)-hydroxyapatite (HAP) materials. Factors such as HAP weight percentage (wt%), compaction pressure (CP), heating rate (HR), sintering temperature (ST), and dwell time (DT) were examined. Static immersion test was performed to determine the CR of the samples. The results showed an increase in CR with increased HAP wt%, while factors like CP, HR, and ST led to lower CR. The CR decreased with an increase in DT upto 18 min and thereafter increased. HAP wt% was found to be the most significant factor, contributing 57.95% on CR. A genetic algorithm-based optimization was conducted to minimize CR of Zn-HAP materials. The experimental CR value obtained at optimized levels, i.e., 3 wt% HAP, 34 MPa CP, 25 °C/min HR, 480 °C ST, and 30 min DT, were found to be 0.121 mm/yr, which was within the range of the predicted value 0.08 ± 0.044 mm/yr. This work presents a statistical modeling approach for predicting the CR of Zn-HAP composite for biomedical applications. [ABSTRACT FROM AUTHOR]

AbstractOur research described in this report describes our advanced thermo-electric characterization of hydroxyapatite (HA) and multi-walled carbon nanotube (MWCNT) reinforced polyether ether ketone (PEEK) polymer composites. The incorporation of HA and MWCNTs was aimed to enhance the thermo-electric properties of PEEK while maintaining its biocompatibility. Three different methodologies were followed for development of the polymer nanocomposites with the effect of varying the methodologies investigated in the present study. FTIR analysis showed the presence of HA, MWCNT and PEEK, confirming the formation of the nanocomposite. HA and MWCNT addition enhanced the dielectric constant and conductivity compared to pure epoxy. This corresponds to enhanced interfacial polarization and charge transfer capabilities. Differential Scanning Calorimetry (DSC) analysis confirmed the modification of the glass transition temperatures, with the addition of HA and MWCNT indicating enhanced thermal stability as well as resistance to degradation. This research, we suggest, paves the way for innovative materials that bridge the gap between functionality and biocompatibility in advanced engineering applications. [ABSTRACT FROM AUTHOR]

In this study, hydroxyapatite‐gelatin (HAp‐Gel) composite using Ca precursor from cuttlefish bone (Sepia Sp.) has great potential to be used in hydroxyapatite synthesis. The HAp‐Gel composite was synthesized in‐situ by sol‐gel method with varying concentrations to see its ability to adsorb rhodamine b dye. XRF analysis results obtained a CaO content of 95.561 %. The 40 % HAp‐Gel composite showed the best adsorption capacity, with a percentage of 27.326 %, which experienced an increase in the percentage of hydroxyapatite adsorption capacity, namely 4.6881 %. FTIR results from 40 % HAp‐Gel composite obtained characteristic peaks of functional groups contained in hydroxyapatite and gelatin. XRD analysis showed the diffraction pattern of HAp by the ICSD standard spectrum (#157481), and the average size of the hydroxyapatite crystal was 9.72 nm. In comparison, the 40 % HAp‐Gel composite crystal was 5.25 nm. SEM‐EDS results showed that the composite morphology was agglomerated with irregular shapes and a Ca/P ratio 1.56. SAA results showed a composite surface area of 55.256 m2/g. The 40 % HAp‐Gel composite sorption application followed the Freudlich isotherm model with multilayer adsorption on the heterogeneous adsorbent surface. The interaction between rhodamine B and HAp‐Gel 40 % occurs at pseudo‐second‐order and can be reused up to two cycles when interacting with rhodamine B. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) is a bioceramic material widely used as a bone biomimetic substitute and can be synthesized by biomineralization, according to which HA nanoparticles are formed on a polymer template. Nevertheless, little is known about the effect of ion doping and biomineralization on cell metabolism, oxidative stress, and DNA damage. In the present contribution, we report on synthesizing and characterizing biomineralized chitosan as a polymer template with HA nanoparticles doped with magnesium (MgHA) and iron ions (FeHA). The physical-chemical and morphological characterization confirmed the successful synthesis of low crystalline ions-doped HA nanoparticles on the chitosan template, whereas the biochemical activity of the resulting nanoparticles towards human osteoblasts-like cells (MG63 and HOBIT) was investigated considering their effect on cell metabolism, proliferation, colony formation, redox status, and DNA damage extent. Data obtained suggest that particles enhance cell metabolism but partially limit cell proliferation. The redox status of cells was measured suggesting a slight increase in Reactive Oxygen Species production with chitosan biomineralized with iron-doped HA, whereas no effect with magnesium-doped HA and no effect of all formulations on the oxidation level of Peroxiredoxin. On the other hand, DNA damage was investigated by COMET assay, and expression and foci γH2AX. These latter tests indicated that HA-based nanoparticles promote DNA damage which is enhanced by chitosan thus suggesting that chitosan favors the nanoparticles' internalization by cells and modulates their biological activity. The potential DNA damage should be considered – and potentially exploited for instance in anticancer treatment – when HA-based particles are used to devise biomaterials. [ABSTRACT FROM AUTHOR]

Highlights The characterization of S. persica (Salvadora persica) extract, which involved evaluating its antibacterial activity, demonstrated the extract's strong efficacy. Additionally, incorporating it into PMMA/HA showcased the composite's good antibacterial activity. The objective of this work is to evaluate how the incorporation of S. persica extract affects the wear resistance of the dental composite PMMA/HA, considering the critical importance of wear resistance in dental applications. The wear response of this biocomposite was tested against an Alumina ball using a pin‐on‐disc tribometer. Initially, the hydroxyapatite (HA) micro particles demonstrate a remarkable influence on wear behavior when incorporated at an optimal percentage (10%wt). This optimal inclusion rate not only significantly increases the wear rate but also instigates a shift in the wear mechanism, favoring abrasive wear while minimizing adhesive wear comparing to PMMA. The addition of the extract nanoparticles to the composite PMMA/HA decreases the wear rate except the composite containing 10 wt% of each filler. Additionally, it introduces adhesive wear, in addition to the existing fatigue and abrasion wear. Thus, the composite PMMA/HA could accommodate up to 10 wt% of the S. persica extract as the optimal percentage that provides antibacterial activity to this biocomposite without exhibiting a deterioration in wear performance. The evaluation of the effect of incorporating S. persica extract, which provides antibacterial activity, on the wear resistance of the PMMA/HA dental composite generally demonstrates a reduction in this property. The addition of S. persica extract introduces adhesive wear in addition to the fatigue and abrasion wear already present in the PMMA/HA composite. The composite PMMA/HA can accommodate up to 10 wt% of S. persica extract without compromising its wear performance. [ABSTRACT FROM AUTHOR]

Hydroxyapatite, a calcium phosphate compound, is a popular biomaterial due to its biocompatibility, bioactivity, biodegradability and non-toxicity. As strong candidates for interdisciplinary materials science applications, core-shell and hollow-core hydroxyapatite particles have emerged as promising materials with their capability for loading and releasing materials. This literature review provides a comprehensive overview of the synthesis and applications of micro- and nanostructured core-shell and hollow-core hydroxyapatite particles. Their applications in material loading, transfer and controlled release are highlighted and the potential of these particles for use in all disciplines of material transportation is emphasized. [ABSTRACT FROM AUTHOR]

At the nanoscale, bones are made up of collagen fibrils, the mineralization of bones takes place when ions of calcium and phosphate form hydroxyapatite (HAP) crystals. HAP due to its osteogenic and biocompatible properties has been widely used in conventional bone tissue engineering. 3D and 4D printing techniques have been explored to manufacture unique HAP scaffolds according to each patient's needs, although the clinical use is not yet ready, and the techniques are still being developed. The incorporation of different biomolecules like growth factors, peptides, drug molecules and nanomaterials etc. improves the biocompatibility and bio-functionality of these printed scaffolds. This critical review describes the evolution of HAP in conventional bone tissue engineering, and summarizes the new approaches, clinical applications and future perspectives of HAP in 3D-4D printing techniques. The synergistic potential and future clinical prospects for bone tissue engineering offered by various functionalization of hydroxyapatite-incorporated 3D and 4D printed scaffolds has been discussed. [ABSTRACT FROM AUTHOR]

Tricalcium silicate (C3S) is one of the main components of mineral trioxide aggregates, which is used in dental endodontic treatment. C3S provides workable viscosity itself and fast hydration when water is added, and it is known to be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, and insoluble in tissue fluids. In this study, C3S is added to synthetic bone‐graft materials from 30% to 60% to deliver viscosity to increase workability in the early stage of implant surgical procedure and to attain some degree of compressive strength after the hydration. Additionally, the porosity is not overly reduced to maintain the ability for bone regeneration. The porosity of the samples was confirmed to be 40%–50% with the formation of the C3S matrices. Simultaneously, the maximum compressive strength was ensured at 14.9 MPa within 24 h of curing time. The radiopacity required for post‐procedural diagnosis was evaluated. The radiopacity of the samples with 50% and 60% C3S was 1.0 mm Al and 1.1 mm Al, respectively. When ZrO2 was added, the radiopacity was enhanced to 1.6 mm Al. Overall, the experimental results showed that the bone‐graft added C3S would be suitable for alveolar bone support and rigid matrix formation in implant surgery. [ABSTRACT FROM AUTHOR]

In this work, ion-doped hydroxyapatite materials were synthesized using the sol-gel technique. XRD analysis confirmed the purity of the products, with no secondary peaks observed. Doping with manganese, lithium, potassium, and zinc ions resulted in a crystalline size of 47–48 nm. Fourier transform infrared spectroscopy validated the structural bands, while scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed nano-rod-like particles with sizes ranging from 30 to 80 nm in length and 13 to 40 nm in width. Impedance spectroscopy and dielectric relaxation studies showed electrical behaviour following the Maxwell-Wagner mechanism and non-Debye type relaxation. The materials exhibited strong antibacterial properties, making them promising for medical implant applications. [ABSTRACT FROM AUTHOR]

Effective antibacterial therapy while accelerating the repair of bone defects is crucial for the treatment of osteomyelitis. Inspired by the protective mechanism of Andrias davidianus, we constructed an antibacterial hydrogel scaffold with excellent rigidity and long-term slow-release activity. While retaining the toughness of the skin secretion of Andrias davidianus (SSAD), the rigidity of the hydrogel material is increased by incorporating hydroxyapatite to meet the demands of bone-defect-filling materials. It also exerted antibacterial effects via the slow-release of vancomycin from local osteomyelitis lesions. Notably, the hydrogel can also carry a high stable recombinant miR-214-3p inhibitor (MSA-anti214). By the delivery of nano vector polyvinylamine, the long-term slow-release of MSA-anti214 is achieved to promote bone repair, making this composite hydrogel a potential SSAD-based osteomyelitis alleviator (SOA). In vitro and vivo results verified that the SOA effectively eliminated Staphylococcus aureus and repaired bone defects, ultimately mitigating the progression of osteomyelitis. This composite hydrogel extends the economic application prospects of A. davidianus and has provided new insights for the treatment of osteomyelitis. The study also explored new insights for the bone filling materials of bone defection and other skeletal system diseases. [ABSTRACT FROM AUTHOR]

High viscosity glass ionomer cements (GICs) are widely used in various clinical applications, being particularly effective in atraumatic restorative treatment (ART) due to the synergistic interaction between the material and the technique. However, the inadequate mechanical properties of GICs raise concerns regarding the predictability and longevity of these restorations in areas exposed to occlusal stress. Various modifications of the powder components have been proposed to improve the mechanical strength of GICs to withstand occlusal loading during mastication. In this in vitro study, we investigated whether the nanoparticles (NPs) added to commercially available GICs could fulfill this requirement, which would likely broaden the spectrum of their potential clinical applications. Two commercially available GIC powders (Fuji IX and Ketac Molar), modified by the addition of 5 wt.% TiO2, MgHAp100 or MgHAp1000 NPs, were incorporated into the corresponding liquid in an appropriate ratio, and the mixed cements were evaluated in terms of fracture toughness, flexural strength, Vickers microhardness and rheological tests and compared with the original material. Fuji IX containing 5 wt.% MgHAp100 NPs had lower flexural strength, while Ketac Molar with 5 wt.% TiO2 NPs showed increased fracture toughness. Vickers microhardness increased in Fuji IX following the addition of 5 wt.% TiO2 and MgHAp100 but decreased in Ketac Molar comprising 5 wt.% MgHAp100 (p < 0.05). Achieving a predictable bond between NPs and cement matrix, as well as ensuring a uniform distribution of the NPs within the cement, are critical prerequisites for enhancing the mechanical performance of the original cement. [ABSTRACT FROM AUTHOR]

The need to develop synthetic bone substitutes with structures, properties, and functions similar to bone and capable of preventing microbial infections is still an ongoing challenge. This research is focused on the preparation and characterization of three-dimensional porous scaffolds based on hydroxyapatite (HA)-functionalized calcium carbonate loaded with silver nanoparticles and simvastatin (SIMV). The scaffolds were prepared using the foam replica method, with a polyurethane (PU) sponge as a template, followed by successive polymer removal and sintering. The scaffolds were then coated with poly(lactic-co-glycolic) acid (PLGA) to improve mechanical properties and structural integrity, and loaded with silver nanoparticles and SIMV. The scaffolds were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), ATR FT-IR, and silver and SIMV loading. Moreover, the samples were analyzed by Brillouin and Raman microscopy. Finally, in vitro bioactivity, SIMV and silver release, and antimicrobial activity against Staphylococcus aureus and Staphylococcus epidermidis were evaluated. From the Brillouin spectra, samples showed characteristics analogous to those of bone tissue. They exhibited new hydroxyapatite growth, as evidenced by SEM, and good antimicrobial activity against the tested bacteria. In conclusion, the obtained results demonstrate the potential of the scaffolds for application in bone repair. [ABSTRACT FROM AUTHOR]

In this work, composite materials were obtained for the first time using various methods and the dependences of the resulting surface morphologies were investigated. This involves modifying the surface with cucurbit[n]urils, which are highly promising macrocyclic compounds. The process includes applying cucurbit[6]uril to the hydroxyapatite surface in water using different modification techniques. The first method involved precipitating a dispersion of CB[6] in undissolved form in water. The second method involved using fully dissolved CB[6] in deionized water, after which the composite materials were dried to constant weight. The third method involved several steps: first, CB[6] was dissolved in deionized water, then, upon heating, a dispersion of CB[6] was formed on the surface of HA. The fourth method involved using ultrasonic treatment. All four methods yielded materials with different surface morphologies, which were studied and characterized using techniques such as infrared (IR) spectroscopy and scanning electron microscopy (SEM). Based on these results, it is possible to vary the properties and surface morphology of the obtained materials. Depending on the method of applying CB[6] to the surface and inside the HA scaffold, it is possible to adjust the composition and structure of the target composite materials. The methods for applying CB[6] to the hydroxyapatite surface enhance its versatility and compatibility with the body's environment, which is crucial for developing new functional composite materials. This includes leveraging supramolecular systems based on the CB[n] family. The obtained results can be used to model the processes of obtaining biocomposite materials, as well as to predict the properties of future materials with biological activity. [ABSTRACT FROM AUTHOR]

The fabrication of hydroxyapatite (HAP)/MgO composite coatings on Mg alloy is crucial for enhancing the corrosion resistance and biocompatibility of biomedical implants. In this study, we aimed to investigate the effects of two different surface modification methods, i.e., electrochemical (electrodeposition, ED) and chemical (solution treatment, ST), on the phase structure, degradation properties, and biocompatibility of the composite coatings in comparison to the anodized coating. The surface morphologies and crystalline structures of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Subsequently, the degradation rate of the coatings in simulated body fluid were comprehensively evaluated by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electrochemical microscopy (SECM) tests. Additionally, in-vitro cell proliferation assays were employed to quantitatively assess the biocompatibilities of the coatings. The results showed that both ED and ST methods were effective in depositing HAP on anodized Mg alloy, resulting in different surface morphologies with hydroxyapatite layer thicknesses of 2.71 μm and 3.56 μm, respectively. In this way, the HAP-deposited coatings exhibited improved corrosion resistances and biocompatibilities compared with those of the anodized coating. Specifically, the ST-deposited composite film displayed superior degradability and biocompatibility which was attributed to its filiform surface morphology and thicker HAP layer. Overall, the present study demonstrates the potential of HAP/MgO composite coatings for biomedical applications, with implications for the development of advanced implant materials with improved performance and biocompatibility. [ABSTRACT FROM AUTHOR]

Mineralized hydrogels have attracted significant attention in the field of bone repair. Herein, an innovative strategy of "freezing, salting‐out and mineralizing" (FSM) is proposed for the construction of mineralized hydrogels. Based on this strategy, a collagen/hydroxyapatite (HA) mineralized hydrogel is synthesized as the template of mineralized hydrogels, and the critical roles of freezing and salting‐out in the formation of hydrogels are demonstrated. Comparative analyses with collagen/HA mineralized hydrogels synthesized through two other traditional methods reveal that the hydrogel constructed by FSM exhibits satisfactory operation simplicity, mineralization degree, uniformity distribution, mechanical property, degradation stability, cytocompatibility, and osteogenic property, indicating that it can serve as an ideal mineralized hydrogel scaffold for bone repair. Furthermore, 16 other kinds of mineralized hydrogels with different systems are constructed by modularly expanding the raw materials used in the FSM process to nine common biomedical polymers, four metal cations and three anions, confirming the universality of the proposed FSM strategy for most mineralized hydrogel. Overall, the three‐step FSM strategy, which integrates the salting‐out effect with mineralization, represents a groundbreaking approach for the fabrication of mineralized hydrogels, offering a simple, universal and modular method for their construction. [ABSTRACT FROM AUTHOR]

Objective: In this study we have focused on biocompatibility and osteoinductive capacity analysis of self-manufactured single-phase (HAP) and two-phase (HAP and β-ТСР) bioactive ceramics with various chemical modifications (Fig. 1). Results: We demonstrate a reduction in solubility for all analyzed composite after the treatment with H2O and H2O2, accompanied by an enhancement in adsorption activity. This modification also resulted in an increase in micro- and macroporosity, along with a rise in the open porosity. Adipose-derived mesenchymal stromal cells demonstrated excellent cell adhesion and survival when cultured with these ceramics. Calcium phosphate ceramics (H-500, HT-500, and HT-1 series) stimulated alkaline phosphatase expression, promoted calcium deposition, and enhanced osteopontin expression in ADSCs, independently inducing osteogenesis without additional osteogenic stimuli. These findings underscore the promising potential of HAP-based bioceramics for bone regeneration/reconstruction. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) is an extensively used biomaterial for dental and orthopaedic applications because of its biocompatibility and biomimetic nature. HA is extensively used as a bone-graft substitute. HA bone graft substitutes of bovine or synthetic origins have been extensively studied. However, caprine-based HA has not been explored. In this study, we aimed to determine the utilization of goat bone-derived HA for commercial applications. HA from caprine bone and teeth was isolated using thermal calcination. The developed HA can be used as a bone graft substitute. Chemical characterization of the isolated HA was carried out using Fourier transform infrared spectroscopy, X-Ray Diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The biocompatibility and apatite formation of isolated HA were assessed using MG-63 cells, MC3T3-E1, L929 cells, MSCs, adipose derived stem cells, human dermal tissue derived fibroblast cells and osteoblast-like cell line, The studies demonstrate that HA support cell adhesion and osteogenic properties. To improve sheep, lamp, or caprine bone-derived HA, several other composites have been developed with MgO2, ZrO2, ZnO2, and other polymeric substances. 3D printed technology was used to develop a bioink using sheep-derived HA and printed the composite scaffold as a bone graft substitute. Furthermore, the biomedical applications of sheep-derived HA been studied in terms of their antimicrobial activity, bone-forming ability, and wound healing applications. Sheep-, goat-, and caprine-derived HA are still underutilized and require further research to develop commercial possibilities and sustainable raw materials for HA-based bone graft substitutes. [ABSTRACT FROM AUTHOR]

Background: Craniofacial bone regeneration represents a dynamic area within tissue engineering and regenerative medicine. Central to this field, is the continual exploration of new methodologies for template fabrication, leveraging established bio ceramic materials, with the objective of restoring bone integrity and facilitating successful implant placements. Methods: Photopolymerized templates were prepared using three distinct bio ceramic materials, specifically a wet chemically synthesized bioactive glass and two commercially sourced hydroxyapatite variants. These templates underwent comprehensive characterization to assess their physicochemical and mechanical attributes, employing techniques including Fourier transform infrared spectroscopy, scanning electron microscopy, and nano-computed tomography. Evaluation of their biocompatibility was conducted through interaction with primary human osteoblasts (hOB) and subsequent examination using scanning electron microscopy. Results: The results demonstrated that composite showed intramolecular hydrogen bonding interactions with the photopolymer, while computerized tomography unveiled the porous morphology and distribution within the templates. A relatively higher porosity percentage (31.55 ± 8.70%) and compressive strength (1.53 ± 0.11 MPa) was noted for bioactive glass templates. Human osteoblast cultured on bioactive glass showed higher viability compared to other specimens. Scanning micrographs of human osteoblast on templated showed cellular adhesion and the presence of filopodia and lamellipodia. Conclusion: In summary these templates have the potential to be used for alveolar bone regeneration in critical size defect. Photopolymerization of bioceramics may be an interesting technique for scaffolds fabrication for bone tissue engineering application but needs more optimization to overcome existing issues like the ideal ratio of the photopolymer to bioceramics. [ABSTRACT FROM AUTHOR]

Introduction: Glass Ionomer Cement (GIC) is widely used as a restorative material, but it still exhibits some limitations that pose significant drawbacks in clinical use. The composition of Hydroxyapatite (HA) mimics the inorganic fraction of mineralised tissues such as bones and teeth. HA possesses osteoconductive and bioactive properties, making it favourable for orthopaedic and dental applications. Aim: The aim of this study was to evaluate and compare the setting time, compressive strength, microleakage and antibacterial properties of nano-HA incorporated GIC (NHa-GIC) at various concentrations with Type-II GIC. Materials and Methods: This in-vitro study was conducted in the Department of Paediatric and Preventive Dentistry at Sri Aurobindo College of Dentistry in Indore, Madhya Pradesh, India, for a duration of nine months, from May 2023 to January 2024. The study comprised five study groups as follows: Group-1-Type-II GIC (control), Group-2-NHA-GIC 4%, Group-3-NHA-GIC 8%, Group-4-NHA-GIC 10% and Group-5-NHA-GIC 15%. A total of 50 acrylic moulds containing the test material and Type-II GIC, with 10 in each group (n=10), were prepared to record the setting time, which was tested using a Gillmore needle. The compressive strength was checked using a Universal Testing Machine. Additionally, 50 primary molars were selected according to inclusion and exclusion criteria and randomly divided into five groups (n=10) to evaluate microleakage. Microleakage was assessed using the dye penetration method under a stereomicroscope. For antibacterial properties, 50 samples (n=10) were taken for each strain, i.e., Strain A: S. mutans and Strain B: L. fermentum and the disk diffusion method was employed. Thus, a total sample size of 250 was used. The preparation of GIC-NHAp was done by adding nano-HA to GIC at selected concentrations by weight/weight percentage (w/w%). The results were analysed using a one-way Analysis of Variance (ANOVA) test. Results: A statistically significant difference was observed (p<0.001) between Group-1 (GIC II) and Group-II (4% GICNHAp), III (8% GIC-NHAp), IV (10% GIC-NHAp) and V (15% GIC-NHAp) regarding setting time, compressive strength, microleakage and antibacterial properties. Conclusion: It can be concluded that adding NHAp crystals to GIC enhances its properties, such as compressive strength and antimicrobial efficiency, as the concentration increases. The microleakage property showed a consistent decrease with increasing concentration. However, the setting time increased with higher concentrations of NHAp in GIC. [ABSTRACT FROM AUTHOR]