Hydroxyapatite Coatings Research Articles

Study of Mg-Rich Sulfato-Calcium Hydroxyapatite Coating on Anodized Ti6Al4V-Alloy for Biomedical Applications

Study of Mg-Rich Sulfato-Calcium Hydroxyapatite Coating on Anodized Ti6Al4V-Alloy for Biomedical Applications

The influence of hydroxyapatite coatings with different structure and crystallinity on osteogenesis stimulation

NiTi alloys are actively used in medicine as implants because of their mechanical properties. At the same time, however, the NiTi surface is not biologically active, which has a negative effect on osteogenesis. In addition, Ni is capable of causing various toxic reactions in the human body. It is therefore necessary to create a composite coating that is both bioactive and prevents the release of Ni ions. It has been shown that by changing the modes of plasma assisted RF sputtering of a calcium phosphate target, it is possible to obtain coatings with different contents of the amorphous phase. The coatings formed consist of hydroxyapatite and amorphous calcium phosphate. On the surface of a sample not treated with argon plasma, there are no phases containing calcium or phosphorus, although these elements are present on the surface. The different ways in which the CaP coatings were applied also affected their structure. It was found that the CaP coatings of samples M2 and M3 have mediocre corrosion resistance, dissolving quickly. This has a positive effect on the ability to osteogenesis, which was discovered as a result of in vitro tests. These tests have shown that the sample obtained at Idischarge = 30 A and Ubias = 30 V has the highest bioactivity and produces the lowest percentage of dead cells.

Effect of non-contact induction heating on HA coatings and bone cement, an ex vivo study

Background Prosthetic joint infection is a serious complication that can arise after total joint replacement surgery. When bacteria colonise an orthopaedic implant, they form biofilms that protect them from their environment, making them difficult to remove. Treatment is further complicated by a global rise of antimicrobial resistance. These protective mechanisms make treatment of prosthetic joint infection increasingly complex. Non-contact induction heating is an upcoming technology that uses heat to eradicate bacteria that are present on the surface of metallic implants. This study aims to provide insight into the feasibility of using non-contact induction heating on metallic implants that are in direct contact with other biomaterials, such as coatings composed of hydroxyapatite and bone cement composed of poly (methyl methacrylate) (PMMA). Methods Characterisation of hydroxyapatite coatings and adhesion strength tests were conducted according to standards set by the International Organisation for Standardisation (ISO 13779-2). The fixation strength of acrylic bone cement was tested according to an adapted method from ISO. Results It was found that non-contact induction heating did not significantly affect the adhesion strength of hydroxyapatite coatings (p=0.697). In contrast to hydroxyapatite coatings, acrylic bone cement softened temporarily as the temperature exceeded the glass transition temperature (83.38 ± 10.88°C). However, the induction heating temperature had no significant effect on the fixation strength after the cement was allowed to cool down (p=0.535). Conclusion This study shows the feasibility of using non-contact induction heating up to 80°C when bone cement or ceramic coatings are present in contact with infected metallic implants.

Comparative study on physicochemical properties of macroporous hydroxyapatite coatings on 316L stainless steel implants using sol-gel and inverse opal templating

This study focuses on enhancing metallic implant biocompatibility by fabricating a three-dimensional ordered macroporous hydroxyapatite (HAP) architecture through inverse opal technology. Utilizing colloidal crystal templates on 316L stainless steel, specifically with polystyrene and polymethyl methacrylate, successful fabrication was achieved through H2O2 plus H2SO4 etching. The calcination process at different temperatures (350, 500 and 700°C) resulted in distinct HAP structures, and the sample was calcined at 500°C (HAP500), exhibiting superior physicochemical properties, including enhanced crystallinity, surface roughness and wettability. Biological experiments demonstrated that HAP500 significantly promoted mesenchymal stem cell adhesion and proliferation compared to HAP350 and bare 316LSS, suggesting its potential as a highly effective medical device for bone implantation.

TiSZ-reinforced hydroxyapatite coatings on magnesium substrate with titanium interlayer

ABSTRACT In this study, pure and 10% wt. Titania-Stabilised Zirconia (TiSZ) -reinforced Hydroxyapatite (HA) coatings were deposited on magnesium substrate using plasma spray as a single layer and double layer with an HVOF sprayed Ti bond coat. The coated specimens were characterised by X-ray diffraction (XRD) analysis, and scanning electron microscopy equipped with energy dispersive spectroscopy (SEM, EDS). Rockwell-C adhesion and scratch tests were performed. The corrosion behaviours in simulated body fluid (SBF) of coatings were investigated by an electrochemical corrosion test. Analyses confirmed successful coating with a dense titanium buffer layer. The double-layered HA-titanium combination offered superior corrosion resistance compared to single layers. While adding TiSZ enhanced adhesion, it compromised scratch resistance. The titanium bond coat had minimal impact on adhesion and cohesion behaviour of coatings.

Surface Modification of Hydroxyapatite Coating for Enhanced Antibiotic Therapy

A major strategy to combat implant-associated infections is to develop implant coatings with intrinsic antibacterial activity. Since hydroxyapatite (HAp) coatings and antibiotic administration are commonly used in clinical settings, developing HAp-coated implants with localized antibiotic-releasing properties has attracted popularity. Considering the antibacterial metal species (Ag, Zn, Cu, etc.) in metal–organic frameworks and their drug delivery capacity, in this study, a gentamicin-loaded zeolitic imidazolate framework-8 nanolayer was deposited on a plasma-sprayed HAp coating (HAp/ZIF-8@Gent), which served as a Gent and Zn2+ reservoir. The investigation on the binding interaction between ZIF-8 and HAp indicated that the growth of ZIF-8 was through a Zn2+ seed layer on the HAp coating via an adsorption–replacement mechanism, instead of simple physical adsorption. The HAp/ZIF-8@Gent coating exhibited a sustained drug-release property, and the cumulative concentration of released Gent reached 239.8 ± 7.1 μg/mL on day 8. Compared to the HAp-Zn and HAp/ZIF-8 coatings, the HAp/ZIF-8@Gent coating exhibited significantly higher antibacterial activity against E. coli. This was ascribed to the combined antibacterial effects of Zn2+ and Gent. The cytocompatibility of the HAp/ZIF-8@Gent coating was confirmed via cell proliferation. Above all, the ZIF-8-modified HAp coating with localized delivery of Gent and Zn2+ possessed excellent antibacterial activity and acceptable cytocompatibility, showing potential in mitigating implant-associated infections.

Bone-like microtextures of HA coatings prepared by nanosecond laser and their properties

Although the hydroxyapatite (HA) coating implant prepared by laser cladding exhibits good biological activity due to its chemical composition similar to biological bone, the original surface roughness of the laser-clad coating is high, which is unfavorable for long-term cell adhesion and proliferation. In order to improve the biological activity of HA coating implants and increase the adhesion and proliferation rate of osteoblasts on their surface, microtextures with different length-diameter ratios and depth gradients were prepared on the HA coating surface by nanosecond laser with reference to the microscopic morphology characteristics of the biological bone surface. By investigating the effects of microtexture aspect ratio and depth gradient on osteoblast adhesion characteristics, it was found that bone-like microtextures better controlled and simulated cell-material surface interactions. The geometric morphology of microtextured bone with a wide front end and narrow rear end and a depth gradient from front to back was an important signal for osteoblast proliferation. When the aspect ratio of bone microtexture was 2.5:1 and the maximum depth gradient was 15.7 μm, osteoblasts within the microtexture showed optimal growth, proliferation, and adhesion. Additionally, due to induction by microtexture contour shape and depth gradient morphology, cell morphology showed varying adhesion morphology from the front to the back of the microtexture. The results demonstrated that HA coatings with bone-like microtextures had superior osteoblast proliferation and adhesion properties compared to the original cladded coating surface, beneficial for enhancing the application of HA-coated bone implants in large segment bone repair.

Nanohydroxyapatite/Peptide Composite Coatings on Pure Titanium Surfaces with Nanonetwork Structures Using Oyster Shells.

Titanium and its alloys are extensively applied in artificial tooth roots because of their excellent corrosion resistance, high specific strength, and low elastic modulus. However, because of their biological inertness, their surface needs to be modified to improve the osteointegration of titanium implants. The preparation of biologically active calcium-phosphorus coatings on the surface of an implant is one effective method for enhancing the likelihood of bone integration. In this study, osteoinductive peptides were extracted from oyster shells by using acetic acid. Two peptide-containing hydroxyapatite (HA) composite coatings were then prepared: one coating was prepared by hydrothermally synthesizing an HA coating in the presence of peptides (HA/P/M), and the other coating was prepared by hydrothermally synthesizing HA and then immersing the hydrothermally synthesized HA in a peptide solution (HA/P/S). Characterization results indicated that the composite HA coatings containing oyster shell-based peptides were successfully prepared on the alkali-treated pure titanium surfaces. The HA/P/M and HA/P/S composite coatings were found to exhibit excellent hydrophilicity. Protein adsorption tests confirmed that the HA/P/M and HA/P/S coatings had an approximately 2.3 times higher concentration of adsorbed proteins than the pure HA coating.

Improving osseointegration and antimicrobial properties of titanium implants with black phosphorus nanosheets-hydroxyapatite composite coatings for vascularized bone regeneration.

For decades, titanium implants have shown impressive advantages in bone repair. However, the preparation of implants with excellent antimicrobial properties as well as better osseointegration ability remains difficult for clinical application. In this study, black phosphorus nanosheets (BPNSs) were doped into hydroxyapatite (HA) coatings using electrophoretic deposition. The coatings' surface morphology, roughness, water contact angle, photothermal properties, and antibacterial properties were investigated. The BP/HA coating exhibited a surface roughness of 59.1 nm, providing an ideal substrate for cell attachment and growth. The water contact angle on the BP/HA coating was measured to be approximately 8.55°, indicating its hydrophilic nature. The BPNSs demonstrated efficient photothermal conversion, with a temperature increase of 42.2°C under laser irradiation. The BP/HA composite coating exhibited a significant reduction in bacterial growth, with inhibition rates of 95.6% and 96.1% against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility of the composite coating was evaluated by cell adhesion, CCK8 and AM/PI staining; the effect of the composite coating in promoting angiogenesis was assessed by scratch assay, transwell assay, and protein blotting; and the osteoinductivity of the composite coating was evaluated by alkaline phosphatase assay, alizarin red staining, and Western blot. The results showed that the BP/HA composite coating exhibited superior performance in promoting biological functions such as cell proliferation and adhesion, antibacterial activity, osteogenic differentiation, and angiogenesis, and had potential applications in vascularized bone regeneration.

Strontium-Doped Hydroxyapatite Coating Improves Osteo/Angiogenesis for Ameliorative Graft-Bone Integration via the Macrophage-Derived Cytokines-Mediated Integrin Signal Pathway.

Polyethylene terephthalate (PET) artificial ligaments, renowned for their superior mechanical properties, have been extensively adopted in anterior cruciate ligament (ACL) reconstruction surgeries. However, the inherent bio-inertness of PET introduces formidable barriers to graft-bone integration, a critical aspect of rehabilitation. Previous interventions, ranging from surface roughening to chemical modifications, have aimed to address this challenge; however, consistently effective techniques for inducing graft-bone integration remain scarce. Our study employed advanced surface-coating methodologies to introduce strontium-doped hydroxyapatite (SrHA) onto PET ligaments. Detailed scanning electron microscopy (SEM) examinations revealed a uniform and integrative coating of SrHA on PET fibers. Furthermore, spectroscopic analysis confirmed the steady release of strontium ions from the coated surface under physiological conditions. In-depth cellular studies proved that extracellular strontium emanating from SrHA-coated PET (PET@SrHA) ligaments actively steers the M2 macrophage polarization. Additionally, macrophages (Mφs) manifested a heightened secretion of prohealing cytokines when exposed to PET@SrHA. Subsequent investigations showed that these cytokines acted as mediators, activating integrin signaling pathways among macrophages, vascular endothelial cells, and osteoblasts. As a direct consequence, an increased rate of angiogenesis and osteogenic differentiation was observed, vital for graft-bone integration following ACL reconstruction with PET@SrHA ligaments. From a biochemical standpoint, our results pinpoint strontium ions as influential immunomodulators, sculpting the graft-bone interface's immune environment. This insight presents the SrHA-coating technique as a viable therapeutic strategy, holding sound promise for improving angiogenesis and osseointegration outcomes during ACL reconstruction using PET-based grafts.

Annealing-temperature dependence of adhesion strength of hydroxyapatite layers coated on zirconia substrates by droplet elimination pulsed-laser deposition scheme

High-purity, high-crystallinity hydroxyapatite coatings on zirconia substrates were successfully fabricated at annealing temperatures >360 °C. The coatings did not dissolve in vivo within a short period and enhanced the formation of new bone. If the coating layer physically adheres to the zirconia substrate, strong bonding is expected on the coating layer. The adhesion strength of the coating layer was measured using an oscillation-type micro-scratch test. The adhesion strength was found to increase with increasing substrate surface temperature during deposition, irrespective of whether an in situ annealing process or a post-annealing process was used. These results indicated that the proposed coating layer will survive for a prolonged period in vivo and enable strong bone bonding with medical implants.

Surface modification of PEEK implants for craniofacial reconstruction and aesthetic augmentation-fiction or reality?

Facial implantology, a crucial facet of plastic and reconstructive surgery, focuses on optimizing implant materials for facial augmentation and reconstruction. This manuscript explores the use of Polyetheretherketone (PEEK) implants in craniofacial surgery, highlighting the challenges and advancements in this field. While PEEK offers mechanical resilience, durability, and compatibility with imaging modalities, its biologically inert nature hinders integration with the host tissue, which may lead to complications. In this systematic review, our aim was to assess the current state of knowledge regarding the clinical evaluation of Polyetheretherketone (PEEK) implants in facial implantology, with a focus on craniofacial augmentation and reconstruction in human studies. Additionally, we explore and discuss surface and structural modifications that may enhance bioreactivity and reduce complications in PEEK implants. A systematic review identified 32 articles detailing the use of PEEK Patient-Specific Implants (PSIs) in 194 patients for both reconstructive and aesthetic purposes. Complications, including infections and implant failures, were reported in 18% of cases, suggesting the need for improved implant materials. The discussion delves into the limitations of PEEK, prompting the exploration of surface and structural modifications to enhance its bioreactivity. Strategies, such as hydroxyapatite coating, titanium coating, and porous structures show promise in improving osseointegration and reducing complications. However, the literature review did not reveal reports of coated or modified PEEK in facial reconstructive or aesthetic surgery. In conclusion, although PEEK implants have been successfully used in craniofacial reconstruction, their biological inertness poses challenges. Surface modifications, particularly hydroxyapatite coatings, provide opportunities to promote osseointegration. Future research should focus on prospective long-term studies, especially in craniofacial surgery, to investigate the stability of uncoated PEEK implants and the potential benefits of surface modifications in clinical applications. Patient-specific PEEK implants hold promise for achieving durable craniofacial reconstruction and augmentation.

Microstructural and micromechanical characteristics of composite osteoconductive coatings deposited by the atmospheric pressure plasma technique.

Long-term placement of facial implants requires avoiding the formation of fibrous tissue capsules around the artificial material by creating osteoconductive properties of the surface. Most promising approach is the deposition coatings made of materials very similar to bone mineral components, that is, calcium phosphates such as hydroxyapatite (HAp). As part of the research work, an innovative, cost-effective atmospheric pressure plasma deposition (APPD) system was used as a low-temperature coating technology for generating the HAp coatings deposition. Full microstructural characterisation of the coatings using SEM and TEM techniques was carried out in the work. It has been shown that the fully crystalline HAp powder undergoes a transformation during the coatings deposition and the material had a quasi-sintered structure after deposition. The crystalline phase content increased at the coating/substrate interface, while the surface of the HAp was amorphous. This is a very beneficial phenomenon due to the process of bioresorption. The amorphous phase undergoes much faster biodegradation than the crystalline one. In order to increase the bioactivity of the HAp, Zn particles were introduced on the surface of the coating. The TEM microstructural analysis in conjunction with the qualitative analysis of the EDS chemical composition showed that the binding of the Zn particles within the HAp matrix had diffusive character, which is very favourable from the point of view of the quality of the adhesion and the bioactivity of the coating. In the case of such a complex structure and due to its very porous nature, micromechanical analysis was carried out in situ in SEM, that is, by microhardness measurements of both the HAp matrix and the Zn particle. It was shown that the average value of HAp microhardness was 4.395GPa ± 0.08, while the average value of Zn microhardness was 1.142GPa ± 0.02.

Mechanical hydroxyapatite coatings on PEO-treated Ti–6Al–4V alloy for enhancing implant's surface bioactivity

In this study, to reactivate the oxide film and to secure biocompatibility, plasma electrolytic oxidation (PEO) treatment and hydroxyapatite (HA) deposition via mechanical coating (MC) processes were investigated. This experimental approach involved subjecting the Ti–6Al–4V alloy specimens to PEO treatment, followed by MC with HA powder for different hours as HA has the potential to increase bioactivity and surface characteristics due to its chemical composition and structural properties similar to natural bone. Therefore, the study aimed to examine the effects of MC with HA powder for 0, 1, 3, 5, 7, and 9 h on PEO-coated Ti–6Al–4V alloy discs for analyzing the surface characterization, phase analysis, surface roughness, wettability, adhesion strength, hardness, corrosion behavior, and cell proliferation properties for dental implant use. The findings demonstrate that prolonged HA milling enhances the substrate's mechanical strength, corrosion resistance, and adhesion properties. The presence of prominent anatase and HA peaks, particularly in the 5 MC-PEO, 7MC-PEO, and 9 MC-PEO samples, validates the synergistic impact of the PEO oxide layer and HA milling, resulting in outstanding corrosion resistance and biocompatibility. Cell culture analysis reveals a positive correlation between increased milling time and enhanced cell proliferation, particularly towards small-sized HA particles.

Ceramic coating on Mg alloy for enhanced degradation resistance as implant material

Magnesium (Mg) alloys display very appealing characteristics, including biocompatibility, bioactivity, biodegradability, lightweightness, and a similar density to cortical bone tissue, but they have some constraints, such as inappropriate corrosion and degradation resistance, which lead to failing early mechanical strength. Therefore, calcium phosphate (CaP)-based ceramic coating like hydroxyapatite (HA) coating is fabricated on the anodization-induced surfaces of pure Mg and ZK41 Mg alloy specimens to overcome those constraints in medical applications. In mechanical integrity like microhardness, adhesion strength tests demonstrated that HA coated ZK41 and Mg specimens significantly increased Vickers' hardness number (about 2 times) compared to unmodified substrates and had greater adhesion strength in comparison with the anodization-induced layer, respectively. In the in vitro immersion test, the HA-coated samples showed plate-like and needle-like crystal formations. This provided more surface area, which improved the corrosion and degradation resistance characteristics. As a consequence, the least amount of weight loss has occurred.Additionally, the anodized (AN) Mg, HA coated Mg, untreated ZK41, and anodized ZK41 samples all have higher corrosion rates than the HA coated ZK41 (0.018 mm/year). Cell viability of HA coated Mg and its alloy ZK41 was comparatively high, which ensures biocompatibility as an implant material. Therefore, HA coatings for Mg and ZK41 alloys for clinical applications could be more promising. In this study, ZK41 Mg alloy has been used as an inventive substrate for HA coating in place of the prior Mg alloys, with the intention of addressing the earlier drawbacks.

Enhancing the performance of reinforced hydroxyapatite coatings through post coating treatment

To enhance the metallurgical, mechanical, and biological properties of medical implants in bodily fluid environments, biocompatible coatings are applied to biomaterials. These biocompatible coatings have a porous structure that promotes effective osseointegration and the ability to prevent harmful ions from metal from seeping into the surrounding bodily environment. In the present study, the impact of the addition of Tantlum carbide (TaC) with 5 and 10 wt% as reinforcement in hydroxyapatite (HA) on the morphology, mechanical and cell viability of plasma-sprayed coatings were investigated. The post-coating treatments are carried on pure HA, HA-R5(HA+5%TaC) & HA-R10 (HA+10%TaC) coatings at 900 °C and at low-temperature treatment at −196 °C. The results showed that heat treatment affects the crystallinity, surface roughness, and bond strength under different high-temperature and low-temperature treatments. Further, in-vitro results show that post-treated samples have more survival of cells as compared to as-sprayed samples. Also, heat-treated and reinforced HA coatings showed no toxicity.

The Minimum 5-Year Follow up of a Highly Versatile Distally Anchored Femoral Revision System With Hydroxyapatite Coating

BackgroundTotal hip arthroplasty is one of the most successful operations medicine can offer. As more patients undergo total hip arthroplasty the revision burden increases proportionately. This is a cohort study of the Arcos Modular Femoral Revision System. MethodsThe primary outcome was rerevision of the femoral component. Secondary outcomes include complications and radiological and clinical outcomes over 5 years. ResultsA total of 74 patients were recruited, and the femoral survival rate was 100% at 5 years with 12 censorships. A total of 31 patients were given Proprosky 3/4 preoperatively. Eleven patients underwent further procedures; however, no femoral components were revised. Kaplan-Meier analysis was performed by a biostatistician. Patients demonstrated a consistent and sustained improvement in Harris hip score, Oxford hip score, and EQ-5D. Radiological review revealed minimal and stable lysis around the femoral components. ConculsionThe ARCOS Modular Femoral Revision System was designed to offer a range of options to allow femoral bone stock preservation and avoiding conversion to an endoprosthetic and seems to be effective in the medium term.

Antibacterial effect of Ag-containing hydroxyapatite thin film fabricated by sputtering.

Infections related to joint prosthesis are still a major concern for orthopedic surgeons. Hydroxyapatite (HA) is a useful biocompatible material because of its good osteocompatibility. Antibacterial HA coatings have been fabricated with addition of antibacterial agents such as Ag to HA using the plasma spraying method. However, the plasma-sprayed HA coating suffers from fractures at large thicknesses. The sputter-coated HA thin film has a high density, and has been applied clinically for dental implants. However, there are no extensive studies on Ag-containing HA thin films. The aim of this study was to prepare an Ag-containing HA thin film by sputtering, and evaluate its antibacterial effect and cytotoxicity. The Ag-containing HA thin films were prepared by radio-frequency magnetron sputtering. The films were characterized using X-ray photoelectron spectroscopy, X-ray diffractometry, and scanning electron microscopy (SEM). The antibacterial activities and cytotoxicities of the films were also evaluated. The Ag/Ca molar ratio of the films increased with the Ag ratio in the target. The SEM observation of the hydrothermally treated films showed surfaces covered with globular particles. All Ag-containing HA films exhibited an antibacterial effect against E. Coli. The number of cells of the films decreased with the Ag ratio. The films subjected to the hydrothermal treatment exhibited a higher number of cells than the as-sputtered films. The Ag-containing HA thin film was effective in terms of antibacterial effect, and had a low cytotoxicity in the proliferation of osteoblast cells at a low Ag ratio in the target.

Characterization, mechanical properties, corrosion behavior and bone-like apatite formation ability of fluorine substituted hydroxyapatite coating

Hydroxyapatite (HA) is a non-bioceramic commonly used in human implants in the form of coatings, which are limited in their application by mechanical and wear resistance properties, as well as biodegradability. In this study, fluorine substituted hydroxyapatite (FHA) coatings were prepared on Ti–6Al–4V surfaces by plasma spraying method using a mixture of calcium fluoride and hydroxyapatite powders. The prepared coatings were characterized by X-ray diffraction and fourier transform infrared (FTIR) spectroscopy at different levels of calcium fluoride (3 wt%, 6 wt%, 9 wt%, and 12 wt%). The biocompatibility of the coatings was evaluated by in vitro mineralization experiments. Experimental results showed that at 9 wt% of calcium fluoride, the prepared FHA coatings had better mechanical properties, with improved bond strength (28.2 MPa). The X-ray diffraction patterns of the coatings reflect the fluorine substitution during the spraying process and the 9FHA has the highest crystallinity according to the XRD analysis, which is closely related to the biological activity of the coating. In addition, Potentiodynamic polarisation showed that the sample coated with the 9FHA coating had the highest Ecorr and lowest Icorr, indicating the best corrosion resistance. The FHA coating exhibits faster apatite deposition in simulated body fluid, and the efficiency of apatite deposition increases with the increase of CaF2.

A Comprehensive Review of Fabrication and Characterization Methods of Hydroxyapatite

This synthesis article expands on the applications of hydroxyapatite (HA) coatings on titanium dioxide (TiO2) substrates for biomedical applications, focusing on the methods of deposition and their impact on the material’s properties. Various techniques, including sol-gel, electrochemical deposition and ultrasonic spray-pyrolysis are discussed because of their ability to enhance the mechanical resistance, biocompatibility and osteointegration of implants. The analysis methods used are X-Ray Diffraction (XRD), Scanning electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). They provide insights into the structural, chemical and physical characteristics of the HA coatings. The results indicate that these hybrid coatings significantly improve the performance and longevity of implants in orthopedic and dental applications. Keywords: Hydroxyapatite, Titanium Dioxide, Biomedicine, biocompatibility, Osteointegration, Sol-Gel dip-coating, Electrochemical Deposition, Ultrasonic Spray Pyrolysis, X-Ray Diffraction, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, hybrid coatings