Polyetheretherketone Surface Research Articles

Additive manufacturing and in vitro study of biological characteristics of sulfonated polyetheretherketone-bioactive glass porous bone scaffolds

Polyetheretherketone (PEEK), a high-performance special engineering plastic, has gradually been used in bone substitutes due to its wear resistance, acid and alkali resistance, non-toxicity, radiolucency, and modulus close to that of human bone. However, its stable biphenyl structure determines strong biological inertness, thus artificial interventions are required to improve the biological activity of fabricated PEEK parts for better clinical applications. This study developed a novel strategy for grafting bioactive glass (BAG) onto the surface of PEEK through sulfonation reaction with concentrated sulfuric acid (H2SO4), aiming to improve the bioactivity of printed porous bone scaffolds manufactured by fused deposition modeling (FDM) to meet clinical individual needs. In vitro biological study was conducted on sulfonated polyetheretherketone-bioactive glass (SPEEK-BAG) scaffolds obtained by this strategy. The results demonstrated that the optimal modification condition was a 4-hour sulfonation reaction with 1 mol/L concentrated H2SO4 at high temperature and high pressure. The scaffold obtained under this condition showed minimal cytotoxicity, and the Ca/P molar ratio, yield compressive strength, and compressive modulus of this scaffold were 2.94 ± 0.02, 62.78 MPa, and 0.186 GPa respectively. The hydrophilicity and the biomineralization ability of PEEK modified by the proposed strategy were substantially improved. The SPEEK-BAG bone scaffolds exhibited excellent biocompatible properties, suggesting that the sulfonation reaction and BAG effectively enhanced the proliferation and differentiation of osteoblasts. The presented method provides an innovative, highly effective, and customized strategy to improve the biocompatibility and bone repair ability of printed PEEK bone scaffolds for virous biomedical applications.

Fabrication of a macro-micro porous structure on PEEK surface by ultrasound-assisted sulfonation

A multiscale porous surface can significantly improve the osseointegration of biomedical implants, but it cannot be facilely achieved on the Poly-ether-ether-ketone (PEEK) surface. In this work, a macro-micro porous structure was prepared on the PEEK surface by ultrasound-assisted sulfonation. The surface morphologies, chemical compositions, functional groups, surface roughness, and wettability of the porous structures at different sulfonation times were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectrometer (FTIR), laser scanning confocal microscope (LSCM), and contact angle measurement, respectively. The results demonstrate that a macro-micro porous structure is formed on the PEEK surface, with macropore sizes ranging from 50 to 250 μm and micro-sized pore sizes ranging from 0.2 to 1.5 μm. Moreover, the results of in vitro cellular experiments demonstrate that the macro-micro porous structure can promote cell adhesion and proliferation of BMCSc. The formation mechanism of the multiscale porous structures has also been discussed. This novel approach may provide a simple and effective strategy for surface modification of PEEK to improve its mechanical and biological response.

Engineering Ga-doped mesoporous bioactive glass-integrated PEEK implants for immunomodulatory and enhanced osseointegration effects

With the increasing aging population, the demand for orthopedic implants is also growing. Polyether ether ketone (PEEK) is considered a promising material for orthopedic implants due to its excellent biocompatibility. However, the lack of bioactivity and excessive immune response post-implantation often impair bone integration. Therefore, it is urgent to bio-functionalize PEEK-based implants to promote bone integration. This study employs a simple, economical, and feasible method to coat Ga-ion doped bioactive glass nanoparticles (Ga-MBGs) onto sulfonated PEEK surfaces, constructing a multifunctional PEEK-based orthopedic implant. The resulting bio-functionalized PEEK implants promote macrophage M2 phenotype polarization, thus fostering an anti-inflammatory immune microenvironment. Moreover, the direct osteogenic effect of Ga ions and the immuno-osteogenic effect through promoting macrophage M2 polarization enhance osteogenic differentiation potential in vitro and bone integration in vivo. A sequence of in vivo and in vitro experiments substantiates the essential and intricate function of this innovative orthopedic implants. in regulating normal bone immunity and metabolism. Overall, the application of Ga-MBGs provides a simple, economical, and effective method for developing multifunctional orthopedic implants. This surface bio-functionalized PEEK implant, capable of modulating immunity and bone metabolism, holds significant clinical application potential as an orthopedic implant.

Enhanced osteogenesis and antibacterial activity of dual-functional PEEK implants via biomimetic polydopamine modification with chondroitin sulfate and levofloxacin

Polyetheretherketone (PEEK) implants have emerged as a clinically favored alternative to titanium alloy implants for cranial bone substitutes due to their excellent mechanical properties and biocompatibility. However, the biological inertness of PEEK has hindered its clinical application. To address this issue, we developed a dual-functional surface modification method aimed at enhancing both osteogenesis and antibacterial activity, which was achieved through the sustained release of chondroitin sulfate (CS) and levofloxacin (LVFX) from a biomimetic polydopamine (PDA) coating on the PEEK surface. CS was introduced to promote cell adhesion and osteogenic differentiation. Meanwhile, incorporation of antibiotic LVFX was essential to prevent infections, which are a critical concern in bone defect repairing. To our delight, experiment results demonstrated that the SPKD/CS-LVFX specimen exhibited enhanced hydrophilicity and sustained drug release profiles. Furthermore, in vitro experiments showed that cell growth and adhesion, cell viability, and osteogenic differentiation of mouse calvaria-derived osteoblast precursor (MC3T3-E1) cells were significantly improved on the SPKD/CS-LVFX coating. Antibacterial assays also confirmed that the SPKD/CS-LVFX specimen effectively inhibited the growth of Escherichia coli and Staphylococcus aureus, attributable to the antibiotic LVFX released from the PDA coating. To sum up, this dual-functional PEEK implant showed a promising potential for clinical application in bone defects repairing, providing excellent osteogenic and antibacterial properties through a synergistic approach.

Study of structural, surface energies, and tribomechanical properties of thermoplastics irradiated by electron beam

This study investigates the effects of electron irradiation on the structural, surface energy, and tribomechanical properties of two key thermoplastics: polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE). The experimental methods included electron beam irradiation using the ILU-10 pulsed linear accelerator, Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD), microhardness testing, surface roughness assessment, tribology tests, and contact angle measurements.The FT-IR analysis revealed significant chemical changes on the surfaces of the polymers, including oxidation processes and the breaking of molecular bonds. XRD analysis showed an increase in the crystallinity of PTFE after irradiation, while the structure of PEEK remained stable. Microhardness testing indicated a notable increase in hardness for both polymers, particularly for PTFE, suggesting cross-linking of molecular chains. Surface roughness measurements demonstrated a decrease in roughness for both irradiated polymers. Tribology tests revealed that electron irradiation increased the coefficient of friction for PTFE and PEEK under various loads, which can be attributed to the alterations in their surface properties. Contact angle measurements indicated improved wettability of the irradiated surfaces, especially for PEEK, due to the formation of new functional groups. The total surface energy increased for both polymers post-irradiation, as determined using the Owens-Wendt-Rabel-Kaeble method. Electron irradiation leads to significant modifications in the surface and bulk properties of PEEK and PTFE, enhancing their tribomechanical and adhesive properties. These changes open new opportunities for the application of these materials in various engineering fields where specific performance characteristics are required.

Black Phosphorus and E7-Functionalized Sulfonated Polyetheretherketone with Effective Osteogenicity and Antibacterial Activity

Given its excellent biological properties and the matching of its elastic modulus with that of human bone tissue, medical polyetheretherketone (PEEK) is considered a desirable candidate for bone-implant materials. However, its poor osseointegrative and antibacterial properties greatly limit its clinical application. To address these concerns, a functional PEEK implant is needed. Herein, a novel photo-responsive multifunctional PEEK-based implant material (sPEEK/BP/E7) with both effective osteogenesis and good disinfection properties was constructed via the self-assembly of black phosphorus (BP) nanosheets, mussel-inspired polydopamine (PDA), and bioactive short peptide E7 on sulfonated PEEK (sPEEK). The versatile micro-/nano-structured PEEK surface provides superior hydrophilicity, a favorable osteogenic microenvironment, and excellent photothermal effects under near-infrared (NIR) irradiation. The in vitro results showed that sPEEK/BP/E7 displays enhanced cytocompatibility and osteogenicity in terms of cell adhesion, proliferation, alkaline phosphatase (ALP) activity, matrix mineralization, and osteogenesis-related gene expression, superior to those of the sPEEK and sPEEK/BP samples. In addition to osteogenesis, the multifunctional coating exhibited strong antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, it was confirmed in a rat femoral infection model that sPEEK/BP/E7 effectively resisted infection caused by S. aureus under NIR light irradiation and promoted osseointegration in vivo. Thus, this work presents a facile strategy to realize improvement of the “functional integration” of new polymer bone-implant materials and provide new ideas for their clinical application.

Enhancing osteointegration and antibacterial properties of PEEK implants via AMP/HA dual-layer coatings

Polyetheretherketone (PEEK) is a widely used engineering plastic in orthopedic and dental implants, but its bioinertness leads to poor bone integration. To overcome this, a sulfonation treatment was applied to PEEK first to create a rough, microporous surface enhancing cellular adherence and integration. Subsequently, amorphous magnesium phosphate (AMP) nanosheets were produced through microwave-assisted synthesis, and hydroxyapatite (HA) was generated using a bionic solution hydrothermal method. A dual-layer coating system composed of an interlayer AMP and a top layer HA on the surface of PEEK was developed to enhance osteointegration. Surface analysis confirms the creation of increased surface area, improved hydrophilicity with introduced hydrophilic groups, and enhanced protein attraction. In vitro assessments on mouse embryonic osteoblasts (MC3T3-E1) demonstrate the non-toxicity of these coatings and their efficacy in promoting cell proliferation. Moreover, antimicrobial evaluations against E. coli and S. aureus highlight the potential of these composite coatings in preventing implant-related infections. The AMP/HA dual-layer coating on sulfonated PEEK emerges as a potent method for enhancing osteointegration and antibacterial properties, offering a promising approach to improve bone repair efficiency in clinical applications.

Surface bioactivation of Polyetheretherketone (PEEK) by magnesium chondroitin sulfate (MgCS) as orthopedic implants for reconstruction of skeletal defects

Polyether-ether-ketone (PEEK) is clinically used as a bio-implant for the healing of skeletal defects. However, the osseointegration of clinical-sized bone grafts remains limited. In this study, surface-porous PEEK was created by using a sulfonation method and a metal-polysaccharide complex MgCS was introduced on the surface of sulfonated PEEK to form MgCS@SPEEK. The as-prepared MgCS@SPEEK was found to have a porous surface with good hydrophilicity and bioactivity. This was followed by an investigation into whether MgCS loaded onto sulfonated PEEK surfaces could promote osseointegration and angiogenesis. The in vitro results showed that MgCS@SPEEK had a positive effect on reducing the expression levels of inflammatory genes and promoting osteogenesis and angiogenesis-related genes expression levels. Furthermore, porous MgCS@SPEEK was implanted in critical-sized rat tibial defects for in vivo evaluation of osseointegration. The micro-computed tomography evaluation results revealed substantial bone formation at 4 and 8 weeks. Collectively, these findings indicate that MgCS@SPEEK could provide improved osseointegration and an attractive strategy for orthopaedic applications.

Enhancing bioactivity and biocompatibility of polyetheretherketone (PEEK) for dental and maxillofacial implants: A novel sequential soaking process

Polyetheretherketone (PEEK) exhibits excellent biocompatibility, fatigue resistance, and an elastic modulus similar to bone, presenting broad application prospects in the field of dental and maxillofacial implants. However, the bioinertness of PEEK limits its applications. In this study, we developed a method to generate biocompatible and bioactive PEEK through a simple sequential soaking process, aimed at inducing bone differentiation and enhancing antibacterial properties. Initially, a three-dimensional (3D) porous network was introduced on the PEEK surface by soaking in concentrated sulfuric acid and water. Subsequently, the sulfonated PEEK surface was treated with oxygen plasma, followed by immersion in a dopamine solution to coat a polydopamine (PDA) layer. Finally, polydopamine phosphate ester-modified 3D porous PEEK was obtained through the reaction of phosphoryl chloride with surface phenolic hydroxyl groups. Systematic studies were conducted using scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle analysis, cell proliferation and adhesion, osteogenic gene expression detection, alkaline phosphatase staining, alizarin red staining, and bacterial culture. Overall, compared to unmodified PEEK, the modified PEEK significantly enhanced in vitro cell proliferation and adhesion, osteogenic differentiation, and antibacterial properties. The simple surface modification measures combined in this study may represent a promising technology and could facilitate the application of PEEK in dental and maxillofacial implants.

Plasma assisted fluorination of polyether ether ketone for stable antimicrobial performance

Polyether ether ketone (PEEK) has been extensively used in healthcare due to its excellent mechanical properties, chemical resistance, and biocompatibility. Still, its weak bactericidal performance allows pathogenic bacteria to easily adhere to and proliferate on the PEEK surface. In this research, physical plasma treatment and chemical fluoridation have been combined to enable the PEEK surface with stable antibacterial performance. The characteristics of surface morphology, elemental composition, and hydrophilicity for the samples have been characterized. In vitro experiments reveal that the obtained PEEK surface exhibited great antimicrobial activity. Furthermore, the antimicrobial effect of the modified PEEK surface has shown almost no variation after 28 days of storage at room temperature and 4 h at 121 °C, confirming its excellent storage property and high-temperature stability. This study presents an efficient and practical method to enhance the cytocompatibility and the antimicrobial properties of the PEEK surface, making it a potential medical device material.

Peculiarities of tribological behavior of composites based on polyether ether ketone (PEEK) and whisker carbon nanotubes

Herein, the internal lubrication of polyether ether ketone (PEEK) with added whiskered carbon nanotubes (Wh-CNTs) was investigated under point-contact dry sliding conditions with various loads and velocities. The wear rate of the composite was reduced by 86.99% at a maximum Hertzian contact pressure of 344.69 MPa, which was attributed to the addition of additives with excellent mechanical properties and high-temperature stability. Wh-CNTs could be uniformly distributed in the PEEK to form a three-dimensional (3D) network structure with load-bearing capacity, thus the load could be effectively borne to prevent crack propagation on the PEEK surface. Besides, the filler was induced to form a micron-sized 3D spherical structure with a ball bearing effect, which promotes lubrication more effectively than the fragment structure.

Sulfonation Treatment of Polyether-Ether-Ketone for Dental Implant Uses

There has been a recent uptake in the use of polyether-ether-ketone (PEEK), which is an organic thermoplastic polymer, in the manufacturing of various medical devices, implants, and equipment. Finding the best time and procedure for PEEK after sulfonation is the goal of this research. A total of 30 PEEK discs were sulfonated in this study by immersing them in concentrated (H2SO4) sulfuric acid for various durations and subsequently treated using various post-treatment techniques. Five experiments were carried out, aimed studying the effect of immersion time (5 s–2 min). The methods used as post-treatment were hydrothermal treatment, immersion in NaOH, and washing with acetone. The sulfonation time was measured, and the post-treatment techniques, surface characterizations, were conducted using scanning electron microscopy (SEM) (Electron Optics Instruments, LLC., West Orange, NJ, USA), atomic force microscopy (AFM) (AFM, Vía Burton, CA, USA), and hydrophilic properties. The results were confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The findings of this study demonstrate that sulfonating PEEK caused a structure with a porous network to form in every sample. As the sulfonation time increased, the porous structure became more noticeable and the concentration increased. As a consequence, the roughness of the surface increased notably, and the modified PEEK surface’s wettability improved noticeably. Hydrothermal treatment was determined to be the most successful way for eliminating the leftover sulfuric acid, and sulfonation for 2 min was determined to be ideal. By understanding the best post-treatment procedures and ideal sulfonation duration, a theoretical foundation for the production of sulfonated PEEK for orthopedic uses may be laid.

An investigation of methods to enhance adhesion of conductive layer and dielectric substrate for additive manufacturing of electronics

Additive manufacturing of conductive layers on a dielectric substrate has garnered significant interest due to its promise to produce printed electronics efficiently and its capability to print on curved substrates. A considerable challenge encountered is the conductive layer’s potential peeling due to inadequate adhesion with the dielectric substrate, which compromises the durability and functionality of the electronics. This study strives to facilitate the binding force through dielectric substrate surface modification using concentrated sulfuric acid and ultraviolet (UV) laser treatment. First, polyetheretherketone (PEEK) and nanoparticle silver ink were employed as the studied material. Second, the surface treatment of PEEK substrates was conducted across six levels of sulfuric acid exposure time and eight levels of UV laser scanning velocity. Then, responses such as surface morphology, roughness, elemental composition, chemical bonding characteristics, water contact angle, and surface free energy (SFE) were assessed to understand the effects of these treatments. Finally, the nanoparticle silver ink layer was deposited on the PEEK surface, and the adhesion force measured using a pull-off adhesion tester. Results unveiled a binding force of 0.37 MPa on unmodified surface, which escalated to 1.99 MPa with sulfuric acid treatment and 2.21 MPa with UV laser treatment. Additionally, cross-approach treatment investigations revealed that application sequence significantly impacts results, increasing binding force to 2.77 MPa. The analysis further delves into the influence mechanism of the surface modification on the binding force, elucidating that UV laser and sulfuric acid surface treatment methods hold substantial promise for enhancing the binding force between heterogeneous materials in the additive manufacturing of electronics.

Whey protein fouling on polymeric heat exchangers

AbstractThe fouling behavior of whey protein concentrate (WPC) in food‐grade polyether ether ketone (PEEK) heat exchangers was compared to benchmark stainless steel (SS) to evaluate if fouling can be better mitigated by using PEEK. No research has been conducted on WPC fouling behavior of PEEK at WPC concentrations of 2–6 g/L and heat flux densities of 45–55 kW/m2. It was found that PEEK materials led to a reduction in heat resistance of up to 40%. At WPC concentrations of 6 g/L, a fouling factor of 0.9 m2 K/kW was measured for PEEK compared to 1.6 m2 K/kW for SS. Despite a constant heat flux, fouling curves for PEEK showed an asymptotic behavior, whereas linear fouling was observed for SS. To achieve a comparable heat resistance between PEEK and SS heat exchangers, the operating time could be extended by 9 h when using PEEK materials. Investigations of the deposit mass showed that even though the heat transfer resistance is limited on PEEK, fouling continued to grow at a decreased rate. It was found that the fluid started to evaporate underneath the fouling layer, which led to a partial detachment of the fouling layer and therefore mitigated the heat resistance effects of fouling. To test whether these results are transferable to larger setups, experiments on a scale‐up apparatus were conducted. A very similar behavior was qualitatively observed; however, measured deposition deviated on average by 18%. PEEK surfaces also showed great promise regarding cleanability, with fouling layers detaching completely after drying for 10 min and restarting the process. This restored the heat transfer coefficient to its clean state. A cleaning in place therefore seems feasible. In contrast, fouling layers on SS did not detach through drying and had to be chemically cleaned to restore its heat transfer capacity.

Enhancing interfacial bond strength between PEEK and inkjet-printed silver film through laser surface modification for additive manufacturing of electronics

Electronic 3D printing is a very promising technology, which is widely used in the manufacturing of conformal antennas, flexible electronics and sensors. Polyether ether ketone (PEEK) is one of the most popular substrate materials for electronic 3D printing due to its superior fatigue resistance, heat tolerance, chemical resistance, and mechanical properties. However, the deficient bond between the PEEK substrate and the conductive ink leads to the peeling and shedding of the conductive pattern. This paper investigated the enhancement of the bond strength between the PEEK substrate and the conductive layer through PEEK surface modification. A 355 nm ns solid-state laser was used to treat the PEEK surface with different values of laser scanning spacing (S) and spot overlap rate (R). The surface microstructure, surface roughness, wettability, and functional groups of the treated substrates have been measured. Then the nanoparticle silver ink was printed and cured on the treated substrate. After that, the bonding strength was measured using a pull-off adhesion tester. Results showed that regular grooves were generated and the content of active oxygen atoms was increased on the PEEK surface through laser modification. The mechanical interlocking between the grooves and silver particles and hydrogen bonds induced by the active oxygen atoms and the hydroxyl groups contribute to the enhancement of bond strength between PEEK and silver film. The bond strength for the laser treated PEEK reached the maximum of 1.9 MPa, which was 413.51% higher than that of the untreated PEEK. The laser modification can effectively enhance the interfacial bond strength for additive manufacturing of reliable electronics.

Effect of different surface roughening treatment on polyether ether ketone and acrylic resin bonding: A pilot study.

As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other. The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding. Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey's multiple comparison test. The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa). The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Tribological Performance and Enhancing Mechanism of 3D Printed PEEK Coated with In Situ ZIF-8 Nanomaterial.

Polyether ether ketone (PEEK) is esteemed as a high-performance engineering polymer renowned for its exceptional mechanical properties and thermal stability. Nonetheless, the majority of polymer-based lubricating materials fail to meet the contemporary industrial demands for motion components regarding high speed, heavy loading, temperature resistance, and precise control. Utilizing 3D printing technology to design and fabricate intricately structured components, developing high-performance polymer self-lubricating materials becomes imperative to fulfill the stringent operational requirements of motion mechanisms. This study introduces a novel approach employing 3D printing technology to produce PEEK with varying filling densities and conducting in situ synthesis of zeolitic imidazolate framework (ZIF-8) nanomaterials on its surface to enhance PEEK's frictional performance. The research discusses the synthetic methodology, characterization techniques, and tribological performance evaluation of in situ synthesized ZIF-8 nanomaterials on PEEK surfaces. The findings demonstrate a significant enhancement in frictional performance of the composite material under low-load conditions, achieving a minimum wear rate of 4.68 × 10-6 mm3/N·m compared to the non-grafted PEEK material's wear rate of 1.091 × 10-5 mm3/N·m, an approximately 1.3 times improvement. Detailed characterization and analysis of the worn surface of the steel ring unveil the lubrication mechanism of the ZIF-8 nanoparticles, thereby presenting new prospects for the diversified applications of PEEK.

Multifaceted Materials for Enhanced Osteogenesis and Antimicrobial Properties on Bioplastic Polyetheretherketone Surfaces: A Review.

Implant-associated infections and the increasing number of bone implants loosening and falling off after implantation have become urgent global challenges, hence the need for intelligent alternative solutions to combat implant loosening and falling off. The application of polyetheretherketone (PEEK) in biomedical and medical therapy has aroused great interest, especially because its elastic modulus close to bone provides an effective alternative to titanium implants, thereby preventing the possibility of bone implants loosening and falling off due to the mismatch of elastic modulus. In this Review, we provide a comprehensive overview of recent advances in surface modifications to prevent bone binding deficiency and bacterial infection after implantation of bone implants, starting with inorganics for surface modification, followed by organics that can effectively promote bone integration and antimicrobial action. In addition, surface modifications derived from cells and related products of biological activity have been proposed, and there is increasing evidence of clinical potential. Finally, the advantages and future challenges of surface strategies against medical associated poor osseointegration and infection are discussed, with promising prospects for developing novel osseointegration and antimicrobial PEEK materials.

Dual-functional polyetheretherketone surface modification for enhanced osseointegration and antibacterial activity in pH-responsive manner

Polyetheretherketone (PEEK) has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones. However, the inherent bioinertness of pristine PEEK results in insufficient osseointegration. Moreover, implant-associated infection (IAI) has become a serious threat in orthopedic surgery. These risks usually lead to implant loosening, delayed healing, and even the failure of implantation, hampering many clinical applications of PEEK. In this study, we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity. Briefly, pristine PEEK was first treated with mixed acids to obtain a porous structure (referred to as SNPEEK), and then the metal-phenolic networks (MPN) coating was prepared using layer-by-layer (LbL) assembly consisting of Sr2+ and tannin acid (TA) (referred to as ST coating). The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activity in pH-responsive manner. At pH 7.4, the antibacterial ratios were 71.72% and 66.79% against Staphylococcus aureus (MSSA, ATCC 25,923) and methicillin-resistant Staphylococcus aureus (MRSA, ATCC BAA-40), respectively. Remarkably, at pH 5.5, the antibacterial activities significantly increased, resulting in killing ratios of 99.98% and 100%, respectively. Furthermore, the dual-functional PEEK promoted osteogenic differentiation of pre-osteoblasts (MC3T3-E1) and migration of human umbilical vascular endothelial cells (HUVECs). In addition, the dual-functional PEEK demonstrated effective anti-infection ability and desirable new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants. Overall, this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability, representing a prospective solution to address current clinical challenges associated with PEEK implants.

Plasma bias homopolar sputtering technology and its application to enhance bioactivity of polyetheretherketone surface

Numerous strategies have been developed to deposit metal-based films on biomedical implants to improve their performances. As a promising strategy, vacuum plasma plating technology can introduce many bioactive metals on the implant surface and achieve strong interfacial bonding. However, there are still limitations in the surface modification of a non-conductive matrix. Here, a simple and universal plasma-based technique termed plasma bias homopolar sputtering (PBHS) was presented to modify the insulating and conductive materials. The technical principles and characteristics of PBHS were comprehensively studied. As a demonstration, the Fe-based film was prepared on the surface of an insulating polyetheretherketone (PEEK) by PBHS to improve its biological performance. The as-prepared Fe-based film exhibited low elasticity modulus and good hydrophilicity, enhancing the adhesion, proliferation, and osteogenic differentiation of rat bone marrow mesenchymal stem cells. This work provides a simple and universal technique for the preparation of metal-based films, holding great potential for the surface modification of biomedical implants.