Porous Polyetheretherketone Research Articles

A 3D printing-based hybrid manufacturing method for high-strength polymeric medical implant fabrication

This paper presents a novel 3D printing-based hybrid manufacturing method to fabricate high-strength polymeric medical implants. Poly-ether-ether-ketone (PEEK) and polyether sulfone (PES) are blended to make filament for use with the fused filament fabrication technique to print custom designed implants. After printing and annealing, PES is removed by leaching to create interconnected porous PEEK structure with suitable pore size and porosity for bone tissue ingrowth. The proposed method provides a versatile approach to fabricating medical implants that are both mechanically strong and microstructurally inducive to osseointegration. The polymeric implants are also X-ray transparent to allow post-surgery evaluations using an imaging method. An intervertebral spacer implant example is used to demonstrate the proposed fabrication method.

Investigating the Impact of Pore Size and Specification on Soft Tissue Ingrowth in 3D-Printed PEEK Material.

Bone pelvis tumor resection and reconstruction is a complex surgical procedure that poses challenges in soft tissue reconstruction despite advancements in stabilizing pelvic structure. This study aims to investigate the potential of using Polyetheretherketone (PEEK) material in repairing and reconstructing soft tissues surrounding pelvic implants. Specifically, the study focuses on exploring the effectiveness of 3D printed porous PEEK material in promoting cell growth and adhesion. The interaction between PEEK materials with different pore sizes (200, 400, 600µm) and different specifications (through-hole (T)/non-through-hole (C)) is evaluated by cell experiments and animal experiments. The soft tissue ingrowth potential of PEEK materials is evaluated by cell growth and adhesion observation. The findings indicate that PEEK material, particularly the T400 variant, exhibits stronger interaction with muscle tissue compared to its interaction with bone and fibrous tissue. The moderately sized pores present in the T400 material facilitate enhanced cell adhesion and penetration, thereby promoting cell growth and differentiation. PEEK materials with through-hole structures show promise for applications involving the repair and reconstruction of soft tissues and muscle tissue. The study provides valuable insights into the development and application of biomedical materials, specifically PEEK, contributing to the advancement of pelvic tumor resection and reconstruction techniques.

A Surface-Mediated Biomimetic Porous Polyether-Ether-Ketone Scaffold for Regulating Immunity and Promoting Osteogenesis.

The repair of critical-sized bone defects remains a major challenge for clinical orthopedic surgery. Here, we develop a surface biofunctionalized three-dimensional (3D) porous polyether-ether-ketone (PEEK) scaffold that can simultaneously promote osteogenesis and regulate macrophage polarization. The scaffold is created using polydopamine (PDA)-assisted immobilization of silk fibroin (SF) and the electrostatic self-assembly of nanocrystalline hydroxyapatite (nano-HA) on a 3D-printed porous PEEK scaffold. The SF/nano-HA functionalized surface provides a bone-like microenvironment for osteoblastic cells' adhesion, proliferation, mineralization and osteogenic differentiation. Moreover, the biofunctionalized surface can effectively drive macrophages polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Integrin β1-specific cell-matrix binding and the activation of Ca2+ receptor-mediated signaling pathway play critical roles in the regulation of macrophage polarization. Compared with the as-printed scaffold, the SF/nano-HA functionalized porous PEEK scaffold induces minimal inflammatory response, enhanced angiogenesis, and substantial new bone formation, resulting in improved osseointegration in vivo. This study not only develops a promising candidate for bone repair but also demonstrates a facile surface biofunctionalization strategy for orthopedic implants to improve osseointegration by stimulating osteogenesis and regulating immunity.

Effects of porosity distribution on mechanical properties and osseointegration of porous polyetheretherketone

Porous polyetheretherketone (P-PEEK) is widely used as the material for making implant screws, and yet its mechanical properties and osseointegration for ultilization are still unsatisfied. In this work, the effects of the porosity distribution on the mechanical properties and osseointegration were investigated. Functionally graded P-PEEK (FGP-PEEK) and uniform P-PEEK (UP-PEEK) were developed by infiltration casting technology. The mechanical properties of the P-PEEK were studied by compressive and bending tests, and the osseointegration was evaluated by in vitro and rabbit femur experiments. The prepared FGP-PEEK was composed of the central dense part and its surrounding porous one where the pores were isodiametric and interconnected. Both the compressive strength and bending strength of the FGP-PEEK with graded porosity were higher than those of the UP-PEEK with uniform porosity. The mechanical properties of the FGP-PEEK were comparable to that of the human cancellous bone. The in vitro and in vivo experiments indicated the FGP-PEEK had no cytotoxicity, and its osseointegration was better than the UP-PEEK. The results demonstrated that the graded porosity had a superiority in the mechanical properties and osseointegration of the P-PEEK scaffolds compared to the uniform porosity. The influencing mechanisms of the porosity distribution on the mechanical properties and osseointegration were also clarified. Additionally, the osseointegration of the FGP-PEEK gradually increased as the surface porosity increased from 30 % to 50 %. The 50 %-surface porosity FGP-PEEK was a promising material on the application of the implant screws.

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.

L-arginine loading porous PEEK promotes percutaneous tissue repair through macrophage orchestration

Infection and poor tissue repair are the key causes of percutaneous implantation failure. However, there is a lack of effective strategies to cope with due to its high requirements of sterilization, soft tissue healing, and osseointegration. In this work, l-arginine (L-Arg) was loaded onto a sulfonated polyetheretherketone (PEEK) surface to solve this issue. Under the infection condition, nitric oxide (NO) and reactive oxygen species (ROS) are produced through catalyzing L-Arg by inducible nitric oxide synthase (iNOS) and thus play a role in bacteria sterilization. Under the tissue repair condition, L-Arg is catalyzed to ornithine by Arginase-1 (Arg-1), which promotes the proliferation and collagen secretion of L929 and rBMSCs. Notably, L-Arg loading samples could polarize macrophages to M1 and M2 in infection and tissue repair conditions, respectively. The results in vivo show that the L-Arg loading samples could enhance infected soft tissue sealing and bone regeneration. In summary, L-Arg loading sulfonated PEEK could polarize macrophage through metabolic reprogramming, providing multi-functions of antibacterial abilities, soft tissue repair, and bone regeneration, which gives a new idea to design percutaneous implantation materials.

Application of 3D‑printed porous titanium interbody fusion cage vs. polyether ether ketone interbody fusion cage in anterior cervical discectomy and fusion: A systematic review and meta‑analysis update.

The present study aimed to compare the differences between 3D-printed porous titanium and polyether ether ketone (PEEK) interbody fusion cages for anterior cervical discectomy and fusion (ACDF). Literature on the application of 3D-printed porous titanium and PEEK interbody fusion cages for ACDF was searched in the PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang and VIP databases. A total of 1,181 articles were retrieved and 12 were finally included. The Cochrane bias risk assessment criteria and Newcastle-Ottawa scale were used for quality evaluation and Review Manager 5.4 was used for data analysis. The 3D cage group was superior to the PEEK cage group in terms of operative time [mean difference (MD): -7.68; 95% confidence interval (CI): -11.08, -4.29; P<0.00001], intraoperative blood loss (MD: -6.17; 95%CI: -10.56, -1.78; P=0.006), hospitalization time (MD: -0.57; 95%CI: -0.86, -0.28: P=0.0001), postoperative complications [odds ratio (OR): 0.35; 95%CI: 0.15, 0.80; P=0.01], C2-7 Cobb angle (MD: 2.85; 95%CI: 1.45, 4.24; P<0.0001), intervertebral space height (MD: 1.20; 95%CI: 0.54, 1.87; P=0.0004), Japanese Orthopaedic Association Assessment of Treatment (MD: 0.69; 95%CI: 0.24, 1.15; P=0.003) and visual analogue scale score (MD: -0.43; 95%CI: -0.78, -0.07; P=0.02). The difference was statistically significant, while there was no significant difference between the two groups in terms of fusion rate (OR: 1.74; 95%CI: 0.71, 4.27; P=0.23). The use of 3D-printed porous titanium interbody fusion cage in ACDF has the advantages of short operation time, less bleeding loss, shorter hospitalization time and fewer postoperative complications. It can better maintain the cervical curvature and intervertebral height, relieve pain and accelerate postoperative functional recovery.

Comprehensive Evaluation of Novel Biomaterials for Dental Implant Surfaces: An In Vitro Comparative Study.

Dental implantology is continually evolving in its quest to discover new biomaterials to improve dental implant success rates. The study explored the potential of innovative biomaterials for dental implant surfaces, including titanium-zirconium (Ti-Zr) alloy, hydroxyapatite-coated titanium (HA-Ti), and porous polyetheretherketone (PEEK), in comparison to conventional commercially pure titanium (CP Ti). A total of 186 samples were harvested for the analysis. Biomaterials were thoroughly evaluated in terms of surface topography, chemical composition, biocompatibility, mechanical properties, osseointegration performance, and bacterial adhesion. Study methods and techniques included scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), cell culture variants, tensile tests, hardness measurements, histological analysis, and microbiological testing. Surface topography examination showed significant disparities between the biomaterials: Ti-Zr had a better roughness of 1.23 μm, while HA-Ti demonstrated a smoother surface at 0.98 μm. Chemical composition evaluation indicated the presence of a Ti-Zr alloy in Ti-Zr, calcium-phosphorus richness in HA-Ti, and high titanium amounts in CP Ti. The mechanical properties assessment showed that Ti-Zr and CP Ti had good tensile strengths of 750 MPa and 320 HV. In addition, bacterial adhesion tests showed low propensities for Ti-Zr and HA-Ti at 1200 and 800 cfu/cm2, respectively. Ti-Zr and HA-Ti performed better than the other biomaterials in surface topography and mechanical properties and against bacterial adhesion. This study emphasizes that multi-parameter analysis is critical for clinical decision-making, allowing for the selection of the currently available biomaterial, which could be conducive to the long-term success of the implant.

Dual-energy computed tomography and micro-computed tomography for assessing bone regeneration in a rabbit tibia model

To gain a more meaningful understanding of bone regeneration, it is essential to select an appropriate assessment method. Micro-computed tomography (Micro-CT) is widely used for bone regeneration because it provides a substantially higher spatial resolution. Dual-energy computed tomography (DECT) ensure shorter scan time and lower radiation doses during quantitative evaluation. Therefore, in this study, DECT and Micro-CT were used to evaluate bone regeneration. We created 18 defects in the tibial plateau of the rabbits and filled them with porous polyetheretherketone implants to promote bone regeneration. At 4, 8, and 12 weeks, Micro-CT and DECT were used to assess the bone repair in the defect region. In comparison to Micro-CT (152 ± 54 mg/cm3), the calcium density values and hydroxyapatite density values obtained by DECT [DECT(Ca) and DECT(HAP)] consistently achieved lower values (59 ± 25 mg/cm3, 126 ± 53 mg/cm3). In addition, there was a good association between DECT and Micro-CT (R = 0.98; R2 = 0.96; DECT(Ca): y = 0.45x–8.31; DECT(HAP): y = 0.95x–17.60). This study highlights the need to use two different imaging methods, each with its advantages and disadvantages, to better understand the bone regeneration process.

Fabricating biomimetic porous PEEK scaffolds for bone implants

Poly-ether-ether-ketone (PEEK) is a high strength polymer with strong potential for medical use, especially for bone implants. In this research, a novel method of making biomimetic porous PEEK scaffolds is developed. PEEK and polyethersulfone (PES) are blended at a proper ratio to generate a co-continuous phase structure. With solid-state foaming, PES is efficiently removed by leaching to yield interconnected porous PEEK scaffolds. The pore size and pore gradient of the PEEK scaffolds can be easily controlled by controlling the annealing time and temperature of the PEEK/PES blend. This study presents the conditions of the proposed fabrication process and compares the fabricated porous PEEK scaffolds with those fabricated using other methods. It is shown that the structural morphology and mechanical properties of the fabricated porous PEEK is generally comparable to those of trabecular bones, suggesting these scaffolds could be excellent candidates for bone implant applications.

Performance of 3D printed porous polyetheretherketone composite scaffolds combined with nano-hydroxyapatite/carbon fiber in bone tissue engineering: a biological evaluation

Polyetheretherketone (PEEK) has been one of the most promising materials in bone tissue engineering in recent years, with characteristics such as biosafety, corrosion resistance, and wear resistance. However, the weak bioactivity of PEEK leads to its poor integration with bone tissues, restricting its application in biomedical fields. This research effectively fabricated composite porous scaffolds using a combination of PEEK, nano-hydroxyapatite (nHA), and carbon fiber (CF) by the process of fused deposition molding (FDM). The experimental study aimed to assess the impact of varying concentrations of nHA and CF on the biological performance of scaffolds. The incorporation of 10% CF has been shown to enhance the overall mechanical characteristics of composite PEEK scaffolds, including increased tensile strength and improved mechanical strength. Additionally, the addition of 20% nHA resulted in a significant increase in the surface roughness of the scaffolds. The high hydrophilicity of the PEEK composite scaffolds facilitated the in vitro inoculation of MC3T3-E1 cells. The findings of the study demonstrated that the inclusion of 20% nHA and 10% CF in the scaffolds resulted in improved cell attachment and proliferation compared to other scaffolds. This suggests that the incorporation of 20% nHA and 10% CF positively influenced the properties of the scaffolds, potentially facilitating bone regeneration. In vitro biocompatibility experiments showed that PEEK composite scaffolds have good biosafety. The investigation on osteoblast differentiation revealed that the intensity of calcium nodule staining intensified, along with an increase in the expression of osteoblast transcription factors and alkaline phosphatase activities. These findings suggest that scaffolds containing 20% nHA and 10% CF have favorable properties for bone induction. Hence, the integration of porous PEEK composite scaffolds with nHA and CF presents a promising avenue for the restoration of bone defects using materials in the field of bone tissue engineering.

Sand casting-inspired surface modification of 3D-printed porous polyetheretherketone scaffolds for enhancing osteogenesis

3D-printed polyetheretherketone (PEEK) scaffolds are developed as novel bone substitutes, however, their bioinert surface hinders osteogenesis and modifying PEEK scaffolds without blocking their inter-connected porous structure is challenged. In this study, 45S5 bioactive glasses (BG) were homogeneously coated on PEEK scaffolds inspired by traditional sand-casting. The structure of PEEK scaffolds was preserved under shaping effect of BG fillers. Modulus, coating yield and hydrophilicity of scaffolds after different thermal treatment time were comparatively investigated. Excellent hydroxyapatite-forming ability of BG-coated scaffolds was confirmed by mineralization study. In-vitro assessments, BG-coated scaffolds cultured with MC3T3-E1 cells presented potential as bone implants with excellent cytocompatibility and osteogenic properties. Following similar coating strategy, conductive particles, multi-component particles and template particles were also coated on PEEK surface. The proposed methodology highlights a useful approach towards producing tunable biomedical coatings and microstructure on porous PEEK scaffolds for bone tissue engineering.

Bioinspired Hard–Soft Composite Scaffold with Excellent Lubrication and Osteogenic Properties for the Treatment of Osteochondral Defect

AbstractNatural articular cartilage is a typical self‐healing and superlubrication system capable of maintaining extremely low friction under physiological loadings. Cartilage wear and accidental trauma can cause irreversible defects to cartilage and subchondral bone with a significant decrease in intra‐articular lubrication, leading to the development of severe osteoarthritis and osteochondral defect. To address the important clinical problem of osteochondral defect, a bioinspired hard–soft (PEEK‐lubrication hydrogel) composite scaffold is designed and developed. The polymerization of polyethylene glycol diacrylamide (PEGDAA) and 2‐methacryloyloxyethyl phosphorylcholine (MPC) on polyetheretherketone (PEEK) substrate is achieved by UV initiation to form a strong interfacial bonding, and nano‐hydroxyapatite is deposited on porous PEEK substrate via polydopamine coating to improve osteogenic capability. Accordingly, the composite scaffold is successfully developed with lubrication and osteogenic activity. The tribological tests show that the lubrication performance of the composite scaffold is based on the hydration lubrication mechanism of the upper hydrogel layer, and the in vitro and in vivo experiments demonstrate that the composite scaffold is endowed with excellent biocompatibility and bioactivity. In conclusion, the bioinspired strategy for preparing a hard–soft composite scaffold shows a promising way in the treatment of osteochondral defect and provided a guideline for designing functional PEEK‐based biomaterials in tissue engineering scaffolds.

Surface modification of Polyether-ether-ketone for enhanced cell response: a chemical etching approach.

Polyether-ether-ketone (PEEK) is increasingly becoming popular in medicine because of its excellent mechanical strength, dimensional stability, and chemical resistance properties. However, PEEK being bioinert, has weak bone osseointegration properties, limiting its clinical applications. In this study, a porous PEEK structure was developed using a chemical etching method with 98wt% sulfuric acids and three post-treatments were performed to improve bone cell adhesion and proliferation. Four groups of PEEK samples were prepared for the study: Control (untreated; Group 1); Etched with sulfuric acid and washed with distilled water (Group 2); Etched with sulfuric acid and washed with acetone and distilled water (Group 3); and Etched with sulfuric acid and washed with 4wt% sodium hydroxide and distilled water (Group 4). Surface characterization of the different groups was evaluated for surface topology, porosity, roughness, and wettability using various techniques, including scanning electron microscopy, profilometer, and goniometer. Further chemical characterization was done using Energy-dispersive X-ray spectroscopy to analyze the elements on the surface of each group. Bone cell studies were conducted using cell toxicity and alkaline phosphatase activity (ALP) assays. The SEM analysis of the different groups revealed porous structures in the treatment groups, while the control group showed a flat topology. There was no statistically significant difference between the pore size within the treated groups. This was further confirmed by the roughness values measured with the profilometer. We found a statistically significant increase in the roughness from 7.22 × 10-3μm for the control group to the roughness range of 0.1µm for the treated groups (Groups 2-4). EDX analysis revealed the presence of a 0.1% weight concentration of sodium on the surface of Group 4, while sulfur weight percentage concentration was 1.1%, 0.1%, and 1.4% in groups 2, 3, and 4, respectively, indicating different surface chemistry on the surface due to different post-treatments. Cell toxicity decreased, and ALP activity increased in groups 3 and 4 over 7days compared with the control group. It is demonstrated that the surface modification of PEEK using a chemical etching method with post-processing with either acetone or sodium hydroxide provides a nano-porous structure with improved properties, leading to enhanced osteoblastic cell differentiation and osteogenic potential.

Facile fabrication of FAS-PDMS/PEEK composite hollow fiber membrane with honeycomb-like structure for CO2 capture from flue gas by membrane absorption

In this study, as an efficient technology membrane absorption was applied with newly developed polyetheretherketone (PEEK) hollow fiber membrane (HFM) to remove CO2 from flue gas. To alleviate membrane wetting issue, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS) was integrated into polydimethylsiloxane (PDMS) and then crosslinked FAS-PDMS was coated on porous PEEK membranes to prepare composite membranes. Surface characterization verified that PDMS layer containing fluoroalkylsilane had been successfully formed on membrane surface. As mass ratio of FAS to PDMS in coating solution raised, an interesting honeycomb-like structure was observed dispersing on composite membrane surface. Meanwhile, water contact angle was improved from 90.0° to 133.5° indicating enhanced membrane hydrophobicity. The effects of gas and liquid flow velocities on CO2 absorption performance of FAS-PDMS/PEEK HFM were systematically studied. The highest CO2 removal efficiency of 99.6% was achieved when gas and liquid velocity were 0.027 and 0.019 m s−1. When gas velocity raised to 0.110 m s−1, the maximum absorption flux of 1.22 × 10-4 mol m−2 s−1 and overall mass-transfer coefficient of 2.69 × 10−5 m s−1 could be obtained. Compared with the original membrane, the CO2 absorption flux of FAS-PDMS-0.6 HFM was increased by 50.9%, and the performance had no degradation in 36 h test. This study provides a novel strategy to alleviate the membrane wetting problem during CO2 membrane absorption process.

Polyether-Ether-Ketone (PEEK) and Its 3D-Printed Quantitate Assessment in Cranial Reconstruction.

Three-dimensional (3D) printing, medical imaging, and implant design have all advanced significantly in recent years, and these developments may change how modern craniomaxillofacial surgeons use patient data to create tailored treatments. Polyether-ether-ketone (PEEK) is often seen as an attractive option over metal biomaterials in medical uses, but a solid PEEK implant often leads to poor osseointegration and clinical failure. Therefore, the objective of this study is to demonstrate the quantitative assessment of a custom porous PEEK implant for cranial reconstruction and to evaluate its fitting accuracy. The research proposes an efficient process for designing, fabricating, simulating, and inspecting a customized porous PEEK implant. In this study, a CT scan is utilized in conjunction with a mirrored reconstruction technique to produce a skull implant. In order to foster cell proliferation, the implant is modified into a porous structure. The implant's strength and stability are examined using finite element analysis. Fused filament fabrication (FFF) is utilized to fabricate the porous PEEK implants, and 3D scanning is used to test its fitting accuracy. The results of the biomechanical analysis indicate that the highest stress observed was approximately 61.92 MPa, which is comparatively low when compared with the yield strength and tensile strength of the material. The implant fitting analysis demonstrates that the implant's variance from the normal skull is less than 0.4436 mm, which is rather low given the delicate anatomy of the area. The results of the study demonstrate the implant's endurance while also increasing the patient's cosmetic value.

Dopamine and epigallocatechin-3-gallate cross-linked coating demonstrates improved osteointegration of polyetheretherketone in rabbits

The increasing demand for enhanced osteointegration calls for next-generation polyetheretherketone (PEEK) that can offer fast bone integration. Whether polydopamine (PDA) and epigallocatechin-3-gallate (EGCG) cross-linked coatings could improve osteointegration of PEEK remains unclear. Here, we fabricated a series of PDA and EGCG cross-linked coatings (PE coatings: P2E0.1, P2E0.5, P2E1, and P2E2 coatings) to enhance osteointegration of PEEK. The material characteristics of coatings were studied using scanning electron microscopy, X-ray photoelectron spectroscopy, micro-BCA tests, and static water contact angle tests. We evaluated the cytotoxicity, cell adhesion, and osteogenic effects of the coatings in vitro. Furthermore, the P2E0.5 coating was selected to coat porous PEEK scaffold to observe osteointegration using micro-computed tomography and histology in a rabbit. The results show that the PE coatings provide phenolic hydroxyl and amino groups and enhanced hydrophilicity of PEEK, especially in the P2E0.5 coating. Several lines of cellular evidence suggest that P2E0.5 coatings exhibit a noncytotoxic and excellent osteogenic effect. Compared with PEEK, the P2E0.5-coated PEEK shows higher values of bone volume, trabecular number, and trabecular thickness. This study suggests that the PE coating is a promising candidate for surface modification of PEEK and may lay the foundation for further application of PE coatings in clinical practice.

High-strength porous polyetheretherketone/hydroxyapatite composite for the treatment of bone defect

Although polyetheretherketone has prospective applications in bone repair, its biological inertness limits its application. In this article, a high-strength porous polyetheretherketone/hydroxyapatite composite (hp-PK-HA) was developed through thermally induced phase separation and hydrothermal synthesis methods. The synthesized hp-PK-HA possesses an interconnected pore structure. The mechanical properties and porosity can be adjusted by changing the solid content. The maximum compressive modulus of the synthesized material is close to 1 GPa, and the porosity is between 30% and 60%, which conforms to the physical structure of the human skeleton. In vitro osteoblast differentiation experiments, compared with nonporous injection-molded polyetheretherketone (IM-PK) and high-strength porous polyetheretherketone (hp-PK, without HA), hp-PK-HA exhibited an outstanding osteogenic differentiation capacity in alkaline phosphatase (ALP), alizarin red S (ARS) and polymerase chain reaction (PCR) assays. In rat calvarial defects experiments, hp-PK-HA exhibited excellent osseointegration and bone regeneration ability and was confirmed by microcomputed tomography analysis, hard tissue sections, and immunohistochemistry staining. Overall, polyetheretherketone/hydroxyapatite composites may provide an efficient platform for the treatment of bone defects.

Preparation and Modification of Porous Polyetheretherketone (PEEK) Cage Material Based on Fused Deposition Modeling (FDM).

To address the problems of the difficult processing and internal microstructure disorder of porous bearing cages, Polyetheretherketone (PEEK) porous self-lubricating bearing cage material was prepared based on a fused deposition molding (FDM) process, and the porous samples were heat-treated on this basis, the research was carried out around the synergistic design of the material preparation, microstructure, and tribological properties. The results show that the pore size of the PEEK porous material prepared by the FDM process meets the requirements of the porous bearing cage; the samples with higher porosity also have higher oil content, and all the samples show high oil retention. Under dry friction conditions, the higher the porosity of the porous material, the larger the friction coefficient, and the friction coefficients of each sample after heat treatment show the same pattern; under starved lubrication conditions, the friction coefficient of the porous PEEK material decreased significantly compared to the compact PEEK material, showing a better self-lubrication effect, and the porous samples reached the best self-lubrication effect after heat treatment. The optimal process parameters were 60% mass fraction of NaCl, 40% mass fraction of PEEK, and the applied heat treatment process.

Integrated porous polyetheretherketone implants for treating skull defect

Skull defect is a common clinical disease, and the corresponding treatment is still a grand challenge. No artificial product can perfectly integrate with human skull and match the skull defect during growth. Herein, we report a porous polyetheretherketone (PEEK) implant with the microstructures almost identical to natural bones for repairing skull defect. Compared to non-porous PEEK controls, the porous PEEK implants efficiently promote cell adhesion, regenerate skull tissues, and finally achieve perfect healing with surrounding tissues within 6 months. This work suggests the important potential of integrated porous PEEK implants for treating skull defect in clinic, especially for children with rapidly growing skulls.