Bone implants of polyetheretherketone (PEEK) have become increasingly popular in the orthopedic field but its bioinertness and poor osteogenic properties significantly limit its applications for bone regeneration and osseointegration with host bone. In this study, by incorporation of mesoporous diopside (MD) into the PEEK matrix, macro-mesoporous PEEK/MD (PM) composites as bone implants with interconnected macropores of 300–400 μm were fabricated using the method of cold press-sintering and salt-leaching. The results showed that the compressive strength, porosity and water absorption of the porous PM composites significantly increased with an increase in the MD content. In addition, the incorporation of MD into PEEK obviously enhanced the mineralization ability of the PM composites, indicating good bioactivity. Moreover, the in vitro cell experiments indicated that the macro-mesoporous PM composites significantly promoted the adhesion and proliferation as well as osteogenic differentiation of MC3T3-E1 cells, which depended on the MD content. The results of synchrotron radiation-based micro-computed tomography (SRmCT) and histological analysis revealed that the porous PM composites possessed excellent osteogenic properties in vivo, which were obviously enhanced with an increase in the MD content. Moreover, the immunohistochemistry evaluation of type I collagen (COL I) and vascular endothelial growth factor (VEGF) confirmed that addition of MD into PEEK obviously enhanced the osteogenesis and vascularization potential of the macro-mesoporous PM composites in vivo. The results suggested that the PM composites containing macropores and mesopores as bone implants had great potential for bone repair/substitution.

•Composites were fabricated with excellent hemostatic and antibacterial properties.•The influences of m-ZCS on the properties of composites were investigated.•15mZSC composite with good performance might be a candidate as hemostat.Efficacious hemostatic agents have significant potential application in visceral organ or large vessel arterial injure. In this study, mesoporous zinc-calcium silicate (m-ZCS) was synthesized, and microporous starch (MS) based hemostatic agents of m-ZCS/MS composites for hemorrhage control was fabricated. The results showed that the incorporation of m-ZCS into MS significantly enhanced the water absorption and degradability of the composites, which were dependent on the m-ZCS content. Moreover, the composites with antibacterial property could inhibit the growth of Escherichia coli (E. coli) and the antibacterial ratios increased with the m-ZCS content. The in vitro coagulation evaluation by using activated partial thromboplastin time (APTT) and prothrombin time (PT) revealed that the composites significantly activated the intrinsic and extrinsic pathway of coagulation cascade. In addition, for the animal model of rabbits in ear vein, skin, arterial and liver injuries, the hemostatic time of the composites obviously reduced with the increase of m-ZSC content, in which the composite with 15 wt% m-ZCS content (15mZSC) showed remarkable efficacy on bleeding control. The composites could promote the viability of L929 cells, indicating no cytotoxicity of the composites. The results suggested that the m-ZCS/MS composites with excellent hemostatic and antibacterial properties might be a candidate for controlling bleeding and infection.Download high-res image (214KB)Download full-size image

For emergency control of bleeding, there is a strong demand for topical hemostatic materials that can not only stop bleeding rapidly but also be carried and used conveniently. The aim of this work was to develop a novel type of porous silica material and investigate its hemostatic performance. The porous silica spherical-like granules were prepared via dry-mixing and wet-granulation with diameters of 0.40–1.10 mm. Granulation reinforced the infiltrating ability of the porous silica materials with fluid and stabilized their capillary structure. The rapid water absorption ability was enhanced 130% for the porous silica granules compared to the mesoporous silica particles. In vitro coagulation studies showed the clotting time of blood was shorten greatly from 150 seconds for mesoporous silica particles to 30 seconds for mesoporous silica granules at the early stage of hemostasis. In vivo studies using a rat injury model demonstrated the granules' ability to aid in rapid hemostasis. The usability of silica material was improved significantly by granulation through enhancing its flowability and eliminating dust. This study suggested the porous silica granules are a good candidate as a hemostatic agent in clinical and family applications.

•An innovative p-MSNs are synthesized to slow-release peptide osteogenic factor.•The p-MSNs induce the adhesion and proliferation of MG-63 cells.•The osteo-differentiation of the p-MSNs is enhanced after decoration of peptide.•Combination of MSNs and growth factors presents a potential for tissue engineering.Combination of mesoporous silica materials and bioactive factors is a promising niche-mimetic solution as a hybrid bone substitution for bone tissue engineering. In this work, we have synthesized biocompatible silica-based nanoparticles with abundant mesoporous structure, and incorporated bone-forming peptide (BFP) derived from bone morphogenetic protein-7 (BMP-7) into the mesoporous silica nanoparticles (MSNs) to obtain a slow-release system for osteogenic factor delivery. The chemical characterization demonstrates that the small osteogenic peptide is encapsulated in the mesoporous successfully, and the nitrogen adsorption–desorption isotherms suggest that the peptide encapsulation has no influence on mesoporous structure of MSNs. In the cell experiment, the peptide-laden MSNs (p-MSNs) show higher MG-63 cell proliferation, spreading and alkaline phosphatase (ALP) activity than the bare MSNs, indicating good in vitro cytocompatibility. Simultaneously, the osteogenesis-related proteins expression and calcium mineral deposition disclose enhanced osteo-differentiation of human mesenchymal stem cells (hMSCs) under the stimulation of the p-MSNs, confirming that BFP released from MSNs could significantly promote the osteogenic differentiation of hMSCs, especially at 500 μg/mL of p-MSNs concentration. The peptide-modified MSNs with better bioactivity and osteogenic differentiation make it a potential candidate as bioactive material for bone repairing, bone regeneration, and bio-implant coating applications.

As FDA-approved implantable material, polyetheretherketone (PEEK) is becoming a prime candidate to replace traditional surgical metallic implants made of titanium (Ti) and its alloys, since it has a lower elastic modulus than Ti. The bioinertness and defective osteointegration of PEEK, however, limit its clinical adoption as load-bearing dental/orthopedic material. The present work aimed at developing a PEEK bioactive ternary composite, polyetheretherketone/nano-hydroxyapatite/carbon fiber (PEEK/n-HA/CF), and evaluating it as a potential bone-repairing material by assessment of growth and differentiation of osteoblast-like MG63 cells and by estimation of osteointegration in vivo. Our results indicated that the adhesion, proliferation and osteogenic differentiation of cells, as well as the mechanical properties were greatly promoted for the PEEK/n-HA/CF biocomposite compared with pure PEEK matrix. More importantly, the ternary composite implant boosted in vivo bioactivity and osseointegration in canine tooth defect model. Thus, the PEEK/n-HA/CF ternary biocomposite with enhanced mechanics and biological performances hold great potential as bioactive implant material in dental and orthopedic applications.

In this study, a nanocalcium silicate (n-CS)/polyetheretherketone (PEEK) bioactive composite was prepared using a process of compounding and injection-molding. The mechanical properties, hydrophilicity, and in vitro bioactivity of the composite, as well as the cellular responses of MC3T3-E1 cells (attachment, proliferation, spreading, and differentiation) to the composite, were investigated. The results showed that the mechanical properties and hydrophilicity of the composites were significantly improved by the addition of n-CS to PEEK. In addition, an apatite-layer formed on the composite surface after immersion in simulated body fluid (SBF) for 7 days. In cell culture tests, the results revealed that the n-CS/PEEK composite significantly promoted cell attachment, proliferation, and spreading compared with PEEK or ultrahigh molecular weight polyethylene (UHMWPE). Moreover, cells grown on the composite exhibited higher alkaline phosphatase (ALP) activity, more calcium nodule-formation, and higher expression levels of osteogenic differentiation-related genes than cells grown on PEEK or UHMWPE. These results indicated that the incorporation of n-CS to PEEK could greatly improve the bioactivity and biocompatibility of the composite. Thus, the n-CS/PEEK composite may be a promising bone repair material for use in orthopedic clinics.Keywords: bioactivity; calcium silicate; cellular responses; composite; polyetheretherketone

An ordered mesoporous calcium–magnesium silicate (om-CMS) for bone repair was synthesized and characterized, and the in vitro bioactivity, degradability and primary cell responses to the om-CMS were investigated. The results showed that the om-CMS possessed a large surface area of 1017 m2/g and highly ordered hexagonal channel pores of around 7 nm. The om-CMS had good bioactivity, which could induce apatite formation on its surfaces after 5 d of soaking in simulated body fluid (SBF), and the om-CMS exhibited enhanced bioactive behavior, with even faster apatite formation than calcium–magnesium silicate (CMS). Furthermore, the om-CMS could be degradable in Tris–HCl solution with the weight loss ratio of 40 wt.% after immersion for 84 d. In cell cultural experiments, the results revealed that om-CMS could promote proliferation and differentiation of the MC3T3-E1 cells with time, and the cells with a normal morphology spread well on the om-CMS surface, which showed no negative effects of the substrate on cells. In conclusion, the results demonstrated that the degradable om-CMS with good bioactivity had the ability to support cell attachment, proliferation and differentiation, and exhibited good cytocompatibility.Graphical abstractHighlights► This is the first time to synthesize ordered mesoporous CaMgSi2O6. ► The om-CMS exhibited large surface area of 1017 m2/g and pore volume of 1 cm3/g. ► The material shows good bioactivity, degradability and cytocompatibility.

In the present study, we fabricated magnesium doped apatite cement (md-AC) with rapid self-setting characteristic by adding the mixed powders of magnesium oxide and calcium dihydrogen phosphate (MO–CDP) into hydroxyapatite cement (HAC). The results revealed that the md-AC with 50 wt% MO–CDP could set within 6 min and the compression strength could reach 51 MPa after setting for 1 h, indicating that the md-AC had highly initial mechanical strength. The degradability of the md-AC in Tris–HCl solution increased with the increase of MO–CDP amount, and the weight loss ratio of md-AC with 50 wt% MO–CDP was 57.5 wt% after soaked for 12 weeks. Newly flake-like apatite could be deposited on the md-AC surfaces after soaked in simulated body fluid (SBF) for 7 days. Cell proliferation ratio of MG63 cells on md-AC was obviously higher than that of HAC on days 4 and 7. The cells with normal phenotype spread well on the md-AC surfaces and attached intimately with the substrate, and alkaline phosphatase (ALP) activity of the cells on md-AC significantly improved compared with HAC on day 7. The results demonstrate that the md-AC has a good ability to support cell proliferation and differentiation, and indicate a good cytocompatibility.

A novel biocomposite of nano-apatite (NA)/polyamide6 (PA6) was prepared with a co-solution method. The NA with the size of 10–30 nm in diameter and 70–90 nm in length was uniformly distributed into PA6 matrix to form the composite. Molecular interaction and chemical bonding existed between NA and PA6, which greatly improved the mechanical properties and integrity of the composite. It was found that the composite with a high NA content (around 65%) has good homogeneity and mechanical strength, which are close to the natural bone. An interconnected porous material with porosity of 80% and mean pore size of approximately 300 μm was prepared by an injecting foam method. When implanted into cortical bone, the composite combined directly with the natural bone without fibrous capsule tissue between implant and host bone. The results indicated that the NA/PA6 composite has an excellent bioactivity.

A new type of biocomposite of nano aptite (NAP)/poly(1,4-phenylene sulfide)–poly (2,4-phenylene sulfide acid) (PPS–PPSA) copolymer (NAP/PPS–PPSA) was prepared by polycondensation in 1-methyl-2-pyrrolidone (NMP). The NAP particles with a size of about 40–60 nm in diameter and 60–80 nm in length uniformly distributed in the composite. The presence of 2,4-phenylene sulfide acid in copolymer increased the copolymer affinity to NAP. Duo to some strong combinations of calcium ion (Ca2+), carboxyl (–COO−) and phosphate radicals ion (PO43-) in the composite, interfacial chemical binding exists between copolymer and NAP. The NAP/PPS–PPSA biocomposite not only had good homogeneity but also had high NAP content of 60%, which was a potential bioactive material to be used as load-bearing implants or fixation in bone repair.

A novel bioactive composite based on wheat protein (WP) and mesoporous magnesium silicate (m-MS) with a high specific surface area is presented in this study for potential bone tissue regeneration. Wheat protein (WP) is a type of a biodegradable natural polymer material. The m-MS was prepared by the sol–gel technique, which was incorporated into WP to fabricate m-MS/WP composites. The increasing amount of m-MS improved the surface hydrophilicity of m-MS/WP composites. The results showed that the degradation ratio of the m-MS/WP composites increased with an increase in the m-MS content after it was soaked in a Tris–HCl solution for 12 weeks. Moreover, the m-MS/WP composites with 40 wt% m-MS content (WP40) were able to maintain a suitable pH value over a prolonged soaking time, which might be dependent on the content of the m-MS. The WP40 showed a good apatite formation ability after it was soaked in simulated body fluid (SBF) for 7 days, indicating good bioactivity. Moreover, the WP40 with cytocompatibility stimulated the attachment, proliferation and differentiation of MC3T3-E1 osteoblast cells. Briefly, the results indicated that WP40 had good bioactivity, degradability, cytocompatibility and osteogenesis and might be a new biomaterial for bone regeneration.

Bioactive scaffolds of magnesium silicate (m-MS)/poly(butylene succinate) (PBSu) composites were fabricated by a solvent casting–particulate leaching method for bone regeneration. The scaffolds had a hierarchical porous structure with interconnected macropores (300–500 μm), micropores (1–10 μm) and mesopores (∼5 nm). In addition, the composite scaffolds were degradable in Tris-HCl solution and formed apatite on their surfaces in simulated body fluid, indicating good degradability and bioactivity in vitro. Compared with PBSu scaffolds, the composite scaffolds improved the in vitro attachment, proliferation and osteogenic differentiation of MC3T3-E1 cells, revealing good cytocompatibility. Furthermore, the model of rabbit femur cavity defects was used to evaluate the in vivo osteogenesis of the composite scaffolds. The results of synchrotron radiation-based mCT (SRmCT) imaging, histological analysis and immunohistochemistry showed that the composite scaffolds were gradually degraded and replaced by new bone, and the scaffolds with 40 wt% m-MS (C40) almost completely disappeared after 12 weeks of implantation, indicating that the scaffolds containing m-MS enhanced new bone formation. The results demonstrated that the bioactive m-MS/PBSu composite scaffolds with good biocompatibility, degradability, bioactivity and osteogenesis are promising biomaterials for bone repair.