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As an implantable biomaterial, polyetherketoneketone (PEKK) exhibits good mechanical strength but it is biologically inert while tantalum (Ta) possesses outstanding osteogenic bioactivity but has a high density and elastic modulus. Also, silicon nitride (SN) has osteogenic and antibacterial activity. In this study, a microporous surface containing both SN and Ta microparticles on PEKK (STP) exhibiting excellent osteogenic and antibacterial activity was created by sulfonation. Compared with sulfonated PEKK (SPK) without microparticles, the surface properties (roughness, surface energy, hydrophilicity and protein adsorption) of STP significantly increased due to the SN and Ta particles presence on the microporous surface. In addition, STP also exhibited outstanding antibacterial activity, which inhibited bacterial growth in vitro and prevented bacterial infection in vivo because of the presence of SN particles. Moreover, the microporous surface of STP containing both SN and Ta particles remarkably induced response (e.g., proliferation and differentiation) of rat bone mesenchymal stem (rBMS) cells in vitro. Furthermore, STP significantly improved new bone regeneration and osseointegration in vivo. Regarding the induction of cellular response in vitro and improvement of osseointegration in vivo, the microporous surface containing Ta was better than the surface with SN particles. In conclusion, STP with optimized surface properties activated cellular responses in vitro, enhanced osseointegration and prevented infection in vivo. Therefore, STP possessed the dual biofunctions of excellent osteogenic and antibacterial activity, showing great potential as a bone substitute., Graphical abstract Image 1, Highlights •Microporous surface containing SN/Ta microparticles on PEKK (STP) was created. •Surface performances (e.g., roughness) of STP were significantly increased. •STP exhibited antibacterial activity in vitro and prevented infection in vivo. •STP remarkably induced response of bone mesenchymal stem cells in vitro. •STP obviously improved bone regeneration and osseointegration in vivo.

The functions of implants like medical devices are often compromised by the host's foreign-body response (FBR). Herein, we report the development of low-FBR materials inspired by serine-rich sericin from silk. Poly-β-homoserine (β-HS) materials consist of the hydrophilic unnatural amino acid β-homoserine. Self-assembled monolayers (SAMs) of β-HS resist adsorption by diverse proteins, as well as adhesion by cells, platelets, and diverse microbes. Experiments lasting up to 3 months revealed that, while implantation with control PEG hydrogels induced obvious inflammatory responses, collagen encapsulation, and macrophage accumulation, these responses were minimal with β-HS hydrogels. Strikingly, the β-HS hydrogels induce angiogenesis in implant-adjacent tissues. Molecular dynamics simulations indicated that the low FBR performance of β-HS results from what we term "dual hydrogen bonding hydration", wherein both the backbone amide groups and the sidechain hydroxyl groups of β-HS undergo hydration.

Poly(propylene carbonate) (PPC) has aroused extensive attention in the biomaterial field because of its excellent biocompatibility and appropriate degradability, but surface hydrophobicity and bioinertness limit its applications for bone repair and tissue engineering. In this study, a bioactive PPC/laponite (LAP) nanocomposite (PL) was prepared by a melt-blending method, and a microporous surface on PPC and PL (PT and PLT) was created by sodium hydroxide (NaOH) treatment. The results demonstrated that the surface roughness, hydrophilicity, surface energy, and degradability as well as protein adsorption of PLT were obviously improved compared with PPC. Moreover, the degradability of PLT was remarkably enhanced with a slight increase of pH values in Tris-HCl solution. Furthermore, adhesion and proliferation as well as osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) to PLT were significantly promoted compared with PPC. The results suggested that incorporating LAP into PPC obviously improved the surface performance of PL (with nanotopography), and surface treatment with NaOH further enhanced surface properties of PLT (with micronanotopography and hydrophilic groups), which significantly promoted responses of rBMSCs. In short, PLT displayed excellent cytocompatibility, which would have great potential for bone regeneration.

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.

Poor osteogenesis and bacterial infection lead to the failure of implants, thus enhancements of osteogenic activity and antibacterial activity of the implants have significances in orthopedic applications. In this study, macro-microporous bone implants of nano-bioglass (nBG) and polyetheretherketone (PK) composite (mBPC) were fabricated. The results indicated that the mBPC with the porosity of around 70% exhibited interconnected macropores (sizes of about 400 μm) and micropores (sizes of about 10 μm). The apatite mineralization ability of mBPC in simulated body fluid (SBF) was significantly improved compared with macroporous nBG/PK composite (BPC) without micropores and macroporous PK (mPK). Drug of hinokitiol (HK) was loaded into mBPC (dmBPC), which displayed excellent in vitro antibacterial activity against Staphylococcus aureus. The MC3T3-E1 cells proliferation and ALP activity were significantly promoted by mBPC and dmBPC as compared with BPC and mPK. The micro-CT and histological evaluation showed that both mBPC and dmBPC containing nBG and micropores induced higher new bone formation into porous implants than mPK and BPC. The immunohistochemistry analysis indicated that the expression of BMP-2 in mBPC and dmBPC exhibited obviously higher level than mPK and BPC. The results suggested that the incorporation of nBG and micropores in mBPC obviously improved the osteogenic activity, and mBPC load with HK also promoted osteogenesis, indicating good biocompatibility. The dmBPC with HK significantly enhanced osteogenesis and antibacterial activity, which had great potential as bone implant for hard tissue repair.

To improve mechanical, tribological and biological performances of polyetheretherketone (PEEK) for artificial joints applications, molybdenum disulfide (MoS2, MS) nanosheets were incorporated into PEEK to fabricate MS/PEEK biocomposites (MPC) with MS content of 4 w% (MPC4) and 8 w% (MPC8). The results revealed that the MS nanosheets with the size of about 400 nm and sheet thickness of about 70 nm were distributed into PEEK matrix, and surface roughness as well as hydrophilicity of MPC increased with the MS content increasing. Moreover, the compressive strength and shore hardness of the MPC were accordingly enhanced. Furthermore, the coefficient of friction of the MPC decreased while the wear resistance of the MPC increased with the MS content increasing in both water-sliding and dry-sliding contact. In addition, rat bone marrow derived stromal cells adhered and proliferated on the composites, indicating that the MPC had no adverse influences on cell behaviors, indicating good cytocompatibility. The results demonstrated that incorporation of MS nanosheets into PEEK produced biocomposites with improved mechanical, tribological and biological performances. MPC8 with no cytotoxicity would have a great potential for artificial joints applications.

Rui Ma,1,2 Zhifeng Yu,1 Songchao Tang,3 Yongkang Pan,3 Jie Wei,3 Tingting Tang1 1Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People’s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, People’s Republic of China; 2Department of OrthopedicSurgery, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shanxi Province, People’s Republic of China; 3Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China Abstract: Polyetheretherketone (PEEK) exhibits appropriate biomechanical strength as well as good biocompatibility and stable chemical properties but lacks bioactivity and cannot achieve highly efficient osseointegration after implantation. Incorporating bioceramics into the PEEK matrix is a feasible approach for improving its bioactivity. In this study, nanohydroxyapatite (n-HA) and nano-calcium silicate (n-CS) were separately incorporated into PEEK to prepare n-HA/PEEK and n-CS/PEEK biocomposites, respectively, using a compounding and injection-molding technique, and the in vitro degradation characteristics were evaluated. Discs with a diameter of 8 mm were inserted in 8 mm full-thickness cranial defects in rabbits for 4 and 8weeks, and implantation of pure PEEK was used as the control. Three-dimensional microcomputed tomography, histological analysis, fluorescence microscopy of new bone formation, and scanning electron microscopy were used to evaluate the osseointegration performance at the bone/implant interface. The results of the in vitro degradation study demonstrated that degradation of n-CS on the surface of n-CS/PEEK could release Ca and Si ions and form a porous structure. In vivo tests revealed that both n-CS/PEEK and n-HA/PEEK promoted osseointegration at the bone/implant interface compared to PEEK, and n-CS/PEEK exhibited higher bone contact ratio and more new bone formation compared with those of n-HA/PEEK, implying that n-CS/PEEK possessed a stronger ability to promote osseointegration. These two PEEK biocomposites are promising materials for the preparation of orthopedic or craniofacial implants. Keywords: polyetheretherketone, composite, osseointegration, hydroxyapatite, calcium silicate

Dental implanted materials require excellent mechanical properties, biocompatibility as well as integration with bone tissue and gingival tissue to achieve early loading and long-term stability. In this study, cubic shape sodium tantalite (ST) submicro-particles with the size of around 180 nm were synthesized by a hydrothermal method, and ST/polyetheretherketone (PEEK) composites (TPC) with ST content of 20 w% (TPC20) and 40 w% (TPC40) were prepared by melting blend. The results showed that the compressive strength, thermal properties, surface roughness, hydrophilicity and surface energy as well as adsorption of proteins on TPC40 were also significantly enhanced compared with TPC20 and PEEK. Moreover, the responses (adhesion and proliferation as well as differentiation) of rat bone marrow mesenchymal stem cells (rBMSCs), and responses (adhesion, and proliferation) of human gingival epithelial (HGE-1) cells to TPC40 were significantly promoted compared with TPC20 and PEEK. The results demonstrated that ST content in TPC had remarkable effects on the surface properties, which played key roles in stimulating the responses of both rBMSCs and HGE-1 cells. TPC40 with increased surface properties and excellent cytocompatibility might have great potential as an implanted material for dental application.

Absorbable hemostatic agents with a high hemostatic efficacy play an important role in surgical and severely traumatic hemostasis. In the present study, by applying polyelectrolyte assembly, polyelectrolyte complexes (PECs), using carboxymethyl starch (CMS) and chitosan oligosaccharide (COS), with controllable physicochemical properties were prepared and optimized for hemorrhage control. Particle size, zeta potential, morphology and water absorption of the PECs with different CMS/COS ratios were systematically evaluated. The results of in vitro degradation in PBS suggested that CMS/COS PECs were degradable and their degradation rates, which decreased with the increase of the COS content, were suitable for absorbable hemostatic agents. The in vivo hemostatic efficacy of the PECs with 10 wt% COS content (PEC 10), which was evaluated in a rabbit hepatic hemorrhage model, was better than CMS but decreased with the increase of the COS content. The plasma coagulation evaluation revealed that the PECs could significantly activate and accelerate the coagulation cascade through both the intrinsic and extrinsic pathways but could not directly affect the common pathway. CMS/COS PECs also showed antimicrobial activity against S. aureus, which enhanced with the increase of the COS content, but failed against E. coli. Moreover, PEC 10 displayed excellent cytocompatibility with MC3T3-L1 and good tissue compatibility in a rabbit liver model. These findings not only suggest that CMS/COS PECs with a suitable COS content were promising absorbable hemostatic agents for internal use but they are also useful to understand the underlying principles for designing PEC based hemostatic agents.

Homo-crystallization and melting behavior of poly(L-lactic acid) (PLLA) with poly(D-lactic acid) (PDLA) (≤10 wt.%) was studied. The different thermal history had been applied to exert structural variation on stereocomplex (SC). The PLLA/PDLA blend showed different crystallization and melting behavior when cooled from 250°C or 200°C. Double melting peaks were observed after the blend was cooled from 250°C. SC annealing at different temperatures exhibited significant effect for melt-crystallization of PLLA. Influence of initial melting condition before cooling was also investigated. The cold crystallization of amorphous blend initially was studied and some novel results had been observed.

Osseointegration is crucial for early fixation as well as long-term success of orthopedic implants. Bioactive composite containing lithium doping silica nanospheres (LSNs) and poly(dopamine) (PDA) were coated on polyetheretherketone (PK) surface (LPPK), and effects of the LSNs/PDA composite (LPC) coating on the biological properties of LPPK were assessed both in vitro and in vivo. Results showed that LPPK with improved bioactivity remarkably promoted apatite mineralization in simulated body fluid (SBF) compared with PDA coated on PK (PPK) and PK. Moreover, the LPPK remarkably stimulated rat bone marrow stromal cells (rBMSCs) responses compared with PPK and PK. Furthermore, the LPPK significantly promoted bone tissues responses in vivo compared with PPK and PK. It could be suggested that the improvements of cells and bone tissues responses were attributed to the surface characteristics of the bioactive LPC coating on LPPK. The LPPK would be a great candidate for orthopedic and dental applications.

Poly(L-lactide)(PLLA)-based composites have been widely used for tissue regeneration. Novel polyelectrolyte complexes (PECs) consisted of carboxymethyl starch sodium (CMS) and chitosan oligosaccharide (COS) was fabricated and evaluated. The results suggested that the CMS/COS-PECs (CC-PECs) distinguished from the original polymers alone, presenting an amorphous structure. Then, the CC-PECs/PLLA composites were prepared by varying the relative amount of CC-PECs in the PLLA-matrix, demonstrated by means of the surface morphology, hydrophilicity, water uptake, in vitro degradability and primary cell responses. The results suggested that the CC-PECs physically attached on the PLLA surface enhanced the formation of the surface seepage network, which could target modification of the surface biological behavior of the materials. The phenomena had been evidenced by the performed tests in respect to hydrophilicity, water uptake and degradation in PBS, which also may provide effective support for cell adhesion and proliferation. Further, the CC-PECs/PLLA surfaces clearly promoted the adhesion and proliferation of MC3T3-E1 cells compared with PLLA materials, indicating excellent cytocompatibility. This study suggested that the CC-PECs/PLLA-50 composite with excellent biological behavior could be a promising candidate for bone repair.

Zhaoying Wu,1 Quan Li,2 Yongkang Pan,1 Yuan Yao,1 Songchao Tang,1 Jiacan Su,2 Jung-Woog Shin,3 Jie Wei,1 Jun Zhao4,5 1Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, 2Department of Orthopaedics Trauma, Changhai Hospital, Second Military Medical University, Shanghai, People’s Republic of China; 3Department of Biomedical Engineering, Inje University, Gimhae, Republic of Korea; 4Department of Orthodontics, 5Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai, People’s Republic of China Abstract: Bioactive composite macroporous scaffold containing nanoporosity was prepared by incorporation of nanoporous magnesium silicate (NMS) into poly(butylene succinate) (PBSu) using solvent casting–particulate leaching method. The results showed that the water absorption and in vitro degradability of NMS/PBSu composite (NMPC) scaffold significantly improved compared with magnesium silicate (MS)/PBSu composite (MPC) scaffold. In addition, the NMPC scaffold showed improved apatite mineralization ability, indicating better bioactivity, as the NMPC containing nanoporosity could induce more apatite and homogeneous apatite layer on the surfaces than MPC scaffold. The attachment and proliferation of MC3T3-E1 cells on NMPC scaffold increased significantly compared with MPC scaffold, and the alkaline phosphatase (ALP) activity of the cells on NMPC scaffold was expressed at considerably higher levels compared with MPC scaffold. Moreover, NMPC scaffold with nanoporosity not only had large drug loading (vancomycin) but also exhibited drug sustained release. The results suggested that the incorporation of NMS into PBSu could produce bioactive composite scaffold with nanoporosity, which could enhance water absorption, degradability, apatite mineralization and drug sustained release and promote cell responses. Keywords: nanocomposite, degradability, apatite mineralization, cell behaviors, drug release

Polylactide (PLA) and its copolymers have been widely used for bone tissue regeneration. In this study, a bioactive composite of ordered mesoporous calcium–magnesium silicate (m-CMS) and poly( l -lactide) (PLLA) was fabricated by melt blending method. The results indicated that the m-CMS particles were entrapped by polymer phase, and crystallinity of PLLA significantly decreased while the thermal stability of the m-CMS/PLLA composites was not obviously affected by addition of the m-CMS into PLLA. In addition, compared to PLLA, incorporation of the m-CMS into PLLA significantly improved the hydrophilicity, in vitro degradability and bioactivity (apatite-formation ability) of the m-CMS/PLLA composite, which were m-CMS content dependent. Moreover, it was found that incorporation of the m-CMS into PLLA could neutralize the acidic degradation by-products and thus compensated for the decrease of pH value. In cell culture experiments, the results showed that the composite enhanced attachment, proliferation and alkaline phosphatase activity (ALP) of MC3T3-E1 cells, which were m-CMS content dependent. The results indicated that the addition of bioactive materials to PLLA could result in a composite with improved properties of hydrophilicity, degradability, bioactivity and cytocompatibility.

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 15wt% 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.

Poly(lactic-b-4-vinylpyridine) (PDLA-b-P4VP) was first synthesized by atom transfer radical polymerization (ATRP), and then it was introduced into the surface of polylactic acid material through PLLA/PDLA stereocomplexation. After soaking in AgNO3 solution, the antibacterial polylactic acid material surface was obtained. The structures and properties of PDLA-b-P4VP, PLLA/PDLA-b-P4VP and PLLA/PDLA-b-P4VP/Ag were characterized by gel permeation chromatography, magnetic resonance spectroscopy, x-ray diffraction, differential scanning calorimetry, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscope and antibacterial experiment. The results showed that PDLA-b-P4VP block with different chain length were synthesized successfully and compounded on the surface of PLLA material by stereocomplexation, which made the thermal stability of the surface of the PLLA material improved. After soaking in AgNO3 solution, nano-silver was prepared through reducing Ag+ in situ and evenly dispersed on the surface of the PLLA material. After ultrasonic washing, a large amount of nano-silver remains, and the antibacterial rate of the surface of the material against E. coli reaches 100%, which had a strong antibacterial effect.

Effect of the addition of poly(D-lactic acid) (PDLA) as stereocomplex (SC) on crystallization behavior of poly(L-lactic acid) (PLLA) had been systemically investigated. The result indicated that the inclusion of PDLA with higher MW into PLLA exhibited lower t 1/2 and showed accelerated crystallization behavior. Meanwhile, SC formed in blends with higher MW of PDLA exhibited enhanced nucleation activity. In combination with both DSC and WAXD analysis, it was believed that nucleation process was more related to the crystalline size of SC. The result in this study would provide guidance for the application of SC as nucleating agent for the PLA-based products.

l-Lactide-rich poly(l-lactide) (LR-PLLA)/d-lactide-rich poly(d-lactide) (DR-PDLA) blends with moderate optical purity were prepared by conventional extrusion and followed by injection-molding process in this study. Thermal properties, crystalline structure, spherulite morphology, melt degradability, and thermal mechanical property were investigated by means of DSC, WAXD, POM, TG, and DMA. In comparison with LR-PLLA/DR-PDLA blends with higher optical purity, stereocomplex with less perfect structure was partially formed from the LR-PLLA/DR-PDLA blends with various compositions and showed lower melting temperature. Surprisingly, double melting peaks have appeared in blends with 40 or 50 wt% DR-PDLA. Annealing at higher temperature for blends with 50 wt% DR-PDLA resulted in three melting peaks. It is assumed that the optical purity would play a critical role, thus, producing limited amount of stereocomplex with less imperfect structure. Annealing would also induce the micro-phase separation behavior in LR-PLLA/DR-PDLA blends and significantly influence the thermal and degradable properties of blends.

The impact toughness of polycarbonate modified with acrylic core-shell latex particles was investigated. Addition of impact modifiers with size ranging from 115.7 to 231.4 nm can result in maximum impact strength. Equations for spatial distribution of modified particles were proposed to associate the interparticle distance with particle size and modifier volume fraction in terms of two possible morphologies, given by T = d[0.91/(φ)1/3 − 1] or T = d[0.88/(φ)1/3 − 1]. The influence of particle size on brittle-ductile transition was also studied. The results indicated that critical interparticle distance was not a definitive value and had a narrow region. Moreover, there existed a linear relationship between critical interparticle distance and modifier size, that is, critical interparticle distance would enlarge with the increasing of core-shell particle size. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1970–1977, 2010

Mesoporous calcium sulfate-based bone cements (m-CSBC) were prepared by introducing mesoporous magnesium–calcium silicate (m-MCS) with specific surface area (410.9 m² g −1 ) and pore volume (0.8 cm³ g −1 ) into calcium sulfate hemihydrate (CSH). The setting time of the m-CSBC was longer with the increase of m-MCS content while compressive strength decreased. The degradation ratio of m-CSBC increased from 48.6 w% to 63.5 w% with an increase of m-MCS content after soaking in Tris–HCl solution for 84 days. Moreover, the m-CSBC containing m-MCS showed the ability to neutralize the acidic degradation products of calcium sulfate and prevent the pH from dropping. The apatite could be induced on m-CSBC surfaces after soaking in SBF for 7 days, indicating good bioactivity. The effects of the m-CSBC on vitamin D 3 sustained release behaviours were investigated. It was found that the cumulative release ratio of vitamin D 3 from the m-CSBC significantly increased with the increase of m-MCS content after soaking in PBS (pH = 7.4) for 25 days. The m-CSBC markedly improved the cell-positive responses, including the attachment, proliferation and differentiation of MC3T3-E1 cells, suggesting good cytocompatibility. Briefly, m-CSBC with good bioactivity, degradability and cytocompatibility might be an excellent biocement for bone regeneration.

A novel mesoporous magnesium-based cement (MBC) was fabricated by using the mixed powders of magnesium oxide, sodium dihydrogen phosphate, and mesoporous magnesium silicate (m-MS). The results indicate that the setting time and water absorption of the MBC increased as a function of increasing m-MS content, while compressive strength decreased. In addition, the degradability of the MBC in a solution of Tris-HCl and the ability of apatite formation on the MBC were significantly improved with the increase in m-MS content. In cell culture experiments, the results show that the attachment, proliferation, and alkaline phosphatase activity of the MC3T3-E1 cells on the MBC were significantly enhanced with the increase of the content of m-MS. It can be suggested that the MBC with good cytocompatibility could promote the proliferation and differentiation of the MC3T3-E1 cells. In short, our findings indicate that the MBC containing m-MS had promising potential as a new biocement for bone regeneration and repair applications.

Poly(l-lactide) (PLLA)-based biocomposites incorporated with different amounts of chitosan oligosaccharide (COS) were developed through solvent-casting method. Then, the physical–chemical properties, surface morphology, hydrophilicity, water uptake, biodegradability, and biocompatibility of the COS/PLLA composites were investigated. Fourier transform infrared and X-ray diffraction results showed that strong hydrogen-bonding interactions were presented between the COS and PLLA components. Scanning electron microscope and atomic force microscope images revealed that COS physically attached on the PLLA surface enhanced the formation of the surface seepage network, which led to the improvement of the surface biological features. A gradual rise in the level of hydrophilicity, water uptake, and degradation rate in phosphate buffered saline solution were found on increasing COS content in the COS/PLLA composites, which may provide effective support for cell adhesion and proliferation. Further, the results of cell experiments also suggested that the COS/PLLA composites had better cytocompatibility compared with PLLA. Thus, the COS/PLLA composites may have the great potential to be used for soft and bone tissue repair. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45724.

Rui Ma,1 Songchao Tang,2 Honglue Tan,1 Wentao Lin,1 Yugang Wang,1 Jie Wei,2 Liming Zhao,2 Tingting Tang1 1Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 2Key Laboratory for Ultrafine Materials of Ministry of Education and The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China Abstract: A bioactive composite was prepared by incorporating 40 wt% nano-­hydroxyapatite (nHA) into polyetheretherketone (PEEK) through a process of compounding, injection, and molding. The mechanical and surface properties of the nHA/PEEK composite were characterized, and the in vitro osteoblast functions in the composite were investigated. The mechanical properties (elastic modulus and compressive strength) of the nHA/PEEK composite increased significantly, while the tensile strength decreased slightly as compared with PEEK. Further, the addition of nHA into PEEK increased the surface roughness and hydrophilicity of the nHA/PEEK composite. In cell tests, compared with PEEK and ultra-high-molecular-weight polyethylene, it was found that the nHA/PEEK composite could promote the functions of MC3T3-E1 cells, including cell attachment, spreading, proliferation, alkaline phosphatase activity, calcium nodule formation, and expression of osteogenic differentiation-related genes. Incorporation of nHA into PEEK greatly improved the bioperformance of PEEK. The nHA/PEEK composite might be a promising orthopedic implant material. Keywords: polyetheretherketone, nano-hydroxyapatite, biocomposite, osteoblast functions, orthopedic implant material

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.

Xingtao Chen,1 Guoyue Lv,1 Jue Zhang,2 Songchao Tang,2 Yonggang Yan,1 Zhaoying Wu,2 Jiacan Su,2 Jie Wei2 1College of Physical Science and Technology, Sichuan University, Chengdu, 2Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People’s Republic of China Abstract: A multi-(amino acid) copolymer (MAC) based on ω-aminocaproic acid, γ-aminobutyric acid, L-alanine, L-lysine, L-glutamate, and hydroxyproline was synthetized, and MAC microspheres encapsulating bovine serum albumin (BSA) were prepared by a double-emulsion solvent extraction method. The experimental results show that various preparation parameters including surfactant ratio of Tween 80 to Span 80, surfactant concentration, benzyl alcohol in the external water phase, and polymer concentration had obvious effects on the particle size, morphology, and encapsulation efficiency of the BSA-loaded microspheres. The sizes of BSA-loaded microspheres ranged from 60.2 µm to 79.7 µm, showing different degrees of porous structure. The encapsulation efficiency of BSA-loaded microspheres also ranged from 38.8% to 50.8%. BSA release from microspheres showed the classic biphasic profile, which was governed by diffusion and polymer erosion. The initial burst release of BSA from microspheres at the first week followed by constant slow release for the next 7 weeks were observed. BSA-loaded microspheres could degrade gradually in phosphate buffered saline buffer with pH value maintained at around 7.1 during 8 weeks incubation, suggesting that microsphere degradation did not cause a dramatic pH drop in phosphate buffered saline buffer because no acidic degradation products were released from the microspheres. Therefore, the MAC microspheres might have great potential as carriers for protein delivery. Keywords: poly (amino acid) copolymer, release, degradation

Mesoporous magnesium silicate (m-MS) was synthesized, and the in vitro degradability, bioactivity and primary cell responses to m-MS were investigated. The results suggested that the m-MS with mesoporous channels of approximately 5 nm possessed the high specific surface area of 451.0 m(2)/g and a large specific pore volume of 0.41 cm(3)/g compared with magnesium silicate (MS) without mesopores of 75 m2/g and 0.21 cm(3)/g, respectively. The m-MS was able to absorb a large number of water, with water absorption of 74% compared with 26% for MS. The m-MS was also degradable in a Tris-HCI solution, with a weight loss ratio of 40 wt% after a 70-day immersion period. The m-MS exhibited good in vitro bioactivity, inducing apatite formation on its surfaces after soaking in simulated body fluid (SBF) at a faster rate than observed for MS. The m-MS surface clearly promoted the proliferation and differentiation of MC3T3-E1 cells, and their normal cell morphology indicated excellent cytocompatibility. This study suggested that mesoporous magnesium silicate with a high specific surface area and pore volume had suitable degradability and good bioactivity and biocompatibility, making it an excellent candidate biomaterial for the induction of bone regeneration. (C) 2014 Elsevier B.V. All rights reserved.

Mesoporous magnesium silicate (m-MS) and poly(e-caprolactone)–poly(ethylene glycol)–poly(e-caprolactone) (PCL–PEG–PCL) composite scaffolds were fabricated by solvent-casting and particulate leaching method. The results suggested that the incorporation of m-MS into PCL–PEG–PCL could significantly improve the water adsorption of the m-MS/PCL–PEG–PCL composite (m-MPC) scaffolds. The in vitro degradation behavior of m-MPC scaffolds were determined by testing weight loss of the scaffolds after soaking into phosphate buffered saline (PBS), and the result showed that the degradation of m-MPC scaffolds was obviously enhanced by addition of m-MS into PCL–PEG–PCL after soaking for 10 weeks. Proliferation of MG63 cells on m-MPC was significantly higher than MPC scaffolds at 4 and 7 days. ALP activity on the m-MPC was obviously higher than MPC scaffolds at 7 days, revealing that m-MPC could promote cell differentiation. Histological evaluation showed that the introduction of m-MS into PCL–PEG–PCL enhanced the efficiency of new bone formation when the m-MPC scaffolds implanted into bone defect of rabbits. The results suggested that the inorganic/organic composite of m-MS and PCL–PEG–PCL scaffolds exhibited good biocompatibility, degradability and osteogenesis.

Bioactive mesoporous diopside (m-DP) and poly( l -lactide) (PLLA) composite scaffolds with mesoporous/macroporous structure were prepared by the solution-casting and particulate-leaching method. The results demonstrated that the degradability and bioactivity of the mesoporous/macroporous scaffolds were significantly improved by incorporating m-DP into PLLA, and that the improvement was m-DP content-dependent. In addition, the scaffolds containing m-DP showed the ability to neutralize acidic degradation products and prevent the pH from dropping in the solution during the soaking period. Moreover, the scaffolds containing m-DP enhanced attachment, proliferation and alkaline phosphatase activity of MC3T3-E1 cells, which were also m-DP content-dependent. Furthermore, the histological and immunohistochemical analysis results showed that the scaffolds with m-DP significantly promoted new bone formation and improved the materials degraded in vivo , indicating good biocompatibility. The results suggested that the mesoporous/macroporous scaffolds of the m-DP/PLLA composite with osteogenesis had a potential for bone regeneration.

Gangfeng Hu,1,2 Hui Wang,1 Xiaocong Yao,1 Dawei Bi,1 Gang Zhu,1 Songchao Tang,2 Jie Wei,2 Lili Yang,3 Peijian Tong,4 Luwei Xiao4 1The First People’s Hospital of Xiaoshang, Hangzhou, People’s Republic of China; 2Key Laboratory of Ultra-fine Materials, Ministry of Education, East China University of Science and Technology, Shanghai, People’s Republic of China; 3Department of Orthopedic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai, People’s Republic of China; 4Zhejiang Traditional Chinese Medical University, Hangzhou, People’s Republic of China Abstract: Fluorapatite with low solubility is a promising biomaterial due to its structure, which is similar to hydroxyapatite. In this study a bioactive composite of nanofluorapatite (n-FA) and polyamide 12(PA12) was fabricated. The results revealed that the mechanical properties (such as compressive strength and elastic modulus), hydrophilicity, and antibacterial properties of n-FA/PA12composite were obviously improved by adding n-FA into PA12as compared with PA12. In addition, cell proliferation of MC3T3-E1cells cultured on n-FA/PA12composite was significantly higher than with PA12, and alkaline phosphatase activity of MC3T3-E1cells on the n-FA/PA12composite was expressed at obviously higher levels as compared with PA12. The results suggest that n-FA/PA12composite could support cell proliferation and differentiation, showing good cytocompatibility. Histological evaluation indicates that n-FA/PA12composite enhances the efficiency of new bone formation with the introduction of n-FA into PA12, and the quantity of the newly formed bone for n-FA/PA12composite is significantly higher than with PA12. In conclusion, n-FA/PA12composite exhibits good biocompatibility and osteogenesis, which might be used for various orthopedic prostheses and dental implants. Keywords: nanofluorapatite, bioactive composites, cell behavior, orthopedic implants