One-Step Polymerizations Enable Facile Construction and Structural Optimization of Graft Copolymer Electrolytes

The development of poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) is limited by the semi-crystalline nature of PEO and the extremely strong EO-Li⁺ interactions. To promote the rapid migration of Li⁺, a one-step method combining radical polymerization and ring-opening polymerization catalyzed simultaneously by lithium carboxylate is proposed to construct multi-component graft copolymer electrolytes (GCPEs) in this study. Tailored macroinitiator with catalytic and initiated sites (PAALi(OH-Br)) realizes one-step polymerizations of vinyl monomers and cyclic monomers, and provides GCPEs with poly(ethylene glycol) (PEG) and poly(ε-caprolactone) (PCL) side chains. The grafted structure of GCPE greatly facilitates the intra-chain hopping of Li⁺, resulting in excellent ionic conductivity. The introduction of PCL further improves the t_Li+ of GCPE. The three-component graft copolymer electrolyte constructed by polystyrene (PS), PEO, and PCL exhibits high tensile stress (1.62 MPa), a high ionic conductivity (2.4 × 10⁻⁵ S cm⁻¹, 30 °C), and a high t_Li+ of 0.47 and high electrochemical stability.     

High Ion Conducting Dobule Network Crosslinked Gel Polymer Electrolytes for High-Performance Supercapacitors

As the demand for electrical energy storage devices increases, various electrolytes are being studied. In particular, gel polymer electrolytes (GPEs) with excellent physical properties can improve safety and cycle life, so attempts are underway to replace organic liquid electrolytes facing fire or explosion issues. However, the intrinsic poor electrochemical properties of GPEs limit their commercialization in all-solid-state energy storage devices. In an attempt to solve this problem, epoxy/poly(ethylene glycol) (PEG)-based double network electrolytes (DNEs) containing a mixture of bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) are designed to enhance the electrochemical properties of traditional single network electrolytes (SNEs). The synthesized epoxy/PEG-based DNE has higher mechanical strength (G′ = 1.7 MPa) with outstanding ionic conductivity (σ_DC ≈ 5.8 × 10⁻⁴ S cm⁻¹) at room temperature, compared to the epoxy-based SNE. Then, an all-solid-state supercapacitor based on the DNE and activated carbon electrodes exhibits higher specific capacitance (≈153 F g⁻¹) and power density (833 W kg⁻¹), compared to the SNE-based supercapacitor.     

Solid Polymer Electrolytes from Copolymers Based on Vinyl Dimethyl Phosphonate and Vinylidene Fluoride

Solid polymer electrolytes are prepared by mixing various amounts of lithium bis(trifluoromethanesulfonyl)imide with poly(vinylidene fluoride‐co‐vinyl dimethyl phosphonate) statistical copolymers with different compositions. Such copolymers are obtained by conventional radical copolymerization of vinylidene fluoride (VDF) with vinyl dimethyl phosphonate (VDMP) initiated by peroxides. A morphological study of the obtained solid polymer electrolytes (SPEs) shows that only samples prepared from the copolymer with the lower amount of VDMP (16 mol%) result in the formation of homogeneous electrolytes while aggregates of lithium salts are observed for the other copolymers. The best ionic conductivity values are accordingly observed for the copolymers with the lower VDMP amount and are reaching 5 × 10^?3 mS cm^?1 at 100 °C. The dependence of the ionic conductivity versus temperature suggests that the ionic conductivity is controlled by the motion of polymer segments. Indeed, the ionic conductivity can be increased by adding a small amount of trimethylphosphate plasticizer and can reach 1.9 × 10^?2 mS cm^?1 at 20 °C. Finally, the prepared SPEs exhibit a high electrochemical stability and a good resistance to flame because of the presence of fire‐retardant phosphate groups in their structure.     

Metallopolymers with Ferrocenyl and TEMPO Radical Units and Thermoelectric Properties of their Composites with Single-Wall Carbon Nanotubes

Radical-containing metallopolymers (RCMPs) represent a promising class of thermoelectric (TE) materials. Here, three RCMPs with the ferrocenyl moiety R1 , R2, and R3 are synthesized. Single-walled carbon nanotubes (SWCNTs) are used to form the composites with each of these RCMPs and the morphological, spectroscopic electrochemical, and thermoelectric properties of the three polymer composites are studied. Composite R3 /SWCNT shows the highest electrical conductivity (675.7 ± 36.0 S cm⁻¹) and power factor (174.3 ± 5.5 µW m⁻¹ K⁻²) compared to R1 and R2 . It is shown that when the ferrocenyl unit is incorporated into the main chain of the polymer backbone, it reveals a better TE performance than that with the ferrocenyl unit at the periphery.     

Influence of Anion and Crosslink Density on the Ionic Conductivity of 1,2,3‐Triazolium‐Based Poly(ionic liquid) Polyester Networks

Covalently crosslinked, 1,2,3‐triazolium‐containing poly(ionic liquid) networks are prepared using Michael addition polymerization. Crosslink density and counteranion are varied in order to decipher the relationships between poly(ionic liquid) (PIL) structure and their thermal, mechanical, and conductive properties. An increase in acrylate concentration leads to a higher crosslink density, as reflected by an increase in the differential scanning calorimetry T _g, dynamic mechanical analyzer E ′, and a decrease in the ionic conductivity. Most notable with variable counteranion PILs is that analysis of the ionic conductivity curves reveals a common “crossover” point at ≈85 °C (same acrylate:acetoacetate ratio). Below this crossover temperature, the ionic conductivity appears to be more dependent upon network/polymer chain dynamics. Above 85 °C, the conductivity correlates best with the size of the counteranion. All of the PILs reported here exhibit good ionic conductivities (10⁻⁶ to 10⁻⁸ S cm⁻¹@25 °C, 30% RH), supporting the notion that 1,2,3‐triazolium‐containing PILs represent a vastly underrated electroactive material platform.     

Sodium Alginate Doped with Magnesium Perchlorate as Solid Biopolymer Electrolytes for Energy Storage Applications

This paper deals with development and characterization of the solid biopolymer electrolyte using Sodium alginate as the host biopolymer and magnesium perchlorate used as a doping salt. Membranes are prepared via solution casting technique. Several characterization techniques, such as X-ray and diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, AC impedance spectroscopy, linear sweep voltammetry, and transference number measurement are performed to characterize the prepared biopolymer membrane. The highest ionic conductivity 2.41 × 10⁻³ S cm⁻¹ is observed for prepared solid biopolymer electrolyte contains 40:60 m wt% of NaAlg:Mg(ClO₄)₂. The electrochemical stability of highest ion conducting biopolymer membrane is observed at 3.62 V. A primary magnesium battery is constructed using the highest ionic conducting biopolymer membrane and the open circuit voltage of the fabricated magnesium battery is found to be 2.0 V.     

Effective Enhancement of Thermal Conductivity and Electrical Conductivity with Poly(3,4-ethylenedioxythiophene):Poly(4-styrenesulfonate) through Solvent Treatment

The preparation of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) film is proposed as a simple and industrialized approach. PEDOT:PSS is diluted with deionized water, tetrahydrofuran, dimethyl formamide, and dimethyl sulfoxide before being dry and suction filtered to create a membrane. After treatment with polar organic solvent, the in-plane thermal conductivity of sample is increased from 1.386 to 2.375 Wm⁻¹ K⁻¹. The electrical conductivity increases from 1.8 to 592 S cm⁻¹. The structural modifications of PEDOT:PSS considerably increase the heat conductivity, according to UV, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM) characterization. This modification improves the polymer's thermal conductivity by increasing the contact force between molecules and changing the long chain conformation of polymers.     

Mixed (electronic and ionic) conductive solid polymer matrix, 1. Synthesis and properties of poly(2,5,8,11,14,17,20,23-octaoxapentacosyl methacrylate)-block-poly(4-vinylpyridine)

Poly(2,5,8,11,14,17,20,23-octaoxapentacosyl methacrylate)-block-poly(4-vinylpyridine) semicomb polymers were synthesized using anionic living polymerization techniques. The polymers are white, powdery materials and were characterized by ¹H and ¹³C nuclear magnetic resonance spectroscopy and gel-permeation chromatography. The polymers display monomodal molecular weight distributions which are relatively narrow. The block copolymers show microphase separation as indicated by the presence of two glass transition temperatures (T_g), a soft (oxyethylene) phase T_g is observed between ?60°C and ?45°C and a hard (4-vinylpyridine) phase T_g is observed between 135°C and 150°C. The soft oxyethylene phase has been doped with LiClO₄ to obtain ionic conductors with electrical conductivities around 5 · 10^?6 S · cm^?1 at 25°C and the hard 4-vinylpyridine phase has been complexed with 7,7,8,8-tetracyano-1,4-quinodimethane (TCNQ, 2,5-cyclohexadiene-1,4-diylidenedimalonitrile) to obtain electronic conductivities around 10^?6 S · cm^?1 at 25°C. The mixed (electronic and ionic) conductivities are intermediate between the ionic and electronic conductivities. Higher electronic conductivities (≈ 10^?5 S · cm^?1 at 30°C) are obtained for the polycation TCNQ^?/TCNQ⁰ complexes.     

Synthesis of Crosslinked Microparticles Based on Glycidyl Methacrylate and N-Vinylimidazole

In this study, suspension polymerization technique is used to obtain 3D porous networks based on two monofunctional monomers (glycidyl methacrylate and N-vinylimidazole) and one of the following difunctional monomers known as crosslinking agents: mono-, di-, and triethylene glycol dimethacrylate or divinylbenzene. The influence of various operational parameters like: monomer molar ratio, amount and type of crosslinkers, composition of stabilization system, stirring speed, amount of porogenic agent on the reaction yield, surface morphologies, particle size distribution, and porous characteristics are investigated in order to find the optimal conditions for the synthesis of microparticles possessing the desired properties for further chemical modification. Crosslinked porous microparticles are structurally characterized by Fourier transform inrared  (FTIR) spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis by determination of nitrogen and epoxy groups. The microparticle morphologies as a function of investigated parameters are revealed by scanning electron microscopy, whereas the porous structure is highlighted by mercury porosimetry and dynamic water vapor sorption methods. All the crosslinked networks exhibit porous structures with different surface morphologies and specific surface area values (1.15–48.32 m² g⁻¹) depending on the operational parameters. These microparticles can be considered precursors for the preparation of various functional polymeric materials.     

Counterion Effect of Amine Salts on Ring‐Opening Polymerization of 1,3‐Benzoxazines

The effect of nucleophilicity of counterions of amine HX salts as catalysts on the ring‐opening polymerization (ROP) of 1,3‐benzoxazines is investigated. The significant reduction observed for the ROP temperature is related to the nucleophilicity of counterions and found to show a general trend as I^? > Br^? > Cl^?, as studied by differential scanning calorimetry and Fourier transform infrared spectroscopy. Moreover, the latent character of the amine salts is also demonstrated by tracking the benzoxazine–amine salt mixtures using ¹H NMR spectroscopy. The spectral analysis gives evidences for the dormant nature of the amine HX salts toward benzoxazine at room temperature in solvent. Besides, thermal stabilities of the cured benzoxazine monomers with and without catalysts are investigated by thermogravimetric analysis.     

Topological Effects on Cyclic Co-Poly(ionic liquid)s Self-Assembly

Topological geometry of poly(ionic liquid)s (PILs), such as brush-like, knot-like, hyperbranched and randomly coiled, often exerts a strong influence on their self-assembly behaviors. As a primary topological form, the cyclic topology-derived effects have not been investigated on PILs, which concerns synergy of charges and zero chain end. Herein, linear and cyclic poly(ionic liquid) copolymers (co-PILs) with randomly distributed counter anions of B(Ph)₄⁻ and Br⁻ by a template method in combination with a follow-up partial anion exchange is prepared. The self-assembly phenomena of linear and cyclic co-PILs are studied in selective solvents, where the hydrophobic counter anions B(Ph)₄⁻ and hydrophilic counter anions Br⁻ aggregated to form cores and corona in the assembled nanospheres, showing the average size of cyclic co-PILs nanospheres is 46.2% smaller (≈120 nm) than linear co-PILs nano-assemblies (≈176 nm). Based on the CGMD simulations, the authors speculate that the spherical aggregates are formed by transitioning from micelles with gradient block-like structures, which formed by enriched hydrophobic counter anions in the core and enriched hydrophilic counter anions in the corona. These results indicate a novel synergy of topology effects and dynamic anion movements, as revealed by cyclic co-PIL self-assembly in this work.     

Production of multienzyme by Bacillus aestuarii UE25 using ionic liquid pretreated sugarcane bagasse

The utilization of sugarcane bagasse (SB) in fermentation requires pretreatment processes to render fermentable components available to microorganisms. Pretreatment by using ionic liquids (ILs) is considered promising but the high cost is an impediment in its adoption, therefore, a mixture of IL pretreated and untreated SB was utilized to obtain bacterial multienzyme under solid-state fermentation (SSF). Bacillus aestuarii UE25, a thermophilic strain was utilized for that purpose. Fermentation conditions were optimized by adopting a central composite design. The model showed a good correlation between the predicted and the experimental values for amylase, xylanase, endoglucanase, and β-glucosidase. Volumetric and specific productivity of xylanase (4580 IU ml⁻¹ h⁻¹, 244.25 IU mg⁻¹ substrate, and 50 IU mg⁻¹ protein) were higher than the other enzymes. Changes in lignin content and reduced cellulose crystallinity due to IL pretreatment, followed by fermentation, were visualized by scanning electron microscopy, Fourier transform infrared spectroscopy, and Nuclear magnetic resonance. The strategy adopted by utilizing a mixture of IL pretreated and untreated SB under SSF proved promising to obtain high titers of different enzymes simultaneously. Since the bacterial strain used is thermophilic, therefore, the multienzyme can find its application in commercial processes which are carried out at high temperatures.     

Polymer‐in‐ionic‐liquid electrolytes

In order to achieve high conductivity in a polymer electrolyte, polymer‐in‐ionic‐liquid electrolytes have been explored. It is found in this study that poly[vinylpyrrolidone‐co‐(vinyl acetate)] (P(VP‐c‐VA)) in 1‐ethyl‐3‐methylimidazolium bis(trifluoromethyl sulfonyl) amide (EtMeIm⁺Tf₂N⁻) and poly(N,N‐dimethyl acrylamide) (PDMAA) in trimethyl butyl ammonium bis(trifluoromethane sulfonyl) amide (N₁₁₁₄⁺Tf₂N⁻) produce ion‐conducting liquids and gels. The P(VP‐c‐VA)/ EtMeIm⁺Tf₂N⁻ mixture has a conductivity around 10⁻³ S · cm⁻¹ at 22 °C, for copolymer concentrations up to 30 wt.‐%. Thermal analysis shows that the T_g of the P(VP‐c‐VA)/ EtMeIm⁺Tf₂N⁻ system is well described by the Fox equation as a function of polymer content. Poly(methyl methacrylate) (PMMA)/ EtMeIm⁺Tf₂N⁻ gel electrolytes were prepared by in‐situ polymerisation of the monomer in the ionic liquid. In the presence of 0.5–2.0 wt.‐% of a crosslinking agent, these PMMA‐based electrolytes displayed elastomeric properties and high conductivity (ca. 10⁻³ S · cm⁻¹) at room temperature.

Conductivity versus temperature in crosslinked PMMA/ EtMeIm⁺Tf₂N⁻ gel electrolytes with different concentrations of crosslinking agent.     

Hydrosilylation of Alkynes Under Continuous Flow Using Polyurethane-Based Monolithic Supports with Tailored Mesoporosity

Non-porous polyurethane-based monoliths are prepared under solvent-induced phase separation conditions. They possess low specific surface areas of 0.15 m² g⁻¹, pore volumes of 1 µL g⁻¹, and a non-permanent, solvent-induced microporosity with pore dimensions ≤1 nm. Mesoporosity can be introduced by varying the monomers and solvents. A tuning of the average solubility parameter of the solvent mixture by increasing the macroporogen content results in a decrease in the volume fraction of micropores from 70% to 40% and an increase in the volume fraction of pores in the range of 1.7–9.6 nm from 22% to 41% with only minor changes in the volume fraction of larger mesopores in the range of 9.6–50 nm. The polymeric monoliths are functionalized with quaternary ammonium groups, which allowed for the immobilization of an ionic liquid that contained the ionic Rh-catalyst [1-(pyrid-2-yl)-3-mesityl)-imidazol-2-ylidene))(η⁴-1,5-cyclooctadiene)Rh(I) tetrafluoroborate]. The supported catalyst is used in the hydrosilylation of 1-alkynes with dimethylphenylsilane under continuous flow using methyl-tert-butyl ether as second liquid transport phase. E/Z-selectivity in hydrosilylation is compared to the one of the analogous biphasic reactions. The strong increase in Z-selectivity is attributed to a confinement effect provided by the small mesopores.     

Ion Conduction and Viscoelastic Response of Epoxy‐Based Solid Polymer Electrolytes Containing Solvating Plastic Crystal Plasticizer

To develop a safe electrolyte for lithium‐ion batteries, solid polymer electrolytes (SPEs) are prepared using a commercially available cross‐linkable diglycidyl ether of bisphenol‐A (DGEBA) epoxy resin, a methyl tetrahydrophthalic anhydride (MeTHPA) curing agent, and a plastic crystal‐based electrolyte containing a mixture of succinonitrile (SN) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) by a simple thermal curing process. For the uncured mixture of DGEBA/MeTHPA/SN/LiTFSI, oscillatory and steady shear measurements are conducted to investigate microstructure and processability; the storage modulus (G′) exceeds the loss modulus (G″) at all frequencies studied (solid‐like behavior) and the viscosity decreases with an increase in the shear rate (shear‐thinning behavior), demonstrating that there is a network structure, and the connected structure changes at high shear rates. Fourier transform infrared spectroscopy confirms the physical interactions between Li⁺ of LiTFSI and anhydride group of MeTHPA, which are responsible for the network structure, and helps to rationalize the observed moduli and viscosity. For the cured epoxy‐based SPEs, their ionic conductivities follow the Arrhenius temperature dependence, and increasing SN/LiTFSI electrolyte content leads to higher conductivity and lower activation energy for conduction, resulting in ionic conductivity σ_DC ≈ 2 × 10^?4 S cm^?1 with a shear modulus approaching G′ ≈ 1 MPa at room temperature.     

Solid Polymer Electrolytes Based on Copolymers of Cyclic Carbonate Acrylate and n‐Butylacrylate

Solid polymer electrolytes (SPEs) are prepared by mixing poly(2‐oxo‐1,3‐dioxolan‐4‐yl)methyl acrylate‐random‐n‐butylacrylate) [P(cyCA‐r‐nBA)] statistical copolymers with bis(trifluoromethane)sulfonimide lithium salt. The P(cyCA‐r‐nBA) copolymers are synthesized by reversible addition‐fragmentation chain transfer polymerization and different molar masses as well as copolymer composition are targeted in order to study the influence of the molecular parameters on the thermal, mechanical, and electrochemical properties of the SPEs obtained after mixing the copolymers with lithium salts. In the investigated experimental window, it is shown that the thermal and mechanical properties of the SPEs mainly depend on the composition of the copolymer and are poorly influenced by the molar mass. In sharp contrast, the ionic conductivities are more deeply influenced by the molar mass than by the composition of the copolymers. In this respect ionic conductivity values ranging from 4.2 × 10^?6 S cm^?1 for the lower molar mass sample to 8 × 10^?8 S cm^?1 for the higher molar mass one are measured at room temperature for the investigated SPEs.     

New monomers and photosensitive polymers: the synthesis and polymerization of 2-, 3- and 4-vinylphenyl thiocyanate

The new monomers 2-vinylphenyl thiocyanate ( 6a ), 3-vinylphenyl thiocyanate ( 6b ) and 4-vinylphenyl thiocyanate ( 6c ) were prepared from 2-, 3- and 4-aminoacetophenone ( 1a–c ) as starting materials. The homopolymers ( 7a–c ) and the copolymers 8a–c of the monomers 6a–c with styrene were prepared via free radical polymerization. The polymers, which were obtained as fully soluble and stable materials, were sensitive to UV light. The crosslinking of the polymers 7a–c and 8a–c was investigated under 254 nm UV radiation. From the sensitivity curves of the polymers, gel doses E_g between 2,6 and 95 mJ · cm^?2 were derived.     

Photopolymerization Behavior of Coordinated Ionic Liquids Formed from Organic Monomers with Alkali and Alkaline Earth Metal Bistriflimide Salts

Coordinated ionic liquid (IL) monomers provide many of the benefits of conventional ILs in radical polymerization with the advantage of relatively simple synthesis and recovery of the polymer product. Previous studies have reported high solubilities of lithium bistriflimide in polar organic monomers such as methyl methacrylate (MMA), 1‐vinylimidazole (VIm) and others. Here, coordinated IL monomers are formed comprising a variety of alkali and alkaline earth M^{n +}(Tf₂N⁻)_n salts with MMA and VIm, and polymerization behavior is investigated using real‐time attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT‐IR). The size and valency of the coordinated M^{n +} cations are observed to strongly influence monomer reactivity, as evidenced by significant changes in FT‐IR spectra. This work further demonstrates that the bulky, delocalized [Tf₂N]⁻ anion allows for facile introduction of a wide range of M^{n +} cations into organic polymers without phase separation, which may open opportunities for new composite materials.

     

Solid Polymer Electrolytes, 2. Preparation and Ionic Conductivity of Solid Polymer Electrolytes Based on Segmented Polysiloxane‐Modified Polyurethane

Segmented polyurethanes (PSEU) were synthesized from polydimethylsiloxane diol (PSi) mixed with poly(ethylene glycol) (PEG) in different ratios as soft segment, 4,4′‐diphenylmethane diisocyanate as hard segment, and ethylene glycol as chain extender. FT‐IR, NMR, and thermal analysis were used to characterize the structure and morphology of these copolymers. These copolymers were then swollen in a LiClO₄ /PC liquid electrolyte solution to obtain gel‐like polymer electrolytes. The Li⁺ ions are more effectively adsorbed in the microphase of PEG, however, the existence of polysiloxane significantly improves the property of solvent resistance. Then, impedance spectroscopy was used to investigate the conductivity of these polymers electrolytes as a function of the content of LiClO₄/PC liquid electrolyte. The ionic conductivity of these systems reaches an order of 2.33×10^–3 S·cm^–1 at 80°C and 5.9×10^–4 S·cm^–1 at 25°C, respectively, where the films with the increase of 50 wt.‐% immersed in 1 M LiClO₄ /PC are homogenous and exhibit good mechanical properties. The correlation between the structure and the ion‐conducting behavior of these copolymers was interpreted by the results of DSC in the presence or absence of Li⁺.     

Effects of hydroxyapatite on endothelial network formation in collagen/fibrin composite hydrogels in vitro and in vivo

Co-culture of endothelial cells (EC) and mesenchymal stem cells (MSC) results in robust vascular network formation in constrained 3-D collagen/fibrin (COL/FIB) composite hydrogels. However, the ability to form endothelial networks is lost when such gels are allowed to compact via cell-mediated remodeling. In this study, we created co-cultures of human EC and human MSC in both constrained and unconstrained COL/FIB matrices and systematically added nanoparticulate hydroxyapatite (HA, 0–20 mg ml⁻¹), a bone-like mineral that has been shown to have pro-vasculogenic effects. Constructs cultured for 7 days were assayed for gel compaction, vascular network formation, and mechanical properties. In vitro, robust endothelial network formation was observed in constrained COL/FIB constructs without HA, but this response was significantly inhibited by addition of 5, 10, or 20 mg ml⁻¹ HA. In unconstrained matrices, network formation was abolished in pure COL/FIB constructs but was rescued by 1.25 or 2.5 mg ml⁻¹ HA, while higher levels again inhibited vasculogenesis. HA inhibited gel compaction in a dose-dependent manner, which was not correlated to endothelial network formation. HA affected initial stiffness of the gels, but gel remodeling abrogated this effect. Subcutaneous implantation of COL/FIB with 0, 2.5 or 20 mg ml⁻¹ HA in the mouse resulted in increased perfusion at the implant site, with no significant differences between materials. Histology at day 7 showed both host and human CD31-stained vasculature infiltrating the implants. These findings are relevant to the design of materials and scaffolds for orthopedic tissue engineering, where both vasculogenesis and formation of a mineral phase are required for regeneration.