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Titanium (Ti) oral implants, as foreign bodies, can easily trigger an inflammatory response, and the metal ions/nanoparticles released by friction/corrosion in the body can also damage soft and hard tissues, leading to implant failure. To make up for deficiencies, a multifunctional composite coating composed of silica (SiO 2) particles and zirconium hydrogen phosphate (ZrP) on the surface of Ti was prepared by combining micro-arc oxidation (MAO) and sol-gel technology. The characterization results of the surface physicochemical properties confirmed that a series of SiO 2 /ZrP-modified MAO coatings were successfully constructed. Compared with the control group, the doping of SiO 2 particles effectively improved the friction resistance of the surface MAO coating, but worsened its corrosion resistance. After the surface was further covered with ZrP coating, the corrosion resistance defect caused by SiO 2 particles was eliminated. With the increase of the ZrP thickness, the friction resistance of the target sample increased gradually. In addition, the specimens coated by ZrP coatings also presented better anti-inflammatory and osteogenic capabilities than the samples subjected to pure/SiO 2 -doped MAO treatment. Based on these advantageous properties, this novel composite coating may project good application prospects in promoting early osseointegration. • Combined application of SiO 2 particle and ZrP coating to modify Ti for the first time. • ZrP coating further enhanced the friction resistance of the SiO 2 -doped MAO coating. • The corrosion defect caused by SiO 2 particles can be eliminate by ZrP coating. • SiO 2 and ZrP synergistically improve the osteoinductive ability of MAO coating. • ZrP coatings significantly reduce the early immune rejection of MAO-treated titanium. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel multiple cross-linked PVA nanocomposite (MPAU) was constructed. • Incorporation of SiO 2 provides physical cross-linking domains. • PVA, TBPU and BGT generate chemical-coordination domains. • MPAU show excellent mechanical strength (58.9 MPa) and toughness (79.5 MJ/m3). Materials based on fiber-reinforced coating have gained increasing attention due to their environmental and industrial application tracks. Polyvinyl alcohol (PVA) composites with interpenetrating cross-linked structures and abundant functional groups exhibit obvious advantages for high-performance coating. In this work, PVA multiple cross-linked network nanocomposites (MPAUs) were established using silica nanoparticles as reinforcing fillers, ingeniously synthesized boronic esters (BGTs) and blocked-diisocyanate polyurethanes (TBPUs) as cross-linkers. Briefly, SiO 2 nanoparticles were evenly dispersed into PVA matrix to fabricate primary physical cross-linked network, which could promote subsequent cross-linking and esterification effects. After deblocking, TBPU molecules were grafted onto PVA chains via radical polymerization. Meanwhile, the borate ions B(OH) 4 − generated by the multi-stage ionization of BGT were re-coordinated with the hydroxyl groups of PVA matrix. These two effects further afforded secondary chemical cross-linking networks and coordination cross-linked domains. The mechanical and microstructural properties of MPAUs were assessed with respect to their cross-link density and multiple cross-linked network structure. Of note, the formation of multiple-cross-linking network enabled MPAU films with substantial enhancements in mechanical strength and toughness, reaching to 58.9 MPa and 79.5 MJ/m3, respectively. The results of application studies indicated that the obtained MPAUs could integrate with cellulose paper to accomplish excellent physical strength and surface properties. In conclusion, this work paves the way to fabricate multifunctional nanocomposites, which enriches the commercial value of versatile paper-based materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel multiple cross-linked PVA nanocomposite (MPAU) was constructed. • Incorporation of SiO 2 provides physical cross-linking domains. • PVA, TBPU and BGT generate chemical-coordination domains. • MPAU show excellent mechanical strength (58.9 MPa) and toughness (79.5 MJ/m3). Materials based on fiber-reinforced coating have gained increasing attention due to their environmental and industrial application tracks. Polyvinyl alcohol (PVA) composites with interpenetrating cross-linked structures and abundant functional groups exhibit obvious advantages for high-performance coating. In this work, PVA multiple cross-linked network nanocomposites (MPAUs) were established using silica nanoparticles as reinforcing fillers, ingeniously synthesized boronic esters (BGTs) and blocked-diisocyanate polyurethanes (TBPUs) as cross-linkers. Briefly, SiO 2 nanoparticles were evenly dispersed into PVA matrix to fabricate primary physical cross-linked network, which could promote subsequent cross-linking and esterification effects. After deblocking, TBPU molecules were grafted onto PVA chains via radical polymerization. Meanwhile, the borate ions B(OH) 4 − generated by the multi-stage ionization of BGT were re-coordinated with the hydroxyl groups of PVA matrix. These two effects further afforded secondary chemical cross-linking networks and coordination cross-linked domains. The mechanical and microstructural properties of MPAUs were assessed with respect to their cross-link density and multiple cross-linked network structure. Of note, the formation of multiple-cross-linking network enabled MPAU films with substantial enhancements in mechanical strength and toughness, reaching to 58.9 MPa and 79.5 MJ/m3, respectively. The results of application studies indicated that the obtained MPAUs could integrate with cellulose paper to accomplish excellent physical strength and surface properties. In conclusion, this work paves the way to fabricate multifunctional nanocomposites, which enriches the commercial value of versatile paper-based materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple process was employed for synthesizing stable lipid-polymer hybrid nanoparticles. • Bone-targeting oligopeptides modified nanoparticles showed bone affinity in vitro and in vivo. • The nanoparticles show a potential in the treatment of osteoporosis. The lack of safety, efficacy, and specificity has made the delivery of anti-osteoporotic drugs at a proper dose a challenge. In our study, cathepsin K inhibitor loaded poly (D, L-lactide-co-glycolide) derived lipid hybrid nanoparticles (DNPs) were modified with bone-specific polyaspartic acid [(Asp) 8 -DNPs] to treat osteoporosis. (Asp) 8 -DNPs showed its hydroxyapatite binding affinity and achieved a sustained release of cathepsin K inhibitor for up to 5 days. Cathepsin K inhibitor loaded (Asp) 8 -DNPs significantly decreased the tartrate-resistant acid phosphatase (TRAP) activity and resorption-related genes in osteoclasts. Animal studies also exhibited high accumulation of (Asp) 8 -DNPs in the tibia and femur and a greater bone mass in trabecular bone and better organized three-dimensional architecture in osteoporotic rat models. Herein, the bone targeting drug delivery system show its potential in treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Introduce the end-blocked structure into the water-based functional polyurethane segments applied as a "latent cross-linker" for surface sizing, • A novel compound sizing system containing water-based blocked polyurethane and polyvinyl alcohol, • Chemical bonding and hydrogen bonding between highly active isocyanate groups and paper fiber after unblocking, • Application of water-based blocked polyurethane in surface sizing of special paper. Efficient improvement of paper strength while optimized sizing technique remains challenging and fascinating since specialty paper are required to low-cost, high printing quality and environmental sustainability. Herein, a novel controlled reactivity polyester glycol-based cross-linker (TBPU) applied in paper surface sizing was exploited by simple two-steps polymerization and blending process. An end-blocked structure design strategy of containing densely distributed multiple soft segments and active hydrogen nucleophilic segments (Butanone oxime, MEKO as end closure units) in isocyanate dispersion was achieved to address the scarcity of mechanical properties and the inconvenient in surface-sizing progress. TBPU can block the NCO groups in IPDI segments at 60 °C, and NCO groups can be deblocked at the temperature higher than 110 °C, which endow TBPU with latent cross-linking property. Afterward, we took advantage of the structural feature of polyhydroxy compounds and the adhesion to cellulose via using polyvinyl alcohol (PVA) as a blending component to form TBPU/PVA emulsion. The organization of NCO groups react with hydroxyl groups, carbamate groups cross-linked with hydrogen bonds, and crystallized PCL segments generates phase-separated hierarchical domains. Serving as high-reactivity paper-sizing fillers capable of cross-linking and disintegration under an external change of temperature, the hierarchical domains can strengthen the specialty papers and enhance their water resistance and ink adhesion. The influences of TBPU content, PVA content and NCO/ OH molar ratio on the physicochemical properties of the resultant emulsions and sized paper have been investigated. As a result, the paper sized with TBPU-1.6/PVA emulsion exhibit a tensile index of ≈107.19 Nm/g, a tearing index of ≈11.79 m N • m2/g, a folding resistance of ≈4511 s, an optimum blending temperature of 70 °C and exceptional cooperation ratio with PVA and TBPU (4.0 wt%, 3.0 wt%), which are 1.649 times, 1.966 times, and 2.652 times than those of untreated papers (65 Nm/g, 6 m N • m2/g, 1701 s). Furthermore, sizing liquid can be conveniently applied and recycled due to their excellent environmental friendliness and Biodegradability, this work provides a promising solution for optimizing surface sizing technology. [ABSTRACT FROM AUTHOR]

• β-estradiol (E2) condensed with Ca2+ precursors to form bioresponsive nanocores. • MC3T3-E1 cell membranes expressing azide groups are used for nanocore coating. • The cell membrane coating is functionalized by alendronate for bone targeting. • The nanoparticles restore bone homeostasis for osteoporosis treatment. Osteoporosis is a common bone disease characterized by the systemic disruption of hone homeostasis, where the imbalance between bone resorption and formation causes deterioration of bone structure and bone mass loss. Targeted restoration of bone hemostasis has thus become a promising strategy for osteoporosis treatment. For this purpose, we report a bone-targeted nanoformulation based on CaCO 3 nanomaterials, which could be activated in the acidic osteoporotic microenvironment and cooperatively regulate the activity of osteoclasts and osteoblasts to reverse bone deterioration. Herein, a clinical antiosteoporosis drug β-estradiol (E2) is first biomineralized using CaCO 3 to form physiologically stable nanocores. Meanwhile, azido groups are introduced onto MC3T3-E1 cells through incubation with AC 4 ManNAz. The azido-tagged MC3T3-E1 cell membranes are extracted for the camouflaging of the CaCO 3 @E2 nanocores to enhance their in vivo stability and availability, while also enabling the surface modification of bone-targeting dibenzocyclooctyne-tagged alendronate moieties via copper-free click reaction. After the selective deposition into acidic osteoporotic bone tissues, the CaCO 3 @E2 cores would be spontaneously degraded to release E2 and Ca2+ ions, which would systematically inhibit the activity of osteoclasts while promoting osteoblast-mediated new bone formation, eventually ameliorating the osteoporosis symptoms. This study offers an effective approach for osteoporosis treatment in the clinics. [ABSTRACT FROM AUTHOR]

Cross-linked polyvinyl alcohol (AZ-CIPVA) for effective paper sizing was prepared by using N-(isobutoxymethyl)acrylamide (IBMA) and aziridine cross-linker (AZ) as modifiers. The structure and the performances of the AZ-CIPVA with different dosage of AZ were characterized. The enhancing mechanism of paper sized by AZ-CIPVA was clarified. The results show that cross-linking structure is formed by the reaction between AZ and carboxyl groups in CIPVA molecules. With the increase of AZ content, the gel content, cross-linking density and thermal stability of the AZ-CIPVA film are increased. When the AZ dosage is 3.5%, both tensile strength and modulus of AZ-CIPVA film reach maximum, and the value are 68.34 MPa and 1037.02 MPa, respectively. The water absorption of the film reaches minimum and the folding endurance of the sizing paper reaches maximum when the content of AZ is 2.8%. When applied to the surface of the paper, the maximum dry and wet tensile indexes of the paper are increased by 223.77% and 432.56%, respectively. Roughness of the sizing paper increases slightly and the surface becomes uneven. The micro-structure shows that larger pores between the paper fibers are filled and cross-linked after sizing, which is beneficial to improve the mechanical strength of paper. • A series of cross-linked polyvinyl alcohol (AZ-CIPVA) modified by IBMA and AZ are successfully prepared. • The increasing of AZ can improve the degree of cross-linking and comprehensive performance of both AZ-CIPVA film and sizing paper. • The enhancing mechanism of paper by AZ-CIPVA is proposed. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S) has been as an essential gasotransmitter and a potential therapeutic approach for several biomedical treatments such as cardiovascular disorders, hypertension, and other diseases. The endogenous and exogenous H 2 S also plays a crucial role in the bone anabolic process and a protective mechanism in cell signalling. In this study, we have utilized two types of polymers, polycaprolactone (PCL) and gelatin (Gel), for the fabrication of JK-2 (H 2 S donor) loaded nanofibrous scaffold via electrospinning process for bone healing and bone tissue engineering. Comparing the PCL/Gel and PCL/Gel-JK-2 scaffolds, the latter demonstrated enhanced cell adhesion and proliferation capabilities. Furthermore, both experimental scaffolds have been subjected to an in vivo experiment for 4 and 8 weeks in a bone-defect model of a rabbit to determine their biological responses under physiological conditions. There was an obvious increase in bone regeneration in the PCL/Gel-JK-2 group compared to the control and PCL/Gel groups. These results indicate the use of PCL/Gel scaffolds loaded with JK-2 should be considered for possible bone regeneration. Scheme of PCL/Gel-JK-2 fabrication and use for improving the bone formation in vitro and in vivo. [Display omitted] • JK-2, a novel donor of H 2 S, is used to prepare electrospun fibers for the first time. • PCL/Gel-JK-2 shows the best osteoinductive ability in vitro by releasing H 2 S slowly. • PCL/Gel-JK-2 nanofibers effectively enhance the regeneration of skull defect in vivo. [ABSTRACT FROM AUTHOR]

Schematic illustration of the PCL/Gel membrane prepared by co-electrospinning technique for bone tissue engineering. PCL was utilized to provide sufficient mechanical strength for enhancing overall integrity of the membranes. These co-electrospun membranes could slow-release hydrophobic drugs (loading in PCL nanofibers) and controlled-release hydrophilic drugs (loading in Gel nanofibers). In addition, the combination of the natural polymers could enhance the biocompatibility of these membranes and perform their respective functions in the bone healing process. [Display omitted] • PCL and Gel synergistically provide the mechanical properties and bioactivity. • Co-electrospun membrane can slowly release both hydrophilic and hydrophobic drugs. • Regulating PCL content can result in a time-tunable release of hydrophilic drugs. • PCL controls drug release by inhibiting the dissolution/diffusion of Gel fibers. The rising popularity of co-electrospinning technique in the field of biomaterial has enabled the possibility of combining various polymers, in which they provide the mechanical properties and the bioactivity for each other. Herein, a series of polycaprolactone/gelatin (PCL/Gel) composite membranes were prepared by co-electrospinning, and their biocompatibility and drug-controlled release ability were evaluated in detail for the first time. The addition of Gel significantly enhanced the adhesion and differentiation of osteoblasts, while the addition of PCL significantly improved the mechanical properties. Moreover, the in vitro degradation and drug release results showed that by adjust the PCL fibers amount and size, the degradation of Gel and the release profile of hydrophilic drugs/proteins could be effectively controlled: in the low PCL groups (PCL/Gel-1 & PCL/Gel-4), the Gel nano-fibers dissolved rapidly, resulting in an early explosive release within 1 week; however, with the increase of PCL content, the drug release rate decreased gradually, and the total release period could be extended to over 2 weeks (PCL/Gel-2, PCL/Gel-3 & PCL/Gel-5) or more (PCL/Gel-6). Therefore, the preparation of a controllable drug delivery system with good biological activity by co-electrospinning of PCL and Gel could provide an effective strategy for bone regeneration. [ABSTRACT FROM AUTHOR]