Construction of a Hierarchical Micro-/Submicro-/Nanostructured 3D-Printed Ti6Al4V Surface Feature to Promote Osteogenesis: Involvement of Sema7A through the ITGB1/FAK/ERK Signaling Pathway

Constructing hierarchical hybrid structures is considered a facile method to improve the osseointegration of implants. Herein, a hierarchical micro-/submicro-/nanostructured surface feature of Ti6Al4V implants (3DAT group) was successfully constructed by combining the inherently formed three-dimensional (3D)-printed microscale topography, acid-etched sub-micropits, and anodized nanotubes. Compared with the classical SLA surface, the microscale topography and sub-micropits increased the three-dimensional space for the cell growth and mechanical stability of implants, while the modification of nanotubes dramatically improved the surface hydrophilicity, protein adsorption, and biomineralization. Most importantly, the 3DAT surface feature possessed excellent osteogenic performance in vitro and in vivo, with the involvement of semaphorin 7A (Sema7A) as revealed by RNA-seq through the ITGB1/FAK/ERK signaling pathway. The present study suggested that the hierarchically structured surface design strategy could accelerate the osseointegration rate of 3D-printed Ti6Al4V implants, promising personalized reconstruction of bone defects

Two-Dimensional Borocarbonitride Nanosheet-Engineered Hydrogel as an All-In-One Platform for Melanoma Therapy and Skin Regeneration

The postoperative tumor recurrence and repairing skin defects in clinical melanoma therapy remain challenging. Recent years have seen the development of visible-to-near-infrared (NIR) light for melanoma therapy or tissue regeneration. For solving the integrated issue of melanoma treatment and skin wounds repair, a gentle and efficient strategy is essential to utilize the multifunction of light. Here, we presented a new light-mediation concept and reported a light-responsive intelligent hydrogel system by introducing two-dimensional (2D) borocarbonitride (BCN) nanosheets into the methacrylated hyaluronic acid (HA) matrix (HA@BCN). The hydrogel was skillfully fabricated under the activation of blue light and exhibited excellent biocompatibility, mechanical robustness, and biodegradability, and then, a gentle and powerful multifunction for cutaneous melanoma therapy and wound healing under NIR light irradiation was performed. Based on this result, multifunctional hydrogels could be triggered by NIR light (0.35 W/cm2) for killing tumor cells, at least an 80% mortality rate in 10 min. Subsequently, the HA@BCN hydrogel could release more boron moieties as the growth promoter under moderate NIR light irradiation, which largely accelerated the wound healing. Therefore, our discovery presented a light-mediated and 2D nanomaterial-functionalized versatile hydrogel system for cutaneous melanoma photothermal therapy

Pulse Electrochemical Driven Rapid Layer-by-Layer Assembly of Polydopamine and Hydroxyapatite Nanofilms via Alternative Redox <i>in Situ</i> Synthesis for Bone Regeneration

Polydopamine (PDA) is an important candidate material for the surface modification of biomedical devices because of its good adhesiveness and biocompatibility. However, PDA nanofilms lack osteoinductivity, limiting their applications in bone tissue engineering. Hydroxyapatite nanoparticles (HA-NPs) are the major component of natural bone, which can be used to effectively enhance the osteoinductivity of PDA nanofilms. Herein, we developed a pulse electrochemical driven layer-by-layer (PED-LbL) assembly process to rapidly deposit HA-NPs and PDA (HA-PDA) multilayer nanofilms. In this process, PDA and HA-NPs are <i>in situ</i> synthesized in two sequential oxidative and reductive pulses in each electrochemical deposition cycle and alternately deposited on the substrate surfaces. PDA assists the <i>in situ</i> synthesis of HA-NPs by working as a template, which avoids the noncontrollable HA nucleation and aggregation. The HA-PDA multilayer nanofilms serve as a tunable reservoir to deliver bone morphogenetic protein-2 and exhibit high osteoinductivity both <i>in vitro</i> and <i>in vivo</i>. This PED-LbL assembly process breaks the limitation of traditional LbL assembly, allowing not only the rapid assembly of oppositely charged polyelectrolytes but also the <i>in situ</i> synthesis of organic/inorganic NPs that are uniformly incorporated in the nanofilm. It has broad applications in the preparation of versatile surface coatings on various biomedical devices

Appendix S1 for Drivers of nematode diversity in forest soils across climatic zones

This document includes: Table S1. Composition of dominant tree species for forest sites and number of woody plant species (diameter at breast height greater > 1 cm) in temperate, warm-temperate, and tropical climatic zones. Table S2. Results (F-values and P-values) of one-way ANOVAs or t-tests (t-values and P-values) testing the effects of climatic zone on climate (MAP and MAT) and plant (alpha-, beta- and gamma-diversity of woody plants and GPP) properties. Table S3. Results of linear mixed models testing the effects of climatic zone on soil pH, soil organic carbon, total soil nitrogen, total soil phosphorus (with forest site as random effect, n = 13; and with plot as random effect, n = 39) and nematode alpha-diversity and total nematode biomass (with forest site as random effect, n = 13; and with plot as random effect, n = 39), nematode beta- and gamma-diversity (with forest site as random effect, n = 13). Table S4. The abundance (individuals/100 g dry soil) of nematode genera/families for tropical, warm-temperate, and temperate forest sites. Table S5. Results of linear mixed models testing the effects of climatic zone on abundance, relative abundance (with forest site as random effect, n = 13; and with plot as random effect, n = 39) and the biomass proportion of different nematode trophic groups (with forest site as random effect, n = 13). 2 Table S6. The mean monthly temperature (℃) for the 39 sampling plots in temperate, warm-temperate, and tropical climatic zones. Table S7. The mean monthly precipitation (mm) for the 39 sampling plots in temperate, warm-temperate, and tropical climatic zones

Additional file 1 of In situ construction of flower-like nanostructured calcium silicate bioceramics for enhancing bone regeneration mediated via FAK/p38 signaling pathway

Additional file 1. Additional figures and tables

Mussel-Inspired Adhesive and Tough Hydrogel Based on Nanoclay Confined Dopamine Polymerization

Adhesive hydrogels are attractive biomaterials for various applications, such as electronic skin, wound dressing, and wearable devices. However, fabricating a hydrogel with both adequate adhesiveness and excellent mechanical properties remains a challenge. Inspired by the adhesion mechanism of mussels, we used a two-step process to develop an adhesive and tough polydopamine-clay-polyacrylamide (PDA-clay-PAM) hydrogel. Dopamine was intercalated into clay nanosheets and limitedly oxidized between the layers, resulting in PDA-intercalated clay nanosheets containing free catechol groups. Acrylamide monomers were then added and in situ polymerized to form the hydrogel. Unlike previous single-use adhesive hydrogels, our hydrogel showed repeatable and durable adhesiveness. It adhered directly on human skin without causing an inflammatory response and was easily removed without causing damage. The adhesiveness of this hydrogel was attributed to the presence of enough free catechol groups in the hydrogel, which were created by controlling the oxidation process of the PDA in the confined nanolayers of clay. This mimicked the adhesion mechanism of the mussels, which maintain a high concentration of catechol groups in the confined nanospace of their byssal plaque. The hydrogel also displayed superior toughness, which resulted from nanoreinforcement by clay and PDA-induced cooperative interactions with the hydrogel networks. Moreover, the hydrogel favored cell attachment and proliferation, owning to the high cell affinity of PDA. Rat full-thickness skin defect experiments demonstrated that the hydrogel was an excellent dressing. This free-standing, adhesive, tough, and biocompatible hydrogel may be more convenient for surgical applications than adhesives that involve in situ gelation and extra agents

Mussel-Inspired Adhesive and Tough Hydrogel Based on Nanoclay Confined Dopamine Polymerization

Adhesive hydrogels are attractive biomaterials for various applications, such as electronic skin, wound dressing, and wearable devices. However, fabricating a hydrogel with both adequate adhesiveness and excellent mechanical properties remains a challenge. Inspired by the adhesion mechanism of mussels, we used a two-step process to develop an adhesive and tough polydopamine-clay-polyacrylamide (PDA-clay-PAM) hydrogel. Dopamine was intercalated into clay nanosheets and limitedly oxidized between the layers, resulting in PDA-intercalated clay nanosheets containing free catechol groups. Acrylamide monomers were then added and <i>in situ</i> polymerized to form the hydrogel. Unlike previous single-use adhesive hydrogels, our hydrogel showed repeatable and durable adhesiveness. It adhered directly on human skin without causing an inflammatory response and was easily removed without causing damage. The adhesiveness of this hydrogel was attributed to the presence of enough free catechol groups in the hydrogel, which were created by controlling the oxidation process of the PDA in the confined nanolayers of clay. This mimicked the adhesion mechanism of the mussels, which maintain a high concentration of catechol groups in the confined nanospace of their byssal plaque. The hydrogel also displayed superior toughness, which resulted from nanoreinforcement by clay and PDA-induced cooperative interactions with the hydrogel networks. Moreover, the hydrogel favored cell attachment and proliferation, owning to the high cell affinity of PDA. Rat full-thickness skin defect experiments demonstrated that the hydrogel was an excellent dressing. This free-standing, adhesive, tough, and biocompatible hydrogel may be more convenient for surgical applications than adhesives that involve <i>in situ</i> gelation and extra agents

Mussel-Inspired Adhesive and Tough Hydrogel Based on Nanoclay Confined Dopamine Polymerization

Adhesive hydrogels are attractive biomaterials for various applications, such as electronic skin, wound dressing, and wearable devices. However, fabricating a hydrogel with both adequate adhesiveness and excellent mechanical properties remains a challenge. Inspired by the adhesion mechanism of mussels, we used a two-step process to develop an adhesive and tough polydopamine-clay-polyacrylamide (PDA-clay-PAM) hydrogel. Dopamine was intercalated into clay nanosheets and limitedly oxidized between the layers, resulting in PDA-intercalated clay nanosheets containing free catechol groups. Acrylamide monomers were then added and in situ polymerized to form the hydrogel. Unlike previous single-use adhesive hydrogels, our hydrogel showed repeatable and durable adhesiveness. It adhered directly on human skin without causing an inflammatory response and was easily removed without causing damage. The adhesiveness of this hydrogel was attributed to the presence of enough free catechol groups in the hydrogel, which were created by controlling the oxidation process of the PDA in the confined nanolayers of clay. This mimicked the adhesion mechanism of the mussels, which maintain a high concentration of catechol groups in the confined nanospace of their byssal plaque. The hydrogel also displayed superior toughness, which resulted from nanoreinforcement by clay and PDA-induced cooperative interactions with the hydrogel networks. Moreover, the hydrogel favored cell attachment and proliferation, owning to the high cell affinity of PDA. Rat full-thickness skin defect experiments demonstrated that the hydrogel was an excellent dressing. This free-standing, adhesive, tough, and biocompatible hydrogel may be more convenient for surgical applications than adhesives that involve in situ gelation and extra agents