Remotely Temporal Scheduled Macrophage Phenotypic Transition Enables Optimized Immunomodulatory Bone Regeneration.

Precise timing of macrophage polarization plays a pivotal role in immunomodulation of tissue regeneration, yet most studies mainly focus on M2 macrophages for their anti-inflammatory and regenerative effects while the essential proinflammatory role of the M1 phenotype on the early inflammation stage is largely underestimated. Herein, a superparamagnetic hydrogel capable of timely controlling macrophage polarization is constructed by grafting superparamagnetic nanoparticles on collagen nanofibers. The magnetic responsive hydrogel network enables efficient polarization of encapsulated macrophage to the M2 phenotype through the podosome/Rho/ROCK mechanical pathway in response to static magnetic field (MF) as needed.

Anisotropic magneto-mechanical stimulation on collagen coatings to accelerate osteogenesis.

Mechanical stimulation has been considered to be critical to cellular response and tissue regeneration. However, harnessing the direction of mechanical stimulation during osteogenesis still remains a challenge. In this study, we designed a series of novel magnetized collagen coatings (MCCs) (randomly or parallel-oriented collagen fibers) to exert the anisotropic mechanical stimulation using oriented magnetic actuation during osteogenesis.

Periodic-Mechanical-Stimulus Enhanced Osteogenic Differentiation of Mesenchymal Stem Cells on FeO/Mineralized Collagen Coatings.

Mechanical stimulus has been demonstrated to be critical to stem cell fate commitment and tissue repair. However, it still remains a challenge to remote control of the mechanical stimulus acting on cells. Here, we designed a magnetic FeO/mineralized collagen coating on titanium substrate to regulate the osteogenic differentiation of mesenchymal stem cells (MSCs).

Graphene/Si-Promoted Osteogenic Differentiation of BMSCs through Light Illumination.

Graphene (Gr) presents promising applications in regulating the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Light illumination is regarded as a spatiotemporally controllable, easily applicable, and noninvasive mean to modulate material responses. Herein, Gr-transferred silicon (Gr/Si) with a Schottky junction is utilized to evaluate the visible-light-promoted osteogenic differentiation of BMSCs.

Insights into the Osteogenic Differentiation of Mesenchymal Stem Cells on Crystalline and Vitreous Silica.

Cell responses to oxide biomaterials depend on the protein adsorption behavior of the biomaterial surface. Thus, the inherent properties of oxide biomaterial surfaces play a key role in this process. However, commonly used biomaterials, such as calcium phosphate and titanium dioxide, have surfaces with strong mineralization, which may interfere with the ability to clarify the key aspects of the oxide biomaterial regarding protein adsorption and cellular processes.

Comprehensive Evaluation of Surface Potential Characteristics on Mesenchymal Stem Cells' Osteogenic Differentiation.

The surface electric potential of biomaterials has been extensively proven to play a critical role in stem cells' fate. However, there are ambiguous reports on the relation of stem cells' osteogenic capacity to surface potential characteristics (potential polarity and intensity). To address this, we adopted a surface with a wide potential range and both positive/negative polarity in a comprehensive view to get insight into surface potential-regulating cellular osteogenic differentiation.

Magnetically Assisted Electrodeposition of Aligned Collagen Coatings.

Well-aligned collagen nanofibers are crucial in engineering bioinspired regenerative strategies, such as bone, muscle and cornea. However, keeping the natural bioactive of collagen and controlling its orientation in a coating still remain a challenge. Here we present a novel magnetically assisted electrochemical technique to deposit type-I collagen nanofibers with high alignment onto titanium.

Magnetically actuated mechanical stimuli on FeO/mineralized collagen coatings to enhance osteogenic differentiation of the MC3T3-E1 cells.

Unlabelled: Mechanical stimuli at the bone-implant interface are considered to activate the mechanotransduction pathway of the cell to improve the initial osseointegration establishment and to guarantee clinical success of the implant. However, control of the mechanical stimuli at the bone-implant interface still remains a challenge. In this study, we have designed a strategy of a magnetically responsive coating on which the mechanical stimuli is controlled because of coating deformation under static magnetic field (SMF).

Harnessing Cell Dynamic Responses on Magnetoelectric Nanocomposite Films to Promote Osteogenic Differentiation.

The binding of cell integrins to proteins adsorbed on the material surface is a highly dynamic process critical for guiding cellular responses. However, temporal dynamic regulation of adsorbed proteins to meet the spatial conformation requirement of integrins for a certain cellular response remains a great challenge. Here, an active CoFeO/poly(vinylidene fluoride-trifluoroethylene) nanocomposite film, which was demonstrated to be an obvious surface potential variation (Δ V ≈ 93 mV) in response to the applied magnetic field intensity (0-3000 Oe), was designed to harness the dynamic binding of integrin-adsorbed proteins by in situ controlling of the conformation of adsorbed proteins.

Controlled Release of Naringin in Metal-Organic Framework-Loaded Mineralized Collagen Coating to Simultaneously Enhance Osseointegration and Antibacterial Activity.

Two important goals in orthopedic implant research are to promote osseointegration and prevent infection. However, much previous effort has been focused on the design of coatings to either enhance osseointegration while ignoring antibacterial activity or vice versa, to prevent infection while ignoring bone integration. Here, we designed a multifunctional mineralized collagen coating on titanium with the aid of metal-organic framework (MOF) nanocrystals to control the release of naringin, a Chinese herbal medicine that could promote osseointegration and prevent bacterial infection.

Chromium removal using resin supported nanoscale zero-valent iron.

Resin supported nanoscale zero-valent iron (R-nZVI) was synthesized by the borohydride reduction method. Batch experiments were conducted to evaluate the factors affecting Cr(VI) removal. It was found that nZVI loads, resin dose, pH value and initial concentration of Cr(VI) were all important factors.