JDBM extracts regulated the inflammatory responses of macrophages.

(A) TNF-α expression level in cell treated with different extract concentration with or without LPS (200ng/ml) for 24h by ELISA.RPMI 1640 treatment alone was neg-ctr, RPMI 1640 with LPS treatment was pos-ctr. (B) LDH test for assessment of cell viability of macrophages treated with indicated. #P P < 0.05 vs pos-ctr.</p

In vitro study of the inflammatory cells response to biodegradable Mg-based alloy extract

<div><p>Biodegradable Mg-based alloys have shown great potential as bone fixation devices or vascular stents. As implant biomaterials, the foreign body reaction (FBR) is an important issue to be studied, where the inflammatory cells play a key role. Here, we used two inflammatory cell lines i.e. THP-1 cells and THP-1 macrophages, to evaluate the effect of Mg–Nd–Zn–Zr alloy (denoted as JDBM) extracts on cell viability, death modes, cell cycle, phagocytosis, differentiation, migration and inflammatory response. The results showed that high-concentration extract induced necrosis and complete damage of cell function. For middle-concentration extract, cell apoptosis and partially impaired cell function were observed. TNF-α expression of macrophages was up-regulated by co-culture with extract in 20% concentration, but was down-regulated in the same concentration in the presence of LPS stimulation. Interestingly, the production of TNF-α decreased when macrophages were cultured in middle and high concentration extracts independent of LPS. Cell viability was also negatively affected by magnesium ions in JDBM extracts, which was a potential factor affecting cell function. Our results provide new information about the impact of Mg alloy extracts on phenotype of immune cells and the potential mechanism, which should be taken into account prior to clinical applications.</p></div

The impact of JDBM extracts on the phagocytic function of macrophages.

<p>(A) A representative result of cell phagocytic performance with beads for 4h after induced by JDBM extracts or RPMI 1640 (ctr) for 24h by FACS. (B) Statistical results of FACS. *<i>P</i> < 0.05 vs ctr.</p

The effect of JDBM extracts cell viability of THP-1 cells and macrophages.

CCK-8 test (A andC) and LDH tests (B andD) were assayed at 24h (A andB) and 72h (C andD). (E and F) Cytomorphology change of THP-1 cells and macrophages in the presence of JDBM extracts was observed at 0h and 72h. *P < 0.05 vs ctr. Abbrevations: ctr, control which was culture in RPMI 1640 medium. Scale bar = 100μm.</p

The impact of JDBM extracts on the migration function of macrophages.

<p>(A) A representative result of scratch assay after treated with JDBM extracts or RPMI 1640 (ctr) at 0, 24, 48h, respectively. Scale bar = 100μm. (B) statistical results of scratch assay. ^#<i>P</i> < 0.05 vs 0hr related group*<i>P</i> < 0.05 vs 24hr related group.</p

The physicochemical characteristics of JDBM extract.

<p>The physicochemical characteristics of JDBM extract.</p

The impact JDBM extract on cell cycle of THP-1 cells.

<p>(A) A representative result of cell cycle after treatment of RPMI 1640 medium (Ctr) or JDBM extract for 72h. (B) Statistical results of cell cycle of THP-1 cells in extract culture for 72h. (C) The expression of cell cycle related genes of THP-1 cell treated with indicated for 24h *<i>P</i> < 0.05 vs ctr.</p

The test on death modes of THP-1 cells and macrophages induced by JDBM extract with different concentration or RPMI 1640 medium (Ctr).

<p>(A) A representative result of cell performance in various extract assayed by FACS for 72h. (B and C) Percentage of THP-1 cells and macrophages in different death mode, respectively, which cultured in JDBM extract or ctr for 72h.(D and E) The expression of aptosis-related genes in THP-1 cells and macrophages treated with indicated *<i>P</i> < 0.05 vs ctr.</p

The impact of PMA and JDBM extracts on cell differentiation of THP-1 cells into macrophage.

<p>PMA treatment alone was pos-ctr, PRMI 1640 treatment alone was neg-ctr. (A-C) representative results of FACS test on CD14, CD54 and TLR-2, respectively, after induced by JDBM extract cell differentiation performance in various extract assayed. THP-1 cell without PMA was THP-1 and with PMA was ctr. (D) Statistical results of the expression change on CD14, CD54 and TLR-2 of cell under various extracts. *<i>P</i> < 0.05 vs ctr, ^▲<i>P</i> < 0.05 vs THP-1.</p

Enhanced Adsorption Stability and Biofunction Durability with Phosphonate-Grafted, PEGylated Copolymer on Hydroxyapatite Surface

Nonfouling surfaces are crucial in applications such as biosensors, medical implants, marine coatings, and drug delivery vehicles. However, their long-term coating stability and robust surface binding strength in physiological media remain challenging. Herein, a phosphonate-grafted, PEGylated copolymer on the hydroxyapatite (HA) surface is proposed to significantly improve the adsorption stability and thus enhance the biofunction durability accordingly. The phosphoryl (−PO3) grafted branch is employed in the functional polymer to facilitate attaching to the HA substrate. In addition, the polymer integrates the nonfouling polymer brushes of poly­(ethylene glycol) (PEG) with the cell-adhesive moiety of cyclic Arg-Gly-Asp-d-Phe-Cys peptides (cRGD). A systematic study on the as-synthesized PEGylated graft copolymer indicates a synergistic binding mechanism of the NH2 and PO3 groups to HA, achieving a high surface coverage with desirable adsorption stability. The cRGD/PEGylated copolymers of optimized grafting architecture are proven to effectively adsorb to HA surfaces as a self-assembled copolymer monolayer, showing stability with minimal desorption even in a complex, physiological medium and effectively preventing nonspecific protein adsorption as examined with X-ray photoelectron spectroscopy (XPS) and a quartz crystal microbalance with dissipation (QCM-D). Direct adhesion assays further confirm that the enhanced coating stability and biofunction durability of the phosphonate-grafted, cRGD-PEGylated copolymer can considerably promote osteoblast attachment on HA surfaces, meanwhile preventing microbial adhesion. This research has resulted in a solution of self-assembly polymer structure optimization that exhibits stable nonfouling characteristics