Additional file 1 of Psoralen synergies with zinc implants to promote bone repair by regulating ZIP4 in rats with bone defect

Supplementary Figure S1. (A) MC3T3-E1 cells were transfected with siRNA-Control or siRNA-ZIP4 for 24 h, and then incubated with cell medium containing excessive Zn2+ (180 µM) or control for 24 h, and cell counting kit-8 (CCK-8) assay was used to detect cell viability. (B) Apoptotic cells were detected using a Terminal dUTP nick-end labeling (TUNEL) assay. (C) The quantification analysis of positive TUNEL cells. Bars represent mean ± S.D. *, p < 0.05; **, p < 0.0

Proliferation and alkaline phosphatase (ALP) activity of osteoblasts.

<p>(A) Osteoblast proliferation on the titanium surfaces after incubation for 1 d, 3 d and 5 d. (B) Alkaline phosphatase activity of osteoblasts on the titanium surfaces after incubation for 3 d, 7 d and 14 d (mean±SD, n = 6; **<i>p</i><0.01, *<i>p</i><0.05).</p

Initial morphologies of the MG-63 osteoblasts on the titanium surface.

<p>(3000X, bar = 10 µm) SEM images of cells on the MAO, UVA-treated and UVC-treated surfaces after (A–C) 1 h and (D–F) 4 h incubation; (400X, bar = 50 µm) Fluorescence microscopy images of cells on the MAO, UVA-treated and UVC-treated surfaces after (G–I) 24 h incubation.</p

SEM images of the titanium surfaces after immersion in SBF.

<p>SEM micrographs of (A, C) UVA-treated and (B, D) UVC-treated surfaces after immersion in SBF for (A, B) one week (3000X, bar = 5 µm) and (C, D) three weeks (500X, bar = 20 µm).</p

Photographic images of H₂O droplets pipetted onto the titanium surfaces.

<p>(A) MAO, (B) UVA-treated and (C) UVC-treated.</p

XRD spectra of the titanium surfaces after immersion in SBF.

<p>(A) one week and (B) three weeks. (a) UVA-treated and (b) UVC-treated.</p

SEM images of the titanium surface used in this study.

<p>(A) MAO titanium surface (3000X) and (B) cross-sectional view (200X).</p

XPS high-resolution spectra of the titanium surfaces after UV treatment.

<p>(Ti 2p, C 1s and O 1s).</p

Albumin adsorption and cell attachment to the surfaces.

<p>(A) The rate of albumin adsorption to the titanium surface after incubation for 2 h, 6 h and 24 h. (B) The rate of osteoblasts attached to the titanium surfaces after 1 h, 2 h and 4 h incubation (mean±SD, n = 6; **<i>p</i><0.01, *<i>p</i><0.05).</p

Osteoblast-Targeting-Peptide Modified Nanoparticle for siRNA/microRNA Delivery

Antiosteoporosis gene-based drug development strategies are presently focused on targeting osteoblasts to either suppress bone loss or increase bone mass. Although siRNA/microRNA-based gene therapy has enormous potential, it is severely limited by the lack of specific cell-targeting delivery systems. We report an osteoblast-targeting peptide (SDSSD) that selectively binds to osteoblasts <i>via</i> periostin. We developed SDSSD-modified polyurethane (PU) nanomicelles encapsulating siRNA/microRNA that delivers drugs to osteoblasts; the data showed that SDSSD–PU could selectively target not only bone-formation surfaces but also osteoblasts without overt toxicity or eliciting an immune response <i>in vivo</i>. We used the SDSSD–PU delivery system to deliver anti-miR-214 to osteoblasts and our results showed increased bone formation, improved bone microarchitecture, and increased bone mass in an ovariectomized osteoporosis mouse model. SDSSD–PU may be a useful osteoblast-targeting small nucleic acid delivery system that could be used as an anabolic strategy to treat osteoblast-induced bone diseases