Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: Flowchart of the study design. Briefly, micropores and nanopores were identified in Spongostan, followed by assessment of their capacity for osteoinduction in vitro and bone regeneration in vivo. CLSM, confocal laser scanning microscopy; SEM, scanning electron microscopy; ICC, immunocytochemistry; µCT, micro-computed tomography.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: In Vitro, In Vivo, Confocal Laser Scanning Microscopy, Electron Microscopy, Immunocytochemistry, Micro-CT

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: The collagen sponge Spongostan reveals micropores of 60.66 ± 24.48 µm diameter. ( A – B ) Macro- and light microscopical images of dry Spongostan showing the presence of micropores. ( C – D ) Confocal laser scanning microscopy utilizing the autofluorescence of Spongostan identified micropores of 130.52 ± 42.15 µm diameter in dry Spongostan, while pre-wetted Spongostan showed micropores of 60.66 ± 24.48 µm diameter.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: Confocal Laser Scanning Microscopy

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: Identification of 32.97 ± 1.41 nm pores on the surface of Spongostan. ( A ) The surface of a native collagen type I fibril comprises pores with 31.93 ± 0.97 ± nm size . ( B ) Light micrograph revealing a microstructural cell network of very thin membranes. ( C ) Scanning electron microscopy (SEM) micrograph of the area depicted in (B) showed the corrugated, nanoporous surface of Spongostan. ( D ) Representation of the corrugated surface of Spongostan as a model assuming a close packing of collagen fibers. Structures (1)–(3) observed in (C) are visualized as (1)–(3) in the model. ( E – F ) Analyses by autocorrelating the underlying intensity profile of SEM images resulted in R(K) min (mean size of objects present in the total intensity profile) and R(K) max (mean separation distance between these objects) values, which identify the distinct nanotopography of Spongostan, comprising 32.97 ± 1.41 nm pores. Equation and detailed definitions of R(K) min and R(K) max are included below.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: Electron Microscopy

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: Osteogenic differentiation of human stem cells by the micro- and nanotopography present on Spongostan. ( A ) Adult human inferior turbinate stem cells (ITSCs) and adult human skeletal stem cells (MSCs) showed Alizarin Red S-positive calcium deposition after cultivation in the collagen sponge for up to 28 days, indicating successful osteogenic differentiation. ( B ) Additional exposure of MSCs and ITSCs cultivated in Spongostan to an osteogenic induction medium (OIM) resulted in increased Alizarin Red S-stained calcium deposition. ( C ) Quantification of Alizarin Red staining validated the observed osteoinductive effects of Spongostan, while also revealing an increased osteoinduction of Spongostan and OIM compared to sole Spongostan in MSCs. ( D ) Cell-free Spongostan showed a microstructural network of densly-packed collagen fibers (arrowheads), which form the micropores. ( E ) ITSCs successfully migrated into Spongostan followed by differentiation into Osterix-positive osteoblasts after 21 days (arrows), which were localized directly at the border of the micropores in direct contact with closely packed collagen fibers (arrowheads).

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: Staining

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: The micro- and nanotopography of Spongostan drives regeneration of a critical-size calvarial rat bone defect. ( A ) Schematic depiction of the transplantation strategy. ( B ) Analysis of bone volume demonstrated significantly increased bone regeneration 4 weeks after transplantation of Spongostan compared to sole collagen fibers or untreated control. ( C – E ) Representative micro-computed tomography (µCT) images of rat cranial defects 4 weeks after transplantation revealed a complete closure of the lesion in the Spongostan group, which was only in partially observable after transplantation of collagen fibers and was not observable in the control. ( F ) Histological examination of the newly formed bone using trichrome staining confirmed the increase in bone tissue volume 4 weeks after transplantation of Spongostan in comparison to control and sole collagen fibers. Bright green staining: mineralized bone tissue and collagen; light green staining: calcified cartilage matrix; red staining: osteoid; blue-black staining: nuclei; red-brown staining: cytoplasm; orange staining: erythrocytes.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: Transplantation Assay, Control, Micro-CT, Staining, Comparison

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: A successful masking of micro- and nanopores present on Spongostan using SiO2 nanoparticles. ( A ) Schematic depiction of the coating of Spongostan with 146 nm SiO 2 nanoparticles to mask its micro- and nanotopography. ( B ) Manual coating of Spongostan with 146 nm SiO 2 nanoparticles led to masking of its microporous surface. ( C – D ) Scanning electron microscopy showed the presence of 146 nm SiO 2 nanoparticles as unordered 3D layers on the surface of collagen sponge after nanoparticle coating compared to uncoated Spongostan.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: Electron Microscopy

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: Masking of micro- and nanopores on Spongostan prevents bone regeneration in vivo. ( A ) Schematic depiction of the transplantation strategy. ( B ) Transplantation of nanoparticle-coated Spongostan into critical-size calvarial defects resulted in a significantly reduced bone volume compared to uncoated Spongostan. ( C ) Representative µCT images of rat cranial defects 4 weeks after transplantation showed no signs of closure of the lesion in the group, which received nanoparticle-coated Spongostan.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: In Vivo, Transplantation Assay

Journal: Cells

Article Title: Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography

doi: 10.3390/cells9030654

Figure Lengend Snippet: Bone regeneration by the interplay of micro- and nanotopography present on Spongostan. ( A ) Photographic and schematic illustration of the critical-size calvarial defect in rats. ( B ) Schematic depiction of our present approach, which allows migration of endogenous stem cells and osteogenic progenitor cells into the collagen scaffold microscale architecture, while osteogenic differentiation is further guided by the nanotopography of 30 nm pores. ( C ) Schematic depiction Spongostan coated with thick 3D layers of 146 nm SiO 2 nanoparticles, which blocks migration of stem cells into the Spongostan microstructure, while masking its nanotopography further impairs the osteoinductive capability.

Article Snippet: Light microscopic imaging of dry Spongostan was done using the Keyence VHX microscope (Keyence, Osaka, Japan) without prior embedding.

Techniques: Migration

Journal: Nanomaterials

Article Title: A Biodegradable Flexible Micro/Nano-Structured Porous Hemostatic Dental Sponge

doi: 10.3390/nano12193436

Figure Lengend Snippet: Some marketed hemostatic gelatin-based sponges.

Article Snippet: The produced sponge exhibits a BCI of 10.67 ± 0.004% while the commercial ones show a BCI of 75.19 ± 0.028% for GELITA-SPON and 85.15 ± 0.038% for Spongostan ® , respectively.

Techniques: