Layer-by-Layer Deposition of Regenerated Silk Fibroin─An Approach to the Surface Coating of Biomedical Implant Materials

TY - JOUR

T1 - Layer-by-Layer Deposition of Regenerated Silk Fibroin─An Approach to the Surface Coating of Biomedical Implant Materials

AU - Fuest, Sandra

AU - Smeets, Ralf

AU - Gosau, Martin

AU - Aavani, Farzaneh

AU - Knipfer, Christian

AU - Grust, Audrey Laure Céline

AU - Kopp, Alexander

AU - Becerikli, Mustafa

AU - Behr, Björn

AU - Matthies, Levi

PY - 2023/12/11

Y1 - 2023/12/11

N2 - Biomaterials and coating techniques unlock major benefits for advanced medical therapies. Here, we explored layer-by-layer (LbL) deposition of silk fibroin (SF) by dip coating to deploy homogeneous films on different materials (titanium, magnesium, and polymers) frequently used for orthopedic and other bone-related implants. Titanium and magnesium specimens underwent preceding plasma electrolytic oxidation (PEO) to increase hydrophilicity. This was determined as surface properties were visualized by scanning electron microscopy and contact angle measurements as well as Fourier transform infrared spectroscopy (FTIR) analysis. Finally, biological in vitro evaluations of hemocompatibility, THP-1 cell culture, and TNF-α assays were conducted. A more hydrophilic surface could be achieved using the PEO surface, and the contact angle for magnesium and titanium showed a reduction from 73 to 18° and from 58 to 17°, respectively. Coating with SF proved successful on all three surfaces, and coating thicknesses of up to 5.14 μm (±SD 0.22 μm) were achieved. Using FTIR analysis, it was shown that the insolubility of the material was achieved by post-treatment with water vapor annealing, although the random coil peak (1640-1649 cm-1) and the α-helix peak (at 1650 cm-1) were still evident. SF did not change hemocompatibility, regardless of the substrate, whereas the PEO-coated materials showed improved hemocompatibility. THP-1 cell culture showed that cells adhered excellently to all of the tested material surfaces. Interestingly, SF coatings induced a significantly higher amount of TNF-α for all materials, indicating an inflammatory response, which plays an important role in a variety of physiological processes, including osteogenesis. LbL coatings of SF are shown to be promising candidates to modulate the body's immune response to implants manufactured from titanium, magnesium, and polymers. They may therefore facilitate future applications for bioactive implant coatings. However, further in vivo studies are needed to confirm the proposed effects on osteogenesis in a physiological environment.

AB - Biomaterials and coating techniques unlock major benefits for advanced medical therapies. Here, we explored layer-by-layer (LbL) deposition of silk fibroin (SF) by dip coating to deploy homogeneous films on different materials (titanium, magnesium, and polymers) frequently used for orthopedic and other bone-related implants. Titanium and magnesium specimens underwent preceding plasma electrolytic oxidation (PEO) to increase hydrophilicity. This was determined as surface properties were visualized by scanning electron microscopy and contact angle measurements as well as Fourier transform infrared spectroscopy (FTIR) analysis. Finally, biological in vitro evaluations of hemocompatibility, THP-1 cell culture, and TNF-α assays were conducted. A more hydrophilic surface could be achieved using the PEO surface, and the contact angle for magnesium and titanium showed a reduction from 73 to 18° and from 58 to 17°, respectively. Coating with SF proved successful on all three surfaces, and coating thicknesses of up to 5.14 μm (±SD 0.22 μm) were achieved. Using FTIR analysis, it was shown that the insolubility of the material was achieved by post-treatment with water vapor annealing, although the random coil peak (1640-1649 cm-1) and the α-helix peak (at 1650 cm-1) were still evident. SF did not change hemocompatibility, regardless of the substrate, whereas the PEO-coated materials showed improved hemocompatibility. THP-1 cell culture showed that cells adhered excellently to all of the tested material surfaces. Interestingly, SF coatings induced a significantly higher amount of TNF-α for all materials, indicating an inflammatory response, which plays an important role in a variety of physiological processes, including osteogenesis. LbL coatings of SF are shown to be promising candidates to modulate the body's immune response to implants manufactured from titanium, magnesium, and polymers. They may therefore facilitate future applications for bioactive implant coatings. However, further in vivo studies are needed to confirm the proposed effects on osteogenesis in a physiological environment.

U2 - 10.1021/acsbiomaterials.3c00852

DO - 10.1021/acsbiomaterials.3c00852

M3 - SCORING: Journal article

C2 - 37983947

VL - 9

SP - 6644

EP - 6657

JO - ACS BIOMATER SCI ENG

JF - ACS BIOMATER SCI ENG

SN - 2373-9878

IS - 12

ER -