Argon plasma improves the tissue integration and angiogenesis of subcutaneous implants by modifying surface chemistry and topography

Abstract

BackgroundTissue integration and vessel formation are important criteria for the successful implantation of synthetic biomaterials for subcutaneous implantation.ObjectiveWe report the optimization of plasma surface modification (PSM) using argon (Ar), oxygen (O2) and nitrogen (N2) gases of a polyurethane polymer to enhance tissue integration and angiogenesis.MethodsThe scaffold’s bulk and surface characteristics were compared before and after PSM with either Ar, O2 and N2. The viability and adhesion of human dermal fibroblasts (HDFs) on the modified scaffolds were compared. The formation of extracellular matrix by the HDFs on the modified scaffolds was evaluated. Scaffolds were subcutaneously implanted in a mouse model for 3 months to analyze tissue integration, angiogenesis and capsule formation.ResultsSurface analysis demonstrated that interfacial modification (chemistry, topography and wettability) achieved by PSM is unique and varies according to the gas used. O2 plasma led to extensive changes in interfacial properties, whereas Ar treatment caused moderate changes. N2 plasma caused the least effect on surface chemistry of the polymer. PSM-treated scaffolds significantly (P<0.05) enhanced HDF activity and growth over 21 days. Among all three gases, Ar modification showed the highest protein adsorption. Ar-modified scaffolds also showed a significant upregulation of adhesion-related proteins (vinculin, focal adhesion kinase, talin and paxillin; P<0.05) and extracellular matrix marker genes (collagen type I, fibronectin, laminin and elastin) and deposition of associated proteins by the HDFs. Subcutaneous implantation after 3 months demonstrated the highest tissue integration and angiogenesis and the lowest capsule formation on Ar-modified scaffolds compared with O2- and N2-modified scaffolds.ConclusionPSM using Ar is a cost-effective and efficient method to improve the tissue integration and angiogenesis of subcutaneous implants.

Antibacterial and Antifungal Activities of PMMAs Implanted Fluorine and/or Silver Ions by Plasma-Based Ion Implantation with Argon

“…However, Ar is useful for application to dental materials as the improvement of hydrophobicity affects the antifouling property. Additionally, reports show that plasma ion treatment using Ar gas promotes cell adhesion [ 28 , 29 ]. Therefore, in applying our method to titanium devices, such as orthodontic archwires and implants that could be corroded by the F ion, it was concluded that Ag ion implantation by Ar gas, which does not contain F ions, is the most effective due to its antibacterial effect and ability to promote cell attachment.…”

CD34+CD146+ adipose-derived stromal cells enhance engraftment of transplanted fat

“…To ensure large areas of the fat graft were assessed, tiled (3 × 3) z-stacked (8 μm deep) fluorescent images were taken. To quantify graft vascularization, the percent of pixels positive for CD31 staining was calculated for five representative regions of interest (ROIs) of equal areausing ImageJ software (https://imagej.nih.gov/ij/) following methods previously described [24][25][26][27][28]. A threshold was used to select pixels occupied by blood vessels, represented by CD31 staining, and the image was binarized by converting the blood vessels to white (pixel value 255) and background pixels to black (pixel value 0) to form a "mask" of positive CD31 staining.…”

Current Trends in Fabrication of Biomaterials for Bone and Cartilage Regeneration: Materials Modifications and Biophysical Stimulations

“…The effectiveness of plasma modification highly depends on substrate gas used for the treatment, reactor design, or the type of biomaterial subjected to the modification. In engineering of biomaterials, plasma (recently special attention has been paid to atmospheric pressure plasma) combined with argon, oxygen, air, amonia, or nitrogen gas is most often used for surface modifications of primarily polymeric materials [68,69,70,71]. Kostov et al [72] modified polyethyleneterephthalate, polyethylene (PE), and polypropylene with cold atmospheric plasma jet using argon gas and obtained polymers with increased roughness and wettability.…”