A novel coating of type IV collagen and hyaluronic acid on stent material-titanium for promoting smooth muscle cell contractile phenotype

• The coatings of type IV collagen (CoIV) and hyaluronic acid (HA) were successfully prepared on titanium.
• Introducing HA can enhance the amount of immobilized CoIV on the titanium (Ti) surface.
• HA inhibits smooth muscle cell (SMC) adhesion while introducing CoIV can improve more SMC adhesion.
• Coatings prepared by the CoIV and HA mixtures of 500 and 200 μg/ml showed better SMC viability.
• Introducing HA can enhance the effect of CoIV on promoting SMC contractile phenotype.

The method of stent implantation is currently considered an effective means of treating atherosclerosis. However, implanting of cardiovascular stent often leads to intimal breakage and hyperplasia. The phenomenon that vascular smooth muscle cells (SMCs) transform from contractile to synthetic phenotype becomes a serious obstacle to intimal recovery. To improve how SMCs transform from a synthetic to contractile phenotype, a technique of coimmobilization was used to form type IV collagen (CoIV) and hyaluronic acid (HA) coating on the widely used stent material, titanium (Ti). In this work, several bio-functional coatings made of CoIV/HA mixtures in different ratios were fabricated on the Ti surface. The quantitative characterization of CoIV showed that introducing HA could enhance the amount of the immobilized CoIV on the alkali activated Ti (TiOH) surface. The immunofluorescence staining results of myosin heavy chain (MHC) and DAPI showed that the coating of CoIV/HA in ratios of 200 μg/ml (M200) and 500 μg/ml (M500) also could promote SMCs expressing more contractile phenotype compared with TiOH/CoIV control samples, while the AO/PI staining results indicated that SMCs on the M200 and M500 samples showed less apoptosis ratio. Thus, we hope that this study can provide more helpful exploration and application for promoting the SMC contractile phenotype on the cardiovascular stents.

Introducing hyaluronic acid (HA) can enhance the effect of type IV collagen (ColIV) on promoting vascular smooth muscle cell (SMC) contractile phenotype on titanium surface (Ti). This available method was anticipated to be potentially applied for vascular implanted stents.Figure optionsDownload as PowerPoint slide