Biomaterial implants, such as bone implant and endovascular implant, are widely used in modern medical therapies. However, the biocompatibility of these materials is still far from perfection, which might result in the failure of application and bring huge pain to patients. Note that blood is the first body fluid that contacts any implant and thus blood-material interactions have a strong influence in determining the subsequent biocompatibility of implants, particularly of endovascular implants. It is widely recognized that platelet adhesion/activation is a key event in thrombus development in the process of blood-material interactions. Therefore, manipulating platelet adhesion/activation is critical to improve the biocompatibility of endovascular implants.

Previously, most of...[ Read more ]

Biomaterial implants, such as bone implant and endovascular implant, are widely used in modern medical therapies. However, the biocompatibility of these materials is still far from perfection, which might result in the failure of application and bring huge pain to patients. Note that blood is the first body fluid that contacts any implant and thus blood-material interactions have a strong influence in determining the subsequent biocompatibility of implants, particularly of endovascular implants. It is widely recognized that platelet adhesion/activation is a key event in thrombus development in the process of blood-material interactions. Therefore, manipulating platelet adhesion/activation is critical to improve the biocompatibility of endovascular implants.

Previously, most of the researches were devoted to chemical modification of biomaterial surface to control platelet adhesion/activation, but little work focused on surface topography modification. This research project aims at investigating the correlations between surface patterning and platelet adhesion/activation. Micro-groove and pillar patterns were fabricated on silicon substrate by photolithography and micro-fabrication techniques. Micro-patterned surfaces were coated with titanium oxide (TiO₂) thin film by RF sputtering process. Platelet adhesion and activation on these patterned surfaces were quantified by lactate dehydrogenase (LDH) and P-selectin (GMP-140) assay, respectively. The morphology of adherent platelets was observed by scanning electron microscope (SEM).

Experimental results showed that platelet adhesion and activation displayed a good correlation with surface wettability and surface contact area, which can be manipulated by surface patterning. Lower wettability and larger surface contact area appeared to account for higher levels of platelet adhesion and activation on some specific patterned surfaces. In addition, both the groove and the pillar patterns could enhance platelet adhesion and activation, as compared to flat surface. This study demonstrated that surface topography could be an effective factor to control platelet adhesion/activation besides the surface chemistry. The work will offer valuable guidance for designing new endovascular implants.