Blood compatibility of polypropylene surfaces in relation to the crystalline-amorphous microstructure

Abstract

Blood-contacting properties of polypropylene surfaces with different crystalline states at the surface layer were examined in terms of plasma protein adsorption and changes in cytoplasmic free Ca2+ levels in platelets. Though the wettability of polypropylene surfaces was almost constantly independent from the surface layer crystallinity and interlamellar spacing, an increase in adhesiveness was observed with decreasing surface layer crystallinity and interlamellar spacing. It is suggested that the surface properties of the sheets varied in relation to the crystalline-amorphous microstructure. Minimum magnitudes in albumin and fibrinogen adsorption were observed on the polypropylene surface with a particular surface layer crystallinity (c. 55 wt%). A decrease in interlamellar spacing resulted in enhancing albumin adsorption and diminishing fibrinogen adsorption. Transient phenomena in plasma protein adsorption were observed on their surfaces with a plasma concentration. It is considered that the polypropylene surface with a particular crystalline-amorphous microstructure reduces the denaturation of adsorbed proteins. An increase in cytoplasmic free Ca2+ levels in platelets was prevented at the polypropylene surface with a surface layer crystallinity of 55 wt%: the particular crystalline-amorphous microstructure of such apolar surfaces as polypropylenes acts to reduce platelet activation. Thus, it is concluded that the blood compatibility of polypropylene surfaces is greatly improved by controlling a crystalline-amorphous microstructure at the surface layer.

Physical and mechanical properties of poly(L‐lactic acid) nucleated by dibenzoylhydrazide compound

“…15,16,[24][25][26] In most cases, nucleated PP is used for the applications, which need higher stiffness and heat resistance. The stiffness, heat resistance, and processability of nucleated PP is considered to be a targeted value for nucleated PLA from the viewpoint of evaluating the possibility and applicability as molded articles of the nucleated PLA.…”

Blood-contacting properties of polypropylene surfaces

“…6 The advancing and 1 0 the receding contact angles with water were estimated to be 102~ ~ and 840-87 ~ respectively. They were almost constant, in spite of the differences in the crystalline-amorphous microstructure on their surfaces.…”

“…~3 The amount of adsorbed proteins was estimated according to a procedure used in a previous paper. 6 Mini polymer bags equipped with injection ports (Injection plug SR-IP1, Terumo, Tokyo, Japan) were prepared from molded sheets and drawn films by heat-sealing, so that they were 30mm • 35mm inside and had a volume of 2ml. Cytoplasmic free calcium levels ([Ca2+]~) in platelets stored in the polypropylene bags were examined by using a Fura 2-loaded platelet suspension.…”

The role of crystallinity on differential attachment/proliferation of osteoblasts and fibroblasts on poly (caprolactone-co-glycolide) polymeric surfaces

“…The chemical and physical properties of the polymer surface such as chemical composition, topography, surface energy and wettability are important parameters to be considered in the interaction between the material and the biological environment [2][3][4]. Although previous reports suggest that the crystallinity of polymeric materials influences biocompatibility [5][6][7][8][9][10][11], it has been difficult to delineate the effects of crystallinity from other physiochemical properties such as hydrophobicity and nanotopography [10]. Investigating cellmaterial interactions are further complicated by variations in cell populations and culture conditions [12].…”