| Blood compatibility is an important research element of anticoagulant materials,and it is a significant indicator to judge whether a material can be used in the human body.Insects are the only invertebrate flying creatures in nature.Their wing surfaces are complex three-dimensional periodic media with good hydrophobic properties and self-cleaning properties.They are the bionic research objects and replication templates of many scholars.Dimethylsiloxane(PDMS)is safe and non-toxic with high precision for graphic reproduction,and meets the requirements of soft etching technology for elastic template materials.In this research,the three kinds of insect wing surface of Bombus terrestris、Ischnura heterosticta and Locusta migratoria manilensis are used as templates.Using soft etching and adopting secondary reprint method,three insect wings the and PDMS film with micro-rough structure from six different areas are prepared by secondary transfer method(are A-F).By observing the microstructure of insect wing and PDMS film surface,analyzing the chemical composition of insect wing,measuring the wettability of the sample surface to water droplets and blood,calculating the surface free energy,and conducting a preliminary evaluation of the blood compatibility of PDMS film on the surface of insect wing,the following conclusions are drawn in this study:(1)The main chemical functional groups of the characteristic absorption peak in the three insect wings are O-H、N-H、C-H、C-O and double-bond functional group,which are composed of protein,lipid and chitin,are natural hydrophobic surface.(2)The Bombus terrestris’wing surface of A zone and PDMS film surface are distributed with regularly arranged micrometer acetabular structures,and the non-smooth surface is full of nano-scale thread-like engravings.The wing surface of the B zone of the Bombus terrestris and the surface of the PDMS film are distributed with approximately parallelogram-shaped micropapillary structures of different sizes,and the top of the papillae is of the nanoscale structure.The surface of the Ischnura heterosticta wings of C and D zones and the surface of the PDMS film are covered with uneven nano-scale folds.The wing veins of C and D zones are distributed with micron-shaped conical fibrils with different shapes.The wing surface of E and F zones of the Locusta migratoria manilensis and the surface of PDMS biomimetic membrane are distributed with multiple criss-cross ridges and numerous micropapillary structures.Among them,the average ratio of d/l between the wing surface of D zone and the surface of PDMS film is smaller than that of other zones.(3)The surface of the three insect wing surfaces are all of hydrophobic.The water droplet static contact angle(CA_S)is 118.6~145.7°.The water droplet static contact angle of PDMS film is 102.9~135.8°and the contact mode conforms to the Cassie equation.The surface energy values of the insect wing and PDMS film decrease with the decline of the d/l average ratio.The blood contact angle of PDMS film is 108.4°~127.8°and the contact mode also conforms to the Cassie equation.(4)Compared with the smooth PDMS membrane surface of the control group,the number of platelets accumulated and adhered on the surface of the PDMS film in different morphology zones is smaller,and the morphological changes are smaller.In the same field of view,the number of platelets in A~F zones respectively are 1.74×104、2.78×104、0.93×104、0.46×104、1.85×104 and 1.79×104N/cm2.(5)The hemolysis rate of PDMS film(A~F zones)of different morphology zones are 3.43%、4.66%、2.31%、2.06%、3.96%and 3.59%,all of which reached the biomedical standards below 5%,and are below the hemolysis rate of 4.82%of the smooth PDMS membrane.(6)In the dynamic coagulation time experiment of PDMS film in different morphological zones,the absorbance value(0.091 L/(g·cm))of PDMS film in A zone of Bombus terrestris area at 10 min is better than that of other zones;The absorbance value(0.036 L/(g·cm))of PDMS film in C zone of Ischnura heterosticta at 30 min is better than of other areas.The absorbance value(0.058、0.033、0.034 L/(g·cm))of PDMS film in D zone of Ischnura heterosticta at 20 min,40 min,and 50 min are better than those in other zones.These experiments show that the biocompatibility of the bionic membrane in the D zone of Ischnura heterosticta is better than that of other zones.(7)The blood compatibility of PDMS film with micro-rough structure is better than that of smooth PDMS membrane.Among the PDMS film,the blood compatibility of PDMS film in the D zone of Ischnura heterosticta is the best,with the smallest d/l ratio(0.050),maximum roughness,maximum surface energy(9.453 mJ/m~2),the strongest hydrophobicity(the average contact angle is 134.3°)and the strongest hemophobicity(the average contact angle is 127.8°).The number of platelets is small,and the morphology is not activated and the hemolysis rate(2.06%)is the lowest.The absorbance curve of dynamic coagulation time is smoother within 30~50 minutes,and the anticoagulation performance is better than that of PDMS film in other zones,which provides new ideas for the modification of biomedical materials. |
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