Quantitative evaluation by image analysis of platelet morphological modifications after contact with polyvinylacetate.
BACKGROUND
In order to investigate platelet activation after contact with artificial materials, which is an important aspect of biocompatibility especially for the blood-contacting devices, platelet morphological modifications and spread area were evaluated by light microscopy and image analysis after contact with glow discharge-treated polybutylene terephthalate coated with a polymer for platelet concentrate filtration.


METHODS
A hydrophilic polymer made of partially hydrolyzed polyvinyl-acetate containing polyethylene oxide/poly-propylene oxide copolymer block as lateral chains (PVA) (Biofil S.r.l., Cavezzo, Modena, Italy) was evaluated. After contact with PVA, platelets were allowed to settle on a siliconized slide and then fixed and stained. The specimens were analyzed by image analysis. The percentages of spreading, round and dendritic shapes, as well as the presence of aggregates, were evaluated, and the mean area of the spread platelets was measured.


RESULTS
PVA induced significant variations neither in the percentages of shape change distribution, nor of the mean spread area. However it determined a statistically significant reduction in platelets with the area from 60 to 70 mu 2. Such minimal variations agree with the results we obtained in the past, namely a non significant platelet adhesion induced by the same material.


CONCLUSIONS
The method confirms the results of platelet adhesion and release reaction (the study of release reaction needs more refined but more expensive methods). However, the study of morphological modifications by image analysis is not suitable for testing materials that induce massive platelet adhesion, because the number of the residual platelets could be too low for the microscopic evaluation.
Cenni
E
E
Laboratory for Biocompatibility Research on Implant Materials, Istituti Ortopedici Rizzoli, Bologna. elisabetta.cenni@ior.it
Stea
S
S
Cervellati
M
M
Pizzoferrato
A
A
Montanaro
L
L
D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000494:pharmacology*; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects*; D006440:Hemofiltration; D006801:Humans; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D008853:Microscopy; D011091:Polyesters / Q000494:pharmacology; D011145:Polyvinyls / Q000494:pharmacology*; D018709:Statistics, Nonparametric; D014741:Video Recording
D001672:Biocompatible Materials; D011091:Polyesters; D011145:Polyvinyls; C041733:poly(1,4-butylene terephthalate); C013215:polyvinyl acetate