Alternative biomaterials: natural, non-woven, fibroin-based silk nanofibers of weaver ants (Oecophylla smaragdina).

Silks of silkworms and spiders have been widely studied as biomaterials, however, none has been reported on silks produced by weaver ants (Oecophylla smaragdina). This study is the first to report on some properties of natural silk fibers of weaver ants and their potential application as a cell matrix. Weaver ant fibrous mat contained non-woven mesh of fibers with diameters ranging from 266 to 3056 nm. The average diameter of fibers was 766+/-326 nm. The thickness, mass, and apparent density of the fibrous mats were 39.0+/-9.8 microm, 0.8+/-0.1 mg/cm2, and 0.22+/-0.03 g/cm3, respectively. Freshly made fibrous mats by weaver ants were highly hydrophilic as determined by water contact angle analysis, whereas older ones were quite hydrophobic. TG-DTA analysis revealed a major weight loss peak from 260 up to about 330 degrees C, similar to the decomposition peak of Bombyx mori fibroin. FT-IR spectrum showed amide I, amide II, amide III, C-H and C-O peaks, which were attributed to random coil and beta-sheet conformation in the protein structure of the weaver ant fibers. The fibrous mat was slight toxic to the fibroblast NIH 3T3 cells (37.8% cell death), probably due to some toxic particles deposited on the fibers. Nevertheless, weaver ant fibrous mat served as a good matrix for cell adhesion. Results of this work provided evidence for the properties and a potential application of natural weaver ant fibers as an alternative, natural, fibroin-based matrix. Copyright 2010 Elsevier B.V. All rights reserved.