Non-bioengineered silk gland fibroin micromolded matrices to study cell-surface interactions

Abstract

Micropatterning/micromolding of protein molecules has played a significant role in developing biosensors, micro arrays, and tissue engineering devices for cellular investigations. Relevantly, there have been ample scopes for silk to be used as natural biomaterial in tissue engineering applications due to its attractive properties such as slow-controllable degradation, mechanical robustness, and inherent biocompatibility. In this paper, we report the fabrication of micromolded silk fibroin matrices, which have essentially been utilized to study cell-surface interactions. Fibroin protein has been isolated from the silk glands of nonmulberry Indian tropical tasar silkworms, Antheraea mylitta. The surface uniformity has been investigated using atomic force microscopy following the fabrication of silk micromolds. Subsequently, cellular interactions in terms of cell attachment, spreading, mitochondrial activity and proliferation have been studied in vitro using feline fibroblasts. Results have indicated a long term stability of patterns in micromolded silk matrices and negligible swelling. The versatility of described silk dissolution method coupled with ability to process large amount of silk protein into micromolded matrices and controllable surface topology may augment the desirability of silk fibroin as a natural biomaterial for bioengineering and biotechnological applications.

Potential of 2D crosslinked sericin membranes with improved biostability for skin tissue engineering

“…Further, due to the presence of weak hydrogen bonds, alcohol treatment of membrane during processing causes rearrangement of the protein molecules into a stable β-sheet secondary structure (Magoshi et al 1981(Magoshi et al , 1985. Higher β-sheet formation induces protein insolubility making the membrane more resistant to an aqueous environment (Mandal et al 2009b). These data indicate that addition of crosslinking agents form double bonds and amides that drastically change the molecular structures of sericin.…”

Silk-based delivery systems of bioactive molecules

“…Chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) was observed, starting after 2 weeks and more strongly after 3 weeks [119]. Tropical tasar silkworm Antheraea mylitta silk-based 3D matrices were also evaluated for in-vitro drug release and for the study of cell-surface interactions [120,121]. The silk-based matrices contained two different model compounds, bovine serum albumin (66 kDa) and FITC-inulin (3.9 kDa), to characterize release profiles [120].…”

“…Silk fibroin protein blended calcium alginate beads resulted in prolonged drug release without initial burst for 35 days as compared to calcium alginate beads without silk fibroin [120]. Additionally, silk-based micromolded matrices supported a significant enhancement in cell attachment, spreading, mitochondrial activity, and proliferation with feline fibroblasts in comparison to polystyrene plates as controls [121]. These studies indicate the potential use of slow degrading silk fibroin 3D scaffolds and tubes loaded with bioactive molecules such as BMP, HRP, and adenosine for drug-releasing biomaterials.…”

Understanding the molecular mechanism of improved proliferation and osteogenic potential of human mesenchymal stem cells grown on a polyelectrolyte complex derived from non-mulberry silk fibroin and chitosan

“…Moreover, it has been well documented that the Chinese oak silk moth (Antheraea pernyi) produces quite a different fibroin from the domestic silkmoth (Bombyx mori) [2]. The silk isolated from A. pernyi acquires adequate strength and toughness [4] that further enhances osseointegration in in vitro conditions [3] due to the influence of tripeptide RGD (Arg-Gly-Asp) integrin binding sequences [5] which facilitate improved cell attachment and proliferation [6]. Furthermore, the RGD sequence acts as a preferable receptor that increases the binding affinity of cell surface receptors to attain the desired combination of receptor-mediated endocytosis, which is ideal for cell attachment [7,8].…”