Implication of Silk Film RGD Availability and Surface Roughness on Cytoskeletal Organization and Proliferation of Primary Rat Bone Marrow Cells

Abstract

To design and fabricate next-generation tissue engineering materials, the understanding of cell responses to material surfaces is required. Surface topography presents powerful cues for cells and can strongly influence cell morphology, adhesion, and proliferation, but the mechanisms mediating this cell response remain unclear. In this report, we have investigated the effects of nanoroughness assemblies of silk fibroin protein membranes and RGD sequences fabricated from two different silk fibroin sources, that is, mulberry (Bombyx mori) and nonmulberry (Antheraea mylitta), on cytoskeletal organization, proliferation, and viability using primary rat bone marrow cells. To vary surface roughness, silk fibroin substrates were treated with graded ethanol (50%-100% v/v) to produce nanoarchitectures in the range of 1-12 nm height. The graded alcohol treatments have been found to produce nanoscale topographies of reproducible height in a much faster and cheaper way. The results showed no difference in cell proliferation within the same treatment groups for both silk types. However, a change in cell response in terms of good cytoskeleton organization, actin development, cell spreading, and strong binding to substratum using A. mylitta fibroin protein films having RGD sequences was observed. This finding provides the information that the nanoroughness affects cellular processes in a cell-specific manner and may be helpful for the development of smart silk-based biomaterials especially for directing cell differentiation and regenerative therapies.

Milled non-mulberry silk fibroin microparticles as biomaterial for biomedical applications

“…The presence of RGD sequences within non-mulberry silk fibroin promoted better cell attachment, spreading and viability on the silk fibroin microparticles. These results were in agreement with the earlier comparative studies conducted between non-mulberry and mulberry matrices with regard to cell growth, attachment and proliferation [19,20,56]. Therefore, it is expected that RGD sequences would have provided chemical cues for the seeded cells, and thus allows better cell growth and viability of silk particles in general and non-mulberry silk fibroin microparticles in particular for potential biomedical applications.…”

“…Silk fibroin (SF) derived from mulberry silkworm; Bombyx mori (B. mori) has been widely used as suitable matrices/substrates due to its high oxygen permeability, superior mechanical properties and excellent biocompatibility [10][11][12][13][14][15]. Additionally, there is a natural abundance of cell binding motifs, arginine-glycine-aspartic acid (RGD) in non-mulberry silk fibroin, which felicitates better cell attachment and proliferation [16][17][18][19][20][21]. The presence of RGD motifs in non-mulberry silk fibroin based matrices provide a substrate for stem cells differentiation and progenitor cells, which render it as a suitable biomaterial for variety of tissue engineering applications [5,22].…”

Engineered silk fibroin protein 3D matrices for in vitro tumor model

“…mylitta fibroin, however, naturally has the optimal surface roughness for cell attachment [50]. The presence of RGD tripeptides in A. mylitta fibroin [GenBank: AY136274.1 partial cds.…”

“…2b), but after 12 h, cells were more spreaded on the surface of A. mylitta films than on TCP, Matrigel and B. mori fibroin films. The spreading of cells on the surface of B. mori fibroin films was found to be less than on the other matrices, probably due to the presence of topological and biochemical differences [50,51] as discussed in Section 3.1.…”

Wollastonite nanofiber–doped self-setting calcium phosphate bioactive cement for bone tissue regeneration

“…Attachment is a part of the first phase of cell-material interactions, and the quality of this first phase will influence cell growth, morphology, proliferation, and differentiation upon contact with the implant. 25 The results indicate that cells adhered better to wnf-CPC than CPC within the first 4 hours of culture. The superior ability of cells to attach to wnf-CPC compared with CPC is probably associated with different surface features of biomaterials.…”