title: Tuning molecular weights of Bombyx mori (B. mori) silk sericin to modify its assembly structures and materials formation.
abstract: Bombyx mori (B. mori) silk sericin is a protein with features desirable as a biomaterial, such as increased hydrophilicity and biodegradation, as well as resistance to oxidation, bacteria, and ultraviolet light. In contrast to other widely studied B. mori silk proteins such as fibroin, sericin is still unexplored as a building block for fabricating biomaterial, and thus a facile technique of processing it into a material is needed. Here, electrospinning technology was used to fabricate it into biomaterials from two forms of B. mori silk sericin with different molecular weights, one is a low (12.0 kDa) molecular sericin (LS) form and another is a high (66.0 kDa) molecular weight sericin (HS) form. Circular dichroism (CD) spectra showed that LS in hexafluoroacetone (HFA) solvent adopted a predominantly random coil conformation, whereas HS tended to form a β-sheet structure along with a large content of random coils. In addition, LS and HS in HFA solvent were found to form cylinder-like smaller nanoparticles and larger irregular aggregates before electrospinning, respectively. As a result, biomaterials based on microparticles and nanofibers were successfully fabricated by electrospinning of LS and HS dissolved in HFA, respectively. The cell viability and differentiation assay indicated that nanofibers and microparticles improved cell adhesion, growth, and differentiation, proving that the scaffolds electrospun from sericin are biocompatible regardless of its molecular weight. The microparticles, not common in electrospinning of silk proteins reported previously, were found to promote the osteogenic differentiation of mesenchymal stem cells in comparison to the nanofibers. This study suggested that molecular weight of sericin mediates its secondary structure and assembly structure, which in turn leads to a control of final morphology of the electrospun materials. The microparticles and nanofibers of sericin can be potentially used as building blocks for fabricating the scaffolds for tissue engineering.
authors: Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University , Yuhangtang Road 866, Hangzhou, 310058 Zhejiang, China.
authors: Mingying
authors: M
authors: Yang
authors: Yajun
authors: Y
authors: Shuai
authors: Guanshan
authors: G
authors: Zhou
authors: Namita
authors: N
authors: Mandal
authors: Liangjun
authors: L
authors: Zhu
authors: Chuanbin
authors: C
authors: Mao
mesh_terms: D000096:Acetone / Q000031:analogs & derivatives / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000494:pharmacology; D012831:Bombyx / Q000737:chemistry*; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002850:Chromatography, Gel; D002942:Circular Dichroism; D005466:Fluorocarbons / Q000737:chemistry; D057809:HEK293 Cells; D006801:Humans; D008970:Molecular Weight; D057139:Nanofibers / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D047030:Sericins / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D012996:Solutions; D012997:Solvents; D017550:Spectroscopy, Fourier Transform Infrared; D006845:Hydrocarbons, Fluorinated
chemical_list: D000096:Acetone; D001672:Biocompatible Materials; D005466:Fluorocarbons; D047030:Sericins; D012996:Solutions; D012997:Solvents; C017366:hexafluoroacetone; D006845:Hydrocarbons, Fluorinated