Controlling silk fibroin microspheres via molecular weight distribution.
Silk fibroin (SF) microspheres were produced by salting out SF solution via the addition of potassium phosphate buffer solution (K2HPO4-KH2PO4). The morphology, size and polydispersity of SF microspheres were adjusted by changing the molecular weight (MW) distribution and concentration of SF, as well as the ionic strength and pH of the buffer solution. Changing the conditions under which the SF fiber dissolved in the Lithium Boride (LiBr) solution resulted in altering the MW distribution of SF solution. Under optimal salting-out conditions (ionic strength>0.7 M and pH>7) and using a smaller and narrower SF MW distribution, SF microspheres with smoother shapes and more uniform sizes were produced. Meanwhile, the size and polydispersity of the microspheres increased when the SF concentration was increased from 0.25 mg/mL to 20 mg/mL. The improved SF microspheres, obtained by altering the distribution of molecular weight, have potential in drug and gene delivery applications.
National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123, China.
Dong-Mei
DM
Zeng
National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123, China.
Jue-Jing
JJ
Pan
National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123, China.
Qun
Q
Wang
National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123, China.
Xin-Fang
XF
Liu
National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123, China.
Hui
H
Wang
National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123, China; Research Center of Cooperative Innovation for Functional Organic/Polymer Material Micro/Nanofabrication, Soochow University, Suzhou, Jiangsu 215123, China. Electronic address: kqzhang@suda.edu.cn.
Ke-Qin
KQ
Zhang
D000818:Animals; D012831:Bombyx; D005349:Fibroins / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008970:Molecular Weight; D009994:Osmolar Concentration; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity
D010710:Phosphates; D017680:Potassium Compounds; D012996:Solutions; D005349:Fibroins; C013216:potassium phosphate
Ionic strength; Microspheres; Molecular weight; Salting out; Silk fibroin