Optical parameters of human blood plasma, collagen, and calfskin based on the Stokes-Mueller technique.

A decoupled analytical technique based on the Stokes-Mueller matrix decomposition method extracts polarization properties of human blood plasma, collagen solution, and calfskin. The proposed method is applied initially to extract the nine effective optical parameters of human blood plasma samples containing D-glucose powder with concentrations ranging from 0-1 M. The optical rotation angle of circular birefringence (CB) increases linearly with the glucose concentration in human blood plasma samples (r2=0.9782) and in tissue phantom samples (r2=0.9939). Meanwhile, the phase retardance of linear birefringence (LB) increases slightly from 0° to almost 2° as the D-glucose concentration increases. However, for the plasma samples, the optical rotation angle increases by 1.07±0.1 deg for each additional mole of D-glucose, while, for the tissue phantom samples, the optical rotation angle increases by 0.75±0.1 deg. For collagen solutions with concentrations ranging from 0 to 2 mg/mL, a strong linear relationship (r2=0.9936) is observed between the phase retardance of linear birefringence and the collagen concentration. Finally, for the calfskin samples, the linear birefringence reduces exponentially (r2=0.9689) over time following collagenase treatment. Overall, the decoupled analytical model provides a reliable and straightforward technique for detecting the optical properties of laboratory and natural biological samples. As a result, it has significant potential for diagnostic applications and the structural analysis of biological tissues.

Investigate the Effect of Thawing Process on the Self-Assembly of Silk Protein for Tissue Applications.

Biological self-assembly is a process in which building blocks autonomously organize to form stable supermolecules of higher order and complexity through domination of weak, noncovalent interactions. For silk protein, the effect of high incubating temperature on the induction of secondary structure and self-assembly was well investigated. However, the effect of freezing and thawing on silk solution has not been studied. The present work aimed to investigate a new all-aqueous process to form 3D porous silk fibroin matrices using a freezing-assisted self-assembly method. This study proposes an experimental investigation and optimization of environmental parameters for the self-assembly process such as freezing temperature, thawing process, and concentration of silk solution. The optical images demonstrated the possibility and potential of -80ST48 treatment to initialize the self-assembly of silk fibroin as well as controllably fabricate a porous scaffold. Moreover, the micrograph images illustrate the assembly of silk protein chain in 7 days under the treatment of -80ST48 process. The surface morphology characterization proved that this method could control the pore size of porous scaffolds by control of the concentration of silk solution. The animal test showed the support of silk scaffold for cell adhesion and proliferation, as well as the cell migration process in the 3D implantable scaffold.