An approach for preparing an absorbable porous film of silk fibroin–rice starch modified with trisodium trimetaphosphate

Abstract

The absorbable porous material, especially gelatin porous film, is widely used for surgical use to stop bleeding, but its price is quite high. Thus, a new material at lower price with desirable properties is required. This article presents an approach to prepare a porous film of silk fibroin-rice starch (SF-RS) modified with trisodium trimetaphosphate (STMP). The preparation was performed using freeze-drying method aiming to increase the porosity and improve some other properties of the modified porous film. The solutions of SF and RS (5 : 95 weight ratio) and STMP were mixed and adjusted to pH 12 before being neutralized to pH 7 and freeze-dried for 48 h. Result from the SEM images showed that the average pore size of the SF-RS film increased from 17 to 126 lm after STMP was added up to 5.0% w/w. Similar to the SF-RS-STMP hydrogel, the linkages within the modified SF-RS porous film also occurred mainly between the OAH groups of RS and the triphosphate group of STMP. Moreover, cross-linking density of the porous film increased with the increasing content of STMP, evidenced from the increase of relative methylene blue adsorption. The addition of STMP also affected the physical properties of the modified porous film such as degree of swelling, oxygen permeability, but not the water solubility. Whereas, the residual ash of the modified porous films was lower than 2.0% and the degradation of the film ceased after soaking in 0.01M PBS solution for about 2 weeks.

Effect of Sodium Trimetaphosphate on Chitosan-Methylcellulose Composite Films: Physicochemical Properties and Food Packaging Application

“…Sodium trimetaphosphate, a safe and non-toxic crosslinking agent suitable for polysaccharides to improve their functional properties, has been used in many research studies and reports [ 19 ]. For example, it has been used for crosslinking biopolymers such as cellulose [ 20 ], xanthan [ 21 ], and starch [ 22 , 23 , 24 ], and can decrease the solubility of proposed materials [ 25 ]. However, research carried out to crosslink a composite biopolymer film using sodium trimetaphosphate has been rare.…”

Enhancement of Mechanical and Barrier Property of Hemicellulose Film via Crosslinking with Sodium Trimetaphosphate

“…At higher STMP loadings, i.e., greater than 15%, the tensile strength and the elastic modulus film gradually decreased. This observation is mainly due to the gelation phenomenon in some places caused by the excessive addition of STMP, which leads to the decline of mechanical properties [35]. The elongation at break for films with 20% STMP addition was determined to be 1.86%, much lower than 3.48% for unmodified film.…”

“…The main reason for this phenomenon could be that the amount of STMP is not enough to crosslink hemicellulose completely, so that the molecular chain is relatively loose, and the excessive STMP cannot continue to participate in the crosslinking reaction and disperse uniformly in the film matrix, resulting in the increasing surface roughness of the film, and even the appearance of some micropores because of the gel phenomenon [35].…”

“…At the same time, there is less free space inside the film, making it harder for oxygen to enter the film [43]. When the STMP addition amount is more than 15%, over-crosslinking may cause some holes to appear on the film surface, thus slightly increasing the oxygen permeability [35]. Meanwhile, the electrostatic effect caused by the high concentration of crosslinking agent will enlarge the distance of molecular chain and improve the permeability of oxygen [36], which is consistent with the inference in the tensile property test, thermal property test and surface morphology test above.…”

Preparation of porous starch from native starch by using fungal amylase and evaluation of its adsorption property on natural pharmacodynamic compounds

“…With the decomposition of the carrier, the drug was continuously released from the particles, so as to achieve local targeted drug delivery 9 . A porous film of silk fibroin–rice starch modified with trisodium trimetaphosphate was developed in the field of biomedical materials 10 . The excellent adsorption capacity of porous starch as a raw material for the development of hemostatic agents has attracted a lot of attention from researchers at home and abroad 11–13 …”