Natural polymers have the advantages of safety, non-toxicity, biodegradability, abundant sources and low price, especially the reuse of industrial and agricultural waste/by-products can reduce environmental pollution, and has significant economic and ecological benefits, which is a research hotspot at home and abroad. Ningxia has a long history of viticulture and winemaking, and the grape industry is one of the nine pillar industries in the autonomous region. Despite the booming wine industry, grape seed is a valuable by-product that is often overlooked. A large amount of grape seeds are discarded at will, resulting in a waste of resources and a burden on the environment. The use of winemaking waste to build high value-added new materials has a positive effect on the extension of the wine industry chain. The water-soluble extracts in grape seed are mainly glucopolyphenols (GSE) and grape seed protein (GSP). Among them, GSE was condensed by different amounts of catechins, and the extraction rate was about 5 wt%, and the catechol functional groups contained in it provided the possibility of adhesion. However, GSE has a low molecular weight and is expensive, and is mainly used in the field of cosmetics or health products. The extraction rate of GSP is about 12 wt%, the price is low, the molecular weight is high, and the side chain contains functional groups such as carboxyl, amino, sulfhydryl and phenolic hydroxyl groups. The high molecular weight is conducive to ensuring the entropy elasticity and chain entanglement density of the hydrogel, while the side chain contains a large number of carboxyl, amino and other hydrogen bond donors and acceptors to facilitate the use of hydrogen bond cross-linking, and the amide bond backbone has good biocompatibility, and the degradation product amino acids can be absorbed by the human body. Therefore, combining the advantages of GSP and GSE to construct high value-added biomedical polymer materials is expected to improve the utilization rate of brewing product waste, which has important economic and environmental benefits.
鉴于此，北方民族大学雒春辉教授以聚乙烯醇和GSP为原料，不使用有害助剂制备了机械性能接近天然软骨的水凝胶。 （Fabrication of self-healable, conductive, and ultra-strong hydrogel from polyvinyl alcohol and grape seed-extracted polymer，Journal of Applied Polymer Science，引用25次）。 随后，课题组以聚乙烯醇和GSE为凝胶基质，并选择碳纳米管作为导电填料制备了自粘附高灵敏水凝胶传感器。 （From grape seed extract to highly sensitive sensors with adhesive, self-healable and biocompatible properties，European Polymer Journal，JCR一区期刊，影响因子6.0）。 近期，课题组以GSP和单宁酸为原料，制备了性能良好的胶黏剂，研究成果分别发表在《International Journal of Biological Macromolecules》（中科院一区Top期刊，影响因子8.2）和《European Polymer Journal》（JCR一区期刊，影响因子6.0）上。
Due to the low interfacial adhesion energy and the self-lubricating effect of interfacial water, it remains a challenge to quickly establish adhesion between soft and wet materials such as biological tissues and hydrogels. Studies have shown that the aqueous solution of nanoparticles can increase the interfacial bonding energy between hydrogels and biological tissues. Compared to inorganic particles, the deformability of elastic polymer micelles can further dissipate external forces. Therefore, using natural polymer self-assembled nanoparticles as the "glue" and inducing their disintegration into linear molecular chains by heating up is expected to solve the problem that the existing wound dressings cannot be multifunctional and reversible adhesion. In view of this, the authors designed a nanoglue based on grape seed protein and tannic acid (GSP-TA). Due to the high specific surface area and multifunctional group characteristics of nanoparticles, GSP-TANHs can bond together a variety of hydrogels in about 10 seconds, including physically cross-linked polyvinyl alcohol, chemically cross-linked polyacrylamide, anionic poly2-acrylamide-2-methyl-1-propanesulfonic acid, and cationic chitosan. In particular, due to the temperature sensitivity of the hydrogen bonds, the glue can be easily peeled off at temperatures up to 45°C, which makes it a great potential for use in the field of chronic wound dressings.
Graphic courier
Figure 1. Schematic diagram of the preparation of nanoglue.
Figure 2. Adhesion properties of nanoglue to various hydrogels.
Figure 3.Temperature-induced on-demand peel characteristics
Original link:
https://doi.org/10.1016/j.eurpolymj.2024.112902
Due to the presence of interfacial water, the vast majority of hydrogel materials do not possess adhesive properties, and common strategies to impart adhesion properties to them rely on complex surface chemical modifications. To avoid chemical modification, the authors prepared a GSP/TA powder that rapidly converts various non-viscous hydrogels into viscous gels. The powder can quickly absorb interfacial water and diffuse into the hydrogel matrix, establishing a strong interfacial bond within 5 s. In addition, the powder-treated polyacrylamide or polyvinyl alcohol hydrogel is capable of adhering to a variety of solid substrates (wood, cardboard, glass, iron and rubber) and wet tissues (pig skin, muscle, liver and heart) with an adhesive strength of around 100 kPa. Due to the advantages of grape seed protein and plant polyphenols, the powder degrades within 11 days and has excellent biocompatibility. This method is easy to obtain, simple to operate, and has strong universality, which enriches the functions of traditional hydrogels and is expected to broaden its application field.
Graphic courier
Figure 1. Schematic diagram of the conversion of various non-viscous hydrogels into viscous gels.
Figure 2. Adhesion strength of powder-treated PAM hydrogels to various substrates.
Figure 3. The hydrogel treated with GSP-TA powder has rapid adhesion and reversible adhesion ability.
Original link:
https://doi.org/10.1016/j.ijbiomac.2024.131215
Ge Zhuo, a master's student, is the first author of the paper, Professor Chunhui is the corresponding author, and North University for Nationalities is the independent corresponding author. This work was supported by the National Natural Science Foundation of China (52063001), the Ningxia Natural Science Foundation (2023AAC02052), and the High-level Talent Training Program of Beimin University (2019BGGZ11).
Source: Frontiers of Polymer Science