Recent Development of Alginate-Based Materials and Their Versatile Functions in Biomedicine, Flexible Electronics, and Environmental Uses

Abstract

Alginate is a natural polysaccharide that is easily chemically modified or compounded with other components for various types of functionalities. The alginate derivatives are appealing not only because they are biocompatible so that they can be used in biomedicine or tissue engineering but also because of the prospering bioelectronics that require various biomaterials to interface between human tissues and electronics or to serve as electronic components themselves. The study of alginate-based materials, especially hydrogels, have repeatedly found new frontiers over recent years. In this Review, we document the basic properties of alginate, their chemical modification strategies, and the recent development of alginate-based functional composite materials. The newly thrived functions such as ionically conductive hydrogel or 3D or 4D cell culturing matrix are emphasized among other appealing potential applications. We expect that the documentation of relevant information will stimulate scientific efforts to further develop biocompatible electronics or smart materials and to help the research domain better address the medicine, energy, and environmental challenges faced by human societies.

Modification of Alginates to Modulate Their Physic-Chemical Properties and Obtain Biomaterials with Different Functional Properties

“…Due to their faster degradation rate and higher content of reactive groups compared to native alginate, hydrogels based on oxidized alginate (OA) are used widely as biodegradable materials for tissue engineering applications. OA-based hydrogels are used in tissue engineering of bone, cartilage, blood vessels, cornea, and other soft tissues [ 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 ].…”

Bio-based Polymers: A Mini Review

“…While traditionally used as food additives and edible films, alginates recently found applications as plastics, mostly bags, although their potential in biomaterials and flexible electronics have also been reported. 30 The above discussed naturally occurring polysaccharides have inadequate mechanical strength compared to most fossil-based plastics. Even when formulated with reinforcing fillers, impact modifiers, and/or other polymers, as they typically are, their applications as bioplastics have largely been limited to packaging materials.…”

Alginate Modification and Lectin-Conjugation Approach to Synthesize the Mucoadhesive Matrix

“…Alginate is favored for cell encapsulation due to its low toxicity and its gelation ability under cell suitable conditions, because the distribution of M and G fragments along its chain varies with the alginate source and processing methods. The various characteristic affects its biocompatibility, purification, molecular weight, and intrinsic viscosity [13,14]. Further purification is suggested to reduce the risk of immune response to developed antibodies against the encapsulation material [15].…”

“…The phenomenon is related to the hemiacetal formation of a high concentration of aldehyde groups in oxidized urinates [47,48]. The presence of aldehyde can also be investigated with 13 C NMR, and the aldehyde signal clearly appears at 90-95 ppm when the degree of oxidation is 19 mol% or above [47,91].…”