Because of the alarming rate of human population growth, technological improvement should be needed to save the environment from pollution. The practice of business as usual on material production is not creating a circular economy. The circular economy refers to an economic model whose objective is to produce goods and services sustainably, by limiting the consumption and waste of resources (raw materials, water, and energy). Fungal-based composites are the recently implemented technology that fulfills the concept of the circular economy. It is made with the complex of fungi mycelium and organic substrates by using fungal mycelium as natural adhesive materials. The quality of the composite depends on both types of fungi and substrate. To ensure the physicochemical property of the fabricated composite, mycelium morphology, bimolecular content, density, compressive strength, thermal stability, and hydrophobicity were determined. This composite is proven to be used for different applications such as packaging, architectural designs, walls, and insulation. It also has unique features in terms of low cost, low emission, and recyclable.

Chitosan is a natural polymer derived from the deacetylation of chitin. It is mainly derived from crustaceans and fungal sources. It has many intrinsic properties, such as biocompatibility, biodegradability, cationic nature, and nontoxicity. These features of chitosan have made it an attractive material for various applications. Furthermore, these unique properties have found significant biomedical applications, such as in drug delivery, tissue engineering, antimicrobial agent, and wound healing. However, it has its drawbacks, such as the raw material source being seasonal and localized, the extraction procedure being time-consuming, costly, and involving the use of harsh chemicals in substantial amounts, and the quality of chitosan obtained from marine sources being variable. Furthermore, studies are needed to increase the yield and utilization of chitosan for various industrial purposes. Technological improvements, such as gene modification will enhance the yield and application of chitosan. This review focuses primarily on the numerous applications of chitosan in the biomedical field, including tissue engineering, wound dressing, drug delivery, and others.