Spider silk and silkworm silk share similar hierarchical design principles but differ in their molecular composition. Spider silk proteins (spidroins) contain repetitive sequences rich in glycine and alanine that promote the formation of \u03b2-sheet nanocrystals [5]<\/a>. Silkworm silk fibroin, in contrast, consists of a heterodimeric complex composed of a heavy chain and a light chain linked by a disulfide bond, with repetitive domains in the heavy chain driving \u03b2-sheet crystallinity. Silkworm silk is also characterized by the presence of sericin, a glue-like coating protein that surrounds the fibroin core and has historically been discarded during degumming. Sericin is increasingly recognized as a valuable material, with antioxidant, cell-adhesive, and wound-healing properties [6]<\/a>.<\/p>\n\n\n\n Over the past few decades, significant progress has been made in elucidating the design principles underlying the versatility of silks\u2014in particular, the role of amino acid sequence in governing their structure\u2013property relationships [7,8]<\/a>. For instance, spider silk proteins contain highly repetitive amino acid sequences, especially in their large core domain [9]<\/a>. Such insights have, in turn, enabled the recombinant production of silk-inspired proteins, allowing scalable manufacturing and fine control over properties, including mechanical behavior and programmable biodegradability [10]<\/a>.<\/p>\n\n\n\n A major advantage of silk proteins lies in their exceptional ability to be processed into different forms. Silk proteins and their derivatives can be fabricated into a wide range of formats, including particles, fibers, films, and three-dimensional constructs such as hydrogels [3,11]<\/a> (Figure 1<\/a>). Each of these material classes exhibits distinct mechanical and functional characteristics, making them suitable for specific biomedical applications.<\/p>\n\n\n Silk fibers are particularly valued for their high tensile strength, flexibility, and long-term mechanical stability [18]<\/a>. These properties make them ideal candidates for applications such as sutures or tissue engineering scaffolds. Silk films, in contrast, offer excellent surface controllability, optical transparency, and barrier properties [19]<\/a>, making them well suited for biomedical interfaces (e.g., biosensors or health-monitoring devices) [20]<\/a>. Three-dimensional silk-based materials such as hydrogels can provide a mechanical and structural environment that closely mimics the extracellular matrix [21]<\/a>. As a result, they are attractive for tissue engineering and regenerative medicine applications, as well as for cell encapsulation and delivery [3]<\/a>.<\/p>\n\n\n\n Given the central role of electrical and mechanical cues in biological systems\u2014and the growing demand for remote actuation, control, and sensing in biomedical technologies\u2014there is increasing interest in endowing silk-based materials with additional functionalities. These include electrical conductivity or magnetic responsiveness to support emerging bioelectronic and sensing platforms [22,23]<\/a>. Such developments are now enabling applications in sustainable bioelectronics, biosensing, active scaffolds, neural interfaces, implantable systems, and assisted-motion devices [12,24\u201326]<\/a>.<\/p>\n\n\n\n Despite these advances, silk-based devices have so far made minimal impact in the marketplace. This slow translation reflects several technical and economic challenges that remain unresolved [10]<\/a>. The incorporation of conductive or magnetic components often leads to degradation of the intrinsic biological and mechanical properties of silk, frequently as a consequence of harsh processing conditions [27]<\/a>. While silk is often regarded as a renewable and sustainable resource, both sericulture and recombinant protein production remain resource-intensive processes [10,28,29]<\/a>. Moreover, many of the materials used to confer electrical or magnetic functionality are often neither sustainable nor environmentally benign [30]<\/a>. This needs to be reconciled with the growing drive toward all-aqueous, low-energy, and environmentally friendly material fabrication strategies [10]<\/a>. Another factor that remains unresolved is the cost of such materials compared with their synthetic counterparts.<\/p>\n\n\n\n Although numerous studies have explored conductive or functional silk materials, existing reviews typically focus on specific applications such as bioelectronics, tissue engineering, or flexible sensors [22,23,31,32]<\/a>. A systematic analysis of how electrical and magnetic functionalities can be integrated into silk across different material formats and processing strategies is lacking. In particular, the relationship between processing, structural perturbation, and the long-term stability of the functional phase has not been comprehensively addressed.<\/p>\n\n\n\n The present review provides a unified framework for understanding functionalization strategies in silk-based materials by analyzing pre-assembly and post-assembly approaches across fibers, films, and hydrogels, while critically discussing their implications for stability, biocompatibility, and sustainability. Our aim is to identify key limitations and opportunities imposed by conventional processing and to outline potential pathways toward the viable development of high-performance, sustainable silk-based biomedical devices. The lack of standardized methods for benchmarking silk biomaterials is not addressed in this review as a technical challenge, although it remains an equally critical issue.<\/p>\n\n\n\n The exceptional mechanical performance and biocompatibility of silk arise from a hierarchical organization of the protein structure\u2014established during material processing (pre-assembly) and consolidated upon material formation (post-assembly) [3]<\/a>. Introducing additional functionalities, such as magnetic or electrical properties, involves modifications that may perturb protein conformation, intermolecular interactions, or supramolecular organization, altering intrinsic mechanical and biological properties [27]<\/a>. Thus, integrating electrochemical behavior or magnetism into silk depends on how processing alters the native protein structure and whether the added functionality remains stable under mechanical, environmental, and biological stresses. Strategies range from mild surface treatments to composite- and network-based approaches that modify bulk assembly (Figure 2<\/a> and Table 1<\/a>).<\/p>\n\n\n![\"\"](\"https:\/\/renewable-carbon.eu\/news\/media\/2026\/08\/gr1.jpg\")
Functionalization strategies<\/h3>\n\n\n\n
![\"Figure](\"https:\/\/renewable-carbon.eu\/news\/media\/2026\/08\/gr2.jpg\")