Angelica Panico

Articular cartilage is a highly specialized avascular tissue with limited intrinsic regenerative capacity, making the treatment of cartilage defects particularly challenging. Silk fibroin (SF) is a promising biomaterial for cartilage tissue engineering due to its biocompatibility, tunable degradation, and versatile processing into three-dimensional structures. In this study, two SF scaffolds obtained from the same aqueous fibroin solution were fabricated using freeze-drying (FD) or freeze–thawing (FT) to elucidate how processing-induced architectural differences regulate chondrocyte responses. Morphological analysis showed that FD scaffolds exhibited higher porosity and larger pore size, whereas FT scaffolds displayed a denser structure and significantly higher compressive modulus, highlighting distinct structure–property relationships. ATR-FTIR analysis further revealed a higher β-sheet fraction in FT scaffolds, indicating processing-dependent differences in fibroin molecular organization. These structural differences translated into distinct biological outcomes. FD scaffolds supported higher chondrocyte metabolic activity, consistent with their more open porous architecture. In contrast, FT scaffolds promoted stronger expression of cartilage-related markers, including COL2A1 and ACAN, indicating enhanced chondrogenic maturation. Overall, the results demonstrate that silk fibroin scaffold architecture modulates the balance between cellular metabolic activity and cartilage-specific matrix production. The ability to precisely tune scaffold architecture through processing techniques represents a key strategy for optimizing silk fibroin-based systems in cartilage tissue engineering.

Chronic wounds represent a major clinical challenge due to their prolonged healing process and susceptibility to bacterial colonization, particularly by biofilm-forming bacteria. To address these issues, in this work, silver-treated silk fibroin scaffolds were developed and tested as multifunctional wound dressings, combining antimicrobial and regenerative properties. Silk fibroin, a natural protein derived from Bombyx mori cocoons, is widely recognized for its biocompatibility and suitability for tissue engineering. In this study, porous silk fibroin scaffolds were functionalized with silver nanoparticles through a photo-reduction process and were comprehensively tested for their cytocompatibility and wound healing potential. The excellent antibacterial activity of the silver-treated scaffolds was demonstrated against Escherichia coli and antibiotic-resistant Pseudomonas aeruginosa, as was extensively reported in a previous work. Biological assays were performed using 3T3 fibroblasts cultured on both untreated and silver-treated silk fibroin scaffolds. Biocompatibility assays, such as MTT, Live/Dead, and cytoskeleton analyses, demonstrated biocompatibility in both scaffold types, comparable to the control. Wound healing potential was assessed using in vitro scratch assays, revealing full wound closure (100%) after 24 h in cells cultured with untreated and silver-treated silk fibroin scaffolds, in contrast to 78.5% closure in the control. Notably, silver-treated scaffolds exhibited enhanced fibroblast repopulation within the wound gap, suggesting a synergistic effect of silver and fibroin in promoting tissue regeneration. These findings demonstrate that silver-treated silk fibroin scaffolds possess both anti-microbial and regenerative properties, making them promising candidates for chronic wound management applications.

Sericin, a natural glycoprotein constituting 20–30% of the silk cocoon, has emerged as a promising biomaterial due to its excellent biological properties, including biocompatibility, antioxidant properties and potential applications in regenerative medicine. The quality and the features of sericin are strongly dependent on the extraction and purification methods, which can employ mild conditions to preserve the molecular integrity of the protein or recovery techniques from waste streams produced during the industrial degumming processes. The silk industry prioritizes fiber yield over protein preservation, so often harsh alkaline conditions at high temperatures are adopted. These divergent approaches result in fundamentally different products with distinct molecular characteristics and functional capabilities. This review comprehensively examines the current technological approaches for sericin extraction techniques and for its recovery from textile industry waste, focusing on how these aspects affect the biological properties of the protein and the potential applications.

Background/Objectives: The huge concerns associated with biofilm-related infections in surgical procedures, along with the antibiotic resistance demonstrated by an increasing number of bacteria, have highlighted the need for alternative and effective prevention approaches. The aim of this research was to develop novel antimicrobial coatings on surgical sutures for the prevention of surgical site infections through nanotechnology-based methods. Results: The results demonstrated that although very low amounts of silver precursor were adopted for the treatments, the silver coating was effective against Staphylococcus aureus and antibiotic-resistant Pseudomonas aeruginosa in reducing the potential risk of infection. Methods: Nanostructured silver coatings were deposited onto the surface of polyglactin 910 absorbable braided sutures through a technology based on a photo-assisted chemical reaction. The materials were characterized in order to verify the efficacy of the coating in preventing biofilm formation and in reducing the bacterial colonization of the device. Conclusions: As a broad-spectrum antimicrobial agent, silver represents an important option for the prevention and management of surgical site infections. The silver deposition technology adopted in this work provides an interesting strategy for preventing biofilm formation on medical devices such as surgical sutures.