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.

The risk of infections in chronic wounds represents a serious issue, particularly in aged people and in patients affected by diseases such as diabetes and obesity. Moreover, the growing resistance demonstrated by many bacterial strains has significantly reduced the therapeutic options for clinicians and has become a great challenge for the researchers in the definition of novel approaches that promote the wound healing process and reduce the healing time. Tissue engineering approaches based on biomaterials and three-dimensional scaffolds have demonstrated huge potential in supporting cell proliferation; among them, Bombyx mori-derived silk fibroin is a very appealing possibility for the development of devices with regenerative properties for wound healing applications. However, due to the high risk of infections in chronic wounds, an antibacterial treatment is also strongly encouraged for preventing bacterial proliferation at the wound site. In this work, to develop a device with regenerative and antibacterial properties, antibacterial silver coatings were deposited onto silk fibroin scaffolds, and the effect of the treatment in terms of chemical–physical and microbiological properties was investigated. The results demonstrated that the silver treatment improved the mechanical properties of the protein scaffold and provided good antibacterial efficacy against representative bacterial strains in wound infection, namely Escherichia coli and antibiotic-resistant Pseudomonas aeruginosa.

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.

Non-union fractures represent a significant clinical challenge requiring innovative therapeutic approaches. Silk fibroin (SF) scaffolds have gained recognition as advantageous biomaterials for bone tissue engineering due to their biocompatibility and mechanical characteristics. This study investigated the biocompatibility and osteoinductive potential of SF scaffolds functionalized with hydroxyapatite (HA) and loaded with platelet growth factors (PGFs) using hematopoietic stem cells (HSCs). SF scaffolds were prepared and functionalized with HA through methanol impregnation, while PGFs were obtained from platelet lysate via apheresis procedures. HSCs were cultured on different experimental groups, namely SF, SF-HA, PGF, SF-PGF, and SF-HA-PGF, assessing biocompatibility through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Live/Dead staining, and cytoskeleton analysis over 7 days. Osteoinductive properties were evaluated using Alizarin Red staining for mineral matrix deposition at 14 and 21 days. The MTT assay revealed the biocompatibility of all the experimental groups. The Live/Dead assay confirmed high cell viability, while the cytoskeleton analysis revealed well-organized actin filaments comparable to controls. Alizarin Red staining showed that PGF alone promoted early mineral matrix deposition at day 14, while SF-HA, SF-PGF, and SF-HA-PGF groups demonstrated significantly enhanced mineralization at day 21 compared with SF alone. The combination of silk fibroin scaffolds with platelet growth factors alone or with hydroxyapatite and platelet growth factors creates a biomimetic environment that supports cell viability and induces the osteogenic differentiation of hemopoietic stem cells. These findings suggest significant potential for clinical translation in treating non-union fractures and bone defects.

Bacterial infections remain a major challenge to human health, especially in wound healing, where they can cause prolonged inflammation, delayed recovery, and severe complications. Current research is increasingly focused on developing innovative antimicrobial materials capable of overcoming the limitations of conventional antibiotics, whose effectiveness has declined due to the rise in bacterial resistance. Among the various alternatives, silver nanoparticles have gained particular attention for their broad-spectrum antibacterial properties and have already been successfully applied in the functionalization of commercial wound dressings. The aim of this study was to optimize the functionalization of commercial cotton gauzes based on in situ UV-assisted reduction of silver nanoparticles, reducing methanol usage and identifying the minimal silver nitrate precursor concentration to achieve antimicrobial efficacy while maintaining biocompatibility. Different precursor concentrations were then evaluated through cytocompatibility assays (MTT, Live/Dead, and scratch tests on fibroblasts) and antimicrobial analyses against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus (including an antibiotic-resistant strain), and Candida albicans. The results demonstrated that a 0.5% w/w silver nitrate concentration provided strong antimicrobial and antibiofilm activity without compromising textile properties or cytocompatibility. Furthermore, this optimized process reduced material waste, highlighting its potential for scalable production of antimicrobial wound dressings.

Background: Dexamethasone (DEX) is used in vitro to promote osteogenic differentiation of human bone marrow mesenchymal stromal cells (hBMSCs). In clinical use, however, glucocorticoids induce osteoblast and osteocyte apoptosis while increasing osteoclast survival, leading overall to osteoporosis and high fracture risk. The overall impact of DEX on the differentiation of human progenitor cells remains contradictory and not fully understood, highlighting the need for further investigation using sequencing approaches as in vitro results will naturally influence further translational research. Methods: hBMSCs were induced to osteogenic differentiation for 7 days using different concentrations of either DEX or the nonsteroidal glucocorticoid receptor agonist (+)-ZK216348. cDNA library preparation and RNA sequencing (RNAseq) were performed using Oxford Nanopore Technologies. Differentially expressed genes and pathways associated to the transactivation or transrepression activity of DEX were identified. Sequencing results were validated by qPCR, protein analysis, and with a functional assay on peripheral blood mononuclear cells to determine the overall effect of the BMSC supernatant. Results: Hierarchical clustering of RNAseq data identified eight subclusters with shared regulatory patterns. Enrichment analysis revealed that both upregulated and downregulated genes are involved in ossification and extracellular matrix organization pathways. Several pro- and anti-inflammatory genes were differentially regulated. qPCR analysis validated the upregulation of CXCL1 , CXCL8 , IL18 , and COL8A1 , while MMP1 and CXCL12 expression decreased in response to DEX. Comparing DEX results with those obtained using (+)-ZK216348 helped distinguish the potential mechanisms regulating the expression of specific genes. Notably, CXCL8 upregulation occurred through transactivation, whereas COL8A1 upregulation is downstream of a transrepressed gene. Further in vitro experiments confirmed that DEX significantly increased CXCL8 expression and IL-8 secretion. However, hPBMC responses indicated no significant pro- or anti-inflammatory effects from hBMSC conditioned medium. Conclusions: In conclusion, the effects of DEX on the transcriptome of hBMSCs in a pro-osteogenic environment do not fully replicate the acquisition of an osteogenic phenotype. Several genes associated with ossification, extracellular matrix organization, and inflammation were dysregulated. The unique expression patterns of pro-inflammatory cytokines and collagen types warrant further investigation to elucidate their roles in osteogenic differentiation and bone homeostasis.