Collagen-silica bio-composite enriched with Cynodon dactylon extract for tissue repair and regeneration

Synergy of Hydrophilic Properties and Antibacterial Inhibition in Polyvinyl Alcohol Nanofibrous Mats Loaded With Croton Bonplandianum Baill Leaf Extract

The antibacterial nanofibrous mat is crucial in biomedicine as it enhances infection control, expedites wound healing, and mitigates health hazards by decreasing antibiotic usage. A novel synergistic antibacterial and hydrophilic nanofibrous mat successfully fabricated by solution electrospinning from polyvinyl alcohol (PVA) incorporated Croton bonplandianum Baill (CBB) leaves extract. Antioxidant-enriched leaf extract of the CBB plant was integrated with PVA in varying proportions of 30% (CBB-30), 40% (CBB-40), and 50% (CBB-50) to manufacture antibacterial nanofibrous mat. The zone of inhibition (ZOI) was recorded at 16, 18, and 21 mm for CBB-30, CBB-40, and CBB-50, respectively. The wetted radius, a key parameter for moisture management properties, reached up to 20 mm for CBB-40 and CBB-50. This demonstrates the rapid absorption and quick-drying characteristics, highlighting the exceptional hydrophilicity of the nanofibrous mat. The increased dozing of CBB extract into the PVA also reduced its fiber diameter. The diameters of pure PVA, CBB-30, CBB-40, and CBB-50 were found as 396, 388, 279, and 241 nm, correspondingly. The developed nanofibrous mat, exhibiting ZOI of up to 21 mm, efficient moisture management properties, and a nanoscale fiber diameter of 241 nm, may possess significant uses in the biomedical domain.

Impact of SiO2 nanoparticles on the structure and property of type I collagen in three different forms

Silica-based nanoparticles have found application in the development of biocomposites involving reconstituted collagen in tissue engineering and wound healing, and leather modification, specifically targeting collagen fibers. However, a comprehensive investigation into the interaction between collagen-silica nanoparticles and different forms of collagen using biophysical methods remains unexplored. In this study, we examined the interaction between silica (SiO2) nanoparticles and collagen in its fiber, microfibril, and monomer forms through high-resolution scanning electron microscopy, circular dichroism, Fourier-transform infrared spectroscopy, fluorescence analysis, zeta potential measurements, and turbidity assays. Our results reveal that SiO2 nanoparticles exhibited a non-specific attraction towards collagen fibers without disrupting their structural integrity. Interestingly, SiO2 nanoparticles influenced the process of microfibrillation, resulting in heterogeneous fibril diameters while maintaining the natural D-periodicity. This finding is significant, as fibril size variations can impact the properties of collagen composites. Notably, the triple helical structure of collagen in its monomer form remained unaffected in the presence of SiO2 nanoparticles, indicating that the nanoparticles did not disrupt the electrostatic interactions that stabilize the triple helix. Additionally, the increased stability of SiO2 nanoparticles in the presence of collagen confirmed their interaction. These findings provide a promising avenue for the development of SiO2-based nanoparticles to enhance the stability of collagen fibers and control fiber sizes for biomaterial preparation. Moreover, this study advances the potential application of SiO2-based nanoparticles in leather tanning, an emerging field where nanoparticles can play a crucial role.

Experimental Study on Repairing Peripheral Nerve Defects with Novel Bionic Tissue Engineering

Peripheral nerve defects are a worldwide problem, and autologous nerve transplantation is currently the gold-standard treatment for them. Tissue-engineered nerve (TEN) grafts are widely considered promising methods for the same, and have attracted much attention. To improve repair, the incorporation of bionics into TEN grafts has become a focus of research. In this study, a novel bionic TEN graft with a biomimetic structure and composition is designed. For this purpose, a chitin helical scaffold is fabricated by means of mold casting and acetylation using chitosan as the raw material, following which a fibrous membrane is electrospun on the outer layer of the chitin scaffold. The lumen of the structure is filled with human bone mesenchymal stem cell-derived extracellular matrix and fibers to provide nutrition and topographic guidance, respectively. The prepared TEN graft is then transplanted to bridge 10 mm sciatic nerve defects in rats. Morphological and functional examination shows that the repair effects of the TEN grafts and autografts are similar. The bionic TEN graft described in this study shows great potential for application and offers a new way to repair clinical peripheral nerve defects.

Collagen-Based Biomaterials for Tissue Engineering

Collagen is commonly used as a regenerative biomaterial due to its excellent biocompatibility and wide distribution in tissues. Different kinds of hybridization or cross-links are favored to offer improvements to satisfy various needs of biomedical applications. Previous reviews have been made to introduce the sources and structures of collagen. In addition, biological and mechanical properties of collagen-based biomaterials, their modification and application forms, and their interactions with host tissues are pinpointed. However, there is still no review about collagen-based biomaterials for tissue engineering. Therefore, we aim to summarize and discuss the progress of collagen-based materials for tissue regeneration applications in this review. We focus on the utilization of collagen-based biomaterials for bones, cartilages, skin, dental, neuron, cornea, and urological applications and hope these experiences and outcomes can provide inspiration and practical techniques for the future development of collagen-based biomaterials in related application fields. Moreover, future improving directions and challenges for collagen-based biomaterials are proposed as well.

Novel Collagen-Polyphenols-Loaded Silica Composites for Topical Application

Lesions can affect skin functions and cause a simple issue, such as dehydration, or more challenging complications, such as bacterial infections. The purpose of this study was to design composites for topical application that can prevent and/or assist in bacterial infections and support cell regeneration using natural components. A polyphenolic extract obtained from Salvia officinalis was embedded in functionalized mesoporous silica nanoparticles for better stability, followed by their distribution into a collagen porous scaffold. The resulting polyphenols-loaded MSN exhibited enhanced antibacterial activity and good cytocompatibility. Improved thermal stability of the collagen porous scaffold was obtained due to the presence of the functionalized MSN. For the first time, collagen-polyphenols-loaded silica composites were reported in the literature as potential wound dressings. The newly developed composites showed excellent sterility.

Silica/Protein and Silica/Polysaccharide Interactions and Their Contributions to the Functional Properties of Derived Hybrid Wound Dressing Hydrogels

Multifunctional and biocompatible hydrogels are on the focus of wound healing treatments. Protein and polysaccharides silica hybrids are interesting wound dressing alternatives. The objective of this review is to answer questions such as why silica for wound dressings reinforcement? What are the roles and contributions of silane precursors and silica on the functional properties of hydrogel wound dressings? The effects of tailoring the porous, morphological, and chemical characteristics of synthetic silicas on the bioactivity of hybrid wound dressings hydrogels are explored in the first part of the review. This is followed by a commented review of the mechanisms of silica/protein and silica/polysaccharide interactions and their impact on the barrier, scaffold, and delivery matrix functions of the derived hydrogels. Such information has important consequences for wound healing and paves the way to multidisciplinary researches on the production, processing, and biomedical application of this kind of hybrid materials.

Remodeling the ECM: Implications for Metastasis and Tumor Dormancy

While most primary tumors can be effectively treated, therapeutics fail to efficiently eliminate metastases. Metastases arise from cancer cells that leave the primary tumor and seed distant sites. Recent studies have shown that cancer cells disseminate early during tumor progression and can remain dormant for years before they resume growth. In these metastatic organs, cancer cells reside in microenvironments where they interact with other cells, but also with the extracellular matrix (ECM). The ECM was long considered to be an inert, non-cellular component of tissues, providing their architecture. However, in recent years, a growing body of evidence has shown that the ECM is a key driver of cancer progression, and it can exert effects on tumor cells, regulating their metastatic fate. ECM remodeling and degradation is required for the early steps of the metastatic cascade: invasion, tumor intravasation, and extravasation. Similarly, ECM molecules have been shown to be important for metastatic outgrowth. However, the role of ECM molecules on tumor dormancy and their contribution to the dormancy-supportive niches is not well understood. In this perspective article, we will summarize the current knowledge of ECM and its role in tumor metastasis and dormancy. We will discuss how a better understanding of the individual components of the ECM niche and their roles mediating the dormant state of disseminated tumor cells (DTCs) will advance the development of new therapies to target dormant cells and prevent metastasis outgrowth.