Characterization and antimicrobial properties of ferulic acid grafted self‐assembled bacterial cellulose‐chitosan membranes

Bioactive Hydrogel Formulation Based on Ferulic Acid-Grafted Nano-Chitosan and Bacterial Nanocellulose Enriched with Selenium Nanoparticles from Kombucha Fermentation

Selenium nanoparticles (SeNPs) have specific properties that result from their biosynthesis particularities. Chitosan can prevent pathogenic biofilm development. A wide palette of bacterial nanocellulose (BNC) biological and physical-chemical properties are known. The aim of this study was to develop a hydrogel formulation (SeBNCSFa) based on ferulic acid-grafted chitosan and bacterial nanocellulose (BNC) enriched with SeNPs from Kombucha fermentation (SeNPsK), which could be used as an adjuvant for oral implant integration and other applications. The grafted chitosan and SeBNCSFa were characterized by biochemical and physical-chemical methods. The cell viability and proliferation of HGF-1 gingival fibroblasts were investigated, as well as their in vitro antioxidant activity. The inflammatory response was determined by enzyme-linked immunosorbent assay (ELISA) of the proinflammatory mediators (IL-6, TNF-α, and IL-1β) in cell culture medium. Likewise, the amount of nitric oxide released was measured by the Griess reaction. The antimicrobial activity was also investigated. The grafting degree with ferulic acid was approximately 1.780 ± 0.07% of the total chitosan monomeric units, assuming single-site grafting per monomer. Fourier-transform infrared spectroscopy evidenced a convolution of BNC and grafted chitosan spectra, and X-ray diffraction analysis highlighted an amorphous rearrangement of the diffraction patterns, suggesting multiple interactions. The hydrogel showed a high degree of cytocompatibility, and enhanced antioxidant, anti-inflammatory, and antimicrobial potentials.

Recent advances in bacterial cellulose-based antibacterial composites for infected wound therapy

Wound infection arising from pathogenic bacteria brought serious trouble to the patient and medical system. Among various wound dressings that are effective in killing pathogenic bacteria, antimicrobial composites based on bacterial cellulose (BC) are becoming the most popular materials due to their success in eliminating pathogenic bacteria, preventing wound infection, and promoting wound healing. However, as an extracellular natural polymer, BC is not inherently antimicrobial, which means that it must be combined with other antimicrobials to be effective against pathogens. BC has many advantages over other polymers, including nano-structure, significant moisture retention, non-adhesion to the wound surface, which has made it superior to other biopolymers. This review introduces the recent advances in BC-based composites for the treatment of wound infection, including the classification and preparation methods of composites, the mechanism of wound treatment, and commercial application. Moreover, their wound therapy applications include hydrogel dressing, surgical sutures, wound healing bandages, and patches are summarized in detail. Finally, the challenges and future prospects of BC-based antibacterial composites for the treatment of infected wounds are discussed.

Novel Perspectives on Food-Based Natural Antimicrobials: A Review of Recent Findings Published since 2020

Various fruit and vegetable wastes, particularly peels, seeds, pulp, and unprocessed residues from the food industry, are abundant sources of antioxidants and essential antimicrobial agents. These valuable bioactive compounds recovered from the food industry have a great application in food, agriculture, medicine, and pharmacology. Food-derived natural antimicrobials offer advantages such as diminishing microbial loads and prolonging the shelf life of food products particularly prone to microbial spoilage. They not only enrich the foods with antioxidants but also help prevent microbial contamination, thereby prolonging their shelf life. Similarly, incorporating these natural antimicrobials into food packaging products extends the shelf life of meat products. Moreover, in agricultural practices, these natural antimicrobials act as eco-friendly pesticides, eliminating phytopathogenic microbes responsible for causing plant diseases. In medicine and pharmacology, they are being explored as potential therapeutic agents. This review article is based on current studies conducted in the last four years, evaluating the effectiveness of food-based natural antimicrobials in food, agriculture, medicine, and pharmacology.

Bacterial Cellulose-Based Materials as Dressings for Wound Healing

Bacterial cellulose (BC) is produced by several microorganisms as extracellular structures and can be modified by various physicochemical and biological strategies to produce different cellulosic formats. The main advantages of BC for biomedical applications can be summarized thus: easy moldability, purification, and scalability; high biocompatibility; and straightforward tailoring. The presence of a high amount of free hydroxyl residues, linked with water and nanoporous morphology, makes BC polymer an ideal candidate for wound healing. In this frame, acute and chronic wounds, associated with prevalent pathologies, were addressed to find adequate therapeutic strategies. Hence, the main characteristics of different BC structures-such as membranes and films, fibrous and spheroidal, nanocrystals and nanofibers, and different BC blends, as well as recent advances in BC composites with alginate, collagen, chitosan, silk sericin, and some miscellaneous blends-are reported in detail. Moreover, the development of novel antimicrobial BC and drug delivery systems are discussed.

Cellulose-Chitosan Functional Biocomposites

Here, we present a detailed review of recent research and achievements in the field of combining two extremely important polysaccharides; namely, cellulose and chitosan. The most important properties of the two polysaccharides are outlined, giving rise to the interest in their combination. We present various structures and forms of composite materials that have been developed recently. Thus, aerogels, hydrogels, films, foams, membranes, fibres, and nanofibres are discussed, alongside the main techniques for their fabrication, such as coextrusion, co-casting, electrospinning, coating, and adsorption. It is shown that the combination of bacterial cellulose with chitosan has recently gained increasing attention. This is particularly attractive, because both are representative of a biopolymer that is biodegradable and friendly to humans and the environment. The rising standard of living and growing environmental awareness are the driving forces for the development of these materials. In this review, we have shown that the field of combining these two extraordinary polysaccharides is an inexhaustible source of ideas and opportunities for the development of advanced functional materials.

Chitosan–Hydroxycinnamic Acids Conjugates: Emerging Biomaterials with Rising Applications in Biomedicine

Over the past thirty years, research has shown the huge potential of chitosan in biomedical applications such as drug delivery, tissue engineering and regeneration, cancer therapy, and antimicrobial treatments, among others. One of the major advantages of this interesting polysaccharide is its modifiability, which facilitates its use in tailor-made applications. In this way, the molecular structure of chitosan has been conjugated with multiple molecules to modify its mechanical, biological, or chemical properties. Here, we review the conjugation of chitosan with some bioactive molecules: hydroxycinnamic acids (HCAs); since these derivatives have been probed to enhance some of the biological effects of chitosan and to fine-tune its characteristics for its application in the biomedical field. First, the main characteristics of chitosan and HCAs are presented; then, the currently employed conjugation strategies between chitosan and HCAs are described; and, finally, the studied biomedical applications of these derivatives are discussed to present their limitations and advantages, which could lead to proximal therapeutic uses.

Recent Advances in Biological Activity, New Formulations and Prodrugs of Ferulic Acid

Trans-ferulic acid (FA) is a derivative of 4-hydroxycinnamic acid, which is found in many food products, fruits and beverages. It has scientifically proven antioxidant, anti-inflammatory and antibacterial properties. However, its low ability to permeate through biological barriers (e.g., the blood-brain barrier, BBB), its low bioavailability and its fast elimination from the gastrointestinal tract after oral administration limit its clinical use, e.g., for the treatment of neurodegenerative diseases, such as Alzheimer's disease. Therefore, new nanotechnological approaches are developed in order to regulate intracellular transport of ferulic acid. The objective of this review is to summarize the last decade's research on biological properties of ferulic acid and innovative ways of its delivery, supporting pharmacological therapy.

Phenolic Compounds From Brewer's Spent Grains: Toward Green Recovery Methods and Applications in the Cosmetic Industry

Brewers' spent grain (BSG) is the main by-product derived from the brewing industry, where it accounts for 85% of the total waste generated. The total annual production worldwide of this waste is 39 million tons. This lignocellulosic material is traditionally used as cattle feed and sold at a low retail price (~USD 45.00 per ton). However, efforts for the revalorization of this by-product are emerging since research has established that it can be used as a low-cost source of bioactive molecules and commodity chemicals that can bring value to integral biorefinery ventures. Among commodities, phenolic compounds have attracted attention as added-value products due to their antioxidant properties with applications in the food, cosmetic, and pharmaceutical industries. These phytochemicals have been associated with antiaging and anticancer activities that have potential applications on cosmetic products. This mini-review summarizes the most relevant extraction techniques used for the recovery of phenolic compounds from BSG while discussing their advantages and shortcomings and the potential applications from BSG bioactive extracts in the cosmetic industry and their reported beneficial effects. This mini-review also makes a brief comment on the role of phenolic compounds extraction in the economic feasibility of an integral BSG biorefinery.