Development of an antibacterial nanobiomaterial for wound-care based on the absorption of AgNPs on the eggshell membrane

Eggshell membrane and green seaweed (Ulva lactuca) micronized powders for in vivo diabetic wound healing in albino rats: a comparative study

BACKGROUND

Nonhealing diabetic wounds are a serious complication associated with extremely lethargic wound closure and a high risk of infection, leading to amputation or limb loss, as well as substantial health care costs and a poor quality of life for the patient. The effects of either eggshell membrane (ESM) and green seaweed (Ulva lactuca) extracts alone or in combination were evaluated for in vivo skin wound healing in a rat model of induced diabetes.

METHODS

Micronized powders of waste hen ESM, Ulva lactuca, and their 1:1 mixture were prepared using regular procedures. The mechanical, electrical, and surface morphology characteristics of powders were examined using direct compression, LCR-impedancemetry, and scanning electron microscopy. The effect of ESM, Ulva lactuca, and their mixture as compared to standard Dermazin treatments were evaluated on wounds inflicted on male Wistar Albino rats with induced diabetes. Quantitative wound healing rates at baseline and at 3, 7, 14, and 21 days of treatments among all rat groups were conducted using ANOVA. Qualitative histological analysis of epidermal re-epithelization, keratinocytes, basement membrane, infiltrating lymphocytes, collagen fibrines, and blood vessels at day 21 were performed using Image J processing program.

RESULTS

Compressive strength measurements of tablets showed a Young's modulus of 44.14 and 27.17 MPa for the ESM and ESM + Ulva lactuca mixture, respectively. Moreover, both samples exhibited relatively low relative permittivity values of 6.62 and 6.95 at 1 MHz, respectively, due to the porous surface morphology of ESM shown by scanning electron microscopy. On day 21, rats treated with ESM had a complete diabetic wound closure, hair regrowth, and a healing rate of 99.49%, compared to 96.79% for Dermazin, 87.05% for Ulva lactuca, 90.23% for the mixture, and only 36.44% for the negative controls. A well-formed basement membrane, well-differentiated epithelial cells, and regular thick keratinocytes lining the surface of the epidermal cells accompanied wound healing in rats treated with ESM, which was significantly better than in control rats.

CONCLUSION

Ground hen ESM powder, a low-cost effective biomaterial, is better than Ulva lactuca or their mixture for preventing tissue damage and promoting diabetic wound healing, in addition to various biomedical applications.

Preparation of nano-silver containing black phosphorus based on quaternized chitosan hydrogel and evaluating its effect on skin wound healing

Hydrogels with favorable biocompatibility and antibacterial properties are essential in postoperative wound hemorrhage care, facilitating rapid wound healing. The present investigation employed electrostatic adsorption of black phosphorus nanosheets (BPNPs) and nano‑silver (AgNPs) to cross-link the protonated amino group NH3+ of quaternized chitosan (QCS) with the hydroxyl group of hyaluronic acid (HA). The electrostatic interaction between the two groups resulted in the formation of a three-dimensional gel network structure. Additionally, the hydrogel containing AgNPs deposited onto BPNPs was assessed for its antibacterial properties and effects on wound healing. Hydrogel demonstrated an outstanding drug-loading capacity and could be employed for wound closure. AgNPs loaded on the BPNPs released silver ions and exhibited potent antibacterial properties when exposed to 808 nm near-infrared (NIR) radiation. The ability of the hydrogel to promote wound healing in an acute wound model was further evaluated. The BPNPs were combined with HA and QCS in the aforementioned hydrogel system to improve adhesion, combine the photothermal and antibacterial properties of the BPNPs, and promote wound healing. Therefore, the reported hydrogels displayed excellent biocompatibility and hold significant potential for application in the field of tissue engineering for skin wound treatment.

Self-Assembled and Multilayer-Overlapped ESM-PDA@rGO Nanofilm-Based Flexible Wearable Sensor for Real-Time Body Temperature Monitoring

There is an urgent need for wearable sensors that continuously monitor human physiological conditions in real time. Herein, an ESM-PDA@rGO-based flexible wearable temperature sensor was successfully constructed by integrating an eggshell membrane (ESM) with reduced graphene oxide (rGO) through dopamine (DA) polymerization. Depending on the "bridge effect" of diversified polydopamine (PDA) chains, on the one hand, a staggered arrangement of PDA-rGO frameworks and a lot of conductive pathways were produced and acted as an active layer. On the other hand, PDA-rGO frameworks were linked with ESM by PDA chains as a flexible sensing nanofilm. As a result, these mechanical merits of the ESM-PDA@rGO exhibited a 1.8-fold increase in Young' s modulus and 1.4-fold increase in tensile strength. Thereby, the conformability and performance of the temperature sensor were greatly enhanced, showing excellent sensitivity (-2.23%/°C), good linearity (R2 = 0.979), as well as stability. Especially, the flexible sensing nanofilm is evolved from the staggered arrangement of PDA-rGO frameworks, which endows it with rapid response (only 4-8 s), high resolution (0.1 °C), as well as excellent long-term durability (10 weeks). More importantly, the temperature sensor demonstrates insensitivity to bending deformation, ensuring reliable wearing stability. The sensor allows for online, real-time monitoring of human body temperature, encompassing both core (forehead, temple, cochlea, and exhale gas) and shell (palm and back of the hand, fingertip, and instep) temperatures. Particularly, it can accurately assess minor changes in peripheral body temperature before and after exercise, and it is capable of mapping daily patterns of body temperatures. The developed temperature sensor will provide us new materials design concepts and holds considerable promise in the fields of e-skin, disease surveillance, prediction, and diagnose.

Cytotoxic-Ag-Modified Eggshell Membrane Nanocomposites as Bactericides in Concrete Mortar

Against the backdrop of escalating infrastructure budgets worldwide, a notable portion-up to 45%-is allocated to maintenance endeavors rather than innovative infrastructure development. A substantial fraction of this maintenance commitment involves combatting concrete degradation due to microbial attacks. In response, this study endeavors to propose a remedial strategy employing nano metals and repurposed materials within cement mortar. The methodology entails the adsorption onto eggshell membranes (ESM) of silver nitrate (ESM/AgNO3) or silver nanoparticles (ESM/AgNPs) yielding silver-eggshell membrane composites. Subsequently, the resulting silver-eggshell membrane composites were introduced in different proportions to replace cement, resulting in the formulation of ten distinct mortar compositions. A thorough analysis encompassing a range of techniques, such as spectrophotometry, scanning electron microscopy, thermogravimetric analysis, X-ray fluorescence analysis, X-ray diffraction (XRD), and MTT assay, was performed on these composite blends. Additionally, evaluations of both compressive and tensile strengths were carried out. The mortar blends 3, 5, and 6, characterized by 2% ESM/AgNO3, 1% ESM/AgNPs, and 2% ESM/AgNPs cement replacement, respectively, exhibited remarkable antimicrobial efficacy, manifesting in substantial reduction in microbial cell viability (up to 50%) of typical waste activated sludge. Concurrently, a marginal reduction of approximately 10% in compressive strength was noted, juxtaposed with an insignificant change in tensile strength. This investigation sheds light on a promising avenue for addressing concrete deterioration while navigating the balance between material performance and structural integrity.

A drug-incorporated-microparticle-eggshell-membrane-scaffold (DIMES) dressing: A novel biomaterial for localised wound regeneration

Chronic wounds affect millions of people annually and have emotional and financial implications in addition to health issues. The current treatment for chronic wounds involves the repeated use of bandages and drugs such as antibiotics over an extended period. A cost-effective and convenient solution for wound healing is the development of drug-incorporated bandages. This study aimed to develop a biocompatible bandage made of drug-incorporated poly (lactic-co-glycolic acid) (PLGA) microparticles (MPs) and eggshell membrane (ESM) for cornea wound healing. ESM has desirable properties for wound healing and can be isolated from eggshells using acetic acid or ethylenediaminetetraacetic acid (EDTA) protocols. Fluorescein isothiocyanate-labelled Bovine Serum Albumin (FITC-BSA) was used as a model drug, and the PLGA MPs were fabricated using a solvent extraction method. The MPs were successfully attached to the fibrous layer of the ESM using NaOH. The surface features of the ESM samples containing MPs were studied using a field emission scanning electron microscope (FESEM) and compared with blank ESM images. The findings indicated that the MPs were attached to the ESM fibres and had similar shapes and sizes as the control MPs. The fibre diameters of the MPs samples were assessed using Fiji-ImageJ software, and no significant changes were observed compared to the blank ESM. The surface roughness, Ra values, of the MPs incorporated ESM samples were evaluated and compared to the blank ESM, and no significant changes were found. Fourier transform infrared (FTIR) spectroscopy was used to analyse the chemical Composition of the bandage, and the spectra showed that the FBM were effectively incorporated into the ESM. The FTIR spectra identified the major peaks of the natural ESM and the PLGA polymer in the bandage. The bandage was transparent but had a reduced visibility in the waterproof test card method. The bandage achieved sustained drug release up to 10 days and was found to be biocompatible and non-toxic in a chorioallantoic membrane (CAM) assay. Overall, the drug-incorporated PLGA MPs-ESM bandage has great potential for treating chronic wounds.

A Sustainable, Green-Processed, Ag-Nanoparticle-Incorporated Eggshell-Derived Biomaterial for Wound-Healing Applications

The eggshell membrane (ESM) is a natural biomaterial with unique physical and mechanical properties that make it a promising candidate for wound-healing applications. However, the ESM's inherent properties can be enhanced through incorporation of silver nanoparticles (AgNPs), which have been shown to have antimicrobial properties. In this study, commercially produced AgNPs and green-processed AgNPs were incorporated into ESM and evaluated for their physical, biological, and antimicrobial properties for potential dermal application. The ESM was extracted using various techniques, and then treated with either commercially produced AgNPs (Sigma-Aldrich, Poole, UK) or green-synthesized AgNPs (Metalchemy, London, UK) to produce AgNPs-ESM samples. The physical characteristics of the samples were evaluated using scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, and the biological properties were assessed through in vitro studies using human dermal fibroblasts (HDFs) and BJ cells. The SEM analysis of the AgNPs-ESM samples showed localization of AgNPs on the ESM surface, and that the ESM maintained its structural integrity following AgNP incorporation. The FTIR confirmed loading of AgNPs to ESM samples. The biological studies showed that the 5 μg/mL AgNPs-ESM samples were highly biocompatible with both HDFs and BJ cells, and had good viability and proliferation rates. Additionally, the AgNPs-ESM samples demonstrated pro-angiogenic properties in the CAM assay, indicating their potential for promoting new blood vessel growth. Assessment of the antimicrobial activity of the enhanced AgNPs/ESMs was validated using the International Standard ISO 16869:2008 methodology and exploited Cladosporium, which is one of the most commonly identified fungi in wounds, as the test microorganism (≥5 × 106 cells/mL). The AgNPs-ESM samples displayed promising antimicrobial efficacy as evidenced by the measured zone of inhibition. Notably, the green-synthesized AgNPs demonstrated greater zones of inhibition (~17 times larger) compared to commercially available AgNPs (Sigma-Aldrich). Although both types of AgNP exhibited long-term stability, the Metalchemy-modified samples demonstrated a slightly stronger inhibitory effect. Overall, the AgNPs-ESM samples developed in this study exhibited desirable physical, biological, and antimicrobial properties for potential dermal wound-dressing applications. The use of green-processed AgNPs in the fabrication of the AgNPs-ESM samples highlights the potential for sustainable and environmentally friendly wound-healing therapies. Further research is required to assess the long-term biocompatibility and effectiveness of these biomaterials in vivo.

Synthesis and Assessment of Antimicrobial Composites of Ag Nanoparticles or AgNO3 and Egg Shell Membranes

Engineering research has been expanded by the advent of material fusion, which has led to the development of composites that are more reliable and cost-effective. This investigation aims to utilise this concept to promote a circular economy by maximizing the adsorption of silver nanoparticles and silver nitrate onto recycled chicken eggshell membranes, resulting in optimized antimicrobial silver/eggshell membrane composites. The pH, time, concentration, and adsorption temperatures were optimized. It was confirmed that these composites were excellent candidates for use in antimicrobial applications. The silver nanoparticles were produced through chemical synthesis using sodium borohydride as a reducing agent and through adsorption/surface reduction of silver nitrate on eggshell membranes. The composites were thoroughly characterized by various techniques, including spectrophotometry, atomic absorption spectrometry, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, as well as agar well diffusion and MTT assay. The results indicate that silver/eggshell membrane composites with excellent antimicrobial properties were produced using both silver nanoparticles and silver nitrate at a pH of 6, 25 °C, and after 48 h of agitation. These materials exhibited remarkable antimicrobial activity against Pseudomonas aeruginosa and Bacillus subtilis, resulting in 27.77% and 15.34% cell death, respectively.

Bacterial cellulose membrane incorporated with silver nanoparticles for wound healing in animal model

The bacterial cellulose membrane (CM) is a promising biomaterial due to its easy applicability and moist environment. Moreover, nanoscale silver compounds (AgNO₃) are synthesized and incorporated into CMs to provide these biomaterials with antimicrobial activity for wound healing. This study aimed to evaluate the cell viability of CM incorporated with nanoscale silver compounds, determine the minimum inhibitory concentration (MIC) for Escherichia coli and Staphylococcus aureus, and its use on in vivo skin lesions. Wistar rats were divided according to treatment: untreated, CM (cellulose membrane), and AgCM (CM incorporated with silver nanoparticles). The euthanasia was performed on the 2nd, 7th, 14th, and 21st days to assess inflammation (myeloperoxidase-neutrophils, N-acetylglucosaminidase-macrophage, IL-1β, IL-10), oxidative stress (NO-nitric oxide, DCF-H₂O₂), oxidative damage (carbonyl: membrane's damage; sulfhydryl: membrane's integrity), antioxidants (superoxide dismutase; glutathione), angiogenesis, tissue formation (collagen, TGF-β1, smooth muscle α-actin, small decorin, and biglycan proteoglycans). The use of AgCM did not show toxicity, but antibacterial effect in vitro. Moreover, in vivo, AgCM provided balanced oxidative action, modulated the inflammatory profile due to the reduction of IL-1β level and increase in IL-10 level, in addition to increased angiogenesis and collagen formation. The results suggest the use of silver nanoparticles (AgCM) enhanced the CM properties by providing antibacterial properties, modulation the inflammatory phase, and consequently promotes the healing of skin lesions, which can be used clinically to treat injuries.

Fabrication and evaluation of herbal beads to slow cell ageing

Several therapies and cosmetics are available commercially to prevent or delay cell ageing, which manifests as premature cell death and skin dullness. Use of herbal products such as Aloe vera, curcumin, vitamin C-enriched natural antioxidant, and anti-inflammatory biomolecules are potential ways to prevent or delay ageing. Eggshell membrane (ESM) is also a rich source of collagen; glycosaminoglycans (GAGs) also play an essential role in healing and preventing ageing. It is important to use an extended therapeutic process to prolong the effectiveness of these products, despite the fact that they all have significant anti-ageing properties and the ability to regenerate healthy cells. Encapsulated herbal components are therefore designed to overcome the challenge of ensuring continued treatment over time to prolong the effects of a bioactive component after in situ administration. To study their synergistic effects on a cellular level, alginate, Aloe vera, and orange peel extract were encapsulated in bio-polymeric foaming beads and modified with eggshell membrane protein (ESMP) at various concentrations (1 gm, 2 gm, and 5 gm): (A-Av-OP, A-Av-OP-ESMP1, ESMP2, and ESMP3). Analysis of the structural and functional properties of foaming beads showed interconnected 3D porous structure, a surface-functionalized group for entrapment of ESMP, and a significant reduction in pore size (51-35 m) and porosity (80%-60%). By performing DPPH assays, HRBC stabilization assays, and antibacterial tests, the beads were assessed as a natural anti-ageing product with sustained release of molecules effective against inflammatory response, oxidative stress, and microbial contamination. MTT assays were conducted using in vitro cell cultures to demonstrate cytocompatibility (in mouse 3T3 fibroblast cells) and cytotoxicity (in human carcinoma HeLa cells). Our study demonstrates that bio-polymeric ESMP beads up to 2 g (A-Av-OP-ESMP2) are practical and feasible natural remedies for suspending defective cell pathways, preventing cell ageing, and promoting healthy cell growth, resulting in a viable and practical natural remedy or therapeutic system.

Biopolymer-based electrospun fibers in electrochemical devices: versatile platform for energy, environment, and health monitoring

Electrochemical power tools are regarded as essential keys in a world that is becoming increasingly reliant on fossil fuels in order to meet the challenges of rapidly depleting fossil fuel supplies. Additionally, due to the industrialization of societies and the growth of diseases, the need for sensitive, reliable, inexpensive, and portable sensors and biosensors for noninvasive monitoring of human health and environmental pollution is felt more than ever before. In recent decades, electrospun fibers have emerged as promising candidates for the fabrication of highly efficient electrochemical devices, such as actuators, batteries, fuel cells, supercapacitors, and biosensors. Meanwhile, the use of synthetic polymers in the fabrication of versatile electrochemical devices has raised environmental concerns, leading to an increase in the quest for natural polymers. Natural polymers are primarily derived from microorganisms and plants. Despite the challenges of processing bio-based electrospun fibers, employing natural nanofibers in the fabrication of electrochemical devices has garnered tremendous attention in recent years. Here, various natural polymers and the strategies employed to fabricate various electrospun biopolymers are briefly covered. The recent advances and research strategies used to apply the bio-based electrospun membranes in different electrochemical devices are carefully summarized, along with the scopes in various advanced technologies. A comprehensive and critical discussion about the use of biopolymer-based electrospun fibers as the potential alternative to non-renewable ones in future technologies is briefly highlighted. This review will serve as a field opening platform for using different biopolymer-based electrospun fibers to advance the electrochemical device-based renewable and sustainable technologies, which will be of high interest to a large community. Accordingly, future studies should focus on feasible and cost-effective extraction of biopolymers from natural resources as well as fabrication of high-performance nanofibrous biopolymer-based components applicable in various electrochemical devices.

Interaction research of resveratrol and phosvitin based on fluorescence spectroscopy and molecular docking analysis

Phosvitin (PV) is the main phosphoprotein in egg yolk, with the highest degree of phosphorylation known in nature. The PV and resveratrol (Res) can form a complex, thus effectively improve the solubility of Res. In this work, the interaction between Res and PV was investigated by the fluorescence spectroscopy and molecular docking. The fluorescence emission intensity of PV became weak along with a red shift when it interacted with Res and the antioxidant activity was enhanced. The quenching constants of the interaction systems were 1.12×10⁴  M^-1 and 9.40×10³  M^-1 at 25°C and 35°C, respectively, which indicated the presence of static quenching phenomena between them. The binding constant was 1.80×10⁴  M^-1 , and the number of corresponding binding sites was approximately equal to one. The thermodynamic results revealed the combination was spontaneous, and the change of enthalpy and entropy was ∆H = 53.50 kJ/mol, ∆S = 261.00 J/mol·K, respectively. It indicated that the interaction forces between Res and PV were mainly hydrophobic interaction and hydrogen bonding. Molecular docking showed the binding mode, which was consistent with the experiment results. The research on the interaction between Res and PV provided theoretical guidance for the application of Res in food. PRACTICAL APPLICATION: PV is the most highly phosphorylated protein in nature and has pro-calcium absorption effects. Res is a polyphenol with strong antioxidant and anti-inflammatory activity, but its poor solubility limits its application. In this study, the solubility of Res was considerably enhanced by compounding Res and PV, and the antioxidant activity of Res was well retained. It increases the value of Res in food and other applications and opens up new possibilities for processing and utilization of PV.

Long-term monitoring of blood biomarkers related to intrauterine growth restriction using AgNPs SERS tags-based lateral flow assay

Sensitive and accurate early detection of fetal growth restriction (FGR) is of vital importance in the development of the fetus during pregnancy and even the health of future life. Here, an ultrasensitive and straightforward surface-enhanced Raman scattering (SERS)-based double targets detection in pregnancy is implemented by utilizing functionalized Ag nanoparticles (AgNPs). Through fabricating 4-MPA antibody-modified AgNPs on the lateral flow assay (LFA) strips as the SERS nanotags, the target proteins in blood samples from pregnancy were accurately captured, which further quantizing PI3K and CRAF in unprocessed blood. This strategy warrant excellent selectivity and sensitivity with the limits of detection (LODs) are 0.76 fg mL^-1 for PI3K and 0.61 fg mL^-1 for CRAF, leading reliable quantification for these two targets. Meanwhile, the feasibility of this assembly was testified by comparing with conventional ELISA method, and the results showed that a high degree of consistency was obtained in these two detection assays. This SERS-colorimetric dual-signal LFA strip can provide a novel strategy for early diagnosis of fetal-related disorders, which is essential for disease diagnosis and treatment guidance during pregnancy.

Avian Eggshell Membrane as a Novel Biomaterial: A Review

The eggshell membrane (ESM), mainly composed of collagen-like proteins, is readily available as a waste product of the egg industry. As a novel biomaterial, ESM is attractive for its applications in the nutraceutical, cosmetic, and pharmaceutical fields. This review provides the main information about the structure and chemical composition of the ESM as well as some approaches for its isolation and solubilization. In addition, the review focuses on the role and performance of bioactive ESM-derived products in various applications, while a detailed literature survey is provided. The evaluation of the safety of ESM is also summarized. Finally, new perspectives regarding the potential of ESM as a novel biomaterial in various engineering fields are discussed. This review provides promising future directions for comprehensive application of ESM.

A review on recent advances of egg byproducts: Preparation, functional properties, biological activities and food applications

The rapid development of egg industries produced vast byproducts that have not been effectively used. In this paper, the comprehensive utilization of egg byproducts was reviewed. Protein extraction and enzymatic hydrolysis were the main used ways for recycle of egg byproducts. The fact that eggshell membrane could accelerate would healing and improve facial skin of healthy people for 12 weeks was found. However, salted egg white had poor functional properties owing to high salt and ultrafiltration was an effective technology to remove 92.93% of salt. Moreover, Defatted yolk protein had the great potential to be used as food additives and functional foods. Other egg byproducts such as egg inhibitor and eggshells also were discussed. The novel applications of egg byproducts in the food field included food additives, feeds, food packaging materials and nutraceuticals based on current knowledge, but the proportion needed to be improved. This paper would provide a new insight for comprehensive utilization of egg byproducts.

Biopolymer and Synthetic Polymer-Based Nanocomposites in Wound Dressing Applications: A Review

Biopolymers are materials obtained from a natural origin, such as plants, animals, microorganisms, or other living beings; they are flexible, elastic, or fibrous materials. Polysaccharides and proteins are some of the natural polymers that are widely used in wound dressing applications. In this review paper, we will provide an overview of biopolymers and synthetic polymer-based nanocomposites, which have promising applications in the biomedical research field, such as wound dressings, wound healing, tissue engineering, drug delivery, and medical implants. Since these polymers have intrinsic biocompatibility, low immunogenicity, non-toxicity, and biodegradable properties, they can be used for various clinical applications. The significant advancements in materials research, drug development, nanotechnology, and biotechnology have laid the foundation for changing the biopolymeric structural and functional properties. The properties of biopolymer and synthetic polymers were modified by blending them with nanoparticles, so that these materials can be used as a wound dressing application. Recent wound care issues, such as tissue repairs, scarless healing, and lost tissue integrity, can be treated with blended polymers. Currently, researchers are focusing on metal/metal oxide nanomaterials such as zinc oxide (ZnO), cerium oxide (CeO₂), silver (Ag), titanium oxide (TiO₂), iron oxide (Fe₂O₃), and other materials (graphene and carbon nanotubes (CNT)). These materials have good antimicrobial properties, as well as action as antibacterial agents. Due to the highly antimicrobial properties of the metal/metal oxide materials, they can be used for wound dressing applications.

State-of-the-Art of Eggshell Waste in Materials Science: Recent Advances in Catalysis, Pharmaceutical Applications, and Mechanochemistry

Eggshell waste is among the most abundant waste materials coming from food processing technologies. Despite the unique properties that both its components (eggshell, ES, and eggshell membrane, ESM) possess, it is very often discarded without further use. This review article aims to summarize the recent reports utilizing eggshell waste for very diverse purposes, stressing the need to use a mechanochemical approach to broaden its applications. The most studied field with regards to the potential use of eggshell waste is catalysis. Upon proper treatment, it can be used for turning waste oils into biodiesel and moreover, the catalytic effect of eggshell-based material in organic synthesis is also very beneficial. In inorganic chemistry, the eggshell membrane is very often used as a templating agent for nanoparticles production. Such composites are suitable for application in photocatalysis. These bionanocomposites are also capable of heavy metal ions reduction and can be also used for the ozonation process. The eggshell and its membrane are applicable in electrochemistry as well. Due to the high protein content and the presence of functional groups on the surface, ESM can be easily converted to a high-performance electrode material. Finally, both ES and ESM are suitable for medical applications, as the former can be used as an inexpensive Ca2+ source for the development of medications, particles for drug delivery, organic matrix/mineral nanocomposites as potential tissue scaffolds, food supplements and the latter for the treatment of joint diseases, in reparative medicine and vascular graft producing. For the majority of the above-mentioned applications, the pretreatment of the eggshell waste is necessary. Among other options, the mechanochemical pretreatment has found an inevitable place. Since the publication of the last review paper devoted to the mechanochemical treatment of eggshell waste, a few new works have appeared, which are reviewed here to underline the sustainable character of the proposed methodology. The mechanochemical treatment of eggshell is capable of producing the nanoscale material which can be further used for bioceramics synthesis, dehalogenation processes, wastewater treatment, preparation of hydrophobic filters, lithium-ion batteries, dental materials, and in the building industry as cement.

Functionalization of eggshell membranes with CuO-ZnO based p-n junctions for visible light induced antibacterial activity against Escherichia coli

Biopolymers provide versatile platforms for designing naturally-derived wound care dressings through eco-friendly pathways. Eggshell membrane (ESM), a widely available, biocompatible biopolymer based structure features a unique 3D porous interwoven fibrous protein network. The ESM was functionalized with inorganic compounds (Ag, ZnO, CuO used either separately or combined) using a straightforward deposition technique namely radio frequency magnetron sputtering. The functionalized ESMs were characterized from morphological, structural, compositional, surface chemistry, optical, cytotoxicity and antibacterial point of view. It was emphasized that functionalization with a combination of metal oxides and exposure to visible light results in a highly efficient antibacterial activity against Escherichia coli when compared to the activity of individual metal oxide components. It is assumed that this is possible due to the fact that an axial p-n junction is created by joining the two metal oxides. This structure separates into components the charge carrier pairs promoted by visible light irradiation that further can influence the generation of reactive oxygen species which ultimately are responsible for the bactericide effect. This study proves that, by employing inexpensive and environmentally friendly materials (ESM and metal oxides) and fabrication techniques (radio frequency magnetron sputtering), affordable antibacterial materials can be developed for potential applications in chronic wound healing device area.

A puzzle piece of protein N-glycosylation in chicken egg: N-glycoproteome of chicken egg vitelline membrane

The chicken egg vitelline membrane (CEVM) is an important structure for the transmembrane transport of egg yolk components, protection of the blastodisc, and separation of egg white and egg yolk. In this study, the N-glycoproteome of the CEVM was mapped and analyzed in depth. Total protein of the CEVM was digested, and the glycopeptides were enriched by a hydrophilic interaction liquid chromatography microcolumn and identified by nano liquid chromatography/tandem mass spectrometry. A total of 435 N-glycosylation sites on 208 N-glycoproteins were identified in CEVM. Gene Ontology enrichment analysis showed that CEVM N-glycoproteins are mainly involved in the regulation of proteinases/inhibitors and transmembrane transport of lipids. Mucin-5B is the primary N-glycoprotein in the CEVM. Comparison of the main N-glycoproteins between the CEVM and other egg parts revealed the tissue specificity of N-glycosylation of egg proteins. The results provide insights into protein N-glycosylation in the chicken egg, CEVM functions and underlying mechanisms.

Removal of Basic Fuchsin from water by using mussel powdered eggshell membrane as novel bioadsorbent: Equilibrium, kinetics, and thermodynamic studies

This study aims to remove organic cationic dye Basic Fuchsin (BF) by adsorption onto a low cost eggshell membrane (ESM) in batch mode at 293 K. XRD analysis confirms the amorphous nature of ESM meanwhile FTIR spectroscopy reveals the presence of several functional groups such as hydroxyl (-OH), sulfhydryl (-SH), carboxyl (-COOH), and amino (-NH₂). Morphological observations by SEM indicate its fibrous microstructure. BET analysis shows a surface area of 11.56 m² g^-1 and the presence of mesopores with a volume of 6.173 10^-3 cm³ g^-1. The value of pH_PZC of ESM is 7.05. The influence of adsorbent dose, contact time, pH, temperature and dye concentration is examined. The highest adsorption capacity around 48 mg.g^-1is achieved for a dye concentration 250 ppm, pH 6 and 25 °C. In addition, adsorption has been found to follow pseudo-second order kinetics. The analysis of the experimental data using linear forms based on Langmuir, Freundlich and Temkin isotherm models indicate that the best fit is obtained with Freundlich model. Thermodynamic parameters (Gibbs free energy, enthalpy, and entropy) reveal that the adsorption of BF onto ESM is an exothermic and spontaneous process. A comprehensive mechanism for BF adsorption by ESM has been proposed.

Effect of eggshell membrane as porogen on the physicochemical structure and protease immobilization of chitosan-based macroparticles

Chitosan-based macroparticle is a common carrier for enzyme immobilization applied in food industry. Driven by the requirement of large carrier pores for the biomacromolecular substrates such as protein, the eggshell membrane powder (ESMP) was employed as multifunctional porogen to improve the physicochemical structure of chitosan-based macroparticles. The prepared macroparticles were characterized by SEM, XRD, FTIR, Raman spectroscopy, nitrogen adsorption-desorption isotherms, and thermogravimetric analysis. The results showed that an increase of ESMP percentage could improve the porosity of macro holes in macroparticles, and it also enlarged the size of mesopores. Moreover, the ESMP significantly increased (P < 0.05) the amount of papain immobilization, whereas the specific activity of immobilized papain achieved a maximum value of 871.95 U/mg at CSESM2 and then declined with the increase of ESMP. Therefore, the inclusion of 20 % ESMP in chitosan-based macroparticles gave the highest activity of its immobilized protease.

Separation and Identification of Highly Efficient Antioxidant Peptides from Eggshell Membrane

The enzymatic hydrolysates (EHs) of the eggshell membrane (ESM) were obtained after incubating eggshell membrane in solutions prepared with Na₂SO₃ and alkaline protease combinations. The effects of enzyme species, enzyme dosage, Na₂SO₃ concentration, and hydrolysis time on the antioxidant activity of the ESM-EH were determined. Also, the correlation between the degree of hydrolysis (DH) and the antioxidant activity of ESM-EH was analyzed. The DH of ESM-EH showed a highly positive correlation with the reducing power (R² = 0.857) and total antioxidant activity (TAA) (R² = 0.876) and performed negative correlation with the Fe²⁺-chelating ability (R² = −0.529). The molecular weight distribution of the ESM-EH was determined by MALDI-TOF/MS. Cation exchange chromatography (Sephadex C-25) was used to isolate the ESM-EH and then the enzymatic hydrolysis fragment (EHF) was obtained. Among the five isolated fragments (F1~F5), fragment 3 (F3), which was composed of 28 polypeptides, showed the highest ability to quench ABTS• (2,2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid) (90.44%) and also displayed stronger TBARS (thiobarbituric acid– reactive substances) (58.17%) and TAA (303.82 µg /mL) than the ESM-EH. Further analysis of the 28 peptides in F3 identified using LC-MS/MS indicated that five peptides (ESYHLPR, NVIDPPIYAR, MFAEWQPR, LLFAMTKPK, MLKMLPFK) showed high water-solubility, biological activities, and antioxidant characteristics. Finally, the TAA of the synthetic peptide was verified, the synthetic peptides ESYHLPR and MFAEWQPR performed the best activity and have high potentials to be used as antioxidant agents in functional foods, pharmaceuticals, or cosmetics.