Harnessing potential of avian eggshell membrane derived collagen hydrolysate for bone tissue regeneration.

BACKGROUND: Natural bone grafts are the highly preferred materials for restoring the lost bone, while being constrained of donor availability and risk of disease transmission. As a result, tissue engineering is emerging as an efficacious and competitive technique for bone repair. Bone tissue engineering (TE) scaffolds to support bone regeneration and devoid of aforesaid limitations are being vastly explored and among these the avian eggshell membrane has drawn attention for TE owing to its low immunogenicity, similarity with the extracellular matrix, and easy availability. METHODOLOGY AND RESULTS: In this study, the development of bone ingrowth support system from avian eggshell membrane derived collagen hydrolysates (Col-h) is reported. The hydrolysate, cross-linked with glutaraldehyde, was developed into hydrogels with poly-(vinyl alcohol) (PVA) by freeze-thawing and further characterized with ATR-FTIR, XRD, FESEM. The biodegradability, swelling, mechanical, anti-microbial, and biocompatibility evaluation were performed further for the suitability in bone regeneration. The presence of amide I, amide III, and -OH functional groups at 1639 cm- 1,1264 cm- 1, and 3308 cm- 1 respectively and broad peak between 16°-21° (2θ) in XRD data reinstated the composition and form. CONCLUSIONS: The maximum ratio of Col-h/PVA that produced well defined hydrogels was 50:50. Though all the hydrogel matrices alluded towards their competitive attributes and applicability towards restorative bone repair, the hydrogel with 40:60 ratios showed better mechanical strength and cell proliferation than its counterparts. The prominent E. coli growth inhibition by the hydrogel matrices was also observed, along with excellent biocompatibility with MG-63 osteoblasts. The findings indicate strongly the promising application of avian eggshell-derived Col-h in supporting bone regeneration.

Preparation and characterization of propolis reinforced eggshell membrane/ GelMA composite hydrogel for biomedical applications.

Gelatin methacrylate-based hydrogels (GelMA) were widely used in tissue engineering and regenerative medicine. However, to manipulate their various chemical and physical properties and create high-efficiency hydrogels, different materials have been used in their structure. Eggshell membrane (ESM) and propolis are two nature-derived materials that could be used to improve the various characteristics of hydrogels, especially structural and biological properties. Hence, the main purpose of this study is the development of a new type of GelMA hydrogel containing ESM and propolis, for use in regenerative medicine. In this regard, in this study, after synthesizing GelMA, the fragmented ESM fibers were added to it and the GM/EMF hydrogel was made using a photoinitiator and visible light irradiation. Finally, GM/EMF/P hydrogels were prepared by incubating GM/EMF hydrogels in the propolis solution for 24 h. After various structural, chemical, and biological characterizations, it was found that the hydrogels obtained in this study offer improved morphological, hydrophilic, thermal, mechanical, and biological properties. The developed GM/EMF/P hydrogel presented more porosity with smaller and interconnected pores compared to the other hydrogels. GM/EMF hydrogels due to possessing EMF showed compressive strength up to 25.95 ± 1.69 KPa, which is more than the compressive strength provided by GM hydrogels (24.550 ± 4.3 KPa). Also, GM/EMF/P hydrogel offered the best compressive strength (44.65 ± 3.48) due to the presence of both EMF and propolis. GM scaffold with a contact angle of about 65.41 ± 2.199 θ showed more hydrophobicity compared to GM/EMF (28.67 ± 1.58 θ), and GM/EMF/P (26.24 ± 0.73 θ) hydrogels. Also, the higher swelling percentage of GM/EMF/P hydrogels (343.197 ± 42.79) indicated the high capacity of this hydrogel to retain more water than other scaffolds. Regarding the biocompatibility of the fabricated structures, MTT assay results showed that GM/EMF/P hydrogel significantly (p-value < 0.05) supported cell viability. Based on the results, it seems that GM/EMF/P hydrogel could be a promising biomaterial candidate for use in various fields of regenerative medicine.

Synthesis of lysinonorleucine and mass spectrometric analysis of lysinonorleucine and merodesmosine in bovine ligament and eggshell membrane.

Elastin is an important extracellular matrix protein that contributes to the elasticity of cells, tissues, and organs. Although crosslinking amino acids such as desmosine and isodesmosine have been identified in elastin, details regarding the structure remain unclear. In this study, an elastin crosslinker, lysinonorleucine, was chemically synthesized and detected in hydrolyzed bovine ligament and eggshell membrane samples utilizing tandem mass spectrometry. Merodesmosine, another crosslinker of elastin, was also measured in the same samples using the same analytical method. The resulting data should aid in the elucidating the crosslinking structure of elastin and eggshell membranes.

Optical and biological properties of MgO/ZnO nanocomposite derived via eggshell membrane: a bio-waste approach.

A novel synthesis of MgO/ZnO nanocomposite using a template, namely an eggshell membrane (ESM) was attempted. The nanocomposite was characterized by XRD, UV-visible, FTIR, Raman, DLS (zeta potential and particle size distribution), FESEM with EDX, and HRTEM analysis. The presence of periclase cubic MgO (space group Fm3m) and hexagonal wurtzite ZnO (space group P63mc) structures was verified by the XRD results. The average crystallite size of the MgO/ZnO nanocomposite was equal to 9.43 nm. The nanocomposite exhibited an on-set of absorbance close to 300 nm. From the taucs plot, the bandgap of the composite was calculated, and it was equal to 3.63 eV. The FTIR spectrum of the composite showed Mg-O stretching vibration at 455 cm-1 and that of Zn-O at 564 cm-1. The zeta potential and the particle size distribution of the nanocomposite were equal to - 35.5 mV and 176.1 nm. The FESEM images of the nanocomposite appeared as an aggregated honeycomb with a cubic and hexagonal structure. The EDX analysis showed the presence of Mg (23.65 atom%), Zn (27.95 atom%), and O (48.40 atom%). The antibacterial and antifungal activities of the nanocomposite were investigated using the agar-well diffusion method. The antibacterial activity exhibited the highest zone of inhibition for Bacillus subtilis (25 ± 0.41 mm) and Shigella dysenteria (25 ± 0.19 mm), whereas the antifungal activity showed the highest zone of inhibition for Aspergillus terrus (27 ± 0.25 mm). The MIC value of the nanocomposite was equal to 9.37 (µg/mL) for all the bacteria. Hence, it is verified that the present MgO/ZnO nanocomposite could very well be used to treat bacterial and fungal infections.

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.

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.

Fabrication and characterization of gelatin-based nanocomposite edible film prepared from eggshell with anthocyanin as pH indicator to assure quality of food.

Intelligent packaging with a pH indicator is a protective measure that can assure the food quality at the point of delivery or usage. This research targets to develop eggshell membrane gelatin-based hydroxyapatite (HAP) nanocomposite edible film incorporated with anthocyanin extracted from Jambolão (Syzygium cumini). The HAP nanoparticles were synthesized from eggshells, the size (< 100 nm) and morphology were confirmed by Dynamic light scattering (DLS), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). Eggshell gelatin film, eggshell gelatin film reinforced with HAP (Gel-HAP), and anthocyanin incorporated eggshell gelatin film reinforced with HAP (Gel-HAP-ACN) were prepared. The physicochemical, optical, and surface properties of the nanocomposite films were evaluated. Gel-HAP-ACN film had excellent light barrier characteristics than Gel-HAP and Gel films. The Gel-HAP-ACN film had enhanced antioxidant (57.71%) property than the gelatin film and also had antibacterial action against Salmonella typhi, Escherichia coli and Staphylococcus aureus. Hence, this report suggests Gel-HAP-ACN film for food packaging to assure the safety of the food. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05685-4.

Eggshell Biliverdin as an Antioxidant Maternal Effect: Biliverdin as an Antioxidant Resource in Oviparous Animals.

In this essay, the hypothesis that biliverdin pigment plays an antioxidant role in the avian eggshell is proposed. Due to its ability to scavenge free radical species and to reduce mutation, biliverdin potentially counteracts the oxidative action of pathogens that penetrate the eggshell and/or protects the shell membrane from oxidation, thus promoting the proven antioxidant and antimicrobial capacities of the shell membrane itself. Additionally, biliverdin may be able to inhibit viral replication in the eggshell due to its ascribed antiviral properties. Moreover, previous results in other taxa leave open the question of whether biliverdin can be absorbed by the embryo from the eggshell and play a role in embryogenesis. These mechanisms of antioxidant action of eggshell biliverdin remain totally unexplored in birds and in other oviparous animals. The main assumptions and predictions of the antioxidant hypothesis are developed, and directions for future research are proposed.

Novel combination of bioactive agents in bilayered dermal patches provides superior wound healing.

In present study, multifunctional bilayered dermal patches with antibacterial, antioxidant and anti-inflammatory properties were developed using solvent casting or electrospinning methods and compared for performance. Top layer was made up of polycaprolactone (PCL) and chitosan (CS) while bottom layer was made of polyvinyl alcohol (PVA) with curcumin nanoparticles and soluble eggshell membrane protein (SESM) as the wound healing agents. Curcumin nanoparticles showed reduction in the production of reactive oxygen species (ROS) and inflammatory cytokines and markers in mice T cells or human macrophages, confirming their antioxidant and anti-inflammatory properties while SESM improved migration of human adult dermal fibroblasts, suggesting its contribution to wound healing. The dermal patches were hemocompatible and antibacterial and also provided adequate absorption of wound exudates, support and components required for recruitment of cells and deposition of extracellular matrix to enable superior wound healing than its commercial counterpart in a full thickness excision wound model in rats.

Parameter Screening and Optimization for a Polycaprolactone-Based GTR/GBR Membrane Using Taguchi Design.

Our objective was to determine and optimize the significant parameters affecting mechanical properties and mean fiber diameter (MFD) of a novel GTR/GBR membrane composed of polycaprolactone (PCL) and chicken eggshell membrane (ESM). For this, we prepared electrospun membrane specimens (n = 16) with varying concentrations of PCL, ESM, nano-hydroxyapatite (HAp), and altered electrospinning parameters as generated by DOE++ software. After the determination of MFD and mechanical properties for all specimens, Taguchi orthogonal array L8 design was used to screen significant factors affecting the MFD and mechanical properties. PCL wt%, ESM wt%, HAp wt%, applied voltage (AV), flow rate (FR), and spinneret-collector distance (SCD) were the independent variables investigated. The response variables analyzed were MFD, tensile strength (TS), and elastic modulus. ANOVA outlined ESM wt%, HAp wt%, AV, FR, SCD, and an interactive effect between PCL wt% and AV to be the significant factors affecting modulus values of an electrospun PCL/ESM membrane (p < 0.05). Furthermore, concentrations of PCL and ESM were the significant factors affecting MFD (p < 0.05) and there were no significant factors affecting the TS values. Optimization using DOE++ software predicted that the maximal TS of 3.125 MPa, modulus of 278.168 MPa, and MFD of 882.75 nm could be achieved.

Eggshell membrane as a bioactive agent in polymeric nanotopographic scaffolds for enhanced bone regeneration.

A bone regeneration scaffold is typically designed as a platform to effectively heal a bone defect while preventing soft tissue infiltration. Despite the wide variety of scaffold materials currently available, such as collagen, critical problems in achieving bone regeneration remain, including a rapid absorption period and low tensile strength as well as high costs. Inspired by extracellular matrix protein and topographical cues, we developed a polycaprolactone-based scaffold for bone regeneration using a soluble eggshell membrane protein (SEP) coating and a nanotopography structure for enhancing the physical properties and bioactivity. The scaffold exhibited adequate flexibility and mechanical strength as a biomedical platform for bone regeneration. The highly aligned nanostructures and SEP coating were found to regulate and enhance cell morphology, adhesion, proliferation, and differentiation in vitro. In a calvaria bone defect mouse model, the scaffolds coated with SEP applied to the defect site promoted bone regeneration along the direction of the nanotopography in vivo. These findings demonstrate that bone-inspired nanostructures and SEP coatings have high potential to be applicable in the design and manipulation of scaffolds for bone regeneration.

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 pHPZC 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.

Processed Eggshell Membrane Powder Is a Promising Biomaterial for Use in Tissue Engineering.

The purpose of this study was to investigate the tissue regenerating and biomechanical properties of processed eggshell membrane powder (PEP) for use in 3D-scaffolds. PEP is a low-cost, natural biomaterial with beneficial bioactive properties. Most importantly, this material is available as a by-product of the chicken egg processing (breaking) industry on a large scale, and it could have potential as a low-cost ingredient for therapeutic scaffolds. Scaffolds consisting of collagen alone and collagen combined with PEP were produced and analyzed for their mechanical properties and the growth of primary fibroblasts and skeletal muscle cells. Mechanical testing revealed that a PEP/collagen-based scaffold increased the mechanical hardness of the scaffold compared with a pure collagen scaffold. Scanning electron microscopy (SEM) demonstrated an interconnected porous structure for both scaffolds, and that the PEP was evenly distributed in dense clusters within the scaffold. Fibroblast and skeletal muscle cells attached, were viable and able to proliferate for 1 and 2 weeks in both scaffolds. The cell types retained their phenotypic properties expressing phenotype markers of fibroblasts (TE7, alpha-smooth muscle actin) and skeletal muscle (CD56) visualized by immunostaining. mRNA expression of the skeletal muscle markers myoD, myogenin, and fibroblasts marker (SMA) together with extracellular matrix components supported viable phenotypes and matrix-producing cells in both types of scaffolds. In conclusion, PEP is a promising low-cost, natural biomaterial for use in combination with collagen as a scaffold for 3D-tissue engineering to improve the mechanical properties and promote cellular adhesion and growth of regenerating cells.

Solubilized eggshell membrane supplies a type III collagen-rich elastic dermal papilla.

Signs of aging in facial skin correlate with lifespan and chronic disease; however, the health of aging skin has not been extensively studied. In healthy young skin, the dermis forms a type III collagen-rich dermal papilla, where capillary vessels supply oxygen and nutrients to basal epidermal cells. Chicken eggshell membranes (ESMs) have been used as traditional medicines to promote skin wound healing in Asian countries for many years. Previously, we designed an experimental system in which human dermal fibroblasts (HDFs) were cultured on a dish with a solubilized ESM (S-ESM) bound to an artificial phosphorylcholine polymer; we found that genes that promoted the health of the papillary dermis, such as those encoding type III collagen, were induced in the S-ESM environment. The present study found that a gel with a ratio of 20% type III/80% type I collagen, similar to that of the baby skin, resulted in a higher elasticity than 100% type I collagen (p < 0.05) and that HDFs in the gel showed high mitochondrial activity. Thus, we decided to perform further evaluations to identify the effects of S-ESM on gene expression in the skin of hairless mice and found a significant increase of type III collagen in S-ESM. Picrosirius Red staining showed that type III collagen significantly increased in the papillary dermis after S-ESM treatment. Moreover, S-ESM application significantly improved human arm elasticity and reduced facial wrinkles. ESMs may have applications in extending lifespan by reducing the loss of tissue elasticity through the increase of type III collagen.

Eggshell membrane as a novel bio sorbent for remediation of boron from desalinated water.

This study investigated the use of eggshell membrane (ESM) as a bio-sorbent and the effect of temperature, pH, and initial concentration on its efficiency. Furthermore, by altering the chemical composition, modified eggshell membrane (MESM) was prepared, and its efficiency was compared with the ESM. Results showed that the adsorption of boron preferred an acidic condition; pH 6 at 35 °C. In addition, the positive value of ΔH° suggested that the reaction favored endothermic pathway, while the negative value for ΔG° further suggested that the adsorption process was spontaneous. Furthermore, the ESM could adsorb 97% of boron, while MESM was able to adsorb 95%. From the Fourier transform infrared (FTIR), different functional groups were recorded on the surface of the ESM and MESM, and they played key role in the boron adsorption mechanisms. Linear Freundlich model was suggested to best describe the experimental data with 99.4% correlation coefficient.

The effect of ultrasound on the alkali extraction of proteins from eggshell membranes.

BACKGROUND: Eggshell contains two layers formed by a dense network of fibrous proteins. These proteins are highly insoluble in a broad variety of solvents, but their composition makes them suitable for a broad range of applications. In this study, in order to extract and solubilise these proteins, the eggshell membranes were treated in an alkali solution. A Box-Behnken design was employed to determine the influence of the treatment variables on the amount of protein solubilised. Furthermore, the effect of ultrasound on the protein recovery yield was also evaluated and compared with the unmodified process. RESULTS: A solubilised protein yield close to 100% of the total eggshell membrane protein was obtained. The optimal conditions could be set at 70 °C in a 1.0 mol L-1 NaOH solution for 60 min. However, when ultrasound was applied, it was possible to decrease the time of reaction by half. In the two processes, the temperature was found to be the most important independent variable evaluated. Finally, the antioxidant properties of the proteins obtained in each case were similar. CONCLUSIONS: Ultrasound favours the detachment of big clumps of proteins from the eggshell membrane, facilitating the solubilisation of its compounds. The ultrasound had no effect on the protein properties tested in this study. © 2017 Society of Chemical Industry.

Silver nanoparticles decorated eggshell membrane as an effective platform for interference free sensing of dopamine.

In this paper a simple electrochemical sensing of dopamine by a new effective immobilization of tyrosinase (Tyr) enzyme on eggshell membrane (ESM) along with silver nanoparticles (AgNPs) is reported. The modified membrane was characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDAX), X-Ray diffraction (XRD). A simple solution based approach was used to prepare AgNPs on biomembrane followed by glutaraldehyde activation to immobilize Tyr on the nanoparticles decorated ESM. The direct electrochemistry of DA oxidation was performed through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Characterization of membrane was accomplished by electrochemical impedance spectroscopy (EIS). Prepared electrode showed very good stability, reproducibility, high selectivity, easy preparation and regeneration of electrode. The proposed sensor exhibited low detection limits 1.7ngL-1 with wide linear range 10-1000 ngL-1, excellent sensitivity (14.28µA µgL-1cm-2) with good storage and operational stabilities. The accurate measurement of dopamine in blood serum and good recoveries in spiked serum samples ensured great potential for medical diagnostics.

Evaluation of a mixed anionic-nonionic surfactant modified eggshell membrane as an advantageous adsorbent for the solid-phase extraction of Sudan I-IV as model analytes.

The coadsorption of mixed anionic-nonionic surfactants, sodium dodecylbenzenesulfonate with Triton X-100, on the surface of eggshell membrane was investigated based on adsorption isotherms to improve the solid-phase extraction performance of eggshell membrane toward organic contaminants. Results showed that even though excess Triton X-100 might inhibit the adsorption of sodium dodecylbenzenesulfonate, a low dosage of Triton X-100 can significantly improve sodium dodecylbenzenesulfonate modification and enhance the extraction efficiency of eggshell membrane from 73.7 to 100.4% because of the formation of mixed hemimicelles. The highest recovery was achieved at 2:8 (Triton X-100/sodium dodecylbenzenesulfonate mass ratios), and multiple mechanisms involving π-π interactions, hydrophobic effect, and π-π electron donor-acceptor interactions contributed to the strong extraction affinity. When mixed, the Triton X-100 and sodium dodecylbenzenesulfonate modified eggshell membrane packed cartridge coupled with high-performance liquid chromatography was applied for the simultaneous determination of trace Sudan I-IV, and low detection limits (0.16-0.26 ng/L) were achieved with satisfactory linearity (R2  > 0.999) in 10-10 000 µg/L. For real samples, Sudan II and III in one chilli sauce sample were found at 4.3 and 1.7 µg/kg. Sudan I-IV recoveries at three spiked levels were 87.4-102.9% with precisions <6.8%. Comparison with commonly used solid-phase extraction adsorbents and methods further reflected the superiorities of the proposed adsorbent in sensitivity, retention ability, and applicability.

Production and characterization of functional properties of protein hydrolysates from egg shell membranes by lactic acid bacteria fermentation.

This study aimed to ferment the chicken eggshell membrane (ESM) using the lactic acid bacteria, Lactobacillus plantarum for preparation of functional and bioactive protein hydrolysates. Cultivation at an initial pH of 8.0 for 36 h resulted in maximum protein concentration (177.3 mg/g) and degree of hydrolysis (25.1%) of the hydrolysates. Fermentation resulted in the production of hydrolysates that demonstrated excellent solubility (90.7%), good foaming capacity (36.7%) and emulsification activity (94.6 m2/g). Additionally, these protein hydrolysates exhibited remarkable bioactive properties for instance reducing power (2.53), protection from DPPH radical (70.5%) and angiotensin I converting enzyme inhibition (49.3%). The fermented protein hydrolysates were also found effective against various foodborne pathogens. The protein hydrolysates obtained by fermentation of ESM can be potentially incorporated in functional foods and nutraceuticals resulting in valorization of the ESM waste.

Mechanical design principles of avian eggshells for survivability.

Biological materials exhibit complex structure-property relationships which are designed by nature's evolution over millions of years. Unlocking the fundamental physical principles behind these relationships is crucial for creating bioinspired materials and structures with advanced functionalities. The eggshell is a remarkable example with a well-designed structure to balance the trade-off as it provides mechanical protection while still being easy for hatching. In this study, we investigate the underlying mechanical design principles of chicken eggshells under various loading conditions through a combination of experiments and simulations. The unique geometry and structure of the eggshell play a critical role in achieving an excellent balance between mechanical toughness and ease of hatching. The effects of eggshell membranes are elucidated to tune the mechanical properties of the eggshell to further enhance this balance. Moreover, a mechanics-based three-index model is proposed based on these design principles, suggesting the optimal eggshell thickness design to improve survivability across a broad range of avian species with varying egg sizes. The survivability-design relationships hold great potential for the development of improved structural materials for applications in sports safety equipment and the packaging industry. STATEMENT OF SIGNIFICANCE: The fundamental physical principles underlying the complex structure-property relationships in biological materials are uncovered in this study, with a particular focus on chicken eggshells as a prime example. Through the investigation of their mechanical design, we reveal the critical role of eggshell geometry and structure in achieving a balance between toughness and ease of hatching. Specifically, the crack resting effect is observed, making the eggshell easier to break from the inside than from the outside. Additionally, we explore the influence of eggshell membranes on this balance, contributing to the enhancement of the eggshell's mechanical properties. For the first time, we propose a three-index model that uncovers the underlying principles governing the evolution of eggshell thickness. This model suggests optimal thickness designs for diverse avian species, with the goal of enhancing egg survivability. These findings can guide the development of improved structural materials with advanced functionalities, enabling greater safety and efficiency in a wide range of applications.