Search Results (147)

Collagen, the most abundant structural protein in animals, is fundamental for tissue integrity and regeneration. Conventional mammalian sources face limitations related to sustainability, safety, and ethical concerns, underscoring the need for alternative biomaterials. Marine organisms, particularly jellyfish, offer a promising eco-friendly collagen source. In this study, collagen and collagen-derived peptides were extracted from the cnidarian Physalia physalis and biochemically characterized. Circular dichroism demonstrated partial loss of triple-helix structure, while SDS-PAGE revealed type I collagen related α-chains together with low-molecular-weight fragments. The hydrolyzed collagen fractions exhibited keratinocyte and fibroblast cytocompatibility and increased keratinocyte migration. Moreover, P. physalis-derived peptides modulated inflammatory cytokine release in lipopolysaccharide-stimulated macrophages reducing tumor necrosis factor (TNF)-α by 38% and increasing interleukin (IL)-10 by 29%. Based on these results, a stable bioactive serum formulation incorporating P. physalis collagen peptides was developed. Overall, this work demonstrates that bioactive peptides from P. physalis possess immunomodulatory and regenerative potential and represent a promising new marine resource for cosmetic applications. Full article

Eel (Anguilla) is an aquatic animal with high nutritional value and multiple health benefits for the human body. To fully utilize its processing by-products fish bone, this study optimized the enzymatic preparation process of using BP neural network and GA genetic algorithm, with collagen extraction yield as the key evaluation metric, and characterized the properties of the obtained collagen. The results demonstrated that the optimal extraction conditions for eel bone collagen were as follows: enzyme dosage of 2%, hydrolysis time of 2.65 h, solid-to-liquid ratio of 1:22, and ultrasonic pretreatment for 21 min at 250 W power, achieving an extraction yield of 57.6%. The main amino acids identified were glycine, glutamic acid, proline, and arginine. SDS-PAGE electrophoresis revealed that eel bone collagen exhibited structural characteristics of type I collagen. Raman spectroscopy and X-ray diffraction indicated an intact triple-helix structure with partial ordered features. The DSC and TGA results demonstrated good thermal stability, with a denaturation temperature of 106.73 °C. SEM imaging displayed a loose, porous fibrous network structure, while rheological analysis suggested potential biomedical material properties. The findings of this study provide fundamental data for the high-value utilization and development of eel bone resources. Full article

Background/Objectives: Chlorella pyrenoidosa polysaccharides (CPPs) exhibit digestion-resistant properties, with their bioactivity largely driven by gut microbiota metabolism. However, the fermentation characteristics of CPPs within the intestinal tract remain to be fully elucidated. Elucidating the utilization and metabolic processes of CPPs with respect to the gut microbiota aids in understanding the potential mechanisms underlying the biological activity of these polysaccharides. Methods: This work fractionated CPPs into a neutral polysaccharide fraction (CPP-1) and an acidic polysaccharide fraction (CPP-2), followed by the characterization of their structure, physicochemical properties, and in vitro fermentation characteristics. Results: The results demonstrated that both CPP-1 and CPP-2 were non-starch heteropolysaccharides linked primarily by α-glycosidic bonds and lacking a triple helix structure. Both samples exhibited exceptional thermal stability, high water solubility, and low viscosity properties. CPP-2 selectively promoted Enterocloster, whereas CPP-1 significantly enriched Bacteroides and Bifidobacterium in gut microbiota. This differential regulation may be attributable to structural variations between the polysaccharides. Functional predictions indicated that CPP-1 enhances intestinal barrier integrity and immune homeostasis, whereas CPP-2 has anti-inflammatory activity. CPP-1 and CPP-2 interventions significantly upregulated the levels of health-promoting metabolites, including nicotinamide adenine dinucleotide, putrescine, and 3′-adenosine monophosphate. CPP-1 predominantly modulated amino acid metabolic pathways, while CPP-2 could effectively regulate purine, pyrimidine, amino acid, and butanoate metabolic pathways. Conclusions: This work identifies CPPs (CPP-1 and CPP-2) as novel modulators of gut homeostasis and host metabolism through microbiota–metabolite axis remodeling, supporting their prebiotic potential for functional food innovation. Full article

In this study, we propose the Integrated Developmental Entrepreneurship Resiliency Framework (IDERF), a conceptual model positioning universities as orchestrators of stakeholder networks for entrepreneurial resilience and sustainability. Review and analysis of historical and contemporary research revealed gaps in existing approaches to sustainable entrepreneurship. Entrepreneurship education has evolved from isolated curricula to formal programs that incorporate experiential learning and multilateral institutional access, which appreciably enhance entrepreneurial resilience and venture longevity. The integration of resilience theory with entrepreneurship research has identified multi-level sustainment factors across the disciplines of psychology, organizational theory, and structural economic development. The IDERF addresses this limitation by adapting the triple helix model to a quadruple helix framework that encompasses academia, government, industry, and community stakeholders. Our proposed conceptual framework was developed through conceptual synthesis based on a structured literature review of 212 publications on university-led entrepreneurship programs and entrepreneur sustainability and resilience since 1940. Our findings revealed the need for more resiliency-focused entrepreneurship program designs, synthesis between resilience and sustainability education, analysis of educational program impacts on business development sustainability, and practical entrepreneur training in real-world economic contexts. The resulting IDERF encompasses five dimensions of adaptive entrepreneurial capacity, stakeholder governance, economic transformation, social–environmental integration, and institutional reform as novel components of entrepreneurial resilience and sustainability. We propose an integrated mixed-methods research agenda that includes proposed research questions to instigate the development of measurement frameworks and cross-cultural validation to empirically test the IDERF’s effectiveness in fostering entrepreneurial resilience across diverse contexts and economic regions. Full article

The recycling of by-products from fish processing procedures has recently been attracting increased attention. In this study, three types of gelatin were isolated from grass carp skin, bone, and scales, named SKG, BG, and SCG, respectively, and their structural and functional characteristics were investigated. Compared with BG and SCG, SKG exhibited the highest extraction yield (18.30 ± 0.24%) and protein content (90.12 ± 0.21%) and the lowest ash content (1.50 ± 0.08%). Electrophoresis analysis revealed that SKG contained more α chains than BG and SCG. Fourier transform infrared spectra showed that the absorption peaks of gelatin were mainly positioned in amide band regions, whereas some of the triple helix structure was lost. More than 85% solubility was observed in all gelatin types with pH 3–10. Meanwhile, there was a higher gel strength in SKG (288.2 g) than in BG (270.2 g) and SCG (245.1 g). Furthermore, the water or oil absorption and emulsifying characteristics of SKG were also better than those of BG and SCG. The differences in functional properties between gelatin types appear to be related to protein distribution and composition. All the results indicate that grass carp skin is a material with the potential to extract gelatin with a higher yield and gel strength and better functional characteristics compared with bone and scales. Full article

The processing of fishery products generates a substantial amount of by-products, which can be utilized to promote a circular economy. The objective of the present study was to extract and characterize native collagen and total lipid extract from the fish skin and bones of crevalle jack (Caranx hippos). Physicochemical, structural, and morphological properties were evaluated for collagens. Chemical composition and functional properties were evaluated for lipid extracts. Native type I collagens were obtained by acid extraction, yielding approximately 2.64–6.16% (d.b.). The elemental chemical analysis showed its purity. The stability of the triple helix of collagen was verified through characteristic bands in the FTIR and UV spectra, the peaks at 2θ, around 7.5° and 19.5° obtained by XRD, and the bands of SDS-PAGE. Collagens show isoelectric points of 4.94 (skin) and 4.90 (bone), thermal stabilities of 53.40 °C (skin) and 46.88 °C (bone), and the percentage surface porosities of 41.28 (skin) and 38.84 (bone), all of which demonstrate their potential as a raw material in the biomedical field. The total lipids obtained were extracted using the Soxhlet and Folch methods. The extracts show EPA (1.26–3.16%) and DHA (3.94–9.78%) contents, with inhibition percentages of 32.7% (ABTS), 19.6% (DPPH), and 70.83% (β-carotene). These results highlight the potential of total lipid extract for nutraceutical and food applications. Full article

Destinations such as Bali face intensifying overtourism, which undermines ecological integrity, cultural authenticity, and local livelihoods. Traditional sustainable tourism approaches have proven insufficient, leading to calls for regenerative tourism that restores ecosystems and strengthens communities. This study examines how Penta-Helix collaboration can drive regenerative tourism, mitigate overtourism, and deliver sustainability outcomes. A mixed-methods design was employed. Survey data from 220 domestic and international visitors were analyzed using structural equation modeling (SEM–PLS) to test relationships among Penta-Helix collaboration, regenerative tourism, overtourism mitigation, and sustainability outcomes. To complement these findings, an analytic hierarchy process (AHP) was conducted with 30–40 key stakeholders drawn from 100 informants (government, businesses, communities, academia, and media) to prioritize mitigation strategies. SEM–PLS results indicate that Penta-Helix collaboration significantly enhances regenerative tourism practices (β = 0.62), which strongly reduce overtourism impacts (β = 0.58). Mediation tests reveal that overtourism mitigation is a key mechanism linking regenerative tourism to triple bottom line outcomes (economic, socio-cultural, environmental). AHP results show that carrying capacity enforcement and participatory governance emerge as the top-priority strategies, underscoring the dual importance of institutional policy and community empowerment. The findings advance theoretical debates by positioning regenerative tourism as a systemic innovation enabled by networked governance and operationalized through overtourism mitigation strategies. Practically, the study highlights the need for policy enforcement, participatory governance, and adaptive destination management to embed regenerative principles in overtourism hotspots. Full article

RNA triple helices are relatively understudied, including their interactions with small molecules. In this study, we evaluated eight previously reported triplex-binding molecules (TBMs) for their functional effects on the premature and mature MALAT1 triple helix. Based on UV thermal denaturation experiments, the TBMs berberine, coralyne, sanguinarine, berenil, and neomycin selectively stabilize the Hoogsteen interface of the MALAT1 triple helix. Moreover, fisetin, luteolin, and quercetin were more sensitive to nucleotide composition, whereas berberine, coralyne, sanguinarine, and berenil were more sensitive to changes in the length of the major-groove triple helix. Most TBMs could not outcompete MALAT1 triple helix-binding proteins, except for neomycin. Surface plasmon resonance experiments demonstrated that berberine and sanguinarine display relatively quick association and dissociation binding profiles. Treating human colorectal carcinoma cells with each of the TBMs reduced MALAT1 levels by ~20–60%. This study demonstrates that TBMs broadly recognize the premature and mature MALAT1 triple helix but exhibit subtle sensitivities, suggesting that TBMs can be designed to selectively bind triple helices based on nucleotide composition, length, and structural context. Full article

Type II collagen (Col2), a crucial structural protein in hyaline cartilage, is essential for cartilage integrity and facilitating injury repair. However, research on recombinant type II collagen still faces many challenges, such as structure and yield, which limit the application of recombinant Col2 in biomedical fields. In this study, we achieved high-yield expression of full-length human Col2 (rhCol2) in CHO cells. The physical and chemical properties of rhCol2 were very close to native Col2, including molecular weight, triple helix structure, thermal stability and self-assembly capacity. Functional assays of primary chondrocytes have demonstrated that rhCol2 can effectively promote chondrocyte proliferation and increase the expression levels of cartilage-specific genes (Col2a1, Aggrecan, and Sox-9). Moreover, a cartilage defect model was surgically created in SD rats demonstrated that rhCol2 significantly enhanced cartilage repair, and the severity of the defect was assessed through histological and micro-CT analyses. Human chondrocytes were utilized to compare the effects of different collagens and verified through a series of functional experiments. In conclusion, these findings indicate that rhCol2 is an effective biomaterial and is expected to promote the application of recombinant collagen in the field of cartilage repair. Full article

Collagen is a family of large, fibrous biomacromolecules common in animals, distinguished by unique molecular, structural, and functional properties. Despite the relatively low complexity of their sequences and the repetitive conformation of the triple helix, which is the defining feature of this family, unraveling sequence–stability and structure–function relationships in this group of proteins remains a challenging task. Considering the importance of the structural aspects in collagen chain recognition and selection, we reviewed our current knowledge of the heterotrimeric structures of non-collagenous (NC) regions that lack the triple helix sequence motif, Gly-X-Y, and are crucial for the correct folding of the functional states of these proteins. This study was conducted by simultaneously surveying the current literature, mining the structural database, and making predictions of the three-dimensional structure of these domains using highly reliable approaches based on machine learning techniques, such as AlphaFold. The combination of experimental structural data and predictive analyses offers some interesting clues about the structural features of heterotrimers formed by collagen NC regions. Structural studies carried out in the last decade show that for fibrillar collagens (types I, V, XI, and mixed V/XI), key factors include the formation of specific disulfide bridges and electrostatic interaction patterns. In the subgroup of collagens whose heterotrimers create supramolecular networks (types IV and VIII), available structural information provides a solid ground for the definition of the basis of the molecular and supramolecular organization. Very recent AlphaFold predictions and structural analyses of type VI collagen offer strong evidence of the specific domains in the NC region of the protein that are involved in chain selection and their staggering. Insightful crystallographic studies have also revealed some fundamental elements of the chain selection process in type IX collagen. Collectively, the data reported here indicate that, although some aspects (particularly the quantification of the relative contribution of the NC and triple helix regions to correct collagen folding) are yet to be fully understood, the available structural information provides a solid foundation for future studies aimed at precisely defining sequence–structure–function relationships in collagens. Full article

The by-products of Cavia porcellus (legs and head) were valorized for collagen extraction using ultrasound-assisted extraction (UAE). Process optimization was performed through response surface methodology (central composite design) considering amplitude, cycle, and time as factors. Samples were pretreated with NaOH and butyl alcohol, followed by acetic acid extraction under controlled sonication. The quadratic models for yield and hydroxyproline showed excellent fit (high R², R²adj, and R²pred) with no significant lack of fit. The optimal conditions were identified at 100% amplitude, cycle = 1, and 27.47 min, and these were validated experimentally, yielding 28.15 ± 0.19% collagen and 4.18 ± 0.12% hydroxyproline, values that closely matched predictions. The optimal extract exhibited a hydrodynamic diameter of 599.3 nm, a ζ-potential of −61.3 mV, and a polydispersity index of 0.33, indicating a highly stable colloidal dispersion with submicron fibrils. SEM micrographs confirmed fibrillar bundles consistent with the particle size distribution, while FTIR spectra showed characteristic amide bands indicative of triple-helix preservation. These results demonstrate that UAE of guinea pig by-products produces collagen with high structural integrity and colloidal stability, highlighting its potential for food and biomaterial applications. Full article

β-Hydroxy-β-methylbutyrate (HMB), a natural metabolite derived from the essential amino acid leucine, is primarily recognised for its anabolic and anti-catabolic effects on skeletal muscle tissue. Recent studies indicate that HMB may also play a role in influencing the structural organisation of extracellular matrix (ECM) components, particularly collagen, which is crucial for maintaining the mechanical integrity of connective tissues. In this investigation, bovine type I collagen was polymerised in the presence of two concentrations of HMB (0.025 M and 0.25 M) to explore its potential function as a molecular modulator of fibrillogenesis. The morphology of the resulting collagen fibres and their molecular architecture were examined using atomic force microscopy (AFM) and Fourier-transform infrared (FTIR) spectroscopy. The findings demonstrated that lower levels of HMB facilitated the formation of more regular and well-organised fibrillar structures, exhibiting increased D-band periodicity and enhanced stabilisation of the native collagen triple helix, as indicated by Amide I and III band profiles. Conversely, higher concentrations of HMB led to significant disruption of fibril morphology and alterations in secondary structure, suggesting that HMB interferes with the self-assembly of collagen monomers. These structural changes are consistent with a non-covalent influence on interchain interactions and fibril organisation, to which hydrogen bonding and short-range electrostatics may contribute. Collectively, the results highlight the potential of HMB as a small-molecule regulator for soft-tissue matrix engineering, extending its consideration beyond metabolic supplementation towards controllable, materials-oriented modulation of ECM structure. Full article

Fish-derived collagen can reduce the risk of disease transmission and has no religious or cultural restrictions. However, it has limited applications due to its poor thermal stability. In this study, black carp swim bladder collagen (BBC), classified as a type I collagen, was extracted. Amino acid composition analysis revealed that BBC had a higher proline hydroxylation rate of 39.57%. Fourier transform infrared spectroscopy revealed that BBC exhibited a complete triple-helix structure. The fractional viscosity curve and differential scanning calorimetry curves revealed that the thermal denaturation temperature (Td) and the melting temperature (Tm) were 30.85 °C and 107.19 °C, respectively. The dynamic rheological analysis showed that as the concentration increased from 5 mg/mL to 20 mg/mL at 0.01 Hz, the storage modulus increased from 0.979 Pa to 84.2 Pa. When the temperature exceeded the Td, the BBC solution exhibited viscous behaviour as the frequency increased. The steady-shear analysis showed that the BBC was a shear-thinning fluid. Functional properties analysis revealed that BBC exhibited better emulsification properties, foaming properties, water absorption capacity and oil absorption capacity than land-derived collagen, making it suitable for emulsifiers, bubbling beverages, and frozen meat preservation. Additionally, BBC promoted the growth of MT3C3-E1 cells and maintained the normal morphology of the cells. These results showed that BBC is a promising substitute for terrestrial collagen in functional foods, cosmetics, and biofunctional materials. Full article

The root of Arnebia szechenyi Kanitz, known as “Mongolia Zicao,” has been widely used in traditional Chinese and Mongolia medicine. Herein, we aimed to characterize a pectin polysaccharide extracted from A. szechenyi Kanitz root (ASP), elucidate its structure, and evaluate potential immunomodulatory activities through in vitro assays. Sugar composition analysis and high-performance gel permeation chromatography (HPGPC) revealed that ASP is predominantly composed of GalA (45.44%), Gal (22.13%), and Ara (19.86%) with a homogenous molecular weight of 18.4 kD. ASP was identified as a typical pectin-like polysaccharide containing linear HG domains and potentially linked to complex branches with Ara and Glu residues. The monosaccharide analysis of the digestion product, D-ASP, supported this hypothesis. The Congo red test indicated the absence of a triple-helix structure in ASP and its digestion product D-ASP. ASP exhibited an irregular structure due to the branching fork, which disappeared after digestion, as observed by scanning electron microscopy. Additionally, ASP and D-ASP had certain antioxidant activities and significantly stimulated the release of cytokines (IL-1β, IL-6, TNF-a, NO), macrophage proliferation and phagocytic capability in RAW 264.7 cells in a dose-dependent manner. These findings outline the chemical and biological foundation for the development of novel drug candidates in the food and pharmaceutical industries. Full article

By integrating waste valorization with green extraction, in the current study, the impacts of distinct extraction methods on the extraction yield, structural characterization, in vitro antioxidant abilities and in vitro immunomodulatory activity of polysaccharides from Pholiota nameko residue (PNRP) were determined, providing assistance for the resource utilization of Pholiota nameko. Six PNRPs were obtained by hot water extraction, ultrasonic-assisted extraction, acid-assisted extraction, base-assisted extraction, acid–base extraction and hot water–alkaline-assisted extraction, named PNRP-HWE, PNRP-UAE, PNRP-AE, PNRP-BE, PNAP-ABE and PNRP-HAE, respectively. PNRPs were heteropolysaccharides with similar functional groups, abundant branched chains and a triple helix conformation, but varied monosaccharide molar ratios and molecular weights (382.6–601.7 kDa). PNRP-HAE exhibited the highest yield (3.92%) and superior antioxidant activities, including DPPH, ABTS and hydroxyl radical scavenging capacities, attributed to its low molecular weight and high xylose content. Additionally, PNRP-HAE and PNRP-UAE demonstrated potent immunomodulatory effects by enhancing macrophage phagocytosis and cytokine secretion (NO, IL-1β, IL-6, TNF-α). These findings highlight HAE as an optimal method for extracting high-quality PNRPs, offering a sustainable strategy for valorizing mushroom residue in functional foods and nutraceuticals. Full article