Search Results (311)

The development of collagen-based composite materials for bone tissue engineering requires a comprehensive understanding of their rheological and structural behavior to ensure processability and functional stability. This study investigates the viscoelastic and morphological properties of nanocomposite slurries composed of hydroxyapatite (HA) nanoparticles dispersed in acetic acid solutions of bovine or fish-derived collagen peptides. Frequency and strain sweep tests revealed solid-like behavior and shear-thinning characteristics consistent with printable bioinks. Both formulations yield stresses between 0.7 and 1.5 kPa, values comparable to those reported for 3D-printable HA composites. Over ten days of aging, fish-based formulations retained higher viscosity and modulus, indicating improved temporal stability relative to bovine-based ones. Drop-casting tests confirmed the formation of homogeneous, highly opalescent films, with surface profilometry showing lower waviness for the fish-derived blend, suggesting enhanced microstructural uniformity. These results demonstrate that acetic acid-mediated collagen–HA interactions generate stable, high-fidelity slurries suitable for additive manufacturing applications. The superior rheological properties of fish collagen formulations highlight the influence of peptide source on network evolution, offering valuable insight for optimizing collagen–ceramic composites in regenerative and biomedical applications. Full article

Oxidative stress compromises follicle survival during in vitro culture. Natural antioxidants may reduce cellular damage and preserve tissue integrity. This study evaluated the ethanolic extract from Punica granatum L. (EE-PG) on bovine ovarian tissue cultured in vitro. Bovine ovarian (n = 24) fragments were cultured for 6 days in αMEM⁺ medium with or without EE-PG at 10, 50, or 100 µg/mL. At the end of the in vitro culture, the medium was used to evaluate antioxidant capacity (DPPH and ABTS assays), while the fragments were collected for morphological and biochemical analyses. HPLC-UV-Vis confirmed the presence of α-punicalagin in the pure EE-PG. At 100 µg/mL, EE-PG showed the strongest effects: it had higher antioxidant capacity, preserved follicle morphology and ultrastructure, and promoted follicle activation. At 50 and 100 µg/mL, the extract also reduced malondialdehyde (MDA) and increased thiol levels, indicating protection against lipid peroxidation. In contrast, 10 µg/mL had little effect. Follicle and oocyte diameters were not significantly altered, but the collagen I/III ratio increased at higher concentrations, suggesting extracellular matrix remodeling. Together, these findings demonstrate that EE-PG protects bovine preantral follicles from oxidative stress, maintains redox balance, and preserves tissue integrity. These results reinforce the potential of Punica granatum L. extract as a natural antioxidant in reproductive biotechnologies and fertility preservation. Full article

Cortical laminar bone membranes (CLBMs) combine mechanical strength with controlled resorption to overcome the limitations of conventional guided bone regeneration membranes. This narrative review synthesizes the clinical efficacy and comparative outcomes of CLBMs from human studies. A systematic literature search identified 13 human clinical studies evaluating CLBMs from xenogeneic (porcine, equine, bovine) and autogenous sources. Compared to conventional alternatives, CLBMs demonstrated superior outcomes: horizontal ridge augmentation achieved 3.1–5.8 mm gains with CLBMs versus 2.0–3.0 mm with collagen membranes (50–100% improvement); membrane exposure rates were 3–8% (CLBMs) versus 15–30% (titanium mesh); and socket preservation achieved a 72% resorption reduction versus natural healing controls. Vertical augmentation achieved 7–11 mm gains. Maxillary sinus augmentation achieved a 100% implant success (1–5 year follow-up). The overall implant survival rates ranged 90.9–100% with CLBMs, exceeding the reported success rates (85–95%) of conventional GBR approaches, with complication rates of 0–12.5%. A histomorphometric analysis demonstrated new bone formation of 29.7–40% at 6 months, with a residual biomaterial of 26.2–35%. CLBMs demonstrate favorable exposure rates and excellent biocompatibility. These membranes support lateral, vertical, and combined defect reconstruction, with reduced donor-site morbidity compared to autogenous approaches. High-quality comparative trials and extended follow-up studies are needed to establish definitive clinical guidelines. Full article

This study evaluated the effects of enzymatically produced collagen hydrolysate and Salicornia perennans extract on the quality, oxidative stability, and nutritional composition of canned canine meat pâtés. Two formulations were prepared: a control 2% NaCl, no hydrolysate and an experimental sample containing 3% collagen hydrolysate sheep:camel:bovine = 1:1:1, 1% Salicornia perennans extract, and 1% NaCl. Physicochemical, textural, amino-acid, fatty-acid, and oxidative parameters were monitored over 10 days of storage. The treated pâtés showed similar proximate composition moisture 76.1%, protein 9.2%, metabolizable energy (ME) 102 kcal·100 g⁻¹; p > 0.05 but exhibited enhanced functional stability, with reduced water loss syneresis 1.8 vs. 3.1%; p < 0.05 and improved cohesiveness 0.46 vs. 0.41; p < 0.05. Amino-acid enrichment included higher aspartic acid +33%; p < 0.05, methionine +53%; p < 0.05, and tryptophan +39%; p < 0.05, while the lipid profile showed lower SFA 52.8 vs. 56.4%; p < 0.05, higher n-3 PUFA 1.5 vs. 0.8%; p < 0.05, and a reduced n-6:n-3 ratio 3.8 vs. 5.6; p < 0.05. During storage, oxidative markers decreased: TBARS −45%, carbonyls −14%, acid value −18%, and color stability improved by +2.0 pp. These findings confirm the synergistic antioxidant and structuring effects of collagen-derived peptides and Salicornia polyphenols, as evidenced by a 45% reduction in TBARS, 14% lower protein carbonyls, and 18% lower acid value relative to the control (p < 0.05). This synergy enabled a sodium-reduced, clean-label formulation with improved technological performance, oxidative resistance, and shelf-life stability for functional wet dog foods. In addition, it enhanced the color and visual appeal—key attributes that influence both animal palatability and the purchasing decisions of pet owners. Full article

Background/Objectives: The use of dentin grafts in bone regeneration has gained increasing attention as an alternative to conventional grafting materials. Mesenchymal stem cells (MSCs), known for their osteogenic potential, have been combined with various biomaterials to enhance regenerative outcomes. This study aimed to evaluate the regenerative potential of dentin grafts and bovine-derived xenografts, with or without MSCs, in experimentally created bone defects in a rat model. Methods: A total of 25 male rats were randomly assigned to five groups: control, dentin graft, dentin graft and MSC, xenograft, and xenograft and MSC. Standardized 2-mm cortical defects were created bilaterally in the femoral shafts. Histological and immunohistochemical analyses were performed after a 90-day healing period. Statistical evaluation was carried out using the Kruskal–Wallis H test and Bonferroni-adjusted pairwise comparisons. Results: Complete healing was achieved in all groups without evidence of complications or inflammatory reactions. Immunohistochemical staining demonstrated no positive vascular endothelial growth factor (VEGF), collagen type I (COL1), or osteopontin (OPN) reactions in defect areas, consistent with complete maturation, although collagen type 3 (COL3) positivity was observed in residual xenograft material. Quantitative analysis showed that the dentin graft and MSC group achieved the highest degree of new bone formation (M = 92.88%, SD = 6.09), significantly greater than the control (p = 0.002) and xenograft groups (p = 0.013). Conclusions: Both dentin grafts and xenografts demonstrated enhanced bone defect healing when combined with MSCs. Nevertheless, dentin grafts in conjunction with MSCs yielded the most favorable regenerative outcomes, suggesting their clinical superiority over conventional xenografts. Full article

Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) secrete a rich array of paracrine factors including growth factors, cytokines, and extracellular vesicles that hold promises for regenerative medicine. This study evaluated the effects of WJ-MSC-derived secretome on adipose-derived mesenchymal stem cells (AD-MSCs) and human dermal fibroblasts (HDFs), focusing on their adhesion, spreading, proliferation, endogenous collagen secretion, and migration. Morphometric analysis revealed that the secretome enhanced cell adhesion and spreading on rat tail collagen (RTC) substrates after 24 h. AD-MSCs showed a ~30% increase in the cell spreading area (from 4007 μm² to 5081 μm²p < 0.05), though without notable shape changes. In contrast, fetal bovine serum (FBS) promoted cell elongation with a reduced aspect ratio. Proliferation assays demonstrated a selective stimulatory effect of the secretome on AD-MSCs with a significant increase at day 3, while HDFs’ proliferation remained unchanged. Cell cycle profiling showed transient S-phase accumulation in AD-MSCs (24–48 h), followed by G0/G1 arrest (72 h), while HDFs remained in G0/G1. Immunofluorescence analysis confirmed the enhanced extracellular deposition of endogenously synthesized collagen in AD-MSCs, while no comparable response was observed in HDFs. Scratch assays showed increased migration in both cell types upon secretome exposure compared to collagen-only controls, suggesting a paracrine-mediated pro-migratory effect. These results demonstrate that WJ-MSC secretome boosts the regenerative capacity in AD-MSCs while keeping fibroblasts quiescent, highlighting its strong potential for cell-free therapies in tissue engineering, wound repair, and regenerative medicine. Full article

Background: The periosteum and periosteum-derived cells have attracted considerable attention for their potential use in clinical applications for treating bone defects. Bovine periosteum-derived cells have been investigated because of their capability for scaffold-free bone regeneration. Previous mass spectrometry (MS) and immunohistochemistry studies have shown the presence of F-box/leucine-rich repeat protein 14 (FBXL14) in bovine periosteum and periosteum-derived cells. Recently, studies using ESI-Q-Orbitrap MS suggested the presence of type IV collagen in the periosteum. The aim of the present study was to clarify the relationship between type IV collagen and FBXL14 in the formation of periosteum-derived cells. Methods: Bovine periosteum-derived cells were obtained from Japanese Black Cattle’s legs in Medium 199 with ascorbic acid and 10% fetal bovine serum. Immunohistochemistry for type IV collagen and FBXL14 was performed using bovine bone with periosteum and periosteum alone for explant culture. Results: Both type IV collagen and FBXL14 were expressed in Volkmann’s canals and the Haversian canals in bone and periosteum. After 5 weeks, type IV collagen and FBXL14 surrounded crystals containing osteocalcin and had formed periosteum-derived cells. Von Kossa staining and immunostaining of osteocalcin revealed that the crystals contained calcified substances and osteocalcin. Conclusions: Clinically, understanding osteocalcin-interacting proteins will help promote bone regeneration. Interactions between type IV collagen and FBXL14 may contribute to scaffold-free bone regeneration. Full article

Background and Objectives: Adequate buccal bone thickness is critical for long-term peri-implant health and stability. When residual alveolar bone volume is insufficient, guided bone regeneration (GBR) is a widely adopted technique. While non-resorbable membranes provide structural support, they carry a higher risk of complications and require secondary surgery. Resorbable collagen membranes, offer promising biological properties and easier clinical handling, yet clinical data remain limited. This prospective cohort study aimed to evaluate the clinical and radiographic outcomes of horizontal GBR using a native, non–cross-linked resorbable porcine pericardium membrane fixed with titanium pins, in conjunction with simultaneous implant placement. Materials and Methods: Eighteen patients (26 implants) with horizontal alveolar defects (<6 mm) underwent implant placement and GBR with deproteinized bovine bone mineral and a porcine pericardium collagen membrane. Horizontal bone gain and buccal bone thickness were measured at baseline and 6 months post-operatively. Post-operative complications, patient-reported outcomes (PROMs), and peri-implant tissue health were assessed up to 1 year post-loading. Results: Mean bone gain was 2.95 ± 0.95 mm, and all sites achieved a buccal bone thickness ≥ 1.5 mm. No membrane-related complications occurred. PROMs revealed low morbidity. At 1-year follow-up, marginal bone loss averaged 0.54 ± 0.7 mm, mean probing depth was 2.79 ± 0.78 mm, 92% of sites exhibited keratinized mucosa ≥ 2 mm. Conclusions: Native resorbable porcine pericardium membranes, when combined with DBBM and mechanical stabilization, seem to be effective for horizontal bone regeneration. 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

Over the past years, with the growing interest in sustainable biomaterials, marine collagen has been emerging as an interesting alternative to bovine collagen. It is more easily absorbed by the body and has higher bioavailability. In this study, collagen was extracted from Dicentrarchus labrax (sea bass) skin, a fishery by-product, thus valorizing waste streams while reducing environmental impact. To overcome the intrinsic weak mechanical of collagen, it was combined with chitosan to produce composite scaffolds for skin tissue engineering. The incorporation of collagen proved crucial for scaffold performance: (i) it promoted the formation of an open-pore architecture, favorable for cell infiltration and proliferation; (ii) it enhanced swelling behavior suitable for exudate absorption and maintenance of a moist wound environment; (iii) by tuning the chitosan/collagen ratio, it enabled us to control the degradation rate; (iv) it conferred antioxidant properties; and (iv) by adjusting collagen/chitosan concentrations, it allowed fine-tuning of mechanical properties, ensuring sufficient strength to resist stresses encountered during wound healing. In vitro assays demonstrated that the scaffolds were non-cytotoxic and effectively supported mouse adipose tissue fibroblasts’ adhesion and proliferation. Finally, all formulations exhibited marked bactericidal activity against the human pathogen Staphylococcus aureus and the methicillin-resistant Staphylococcus aureus, with a Log reduction greater than 3 (a reduction of at least 99.9% in bacterial growth) compared to the control. Collectively, these findings highlight collagen not only as a sustainable resource but also as a functional component that drives the structural, physicochemical, biological, and antimicrobial performance of chitosan/collagen scaffolds for skin tissue engineering. Full article

Collagen and its derivatives, including hydrolyzed collagen peptides, have emerged as promising bioactive compounds with potential benefits in obesity and metabolic syndrome prevention and management. This study aimed to evaluate the potential effects of a low-molecular-weight bovine collagen hydrolysate (COLLinstant^® LMW) on metabolic health using Caenorhabditis elegans and C57BL/6 diet-induced obese mice. In C. elegans, C-LMW (2 mg/mL) improved healthspan by significantly reducing fat accumulation (as measured with Nile Red) and reactive oxygen species measured through dihydroethidium, slowing the aging process measured with lipofuscin, and extending the median lifespan of the nematodes. In 32 male 20-week-old diet-induced obese mice, C-LMW supplementation (1 mg/animal/day) for 8 weeks led to a significant reduction in mesenteric, visceral and total adipose tissue (−28% −15% and −18%, respectively; p > 0.05), improved glucose tolerance, and partially restored glucose homeostasis, as demonstrated by intraperitoneal glucose tolerance (−26% AUC, p < 0.05). Additionally, collagen hydrolysate supplementation led to a significant impact on gut microbiota composition by increasing microbial diversity and modulating beneficial bacterial populations, which may contribute to the observed metabolic improvements. These findings suggest that bovine-derived collagen peptides exert anti-obesogenic and metabolic regulatory effects, supporting their potential as functional dietary ingredients for obesity management. Full article

Collagen is the primary load-bearing component in connective tissues, and its organization dictates the biomechanical properties and functions of the tissue. Polarized light imaging has been an effective tool for characterizing collagen organization. Recently, with the integration of structured light illumination (SLI), structured polarized light imaging (SPLI) has enabled quantification of collagen fiber orientation in the superficial layers of thick tissues with higher specificity and accuracy. However, SPLI typically requires 12 images to perform depth discrimination and collagen quantification, limiting its application in imaging tissue dynamics. To overcome this limitation, we developed a high-speed SPLI system that can perform continuous tracking and quantification of tissue deformation at 75 frames per second (FPS). High-speed SPLI was achieved by pairing a polarization camera with a rolling image processing technique. We evaluated the performance of high-speed SPLI on a bovine heart valve leaflet under uniaxial deformation. We were able to continuously track and quantify collagen fiber orientation at 75 FPS, with improved accuracy due to effective depth discrimination using SLI. Additionally, we demonstrated that reflectance with SLI is more sensitive to local collagen deformation compared to imaging without SLI, offering a complementary perspective for studying the dynamics of collagenous tissues. Full article

Background/Objectives: Within the minimum intervention oral care (MIOC) delivery framework, the management and improvement in the esthetics of enamel white spot lesions (WSLs) are recommended. This study evaluated the chemomechanical and morphological characteristics of WSLs treated by four therapeutic approaches using Raman spectroscopy, Knoop microhardness (KH), and field-emission scanning electron microscopy (FESEM). Methods: Sixty human enamel slabs were divided into six groups: non-treated (baseline), WSLs (8% methylcellulose gel with 0.1 M lactic acid, pH 4.6 at 37 °C for 21 days), and four treated groups, namely bovine collagen supplement (Nutravita Ltd., Maidenhead, Berkshire, UK), Regenerate system (NR-5, Bordeaux, France), Sylc air abrasion (AquaCare, Denfotex Research Ltd., Edinburgh, UK), and CO₂ laser (JHC1180, Jinan, China). Treatment lasted 28 days, followed by four weeks of storage in artificial saliva (pH = 7.0, 37 °C). Bovine collagen was analyzed using Fourier-Transform Infrared Spectroscopy (FTIR). The mineral content, including the phosphate peak intensities (PO₄ ν₁, ν₂, and ν₄) and carbonate (CO₃), as well as tissue microhardness, were assessed at varying depths (50–200 µm), followed by morphological assessment. Results: The FTIR spectrum of bovine collagen powder confirms the presence of amide I, II, and III. It produced a statistically significant enhancement in the phosphate content and KHN compared to WSLs of up to 150 µm in depth (p < 0.001). Regenerate-treated surfaces recorded the highest phosphate content among groups at the superficial layer. All treatment interventions enhanced the morphology of lesions by covering the exposed prisms and inter-prismatic structure. Conclusions: Bovine collagen supplements can enhance the phosphate content and surface properties of enamel white spot lesions (WSLs) and could be considered a potential modality comparable to other micro-invasive approaches for addressing incipient enamel lesions. This could significantly impact dental care management. Full article

Candida species commonly secrete aspartic peptidases (Saps), which are virulence factors involved in nutrient acquisition, colonization, tissue invasion, immune evasion and host adaptation. However, the regulation of Sap production remains poorly characterized in emerging, widespread and multidrug-resistant members of the Candida haemulonii clade (C. auris, C. haemulonii, C. haemulonii var. vulnera and C. duobushaemulonii). This study investigated the influence of temperature, pH and protein substrate on Sap production using bloodstream isolates of the C. haemulonii clade. Sap activity was initially assessed using the enzyme coefficient (Pz) in fungal cells grown on yeast carbon base (YCB) agar supplemented with bovine serum albumin (BSA) to determine optimal conditions for enzymatic production. C. auris and C. duobushaemulonii exhibited the highest Sap activity at 96 h, pH 4.0–5.0, and 37 °C, whereas C. haemulonii and C. haemulonii var. vulnera displayed more variable and isolate-dependent profiles. Sap production was markedly suppressed at pH 6.0. The addition of pepstatin A, an inhibitor of aspartic peptidases, abolished Sap activity and impaired fungal growth in a dose-dependent manner, confirming both the enzymatic identity and its critical role in nitrogen acquisition. Conversely, YCB supplemented with an inorganic nitrogen source (ammonium sulfate) supported fungal growth but did not induce Sap production. To explore substrate specificity, YCB was supplemented with a panel of proteins. Serum albumins (bovine and human) induced the highest Sap production, followed by globulin, gelatin, hemoglobin, collagen and immunoglobulin G, while elastin and mucin elicited the lowest Sap production. Isolate-specific preferences for protein substrates were observed. Finally, fluorometric assays using a Sap-specific fluorogenic peptide substrate confirmed the presence of Sap activity in cell-free supernatants, which was consistently and entirely blocked by pepstatin A. These findings highlight inter- and intraspecies variability in Sap regulation among C. haemulonii clade, stressing the critical roles of substrate availability, pH and temperature in shaping fungal adaptation to host environments. Full article

Background: Skin aging is mainly associated with oxidative stress and enzymatic degradation of collagen and elastin by protease activity. Peptides have antioxidant capacity and inhibitory effects on protease enzymes. Objective: The purpose of this study was to obtain peptides with in vitro anti-aging activity from the enzymatic hydrolysis of bovine casein with actinidin, a protease extracted from the green kiwi fruit (Actinidia deliciosa) Methodology: The enzyme actinidin was extracted from the pulp of the kiwi fruit, purified by ion exchange chromatography and characterized by polyacrylamide electrophoresis (SDS-PAGE). Subsequently, the extracted enzyme was used to hydrolyze commercial bovine casein at 37 °C for 30 min, precipitating the peptide fraction with trichloroacetic acid (TCA), and centrifuged. To determine the anti-aging potential of the peptides in vitro, antioxidant activity was evaluated using the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical. Additionally, the inhibitory capacity of the peptides against collagenase and elastase enzymes was also studied. To complement the in vitro results, the enzymatic hydrolysis of casein with actinidin was simulated. The binding energy (ΔG) of each of the hydrolysates with the collagenase and elastase enzymes was calculated using molecular docking to predict the peptide sequences with the highest probability of interaction. Results: Actinidin was extracted and purified exhibiting a molecular weight close to 27 kDa. The enzyme hydrolyzed the substrate by 91.6%, and the resulting hydrolysates showed moderate in vitro anti-aging activity: antioxidant (17.5%), anticollagenase (18.55%), and antielastase (28.6%). In silico results revealed 66 peptide sequences of which 30.3% consisted of 4–8 amino acids, a suitable size to facilitate interaction with structural targets. The sequences with the highest affinity were FALPQYLK and VIPYVRYL for collagenase and elastase, respectively. Conclusions: Despite the modest inhibition values, the use of a fruit-derived enzyme and a food-grade substrate is in line with current trends in sustainable and natural cosmetics. These findings highlight the great potential for laying the groundwork for future research into actinidin-derived peptides as multifunctional and eco-conscious ingredients for the development of next-generation anti-aging formulations. Full article