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Bovine bone is rich in collagen and is a good material for collagen peptide preparation. Although thermolysin-like proteases (TLPs) have been applied in different fields, the potential of TLPs in preparing bioactive collagen peptides has rarely been evaluated. Here, we characterized a thermophilic TLP, A69, from a hydrothermal bacterium Anoxybacillus caldiproteolyticus 1A02591, and evaluated its potential in preparing bioactive collagen peptides. A69 showed the highest activity at 60 °C and pH 7.0. We optimized the conditions for bovine bone collagen hydrolysis and set up a process with high hydrolysis efficiency (99.4%) to prepare bovine bone collagen peptides, in which bovine bone collagen was hydrolyzed at 60 °C for 2 h with an enzyme–substrate ratio of 25 U/g. The hydrolysate contained 96.5% peptides that have a broad molecular weight distribution below 10000 Da. The hydrolysate showed good moisture-retention ability and a high hydroxyl radical (•OH) scavenging ratio of 73.2%, suggesting that the prepared collagen peptides have good antioxidative activity. Altogether, these results indicate that the thermophilic TLP A69 has promising potential in the preparation of bioactive collagen peptides, which may have potentials in cosmetics, food and pharmaceutical industries. This study lays a foundation for the high-valued utilization of bovine bone collagen.

Type I collagen is a major protein in animals, and its hydrolyzed products, collagen peptides, have wide-ranging applications. This article reviews collagen peptides’ preparation methods, biological activities, and application progress in the fields of food, cosmetics, and medicine. By employing various extraction and hydrolysis methods, collagen peptides with different molecular weights can be obtained, and their biological activities are closely related to their molecular weight and amino acid sequence. Studies have revealed that collagen peptides possess a variety of biological activities, including antioxidant, hematopoietic promotion, osteogenic differentiation promotion, antihypertensive, and anti-diabetic effects. In the food industry, their antioxidant and hypoglycemic properties have opened new avenues for the development of healthy foods; in the cosmetics field, the moisturizing, anti-aging, and repair functions of collagen peptides are favored by consumers; in the medical field, collagen peptides are used in wound dressings, drug carriers, and tissue engineering scaffolds. Looking to the future, the development of green and efficient preparation technologies for collagen peptides and in-depth research into the relationship between their structure and function will be important research directions. The multifunctional properties of collagen peptides provide a broad prospect for their further application in the health industry.

Ageing is a complex and progressive phenomenon, during which the accumulation of morphological and chemical changes seriously compromises the capacity of the cells to proliferate and fulfil their biological tasks. The increase in the average age of the world population, associated with a higher occurrence of age-related diseases, is prompting scientific research to look for new strategies and molecular targets that may help in alleviating age-related phenotypes. Growth factors, responsible for modulating several aging markers in many tissues and organs, represent valuable targets to fight age-associated dysfunctions. The growth differentiation factor GDF11, a TGF-β family member, has been associated with the maintenance of youth phenotypes in different human tissues and organs, and in the skin has been related to an inhibition of the inflammatory response. We investigated the role of GDF11 in skin dermal fibroblasts, and we observed that its expression and activity were reduced in fibroblasts deriving from adult donors compared to neonatal ones. The main effect of GDF11 was the induction of collagen I and III, in both neonatal and adult fibroblasts, by triggering Smad signalling in a TGF-β-like fashion. Moreover, by analysing a number of plant extracts having GDF11 inducing activity, we found that a peptide/sugar preparation, obtained from Lotus japonicus somatic embryo cultures, was capable of restoring GDF11 expression in older fibroblasts and to activate the synthesis of collagen I, collagen III and periostin, an important protein involved in collagen assembly.

In Alzheimer’s disease, the blood–brain barrier breakdown, blood vessel damage and re-organization are early events. Deposits of the small toxic peptide beta-amyloid (Aβ) cause the formation of extracellular plaques and accumulate in vessels disrupting the blood flow but may also play a role in blood clotting. In the present study, we aim to explore the impact of Aβ on the migration of endothelial cells and subsequent vessel formation. We use organotypic brain slices of postnatal day 10 wildtype mice (C57BL/6) and connect them to small microcontact prints (µCPs) of collagen. Our data show that laminin-positive endothelial cells migrate onto collagen µCPs, but without any vessel formation after 4 weeks. When the µCPs are loaded with human Aβ40, (aggregated) human Aβ42 and mouse Aβ42 peptides, the number and migration distance of endothelial cells are significantly reduced, but with a more pronounced subsequent vessel formation. The vessel formation is verified by zonula occludens (ZO)-1 and -2 stainings and confocal microscopy. In addition, the vessel formation is accompanied by a stronger GFAP-positive astroglial formation. Finally, we show that vessels can grow towards convergence when two opposed slices are connected via microcontact-printed lanes. In conclusion, our data show that Aβ promotes vessel formation, and organotypic brain slices connected to collagen µCPs provide a potent tool to study vessel formation.

Collagen is a popular nutricosmetic ingredient in food supplements due to its anti-aging and other positive effects on the skin. Due to its widespread use and the lack of regulation in this area, appropriate quality control is required to ensure efficacy and safety, with the development of analytical methods playing an important role. Currently, the quantitative determination of collagen is mainly based on time-consuming derivatization-based spectroscopic methods or on complex chromatographic methods with mass spectrometric detection. Therefore, in this study, two new, simple chromatographic methods have been developed. One is intended for the analysis of untreated samples and is characterized by the speed and simplicity of sample preparation. The other method quantifies collagen via the underivatized tripeptide Gly-Pro-Hyp formed by bacterial collagenase hydrolysis and is characterized by its specificity and ability to distinguish between marine and terrestrial collagen. The latter is a novelty in the field of simple methods for collagen analysis and is particularly important in terms of safety. Our comparison with established analytical methods (e.g., via hydroxyproline after complete hydrolysis) for collagen analysis undoubtedly showed the superiority of these new methods for the routine quality control of collagen supplements in terms of specificity, repeatability, sample stability, and simplification in sample preparation. The collagen content in the supplements tested was found to be adequate; however, some discrepancies were found regarding the labeling and origin of the collagen, with possible safety implications.

Biopolymers, such as collagens, elastin, silk fibroin, spider silk, fibrin, keratin, and resilin have gained significant interest for their potential biomedical applications due to their biocompatibility, biodegradability, and mechanical properties. This review focuses on the design and integration of biomimetic peptides into these biopolymer platforms to control the release of bioactive molecules, thereby enhancing their functionality for drug delivery, tissue engineering, and regenerative medicine. Elastin-like polypeptides (ELPs) and silk fibroin repeats, for example, demonstrate how engineered peptides can mimic natural protein domains to modulate material properties and drug release profiles. Recombinant spider silk proteins, fibrin-binding peptides, collagen-mimetic peptides, and keratin-derived structures similarly illustrate the ability to engineer precise interactions and to design controlled release systems. Additionally, the use of resilin-like peptides showcases the potential for creating highly elastic and resilient biomaterials. This review highlights current achievements and future perspectives in the field, emphasizing the potential of biomimetic peptides to transform biopolymer-based biomedical applications.

There are a number of challenges associated with designing nanoparticles for medical applications. We define two challenges here: (i) conventional targeting against up-regulated cell surface antigens is limited by heterogeneity in expression, and (ii) previous studies suggest that the optimal size of nanoparticles designed for systemic delivery is approximately 50-150 nm, yet this size range confers a high surface area-to-volume ratio, which results in fast diffusive drug release. Here, we achieve spatial control by biopanning a phage library to discover materials that target abundant vascular antigens exposed in disease. Next, we achieve temporal control by designing 60-nm hybrid nanoparticles with a lipid shell interface surrounding a polymer core, which is loaded with slow-eluting conjugates of paclitaxel for controlled ester hydrolysis and drug release over approximately 12 days. The nanoparticles inhibited human aortic smooth muscle cell proliferation in vitro and showed greater in vivo vascular retention during percutaneous angioplasty over nontargeted controls. This nanoparticle technology may potentially be used toward the treatment of injured vasculature, a clinical problem of primary importance.

Marine-derived proteins, rich in amino acids and bioactivity, serve as a natural and safe alternative to chemical haircare products. This study selected three highly bioactive fish-derived protein peptides and determined their optimal repair ratio using FTIR structural analysis and response surface methodology (RSM). A collagen peptide-based composite human hair repair emulsion (CHFRE) was formulated, and its repair efficacy on damaged hair (DH) was evaluated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and amino acid analysis. Following CHFRE treatment, the physical and chemical properties of damaged hair improved significantly. SEM analysis revealed enhanced hair luster, aligned cuticle scales, and a denser cortex. FTIR and DSC analyses showed a 5.94% increase in α-conformation content and a 28.44% rise in relative helical content (RHC), indicating enhanced protein stability and a conformation closer to that of normal hair. Additionally, the 14.63% increase in S=O transmittance suggested reduced oxidative damage. Amino acid analysis and hydrophobic amino acids, with specific increments of 16.77 g/100 g and 2.47 g/100 g, respectively, enhance hair affinity and keratin stability. This bio-based repair material effectively restores damaged hair structure, strengthens resistance to chemical damage, and ensures sustainability, safety, and biocompatibility, providing a promising approach for the development of natural hair repair products.

Collagen peptide was identified as a prebiotic that can provide nitrogen and carbon sources for probiotics to achieve antiobesity, anti‐inflammatory, antioxidant, and immunoregulatory effects by improving the gut microbiota. Also, obesity is a high‐risk factor for psychological and cognitive diseases. This study used a commercialized collagen peptide probiotic (CPP) containing 12 strains of proprietary probiotics with collagen peptides from fish skin to evaluate weight control, fat formation, blood sugar control, and anxiety behavior effects in mice fed a high‐fat diet (HFD) or high‐carbohydrate diet (HCD) and compared the effects by the clinical weight loss drug orlistat (ORL). The results showed that CPP was more effective than ORL in slowing the weight gain in HCD‐ or HFD‐fed male mice. However, the effects of CPP and ORL in female mice were slightly different. Regardless of gender, CPP significantly reduced fat formation and improved glucose tolerance caused by HCD or HFD. Blood biochemical analysis also revealed that CPP could restore HCD‐ and HFD‐induced liver and kidney dysfunction in male but not in female mice. The total cholesterol, triglycerides, and leptin concentrations in the blood decreased with CPP compared to the ORL intervention. In addition, CPP alleviated HCD‐ and HFD‐induced anxiety in mice and improved their gut microbiota. This study confirmed that this CPP product has more antiobesity effects and can ameliorate other related damage caused by HCD and HFD than the clinical weight loss drug ORL. Thus, CPP has a strong potential to be widely used for human health promotion and disease prevention.

Osteopontin (OPN) is involved in various physiological processes such as inflammatory and wound healing. However, little is known about the effects of OPN on these tissues. OPN is cleaved by thrombin, and cleavage of the N-terminal fragment exposes a SVVYGLR sequence on its C-terminus. In this study, we examined the effects of the thrombin-cleaved OPN fragments on fibroblasts and myocardial fibrosis, particularly the role of the SVVYGLR sequence. The recombinant thrombin-cleaved OPN fragments (N-terminal fragment [N-OPN], C-terminal fragment [C-OPN], and the N-terminal fragment lacking the SVVYGLR sequence [ΔSV N-OPN]) were added to fibroblasts, and the cellular motility, signal activity, and production of collagen were evaluated. A sustained-release gel containing an OPN fragment or SVVYGLR peptide was transplanted into a rat model of ischemic cardiomyopathy and the quantities and ratio of collagen type I (COL I) and type III (COL III) were estimated. N-OPN significantly promoted fibroblast migration. Smad signal activity, expression of smooth muscle actin (SMA), and the production of COL III were enhanced by N-OPN and SVVYGLR peptide. Conversely, ΔSV N-OPN and C-OPN had no effect. In vivo, the expression level of N-OPN was associated with COL III distribution, and the COL III/COL I ratio was significantly increased by the sustained-release gel containing N-OPN or SVVYGLR peptide. The cardiac function was also significantly improved by the N-OPN- or SVVYGLR peptide-released gel treatment. The N-terminal fragment of thrombin-cleaved OPN-induced Smad signal activation, SMA expression, and COL III production, and its SVVYGLR sequence influences this function.