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BACKGROUND: Sturgeon is a popular aquaculture species in many countries. Its swim bladder is rich in collagen but has not yet been exploited scientifically. RESULTS: Collagen peptides (CPs) prepared from sturgeon swim bladder by trypsinolysis had an average molecular weight of 528.5 Da and consisted of 407 peptides, 16.1% of the content of which was GFPGADGSAGPK. The CPs at 25 mg mL‐1 extended the lifespan of Caenorhabditis elegans by 22.6%, which was significantly higher than the extension achieved by other hydrolysis methods and source materials. They also improved fitness‐related traits (body size, motor capacity, oxidative stress, cell apoptosis, and epidermal barrier function), indicating prolonged healthspan. Transcriptome analysis showed that the effect was mediated by the mitogen‐activated protein kinase pathway, which enhanced stress resistance, the insulin/IGF‐1 pathway, which inhibited protein aggregation, and the NHR‐80/FAT‐6 pathway, which regulated lipid metabolism. CONCLUSION: Collagen peptides from sturgeon swim bladder by trypsinolysis prolonged the lifespan and healthspan in C. elegans, and might be promising anti‐aging agents. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The purpose of this research was to explore the impact of collagen peptides derived from cod (Gadus) skin on H2O2-induced 2BS senescence cells. The senescence model induced by H2O2 was established to determine the cell proliferation rate, ROS level, cell apoptosis, and peroxidase content after the intervention of the optimal dose of collagen peptides. Collagen peptides effectively suppressed apoptosis in 2BS senescence cells, substantially decreasing ROS and MDA levels. Furthermore, SOD and CAT activities were significantly elevated. In summary, collagen peptides have demonstrated a significant capacity to impede the process of cellular senescence in 2BS cells through the reduction of oxidative stress and apoptosis. [ABSTRACT FROM AUTHOR]

Background: Oral collagen peptides supplementation was reported to improve skin integrity and counteract skin aging. Aims: A randomized, double‐blinded, placebo‐controlled study was conducted to clinically evaluate the impact of low‐molecular‐weight collagen peptides on the human skin. Patients/Methods: Healthy adult participants (n = 100) were randomly assigned to receive a test product containing low‐molecular‐weight collagen peptides or a placebo. Parameters of skin wrinkles, elasticity, hydration, and whitening (melanin and erythema indexes) were measured at baseline and after 4, 8, and 12 weeks. Results: Compared with the placebo group, the average skin roughness, maximum of all peak‐to‐valley values, maximum peak height of the wrinkle, and average maximum height of the wrinkle were significantly improved in the test group. Parameters of skin elasticity, including overall elasticity, net elasticity, and biological elasticity, were also significantly improved in the test group at Week 12 as compared with the placebo group. Moreover, skin hydration and whitening parameters changed more significantly in the test group than in the placebo group. None of the participants experienced adverse events related to the test product. Conclusions: Taken together, these findings suggest that low‐molecular‐weight collagen peptides supplementation can safely ehance human skin wrinkling, hydration, elasticity, and whitening properties. [ABSTRACT FROM AUTHOR]

A bioactive compound, collagen peptide (CP), is widely used for biological activities such as anti-photoaging and antioxidant effects, with increased oral bioavailability because of its low molecular weight and high hydrophilicity. However, controlling release time and increasing retention time in the digestive tract for a more convenient oral administration is still a challenge. We developed CP-loaded chitosan (CS) microcapsules via strong and rapid ionic gelation using a highly negative phytic acid (PA) crosslinker. The platform enhanced the oral bioavailability of CP with controlled gastrointestinal delivery by utilizing the mucoadhesiveness and tight junction-opening properties of CS. CS and CP concentrations varied from 1.5 to 3.5% and 0–30%, respectively, for optimal and stable microcapsule synthesis. The physicochemical properties, in vitro release profile with intestinal permeability, in vivo oral bioavailability, in vivo biodistribution, anti-photoaging effect, and antioxidant effect of optimized CS microcapsules were analyzed to investigate the impact of controlling parameters. The structure of CS microcapsules was tuned by PA diffused gradient ionic cross-linking degree, resulting in a controlled CP release region in the gastrointestinal tract. The optimized microcapsules increased C max , AUC, and t max by 1.5-, 3.4-, and 8.0-fold, respectively. Furthermore, CP in microcapsules showed anti-photoaging effects by downregulating matrix metalloproteinases-1 via antioxidant effects. According to our knowledge, this is the first study to microencapsulate CP for oral bioavailability enhancement. The peptide delivery method employed is simple, economical, and can be applied to customize bioactive compound administration. [Display omitted] [ABSTRACT FROM AUTHOR]

Antler ossified tissue has been widely used for the extraction of bioactive peptides. In this study, collagen was prepared from antler ossified tissue via acetic acid and pepsin. Five different proteases were used to hydrolyze the collagen and the hydrolysate treated by neutrase (collagen peptide named ACP) showed the highest DPPH radical clearance rate. The extraction process of ACP was optimized by response surface methodology, and the optimal conditions were as follows: a temperature of 52 °C, a pH of 6.1, and an enzyme concentration of 3200 U/g, which resulted in the maximum DPPH clearance rate of 74.41 ± 0.48%. The peptides (ACP-3) with the strongest antioxidant activity were obtained after isolation and purification, and its DPPH free radical clearance rate was 90.58 ± 1.27%; at the same time, it exhibited good scavenging activity for ABTS, hydroxyl radical, and superoxide anion radical. The study investigated the protective effect of ACP-3 on oxidative damage in HaCaT cells. The findings revealed that all groups that received ACP-3 pretreatment exhibited increased activities of SOD, GSH-Px, and CAT compared to the model group. Furthermore, ACP-3 pretreatment reduced the levels of ROS and MDA in HaCaT cells subjected to H2O2-induced oxidative damage. These results suggest that collagen peptides derived from deer antler ossified tissue can effectively mitigate the oxidative damage caused by H2O2 in HaCaT cells, thereby providing a foundation for the utilization of collagen peptides in pharmaceuticals and cosmetics. [ABSTRACT FROM AUTHOR]

Background: The management of knee osteoarthritis involves various treatment strategies. It is important to explore alternative therapies that are both safe and effective. Collagen peptides have emerged as a potential intervention for knee osteoarthritis. This study aims to evaluate the analgesic effects and safety of collagen peptide in patients diagnosed with knee osteoarthritis. Methods: We conducted a systematic literature search following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Multiple databases including PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) published up to 27 May 2023 that focused on the analgesic outcomes and adverse events associated with collagen peptides or hydrolyzed collagen in patients with osteoarthritis. We assessed the quality of the included studies and the strength of evidence using the Cochrane ROB 2.0 tool and Grading of Recommendations, Assessment, Development, and Evaluations. Results: Four trials involving 507 patients with knee osteoarthritis were included and analyzed using the random-effects model. All these trials were considered to have a high risk of bias. Our results revealed a significant difference in pain relief between the collagen peptide group and the placebo group in patients with knee osteoarthritis (standardized mean difference: − 0.58; 95% CI − 0.98, − 0.18, p = 0.004; I2: 68%; quality of evidence: moderate). However, there was no significant difference in the risk of adverse events between collagen peptide and placebo (odds ratio: 1.66; 95% CI 0.99, 2.78, p = 0.05; I2: 0%; quality of evidence: very low). Conclusions: Our findings demonstrate significant pain relief in patients with knee osteoarthritis who received collagen peptides compared to those who received placebo. In addition, the risk of adverse events did not differ significantly between the collagen peptide group and the placebo group. However, due to potential biases and limitations, well-designed randomized controlled trials are needed to validate and confirm these findings. [ABSTRACT FROM AUTHOR]

Collagen peptides (CPs) are food-derived peptides that possess a variety of bioactive properties. Our study investigates the effects of CP on pulmonary fibrosis in bleomycin (BLM)-treated mice. C57BL/6J mice were subcutaneously injected with BLM for two weeks followed by a three-week experimental diet containing 25 mg/g of CP derived from chicken feet. Supplementation with CP suppressed the increase in lung weight and disruption of lung architecture observed in mice treated with BLM. BLM-treated mice also exhibited higher hydroxyproline content and increased expression levels of type I and III collagen subunit genes in the lungs. CP supplementation exerted no effect on these collagen-related factors; however, it significantly suppressed the gene expression of fibronectin and inflammation-related molecules in the lungs of BLM-treated mice. These findings suggest that CP administration prevents the development of pulmonary fibrosis by acting as an anti-inflammatory agent. [ABSTRACT FROM AUTHOR]

This study aims to isolate collagen peptides from waste sturgeon fish skin, and prepare nanoemulsions for studying their anti-diabetic and wound-healing effects in mice. Collagen peptides were extracted and purified by acetic acid with sonication, followed by two-stage hydrolysis with 0.1% pepsin and 5% flavourzyme, and ultrafiltration with 500 Da molecular weight (MW) cut-off dialysis membrane. Animal experiments were performed with collagen peptides obtained by pepsin hydrolysis (37 kDa) and pepsin plus flavourzyme hydrolysis (728 Da) as well as their nanoemulsions prepared at two different doses (100 and 300 mg/kg/day). The mean particle size of low-MW and low-dose nanoemulsion, low-MW and high-dose nanoemulsion, high-MW and low-dose nanoemulsion and high-MW and high-dose nanoemulsion was, respectively, 16.9, 15.3, 28.1 and 24.2 nm, the polydispersity index was 0.198, 0.215, 0.231 and 0.222 and zeta potential was −61.2, −63.0, −41.4 and −42.7 mV. These nanoemulsions were highly stable over a 90-day storage period (4 °C and 25 °C) and heating at 40–100 °C (0.5–2 h). Experiments in mice revealed that the low-MW and high-dose nanoemulsion was the most effective in decreasing fasting blood glucose (46.75%) and increasing wound-healing area (95.53%). Collectively, the sturgeon fish skin collagen peptide-based nanoemulsion is promising for development into a health food or wound-healing drug. [ABSTRACT FROM AUTHOR]

BACKGROUND: Collagen peptide is a low molecular active peptide obtained by hydrolysis of collagen. It can be digested and absorbed, and participate in protein synthesis and metabolism in the human body. It has a positive effect on skin health. However, the absorption and delivery mechanism of collagen peptides is not completely clear, and another problem is its low bioavailability. OBJECTIVE: To explore the potential measures to increase the bioavailability of collagen peptides for promoting skin health. METHODS: The articles related to the preparation, composition, digestion and bioavailability of collagen peptide, skin structure, photoaging and natural aging, transport mechanism of collagen peptide by oral in vivo, transdermal absorption mechanism of collagen peptide, and synergistic absorption of collagen peptide with other substances, were searched on ScienceDirect, PubMed, CNKI, Sci-Hub, and Baidu Academic Database from January 2009 to March 2022. The main keywords used were “collagen, collagen peptide, preparation of collagen peptide, photoaging, percutaneous absorption of collagen peptide” in Chinese and “collagen, collagen peptide, preparation of collagen peptide, photoaging, oral absorption” in English. Finally, 82 articles were included for review. RESULTS AND CONCLUSION: (1) Photoaging and natural aging cause skin tissue damage. Collagen peptides can be transported to the skin through the blood after oral gastrointestinal digestion, and build skin tissue through internal molecular mechanisms, and can also be absorbed through the skin surface to have a positive effect on the dermis. (2) At present, the bioavailability of oral collagen peptide is low, and its delivery mechanism is mainly concentrated in the gastrointestinal stage, and there is also the problem of excessive epidermal resistance in percutaneous absorption. (3) The source, amino acid composition, peptide sequence, molecular weight and dosage of collagen peptide and synergistic absorption with different substances or enzyme cofactors should be paid more attention, looking for more high-quality delivery carriers to improve the bioavailability of collagen peptides. (4) For percutaneous absorption, advanced technology or improved physical and chemical methods should be applied to reduce skin physical resistance or improve molecular penetration efficiency. (5) In future, both oral and percutaneous absorption of collagen peptide could be used to recover skin tissue problems caused by photoaging and natural aging more quickly and effectively. [ABSTRACT FROM AUTHOR]

Collagen-derived dipeptides and tripeptides have various physiological activities. In this study, we compared the plasma kinetics of free Hyp, peptide-derived Hyp, Pro-Hyp, cyclo(Pro-Hyp), Hyp-Gly, Gly-Pro-Hyp, and Gly-Pro-Ala after ingestion of four different collagen samples: AP collagen peptide (APCP), general collagen peptide, collagen, and APCP and γ-aminobutyric acid (GABA) combination. Each peptide was measured by high-performance liquid chromatography and triple quadrupole mass spectrometer. We found that, among all the peptides that were analyzed, only Gly-Pro-Hyp was significantly increased after ingestion of APCP compared with that of general collagen peptides and collagen. In addition, ingestion of the APCP and GABA combination improved the absorption efficiency of Gly-Pro-Ala. Finally, we reveal that Gly-Pro-Hyp was effective for preventing H2O2-induced reduction in extracellular matrix (ECM)-related genes, COL1A, elastin, and fibronectin, in dermal fibroblasts. Taken together, APCP significantly enhances the absorption of Gly-Pro-Hyp, which might act as an ECM-associated signaling factor in dermal fibroblasts, and the APCP and GABA combination promotes Gly-Pro-Ala absorption. Clinical Trial Registration number: UMIN000047972. [ABSTRACT FROM AUTHOR]

This study attempts to identify the significant role played by the secondary and tertiary structure of collagen-derived peptides that are involved in lipid peroxide quenching in food products. Fish collagen hydrolysate (CH) was extracted with an efficiency of 70%. The constituent peptides of CH (8.2–9.7 kDa) existed in a polyproline-II (PP-II) conformation and at a minimum concentration of 1 mg ml−1 and pH range 7 to 8, assembled into a stable, hierarchical, quasi-fibrillar (QF) network. The peroxide quenching activity of this QF-CH increased with increasing ionic stability of the assembly and decreased upon proteolytic dismantling. Upon being used as an additive, the QF-CH reduced peroxide formation by 84.5% to 98.9% in both plant and fish-based oil and increased the shelf life of soya oil by a factor of 5 after 6 months of storage. The addition of QF-CH to cultured cells quenched peroxide ions generated in situ and decreased stressor activity by a factor of 12.16 abundant peptides were identified from the CH. The reason behind the high efficacy displayed by CH was attributed to its unique charge distribution, prevalence of proton-donating amino acid residues and proximal charge delocalization by the QF network, making fish derived CH a suitable substitute for antiperoxide agents in lipid-rich food. [ABSTRACT FROM AUTHOR]

Catla collagen hydrolysate (CH) was fractionated by chromatography and each fraction was subjected to HA nucleation, with the resultant HA-fraction composites being scored based on the structural and functional group of the HA formed. The process was repeated till a single peptide with augmented HA nucleation capacity was obtained. The peptide (4.6 kDa), exhibited high solubility, existed in polyproline-II conformation and displayed a dynamic yet stable hierarchical self-assembling property. The 3D modelling of the peptide revealed multiple calcium and phosphate binding sites and a high propensity to self-assemble. Structural analysis of the peptide-HA crystals revealed characteristic diffraction planes of HA with mineralization following the (002) plane, retention of the self-assembled hierarchy of the peptide and intense ionic interactions between carboxyl groups and calcium. The peptide-HA composite crystals were mostly of 25–40 nm dimensions and displayed 79% mineralization, 92% crystallinity, 39.25% porosity, 12GPa Young's modulus and enhanced stability in physiological pH. Cells grown on peptide-HA depicted faster proliferation rates and higher levels of osteogenic markers. It was concluded that the prerequisite for HA nucleation by a peptide included: a conserved sequence with a unique charge topology allowing calcium chelation and its ability to form a dynamic self-assembled hierarchy for crystal propagation. [ABSTRACT FROM AUTHOR]

Type I and V collagens are the major components of fibrillogenic proteins in fish skin, and their hydrolysis products possess hyaluronidase inhibitory activity. In this study, for the first time, type I and V collagens were isolated from the skin of shortbill spearfish and striped marlin. Type I (2α1[I]α2[I]) and type V (α1[V]α3[V]α2[V]) collagens composed of distinct α-peptide chains with comparable structures were investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and UV spectrophotometric chromatography. After enzymatic digestion, the collagen peptides were purified by using ultrafiltration (30 KDa) and high-performance liquid chromatography (RP-HPLC) to yield CPI-F3 and CPV-F4 fractions with strong hyaluronidase inhibition rates (42.17% and 30.09%, respectively). Based on the results of simulated gastrointestinal fluid, temperature, and pH stability assays, CPI-F3 and CPV-F4 exhibited stability in gastric fluid and showed no significant changes under the temperature range from 50 to 70 °C (p > 0.05). The results of this first research on the bioactivity of type V collagen peptides provide valuable information for the biomedical industry and show the potential for future bioactivity investigations of type V collagen and its peptides. [ABSTRACT FROM AUTHOR]

Orally administered collagen peptides could contribute to antiaging by replacing the degraded extracellular matrix proteins caused by photoaging. This study aimed to evaluate the efficacy and safety of low-molecular-weight collagen peptides for treating photoaged and dry skin. In this randomized, placebo-controlled, parallel-group, double-blinded trial, we randomly assigned study participants (n = 100) to either the test product group or placebo group at a 1:1 ratio for 12 weeks. The wrinkle scale score, eye wrinkle volume, roughness parameters, such as the average maximum height of the wrinkle (Rz), arithmetic average within the total measuring length of the wrinkle (Ra), maximum profile valley depth of the wrinkle (Rv), and skin hydration, transepidermal water loss (TEWL), overall elasticity (R2), and ratio of elastic recovery to total deformation (R7) were evaluated at baseline, 6 weeks, and 12 weeks. Safety assessments with serial blood tests were also conducted. Efficacy assessments of data from 84 participants were conducted as the per-protocol analysis. After 12 weeks, the 10-grade crow's feet photo scale score, eye wrinkle volume, skin roughness parameters (Rz, Ra, and Rv), skin elasticity (R2 and R7), skin hydration, and TEWL were significantly improved in the test product group compared to the placebo group. There were no adverse events or abnormalities according to laboratory analysis associated with using the test material during the study period. This study showed that the oral supplementation of low-molecular-weight collagen peptides could improve the wrinkles, elasticity, hydration, and barrier integrity of photoaged facial skin. This clinical study was registered with the Korean Clinical Research Information Service and International Clinical Trials Registry Platform (No: KCT0006500). [ABSTRACT FROM AUTHOR]

The promising applications of collagen in tissue engineering, regenerative medicine and biomaterials have intrigued great interest in development of collagen mimetic peptides (CMPs). In past decades, the large-scale collagen structures via the self-assembly of small CMPs have been extensively explored. Moreover, CMPs entail novel strategies in order to play a critical role in the discovery of new generation biomaterials. In this regard, we herein have synthesized a CMP, (Pro-Hyp-Gly) 10 i.e. POG10. CMP has been examined in the presence of varying concentration of choline chloride (ChCl) by using various biophysical techniques such as circular dichroism (CD), UV–vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) spectroscopy, differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and dynamic light scattering (DLS). For the first time, we have demonstrated the use of choline chloride (ChCl) to manipulate stability and aggregation of CMP triple helices in order to delineate the factors responsible for the stability of triple helices. [Display omitted] • Synthesis and Characterization of Collagen Mimetic Peptide, POG10. • Thermal stability analysis of POG10 in the presence of choline chloride. • Differential scanning calorimetric thermographs of POG10 in the presence of choline chloride. • Choline chloride provides thermal stability to POG10. • Transmission electron micrographs of POG10 in the presence of choline chloride [ABSTRACT FROM AUTHOR]

[Display omitted] • The preparation of squid cartilage type II collagen peptides (SCIIP) was studied. • SCIIP had typical collagen characteristics with 87.7 % of it below 5 kDa. • SCIIP may inhibit TLR4/MD-2 activation as predicted by molecular docking. • SCIIP alleviated the inflammation in cells by inhibiting the TLR4/NF-κB pathway. • Oral SCIIP relieved the pathological changes of osteoarthritis in rats. The promoting effects of collagen and its derivatives on bone health have been uncovered. However, the structure and effects of type II collagen peptides from squid cartilage (SCIIP) on osteoarthritis still need to be clarified. In this study, SCIIP was prepared from squid throat cartilage with pretreatment by 0.2 mol/L NaOH at a liquid–solid ratio of 10:1 for 18 h and hydrolyzation using alkaline protease and flavourzyme at 50 °C for 4 h. The structure of SCIIP was characterized as a molecular weight lower than 5 kDa (accounting for 87.7 %), a high glycine level of 35.0 %, typical FTIR and CD features of collagen peptides, and a repetitive sequence of Gly–X–Y. GP(Hyp)GPD and GPAGP(Hyp)GD were separated and identified from SCIIP, and their binding energies with TLR4/MD-2 were − 8.4 and − 8.0 kcal/mol, respectively. SCIIP effectively inhibited NO production in RAW264.7 macrophages and alleviated osteoarthritis in rats through the TLR4/NF-κB pathway. Therefore, SCIIP exhibited the potential for application as an anti-osteoarthritis supplement. [ABSTRACT FROM AUTHOR]

• Effect of peptide concentration on high internal phase emulsion (HIPE) was studied. • Effect of HIPE on the three-dimensional - printing surimi ink was studied. • Peptide concentration affected the microstructure and rheology of HIPE. • The addition of HIPE decreased the porosity of surimi. The effect of a high internal phase emulsion (HIPE) on three-dimensional-printed surimi gel inks was studied. Increasing the concentration of collagen peptide decreased the particle size of HIPE droplets and improved the viscoelasticity and stability. For example, when the collagen peptide concentration was 5 wt%, the viscoelasticity of the HIPE was high, as indicated by the presence of small and uniform particles, which formed a monolayer in the outer layer of the oil droplets to form stable a HIPE. A HIPE was used as the filling material to fill the surimi gel network, which reduced the porosity of the network. Surimi protein and peptides have dual emulsifying effects on the stabilization of oil. After adding the emulsion, the texture, gel properties and rheological properties of the surimi were reduced, and its printing adaptability was improved. This study provides new ideas for the production of surimi and its application in 3D printing. [ABSTRACT FROM AUTHOR]

In biology, collagen-biomaterial regulates several signaling mechanisms of bone and immune cells involved in tissue repair and any imbalance in collagen turnover may affect the homeostasis of cells, becoming a major cause of several complications. In this case, the administration of oral collagen may play a potential role in returning cells to their normal function. For several decades, the beneficial effects of collagen have been explored widely, and thus many commercial products are available in cosmetics, food, and biomedical fields. For instance, collagen-based-products have been widely used to treat the complications of cartilage-related-disorders. Many researchers are reporting the anti-arthritogenic properties of collagen-based materials. In contrast, collagen, especially type-II collagen (CII), has been widely used to induce arthritis by immunization in an animal-model with or without adjuvants, and the potentially immunogenic-properties of collagen have been continuously reported for a long time. Additionally, the immune tolerance of collagen is mainly regulated by the T-lymphocytes and B-cells. This controversial hypothesis is getting more and more evidence nowadays from both sides to support its mechanism. Therefore, this review links the gap between the arthritogenic and anti-arthritogenic effects of collagen and explored the actual mechanism to understand the fundamental concept of collagen in arthritis. Accordingly, this review opens-up several unrevealed scientific knots of collagen and arthritis and helps the researchers understand the potential use of collagen in therapeutic applications. [ABSTRACT FROM AUTHOR]

Introduction: We examined the effect of 5.0 g/day of collagen peptide (CP) or collagen peptide fermented with Aspergillus sojae (FCP) on skin pigmentation in healthy participants. Methods: In this randomized, double-blind, placebo-controlled study, 44 men and women aged 25–63 years were placed into three groups by stratified random allocation and treated with CP, FCP, or placebo (PL) at 5.0 g/day for 3 months. Their skin condition was measured monthly from baseline to 3 months of intake. Results: No adverse events were identified in any group. The CP group showed a significant reduction in pigmented patches and redness after 1 and 3 months of intake, respectively. In the FCP group, pigmented macules were significantly reduced after 1 month, and pigmented patches after 2 months. Both the all-ages analysis and the hierarchical analysis below 55 years old yielded similar results. Conclusion: Intake of 5.0 g/day of FCP for 3 months is safe. CP and FCP intake is useful for suppressing pigmentation. In addition, CP intake may be useful for reducing redness. These results suggest a new beneficial effect on the skin of CP supplementation. Trial Registration: UMIN clinical trials registry system, UMIN000040736. [ABSTRACT FROM AUTHOR]

Three dimensional (3D) bioprinting technology has been making a progressive advancement in the field of tissue engineering to produce tissue constructs that mimic the shape, framework, and microenvironment of an organ. The technology has not only paved the way to organ development but has been widely studied for its application in drug and cosmetic testing using 3D bioprinted constructs. However, not much has been explored on the utilization of bioprinting technology for the development of tumor models to test anti-cancer drug efficacy. The conventional methodology involves a two dimensional (2D) monolayer model to test cellular drug response which has multiple limitations owing to its inability to mimic the natural tissue environment. The choice of bioink for 3D bioprinting is critical as cell morphology and proliferation depend greatly on the property of bioink. In this study, we developed a multicomponent bioink composed of alginate, diethylaminoethyl cellulose, gelatin, and collagen peptide to generate a 3D bioprinted construct. The bioink has been characterised and validated for its printability, shape fidelity and biocompatibility to be used for generating tumor models. Further, a bioprinted tumor model was developed using lung cancer cell line and the efficacy of 3D printed construct for drug screening application was established. [Display omitted] [ABSTRACT FROM AUTHOR]

Renal fibrosis is a process in which excessive deposition of extracellular matrix leads to an increase in tissue hardness and gradual destruction of the renal parenchyma. Chronic kidney disease (CKD) commonly progresses to end-stage renal disease (ESRD), ultimately leading to renal failure. This disease has high incidence and mortality rates, but to date, effective treatment options are lacking. PEP-Z-2 is a collagen peptide isolated from redlip croaker scales and may have potential fibroprotective activity. In this study, PEP-Z-2 was found to alleviate unilateral ureteral obstruction (UUO)- and folic acid (FA)-induced kidney injury in a mouse model, reduce collagen deposition in tissues, normalize renal function, reduce the expression of fibrosis markers, reduce reactive oxygen species (ROS) production, and restore the balance of the oxidant/antioxidant system. In vitro experiments also demonstrated that PEP-Z-2 inhibits the TGF-β-induced differentiation of fibroblasts and renal tubular epithelial cells into myofibroblasts and reduces the production of extracellular matrix (ECM) proteins such as fibronectin, Col I, and α-SMA, demonstrating notable therapeutic effects on renal fibrosis. This effect is achieved by regulating the TGF-β/Smad/AKT/MAPK pathway. Our research suggested that PEP-Z-2 is a potential therapeutic drug for renal fibrosis, and peptides from aquatic organisms may constitute a new class of candidate drugs for the treatment of renal fibrosis and even other types of organ fibrosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Collagen peptide, the peptide mixtures formed by the disassembly and breakage of molecular chains of collagen, is applied widely across domains including biomedicine, cosmetics and food thanks to its characteristics of low molecular weight, excellent biocompatibility, and good absorptivity. OBJECTIVE: To introduce the structural characteristics, classification and sources of collagen and collagen peptides, focus upon the preparation and bioactivity of collagen peptide and the evaluation of transdermal absorption. We prospected the future to obtain quality collagen peptide material from aquatic animal and to apply it to domains with high added value including biomedicine and cosmetics. METHODS: We searched the articles published from January 1997 to June 2020 in PubMed, CNKI, and Wanfang databases about the preparation and examination of collagen peptide and the methods of evaluating transdermal absorption with the keywords including “collagen, collagen peptide, transdermal absorption, preparation of collagen peptide, collagen peptide detection” in Chinese and English respectively. RESULTS AND CONCLUSION: Studies into evaluation methods of the transdermal absorption of collagen peptides remain to be few in numbers, though there has been a lot about the preparation of collagen peptides. The existing studies upon the evaluation methods are majorly based upon those into the transdermal penetration of drugs. In the context where the collagen peptide industry in China remains to be immature, full attention should be paid to the actual effect and the products should be refined with the more specifically classified functions in the progress of product research and development. [ABSTRACT FROM AUTHOR]

Collagen peptides are collagen derived products by enzymatic proteolysis, which is widely distributed in mammalian connective tissues. They have exhibited various bioactivities, including antioxidant activity, antihypertensive activity, improvement of joint pain, etc. However, the immunomodulatory effects of collagen peptides in the condition of immune suppression have not been elucidated. The objective of this study was to investigate the effects of collagen peptides on immune function in immunosuppressed mice. The immunosuppression was induced by intraperitoneal injection of dexamethasone for three days and at same time, collagen peptides (0, 300, 600, 900 mg/kg body weight) were given by gavage for seven days. On the day 8, the mice were sacrificed by decapitation. The body weight and the weights of thymus and spleen were recorded. Thymus and spleen indexes were calculated. The proliferation and interleukin-2 production of splenic T lymphocytes and ratio of CD4+/CD8+T lymphocytes in the peripheral blood were examined. Compared with the control mice, the body weight, thymus and spleen indexes, the proliferations and interleukin-2 production in T lymphocytes and the ratios of CD4+/CD8+T cells were significantly decreased in dexamethasone induced immunosuppressed mice. However, in collagen peptides treated mice, the thymus indexes, proliferation index, secretion of interleukin-2 and the ratio of CD4+/CD8+ were significantly increased compared with the mice in experimental model group. These results indicate that collagen peptides could play a protect role in glucocorticoid-induced immunosuppression. [ABSTRACT FROM AUTHOR]

In the present study, antioxidant activities and functional properties of cowhide collagen antioxidant peptides (CCAPs) with different molecular weight (MW) were investigated. The optimum preparation conditions of CCAPs were hydrolysis time of 1.53 hr, temperature of 54.9 °C, pH 7.38, and neutral enzyme to trypsin ratio of 0.048 g: 0.016 g according to single factor test and response surface methodology (RSM). Three fractions (CCAP‐I, CCAP‐II, and CCAP‐III) were obtained by ultrafiltration and lyophilization. Antioxidant activities revealed that CCAP‐III had high reducing power activity (0.323 ± 0.035) and scavenging effect on 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals (64.30 ± 5.99%), 2,2‐azino‐bis‐(3‐ethylbenzothiazoline)‐6‐sulfonic acid (ABTS) radicals (75.25 ± 3.14%), and hydroxyl radicals (68.26 ± 6.74%) compared to the other fractions. In addition, LC‐MS/MS analysis showed that Ala‐Gly‐Glu‐Arg, Gly‐Ile‐Ala‐Gly‐Glu‐Arg, Gly‐Pro‐Ala‐Gly‐Pro‐Ala‐Gly‐Pro‐Arg, Gly‐Val‐Val‐Gly‐Pro‐Glu‐Gly‐Ala‐Arg and Gly‐Phe‐Ser‐Gly‐Leu‐Asp‐Gly‐Ala‐Lys were the major peptides of CCAP‐III. CCAP‐III showed good hygroscopicity (HYG), water holding capacity (WHC), and oil holding capacity (OHC) when compared with CCAP‐I and CCAP‐II. However, CCAP‐II has great emulsifying properties, and CCAP‐I has excellent foaming properties. Therefore, CCAPs can be used as a promising source of functional peptides with antioxidant properties. Practical Application: This study demonstrated the peptides of cowhide collagen has superior antioxidant and functional properties. This study provided a scientific basis for the preparation of antioxidant peptides from cowhide collagen. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to investigate the effect of orally ingested collagen peptides (CPs) on skin condition and elucidate their mechanism of action. Methods: A randomized, placebo-controlled, double-blind trial was conducted in 99 healthy Japanese women, aged 35–50 years. The subjects were randomized into 3 groups (33 subjects/group) to receive 1 or 5 g of CP or placebo once daily for 12 weeks. Skin water content, transepidermal water loss (TEWL), skin elasticity, and skin thickness were evaluated before treatment and after 4, 8, and 12 weeks of treatment. The level of natural moisturizing factor (NMF) constituents in the stratum corneum (SC) was quantified before treatment and after 12 weeks of treatment. Results: Oral ingestion of CP increased the water content in the SC and epidermis and decreased TEWL. Furthermore, the NMF level in the SC was increased. However, skin elasticity and skin thickness remained unchanged. Conclusions: The improvement in skin water content following the oral ingestion of CP can be attributed to an increase in the level of NMF in the SC. Trial Registration: UMIN000030375 (retrospectively registered). [ABSTRACT FROM AUTHOR]

Conventional collagen-based hydrogels as wound dressing materials are usually lack of antibacterial activity and easily broken when encountering external forces. In this work, we developed a collagen peptide-based hydrogel as a wound dressing, which was composed of adipic acid dihydrazide functionalized collagen peptide (Col-ADH), oxidized dextran (ODex), polyvinyl alcohol (PVA) and borax via multiple-dynamic reversible bonds (acylhydrazone, amine, borate ester and hydrogen bonds). The injectable hydrogel exhibited satisfactory self-healing ability, antibacterial activity, mechanical strength, as well as good biocompatibility and biodegradability. In vivo experiments demonstrated the rapid hemostasis, accelerated cell migration, and promoted wound healing capacities of the hydrogel. These results indicate that the multifunctional collagen peptide-based hydrogel has great potentials in the field of wound dressings. [Display omitted] • An injectable hydrogel with excellent self-healing ability was prepared. • The hydrogel with interconnected pores was cross-linked by multiple-dynamic bonds. • Satisfactory antibacterial activity was obtained by the non-releasing hydrogel. • Good biocompatibility ensures its safe use as a wound dressing. • Accelerated wound closure and enhanced collagen deposition were realized. [ABSTRACT FROM AUTHOR]

Collagen peptide exhibits a great activity in osteogenic differentiation and wound healing. However, uncontrolled collagen peptide release in bone defects leads to unsatisfactory bone regeneration. In this work, we prepared collagen peptide loaded calcium alginate hydrogel (SA-CP/Ca) derived from Asia carp scales by mixing sodium alginate solution, collagen peptides, calcium carbonate, covalent cross-linking agents N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) in one pot. Physically and chemically double cross-linking realized higher crosslink density, smaller porosity and pore size, and higher energy storage modulus and loss modulus, achieving sustained release of collagen peptides. The release profile is fitted to Keppas-Sahlin model, to find SA-CP/Ca hydrogels are more inclined to release collagen peptides through expansion and degradation. The compatibility and osteogenic ability of SA-CP/Ca are demonstrated in vitro and in vivo. • Carp scale collagen peptide/sodium alginate hydrogels (SA-CP/Ca) were prepared by one-pot method; • The SA-CP/Ca hydrogels exhibited sustained release properties; • The SA-CP/Ca hydrogels loaded with collagen peptides of high hydrolysis degree showed excellent osteogenic differentiation activity in vivo and in vitro. [ABSTRACT FROM AUTHOR]

Collagen peptide exhibits a great activity in osteogenic differentiation and wound healing. However, uncontrolled collagen peptide release in bone defects leads to unsatisfactory bone regeneration. In this work, we prepared collagen peptide loaded calcium alginate hydrogel (SA-CP/Ca) derived from Asia carp scales by mixing sodium alginate solution, collagen peptides, calcium carbonate, covalent cross-linking agents N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) in one pot. Physically and chemically double cross-linking realized higher crosslink density, smaller porosity and pore size, and higher energy storage modulus and loss modulus, achieving sustained release of collagen peptides. The release profile is fitted to Keppas-Sahlin model, to find SA-CP/Ca hydrogels are more inclined to release collagen peptides through expansion and degradation. The compatibility and osteogenic ability of SA-CP/Ca are demonstrated in vitro and in vivo. • Carp scale collagen peptide/sodium alginate hydrogels (SA-CP/Ca) were prepared by one-pot method; • The SA-CP/Ca hydrogels exhibited sustained release properties; • The SA-CP/Ca hydrogels loaded with collagen peptides of high hydrolysis degree showed excellent osteogenic differentiation activity in vivo and in vitro. [ABSTRACT FROM AUTHOR]

• Density functional theory proves that LAA IL is connected by hydrogen bonds and can exist stably. • 5D LAA-Collagen peptide can penetrate the stratum corneum to the dermis and epidermis layers. • 5D-LAA collagen peptide can promote skin permeability. • 5D LAA-Collagen peptide has a good antioxidant capacity, increases skin hydration, and induces collagen production. • 5D LAA-Collagen peptide has improved the skin barrier function and delayed cell aging and death. Lactobionic acid-arginine (LAA) ionic liquid was prepared using an ion-exchange method. The LAA ionic liquid and five kinds of different molecular weights of collagen can self-assemble into spherical 5D LAA-Collagen peptides in solution. The 5D LAA-Collagen peptide has a small particle size, good stability, and biocompatibility, and can transdermally deliver collagen with different molecular weights to the epidermis and dermis through the skin. The activity and expression of IL-1β, MMP-1, and TNF-α decreased after adding 5D LAA-Collagen peptide. 5D LAA-Collagen peptide can inhibit MAPKs phosphorylation, activate the PI3K/AKT signaling pathway, increase the protein expression of Nrf2, and inhibit the high protein expression of Keapl to play an anti-aging role in multiple ways. The 5D LAA-Collagen peptide has a good antioxidant ability, can delay cell aging and death, and can reduce the length and number of facial wrinkles, fine facial lines, and texture to achieve an anti-wrinkle effect. Therefore, 5D LAA-Collagen peptide has potential applications in the field of cosmetics. [ABSTRACT FROM AUTHOR]

Increasing evidence has shown that collagen peptides had various biological activities. In this study, a novel antiplatelet peptide Met‐Glu (ME) was separated and identified from silver carp skin by YMC ODS‐A C18 separation and ESI‐MS/MS analysis. Peptide ME inhibited platelet aggregation and secretion of platelet granules induced by ADP, thrombin and collagen, and significantly attenuated ferric chloride‐induced thrombus formation in rats. It did not prolong the bleeding time in mice even at the dose of 300 μmol/kg body weight that showed potent anti‐thrombosis effects. Additionally, peptide ME targeted at Gq‐protein to downregulate the phosphorylation of PLCβ, an important upstream effector of PI3K/Akt and Erk/MAPK signaling to inhibit intracellular calcium ion mobilization. These results suggest that peptide ME inhibited thrombosis in vivo and inhibited Gq‐mediated signaling in platelets, indicating the possibility that ME could potentially be developed as a novel therapeutic agent in the prevention and treatment of thrombotic diseases. Practical applications: Cardiovascular diseases (CVDs) are the leading cause of mortality and morbidity worldwide. The proximal cause of CVDs is intravascular thrombosis formation, which mostly results from platelet activation, aggregation, and granules secretion. Traditional drugs in the prevention of thrombotic disease, such as aspirin and clopidogrel, are still limited for their side effects, especially bleeding complications. Collagen is a natural source for bioactive peptides and our previous study has shown that collagen peptides could inhibit platelet aggregation in vitro. Understanding the mechanism of collagen peptides on regulation of platelet activation and their in vivo anti‐thrombosis activities were important for the development of novel‐specific medical food in the prevention of thrombotic diseases. [ABSTRACT FROM AUTHOR]

Medical dressings are used to protect damaged skin from external factors and provide a good healing environment. Hydrogels are aggregates of hydrophilic polymers and water that have a three-dimensional space and can absorb large amounts of water. It has been widely studied in the field of biomedical materials. In this study, we prepared a novel composite hydrogel combined carboxymethyl chitosan, collagen peptide and oxidized konjac, all three materials have been shown to be biocompatible. Then, we set up different hydrogels and tested hydrogels with different proportions. The structures of CMCS (carboxymethyl chitosan)/COP (collagen peptide)/OKGM (oxidized konjac) hydrogels were characterized by IR, NMR, X-ray diffraction and SEM. The effects of hydrogels on the growth of NS-FB and HS-FB cells were studied in vitro. The results of these tests show that the composite hydrogel has excellent mechanical properties and biological activity, and has potential application in wound dressing field. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of bone collagen peptide combined with alendronate on bone mineral density and bone metabolism in elderly patients with osteoporosis. Methods 138 elderly patients with osteoporosis were randomly divided into treatment group and control group, with 69 cases in each group. Patients in the control group were treated with alendronate, and patients in the treatment group were treated with collagen-peptide combined with alendronate for 12 months. BMD of lumbar anteroposterior(L1-4) and left femoral neck, bone alkaline phosphatase(BALP) and tartrate-resistant acid phosphatase-5 b(TRAP-5 b) levels were examined before treatment and after 12 months of treatmentas and treatment efficiency and adverse reactions were recorded in the two groups. Results After 12 months of treatment, patients in the treatment group had significantly higher lumbar spine(L1-4) and left femoral neck BMD than those in the control group(P<0.05). After 12 months of treatment, serum BALP and serum phosphorus levels in the two groups were significantly lower than those before treatment, serum TRAP-5 b and serum calcium levels were significantly higher than those before treatment, both of statistical significance(P<0.05), and the treatment group had greater improvement than the control group(P<0.05). The effective rate of treatment in the treatment group was better than that in the control group(P <0.05), and there was no significant difference in adverse reactions between the two groups(P>0.05). Conclusion Collagen peptide combined with alendronate sodium could safely and effectively improve bone mineral density and improve bone metabolism in elderly osteoporosis patients. [ABSTRACT FROM AUTHOR]

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology. Cod (Gadus), a kind of herb from the Chinese herb. Traditionally, it has used to treat trauma, reduce swelling and relieve pain in order to exert its anti-inflammatory activity. Recent reports based on its hydrolyzed or enzymatic extracts have shown its anti-inflammatory, mucosal barrier protecting properties. However, its mechanism of improvement in ulcerative colitis is not clear. This study aimed to explore the preventive and protective effect of cod skin collagen peptide powder (CP) on mice with UC and to explore the underlying mechanism. Mice with dextran sodium sulfate (DSS)-induced UC were treated with CP by gavage, and the anti-inflammatory effects of CP were assessed using general physical, pro-inflammatory cytokine, histopathological, immunohistochemical, macrophage flow cytometry, and inflammatory signaling pathway assays. CP ameliorates inflammation by upregulating mitogen-activated protein kinase phosphatase-1 (MKP-1) and thereby decreasing the phosphorylation levels of P38 and JNK. It also polarizes macrophages in the colon towards the M2 phenotype, which helps to reduce tissue damage and promotes colon repair. At the same time, CP also inhibits the development of fibrosis, one of the complications of UC, by upregulating ZO-1, Occludin, and downregulating α-SMA, Vimentin, Snail, and Slug. In this study, we found CP reduced inflammation in mice with UC by inducing MKP-1 expression, which caused dephosphorylation of mitogen-activated protein kinase (MAPK). CP also restored mucosal barrier function and inhibited the development of fibrosis complicating UC in these mice. Taken together, these results suggested that CP improved the pathological manifestations of UC in mice, suggesting that it can play a biological role as a nutritional supplement for preventing and treating UC. [Display omitted] • Cod skin collagen peptide powder can reduce colonic inflammation. • Cod skin collagen peptide powder can polarize the macrophage phenotype toward M2. • Cod skin collagen peptide powder can restore mucosal barrier. • Cod skin collagen peptide powder can inhibit the development of colonic fibrosis. [ABSTRACT FROM AUTHOR]

• Hydrothermal process showed efficacy for collagen hydrolysis. • Elevated temperature and pressure are synergistic in hydrothermal hydrolysis. • Hydrothermal process is an environmentally friendly and effective technology. • An ultrafiltration membrane is useful for separation of bioactive peptides. • Collagen peptides exhibited superior antioxidant and anti-aging abilities. Collagen, in a form suitable for human consumption, can be obtained from the large amounts of fish skin via protein hydrolysis to produce low-molecular-weight substances with enhanced bioavailability and function. To optimize this method, we investigated the synergistic effect of elevated temperature (150–250 °C) and pressure (350–3900 kPa) of a hydrothermal process on the hydrolytic ability and characteristics of collagen hydrolysates. Elevated temperature and pressure of the hydrothermal process increased the levels of free amino groups and lower-molecular-weight collagen hydrolysates, particularly at 210 °C and 2100 kPa. The resulting hydrolysates were fractionated by ultrafiltration membranes of different molecular weight cutoff and evaluated for their antioxidant (ABTS radical scavenging activity and reducing power) and anti-aging (tyrosinase and collagenase inhibition) activities. The <1 kDa fraction had the highest antioxidant activities, whereas the 5–10 kDa fraction had the highest anti-aging activities. Therefore, fish skin could be successfully modified into biologically active collagen peptides by a hydrothermal process (hydrolysis) and ultrafiltration (separation), and the resulting bioactive peptides have potential for development as antioxidants and anti-aging ingredients in the food, nutraceutical, and cosmetic industries. [ABSTRACT FROM AUTHOR]

Highlights • Carboxymethyl chitosan sulfate granted with collagen peptides were prepared, transglutaminase as a cross-linking agent. • The polymer has antioxidant, reductive, anticoagulant properties. • The polymer promotes cell growth, proliferation, differentiation. • CMCS-COP would appear to be a promising candidate for wound dressing application. Abstract Free radicals are closely related to the occurrence and development of aging, cancer and inflammation. In this paper, the microbial transglutaminase (MTGase) was used as a catalyst to graft the collagen peptide (COP) molecules on the amino group of carboxymethyl chitosan sulfate (CMCS) to improve the antioxidant effects. FT-IR and NMR spectroscopy were used to confirm the successful grafting of COP to CMCS. Degree of substitution (DS) of CMCS-COP could be controlled by adjusting the reaction conditions. With the increase of concentration, the ability of each sample on scavenging capacity and reducibility tends to increase obviously. The results of anticoagulant experiments showed that the ability of CMCS and CMCS-COP with three different degrees of substitution on activated partial thrombin time (APTT) and prothrombin time (PT) values were all increased to compare with the control group. No relevant cytotoxicity against NIH-3T3 mouse fibroblasts was found for the copolymers. These results suggested that CMCS-COP would appear to be a promising candidate for wound dressing application. [ABSTRACT FROM AUTHOR]

Objective 　To study the effects of bone collagen peptide combined with Caltrate D on the treatment of postmenopausal osteoporosis. Methods 　202 postmenopausal women with osteoporosis were randomized to receive oral administration of 10 g collagen peptide combined with 600 mg Caltrate D (experimental group) or 600 mg Caltrate D (control group) daily for 6 months. Serum total N-terminal propeptide of type I procollagen (PINP), β-isomerized C-terminal cross-linked telopeptide of type I collagen ( β-CTX), N-MID Osteocalcin ( OC), 25-hydroxyvitamin D3 (25-OH D3) and parathyroid hormone (PTH) were detected by chemiluminescence. BMD of the lumbar spine and the femur was measured using dual-energy X-ray absorption. Results　After 6 months of treatment, oral collagen peptide combined with Caltrate D was more effective in alleviating bone pain caused by osteoporosis. The levels of serum PTH, 25-OH D3 and N-MID Osteocalcin ( OC ) in the experimental group were significantly higher than those before treatment (P <0． 01) and the control group (P <0． 01). Serum PINP level of the control group after treatment was significantly lower than that before treatment (P<0． 01), while the levels of PTH, 25-OH D3 and β -CTX were significantly higher than those before treatment ( P < 0． 01). Serum PINP level in the experimental group was significantly higher than that in the control group ( P < 0． 01), while the level of β-CTX in the experimental group was lower than that in the control group (P<0． 05). BMD of L2-L4 of lumbar spine and of femoral neck and intertrochanter of femur in the experimental group was significantly higher than that before treatment (P<0． 01) and the control group (P<0． 05). BMD of all sites in the experimental group was significantly higher than that before treatment (P<0． 01), but there was no statistical significance in the above indexes after treatment in the control group (P > 0． 05). Conclusion 　Oral collagen peptide combined with Caltrate D not only could promote bone formation, but also could inhibit bone absorption, further increase BMD and alleviate the pain caused by osteoporosis. [ABSTRACT FROM AUTHOR]

• SA successfully coated on the CP-Lip surface and formed a network structure on bulk phase. • SA coating favored the entrapment of CP into the liposomes, with a 15% increase in EE. • SA coating showed a better storage stability at 4 ℃ during one month. • SA coating enhanced the in vitro stability of CP-Lip in gastrointestinal tract, with a 1.5 times bioavailability than the uncoated CP-Lip. • SA coating on CP-Lip improved the transcellular permeability of collagen peptides with a 30% increase in P app compared to the uncoated CP-Lip. Sodium alginate (SA) was used to coat liposomes containing DPP-IV inhibitory collagen peptides to improve their stability and in vitro absorption for intra-oral delivery. The liposome structure as well as entrapment efficiency and DPP-IV inhibitory activity was characterized. The liposome stability was determined by measuring in vitro release rates and their gastrointestinal stability. Transcellular permeability of liposomes was further tested to characterize their permeability in small intestinal epithelial cells. The results showed that the 0.3% SA coating increased the diameter (166.7 nm to 249.9 nm), absolute value of zeta potential (30.2 mV to 40.1 mV) and entrapment efficiency (61.52% to 70.99%) of liposomes. The SA-coated liposomes containing collagen peptides showed enhanced storage stability within one month, gastrointestinal stability increased by 50% in bioavailability, transcellular permeability increased by 18% in transmission percentage, and in vitro release rates reduced by 34%, compared to uncoated liposomes. SA coating liposomes are promising carriers for transporting hydrophilic molecules, may be beneficial for improving nutrient absorption and can protect bioactive compounds from being inactivated in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Small collagen peptides are associated with various benefits, such as bone and skin health. However, preparation of small collagen peptides from terrestrial vertebrate origins remains a challenge. Here, we show that pretreatment with formic acid enhanced the production of small collagen peptides from spent hen skin. After pretreatment with formic acid, the percentage of small peptides below 2 kDa increased to 48.92% and 43.34% from 33.79% and 36.32% for heat-soluble collagen (HSC) and pepsin-soluble collagen (PSC), respectively. Pretreatment with formic acid degraded telopeptides and released the cross-links (pyrrole and pyridinoline), which made hen collagen more susceptible to papain hydrolysis. LC-MS/MS results revealed that none of the peptides identified from HSC-FA (formic acid)-Papain and PSC-FA-Papain were derived from cross-linked telopeptides. These results demonstrated that formic acid assisted the hydrolysis of highly cross-linked collagen of spent hens, and it might also be used to produce small collagen peptides from other aged, vertebrate collagens. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Collagen peptides have been widely used as a food supplement. After ingestion of collagen peptides, oligopeptides containing hydroxyproline (Hyp), which are known to have some physiological activities, are detected in peripheral blood. However, the effects of collagen‐peptide administration on immune response are unclear. In the present study, we tested the effects of collagen‐peptide ingestion on allergic response and the effects of collagen‐derived oligopeptides on CD4+ T‐cell differentiation. Methods: BALB/c mice fed a collagen‐peptide diet were immunized with ovalbumin (OVA), and their serum IgE and IgG levels, active cutaneous anaphylaxis, and cytokine secretion by splenocytes were examined. Naive CD4+ T cells were stimulated with anti‐CD3 and anti‐CD28 in the presence of collagen‐derived oligopeptides, and the expression of IFN‐γ, IL‐4, and Foxp3 was analyzed. Results: In an active anaphylaxis model, oral administration of collagen peptides suppressed serum OVA‐specific immunoglobulin E (IgE) production and diminished anaphylaxis responses. In this model, the ingestion of collagen peptides skewed the pattern of cytokine production by splenocytes toward T‐helper (Th) type 1 and regulatory T (Treg) cells. In vitro T‐helper cell differentiation assays showed that Hyp‐containing oligopeptides promoted Th1 differentiation by upregulating IFN‐γ‐induced signal transducer and activator of transcription 1 (STAT1) signaling. These oligopeptides also promoted the development of Foxp3+ Treg cells in response to antigen stimulation in the presence of TGF‐β. Conclusions: Collagen‐peptide ingestion suppresses allergic responses by skewing the balance of CD4+ T cells toward Th1 and Treg cells and seems to be a promising agent for preventing allergies and inflammatory diseases. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Daily ingestion of collagen hydrolysate for a long period improves skin and joint conditions. It has been speculated that the beneficial effects are exerted by food‐derived hydroxyproline (Hyp) peptides, which are detected in human blood after single ingestions. In the present study, to investigate the effect of long‐term ingestion of collagen hydrolysate on Hyp peptides profile in blood, the concentrations of Hyp‐peptides in human blood before and after daily ingestion for a long period were examined. RESULTS: Hyp‐peptides increased to a maximum level at 1 h after ingestion and reverted to their initial levels within 24 h during experimental period. Pro‐Gly and Hyp‐peptides such as Pro‐Hyp‐Gly, Pro‐Hyp, Ile‐Hyp, Leu‐Hyp, Hyp‐Gly, Glu‐Hyp and Ala‐Hyp were identified in the blood after ingestion of collagen hydrolysate at 4.5 g day−1 for 4 weeks. For the whole period, Pro‐Hyp was the leading compound. The compositional rate of Hyp‐Gly showed a tendency to increase, while that of Pro‐Hyp tended to decrease after daily ingestion. CONCLUSION: The present results indicate that daily ingestion of collagen hydrolysate for a long period can change compositional rate of Hyp peptides in human blood. This fact suggests that long‐term ingestion of collagen hydrolysate might change exo‐ or endo‐type protease activity in the digestive tract, which may consequently promote beneficial effects. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Preventing the precipitation of collagen peptide-fruit juice drinks during production and storage is a current challenge. This study investigated the efficiency and mechanism of β-glucan, low methoxyl pectin, and chitosan (a neutral, anionic, and cationic polysaccharide, respectively) for enhancing the stability of a fish collagen peptide-cranberry juice drink. The effects of mixing sequence, mixing temperature, pH, and polysaccharide concentration on stability were studied by conducting centrifugal precipitation rate, turbidity, relative turbidity, zeta potential, rheology, confocal laser scanning microscopy, and storage (4 °C, 25 °C, 40 °C, 14 d) experiments. All three polysaccharides effectively improved the stability of the drink mixture, but to different extents, as the stability was highly dependent on pH and the type and concentration of the polysaccharide. Steric hindrance, electrostatic repulsion, and increased viscosity were the main reasons underlying the improvements in the stability of the system. The stability mechanisms were also related to a competition or ternary complex mechanism. The results of storage experiments showed that chitosan could only temporarily stabilize system (25 °C, 2d), whereas β-glucan (4 °C, 14d) and low-methoxyl pectin (4 °C, 25 °C, 14d) provided the continuous stability. Overall, these results can provide important guidance for the application of these three polysaccharide types in the beverage industry to develop and select ideal formulations for collagen peptide-juice drinks. [Display omitted] • Collagen peptides-fruit juice drinks are prone to turbidity and precipitation. • Three functional polysaccharides improve the stability of a collagen peptides-cranberry juice drink. • Steric hindrance, electrostatic repulsion, and increased viscosity contribute to stability. • β-glucan provides the best stability. [ABSTRACT FROM AUTHOR]

The preparation of aminoethyl hydroxypropyl starch collagen peptide (AEHPS-COP) was via an enzyme-catalyzed reaction between amino groups in aminoethyl hydroxypropyl starch (AEHPS) and γ-carboxamide groups in collagen peptide (COP) by using microbial transglutaminase (MTGase) as biocatalyst. As an intermediate reactant, AEHPS was synthesized from hydroxypropyl starch (HPS) and 2-chloroethylamine hydrochloride (CEH). The chemical structures of HPS, AEHPS and AEHPS-COP were characterized by Fourier transform infrared spectroscopy (FT-IR) and 13 C nuclear magnetic resonance ( 13 C NMR). The reaction conditions that influenced the degree of substitution (DS) of AEHPS-COP were optimized, which included the reaction temperature, the reaction time, the mass ratio of collagen peptide to aminoethyl hydroxypropyl starch and the pH value. In addition, in vitro antioxidant activities of AEHPS-COP were evaluated through the scavenging activity of hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Furthermore, the methylthiazol tetrazolium (MTT) assay was applied to investigate the cell viability of AEHPS-COP. The results indicated that the AEHPS-COP exhibited better cell viability to L929 mouse fibroblast cells. Therefore, the AEHPS-COP showed a promising potential application in cosmetic, biomedical and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

First documented in Shennong Bencao Jing (about 200 B.C.–200 A.D.), Elaphuri Davidiani Cornu (EDC) has been recorded for its effects in strengthening bones and balancing other aspects of overall health for approximately 2000 years. In the present study, our aim was to investigate which are the components of the active EDC fraction by a peptidomic strategy. We explored the extent to which EDC increases the proliferation of osteoblasts by measuring the elevations in osteonectin and type I collagen mRNA levels and characterized it using nano-flow liquid chromatography in tandem with orbitrap mass spectrometry. In total, 272 peptide sequences from collagens were determined. “Hot regions” in parent proteins determined by peptide heat maps which indicated that amino acid sequences in the regions might undergo proteolysis easily and generate peptides. Among the identified peptides, 90.2% were hydrophilic, and the molecular weight of 97.1% of identified peptides was lower than 2000 Da. According to these results, EDC collagen-derived peptides were easily analyzed and identified. Moreover, this methodology is feasible to characterize the active peptides matrices originated from collagen hydrolysates or some other animal horn- derived TCMs. [ABSTRACT FROM AUTHOR]

Bone substitute is a therapeutic approach to treat bone abnormalities. A scaffold serves mainly as osteoconductive elements. To facilitate a better biological performance, short collagen peptide was immobilized onto hydrolyzed poly(butylene succinate)/β-tricalcium phosphate (HPBSu/TCP) scaffolds. PBSu/TCP (80:20) scaffolds were fabricated by a supercritical CO2 technique, hydrolyzed with 0.6 M NaOH and conjugated with short collagen peptide tagged with or without red fluorescence. The surface morphology and porous structure of scaffolds were characterized by scanning electron microscopy and micro-computed tomography. Human mesenchymal stem cells were cultured onto the scaffolds and examined for osteogenic differentiation and biomineralization in vitro by means of alkaline phosphatase activity, alizarin red staining, and reverse transcription-polymerase chain reaction. The PBSu/TCP and HPBSu/TCP scaffolds were successfully prepared. Scanning electron microscopy and micro-computed tomography results showed that the porosity was distributed throughout the scaffolds with the pore sizes in the range of 250–900 µm. Fluorescence microscopy demonstrated retention of tagged short collagen peptide on the scaffold. Mesenchymal stem cells adhered and grew well on the material. Under osteogenic induction, cells cultured on the short collagen peptide -immobilized scaffold significantly produced a greater amount of alkaline phosphatase activity and positive mineralization than those cultured on the control scaffold. The present results have shown that the short collagen peptide-immobilized HPBSu/TCP scaffold enhanced osteoinduction and biomineralization of stem cell-derived osteoblasts, possibly via stimulation of alkaline phosphatase activity. This suggests the potential use of osteogenic peptide-immobilized material in bone tissue engineering for correcting bone defects. [ABSTRACT FROM AUTHOR]

In recent years, nanoparticles (NPs) based on biopolymers or peptides are gaining popularity for the encapsulation and release of drug molecules, especially for cancer therapy, due to their ability for targeted and controlled release. The use of collagen peptide (CP) for the preparation of chitosan (CN) NPs is especially interesting as it results in NPs that are stable under physiological conditions. In this work, mono-dispersed pH responsive CPCN NPs of about 100 nm were prepared via ionic gelation method by simple and mild co-precipitation of CN and CP. Investigation of NPs with Fourier transform infra-red (FTIR) spectroscopy and dynamic light scattering (DLS) measurements reveals that hydrogen bonding and electrostatic interactions are believed to be major driving forces for NP formation and drug encapsulation, respectively. Scanning electron microscopic (SEM) investigations show that hard and fine CPCN NPs transform to soft and bigger gel like particles as a function of collagen concentration. The unique “polymeric gel” structure of NPs showed high encapsulation efficiency towards doxorubicin hydrochloride (DOX) as well as pH controlled release. Anti-proliferative and cell viability analysis revealed that DOX loaded NPs showed excellent anti-proliferative characteristics against HeLa cells with favorable biocompatibility against normal cells. Such NPs have high potential for use as smart drug delivery carriers in advanced cancer therapy. [ABSTRACT FROM AUTHOR]

Collagen peptide (COP) had been grafted to hydroxypropyl chitosan (HPCS) by using microbial transglutaminase (MTGase) as biocatalyst. HPCS was synthesized from chitosan and propylene oxide under alkali condition. The chemical structures of derivative were characterized by FT-IR and 1 H NMR spectroscopy. The process conditions were optimized from the aspects of the reaction time, the reaction temperature, the molar ratio of COP and the mass ratio of MTGase to HPCS. In this study, HPCS-COP could serve not only to reduce the loss of moisture but also to absorb the moisture, and the moisture absorption and moisture retention abilities were closely related to the degree of substitution (DS) values. In addition, with the DS and concentration increase of HPCS-COP, the radical scavenging activity increased in vitro antioxidant activity. Furthermore, the methyl thiazolyl tetrazolium assay (MTT) was applied to evaluate the biocompatibility of HPCS-COP, and the result indicated that HPCS-COP with the DS of 0.34 displayed pronounced cell viability at 50 ppm. Therefore, the results suggest that HPCS-COP could be potential wound dressings for clinical applications. [ABSTRACT FROM AUTHOR]

In this study, tilapia collagen peptide ( TCP) was prepared by alcalase hydrolysis of tilapia skin, and the antioxidant and hypoglycaemic effects of TCP were investigated. The results showed that TCP possessed DPPH and ABTS+ free radicals-scavenging activities. In diabetic mice in which diabetes was induced by injection of alloxan (50 mg kg−1 bw), high-dose TCP (1.7 g kg−1 bw) and the drug metformin (1.0 g kg−1 bw) were found to reduce 31.8% and 30.3% of blood glucose levels in 25 days, respectively. Moreover, in diabetic mice receiving high-dose TCP, antioxidant enzymes SOD and CAT were increased by 23% and 59.2%, respectively, and MDA was decreased by 39.1%. Comparing the treated high-dose TCP group with the metformin group, there were similar SOD (61.5 U mg−1 vs. 60.2 U mg−1) and MDA (1.4 nmol mg−1 vs. 1.3 nmol mg−1), but more (~7%) CAT (359.8 U g−1 vs. 336.1 U g−1). Together, the present data, for the first time, demonstrated that TCP possessed hypoglycaemic effects in mice. [ABSTRACT FROM AUTHOR]

The effects of collagen and collagen peptide from goose bone on osteoporosis were studied. Fourier transform infrared spectrometry, ultraviolet spectrum, differential scanning calorimetry, and sodium dodecyl sulfate polyacrylamide gel electrophoresis identified the goose collagen as typical type I collagen. Results showed that osteopontin, bone morphogenetic protein 2, runt-related transcription factor 2, and type I collagen levels in bone marrow mesenchymal stem cells supernatant were dramatically higher in the experimental groups than in the control group (p <0.05), and was highest in the experimental group composed of low molecular weight collagen peptide linked with calcium. Then the osterix, runt-related transcription factor 2, transforming growth factor-β1, and bone morphogenetic protein 2 expression levels related to osteogenetic differentiation were detected by real-time fluorescent quantitative polymerase chain reaction. The findings showed that goose collagen and collagen peptide can improve the gene expression related to osteogenetic differentiation which reflected the level of bone marrow mesenchymal stem cells to osteoblasts. [ABSTRACT FROM PUBLISHER]

[Display omitted] • The anti-OA effect of Salmonidae bone collagen peptide (CP) was assessed. • CP was confirmed to inhibit the matrix degradation both in vitro and in vivo. • CP suppressed the role of pro-inflammatory via inhibiting NF-κB signal. • CP impeded the serious destruction of subchondral bone. • CP effectively prevent osteoarthritis in pMMx models as a dietary supplement. Nowadays, the biological activity of collagen peptides has been revealed, but the effect of Atlantic salmon (Salmo salar) bone-derived collagen peptide (CPs) on osteoarthritis remains unclear. In this study, CPs was identified as a small molecular weight peptide rich in Gly-X-Y structure. Meanwhile, interleukin-1β (IL-1β)-induced hypertrophic chondrocytes and partial medial meniscectomy (pMMx) surgery model in rats were performed. In IL-1β stimulated chondrocytes, CPs significantly increased the type-II collagen content, reduced the type-X collagen abundance and chondrocytes apoptosis. Meanwhile, CPs reversed the increased expression of matrix metalloproteinase, metalloproteinase with thrombospondin motifs and RUNX family transcription factor 2 in chondrocytes induced by IL-1β. In vivo , CPs increased pain tolerance of rats and without organ toxicity at 1.6 g/ kg.bw. CPs significantly decreased the levels of COMP and Helix-II in serum. Furthermore, a significant decrease of IL-1β in synovial fluid and cartilage tissue were observed by CPs intervention. From Micro-CT, CPs (0.8 g/ kg.bw) significantly decreased Tb.sp and SMI value. Meanwhile, the expression of tumor necrosis factor and interleukin-6 were reduced by CPs administration both in vitro and in vivo. Together, CPs showed potential to be a novel and safe dietary supplement for helping anti-inflammatory and cartilage regeneration, ultimately hindering osteoarthritis development. However, the clear mechanism of CPs's positive effect on osteoarthritis needs to be further explored. [ABSTRACT FROM AUTHOR]