Hydrolyzed Collagen-Sources and Applications

Effect of Collagen Types, Bacterial Strains and Storage Duration on the Quality of Probiotic Fermented Sheep’s Milk

Collagen has become popular in dietary supplements, beverages and sports nutrition products. Therefore, the aim of this study was to evaluate the possibility of using various doses of collagen and collagen hydrolysate to produce probiotic sheep’s milk fermented with Lactobacillus acidophilus, Lacticaseibacillus casei, Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus. The effects of storage time, type and dose of collagen, and different probiotic bacteria on the physicochemical, organoleptic and microbiological properties of fermented sheep’s milk at 1 and 21 days of refrigerated storage were investigated. The addition of collagen to sheep’s milk increased the pH value after fermentation and reduced the lactic acid contents of fermented milk compared to control samples. After fermentation, the number of probiotic bacteria cells was higher than 8 log cfu g⁻¹. In sheep’s milk fermented by L. acidophilus and L. casei, good survival of bacteria during storage was observed, and there was no effect of collagen dose on the growth and survival of both strains. The addition of collagen, both in the form of hydrolysate and bovine collagen, resulted in darkening of the color of the milk and increased the sweet taste intensity of the fermented sheep’s milk. However, the addition of hydrolysate was effective in reducing syneresis in each milk sample compared to its control counterpart.

Extraction and Characterization of Bioactive Fish By-Product Collagen as Promising for Potential Wound Healing Agent in Pharmaceutical Applications: Current Trend and Future Perspective

Collagen is a structural protein naturally found in mammals. Vertebrates and other connective tissues comprise about 30% of an animal’s overall protein. Collagen is used in a variety of applications including cosmetics, biomedical, biomaterials, food, and pharmaceuticals. The use of marine-based collagen as a substitute source is rapidly increasing due to its unique properties, which include the absence of religious restrictions, a low molecular weight, no risk of disease transmission, biocompatibility, and ease of absorption by the body system. This review discusses recent research on collagen extraction from marine-based raw material, specifically fish by-products. Furthermore, pretreatment on various sources of fish materials, followed by extraction methods, was described. The extraction procedures for acid soluble collagen (ASC) and pepsin soluble collagen (PSC) for fish collagen isolation are specifically discussed and compared. As a result, the efficacy of collagen yield was also demonstrated. The recent trend of extracting fish collagen from marine biomaterials has been summarized, with the potential to be exploited as a wound healing agent in pharmaceutical applications. Furthermore, background information on collagen and characterization techniques primarily related to the composition, properties, and structure of fish collagen are discussed.

Influence of Proteins on the Absorption of Lipophilic Vitamins, Carotenoids and Curcumin - A Review

While proteins have been widely used to encapsulate, protect, and regulate the release of bioactive food compounds, little is known about the influence of co-consumed proteins on the absorption of lipophilic constituents following digestion, such as vitamins (A, D, E, K), carotenoids, and curcumin. Their bioavailability is often low and very variable, depending on the food matrix and host factors. Some proteins can act as emulsifiers during digestion. Their liberated peptides have amphiphilic properties that can facilitate the absorption of microconstituents, by improving their transition from lipid droplets into mixed micelles. Contrarily, the less well digested proteins could negatively impinge on enzymatic accessibility to the lipid droplets, slowing down their processing into mixed micelles and entrapping apolar food compounds. Interactions with mixed micelles and proteins are also plausible, as shown earlier for drugs. This review focuses on the ability of proteins to act as effective emulsifiers of lipophilic vitamins, carotenoids, and curcumin during digestion. The functional properties of proteins, their chemical interactions with enzymes and food constituents during gastro-intestinal digestion, potentials and limitations for their use as emulsifiers are emphasized and data from human, animal, and in vitro trials are summarized.

Aquaponics-Derived Tilapia Skin Collagen for Biomaterials Development

Collagen is one of the most widely used biomaterials in health-related sectors. The industrial production of collagen mostly relies on its extraction from mammals, but several issues limited its use. In the last two decades, marine organisms attracted interest as safe, abundant, and alternative source for collagen extraction. In particular, the possibility to valorize the huge quantity of fish industry waste and byproducts as collagen source reinforced perception of fish collagen as eco-friendlier and particularly attractive in terms of profitability and cost-effectiveness. Especially fish byproducts from eco-sustainable aquaponics production allow for fish biomass with additional added value and controlled properties over time. Among fish species, Oreochromis niloticus is one of the most widely bred fish in large-scale aquaculture and aquaponics systems. In this work, type I collagen was extracted from aquaponics-raised Tilapia skin and characterized from a chemical, physical, mechanical, and biological point of view in comparison with a commercially available analog. Performed analysis confirmed that the proprietary process optimized for type I collagen extraction allowed to isolate pure native collagen and to preserve its native conformational structure. Preliminary cellular studies performed with mouse fibroblasts indicated its optimal biocompatibility. All data confirmed the eligibility of the extracted Tilapia-derived native type I collagen as a biomaterial for healthcare applications.

A Novel Facial Cream Based on Skin-penetrable Fibrillar Collagen Microparticles

BACKGROUND

Collagen protein plays a notable role maintaining firm skin. Topical creams containing collagen fibers are widely available, but their usefulness is questionable due to limited skin penetration. When applied in a cream, collagen does not penetrate the skin leaving the skin structure unaffected.

OBJECTIVE

We formulated micronized collagen in a cream base. Using human skin samples, we sought to investigate the ability of the micronized collagen cream to penetrate human skin.

METHODS

Particle sizes of micronized marine collagen were evaluated using electron microscopy. Optical profilometry was conducted to evaluate skin topography and roughness. The antioxidant activity of the collagen was evaluated using the electron paramagnetic resonance technique by measuring the changes in free radical production. Collagen penetration depth in human skin samples was monitored using a non-invasive optical technique known as iterative multiplane optical property extraction, which works based on the detection of laser light phase changes following the presence of collagen particles in deep skin layers.

RESULTS

According to the electron microscopy, collagen particles were found to be of various sizes, the smallest being about 120nm in diameter. Skin topography measurements revealed that the treated collagen cream increased skin smoothness of the samples. Our results derived from the iterative multiplane optical property extraction indicated that micronized collagen in a cream base penetrates both the stratum corneum and the deep epidermal layers toward the dermis.

CONCLUSION

Our investigation suggests that the collagen in the studied cream formulation was able to penetrate the stratum coreum and deep epidermal layers in human skin samples.

Wound Healing Modulation through the Local Application of Powder Collagen-Derived Treatments in an Excisional Cutaneous Murine Model

Wound healing includes dynamic processes grouped into three overlapping phases: inflammatory, proliferative, and maturation/remodeling. Collagen is a critical component of a healing wound and, due to its properties, is of great interest in regenerative medicine. This preclinical study was designed to compare the effects of a new collagen-based hydrolysate powder on wound repair to a commercial non-hydrolysate product, in a murine model of cutaneous healing. Circular excisional defects were created on the dorsal skin of Wistar rats (n = 36). Three study groups were established according to the treatment administered. Animals were euthanized after 7 and 18 days. Morphometric and morphological studies were performed to evaluate the healing process. The new collagen treatment led to the smallest open wound area throughout most of the study. After seven days, wound morphometry, contraction, and epithelialization were similar in all groups. Treated animals showed reduced granulation tissue formation and fewer inflammatory cells, and induction of vasculature with respect to untreated animals. After 18 days, animals treated with the new collagen treatment showed accelerated wound closure, significantly increased epithelialization, and more organized repair tissue. Our findings suggest that the new collagen treatment, compared to the untreated control group, produces significantly faster wound closure and, at the same time, promotes a slight progression of the reparative process compared with the rest of the groups.

Sustainable Applications of Animal Waste Proteins

Currently, the growth of the global population leads to an increase in demand for agricultural products. Expanding the obtaining and consumption of food products results in a scale up in the amount of by-products formed, the development of processing methods for which is becoming an urgent task of modern science. Collagen and keratin make up a significant part of the animal origin protein waste, and the potential for their biotechnological application is almost inexhaustible. The specific fibrillar structure allows collagen and keratin to be in demand in bioengineering in various forms and formats, as a basis for obtaining hydrogels, nanoparticles and scaffolds for regenerative medicine and targeted drug delivery, films for the development of biodegradable packaging materials, etc. This review describes the variety of sustainable sources of collagen and keratin and the beneficial application multiformity of these proteins.

Microstructural and Physicochemical Analysis of Collagens from the Skin of Lizardfish (Saurida tumbil Bloch, 1795) Extracted with Different Organic Acids

Marine fish collagen has attracted considerable attention due to its characteristics, including its biodegradability, biocompatibility, and weak antigenicity, and is considered a safer material compared to collagen from terrestrial animals. The aim of this study was to extract and characterize collagen from the skin of lizardfish (Saurida tumbil Bloch, 1795) with three different acids. The yields of acetic acid-extracted collagen (AESkC), lactic acid-extracted collagen (LESkC), and citric acid-extracted collagen (CESkC) were 11.73 ± 1.14%, 11.63 ± 1.10%, and 11.39 ± 1.05% (based on wet weight), respectively. All extracted collagens were categorized as type I collagen with mainly alpha chains (α₁ and α₂) detected and γ and β chains to some extent. Fourier transform infrared (FTIR) spectra showed an intact triple-helical structure in the AESkC, LESkC, and CESkC. UV-vis spectra and X-ray diffraction further demonstrated the similarity of the extracted collagens to previously reported fish skin collagens. AESkC (T_max = 40.24 °C) had higher thermostability compared to LESkC (T_max = 38.72 °C) and CESkC (T_max = 36.74 °C). All samples were highly soluble in acidic pH and low concentrations of NaCl (0-20 g/L). Under field emission scanning electron microscopy (FESEM) observation, we noted the loose, fibrous, and porous structures of the collagens. The results suggest that the lizardfish skin collagens could be a potential alternative source of collagen, especially the AESkC due to its greater thermostability characteristic.

Formulation and Evaluation of Novel Film Wound Dressing Based on Collagen/Microfibrillated Carboxymethylcellulose Blend

Collagen is essential as a physiological material in wound healing, so it is often used in wound management, mainly as a lyophilisate. Collagen also has excellent film-forming properties; unfortunately, however, its utilisation as a film wound dressing is limited because of its weak mechanical properties, especially in its wet state. For this reason, modifications or combinations with different materials are investigated. The combination of collagen with partially modified microfibrillar carboxymethylcellulose (CMC), which has not previously been described, provided a new possibility for strengthening collagen films and was the aim of this work. The collagen–CMC films based on three types of collagens, two plasticizers and two collagen. Plasticiser ratios were prepared using the solvent casting method; partially modified CMC served here as both a film-forming agent and a filler, without compromising the transparency of the films. The presence of microfibrils was confirmed microscopically by SEM. Organoleptic and physicochemical evaluation, especially in terms of practical application on wounds, demonstrated that all the samples had satisfactory properties for this purpose even after wetting. All the films retained acidic pH values even after 24 h, with a maximum of 6.27 ± 0.17, and showed a mild degree of swelling, with a maximum of about 6 after 24 h.

Dual-Layered Approach of Ovine Collagen-Gelatin/Cellulose Hybrid Biomatrix Containing Graphene Oxide-Silver Nanoparticles for Cutaneous Wound Healing: Fabrication, Physicochemical, Cytotoxicity and Antibacterial Characterisation

Tissue engineering products have grown rapidly as an alternative solution available for chronic wound and burn treatment. However, some drawbacks include additional procedures and a lack of antibacterial properties that can impair wound healing, which are issues that need to be tackled effectively for better wound recovery. This study aimed to develop a functionalized dual-layered hybrid biomatrix composed of collagen sponge (bottom layer) to facilitate cell proliferation and adhesion and gelatin/cellulose hydrogel (outer layer) incorporated with graphene oxide and silver nanoparticles (GC-GO/AgNP) to prevent possible external infections post-implantation. The bilayer hybrid scaffold was crosslinked with 0.1% (w/v) genipin for 6 h followed by advanced freeze-drying technology. Various characterisation parameters were employed to investigate the microstructure, biodegradability, surface wettability, nanoparticles antibacterial activity, mechanical strength, and biocompatibility of the bilayer bioscaffold towards human skin cells. The bilayer bioscaffold exhibited favourable results for wound healing applications as it demonstrated good water uptake (1702.12 ± 161.11%), slow rate of biodegradation (0.13 ± 0.12 mg/h), and reasonable water vapour transmission rate (800.00 ± 65.85 gm−2 h−1) due to its porosity (84.83 ± 4.48%). The biomatrix was also found to possess hydrophobic properties (48.97 ± 3.68°), ideal for cell attachment and high mechanical strength. Moreover, the hybrid GO-AgNP promoted antibacterial properties via the disk diffusion method. Finally, biomatrix unravelled good cellular compatibility with human dermal fibroblasts (>90%). Therefore, the fabricated bilayer scaffold could be a potential candidate for skin wound healing application.

Noordin WN, Huda N. Biochemical analysis of collagens from the bone of lizardfish (Saurida tumbil Bloch, 1795) extracted with different acids

Background

Lizardfish (Saurida tumbil Bloch, 1795) bone is a fish by-product generated during industrial surimi processing. This by-product is an important source of collagen production since the use of terrestrial animal-based collagens no longer sought due to concern regarding the transfer of infectious diseases and religious issues. Hence, this study was carried out to determine the biochemical analysis of collagens from the bone of lizardfish extracted with different acids.

Methods

Lizardfish bone collagens were extracted with various acids (i.e., acetic, lactic and citric acids). All extraction processes were conducted in a chiller room (4 °C). The extracted collagens were biochemically characterized, such as hydroxyproline content, Ultraviolet (UV) absorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy spectra (FTIR), Differential scanning calorimetry (DSC) and solubility in different pH values and NaCl concentrations.

Results

The yield of extracted collagens ranged between 1.73% and 2.59%, with the highest (p < 0.05) observed in citric acid-extracted collagen (CaEC). Protein patterns confirmed that all-collagen samples had two identical subunits, α1 and α2, representing type I collagen. The highest whiteness value was found in acetic acid-extracted collagen (AaEC), but there was no significant difference (p ≥ 0.05) compared to lactic acid-extracted collagen (LaEC). UV absorption and XRD analysis reflected the characteristics of the collagen, as reported in the literature. For the FTIR, all acid-extracted collagen samples presented a triple helical structure. The thermal transition temperature (T _max = 77.92-89.04 °C) was in accordance with collagen extracted from other fish species. All extracted collagens were highly soluble in acidic pH and low concentrations of NaCl (0-20 g/L). In conclusion, collagens extracted from lizardfish bone may be used as alternative sources of collagen in industrial settings, and AaEC would be considered superior in terms of the characteristics evaluated in this study.

Development and evaluation of a multicomponent bioink consisting of alginate, gelatin, diethylaminoethyl cellulose and collagen peptide for 3D bioprinting of tissue construct for drug screening application

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.

Sirolimus Release from Biodegradable Polymers for Coronary Stent Application: A Review

Drug-eluting stents (DESs) are commonly used for the treatment of coronary artery disease. The evolution of the drug-eluting layer on the surface of the metal stent plays an important role in DES functionality. Here, the use of biodegradable polymers has emerged as an attractive strategy because it minimizes the occurrence of late thrombosis after stent implantation. Furthermore, understanding the drug-release behavior of DESs is also important for improving the safety and efficacy of stent treatments. Drug release from biodegradable polymers has attracted extensive research attention because biodegradable polymers with different properties show different drug-release behaviors. Molecular weight, composition, glass transition temperature, crystallinity, and the degradation rate are important properties affecting the behavior of polymers. Sirolimus is a conventional anti-proliferation drug and is the most widely used drug in DESs. Sirolimus-release behavior affects endothelialization and thrombosis formation after DES implantation. In this review, we focus on sirolimus release from biodegradable polymers, including synthetic and natural polymers widely used in the medical field. We hope this review will provide valuable up-to-date information on this subject and contribute to the further development of safe and efficient DESs.

Characterization of Collagen from Three Genetic Lines (Gray, Red and F1) of Oreochromis niloticus (Tilapia) Skin in Young and Old Adults

From tilapia (Oreochromis niloticus) farming, the by-products have been identified as a source of collagen that could be used for the development of dermocosmetics or pharmaceutical products. However, the characteristics of collagen related to a specific strain or culture must be well defined prior to its application. Collagen was extracted from the skin of three strains of tilapia: red YY males (YY: two Y-type sex chromosomes), XX gray females, and the F1: offspring of crossing red YY males with XX gray females; at different ages in the adult phase, using acetic acid and pepsin enzyme. The characteristics of acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were shown by SDS-PAGE band profiles to be similar to bovine collagen type I (SIGMA), the PSC of gray tilapia being more fragile to temperature changes, consistent with the results of fractional viscosity. The characteristics of the F1 progeny were prioritized for being a commercially productive and sustainable source for the extraction of collagen, and the ASC form, being the one with the greatest stability and advantage over PSC, of importance to our investigations, leads to a controlled digestion as in the case of peptide induction, and also in the development of natural products in the pharmaceutical and/or dermocosmetic industry. Evaluations of the triple helix structure by FT-IR, X-ray diffraction and UV-visible spectroscopy give similar results between the strains: red, gray, and F1, and between ages in the adult form F1 (15, 24, and 36 months of age). Consequently, the skin of tilapia in adult form is recommended sustainably for up to 24 months of age where the collagen is obtained with the use of acetic acid without enzymatic treatment.

Feasibility and acceptability of a mixed model digital study to explore the effect of a daily collagen peptide supplement on digestive symptoms in healthy females: findings from a pilot study. (Preprint)

Background

Objective

Methods

Results

Conclusions

Trial Registration

Marine Collagen: A Promising Biomaterial for Wound Healing, Skin Anti-Aging, and Bone Regeneration

Marine organisms harbor numerous bioactive substances that can be utilized in the pharmaceutical and cosmetic industries. Scientific research on various applications of collagen extracted from these organisms has become increasingly prevalent. Marine collagen can be used as a biomaterial because it is water soluble, metabolically compatible, and highly accessible. Upon review of the literature, it is evident that marine collagen is a versatile compound capable of healing skin injuries of varying severity, as well as delaying the natural human aging process. From in vitro to in vivo experiments, collagen has demonstrated its ability to invoke keratinocyte and fibroblast migration as well as vascularization of the skin. Additionally, marine collagen and derivatives have proven beneficial and useful for both osteoporosis and osteoarthritis prevention and treatment. Other bone-related diseases may also be targeted by collagen, as it is capable of increasing bone mineral density, mineral deposition, and importantly, osteoblast maturation and proliferation. In this review, we demonstrate the advantages of marine collagen over land animal sources and the biomedical applications of marine collagen related to bone and skin damage. Finally, some limitations of marine collagen are briefly discussed.

Screening of Self-Assembling of Collagen IV Fragments into Stable Structures Potentially Useful in Regenerative Medicine

The aim of the research was to check whether it is possible to use fragments of type IV collagen to obtain, as a result of self-assembling, stable spatial structures that could be used to prepare new materials useful in regenerative medicine. Collagen IV fragments were obtained by using DMT/NMM/TosO- as a coupling reagent. The ability to self-organize and form stable spatial structures was tested by the CD method and microscopic techniques. Biological studies covered: resazurin assay (cytotoxicity assessment) on BJ, BJ-5TA and C2C12 cell lines; an alkaline version of the comet assay (genotoxicity), Biolegend Legendplex human inflammation panel 1 assay (SC cell lines, assessment of the inflammation activity) and MTT test to determine the cytotoxicity of the porous materials based on collagen IV fragments. It was found that out of the pool of 37 fragments (peptides 1-33 and 2.1-2.4) reconstructing the outer sphere of collagen IV, nine fragments (peptides: 2, 4, 5, 6, 14, 15, 25, 26 and 30), as a result of self-assembling, form structures mimicking the structure of the triple helix of native collagens. The stability of spatial structures formed as a result of self-organization at temperatures of 4 °C, 20 °C, and 40 °C was found. The application of the MST method allowed us to determine the Kd of binding of selected fragments of collagen IV to ITGα1β1. The stability of the spatial structures of selected peptides made it possible to obtain porous materials based on their equimolar mixture. The formation of the porous materials was found for cross-linked structures and the material stabilized only by weak interactions. All tested peptides are non-cytotoxic against all tested cell lines. Selected peptides also showed no genotoxicity and no induction of immune system responses. Research on the use of porous materials based on fragments of type IV collagen, able to form stable spatial structures as scaffolds useful in regenerative medicine, will be continued.

Heterologous expression, fermentation strategies and molecular modification of collagen for versatile applications

Collagen is a kind of high macromolecular protein with unique tissue distribution and distinctive functions in the body. At present, most collagen products are extracted from the tissues and organs of mammals or marine fish. However, this method exhibits several disadvantages, including low efficiency and serious waste generation, which makes it difficult to meet the current market demand. With the rapid development of synthetic biology and the deepening of high-density fermentation technology, the collagen preparation by biosynthesis strategy emerges as the times require. Co-expression with the proline hydroxylase gene can solve the problem of non-hydroxylated collagen, but the yield may be affected. Therefore, improving the expression through molecular modification and dynamic regulation of synthesis is an entry point for future research. Due to the defects in certain properties of the natural collagen, modification of properties would be benefit for meeting the requirements of practical application. In this paper, in-depth investigations on recombinant expression, fermentation, and modification studies of collagen are conducted. Also, it summarizes the research progress of collagen in food, medicine, and beauty industry in recent years. Furthermore, the future development trend and application prospect of collagen are discussed, which would provide guidance for its preparation and application.

Marine Biopolymers: Applications in Food Packaging

Marine sources are gaining popularity and attention as novel materials for manufacturing biopolymers such as proteins and polysaccharides. Due to their biocompatibility, biodegradability, and non-toxicity features, these biopolymers have been claimed to be beneficial in the development of food packaging materials. Several studies have thoroughly researched the extraction, isolation, and latent use of marine biopolymers in the fabrication of environmentally acceptable packaging. Thus, a review was designed to provide an overview of (a) the chemical composition, unique properties, and extraction methods of marine biopolymers; (b) the application of marine biopolymers in film and coating development for improved shelf-life of packaged foods; (c) production flaws and proposed solutions for better isolation of marine biopolymers; (d) methods of preparation of edible films and coatings from marine biopolymers; and (e) safety aspects. According to our review, these biopolymers would make a significant component of a biodegradable food packaging system, reducing the amount of plastic packaging used and resulting in considerable environmental and economic benefits.

Main and Minor Types of Collagens in the Articular Cartilage: The Role of Collagens in Repair Tissue Evaluation in Chondral Defects

Several collagen subtypes have been identified in hyaline articular cartilage. The main and most abundant collagens are type II, IX and XI collagens. The minor and less abundant collagens are type III, IV, V, VI, X, XII, XIV, XVI, XXII, and XXVII collagens. All these collagens have been found to play a key role in healthy cartilage, regardless of whether they are more or less abundant. Additionally, an exhaustive evaluation of collagen fibrils in a repaired cartilage tissue after a chondral lesion is necessary to determine the quality of the repaired tissue and even whether or not this repaired tissue is considered hyaline cartilage. Therefore, this review aims to describe in depth all the collagen types found in the normal articular cartilage structure, and based on this, establish the parameters that allow one to consider a repaired cartilage tissue as a hyaline cartilage.

Methodology to Quantify Collagen Subtypes and Crosslinks: Application in Minipig Cartilages

INTRODUCTION

This study develops assays to quantify collagen subtypes and crosslinks with liquid chromatography-mass spectrometry (LC-MS) and characterizes the cartilages in the Yucatan minipig.

METHODS

For collagen subtyping, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was performed on tissues digested in trypsin. For collagen crosslinks, LC-MS analysis was performed on hydrolysates. Samples were also examined histologically and with bottom-up proteomics. Ten cartilages (femoral condyle, femoral head, facet joint, floating rib, true rib, auricular cartilage, annulus fibrosus, 2 meniscus locations, and temporomandibular joint disc) were analyzed.

RESULTS

The collagen subtyping assay quantified collagen types I and II. The collagen crosslinks assay quantified mature and immature crosslinks. Collagen subtyping revealed that collagen type I predominates in fibrocartilages and collagen type II in hyaline cartilages, as expected. Elastic cartilage and fibrocartilages had more mature collagen crosslink profiles than hyaline cartilages. Bottom-up proteomics revealed a spectrum of ratios between collagen types I and II, and quantified 42 proteins, including 24 collagen alpha-chains and 12 minor collagen types.

DISCUSSION

The novel assays developed in this work are sensitive, inexpensive, and use a low operator time relative to other collagen analysis methods. Unlike the current collagen assays, these assays quantify collagen subtypes and crosslinks without an antibody-based approach or lengthy chromatography. They apply to any collagenous tissue, with broad applications in tissue characterization and tissue engineering. For example, a novel finding of this work was the presence of a large quantity of collagen type III in the white-white knee meniscus and a spectrum of hyaline and fibrous cartilages.

The Potential Use of Novel Plant-Derived Recombinant Human Collagen in Aesthetic Medicine

SUMMARY

Recombinant human type I collagen, identical in structure and functionality to human type I collagen, was successfully expressed and extracted from genetically modified tobacco plants. Contrarily to tissue extracted protein, rhCollagen is not immunogenic and not allergenic and has an intact triple helix structure showing superior biological functionality. A photocurable rhCollagen was developed by chemically modifying the protein to allow cross-linking under illumination at various wavelengths, maintaining the protein structural and biological functions. The use of the photocurable rhCollagen in aesthetic medicine, especially as a dermal filler and as a bioink for 3D-printed breast implant is discussed in this article.

Maturation process and characterization of a novel thermostable and halotolerant subtilisin-like protease with high collagenolytic but low gelatinolytic activity

Enzymatic degradation of collagen is of great industrial and environmental significance; however, little is known about thermophile-derived collagenolytic proteases. Here, we report a novel collagenolytic protease (TSS) from thermophilic Brevibacillus sp. WF146. The TSS precursor comprises a signal peptide, an N-terminal propeptide, a subtilisin-like catalytic domain, a β-jelly roll (βJR) domain, and a prepeptidase C-terminal (PPC) domain. The maturation of TSS involves a stepwise autoprocessing of the N-terminal propeptide and the PPC domain, and the βJR rather than the PPC domain is necessary for correct folding of the enzyme. Purified mature TSS displayed optimal activity at 70°C and pH 9.0, a half-life of 1.5 h at 75°C, and an increased thermostability with rising salinity up to 4 M. TSS possesses an increased number of surface acidic residues and ion pairs, as well as four Ca 2+ -binding sites, which contribute to its high thermostability and halotolerance. At high temperatures, TSS exhibited high activity toward insoluble type I collagen and azocoll, but showed a low gelatinolytic activity, with a strong preference for Arg and Gly at the P1 and P1’ positions, respectively. Both the βJR and PPC domains could bind but not swell collagen, and thus facilitate TSS-mediated collagenolysis via improving the accessibility of the enzyme to the substrate. Additionally, TSS has the ability to efficiently degrade fish scale collagen at high temperatures.

IMPORTANCE

Proteolytic degradation of collagen at high temperatures has the advantages of increasing degradation efficiency and minimizing the risk of microbial contamination. Reports on thermostable collagenolytic proteases are limited, and their maturation and catalytic mechanisms remain to be elucidated. Our results demonstrate that the thermophile-derived TSS matures in an autocatalytic manner, and represents one of the most thermostable collagenolytic proteases reported so far. At elevated temperatures, TSS prefers hydrolyzing insoluble heat-denatured collagen rather than gelatin, providing new insight into the mechanism of collagen degradation by thermostable collagenolytic proteases. Moreover, TSS has the potential to be used in recycling collagen-rich wastes such as fish scales.

Potential of Thermolysin-like Protease A69 in Preparation of Bovine Collagen Peptides with Moisture-Retention Ability and Antioxidative Activity

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.

Possible Treatment of Myocardial Infarct Based on Tissue Engineering Using a Cellularized Solid Collagen Scaffold Functionalized with Arg-Glyc-Asp (RGD) Peptide

Currently, the clinical impact of cell therapy after a myocardial infarction (MI) is limited by low cell engraftment due to low cell retention, cell death in inflammatory and poor angiogenic infarcted areas, secondary migration. Cells interact with their microenvironment through integrin mechanoreceptors that control their survival/apoptosis/differentiation/migration and proliferation. The association of cells with a three-dimensional material may be a way to improve interactions with their integrins, and thus outcomes, especially if preparations are epicardially applied. In this review, we will focus on the rationale for using collagen as a polymer backbone for tissue engineering of a contractile tissue. Contractilities are reported for natural but not synthetic polymers and for naturals only for: collagen/gelatin/decellularized-tissue/fibrin/Matrigel™ and for different material states: hydrogels/gels/solids. To achieve a thick/long-term contractile tissue and for cell transfer, solid porous compliant scaffolds are superior to hydrogels or gels. Classical methods to produce solid scaffolds: electrospinning/freeze-drying/3D-printing/solvent-casting and methods to reinforce and/or maintain scaffold properties by reticulations are reported. We also highlight the possibility of improving integrin interaction between cells and their associated collagen by its functionalizing with the RGD-peptide. Using a contractile patch that can be applied epicardially may be a way of improving ventricular remodeling and limiting secondary cell migration.

A Review of the Effects of Collagen Treatment in Clinical Studies

Collagen, an abundant extracellular matrix protein, has been found to have a lot of pharmaceuticals, medicine, food, and cosmetics applications. Increased knowledge of collagen sources, extraction techniques, structure, and properties in the last decades has helped develop more collagen-based products and tissue engineering biomaterials. Collagen products have been playing an important role in benefiting the health of the human body, especially for aging people. In this paper, the effects of collagen treatment in different clinical studies including skin regeneration, bone defects, sarcopenia, wound healing, dental therapy, gastroesophageal reflux, osteoarthritis, and rheumatoid arthritis have been reviewed. The collagen treatments were significant in these clinical studies. In addition, the associations between these diseases were discussed. The comorbidity of these diseases might be closely related to collagen deficiency, and collagen treatment might be a good choice when a patient has more than one of these diseases, including the coronavirus disease 2019 (COVID-19). It concludes that collagen-based medication is useful in treating comorbid diseases and preventing complications.

Biomineralization induced by chitosan and collagen-based materials with fluoride for dentin coverage: Chemical and morphological analysis

The prevention and treatment of erosive tooth wear are becoming increasingly important due to its increasing prevalence. The use of natural solutions to modify dental surfaces has become an area of research. Organic materials such as chitosan and hydrolyzed collagen may be a promising option to treat dentin. This in vitro study aimed to evaluate the influence of chitosan or hydrolyzed collagen, alone or combined with acidulated phosphate fluoride (APF) gel, on the composition and morphology of dentin after erosion. Bovine dentin samples were prepared (n = 84) and treated with artificial saliva (AS, negative control); APF gel (F, positive control); chitosan solution (Chi); hydrolyzed collagen solution (Col); fluoride/chitosan composition (F_Chi); and fluoride/hydrolyzed collagen composition (F_Col). Erosive cycles (six cycles of immersion in orange juice for 1 min, followed by immersion in AS for 1 hr) were performed. The materials were characterized by their morphology, composition, and particle size distribution. Micro-energy dispersive X-ray fluorescence spectroscopy and scanning electron were used to evaluate the dentin's inorganic chemical composition and morphology. The F_Col and F groups had a reduction in calcium loss by 17 and 26%, respectively (p < .001). Both of these groups still had a covering layer of agglomerates at the dentin surface after the erosive cycles. The fluoridated chitosan or collagen solutions improved the dentin resistance to erosion as a novel hybrid-fluoride-based material approach to provide surface protection from erosion.

Time scale of glycation in collagen of bovine pericardium-derived bio-tissues

Glycosyl-ation is the process of combining one or more glucose molecules (or other monosaccharides) with molecules of a different nature (which are therefore glycosyl-ated). In biochemistry, glycosyl-ation is catalyzed by several specific enzymes, and assumes considerable importance since it occurs mainly at the expense of proteins and phospho-lipids which are thus transformed into glycoproteins and glycolipids. Conversely, in diabetes and aging, glycation of proteins is a phenomenon of non-enzymatic nature and thus not easily controlled. Glycation of collagen distorts its structure, renders the extracellular matrix stiff and brittle and at the same time lowers the degradation susceptibility thereby preventing renewal. Based on models detailed in this paper and with parameters determined from experimental data, we describe the glycation of type 1 collagen in bovine pericardium derived bio-tissues, upon incubation in glucose and ribose. With arginine and lysine/hy-droxy-lysine amino acids as the primary sites of glycation and assuming that the topological polar surface area of the sugar molecules determines the glycation rates, we modelled the glycation as a function of time and determined the glycation rate and thus the progression of glycation as well as the resulting volume increase.

A White Paper on Collagen Hydrolyzates and Ultrahydrolyzates: Potential Supplements to Support Joint Health in Osteoarthritis?

PURPOSE OF REVIEW

Osteoarthritis (OA) is the most common forms of arthritis in the general population, accounting for more pain and functional disability than any other musculoskeletal disease. There are currently no approved disease modifying drugs for OA. In the absence of effective pharmacotherapy, many patients with OA turn to nutritional supplements and nutraceuticals, including collagen derivatives. Collagen hydrolyzates and ultrahydrolyzates are terms used to describe collagens that have been broken down into small peptides and amino acids in the presence of collagenases and high pressure.

RECENT FINDINGS

This article reviews the relevant literature and serves as a White Paper on collagen hydrolyzates and ultrahydrolyzates as emerging supplements often advertised to support joint health in OA. Collagen hydrolyzates have demonstrated some evidence of efficacy in a handful of small scale clinical trials, but their ability to treat and reverse advanced joint disease remains highly speculative, as is the case for other nutritional supplements. The aim of this White Paper is to stimulate research and development of collagen-based supplements for patients with OA and other musculoskeletal diseases at academic and industrial levels. This White Paper does not make any treatment recommendations for OA patients in the clinical context, but simply aims to highlight opportunities for scientific innovation and interdisciplinary collaboration, which are crucial for the development of novel products and nutritional interventions based on the best available and published evidence.

Collagen-based formulations for wound healing: A literature review

Wounds have always been the point of concern owing to the involvement of infections and the level of severity. Therefore, the management of wounds always requires additional effort for comprehensive healing and subsequent removal of the scar from the wound site. The role of biomaterials in the management of chronic wounds has been well established. One of such biomaterials is collagen (Col) that is considered to be the crucial component of most of the formulations being developed for wound healing. The role of Col extracted from marine invertebrates remains an unmarked origin of the proteinaceous constituent in the evolution of innovative pharmaceuticals. Col is a promising, immiscible, fibrous amino acid of indigenous origin that is ubiquitously present in extracellular matrices and connective tissues. There are different types of Col present in the body such as type I, II, III, IV, and V however the natural sources of Col are vegetables and marine animals. Its physical properties like high tensile strength, adherence nature, elasticity, and remodeling contribute significantly in the wound healing process. Col containing formulations such as hydrogels, sponges, creams, peptides, and composite nanofibers have been utilized widely in wound healing and tissue engineering purposes truly as the first line of defense. Here we present the recent advancements in Col based dosage forms for wound healing. The Col based market of topical preparations and the published reports identify Colas a useful biomaterial for the delivery of pharmaceuticals and a platform for tissue engineering.

Collagen- and hyaluronic acid-based hydrogels and their biomedical applications

Hydrogels have been widely investigated in biomedical fields due to their similar physical and biochemical properties to the extracellular matrix (ECM). Collagen and hyaluronic acid (HA) are the main components of the ECM in many tissues. As a result, hydrogels prepared from collagen and HA hold inherent advantages in mimicking the structure and function of the native ECM. Numerous studies have focused on the development of collagen and HA hydrogels and their biomedical applications. In this extensive review, we provide a summary and analysis of the sources, features, and modifications of collagen and HA. Specifically, we highlight the fabrication, properties, and potential biomedical applications as well as promising commercialization of hydrogels based on these two natural polymers.

INFLUENCE OF THE HYDROTHERMAL TREATMENT TEMPERATURE CONDITIONS ON POULTRY MEAT

The poultry production is growing rapidly every year. Having a rapid pace of development and reproduction, and greater affordability, the poultry products are in high demand from the population. In this regard, the industry is in demand for deep processing of poultry meat, which is not only economically feasible, but also makes it possible to expand the scope of use of this product. The complex morphological structure of the poultry complicates its use as the main raw material for meat products, and poultry meat is mainly sold in the form of natural semi-finished products with a limited shelf life. It is possible to expand the range of poultry products through the production of canned food. A new technology for the production of pasteurized canned poultry meat was developed at the Department of Meat, Fish and Seafood Technology of the Odessa National Academy of Food Technologies. This technology involves hydrothermal treatment of the raw materials, hot boning, mixing of components of the formulation and pasteurization. This article reveals the issue of the first stage of production, namely the establishment of rational meat hydrothermal treatment conditions. The problem of choosing the heat treatment conditions is extremely important, because depending on the process conditions and the final heating temperature, the transformation of the components and the properties of the finished products differ significantly. The paper studies the effect of temperature in the range from 65 to 95°C in 5°C increment on the rate and degree of cooking of collagen, the formation of the required structure of the product (hydrogel base filled with individual muscle fibers), hardness and tenderness of meat. It is established that the optimal processing temperature of poultry meat is 65°C. The meat processed at this temperature had the highest degree of collagen cooking, the highest viscosity of the broth, the lowest shear stress, and the best organoleptic characteristics.

Current Trends on Protein Driven Bioinks for 3D Printing

In the last decade, three-dimensional (3D) extrusion bioprinting has been on the top trend for innovative technologies in the field of biomedical engineering. In particular, protein-based bioinks such as collagen, gelatin, silk fibroin, elastic, fibrin and protein complexes based on decellularized extracellular matrix (dECM) are receiving increasing attention. This current interest is the result of protein's tunable properties, biocompatibility, environmentally friendly nature and possibility to provide cells with the adequate cues, mimicking the extracellular matrix's function. In this review we describe the most relevant stages of the development of a protein-driven bioink. The most popular formulations, molecular weights and extraction methods are covered. The different crosslinking methods used in protein bioinks, the formulation with other polymeric systems or molecules of interest as well as the bioprinting settings are herein highlighted. The cell embedding procedures, the in vitro, in vivo, in situ studies and final applications are also discussed. Finally, we approach the development and optimization of bioinks from a sequential perspective, discussing the relevance of each parameter during the pre-processing, processing, and post-processing stages of technological development. Through this approach the present review expects to provide, in a sequential manner, helpful methodological guidelines for the development of novel bioinks.