Skin Collagen Research Articles

Bacillus amyloliquefaciens Increases the GABA in Rice Seed for Upregulation of Type I Collagen in the Skin

Biosynthesis of gamma-aminobutyric acid (GABA) can be achieved by naturally occurring microorganisms with the advantages of cost-effectiveness and safety. In this study, Bacillus amyloliquefaciens EH-9 strain (B. amyloliquefaciens EH-9), a soil bacterium, was used to promote the accumulation of GABA in germinated rice seed. Further, the topical application of supernatant from rice seed co-cultivated with soil B. amyloliquefaciens EH-9 can significantly increase the production of type I collagen (COL1) in the dorsal skin of mice. The knocking down of the GABA-A receptor (GABAA) significantly reduced the production of COL1 in the NIH/3T3 cells and in the dorsal skin of mice. This result suggests that topical application of GABA can promote the biosynthesis of COL1 via its interaction with the GABAA receptor in the dorsal skin of mice. In summary, our findings illustrate for the first time that soil B. amyloliquefaciens EH-9 elicits GABA production in germinated rice seed to upregulate the formation of COL1 in the dorsal skin of mice. This study is translational because the result shows a potential remedy for skin aging by stimulating COL1 synthesis using biosynthetic GABA associated with B. amyloliquefaciens EH-9.

A fluorescent sensing platform based on collagen peptides-protected Au/Ag nanoclusters and WS2 for determining collagen triple helix integrity.

The unique triple helix structure of collagen plays an important role in its biological properties, and the triple helix integrity is closely correlated with its molecular behavior and biological functions. Nevertheless, there is still a lack of convenient, accurate and practical methods for quantitatively determining collagen triple helix integrity. Herein, we first prepared bovine skin collagen peptide (BSCP)-protected Au/Ag nanoclusters (Au/AgNCs@BSCP) with excellent optical properties, high stability and good biocompatibility, which could adsorb on WS2 surface leading to fluorescence quenching. Upon the addition of collagen, the interaction of collagen and Au/AgNCs@BSCP led to the detachment of Au/AgNCs@BSCP from the WS2 surface, causing an increase in the fluorescence signal. Using the difference in the fluorescence recovery of the different samples, we achieved the quantitative determination of collagen triple helix integrity. This developed strategy exhibited excellent accuracy, selectivity, and practicality, thus showing promising potentials in biomedical applications.

Xenogeneic mesenchymal stem cell biocurative improves skin wounds healing in diabetic mice by increasing mast cells and the regenerative profile.

Diabetes mellitus (DM) is a chronic disease and a major cause of mortality and morbidity worldwide. The hyperglycemia caused by DM induces micro and macrovascular complications that lead, among other consequences, to chronic wounds and amputations. Cell therapy and tissue engineering constitute recent therapeutic alternatives to improve wound healing in diabetic patients. The current study aimed to analyze the effectiveness of biocuratives containing human mesenchymal stem cells (MSCs) associated with a hydrogel matrix in the wound healing process and related inflammatory cell profile in diabetic mice. Biocuratives containing MSCs were constructed by 3D bioprinting, and applied to skin wounds on the back of streptozotocin (STZ)-induced type 1 diabetic (T1D) mice. The healing process, after the application of biocuratives with or without MSCs was histologically analyzed. In parallel, genes related to growth factors, mast cells (MC), M1 and M2 macrophage profiles were evaluated by RT-PCR. Macrophages were characterized by flow cytometry, and MC by toluidine blue staining and flow cytometry. Mice with T1D exhibited fewer skin MC and delayed wound healing when compared to the non-diabetic group. Treatment with the biocuratives containing MSCs accelerated wound healing and improved skin collagen deposition in diabetic mice. Increased TGF-β gene expression and M2 macrophage-related markers were also detected in skin of diabetic mice that received MSCs-containing biocuratives. Finally, MSCs upregulated IL-33 gene expression and augmented the number of MC in the skin of diabetic mice. These results reveal the therapeutic potential of biocuratives containing MSCs in the healing of skin wounds in diabetic mice, providing a scientific base for future treatments in diabetic patients.

Proton FLASH effects on mouse skin at different oxygen tensions

Objective. Irradiation at FLASH dose rates (>40 Gy s−1) has received great attention due to its reported normal tissue sparing effect. The FLASH effect was originally observed in electron irradiations but has since been shown to also occur with both photon and proton beams. Several mechanisms have been proposed to explain the tissue sparing at high dose rates, including effects involving oxygen, such as depletion of oxygen within the irradiated cells. In this study, we investigated the protective role of FLASH proton irradiation on the skin when varying the oxygen concentration. Approach. Our double scattering proton system provided a 1.2 × 1.6 cm2 elliptical field at a dose rate of ∼130 Gy s−1. The conventional dose rate was ∼0.4 Gy s−1. The legs of the FVB/N mice were marked with two tattooed dots and fixed in a holder for exposure. To alter the skin oxygen concentration, the mice were breathing pure oxygen or had their legs tied to restrict blood flow. The distance between the two dots was measured to analyze skin contraction over time. Main results. FLASH irradiation mitigated skin contraction by 15% compared to conventional dose rate irradiation. The epidermis thickness and collagen deposition at 75 d following 25 to 30 Gy exposure suggested a long-term protective function in the skin from FLASH irradiation. Providing the mice with oxygen or reducing the skin oxygen concentration removed the dose-rate-dependent difference in response. Significance. FLASH proton irradiation decreased skin contraction, epidermis thickness and collagen deposition compared to standard dose rate irradiations. The observed oxygen-dependence of the FLASH effect is consistent with, but not conclusive of, fast oxygen depletion during the exposure.

In silico and in vitro assessment of yellowfin tuna skin (Thunnus albacares) hydrolysate antioxidation effect

The protein hydrolysate that contains bioactive peptides of yellowfin tuna (Thunnus albacares) skin collagen with antioxidant activity has been successfully studied by using in silico and in vitro assays. We found that using the in silico assessment, the antioxidant peptides can be found from the precursor (type I α1 and α2 collagen of yellowfin tuna). Applying papain as a protease will also provide the greatest degree of hydrolysis for antioxidative peptides. The highest peptide rank peptides sequence such as Pro-Trp-Gly (PWG), Pro-His-Gly (PHG), His-Leu (HL), Ile-Arg (IR), Ala-His (AH), Glu-Leu (EL) that predicted using papain in silico. Molecular docking analysis showed all peptides derived from yellowfin tuna have hindered the substrate to access the active site of myeloperoxidase (MPO). Interestingly, the substitution of the amino acid from His (PHG, 7.1 kcal/mol) to Trp (PWG, 8.0 kcal/mol) has increased the affinity of the peptide towards MPO. They have antioxidative activities used in silico approach to MPO enzyme. We also confirm the in vitro assays for the protein hydrolysate after proteolysis using papain. The concentration and hydrolysis time will give influence the degree of hydrolysis, and antioxidant activities (P < 0.05). In conclusion, hydrolysate protein of type I α1 and α2 collagen from yellowfin tuna produced by papain hydrolysis has the potential to be used in food, active packaging material until health applications..

Evaluation of cattle skin collagen for producing co-extrusion sausage casing

Co-extrusion is a fully automated sausage production process that employs a continuous stream of collagen dispersion to encase the extruded meat mass to form an endless sausage rope, that is later crimped into links of selected sizes. Fibrous and soluble type I collagen dispersions obtained from bovine skins of animals aged 18–36 months is used as the raw material for these dispersions.In this study, the chemical and physical properties of cattle skin collagen preparations from four sources [American Calf (AC), Dutch Heavy Veal (DHV), Danish Ox and/or Heifer (DOH), and Heavy German Cow (HGC)] were investigated for their potential application as collagen source for co-extrusion.All dispersions exhibited shear-thinning behavior, following a power-law model with k* values for HGC, DHV, AC, and DOH dispersions of 59, 68, 95 and 114 Pa sn*, respectively. Rheological measurements showed for all dispersions a decrease in elasticity and loss modulus at 35–40 °C. SDS-PAGE indicated the presence of α1(I)- and α2(I)-chains of type I collagen for all dispersions. The mechanical strength of the films was 1.6, 1.6, 1.3 and 1.2 MPa for films prepared from AC, DOH, DHV and HGC dispersions, respectively. After crosslinking a 27% reduction of free amine groups was found for HGC and DOH, followed by 26 and 19% for AC and DHV, respectively.Based on the properties of the dispersions and the films in relation to the co-extrusion process AC, DHV and DOH are potentially suitable as an alternative collagen source.

Alternative sources of marine bioactive compounds from the Black Sea: Isolation and characterization of fish skin collagen from Neogobius melanostomus (Pallas 1814) (Perciformes: Gobiidae)

Round goby-Neogobius melanostomus is the common discard catch species from the shelf zone in the Black Sea, and the abundance rate increases yearly. The aim of this work was the isolation and characterization of collagen from the skin of round goby-N. melanostomus in the Black Sea. The results revealed that the skin of N. melanostomus presented high protein concentration (80%), rich in glycine (34%), alanine (11%), proline (9%) and hydroxyproline (7%), which are characteristic of typical molecules of collagen protein. Thus, the yield of collagen is estimated at 10%. The zero surface net charge of the sample was estimated between pH 5–6, indicating its proximity to the collagen isoelectric point. In addition, FTIR results confirmed its highly organized helical structure, which was preserved in Round Goby species. The biological assays showed that there is a significant increase in cell viability according to control samples in 48 h. Cytotoxicity behavior​ demonstrated that the marine collagen obtained by round goby fish skin is noncytotoxic. In conclusion, these results indicate that this goby species is a potential marine source of collagen.

Effective and cleaner Zr (IV) tanning process based on the inert-surface modification of skin collagen by PEGylated epoxy copolymers

Zirconium tanning agent, which is mainly composed of low-toxic tetravalent zirconium (Zr4+) salts, has been considered the most promising eco-friendly tanning agent for leather manufacturing, due to its comparable tanning performance with trivalent chrome. However, in the initial penetration stage of the zirconium tanning process, macromolecular multinuclear complexes are commonly formed because of the rapid coordination between hydrated Zr4+, which can easily cross-link with active groups of neighboring collagen fibers and thus block subsequently even penetration of zirconium tanning agents, resulting in surface over-tanning and ununiform tanning effects. Herein, to address the aforementioned issues of conventional zirconium tanning, inert-surface modification of collagen fibers was proposed by using PEGylated epoxy copolymers (PEGMA-co-GMA, defined as PPG) to pretreat bated hide, based on the covalent reactions and hydrogen-bond interactions of PPG with amino and carboxyl groups on collagen fibers, respectively. After modification, the surface reactivity of skin collagen was significantly reduced, which was able to delay the cross-linking interactions with zirconium tanning agents and thus promote uniform penetration. Simultaneously, the extra hydroxyls produced from the ring-open reactions of epoxy groups could also mitigate the excessive coordinated complexation of hydrated Zr4+, leading to efficient penetration of zirconium tanning agents. Compared with conventional zirconium tanning, research results showed that this inert-surface modification strategy could comprehensively improve the overall leather performance with both efficient and uniform tanning effects. Moreover, the resultant leather qualities, including thermal stability, physical and mechanical properties, and organoleptic properties, are very comparable with chrome-tanned leather. In addition, attributing to the reaction between collagen amino and PPG, the use of sodium chloride was avoided, resulting in a cleaner salt-free pickling process. Altogether, this inert-surface modification strategy represents a significant step forward for effective and cleaner tanning technology, which will accelerate the wide application of Zr(IV) in place of traditional chrome tanning agents.

Formulation of Natural Coffee Cream in Increasing Antioxidants as an Effort to Prevent Skin Aging

Skin aging is caused by the excessive production of free radicals in the body, thus causing damage to skin tissue; this also results in damage to skin collagen, which further accelerates the aging process of the skin. The purpose of this study was to determine the effect of giving coffee cosmetic creams on reducing superoxide dismutase (SOD) levels in the skin aging process. This study used a true experiment design with a post-test-only group design research design. The population in this study was an old female Wistar (Rattus norvegicus) weighing 200-250 grams and aged 14-16 months. The overall sample count was 24 female wistars divided for each group was 6 in 4 treatment groups. SOD level data were measured using the ELISA (Enzyme Linked Immune-Sorbent Assay) method. The data obtained were analyzed using the Kruskal Wallis Test and the Mann Whitney Test. The results showed that there was a significant increase in SOD levels (p&lt; 0.05), so it can be concluded that giving coffee cosmetic creams increases SOD levels, meaning that there is an increase in SOD or the main antioxidant enzyme that can ward off free radicals.

Type I Collagen from the Skin of Barracuda (Sphyraena sp.) Prepared with Different Organic Acids: Biochemical, Microstructural and Functional Properties

This study was carried out to compare the extractability and characteristics of barracuda (Sphyraena sp.) skin collagen using various organic acids. Acetic-solubilized collagen (ASBS), lactic-solubilized collagen (LSBS) and citric-solubilized collagen (CSBS) yielded 6.77 g/100 g, 10.06 g/100 g and 8.35 g/100 g, respectively, and those yields were significantly different (p < 0.05). All acid-solubilized collagens were considered as type I because of their two alpha chains (α1 and α2) detected in acrylamide gel after electrophoresis. Ultraviolet-visible (UV-vis) analysis confirmed that ASBS, LSBS and CSBS had similar absorption peaks (230.5 nm) and the results were in accordance with other fish collagens. Under infrared (IR) and X-ray diffraction (XRD) analysis, the triple helical structure of type I collagens extracted from barracuda skin was maintained. From a thermostability study, all type I collagens showed a higher maximum transition temperature (Tmax = 40.16 to 41.29 °C) compared to other fish skin collagens. In addition, the functional properties of the extracted collagens revealed the ASBS had higher water and oil absorption capacities than the CSBS and LSBS samples. The highest level of the emulsion ability index (EAI) (>200 m2/g) was detected under acidic conditions (pH 4), while lower EAIs were recorded under the alkaline (pH 10) and neutral treatments (pH 7). All type I collagens had a higher relative solubility (>60%) at a low pH test but the solubility level sharply decreased at a neutral pH. In addition to this, a lower concentration of NaCl (0-20 g/L) showed the higher percentage of solubility (>60%) while adding over 30 g/L of NaCl decreased solubility (>40%). From a microstructural test, all type I samples had an irregular and dense flake structure with random coiled filaments. Overall, collagen extracted from the barracuda skin may be applied as an alternative collagen from an industry perspective.

Hydrogel Complex Containing the Antimicrobial Peptide HX-12C Accelerates Healing of Infected Wounds.

Bacterial infections of the wound surface can be painful for patients, and traditional dressings do not effectively address this problem. In this study, an antimicrobial wound dressing is prepared using a novel antimicrobial peptide, HX-12C. This hydrogel system is based on the natural biomaterials sodium alginate and gelatin, utilizing calcium carbonate as a source of Ca2+ , and ionic cross-linking is facilitated by lowering the solution pH. The resulting sodium alginate/gelatin HX-12C-loaded hydrogel (CaAGEAM) has good mechanical and adhesion properties, biocompatibility and in vitro degradability. Its extraordinary antibacterial efficacy (>98%) is verified by an antibacterial experiment. More importantly, in vivo experiments further demonstrate its healing-promotion effect, with a 95% wound healing rate by day 9. Tissue staining demonstrates that the hydrogel containing antimicrobial peptides is effective in suppressing inflammation. The dressing promotes wound healing by stimulating the deposition of skin appendages and collagen. The results of this study suggest that composite hydrogels containing antimicrobial peptides are a promising new type of dressing to promote the healing of infected wounds.

Synergistic use of bioactive agents for the management of different skin conditions: an overview of biological activities.

Recently, many plant-derived bioactive agents have been included in dermo-cosmetics formulations. This leads to an extensive portfolio of innovative products with an expanded range of benefits, including anti-aging, antioxidant, hydrating and depigmenting. Although different technologies drawing on science and nature are used to create these high-performing molecules, there remains some debate about the mechanism of action of the natural bioactive ingredients within dermo-cosmetics. This review recapitulates the main biological mechanisms underlying the activity of natural active ingredients, with a specific focus on their synergistic use for the management of common, yet quite specific, skin conditions. A total of 28 plant-derived bioactives were selected from the Givaudan Active Beauty (Argenteuil, France) portfolio, a multinational company specializing in innovative natural actives research. An extensive literature review about their biological activity was conducted by a PubMed search using different keywords. No language or publication date restrictions were used. Givaudan Active Beauty data on file were also considered. The bioactive ingredients were described according to the pathogenetic mechanisms underlying 10 common skin conditions that dermo-cosmetics may address. Literature data have shown that plant-derived bioactives are involved in a wide range of biological mechanisms showing anti-inflammatory, antioxidant, and moisturizing properties, along with skin barrier protection and collagen synthesis activities. As a result, different combinations of bioactives within dermo-cosmetics can be defined to counteract simultaneously the different pathogenetic mechanisms underlying different skin conditions. Available literature supports the synergistic use of plant-derived bioactive agents within dermo-cosmetics as a viable and safe option for managing the most common skin conditions.

Preparation of Cod Skin Collagen Peptides/Chitosan-Based Temperature-Sensitive Gel and Its Anti-Photoaging Effect in Skin.

Photoaging decreases quality of life and increases the risk of skin cancer, underscoring the urgent need to explore natural, high-efficacy, anti-skin photoaging (SP) active substances. In this study, a gel (CS/CSCPs/β-GP gel) was prepared using chitosan (CS) and sodium β-glycerophosphate (β-GP) through crosslinking with small molecular CSCPs as the carried drug. We evaluated its structural characteristics and properties. The effect of CS/CSCPs/β-GP gel on the degree of ultraviolet (UV)-induced skin aging of mice was investigated through comparative analysis of skin damage, the integrity of collagen tissues and elastic fibers, levels of reactive oxygen species (ROS) and key inflammatory factors (tumor necrosis factor [TNF]-α and interleukin [IL]-1β, IL-6, and IL-10), and tissue expression of matrix metalloproteinase-3 (MMP-3) after repeated UV irradiation in a nude mice SP model. The results showed that CS/CSCPs/β-GP gel was successfully prepared and had the desired characteristics. Compared with CSCPs alone, the CS/CSCPs/β-GP gel more evidently improved typical photoaging characteristics on mouse dorsal skin. It also increased the moisture content, causing the skin to become glossy and elastic. Pathological skin analysis revealed that this peptide-carrying gel can effectively inhibit epidermal thickening, reduce tissue inflammatory infiltration, suppress collagen fiber degradation, increase the collagen content, alleviate structural elastic fiber damage, and significantly inhibit abnormal MMP-3 expression. In addition, biochemical analysis showed that the CS/CSCPs/β-GP gel can effectively inhibit the elevated expressions of ROS and key proinflammatory factors (TNF-α, IL-1β, IL-6) in photoaging skin tissues and promote expression of the anti-inflammatory factor IL-10. SP can cause many clinical skin diseases, such as solar freckle-like nevus, solar keratosis, cutaneous melanoma, and squamous cell carcinoma. CSCPs are a high-efficacy anti-SP natural active substance and CS/CSCPs/β-GP gel can synergistically enhance the CSCPs' anti-SP effect. The mechanism is likely related to the inhibited activation of ROS/nuclear transcription factor-κB signaling and the expression of downstream inflammatory factors.

Clinical Efficacy of Medical Dextrose Tincture Liquid in the Treatment of Facial Photoaging.

Exogenous aging mainly refers to photo-aging, which is caused by environmental factors including ultraviolet exposure. Dextran is a homopolysaccharide composed of glucose as monosaccharide, and glucose units are connected by glycosidic bonds. The purpose of this study was to explore the clinical efficacy of medical dextrose tincture liquid (medical dextrose tincture) in the treatment of facial photoaging. Thirty-four volunteers were included in the randomized double-blind study. According to the random number table method, the subjects were randomized into control and treatment groups. The subjects in the control and treatment groups were treated with medical hyaluronic acid gel and medical dextrose tincture, respectively. They received mesotherapy therapy three times with an interval of 28 days between treatments. Video image acquisition was performed before treatment and 28 days after treatment. Skin moisture content, glossiness, heme content, collagen density, and elasticity were tested. The subjective evaluations of subjects and doctors before and after treatment were compared. Compared with the pre-treatment baseline, medical dextran tincture significantly increased skin moisture retention, skin gloss, and skin collagen density (p<0.001). Additionally, the skin retraction time was significantly reduced, and the skin retraction time was also markedly decreased after treatment with medical dextran tincture (p<0.001). The effects of medical dextran tincture were more significant in comparison with medical hyaluronic acid gel (p<0.05). The subjective evaluation results of doctors showed that after 84 days of treatment, the overall skin photoaging score was significantly reduced (p<0.001). The subjective evaluation results of volunteers showed that the various skin problems of more than 50% of volunteers were improved after treatment. Medical dextran tincture has obvious effects of moisturizing, increasing luster, improving skin redness, increasing skin collagen content and enhancing skin elasticity.

Preventive effect of tilapia skin collagen hydrolysates on ulcerative colitis mice based on metabonomic and 16 S rRNA gene sequencing.

Tilapia skin collagen hydrolysates (TSCHs) are the product of enzymatic hydrolysis of collagen, which is mainly extracted from tilapia skin. The components of TSCHs have recently been reported to play a preventive role in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). However, it has not been illustrated whether TSCHs can prevent against DSS-induced UC via the gut microbiota and its derived metabolites. TSCHs are mainly composed of amino acids, which have similar characteristics to collagen, with most having a molecular weight below 5 kDa. In a mouse model of UC, TSCHs had no toxic effect at a dose of 60 g kg-1 and could reduce body weight changes, colon length, histopathological changes and score, and the level of the serum inflammatory cytokine interleukin (IL)-6. Concurrently, 16 S rRNA sequencing showed that TSCHs significantly reduced the abundance of Bacteroidetes and Proteobacteria at the phylum level and norank_f__Muribaculaceae and Escherichia-Shigella at the genus level, while they increased the abundance of Firmicutes at the phylum level and Lachnoclostridium, Allobaculum, Enterorhabdus, and unclassified__f__Ruminococcaceae at the genus level. Target metabolomic analysis showed that TSCHs elevated the concentration of total acid, acetic acid, propanoic acid, and butanoic acid, but reduced isovaleric acid concentrations. Moreover, Pearson correlation analysis revealed that Allobaculum, unclassified_Ruminococcaceae, and Enterorhabdus were positively correlated with acetic acid and butyric acid, but not Escherichia-Shigella. These findings suggest that TSCHs can prevent UC by modulating gut microbial and microbiota-derived metabolites. © 2023 Society of Chemical Industry.

Enrichment of antiplatelet peptides and removal of fishy odor from silver carp skin collagen hydrolysates by macroporous resins: pH value of loading sample affects the peptides separation

Enrichment of antiplatelet peptides from silver carp skin collagen hydrolysates (CH) was studied using macroporous resins. Static adsorption showed that XAD-16 resin was the suitable resin due to its high adsorption capacity. The dynamic desorption of CH was studied on XAD-16 resin by ethanol gradient elution. Interestingly, pH value of loading sample had a great impact on the peptides separation. Results revealed that the yield and the antiplatelet activity of Ethl-20% fraction were highest at loading sample pH 6.0. The antiplatelet peptides were enriched in the 20% ethanol fraction with IC50 2.03 mg/mL compared to IC50 of CH, 4.7 mg/mL. Besides, the Ethl-20% fraction had a weakest fishy odor. Moreover, a series of peptides containing Hyp-Gly or Pro-Gly were identified from Ethl-20% fraction, which contributed to the antiplatelet activities. This study provided a simple and efficient method for large-scale separation enrichment of antiplatelet peptides as functional foods from CH.

Preparation and evaluation of stingray skin collagen/oyster osteoinductive composite scaffolds

The regeneration of bone defects is a major challenge for clinical orthopaedics. Herein, we designed and prepared a new type of bioactive material, using stingray skin collagen and oyster shell powder (OSP) as raw materials. A stingray skin collagen/oyster osteoinductive composite scaffold (Col-OSP) was prepared for the first time by genipin cross-linking, pore-forming and freeze-drying methods. These scaffolds were characterized by ATR-FTIR, SEM, compression, swelling, cell proliferation, cell adhesion, alkaline phosphatase activity, alizarin red staining and RT-PCR etc. The Col-OSP scaffold had an interconnected three-dimensional porous structure, and the mechanical properties of the Col-OSP composite scaffold were enhanced compared with Col, combining with the appropriate swelling rate and degradation rate, the scaffold was more in line with the requirements of bone tissue engineering scaffolds. The Col-OSP scaffold was non-toxic, promoted the proliferation, adhesion, and differentiation of MC3T3-E1 cells, and stimulated the osteogenesis-related genes expressions of osteocalcin (OCN), collagen type I (COL-I) and RUNX2 of MC3T3-E1 cells.

Isolation of acid soluble collagen from daggertooth pike conger (Muraenesox cinereus) and evaluation of its antimicrobial activity

The study was conducted to isolate acid soluble collagen (ASC) from daggertooth pike conger eel and to evaluate the antimicrobial activity of the isolated protein. Conger eels were collected from Kochi harbour. The proximate composition of eel skin consisted of 68.73 per cent of moisture on a wet basis with a crude protein, crude fat and total ash of 30.24 per cent, 12.17 per cent and 2.16 per cent respectively on a dry matter basis. Conger eel skin collagen was isolated by treating with 0.5 M acetic acid after pretreatment with 0.1 N NaOH and 10 per cent butanol. Salting out and precipitation of ASC was carried out by adding NaCl to a final concentration of 2.3 M. Precipitated ASC was then dialysed against 0.1 M acetic acid for 24h and then in distilled water until neutral pH was obtained. The yield of ASC was 12.78 per cent on a wet basis and 31.95 per cent on a dry basis. The antimicrobial activity of ASC was determined by the agar diffusion method. ASC showed antimicrobial activity against both E. coli and S. aureus.

Evaluation of the biocompatibility of fish skin collagen with the mesenchymal stem cells in in vitro cultures.

There are scarce published data suggesting, that collagen extracted from fish skin may be an attractive alternative to mammalian-derived collagen for the in vitro cell cultures. In this study, we investigated proliferation potential and differentiation capability into osteogenic and adipogenic lineages of rat adipose-derived mesenchymal stem cells (rASCs) and human adipose-derived mesenchymal stem cells (hASCs) cultured on collagen extracted from silver carp and African sharptooth catfish skins, compared with commercially available mammalian collagen and collagen-free culture dishes. Our results revealed no significant differences between fish collagen and mammalian collagen in supporting cell viability and proliferation capacity. Fish-derived collagen is a cheap material derived from production waste, does not contain transmissible pathogens of mammalian origin, supports human cell cultures at comparable level to conventional collagen sources, and may be considered as the product of choice for the in vitro cell cultures.

Facile construction of electrospun zein nanofiber loaded with Rana chensinensis skin collagen for wound care after caesarean section surgery

Numerous types of biomedical applications have found success using electrospun nanofibers. However, electrospinning techniques overlook Zein fibers favoring monolithic and coaxial fibers. Uniaxial electrospinning was used to construct Zein-structured nanofibers for wound healing, with the phase separation of electrospun polycaprolactone (PCL)/polyvinyl alcohol (PVA) in solution, providing the basis for the investigation. Successful loading of silver nanoparticles (AgNPs) and Rana chensinensis skin collagen (RCSCs) into Zein nanofibers (NFs) improved their bioactivity and antibacterial activity as wound dressings. Zein nanofibers were investigated for their heat conductivity, wettability, and mechanical characteristics. The cytotoxic effects of fabricated nanofibers were examined by using L929 fibroblast cells. Ag@RCSCs-NFs also increased cell migration and proliferation, and the wound scratch model was significantly reduced in size using an in vitro scratch assay. The antibacterial studies showed that the Ag@RCSCs-NFs have a potent antibacterial effect against the tested microbial pathogens (Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus)). Finally, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PCL/PVP, RCSCs, and Ag@RCSCs against two different bacteria were determined. These results suggest that wound care using Zein nanofibers loaded with RCSCs and AgNPs during cesarean section surgery has great promise.