A New Kind of Biomaterials—Bullfrog Skin Collagen

Pepsin-soluble collagen was prepared from bullfrog skin and partially characterized. This study revealed interesting differences, such as molecular weight, amino acid composition, denaturation temperature (Td), in the frog skin collagen when compared to the known vertebrate collagens. This study gives hints that bullfrog skin can be a potential, safe alternative source of collagen from cattle for use in various fields.

Beneficial effects of a novel shark-skin collagen dressing for the promotion of seawater immersion wound healing

Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing.Methods: Shark skin collagen(SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for p H. A shark skin collagen sponge(SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane(PU) film(SSCS+PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS+PU on the healing of seawaterimmersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawaterimmersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3 rd day group, 5 th day group, 7 th day group and 12 th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS+PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze(GZ)+PU group, chitosan(CS)+PU group and SSCS+PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-β expression levels in the wounded tissues were measured by standard methods.Results: The results of Ultraviolet-visible(UV-vis) spectrum, Fourier-transform infrared(FTIR) spectrum, circular dichroism(CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200μm, porosity rate of 83.57%±2.64%, water vapor transmission ratio(WVTR) of 4500 g/m2, tensile strength of 1.79±0.41 N/mm, and elongation at break of 4.52%±0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3 rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94%±5.50%, 29.40%±1.10% and 47.24%±8.40%, respectively. SSCS also enhanced TGF-in the initial stage of the healing period. The SSCS+PU dressing effectively protected woundsβ and CD31 expression from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS+PU dressing also enhanced expression of TGF-n and gauze dressings.β and CD31. The effects of SSCS and SSCS+PU were superior to those of both the chitosaConclusion: SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS+PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.

Deciphering the Hidden Secrets between the Early Skin Wrinkling & the Metabolic (X) Syndrome with the Possible Reversal of This Process at the Molecular Level

The aging process is a group of degenerative changes that physiologically occur in most of the people in the elderly. This affects one or more of the human body systems. The treatment of diseases related to the aging process has a huge impact on the economy of all nations. Aging of the skin comes on the top and despite that, the results of the already present lines of treatment are not always satisfactory. This acts as a stimulus for us to dig deeper to discover the root causes of the premature aging of the skin. This was simply caused by the accumulation of repeated minute damage to the internal structure skin. In other words, if the degree of minute damage is more than the capacity of the skin to repair, the repeated micro-damage is presented in the long run as a skin wrinkling. Moreover, the skin acts as a mirror that reflects the internal structures of the human body. Thus, the more degenerative changes in the human body systems, the more the skin could become wrinkled. Our strategy to prevent or at least slow down the aging process of the skin depends on 2 main steps;the 1st is to reduce the micro-damage as can as possible, and the 2nd is to enhance the capacity of tissue regeneration to be able to reverse the already present damaged skin. As the 2 processes are synchronized with each other, this strategy would be considered the ideal for prevention of skin wrinkling especially premature ones. This not only reverses premature skin wrinkling but also protects it from future wrinklings. This review sharply pointed out the role of the functional collagen of the dermal layer of the skin in the prevention of skin wrinklings. Therefore, it would be the target to study how collagen works in the complex machinery of the dermal layer of the skin. This concept deeply believes that the recovery of dermal collagen has a much better effect than simply ingesting collagen or receiving a topical collagen booster. .

Skin collagen fiber-based radar absorbing materials

By using skin collagen fiber (CF) as raw material,Schiff base structure containing CF (Sa-CF) was synthesized through CF-salicylaldehyde reaction.Then a novel radar absorbing material (Fe-Sa-CF) was prepared by chelating reaction between Sa-CF and Fe 3+.The coaxial transmission and reflection method was used to analyze the complex permittivity and complex magnetic permeability of these CF-based materials,and the radar cross section (RCS) method was used to investigate their radar absorbing properties in the frequency range of 1.0-18.0 GHz.Experimental results indicated that the conductivity of CF increased from initial 1.08×10-11 to 2.86×10-6 S/cm after being transferred into Fe-Sa-CF,and its dielectric loss tangent (tanδ) in the frequency range of 1.0-17.0 GHz also increased.These facts suggest that the Fe-Sa-CF is electric-loss type radar absorbing material.In the frequency range of 3.0-18.0 GHz,Sa-CF (1.0 mm in thickness) exhibited somewhat radar absorbing property with maximum radar reflection loss (RL) of-4.73 dB.As for Fe-Sa-CF,the absorbing bandwidth was broadened,and the absorbing intensity significantly increased in the frequency range of 1.0-18.0 GHz where a maximum radar RL of-9.23 dB was observed.In addition,the radar absorbing intensity of Fe-Sa-CF can be further improved by increasing membrane thickness.When the thickness reached to 2.0 mm,the RL values of Fe-Sa-CF were-15.0-18.0 dB in the frequency range of 7.0-18.0 GHz.Consequently,a kind of novel radar absorbing material can be prepared by chemical modification of collagen fiber,which is characterized by thin thickness,low density,broad absorption bandwidth and high absorption intensity.

Inhibition of elastin and collagen networks degradation in human skin by gingival fibroblast. In vitro, ex vivo and in vivo studies.

Skin aging shows an imbalance between synthesis and degradation of the extracellular matrix. The overproduction of degradative enzymes (MMPs) during the chronology- and photo-induced aging leads to a degradation of the elastic and collagen networks. In a model of collagen and elastin destruction, we showed that the gingival fibroblast was able to preserve these macromolecules by inhibiting the overproduction of metalloproteinases by overproduction of TIMP-1 and modulation of the inflammatory cytokines activity. The objective of this study is to evaluate the effect of the gingival fibroblasts on human skin. The results in vitro and ex vivo show that the gingival fibroblast protects the skin collagen and elastic network by the inhibition of MMPs which leads to an overproduction of the TIMP-1. Moreover, the gingival fibroblast modulates the activity of some enzymes responsible for the inflammation;they inhibit the IL-1β and stimulate the production of TGF-β1. In vivo studies with a duration of six months and 50 women with pronounced wrinkles show that the culture supernatant of gingival fibroblasts diluted to 5% leads to a statistically significant decrease in the number and length of wrinkles.

Isolation and Properties of Collagen from the Skin of Andrias davidianus

[ Objective] To explore and utilize the collagen from the skin of bred Andrias davidianus. [ Method] Collagen was isolated with enzymolysis technology at 4℃, and the compositions and some biochemical properties were studied. [ Result] The content of the hydroxyproline in the skin ofA. davidianus was 22.3 %, the collagen extraction ratio was 26.7% （ based on wet weight）, the contents of the moisture, crude ash, crude fat, and crude protein were 6.75%, 0.62%, 0.38% and 92.10%, respectively. The collagen contained 8 essential amino acids for adult and 2 essential amino acids for children, the contents of the imlno acid was 171 residues/1 000 residues, and hydroxylation of proline was 51.5%. As ultraviolet （UV） absorption spectrum showed, the strong absorption peak was near 230 nm, according to the SDS - PAGE, it consisted of two diffcremt α chains （ αl and α2） which was characterized to be type I collagen. [ Conclusion] Extraction of collagen from the skin of bred A. davidianus is feasible theoretically, the extraction rate and purity arc very high.

Characterization of Acid-Soluble Collagen from Skins of Surf Smelt (Hypomesus pretiosus japonicus Brevoort)

Acid-soluble collagen was extracted from the skins of surf smelt and characterized. The yield of collagen was high about 24.0% on a dry weight basis. By SDS-polyacrylamide gel electrophoresis and CM-Toyopearl 650 M column chromatography, this collagen is a heterotrimer with a chain composition of α1α2α3. The denaturation temperature was 32.5℃, about 4.5℃ lower than that from porcine skin. Attenuated total reflectance-fourier transform infrared analysis showed that the percentage of secondary structural components in this collagen were 11% α-helix, 34% β-sheet, 19% β-turn, and 21% others. It suggests that the triple helical structure is present in the acid-soluble collagen from the skins of the surf smelt in comparison to that from the skin of porcine.

Characterization of Turbot(Scophthalmus maximus) Skin and the Extracted Acid-Soluble Collagen

The biochemical composition of the turbot skin was investigated. The moisture level of the skin was found to be 51.4%. Based on dry matter content, there were relatively high protein(82.1%) and lipid(13.1%) concentrations in the turbot skin. Mineral element analysis revealed that the turbot skin had high Ca content(2069.0 mg kg^-1), and the concentrations of toxic heavy metals Hg and Pb were less than 0.005 mg kg^-1, which indicates that the turbot skin is a safe resource for collagen production. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analysis showed that acid-soluble collagen(ASC) extracted from the turbot skin was type-I collagen. The imino acid content of the ASC was 241.6 per 1000 amino acids, which suggests a relatively high denaturation temperature. The Fourier transform infrared(FTIR) spectra of ASC reflected a highly stable structure, and the measured denaturation temperature of ASC was 29.5℃, which is higher than those from many temperate fishes. ASC was the most soluble at pH 4.0, and when the pH values were below or above 4.0, the solubility decreased rapidly. The ASC exhibited a relatively high solubility when NaCl concentration was lower than 2%. These results show that turbo skin can be employed as a source for producing collagen with high quality.

Isolation and Characterization of Pepsin-Solubilized Collagen from the Skin of Black Carp (<i>Mylopharyngdon piceus</i>)

To make more effective use of underutilized resources, pepsin-solubilized collagen (PSC) was successfully extracted from the skin of black carp (Mylopharyngdon piceus) with a yield of 45.7% based on dry weight. The PSC comprising two identical α1-chains and one α2-chain with no disulfide bond was characterized as type I, and it contained 195 imino acid residues vs. 1000 amino acid residues. The collagen showed an absorption edge around 218 nm, which was lower than the maximum absorption wavelength of other PSC. The denaturation temperature of PSC was 25.6°C, which was lower than that of porcine collagen by approximately 11°C. The isoelectric point (pI) was estimated to be 8.23, and the collagen was soluble at an acidic pH as well as below 40 g/L NaCl. It is thought that the high yield and stability of PSC from the skin of black carp warrant its application as a new source of collagen for industrial purposes.

微针导入重组Ⅲ型人源化胶原蛋白在皮肤屏障功能修复中的应用效果

目的探究微针导入重组Ⅲ型人源化胶原蛋白治疗因皮肤炎性衰老导致的皮肤屏障功能下降的有效性及安全性。方法选取2020年6月至2021年5月在本院接受面部皮肤治疗的30例患者作为研究对象,采用随机数字表法将其分为对照组(重组Ⅲ型人源化胶原蛋白)与治疗组(微针导入重组Ⅲ型人源化胶原蛋白),各15例。治疗后定期对患者进行随访,分别进行主观疗效评价及客观疗效评价。结果治疗后4、8、12周,治疗组的满意度显著高于对照组(P<0.05)。治疗后,治疗组的皮肤皱纹、纹理、红区、毛孔、弹性、皮肤经皮失水及皮肤含水量改善明显(P<0.05);对照组治疗后油脂改善明显(P<0.05)。治疗后12周,治疗组的总症状评分显著低于对照组(P<0.05)。结论微针导入重组Ⅲ型人源化胶原蛋白对皮肤修复有较好的疗效,可增强皮肤屏障功能,为改善皮肤屏障功能、治疗因皮肤屏障受损引起的炎性衰老提供了新选择。

红鳍东方鲀鱼皮胶原蛋白制备抗酪氨酸酶活性肽及其活性表征

为有效利用红鳍东方鲀鱼皮制备胶原蛋白活性肽,本研究采用响应面法优化水解条件,制备红鳍东方鲀鱼皮酸溶性胶原蛋白的抗酪氨酸酶活性肽,通过评价经超滤分级后不同分子质量肽的抗酪氨酸酶活性、抗氧化活性、模拟消化后活性动态变化及吸湿、保湿性能差异,探究其应用潜力。结果表明,利用中性蛋白酶进行酶解,最佳工艺条件为底物质量浓度2.9 g/100 mL、酶解时间7.8 h、酶添加量7862 U/g。在此条件下,酪氨酸酶活性抑制率为(35.14±0.03)%。酶解产物分子质量主要分布于0~5 kDa。抗酪氨酸酶活性较高组分为CP-1(<3 kDa),其1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基和羟自由基清除率的半抑制浓度分别为9.51、2.03 mg/mL和7.29 mg/mL。经体外模拟消化后CP-1仍具有较高的抗酪氨酸酶活性和抗氧化活性。此外,CP-1具有较高的吸湿、保湿性能,可代替甘油。本研究可为红鳍东方鲀鱼皮胶原蛋白肽的精深加工与应用提供理论依据。

基于遗传算法-反向传播神经网络优化高压-超声-酶解法提取羊皮胶原蛋白工艺

采用高压-超声-酶解法提取羊皮胶原蛋白,对比遗传算法-反向传播(genetic algorithm-back propagation,GA-BP)神经网络模型和响应面模型的优化效果,确定最佳工艺参数。结果表明:GA-BP神经网络在模型拟合和预测方面表现优于响应面模型;最佳提取参数为高压时间23 min、超声时间22 min、酶添加量3.2%、酶解时间222 min,羊皮胶原蛋白提取率达到(80.5±1.6)%,较传统的木瓜蛋白酶法提高40%;紫外-可见吸收光谱和傅里叶变换红外光谱结果显示,此条件下提取的羊皮胶原蛋白结构完整,高压-超声-酶解法对胶原蛋白的破坏较小。

漆酶-原儿茶醛交联鱼皮胶原蛋白水凝胶的研究

与哺乳动物蛋白相比,鱼皮胶原蛋白未受到克雅氏病和牛海绵状脑病流行的限制,具有较大的应用潜力,然而较差的力学性能和耐降解性质限制了鱼皮胶原的应用。论文探究了漆酶(LAC)和原儿茶醛(PAL)交联制备胶原蛋白水凝胶的交联机理,凝胶微观结构,力学性能和耐降解性质。结果表明,漆酶能够交联胶原成胶。同时,原儿茶醛的引入增强了漆酶交联胶原的作用,提升了胶原蛋白水凝胶的结构稳定性和耐降解性质。LAC-PAL交联胶原是一种构建胶原蛋白水凝胶的有效策略。

胶原蛋白肽功能饮料的贮藏稳定性及体内抗血栓活性评价

抗血小板活性功能食品可以代替药物在血栓的预防中发挥作用。前期研究表明,鲢鱼皮胶原蛋白肽(Silver Carp Skin Collagen Peptides,SCPs)具有良好的抗血小板活性,开发基于SCPs的饮料有望起到预防血栓的作用。该研究探究SCPs粉末和饮料在不同贮藏条件下的稳定性,并采用尾血栓模型对贮藏前后的SCPs粉末和饮料进行体内抗血栓活性评价。结果显示,真空包装的SCPs粉末常温(25℃)贮藏两个月肽损失率约为1.43%;SCPs饮料常温贮藏三个月肽损失率约为5.90%,高温(37℃)贮藏三个月肽损失率约为12.87%,且伴随着美拉德反应、菌落数的生长和感官品质的下降;SCPs粉末在200 mg/kg.bw的饲喂剂量下对小鼠尾血栓形成的抑制率为66.4%,常温贮藏两个月后的SCPs粉末相较于贮藏前体内活性未发生显著下降;SCPs饮料对小鼠尾血栓形成的抑制率为58.7%,高温贮藏三个月后抑制率降至45.3%,但仍能与25 mg/kg.bw饲喂剂量的阿司匹林作用效果相似。该研究表明,SCPs作为粉末或开发成液体饮料的产品形式均为可行方案,二者均可作为预防血栓的膳食补充剂。

乌鳢鱼皮中胶原蛋白的提取工艺及特性研究

该研究利用醋酸和胃蛋白酶结合从乌鳢鱼皮中提取胶原蛋白。采用单因素试验和正交试验考察了醋酸浓度、料液比、酶用量、提取时间等条件对胶原蛋白提取率的影响。结果表明,当醋酸的浓度为0.5 mol/L,胃蛋白酶的添加量为鱼皮质量的1%,提取时间48 h,料液比1∶70,胶原蛋白提取率达到51.2%。通过氨基酸组成分析、圆二色谱、聚丙烯酰胺凝胶电泳等方法对胶原蛋白的结构进行测试,发现该法提取的胶原蛋白具有典型Ⅰ型胶原蛋白特征,其三螺旋结构保持完整,分子质量约为340 kDa。成品中蛋白质含量>95%,羟脯氨酸的含量>5%,灰分<1%(均为质量分数),可用于医用材料、化妆品、功能食品等领域。

TGF-β/Smad信号转导通路对紫外线致人工皮肤光损伤中MMP-1、pro-collagen Ⅰ mRNA表达影响的初步研究

目的探讨人工皮肤光损伤中TGF-β/Smad信号转导通路与基质金属蛋白酶1及Ⅰ型前胶原蛋白的相互作用。方法以紫外线照射人工皮肤后,通过Real-Time RT-PCR法(荧光染料掺入法)检测其中基质金属蛋白酶1、Ⅰ型前胶原蛋白、TGFβRⅠ及TGFβRⅡmRNA的表达量。结果紫外线使人工皮肤中基质金属蛋白酶1(MMP-1)的mRNA表达量明显增加,而Ⅰ型前胶原蛋白mRNA的表达下调(P<0.05),TGFβRⅡmRNA表达显著下调(P<0.01);加入TGF-β1后MMP-1表达显著下调(P<0.01),Ⅰ型前胶原蛋白及TGFβRⅡmRNA表达显著增高(P<0.01);而UV照射后8小时加入TGF-β1,MMP-1表达量较对照组高(P<0.05),Ⅰ型前胶原蛋白及TGFβRⅡmRNA表达量均较对照组低(P<0.05)。结论 UV可以抑制人工皮肤中Ⅰ型前胶原mRNA的表达、上调MMP-1的表达,而这种调控作用可能与TGF-βRⅡ的表达受抑制,TGF-β/Smad信号传导通路被削弱有关。

罗非鱼皮硫酸皮肤素与胶原蛋白同时提取工艺优化及初步鉴定

针对鱼皮单独提取硫酸皮肤素造成资源利用率不高的问题,该研究以罗非鱼皮为原料,采用低温酶提酸促溶法同时提取硫酸皮肤素与胶原蛋白,通过单因素试验及响应面优化提取工艺,并利用醋酸纤维素薄膜电泳、聚丙烯酰胺凝胶电泳、傅里叶变换红外光谱等对罗非鱼皮硫酸皮肤素与胶原蛋白进行初步鉴定。结果表明,最佳提取工艺为中性蛋白酶加酶量5930 U/g,提取时间25.8 h,提取温度28.5℃,料液比1∶40(g∶mL),在此条件下罗非鱼皮硫酸皮肤素得率为132.12 mg/100 g,胶原蛋白提取率为53.14%,二者分别具有典型的硫酸皮肤素及胶原蛋白特征。该研究为同时提取罗非鱼皮硫酸皮肤素与胶原蛋白提供了理论依据,为罗非鱼皮下脚料的高效利用提供了一种新途径。

艾灸对D-半乳糖致亚急性衰老模型大鼠皮肤组织胶原蛋白含量及雌二醇水平的影响

目的:观察艾灸对D-半乳糖致亚急性衰老模型大鼠皮肤组织中Ⅰ、Ⅲ型胶原蛋白含量及雌二醇水平的影响,探讨艾灸延缓皮肤衰老的作用机制。方法:大鼠颈背部皮下注射D-半乳糖制备亚急性衰老模型,连续42 d。造模第22天,实验组予以艾灸“足三里”“关元”穴。42 d后,应用酶联免疫吸附法(ELISA)检测大鼠胶原蛋白含量及皮肤雌二醇(Estradiol)水平。结果:与正常组比较,模型组大鼠皮肤组织Ⅰ、Ⅲ型胶原蛋白含量和雌二醇水平显著下降(P<0.01)。与模型组比较,艾灸可增加大鼠皮肤组织Ⅰ、Ⅲ型胶原蛋白含量和雌二醇水平(P<0.01)。结论:艾灸能显著缓解D-半乳糖所致的亚急性皮肤衰老。

口服胶原蛋白肽对皮肤疗效功能的研究进展

胶原蛋白是皮肤中最主要的结构蛋白质之一,对于皮肤的健康和美容具有重要作用。随着口服胶原蛋白肽产品的广泛应用,越来越多的研究关注口服胶原蛋白肽对皮肤的疗效功能,并且其在实际中也得到了广泛的关注,受到了大家的一致认可。本综述梳理了口服胶原蛋白肽在皮肤健康、皮肤老化、皮肤美容和皮肤病理改善等方面的研究进展,通过对相关研究的深入剖析,我们总结了胶原蛋白肽在这些领域的应用进展,并探讨了其潜在的作用机制,力图为胶原蛋白肽的开发和应用提供科学的依据。

密斑刺鲀鱼皮胶原蛋白对UVB诱导小鼠皮肤急性光损伤的保护作用

初步探究密斑刺鲀鱼皮胶原蛋白(Diodon hystrix skin collagen,DHSC)对紫外线B(ultraviolet B,UVB)诱导的小鼠皮肤急性光损伤的保护作用。将Balb/c小鼠分为正常组(CTL)、模型组(MOD)、DHSC低剂量组(L)、DHSC中剂量组(M)、DHSC高剂量组(H)、基质对照组(B)、阳性对照组(Y),以UVB诱导法建立小鼠皮肤急性光损伤模型。实验结束后观察DHSC对小鼠背部皮肤的作用情况并进行双盲法红斑评分,HE染色后观察DHSC对皮肤组织病理的影响,Masson染色后观察组织中胶原蛋白的结构,并通过比色法检测组织中超氧化物歧化酶(superoxide dismutase,SOD)的活力及丙二醛(malondialdehyde,MDA)的含量。结果表明,密斑刺鲀鱼皮胶原蛋白可以有效减轻UVB辐射引起的小鼠皮肤外观形态、组织结构及胶原蛋白组织的改变,通过抑制抗氧化酶活性降低和减少脂质过氧化物堆积,表现出对小鼠皮肤急性光损伤的保护作用。