¿Qué es el ácido hialurónico?

Ácidohialurónico (HA) is a high-molecular-pesolinear macromolecular acidic mucopolysaccharide composed derepeating disaccharide units deD-glucuronic Ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidoyN-acetyl-D-glucosamine [1]. Hyaluronic Ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidowas first isolated De lavitreous humour decattle en1934, yit was discovered that hialurónicaÁcido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidois also widely found enelinterstitial matrix deconnective tissue enanimals yhumans. Among these, the vitreous humour dethe eye, skin, umbilical cord, cartilage ysynovial fluid dejoints have high levels De hialurónicoacid. Hyaluronic Ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidofrom different sources has basically the same structure, but hialurónicaÁcido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidofrom different sources has different molecular weights[2]. As a multifunctional matrix in the body, hialurónicaÁcido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidohas important physiological functions such as regulating cell proliferation, differentiation, migration, lubricating joints, protecting cartilage, promoting wound healing, resisting oxidation, yanti-aging.

Hyaluronic Ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácido ácidohas a strong water-retaining effect, yits moisturising Efecto efectois higher than that deother moisturising substances found in nature. It is known as an ideal natural moisturising factor yhas been widely used in clinical medicine and cosmetics production. With the approval De hialurónicoacid as a new raw material for food this year, the aplicaciónfields dehialurónicaacid are constantly expanding. At the same time, consumers' La sensibilización sanitaria mejora constantemente y la demanda de materias primas de ácido hialurónico aumenta constantemente. Es esencial la preparación Industrial de ácido hialurónico de alta calidad. Este artículo ofrece una visión general de las funciones fisiológicas, preparación, separación y purificación, y campos de aplicación del ácido hialurónico natural, celel objetivo de proporcionar una referencia para el desarrollo y utilización del ácido hialurónico.

1 distribución y funciones fisiológicas del ácido hialurónico en el cuerpo

1.1 distribución del ácido hialurónico en el organismo

Natural hyaluronic acid is widely distributed in varioustissues of higher animals, although the amount varies. It is mainly distributed in the cell matrix and lubricating fluid, including humanaumbilical cord, synovial fluid, skin, thoracic lymphatic fluid, vitreous humour, and rooster comb. The rooster comb is currently the animal tissue with the highest hyaluronic acid content. The hyaluronic acid content of various organisms is shown in Table 1 [3]. Hyaluronic acid is widely distributed in various tissues of the human body. The distributIelionof hyaluronic acid in the tissues of different organisms is basically the same, with the main difference being in molecular weight. The molecular weight of hyaluronic acid in normal biological tissues is approximately 1000–8000 kDa. Different molecular weights stimulate different receptors or pathways in three-dimensional structures, exerting different effects [4].

1.2 funciones fisiológicas del ácido hialurónico

1.2.1 lubrica las articulaciones y protege el cartílago

Hyaluronic acid is widely distributed in the intercellular matrix and cell matrix. It is the main component of synovial fluid in the joints and is distributed on the surfaces of cartilage and ligaments. Hyaluronic acid has good viscoelasticity. When walking, the synovial fluid is viscous to reduce joint friction. When performing high-impact actions such as running, the synovial fluid is elastic to buffer the stress on the joints. When the joint is under load, the synovial fluid changes from a fluid to an elastic body to protect the articular cartilage [5]. There is a lot of evidence to suggest that osteoarthritis in elderly patients is caused poroxidative stress. Osteoarthritis is the wear and tear of articular cartilage. When attacked porreactive oxygen species, the long-chain hyaluronic acid is broken down into hyaluronic acid fragments, weakening the overall structure of the cartilage [6].

1.2.2 promueve la cicatrización de heridas

The wound healing process can be divided into four stages: hemostasis, inflammation, proliferation and maturation. When an injury occurs, the amount of hyaluronic acid in the wound increases. Due to its large molecular weight, hyaluronic acid is used as an early temporary structure [7]. During the inflammation stage, damaged cells begin to secrete exudates containing salts, water and proteins [8]. This stage is characterised porredness and heat at the injury site, pain and dysfunction [9]. Hyaluronic acid binds to the CD44 receptor on the surface of leukocytes and endothelial cells, causing fewer leukocytes to migrate to the inflammation site and reducing the degree of wound swelling [10]. The CD44 receptor plays an important role in the inflammatory response, in which high molecular weight hyaluronic acid stimulates the anti-inflammatory response and Ácido hialurónico de bajo peso molecularinduces the inflammatory response. In the proliferation phase, the wound is rebuilt with new collagen tissue, the extracellular matrix is secreted, and the wound begins to shrink under the action of myofibroblasts [11]. In the maturation phase, the unorganized collagen forms cross-links, reducing scarring and enhancing the elasticity of the Piel de pielin the wound area.

1.2.3 regular la proliferación, migración y diferenciación celular

Hyaluronic acid is an important regulatory factor affecting the processes of cell proliferation, migration and differentiation. The presence of hyaluronic acid helps to hydrate local tissues, weaken the fixation of cells to the extracellular matrix, and promote cell separation, migration and even division. The hyaluronic acid receptors on the cell surface can also be linked to some kinases related to cell movement[12].

During the early stages of mitosis, hyaluronic acid levels increase, and levels drop sharply after mitosis enters the G1 phase (the period between the completion of the previous mitosis and the beginning of the synthesis phase). High levels of hyaluronic acid cause the release of growth factors, and by forming an extra-cellular membrane, it affects cell-cell interactions and accelerates cell proliferation [13]. However, it has not yetbeen observed that hyaluronic acid directly promotes mitotic activity. This signalling and regulatory effect of hyaluronic acid is related to its molecular weight. Different molecular weights trigger different signalling pathways. Low molecular weight hyaluronic acid induces cell proliferation. In addition, low molecular weight hyaluronic acid can enhance the expression of pro-inflammatory factors, while high molecular weight hyaluronic acid has the opposite effect [14].

1.2.4 efecto angiogénico

Se ha informado de ellolow molecular weight hyaluronic acid can stimulate the expression of signal molecules, stimulate the proliferation and migration of Vascular vascularendothelial cells, and high molecular weight hyaluronic acid can inhibit endothelial cell proliferation and migration, thus having an anti-angiogenic effect [15]. However, most of the evidence supporting the effect of hyaluronic acid on cell growth has been produced using tumour xenografts. Some data show that injecting low molecular weight hyaluronic acid can inhibit tumour growth [16], which conflicts with the above concept and indicates that there may be more complex pathways and interactions that require further research.

1.2.5 actividad antioxidante

Studies have found that hyaluronic acid can eliminate free radicals and has a certain degree of antioxidant activity. High molecular weight hyaluronic acid can protect cells from the effects of reactive oxygen species, which, in excess, can damage proteins, lipids and DNA. Some of the antioxidant properties of hyaluronic acid include its ability to reduce ultraviolet-induced apoptosis and acid-induced DNundamage [17]. Feng Ning et Al.[18] studied the serum superoxide dismutase activity after oral administration of hyaluronic acid and found that hyaluronic acid has an in vivo antioxidant effect. Yu Haihui et al. [19] found that the mucus hyaluronic acid of Andrias davidianus has a certain in vitro antioxidant activity and can scavenge DPPH.,.OH, ABTS+.and reduce Fe3+. Some scholars speculate that the antioxidant properties of hyaluronic acid are due to the hydroxyl functional groups in the structure of hyaluronic acid, which can absorb reactive oxygen species [14].

1.2.6 efecto antienvejecimiento

Studies have found that the amount of hyaluronic acid in the human body decreases with age. Compared to the age of 20, the amount of hyaluronic acid decreases by 75% at the age of 60. The older the person, the lower the amount of hyaluronic acid in the body. The amount of hyaluronic acid in the body also varies among people of the same age. People with a high amount of hyaluronic acid in the body look younger, while people with symptoms of aging have significantly lower amounts of hyaluronic acid in the body [20]. A decrease in the amount of hyaluronic acid in the skin reduces the space filled by the intercellular gel-like matrix, causing the cells to be arranged closely together. Collagen loses water and hardens, making the skin rough and losing its elasticity. Studies have found that hyaluronic acid can heal skin damage caused by ultraviolet radiation, and high concentrations of hyaluronic acid can affect collagen expression [21].

In summary, the physiological functions of hyaluronic acid are closely related to its molecular weight. Hyaluronic acids with different molecular weights play different roles in physiological functions such as wound healing, regulation of cell proliferation, migration, differentiation, angigénesisand antioxidant activity. Low molecular weight hyaluronic acid induces inflammatory responses, induces cell proliferation, stimulates the proliferation and migration of vascular endothelial cells, and high molecular weight hyaluronic acid has better antioxidant activity than low molecular weight hyaluronic acid. This difference in physiological function leads to differences in its ultimate application in products.

2 estructura y propiedades del ácido hialurónico

2.1 estructura del ácido hialurónico

Hyaluronic acid is a high molecular weight acidic mucopolysaccharide composed of alternating glucose units linked by β-1,3-glycosidic bonds and N-acetylglucosamine units linked by β-1,4-glycosidic bonds. The primary structure of hyaluronic acid is shown in Figure 1 [22]. Hyaluronic acid, as the only currently discovered non-sulfur-containing glycosaminoglycan, differs from common glycosaminoglycans in that it is synthesized via cell membrane surface membrane proteins rather than by the cell' aparato s Golgi [23].

2.2 propiedades físicas y químicas del ácido hialurónico

Hyaluronic acid is a white amorphous solid with the common properties of acidic mucopolysaccharides. It is soluble in water but insoluble in organic solvents such as ethanol [24]. Hyaluronic acid aqueous solutions have specific rheological properties, with good viscoelasticity. Low concentrations or small molecular weight hyaluronic acid exist as monomers, with little change in viscosity. High molecular weight and high concentration hyaluronic acid has good viscoelasticity[25], and exhibits non-Newtonian fluid characteristics, making it very suitable for simulating synovial fluid. The viscoelasticity of synovial fluid is related to the concentration of hyaluronic acid[13].

A reasonable change in the molecular weight and solution concentration of hyaluronic acid can obtain better viscoelasticity. Due to the presence of hydrogen bonds between the monosaccharides in the hyaluronic acid molecule chain, hyaluronic acid at low concentrations can also form a unique honeycomb network structure, allowing hyaluronic acid to adsorb about 1000 times its own moisture, which has strong moisturising properties[26]. Hyaluronic acid with different molecular weights has different physical and chemical properties. High molecular weight hyaluronic acid has higher viscosity, while the random curled structure of long-chain hyaluronic acid is more stable, and short chains are more likely to expand [27]. The method and biological pathway by which cells differentiate between high molecular weight and low molecular weight hyaluronic acid are still unknown.

3 preparación y purificación del ácido hialurónico

3.1 fuentes de ácido hialurónico

3.1.1 fuentes de tejidos animales

Animal tissue sources can be divided into terrestrial sources and marine sources. Currently, hyaluronic acid is mainly extracted from terrestrial animal tissues such as the rooster comb, human umbilical cord, egg shell membrane, and pig skin. The rooster comb is widely used for hyaluronic acid extraction because it is an animal tissue with a high hyaluronic acid content. Due to the limited supply of terrestrial animal tissue, large-scale production is not possible. Researchers are constantly trying to extract hyaluronic acid from other animal tissues or other sources of raw materials. Marine biological resources such as animal residues, waste, and by-products have always received widespread attention due to their long-term economic and environmental benefits.

They have significant potential as a source of substances such as hyaluronic acid [28]. Researchers have extracted hyaluronic acid from biological tissues such as the ocular vitreous of marine organisms such as the eyes of cuttlefish, squid, tuna, frog skin, fish mucus, and the aqueous humour of freshwater mussels [19, 25, 29]. Yi et al. [29] first extracted hyaluronic acid from the ocular vitreous of tuna, with a final extraction rate of 0.013%. and Haihui Yu et al. [19] extracted it from the surface mucus of the Chino chinogiant salamander. When the amount of added trypsin was 1.5%, the yield of hyaluronic acid was 1.7041 mg/g. The structure of the extracted hyaluronic acid was the same as the standard product. Compared with the tissues of land animals such as the rooster comb and umbilical cord, the extraction rate was low, but it can be used as a stable source of hyaluronic acid extraction.

3.1.2 vía de la fuente de fermentación microbiana

Hyaluronic acid is widely distributed in the cell envelope of some bacteria, protecting the cells from oxygen damage. Previous research on hyaluronic acid in bacteria was mainly aimed at exploring the composition and function of the envelope. Shiseido in Japan was the first to apply the fermentation method to the industrial production of hyaluronic acid. The synthesis of hyaluronic acid in the cell is complex and continuous. Glucose is converted to gluco-6-phosphate by glucokinase, and then to the precursors uridine diphosphate N-acetylglucosamine and uridine diphosphate glucuronic acid by various enzymes such as isomerase and glucuronic acid phosphatase and other enzymes to produce the precursor substances uridine diphosphate-N-acetyl-glucosamine and uridine diphosphate-glucuronic acid, which are alternately added to the hyaluronic acid molecule chain under the action of hyaluronic acid synthase [30].

Streptococcus zooepidemicus from group C is the main source of hyaluronic acid [31]. Due to its pathogenicity and endotoxins in wild-type strains, it has become common practice in actual production to modify wild-type strains and produce hyaluronic acid through non-pathogenic strains [32]. The main means of strain treatment are genetic engineering, mutagenesis breeding and protoplast breeding. JIN et al. [33] improved the hyaluronic acid synthesis pathway of Bacillus subtilis by integrating the leech-derived hyaluronidase LHyal gene, regulating the expression of LHyal by sequence optimization and N-terminal fusion His tag strategy, and obtaining a high-yield strain that accumulates hyaluronic acid to 19.38 g/L after 100 h of fermentation in a 3 L fermenter. Wei Chaobao et al. [34] selected Streptococcus zooepidemicus, which has a short production cycle and high strength, for construction on this basis, and obtained a high-yield strain that can alleviate the problem of dissolved oxygen during fermentation. At present, the synthesis of hyaluronic acid has been achieved through the heterologous expression of hyaluronic acid synthase in different hosts such as Bacillus subtilis [35], Lactobacillus [36] and Bacillus glutamicum [37].

3.2 preparación de ácido hialurónico

3.2.1 preparación de ácido hialurónico a partir de tejidos animales

The production of hyaluronic acid from animal tissue sources often involves tissue extraction. The complete process includes pretreatment, extraction, separation and purification, drying, etc. The processing technology is relatively mature, the extraction method is simple, and most of the extracted hyaluronic acid is of high molecular weight [38], with high viscosity and good moisturising properties. It is mainly used in the pharmaceutical and cosmetics industries. The main extraction methods are salt extraction and enzyme extraction. The addition of inorganic salts and enzymes can break the complexation of hyaluronic acid and proteins in animal tissue. In addition, enzymes can hydrolyse impurities such as proteins and nucleic acids, which is beneficial for the extraction of hyaluronic acid [39].

KALKANDELEN et al. [40] successfully extracted hyaluronic acid from the comb of a chicken by defatting the tissue homogenate with acetone and extracting it multiple times with a sodioacetate solution. However, the tissue extraction method is complicated and the extraction rate is low. Enzyme extraction has become a research hotspot due to its high efficiency. Currently, the commonly used enzymes for extraction include neutral proteases, pepsin, trypsin, papain, etc. Ürgeová et al. [41] compared the results of extracting hyaluronic acid from eggshell membranes using pepsin, trypsin and papain. The results showed that trypsin was more effective than the other two enzymes. At a pHof 8, 37 °C and a trypsin dosage of 50 U/g for enzymolysis of eggshell membranes, the hyaluronic acid extraction rate was 44.82 mg/g eggshell membrane. In order to obtain a better extraction effect, enzyme mixtures or ultrasound are often used in experiments to assist extraction. Chen Shengjun et al. [42] used ultrasound (200 W, 30 kHz) to assist trypsin and complex protease to extract from tilapia eyes. After optimisation, the hyaluronic acid yield was 11.44%, which is about 5% higher than that obtained by simple enzimenzimenzimhydrolysis.

3.2.2 preparación de ácido hialurónico microbiano

The microbianofermentation process mainly includes the following steps: seed culture, fermentation, separation and purification, and drying. At present, research on improving the extraction efficiency of microbial fermentation mainly focuses on cultivating excellent strains, selecting suitable culture media, and optimizing fermentation conditions. There have been many studies on obtaining high yields of hyaluronic acid by controlling the conditions of the culture medium and fermentation process. Compared to the preparation of hyaluronic acid by tissue extraction, one advantage of the microbial fermentation method is that the molecular weight of hyaluronic acid can be controlled during the fermentation process. This is also the main content of current research on the fermentation process of hyaluronic acid. The regulation of hyaluronic acid molecular weight is affected by hyaluronic acid synthase and the relative strength of its binding to the substrate, the concentration ratio of hyaluronic acid precursor substances to hyaluronic acid synthase concentration [43]. Fructose-6-phosphate produced from carbon sources can be used to synthesise lactic acid, inhibit bacterial growth and hyaluronic acid synthesis. It is possible to inhibit other pathways that compete with hyaluronic acid for carbon sources (such as glycolytic pathways), so that more carbon sources can be used for hyaluronic acid synthesis, thereby increasing hyaluronic acid production and molecular weight [44].

The balance of metabolic fluxes can affect the molecular weight of hyaluronic acid [45]. investigaciónhas been carried out on fermentation conditions that affect hyaluronic acid production and molecular weight, such as temperature, aeration, pH, stirring speed, etc. Certain research has been conducted on fermentation conditions that affect the yield and molecular weight of hyaluronic acid, such as Liu Jinlong et al. [46] who studied the effect of fermentation conditions on the molecular weight of hyaluronic acid synthesized by Streptococcus equi subsp. zooecium. Batch culture fermentation mode is more conducive to the production of high molecular weight hyaluronic acid than glucose feeding culture mode. Within the range of 0–45% dissolved oxygen concentration, the relative molecular weight increased by 109.4% with increasing dissolved oxygen levels. Low temperatures are conducive to hyaluronic acid synthesis, and the yield and molecular weight of hyaluronic acid are relatively high at low temperatures. At 33 °C, the yield and molecular weight of hyaluronic acid are 4.41 g/L and 2.54×106, respectively. pH has a different effect on the yield and molecular weight of hyaluronic acid. The highest yield of hyaluronic acid (3.72 g/L) was obtained at pH 7, and the lowest yield (3.01 g/L) was obtained at pH 8. However, the highest molecular weight (2.38×106) was obtained at pH 8, indicating that Ácido hialurónico de alta calidad production can be achieved by controlling the fermentation process conditions during the production process.

La extracción de tejido Animal y la fermentación microbiana son los dos métodos más comunes para producir ácido hialurónico. La extracción de tejido se utiliza para extraer ácido hialurónico de tejido animal. Este método fue utilizado a menudo en los primeros días, pero el proceso de extracción es complicado, el rendimiento de ácido hialurónico es bajo, y hay restricciones en la fuente de materias primas. Con el progreso de la ciencia y la tecnología, la fermentación se ha convertido en el método principal para la producción industrial de ácido hialurónico debido a sus ventajas de bajo costo, alto rendimiento y facilidad de producción a gran escala. Con la mejora continua del método de preparación, people's demand for hyaluronic acid production has gradually shifted from high yield to high quality. Current research focuses on producing hyaluronic acid with specific molecular weight through genetic engineering, mutagenesis and other methods to meet the needs of hyaluronic acid in different applications. Establishing an efficient and safe preparation method of hyaluronic acid to produce hyaluronic acid with specific molecular weight that meets various application scenarios will become a research hotspot.

3.3 separación y purificación del ácido hialurónico

Regardless of whether the tissue extraction method or the fermentation method is used, the crude hyaluronic acid extracted contains some proteins, nucleic acids and other impurities, which need to be separated and purified to obtain pure hyaluronic acid. According to the principle of separation and purification, it can be roughly divided into three methods: precipitation, Filtración de filtraciónand adsorption.

3.3.1 precipitación

The main precipitation methods are quaternary ammonium salt precipitation and organic solvent precipitation. The principle of the quaternary ammonium salt purificationmethod is that the quaternary ammonium salt and hyaluronic acid have different charges in an aqueous solution. The two form a complex and precipitate out in a low salt solution, but dissociate and dissolve in a high salt solution, thereby achieving the purpose of removing impurities that do not complex with hyaluronic acid. Commonly used quaternary ammonium salts include cetylpyridinium bromide (CPB), cetyltrimethylammonium bromide (CTAB), cetylpyridinium chloride (CPC) and other long-chain quaternary ammonium salts [47]. This method of purification yields high-purity hyaluronic acid with good results, and can remove impurities that do not complex with quaternary ammonium salts. The organic solvent precipitation method mainly affects the dielectric constant of the medium to cause intra- and intermolecular aggregation, thereby achieving the purpose of removing proteins [48]. 

Compared with restricted reagents such as chloroform and acetone, ethanol is more widely used due to its safety and low cost. Song Lei et al. [49] optimised the factors affecting the purity of hyaluronic acid after ethanol extraction by combining plate and frame filtration to obtain a high purity hyaluronic acidCon un contenido del 93.71%. CAVALCANTI et al. [50] investigaron el efecto de la relación de etanol a caldo de fermentación en la constante dieléctrica y el efecto del pH en la purificación del ácido hialurónico. A un pH de 4 y una relación líquida de fermentación de etanol de 2:1, la pureza del ácido hialurónico fue de 55%, la tasa de recuperación fue de 85%, y la precipitación del solvente orgánico se utilizó para la purificación inicial del ácido hialurónico con buenos resultados.

3.3.2 filtración

The principle of filtration is to retain particles on a porous membrane based on particle size. Compared to organic solvent precipitation, filtration does not involve the consumption of organic solvents, is simple to implement, and can be industrialised. However, the protein removal effect of filtration alone is not good, and pore blockage will occur as purification progresses, limiting its application in the purification of hyaluronic acid. Tangential filtration or the use of filter aids can greatly reduce pore blockage [51]. GÖZKE et al.[52] proposed an electrofiltration technique combining membrane filtration and electrophoresis. The electric field has a strong promoting effect on the filtration of hyaluronic acid. Compared with conventional filtration, the concentration factor based on the sample osmotic mass is increased by nearly 4 times in the same experimental time. Moreover, this filtration method will not negatively affect the molecular structure and average molecular weight of hyaluronic acid, providing new possibilities for the downstream purification process of hyaluronic acid.

3.3.3 adsorción

La adsorción es un método de purificación del ácido hialurónico que se basa en la retención selectiva de compuestos en la superficie de un sólido poroso. Los adsorbentes comúnmente utilizados incluyen carbón activo, resinas y gel de sílice. El carbón activo es un material ideal para separar y puriel ácido hialurónico porque tiene una fuerte adsorde proteínas y ácidos nucley una débil adsorde polisacáridos neude alto peso molecular. Wei Linna et al. [53] utilizaron la precipitación de etanol combinada con la adsordel carbón activo en el proceso de extracción del ácido hialurónico de la meseta zokor tissues. The recovery rate of the extracted hyaluronic acid can reach 72.73%. CAVALCANTI et al. [50] found that the structure of hyaluronic acid at different pH values has an important effect on the precipitation performance. At pH 4, the recovery rate of hyaluronic acid was 85%, and at pH 7, the recovery rate of hyaluronic acid was 70%. During the use of activated carbon, adjusting the pH to an appropriate value can increase the recovery rate of hyaluronic acid.

Electrophoresis is a widely used method for separating proteins, and its separation efficiency is affected by the gel. Compared with other operations, it has a lower purification efficiency for hyaluronic acid. Ion intercambiochromatography is also one of the widely used methods for purifying biological macromolecules. This method is gentle and does not cause changes in molecular structure, but it is relatively expensive. It is necessary to select suitable exchange resins and exchange conditions, and the operation is complex. It is mainly used in the production of medical grade hyaluronic acid. Ni Hangsheng et al. [54] used a strong acid cation exchange resin in tandem with a strong base anion exchange resin modified with a histidine group. The impurity proteins in the crude hyaluronic acid were purified by exchange adsorption with the strongly acidic cation exchanger in an acidic solution, and eluted with sodiochloride solution. The protein content of the obtained high-quality hyaluronic acid is less than 0.075%, the average molecular weight is greater than 9.41×105, and the yield of purified weight is 58%~61%.

Separation and purification is an essential step in the preparation of high-purity, high-quality hyaluronic acid. At present, there is relatively little research on the effect of various purification operations on the purity of hyaluronic acid during purification. CAVALCANTI et al. [51] expressed the degree of purification as a percentage of hyaluronic acid or protein in the solution, and summarized the change in the purity of hyaluronic acid during the purification process.

The hyaluronic acid fermentation broth derived from Streptococcus zooepidemicus first underwent an isopropanol precipitation operation, with a protein content of 14.1%; a silica gel adsorption operation, with a protein content of 4.5%; and a charcoal filter module combining filtration and adsorption, with a protein content of only 0.6%. Finally, the protein content reached 0.06% after dialysis filtration. Each separation and purification method has its own advantages and disadvantages. In actual industrial production, a reasonable combination of several separation and purification methods is often used to achieve the maximum effect, depending on the source of the raw materials and the different requirements of the end products.

4 aplicación de ácido hialurónico

4.1 aplicación en el sector alimentario

Hyaluronic acid is widely used in the Japanese food market. In addition to Salud saludfoods, it is also widely used in ordinary foods such as beverages, soft candies, and jams. In the USfood market, hyaluronic acid is mainly used as a dietary supplement [55]. At present, the main products containing hyaluronic acid in China are health foods, and the main effect is to improve skin moisture. Cha Shenghua et al. [56] developed a kind of bird's nest puede con hialuronato de sodio como principal materia prima, que puede mejorar eficazmente la humedad de la piel sin otras reacciones adversas. Los principales tipos en el mercado son cápsulas, administración oral y bebidas en polvo. Después de que el ácido hialurónico es absorbido a través de la digestión oral, el precursor de la síntesis de ácido hialurónico en el cuerpo aumenta, lo que aumenta el contenido de ácido hialurónico en el cuerpo y lo concentra en el tejido cutáneo, mejorando así la piel#39;s capacidad de retención de agua, suavidel stratum corne, mejorando aún más la elasde la piel y reduciendo las arru[57].

4.2 aplicación en cosméticos y artículos de uso diario

Hyaluronic acid is found in large quantities in the human body and other living tissues. It has extremely strong moisturising properties and is mainly used in cosmetics as a moisturising agent, thickener and emulsifier [58−59]. At present, almost all types of cosmetic formulations on the market contain hyaluronic acid. Hyaluronic acid can easily form a hydrated film on the skin to enhance the lubrication of the skin, promote the absorption of active substances by the skin, and to a certain extent, the formaciónof the film can isolate bacteria, which is beneficial to anti-inflammatory and repair of the skin and delay skin aging [60]. Hyaluronic acid is a component that exists in skin tissue itself, which is safer. In addition, as hyaluronic acid has an anti-inflammatory and restorative effect in the mouth, it can be added to toothpaste to provide a certain degree of moisturising and efficacy[61]. The application of hyaluronic acid in daily necessities is constantly expanding and deepening.

4.3 aplicaciones médicas

Hyaluronic acid is an important component of synovial fluid in the joints and plays an important physiological role in joint protection. Abnormal synthesis or metabolism of hyaluronic acid in the joints can lead to joint diseases. At this time, exogenous hyaluronic acid can be injected to supplement the synovial fluid and improve the physiological function of the joints[62]. Due to its unique physical and chemical properties and biocompatibility, hyaluronic acid is widely used in ophthalmic surgeries related to the retina and cataracts.

El ácido hialurónico se utiliza como un relleno en la estética médica para inyecdebajo de la piel para eliminar arrufaciy cicatrices y dar a la cara un aspecto abultado [63]. El aerosol de ácido hialurónico puede usarse para reparar el paciente#39;s face after laser surgery, effectively restoring skin barrier damage[64]. Hyaluronic acid derivatives are also widely used in ophthalmic preparations. For example, sodium Hialuronato de hialuronatocan replace the role of tear mucin and is used to tratardry eye disease and relieve dry eye symptoms [65]. Studies have found that the body's el contenido de ácido hialurónico aumentará durante la aparición de muchas enfermedades. Por lo tanto, clínicamente, el nivel de ácido hialurónico en el suero puede ser utilizado para reflejar cambios en diversas enfermedades, lo cual es de gran importancia para el diagnóstico auxiliar.

Hyaluronic acid is widely used in food, cosmetics, daily necessities and medicine. Its application in functional skin care products, ophthalmology and orthopedics is relatively mature. There is still huge potential for its application in the food industry. Oral hyaluronic acid is milder than external application and injection, and can stimulate vitality from the inside out. In January 2021, the National Health Commission approved the addition of hyaluronic acid as a new raw material for food to be added to ordinary foods. This indicates that the application of hyaluronic acid in the food sector will see large-scale growth. In addition, there are many modification sites on the hyaluronic acid molecule, and modification of its active groups, such as cross-linking, esterification, and grafting, gives it better physicochemical properties and resistance to enzymatic hydrolysis [66], allowing hyaluronic acid to be used in more complex environments. With technological progress, the application of hyaluronic acid in various fields will become more and more in-depth.

5 conclusiones y perspectivas

Hyaluronic acid has important physical and chemical properties and physiological functions. It has a wide range of applications and a large market demand. Global sales of hyaluronic acid raw materials are showing an upward trend. At present, the main methods for industrial production of hyaluronic acid are animal tissue extraction and microbial fermentation. The microbial fermentation method has the advantages of low cost and easy mass production. With the continuous expansion of hyaluronic acid application scenarios and the growing market demand, establishing an efficient and safe hyaluronic acid extraction and purification process, modifying hyaluronic acid molecules to produce specific molecular weight hyaluronic acid that meets different application scenarios will become research hotspots.

referencia

[1]ZHANG K, JIAN J,  ZHANG Z P. progreso de la investigación sobre la estructura, propiedades, modi-  fication  and  application  of hyaluronic  Ácido [J]. Polímeros polímeros Boletín, 2015,9:217 × 226.

[2] JEON O, SONG S J, LEE K, et al. Propiedades mecánicas y  Comportamiento de degradación de hidrogeles de ácido hialurónico reticulat  various  interenlaces Densidades [J]. Hidratos de carbono Polymers,2007, 70(3):251 × 257.

[3] KOGAN G, Š OLTES L,STERN R, et al. Ácido hialurónico: un biopolímero natural con una amplia gama de aplicaciones biomédicas e industriales [J]. Biotechnology Letters,2006,29(1):17 × 25.

[4] COWMAN MK, LEE HG, SCHWERTFEGERK L,et al. The content and size of hyaluronan in biological (en inglés) Fluidos y tejidos [J]. Frontiers in Immunology,2015(6):261.

[5] HLAVACEK M. función de la filtración del líquido sinovial por cartil- age en la lubricación de las articulaciones sinoviales. Modelo de mezcla de líquido sinovial [J]. revistaof Biomechanics,1993,26(10):1145 × 1160.

[6] MAREK P, MA × GORZATA K, JACEK K, et al. el Estrés oxidativo en pacientes con osteoartritis de rodilla un intento de evaluación de los posibles efectos compensatorios que se producen en el desarrollo de la enfermedad. Medicina,2019,55(5):150.

[7] VOIGT J, VICKIE R. Hyaluronic Derivados ácidos y su curación effect  on  quemquem, epiteli Quirúrgica quirúrgica Heridas, and  Heridas crónicas: una revisión sistemática y meta-análisis de ensayos controlados aleatorios [J]. Reparación y regeneración de heridas,2012,20(3):317− 331.

[8] HOTAMISLIGILG S. inflamación, metaflammation and im- munometabolic disorders[J]. Nature,2017,542(7640):177 × 185.

[9] KOJOUHAROV H V, TREJO I, CHEN B M. Modeling the ef- fects of inflamación in Bone fracture Healing [C]// American instituciones De la física Conferencia conferencia Serie. americano Instituto Serie de conferencias de física, 2017.

[10] GRISHMA S P, ROHAN B, CHARLES D E. Numerical investigación De leucoleucoro, Adhesión a la adhesión Y bonos formation  Sobre superficies recubiercon densidad variable de p-selectina [J]. Cell Press, 2019, 116(3): 18.

[11] LANDEN N X, LID Q, STAHLE M. Transition from In - flammation to proliferation: A critical Step during Wound Healing [J] (en inglés). Celular celular celular celular celular celular celular celular celular celular celular celular celular celular and  Molecular Vida vida vida vida vida Ciencias: Cmls,2016,73(20):3861 × 3885.

[12] JOHN CH W Y,ABATANGELO G. funciones de hyaluron-  Una reparación de heridas [J]. Reparación y regeneración de heridas,1999,7(2): 79−89.

[13] HUI E, GIMENO K I, GUAN G, et al. espaciotemporal Control de la viscoelasen hidrogeles de ácido hialurónico fototimables [J]. Biomacromolecules,2019,20(11):4126 × 4134.

[14] DOVEDYTIS M, LIU Z J, BARTLETT S. Hyaluronic acid and ITS biomedical applications: A review[J]. Regeneración por ingeniería,2020,1:102−113.

[15] SLEVIN M, KRUPINSKI J, GAFFNEY J, et al Hyaluronan- mediado angiogenesis  in  vascular  Enfermedad: El descubrimiento Vías de señalización de receptores RHAMM y CD44 [J]. Matrix Biology: revistaof the International Society for Matrix Biology, 2007, 26(1): 58-68.

[16] ZHONG Y N, KATHARINA G, CHENG L, et al. Hyaluron- ic acid-shelled Ácido activable Paclitaxel prodrug mic Efecto de objetivo and  treat  Cd44-sobrexpressing (en inglés) human  Seno (mama). Xenoinjertumin vivo[J]. Biomaterials,2016:84.250−261.

[17] MOSELEY R, LEAVER M, WALKER M, et al. Comparación de las propiedades antioxidantes de HYAFF → -11p75, AQUACEL ® e hyaluronan frente a especies reactivas del oxígeno in vitro[J]. Bioma- terials,2002,23(10):2255 × 2264.

[18]FENG N, SHI Y L, GUO F X, et al. Estudio sobre el efecto  Ácido hialurónico oral en la mejora de la hidratde la piel e in vivo  Efecto antioxidante [J]. Food and Drugs,2016,18(6):386−390.

[19]YU H H, LI W, TONG C Q. extracción de ácido hialurónico de la mucosa de la superficie corporal de salamangigante y su actividad antioxidante [J]. Procesamiento de productos agrícolas,2018,10:18−21.

[20]GUO X P, HE Y  L,  sol M  L,  et  al.  aplicación  of  hyaluronic  acid  in  health   Productos [J]. Revista China de la revista China de bioquímica farmacéutica,2002, 23(1):49−51.

[21]WU B J, NI H  L, ZHU M L, et al. Progreso de la investigación y aplicación de hialurónico  Ácido [J]. Chinese Journal of Aesthetic Plastic Surgery,2018,29(4): 252 × 254.

[22] LAURENT T C. Biochemistry of hyaluronan[J]. Acta Oto- laryngologica Supplementum,1987,442:7 × 24.

[23]CHEN J S,  WANG J Q, YI Y, et al. Progreso de la investigación del ácido hialurónico y ITS  Derivados [J].  Chinese   Journal   of  Bioingeniería,2015,35(2): 111 × 118.

[24] WANG C F. el estado de aplicación de hy-  Ácido alurónico [J]. Revista China de dispositivos médicos,2018,42(1): 74 × 76,78.

[25] SHA K. investigación sobre la técnica de extracción of hyaluronic  acid  from the  skin  De chino bosque Rana [D]. Changchun: universidad agrícola de Jilin, 2004.

[26] JIANG S, LIANG H. Hyaluronic acid — a highly after beauty tool[J] (en inglés). Mundo saludable,2020(2):25−27.

[27] MARY K. C, SHIRO M. Experimental approaches to hyalur- Onan structure [J]. Carbohidrresearch,2005,340(5):791 × 809.

[28] TRIVEDI N, BAGHEL R S, BOTHWELL J, et al. Un proceso integ- rated para la extracción de combustible y productos químicos a partir de biomasa marina macroalgal [J]. Scientific Reports,2016,6(1):30728.

[29] I Y, XU J,  MEI J F, et al. Estudio del proceso de extracción del ácido hialurónico  De tuna eyes[J]. Revista de la universidad de tecnología de Zhejiang, 2018,46(3):276−281.

[30] ARINOBU Y, ATAMAS S P, OTSUKA T, et al. La clonación Molecular y Caracterización de un supuesto ratón hialuronano SYN - thase[J]. Biological Chemistry,1996,271(38):23400 × 23406.

[31]DONATELLA C, iled I, ELISABETTA C, et al. Ingeniería de S. equi subsp. Zooepidemicus towards concurrenttion of hyalurronic (en inglés)  acid    and    condroitina  biopolímeros   of   Interés biomédico [J]. AMB Express,2017,7(1):61.

[32] PAN N C, PEREIRA H C B, SILVA M L C, et al. Mejora de la producción de hialurácido por Streptococcus zooepidemicus en melaza de caña de azúcar [J]. Biotecnología y química aplicada,2017,182(1):276 × 293.

[33] JIN P, KANG Z, YUAN P H, et al. Producción de hialuronde de peso molecular específico mediante ingeniería metabólica de bacisubtilis 168[J]. Ingeniería metabólica 2016, 35: 21-30.

[34]WEI C B, DU G C, CHEN J, et al. Construcción de un  Cepa de la fermentación de ácido hialurónico oligosacárido Streptococcus  Zooepidemimicus [J]. China revista China de ingeniería biológica,2019, 35(5):805 × 815.

[35] ADAM W, WESTBROO K, XIANG R, et al. Ingeniería metabólica para aumentar la producción heteróloga de ácido hialurónico en Bacillus subtilis[J]. Ingeniería metabólica,2018,47:401 × 413.

[36] SUNGURO × LU C, SEZGIN D E, AYTAR C P, et al. Producción de ácido hialurónico en alto título en Lactococcus lactis recombin[J]. Bioquímica preparativa & Biotechnology,2018,48(8): 734 × 742.

[37] CHENG F, YU H, STEPHANOPOULO G, et al. Corynebacterium glutamicum es un ingeniero en biosíntesis de ácidos hya- luronic acid[J]. Ingeniería metabólica,2019,55:276−289.

[38] YAMADA T, KAWASAKI T. Microbial synthesis of hyalur- Onan and chitin: New approaches[J]. Biosci Bioeng, 2005, 99(6): 521-528.

[39] SADHASIVAM G, MUTHUVEL A. aislamiento y caracterización del ácido hialurónico a partir de organismos marinos [J]. Avances en investigación alimentaria y nutricional,2014,72:61−77.

[40] KALKANDELEN C, SU S, SAATCIOGLU E, et al. Producción de ácido hialurónico y análisis de Rooster Comb [C]// 2020 Med- ical Technologies Congress (TIPTEKNO). Antalya, 2020: 1−4.

[41] URGEOVA E, VULGANOVA K. comparación de la hidrólisis enzimde los polisacáridos de las membranas de las cáscaras de huevo [J]. Nova- Biotechnologica et Chimica,2016,15(2):133−141.

[42]CHEN S J, CHEN H, GAO R C, et al. Condiciones tecnológicas para la extracción de ácido hialurónico de los ojos de tilapia por ultrasonido - como -  sisted enzymatic  Hidróli[J]. Journal  of  Nuclear Nuclear Nuclear Agricultura, 2014,28(8):1446 × 1452.

[43]GAO J J, YANG S L. progreso de la investigación sobre la producción de alta Comisión de las comunidades europeas  weight   hyaluronic   acid   by   microbial   Fermentación [J]. Chinese Journal of Bioengineering,2017,37(5):118 × 125.

[44]DONG Z H. Research on mutation breeding and molecular weight controltechnology of hialuronic acid production by fermentación [D]. Hangzhou: Zheji- universidad de tecnología de ang, 2017.

[45] KARAMI M, SHAHRAKY M K, RANJBAR M, et al. Preparación, purificación y caracterización del ácido hialurónico de bajo peso molecular [J]. Biotechnology Letters,2021,43(1):133 × 142.

[46]  LIU J L, ZHAO G Q, Li Z M, et al. Efecto de la condición de cultivo sobre el peso molecular del ácido hialurónico sintetizado por Streptococcus equisimilis[J]. Journal of Food Science and Biotechnology,2015,34(2):209−214.

[47] AMAGAI I, TASHIRO Y, OGAWA H. mejora del procedimiento de extracción de hialuronan del globo ocular de los peces Y de la caracterización lunar - cular [J]. Fisheries Science,2009,75(3):805 × 810.

[48] LI Y, SHI S, YANG X, et al. La desproteinización, las acticidades antioxides y el efecto inhibitsobre la a-amilasa de los polisacáridos de la seda de maíz [J]. Biochem Biotechnol, 2019, 15(2): 83-90.

[49]SONG L, MENG G Q, GUO Y F, et al. Estudio sobre el proceso de extracción y purificación del ácido hialurónico en caldo de fermentación [J]. ShandongAgricultural Sciences,2017,49(3):134−139.

[50] CAVALCANTI A D D, MELO B A G, OLIVEIRA R C, et al. Recuperación y pureza del ácido biohialurónico de alta masa molar por precipitación estrategias modulmodul by  pH  and  sodium  Clorclor[J]. Biochem Biotechnol, 2019, 188: 527-539.

[51] CAVALCANTI A, MELO B, FERREIRA B, et al. Realizar las principales operaciones posteriores de depuración del ácido hialurónico [J]. Process Biochemistry,2020,99:160−170.

[52] GOZKE G, KIRSCHHOFER F, PRECHTL C, et al. electrofiltración  mejora  El callejón sin salida  filtration   of  hyaluronic   acid   Y presenta un paso alternativo de procesamiento posterior que supera los desafíos tecnológicos de los métodos convencionales [J]. Ingeniería en ciencias de la vida,2017,17(9):970 × 975.

[53]WEI L N, WANG Y, WEI D B, et al. Tecnología de extracción y caracterización molecular del ácido hialurónico de la meseta zokor tis [J]. Biotechnology Bulletin,2017,33(3):151−161.

[54]NI H S, LI R, HE Y L, et al. Purificación purificación of  hyaluronic  acid  by  ion  exchange  Cromato[J]. Chinese Journal of Pharmaceuticals,2001,11:5 × 8.

[55]LIU S, WANG J Z. las características del ácido hialurónico y su aplicación en los alimentos [J]. Química químicaEngineering Design Communications,2018,44(8):62.

[56] CHA S H, WANG J L, LIAN C C, et al. desarrollo  Of hyaluronic acid Collagen rock Sugar bird&#Nido 39;s y su efecto en la mejora de la humedad de la piel [J]. Food Industry,2020,41(2):129−134.

[57]JIANG Q Y,  LING P X, CHENG Y N, et al. Distribución del ácido hialurónico oral  En animales [J]. China revista de la revista China de bioquímica farmacéutica,2008, 29(2):73−76.

[58]ZHU C, ZHU Y, WEI W, et al. Preparación y aplicación de emulsionante granular de ácido hialurónico modificado con cumarina [J]. Diario de Func- tional Polymers,2016,29(4):388−396.

[59]FU S  Y,  LI  J. Research  on  the  Progresos progresos of  facial  Máscara [J]. Chemical Management,2017,26:117−119.

[60]MENG L L, DU T,  WANG X X, et al. Progreso de la investigación en la aplicación de hialurónico  acid  in   Cosméticos [J].   Shandong    Chemical   Industria,2018, 47(18):52 × 54,56.

[61]XU H Y, WANG H Y, XIAO X H, et al. Aplicación de ácido hialurónico en pasta dentífrica [J]. Industria de productos para el cuidado Oral,2020,30(6):13−17.

[62] YANG W, CHEN Z H, YI Z Y, et al. El efecto de Inyección intraarticular de ácido hialurónico y placebo en el treat-  ment  de and  En el estadio intermedio La rodilla rodilla. Osteoartritis: A  meta-análisis  Con base en ensayos aleatori, doble ciego, controlados y clínicos [J].  Chinese Tissue Engineering Research,2021,25(23):3760 × 3766.

[63]LIU L T, WU L, ZENG D L, et al. El progreso de la aplicación del ácido hialurónico en la inyección [J]. Journal of Practical Dermatology,2020,13(6):352−355.

[64]MA Y, PENG P, ZHAO Q. efecto de aplicación  Y seguridad del spray de ácido hialurónico en la reparación cutánea de pacientes después de cirugía facial con láser [J]. Investigación y práctica clínica médica,2020, 5(36):175 × 177.

[65]YU H L. Clinical observación of  0,3% sodium  hyaluronate  en Con pranoprofeno en el tratamiento de ojo seco [J]. Electronic Journal of Clinical Medicine,2019,6(60):71.

[66]HU L J, LIU F L, LI L C, et al. Síntesis de  Derivados del ácido hialurónico anfifílico y su aplicación en la administración de nanofármacos antitumorales [J]. Avances en el sector farmacéutico  Sciences,2017,41(11):804 × 811.