Preparation and Properties of the Sodium Hyaluronate Composite Hydrogel for Medical Cosmetology

As society advances, an increasing number of people are focusing on the antiaging process of the body and seeking ways to maintain youthful facial features. Intradermal injection has been used to effectively improve the rough and wrinkled skin, playing a role in skin rejuvenation. However, the main component of intradermal injection products is cross-linked sodium hyaluronate (SHA), which has biological toxicity and potential carcinogenicity. In this study, amino acids were used as hyaluronidase inhibitors and combined with non-cross-linked SHA to prepare a synergically stable SHA composite hydrogel. The effects of amino acids on the viscosity and enzyme activity of the hydrogel were investigated. To determine the stability and antioxidant properties of the composite hydrogel, the effects of the introduction of stabilizer and antioxidant on the hydrogel properties were systematically studied. The results of the <i>in vitro</i> study showed that the introduction of amino acids effectively reduced the activity of hyaluronidase, addressing the problem of rapid hydrolysis and the short half-life of SHA hydrogel <i>in vivo</i>. In addition, the results revealed that NaCl stabilizer, niacinamide, and vitamin B12 antioxidants effectively maintained the stability and antioxidant properties of the hydrogels. <i>In vivo</i> results showed that SHA composite hydrogels had no irritating effect on the skin, and the subcutaneous experiments of mice showed that SHA composite hydrogel still retained a high content after 4 weeks. Therefore, the SHA composite hydrogels have promising applications in the field of medical cosmetology.