Design, Synthesis, Characterization, and In Vitro Evaluation of a New Cross-Linked Hyaluronic Acid for Pharmaceutical and Cosmetic Applications

A structure-functionality insight into the bioactivity of microbial polysaccharides toward biomedical applications: A review

Microbial polysaccharides (MPs) are biopolymers secreted by microorganisms such as bacteria and fungi during their metabolic processes. Compared to polysaccharides derived from plants and animals, MPs have advantages such as wide sources, high production efficiency, and less susceptibility to natural environmental influences. The most attractive feature of MPs lies in their diverse biological activities, such as antioxidative, anti-tumor, antibacterial, and immunomodulatory activities, which have demonstrated immense potential for applications in functional foods, cosmetics, and biomedicine. These bioactivities are precisely regulated by their sophisticated molecular structure. However, the mechanisms underlying this precise regulation are not yet fully understood and continue to evolve. This article presents a comprehensive review of the most representative species of MPs, including their fermentation and purification processes and their biomedical applications in recent years. In particular, this work presents an in-depth analysis into the structure-activity relationships of MPs across multiple molecular levels. Additionally, this review discusses the challenges and prospects of investigating the structure-activity relationships, providing valuable insights into the broad and high-value utilization of MPs.

Advances in hyaluronic acid production: Biosynthesis and genetic engineering strategies based on Streptococcus - A review

Hyaluronic acid (HA), which is a highly versatile glycosaminoglycan, is widely applied across the fields of food, cosmetics, and pharmaceuticals. It is primary produced through Streptococcus fermentation, but the product presents inherent challenges concerning consistency and potential pathogenicity. However, recent strides in molecular biology have paved the way for genetic engineering, which facilitates the creation of high-yield, nonpathogenic strains adept at synthesizing HA with specific molecular weights. This comprehensive review extensively explores the molecular biology underpinning pivotal HA synthase genes, which elucidates the intricate mechanisms governing HA synthesis. Moreover, it delineates various strategies employed in engineering HA-producing strains.

Concentrated Growth Factor (CGF): The Newest Platelet Concentrate and Its Application in Nasal Hyaluronic Acid Injection Complications

BACKGROUND

Several cases of wounds caused by vascular compromise after facial cosmetic injection have been reported in recent years. How to promote wound healing, restore facial appearance, and avoid secondary injury in such patients have remained a clinical challenge. Our study was designed to assess the effect of concentrated growth factor (CGF) for repairing nasal wounds after nasal hyaluronic acid injection.

METHODS

Six women with nasal wounds after hyaluronic acid injection were enrolled from June 2019 to June 2022. The average time of the first CGF treatment from admission was 2-4 days. CGF gel was prepared from each patient's blood by using a Medifuge™ system. After debridement of the wound, the prepared CGF gel was applied on the wound surface, and the wound dressing was fixed to stabilize the CGF gel. The CGF treatment interval was 3-4 days.

RESULTS

The wound began to heal after the first CGF treatment. After 2-3 CGF treatments, the wound was almost completely healed. There was no deflection of the nasal columella, and nasal ventilation function was good. There was no obvious deformity in the appearance of the nose. After follow-up ranging from 2 months to 1 year, the appearance and function of the nose showed satisfactory recovery.

CONCLUSIONS

CGF has great potential in promoting wound healing and restoring the appearance after complications from nasal hyaluronic acid injection. The preparation of CGF gel is simple, and the clinical application is convenient and safe. In future, more clinical trials are needed to further prove the efficacy and safety of CGF in the treatment of wounds secondary to cosmetic injection.

LEVEL OF EVIDENCE IV

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A Safe-by-Design Approach for the Synthesis of a Novel Cross-Linked Hyaluronic Acid with Improved Biological and Physical Properties

Hyaluronic acid (HA) is a polymer with unique biological properties that has gained in interest over the years, with applications in pharmaceutical, cosmetic, and biomedical fields; however, its widespread use has been limited by its short half-life. Therefore, a new cross-linked hyaluronic acid was designed and characterized using a natural and safe cross-linking agent, such as arginine methyl ester, which provided improved resistance to enzymatic action, as compared to the corresponding linear polymer. The antibacterial profile of the new derivative was shown to be effective against S. aureus and P. acnes, making it a promising candidate for use in cosmetic formulations and skin applications. Its effect on S. pneumoniae, combined with its excellent tolerability profile on lung cells, also makes this new product suitable for applications involving the respiratory tract.

Silica Hydrogels as Platform for Delivery of Hyaluronic Acid

Hyaluronic acid (HA) is chondroprotective and anti-inflammatory drug used clinically for treatment of inflammatory disorders (arthritis, skin diseases, bowel diseases, etc.). In addition, HA is a crucial ingredient in the cosmetic products used to eliminate the unpleasant consequences of inflammatory skin diseases. The main disadvantages that limit its use are its low mechanical properties and its rapid biodegradation. In this paper, silica hydrogels are considered as a promising matrix for HA to improve its properties. The hybrid HA-silica hydrogels were synthesized by the sol-gel method. Morphology of the hydrogels was investigated by optical microscopy and scanning electron microscopy methods. Taking into account their potential applications for topical and injectable delivery, much attention was paid to investigation of deformation properties of the hydrogels under shear, compression, and tension. Their resistance to enzymatic degradation in vitro was estimated. Kinetics and mechanisms of HA release from the hybrid hydrogels in vitro were also studied. It was found that the indicated properties can be controlled by synthesis conditions, HA molecular weight, and its loading in the hydrogels. Silica hydrogels are a prospective platform for the development of new soft formulations and cosmetic compositions of HA with improved pharmacological and consumer properties.

Synthesis, Characterization and In Vitro Evaluation of Chitosan Nanoparticles Physically Admixed with Lactose Microspheres for Pulmonary Delivery of Montelukast

This study aimed to synthesise montelukast-loaded polymeric nanoparticles via the ionic gelation method using chitosan as a natural polymer and tripolyphosphate as a crosslinking agent. Tween 80, hyaluronic acid and leucine were added to modify the physicochemical properties of nanoparticles, reduce the nanoparticles’ uptake by alveolar macrophages and improve powder aerosolisation, respectively. The nanoparticles ranged from 220 nm to 383 nm with a polydispersity index of ≤0.50. The zeta potential of nanoparticles ranged from 11 mV to 22 mV, with a drug association efficiency of 46–86%. The simple chitosan nanoparticles (F2) were more spherical in comparison to other formulations (F4–F6), while the roughness of hyaluronic acid (F5) and leucine (F6) added formulations was significantly high er than F2 and Tween 80 added formulation (F4). The DSC and FTIR analysis depict that the physical and chemical properties of the drug were preserved. The release of the drugs from nanoparticles was more sustained in the case of F5 and F6 when compared to F2 and F4 due to the additional coating of hyaluronic acid and leucine. The nanoparticles were amorphous and cohesive and prone to exhalation due to their small size. Therefore, nanoparticles were admixed with lactose microspheres to reduce particle agglomeration and improve powder dispersion from a dry powder inhaler (DPI). The DPI formulations achieved a dispersed fraction of 75 to 90%, a mass median aerodynamic diameter (MMAD) of 1–2 µm and a fine particle fraction (FPF) of 28–83% when evaluated using the Anderson cascade impactor from Handihaler®. Overall, the montelukast-loaded nanoparticles physically admixed with lactose microspheres achieved optimum deposition in the deep lung for potential application in asthmatic patients.