Enhanced Cellular Cryopreservation by Biopolymer-Associated Suppression of RhoA/ROCK Signaling Pathway

With increasing demands on long-term storage of cells, cryopreservation of cells is gaining more importance in cell-based research and applications. Dimethyl sulfoxide (DMSO) is a commonly used chemical cryoprotectant, providing increased cell survival during the freezing process. However, its use is limited in clinical applications due to its low biocompatibility above cryogenic temperatures. Herein, we present a new approach for reducing the use of DMSO in cryopreservation by using biodegradable hyaluronic acids (HAs). By adding HAs into cryoprotectant media containing a low concentration of DMSO, higher cell viability and cell proliferation rate were observed upon thawing after cryopreservation. The HA-supplemented cryopreservation media did not reduce the size of the ice crystal, which significantly influenced cell viability during cell freezing, but decreased the Ras homolog family member A (RhoA)/Rho-associated protein kinase (ROCK) signaling pathway related to apoptosis. The cell-interactive cryoprotectants containing HA can be applied to the development of a new cryoprotectant that reduces the adverse effect of DMSO.

Prediction of hyaluronic acid target on sucrase-isomaltase (SI) with reverse docking and molecular dynamics simulations for inhibitors binding to SI

Auricularia cornea (E.) polysaccharide is an important component of A. cornea Ehrenb, a white mutant strain of Auricularia with biological activities, such as enhancement of human immune function and cancer prevention. The hyaluronic acids (HAs) are important components of the A. cornea polysaccharide and have extremely high medicinal value. In this study, we used HA to search the target protein sucrase-isomaltase (SI). In addition, we also performed molecular dynamics (MD) simulations to explore the binding of three inhibitors (HA, acarbose and kotalanol) to SI. The MD simulations indicated that the binding of the three inhibitors may induce the partial disappearance of α helix in residues 530–580. Hence, the hydrogen bond for Gly570-Asn572, which was near the catalytic base Asp471 in SI, was broken during the binding of the three inhibitors. We reveal a new inhibitor for SI and provide reasonable theoretical clues for inhibitor binding to SI.

Rheological Properties of Hyaluronic Acid Diluted Solutions as Components of Cosmetics

Rheological measurements were carried out on dilute aqueous solutions of high (HMW-HA, 1150 kDa) and low molecular weight hyaluronic acids (LMW-HA, 8 kDa) along with their mixtures to determine the relationship between the viscosity and concentration of the samples. Molecular weight and polydispersity of low molecular HA have been determined by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). HA diluted solutions were found to be weakly structured liquids with a slight viscosity anomaly. Critical values of concentration were determined at different ratios of HMW-HA and LMW-HA, leading to a sharp increase in the viscosity of solutions. Rheological studies have proved the pseudoplastic nature of the viscous flow of HMW-HA solutions. The possibility of using the Ostwald-de Waele equation for the mathematical description of a viscous flow was established. The results of the rheological analysis might be applied for the rational development of cosmetic formulations containing hyaluronic acid of various molecular weights.

Experimental therapy for rabbits with radiation cystitis

Using a new model of the induction of radiation cystitis (RC) in rabbits, the treatment effectiveness of animals with intravesical administration of a biodegradable drug - a gel containing salts of alginic and hyaluronic acids, as well as dioxidine and lidocaine (AHDL) was assessed. The work was performed on female rabbits of the “Chinchilla” breed. Fractional irradiation of the rabbit urinary bladder was carried out by a linear photon accelerator: a single dose per fraction was 6 Gy administered daily for 5 days to a total focal dose of 30 Gy. As a result of irradiation of the bladder, the animals developed RC. AHDL-gel was injected intravesically using a catheter at a dose of 2500 mg / kg of body weight 3 times a day weekly for 2 months, starting from 1 month after irradiation. The drug had a pronounced therapeutic effect on the rabbits with RC: the values ​​of clinical and laboratory indicators of cystitis in urea and blood were reduced, it was observed regression of morphological manifestations of inflammation in the bladder mucosa.

The development of hyaluronic acids used for skin tissue regeneration

: Burns, mechanical injuries, skin defects, poor wound healing and scars caused by chronic diseases are serious clinical issues that affect millions of people around the world. Hyaluronic acid (HA) is one of the main components of extracellular matrix, which is widely distributed in human body. Because of its unique physical and chemical properties and diversity of physiological functions, hyaluronic acid is widely used in tissue engineering and regenerative medicine. This paper reviews the application of HA and HA based scaffolds in the regeneration and repair of skin tissue, as well as the application of HA in the fields of skin filler, wound healing, beauty, etc.