Inclusion of drugs in liposomes offers the potential for localized and sustained delivery to mucosal surfaces. The inclusion of the carrageenan matrix with echinochrome A ((Ech)—the active substance of the drug Histochrome) in liposomes was studied. According to the spectral characteristics, Ech was not oxidized and retained stability after encapsulation in the liposomes and the lyophilization process. Loading the liposomes with negatively charged polysaccharide results in the increase in the zeta potential to more negative values (from −14.6 to −24.4 mV), that together with an increasing in the sizes of liposomes (from 125.6 ± 2.5 nm to 159.3 ± 5.8 nm) propose of the formation of the polymer coating on liposomes. The interactions of liposomes with porcine stomach mucin was determined by the DLS and SEM methods. The changes in the zeta-potential and size of the mucin particles were observed as the result of the interaction of liposomes with mucin. To evaluate the mucoadhesive properties of liposomes and the penetration of Ech in the mucosa, a fresh-frozen inner surface of the small intestine of a pig as a model of mucous tissue was used. Polysaccharide-coated liposomes exhibit very good mucoadhesive properties −50% of Ech remains on the mucosa.

Screening for chitinolytic activity in the bacterial strains from different Pacific Ocean regions revealed that the highly active representatives belong to the genera Microbulbifer, Vibrio, Aquimarina, and Pseudoalteromonas. The widely distributed chitinolytic species was Microbulbifer isolated from the sea urchin Strongylocentrotus intermedius. Among seventeen isolates with confirmed chitinolytic activity, only the type strain P. flavipulchra KMM 3630^T and the strains of putatively new species Pseudoalteromonas sp. B530 and Vibrio sp. Sgm 5, isolated from sea water (Vietnam mollusc farm) and the sea urchin S. intermedius (Peter the Great Gulf, the Sea of Japan), significantly suppressed the hyphal growth of Aspergillus niger that is perspective for the biocontrol agents’ development. The results on chitinolytic activities and whole-genome sequencing of the strains under study, including agarolytic type strain Z. galactanivorans Dji^T, found the new functionally active chitinase structures and biotechnological potential.

Liposomal drug delivery systems are successfully used in various fields of medicine for external and systemic applications. Marine organisms contain biologically active substances that have a unique structure and exhibit a wide range of biological activities. Polysaccharide of red seaweed (carrageenan (CRG)), and water-insoluble sea urchin pigment (echinochrome (Ech)) interact with each other and form a stable complex. We included the CRG/Ech complex in liposomes for better permeability into cells. In our research, tetramethylrhodamine isothiocyanate TRITC-labeled CRG was synthesized to study the interaction of the complex encapsulated in liposomes with human epidermal keratinocytes (HaCaTs) widely used to expose the skin to a variety of substances. Using confocal microscopy, we found that liposomes were able to penetrate HaCaT cells with maximum efficiency within 24 h, and pre-incubation of keratinocytes with liposomes resulted in the delivery of the CRG/Ech complex into the cytoplasm. We investigated the anti-inflammatory effects of liposomes, including the lysosomal regulation, increased intracellular ROS levels, and increased NO synthesis in lipopolysaccharide (LPS)- or Escherichia coli (E. coli)-induced inflamed skin cells. Liposomes containing the CRG/Ech complex significantly reduced lysosomal activity by 26% in LPS-treated keratinocytes and decreased ROS levels in cells by 23% after LPS exposure. It was found that liposomes with the complex improved the migration of HaCaT keratinocytes incubated with high-dose LPS by 47%. The results of the work, taking into account the good permeability of liposomes into keratinocytes, as well as the anti-inflammatory effect on cells treated with LPS or E. coli, show the prospects of using liposomes containing the CRG/Ech complex as an anti-inflammatory agent in the fight against skin infections.

Sulfated polysaccharides, carrageenans (CRGs) derived from Chondrus armatus, were used as mucoadhesive matrices for incorporating the antiviral drug acyclovir (ACV). Through IR spectroscopy and quantum-chemical calculations, it was demonstrated that CRGs interact with ACV, forming complexes via intermolecular hydrogen bonding and coordination interactions, with an enthalpy of approximately 15–20 kcal/mol. The monomodal ζ-potential distribution observed in the CRG/ACV mixture confirmed the successful formation of this complex. The antiviral efficacy of the CRG/ACV complex was evaluated during the early stages of herpes simple virus (HSV-1) infection, focusing on its ability to inhibit the cytopathic effects of the virus on host cells. Notably, CRGs enhanced antiviral activity by allowing a reduction in the ACV dosage. Unlike ACV alone, the CRG complex exhibited a prophylactic effect, with therapeutic efficacy comparable to that of ACV. When incorporated into liposomes, the CRG/ACV complex displayed excellent mucoadhesive properties. This liposomal formulation demonstrated notable antiviral activity against infected cells with selective index (SI) 344 and a heightened prophylactic effect (SI 128) compared to the complex alone. Overall, these new antiviral compounds show promise in selectively inhibiting viral adsorption and replication processes without adversely affecting the host organism.