Due to their availability and environmental friendliness, alginate polymers are widely used in pharmaceuticals and cosmetics. The most common type of alginate is derived from seaweed and is used to develop topical dosage forms, among other things. However, variability in the seaweed material can lead to instability in the physicochemical parameters. Biotechnologically produced alginate minimizes this drawback through controlled synthesis. However, unlike algal alginates, the safety profile of such polymers has not been well studied. When developing dosage forms intended for wound surfaces, safety is of primary importance. In this study, we developed enzybiotic compositions based on bacterial alginate as an excipient and a novel recombinant modified endolysin, LysSi3-LK, as an antibacterial agent, and assessed their antibacterial properties and safety profile. The study included an in vitro evaluation of the activity spectrum, as well as the cytotoxicity and biocompatibility, of gel and hydrogel compositions. It was demonstrated that bacterial alginate is acceptable for the encapsulation of endolysin. It exhibited medium cytotoxic effects on the HaCaT cells, which were significantly reduced by the LysSi3-LK addition. The migration of cells was diminished following exposure to the gel and hydrogel formulations. However, an improvement in biocompatibility was observed in the cell proliferation assay.

Background/Objectives: Frequently, healthcare-associated and community-acquired skin and soft tissue infections develop in the context of the formation of persistent, multidrug-resistant polymicrobial consortia involving both Gram-negative and Gram-positive pathogens. Non-traditional antibacterials, in particular phage- and bacteria-derived lytic enzymes, are currently the focus of attention. However, in practice their action is not sufficient for a significant effect when used as monotherapy. Here, we propose an enzyme combination approach to obtain an effective antimicrobial composition and to enhance the efficacy of enzyme-based therapy. Methods: The enzymes individual antibacterial properties and the effects of the compositions were assessed in vitro. In vivo evaluation of a combined enzymes preparation was assessed in murine wound infection against polymicrobial biofilm containing Pseudomonas aeruginosa and Staphylococcus aureus. Results: Significant synergy or additive effects of lysins combinations were shown for S. aureus strains, while indifferent or additive effect – for Gram-negative species. Treatment of mixed biofilm-colonized wounds in an animal model showed that the combination halted the chronic process and systematization of infection and promoted accelerated tissue regeneration at the wound site. Conclusions: The combinations of peptidoglycan hydrolases with different substrate specificities can significantly increase the efficacy of the composition against Gram-positive and Gram-negative bacteria resulting in improved in vitro and in vivo antibacterial properties and has a potential to treat polymicrobial infections.