Nisin loaded carbopol gel against Pseudomonas aeruginosa infected third-degree burns: A therapeutic intervention

Bacterial nanocellulose loaded with bromelain and nisin as a promising bioactive material for wound debridement

The bacterial nanocellulose (BnC) membranes were produced extracellularly by a novel aerobic acetic acid bacterium Komagataeibacter melomenusus. The BnC was modified in situ by adding carboxymethyl cellulose (CMC) into the culture media, obtaining a BnC-CMC product with denser fibril arrangement, improved rehydration ratio and elasticity in comparison to BnC. The proteolytic enzyme bromelain (Br) and antimicrobial peptide nisin (N) were immobilized to BnC matrix by ex situ covalent binding and/or adsorption. The optimal Br immobilization conditions towards the maximized specific proteolytic activity were investigated by response surface methodology as factor variables. At optimal conditions, i.e., 8.8 mg/mL CMC and 10 mg/mL Br, hyperactivation of the enzyme was achieved, leading to the specific proteolytic activity of 2.3 U/mg and immobilization efficiency of 39.1 %. The antimicrobial activity was observed against Gram-positive bacteria (S. epidermidis, S. aureus and E. faecalis) for membranes with immobilized N and was superior when in situ modified BnC membranes were used. N immobilized on the BnC or BnC-CMC membranes was cytocompatible and did not cause changes in normal human dermal fibroblast cell morphology. BnC membranes perform as an efficient carrier for Br or N immobilization, holding promise in wound debridement and providing antimicrobial action against Gram-positive bacteria, respectively.

Kinetics of Inflammatory Mediators in the Immune Response to Burn Injury: Systematic Review and Meta-Analysis of Animal Studies

Burns are often accompanied by a dysfunctional immune response, which can lead to systemic inflammation, shock, and excessive scarring. The objective of this study was to provide insight into inflammatory pathways associated with burn-related complications. Because detailed information on the various inflammatory mediators is scattered over individual studies, we systematically reviewed animal experimental data for all reported inflammatory mediators. Meta-analyses of 352 studies revealed a strong increase in cytokines, chemokines, and growth factors, particularly 19 mediators in blood and 12 in burn tissue. Temporal kinetics showed long-lasting surges of proinflammatory cytokines in blood and burn tissue. Significant time-dependent effects were seen for IL-1β, IL-6, TGF-β1, and CCL2. The response of anti-inflammatory mediators was limited. Burn technique had a profound impact on systemic response levels. Large burn size and scalds further increased systemic, but not local inflammation. Animal characteristics greatly affected inflammation, for example, IL-1β, IL-6, and TNF-α levels were highest in young, male rats. Time-dependent effects and dissimilarities in response demonstrate the importance of appropriate study design. Collectively, this review presents a general overview of the burn-induced immune response exposing inflammatory pathways that could be targeted through immunotherapy for burn patients and provides guidance for experimental set-ups to advance burn research.

Organogel mediated co-delivery of nisin and 5-fluorouracil: a synergistic approach against skin cancer

AIM

The present study aimed to develop topical combinatorial therapy of nisin and 5-fluorouracil in a single nanosized formulation against skin cancer.

METHODS

Nisin and 5-fluorouracil were encapsulated in an organogel system (NF-OG) and investigated for morphology, physicochemical properties, cytotoxicity, encapsulation and release. NF-OG was evaluated against DMBA/TPA murine skin cancer in terms of tumour statistics, histoarchitecture, TUNEL and M1/M2 macrophages.

RESULTS

The optimised NF-OG formulation exhibited particle size of 185.1 ± 11.24 nm, zeta potential of -7.93 ± 0.60 mV, offered substantial drug loading and temporal release. NF-OG therapy led to improved cytotoxicity of nisin and 5-FU against B16-F10 cells, significant decrease in tumour volume (84.983 mm³) in treated group as compared to untreated group (490.482 mm³) accompanied by restoration of histoarchitecture and repolarization of macrophages.

CONCLUSION

The study yielded a promising delivery system exhibiting potent anticancer activity and forms the bases for further applications in clinical settings.