The introduction of fish skin as a biological dressing for treating burns and wounds holds great promise, offering an alternative to existing management strategies. However, the risk of disease transmission is a significant concern. Therefore, this study aimed to examine how established sterilization and preservation procedures affected fish skin grafts' microbiological and histological properties for long-term usage. Lyophilization of the fish skin graft followed by rehydration in normal saline for 15 min did not change the collagen content. Furthermore, gamma irradiation of the lyophilized fish skin graft at different lengths 5, 10, and 25 KGy showed a significant reduction in microbial growth (aerobic bacteria, aerobic yeasts, and fungi) at 15- and 30 days after the irradiation. However, exposure to 10 KGy was found to be the most effective intensity among the different gamma irradiation lengths since it preserved the collagen fiber content and intensity in the lyophilized fish skin grafts at 15- and 30 days after the irradiation. These findings provide efficient preservation and sterilization methods for long-term usage of the fresh Tilapia skin grafts used for biological dressings.

Objective: This study’s aim was: (1) introduce the digital drying oven as a reproducible, controllable, and accurate heating device for burn model creation. (2) Define the heating temperature appropriate for developing consistent second and third-degree burn injuries in rats. Results: Burns appeared deeper with more distinct borders in groups (B) and (C) than in group (A). The stainless-steel rod at 100 ºC created burn injuries of the second degree, evidenced by the sloughing of the epidermis and necrosis in the epithelium and upper part of the dermis. Heating at 150 and 200 ºC created third-degree burn injuries, where necrosis involved the epidermis and dermis and extended to the subcutaneous fat and muscles. The depth of the burn wound in the group (B) (371.2 ± 41.3 μm) and (C) (385.2 ± 38.0 μm) was significantly deeper compared with the group (A) (178 ± 46.6 μm) (P < 0.001). The digital drying oven is a reliable, reproducible, and controllable heating device for creating burn models. The stainless-steel rod (63 g and 8 mm) heated at 100 and 150 ºC with a contact time of 30 s is adequate for creating consistent second and third-degree burn injuries in rats, respectively.

This study examines the histological, ultrastructural, and immunohistochemical features of the lip skin of the goldfish (Carassius auratus, Linnaeus, 1758), a sensory-rich region that plays an essential role in feeding and environmental perception. Our findings highlight the coexistence and close association of immune, epithelial, and sensory cells within the epidermis and dermis. For the first time in goldfish, intraepidermal macrophages, eosinophilic granular cells, rodlet cells, Merkel cells, and several specialized sensory structures—neuromasts, taste buds, and tuberous-like sensory units—were simultaneously identified within the same integumentary field. Quantitative morphometry demonstrated a high density of eosinophilic granular cells, rodlet cells, and neuromasts per unit epithelial area, reinforcing the functional specialization of the goldfish lip as a sensory–immune interface. Immunohistochemical markers (CK20, S100, CD68, CD64, CD117, and E-cadherin) were applied as complementary tools to describe phenotypic labeling patterns. These findings are interpreted cautiously as supportive evidence consistent with epithelial, neural-associated, stromal, and immune cell distributions observed morphologically. Transmission electron microscopy further uncovered fine structural details such as synapse-like contacts in taste buds and Merkel cells, dense-core granules in eosinophilic granular cells, and telocyte–nerve fiber associations in the dermis. By integrating cellular, structural, and immunohistochemical perspectives, this study provides a novel descriptive reference for the goldfish lip skin as a region characterized by the close spatial association of sensory and immune-related elements, underscoring its value as a model for vertebrate cutaneous biology and neuroimmunology.

Commercial tobramycin ophthalmic solution is frequently used empirically to treat ocular disorders in equines, despite being primarily formulated for use in humans. It has been noted that tobramycin MIC90 concentration (minimal inhibitory concentration to 90% of microbial growth) rapidly declined following topical administration. It is hypothesized that adjustment of the pH of the empirically used tobramycin ophthalmic solution -prepared for human use- with the pH of the tears of donkeys, could increase the bioavailability of the drug and subsequently improve its penetration to the aqueous humor. Therefore, this study aimed to evaluate the impact of pH adjustment of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus). The study was conducted on six (n = 6) clinically healthy donkeys. In each donkey, one eye was randomly selected to receive 210 µg tobramycin of the commercial tobramycin (CT) and used as a positive control (C group, n = 6). The other eye (treated eye) received 210 µg of the modified tobramycin ophthalmic solution (MT) (T group, n = 6). Tears and aqueous humor samples were collected 5-, 10-, 15-, 30- min, and 1-, 2-, 4-, and 6 h post-instillation. Modifying the pH of the empirically used commercial tobramycin ophthalmic solution in donkeys at a pH of 8.26 enhanced the drug’s bioavailability. The MIC90 of the most hazardous bacteria isolated from equines’ eyes such as Pseudomonas aeruginosa (MIC90 = 128 µg/ml) and Staphylococcus aureus (MIC90 = 256 µg/ml) was covered early (5 min post-instillation) and over a longer period in donkey tears (239–342 min) and aqueous humor (238–330 min) with the modified tobramycin solution. Adjustment of the pH of the commercial tobramycin ophthalmic solution, empirically used by veterinarians to treat donkeys’ ophthalmic infections at a pH of 8.26, isotonic with the donkeys’ tears pH, resulting in higher concentrations of tobramycin in tears and aqueous humor for a longer time.