Background/Objectives: Efficient wound treatment embraces the management of four overlapping phases, starting with hemostasis, an immediate physiological response aimed at stopping bleeding from damaged blood vessels caused by skin injury. This paper proposes an innovative, nature-based hemostatic biomaterial designed to assist natural self-healing regenerative mechanisms. Methods: Light, transparent, and skin-adhesive films based on κ-carrageenan, meadow polyfloral honey, and Calendula officinalis flower extract were fabricated via solution casting. Comprehensive characterization revealed the physicochemical, structural, swelling, and barrier properties and the influence of each bioactive compound utilized for film preparation. Results: The samples subcutaneously implanted in Wistar rats induced vascularization, deposition of collagen, and orientation of collagen fibers while being fully phagocytosed and gradually biodegraded. The rat tail-cut model demonstrated that the films significantly reduced blood loss (0.1875 ± 0.0732 g) compared to the control (0.7837 ± 0.3319 g), and hemostasis was achieved notably faster (355.75 ± 71.42 s) than in the control group (704.25 ± 85.29 s). The rat liver punch biopsy model confirmed reduced blood loss (2.8025 ± 1.5174 g) and shorter time to hemostasis (303.25 ± 77.90 s) compared to the control (3.1475 ± 1.5413 g, 383.00 ± 36.53 s). Conclusions: The results indicate the great potential of the fabricated films as hemostatic wound dressings.

Scar formation and delayed wound healing pose significant challenges in treating skin injuries, especially in severe cases like burns and diabetic wounds. This study investigates the effectiveness of novel Poly(vinyl alcohol) (PVA)/Gentamicin (Gent) and PVA/Chitosan (CHI)/Gent hydrogels in promoting healing of second-degree burn wounds in a rat model. Following in vitro testing, these hydrogels were deemed non-toxic and suitable for in vivo analysis. Clinical evaluations were conducted on the 3rd, 7th, 14th, and 21st post-injury days, assessing parameters such as blistering, edema, redness, crust, bleeding, secretion, scar tissue formation, and wound contraction percentage. Histological analyses focused on re-epithelization and dermal evaluation at specific time points. Results showed that both hydrogels significantly reduced inflammation, particularly redness, by the 14th day and improved re-epithelization, with the PVA/CHI/Gent group outperforming on the 14th day and the PVA/Gent group excelling on the 21st day. Histological findings indicated increased fibroblast proliferation and collagen deposition in treated groups, suggesting enhanced dermal healing. The PVA/CHI/Gent hydrogel demonstrated notable antibacterial properties, likely due to the synergistic effects of CHI and Gent, leading to reduced inflammation and edema. Overall, both hydrogels show promise as effective wound dressings, facilitating faster healing and improved tissue recovery in burn injuries. This study supports the use of biomimetic scaffolds for enhanced wound management in clinical practices.

The ethical dilemmas of using animals as in vivo models in preclinical and clinical examinations have been increasingly present in recent decades. Small laboratory animals (rats, rabbits) will continue to be used because they are cost-effective and permit the formation of statistically testable cohort groups; a task that, for financial, maintenance and care reasons, is almost prohibitive for larger animals. Technological advances in the production of new biomaterials for clinical use are enormous, but screening tests and methods used to assess biocompatibility lag behind these advances. The assessment of biological responses is slow and based on millennial recovery mechanisms in eukaryotic organisms. Therefore, the goal of researchers in this field is to re-evaluate old methods of biocompatibility assessment and introduce new methods of evaluation, especially for in vivo testing. In that sense, a revision of the ISO standards was planned and conducted in 2017, which insisted on cytotoxicity testing in cell lines and produced concrete proposals on how biocompatibility should be quantified. In vivo biocompatibility evaluation of biomaterials used for soft tissue recovery commonly utilises rats. Rabbits are recommended for implants used for hard tissues, because of the rabbit?s size, the possibility of implanting the biomaterials on a larger bone surface, and because of the peculiarities of rabbit bone tissue that favours rapid recovery after bone defects and enables easy reading of the results

In regenerative bone tissue medicine, combining artificial bone substitutes with progenitor cells is a prospective approach. Surface modification via cold atmospheric plasma (CAP) enhances biomaterial–cell interactions, which are crucial for successful bone regeneration. Using a rabbit calvarial critical-size defect model, we assessed the use of CAP-pretreated beta-tricalcium phosphate (β-TCP), alone or with periodontal ligament stem cells (PDLSCs), for bone regeneration. Histological and histomorphometric analyses at two and four weeks revealed significantly improved bone regeneration and reduced inflammation in the CAP-treated β-TCP with PDLSCs compared to β-TCP alone. Immunohistochemical analysis also showed an increase in the bone healing markers, including bone morphogenic proteins 2 and 4, runt-related transcription factor 2, collagen-1, and osteonectin, after two and four weeks in the CAP-treated β-TCP implants with PDLSC. This in vivo study demonstrates for the first time the superior bone regenerative capacity of CAP-pretreated β-TCP seeded with PDLSCs, highlighting the therapeutic potential of this combined approach in osteoregeneration.

Scar formation and delayed wound healing pose significant challenges in treating skin injuries, especially in severe cases like burns and diabetic wounds. This study investigates the effectiveness of novel Poly(vinyl alcohol) (PVA) / Gentamicin (Gent) and PVA / Chitosan (CHI) / Gent hydrogels in promoting healing of second-degree burn wounds in a rat model. Following in vitro testing, these hydrogels were deemed non-toxic and suitable for in vivo analysis. Clinical evaluations were conducted on 3rd, 7th, 14th and 21st post-injury day, assessing parameters such as blistering, edema, redness, crust, bleeding, secretion, scar tissue formation, and wound contraction percentage. Histological analyses focused on re-epithelization and dermal evaluation at specific time points. Results showed that both hydrogels significantly reduced inflammation, particularly redness, by the 14th day, and improved re-epithelization, with the PVA/CHI/Gent group outperforming on the 14th day and the PVA/Gent group excelling at the 21st day. Histological findings indicated increased fibroblast proliferation and collagen deposition in treated groups, suggesting enhanced dermal healing. The PVA/CHI/Gent hydrogel demonstrated notable antibacterial properties, likely due to the synergistic effects of CHI and Gent, leading to reduced inflammation and edema. Overall, both hydrogels show promise as effective wound dressings, facilitating faster healing and improved tissue recovery in burn injuries. This study supports the use of biomimetic scaffolds for enhanced wound management in clinical practices.

Novel poly (vinyl alcohol) (PVA)/gentamicin (Gent) and PVA/chitosan (CHI)/Gent hydrogels have previously demonstrated improved burn wound healing in a rat model, based on clinical assessment and histological analysis. This study aims to provide immunohistochemical insight into the effects of PVA/Gent and PVA/CHI/Gent on burn wound healing by analyzing markers of macrophage presence (CD68), angiogenesis (VEGF and ESM1), proliferation (Ki-67), and apoptosis (TUNEL) on post-burn days 3, 7, 14 and 21. Both hydrogels increased macrophage presence, with PVA/CHI/Gent producing earlier effects. Angiogenesis was more pronounced in the PVA/CHI/Gent-treated group, in terms of both the number of VEGF⁺ cells and the relative density of blood vessels (ESM1), while PVA/Gent generally exceeded the control values without significant differences. On day 21, macrophage presence and angiogenesis were reduced in the treated groups, with significantly higher values in the control group. Proliferation was greater in the treated groups during the early healing phase (on days 3 and 7), whereas it was predominant in the control group during the later stages (on days 14 and 21). Conversely, apoptosis was predominant in the control group at the first three time points; however, by day 21, it was more pronounced in the treated groups, particularly in the PVA/CHI/Gent-treated group. Overall, both hydrogels showed similar temporal cellular and tissue responses, but PVA/CHI/Gent induced earlier and more sustained effects and demonstrated superior pro-angiogenic activity.