Effect of topical bovine colostrum in wound healing of corneal surface after acute ocular alkali burn in mice

Cannabidiol-loaded hydrogel contact lenses for on-demand pH regulation and enhanced corneal alkali burn repair

Corneal alkali burn (CAB) poses a significant therapeutic challenge due to alkali infiltration, bacterial infection, inflammation, and angiogenesis, which collectively hinder recovery. The pH microenvironment after CAB is critical for the healing process, but there are few functional biomaterials for this purpose at present. Herein, we develop a multifunctional hydrogel contact lens (CL) with on-demand release of citric acid (CA) and cannabinoid (CBD), triggered by alkaline conditions, to regulate the microenvironment pH and enhance CAB repair. The CA-functionalized polyvinyl alcohol (PC) and quaternary ammonium chitosan (QCS) are used as hydrogel frameworks, with CBD incorporated as a functional component. The (CBD/QCS/PC, CBD/QPC) hydrogel CL is fabricated using a repeated freeze-thaw process to achieve an interpenetrating network structure. The findings suggest that the 1CBD/QPC hydrogel CL exhibit superior mechanical properties and biocompatibility (hemolysis rate < 0.6 %, cell viability>90 %). These properties enhance wearing comfort and reducing secondary inflammation. Notably, this hydrogel can release CA (52.23 ± 2.78 %) and CBD (59.24 ± 5.15 %) within 24 h under alkaline conditions to neutralize pH, significantly down-regulate the expression level of inflammatory factors and remove hydroxyl radicals. This mechanism fundamentally addressing the secondary damage of residual lye following CAB. Moreover, the hydrogel CL exhibit potent inhibitory effects on the colonization and growth of both E. coli and S. aureus by destroying bacterial membranes, with an inhibition rate > 90 %. In vivo results show that hydrogel CL promote the repair of CAB through anti-inflammatory effects and angiogenesis inhibition. In conclusion, these results demonstrate the potential of this hydrogel CL for treating corneal alkaline burns, providing new insights into treatment of CAB.

Anti-inflammatory and Restorative effects of milk exosomes and Dexamethasone-Loaded exosomes in a corneal alkali burn model

Corneal alkali burn is a common and challenging ocular trauma, necessitating the use of dexamethasone (DXMS) as a therapeutic agent. However, prolonged and frequent administration of this drug can lead to undesirable side effects, limiting its clinical application. This study aimed to investigate the role and mechanism of action of exosomes as drug carriers in corneal alkali burn repair. We employed centrifugation to isolate milk exosomes (EXO) as nanocarriers. We observed that EXO enhanced the activity and migration of corneal epithelial cells, expediting the repair process following corneal injury. Additionally, a nano-drug delivery model (DXMS@EXO) was designed using ultrasound to load DXMS into exosomes, thus enabling targeted delivery to inflammatory cells and enhancing drug efficacy. DXMS@EXO inhibited the inflammatory processes in the corneal alkali burn model by modulating the classical Wnt signaling pathway, thereby promoting corneal re-epithelialization and wound healing and accelerating the repair process of corneal alkali burn. Neither EXO nor DXMS@EXO exhibited significant side effects during the course of treatment. This study highlighted the substantial potential of EXO and DXMS@EXO in improving drug efficacy and facilitating the repair of corneal alkali burn.

Exploring the potential of bovine colostrum as a bioactive agent in human tissue regeneration: A comprehensive analysis of mechanisms of action and challenges to be overcome

The study examines bovine colostrum as a potent source of bioactive compounds, particularly growth factors, for tissue regeneration in humans. While previous research has hinted at therapeutic benefits, a comprehensive understanding of its mechanisms remains elusive, necessitating further investigation. This review analyzes nine selected scientific articles on bovine colostrum's bioactive potential in tissue regeneration. In vitro studies highlight its positive impact on cell behavior, including reduced proliferation and induced differentiation. Notably, optimal concentrations and specific colostrum components, such as extracellular vesicles and insoluble milk fat, show more favorable outcomes. In vivo studies underscore bovine colostrum as a promising natural resource for wound healing, despite some studies failing to identify associated benefits. Further research is crucial to unravel the intricate mechanisms, grasp the full potential in regenerative medicine, and develop more effective wound healing therapies. This refined understanding will pave the way for harnessing the complete regenerative potential of bovine colostrum in clinical applications.

TFOS lifestyle: Impact of societal challenges on the ocular surface

Societal factors associated with ocular surface diseases were mapped using a framework to characterize the relationship between the individual, their health and environment. The impact of the COVID-19 pandemic and mitigating factors on ocular surface diseases were considered in a systematic review. Age and sex effects were generally well-characterized for inflammatory, infectious, autoimmune and trauma-related conditions. Sex and gender, through biological, socio-economic, and cultural factors impact the prevalence and severity of disease, access to, and use of, care. Genetic factors, race, smoking and co-morbidities are generally well characterized, with interdependencies with geographical, employment and socioeconomic factors. Living and working conditions include employment, education, water and sanitation, poverty and socioeconomic class. Employment type and hobbies are associated with eye trauma and burns. Regional, global socio-economic, cultural and environmental conditions, include remoteness, geography, seasonality, availability of and access to services. Violence associated with war, acid attacks and domestic violence are associated with traumatic injuries. The impacts of conflict, pandemic and climate are exacerbated by decreased food security, access to health services and workers. Digital technology can impact diseases through physical and mental health effects and access to health information and services. The COVID-19 pandemic and related mitigating strategies are mostly associated with an increased risk of developing new or worsening existing ocular surface diseases. Societal factors impact the type and severity of ocular surface diseases, although there is considerable interdependence between factors. The overlay of the digital environment, natural disasters, conflict and the pandemic have modified access to services in some regions.

A simple but novel glycymicelle ophthalmic solution based on two approved drugs empagliflozin and glycyrrhizin: in vitro/in vivo experimental evaluation for the treatment of corneal alkali burns

A simple but novel ophthalmic solution based on two approved drugs was developed to reposition existing drugs to treat new diseases. This nanoformulation was developed using the phytochemical drug glycyrrhizin as an amphiphilic nanocarrier to micellarly solubilize empagliflozin (EMP), an oral drug that is widely used to control high blood glucose but has poor water solubility. This novel nanoformulation, which we designated the EMP@glycymicelle ophthalmic solution, was obtained using a simple preparation process. The resulting solution was a clear solution with an EMP encapsulation efficiency of 97.91 ± 0.50%, a small glycymicelle size of 6.659 ± 0.196 nm, and a narrow polydispersity index of 0.226 ± 0.059. The optimized formulation demonstrated that EMP was soluble in water up to 18 mg ml^-1 because of its encapsulation within glycymicelles. The EMP@glycymicelle ophthalmic solution exhibited excellent characteristics, including good storage stability, fast in vitro release profiles, improved in vitro antioxidant activity, and no ocular irritation. Ocular permeation evaluation showed that the EMP@glycymicelle ophthalmic solution had strong ocular permeation of EMP, and it reached the posterior segment of mouse eyes after ocular topical administration. The treatment efficacy evaluation showed that the EMP@glycymicelle ophthalmic solution had a significant effect against corneal alkali burns in mice, prompting corneal wound healing, recovering corneal sensitivity, reducing corneal haze, and relieving corneal NV invasion. The mechanism of inhibiting HMGB1 signaling was involved in this strong treatment effect. These results indicated that the EMP@glycymicelle ophthalmic solution provided a new concept of drug repurposing and a promising ocular system for the nano-delivery of EMP with significantly improved in vivo profiles.

Epidemiological features and management of eye burn patients in Wuxi, China

Background

The current study aimed to analyse epidemiological data on eye burns in Wuxi, China, for the years 2015–2021, and to provide insight into the development of appropriate prevention strategies.

Methods

A retrospective study was conducted on 151 hospitalised patients with eye burns. Data collected included gender, age, the monthly distribution of incidence, cause of eye burn, the site of eye burn, the type of surgery, visual outcome, the length of hospital stay and the cost of hospital admission. Statistical analysis was performed using SPSS V.19.0 and Graph Pad Prism V.9.0.

Results

In a total of 151 eye burn patients, 130 were males (86.09%) and 21 were females (13.91%). The proportion of patients classified as grade III was the greatest (46.36%). The average age of our hospitalised patients with eye burns was 43.72 years and the average length of hospital stay was 17 days. The number of injuries was highest in September (14.6%). Among eye burn patients, workers and farmers became the most common occupations (62.91%, 12.58%). The most frequent cause of burns was alkali burns (19.21%), followed by acid burns (16.56%). When admitted to the hospital, patients’ average vision was 0.06, and 49% of them had a poor vision (<0.3, ≥0.05).

Conclusion

With an investigation of 7-year hospitalisation data, the current study provided a fundamental reference for epidemiological features and management of eye burns in Wuxi, China, which could contribute to the development of treatment and prevention strategies.

CXCR3 deletion aggravates corneal neovascularization in a corneal alkali-burn model

Corneal neovascularization can cause devastating consequences including vision impairment and even blindness. Corneal inflammation is a crucial factor for the induction of corneal neovascularization. Current anti-inflammatory approaches are of limited value with poor therapeutic effects. Therefore, there is an urgent need to develop new therapies that specifically modulate inflammatory pathways and inhibit neovascularization in the cornea. The interaction of chemokines and their receptors plays a key role in regulating leukocyte migration during inflammatory response. CXCR3 is essential for mediating the recruitment of activated T cells and microglia/macrophages, but the role of CXCR3 in the initiation and promotion of corneal neovascularization remains unclear. Here, we showed that the expression of CXCL10 and CXCR3 was significantly increased in the cornea after alkali burn. Compared with WT mice, CXCR3-/- mice exhibited significantly increased corneal hemangiogenesis and lymphangiogenesis after alkali burn. In addition, exaggerated leukocyte infiltration and leukostasis, and elevated expression of inflammatory cytokines and angiogenic factor were also found in the corneas of CXCR3-/- mice subjected to alkali burn. With bone marrow (BM) transplantation, we further demonstrated that the deletion of CXCR3 in BM-derived leukocytes plays a key role in the acceleration of alkali burn-induced corneal neovascularization. Taken together, our results suggest that upregulation of CXCR3 does not exhibit its conventional action as a proinflammatory cytokine but instead serves as a self-protective mechanism for the modulation of inflammation and maintenance of corneal avascularity after corneal alkali burn.

Effect of Bovine Colostrum Dietary Supplementation on Rabbit Meat Quality

Bovine colostrum (BC) is rich in nutrients, antimicrobial, and antioxidant factors; for these reasons, it has been used as supplement in animal nutrition. However, its possible effects on meat quality have not been studied yet. Thirty-nine New Zealand White rabbits (n = 13/group) were assigned to three groups and fed until slaughter with a commercial standard diet, control group (C), and C supplemented with 2.5% and 5% (w/w) of BC (BC-2.5 and BC-5 groups, respectively). After slaughtering, the effect of dietary supplementation on microbiological and chemical characteristics of the rabbit loins was evaluated at 48 h postmortem (D0) and after 3 (D3) and 8 (D8) days of refrigerated storage. Results showed no difference in the microbiological parameters. In the supplemented groups, TBARS and TVBN values were lower and higher than in the C group, respectively (p < 0.01), and their fatty-acid profile was increased in SFA and decreased in MUFA (p < 0.05). In conclusion, research must continue to examine in depth the possible effects of BC byproduct reuse in animal nutrition on meat quality (e.g., antioxidant power, and physical and sensory characteristics).

Concentration-associated pathology of alkali burn in a mouse model using anterior segment optical coherence tomography with angiography

Pathological features of alkali concentration-associated burn were studied using non-invasive anterior segment optical coherence tomography (AS-OCT) and OCT angiography (OCTA). Alkali burn was induced in C57BL/6J mice (n = 20) by placing filter paper soaked in 0.1, 0.25, 0.5, and 1 M NaOH for 30s on the right eye (left eye control). Longitudinal imaging was performed with AS-OCT/OCTA and fluorescein angiography over 14 days, after which eyes were enucleated at 7 and 14 days for histology and immunofluorescence. Concentration-associated corneal swelling was maximal at 0.5M, increasing linearly in a concentration-dependent fashion at 0.1, 0.25, and 0.5 M NaOH, to levels of 50%, 100%, and 175% of control, respectively. At 0.1M, corneal swelling and surface erosions were prominent, while at 0.25M, deep tissue damage, limbal neovascularization, and stromal haze were evident at 7 days. At 0.5M and 1M, severe exacerbation of the corneal swelling, angle closure, Descemet's membrane detachment, hyphema, and profuse central neovascularization were noted as early as day 3, which further progressed to inflammation, fibrosis, and opacity by day 7. We conclude that alkali concentration-dependent burn intensity biomarkers can be assessed by non-invasive AS-OCT/OCTA, distinguishing between mild, moderate, and severe ocular injury, with potential relevance toward clinical utilization in human eyes.