Analysis of the Cicatricial Acceleration Method (MAC®) in Skin Repair in Wistar Rattus norvegicus with Induced Chemical Burns

Introduction: The cicatricial acceleration method (MAC®) promotes photobiological effects of an anti-inflammatory and healing nature. Its therapeutic radiation is emitted, producing photobiostimulant effects that result in rapid tissue repair and better tissue quality. The treatment of burns has always been a challenge, which involves both performing surgery and controlling and guiding scar regeneration, avoiding possible morbidities. Objective: To evaluate the effects of applying the MAC methodology with an AlGa (aluminum, gallium arsenide) laser on the time and quality of tissue repair in the skin of rats after induced chemical burns. Method: 22 adult male rats were subjected to a second-degree chemical burn on the back using 50% trichloroacetic acid. After the burns, the animals were randomly separated into 2 groups: control and experimental. The control group (G1) received placebo laser therapy and the laser group (G2) underwent laser irradiation with an energy density of 100 J/cm2. Histological analysis and macroscopic evaluation were carried out by means of the paper template method. Results: Group G1 showed (53%) of the necrosis area and group G2 showed (11%) necrosis area. Conclusion: The cicatricial acceleration method (MAC®) favored the repair of wounds caused by a 2nd-degree chemical burn, optimizing time and improving quality.

A Rational Design of Metal–Organic Framework Nanozyme with High‑Performance Copper Active Centers for Alleviating Chemical Corneal Burns

Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a significant challenge.Inspired by metalloenzymes with well-defined coordination structures,a series of MOFs containing halogen-coordinated copper nodes(Cu-X MOFs,X=Cl,Br,I)are employed to elucidate their structure–activity relationship.Intriguingly,experimental and theoretical results strongly support that precisely tuning the coordination of halogen atoms directly regulates the enzyme-like activities of Cu-X MOFs by influencing the spatial configuration and electronic structure of the Cu active center.The optimal Cu–Cl MOF exhibits excellent superoxide dismutase-like activity with a specific activity one order of magnitude higher than the reported Cu-based nanozymes.More importantly,by performing enzyme-mimicking catalysis,the Cu–Cl MOF nanozyme can significantly scavenge reactive oxygen species and alleviate oxidative stress,thus effectively relieving ocular chemical burns.Mechanistically,the antioxidant and antiapoptotic properties of Cu–Cl MOF are achieved by regulating the NRF2 and JNK or P38 MAPK pathways.Our work provides a novel way to refine MOF nanozymes by directly engineering the coordination microenvironment and,more significantly,demonstrating their potential therapeutic effect in ophthalmic disease.

Inhibitory effect of polysulfated heparin endostatin on alkali burn induced corneal neovascularization in rabbits

AIM: To investigate anti-angiogenic effects of polysulfated heparin endostatin(PSH-ES) on alkali burn induced corneal neovascularization(NV) in rabbits.METHODS: An alkali burn was made on rabbit corneas to induce corneal NV in the right eye of 24 rabbits. One day after burn creation, a 0.2 m L subconjunctival injection of 50 μg/m L PSH-ES, 50 μg/m L recombinant endostatin(ES), or normal saline was administered every other day for a total of 14d(7 injections). Histology and immunohistochemisty were used to examine corneas.Corneal NV growth was evaluated as microvessel quantity and corneal vascular endothelial growth factor(VEGF)expression was measured by immunohistochemical assay.RESULTS: Subconjunctival injection of ES and PSHES resulted in significant corneal NV suppression, but PSH-ES had a more powerful anti-angiogenic effect than ES. Mean VEGF concentration in PSH-ES treated corneas was significantly lower than in ES treated and saline treated corneas. Histological examination showed that corneas treated with either PSH-ES or ES had significantly fewer microvessels than eyes treated with saline. Additionally corneas treated with PSH-ES had significantly fewer microvessels than corneas treated with ES.CONCLUSION: Both PSH-ES and recombinant ES effectively inhibit corneal NV induced by alkali burn.However, PSH-ES is a more powerful anti-angiogenic agent than ES. This research has the potential to provide a new treatment option for preventing and treating corneal NV.

Serious Burn by Sulfuric Acid: Case Report of Particular Therapeutic Strategy in a Non-Specialized ICU at Hôpital Principal de Dakar (HPD) Sénégal

Managing severe burns remains problematic due to the lack of specialized units, but also because of the delay in implementing emergency care. The aim is to show that an adapted strategy, can lead to satisfying management of chemical burns. The authors report retrospectively the case of a patient admitted for chemical burns, and treated in a non-specialized intensive care unit;a 38 years old male, referred for burns by sulfuric acid at his workplace. On admission to H15, the clinic did not reveal any vital organs failure. Burns were localized on two legs and soles of the two feet (18% TBSA). Treatment combined daily dressings with silver sulfadiazine. On day 14, the wound healing associated occlusive gauze dressing, iodine cream application, and mechanical debridement. On day 47, a 5% dermal autograft performed on right foot favored with good attachment grafts. On day 58, the patient was released after complete skin recovery. Then, in a non-specialized burn unit and without early surgery access, our wound healing adapted strategy was successful. In Senegal, chemical burns represent about 2.5% of burn cases. They are often from accidents on occupation job, while generally in Africa chemical burns result from criminal attacks. Patients with severe lesions are admitted in non-specialized environments after an extended time of transfer, and don’t have efficient initial care. This may explain the high morbidity and mortality after burns in our country. The lack of surgical facilities such as skin substitutes, in non-specialized unit on low or median income countries (LMICs), explains this long period of wound healing. The treatment of severe burn in LMICs is hazardous.

Paediatric burns secondary to nail adhesives: a case series

Background:Nail adhesives are widely available beauty products that are used in the cosmetic industry and households to attach false nails.Nail adhesive burns are uncommon,and it is crucial that healthcare providers and the public are aware of its potential to cause chemical burn.Case Presentation:Case series of accidental burns secondary to cyanoacrylate nail glue treated at the Welsh Centre for Burns and Plastic Surgery(WCBPS)in Swansea,United Kingdom.Conclusion:All of the burns were observed in children and occurred due to accidental spillage.Therefore,it is important for the public to be aware that nail glue is a chemical agent which should be stored safely away from the reaches of young children.The case series highlights the importance of first aid in reducing the severity of chemical burns secondary to the nail adhesives,and its early recognition and treatment are emphasised.

Transplantation of corneal stem cells cultured on amniotic membrane for corneal burn: experimental and clinical study

OBJECTIVE: To investigate the proliferation and differentiation of cultured corneal stem cells and determine the effect of corneal stem cells cultured on amniotic membranes on the limbal area for treating corneal burns. METHODS: The proliferation and differentiation of corneal stem cells in vitro had been examined using colony-forming efficiency and immunohistochemistry. The stem cells had been cultured on amniotic membranes and transplanted to the limbal area for treating corneal burns. RESULTS: Corneal stem cells had a high proliferation capacity in primary and first passage, cytokeratin 3 was not expressed in primary culture but partly in first passage. The stem cells could proliferate to form cell layer on an amniotic membrane. When transplanted, stem cells could survive on limbus. After transplantation, ocular inflammation resolved, the cornea re-epithelialized, the stromal opacity reduced, the superficial neovascularity was lessened and the conjunctival fornix re-established. CONCLUSIONS: Ocular surface conditions could be improved by allograft of corneal stem cells cultured on amniotic membranes.

Transplantation of human limbal cells cultivated on amniotic membrane for reconstruction of rat corneal epithelium after alkaline burn

BACKGROUND: The transplantation of limbal epithelial cells cultivated on amniotic membrane is a newly developed treatment for limbal stem cell deficiency. The purpose of our study was to investigate the biological characteristics of limbal epithelial cells and evaluate the effect of transplantation of cultivated human limbal epithelial cells on ocular surface reconstruction in limbal stem cell deficiency rat model. METHODS: Human limbal cells were isolated and cultivated in vitro. Cytokeratins 3, 12, and 19 (K3, K12 and K19) and p63 were detected by immunofluorescent staining or RT-PCR. BrdU labelling test was used to identify the slow cycling cells in the cultures. Limbal stem cell deficiency was established in rat cornea by alkali burn. Two weeks after injury, the rats received transplants of human limbal stem cells cultivated on amniotic membrane carrier. The therapeutic effect was evaluated by slit lamp observation, Hemotoxin and Eosin (HE) staining and immunofluorescent staining. RESULTS: On day 7 in primary culture, p63 and K19 were strongly expressed by most cells but only a few cells expressed K3. On days 14 and 21, p63 and K19 were still expressed by a majority of cells, but the expressive intensity of p63 decreased in a number of cells, while the proportion of K3 positive cells increased slightly and some cells coexpressed p63 and K3. RT-PCR showed that gene expression of both p63 and K12 were positive in cultivated limbal cells, but in mature superficial epithelial cells, only K12 was detected. BrdU labelling test showed that most cells were labelled with BrdU after 7 days' labelling and BrdU label retaining cells were observed after chasing for 21 days with BrdU free medium. For in vivo test, slit lamp observation, HE staining and immunofluorescent staining showed that the rats receiving transplant of human limbal stem cells cultivated on amniotic membrane grew reconstructed corneas with intact epithelium, improved transparency and slight or no neovascularization. A majority of epithelial cells of the reconstructed cornea were positive to antihuman nuclear antibody and cells expressing K3 were found mainly in superfacial epithelium. CONCLUSIONS: Limbal stem cells can be cultivated in vitro: the cells are characterized by high proliferation and slow cycling and identified as p63/K19 positive and K3/K12 negative. During culture, some stem cells can proliferate and differentiate into mature cornea epithelial cells. Amniotic membrane is a suitable carrier for limbal stem cells. Transplantation of human limbal stem cells cultivated on amniotic membrane can functionally reconstruct rat cornea with limbal stem cell deficiency.