RESUMO

In chronic wound treatment, the debridement of devitalized tissue and the eradication of the biofilm must balance aggressiveness with care to protect regenerating tissues. In this study, urea, a potent chaotropic molecule, was modulated through the formation of a Natural Deep Eutectic Solvent (NADES) with betaine to develop a new debriding material (BU) suitable for application into injured dermal tissues. To evaluate BU's debriding capacity, along with its antibiofilm effect and biocompatibility, pre-clinical to clinical methods were employed. In vitro determinations using artificial and clinical slough samples indicate that BU has a high debriding capacity. Additionally, BU's de-structuring effects lead to a strong antibiofilm capability, demonstrated by a reduced bacterial load compared to the antiseptic PHMB-Betaine or medical honey, evaluated in artificial slough and ex vivo human skin. Furthermore, BU's efficacy was evaluated in a murine model of diabetic wound, demonstrating significant effects on debriding and antibiofilm capacity, similar to those observed in PHMB-Betaine and medical honey-treated animals. Finally, BU was clinically evaluated in leg ulcers, showing superiority in reduction of bacterial load and wound area compared to honey, with no adverse effects. Thus, BU represents a simple and non-biocidal option that could contributes to chronic wound care.

Assuntos

Betaína , Biofilmes , Desbridamento , Solventes , Cicatrização , Biofilmes/efeitos dos fármacos , Animais , Betaína/farmacologia , Betaína/química , Humanos , Solventes/química , Cicatrização/efeitos dos fármacos , Desbridamento/métodos , Camundongos , Masculino , Feminino , Ureia , Mel , Pele/microbiologia , Pele/efeitos dos fármacos , Doença Crônica , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/química , Pessoa de Meia-Idade , Diabetes Mellitus Experimental/tratamento farmacológico , Idoso

RESUMO

There are several reasons for skin damage, including genetic factors, disorders, acute trauma, hard-to-heal wounds, or surgical interventions. Whatever the cause, wounds have a substantial impact on people who experience them, their caregivers and the healthcare system. Advanced wound care products have been researched and developed, providing an opportunity for faster and more complete healing. Tissue engineering (TE) is a promising strategy that can overcome limitations when choosing a graft for a wound. Amniotic membrane is a highly abundant, readily available, and inexpensive biological tissue that does not raise ethical concerns, with many applications in different fields of TE and regenerative medicine. It has attractive physical characteristics, such as elasticity, rigidity and mechanical strength, among others. The effects can also be potentiated by association with other substances, such as hyaluronic acid and growth factors. This paper describes new perspectives involving the use of amniotic membranes.

Assuntos

Âmnio , Engenharia Tecidual , Cicatrização , Humanos , Âmnio/transplante , Ferimentos e Lesões/terapia , Medicina Regenerativa/métodos

RESUMO

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

RESUMO

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with borate glasses of 45B5 composition doped with Co2+, Cu2+, and Zn2 +(46.1 B2O326.9-X CaO24.4 Na2O2.6 P2O5, X CoO/CuO/ZnO mol % (X = 0-5)) were produced by electrospinning for wound healing applications. Prior to their addition, the glasses exhibited two broad halos typical of a vitreous borate network, which were mainly composed of ring-type metaborate structural units. The particle distribution in the PHBV nanofibers embedded with 45B5 borate bioactive glasses is present in isolated and agglomerated states, being partially coated by a polymeric layer-except for the cobalt-doped glass, which resulted in a successful encapsulation with 100% embedding efficiency. The incorporation of the glasses reduced the PHBV crystallinity degree and its decomposition temperature, as well as its mechanical properties, including Young's modulus, tensile strength, and elongation at break. The neat PHBV fibers and those containing the cobalt-doped glasses demonstrated great cytocompatibility with human keratinocytes (HaCat), as suggested by the high cell viability after 7 days of exposure. Further studies are needed to fully understand the wound healing potential of these fibers, but our results significantly contribute to the area.

Assuntos

Bandagens , Boratos , Cobalto , Cobre , Poliésteres , Zinco , Humanos , Cobre/química , Cobalto/química , Poliésteres/química , Boratos/química , Zinco/química , Vidro/química , Teste de Materiais , Cicatrização , Nanofibras/química , Linhagem Celular , Poli-Hidroxibutiratos

RESUMO

Bacterial cellulose (BC), produced by bacterial fermentation, is a high-purity material. BC can be oxidized (BCOXI), providing aldehyde groups for covalent bonds with drugs. Frutalin (FTL) is a lectin capable of modulating cell proliferation and remodeling, which accelerates wound healing. This study aimed to develop an FTL-incorporated dressing based on BC, and to evaluate its physicochemical properties and biological activity in vitro. An experimental design was employed to maximize FTL loading yield onto the BC and BCOXI, where independent variables were FTL concentration, temperature and immobilization time. BCOXI-FTL 1 (44.96 % ± 1.34) had the highest incorporation yield (IY) at the experimental conditions: 6 h, 5 °C, 20 µg mL-1. The second highest yield was BCOXI-FTL 6 (23.28 % ± 1.43) using 24 h, 5 °C, 100 µg mL-1. Similarly, the same reaction parameters provided higher immobilization yields for native bacterial cellulose: BC-FTL 6 (16.91 % ± 1.05) and BC-FTL 1 (21.71 % ± 1.57). Purified FTL displayed no cytotoxicity to fibroblast cells (<50 µg mL-1 concentration) during 24 h. Furthermore, BCOXI-FTL and BC-FTL were non-cytotoxic during 24 h and stimulated fibroblast migration. BCOXI-FTL demonstrated neutrophil activation in vitro similar to FTL. These promising results indicate that the bacterial cellulose matrices containing FTL at low concentrations, could be used as an innovative biomaterial for developing wound dressings.

Assuntos

Artocarpus , Bandagens , Celulose , Lectinas de Plantas , Artocarpus/química , Celulose/química , Celulose/farmacologia , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Animais , Camundongos , Fibroblastos/efeitos dos fármacos , Cicatrização/efeitos dos fármacos

RESUMO

Only 0.1% of polyurethanes available on the market are from renewable sources. With increasing concern about climate change, the substitution of monomers derived from petrochemical sources and the application of eco-friendly synthesis processes is crucial for the development of biomaterials. Therefore, polyhydroxyurethanes have been utilized, as their synthesis route allows for the carbonation of vegetable oils with carbon dioxide and the substitution of isocyanates known for their high toxicity, carcinogenicity, and petrochemical origin. In this study, polyhydroxyurethanes were obtained from carbonated soybean oil in combination with two diamines, one that is aliphatic (1,4-butadiamine (putrescine)) and another that is cycloaliphatic (1,3-cyclohexanobis(methylamine)). Four polyhydroxyurethanes were obtained, showing stability in hydrolytic and oxidative media, thermal stability above 200 °C, tensile strength between 0.9 and 1.1 MPa, an elongation at break between 81 and 222%, a water absorption rate up 102%, and contact angles between 63.70 and 101.39. New formulations of bio-based NIPHUs can be developed with the inclusion of a cycloaliphatic diamine (CHM) for the improvement of mechanical properties, which represents a more sustainable process for obtaining NIPHUs with the physicochemical, mechanical, and thermal properties required for the preparation of wound dressings.

RESUMO

Bacterial cellulose (BC) represents a promising biomaterial, due to its unique and versatile properties. We report, herein, on purposely-designed structural modifications of BC that enhance its application as a wound dressing material. Chemical modification of the functional groups of BC was performed initially to introduce a hydrophobic/oleophilic character to its surface. Specifically, silanization was carried out in an aqueous medium using methyltrimethoxisilane (MTMS) as the silanizing agent, and aerogels were subsequently prepared by freeze-drying. The BC-MTMS aerogel obtained displayed a highly porous (99 %) and lightweight structure with an oil absorption capacity of up to 52 times its dry weight. The XRD pattern indicated that the characteristic crystallographic planes of the native BC were maintained after the silanization process. Thermal analysis showed that the thermal stability of the BC-MTMS aerogel increased, as compared to the pure BC aerogel (pBC). Moreover, the BC-MTMS aerogel was not cytotoxic to fibroblasts and keratinocytes. In the second step of the study, the incorporation of natural oils into the aerogel's matrix was found to endow antimicrobial and/or healing properties to BC-MTMS. Bourbon geranium (Pelargonium X ssp.) essential oil (GEO) was the only oil that exhibited antimicrobial activity against the tested microorganisms, whereas buriti (Mauritia flexuosa) vegetable oil (BVO) was non-cytotoxic to the cells. This study demonstrates that the characteristics of the BC structure can be modified, while preserving its intrinsic features, offering new possibilities for the development of BC-derived materials for specific applications in the biomedical field.

Assuntos

Celulose , Óleos Voláteis , Óleos de Plantas , Celulose/química , Celulose/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Géis/química , Cicatrização/efeitos dos fármacos , Fabaceae/química , Humanos , Fibroblastos/efeitos dos fármacos , Pelargonium/química , Silanos/química

RESUMO

Leishmaniasis, caused by Leishmania parasites, is a neglected tropical disease and Cutaneous Leishmaniasis (CL) is the most common form. Despite the associated toxicity and adverse effects, Meglumine antimoniate (MA) remains the first-choice treatment for CL in Brazil, pressing the need for the development of better alternatives. Bacterial NanoCellulose (BNC), a biocompatible nanomaterial, has unique properties regarding wound healing. In a previous study, we showed that use of topical BNC + systemic MA significantly increased the cure rate of CL patients, compared to treatment with MA alone. Herein, we performed a study comparing the combination of a wound dressing (BNC or placebo) plus systemic MA versus systemic MA alone, in CL caused by Leishmania braziliensis. We show that patients treated with the combination treatment (BNC or placebo) + MA showed improved cure rates and decreased need for rescue treatment, although differences compared to controls (systemic MA alone) were not significant. However, the overall time-to-cure was significantly lower in groups treated with the combination treatment (BNC+ systemic MA or placebo + systemic MA) in comparison to controls (MA alone), indicating that the use of a wound dressing improves CL treatment outcome. Assessment of the immune response in peripheral blood showed an overall downmodulation in the inflammatory landscape and a significant decrease in the production of IL-1a (p < 0.05) in patients treated with topical BNC + systemic MA. Our results show that the application of wound dressings to CL lesions can improve chemotherapy outcome in CL caused by L. braziliensis.

RESUMO

OBJECTIVE: Accurate assessment of burn depth and burn wound healing potential is essential to determine early treatments. Infrared thermography (IRT) is a non-invasive and objective tool to do this. This systematic review evaluated the accuracy of IRT to determine burn wound healing potential. METHOD: This systematic review and meta-analysis used MEDLINE, EMBASE, CINAHL, PEDro, DiTA and CENTRAL databases. IRT data were extracted from primary studies and categorised into four cells (i.e., true positives, false positives, true negatives and false negatives). Subgroup analysis was performed according to methods used to capture thermal images. RESULTS: The search strategy identified 2727 publications; however, 15 articles were selected for review and 11 for meta-analysis. In our meta-analysis, the accuracy of IRT was 84.8% (63% sensitivity and 81.9% specificity). CONCLUSION: IRT is a moderately accurate tool to identify burn depth and healing potential. Thus, IRT should be used carefully for evaluating burn wounds.

Assuntos

Queimaduras , Termografia , Humanos , Termografia/métodos , Cicatrização , Queimaduras/diagnóstico , Queimaduras/terapia , Acetofenonas

RESUMO

Diabetic foot ulcers are a serious complication of uncontrolled diabetes, emphasizing the need to develop wound healing strategies that are not only effective but also biocompatible, biodegradable, and safe. We aimed to create biomatrices composed of semi-interpenetrated polymer networks of collagen, polyurethane, and dextran, to enhance the wound healing process. The hydrogels were extensively characterized by various analytical techniques, including analysis of their structure, crystallinity, thermal properties, gelation process, reticulation, degradation, cell proliferation, and healing properties, among others. Semi-interpenetrated hydrogels containing dextran at levels of 10%, 20%, and 30% exhibited porous interconnections between collagen fibers and entrapped dextran granules, with a remarkable crosslinking index of up to 94% promoted by hydrogen bonds. These hydrogels showed significant improvements in mechanical properties, swelling, and resistance to proteolytic and hydrolytic degradation. After 24 h, there was a significant increase in the viability of several cell types, including RAW 264.7 cells, human peripheral blood mononuclear cells, and dermal fibroblasts. In addition, these hydrogels demonstrated an increased release of interleukin-10 and transforming growth factor-beta1 while inhibiting the release of monocyte chemotactic protein-1 and tumor necrosis factor-alpha after 72 h. Furthermore, these hydrogels accelerated the wound healing process in diabetic rats after topical application. Notably, the biomaterial with 20% dextran (D20) facilitated wound closure in only 21 days. These results highlight the potential of the D20 hydrogel, which exhibits physicochemical and biological properties that enhance wound healing by inhibiting inflammation and fibrillogenesis while remaining safe for application to the skin.

Assuntos

Colágeno , Dextranos , Hidrogéis , Inflamação , Poliuretanos , Cicatrização , Hidrogéis/química , Hidrogéis/farmacologia , Animais , Cicatrização/efeitos dos fármacos , Dextranos/química , Dextranos/farmacologia , Poliuretanos/química , Poliuretanos/farmacologia , Camundongos , Humanos , Colágeno/química , Inflamação/patologia , Inflamação/tratamento farmacológico , Células RAW 264.7 , Ratos , Masculino

RESUMO

OBJECTIVE: To examine the relationship between pressure injury (PI) development and achievement of nutritional goals (protein and caloric), as well as consider the clinical conditions, hospitalisation factors, and risk assessment for PI development in patients who are critically ill and receiving enteral nutrition (EN) in the intensive care unit (ICU). METHOD: An observational cohort study was conducted in the ICU of the University Hospital in São Paulo, Brazil. Inclusion criteria were as follows: age ≥18 years; length of ICU stay ≥24 hours; without PI at ICU admission; and receiving EN exclusively during ICU stay. The development of PI was considered the dependent variable. The Chi-squared test was applied to compare categorical variables, and the Mann-Whitney U test was used to compare continuous variables between groups of patients with and without a PI. The analysis of the achievement of nutritional goals was performed using Fisher's exact test. A significance level of 5% (p-value<0.05) and a confidence interval (CI) of 95% was adopted in all statistical tests. RESULTS: A total of 181 patients met the inclusion criteria, of whom 102 (56.4%) were male and 79 (43.6%) were female. Mean age was 55.1 years, and mean length of ICU stay was 17.5 days. PI development was associated with not achieving nutritional goals. There was a higher percentage (65.3%) of patients without a PI when both protein and caloric goals were achieved. In contrast, 45.6% of patients developed a PI when the goals were not achieved. The mean days for sedation, vasoactive drugs and mechanical ventilation were all significantly higher in patients who developed a PI (p<0.001). CONCLUSION: There was a significant association between patients developing a PI and deficits in caloric and protein intake. Patients who did not develop PIs had a greater calorie and protein intake compared with those who developed a PI.

Assuntos

Nutrição Enteral , Úlcera por Pressão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Brasil/epidemiologia , Cuidados Críticos , Ingestão de Energia , Nutrição Enteral/efeitos adversos , Objetivos , Unidades de Terapia Intensiva , Tempo de Internação , Úlcera por Pressão/prevenção & controle , Adulto

RESUMO

Second-degree burns require greater care, as the damage is more extensive and worrisome and the use of a biomaterial can help in the cell repair process, with better planning, low cost, and better accessibility. Arnica has anti-inflammatory and analgesic properties in skin lesions treatments and laser therapy is another therapeutic alternative for burns. Evaluate the effects of arnica incorporated into PVA associated or not with low intensity laser on burns in rats. PVA and PVA with arnica (PVA+A) were obtained and characterized physicochemically. Through in vivo studies, the effects of PVA and PVA+A with or without the application of laser on the lesions allowed histological and immunohistochemical analyzes. PVA+A was biocompatible and with sustained release of the active, being a promising pharmacological tool and confirmed that laser therapy was effective in accelerating the healing process, due to its potential biomodulator, improving inflammatory aspects, promoting rapid healing in skin lesions.

Assuntos

Queimaduras , Álcool de Polivinil , Cicatrização , Animais , Álcool de Polivinil/química , Queimaduras/terapia , Cicatrização/efeitos dos fármacos , Ratos , Ratos Wistar , Masculino , Pele/lesões , Pele/patologia , Materiais Biocompatíveis/química , Extratos Vegetais/química , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Terapia a Laser/métodos , Membranas Artificiais , Terapia com Luz de Baixa Intensidade/métodos

RESUMO

OBJECTIVE: This study aimed to analyse the nutritional factors and pressure injury (PI) risk in hospitalised patients post-stroke. METHOD: The research employed a descriptive observational method in which patients ≥18 years of age were followed for six days. Nutritional evaluation was based on anthropometric and dietary factors. The nutritional risk was assessed via anthropometric measurements, Braden nutrition subscale and daily dietary intake. PI risk was evaluated through the Braden Scale. The Wilcoxon test, paired t-test, and Kruskal-Wallis test were applied and corrected with Bonferroni correction or analysis of variance, followed by the post hoc Tukey test. RESULTS: During their hospital stays, the participating 59 patients had an increase in sensory perception (p=0.02) and nutrition (p=0.005) scores. It was observed that patients at high risk of PI did not meet daily nutritional recommendations for calories, proteins, carbohydrates, lipids and micronutrients (zinc, selenium and copper) compared with patients at low-to-moderate risk. Weight (p<0.001), body mass index (p<0.001), calf (p=0.01) and arm (p=0.04) circumferences, and subscapular (p=0.003) and triceps (p<0.001) skinfolds decreased during the six days of hospitalisation. CONCLUSION: From the findings of this study, it was concluded that nutritional factors, such as unmet recommended daily nutritional requirements of macronutrients and micronutrients, and nutritional status are associated with a higher risk of developing a PI.

Assuntos

Úlcera por Pressão , Humanos , Recém-Nascido , Índice de Massa Corporal , Ingestão de Energia , Micronutrientes , Estado Nutricional , Úlcera por Pressão/etiologia , Fatores de Risco

RESUMO

OBJECTIVE: This article aims to present a narrative review of current literature about the anatomical characteristics of the scalp as well as current practices in the management of surgical, traumatic and pressure injuries in the scalp, which are common in neurosurgery practice. METHOD: We searched PubMed for publications and book chapters in English from 2011 to 2021. We also included commonly referenced papers that we considered relevant to the subject with publication before these dates. We used the search terms 'laceration,' and/or 'neurosurgery' and/or, 'pressure injury,' and/or 'craniotomy,' and/or 'surgical incision' in combination with 'scalp,' and/or 'wound care.' We also searched the reference lists of publications identified by the search strategy and selected those that we judged relevant. RESULTS: We pre-selected 52 articles that covered various aspects of anatomy, pathophysiology, scalp wound management, or general wound care that we considered applied to the anatomical region of our interest. After abstract review, we selected 34 articles that met our search criteria and were included in our review. CONCLUSION: There is limited evidence regarding classification and care of scalp wounds. As a result, many of the current practices for scalp wound management are based on evidence derived from studies involving different anatomical regions, not considering its particular anatomy, vasculature and microbiome. Further research is needed for more comprehensive and effective protocols for the management of scalp injuries. However, this present review proposes responses to the identified gaps concerning the management of scalp wounds.

Assuntos

Couro Cabeludo , Ferida Cirúrgica , Humanos , Couro Cabeludo/cirurgia , Cicatrização , Infecção da Ferida Cirúrgica , Craniotomia

RESUMO

Ideally, the dressings used in the clinic have characteristics that help the wound closure process. Among several factors that affect the success of this healing process, there is debridement. It manages the wound bed components and the re-epithelialization process. Still, the property of debridement is not generally associated with dressings. Here, we show a chemically modified bacterial cellulose film conjugated to a proteolytic enzyme, papain, as a dressing with debridement properties. Bacterial cellulose films were reacted with a spacer derived from succinic acid and finally had this enzyme covalently immobilized in its structure by an amide bond. FT-IR and UV-vis showed bands typically of bioconjugated polymer. Enzymatic immobilization was very effective under the conditions applied with high yield (33% w/w), and these remained activated after the coupling reaction. The bacterial cellulose film with the enzyme papain attached to it was also very compatible with fibroblast cells, suggesting that it could be a promising wound dressing material for future research.

Assuntos

Celulose , Papaína , Celulose/química , Espectroscopia de Infravermelho com Transformada de Fourier , Cicatrização , Bandagens

RESUMO

Papain (an enzyme from the latex of Carica papaya) is an interesting natural bioactive macromolecule used as therapeutic alternative for wound healing due to debridement action in devitalized or necrotic tissues. However, its use in high doses can induce potential skin irritation and side effects. In this study, experiments explored the ability of chitosan membrane to immobilize papain, consequently improving enzymatic activity and controlling enzyme release. Papain-loading capacity was tested via experiments of force microscopy (AFM), scanning electron microscopy (SEM-FEG), and X-ray diffraction analyses. Fourier transform infrared spectroscopy and thermal analyses assessed the enzyme interactions with the copolymer. The investigation of the feasibility of membranes included pH on the surface, elasticity, and breaking strength measurements. The surface wettability and swelling capacity of different formulations revealed the best formulation for in vitro papain release experiments. The membranes had a transparent, rough, crystalline characteristic, which was homogeneous with the membrane within the neutrality. The immobilization of papain in the chitosan membrane resulted in a decrease in the vibration band characteristic of pure papain, suggesting a displacement in the vibration bands in the FTIR spectrum. The presence of papain decreased hydrophobicity on the surface of the membrane and disturbed the membrane's ability to swell. Chitosan membranes containing papain 2.5% (0.04 g) and 5.0% (0.08 g) preserved feasible properties and improved the enzymatic activity compared (0.87 ± 0.12 AU/mg and 1.59 ± 0.10 AU/mg) with a free papain sample (0.0042 ± 0.001 AU/mg). Concentrations of over 10% (0.16 g) led to phase separation into membranes. Chitosan membranes exhibited a slow papain release behavior adjusted via the Higushi model. The experimental achievements suggest a novel and promising method for the enhancement of papain. The results indicate the potential for prolonged bioactivity for use on wounds.

RESUMO

Skin wound healing is a complex biological process of tissue regeneration in which the wound dressing is crucial for rapid healing; it must protect the wound keep an adequate level of moisture and prevent infections. Alginate (AL), a polysaccharide from brown algae, has been extensively studied for wound treatment, and aloe vera gels (AVGs) have also been used in the treatment of skin. The AVG main bioactive polysaccharide was combined with AL for the preparation of membranes. Two-dimensional membranes were prepared by casting and, for comparison, transparent nanoparticle 3D membranes were produced by high-intensity ultrasonication followed by ionotropic crosslinking. The effects of the amount of AVG, ionotropic gelation, and the structure (2D or 3D) of the AL-AVG membranes were compared. Scanning electron microscopy (SEM) showed higher surface roughness on 3D membranes. Three-dimensional membranes showed a higher swelling ratio, and swelling increased with AVG content and decreased with higher calcium concentration and longer gelation times. The degradation of the membranes was evaluated with and without a lysozyme at pH 5.5, 7.5, and 8.5, to simulate different skin conditions; the results evidence that pH had a higher effect than the enzyme. The cytotoxicity of the membranes was evaluated with ATCC CCL 163 and ATCC CCL 81 cells, and an excellent biocompatibility of both cell types (>90% of cell viability after 48 h incubation) was observed for all AL-AVG membranes.

RESUMO

OBJECTIVE: To evaluate the local effect of a slow oxygen-release gel on the healing of standardised skin wounds caused in rats. METHOD: Skin wounds were created on the backs of male rats (Rattus norvegicus, Wistar) that were randomly allocated into two groups. In the treated (T) and control (C) groups, oxygen gel and distilled water, respectively, were applied to the wounds on alternate days for 28 days. Postoperatively, euthanasia was performed at 5, 10, 14, 21 and 28 days, followed by clinical, histological (Masson's trichrome) and immunohistochemical analysis. Data were subjected to analysis of variance (ANOVA) and Bonferroni's test. RESULTS: The cohort comprised 50 rats. On clinical and histological analysis, groups C and T showed similar characteristics 5 days post-operation. Subsequently, group T showed better healing at 14, 21 and 28 days and presented more intense inflammatory infiltrate up to 10 days. At days 14, 21 and 28, group T exhibited a reduction in oedema and increased angiogenesis, granulation tissue formation, and deposition of collagen fibres than group C. Immunohistochemical analysis showed the presence of tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) in both the groups, but the levels were significantly higher in group T (p<0.05). CONCLUSION: The local application of slow oxygen-release gel accelerated the healing of standardised skin wounds created surgically in rats, with increased angiogenesis and better collagen fibre formation.

Assuntos

Anormalidades da Pele , Lesões dos Tecidos Moles , Humanos , Ratos , Masculino , Animais , Fator A de Crescimento do Endotélio Vascular , Ratos Wistar , Cicatrização , Pele/lesões , Colágeno/farmacologia

RESUMO

Hydrogels made with depolymerized guar gum, oxidized with theoretical oxidation degrees of 20, 35 and 50 %, were obtained via Schiff's base reaction with N-succinyl chitosan. The materials obtained were subjected to characterization by FT-IR, rheology, swelling, degradation, and morphology. Additionally, their gelation time categorized all three hydrogels as injectable. The materials' swelling degrees in Phosphate-Buffered Saline (PBS) were in the range of 26-35 g of fluid/g gel and their pore size distribution was heterogeneous, with pores varying from 67 to 93 µm. All hydrogels degraded in PBS solution, but maintained around 40 % of their initial mass after 28 days, which was more than enough time for wound healing. The biomaterials were also flexible, self-repairing, adhesive and cytocompatible and presented intrinsic actions, regardless of the presence of additives or antibiotics, against gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and gram-negative bacteria (Escherichia coli). However, the most pronounced bactericidal effect was against resistant Staphylococcus aureus - MRSA. In vivo assays, performed with 50 % oxidized gum gel, demonstrated that this material exerted anti-inflammatory effects, accelerating the healing process and restoring tissues by approximately 99 % within 14 days. In conclusion, these hydrogels have unique characteristics, making them excellent candidates for wound-healing dressings.

Assuntos

Quitosana , Staphylococcus aureus Resistente à Meticilina , Hidrogéis/farmacologia , Quitosana/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Bandagens , Bactérias , Antibacterianos/farmacologia , Staphylococcus aureus

RESUMO

Oral mucosal ulcerations expose connective tissue to different pathogens and this can progress to systemic infection. This study aimed to synthesize environmentally-friendly films with chitosan and protic ionic liquids, possessing mucoadhesive properties, activity against opportunistic microorganisms, enhanced malleability and mechanical resistance to be used as a wound dressing on the oral mucosa. Therefore, films with chitosan and 10, 35, and 50 % (wt/wt) of 2-hydroxy diethylammonium lactate, salicylate, and maleate protic ionic liquids were synthesized. Thickness measurements and mechanical properties analysis were performed. In addition, oral mucoadhesion, antimicrobial activity, and cytotoxicity properties were investigated. Results showed that the addition of 35wt% and 50wt% of all kinds of protic ionic liquids tested presented significant improvements in film thickness and mechanical properties. Films based on chitosan and the protic ionic liquid 2-hydroxy diethylammonium salicylate at percentages of 35 and 50wt% exhibited superior mucoadhesive properties, antimicrobial activity on opportunistic microorganisms and an improvement in their flexibility after immersion in synthetic saliva. Cytotoxicity results suggest that all kinds of chitosan/protic ionic liquids films tested are safe for intra-oral use. Therefore, the results of this study indicate that these materials could be good candidates for efficient and environmentally-friendly wound dressing films on the oral mucosa.

Assuntos

Anti-Infecciosos , Quitosana , Líquidos Iônicos , Mucosa Bucal , Bandagens , Salicilatos