RESUMO
Marine green algae produce sulfated polysaccharides with diverse structures and a wide range of biological activities. This study aimed to enhance the biotechnological potential of sulfated heterorhamnan (Gb1) from Gayralia brasiliensis by chemically modifying it for improved or new biological functions. Using controlled Smith Degradation (GBS) and O-alkylation with 3-chloropropylamine, we synthesized partially water-soluble amine derivatives. GBS modification increase sulfate groups (29.3 to 37.5 %) and α-l-rhamnose units (69.9 to 81.2 mol%), reducing xylose and glucose, compared to Gb1. The backbone featured predominantly 3- and 2-linked α-l-rhamnosyl and 2,3- linked α-l-rhamnosyl units as branching points. Infrared and NMR analyses confirmed the substitution of hydroxyl groups with aminoalkyl groups. The modified compounds, GBS-AHCs and GBS-AHK, exhibited altered anticoagulant properties. GBS-AHCs showed reduced effectiveness in the APTT assay, while GBS-AHK maintained a similar anticoagulant activity level to Gb1 and GBS. Increased nitrogen content and N-alkylation in GBS-AHCs compared to GBS-AHK may explain their structural differences. The chemical modification proposed did not enhance its anticoagulant activity, possibly due to the introduction of amino groups and a positive charge to the polymer. This characteristic presents new opportunities for investigating the potential of these polysaccharides in various biological applications, such as antimicrobial and antitumoral activities.
Assuntos
Anticoagulantes , Clorófitas , Mananas , Alga Marinha , Sulfatos , Anticoagulantes/farmacologia , Anticoagulantes/química , Anticoagulantes/síntese química , Clorófitas/química , Alga Marinha/química , Sulfatos/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Polissacarídeos/síntese química , Humanos , Desoxiaçúcares/química , Desoxiaçúcares/farmacologiaRESUMO
Alginate, a polyuronic biopolymer composed of mannuronic and guluronic acid units, contain hydroxyl and carboxyl groups as targeting modification sites to obtain structures with new and/or improved biological properties. The copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a versatile click reaction for polymer functionalization, but it typically requires a "pre-click" modification to introduce azide or alkyne groups. Here, we described a straightforward chemical path to selectively modify alginate carboxyl groups producing versatile azido derivatives through N-acylation using 3-azydopropylamine. The resulting azide-functionalized polysaccharides underwent click chemistry to yield amino derivatives, confirmed by NMR and FTIR analyses. The 1H NMR spectrum reveals a characteristic triazole group signal at 8.15 ppm. The absence of the azide FTIR band for all amino derivatives, previously observed for the N-acylation products, indicated reaction success. Antibacterial and antioxidant assessments revealed that the initial polysaccharide lacks E. coli inhibition, while the click chemistry-derived amine products exhibit growth inhibition at 5.0 mg/mL. Lower molecular weight derivatives demonstrate superior DPPH scavenging ability, particularly amino-derivatives (24-33 % at 1.2 mg/mL). This innovative chemical pathway offers a promising strategy for developing polysaccharide structures with enhanced properties, demonstrating potential applications in various fields.
Assuntos
Alginatos , Azidas , Azidas/química , Escherichia coli , Polímeros/química , Química Click , Alcinos/química , Cobre/química , Reação de CicloadiçãoRESUMO
Abstract The high consumption of antiaging cosmetics represents an outstanding opportunity for the development of new processes and attractive products in the cosmetic industry. Stability studies and sensory analyses are critical steps in the development process and production chain. Here we present a potential antiaging cosmetic product with innovative sensory characteristics. Caviar extract antioxidant properties were firstly evaluated by the DPPH method since it is an important mechanism against skin aging. Ca-alginate beads containing 2% of caviar extract and 0.2% of black pigment were prepared to obtain spheres similar to caviar. The beads were incorporated in a gel phase (hydroxyethylcellulose 2.5%) containing 3% of dimethylaminoethanol. Stability was evaluated in different storage conditions (sunlight exposure, 5 ± 2 °C, 37 ± 2 °C and r.t.) through the parameters: appearance, color and odor, pH (6-7), density (0.98-1.14 g.mL-1), centrifugation and average size. After approval by the Committee for Ethics in Research (n° 3.503.061), 30 volunteers tested the new formulation and answered a questionnaire. At 2%, caviar extract was able to scavenge 10.9% ± 0.58 of DPPH radical. Formulations showed good stability after 90 days, even considering the average size (7.47 ± 0.41 - 8.4 ± 0.65 mm2). 90% of the sensory test participants reported that they would buy the new product. Therefore, the new product developed demonstrates a promising potential as an attractive cosmetic product.
Assuntos
Cosméticos , Alginatos , Loções de Beleza , Envelhecimento da Pele/efeitos dos fármacosRESUMO
ABSTRACT Objective Diabetes mellitus (DM) is a chronic disease with great impact on patients' quality of life (QoL). This variable can be measured using reliable, standardized, and validated instruments. The purpose of this study was to evaluate the application and reporting of the Diabetes Quality of Life Measure (DQOL) or the Diabetes Quality of Life for Youths Measure (DQOLY), an adapted version for young patients with DM. Materials and methods A systematic review of interventional and observational studies using the DQOL or DQOLY was performed. Searches were conducted in the electronic databases Medline, Scopus, Web of Science, Lilacs, and SciELO. Results After conducting the searches, 111 studies met the inclusion criteria and were included in the qualitative analysis. Of these, 32 studies were classified as interventional and 79 as observational, with 27,481 patients. The DQOL was applied in 82 studies, the DQOLY in another 27, and two studies used both instruments. DM was classified as type 1 DM in 69 studies and type 2 DM in 35 studies. Six studies included both patients. Improvement in patients' QoL after an intervention was observed in 13 interventional studies. Most of the studies (90%) provide a detailed description of the instrument and 52% the previous validation. The interpretation of the scores obtained varies among the studies, probably due to the differences inherent in cultural validations, translations, and adaptations. Conclusion The application of the instruments in clinical practice must be rigorously standardized and requires an accurate understanding of psychometric and statistical concepts. Arch Endocrinol Metab. 2020;64(1):59-65
Assuntos
Humanos , Masculino , Feminino , Adolescente , Qualidade de Vida/psicologia , Inquéritos e Questionários , Diabetes Mellitus Tipo 1/psicologia , Diabetes Mellitus Tipo 2/psicologia , PsicometriaRESUMO
Antibacterial activity and good mechanical properties are some of the characteristics required for an appropriate film dressing. A novel polymer blend was developed for wound healing application. Twenty-four formulations using the polymers chitosan, poly(vinyl alcohol) and/or É-Polylysine and the plasticizer glycerol were designed using factorial design and then the films were prepared by the casting/solvent evaporation method. Seventeen films were obtained among the twenty-four proposed formulations that were characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Mechanical properties, such as tensile strength (σ), elongation at break (É) and Young's modulus (Y) as well as antibacterial properties were determined. The best candidate was then further analyzed with regard to porosity, Water Vapor Transmission Rate (WVTR), swelling and cytotoxicity experiments. The results showed a film with semi-occlusive characteristics, good mechanical properties and no toxic. Incorporation of É-Polylysine increased antibacterial activity against gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria
Assuntos
Bandagens , Quitosana/farmacologia , Polilisina/farmacologia , Cicatrização/efeitos dos fármacos , Microscopia Eletrônica de Varredura/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Glicerol/farmacologiaRESUMO
ABSTRACT Skin aging causes changes such as wrinkles and flaccidity leading to a large demand for aesthetic procedures, including dermal filling. A key agent in dermal filling is hyaluronic acid (HA), which is a naturally occurring glycosaminoglycan. However, it is a hydrophilic macromolecule that experiences great difficulty in crossing the skin barrier causing most commercial formulations containing it to be injectable, which in turn brings risks since they involve an invasive technique. In that sense, the aim of this study was to develop and characterize nanoparticles obtained from ionic interaction between HA and lysine (Lys) for use as a potential agent of dermal filling for topical application, increasing and improving its applicability and safety. To this end, nanoparticles were obtained by dripping of Lys over HA under magnetic stirring. A nanometric size was confirmed and a suitable surface charge was obtained by zeta potential. Nanoparticles were almost spherical in shape with a smooth surface. Interaction between raw materials for preparing nanoparticles was studied by FTIR and NMR spectroscopy and an ionic interaction was confirmed. These physicochemical features suggest that obtained nanoparticles can be further used as a topical dermal filling.
Assuntos
Envelhecimento da Pele/genética , Nanotecnologia/classificação , Ácido Hialurônico/análise , Lisina/análise , Espectroscopia de Ressonância Magnética/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Preenchedores Dérmicos/efeitos adversosRESUMO
CONTEXT: Hypothyroidism is more prevalent in the elderly and its symptoms can be confused with other changes due to aging. Doctors caring for the elderly need to be attentive to this diagnostic possibility. This case report case is notable not only because it presents a rare complication of hypothyroidism (kidney failure), but also because patients with chronic kidney failure of any etiology may suffer increased renal dysfunction as a result. CASE REPORT: This was a 66-year-old male outpatient with a history of generalized edema over the preceding eight years, with periods of worsening, that was intractable to treatment with diuretics. Physical examination revealed bradycardia (heart rate: 52 bpm), pallor, dry and infiltrated skin, macroglossia, edema in the lower limbs and a palpable thyroid with hard consistency. Laboratory tests showed: creatinine 3.9 mg/dl; urea 95 mg/dl; potassium 6.0 mEq/l; thyroid-stimulating hormone > 100 mUI/ml; triiodothyronine 0.01 ng/dl; free thyroxin 0.01 ng/dl; antithyroglobulin 31 IU/ml (normal values: < 40 IU/ml); antithyroperoxidase 85 IU/ml (normal values: < 15 IU/ml); creatinine clearance 30 ml/min/1.73 m²; and proteinuria 122 mg/24 h. After five months of treatment with thyroxin (100 mcg/day), the patient returned without any symptoms and presented the following test results: urea 48 mg/dl; creatinine 1.4 mg/dl; creatinine clearance 67 ml/min/1.73 m²; potassium 4.2 mEq/l; thyroid-stimulating hormone: 20.85 mUI/ml; free thyroxin: 0.71 ng/dl. Hypothyroidism alone can cause renal impairment or worsen renal function in preexisting illnesses. Its treatment can stabilize the clinical condition, or possibly improve it.
CONTEXTO: O hipotireoidismo tem uma prevalência elevada em idosos e sua sintomatologia pode ser confundida com alterações próprias do envelhecimento, obrigando o médico que atende o idoso sempre estar atento a essa possibilidade diagnóstica. O relato deste caso chama atenção não somente para uma rara complicação do hipotireoidismo, a insuficiência renal, como para o fato de pacientes portadores de insuficiência renal crônica de qualquer outra etiologia poderem ter piora da disfunção renal devido a esse quadro. RELATO DO CASO: Homem de 66 anos foi atendido em nosso ambulatório com história de edema generalizado há oito anos, com períodos de piora, refratário a tratamento com diuréticos. Ao exame físico encontrava-se bradicárdico (freqüência cardíaca 52 bpm), hipocorado; pele ressecada e infiltrada; macroglossia; edema de membros inferiores; tireóide palpável e de consistência endurecida. Exames laboratoriais mostraram: creatinina 3,9 mg/dl; uréia 95 mg/dl; potássio 6,0 mEq/l; hormônio estimulante da tireóide, TSH > 100 mUI/ml; T3 0,01 ng/dl; T4 0,01 ng/dl; anti-tireoglobulina 31 UI/ml (< 40 UI/ml); anti-tiroperoxidase 85 UI/ml (< 15 UI/ml); clearence de creatinina 30 ml/min/1,73 m²; proteinúria 122 mg/24 h. Após cinco meses de tratamento com tiroxina 100 mcg/dia o paciente retornou ao ambulatório assintomático, apresentando os seguintes exames: uréia 48 mg/dl; creatinina 1,4 mg/dl; clearence de creatinina 67 ml/min/1,73 m²; potássio 4,2 mEq/l; TSH 20,85 mUI/ml; T4 livre 0,71 ng/dl. CONCLUSÃO: O hipotireoidismo per se pode levar a insuficiência renal ou piorar a função renal em doenças preexistentes. Seu tratamento pode reverter essa condição clínica ou, pelo menos, melhorá-la.