RESUMO
The insertion of topical antimicrobials in wound treatment represented an important role in patient management. Among these agents, silver sulfadiazine (AgSD), introduced in the therapy of wounds and burns in the 1960s, is considered the gold standard in treatment due to its mechanism of action, in addition to its proven efficacy and safety. The association of AgSD with polymers for the development of curative formulations has been reported. The evaluation of the physical-chemical properties of these systems with the aid of analytical techniques of characterization is essential for the determination of their activities, besides allowing the detection of possible incompatibilities between AgSD and polymers. Thus, this review presents the main techniques of physicochemical characterization used in the evaluation of systems containing AgSD with curative purposes in order to provide parameters to ensure the efficacy and safety of these new therapeutic options. Microscopic, thermoanalytical, and spectroscopic techniques, for example, provide information on system properties such as surface chemical composition, crystallinity, morphology, and thermal stability of curative formulations containing AgSD. These techniques are important in the selection of the most appropriate techniques during the development of a polymeric curative system containing AgSD, in addition to providing information for cost reduction of a possible scale-up and the establishment of methodologies for quality control of these systems to ensure their efficacy and safety.
Assuntos
Anti-Infecciosos Locais , Sulfadiazina de Prata , Humanos , Sulfadiazina de Prata/farmacologia , Sulfadiazina de Prata/química , Bandagens , PolímerosRESUMO
(Bio)nanocomposites have been studied for biomedical applications, including the treatment of wounds. However, wound infection is one of the main problems of wound care management, and the use of wound dressings with antibacterial agents is essential. This work focused on developing and characterizing silver sulfadiazine-loaded halloysite/cassava starch-based (bio)nanocomposites potentially suitable as antimicrobial dressing. Silver sulfadiazine was complexed inside the halloysite nanotubes lumen, and the drug-loaded nanotubes were incorporated in thermoplastic starch dispersion, forming the (bio)nanocomposites. The silver sulfadiazine-loaded halloysite and the (bio)nanocomposite were characterized by zeta potential, scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. The dressing properties of (bio)nanocomposites (water vapor permeability and mechanical stability) and their antimicrobial efficacy by Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were also evaluated. Physicochemical studies suggested the silver sulfadiazine-loaded halloysite complexation (zeta potential of -38.9 mV) and its interactions with the starch forming the nanocomposites. The silver sulfadiazine-loaded halloysite/starch-based (bio)nanocomposites possessed a homogeneous and organized structure. Also, they had mechanical properties to be used as a dressing (13.73 ± 3.09 MPa and 3.17 ± 1.28% of elongation at break), and its permeability (6.18 ± 0.43 (10-13) g.Pa-1.s-1.m-1) could be able to maintain the environmental moisture at the wound surface. Besides that, the (bio)nanocomposites acted against the studied bacteria, being a potential contact antimicrobial and biodegradable wound dressing. Finally, the developed (bio)nanocomposites are semi-occlusive and good candidates for dry wounds to be widely in vitro and in vivo tested as controlled silver sulfadiazine delivery dressing.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Bandagens , Nanocompostos/química , Sulfadiazina de Prata/química , Materiais Biocompatíveis/química , Argila/química , Escherichia coli/efeitos dos fármacos , Manihot/química , Permeabilidade , Pseudomonas aeruginosa/efeitos dos fármacos , Sulfadiazina de Prata/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Amido/química , Vapor , Difração de Raios XRESUMO
In the present study, supramolecular polyelectrolyte complexes (SPEC) based on a cyclodextrin-grafted chitosan derivative and carrageenan were prepared and evaluated for controlled drug release. Samples were characterized by FTIR, SEM, and ζ-potential measurements, which confirmed the formation of the polymeric complex. The phenolphthalein test confirmed the presence and availability of inclusion sites from the attached ßCD. Silver sulfadiazine was used as the model drug and the association with the SPEC was studied by FTIR and computational molecular modeling, using a semi-empirical method. DRS and TEM analyses have shown that Ag+ ions from the drug were reduced to form metallic silver nanostructures. In vitro tests have shown a clear bacterial activity toward Gram-positive bacteria Staphylococcus aureus and Enterococcus durans/hirae and Gram-negative bacteria Klebsiella pneumoniae and Escherichia coli. Finally, this work shows that ßCD-chitosan/carrageenan supramolecular polyelectrolyte complexes hold an expressive potential to be applied as a polymer-based system for controlled drug release.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Carragenina/química , Quitosana/química , Ciclodextrinas/química , Liberação Controlada de Fármacos/efeitos dos fármacos , Polieletrólitos/química , Polieletrólitos/farmacologia , Biologia Computacional/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Íons/química , Testes de Sensibilidade Microbiana , Nanoestruturas/química , Prata/química , Sulfadiazina de Prata/química , Sulfadiazina de Prata/farmacologiaRESUMO
Alginate (ALG) is an abundant, biocompatible, regenerative, and nontoxic polysaccharide that has potential applications in tissue engineering. Silver sulfadiazine (SDZ) is a topical antibiotic used to control bacterial infection in burns. Aiming to combine the intrinsic alginate characteristics and silver sulfadiazine antimicrobial properties, hydrotalcite ([Mg-Al]-LDH) was used as a host matrix to obtain a system efficient in delivering SDZ from alginate films. SDZ was successfully intercalated in [Mg-Al]-LDH through structural reconstruction. Different solutions were prepared using sodium alginate at 10â¯wt%, glycerol at 10â¯wt% as a plasticizer and [Mg-Al]-LDH and [Mg-Al]-LDH/SDZ as fillers at 1â¯wt% and 5â¯wt%. Films were obtained by continuous casting and further characterized for their microstructural, mechanical, water barrier and antimicrobial properties. Cytotoxicity tests were also performed on fibroblasts cells. The incorporation of [Mg-Al]-LDH and [Mg-Al]-LDH/SDZ presented neither negative nor positive effects on the mechanical properties and morphology of the alginate films. Moreover, samples containing SDZ exhibited inhibitory activity against S. aureus, E. coli, and S. enterica. The addition of [Mg-Al]-LDH/SDZ even at the highest concentration did not afford a very significant cytotoxicity to the alginate-[Mg-Al]-LDH/SDZ films. These results describe a suitable approach for preparing innovative active wound dressings integrated to efficient drug delivery.
Assuntos
Alginatos , Antibacterianos , Bactérias/crescimento & desenvolvimento , Bandagens , Membranas Artificiais , Sulfadiazina de Prata , Cicatrização/efeitos dos fármacos , Alginatos/química , Alginatos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Humanos , Teste de Materiais , Sulfadiazina de Prata/química , Sulfadiazina de Prata/farmacologiaRESUMO
Hybrid delivery systems can release multiple drugs with different profiles and have several applications, including skin dressing. In this work, the co-solvent technique was used for the preparation of nanometric vesicles based on poly(styrene-b-ethylene oxide) block copolymer (BCPVs) containing adapalene (AD). The BCPVs were incorporated into collagen and gelatin matrices together with free AD and silver sulfadiazine (SSD). The AD content of BCPVs and their release capacity were analyzed by using ultraviolet-visible spectroscopy (UV-Vis). The gelatin and collagen matrices were evaluated for their ability to release AD and SSD through an in vitro release study. The obtained results confirmed that the production of empty and AD-loaded BCPVs was viable. The degree of AD encapsulation in BCPVs was 9.0% and the in vitro test revealed a constant, slow, and prolonged release of AD content from AD-loaded BCPVs. The combination of free and encapsulated multiple drugs in hybrid delivery systems based on gelatin and collagen matrices was shown to act as a skin dressing that combined the progressive release of large amounts of drugs within the first hours of use (to restrict infection) with a more prolonged and slow release of AD to enhance skin healing.
Assuntos
Colágeno/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Gelatina/química , Polietilenoglicóis/química , Poliestirenos/química , Adapaleno/química , Sulfadiazina de Prata/química , Propriedades de SuperfícieRESUMO
Cooperation between researchers in the areas of medical, pharmaceutical and materials science has facilitated the development of pharmaceutical dosage forms that elicit therapeutic effects and protective action with a single product. In addition to optimizing pharmacologic action, such dosage forms provide greater patient comfort and increase success and treatment compliance. In the present work, we prepared semipermeable bioactive electrospun fibers for use as wound dressings containing silver sulfadiazine complexed with ß-cyclodextrin in a poly(Æ-caprolactone) nanofiber matrix aiming to reduce the direct contact between silver and skin and to modulate the drug release. Wound dressings were prepared by electrospinning, and were subjected to ATR-FT-IR and TG/DTG assays to evaluate drug stability. The hydrophilicity of the fibrous nanostructure in water and PBS buffer was studied by goniometry. Electrospun fibers permeability and swelling capacity were assessed, and a dissolution test was performed. In vitro biological tests were realized to investigate the biological compatibility and antimicrobial activity. We obtained flexible matrices that were each approximately 1.0 g in weight. The electrospun fibers were shown to be semipermeable, with water vapor transmission and swelling indexes compatible with the proposed objective. The hydrophilicity was moderate. Matrices containing pure drug modulated drug release adequately during 24 h but presented a high hemolytic index. Complexation promoted a decrease in the hemolytic index and in the drug release but did not negatively impact antimicrobial activity. The drug was released predominantly by diffusion. These results indicate that electrospun PCL matrices containing ß-cyclodextrin/silver sulfadiazine inclusion complexes are a promising pharmaceutical dosage form for wound healing.
Assuntos
Portadores de Fármacos/síntese química , Nanofibras/química , Poliésteres/química , Sulfadiazina de Prata/administração & dosagem , Cicatrização , beta-Ciclodextrinas/administração & dosagem , Bandagens , Células Sanguíneas/efeitos dos fármacos , Células Sanguíneas/fisiologia , Fenômenos Químicos , Formas de Dosagem , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Galvanoplastia , Hemólise/efeitos dos fármacos , Humanos , Teste de Materiais , Testes de Sensibilidade Microbiana , Sulfadiazina de Prata/química , Termogravimetria , Cicatrização/efeitos dos fármacos , beta-Ciclodextrinas/químicaRESUMO
Development and optimization of a hydrogel with impregnated silver sulfadiazine was pursued, for antimicrobial topical applications. The selected hydrogel exhibited a homogeneous appearance, with whitish colloration and devoid of any fractures or cracks. The content in impregnated silver sulfadiazine was within established limits (1%, w/w) with a standard deviation of up to 1.28%. The hydrogel presented a good characteristic in relation to release of the active antimicrobial principle, verified through swelling tests and antimicrobial activity. The swelling tests indicated a higher increase in weight during the first 6 h of contact with a moist environment, with a maximum value of 266.00 ± 0.81, and with maintenance of the original shape of the hydrogel. The impregnated silver sulfadiazine presented antimicrobial activity, as expected, indicating a prolonged release of the drug. The infrared spectra of the hydrogel with impregnated silver sulfadiazine indicated that the drug did not engage in any bonds with the polymeric matrix, which otherwise could have reduced its antimicrobial activity. The mechanical resistance tests produced good results, indicating that the hydrogels may be utilized in different locations of the human body with skin lesions.
Assuntos
Antibacterianos/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Sulfadiazina de Prata/química , Prata/química , Antibacterianos/farmacologia , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Prata/farmacologia , Sulfadiazina de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacosRESUMO
The production and evaluation of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices are reported herein. The matrices were melt extruded under nine different conditions, altering the temperature and the screw speed values. The surface morphology of the matrices was examined by scanning electron microscopy. The micrographs revealed the presence of non-melted silver sulfadiazine microparticles in the matrices extruded at lower temperature and screw speed values. The thermal properties were evaluated and the results for both the biopolymer and the drug indicated no thermal degradation during the melt extrusion process. The differential scanning analysis of the extrudate matrices showed a shift to lower temperatures for the silver sulfadiazine melting point compared with the non-extruded drug. The starch/cellulose acetate matrices containing silver sulfadiazine demonstrated significant inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus. In vivo inflammatory response tests showed that the extrudate matrices, with or without silver sulfadiazine, did not trigger chronic inflammatory processes.
Assuntos
Celulose/análogos & derivados , Sulfadiazina de Prata/química , Amido/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Celulose/química , Cromatografia Líquida de Alta Pressão , Interleucina-10/sangue , Interleucina-6/sangue , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos , Ratos Wistar , Sulfadiazina de Prata/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacosRESUMO
Ultraviolet B (UVB) irradiation mainly affects biological tissues by inducing an increase in reactive oxygen species (ROS) production which leads to deleterious outcomes for the skin, including pain and inflammation. As a protective strategy, many studies have focused on the use of natural products. The aim of this study was to investigate the effects of Aloe saponaria on nociceptive, inflammatory, and oxidative parameters in a model of UVB-induced sunburn in adult male Wistar rats. Sunburned animals were topically treated with vehicle (base cream), 1% silver sulfadiazine (positive control) or A. saponaria (10%) once a day for 6days. UVB-induced nociception (allodynia and hyperalgesia), inflammation (edema and leukocyte infiltration) and oxidative stress (increases in H2O2, protein carbonyl levels and lipid peroxidation and a decrease in non protein thiol content) were reduced by both A. saponaria and sulfadiazine topical treatment. Furthermore, A. saponaria or its constituents aloin and rutin reduced the oxidative stress induced by H2O2 in skin homogenates in vitro. Our results demonstrate that topical A. saponaria treatment displayed anti-nociceptive and anti-inflammatory effects in a UVB-induced sunburn model, and these effects seem to be related to its antioxidant components.