RESUMO
Biofilms of multidrug-resistant bacteria in chronic wounds pose a great challenge in wound care. Herein, we report the topical delivery of molecularly engineered antimicrobial peptides using electrospun nanofiber dressings as a carrier for the treatment of biofilms of multidrug-resistant bacteria in diabetic wounds. Molecularly engineered human cathelicidin peptide 17BIPHE2 was successfully encapsulated in the core of pluronic F127/17BIPHE2-PCL core-shell nanofibers. The in vitro release profiles of 17BIPHE2 showed an in initial burst followed by a sustained release over 4 weeks. The peptide nanofiber formulations effectively killed methicillin-resistant Staphylococcus aureus (MRSA) USA300. Similarly, the 17BIPHE2 peptide containing nanofibers could also effectively kill other bacteria including Klebsiella pneumoniae (104 to 106 CFU) and Acinetobacter baumannii (104 to 107 CFU) clinical strains in vitro without showing evident cytotoxicity to skin cells and monocytes. Importantly, 17BIPHE2-containing nanofiber dressings without debridement caused five-magnitude decreases of the MRSA USA300 CFU in a biofilm-containing chronic wound model based on type II diabetic mice. In combination with debridement, 17BIPHE2-containing nanofiber dressings could completely eliminate the biofilms, providing one possible solution to chronic wound treatment. Taken together, the biodegradable nanofiber-based wound dressings developed in this study can be utilized to effectively deliver molecularly engineered peptides to treat biofilm-containing chronic wounds.
Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bandagens , Biofilmes/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Nanofibras/administração & dosagem , Engenharia de Proteínas , Infecção dos Ferimentos/tratamento farmacológico , Administração Cutânea , Animais , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Sobrevivência Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/complicações , Modelos Animais de Doenças , Liberação Controlada de Fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Nanofibras/química , Poloxâmero/química , Poliésteres/química , Pele/efeitos dos fármacos , Pele/microbiologia , Infecção dos Ferimentos/patologia , CatelicidinasRESUMO
Biofilms pose a major challenge to control wound-associated infections. Due to biofilm impenetrability, traditional antimicrobial agents are often ineffective in combating biofilms. Herein, a biphasic scaffold is reported as an antimicrobial delivery system by integrating nanofiber mats with dissolvable microneedle arrays for the effective treatment of bacterial biofilms. Different combinations of antimicrobial agents, including AgNO3 , Ga(NO3 )3 , and vancomycin, are incorporated into nanofiber mats by coaxial electrospinning, which enables sustained delivery of these drugs. The antimicrobial agents-incorporated dissolvable microneedle arrays allow direct penetration of drugs into biofilms. By optimizing the administration strategies, drug combinations, and microneedle densities, biphasic scaffolds are able to eradicate both methicillin-resistant Staphylococcus aureus (MRSA) and MRSA/Pseudomonas aeruginosa blend biofilms in an ex vivo human skin wound infection model without necessitating surgical debridement. Taken together, the combinatorial system comprises of nanofiber mats and microneedle arrays can provide an efficacious delivery of multiple antimicrobial agents for the treatment of bacterial biofilms in wounds.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecção dos Ferimentos , Antibacterianos/farmacologia , Biofilmes , Humanos , Pseudomonas aeruginosa , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
Biofilms in chronic wounds, including diabetic foot ulcers, pressure ulcers, and venous leg ulcers, pose a major challenge to wound management. Herein, we report a Janus-type antimicrobial dressing for eradication of biofilms in chronic wounds. The dressing consists of electrospun nanofiber membranes coupled with dissolvable microneedle arrays to enable effective delivery of a database-designed antimicrobial peptide to both inside and outside biofilms. This antimicrobial dressing exhibited high efficacy against a broad spectrum of resistant pathogens in vitro. Importantly, such a dressing was able to eradicate methicillin-resistant Staphylococcus aureus (MRSA) biofilms in both an ex vivo human skin wound infection model and a type II diabetic mouse wound infection model after daily treatment without applying surgical debridement. Most importantly, the dressing can also completely remove the Pseudomonas aeruginosa and MRSA, dual-species biofilm in an ex vivo human skin infection model. In addition, our computational simulations also suggested that microneedles were more effective in the delivery of peptides to the biofilms than free drugs. Our results indicate that the Janus-type antimicrobial dressings may provide an effective treatment and management of chronic wound polymicrobial infections.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Nanofibras , Infecção dos Ferimentos , Antibacterianos , Bandagens , Biofilmes , Humanos , Proteínas Citotóxicas Formadoras de Poros , Pseudomonas aeruginosa , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
AIM: The aim of this study was to develop a nanofiber-based dressing capable of local sustained delivery of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) and augmenting human CAMP induction. MATERIALS & METHODS: Nanofibrous wound dressings containing 1,25(OH)2D3 were successfully prepared by electrospinning, which were examined in vitro, in vivo and ex vivo. RESULTS: 1,25(OH)2D3 was successfully loaded into nanofibers with encapsulation efficiency larger than 90%. 1,25(OH)2D3 showed a sustained release from nanofibers over 4 weeks. Treatment of U937 and HaCaT cells with 1,25(OH)2D3-loaded poly(ϵ-caprolactone) nanofibers significantly induced hCAP18/LL37 expression in monocytes and keratinocytes, skin wounds of humanized transgenic mice and artificial wounds of human skin explants. CONCLUSION: 1,25(OH)2D3 containing nanofibrous dressings could enhance innate immunity by inducing antimicrobial peptide production.
Assuntos
Anti-Infecciosos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/metabolismo , Nanofibras/administração & dosagem , Vitamina D/análogos & derivados , Animais , Anti-Infecciosos/química , Peptídeos Catiônicos Antimicrobianos/química , Bandagens/microbiologia , Linhagem Celular , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/microbiologia , Camundongos , Camundongos Transgênicos , Monócitos/efeitos dos fármacos , Nanofibras/química , Vitamina D/administração & dosagem , Vitamina D/química , Técnicas de Fechamento de FerimentosRESUMO
Estrogens are a known risk factor for breast cancer. Studies indicate that initiation of breast cancer may occur by metabolism of estrogens to form abnormally high levels of catechol estrogen-3,4-quinones, which can then react with DNA to form depurinating adducts and, subsequently, induce mutations that lead to cancer. Among the key enzymes metabolizing estrogens are two activating enzymes: cytochrome P450 (CYP)19 (aromatase), which converts androgens to estrogens, and CYP1B1, which converts estrogens predominantly to the 4-catechol estrogens that are further oxidized to catechol estrogen-3,4-quinones. Formation of the quinones is prevented by methylation of the 4-catechol estrogens by the enzyme, catechol-O-methyltransferase (COMT). In addition, catechol estrogen quinones can be reduced back to catechol estrogens by NADPH quinone oxidoreductase 1 (NQO1) and/or are coupled with glutathione, preventing reaction with DNA. Thus, COMT and NQO1 are key deactivating enzymes. In this initial study, we examined whether the expression of these four critical estrogen activating/deactivating enzymes is altered in breast cancer. Control breast tissue was obtained from four women who underwent reduction mammoplasty. Breast tissues from five women with breast carcinoma, who underwent mastectomy, were used as cases. The level of expression of CYP19, CYP1B1, COMT and NQO1 mRNAs was quantified from total RNA using a real time RT-PCR method in an ABI PRISM 7700 sequence detection system. The control breast tissues showed lower expression of the activating enzymes, CYP19 and CYP1B1, and higher expression of the deactivating enzymes, COMT and NQO1, compared to the cases. In the cases, the reverse pattern was observed: greater expression of activating enzymes and lower expression of deactivating enzymes. Thus, in women with breast cancer, estrogen metabolism may be related to altered expression of multiple genes. These unbalances appear to be instrumental in causing excessive formation of catechol estrogen quinones that, by reacting with DNA, initiate the series of events leading to breast cancer.
Assuntos
Neoplasias da Mama/metabolismo , Carcinoma/metabolismo , Estrogênios/metabolismo , Regulação Neoplásica da Expressão Gênica , Tecido Adiposo/metabolismo , Adulto , Idoso , Aromatase/metabolismo , Hidrocarboneto de Aril Hidroxilases/metabolismo , Mama/metabolismo , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Carcinoma/enzimologia , Catecol O-Metiltransferase/metabolismo , Citocromo P-450 CYP1B1 , DNA/química , DNA/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Modelos Químicos , Mutação , NAD(P)H Desidrogenase (Quinona)/metabolismo , Oxigênio/química , RNA/química , RNA/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco , Fatores de TempoRESUMO
BACKGROUND: Mandibular reconstruction using free fibular flaps can be performed using various plating techniques. Miniplates (