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1.
Ann Lab Med ; 42(1): 36-46, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34374347

RESUMEN

Background: The emergence of carbapenemase-producing Enterobacteriaceae (CPE) represents a major clinical problem. Recently, the occurrence of CPE has increased globally, but epidemiological patterns vary across region. We report the trends in the genotypic distribution and antimicrobial susceptibility of CPE isolated from rectal and clinical samples during a four-year period. Methods: Between January 2016 and December 2019, 1,254 nonduplicated CPE isolates were obtained from four university hospitals in Korea. Carbapenemase genotypes were determined by multiplex real-time PCR. Antimicrobial susceptibility was profiled using the Vitek 2 system (bioMérieux, Hazelwood, MO, USA) or MicroScan Walkaway-96 system (Siemens West Sacramento, CA, USA). The proportions of carbapenemase genotypes and nonsusceptibility were analyzed using Pearson's chi-square test. Results: Among the 1,254 CPE isolates, 486 (38.8%), 371 (29.6%), 357 (28.5%), 8 (0.6%), 8 (0.6%), and 24 (1.9%) were Klebsiella pneumoniae carbapenemase (KPC), oxacillinase (OXA)-48-like, New Delhi metallo-ß-lactamase (NDM), imipenemase (IMP), Verona integron-encoded metallo-ß-lactamase (VIM), and multiple producers, respectively. The predominant species was K. pneumoniae (72.6%), followed by Escherichia coli (6.5%). More than 90% of the isolates harboring KPC, NDM, and OXA-48-like were nonsusceptible to cephalosporins, aztreonam, and carbapenems. Conclusions: The impact of CPE is primarily due to KPC-, NDM-, and OXA-48-like-producing K. pneumoniae isolates. Isolates carrying these carbapenemase are mostly multidrug-resistant. Control strategies based on these genotypic distributions and antimicrobial susceptibilities of CPE isolates are required.


Asunto(s)
Antiinfecciosos , Enterobacteriaceae Resistentes a los Carbapenémicos , Infecciones por Enterobacteriaceae , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Infecciones por Enterobacteriaceae/epidemiología , Genotipo , Hospitales Universitarios , Humanos , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , República de Corea , beta-Lactamasas/genética
2.
J Hazard Mater ; 416: 125847, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-34492800

RESUMEN

Microplastics (MPs) and antibiotic resistance genes (ARGs) are two classes of emerging and prevalent contaminants in terrestrial environments. To date, effects of MPs on the occurrence of ARGs in terrestrial invertebrates remain uncertain. Here we exposed earthworms to a soil amended with polystyrene MPs at two environmentally relevant concentrations to elucidate the occurrence and mechanisms of ARGs in earthworms impacted by MPs with different sizes. Nano-size and 10 mg/kg of 100 µm MPs slightly affected the occurrence of ARGs in earthworms. Highest abundance of ARGs was found in the presence of 10 mg/kg of 10 µm MPs, whereas 100 mg/kg of 10 µm MPs significantly changed the profile of ARGs. Metagenomics sequencing and toxicity tests indicated that MPs caused toxicity and influenced the abundance of microbial community in earthworms, resulting in the changes of ARGs. Results of proteomics and metabolomics demonstrated that 100 mg/kg of 10 µm MPs changed the microenvironment of earthworm gut, built a new homeostatic process, and thus increased the abundance of key bacterial that carried a variety of ARGs. This study highlights the size-dependent toxic effects of MPs and their impacts on the transfer of ARGs in terrestrial environments.


Asunto(s)
Microplásticos , Oligoquetos , Animales , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Genes Bacterianos , Oligoquetos/genética , Plásticos , Poliestirenos , Suelo
3.
J Hazard Mater ; 416: 125865, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-34492813

RESUMEN

Anaerobic biological treatment technologies are one of the major hotspots of antibiotic resistance genes (ARGs). Previous studies have applied the electrochemical process to improve biogas production, however, it was challenged that high voltages might promote membrane permeability and reactive oxygen species overproduction to promote ARGs proliferation. Herein, the biogas production and ARGs proliferation in an anaerobic electrochemical membrane bioreactor (AnEMBR) were investigated at the gradient voltages of 0-0.9 V. Results show the reactor performances (average CH4 production and current generation) were distinctly improved with the increase of applied voltage, and reached the optimum at 0.9 V. However, long-term application (>30 day) of 0.9 V deteriorated the reactor performances. Meanwhile, the relative abundances of most target ARGs in the supernatant and effluent of AnEMBR at 0.9 V increased by 0.68-1.55 and 0.42-1.26 logs compared to those before applying voltage, respectively. After disconnecting the circuit, these ARGs abundances all decreased to the original level. Significant correlations between intlI and ARGs (e.g., tetA, tetQ, sulI, and sulII) were observed, indicating horizontal gene transfer may contribute to the increased ARGs. Moreover, the shift of microbial communities caused by the applied voltage enriched potential ARGs-hosts (e.g., Tolumonas), contributing to the proliferation of ARGs.


Asunto(s)
Antibacterianos , Biocombustibles , Anaerobiosis , Antibacterianos/farmacología , Reactores Biológicos , Proliferación Celular , Farmacorresistencia Microbiana/genética , Genes Bacterianos
4.
J Hazard Mater ; 416: 125868, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-34492815

RESUMEN

Comprehensive studies on the effects of cold stress on antibiotic resistance genes (ARGs) in the intestines and feces remain scarce. In this study, pigs were selected as the animal model and divided into a normal temperature group and a 48-h short-term cold stress group. The ARG profiles in fecal, cecal content and cecal mucosa samples were analyzed. The results showed that the normalized abundance of ARGs in the cecal mucosa samples in the cold stress group was significantly higher than that in the normal temperature group, while the normalized ARG abundances in the fecal and cecal content samples were significantly lower than those in the normal temperature group (P < 0.05). The bacterial community composition (especially Firmicutes) was the major driver impacting the ARG profile and accounted for 32.2% of the variation in the ARG profile, followed by metabolites (especially creatinine and oxypurinol) and mobile genetic elements (MGEs) (especially plasmids and insertion elements). And it was found that creatinine and oxypurinol can reduce the abundance of ARGs and Firmicutes in the in vitro experiment. The results indicate that short-term cold stress can reduce the abundance of ARGs in the cecum and feces of pigs, providing reference data for environmental safety.


Asunto(s)
Antibacterianos , Genes Bacterianos , Animales , Antibacterianos/farmacología , Ciego , Respuesta al Choque por Frío , Farmacorresistencia Microbiana/genética , Heces , Porcinos
5.
J Hazard Mater ; 416: 125888, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-34492826

RESUMEN

Fabrication of simple and efficient adsorbents is greatly vital to satisfy the requirements of removal of tellurium in wastewater treatment, yet remains challenging. Here, a facile and cost-effective strategy to develop ZIF-L coated self-crosslinking cellulose membrane (ZIF-L/SC membrane) for tellurium adsorption was presented. In-situ vertical growth of ZIF-L nanoplates with functional properties on membrane substrate is an available strategy, effectively remedying deficiency of pure nanosized sorbent in agglomeration problem and unhandy recovery. The SC membrane formed by strong hydrogen bonding among cellulose fibers is an excellent substrate, due to the favorable mechanical strength and abundant hydroxyl groups. The as-prepared ZIF-L/SC membrane shows advantageous morphology of large contact surface, fine thermal stability and eligible mechanical strength. The adsorption performance and possible mechanism of ZIF-L/SC membrane for Te (IV) were investigated by diverse characterization methods, showing admirable adsorption effect. Furthermore, the ZIF-L/SC membrane has excellent antibacterial properties, thus it is expected to deal with membrane fouling caused by microorganism breeding. Therefore, the bifunctional ZIF-L/SC membrane with excellent antibacterial activity is anticipated to be a promising candidate for efficient tellurium adsorbents, and simultaneously have potential in various fields in the future.


Asunto(s)
Zeolitas , Adsorción , Antibacterianos/farmacología , Celulosa , Telurio
6.
Mater Sci Eng C Mater Biol Appl ; 128: 112265, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474824

RESUMEN

Spurred by recent progress in biomaterials and therapeutics, stimulus-responsive strategies that deliver an active substance in temporal-, spatial-, and dose-controlled fashions have become achievable. Implementation of such strategies necessitates the use of bio-safe materials that are sensitive to a specific pathological incitement or that, in response to a precise stimulus, undergo hydrolytic cleavage or a change in biomolecular conformation. An innovative design of polymeric stimulus-responsive systems should controllably release a drug or degrade the drug carrier in response to specific lesion enzymes. Wound healing is a great challenge due to various hidden factors such as pathogenic infections, neurovascular diseases, excessive exudates, lack of an effective therapeutic delivery system, low cell proliferation, and cell migration. In addition, long-term use of antibiotics in chronic wound management can result in side effects and antimicrobial resistance. Novel treatments with antibacterial pharmaceuticals thus vitally need to be developed. Recently, graphene and graphene family members have emerged as shining stars among biomaterials for wound-healing applications due to their excellent bioactive properties, which can overcome limitations of current wound dressings and fulfill wound-healing requirements. Herein, we developed a feasible approach to impregnate graphene oxide (GO) into genipin-crosslinked gelatin (3GO) hydrogels to enzymatically control GO release. The developed hydrogels were characterized by chemical, physical, morphological, and cellular analyses. The results proved that the 3GO1 hydrogel is biocompatible and significantly enhanced the mechanical strength by encapsulating GO. Moreover, the rate of GO release depended on the crosslinking degree and environmental enzyme levels. Enzymatically released GO displayed uniform dispersity, retained its antibacterial activities against Staphylococcus aureus and Pseudomonas aeruginosa through sharp edges and wrapping mechanisms, and promoted human fibroblast migration. This multifunctional hydrogel we developed with antibacterial efficacy is suitable for future application as wound dressings.


Asunto(s)
Grafito , Antibacterianos/farmacología , Vendajes , Humanos , Hidrogeles , Cicatrización de Heridas
7.
Mater Sci Eng C Mater Biol Appl ; 128: 112266, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474825

RESUMEN

The precipitates in Ti-Ag alloy made an important contribution to antibacterial activity. In order to study this specific effects, Ti-Ag samples with different forms of precipitates were produced by powder metallurgy and ingot metallurgy followed by heat treatment: Ti-Ag(T4) with no precipitate, Ti-Ag(as-cast) and Ti-Ag(T6) with Ti2Ag and Ti-Ag(PM) with Ti2Ag and Ag-rich phase. Microstructure was analyzed by scanning electronic microscope (SEM), and the antibacterial effects, expression of reactive oxygen species (ROS), protein leakage and biocompatibility were investigated by plate count method, staining technology and cell test. The antibacterial ability was in the following order from low to high: Ti-Ag(T4) < Ti-Ag(as-cast) < Ti-Ag(T6) < Ti-Ag(PM). It was elucidated that Ag-containing phase was the major controlling factor of Ti-Ag antibacterial property and Ti-Ag(PM) with micro-size Ti2Ag and Ag-rich phase exhibited high antibacterial activity. It was proposed that the existence of Ag-containing phases induced high expression of ROS in bacteria, which destroyed the homeostasis of the bacteria and eventually leads to the rupture of the bacterial membrane. Cell test indicated that Ti-Ag samples had no adverse effect on cells and had good biocompatibility.


Asunto(s)
Aleaciones , Staphylococcus aureus , Aleaciones/farmacología , Antibacterianos/farmacología , Ensayo de Materiales , Metalurgia , Titanio/farmacología
8.
Mater Sci Eng C Mater Biol Appl ; 128: 112286, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474837

RESUMEN

The number of total knee and/or hip replacements are expected to exceed 5 million a year by 2030; the incidence of biofilm-associated complications can vary from 1% in primary implants to 5.6% in case of revision. The purpose of this study was to test the ability of sHA-DA, a partially sulphated hyaluronic acid (sHA) functionalized with a dopamine (DA) moiety, to prevent acute bacterial growth in an in vivo model of an intra-operatively highly contaminated implant. Previously, in vitro studies showed that the DA moiety guarantees good performance as binding agent for titanium surface adhesion, while the negatively charged sHA has both a high efficiency in electrostatic binding of positively charged antibiotics, and bone regenerative effects. The in vitro testing also highlighted the effectiveness of the sHA-DA system in inhibiting bacterial spreading through a sustained release of the antibiotic payload from the implant coating. In this study the chemical stability of the sHA-DA to ß-ray sterilization was demonstrated, based on evaluation by NMR, SEC-TDA Omnisec and HPLC-MS analysis, thus supporting the approach of terminal sterilization of the coated implant with no loss of efficacy. Furthermore, an in vivo study in rabbits was performed according to UNI EN ISO 10993-6 to assess the histocompatibility of titanium nails pre-coated with sHA-DA. The implants, placed in the femoral medullary cavity and harvested after 12 weeks, proved to be histocompatible and to allow bone growth in adhesion to the metal surface. Finally, an in vivo model of bacterial contamination was set up by injecting 1 mL of bacterial suspension containing 104 or 106 CFU of methicillin-resistant Staphylococcus aureus (MRSA) into the femoral medullary cavity of 30 rabbits. Titanium nails either uncoated or pre-coated with sHA-DA and loaded directly by the surgeon with 5% vancomycin were implanted in the surgical site. After 1 week, only the animals treated with pre-coated nails did not show the presence of systemic or local bacterial infection, as confirmed by microbiology and histology (Smeltzer score). Further insights into the animal model setup are crucial, however the results obtained suggest that the system can be effective in preventing the onset of the bacterial infective process.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Animales , Antibacterianos/farmacología , Materiales Biocompatibles Revestidos/farmacología , Dopamina , Ácido Hialurónico/farmacología , Conejos , Titanio/farmacología
9.
Mater Sci Eng C Mater Biol Appl ; 128: 112292, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474843

RESUMEN

The ever-growing threat of drug-resistant pathogens and their biofilms based persistent, chronic infections has created an urgent call for new strategies to deal with multidrug resistant bacteria (MDR). Near-infrared (NIR) laser-induced photothermal treatment (PTT) of gold nanorods (AuNRs) disinfects microbes by local heating with low possibility to develop resistant. However, PTT disinfection strategy of AuNRs alone shows less efficiency in killing multidrug resistant strains (i.e. Methicillin-resistant Staphylococcus aureus, MRSA) and their matured biofilms. Herein, a novel synergistic chemo-photothermal integrated antimicrobial platform (P(Cip-b-CB)-AuNRs) was fabricated which show enhanced killing efficiency against MRSA in both planktonic and biofilm phenotypes. Polymethacrylate copolymers with pendant ciprofloxacin (Cip) and the carboxyl betaine groups (P(Cip-b-CB)) were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. P(Cip-b-CB) was decorated onto AuNRs via gold-thiol bond which resulted in AuNRs with acidic-induced surface charge-switchable activities and lipase triggered Cip release properties (P(Cip-b-CB)-AuNRs). The lower pH value and overexpress of lipase are characteristics for microenvironment of microbial infections and their biofilms, which ensure the targeting on, penetration into and on-demand release of Cip from the nanocomposites in bacterial infection sites and their biofilms. The bacterial cell membrane was disrupt by photothermal therapy which could improve its permeability and sensitivity to antibiotics, meanwhile lipase-triggered release of Cip ensures a high concentration of antibiotics at the site of bacterial infection. Besides their NIR induced PTT disinfection activities, the increased local temperature generated by NIR light irradiation accelerated Cip release which further enhanced the antibacterial efficiency, leading to synergistic antibacterial activities of chemo-photothermal therapy. Taken together, the designed synergistic chemo-photothermal integrated antimicrobial platform is a promising antibacterial agent for fighting MDR bacterial infections and their biofilms.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Nanotubos , Preparaciones Farmacéuticas , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Biopelículas , Ciprofloxacina/farmacología , Oro , Concentración de Iones de Hidrógeno
10.
Mater Sci Eng C Mater Biol Appl ; 128: 112294, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474845

RESUMEN

In the present study, new-layered inorganic/organic hybrid of silver/talc nanocomposites (Ag/Tlc-NPs) and its chitosan-capped derivative (Ag/Tlc/Csn NCs) were biochemically synthesized utilizing Lawsonia inermis L. extract. The silver nanoparticles (Ag NPs) were synthesized employing green method on the exterior surface layer of talc mineral as a solid substrate. The negatively charged surface layer of talc might function as templates and can attract the chitosan cations from a solution to yield a layered hybrid structure, whose inorganic phase is formed by Si-O-Ag bonds. Our results revealed that Ag NPs were formed on the exterior surface of talc with a diameter with size of 124-215 nm. In addition, cytotoxicity, in vitro antibacterial activity, and clinical effects of wound-healing ointments containing talc were investigated. The results implied the successful synthesis of Ag/Tlc/Csn NCs using the extract. The structures were safe up to 0.50 mg/mL. In vitro studies confirmed antioxidant and antibacterial properties of Ag/Tlc/Csn NCs. In sum, our findings showed that the ointments improve wound healing process by inducing an anti-inflammatory M2 phenotype and bFGF, CD206, collagen1A, and IL-10 production that causes fibroblast migration and wound closure through influencing M2 macrophage. Ag/Tlc/Csn is suggested to be taken into consideration as a medical combination for improving infected wound healing and as a promising agent for clinical administration.


Asunto(s)
Quitosano , Lawsonia (Planta) , Nanopartículas del Metal , Nanocompuestos , Aceleración , Antibacterianos/farmacología , Pseudomonas aeruginosa , Plata , Staphylococcus aureus , Electricidad Estática , Talco , Cicatrización de Heridas
11.
Mater Sci Eng C Mater Biol Appl ; 128: 112296, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474847

RESUMEN

Hydroxyapatite is widely utilized for different biomedical applications because of its outstanding biocompatibility and bioactivity. Cuttlefish bones, which are available aplenty, are both inexpensive and eco-friendly sources for calcium carbonate. In the present study, cuttlefish bones-derived HAp nanorods have been utilized to fabricate HAp nanocomposites incorporating 1, 3 and 5 wt% each of GO, MWCNTs, GONRs and Ag NPs. Characterization using such techniques as XRD, FTIR, HRSEM and EDS was performed to analyze the physicochemical properties of nanocomposites, and MTT assay, hemolysis, bioactivity and drug release to evaluate the biological properties. The XRD and HRSEM results reveal that crystallite and particle size increase with increasing wt% of carbon nanomaterials and Ag NPs. However, the addition of nanomaterials did not modify the shape of HAp. The MTT assay and hemolysis results suggest GONRs possess better biocompatibility than GO and CNTs due to their smooth edge structure. While adding carbon materials up to 3 wt% caused an increase in the hardness, adding up to 5 wt% of them caused a decrease in the hardness due to the agglomeration of the particles. Biocompatibility and Vicker's hardness studies show that adding carbon nanomaterials up to 3 wt% caused significant improvement in biocompatibility and mechanical properties. Antibacterial activity test was performed to analyze the ability to preclude the formation of biofilms. The results showed better activity for silver-incorporated nanocomposites in the presence of E. coli and S. aureus bacteria. Drug release studies were performed using lidocaine drug and the results showed nearly similar drug release profile for all the samples except HAg3. Finally, nanocomposite HRA3 could be a suitable candidate for biomedical applications since it shows better biological and mechanical properties than GO and MWCNTs nanocomposites.


Asunto(s)
Durapatita , Nanocompuestos , Antibacterianos/farmacología , Carbono , Escherichia coli , Ensayo de Materiales , Plata/farmacología , Staphylococcus aureus
12.
Mater Sci Eng C Mater Biol Appl ; 128: 112318, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474869

RESUMEN

The rapid development of multidrug-resistant (MDR) bacteria due to the improper and overuse of antibiotics and the ineffective performance of antibiotics against the difficult-to-treat biofilm-related infections (BRIs) have urgently called for alternative antimicrobial agents and strategies in combating bacterial infections. Antimicrobial peptides (AMPs), owing to their compelling antimicrobial activity against MDR bacteria and BRIs without causing bacteria resistance, have attracted extensive attention in the research field. With the development of nanomaterial-based drug delivery strategies, AMPs-based nano-formulations have significantly improved the therapeutic effects of AMPs by ameliorating their hydrolytic stability, half-life in vivo, and solubility as well as reducing the cytotoxicity and hemolysis, etc. This review has comprehensively summarized the application AMPs-based nano-formulation in various bacterial infections models, including bloodstream infections (specifically sepsis), pulmonary infections, chronic wound infections, gastrointestinal infections, among others. The design of the nanomaterial-based drug delivery systems and the therapeutic effects of the AMPs-based nano-formulations in literature have been categorized and in details discussed. Overall, this review provides insights into the advantages and disadvantages of the current developed AMPs-based nano-formulations in literature for the treatment of bacterial infections, bringing inspirations and suggestions for their future design in the way towards clinical translation.


Asunto(s)
Antibacterianos , Péptidos Catiónicos Antimicrobianos , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias , Biopelículas , Proteínas Citotóxicas Formadoras de Poros
13.
Mater Sci Eng C Mater Biol Appl ; 128: 112319, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474870

RESUMEN

Chronic wounds are highly susceptible to bacterial infections. Previously, we loaded a natural antimicrobial peptide of low cost and high safety, ε-polylysine (EPL), into the electrospun nanofiber mat of starch. The mat showed comparable antibacterial activity but markedly better biocompatibility than the commercial silver-containing dressing. To further optimize material property, in this paper, we use hyaluronic acid (HA) to replace starch. Results show that EPL-loaded HA nanofiber mats (OHA-EPL) have suitable water vapor permeability, good biocompatibility and broad-spectrum antibacterial property similar to that of EPL-loaded starch nanofiber mat (Starch-EPL). Differently, the content of EPL in OHA-EPL nanofiber mats increases from 19.2% to 27.9%, the tensile strength rises from 0.3 MPa to 0.6 MPa, the elongation grows from 62.0% to 130.0%, and the fiber degradation and EPL release accelerates. In addition, OHA-EPL can absorb up to 26.3-times exudate, which is much higher than Starch-EPL (15.1 times). Combined with the excellent biological activity of HA, OHA-EPL may produce better therapeutic effects than Starch-EPL.


Asunto(s)
Nanofibras , Antibacterianos/farmacología , Vendajes , Ácido Hialurónico , Proteínas Citotóxicas Formadoras de Poros , Plata
14.
Mater Sci Eng C Mater Biol Appl ; 128: 112320, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474871

RESUMEN

This study aimed to fabricate cinnamon essential oil (CO)-laden 45S5 bioactive glass (BG)/soy protein (SP) scaffolds exhibiting antioxidant and antibacterial activity. In this regard, 45S5 BG-based scaffolds were produced by the foam replica method, and subsequently the scaffolds were coated with various concentrations of CO (2.5, 5 and 7 (v/v) %) incorporated SP solution. Scanning electron microscopy images revealed that the CO-laden SP effectively attached to the 45S5 BG scaffold struts. The presence of 45S5 BG, SP and CO was confirmed using Fourier transform infrared spectroscopy. Compressive strength results indicated that SP based coatings improved the scaffolds' mechanical properties compared to uncoated BG scaffolds. The loading efficiency and releasing behaviour of the different CO concentrations were tested by gas chromatography-mass spectroscopy and UV-Vis spectroscopy. The results showed that CO incorporated scaffolds have controlled releasing behaviour over seven days. Furthermore, the coating on the scaffold surfaces slightly retarded, but it did not inhibit, the in vitro bioactivity of the scaffolds. Moreover, the antioxidant and antibacterial activity of CO was studied. The free radical scavenging activity measured by DPPH was 5 ± 1, 41 ± 3, 44 ± 1 and 43 ± 1 % for BGSP, CO2.5, CO5 and CO7, respectively. The antioxidant activity was thus enhanced by incorporating CO. Agar diffusion and colony counting results indicated that the incorporation of CO increased the antibacterial activity of scaffolds against S. aureus and E. coli. In addition, cytotoxicity of the scaffolds was investigated using MG-63 osteoblast-like cells. The results showed that the BG-SP scaffold was non-toxic under the investigated conditions, whereas dose-dependent toxicity was observed in CO-laden scaffolds. Considered together, the developed phytotherapeutic agent laden 45S5 BG-based scaffolds are promising for bone tissue engineering exhibiting capability to combat bone infections and to protect against oxidative stress damage.


Asunto(s)
Antioxidantes , Aceites Volátiles , Antibacterianos/farmacología , Antioxidantes/farmacología , Cerámica , Cinnamomum zeylanicum , Escherichia coli , Vidrio , Aceites Volátiles/farmacología , Estrés Oxidativo , Proteínas de Soja , Staphylococcus aureus , Ingeniería de Tejidos , Andamios del Tejido
15.
Mater Sci Eng C Mater Biol Appl ; 128: 112322, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474873

RESUMEN

Many studies were conducted to change the surface morphology and chemical composition of Ti implants for the improvement of antibacterial ability and osseointegration between medical Ti and surrounding bone tissue. In this study, we successfully prepared a novel dual-function coating on pure Ti surface, i.e. Cu and Mg-co-doped TiO2 nanotube (TN) coating, by combining anodisation and hydrothermal treatment (HT), which could act as a delivery platform for the sustained release of Cu and Mg ions. Results showed that the amounts of Cu and Mg were about 5.43 wt%-6.55 wt% and 0.69 wt%-0.73 wt%, respectively. In addition, the surface morphology of Cu and Mg-co-doped TN (CuMTN) coatings transformed into nanoneedles after HT for 1 h. Compared with TN, CuMTN had no change in roughness and remarkable improved hydrophilicity. Antibacterial tests revealed that CuMTN had an antibacterial rate of more than 93% against Escherichia coli and Staphylococcus aureus, thereby showing excellent antibacterial properties. In addition, CuMTN could induce the formation of apatite well after being immersed in simulated body fluid, showing good biological activity. Preosteoblasts (MC3T3-E1) cultured on CuMTN-coated Ti demonstrated better proliferation and osteogenic differentiation than pristine and as-anodised specimens. To the best of our best knowledge, this study had successfully attempted to combine anodisation and HT, introduce Cu/Mg elements and functionalise Ti-based implant surfaces with enhanced hydrophilicity, osteogenesis and antimicrobial properties that can meet clinical needs for the first time.


Asunto(s)
Nanotubos , Osteogénesis , Antibacterianos/farmacología , Materiales Biocompatibles Revestidos/farmacología , Iones/farmacología , Propiedades de Superficie , Titanio/farmacología
16.
Mater Sci Eng C Mater Biol Appl ; 128: 112328, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474879

RESUMEN

Hydrogel-based drug delivery systems have emerged as a promising platform for chronic tissue defects owing to their inherent ability to inhibit pathogenic infection and accelerate rapid tissue regeneration. Here, we fabricated a stable bio-hybrid hydrogel system comprising collagen, aminated xanthan gum, bio-capped silver nanoparticles and melatonin with antimicrobial, antioxidant and anti-inflammatory properties. Highly colloidal bio-capped silver nanoparticles were synthesized using collagen as a reducing cum stabilizing agent for the first time while aminated xanthan gum was synthesized using ethylenediamine treatment on xanthan gum. The synthesized bio-hybrid hydrogel exhibits better gelation, surface morphology, rheology and degelation properties. In vitro assessment of bio-hybrid hydrogel demonstrates excellent bactericidal efficiency against both common wound and multidrug-resistant pathogens and biocompatibility properties. In vivo animal studies demonstrate rapid tissue regeneration, collagen deposition and angiogenesis at the wound site predominantly due to the synergistic effect of silver nanoparticles and melatonin in the hydrogel. This study paves the way for developing biologically functional bio-nano hydrogel systems for promoting effective care for various ailments, including infected chronic wounds.


Asunto(s)
Melatonina , Nanopartículas del Metal , Animales , Antibacterianos/farmacología , Colágeno , Hidrogeles , Melatonina/farmacología , Plata/farmacología
17.
Mater Sci Eng C Mater Biol Appl ; 128: 112334, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474885

RESUMEN

Surgical sutures are the most widely used medical device in any surgical procedure worldwide. In this study, modified electrospinning technique has been used as manufacturing technique to produce nanofiber bundles twisted simultaneously to obtain nanofiber yarns. Taking the advantage of nanofiber yarns in terms of biomimetic structure, mechanical strength and handling properties, the material is chosen. Curcumin, a natural compound is incorporated to the nanofiber yarns by blend electrospinning technique for its anti-inflammatory, antibiotic and wound healing properties. The synthesized nanofiber yarns were characterized by various characterization techniques such as XRD, FTIR, SEM, Tensile testing, stem cell interaction, hemocompatibility, bacterial response, drug release profiling and in vivo studies. Curcumin loaded nanofiber yarns demonstrated sustained release with improved antibacterial, antiplatelet, cell migration and stem cell interaction in vitro. The results from skin inflammation animal model revealed that curcumin laden nanofiber yarn suture manifested reduced inflammation and cellularity. The three dimensional structure, adequate mechanical strength and biological properties of the nanofiber yarn provide naive environment for wound healing with the balanced degradation of suture material in rat model.


Asunto(s)
Nanofibras , Animales , Antibacterianos/farmacología , Liberación de Fármacos , Ratas , Suturas , Cicatrización de Heridas
18.
Mater Sci Eng C Mater Biol Appl ; 128: 112342, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34474892

RESUMEN

Owing to the structural replication of native extracellular matrix, nonwoven mats of electrospun nanofibers have great potential for use in wound healing. Herein, we report the design and fabrication of a sandwich wound dressing to balance its antimicrobial activity and biocompatibility. This success mainly relies on the incorporation of silver nanoparticles (AgNPs) into electrospun nanofibers, together with the rational design of a sandwich structure for the dressing. The bottom layer was composed of hydrophilic nanofibers made from a blend of polycaprolactone (PCL) and gelatin (Gel). The top layer consisted of hydrophobic PCL nanofibers. AgNP-loaded PCL/Gel nanofibers were sandwiched between the two layers. When compared with a commercial silver sulfadiazine dressing, the designed wound dressing showed competitive antimicrobial properties, lower cell toxicity, and accelerated wound closure for mouse skin injury. By balancing the biocompatibility of electrospun nanofibers and the broad-spectrum antibacterial activity of AgNPs within a sandwich structure, the novel multifunctional wound dressing could be valuable for effective wound healing and related applications.


Asunto(s)
Nanopartículas del Metal , Nanofibras , Animales , Antibacterianos/farmacología , Vendajes , Ratones , Plata , Sulfadiazina de Plata/farmacología , Sulfadiazina , Cicatrización de Heridas
19.
An Acad Bras Cienc ; 93(suppl 3): e20190478, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34468488

RESUMEN

In this study, it was determinated the essential oil of cultivated apple mint, Mentha suaveolens Ehrh. composition and in vitro antibacterial activity of against 11 fish pathogen bacteria including Gram-positive (Staphylococcus warneri, Staphylococcus sp., Lactococcus garvieae, Vagococus salmoninarum) and Gram-negative (Aeromonas hydrophila, Aeromonas sobria Aeromonas cavieae, Vibrio anguillarum, Pseudomonas aeroginosa, Yersinia ruckeri, Edwardsiella tarda) by using agar diffusion assay. The main component of M. suaveolence oil was obtained as piperitenone oxide. The essential oil exhibited strong inhibitory activity such as inhibition zone sizes: 30-50mm at 250-1000 µL mL-1 concentrations against V. anguillarum; 16-20mm at 31.25-125 µL mL-1 concentrations against P. aeroginosa; 15-18mm at 500-1000 µL mL-1 concentrations against A. sobria. However, it was found to be moderately effective against E. tarda (8-15 mm), Y. ruckeri (9-12mm), S. warneri (9-10mm), V. salmoninarum (9mm) and Staphylococcus sp. (8-9mm). The essential oil showed weak inhibitory activity against A. cavieae (5-8), A. hydrophila (6-7mm), L. garvieae (5-7mm). Thus, effect of essential oil of M. suaveolens on immune response and disease resistance against Vibrio anguillarum, A. sobria and P. aeroginosa should be investigated in vivo in cultured fish species in future studies.


Asunto(s)
Aeromonas , Enfermedades de los Peces , Mentha , Aceites Volátiles , Animales , Antibacterianos/farmacología , Enfermedades de los Peces/tratamiento farmacológico , Lactococcus , Aceites Volátiles/farmacología , Staphylococcus , Vibrio
20.
Braz J Biol ; 83: e247165, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34468525

RESUMEN

Now a day's multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.


Asunto(s)
Antibacterianos , Ácido Ascórbico , Antibacterianos/farmacología , Ácido Ascórbico/farmacología , Bacterias Gramnegativas , Bacterias Grampositivas , Humanos , Pruebas de Sensibilidad Microbiana
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