RESUMO
The ocean is a treasure trove of both living and nonliving creatures, harboring incredibly diverse group of organisms. A plethora of marine sourced bioactive compounds are discovered over the past few decades, many of which are found to show antibiofilm activity. These are of immense clinical significance since the formation of microbial biofilm is associated with the development of high antibiotic resistance. Biofilms are also responsible to bring about problems associated with industries. In fact, the toilets and wash-basins also show degradation due to development of biofilm on their surfaces. Antimicrobial resistance exhibited by the biofilm can be a potent threat not only for the health care unit along with industries and daily utilities. Various recent studies have shown that the marine members of various kingdom are capable of producing antibiofilm compounds. Many such compounds are with unique structural features and metabolomics approaches are essential to study such large sets of metabolites. Associating holobiome metabolomics with analysis of their chemical attribute may bring new insights on their antibiofilm effect and their applicability as a substitute for conventional antibiotics. The application of computer-aided drug design/discovery (CADD) techniques including neural network approaches and structured-based virtual screening, ligand-based virtual screening in combination with experimental validation techniques may help in the identification of these molecules and evaluation of their drug like properties.
Assuntos
Antibacterianos , Biofilmes , Antibacterianos/farmacologia , Desenho de FármacosRESUMO
In the last few years, there has been a necessary demand in the pharmaceutical industries for finding a treatment against biofilms formed by different bacterial species. We are aware of the fact that classical processes, which are already there for the removal of bacterial biofilms gives a very low efficiency and consequently antimicrobial resistance makes it even worse. To cope up with the cited problems, scientists from the past few years are inclining toward various types of nanoparticle based treatment procedures as a pharmaceutical agent against bacterial biofilms. Nanoparticles are known for their extremely efficient antimicrobial properties. The current review gives a description of different types of metal oxide nanoparticles and their antibiofilm properties. It also shows a comparative analysis of the nanoparticles and depicts the efficiency rates of biofilm degradation in each of them. It explains the mechanism of the nanoparticles through which the disintegration of bacterial biofilm is carried out. Lastly, the review throws light upon the limitations of different nanoparticles, their safety issues, the mutagenicity, genotoxicity concerns, and toxicity hazards caused by them.
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Anti-Infecciosos , Nanopartículas Metálicas , Nanopartículas , Óxidos/farmacologia , Antibacterianos/farmacologia , Bactérias , Biofilmes , Metais/farmacologiaRESUMO
Biofilm is the syntrophic association of microbial colonies that remain adhered to the biotic and abiotic surfaces with the help of self-secreted polymeric substances also termed extracellular polymeric substances. Chronic pathogenicity caused by biofilm-associated pathogenic microorganisms becomes a significant threat in biomedical research. An extensive search is being made for the antibiofilm agents made from natural sources or their biogenic derivatives due to their effectivity and nontoxicity. Algae being the producer of various biogenic substances are found capable of disintegrating biofilm matrix and eradication of biofilm without exerting any deterrent effect on other biotas in the ecosystem. The current trend in phycological studies includes the exploration of antifouling efficacy among various algal groups. The extracts prepared from about 225 microalgae and cyanobacteria species are found to have antibiofilm activity. Polyunsaturated fatty acids are the most important component in the algal extract with antibacterial and antibiofilm properties. The antibiofilm activity of the sulfated polysaccharides extracted from a marine alga could be effectively used to remove dental biofilm. Algal extracts are also being used for the preparation of different biogenically synthesized nanoparticles, which are being used as potent antibiofilm agents. Genome editing of algal species by CRISPR/Cas9 may make precise modifications in the algal DNA for improving the algal strains and production of a more effective antibiofouling agent.
Assuntos
Bactérias , Ecossistema , Antibacterianos/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana , Extratos VegetaisRESUMO
Biofilm-associated infections have increased excessively over the recent years due to the increased population having impaired immune systems or as a result of certain medical conditions like transplantation, cancer, and any other chronic ailments. The abrupt enhancement of antibiotic resistance and enhanced utilization of biomedical devices offer new opportunities for microbial colonization leading to the development of microbial biofilms. Total eradication of recalcitrant microbial biofilms demands the adoption of a holistic approach and since the fungal metabolites enriched with bioactive compounds show efficacy in inhibiting the multiple factors behind biofilm formation, the anti-biofilm activities of fungal metabolites need to be appraised. Being effective in preventing various steps of biofilm formation, including inhibition of surface adhesion and cell-to-cell communication through quorum quenching, blocking of quorum sensing receptors, and enzymes involved in microbial cell wall biosynthesis, targeting the virulence factors and finally killing of biofilm bound individual cells; myco-metabolites are found effective as a potent holistic anti-biofilm agent. The wide spectrum of bioactive substances of fungi and their anti-biofilm activities against different pathogens and their multitarget characteristics are very promising in the field of treating biofilm infections.
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Antibacterianos , Biofilmes , Antibacterianos/farmacologia , Percepção de Quorum , Fatores de Virulência/metabolismoRESUMO
BACKGROUND: The major activity of ß-amylase (BMY) is the production of maltose by the hydrolytic degradation of starch. BMY is found to be produced by some plants and few microorganisms only. The industrial importance of the enzyme warrants its application in a larger scale with the help of genetic engineering, for which the regulatory mechanism is to be clearly understood. RESULTS AND CONCLUSION: In plants, the activities of BMY are regulated by various environmental stimuli including stress of drought, cold and heat. In vascular plant, Arabidopsis sp. the enzyme is coded by nine BAM genes, whereas in most bacteria, BMY enzymes are coded by the spoII gene family. The activities of these genes are in turn controlled by various compounds. Production and inhibition of the microbial BMY is regulated by the activation and inactivation of various BAM genes. Various types of transcriptional regulators associated with the plant- BMYs regulate the production of BMY enzyme. The enhancement in the expression of such genes reflects evolutionary significance. Bacterial genes, on the other hand, as exemplified by Bacillus sp and Clostridium sp, clearly depict the importance of a single regulatory gene, the absence or mutation of which totally abolishes the BMY activity.
Assuntos
Arabidopsis/enzimologia , Bacillus cereus/enzimologia , Proteínas de Bactérias/biossíntese , Clostridium/enzimologia , Proteínas de Plantas/biossíntese , beta-Amilase/biossíntese , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Domínio Catalítico , Regulação Bacteriana da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Maltose/metabolismo , Engenharia Metabólica/métodos , Proteínas de Plantas/química , Proteínas de Plantas/genética , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Amido/metabolismo , Estresse Fisiológico/genética , beta-Amilase/química , beta-Amilase/genéticaRESUMO
Bacterial cellulose (BC) is recognized as a multifaceted, versatile biomaterial with abundant applications. Groups of microorganisms such as bacteria are accountable for BC synthesis through static or agitated fermentation processes in the presence of competent media. In comparison to static cultivation, agitated cultivation provides the maximum yield of the BC. A pure cellulose BC can positively interact with hydrophilic or hydrophobic biopolymers while being used in the biomedical domain. From the last two decades, the reinforcement of biopolymer-based biocomposites and its applicability with BC have increased in the research field. The harmony of hydrophobic biopolymers can be reduced due to the high moisture content of BC in comparison to hydrophilic biopolymers. Mechanical properties are the important parameters not only in producing green composite but also in dealing with tissue engineering, medical implants, and biofilm. The wide requisition of BC in medical as well as industrial fields has warranted the scaling up of the production of BC with added economy. This review provides a detailed overview of the production and properties of BC and several parameters affecting the production of BC and its biocomposites, elucidating their antimicrobial and antibiofilm efficacy with an insight to highlight their therapeutic potential.
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Antibacterianos/farmacologia , Biopolímeros/farmacologia , Celulose/metabolismo , Celulose/farmacologia , Gluconacetobacter xylinus/metabolismo , Antibacterianos/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Biopolímeros/química , Escherichia coli/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
Extracellular isoamylase produced by Rhizopus oryzae PR7 MTCC 9642 in in Erlenmeyer flasks was purified by ultrafiltration and by two steps of Superose 6 C-10/300GL gel chromatography. The enzyme molecule was found to be a monomer with molecular weight of 68 kDa.The purified isoamylase showed optimum activity at pH 5.5 and temperature 55 °C. The catalytic activity was found to remain stable at a broad range of pH (4-8) and could show remarkable thermo resistance specially in presence of exogenous thiols. The noteworthy enhancement of activity in presence of Mn2+ indicated its role as enzyme cofactor while thermos and chemostability in presence of exogenous thiols indicated the presence of disulfide linkage at active site of the enzyme. Both in vitro study and doking analysis indicated the highest affinity of the isoamylase of R. oryzae PR7 toward glycogen and the enzyme exhibited Km and Vmax values of 0.38 mg/mL and 6.65 mM/min/mL, respectively. Purified debranching amylolytic enzyme from R. oryzae PR7 has potential for the study of glycogen and starch structure and industrial application in combination with other amylolytic enzymes. The rapid, convenient, relatively simple purification process and other functional attributes of the enzyme made it competent to be employed for industrial utilization.
Assuntos
Proteínas Fúngicas/química , Isoamilase/química , Rhizopus oryzae/enzimologia , Ensaios Enzimáticos , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Glicogênio/química , Glicogênio/metabolismo , Concentração de Íons de Hidrogênio , Isoamilase/isolamento & purificação , Isoamilase/metabolismo , Cinética , Simulação de Acoplamento Molecular , Ligação Proteica , Especificidade por Substrato , TemperaturaRESUMO
Protein aggregation generally results from association between hydrophobic regions of individual monomers. However, additional mechanisms arising from specific interactions, such as intermolecular disulfide bond formation, may also contribute to the process. The latter is proposed to be the initiating pathway for aggregation of immunoglobulin (IgG), which is essential for triggering its immune response. To test the veracity of this hypothesis, we have employed fluorescence correlation spectroscopy to measure the kinetics of aggregation of IgG in separate experiments either allowing or inhibiting disulfide formation. Fluorescence correlation spectroscopy measurements yielded a diffusion time (τ(D)) of â¼200 µsec for Rhodamine-labeled IgG, corresponding to a hydrodynamic radius (R(H)) of 56 Å for the IgG monomer. The aggregation kinetics of the protein was followed by monitoring the time evolution of τ(D) under conditions in which its cysteine residues were either free or blocked. In both cases, the progress curves confirmed that aggregation proceeded via the nucleation-dependent polymerization pathway. However, for aggregation in the presence of free cysteines, the lag times were shorter, and the aggregate sizes bigger, than their respective counterparts for aggregation in the presence of blocked cysteines. This result clearly demonstrates that formation of intermolecular disulfide bonds represents a preferred pathway in the aggregation process of IgG. Fluorescence spectroscopy showed that aggregates formed in experiments where disulfide formation was prevented denatured at lower concentration of guanidine hydrochloride than those obtained in experiments where the disulfides were free to form, indicating that intermolecular disulfide bridging is a valid pathway for IgG aggregation.
Assuntos
Dissulfetos/metabolismo , Imunoglobulina G/química , Imunoglobulina G/metabolismo , Agregados Proteicos , Animais , Bovinos , Cisteína/metabolismo , Ácido Ditionitrobenzoico/metabolismo , Guanidina/farmacologia , Cinética , Compostos Organofosforados/metabolismo , Agregados Proteicos/efeitos dos fármacos , Desnaturação Proteica/efeitos dos fármacos , Espectrometria de FluorescênciaRESUMO
Non-native and denatured states of proteins have received increasing attention because of their relevance to issues such as protein folding and stability. In this context, the pathway of polypeptide collapse and random coil formation in a denatured protein is a subject of much interest. Most proteins so far studied have shown monotonic expansion of their hydrodynamic radius (RH) in the presence of increasing concentration of chaotropes. We have studied GdnHCl-induced folding transitions and conformational states of a multi-domain protein, bovine gamma globulin, using fluorescence, circular dichroism and fluorescence correlation spectroscopy (FCS). FCS measurements showed that for gamma globulin, contrary to the observed trend, RH decreases with increasing GdnHCl concentration up to 3 M. At higher GdnHCl concentration, RH starts to increase but exhibits complicated behavior in the form of two sharp maxima at 4 M and 7 M. Further experiments suggest that the maximum at 4 M GdnHCl arises due to electrostatic interaction, whereas the one at 7 M GdnHCl corresponds to the usual expanded conformation due to denaturation. Beyond 7 M GdnHCl, RH decreases drastically and is shown to result from fragmentation of the protein caused by rupture of disulphide bonds by the high GdnHCl concentration. Our results demonstrate the capability of FCS in revealing intricate details of the unfolding trajectory that eludes conventional ensemble techniques such as fluorescence and CD.
Assuntos
gama-Globulinas/química , Animais , Bovinos , Dicroísmo Circular , Espectrometria de FluorescênciaRESUMO
We introduce a new rhodamine-rhodanine-based "turn-on" fluorescent sensor (RR1) and describe its application for detection of mercury, including in solution, in live cells, and in a living vertebrate organism. The sensor RR1, which is a one-pot synthesis from rhodamine B, undergoes a rapid and irreversible 1:1 stoichiometric reaction with Hg(2+) in aqueous medium. Using fluorescence correlation spectroscopy (FCS), RR1 was shown to detect the presence of as low as a 0.5 pM concentration of Hg(2+). It may also lend itself to tagging with biomolecules and nanoparticles, leading to the possibility of organelle-specific Hg detection. Results of experiments with mammalian cells and zebrafish show that RR1 is cell and organism permeable and that it responds selectively to mercury ions over other metal ions. In addition, real-time monitoring of inorganic mercury ion uptake by cells and live zebrafish using this chemosensor shows that saturation of mercury ion uptake occurs within 20-30 min in cells and organisms. We also demonstrate the acquisition of high-resolution real-time distribution maps of inorganic mercury (Hg(2+)) in the zebrafish brain by using a simple fluorescence confocal imaging technique.
Assuntos
Mercúrio/análise , Rodaminas/metabolismo , Rodanina/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Animais , Mercúrio/farmacocinética , Microscopia Confocal , Microscopia de FluorescênciaRESUMO
Colonisation of sessile bacterial species on biotic and abiotic surfaces is responsible for the development of various infections in humans. At present, biofilm-associated chronic infections have been a prime concern among the healthcare practitioners since they are impermeable to drugs, resulting in the development of antibiotic resistance or multi-drug resistance. For a few decades, a lot of research activity has been performed in the development of alternative therapeutics to combat biofilm-associated chronic infections. The presence of extracellular polymeric substance (EPS) prevents the permeation of most of the drugs rendering drug failures. The use of small molecules has been necessary to penetrate easily through the EPS and act on the targeted cells. In present days, the use of antimicrobial peptides (AMPs) has gained immense importance as alternative therapeutics since they exhibit a novel class of antibiotics exhibiting a wide spectrum of activity and possess a low rate of development of resistance. In the last few decades, a large number of AMPs have been identified from varied groups of organisms as effector molecules for innate immune system acting as an important line of defence. In this review, we will discuss the use of AMPs as effective agents to combat various biofilm-associated chronic infections.
Assuntos
Peptídeos Antimicrobianos , Biofilmes , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Humanos , Peptídeos Antimicrobianos/farmacologia , Animais , Antibacterianos/farmacologia , Regulação para Baixo/efeitos dos fármacosRESUMO
In pharmaceutical industries, various chemical carriers are present which are used for drug delivery to the correct target sites. The most popular and upcoming drug delivery carriers are mesoporous silica nanoparticles (MSN). The main reason for its popularity is its ability to be specific and optimize the drug delivery process in a controlled manner. Nowadays, MSNs are widely used to eradicate various microbial infections, especially the ones related to biofilms. Biofilms are sessile groups of cells that live by forming a consortium and exhibit antibacterial resistance (AMR). They exhibit AMR by extracellular polymeric substances (EPS) and various quorum sensing (QS) signaling molecules. Usually, bacterial and fungal cells are capable of forming biofilms. These biofilms are pathogenic. In the majority of the cases, biofilms cause nosocomial diseases. This review will focus on the antibiofilm activities of MSN, its mechanism of target-specific drug delivery, and its ability to disrupt the bacterial biofilms inhibiting the infection. The review will also discuss various mechanisms for the delivery of pharmaceutical molecules by the MSNs to inhibit the bacterial biofilms, and lastly, we will talk about the different types of MSNs and their antibiofilm activities.
RESUMO
The enzyme endoglucanase is responsible for the depolymerization of cellulose. This study focuses on characterization and purification of endoglucanase from Rhizopus oryzae MTCC 9642 through a simple size exclusion method and its effective application as an antibiofilm agent. Extracellular ß-1,4-endoglucanase, an enzyme that catalyzes the hydrolysis of carboxymethyl cellulose, was found to be synthesized by Rhizopus oryzae MTCC 9642. The enzyme was purified up to homogeneity simply by size exclusion process through ultrafiltration and gel chromatography. The molecular weight of purified enzyme protein was estimated to be 39.8 kDa and it showed the highest substrate affinity towards carboxymethyl-cellulose with Km and Vmax values of 0.833 mg ml-1 and of 0.33 mmol glucose min-1 mg-1protein, respectively. The purified enzyme exhibited optimal activity at pH 6 with a broad stability range of pH 3-8. The most preferred temperature was 35 °C and 50% of activity could be retained after the thermal exposure at 40 °C for 25 min. The purified enzyme protein was inactivated by Cu2+, while the activity could be enhanced by the addition of exogenous thiols. Since biofilm is a challenge for health sector, with the aim of eradicating the biofilm, the purified endoglucanase was used to remove biofilm produced by two nosocomial bacteria. As predicted by in silico molecular docking interaction, the purified enzyme could effectively degrade biofilm architecture of bacterial strains S. aureus and P. aeruginosa by 76.52 ± 6.52% and 61.67 ± 8.76%, respectively. The properties of purified enzyme protein, as elucidated by in vitro and in silico characterization, may be favourable for its commercial applications as a potent antibiofilm agent.
Assuntos
Celulase , Rhizopus oryzae , Celulase/metabolismo , Simulação de Acoplamento Molecular , Staphylococcus aureus , Temperatura , Celulose/metabolismo , Concentração de Íons de Hidrogênio , Estabilidade Enzimática , Especificidade por Substrato , Rhizopus/metabolismoRESUMO
The sustainable development of human society in today's high-tech world depends on some form of eco-friendly energy source because existing technologies cannot keep up with the rapid population expansion and the vast amounts of wastewater that result from human activity. A green technology called a microbial fuel cell (MFC) focuses on using biodegradable trash as a substrate to harness the power of bacteria to produce bioenergy. Production of bioenergy and wastewater treatment are the two main uses of MFC. MFCs have also been used in biosensors, water desalination, polluted soil remediation, and the manufacture of chemicals like methane and formate. MFC-based biosensors have gained a lot of attention in the last few decades due to their straightforward operating principle and long-term viability, with a wide range of applications including bioenergy production, treatment of industrial and domestic wastewater, biological oxygen demand, toxicity detection, microbial activity detection, and air quality monitoring, etc. This review focuses on several MFC types and their functions, including the detection of microbial activity.
Assuntos
Fontes de Energia Bioelétrica , Técnicas Biossensoriais , Humanos , Fontes de Energia Bioelétrica/microbiologia , Águas Residuárias , Análise da Demanda Biológica de Oxigênio , Água , Eletricidade , EletrodosRESUMO
Ovarian cancer cells usually spread in the peritoneal region, and if chemotherapeutic drugs can be given in these regions with proximity, then the anticancer property of the chemotherapeutic drugs can enhance. However, chemotherapeutic drug administrations are hindered by local toxicity. In the drug delivery system, microparticles or nanoparticles are administered in a controlled manner. Microparticles stay in a close vicinity while nanoparticles are smaller and can move evenly in the peritoneum. Intravenous administration of the drug evenly distributes the medicine in the target places and if the composition of the drug has nanoparticles it will have more specificity and will have easy access to the cancer cells and tumors. Among the different types of nanoparticles, polymeric nanoparticles were proven as most efficient in drug delivery. Polymeric nanoparticles are seen to be combined with many other molecules like metals, non-metals, lipids, and proteins, which helps in the increase of cellular uptake. The efficiency of different types of polymeric nanoparticles used in delivering the load for management of ovarian cancer will be discussed in this mini-review.
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Antineoplásicos , Nanopartículas , Neoplasias Ovarianas , Humanos , Feminino , Antineoplásicos/uso terapêutico , Polímeros/metabolismo , Polímeros/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Sistemas de Liberação de MedicamentosRESUMO
Leonurus sibiricus (Red verticilla, honeyweed) is a type of herbaceous plant predominantly found in Asian subcontinents as weed in crop fields and is widely used for treating diabetes, bronchitis, and menstrual irregularities. However, there is a dearth of study in the application of the plant phytocompounds for treating biofilm-associated chronic infections. The bioactive compounds mainly comprise of tri-terpenes, di-terpenes, phenolic acid, and flavonoids which may have potential role as antimicrobial and antibiofilm agents. Acute and chronic infection causing microbes usually form biofilm and develop virulence factors and antibiotic resistance through quorum sensing (QS). In this study, the bioactive compounds leosibirin, sibiricinone A, leosibirone A, leonotin, quercetin, lavandulifolioside, and myricetin were identified using GC-MS analysis. These were used for analyzing the antibiofilm and anti-quorum sensing activities (rhamnolipid, AHL assay, swarming motility assay) against the biofilm formed by Pseudomonas aeruginosa, the most significant nosocomial disease-causing bacteria. The compounds were able to bring about maximum inhibition in biofilm formation and QS. Although the antibiofilm activity of the phytoextract was found to be higher than that of individual phytocompounds at a concentration of 250 µg/mL, quercetin and myricetin showed highest antibiofilm activity against Pseudomonas aeruginosa, respectively, at MIC values of 135 µg/mL and 150 µg/mL against P aeruginosa. FT-IR study also revealed that the active ingredients were able to bring about the destruction of exopolysaccharides (EPS). These observations were further validated by molecular docking interactions that showed the active ingredients inhibit the functioning of QS sensing proteins by binding with them. It was observed that myricetin showed better interactions with the QS proteins of P. aeruginosa. Myricetin and quercetin show considerable inhibition of biofilm in comparison to the phytocompounds. Thus, the present study suggests that the active compounds from L. sibiricus can be used as an alternate strategy in inhibiting the biofilm formed by pathogenic organisms.
Assuntos
Leonurus , Pseudomonas aeruginosa , Pseudomonas aeruginosa/metabolismo , Leonurus/metabolismo , Simulação de Acoplamento Molecular , Quercetina , Espectroscopia de Infravermelho com Transformada de Fourier , Antibacterianos/farmacologia , Antibacterianos/química , Biofilmes , Fatores de Virulência/metabolismoRESUMO
Medicinal plants are long known for their therapeutic applications. Tinospora cordifolia (commonly called gulancha or heart-leaved moonseed plant), a herbaceous creeper widely has been found to have antimicrobial, anti-inflammatory, anti-diabetic, and anti-cancer properties. However, there remains a dearth of reports regarding its antibiofilm activities. In the present study, the anti-biofilm activities of phytoextractof T. cordifolia and the silver nanoparticles made from this phytoextract were tested against the biofilm of S.taphylococcus aureus, one of the major nosocomial infection-producing bacteria taking tetracycline antibiotic as control. Both phytoextract from the leaves of T. cordifolia, and the biogenic AgNPs from the leaf extract of T. cordifolia, were found successful in reducing the biofilm of Staphylococcus aureus. The biogenic AgNPs formed were characterized by UV- Vis spectroscopy, Field emission Scanning Electron Microscopy (FE- SEM), and Dynamic light scattering (DLS) technique. FE- SEM images showed that the AgNPs were of size ranging between 30 and 50 nm and were stable in nature, as depicted by the zeta potential analyzer. MIC values for phytoextract and AgNPs were found to be 180 mg/mL and 150 µg/mL against S. aureusrespectively. The antibiofilm properties of the AgNPs and phytoextract were analyzed using the CV assay and MTT assay for determining the reduction of biofilms. Reduction in viability count and revival of the S. aureus ATCC 23235 biofilm cells were analyzed followed by the enfeeblement of the EPS matrix to quantify the reduction in the contents of carbohydrates, proteins and eDNA. The SEM analyses clearly indicated that although the phytoextracts could destroy the biofilm network of S. aureuscells yet the biogenicallysynthesizedAgNPs were more effective in biofilm disruption. Fourier Transformed Infrared Radiations (FT- IR) analyses revealed that the AgNPs could bring about more exopolysaccharide (EPS) destruction in comparison to the phytoextract. The antibiofilm activities of AgNPs made from the phytoextract were found to be much more effective than the non-conjugated phytoextract, indicating the future prospect of using such particles for combatting biofilm-mediated infections caused by S aureus.
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Formation of nitro radical anion (-NO2 â¢-) and other reduction products of 5-nitroimidazoles, although important for antimicrobial activity, makes the drugs neurotoxic. Hence, an appropriate generation and their role in the free radical pathway needs proper realization. This was attempted by studying the action of tinidazole and its CuII complexes on model targets (nucleic acid bases and calf thymus DNA). Results obtained were correlated with studies on biological species where prevention of biofilm formation on Staphylococcus aureus and Pseudomonas aeruginosa was followed. Tinidazole and its CuII complexes subjected to electrochemical reduction in aqueous solution, under de-aerated conditions, interact with model nucleic acid bases and calf thymus DNA. These model targets were followed to realize what happens when such compounds undergo enzymatic reduction within cells of microorganisms that they eventually kill. Studies reveal that CuII complexes were better in modifying nucleic acid bases and calf thymus DNA than tinidazole; damage caused to nucleic acid bases was correlated with that caused to DNA, indicating that compounds affect DNA rich in thymine and adenine. Minimum bactericidal concentrations on sessile S. aureus and P. aeruginosa for the monomeric CuII complex were 12.5 and 20.25 µM respectively, while those for the dimeric complex were 40.0 and 45.0 µM, respectively. Biofilm formation by P. aeruginosa and S. aureus and viability count of sessile cells were also determined. CuII complexes of tinidazole brought about substantial reduction in carbohydrate and protein content in S. aureus and P. aeruginosa. Downregulation of quorum sensing signaling mechanism viz. reduced production of pyocyanin and elastase during biofilm formation was also detected. CuII complexes showed much higher tendency to prevent biofilm formation than tinidazole, almost comparable to amoxicillin, an established drug in this regard.
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Nanoparticles (NPs) designed for various theranostic purposes have hugely impacted scientific research in the field of biomedicine, bringing forth hopes of a future revolutionized area called nanomedicine. A budding advancement in this area is the conjugation of various cell membranes onto nanoparticles to develop biomimetic cells called 'Nanodecoys' (NDs), which can imitate the functioning of natural cells. This technology of coating cell membranes on NPs has enhanced the working capabilities of nano-based techniques by initiating effective navigation within the bodily system. Due to the presence of multiple functional moieties, nanoparticles coated with cell membranes hold the ability to interact with complex biological microenvironments inside the body with ease. Although developed with the initial motive to increase the time of circulation in the bloodstream and stability by coating membranes of red blood cells, it has further outstretched a wide range of cell lines, such as mesenchymal stem cells, beta cells, thrombocytes, white blood cells, and cancer cells. Thus, these cells and the versatile properties they bring along with them open up a brand-new domain in the biomedical industry where different formulations of nanoparticles can be used in appropriate dosages to treat a plethora of diseases. This review comprises recent investigations of nanodecoys in biomedical applications.
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Biofilms are groups of adherent cell communities that cohere to the biotic and abiotic surfaces with the help of extracellular polymeric substances (EPS). EPS allow bacteria to form a biofilm that facilitates their binding to biotic and abiotic surfaces and provides resistance to the host immune responses and to antibiotics. There are efforts that have led to the development of natural compounds that can overcome this biofilm-mediated resistance. Essential oils (EOs) are a unique mixture of compounds that plays a key role in preventing the development of biofilm. The present overview focusses on the role of various types of citrus essential oils in acting against the biofilm, and the antibiofilm properties of natural compounds that may show an avenue to treat the multidrug-resistant bacteria.