China 
Africa 
Explore chapters and articles related to this topic
Chitosan-Based Nanocarriers
Published in Bhupinder Singh, Om Prakash Katare, Eliana B. Souto, NanoAgroceuticals & NanoPhytoChemicals, 2018
Sumit Sharma, V.R. Sinha, Amita Sarwal, Rahul Shukla
Vancomycin, a glycopeptide antibiotic, is used to treat severe intestinal infections like pseudo-membranous colitis and enterocolitis caused by pathogenic bacteria like Clostridium difficile and Staphylococcus aureus. The problem associated with this drug is its acidic degradation in the stomach and hence lesser availability of active drug at the infection site, that is, ileo-caecal and colonic regions. Chitosan nanoparticles have demonstrated promising colonic delivery with improved antibacterial activity on Staphylococcus aureus. The smaller size of chitosan particles provides a larger surface area and better mucoadhesion due to improved electrostatic interactions of sulfonic acid and sialic acid of mucin and amino groups of chitosan. It has also been observed that nanoparticles obtained from spray-drying are of spherical shape and smooth architecture with greater encapsulation efficiency compared with particles obtained from the freeze-drying process. In vitro release studies revealed that chitosan nanoparticles prepared by ionic gelation with molar ratio of chitosan:tripolyphosphate as 8:1.5 and processed by spray-drying, had the ability to control the release of vancomycin. The percentage fractional amount released at pH 7.4 was found to be approximately 35% after 6 h, whereas it was approximately 4% at pH 2.0 (Cerchiara et al., 2015).
Antibacterial Hydrogels and Their Implications
Published in Anujit Ghosal, Ajeet Kaushik, Intelligent Hydrogels in Diagnostics and Therapeutics, 2020
Jyoti Bala, Anupam J. Das, Ajeet Kaushik
Shukla and Shukla (2018) have shown tunable antibiotic delivery from gellan hydrogels. They have synthesized two types of hydrogels using 1% w/v gellan and 1 mM CaCl2 “ointment” hydrogels and those formed by using 4% w/v gellan and 7 mM CaCl2 “sheet” hydrogels [61].Vancomycin, another broad-spectrum antibiotic, was incorporated in hydrogels via direct and/or as in graphitized carbon black nanoparticles (CNPs). Prolonged release of sheet and ointment hydrogels was studied at suitable concentrations. Their data suggest that final drug release amounts are influenced by intermolecular interactions between Vancomycin and gellan. They have shown in vitro growth inhibition of Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus in the presence of chosen hydrogels [62]. Remarkably, they have also found that these hydrogels are non-toxic to wound healing cells including fibroblasts and mesenchymal stem cells. Vancomycin (VAN) is considered the last form of defense against infection. The discovery of VAN-resistant Enterococcus is a crucial concern. Hydrogel has been investigated to tackle this challenge and control Vancomycin delivery. Gustafson et al. synthesized a charged hydrogel as a carrier that was incorporated with Vancomycin [63]. Additionally, various other antibiotic-loaded hydrogels have also been reported in past years such as (i) Ampicillin sodium-loaded PVA-SA hydrogel (gram-positive and gram-negative bacteria), and (ii) Cephalosporin antibiotic and Levo oxacin-loaded hyaluronic acid hydrogels for antibacterial activity [64–66]. Furthermore, Doxycycline (DOX)-loaded thermosensitive hydroxypropyl-β-cyclodextrin (HP-β-CD) hydrogels were also synthesized and characterized for ophthalmic delivery [67].
Bacterial Detection with Magnetic Nanoparticles
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Nayeem A. Mulla, Raghvendra A. Bohara, Shivaji H. Pawar
Vancomycin belongs to the glycopeptide group of antibiotics, which is known to interact strongly with a broad range of Gram-positive bacteria. Vancomycin kills bacteria by inhibiting bacterial cell wall synthesis. This interaction is mediated via five hydrogen bond motifs between the heptapeptide backbone of vancomycin and the D-alanyl-D-alanine dipeptide from the cell wall [57]. As a result, vancomycin-functionalized MNPs are capable of recognizing the cell surfaces of different bacteria. It has been demonstrated that vancomycin offers less specificity when compared with a monoclonal antibody but can bind to different Gram-positive bacteria such as Enterococcus faecalis, Streptococcus pneumoniae, and Staphylococcus aureus but not against Gram-negative bacteria. Gu et al. reported a strategy to use vancomycin-conjugated FePt MNPs of around 4 nm that are water soluble in nature to detect Gram-negative as well as Gram-positive bacteria at low concentrations [58]. As a control experiment, they have used FePt nanoparticles capped with an amine group (FePt–NH2), which failed to capture the bacteria because of the lack of specific molecular recognition. Lin et al. reported vancomycin-immobilized iron oxide nanoparticles that can be used to trap Gram-positive bacteria such as Staphylococcus saprophyticus, S. aureus, and E. faecalis selectively from urine samples, followed by detection with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Their result suggests that this method is capable of rapidly identifying trace pathogens in urine samples [59]. Kell et al. have reported a series of vancomycin-modified Fe3O4 MNPs used in magnetic confinement assay to isolate different Gram-positive and Gram-negative bacteria at a low concentration. Their results demonstrate that small moieties are an excellent alternative to antibody-mediated detection of bacteria, where more precaution is required as compared to small moieties like vancomycin [60]. In 2011,Chung et al. reported that the bio-orthogonal modification of vancomycin and daptomycin, which is lipopeptide in nature and binds to the cell wall of Gram-positive bacteria via its hydrophobic tail, resulted in the depolarization of the bacterial cell membrane. Primarily, they have synthesized trans-cyclooctene derivatives of these antibiotics, which are attached to tetrazine-decorated Fe3O4 fluorescent MNPs. Their result shows that using a two-step labeling procedure, their assay is superior to using direct antibiotic–nanoparticle conjugates [61]. Recently, Chen et al. synthesized fluorescent MNPs with a core–shell structure followed by conjugation of gentamycin, which is a FDA-approved thermal-resistant antibiotic belonging to the aminoglycoside group and used for the treatment of infection caused by Gram-negative bacteria. Their results demonstrate that gentamicin-bioconjugated fluorescent MNPs can capture Gram-negative bacteria, i.e., Escherichia coli (1 × 107 CFU/mL) within 20 min from 10 mL of solution. In addition to this, these gentamycin-modified MNPs are also able to detect diluted E. coli cells at a concentration as low as 1 × 103 CFU/mL [62]. Several such approaches are reported [63].
Evidence of cross-contamination of waste workers and transmission of antimicrobial resistance genes by coagulase-negative Staphylococcus isolated from dental solid waste: an intriguing study
Published in International Journal of Environmental Health Research, 2022
Débora Guimarães Calefi, João Paulo Amaral Haddad, Silvia Helena Souza Pietra Pedroso, Paula Prazeres Magalhães, Luiz Macêdo Farias, Cristina Dutra Vieira, Simone Gonçalves dos Santos
Regarding antimicrobial resistance factors, there is a progressive increase of resistant strains (Morgenstern et al. 2016). Methicillin resistance is encoded primarily by the mecA gene, which is located in a mobile genetic element called Staphylococcal Chromosome Cassette (SCCmec) (Otto 2013). Vancomycin resistance is mediated by the vanA gene, which alters the binding target of this antimicrobial (Xia et al. 2016). Due to resistance, the use of vancomycin has proven effective, and it is still a good therapeutic option to treat infections caused by methicillin-resistant S. aureus (MRSA). However, clinical strains of S. aureus have demonstrated reduced or complete (less common) susceptibility to vancomycin. This category of resistance is attributed to mobile genetic elements, which represent the main mechanism of horizontal transfer of genes between bacteria (McGuinness et al. 2017).
The study of mechanical and drug release properties of the mineralized collagen/polylactic acid scaffold by tuning the crystalline structure of polylactic acid
Published in Journal of Biomaterials Science, Polymer Edition, 2021
HuaJie Ren, Xiaojie Lian, Baolong Niu, Liqin Zhao, Quanyou Zhang, Di Huang, Yan Wei, Zhijun Li, Zhimin He, Zhiye Qiu
Infectious bone defects are very common in the clinic, especially in large bone defects, liable to lead to infection when exposed to the air. Bone replacement surgery failed to restore in the infected state. As an antibiotic, vancomycin is often used clinically to treat some serious surgical infections. Intravenous injection often lead to insufficient drug concentration in the infected area, also have a bad effect on the whole body [1]. Therefore, it is necessary to develop a local controlled drug delivery system that reduces systemic pharmacological response in the case of meeting local drug concentrations. In orthopedics, antibiotic-loaded fillers and bone cements have been used clinically for a number of years. Scaffolds should provide an ideal substrate to deliver long term bactericidal doses of antibiotics to the injury site [2]. Vancomycin has showed anti-infective property when loaded in some biomaterial scaffolds [3–5].
Mini review: Recent advances in long period fiber grating biological and chemical sensors
Published in Instrumentation Science & Technology, 2019
Methicillin has been shown to be an effective to drug resistance following the emergence of methicillin-resistant bacteria. Bandara et al.[21] developed monoclonal antibodies specific to methicillin-resistant Staphylococcus aureus by an antigen-antibody binding method. The sensor was shown to efficiently and specifically identify methicillin-resistance Staphylococcus aureus. Vancomycin is a secretion of the bacteria and an effective and safe antibiotic in the treatment of methicillin-resistance Staphylococcus aureus infection. Korposh et al.[22] deposited molecularly imprinted polymers on an LPFG by molecular imprinting approaches, and provided a universal platform for the creation of artificial receptors that are well controlled and tailored. When other antibiotics were added to the test solution, the sensor also showed good selectivity.