Injectable polyelectrolyte complex-nascent HAP biodegradable antibiotic delivery system for the treatment of osteomyelitis

Author(s):  
Liz Hannah George ◽  
Aswin Arakkal ◽  
Prathapan Sreedharan ◽  
G. S. Sailaja

Abstract An injectable osteoconductive polyelectrolyte complex –hydroxyapatite formulation capable of controlled delivery of ciprofloxacin has been developed from a novel biodegradable polyelectrolyte complex and antibiotic loaded nascent hydroxyapatite (n-HAP) for the treatment of osteomyelitis. A single source (chitosan) derived polyelectrolytes were complexed in situ in the presence of n-HAP, pre-loaded with ciprofloxacin. The PEC- (n-HAP) nanoformulation (HPEC) was characterized by FT-IR, XRD, TGA and TEM analyses. HPEC combines functionalities of n-HAP (crystallinity and osteoconductivity) as well as PEC (biodegradable hydrophilic electrostatically bound macromolecular network) imparting better control over swelling and degradation kinetics favourable for drug release and transport of micronutrients. MTT assay and cytoskeleton staining (MG 63 cells) established cytocompatibility of HPEC. Early biomimetic mineralization of apatite was manifested under simulated physiological condition with a Ca/P of 1.23 (day 3) and 1.55 (day 6) complimented by in vitro biomineralization of MG-63 and Human Osteosarcoma (HOS) cells in a week (Alizarin Red S staining), which was further validated by calcium quantification. Antibacterial efficacy of HPEC has been evaluated by delivery kinetics of ciprofloxacin and by disc diffusion method against S. aureus and E. coli. The injectable system therefore possesses unique combination of functionalities: osteoconduction enriched with early biomineralization, antibacterial activity and is biodegradable; hence highly suitable for osteomyelitis treatment.

2021 ◽  
Vol 72 (1) ◽  
pp. 2703
Author(s):  
I VAR ◽  
S UZUNLU ◽  
I DEĞIRMENCI

The use of natural food additives is currently a rising trend. In the present study, the aim was to determine the antimicrobial effects of plum, pomegranate, Seville orange and sumac sauces on E. coli O157:H7,E. coli type I,Listeriamonocytogenes, Listeria ivanovii, Salmonella Typhimurium and Staphylococcus aureus. Different concentrations (1%, 10%, 100%, v/v) of the sauces were tested on the studied bacteria in vitro using the agar diffusion and minimal inhibition concentration (MIC) methods. The results showed that the sumac sauce had the highest antimicrobial activity. The Seville orange, plum and pomegranate sauces also exerted antimicrobial activity in descending order. The antimicrobial activity of the fruit sauces was more effective at a concentration of 100% than at 10% and 1%, v/v. The most inhibitory effect was recorded for sumac sauce at a concentration of 100% (v/v) on L.monocytogenesand E. coli O157:H7. The findings of the MIC method aligned with the agar diffusion method. In addition, the in situ(food method) antimicrobial effect of the sauces on the indigenous microflora of chicken breast samples sold in stores was determined. Chicken samples hosting aerobic mesophilic bacteria, coliforms and E. coli were treated for two hours at 4 °C with plum, pomegranate, Seville orange and sumac sauces and were then monitored. The findings revealed that the Seville orange and sumac sauces were the most effective in reducing the indigenous microbial growth on the chicken samples. The plum sauce showed higher antimicrobial activity than pomegranate sauce. The phenolic content and acidity of the samples significantly (P< 0.05) affected the antimicrobial activity both in vitro (agar diffusion and MIC) and in situ (chilled chicken breast). In conclusion, the sumac and Seville orange sauces were found to be the most promising natural antibacterial agents, and their use could be recommended, for example, in catering services to reduce the risk of foodborne illness.


2019 ◽  
Vol 59 (7) ◽  
pp. 1271 ◽  
Author(s):  
Juan P. Keim ◽  
Jaime Cabanilla ◽  
Oscar A. Balocchi ◽  
Rubén G. Pulido ◽  
Annick Bertrand

The aim of the present study was to assess and compare the nutrient concentration, the in vitro fermentation and the in situ rumen degradation characteristics of Brassica rapa ssp. rapa L. (turnips) and Brassica napus ssp. biennis L. (forage rape). Five varieties of each species were established in three field replicates and were organised in a randomised complete-block nested design. All varieties were harvested and further analysed for chemical composition, in vitro gas-production kinetics, volatile fatty acid (VFA) production and in situ degradation kinetics of dry matter (DM) and crude protein. Turnips showed higher ash, total sugars, raffinose, sucrose, glucose and fructose concentrations (P &lt; 0.001) than did forage rape. Turnip varieties differed in their sucrose, glucose, fructose and total soluble sugar concentration (P &lt; 0.001), whereas rape varieties differed in their neutral detergent fibre concentration (P = 0.004) and digestible organic matter on a DM basis (P &lt; 0.01). Regarding DM-degradation parameters, turnips had a higher soluble fraction ‘a’ (P &lt; 0.01) and a lower insoluble, but potentially degradable fraction ‘b’ (P &lt; 0.01) than did rape, but the fractional degradation rate ‘c’ (0.18/h) was similar to that of rape. Rates of gas production were slightly higher (P = 0.018) for turnip than for rape. No effects for brassica species nor for varieties within species were detected (P &gt; 0.05) for total in vitro VFA production, as well as for the relative proportions of acetate, propionate, butyrate, branch chained VFA and the actetate:propionate ratio. Our study showed that most of the differences that were observed in terms of chemical composition and degradation kinetics did not result in differences in in vitro fermentation products.


2019 ◽  
Vol 32 (1) ◽  
pp. 91-94
Author(s):  
L. Alphonse ◽  
P. Tharmaraj ◽  
B. Avila Josephine ◽  
V. Mary Teresita

In this work, Mn(II) complex of triazine based ligand has been synthesized and characterized using various physico-chemical methods including C,H,N elemental analysis, FT-IR, 1H NMR and EI-mass analysis. The synthesized compounds serve as potential photoactive material as indicated from its characteristic fluorescent properties. The ligand and its metal complex were assayed for in vitro antimicrobial activity on four bacterial strains (S. aureus, B. subtilis, E. coli and K. pneumoniae) using well-diffusion method and it was observed that metal complex showed enhanced antimicrobial activity against all tested strains as compared to ligand.


2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.


2000 ◽  
Vol 182 (9) ◽  
pp. 2604-2610 ◽  
Author(s):  
Gillian Newman ◽  
Elliott Crooke

ABSTRACT Given the lack of a nucleus in prokaryotic cells, the significance of spatial organization in bacterial chromosome replication is only beginning to be fully appreciated. DnaA protein, the initiator of chromosomal replication in Escherichia coli, is purified as a soluble protein, and in vitro it efficiently initiates replication of minichromosomes in membrane-free DNA synthesis reactions. However, its conversion from a replicatively inactive to an active form in vitro occurs through its association with acidic phospholipids in a lipid bilayer. To determine whether the in situ residence of DnaA protein is cytoplasmic, membrane associated, or both, we examined the cellular location of DnaA using immunogold cryothin-section electron microscopy and immunofluorescence. Both of these methods revealed that DnaA is localized at the cell membrane, further suggesting that initiation of chromosomal replication in E. coli is a membrane-affiliated event.


2020 ◽  
Vol 32 (3) ◽  
pp. 580-586
Author(s):  
Ranjit V. Gadhave ◽  
Bhanudas S. Kuchekar

A new series of N-(benzo[d]thiazol-2-yl)-[1,2,4]triazolo[4,3-c]quinazoline-5-carboxamide derivatives were synthesized by condensation of [1,2,4]triazolo[4,3-c]quinazoline-5-carboxylate derivatives with substituted benzothiazoles. The chemical structures of the synthesized compounds were confirmed by FT-IR, MS and 1H NMR spectra. Designed triazoloquinazoline derivatives were docked with oxido-reductase enzyme (PDB Code 4h1j) and DNA gyrase enzyme (PDB Code 3g75). Based on high binding affinity score, the best compound were selected for synthesis and subjected to in vitro antioxidant and antibacterial activity. Compounds 7a and 7d were found to be most active compounds as antioxidant agent among this series when compared with ascorbic acid. Compounds 7a, 7d and 7f were found to be most active compounds as an antibacterial agents among this series when compared with ciprofloxacin against bacterial strains such as S. aureus (ATCC 25923), E. coli (ATCC 25922) and P. aeruginosa (ATCC 27853). Study revealed that the most active compounds after structural modifications can be exploited as lead molecules for other pharmacological activities such as anti-inflammatory, anticancer and antidepressant activities.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 533 ◽  
Author(s):  
Josué A. Torres-Ávalos ◽  
Leonardo R. Cajero-Zul ◽  
Milton Vázquez-Lepe ◽  
Fernando A. López-Dellamary ◽  
Antonio Martínez-Richa ◽  
...  

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA–BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV–VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.


2012 ◽  
Vol 6 (4) ◽  
pp. 196-202 ◽  
Author(s):  
Naser Maheri-Sis ◽  
Mohammad Chamani ◽  
Ali Asghar Sadeghi ◽  
Ali Mirzaaghaz ◽  
Kambiz Nazeradl ◽  
...  

2016 ◽  
Vol 41 (1) ◽  
pp. 28-36 ◽  
Author(s):  
F. F. Sani ◽  
L. K. Nuswantara ◽  
E. Pangestu ◽  
F. Wahyono ◽  
J. Achmadi

Two adult male sheeps fitted with rumen cannula were used in two experiments to study the effects of synchronization of carbohydrate and nitrogen supply in sugarcane bagasse based total mixed ration (TMR) on in situ nutrient degradation. The first experiment was aimed to create three TMR with different synchronization index. Ingredient feedstuffs of TMR were evaluated for its in situ organic matter (OM) and nitrogen (N) degradation kinetics. On the basis of the OM and N degradation kinetics of feedstuffs, three sugarcane bagasse based TMR were formulated with synchronization indexes of 0.37; 0.50; and 0.63; respectively. The TMR had similar levels of crude protein (CP), total digestible nutrients, and neutral detergent fiber (NDF). In the second experiment, the three TMR with different synchronization index were evaluated for in situ degradability characteristics of OM, CP, NDF, and sulfur. The in situ degradation of OM in TMR were decreased (P<0.05) with the increasing of synchronization index. The higher synchronization index in TMR increased (P<0.05) CP degradation of CP. The NDF degradation decreased slightly by the alteration of synchronization index in TMR. The higher synchronization index in TMR reduced (P<0.05) in situ sulfur degradation, and this may not support to effects of synchronization of carbohydrate and nitrogen supply.  


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