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•Rifampicin and levofloxacin loaded curdlan-cyclodextrin drug delivery system.•Curdlan targets the macrophages while cyclodextrin carries the drugs.•Simultaneous sustained release of ...both the drugs over a prolonged period of time.•Better drug delivery to infected macrophages than free drugs.
In tuberculosis, macrophages serve as a host for Mycobacterium tuberculosis and hence targeting them with nanoparticles-based drug delivery could be the best strategy to achieve high therapeutic efficacy. Two tuberculosis drugs, namely rifampicin and levofloxacin, which have different mechanism of action on the bacteria, were complexed with cyclodextrin and conjugated to curdlan nanoparticles, to achieve simultaneous sustained release of both the drugs over a prolonged period of time. They are non-cytotoxic to both RAW 264.7 and L929 cells. They are taken up ˜1.8 times more by the macrophage cells through dectin-1 receptor than the fibroblast cells. They are also able to kill more than 95% of Mycobacterium smegmatis residing within the macrophages in 4 h. These results demonstrate that curdlan-CD nanoparticles can be a promising system for the loading and intracellular release of hydrophobic drugs into macrophages for various therapeutic applications.
Strontium‐substituted apatites have provoked increased interest in recent years for their beneficial effects on osteoporotic bone treatment and replacement. In this study, rod‐ and acicular‐shaped, ...strontium‐substituted calcium deficient hydroxyapatite (CDHA) nanoparticles with (Ca + Sr)/P ratio of 1.61 were synthesized via accelerated microwave processing. The X‐ray powder diffraction analysis indicates the synthesized nanoparticles as apatite phase with diffraction patterns similar to those of hydroxyapatite. The hydrodynamic diameter of the particles were observed to be ~200–500 nm and found to increase with strontium substitution along with an increase in the negative zeta potential by dynamic light scattering method, suggesting the particles to be agglomerates in water. The morphology of the nanoparticles was studied using transmission electron microscopy (TEM), where, pure CDHA showed globular and strontium substituted CDHAs showed rod and acicular shape for 5% and 10% Sr substitution, respectively. The average size of the particles in TEM was measured to be 33 nm × 5 nm, 40 nm × 6 nm, and 55 nm × 8 nm (L × W) for pure and strontium‐substituted CDHAs, respectively. Inductively coupled plasma spectroscopy, energy dispersive X‐ray analysis, and Fourier transform infrared spectroscopy further confirm the substitution of strontium and deficiency of calcium in the synthesized nanoparticles. Thermal stability and in vitro solubility of CDHA nanoparticles were observed to increase with strontium substitution. The MTT 3‐(4, 5‐Dimethylthiazole‐2‐yl)‐2, 5‐diphenyl tetrazolium bromide assay indicate that the substituted nanoparticles are non‐toxic to human periodontal ligament fibroblast (HPDLF) cells. Cell uptake study by fluorescence microscopy using rhodamine‐123 and actin/DAPI stained HPDLF cells show cellular localization of the nCDHA, nSr5CDHA, nSr10CDHA nanoparticles without any adverse effects. The strontium‐substituted CDHAs showed significant antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria by colony count method. The 10% Sr substituted CDHA show the maximum microbial reduction of around 56% for E. coli and 35% for S. aureus with 1 × 105 cells/mL of respective bacterial culture.
Bioconvection in magneto-nanoliquid embedded with gyrotactic microorganisms across an elongated sheet with velocity slip of second order is addressed. Nonlinear thermal radiation and chemical ...reaction aspects are retained in energy and concentration equations. Numerical simulations for the modeled problem are proposed via Runge–Kutta–Fehlberg-based shooting technique. Special attention is given to the impact of involved parameters on the profiles of motile microorganisms, nanoparticle volume fraction, temperature and velocity. Our simulations figured out that assisting flow generates more heat transfer than the opposing flow situation. The motile microorganism’s boundary layer decayed for higher bioconvection Peclet and bioconvection Lewis numbers.
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Structural hybridization of preclinically and clinically validated pharmacologically active molecules has emerged as a promising tool to develop new generations of safe and highly ...efficient drug candidates against various diseases including microbial infections, virus infections and cancer. Strategies of drug-drug combinations have been adopted to generate hybrid conjugates of many clinically used drugs, designed to address inherent problems associated with these drugs. Thus, the design of hybrids was aimed to achieve higher efficacy through possible multi-target interactions, selective delivery of the drug to the site of action with the aim to improve bioavailability, alleviate toxicity and circumvent drug resistances. In this review article, we summarize the progress made in recent years in the rapidly growing field of drug discovery, focusing on the rationality of the hybrid design with particular emphasis on the linker architecture, which plays a crucial role in the overall success of a hybrid drug.
► Peptide with high antioxidant properties was isolated from the visceral waste of Magalaspis cordyla. ► Two steps of purification were executed using FPLC to obtain the active peptide. ► The ...sequence of purified peptide was determined as Ala–Cys–Phe–Leu (518.5Da). ► Identified peptide proved better than natural antioxidant, α-tocopherol in PUFA protection.
In the present study, a peptide having high antioxidant properties was isolated from horse mackerel viscera protein, Magalaspis cordyla. In vitro gastrointestinal digestion was employed to obtain potential protein hydrolysate and was subjected to consecutive chromatographic methods using fast protein liquid chromatography (FPLC) connected to diethyl amino ethyl (DEAE) anion exchange column and Sephadex G-25 gel filtration column. The activity of the fractions was tested against DPPH and hydroxyl radicals and the isolated peptide showed 89.2 and 59.1 percentage of scavenging. The amino acid sequence of purified peptide was determined using ESI-MS/MS as Ala–Cys–Phe–Leu (518.5Da), it exhibited high activity against polyunsaturated fatty acid (PUFA) peroxidation than that of natural antioxidant, α-tocopherol.
Among the various MPPT algorithms developed until date, Perturb and Observe (P&O) and Incremental conductance (InC) algorithms are most widely used, mainly due to their simplicity and ease of ...implementation. However, both algorithms suffer from the drawbacks of continuous steady state oscillations, and inefficient tracking in case of rapid changes in irradiation. In this article, a SOFT-MPPT algorithm has been proposed which, in a simple way, aims to improve both the steady state as well as the tracking performance of both P&O and InC algorithms. An adaptive step size is used to track the MPP, which provides a faster tracking performance. The proposed algorithm identifies the attainment of the steady state and then stops the artificial perturbations. This stops the oscillations around the MPP and provides a steady power output from the PV panel at the MPP value. The SOFT-MPPT algorithm is also able to detect any change in operating conditions while operating in the steady state, and that too without using any additional sensors. Accordingly, it restarts the tracking process in order to track the new MPP. The detailed theoretical discussions of the SOFT-MPPT algorithm, is followed by the simulation and experimental results to validate the proposed performance improvements.
Insulin resistance is a determining factor in the pathophysiology of type 2 diabetes mellitus (T2DM). Exercise is known to improve insulin resistance, but a systematic review of the literature is ...lacking.
This systematic review and meta-analysis focused on identifying evidence for the effectiveness of a structured exercise intervention program for insulin resistance in T2DM.
We searched MEDLINE via PubMed, CINHAL, Scopus and Web of Science, and the Cochrane Central Register of Controlled Trials for reports of studies on fasting insulin, homeostatic model assessment for insulin resistance (Homa-IR), fasting blood sugar, glycated hemoglobin and body mass index in patients with T2DM and healthy controls that were published between 1990 and 2017. Data are reported as the standardized mean difference or mean difference with 95% confidence intervals (CIs).
Among 2242 records retrieved, only 11 full-text articles were available for meta-analysis. Data for 846 participants were analyzed, 440 in the intervention group, and 406 in the control group. The mean difference for fasting insulin level was−1.64 (95% CI; −3.38 to 0.10), Homa-Ir 0.14 (−1.48 to 1.76), fasting blood sugar−5.12 (−7.78 to−2.45), hemoglobin A1c 0.63 (−0.82 to 2.08) and body mass index−0.36 (−1.51 to 0.79).
The evidence highlights the effectiveness of a structured exercise intervention program for insulin resistance in T2DM with a moderate level 2 of evidence.
Psidium guajava
L. (guava) is predominantly grown throughout the world and known for its medicinal properties in treating various diseases and disorders. The present work focuses on aqueous ...extraction of bioactive compounds from the guava leaf and its utilization in the formulation of jelly to improve the public health. The guava leaf extract has been used in the preparation of jelly with pectin (1.5 g), sugar (28 g) and lemon juice (2 mL). The prepared guava leaf extract jelly (GJ) and the control jelly (CJ, without extract) were subjected to proximate, nutritional and textural analyses besides determination of antioxidant and antimicrobial activities. GJ was found to contain carbohydrate (45.78 g/100 g), protein (3.0 g/100 g), vitamin C (6.15 mg/100 g), vitamin B3 (2.90 mg/100 g) and energy (120.6 kcal). Further, the texture analysis of CJ and GJ indicated that both the jellies showed similar properties emphasizing that the addition of guava leaf extract does not bring any change in the texture properties of jelly. GJ exhibited antimicrobial activity against various bacteria ranging from 11.4 to 13.6 mm. Similarly, GJ showed antioxidant activity of 42.38% against DPPH radical and 33.45% against hydroxyl radical. Mass spectroscopic analysis of aqueous extract confirmed the presence of esculin, quercetin, gallocatechin, 3-sinapoylquinic acid, gallic acid, citric acid and ellagic acid which are responsible for antioxidant and antimicrobial properties.
Curdlan (β‐1,3 glucan) (7 wt%) with polyvinyl alcohol (PVA) (10 wt%) is blended at 1:2 weight ratio and electrospun to get nanofibers and is crosslinked with glutaraldehyde vapor to make it insoluble ...in water. It has a fiber diameter of less than 100 nm and is hydrophilic (contact angle = 35°). It is biodegradable (10% in 14 d) and also has a good swelling behavior (≈170%). More than 100% of L6 cells are viable on this scaffold after 3 d. The scanning electron microscope images also reveal that cells are able to attach and spread in the nanofibrous scaffolds. In vitro scratch assay indicates that the wound closure rate of curdlan/PVA scaffold is better than PVA scaffold probably due to the immunomodulatory properties of the biopolymer. Thus our results indicate that curdlan/PVA scaffold can be an ideal material for wound healing applications.
A nanofibrous scaffold of curdlan/poly(vinyl alcohol) blend is prepared by electrospinning technique. Cells cultured over the scaffold are able to attach and spread well and an increase in cell viability is also observed after 3 days. The presence of curdlan enhances the wound healing effect of the scaffold making it a promising material for wound healing applications.
Friction stir processing (FSP) was successfully adopted to fabricate nano-hydroxyapatite (nHA) reinforced AZ31 magnesium alloy composite as well as to achieve fine grain structure. The combined ...effect of grain refinement and the presence of embedded nHA particles on enhancing the biomineralization and controlling the degradation of magnesium were studied. Grain refinement from 56 to ~4 and 2 μm was observed at the stir zones of FSP AZ31 and AZ31–nHA composite respectively. The immersion studies in super saturated simulated body fluid (SBF 5×) for 24 h suggest that the increased wettability due to fine grain structure and nHA particles present in the AZ31–nHA composite initiated heterogeneous nucleation which favored the early nucleation and growth of calcium-phosphate mineral phase. The nHA particles as nucleation sites initiated rapid biomineralization in the composite. After 72 h of immersion the degradation due to localized pitting was observed to be reduced by enhanced biomineralization in both the FSPed AZ31 and the composite. Also, best corrosion behavior was observed for the composite before and after immersion test. MTT assay using rat skeletal muscle (L6) cells showed negligible toxicity for all the processed and unprocessed samples. However, cell adhesion was observed to be more on the composite due to the small grain size and incorporated nHA.
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