Controlled drug delivery systems for improved efficacy and bioavailability of flavonoids

Purpose In past decades, experiments have been done to find the properties of plant polyphenols and their protective role in various diseases. In the present study, a brief review has been done on flavonoids’ protective role in different diseases and controlled drug delivery systems that can be feasible for improving flavonoids’ bioavailability as well as their efficacy in the biological system. Design/methodology/approach Keywords searched in PubMed, and Google Scholar are “Flavones and cardiovascular diseases, flavones and neurodegenerative diseases, isoflavones and neurodegenerative diseases, Flavonoids and ageing, Flavonoids and diseases, total flavonoid content in vegetables, total flavonoid content in fruits, controlled drug delivery system and flavonoids” and the significant recent articles are selected for writing this review. Findings Flavonoids are active components present in plant products that have been found to exert several health benefits, especially in retarding the deleterious effects of CVD, cancer, ageing, diabetes, and neurodegenerative diseases. The different clinical studies have also supported the above notions, and in this commentary, we have highlighted some important findings in the field of flavonoid research. Even though it has various bioactive efficacy, most flavonoids have less bioavailability, requiring controlled drug delivery methods that can also improve flavonoids' bioavailability and stability. pH-, electro-, infrared radiation-, redox- responsive methods of controlled drug release systems are some of the valuable techniques for improving the rate of drug release and bioavailability at the targeted site. Research limitations/implications Research is warranted in this field for improving and developing various materials that can be utilized in the formation of scaffolds/polymers that improves drug loading and controlled drug release properties at the targeted site. Originality/value This review will help the readers to design new strategies in flavonoid research with the help of controlled drug release methods for increased bioavailability and rate of drug release/ controlled drug release

Nanomedicine - a boon for respiratory disease management

Purpose: Respiratory diseases affect the lungs and other parts of the respiratory system. The respiratory disease affects hundreds of millions of humans, and premature death is observed in nearly four million people yearly. The major cause of the increase in this disease is the increased level of air pollution and higher tobacco usage in public places. Design/methodology/approach: We have used the search engines PubMed and Google Scholar for the keywords Respiratory diseases, Nanomaterials, diagnosis, Nanomedicine, and Target drug delivery; recent and relevant articles are selected for reviewing this paper. Findings: Nanomedicine is a recent field of research that deals with monitoring, repairing, theragnosis, and development of human biological systems at the sub-atomic level, where we utilize engineered nanodevices and nanostructures. The conventional therapeutic strategies designed for respiratory diseases have limited solubility and bioavailability. Moreover, the robust effect of the drugs led to adverse side effects due to their high dose requirement. The local delivery of therapeutic Nanoparticles (NPs) or drug-loaded nano vehicles to the lung is a safe technique for managing various respiratory tract-related diseases like chronic obstructive pulmonary diseases, cystic fibrosis, lung cancer, tuberculosis, asthma, and infection. To overcome the difficulties of conventional treatment with antibiotics and anti-inflammatory drugs, nano-enabled drug delivery, nanoformulations of drugs as well as drug nanoencapsulation have been used recently. In this mini-review, we will discuss the importance and application of nanomedicine for diagnosis, treatment and clinical research involved in the different types of respiratory diseases. Practical implications: Nanomedicine provides an alternative delivery of drugs with the help of various nanocarriers, which enhances controlled drug delivery at the pulmonary region and can be used for treating and diagnosing respiratory diseases in vivo and in vitro studies. Further experiments followed by clinical examination are warranted to prove the potential application of nanomedicine in treating respiratory disease. Originality/value: This mini-review will help the readers and budding scientists apply new methods for developing highly efficient drugs with low side effects and improved targeted sites of action

Upconversion, MRI imaging and optical trapping studies of silver nanoparticle decorated multifunctional NaGdF4:Yb,Er nanocomposite

The multifunctional upconversion nanoparticles (UCNPs) are fascinating tool for biological applications. In the present work, photon upconverting NaGdF4:Yb,Er and Ag nanoparticles decorated NaGdF4:Yb,Er (NaGdF4:Yb,Er@Ag) nanoparticles were prepared using a simple polyol process. Rietveld refinement was performed for detailed crystal structural and phase fraction analysis. The morphology of the NaGdF4:Yb,Er@Ag was examined using high-resolution transmission electron microscope, which reveals silver nanoparticles of 8 nm in size were decorated over spherical shaped NaGdF4:Yb,Er nanoparticles with a mean particle size of 90 nm. The chemical compositions were confirmed by EDAX and inductively coupled plasma-optical emission spectrometry analyses. The upconversion luminescence (UCL) of NaGdF4:Yb,Er at 980 nm excitation showed an intense red emission. After incorporating the silver nanoparticles, the UCL intensity decreased due to weak scattering and surface plasmon resonance effect. The VSM magnetic measurement indicates both the UCNPs possess paramagnetic behaviour. The NaGdF4:Yb,Er@Ag showed computed tomography imaging. Magnetic resonance imaging study exhibited better T1 weighted relaxivity in the NaGdF4:Yb,Er than the commercial Gd-DOTA. For the first time, the optical trapping was successfully demonstrated for the upconversion NaGdF4:Yb,Er nanoparticle at near-infrared 980 nm light using an optical tweezer setup. The optically trapped UCNP possessing paramagnetic property exhibited a good optical trapping stiffness. The UCL of trapped single UCNP is recorded to explore the effect of the silver nanoparticles. The multifunctional properties for the NaGdF4:Yb,Er@Ag nanoparticle are demonstrated

NaGdF4:Yb,Er-Ag nanowire hybrid nanocomposite for multifunctional upconversion emission, optical imaging, MRI and CT imaging applications

The effect of novel silver nanowire encapsulated NaGdF4:Yb,Er hybrid nanocomposite on the upconversion emission and bioimaging properties has been investigated. The upconvension nanomaterials were synthesised by polyol method in the presence of ethylene glycol, PVP and ethylenediamine. The NaGdF4:Yb,Er-Ag hybrid was formed with upconverting NaGdF4:Yb,Er nanoparticles of size ~ 80 nm and silver nanowires of thickness ~ 30 nm. The surface plasmon induced by the silver ion in the NaGdF4:Yb,Er-Ag nanocomposite resulted an intense upconversion green emission at 520 nm and red emission at 660 nm by NIR diode laser excitation at 980 nm wavelength. The UV-Vis-NIR spectral absorption at 440 nm and 980 nm, the intense Raman vibrational modes and the strong upconversion emission results altogether confirm the localised surface plasmon resonance effect of silver ion in the hybrid nanocomposite. MRI study of both NaGdF4:Yb,Er nanoparticle and NaGdF4:Yb,Er-Ag nanocomposite revealed the T1 relaxivities of 22.13 and 10.39 mM−1 s−1, which are larger than the commercial Gd-DOTA contrast agent of 3.08 mM−1 s−1. CT imaging NaGdF4:Yb,Er-Ag and NaGdF4:Yb,Er respectively showed the values of 53.29 HU L/g and 39.51 HU L/g, which are higher than 25.78 HU L/g of the CT contrast agent Iobitridol. The NaGdF4:Yb,Er and NaGdF4:Yb,Er-Ag respectively demonstrated a negative zeta potential of 54 mV and 55 mV, that could be useful for biological application. The in vitro cytotoxicity of the NaGdF4:Yb,Er tested in HeLa and MCF-7 cancer cell line by MTT assay demonstrated a cell viability of 90 and 80 %, respectively. But, the cell viability of NaGdF4:Yb,Er-Ag slightly decreased to 80 and 78%. The confocal microscopy imaging showed that the UCNPs are effectively up-taken inside the nucleolus of the cancer cells, and it might be useful for NIR laser–assisted phototherapy for cancer treatment

"Adaptive response" - some underlying mechanisms and open questions

Organisms are affected by different DNA damaging agents naturally present in the environment or released as a result of human activity. Many defense mechanisms have evolved in organisms to minimize genotoxic damage. One of them is induced radioresistance or adaptive response. The adaptive response could be considered as a nonspecific phenomenon in which exposure to minimal stress could result in increased resistance to higher levels of the same or to other types of stress some hours later. A better understanding of the molecular mechanism underlying the adaptive response may lead to an improvement of cancer treatment, risk assessment and risk management strategies, radiation protection, e. g. of astronauts during long-term space flights. In this mini-review we discuss some open questions and the probable underlying mechanisms involved in adaptive response: the transcription of many genes and the activation of numerous signaling pathways that trigger cell defenses - DNA repair systems, induction of proteins synthesis, enhanced detoxification of free radicals and antioxidant production.Publisher PDFPeer reviewe

High-Throughput Analysis of Alzheimer's beta-Amyloid Aggregation Using a Microfluidic Self-Assembly of Monomersf

The principal histopathological feature of Alzheimer's disease is the presence of ??-amyloid (A??) aggregates in the gray matter of the brain, and researchers believe that various environmental factors play significant roles in the conformational change and self-assembly of A?? peptides. Therefore, discovering a rapid and convenient analytical method of evaluating the environmental factors on A?? aggregation would have a considerable impact. Herein we report our development of a novel microfluidic screening system enabling high-throughput analysis, low-consumption of reagents, and short analytical time. Microchannels with a cross-sectional dimension of 100 ??m ?? 100 ??m were immobilized with A?? monomers via N-hydroxysuccinimide ester activation of the internal surfaces, and then a fresh A?? monomer solution mixed with different small molecules or metal ions was continuously introduced into the microchannels to induce A?? aggregation. In this work, we investigated (1) the temporal evolution of A?? aggregation within microchannels, (2) the high-throughput screening of the inhibitory effect of 12 small molecules against A?? aggregation, and (3) the effect of different metal ions (Fe3+, Cu2+, Zn2+, and Al3+) on A?? aggregation by using thioflavin T (ThT)-induced fluorescence microscopy and ex situ atomic force microscopy. The microfluidic system should contribute to a simultaneous analysis of multiple environmental factors affecting amyloid aggregates in a parallel manner and to screen therapeutic small molecules prior to their in vivo evaluation. 288close201