Review of Nano-Chitosan Based Drug Delivery of Plant Extracts for the Treatment of Breast Cancer

Breast cancer is the most commonly diagnosed cancer and the leading cause of death in females, worldwide. Many therapeutic strategies though available does not effectually reduce the cancer burden. Alternative system of medicine and an effective mode of drug delivery is a major part of ongoing cancer research. Traditional Siddha literature refers to cancer as "Putru"and elucidates the use of extracts from various plant parts for the treatment of cancer. For example, extracts of Mimosa pudica, Plumbago indica, Vitex trifolia, Glycyrrhiza glabra, Alstonia scholaris, Withania somnifera, Aegle marmelos have been studied and shown to possess anticancer property. It is shown to decrease the adverse side effects of chemo and radiotherapy due to the presence of antioxidants. To heighten the bioavailability of the extract and controlled release, it can be delivered along with or encapsulated within a biomaterial. Chitosan and their derivatives are well-known polycationic polymers in the field of biomaterials. Chitosan can be prepared as a colloidal system for delivery in the form of microsphere, hydrogel, nanoparticles and can be modified to improve adhesion by crosslinking, chemical modification and conjugation with macromolecules. They have the advantage of being able to penetrate tight junctions of the cell membrane, biodegradable and mucoadhesive. Glycol-chitosan nanoparticles exhibited tumour-homing property which is an advantage for its use in targeted delivery of anti-Tumour agents. Drug loaded-glycol modified chitosan nanoparticles have tumour inhibitory property because of enhanced permeation and retention capacity. Chitosan as a delivery system enhances the controlled drug release and modulates sustained drug bioavailability thereby delivering effective therapy. The use of chitosan encapsulation of anticancer extracts of medicinal plants can be a promising avenue to explore for their potential in breast cancer therapy. © (2022) Society for Biomaterials & Artificial Organs #20058522

Coconut lethal yellowing diseases: a phytoplasma threat to palms of global economic and social significance

The recent discovery of Bogia coconut syndrome in Papua New Guinea (PNG) is the first report of a lethal yellowing disease (LYD) in Oceania. Numerous outbreaks of LYDs of coconut have been recorded in the Caribbean and Africa since the late Nineteenth century and have caused the death of millions of palms across several continents during the Twentieth century. Despite the severity of economic losses, it was only in the 1970s that the causes of LYDs were identified as phytoplasmas, a group of insect-transmitted bacteria associated with diseases in many other economically important crop species. Since the development of polymerase chain reaction (PCR) technology, knowledge of LYDs epidemiology, ecology and vectors has grown rapidly. There is no economically viable treatment for LYDs and vector-based management is hampered by the fact that vectors have been positively identified in very few cases despite many attempted transmission trials. Some varieties and hybrids of coconut palm are known to be less susceptible to LYD but none are completely resistant. Optimal and current management of LYD is through strict quarantine, prompt detection and destruction of symptomatic palms, and replanting with less susceptible varieties or crop species. Advances in technology such as loop mediated isothermal amplification (LAMP) for detection and tracking of phytoplasma DNA in plants and insects, remote sensing for identifying symptomatic palms, and the advent of clustered regularly interspaced short palindromic repeats (CRISPR)-based tools for gene editing and plant breeding are likely to allow rapid progress in taxonomy as well as understanding and managing LYD phytoplasma pathosystems

Quetiapine: Relatively safe in overdose?

Compared to other antipsychotics quetiapine has been reported to be relatively safer in overdose. We report a case with paranoid schizophrenia who attempted suicide with 1400 mg of quetiapine and manifested drowsiness, supraventricular tachycardia (167/minute) and minimal ST depression in leads V1 to V6 on ECG; all other physiological parameters were normal. Gastric lavage, lorazepam 2mg i/v to control agitation, and 14-hour observation in emergency ended in she being sent home. Subsequently she was successfully managed with ECTs, and quetiapine 600mg and risperidone 6mg daily. This report tends to support the literature suggesting quetiapine as a relatively-safer-in-overdose antipsychotic, and preferable in medication-overdose-suicidal-risk cases

Effect of Electrical and Chemical Autapse on the Firing Pattern and Synchronization of the Rulkov Neuron Model

The Rulkov map model is an efficient model for reproducing different dynamics of the neurons. In specific neurons, the electrical activity is regulated by time-delayed self-feedback called autapse. This paper investigates how the dynamics of the Rulkov model change by considering the autaptic current. Both electrical and chemical autapses are considered, and bifurcation diagrams are plotted for different autapse gains and time delays. Consequently, various firing patterns of the model are illustrated. The results represent that the firing pattern is greatly dependent on the values of autapse parameters. Moreover, the average firing frequency is computed and it is shown that the enhanced firing activity is induced by the inhibitory autapse. The synchronous dynamics of coupled Rulkov maps in the presence of autapse is also studied. It is shown that the electrical autapse enhances synchronization in small time delays, while the enhancement is achieved by chemical autapse in any time delay. However, increasing the time delay reduces the synchronization region

In Situ Immobilized Sesamol-Quinone/Carbon Nanoblack-Based Electrochemical Redox Platform for Efficient Bioelectrocatalytic and Immunosensor Applications

Most of the common redox mediators such as organic dyes and cyanide ligand-associated metal complex systems that have been used for various electrochemical applications are hazardous nature. Sesamol, a vital nutrient that exists in natural products like sesame seeds and oil, shows several therapeutic benefits including anticancer, antidiabetic, cardiovascular protective properties, etc. Herein, we introduce a new electrochemical redox platform based on a sesamol derivative, sesamol-quinone (Ses-Qn; oxidized sesamol), prepared by the in situ electrochemical oxidation method on a carbon nanoblack chemically modified glassy carbon electrode surface (GCE/CB@Ses-Qn) in pH 7 phosphate buffer solution, for nontoxic and sustainable electrochemical, electroanalytical, and bioelectroanalytical applications. The new Ses-Qn-modified electrode showed a well-defined redox peak at Eo = 0.1 V vs Ag/AgCl without any surface-fouling behavior. Following three representative applications were demonstrated with this new redox system: (i) simple and quick estimation of sesamol content in the natural herbal products by electrochemical oxidation on GCE/CB followed by analyzing the oxidation current signal. (ii) Utilization of the GCE/CB@Ses-Qn as a transducer, bioelectrocatalytic reduction, and sensing of H2O2 after absorbing the horseradish peroxidase (HRP)-based enzymatic system on the underlying surface. The biosensor showed a highly selective H2O2 signal with current sensitivity and detection limit values 0.1303 μA μM–1 and 990 nM, respectively, with tolerable interference from the common biochemicals like dissolved oxygen, cysteine, ascorbic acid, glucose, xanthine, hypoxanthine, uric acid, and hydrazine. (iii) Electrochemical immunosensing of white spot syndrome virus by sequentially modifying primary antibody, antigen, secondary antibody (HRP-linked), and bovine serum albumin on the redox electrode, followed by selective bioelectrochemical detection of H2O2