Infectious diseases can be transmitted and they cause a significant burden on public health globally. They are the greatest world killers and it is estimated that they are responsible for the demise of over 17 million people annually. The impact of these diseases is greater in the developing countries. People with compromised immune systems and children are the most affected. Infectious diseases may be caused by bacteria, viruses, and protozoa. The treatment of infectious diseases is hampered by simultaneous resistance to multiple drugs, indicating that there is a serious and pressing need to develop new therapeutics that can overcome drug resistance. This review will focus on the recent reports of metal-based nanoparticles that are potential therapeutics for the treatment of infectious diseases and their biological efficacy (in vitro and in vivo).

Metal-Based Nanoparticles for the Treatment of Infectious Diseases

Chitosan is obtained from alkaline deacetylation of chitin, and acetamide groups are transformed into primary amino groups during the deacetylation. The diverse biological activities of chitosan and its derivatives are extensively studied that allows to widening the application fields in various sectors especially in biomedical science. The biological properties of chitosan are strongly depending on the solubility in water and other solvents. Deacetylation degree (DDA) and molecular weight (MW) are the most decisive parameters on the bioactivities since the primary amino groups are the key functional groups of chitosan where permits to interact with other molecules. Higher DDA and lower MW of chitosan and chitosan derivatives demonstrated higher antimicrobial, antioxidant, and anticancer capacities. Therefore, the chitosan oligosaccharides (COS) with a low polymerization degree are receiving a great attention in medical and pharmaceutical applications as they have higher water solubility and lower viscosity than chitosan. In this review articles, the antimicrobial, antioxidant, anticancer, anti-inflammatory activities of chitosan and its derivatives are highlighted. The influences of physicochemical parameters of chitosan like DDA and MW on bioactivities are also described.

/pdf/competitive-biological-activities-of-chitosan-and-its-3989xpgnwy.pdf

Competitive Biological Activities of Chitosan and Its Derivatives: Antimicrobial, Antioxidant, Anticancer, and Anti-Inflammatory Activities

https://www.fpl.fs.fed.us/documnts/pdf2020/fpl_2020_cai001.pdf

Maleic acid as a dicarboxylic acid hydrotrope for sustainable fractionation of wood at atmospheric pressure and ≤100 °C: mode and utility of lignin esterification

Polyhydroxyalkanoates (PHAs) have become an attractive biomaterial in research in the past few years due to their extensive potential industrial applications Being long chain hydroxyl fatty acid molecules, the PHAs are hydrophobic in nature, and have less functional groups These features limit their applications in various areas To enhance their usage, these polymers may need to be modified including surface and chemical modifications Such modifications may alter their mechanical properties, surface structure, amphiphilic character and rate of degradation to fulfil the requirements for their future applications Chemical modifications allow incorporation of functional groups to PHAs that could not be introduced through biotechnological methods These chemically reformed PHAs, with enhanced properties, could be used for broad range of applications This review aims to introduce different chemical modification approaches including some recent methods that had not been explored or discussed so far for PHAs as possible technologies for widening the range of product and application potentials © 2017 American Institute of Chemical Engineers Biotechnol Prog, 34:29-41, 2018

/pdf/polyhydroxyalkanoates-properties-and-chemical-modification-3lgig5mnp8.pdf

Polyhydroxyalkanoates: Properties and chemical modification approaches for their functionalization.

The wound healing and antibacterial potential of triple-component nanocomposite (chitosan-silver-sericin) films loaded with moxifloxacin

Silver nanoparticles have been studied as an alternative for treatment of microbial infections and leishmaniasis, without promoting induction of microbial or parasite resistance. In this study, chitosan-based silver nanoparticles were synthesized from silver nitrate (AgNO3), sodium borohydride as a reducing agent, and the biopolymer chitosan as a capping agent. The chitosan-based silver nanoparticles were characterized by ultraviolet–visible, Fourier transform infrared, dynamic light scattering, zeta potential, atomic force microscopy, and transmission electron microscope. The antibacterial assay was performed by determination of the minimum inhibitory concentration. The antileishmanial and the cytotoxic effects induced by AgNO3, chitosan, and chitosan-based silver nanoparticles were analyzed by resazurin and MTT colorimetric assays, respectively. AgNO3, chitosan, and chitosan-based silver nanoparticles induced a marked activity against all bacterial strains and promastigote forms of Leishmania amazonensi...

/pdf/chitosan-based-silver-nanoparticles-a-study-of-the-449zejte9n.pdf

Chitosan-based silver nanoparticles: A study of the antibacterial, antileishmanial and cytotoxic effects

Leishmaniasis is a group of infectious-parasitic diseases with high mortality rates, and endemic in many regions of the globe. The currently available drugs present serious problems such as high toxicity, costs, and the emergence of drug resistance. This has stimulated research into new antileishmania drugs based on natural products and their derivatives. β-Ocimene is a monoterpene found naturally in the essential oils of many plant species which presents antileishmanial activity, and which has not yet been evaluated for its potential to inhibit the etiological agent of leishmaniasis. The aim of this work was to evaluate the activity of β-ocimene against Leishmania amazonensis, its cytotoxicity, and potential mechanisms of action. β-Ocimene presented direct activity against the parasite, with excellent growth inhibition of promastigotes (IC50 = 2.78 μM) and axenic amastigotes (EC50 = 1.12 μM) at concentrations non-toxic to RAW 264.7 macrophages (CC50 = 114.5 µM). The effect is related to changes in membrane permeability and resulting abnormalities in the parasitic cell shape. These were, respectively, observed in membrane integrity and atomic force microscopy assays. β-Ocimene was also shown to act indirectly, with greater activity against intra-macrophagic amastigotes (EC50 = 0.89 μM), increasing TNF-α, nitric oxide (NO), and reactive oxygen species (ROS), with lysosomal effects, as well as promoting decreases in IL-10 and IL-6. Against intra-macrophagic amastigote forms the selectivity index was higher than the reference drugs, being 469.52 times more selective than meglumine antimoniate, and 42.88 times more selective than amphotericin B. Our results suggest that β-ocimene possesses promising in vitro antileishmania activity and is a potential candidate for investigation in in vivo assays.

/pdf/cytotoxic-and-antileishmanial-effects-of-the-monoterpene-b-1enpzvpy.pdf

Klinger Af Rodrigues

Papers

Chitosan-based silver nanoparticles: A study of the antibacterial, antileishmanial and cytotoxic effects

Cytotoxic and Antileishmanial Effects of the Monoterpene β-Ocimene