No abstract

The development of biopolymer-based nanogels has gained particular interest to achieve successful delivery of therapeutics for the treatment of various diseases, such as cancer, infection and diabetes. Herein, we report a new and simple methodology for the covalent stabilization of self-assembled gel nanoparticles based on hyaluronic acid (HA) modified with a thermoresponsive ketone-functional copolymer. This relies on the selective formation of hydrazone crosslinks with bishydrazides within the globular domains of the copolymer chains formed above the cloud point temperature. This approach allows tuning of the crosslinking density by varying the dihydrazide crosslinker to ketone molar ratio. The size distributions and morphology of the nanogels were assessed using dynamic light scattering (DLS), cryo-transmission and scanning electron microscopy. In vitro cellular uptake in several cancer cells and in vivo biodistribution of the nanogels in different mouse tumor models were then explored to assess the effectiveness of this crosslinking strategy. The data from these experiments show prolonged blood circulation, longer than 24 hours, for the crosslinked nanogels and high tumor accumulation.

No abstract

Nanogels based on heparosan, which has a chemical structure very similar to hyaluronic acid, accumulate more efficiently at the tumor site.

virus infections persist throughout the lifetime of the host and affect more than 80 % of the humans worldwide. The intensive use of available therapeutic drugs has led to undesirable effects, such as drug-resistant strains, prompting the search for new antiherpetic agents. Although diverse bioactivities have been identified in , its antiviral activity has not attracted much attention. The present study evaluated the antiherpetic effects of a crude hydroethanolic extract from the stem bark of against virus type 1 and as well as its genotoxicity in bone marrow in mammals and established the chemical composition of the crude hydroethanolic extract based on liquid chromatography-diode array detector-mass spectrometry and MS/MS. The crude hydroethanolic extract inhibited all of the tested virus type 1 strains and was effective in the attachment and penetration stages, and showed virucidal activity, which was confirmed by transmission electron microscopy. The micronucleus test showed that the crude hydroethanolic extract had no genotoxic effect at the concentrations tested. The crude hydroethanolic extract afforded protection against lesions that were caused by virus type 1 . Liquid chromatography-diode array detector-mass spectrometry and MS/MS identified 25 substances, which are condensed tannins mainly produced by a B-type linkage and prodelphinidin and procyanidin units.