Plant Vascular Biology and Agriculture

The evolution of animal and plant vascular systems played a pivotal role in the advancement from simple to complex organisms, through the provision of a delivery system for the distribution of components essential for both metabolism and growth. Interestingly, although these two vascular systems conform to the same general rules of fluid dynamics （Murray 1926; McCulloh et al. 2003）, the developmental mechanisms adopted by plants and animals, to generate these long-distance transport systems,

Hyaluronidase Proof for Endothelial Glycocalyx as Partaker of Microcirculation Disturbances

Covalent modification of bovine testicular hyaluronidase with chondroitin sulphate led to changes in the pattern of glycation of native and modified enzyme in its reaction with neutral saccharides and N-acetylhexosamines. Thus, mono- and di-saccharides inactivated the native hyaluronidase to a greater extent than the chondroitin sulfate-modified enzyme. N-acetylhexosamine, on the opposite, inactivated the modified hyaluronidase to a greater extent than the native one. These properties made it possible to use native and modified hyaluronidase as an informative research system for in vivo measurement of the predominant type of saccharide agents in the circulation. The proposed approach was experimentally substantiated by obtained results of the study on these interactions of hyaluronidase derivatives with hyaluronan fragments and their mixture. In a model of post-ischemic perfusion of the rat limb, the effect of hyaluronidase derivatives and their components on restoration of the microcirculation were tracked using laser Doppler flowmetry. Native hyaluronidase accelerated the restoration of initial level of microcirculation, but modified enzyme was markedly inhibited by glycocalyx degradation products. N-acetylhexosamine was positioned at the reducing terminal of these products as a natural label for these glycocalyx fragments. These and other data obtained under various experimental conditions supported the participation of endothelial glycocalyx in microcirculation disturbances.

Advances in hydrogel-based vascularized tissues for tissue repair and drug screening

The construction of biomimetic vasculatures within the artificial tissue models or organs is highly required for conveying nutrients,oxygen,and waste products,for improving the survival of engineered tissues in vitro.In recent times,the remarkable progress in utilizing hydrogels and understanding vascular biology have enabled the creation of three-dimensional(3D)tissues and organs composed of highly complex vascular systems.In this review,we give an emphasis on the utilization of hydrogels and their advantages in the vascularization of tissues.Initially,the significance of vascular elements and the regeneration mechanisms of vascularization,including angiogenesis and vasculogenesis,are briefly introduced.Further,we highlight the importance and advantages of hydrogels as artificial microenvironments in fabricating vascularized tissues or organs,in terms of tunable physical properties,high similarity in physiological environments,and alternative shaping mechanisms,among others.Furthermore,we discuss the utilization of such hydrogels-based vascularized tissues in various applications,including tissue regeneration,drug screening,and organ-on-chips.Finally,we put forward the key challenges,including multifunctionalities of hydrogels,selection of suitable cell phenotype,sophisticated engineering techniques,and clinical translation behind the development of the tissues with complex vasculatures towards their future development.