Sharif Digital Repository

Efficient strategies to promote microvascularization in vascular tissue engineering, a central priority in regenerative medicine, are still scarce; nano- and micro-sized aggregates and spheres or beads harboring primitive microvascular beds are promising methods in vascular tissue engineering. Capillaries are the smallest type and in numerous blood vessels, which are distributed densely in cardiovascular system. To mimic this microvascular network, specific cell components and proangiogenic factors are required. Herein, advanced biofabrication methods in microvascular engineering, including extrusion-based and droplet-based bioprinting, Kenzan, and biogripper approaches, are deliberated with... 

Natural and biodegradable polymers are of particular interest as green sources with low-cost and environmentally friendly features, and have been widely used for polymer composite development. The term “Green Composites” refers to polymer/filler systems in which polymer, filler, or sometimes both components are green in view of sources from which they are yielded or their biodegradability. Natural fibers obtained from plants, animals, and/or geological processes are a big class of green sources widely applied in green composite development. There has also been continued research on recycling of green composite as well as developing hybrid systems for advanced applications. In view of their... 

Natural and biodegradable polymers are of particular interest as green sources with low-cost and environmentally friendly features, and have been widely used for polymer composite development. The term “Green Composites” refers to polymer/filler systems in which polymer, filler, or sometimes both components are green in view of sources from which they are yielded or their biodegradability. Natural fibers obtained from plants, animals, and/or geological processes are a big class of green sources widely applied in green composite development. There has also been continued research on recycling of green composite as well as developing hybrid systems for advanced applications. In view of their... 

In this work, for the first time, different forms of nanocomposites based on rGO and MWCNT were prepared in conjoining with the bioactive glass (BioGlass). In the carbonic layers, a highly toxic nanoparticle, CoNi2S4, was intercalated, and the role of this nanoparticle in the alkaline phosphatase activity, relative cell viability on different cell lines, and also the effect on the cell walls and cell morphologies were investigated. From another perspective, the ability of the chemotherapy drug loading to the prepared nanocomposites was investigated, and the use of leaf extracts was thought of as a green method to lower the cytotoxicity and regulate the genotoxicity of the generated... 

Silk fibroin (SF) has been broadly applied in wound dressing fabrication because of its proper features for wound healing. In this work, we developed a carboxymethyl cellulose (CMC)/gelatin blend film with different concentrations of glycerol, and modified the optimized film with an SF layer through electrospinning process. Tensile strength and cell viability evaluation of blend films demonstrated that the glycerol content of 3% could be suitable as the substrate layer for the two-layer wound dressing. The morphology of the blend film and electrospun nanofibers was obtained from scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). It concluded that... 

Advancements in nanotechnology have resulted in the introduction of several nonviral delivery vectors for the nontoxic, efficient delivery of encapsulated mRNA-based vaccines. Lipid- and polymer-based nanoparticles (NP) have proven to be the most potent delivery systems, providing increased delivery efficiency and protection of mRNA molecules from degradation. Here, the authors provide an overview of the recent studies carried out using lipid NPs and their functionalized forms, polymeric and lipid-polymer hybrid nanocarriers utilized mainly for the encapsulation of mRNAs for gene and immune therapeutic applications. A microfluidic system as a prevalent methodology for the preparation of NPs... 

Humanity's challenges are becoming increasingly difficult, and as these challenges become more advanced, the need for effective and intelligent action becomes more apparent. Meanwhile, the novel coronavirus disease (COVID-19) pandemic, which has plagued the world, could be considered as an opportunity to take a step toward the need for atomic engineering, compared to molecular engineering, as well as to accelerate this type of research. This approach, which can be expressed in terms of picotechnology, makes it possible to identify living cell types or in general, chemical and biological surfaces using their atomic arrays, and applied for early diagnosis even treatment of the disease. © 2020... 

Two non-ionic and hydrophilic surfactant additives, Tetronic-1107 and Triton X-100, were added to poly(vinyl chloride)/NMP polymeric solution to prepare ultrafiltration membranes via immersion precipitation. Surfactants at three different weight percentages up to 6 wt% were added, and the fabricated membranes were characterized and their performance for water treatment in the presence of bovine serum albumin (BSA) as a foulant was assessed. The scanning electron microscopy images indicated remarkable changes in morphology due to higher thermodynamic instability after surfactant addition. The membranes are more porous with more macro-voids in the sub-layer. Plus, the membranes become more... 

With the passage of time and more advanced societies, there is a greater emergence and incidence of disease and necessity for improved treatments. In this respect, nowadays, aptamers, with their better efficiency at diagnosing and treating diseases than antibodies, are at the center of attention. Here, in this review, we first investigate aptamer function in various fields (such as the detection and remedy of pathogens, modification of nanoparticles, antibiotic delivery and gene delivery). Then, we present aptamer-conjugated nanocomplexes as the main and efficient factor in gene delivery. Finally, we focus on the targeted co-delivery of genes and drugs by nanocomplexes, as a new exciting... 

This review covers the development of bioresorbable polymeric composites for applications in tissue engineering. Various commercially available bioresobable polymers are described, with emphasis on recent bioresorbable composites based on natural and synthetic polymers. Bioresorbable polymers contain hydrolyzable bonds, which are subjected to chemical degradation via either reactive hydrolysis or enzyme-catalyzed active hydrolysis. For synthetic polymers, chemical hydrolysis is the most important mode of degradation. The degradation rate can be controlled by varying the molecular weight and crystallinity. Examples of bioresorbable polymers are: polyurethane, poly(D,L)lactide,... 

This review covers the development of bioresorbable polymeric composites for applications in tissue engineering. Various commercially available bioresobable polymers are described, with emphasis on recent bioresorbable composites based on natural and synthetic polymers. Bioresorbable polymers contain hydrolyzable bonds, which are subjected to chemical degradation via either reactive hydrolysis or enzyme-catalyzed active hydrolysis. For synthetic polymers, chemical hydrolysis is the most important mode of degradation. The degradation rate can be controlled by varying the molecular weight and crystallinity. Examples of bioresorbable polymers are: polyurethane, poly(D,L)lactide,... 

Substantial terms have been recognized on the associated risk elements, comorbidities as well as, putative pathophysiological processes of Alzheimer disease and related dementias (ADRDs) as well as, type 2 diabetes mellitus (T2DM), a few from greatest important disease from the moments. Very much is considered regarding the biology and chemistry of each predicament, nevertheless T2DM and ADRDs are an actually similar pattern developing from the similar origins of maturing or synergistic conditions connected by aggressive patho-corporeal terms and continues to be ambiguous. In this depth-critique article, we aimed to investigate all possibilities and represented a novel and applicable... 

Substantial terms have been recognized on the associated risk elements, comorbidities as well as, putative pathophysiological processes of Alzheimer disease and related dementias (ADRDs) as well as, type 2 diabetes mellitus (T2DM), a few from greatest important disease from the moments. Very much is considered regarding the biology and chemistry of each predicament, nevertheless T2DM and ADRDs are an actually similar pattern developing from the similar origins of maturing or synergistic conditions connected by aggressive patho-corporeal terms and continues to be ambiguous. In this depth-critique article, we aimed to investigate all possibilities and represented a novel and applicable... 

The current study investigates the effect of polyacrylonitrile (PAN) addition on morphology and antifouling properties of poly(vinyl chloride) (PVC) asymmetric flat ultrafiltration (UF) membranes. The membranes are prepared via phase inversion method induced by immersion precipitation at different PVC/PAN blending ratio up to 40 wt% PAN. Also, membranes with blending ratio of PVC/ PAN:70/30, which showed the highest water flux and flux recovery ratio, were used for membrane preparation with 4 wt% of Polyethylene glycol (PEG) addition in four different molecular weight, 600 Da, 1,000 Da, 6,000 Da and 20,000 Da, which was used as pore former and hydrophilic polymeric additive. The performance... 

A number of synthetic hydrogels suffer from low mechanical strength. Despite of the recent advances in the fabrication of tough hydrogels, it is still a great challenge to simultaneously construct high stretchability, and self-adhesive and self-healing capability in a hydrogel. Herein, a new type of double network hydrogel was prepared based on irreversible cross-linking of polyacrylamide chains and Schiff-base reversible cross-linking between glycidyl methacrylate-grafted ethylenediamine and oxidized sodium alginate (OSA). The combination of both cross-linkings and their synergistic effect provided a novel hydrogel with high strength, stretchable, rapid self-healing, and self-adhesiveness... 

Deep learning-based graph generation approaches have remarkable capacities for graph data modeling, allowing them to solve a wide range of real-world problems. Making these methods able to consider different conditions during the generation procedure even increases their effectiveness by empowering them to generate new graph samples that meet the desired criteria. This paper presents a conditional deep graph generation method called SCGG that considers a particular type of structural conditions. Specifically, our proposed SCGG model takes an initial subgraph and autoregressively generates new nodes and their corresponding edges on top of the given conditioning substructure. The architecture... 

Doxorubicin (DOX) is a potent anti-cancer agent and there have been attempts in developing nanostructures for its delivery to tumor cells. The nanoparticles promote cytotoxicity of DOX against tumor cells and in turn, they reduce adverse impacts on normal cells. The safety profile of nanostructures is an important topic and recently, the green synthesis of nanoparticles has obtained much attention for the preparation of biocompatible carriers. In the present study, we prepared layered double hydroxide (LDH) nanostructures for doxorubicin (DOX) delivery. The Cu–Al LDH nanoparticles were synthesized by combining Cu(NO3)2·3H2O and Al(NO3)3·9H2O, and then, autoclave at 110. The green... 

Tissue engineering and regenerative medicine have solved numerous problems related to the repair and regeneration of damaged organs and tissues arising from aging, illnesses, and injuries. Nanotechnology has further aided tissue regeneration science and has provided outstanding opportunities to help disease diagnosis as well as treat damaged tissues. Based on the most recent findings, magnetic nanostructures (MNSs), in particular, have emerged as promising materials for detecting, directing, and supporting tissue regeneration. There have been many reports concerning the role of these nano-building blocks in the regeneration of both soft and hard tissues, but the subject has not been... 

Disease prediction is a well-known classification problem in medical applications. Graph Convolutional Networks (GCNs) provide a powerful tool for analyzing the patients’ features relative to each other. This can be achieved by modeling the problem as a graph node classification task, where each node is a patient. Due to the nature of such medical datasets, class imbalance is a prevalent issue in the field of disease prediction, where the distribution of classes is skewed. When the class imbalance is present in the data, the existing graph-based classifiers tend to be biased towards the major class(es) and neglect the samples in the minor class(es). On the other hand, the correct diagnosis... 

Breast and prostate cancers are common types of cancers with various strategies, such as chemotherapy and radiotherapy, for their therapy. Since these methods have undesired side effects and poor target affinity, neoteric strategies—known as aptamer-based smart drug delivery systems (SDDSs)—have been developed in recent years to overcome the obstacles of current treatment, and investigated for a clinical trial. The high affinity and versatility of aptamers for binding to the corresponding targets make them highly noticeable agents in the drug delivery domains. In addition to their exceptional benefits, aptamers are able to overcome tumor resistance because of their high selectivity and low...