/pdf/self-assembled-monolayers-of-thiolates-on-metals-as-a-form-1neb0hj3k4.pdf

Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

In recent years, numerous large-scale seawater desalination plants have been built in water-stressed countries to augment available water resources, and construction of new desalination plants is expected to increase in the near future. Despite major advancements in desalination technologies, seawater desalination is still more energy intensive compared to conventional technologies for the treatment of fresh water. There are also concerns about the potential environmental impacts of large-scale seawater desalination plants. Here, we review the possible reductions in energy demand by state-of-the-art seawater desalination technologies, the potential role of advanced materials and innovative technologies in improving performance, and the sustainability of desalination as a technological solution to global water shortages.

http://science.sciencemag.org/content/sci/333/6043/712.full.pdf

The Future of Seawater Desalination: Energy, Technology, and the Environment

Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures, and serve as adhesives or barriers between tissue and material surfaces. In this work, the properties of hydrogels that are important for tissue engineering applications and the inherent material design constraints and challenges are discussed. Recent research involving several different hydrogels polymerized from a variety of synthetic and natural monomers using typical and novel synthetic methods are highlighted. Finally, special attention is given to the microfabrication techniques that are currently resulting in important advances in the field.

/pdf/hydrogels-in-regenerative-medicine-lx1cllc4g8.pdf

Hydrogels in regenerative medicine

The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201001215

Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms.

Membranes have an increasingly important role in alleviating water scarcity and the pollution of aquatic environments. Promising molecular-level design approaches are reviewed for membrane materials, focusing on how these materials address the urgent requirements of water treatment applications.

Materials for next-generation desalination and water purification membranes

This paper describes the use of surface plasmon resonance (SPR) spectroscopy and self-assembled monolayers (SAMs) to determine the characteristics of functional groups that give surfaces the ability to resist the nonspecific adsorption of proteins from solution. Mixed SAMs presenting different functional groups were prepared for screening using a synthetic protocol based on the reaction of organic amines with a SAM terminated by interchain carboxylic anhydride groups. Surfaces that presented derivatives of oligo(sarcosine), N-acetylpiperazine, and permethylated sorbitol groups were particularly effective in resisting the adsorption of proteins. Incorporation of these groups into single-component SAMs resulted in surfaces that are comparable to (but slightly less good than) single-component SAMs that present oligo(ethylene glycol) in their ability to resist the adsorption of proteins. In the group of surfaces examined, those that resisted the adsorption of proteins had the following properties:  they were ...

A Survey of Structure−Property Relationships of Surfaces that Resist the Adsorption of Protein

Aptamers are synthetic oligonucleotides that fold into flexible structures and bind to a variety of targets. Aptamers are selected using a biochemistry method called Systematic Evolution of Ligands by Exponential enrichment (SELEX), which can identify specific aptamers capable to bind to target from the pool of billions of random sequences. However, this iterative SELEX process is time consuming and requires specialized lab equipment. APTANI is an existing computational tool that can process the billions of random sequences generated from SELEX and generate secondary structure of the selected aptamer sequence. This can significantly reduce the complexity of SELEX and increase accuracy and throughput in lesser time and resources. Here, APTANI is used to analyze existing steroid aptamers (17ß-estradiol, deoxycortisol, estradiol, testosterone) and to identify sequence motifs/patterns and predict their secondary structure. Graphical Abstract Systematic Evolution of Ligands by Exponential enrichment: SELEX begins with an initial library of random sequences in the scale of 10e20 molecules. The library contains a variable region that is flanked by two fixed sequences. The oligonucleotide library is exposed to a desired target. A washing step will remove oligonucleotides that are weakly or unbound to the target. The remaining oligonucleotide-target complex will be separated with an elution step to recover the oligonucleotide sequence and amplified using PCR to regenerate a new pool for the next cycle. The goal of each new cycle is to enrich the high affinity sequences by modifying the binding conditions. The result is high affinity sequences for the target.

Predicting motifs and secondary structure of steroid aptamers using APTANI

Aptamer-based biosensors (Aptasensors) have gained significant interest over the last decade for higher specificity to their targets, lower cost, and longer shelf life compared to their antibodies-based counterparts. However, not much is known about the binding characteristic of aptamers to their targets, i.e molecular recognition properties as this is a relatively unexplored area of research. Therefore, there is a need to better understand how aptamers bind to their targets because it can help the identification of aptamers for specific targets and in turn, lower the cost of aptamer-based biosensors design. In this work, we performed MEME analysis to detect recurring, fixed length patterns (better known as motifs) in our aptamer database. We focused on previously published aptamers that target different steroids. We also conducted another round of MEME on the four aptamer sequence types combined to further understanding of aptamers. We obtained the most likely motif for each steroid group using two accuracy metrics called E-value and p-value. This lays the foundation for exploring different ways on how aptamers bind to a myriad of targets as well as understanding their binding precision.

and Shuichi Takayama

Papers

A Survey of Structure−Property Relationships of Surfaces that Resist the Adsorption of Protein

Predicting motifs and secondary structure of steroid aptamers using APTANI

Identification of Motifs in Aptamers Using MEME Analysis to aid design of Aptasensors