scholarly journals Reaction behaviour of peptide-based single thiol-thioesters exchange reaction substrate in the presence of externally added thiols

2021 ◽  
Author(s):  
Makafui Y. Folikumah ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Rapid Identification ◽  
Water Soluble ◽  
Reaction Pathways ◽  
Combinatorial Screening ◽  
Crosslinker Concentration ◽  
Thioester Exchange ◽  
Effective Design ◽  
Biological And Medical Applications ◽  
Model Reactions

Abstract Identification of patterns in chemical reaction pathways aids in the effective design of molecules for specific applications. Here, we report on model reactions with a water-soluble single thiol-thioester exchange (TTE) reaction substrate, which was designed taking in view biological and medical applications. This substrate consists of the thio-depsipeptide, Ac-Pro-Leu-Gly-SLeu-Leu-Gly-NEtSH (TDP) and does not yield foul-smelling thiol exchange products when compared with aromatic thiol containing single TTE substrates. TDP generates an α,ω-dithiol crosslinker in situ in a ‘pseudo intramolecular’ TTE. Competitive intermolecular TTE of TDP with externally added “basic” thiols increased the crosslinker concentration whilst “acidic” thiols decreased its concentration. TDP could potentially enable in situ bioconjugation and crosslinking applications. Graphic abstract The competition between ‘pseudo intramolecular’ and intermolecular exchange of a peptide-based thiol-thioester exchange (TTE) substrate can be used to control the relative amount of final exchange products based on size and pKa values of externally added thiols. Potential application of this system can be seen in the development of TTE substrates for the rapid identification of thiols by dynamic combinatorial screening.

Functional Poly(p-Xylylene)s via Chemical Reduction of Poly(p-Phenylene Vinylene)s

2019 ◽  
Author(s):  
Ain Uddin ◽  
Weifan Sang ◽  
Yong Gao ◽  
Kyle Plunkett
Keyword(s):  
Film Formation ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Phenylene Vinylene ◽  
Polymer Modification ◽  
Polymer Backbone ◽  
Crosslinking Process ◽  
Conducting Membranes ◽  
In Situ Crosslinking

The synthesis of poly(p-xylylene)s (PPXs) with sidechains containing alkyl bromide functionality, and their post-polymer modification, is described. The PPXs were prepared by a diimide hydrogenation of poly(p-phenylene vinylene)s (PPVs) that were originally synthesized by a Gilch polymerization. The polymer backbone reduction was carried out with hydrazine hydrate in toluene at 80 °C to provide polymers with the sidechain-containing bromide functionality intact. To demonstrate post-polymer modification of the sidechains, the resulting PPX polymers were modified with trimethylamine to form tetraalkylammonium ion functionality and were evaluated as anion conducting membranes. While PPX homopolymers containing tetralkylammonium ions were completely water soluble and not able to form valuable films, PPX copolymers containing mixed tetraalkylammonium ions and hydrophobic chains were capable of film formation and alkaline stability. In addition, an in situ crosslinking process that used N,N,N',N'-tetramethyl-1,6-hexanediamine during the tetraalkylammonium formation of brominated PPX polymers was also evaluated and gave reasonable films with conductivities of ~10 mS-cm-1.

Functional Poly(p-Xylylene)s via Chemical Reduction of Poly(p-Phenylene Vinylene)s

2019 ◽  
Author(s):  
Ain Uddin ◽  
Weifan Sang ◽  
Yong Gao ◽  
Kyle Plunkett
Keyword(s):  
Film Formation ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Phenylene Vinylene ◽  
Polymer Modification ◽  
Polymer Backbone ◽  
Crosslinking Process ◽  
Conducting Membranes ◽  
In Situ Crosslinking

The synthesis of poly(p-xylylene)s (PPXs) with sidechains containing alkyl bromide functionality, and their post-polymer modification, is described. The PPXs were prepared by a diimide hydrogenation of poly(p-phenylene vinylene)s (PPVs) that were originally synthesized by a Gilch polymerization. The polymer backbone reduction was carried out with hydrazine hydrate in toluene at 80 °C to provide polymers with the sidechain-containing bromide functionality intact. To demonstrate post-polymer modification of the sidechains, the resulting PPX polymers were modified with trimethylamine to form tetraalkylammonium ion functionality and were evaluated as anion conducting membranes. While PPX homopolymers containing tetralkylammonium ions were completely water soluble and not able to form valuable films, PPX copolymers containing mixed tetraalkylammonium ions and hydrophobic chains were capable of film formation and alkaline stability. In addition, an in situ crosslinking process that used N,N,N',N'-tetramethyl-1,6-hexanediamine during the tetraalkylammonium formation of brominated PPX polymers was also evaluated and gave reasonable films with conductivities of ~10 mS-cm-1.

scholarly journals A thin, deformable, high-performance supercapacitor implant that can be biodegraded and bioabsorbed within an animal body

2021 ◽  
Vol 7 (2) ◽  
pp. eabe3097
Author(s):  
Hongwei Sheng ◽  
Jingjing Zhou ◽  
Bo Li ◽  
Yuhang He ◽  
Xuetao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Electronic Devices ◽  
Form Factors ◽  
Time Frame ◽  
Water Soluble ◽  
Two Dimensional ◽  
Medical Electronics ◽  
Thin Structure ◽  
Shed Light

It has been an outstanding challenge to achieve implantable energy modules that are mechanically soft (compatible with soft organs and tissues), have compact form factors, and are biodegradable (present for a desired time frame to power biodegradable, implantable medical electronics). Here, we present a fully biodegradable and bioabsorbable high-performance supercapacitor implant, which is lightweight and has a thin structure, mechanical flexibility, tunable degradation duration, and biocompatibility. The supercapacitor with a high areal capacitance (112.5 mF cm−2 at 1 mA cm−2) and energy density (15.64 μWh cm−2) uses two-dimensional, amorphous molybdenum oxide (MoOx) flakes as electrodes, which are grown in situ on water-soluble Mo foil using a green electrochemical strategy. Biodegradation behaviors and biocompatibility of the associated materials and the supercapacitor implant are systematically studied. Demonstrations of a supercapacitor implant that powers several electronic devices and that is completely degraded after implantation and absorbed in rat body shed light on its potential uses.

Synthesis and short DNA in situ loading and delivery of 4 nm-aperture flexible organic frameworks

2021 ◽  
Author(s):  
Ze-Kun Wang ◽  
Jia-Le Lin ◽  
Yun-Chang Zhang ◽  
Chen-Wu Yang ◽  
Ya-Kun Zhao ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Water Soluble

Water-soluble hydrazone-connected 3D flexible organic frameworks have been revealed to in situ load and deliver short DNA into normal and cancer cells.

scholarly journals A novel zinc complex with antibacterial and antioxidant activity

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Yun Zhang ◽  
Xiaojing Li ◽  
Jia Li ◽  
Md. Zaved Hossain Khan ◽  
Fanyi Ma ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Acute Toxicity ◽  
Intestinal Absorption ◽  
Antioxidant Activities ◽  
Zinc Ion ◽  
Water Soluble ◽  
Zinc Supplement ◽  
Citrate Complex ◽  
Morphology Characterization

Abstract Background In order to enhance the antibacterial activity and reduce the toxicity of Zn2+, novel complexes of Zn(II) were synthesized. Results A water-soluble zinc-glucose-citrate complex (ZnGC) with antibacterial activity was synthesized at pH 6.5. The structure, morphology, characterization, acute toxicity, antibacterial and antioxidant activities, and in situ intestinal absorption were investigated. The results showed that zinc ion was linked with citrate by coordinate bond while the glucose was linked with it through intermolecular hydrogen bonding. The higher the molecular weight of sugar is, the more favorable it is to inhibit the formation of zinc citrate precipitation. Compared with ZnCl2, ZnGC complex presented better antibacterial activity against Staphylococcus aureus (S. aureus, Gram-positive) and Escherichia coli (E. coli, Gram-negative). Conclusions The results of acute toxicity showed no obvious toxicity in this test and in situ intestinal absorption study, suggesting that ZnGC complex could be used as a potential zinc supplement for zinc deficiency.

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