Cross-Linking Building Blocks Using a “Boronate Bridge” to Build Functional Hybrid Materials

Abstract Fast and catalyst-free cross-linking strategy is of great significance for construction of covalently cross-linked hydrogels. Here, we report the condensation reaction between o-phthalaldehyde (OPA) and N-nucleophiles (primary amine, hydrazide and aminooxy) for hydrogel formation for the first time. When four-arm poly(ethylene glycol) (4aPEG) capped with OPA was mixed with various N-nucleophile-terminated 4aPEG as building blocks, hydrogels were formed with superfast gelation rate, higher mechanical strength and markedly lower critical gelation concentrations, compared to benzaldehyde-based counterparts. Small molecule model reactions indicate the key to these cross-links is the fast formation of heterocycle phthalimidine product or isoindole (bis)hemiaminal intermediates, depending on the N-nucleophiles. The second-order rate constant for the formation of phthalimidine linkage (4.3 M−1 s−1) is over 3000 times and 200 times higher than those for acylhydrazone and oxime formation from benzaldehyde, respectively, and comparable to many cycloaddition click reactions. Based on the versatile OPA chemistry, various hydrogels can be readily prepared from naturally derived polysaccharides, proteins or synthetic polymers without complicated chemical modification. Moreover, biofunctionality is facilely imparted to the hydrogels by introducing amine-bearing peptides via the reaction between OPA and amino group.

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Heterometallic cobalt(ii)–titanium(iv) oxo cages; key building blocks for hybrid materials

Chemical Communications ◽

10.1039/c0cc00016g ◽

2010 ◽

Vol 46 (26) ◽

pp. 4701 ◽

Cited By ~ 35

Author(s):

Salvador Eslava ◽

Frank Hengesbach ◽

Mary McPartlin ◽

Dominic S. Wright

Keyword(s):

Hybrid Materials ◽

Building Blocks

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Development of endogenous enzyme-responsive nanomaterials for theranostics

Chemical Society Reviews ◽

10.1039/c7cs00663b ◽

2018 ◽

Vol 47 (15) ◽

pp. 5554-5573 ◽

Cited By ~ 79

Author(s):

Jing Mu ◽

Jing Lin ◽

Peng Huang ◽

Xiaoyuan Chen

Keyword(s):

Hybrid Materials ◽

Recent Progress ◽

Organic Molecules ◽

Building Blocks ◽

Small Organic Molecules ◽

Organic Hybrid

This review summarizes the recent progress of endogenous enzyme-responsive nanomaterials based on different building blocks such as polymers, liposomes, small organic molecules, or inorganic/organic hybrid materials for theranostics.

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Preparation of Silicophosphate Alternating Hybrid Copolymers via Nonaqueous Acid-Base Reactions of Phosphoric Acid and Organo-Bridged Bis(chlorosilane)

Molecules ◽

10.3390/molecules25010127 ◽

2019 ◽

Vol 25 (1) ◽

pp. 127

Author(s):

Kenji Okada ◽

Masanari Takano ◽

Yasuaki Tokudome ◽

Yomei Tokuda ◽

Masahide Takahashi

Keyword(s):

Phosphoric Acid ◽

Hybrid Materials ◽

Level Structure ◽

Phosphorous Acid ◽

Building Blocks ◽

Molar Ratio ◽

Network Structures ◽

Acid Base ◽

Alternating Copolymer ◽

Silicon Based

A design of atomic and oligomer level structure in organic-inorganic hybrid materials is highly important for various applications. Nonaqueous acid-base reaction allows us to prepare silicophosphates with controlled inorganic networks (–(O–P–O–Si)n) at atomic level because phosphorous and silicon-based precursors can react directly, resulting in an alternating copolymer network. Organic functionalization in those materials has been realized so far by using organic-modified phosphorous acid and/or organo-chlorosilane as precursors. In the present study, silicophosphate oligomers exhibiting inorganic-organic hybrid chains of (–(O–P–O–Si–R–Si)n) (R: bridging organic functional groups), are prepared from phosphoric acid and organo-bridged bis(chlorosilane). The 1, 2-bis(chlorodimethylsilyl)ethane ((C2H4)(Me2SiCl)2) and 1, 4-bis(chlorodimethylsilyl)benzene ((C6H4)(Me2SiCl)2) were used as organo-bridged bis(chlorosilane). Different types of silicophosphate oligomers with different network structures and terminal groups (P-OH and/or Si-Cl) were prepared by changing the reaction temperature and molar ratio of precursors. The formation of low molecular weight oligomers of ring and cage morphologies (ring tetramer, cage pentamer, and ring hexamer) is suggested in the product prepared from phosphoric acid and (C6H4)(Me2SiCl)2 molecule at 150 °C. Those silicophosphate hybrid oligomers are expected to be used as building blocks of hybrid materials with well-defined network structures for desired functionalities.

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The cubic polyhedral oligomeric silsesquioxanes based hybrid materials have a wide variety of applications, including drug administration, gene therapy, biological imaging, and bone regeneration

10.31219/osf.io/9peq8 ◽

2021 ◽

Author(s):

Moataz Dowaidar

Keyword(s):

Gene Therapy ◽

Bone Regeneration ◽

Hybrid Materials ◽

Drug Administration ◽

Self Assembly ◽

Building Blocks ◽

Research Field ◽

Biological Imaging ◽

High Symmetry ◽

Polyhedral Oligomeric Silsesquioxanes

The cubic polyhedral oligomeric silsesquioxanes (POSS), which has a well-defined compact frame, high symmetry, and various modified organic substitutes, has received much interest as one of the most critical building blocks for hybrid nanomaterials and self-assembly driven amphiphilics. This work assessed current molecular design advances, solution self-assembly capabilities, and anticipated biological applications of POSS-based hybrid materials. By adopting controlled/living polymerization techniques and considerable advancements in efficient chemical coupling techniques, preparation techniques for topological POSS-based hybrid materials have become a rapidly increasing research field with future advances. The resultant POSS hybrids with various functional groups help to create complicated, unique self-assembled morphologies in solutions, induced by discrete intermolecular interactions. POSS-based hybrid materials have a wide variety of applications, including drug administration, gene therapy, biological imaging, and bone regeneration, due to their particular benefits (such as high biocompatibility, low cytototoxicity, and good degradability) and simplicity of self-assembly behaviour.

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