Dual-purpose PEG scaffolds for the preparation of soft and biofunctional hydrogels: the convergence between CuAAC and thiol-ene reactions.

Orthogonally functionalized PEGs displaying alkenes and azides have been prepared and their dual-purpose scaffolding potential was exploited via click chemistry for controlled insertion of biorelevant moieties as well as facile fabrication of soft, non-toxic and degradable hydrogels.

Multipurpose heterofunctional dendritic scaffolds as crosslinkers towards functional soft hydrogels and implant adhesives in bone fracture applications.

Two sets of heterofunctional dendritic frameworks displaying an inversed and exact number of ene and azide groups have successfully been synthesized and post-functionalized with biorelevant molecules. Their facile scaffolding ability enabled the fabrication of soft and azide functional dendritic hydrogels with modulus close to muscle tissue. The dendritic scaffolds are furthermore shown to be promising primers for the development of novel bone fracture stabilization adhesives with shear strengths succeeding commercial Histroacryl®.

Exhaustive glycosylation, PEGylation, and glutathionylation of a [G4]-ene(48) dendrimer via photoinduced thiol-ene coupling.

We report in this paper the use of free-radical thiol-ene coupling (TEC) for the introduction of carbohydrate, poly(ethylene glycol), and peptide fragments at the periphery of an alkene functional dendrimer. Four different sugar thiols including glucose, mannose, lactose and sialic acid, two PEGylated thiols and the natural tripeptide glutathione were reacted with a fourth generation alkene functional dendrimer [G4]-ene(48) upon irradiation at λ(max) 365 nm. In all cases, the (1)H NMR spectra of the crude reaction mixture revealed the complete disappearance of alkene proton signals indicating the quantitative conversion of all 48 alkene groups of the dendrimer. With one exception only, all dendrimer conjugates were isolated in high yields (70-94%), validating the high efficiency of multiple TEC reactions on a single substrate. All isolated and purified compounds were analyzed by MALDI-TOF spectrometry and gave spectra consistent with the assigned structure.

Bifunctional dendronized cellulose surfaces as biosensors.

Well-defined dendronized cellulose substrates displaying multiple representations of dual-functionality were constructed by taking advantage of the efficiency of the click reaction combined with traditional anhydride chemistry. First, activated cellulose surfaces were decorated with several generations of dendrons, and their peripheral reactive groups were subsequently reacted with a trifunctional orthogonal monomer. The generated substrate tool box was successfully explored by accurately tuning the surface function using a versatile orthogonal dual postfunctionalization approach. In general, the reactions were monitored by using a click-dye reagent or a quartz crystal microbalance (QCM) technique, and the resulting surfaces were well-characterized using XPS, FT-IR, and contact angle measurements. Utilizing this approach two different surfaces have been obtained; that is, triethylenglycol oligomers and amoxicillin molecules were efficiently introduced to the dendritic surface. As a second example, mannose-decorated hydroxyl functional surfaces illustrated their potential as biosensors by multivalent detection of lectin protein at concentration as low as 5 nM.

Bifunctional dendrimers: from robust synthesis and accelerated one-pot postfunctionalization strategy to potential applications.

A fourth wheel: Two sets of bifunctional AB(2)C dendrimers having internal acetylene/azides and external hydroxy groups were constructed utilizing benign synthetic protocols. An in situ postfunctionalization strategy was successfully carried out to illustrate the chemoselective nature of these dendrimers. The dendrimers were also transformed into dendritic nanoparticles or utilized as dendritic crosslinkers for the fabrication hydrogels.