Thiol‐Click Based Polyglycerol Hydrogels as Biosensing Platform with In Situ Encapsulated Streptavidin Probes

Abstract

An in situ streptavidin‐encapsulated hydrogel based on dendritic polyglycerol (dPG) which is functionalized with either an acrylate, allyl or acrylamide group and dithiolated polyethylene glycol (PEG) is constructed via a thiol‐click chemistry approach and is investigated for biosensing applications. The hydrogel platform is screened for the encapsulation and release efficiencies of the model protein streptavidin under varying physicochemical conditions, for example, crosslinking chemistry reactions, the molar ratio between the two gel components, macromonomer concentrations or pH‐values. By that, tailor‐made hydrogels can be developed, which are able to encapsulate or release the model protein for several days based on its modality. Furthermore, the accessible binding site of encapsulated streptavidin or in other words, the biotin‐binding performance is quantified, and the stability of the various hydrogel types is studied by rheology measurements, 1H NMR, gel permeation chromatography (GPC), and mass loss experiments.

Polyglycerol‐Based Biomedical Matrix for Immunomagnetic Circulating Tumor Cell Isolation and Their Expansion into Tumor Spheroids for Drug Screening

“…Among olefinic acceptors, acrylate has proven to be a good candidate for thiol‐click coupling to fabricate hydrogel, which can be gradually degraded when incubated at 37 °C. [ 25 ] Herein, we used dPG and four‐arm polyethylene glycol (four‐arm PEG) as the precursors for gelation. dPG, employed as mentioned as a coating polymer on FeNPs, was also used as the main component in hydrogel formation, owing to its efficient functionality and bioinertness.…”

“…Four‐arm PEG‐thiol was synthesized in accordance with the literature with a slight modification (Figure S3). [ 25 ] It was functionalized with thiol group by using thiourea. The thiolation and hydrolysis were carried out at 80 °C after introducing a mesyl group.…”

Sulfated Polyglycerol-Modified Hydrogels for Binding HSV-1 and RSV

“…These two polymers were synthesized according to previously reported methods. , 1 H NMR (D 2 O, δ) of dPG-allyl: 3.34–4.20 (polymer backbone), 5.27–5.35 (CH 2 CH-, 2H) and 5.99 (CH 2 CH–, 1H). 1 H NMR (D 2 O, δ) of PEG-dithiol: 2.67–2.71 (−CH 2 –SH, 2H), 3.48–3.78 (polymer backbone).…”

“…These two compounds were synthesized according to the previous literature. 38 In brief, dPG-acrylate or lPGacrylate was obtained by the substitution reaction between acryloyl chloride and the hydroxyl groups on dPG or lPG (Figure 1a). Synthesis of Allyl-Functionalized dPG (dPG-Allyl) and Thiol Group-Functionalized PEG (PEG-Dithiol).…”

“…These two polymers were synthesized according to previously reported methods. 34,38 Synthesis of Thiol-Functionalized lPGS (lPGS-SH). First, the allyl groups of lPGS-b-PAGE were coupled with cysteamine via thiol−ene reaction through UV initiation to yield the amine groups on the polymer (Figure 1a).…”