title: Designing Visible Light-Cured Thiol-Acrylate Hydrogels for Studying the HIPPO Pathway Activation in Hepatocellular Carcinoma Cells.
abstract: Various polymerization mechanisms have been developed to prepare peptide-immobilized poly(ethylene glycol) (PEG) hydrogels, a class of biomaterials suitable for studying cell biology in vitro. Here, a visible light mediated thiol-acrylate photopolymerization scheme is reported to synthesize dually degradable PEG-peptide hydrogels with controllable crosslinking and degradability. The influence of immobilized monothiol pendant peptide is systematically evaluated on the crosslinking of these hydrogels. Further, methods are proposed to modulate hydrogel crosslinking, including adjusting concentration of comonomer or altering the design of multifunctional peptide crosslinker. Due to the formation of thioether ester bonds, these hydrogels are hydrolytically degradable. If the dithiol peptide linkers used are susceptible to protease cleavage, these thiol-acrylate hydrogels can be designed to undergo partial proteolysis. The differences between linear and multiarm PEG-acrylate (i.e., PEGDA vs PEG4A) are also evaluated. Finally, the use of the mixed-mode thiol-acrylate PEG4A-peptide hydrogels is explored for in situ encapsulation of hepatocellular carcinoma cells (Huh7). The effects of matrix stiffness and integrin binding motif (e.g., RGDS) on Huh7 cell growth and HIPPO pathway activation are studied using PEG4A-peptide hydrogels. This visible light poly-merized thiol-acrylate hydrogel system represents an alternative to existing light-cured hydrogel platforms and shall be useful in many biomedical applications.
authors.affiliation: Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA.
authors.forename: Tsai-Yu
authors.initials: TY
authors.lastname: Lin
authors.affiliation: Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Bragg
authors.affiliation: Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA.
authors.forename: Chien-Chi
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000179:Acrylates / Q000138:chemical synthesis* / Q000494:pharmacology; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D018914:Cells, Immobilized; D055513:Connective Tissue Growth Factor / Q000235:genetics* / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D004229:Dithiothreitol / Q000737:chemistry; D005786:Gene Expression Regulation; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000090683:Hippo Signaling Pathway; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D008027:Light; D010455:Peptides / Q000138:chemical synthesis* / Q000494:pharmacology; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D055668:Photochemical Processes; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000494:pharmacology; D058105:Polymerization; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins
chemical_list: D000179:Acrylates; D048868:Adaptor Proteins, Signal Transducing; C526317:CCN2 protein, human; D003432:Cross-Linking Reagents; D020100:Hydrogels; D010455:Peptides; D010750:Phosphoproteins; D013438:Sulfhydryl Compounds; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins; C088374:YAP1 protein, human; D055513:Connective Tissue Growth Factor; D011092:Polyethylene Glycols; D017346:Protein Serine-Threonine Kinases; D004229:Dithiothreitol
keywords: HIPPO pathway; hydrogels; photopolymerization; poly(ethylene glycol); thiol-acrylate