Utilizing the existence of a sufficiently long induction period during photo-polymerization, defined as the time required to initiate macroscopic gelation after UV irradiation, we propose a new injection method of making a photo-polymerized hydrogel made of thermo-sensitive di-acrylated Pluronic F 127 (DA-PF 127). First, the photo-polymerization of DA-PF 127 solution at the molecular level is initiated by UV irradiation, and this solution is injected into a target site by macroscopic gelation before it becomes viscous. This method can overcome the problems of the existing methods to make an injectable and stable hydrogel by photo-polymerization, reducing the potential damage to normal tissue around the injection site due to direct UV exposure, and the requirement of special equipment for UV crosslinking after injection. By controlling photo-polymerization variables, we found the condition for making an injectable system, where the induction time is equal to or longer than the UV irradiation time. The feasibility of the proposed method was demonstrated in vitro, and the enhanced stability of the produced hydrogels by photo-polymerization was verified. We also characterized the cytotoxicity of the present method using cell cultures and cell encapsulation with the present method, and found minimal cytotoxicity.
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http://dx.doi.org/10.1016/j.jconrel.2007.03.007 | DOI Listing |
J Am Chem Soc
January 2025
Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, 4 place Jussieu, Paris 75005, France.
Controlling the motion of molecular machines to influence higher-order structures is well-established in biological systems but remains a significant challenge for synthetic analogs. Herein, we aim to harness the mechanical switching of switchable molecular tweezers to modulate their self-assembly and produce stimuli-responsive organogels. We report a series of terpy(Pt-salphen) molecular tweezers functionalized with alkyl chains that act as low-molecular-weight gelators (LMWGs) in their open conformation.
View Article and Find Full Text PDFRSC Adv
November 2024
Division of Pharmacy and Optometry, Manchester Institute of Biotechnology, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester UK
Self-assembling peptides remain persistently interesting objects for building nanostructures and further assemble into macroscopic structures, hydrogels, at sufficiently high concentrations. The modulation of self-assembling β-sheet-forming peptide sequences, with a selection from the full library of amino acids, offers unique possibility for rational tuning of the resulting nanostructured morphology and topology of the formed hydrogel networks. In the present work, we explored how a known β-sheet-disassembling amino acid, proline (P), affects the self-assembly and gelation properties of amphipathic peptides.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
This study explores the impact of flavonols (kaempferol, quercetin, kaempferitrin, and isorhamnetin) on the gel properties of myosin derived from silver carp (Hypophthalmichthys molitrix). Before employing a two-stage heating process, myosin samples are pretreated with flavonols, which enhance the structural stability of myosin and aid in the dispersion of myosin molecules. These pretreatments prepare the samples for subsequent thermal processing, where flavonols facilitate myosin unfolding and enhance intermolecular aggregation, thereby improving gel strength.
View Article and Find Full Text PDFNanoscale
December 2024
Research Center for Macromolecules & Biomaterials, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
A racemic mixture of -Fmoc-protected phenylalanine (2) or tryptophan (3) was found to spontaneously afford a gel enriched in either the L- or the D-form of their enantiomers stochastically. Homochiral selective secondary nucleation, promoted by the choice of solvent or stirring, was suggested as the key process for the observed phenomenon.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA, 02115, USA.
The earliest silicon-based aerogels attracted attention due to their nanoscale porous structure and high transparency. Still, they need to be more balanced with the poor mechanical properties. Their brittle structure limits the development of this promising new material.
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