Artificially synthesized poly(ethylene glycol) (PEG)-based hydrogels are extensively utilized as biomaterials for tissue scaffolds and cell culture matrices due to their non-protein adsorbing properties. Although these hydrogels are inherently non-cell-adhesive, advancements in modifying polymer networks with functional peptides have led to PEG hydrogels with diverse functionalities, such as cell adhesion and angiogenesis. However, traditional methods of incorporating additives into hydrogel networks often result in the capping of crosslinking points with heterogeneous substances, potentially impairing mechanical properties and obscuring the causal relationships of biological functions.
View Article and Find Full Text PDFGelatin-based injectable hydrogels capable of encapsulating cells are pivotal in tissue engineering because they can conform to any geometry and exhibit physical properties similar to those of living tissues. However, the slow gelation process observed in these cell-encapsulating hydrogels often causes an uneven dispersion of cells. This study proposes an approach for achieving fast gelation of unmodified gelatin under physiological conditions through gelatin preclustering.
View Article and Find Full Text PDFGelatin hydrogels are used as three-dimensional cell scaffolds and can be prepared using various methods. One widely accepted approach involves crosslinking gelatin amino groups with poly(ethylene glycol) (PEG) modified with -hydroxysuccinimide ester (PEG-NHS). This method enables the encapsulation of live cells within the hydrogels and also facilitates the adhesion of the hydrogel to biological tissues by crosslinking their surface amino groups.
View Article and Find Full Text PDFInjectable hydrogels are biomaterials that can be administered minimally invasively in liquid form and are considered promising artificial extracellular matrix (ECM) materials. However, ordinary injectable hydrogels are synthesized from water-soluble molecules to ensure injectability, resulting in non-phase-separated structures, making them structurally different from natural ECMs with phase-separated insoluble structural proteins, such as collagen and elastin. Here, we propose a simple material design approach to impart phase-separated structures to injectable hydrogels by adding inorganic salts.
View Article and Find Full Text PDFScaffold systems that can easily encapsulate cells and safely retrieve them at the desired time are important for the advancement of cell-based medicine. In this study, we designed and fabricated thioester-based poly(ethylene glycol) (PEG) hydrogels with injectability and on-demand degradability as new scaffold materials for cells. Hydrogels can be formed within minutes thioester cross-linking between PEG molecules and can be degraded under mild conditions in response to l-cysteine molecules through thiol exchange occurring at the thioester linkage.
View Article and Find Full Text PDFBackground: TetraStat is a tetra-armed polyethylene glycol (PEG) hydrogel. It is a synthetic sealant that solidifies instantly in response to pH changes. This study aimed to evaluate the hemostatic effect of TetraStat through experiments evaluating future clinical applications.
View Article and Find Full Text PDFRecently, covering materials for protecting post-endoscopic ulcers are being developed using hydrogels. Existing hydrogels are not ideal coating materials because it is difficult to control their physical properties. Therefore, we conducted an animal pilot study to investigate the protective effect of a novel ulcer coating material, whose physical properties can be easily controlled and designed.
View Article and Find Full Text PDFInjectable hydrogels are considered important to realize safe and effective minimally invasive therapy. Although animal-derived natural polymers are well studied, they typically lack injectability and fail to eliminate the potential risks of immunogenic reactions or unknown pathogen contamination. Despite extensive research activities to explore ideal injectable hydrogels, such state-of-the-art technology remains inaccessible to non-specialists.
View Article and Find Full Text PDFPrimary peritoneal carcinoma is usually advanced at diagnosis and curability is low unless the patient has a small tumor burden. Peritoneal carcinoma can occur in association with hereditary breast and ovarian cancer syndrome, which is thought to account for 5-6% of all breast cancer. Mutations of two breast cancer susceptibility genes, BRCA1 and BRCA2, are responsible for hereditary breast and ovarian cancer.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2016
Hydrogels are promising materials for biomedical applications, where timely degradation is often preferred. In the conventional design, however, the cleavage of polymer networks essentially causes considerable morphological changes (i.e.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
August 2017
We developed two types of polyethylene glycol (PEG)-based surgical sealants, which we have termed the PER and PRO series. In one, the PRO series, an 8-arm PEG containing activated carbonyl end-groups was reacted with a 4-armed amino-PEG. In the second, the PER series, a 4-arm PEG containing bi-functional end groups with four azides and four activated esters was reacted by strain-promoted alkyne-azide cycloaddition with a 4-arm cyclooctyne-PEG to give a near-ideal Tetra-PEG hydrogel.
View Article and Find Full Text PDFHydrogels are considered key tools for the design of biomaterials, such as wound dressings, drug reservoirs, and temporary scaffolds for cells. Despite their potential, conventional hydrogels have limited applicability under wet physiological conditions because they suffer from the uncontrollable temporal change in shape: swelling takes place immediately after the installation. Swollen hydrogels easily fail under mechanical stress.
View Article and Find Full Text PDFHydrogels are three-dimensional polymer networks that contain a large amount of water inside. Certain hydrogels can be injected in solution and transformed into the gel state with the required shape. Despite their potential biomedical applications, the use of hydrogels has been severely limited because all the conventional hydrogels inevitably "swell" under physiological conditions, which drastically degrades their mechanical properties.
View Article and Find Full Text PDFTrehalose has several novel anti-inflammatory and cell-protective functions. We hypothesized that lyophilized aspirin/trehalose could decrease the severity of aspirin-induced gastropathy. Thirteen dogs were assigned into aspirin, lyophilized aspirin/trehalose, and control groups, and the gastric lesions were assessed on gastroscopy with the modified Lanza scale.
View Article and Find Full Text PDFThe prevalence of BRCA1/2 germline mutations in Japanese patients suspected to have hereditary breast/ovarian cancer was examined by a multi-institutional study, aiming at the clinical application of total sequencing analysis and validation of assay sensitivity in Japanese people using a cross-sectional approach based on genetic factors estimated from personal and family histories. One hundred and thirty-five subjects were referred to the genetic counseling clinics and enrolled in the study. Full sequencing analysis of the BRCA1/2 gene showed 28 types of deleterious mutations in 36 subjects (26.
View Article and Find Full Text PDFTelecare is to link and facilitate communications between ordinary individuals and health care professionals electronically. It is expected to enrich people's lives by mediating specific health care services with advanced infrastructure of the high information society. In that sense, telecare is a tool to promote people's wellness rather than a machine to monitor their conditions for medical reasons, and can have a higher cost effectiveness with features adjusted for wellness objectives.
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