The objective of this work was to synthesize an injectable and photopolymerizable hydrogel based on keratin extracted from poultry feather for encapsulation and delivery of stem cells in tissue regeneration. Since feather keratin is rich in cysteine residue, allylation of sulfhydryl groups was used for functionalization of keratin. Keratin was extracted from feather barbs by reducing the disulfide bonds in cysteine residues to sulfhydryl groups (-SH). Next, the free thiol groups were converted to dehydroalanine (Dha) by oxidative elimination using O-(2,4,6-trimethylbenzenesulfonyl) hydroxylamine. Then, the Dha moieties were converted to s-allyl cysteine by reaction with allyl mercaptan to produce keratin allyl thioether (KeratATE) biopolymer. Human mesenchymal stem cell (hMSCs) were suspended in the aqueous solution of KeratATE, injected into a mold, and photopolymerized to generate a KeratATE hydrogel encapsulating hMSCs. The freeze-dried photo-cross-linked KeratATE hydrogels had a porous, interconnected, honeycomb microstructure with pore sizes in the 20-60 μm range. The compressive modulus of the hydrogels ranged from 1 to 8 kPa depending on KeratATE concentration. KeratATE hydrogels had <5% mass loss in collagenase solution after 21 days of incubation, whereas the mass loss was 15% in trypsin solution. Degradation of KeratATE hydrogel was strongly dependent on trypsin concentration but independent of collagenase. hMSCs proliferated and adopted an elongated spindle-shape morphology after seeding on KeratATE hydrogel. KeratATE hydrogel supported differentiation of the encapsulated hMSCs to the osteogenic and chondrogenic lineages to the same extent as those hMSCs encapsulated in gelatin methacryloyl hydrogel. The results suggest that keratin allyl thioether hydrogel with controllable degradation is a viable matrix for encapsulation and delivery of stem cells in tissue regeneration.
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http://dx.doi.org/10.1021/acs.biomac.6b01493 | DOI Listing |
Eur J Clin Pharmacol
December 2024
Department of Pharmacy, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
Purpose: Voriconazole (VRC) is recommended for the prevention and treatment of invasive fungal infections in children undergoing hematopoietic stem cell transplantation (HSCT). It demonstrates nonlinear pharmacokinetics (PK) and exhibits substantial inter- and intraindividual variability. Phenytoin sodium (PHT) and methylprednisolone (MP) are commonly used in the early stages of HSCT to prevent epilepsy and graft-versus-host disease.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Laboratoire de Physique Théorique et Modélisation, CY Cergy Paris Université, CNRS, UMR 8089, 95302 Cergy-Pontoise cedex, France.
Despite the fact that neural dynamics is triggered by discrete synaptic events, the neural response is usually obtained within the diffusion approximation representing the synaptic inputs as Gaussian noise. We derive a mean-field formalism encompassing synaptic shot noise for sparse balanced neural networks. For low (high) excitatory drive (inhibitory feedback) global oscillations emerge via continuous or hysteretic transitions, correctly predicted by our approach, but not from the diffusion approximation.
View Article and Find Full Text PDFParasitol Res
December 2024
Institute of Hygiene and Microbiology, University of Würzburg, Josef-Schneider-Strasse 2, 97080, Würzburg, Germany.
Pluripotent somatic stem cells are the drivers of unlimited growth of Echinococcus multilocularis metacestode tissue within the organs of the intermediate host. To understand the dynamics of parasite proliferation within the host, it is therefore important to delineate basic mechanisms of Echinococcus stem cell maintenance and differentiation. We herein undertake the first step towards characterizing the role of an evolutionarily old metazoan cell-cell communication system, delta/notch signalling, in Echinococcus cell fate decisions.
View Article and Find Full Text PDFJ Clin Immunol
December 2024
Pediatric Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, University of Bologna, Bologna, Italy.
Background: Activated Phosphoinositide 3-Kinase (PI3K) δ Syndrome (APDS), an inborn error of immunity due to upregulation of the PI3K pathway, leads to recurrent infections and immune dysregulation (lymphoproliferation and autoimmunity).
Methods: Clinical and genetic data of 28 APDS patients from 25 unrelated families were collected from fifteen Italian centers.
Results: Patients were genetically confirmed with APDS-1 (n = 20) or APDS-2 (n = 8), with pathogenic mutations in the PIK3CD or PIK3R1 genes.
Methods Mol Biol
December 2024
Department of Experimental Medicine, Biotechnology, and Molecular Biology Section, Luigi Vanvitelli Campania University, Naples, Italy.
Mesenchymal stromal cells (MSCs) are a heterogeneous population of non-hematopoietic adult stem cells derived from the embryonic mesoderm. They possess self-renewal and multipotent differentiation capabilities, allowing them to give rise to mesodermal cell types, such as osteoblasts, chondroblasts, and adipocytes, as well as non-mesodermal cells, including neuron-like cells and endothelial cells. MSCs play a vital role in maintaining homeostasis across various tissues by facilitating tissue repair, immune regulation, and inflammatory response balance.
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