Biology subjects

Binger, K. J.

Publications and source records attributed to Binger, K. J..

3 recordsLinked to original sources

bioRxiv2024

Self-healing, biocompatible bioinks from self-assembled peptide and alginate hybrid hydrogels

1.There is a pressing need for new biomaterials that are printable, stiff and highly biocompatible. This is primarily due to the inverse relationship between the printability and viscosity of hydrogels. Cell-laden, printable, rigid biomaterials are needed for replicating stiffer tissues such as cartilage in regenerative medicine, modelling the fibrosis of tissue and cancer microenvironments, as well as in non-cellular research fields such as biosensors. Here, we have designed a hybrid material compromised of self-assembled Fmoc-FF peptide assemblies dispersed throughout a sodium alginate matrix. The resultant hybrid bioink has a stiffness up to 10 times greater than sodium alginate alone but remains highly printable, even when laden with high concentrations of cells. In addition, the thixotropic self-assembled peptide assemblies gave the hybrid bioinks highly desirable self-healing capabilities. The choice of solvent used to initially dissolve the peptides made significant differences to both the physical properties and the biocompatibility of the bioinks, with the best performing able to support the growth of encapsulated macrophages over 5 days. Our developed hybrid materials allow the bioprinting of materials previously considered too stiff to extrude without causing shear induced cytotoxicity with applications in tissue engineering and biosensing.

bioengineering↗

bioRxiv2024

Holding glycolysis in check though Alox15 activity is required for macrophage M2 commitment and function in tissue repair and anti-helminth immunity.

Macrophage polarization by type-2 cytokines is central to anti-helminth immunity and tissue repair. While some hallmark changes in macrophages are well-characterized and associated with protection against helminths, it is still unclear how macrophages exert their anti-helminth effects. In this context, we investigated Arachidonate 15-lipoxygenase (Alox15), a lipoxygenase well known for its role in macrophage polarization in the context of metabolic diseases, and a hallmark of type-2 macrophage (M2) human polarization. We show that in the absence of Alox15, M2 cannot trap and kill helminths. Surprisingly, expression of M2 markers was normal despite a loss of function. Instead, we found a concomitant increase in pro-inflammatory responses due to an uncontrolled activation of glycolysis. We further show that activation of Peroxisome proliferator-activated receptor-delta (PPAR-{delta}) by lipids downstream of Docosapentaenoic acid (DPA) can restore normal glycolysis control, highlighting a novel role for lipids in the fine-tuning of the metabolic support required for optimal macrophage polarization.

immunology↗

bioRxiv2022

Incorporation of bioactive peptides into peptide nanofibrillar hydrogels affects their nanostructure, mechanical properties and biocompatibility

Self-assembling peptides are promising candidates as scaffolds for 3D cell cultures. These hydrogels offer favourable biocompatibility, nanofibrillar structures that mimic native tissues, and the convenient integration of bioactive peptide sequences, such as arginine-glycine-aspartic acid (RGD), which can enable the development of therapeutically valuable cell types. In the treatment of osteoarthritis (OA) attempts have been made to combine hydrogel scaffolds with mesenchymal stem cells (MSCs) to harness their regenerative potential. This involves the deposition of extracellular matrix (ECM) components like collagen and proteoglycans. Here, we employ the hydrogel-forming peptide Fmoc-diphenylalanine (Fmoc-FF) and incorporate stoichiometric amounts of Fmoc-RGD. We investigate the impact of RGD on nanofibrillar morphologies, hydrogel stability, MSC viability, and the deposition of collagen, proteoglycans, and glycosaminoglycans. Elevating RGD content enhances cell viability and collagen deposition. However, at higher RGD concentrations, the stability of the hydrogels is compromised. To characterise collagen deposition, we introduce a non-destructive and label-free method using a plasmon-enhanced colorimetric histology technique. This innovation provides a practical means to image collagen without resorting to intricate and destructive sample processing and complex immunohistological staining procedures. This simple approach holds broad potential for routine and label-free quantification of collagen-rich biomaterials, promising widespread applications across various research and clinical settings.

bioengineering↗