Fibrin polymer on the surface of biomaterial implants drives the foreign body reaction.

Implantation of biomaterials and medical devices in the body triggers the foreign body reaction (FBR) which is characterized by macrophage fusion at the implant surface leading to the formation of foreign body giant cells and the development of the fibrous capsule enveloping the implant. While adhesion of macrophages to the surface is an essential step in macrophage fusion and implanted biomaterials are known to rapidly acquire a layer of host proteins, a biological substrate that is responsible for this process in vivo is unknown. Here we show that mice with genetically imposed fibrinogen deficiency display a dramatic reduction of macrophage fusion on biomaterials implanted intraperitoneally and subcutaneously and are protected from the formation of the fibrin-containing fibrous capsule.

Reversible Control of Gelatin Hydrogel Stiffness by Using DNA Crosslinkers*.

Biomaterials with dynamically tunable properties are critical for a range of applications in regenerative medicine and basic biology. In this work, we show the reversible control of gelatin methacrylate (GelMA) hydrogel stiffness through the use of DNA crosslinkers. We replaced some of the inter-GelMA crosslinks with double-stranded DNA, allowing for their removal through toehold-mediated strand displacement.

The role of tumor-stroma interactions on desmoplasia and tumorigenicity within a microengineered 3D platform.

The tumor microenvironment has been demonstrated to play a crucial role in modulating cancer progression. Amongst various cell types within the tumor microenvironment, cancer associated fibroblasts (CAFs) are in abundance, serving to modulate the biophysical properties of the stromal matrix, through excessive deposition of extracellular matrix (ECM) proteins that leads to enhanced tumor progression. There is still a critical need to develop a fundamental framework on the role of tumor-stromal cell interactions on desmoplasia and tumorigenicity.

Analysis of defect mode in a one-dimensional symmetric double-negative photonic crystal containing magnetized cold plasma defect.

In this paper, the characteristic matrix method is employed to theoretically investigate properties of the defect mode in a 1D lossy symmetric defective photonic crystal containing two magnetized cold plasma defect layers. The considered photonic crystal is made of double-negative and double-positive materials. The defect mode, as a function of the magnetic field and the electron density, will be investigated in three different structures.