Tunable bioactivity and mechanics of collagen-based tissue engineering constructs: A comparison of EDC-NHS, genipin and TG2 crosslinkers.

Due to its ubiquity and versatility in the human body, collagen is an ideal base material for tissue-engineering constructs. Chemical crosslinking treatments allow precise control of the biochemical and mechanical properties through macromolecular modifications to the structure of collagen. In this work, three key facets regarding the collagen crosslinking process are explored.

Uniform cell colonization of porous 3-D scaffolds achieved using radial control of surface chemistry.

Uniform cellular distribution is a prerequisite to forming tissue within porous scaffolds, but the seeding process often results in preferential adhesion of cells at the periphery. We develop a vapour phase coating strategy which is readily applicable to any porous solid to provide a uniform cellular distribution. Plasma polymerized allyl amine (ppAAm) is used to form a thin nitrogen-containing coating throughout porous three-dimensional (3-D) poly(d,l-lactic acid) scaffolds.

Label-free molecular imaging of immunological synapses between dendritic and T cells by Raman micro-spectroscopy.

Confocal Raman micro-spectroscopy (CRMS) was used to measure spectral images of immunological synapse formation between dendritic and T cells without using molecular labels or other invasive procedures. The purpose-built inverted CRMS instrument integrated an environmental enclosure and a near-infrared laser to allow measurements on live cells maintained under physiological conditions. The integration of the wide-field fluorescence also enabled viability assays and direct comparison between Raman spectral images and gold-standard immuno-fluorescence images for specific molecules.

Laminin and fibronectin treatment leads to generation of dendritic cells with superior endocytic capacity.

Background: Sampling the microenvironment at sites of microbial exposure by dendritic cells (DC) and their subsequent interaction with T cells in the paracortical area of lymph nodes are key events for initiating immune responses. Most of our knowledge of such events in human is based on in vitro studies performed in the absence of extracellular matrix (ECM) proteins. ECM in basement membranes and interstitial spaces of different tissues, including lymphoid organs, plays an important role in controlling specific cellular functions such as migration, intracellular signalling and differentiation.