Bio-Orthogonal Mediated Nucleic Acid Transfection of Cells via Cell Surface Engineering.

The efficient delivery of foreign nucleic acids (transfection) into cells is a critical tool for fundamental biomedical research and a pillar of several biotechnology industries. There are currently three main strategies for transfection including reagent, instrument, and viral based methods. Each technology has significantly advanced cell transfection; however, reagent based methods have captured the majority of the transfection market due to their relatively low cost and ease of use.

General Dialdehyde Click Chemistry for Amine Bioconjugation.

The development of methods for conjugating a range of molecules to primary amine functional groups has revolutionized the fields of chemistry, biology, and material science. The primary amine is a key functional group and one of the most important nucleophiles and bases used in all of synthetic chemistry. Therefore, tremendous interest in the synthesis of molecules containing primary amines and strategies to devise chemical reactions to react with primary amines has been at the core of chemical research.

Scaffold Free Bio-orthogonal Assembly of 3-Dimensional Cardiac Tissue via Cell Surface Engineering.

There has been tremendous interest in constructing in vitro cardiac tissue for a range of fundamental studies of cardiac development and disease and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress towards studying 2-dimensional cardiac function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free 3-dimensional multiple cell type co-culture cardiac tissue models. Herein, we develop a programmed rapid self-assembly strategy to induce specific and stable cell-cell contacts among multiple cell types found in heart tissue to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes.

Generation of a Scaffold-Free Three-Dimensional Liver Tissue via a Rapid Cell-to-Cell Click Assembly Process.

There has been tremendous interest in constructing in vitro liver organ models for a range of fundamental studies of cell signaling, metabolism, and infectious diseases, and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress toward studying two-dimensional hepatic function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free three-dimensional multiple cell line coculture tissue models of liver. Herein, we develop and employ a strategy to induce specific and stable cell-cell contacts among multiple hepatic cell lines to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes.

Rewiring Gram-Negative Bacteria Cell Surfaces with Bio-Orthogonal Chemistry via Liposome Fusion.

The ability to tailor bacteria cell surfaces with non-native molecules is critical to advance the study of bacteria communication, cell behavior, and for next-generation therapeutics to improve livestock and human health. Such modifications would allow for novel control over cell behavior, cell-cell interactions, biofilm formation, adjuvant conjugation, and imaging. Current methods to engineer bacteria surfaces have made major advances but rely on complicated, slow, and often expensive molecular biology and metabolic manipulation methods with limited scope on the type of molecules installed onto the surface.

Spheroid and Tissue Assembly via Click Chemistry in Microfluidic Flow.

Proper cell-cell contact and communication are essential for the correct development and survival of higher order organisms. In order to study complex cell interactions that occur in vivo, model systems that are able to recapitulate 3D cell-cell interactions in vitro are key to advancing new biotechnologies, therapeutics, and tissue engineering applications. Herein, we show a new strategy to rapidly and efficiently generate complex multiple cell line containing spheroids and tissues in microfluidic flow without the use of scaffolds, molecular biology, or metabolic biosynthesis.

Photoreceptor cell death, proliferation and formation of hybrid rod/S-cone photoreceptors in the degenerating STK38L mutant retina.

A homozygous mutation in STK38L in dogs impairs the late phase of photoreceptor development, and is followed by photoreceptor cell death (TUNEL) and proliferation (PCNA, PHH3) events that occur independently in different cells between 7-14 weeks of age. During this period, the outer nuclear layer (ONL) cell number is unchanged. The dividing cells are of photoreceptor origin, have rod opsin labeling, and do not label with markers specific for macrophages/microglia (CD18) or Müller cells (glutamine synthetase, PAX6).