Mark R. Hartman

DNAsomes: Multifunctional DNA-Based Nanocarriers

Nonviral drug delivery systems, [ 1 ] traditionally based on synthetic carriers such as polymeric materials and liposomes offer valuable possibilities for disease prevention and treatment. [ 2 ] Such systems are now being extended to achieve the co-delivery of multiple drugs and/or nucleic acid drugs, which can lead to synergistic effects. [ 3 ] However, due to the fact that most building blocks of polymeric materials and liposomes are isotropic and polydisperse, it remains challenging to rationally engineer building blocks with multiple functionalities within a single molecule for tailored multidrug delivery. The powerful molecular recognition capabilities of DNA [ 4 ] has enabled the controlled assembly of anisotropic building blocks, leading to multifunctional DNA nanostructures. [ 5 ] Recently, we have developed DNA-based anisotropic, branched, crosslinkable (ABC) monomers that can carry multiple moieties on a single molecule with precise control. [ 6 ]

Thermostable Branched DNA Nanostructures as Modular Primers for Polymerase Chain Reaction

Thermostable Branched DNA Nanostructures as Modular Primers for Polymerase Chain Reaction Chemical cross-linking was used to prepare DNA nanostructures with enhanced thermal stability. These thermostable DNA nanostructures were then utilized as modular primers in polymerase chain reaction (PCR; see picture), thus enabling the production of multifunctionalized and branched PCR products for multiplexed detection and hydrogel formation. Angewandte Chemie

Enhanced transcription and translation in clay hydrogel and implications for early life evolution

In most contemporary life forms, the confinement of cell membranes provides localized concentration and protection for biomolecules, leading to efficient biochemical reactions. Similarly, confinement may have also played an important role for prebiotic compartmentalization in early life evolution when the cell membrane had not yet formed. It remains an open question how biochemical reactions developed without the confinement of cell membranes. Here we mimic the confinement function of cells by creating a hydrogel made from geological clay minerals, which provides an efficient confinement environment for biomolecules. We also show that nucleic acids were concentrated in the clay hydrogel and were protected against nuclease, and that transcription and translation reactions were consistently enhanced. Taken together, our results support the importance of localized concentration and protection of biomolecules in early life evolution, and also implicate a clay hydrogel environment for biochemical reactions during early life evolution.

A Universal DNA-Based Protein Detection System

Protein immune detection requires secondary antibodies which must be carefully selected in order to avoid interspecies cross-reactivity, and is therefore restricted by the limited availability of primary/secondary antibody pairs. Here we present a versatile DNA-based protein detection system using a universal adapter to interface between IgG antibodies and DNA-modified reporter molecules. As a demonstration of this capability, we successfully used DNA nano-barcodes, quantum dots, and horseradish peroxidase enzyme to detect multiple proteins using our DNA-based labeling system. Our system not only eliminates secondary antibodies but also serves as a novel method platform for protein detection with modularity, high capacity, and multiplexed capability.

Electrolytic charge inversion at programmable CMOS sensor interfaces

Electrochemical interface layer overcharging is experimentally demonstrated at planar MOS sensor interfaces by controlling the surface charge through nonvolatile charge injection. The electric field across the solid-fluid interface is modulated upon floating-gate program/erase and leads to electrolytic charge reversal, for which an analytical model is derived. This electrofluidic gating effect is further used to repel adsorbed DNA, realizing an electrical surface refreshable biosensor. Quasi-static and impedimetric measurements are presented for validation.

Bio-Mediated Assembly of Ordered Nanoparticle Superstructures

Owing to their unique optical, electronic, magnetic, and catalytic properties, nanoparticles (artificial atoms) have attracted considerable research efforts across various disciplines, spanning chemistry, physics, biology, and materials science. Despite rapid progress in synthesis of nanoparticle over the past decades, it remains a challenge to rationally assemble these artificial atoms into well-defined architectures. Here, we review the latest developments in the utilization of biomolecules for building highly ordered nanoparticle assemblies. In particular, we discuss wet chemistry synthesis and bioconjugation of single crystalline nanoparticles, interaction energetics between biofunctionalized nanoparticles, and the recent achievement of bio-mediated, highly ordered nanoparticle superstructures.