A pinboard by
Jing Ren

VESKI Research Fellow, The University of Melbourne


We use synthetic polymer helices to mimic DNA and make new functional materials

Recent advances in DNA technology have enabled synthetic DNA with targeted sequences to be made as powerful and versatile engineering materials to construct unprecedented nanoscale objects & devices. These new DNA assemblies are not only fundamentally interesting from academic research viewpoint, but also hold great promise for the development of next-generation materials that may address unsolved challenges in areas of information storage, therapeutics & nanoelectronics. However, artificial DNA is made by a costly iterative process, which makes the large-scale production infeasible for many material applications. DNA is susceptible to heat, pH and enzymatic degradation like other biopolymers, which raises additional concern for the use of DNA-based nanomaterials.

Our research team focus on developing synthetic polymer helices that mimic the structure and characteristic properties of the DNA double helix. Through synthetic polymer chemistry, we can prepare polymer helices with controlled dimensions and feature properties based on a cheap commercial polymer - poly(methyl methacrylate) (PMMA) that can be made on multi-gram scale. Furthermore, PMMA are more chemically robust as their structure is held together by non-biodegradable C-C linkages. This would ensure the PMMA-based nanomaterials a long life-time and lasting performance.

Our past studies have verified the structure of the PMMA helix as an exclusive triple-stranded helical assembly that is different from the double helix structure of DNA. More importantly, our studies have enabled a better understanding of the formation & limitations of the PMMA triple-helix. As a result, we can now design and synthesize a variety of functional materials ranging from nanoparticles of less than 100 nm in size to macroscopic polymer fibres and gels based on the PMMA helices. These novel nanomaterials are currently under investigation for applications in the areas of power generation, energy storage, self-healing materials, and polymer therapeutics. We believe our research work has opened up an exciting new research avenue that will bring about scalable synthesis of ‘smart’ nanodevices with capabilities comparable to that of DNA nanotechnology in the near future.


Data Mining as a Guide for the Construction of Cross-Linked Nanoparticles with Low Immunotoxicity via Control of Polymer Chemistry and Supramolecular Assembly.

Abstract: The potential immunotoxicity of nanoparticles that are currently being approved, in different phases of clinical trials, or undergoing rigorous in vitro and in vivo characterizations in several laboratories has recently raised special attention. Products with no apparent in vitro or in vivo toxicity may still trigger various components of the immune system unintentionally and lead to serious adverse reactions. Cytokines are one of the useful biomarkers for predicting the effect of biotherapeutics on modulation of the immune system and for screening the immunotoxicity of nanoparticles both in vitro and in vivo, and they were recently found to partially predict the in vivo pharmacokinetics and biodistribution of nanomaterials. Control of polymer chemistry and supramolecular assembly provides a great opportunity for the construction of biocompatible nanoparticles for biomedical clinical applications. However, the sources of data collected regarding immunotoxicities of nanomaterials are diverse, and experiments are usually conducted using different assays under specific conditions. As a result, making direct comparisons nearly impossible, and thus, tailoring the properties of nanomaterials on the basis of the available data is challenging. In this Account, the effects of chemical structure, cross-linking, degradability, morphology, concentration, and surface chemistry on the immunotoxicity of an expansive array of polymeric nanomaterials will be highlighted, with a focus on assays conducted using the same in vitro and in vivo models and experimental conditions. Furthermore, numerical descriptive values have been utilized uniquely to stand for induction of cytokines by nanoparticles. This treatment of available data provides a simple way to compare the immunotoxicities of various nanomaterials, and the values were found to correlate well with published data. On the basis of the polymeric systems investigated in this study, valuable information has been collected that will aid in the future design of nanomaterials for biomedical applications, including the following: (a) the immunotoxicity of nanomaterials is concentration- and dose-dependent; (b) the synthesis of degradable nanoparticles is essential to decrease toxicity;

Pub.: 27 May '15, Pinned: 31 Jul '17