Logo - Transparent with coloured UQ.gif





Associate Professor Gordon Xu, Associate AIBN Group Leader


Biomedical Applications of Layered Double Hydroxide Nanoparticles


Friday, 12 October 2012




Physiology Lecture Theatres (Building 63) – Lecture Theatre 360


Abstract:  Layered double hydroxides (LDHs), also known as anionic clays, find a high potential in nanomedicinal application as the drug/gene delivery vehicle. These nanomaterials show a number of advantages over the counter-part organic ones, such as easy preparation in lab at low cost, precise control in particle size, low cytotoxicity, good biocompatibility, and high endosomal escapability. We have developed a robust way to control prepare LDH nanoaprticles (NPs) with the particle size of 30-300 nm in a stable homogeneous suspension.


We have first found that LDH NPs can be quickly taken up by various cell lines, in a clathrin-mediated dose-dependent and time-dependent endocytosis pathway. More excitedly, we have for the first time discovered that the rod-like LDH NPs are mostly located in the nucleus while plate-like LDH NPs in the perinuclear area, which may imply a strategy that can be used to target the subcellular compartments by controlling the shape/size of delivery vehicles.


We have then found that LDH NPs can deliver supercoiled plasmid DNA (ca. 6.1k bps) into various cell lines with a transfection efficacy up to 70-80% cells in the optimized conditions.  Moreover, LDH NPs are able to siRNA into CHO cells to knockdown the expression of the target protein with the efficiency compared with the commercial delivery vehicle. We have shown that cultured neurons can more efficiently internalize siRNA-LDH NPs than non-neuronal cells (eg. fibroblasts), and that release of siRNA into the neuronal cytoplasm resulted in knockdown of the axon guidance receptor DCC.


We have also found that LDH NPs are able to deliver anti-restenotic drug, low molecular weight heparin (LMWH) to vascular smooth muscle cells (SMCs). Intercalation of LMWH into LDH enables the release to sustain for over 5 days. LMWH-LDH nanohybrids enhance the inhibition to SMC proliferation and migration by ~60% compared with the control, e.g. promoting the biological functions of LMWH on SMCs, which is actively pursued for anti-restenosis treatment.


Very recently, we have found for the first time that LDH can be used as a good antigen carrier for effective promotion of the antibody response. The activity of LDH nanoparticles is even higher than the commonly used adjuvant QuilA. More works are underway.


******************* Disclaimer *******************
The contents of this electronic message and any attachments are intended only for the addressee and may contain privileged or confidential information. 
They may only be used for the purposes for which they were supplied.
If you are not the addressee, you are notified that any transmission, distribution, downloading, printing or photocopying of the contents of this message 
or attachments is strictly prohibited. 
The privilege of confidentiality attached to this message and attachments is not waived, lost or destroyed by reason of mistaken delivery to you. 
If you receive this message in error please notify the sender by return e-mail or telephone. 
Please note: the Queensland Museum carries out automatic software scanning, filtering and blocking of E-mails and
attachments (including emails of a personal nature) for detection of viruses, malicious code, SPAM, executable programs or content it deems unacceptable. 
All reasonable precautions will be taken to respect the privacy of individuals as outlined in the QM Privacy Plan. 
Personal information will only be used for official purposes, e.g. monitoring Departmental Personnel's compliance with Museum Policies. 
Personal information will not be divulged or disclosed to others, unless as required by Museum Policy and/or State or Commonwealth Law.
******************** Disclaimer *******************