|Asst Prof Terry W.J. Steele |
Division of Materials Technology
School of Materials Science & Engineering
College of Engineering
Phone: (+65)6592 7594
- PhD University of Minnesota 2006
- BSc(Biochemistry) University of Minnesota 2000
|Dr. Terry W.J. Steele currently holds an Assistant Professor position at Materials and Science Engineering-NTU. Currently he focuses energetic engineering students, eccentric technicians, and idiosyncratic graduate students into a research dream team, striving to solve today’s most pressing vascular-related ailments. Formerly, Dr. Steele has studied pulmonary drug delivery at the Philipps-Marburg University in Marburg, Germany and earned his PhD in Medicinal Chemistry at the University of Minnesota. His research interests include vascular medical devices, bioadhesives, and biodegradable polymers.|
|Surface Functionalization of Thin Films|
Surface functionalization of biocompatible materials is an area under tremendous development for medical implants. The medical implant bulk materials often lack the required surface properties needed for blood compatibility (hemocompatibility), tissue adherence, or promotion of host-cell growth. Secondary surface modifications attempt to address these issues with the grafting of known biocompatible polymers.
To address the significant need for a highly versatile surface coating, we have designed a surface function methodology that incorporates water based ‘green chemistry’, acrylate-based combinatorial libraries, and living polymerization techniques. This strategy will be applicable to most known materials typically employed for solid medical implants, while providing an unprecedented versatility with a wide choice of functional groups, surface densities, and layer thicknesses.
Ocular Delivery Through Periocular, Unidirectional, Biodegradable Discs
We propose an innovative practical and proactive strategy to circumvent the practical hurdles in delivering the anti-CMV drug to the retina, in a safe, effective and affordable manner. We propose to develop a unidirectional nano-drug delivery technique that remains periocular (subtenon’s space) but provides drug delivery into the vitreous over a prolonged or intermittent period yet maintain an adequate concentration at the retina. We will design a biodegradable disc with selective permeability on the two surfaces. The surface adjacent to the sclera will be permeable for unidirectional drug delivery into the eye, while the other surface will be non-permeable, thus obviating the risk of diffusion of the drug externally.
The aim of the therapy is to suppress viral replication, halt the progression of disease, minimize retinal damage, prevent drug resistance, prevent local complications and preserve visual function. In short term, the proposed biodegradable disc will aim to deliver the optimal concentration of the drug near site of lesion and the concentration of the drug will remain sustained over period of six months thereby preventing the need for repeated intraocular injections and also prohibit the patient to come to clinic for repeated injections. Removable after six months won’t be necessary as well, as the polymer components are designed to slowly dissolve and be metabolized into the tissue.
Blood Vessel Joining (Anastomosis) With Adhesive Biodegradable Inserts
Anastomosis—the joining of two blood vessels—requires precise placement of sutures through the two blood vessels that need to be healed together. The technique is technically challenging and requires a long learning curve through practice on cadavers, in vivo animal sacrifices, or both. The suturing practice of today has been nearly the same for 100 years.
As the surgical theatre continues toward laparoscopic and keyhole surgeries, catheter based methods for surgical anastomosis will be sorely needed. Practical limitations to vascular surgeon’s abilities limit sutures to only the most easily accessed vessels and vessel diameters greater than 1 mm. New methods are needed for impossible to access areas such a cerebral blood vessels (i.e. stroke treatments). Methods to join micro-vasculature—such as arterioles and venules—are needed to advance severed limbs and associated limb or organ transplants.
Pipe sleeves in construction and plumbing are commonly used to join gaps, protect pipes from the environment, and repair damaged or leaky plumbing. Similarly, we have designed biodegradable pipe sleaves made from FDA approved implantable polymers.
In our design, the polyesters would be cast into thin film cylinders, no longer than 1-2 cm, 0.5-5 mm in diameter, and 100-500 micrometers thin. These cylinders would incorporate pressure sensitive adhesives on their outer surface to seal and join two opposing blood vessels.
|Research Grant |
- Academic Research Fund Tier 1 (2012-)
- Academic Research Fund Tier 2 (2013-)
- NRF Proof of Concept (2011-)
- NTU Internal Funding - Start Up Grant - College of Engineering (2011-)
- NTU Internal Funding – Nanyang Institute of Technology in Health & Medicine (NITHM) (2011-)
- NTU-NHG Innovation Seed Grant (2011-)
|Current Projects |
- Development of sustained release ganciclovir implant for treatment of CMV retinitis in HIV-AIDS patients (Proj Code: ISG/11013)
- Drug Loaded Microparticles Encapsulated into Bioadhesive Films, Locally Delivered by Angioplasty Balloons
- Drug-Eluting Balloons (DEB) Controlled Delivery through Nanoparticulate Coating
- Enhancing biocompatibility of medical devices through living polymerization surface functionalization
- Rapid Development of Biocompatible Surfaces Through Acrylate Combinatorial Libraries
- Tailored soft-tissue bioadhesvies for site-specific therapy
- Steele, Terry; Loo, Joachim; Venkatraman, Subramaniam. (2010). Adhesive Films For In Vivo Local Drug Delivery. US Provisional Patent Application , .
- Steele, T.W.J, W. Thomas Shier. (2010). Dendrimeric alkylated polyethylenimine nano-carriers with acid-cleavable outer cationic shells mediate improved transfection efficiency without increasing toxicity.. Pharmaceutical research, 27(4)(4), 683-698.
- Podetz-Pedersen, Kelly; Bell, Jason; Steele, Terry; Wilber, Andrew; Shier, W. Thomas; Belur, Lalitha; McIvor, Scott; Hackett, Perry. (2010). Gene expression in lung and liver after intravenous infusion of polyethylenimine complexes of Sleeping Beauty transposons.. Human Gene Therapy, 21(2)(2), 210-220.
- Kissel, T., Steele, T.W.J, Nguyen, J. (2009). Poly[vinyl-3-(dialkylamino)alkylcarbamate-co-vinyl acetate-co-vinyl alcohol]-graft-poly(d,l-lactide-co-glycolide) for siRNA delivery" PATENT APPLICATION. Patent Application, .
- *Steele, T.W.J, *Nguyen, J., Merkel, O., Reul, R., Kissel, T. *Shared co-authorship. (2008). Fast degrading polyesters as siRNA nano-carriers for pulmonary gene therapy. Journal of Controlled Release, 132(3), 243-251.