Carbon nanotube based biomedical agents for heating, temperature sensoring and drug delivery

Figures & data

Figure 1. Sketch of a filled carbon nanotube serving as multi-functional container for in vivo applications. A ferromagnet can induce heat in AC magnetic fields and a material with strongly temperature dependent nuclear magnetic resonance (NMR) signal might serve as a thermometer. Additional drug delivery can be envisaged. Exohedral functionalisation to achieve biocompatibility is sketched. Note that single-walled as well as multi-walled CNT can be realised.

Figure 2. Typical SEM and TEM images of well-aligned iron filled multi-walled carbon nanotubes synthesised by LS-CVD.

Figure 3. Specific absorption rate SAR_Fe of Fe nanowires (∼0.08 g Fe/l) encapsulated in CNT. Measurements have been performed at f = 230 kHz after dispersing the CNT by means of human albumin in PBS (4.2 g/l).

Figure 4. Temperature dependencies of ¹²⁷I, ³⁵Cl and ⁶³Cu nuclear magnetic resonance parameters measured on CuI- and AgCl-filled CNT. (a) Nuclear magnetic resonance frequency. (b) Nuclear spin-lattice relaxation rate. The symbols present the experimental data. Solid lines are the fit (see the text).

Table I.  Temperature sensitivity parameters of several filled CNTs. The table shows the filling material, the respective nucleus as well as temperature dependence of resonance frequency and T₁-relaxation time in the temperature range of 300°–320°K.

Material	Nucleus	dνres/dT (Hz/K)	d()/dT (Hz/K)
CuI-CNTs	^63Cu	–	0.27
	^127I	14	0.86
CuBr-CNTs	^63Cu	19	0.15
	^81Br	7	0.75
CuCl2-CNTs	^63Cu	15	0.23
	^35Cl	1	–