Kai Krämer

Carbon nanotubes filled with a chemotherapeutic agent: a nanocarrier mediates inhibition of tumor cell growth

AIM In this paper, carbon nanotubes (CNTs) are presented as feasible carriers for carboplatin, a therapeutic agent for cancer treatment. The drug was introduced into CNTs to demonstrate that they are suited as nanocontainers and nanocarriers and can release the drug to initialize its medical virtue. METHOD The filling was accomplished by a wet-chemical approach after the CNTs were opened. The effect on cell proliferation and cytotoxicity of the carboplatin-filled CNT was investigated by using a viability assays. RESULTS Using different analysis methods such as electron energy loss spectroscopy and x-ray photoelectron spectroscopy the structure of carboplatin incorporated into the CNTs was found to be retained. In vitro studies showed that carboplatin-filled CNTs inhibited growth of bladder cancer cells whereas unfilled, opened CNTs barely affected cancer cell growth. CONCLUSION A reversible filling-emptying process could be performed successfully within this work. This highlights the potential of CNTs for applications in the field of drug delivery.

A carbon-wrapped nanoscaled thermometer for temperature control in biological environments

AIMS A carbon-wrapped nanoscaled thermometer for a contactless temperature control in biological systems on the cellular level is presented. MATERIALS & METHODS The thermometer is based on multiwalled carbon nanotubes (MWCNTs) filled with materials with strongly temperature-dependent nuclear magnetic resonance (NMR) parameters. The NMR frequency shift and relaxation time were measured in cuprous-iodide-filled CNTs at different temperatures. RESULTS The experimental data indicate a pronounced temperature dependence of the NMR parameters, thereby realizing the nanoscaled thermometer. CONCLUSION This study is a proof-of-concept that the functionalized CNTs can be used as a contactless thermometer in biomedical applications.

Feasibility of Magnetically Functionalised Carbon Nanotubes for Biological Applications: From Fundamental Properties of Individual Nanomagnets to Nanoscaled Heaters and Temperature Sensors

We discuss the prospects of applying the magnetic properties of magnetically functionalised carbon nanotubes to biomedical applications. The primary applications are use as a contactless local heating agent, as a standalone thermoablation treatment or in concert with remotely released anti-cancer drugs. Targeted heat treatment is an effective cancer treatment, as tumour tissue has a reduced heat tolerance. To understand the heating process in an applied alternating current (AC) magnetic field the basics of the ferro- and superparamagnetic heating mechanisms are described and brought into context with the material properties. The performance of various materials is compared with respect to heat output, and prospect of additional functionalisation. The actual heating output in AC magnetic fields is studied and discussed in this chapter. Hall magnetometry and Magnetic Force Microscopy are employed to study the magnetic properties of individual nano-ferromagnets, e.g. magnetisation reversal behaviour and domain configuration. NMR studies show that a non-invasive temperature control by virtue of a carbon-wrapped nanoscaled thermometer is feasible.

In vitro and in vivo evaluation of inhibitory nucleic acid constructs for specific therapy of human urinary bladder carcinoma

D. Kunze1 · S. Füssel1 · A. Meye1 · D. Wuttig1 · K. Krämer1 · M. Kotzsch2 · M. Toma2 · B. Schwenzer3 · I. Kausch4 · D. Jocham4 · O.W. Hakenberg5 · M.O. Grimm1 · M.P. Wirth1 1 Klinik für Urologie, Medizinische Fakultät, Technische Universität Dresden, Dresden 2 Institut für Pathologie, Medizinische Fakultät, Technische Universität, Dresden 3 Professur für Allgemeine Biochemie, Technische Universität, Dresden 4 Klinik für Urologie, UKSH Campus Lübeck, Lübeck 5 Urologische Klinik und Poliklinik, Universität, Rostock