Project Overview: General

The Powder Technology Laboratory (LTP) is concerned with the research, development and processing of inorganic particles ranging from the nanoscale of less than 10 nm to the microscale. The processing comprises various stages of materials fabrication from particles (powders), starting with the particle synthesis to the point of forming and densification to reach the final product.

In this range of activities, LTP is dealing with the development and functionalisation of nanoparticles for

a) drug and gene delivery,

b) self assembling of nanoparticles to achieve unique surface structures which controlled porosity and (bio) functionality and

c) the creation of three dimensional building blocks for further processing.

LTP has as its goals the understanding at a fundamental level these various steps with a view to improving the processing routes for materials of technological importance and to contribute in the development of new and intelligent materials. The high quality of particles in regard to narrow size distribution, form factors, functions etc. is guaranteed by the high level of characterisation methods for particles in the nano and micro range which is part of the R&D activity. The activities of LTP are carried out in the form of projects translating the fundamental knowledge into the many different areas of application.

The aim of the research projects is divided in two topics:

    1. development of methods for inorganic (nano)- particle / powder synthesis, having an optimum of control on the particle characteristics, needed to produce materials with optimal performance (e.g. intelligent materials)
    2. development of processing methods for such particles in regard of their use as single particle, nanostructured surfaces and coatings or as three-dimensional building blocks for sintered products.

LTP works towards this goal via the synthesis of nanosized particles by precipitation from aqueous solutions. The first focus field of LTP is the synthesis of polycrystalline particles based on the controlled agglomeration or assembly of primary nanoparticles. This allows tuning physical properties like magnetic strengths, optical absorption and electrical conductivity to enable materials with intelligent functions.

The second focus field is the development of particles for drug and gene delivery as well as for stem cell tracking. Since about 7 years LTP is active in the research of superparamagnetic iron oxide particles (SPION) used as carrier for drugs and factors (together with University of Zurich, Freiburg i.B. and Charité Berlin) and in nonviral gene transfection with DNA and PCR products (together with University Zurich).

Furthermore these particles have successfully been applied in stem cell tracking (co-operation with University of Geneva). Together with University of Geneva further research has been conducted in the special field of hyperthermia and patent has been filed on a SPION reinforced polymer, which can be heated in situ for vertebroplasty applications.

A third focus field is the development of drug eluting coatings based on ceramic nanoparticle technology for implants, in particular for stents and prostheses which show better properties in contact with living tissue. The novel properties of nanostructured materials provided to such devices are not attainable with bulk material. Based on results of fundamental research activities in the field of ordered arrangement of nanosized particles at surfaces, LTP has established the knowledge of processing particles smaller than 10 nm at large scale, a key competence to achieve that goal (projects with industry).

All these innovative ideas and new approaches in the field of (nano)-particles and processing lead LTP to a unique position in the field of particle/powder technology. The transfer of this knowledge in other domains like soft lithography, surface structuring in the nanoscale via particles is the consequent follow up of such R&D. Further powder technology research is done in the area of compaction and sintering of inorganic powders, where special research is performed in the field of the colloidal behavior of suspension with inorganic particles. One focus of activity is the development of bioresorbable materials for bone filling and skeletal reconstruction, which could substitute conventional bone grafts (autografts, allografts and xenografts). Pastes with various consistencies of such materials (Calcium-Phosphate Hydraulic Cements, CPHC) can be prepared and are able to consolidate in vivo.

Beside the synthesis and processing of various nanoparticles and powders, their characterization and that of the suspension is another main activity. LTP has a long-term knowledge in characterizing especially nanoparticles by using sophisticated and well-matured methods. This guarantees the highest quality of research and development in this field and enables the researchers at LTP to gain a complete picture of the particle and suspension properties. The projects undertaken at LTP are in most cases a translation from basic findings into the industrial applications. Therefore many of them are implemented in very close contact with industrial partners.