In vivo medical applications

Biomolecular materials and processes have in the recent decade overlapped with polymer science and engineering. Advancements in polymeric materials research for biomolecular and medical applications are rapidly becoming commercialized, examples include biocompatible adhesives for sutureless tissue bonding, liquid dressings for wounds and many other materials used for in vitro and in vivo medical applications. To keep pace with these advancements, the editor has included useful terms in the main body that are commonly used in the material sciences for these new industries. 

An excellent example of a complex sample is a living cell. Its measured Raman spectrum contains spectral features that correspond to each of the cell s biochemical components (DNA, proteins, carbohydrates, lipids, etc.). A description of the experimental methods used to acquire single-cell Raman spectra are given by Chan et al. [4] elsewhere in this book. For a general discussion of in vivo medical applications of Raman spectroscopy, we refer the reader to the excellent review article by Hanlon et al. [5]... 

In our work we utilized the long-wavelength dye indocyanine green (ICG) (Figure 24), which is widely used in a variety of in vivo medical applications. ICG is not toxic and is approved by the U.S. Food and Drug Administration for use in humans, typically by injection. ICG displays a low quantum yield in solution, 0.016, and a somewhat higher quantum yield when bound to serum albumin. Albumin adsorbs to form a monolayer and ICG spontaneously binds to albumin. ICG is chemically and photochemically unstable, and thus provided us with an ideal opportunity to test deposited silver for both metal-enhanced emission and increased ICG photochemical stability. 

CMUT devices are used in the real-time in vivo imaging applications with an improved performance over the existing medical ultrasound transducers. A wafer-bonded CMUT probe showed a bandwidth of 130 %... 

Inspired by the work of Liu and co-workers who have described a new kind of core-shell (sUica-PEG) nanoparticles as platform for dmg-delivery [71], we have very recently proposed [93] a synthetic strategy that affords monodispersed and ordered core-shell silica nanoparticles. Such systems allow the irreversible inclusion of dye molecules in the silica core and present a stable biocompatible and water soluble polymeric protective shell. For these reasons these materials appear particularly promising in the development of luminescent probes for in vitro and, hopefully, in vivo medical and bio-analytical applications. 

In vivo analytical devices ideally should be capable of monitoring several different physiological parameters simultaneously without interfering with an ongoing medical procedure, such as surgery. The devices should be biocompatible, simple to implement and operate, and highly reliable and safe. Fiber-optic chemical sensors can meet most of these requirements since the optical fibers are small (few hundred micrometers in diameter), flexible, nontoxic, and chemically inert. Optical fibers have already proven to be valuable for in vivo clinical applications such as endoscopic procedures and laser power transmission for surgical applications. 

The development of a range of biodegradable polymer products, with a predetermined lifetime, are of interest in at least four main fields. These are 1) packaging materials, 2) mulching films in agriculture, 3) disposable items in different expendable items (table ware such as cups, spoons etc.), and in 4) medical applications, where an in vivo degradation must occur through natural metabolisms in the human or animal body. 

TPEs are gaining and will capture more ground in the multimiUion-dollar medical supply and artificial organs market as replacement materials for thermosets with aU the performance advantages and low processing costs. However, TPEs have to be specially made for such applications, particularly to withstand the physiological environment in vivo. 

---