Chemistry Reference
In-Depth Information
which enable both good cell growth and functionality or localized spotting of a
siRNA-containing gel or suppression of cell adhesion.
8.2.3.4.8 Summary and Outlook
A wide variety of plasma activation and functionalization processes, with an empha-
sis on creation of amino and carboxylic acid functional groups, has been developed
for the purpose of improvement of interface biocompatibility of artificial bioma-
terials. Two main fields of applications exist: biomaterials in direct contact with
living cells, e.g., implants, bioreactors, and cell culture substrates, and covalent
immobilization of biomolecules, e.g., for diagnostic purposes and implants. Despite
limitations concerning chemical selectivity of functionalization and obtainable den-
sities of functional groups, this type of surface modification is frequently used,
and a number of well-established applications exist. This is due to some specific
advantages like ease of operation and low risk of detrimental impacts on biocompat-
ibility. Future investigation needs to improve specifications of what is necessary for
advanced interface biocompatibility. This will help to direct plasma research on criti-
cal details of the complex modification processes that are currently not yet identified
precisely enough.
8.2.3.5 Plasma Medicine
Surface treatment of various materials is a wide field of plasma application.
Low-pressure plasmas are successfully applied for this task. The development of
nonthermal atmospheric plasma sources that generates cold plasma with gas temper-
atures below 50
◦
C in the free atmosphere, allows the application of so-called tissue
tolerable plasmas (TTP) for treatment of living human and animal tissues and skins,
and opens the door for plasma medicine. Plasma medicine is the topic of instructive
reviews [99,259,260].
Plasma medicine involves three fields, see also [262,263]:
1. Sterilization/decontamination of medical apparatus and tools [264], (see
Section 8.2.1.2), including improvement of cleaning performance in medical
device reprocessing by surface modification as well as inhibition of biofilm
formation by surface treatment and direct action on biofilms.
2. Treatment of biorelevant surfaces for improving the biocompatibility and
the incorporation of implants (e.g., stents, hip prostheses, contact lenses)
into viable tissue by changing the surface characteristics (hydrophobicity,
antifouling properties, cell-adhesive surfaces, application of antimicrobial
active layers with drug delivery functions) [266-269].
3. Direct therapeutic applications of plasmas for prevention and treatment of
diseases, e.g., for chronic wounds healing, skin and mucosal infectious
diseases, localized tumors, keloid formation, promotion of angiogenesis,
blood coagulation, tissue ablation, and hemostasis, dental applications [99],
including promotion of improved penetration of topically applied drugs with
therapeutic outcome [263].
