Amphiphilic coatings deposited by catalyst free PECVD reactor for biological applications
Abstract
Drug delivery systems (DDS) are intensively studied and developed for their application in the
medical treatment of various diseases. By controlling the drug release around a treatment area over
a prolonged period of time it is possible to precisely maintain locally the drug concentration within
a therapeutic window and avoid overdoses as well as a sub-therapeutic concentration of the drug.
Present research work is devoted to developing plasma methods to deposit functional coatings on
collagen membranes by plasma processing to fabricate multi-layered DDS.
Biocompatible collagen membranes were used as substrates. ε-caprolactone and diethylene glycol
dimethyl ether were used as precursors to achieve amphiphilic PCL:PEG films [1]. To fabricate
DDS, the first layer was a dense barrier layer (200 nm) deposited in a low pressure capacitively
coupled plasma reactor (CCP, 13.56 MHz, 25 W, 0.5 mbar). The second layer was a carboplatin
drug, dried from an aqueous solution on the surface of the barrier layer with a drug load of 200
μg/cm2. The third layer was a dense barrier layer deposited at the same conditions as the first layer,
to form “sandwich” like structure of DDS. The last top layer was deposited in soft plasmas at
atmospheric pressure plasma (18 kHz, 2W, in order to preserve the desired chemical moieties of the
precursor). In this paper it will be shown that the compatibility of the mechanical properties of the
biocompatible collagen substrate and that of the first dense barrier layer deposited on top of it
plays an important role in the drug delivery kinetics of the drug determined by ICPMS.
Furthermore the use of low pressure and atmospheric pressure plasmas for the fabrication of DDS
will be discussed. Can dense and crosslinked barrier films be fabricated entirely by DBD discharges
for DDS? To respond to this question the refractive index of the deposited films in optimized
conditions of energy deposit in both CCP and DBD were compared by ellipsometry.
Human ovarian carcinoma cell line (NIH:OVCAR-3) was used for in vitro measurements of cell
interactions with the surface of fabricated DDS. Proposed model of DDS on collagen films prevents
migration, adhesion and growth of cancer cells on its surface, and by tuning the thickness of the
dense barrier films it is possible to control drug release kinetics and improve the therapeutic effect.
In vivo experiments were carried out where mice lymph nodes were injected with OVCAR3 cells
and after development of a tumour DDS membranes were implanted to evaluate the feasibility of
the proposed model.
Keywords: pulsed plasma enhanced CVD, PCL-PEG copolymerization,drug delivery system,
DBD
[1] S. Bhatt, F. Valamanesh, J. Pulpytel, R. Lo Dico, A. Baitukha, I. Al-Dybiat, M. Pocard, F. Arefi-
Khonsari, M. Mirshahi, Oncotarget, 7, 36, 2016.