A comparison on protein, bacterial anti-adhesive and anti-bacterial properties of zwitterionic block copolymer micelle containing ultra-thin films of varying compositions

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye

Tezin Onay Tarihi: 2019

Tezin Dili: İngilizce

Öğrenci: SİNEM ULUSAN

Asıl Danışman (Eş Danışmanlı Tezler İçin): İrem Erel Göktepe

Eş Danışman: Sreeparna Banerjee

Özet:

In this study preparation of ultra-thin coatings of zwitterionic block copolymer micelles and a comparison of their protein adsorption, adhesiveness and anti-bacterial properties as well as adhesiveness against osteoblast-like cells were studied. Zwitterionic block copolymer micelles were obtained through pH-induced self-assembly of poly[3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate-b-2-(diisopropylamino)ethyl methacrylate] (βPDMA-b-PDPA) at pH 7.5. βPDMA-b-PDPA micelles with zwitterionic βPDMA-corona and pH-responsive PDPA-core were then used as building blocks to prepare either 1-layer or layer-by-layer (LbL) assembled multilayer films together with Hyaluronic Acid (HA), Tannic Acid (TA) or poly(sodium 4-styrene sulfonate) (PSS). Protein adsorption tests showed that 3-layer βPDMA-b-PDPA micelles/HA films were the most effective in reducing the adhesion of BSA, lysozyme, ferritin, and casein. In contrast, βPDMA-b-PDPA micelles/TA films were the most attractive surfaces for protein adsorption. Bacterial anti-adhesive tests against a model Gram-negative bacterium, Escherichia coli and a model Gram-positive bacterium, Staphylococcus aureus were in good agreement with the protein adsorption properties of the films. The differences in the anti-adhesive properties between these three different film systems were discussed within vi the context of chemical nature and the functional chemical groups of the polyanions, layer number and surface morphology of the films. Multilayers were found to lose their anti-adhesiveness in the long-term. However, by taking advantage of the pH-responsive hydrophobic micellar cores, an anti-bacterial agent could be loaded into the micelles and multilayers could exhibit anti-bacterial activity in the long-term especially at moderately acidic conditions. In contrast to anti-adhesive properties, no significant differences were recorded in the anti-bacterial properties or osteoblast adhesive properties between the different film types.