Chemical Engineering / Kimya Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/14

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Access Right: Embargoed AccessAuthor: search.filters.author.Polat, Mehmet

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  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Designing Robust Xylan/Chitosan Composite Shells Around Drug-Loaded Msns: Stability in Upper Git and Degradation in the Colon Microbiota
    (Elsevier, 2023) Zeybek, Nüket; Büyükkileci, Ali Oğuz; Güleç, Şükrü; Polat, Mehmet; Polat, Hürriyet
    ong residence times, near-neutral pH values, and release triggered by the enzymatic action of the resident microbiota offer unique opportunities for improved drug delivery in the colon. The fact that a delivery agent must also pass through the complete GI tract without degradation presents a challenge due to widely changing pH conditions. In this study, a promising colon-targeted drug delivery system was composed of a xylan/chitosan composite shell formed on curcumin-loaded mesoporous silica nanoparticles (MSNs). A novel synthesis approach was employed to facilitate precipitation of negatively charged xylan on negatively charged MSNs by concurrent chitosan polymerization. Curcumin-loaded xylan/chitosan-coated MSNs (C-MSNs) were determined to contain nearly 42% xylan by the inclusion of chitosan in a one-to-one ratio with xylan. The xylan/chitosan composite shell demonstrated excellent stability in the acidic upper GI tract. The hydrolysis of glycosidic bonds by resident microbiota was the triggering mechanism for xylan degradation and curcumin release in the colon. The presence of xylan has the further benefit of increasing the number of beneficial bacteria and improving short-chain fatty acid production for improved colon health.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 11
    The Effect of Protein Bsa on the Stability of Lipophilic Drug (docetaxel)-Loaded Polymeric Micelles
    (Elsevier, 2021) Polat, Hürriyet; Çevik Eren, Merve; Polat, Mehmet
    Polymeric micelles are promising delivery vehicles for improving the efficacy of anticancer drugs and reducing their side effects. However, considering the binding ability of serum albumin, the possible interaction of micelles with the native plasma components in the bloodstream raises serious questions on micellar stability. The stability of barren or drug-loaded copolymeric micelles was investigated systematically in distilled water (DW) and simulated body fluid (SBF) solutions in the presence of a model protein. The copolymer was a Pluronic® series triblock copolymer (P-123), the drug was strongly lipophilic docetaxel (DOC) and the protein was Bovine Serum Albumin (BSA). The effect of such factors as BSA and DOC concentrations and the aging of the micellar solutions was studied. Both the barren and drug-loaded micelles were quite stable in blank DW and SBF solutions for long times up to 10 days. They lost integrity and showed no inclination to re-assemble when the BSA concentration reached a critical value, which was very close to the plasma Human Serum Albumin (HSA) concentration. The presence of DOC in the micellar cores could not prevent disintegration. The results illustrate clearly that ensuring the stability of polymeric micelles in blood plasma should be an important design factor in their use as drug carriers.