Medicinal and Pharmaceutical Chemistry Commons^™

Evaluation Of Peptides And Peptide–Doxorubicin Conjugates Designed And Synthesized For Targeting Triple-Negative Breast Cancer Via Cell-Surface Receptors, Shih-Jing (Jane) Yao

Pharmaceutical Sciences (PhD) Dissertations

A significant problem faced in oncology is the lack of chemotherapeutic agents that are tumor site-specific, resulting in reduced therapeutic efficacy and unintended infliction of harm to surrounding healthy tissues and cells that often lead to serious side effects. Current strategies being explored to circumvent this issue aim to refine delivery of  chemotherapeutic agents specifically to tumor sites, which may be achieved via conjugation of these agents to biomarker-specific ligands. This forms the foundation of ligand-targeted drug delivery. Among different breast cancers, treatment of the triple-negative breast cancer (TNBC) subtype has been particularly challenging, largely due to the absence of …

Amphipathic Hybrid Cyclic-Linear Peptides As A Drug Delivery System, Jonathan Moreno

Pharmaceutical Sciences (PhD) Dissertations

Amphipathic Hybrid Cyclic-Linear Peptides as a Drug Delivery System by Jonathan A. Moreno Peptides

[RW]₄ and [R₅W₄] have been previously identified as molecular transporter Cell Penetrating Peptide (CPP) and antimicrobial agents, respectively. These peptides consisted of alternating and non-alternating arginine (R) as positively charged residues and tryptophan (W) as hydrophobic residues. Herein we report the synthesis of two hybrid amphipathic cyclic-linear cell-penetrating peptides [RW]₄K-AH135 (1) and [R₅W₄]K-AH135 (2) composed of [RW]₄ and [R₅W₄] and a linear peptide AH-135 (Ac)NH-RWLRRWLRWWRR-COOH. The …

Genetic Mutations Of KCa2.3 And KCa3.1 Channels Affect Ca2+ Sensitivity, Razan Orfali

Pharmaceutical Sciences (PhD) Dissertations

The Ca²⁺-activated potassium channels K_Ca channels are a unique family of potassium channels activated by intracellular calcium. K_Ca channels are critical for maintaining K⁺ homeostasis and modulate several physiological processes, from the firing properties of neurons to the control of the transmitter release. The Ca²⁺ sensitivity of these channels allows intracellular Ca²⁺ to regulate the electrical activity of the cell membrane. Increased Ca²⁺ sensitivity of K_Ca channels caused by gain of function mutations (GOF) in the KCNN genes results in a broad spectrum of human channelopathies, including Zimmermann- Laband syndrome (ZLS), …

Amphiphilic Cyclic Cell-Penetrating Peptides Containing Tryptophan And Arginine As Anticancer Agents And Drug Delivery System, Khalid Zoghebi

Pharmaceutical Sciences (PhD) Dissertations

Amphiphilic cyclic cell-penetrating peptides composed of an increasing number of alternative tryptophan (W) and arginine (R) were synthesized and evaluated as a molecular transporter and for their ability to deliver doxorubicin (Dox) and large molecular weight molecules, such as siRNA and proteins. We prepared a cyclic peptide containing alternative tryptophan (W) and arginine (R) residues and a lysine containing a free side chain amino group. Cyclic peptide [(WR)8WK βA] was conjugated through the free side chain amino group of β-alanine with Dox via a glutarate linker to afford [(WR)8WK]bA-Dox conjugate. The conjugate inhibited the cell viability of ovarian adenocarcinoma (SK-OV-3) …

Development Of Novel Peptide-Doxorubicin Conjugates For Targeting Triple-Negative Breast Cancer, Azam Saghaeidehkordi

Pharmaceutical Sciences (PhD) Dissertations

Triple-negative breast cancer (TNBC) is the most aggressive and difficult to treat subtype of breast cancer. Chemotherapy is an active treatment option in combination with other treatments; however, the side effects limit the effective therapeutic dose. To selectively target the cancer cells, I have synthesized three peptide-drug conjugates (PDCs) to specifically target the TNBC cells. The first PDC contains peptide 18-4 with an additional cysteine in the N-terminal (NH2- CWxEAAYQrFL-CONH2) linked to aldoxorubicin (Aldox), a modified version of a common chemotherapy drug doxorubicin (Dox). The cytotoxicity of the PDC and free Dox (positive control) were assessed against MDA-MB-231, MDA-MB-468, and …

Design, Synthesis, And Evaluation Of A Novel Cytotoxic Peptide-Doxorubicin Conjugate Targeting Triple-Negative Breast Cancer, Elmira Ziaei

Pharmaceutical Sciences (PhD) Dissertations

The aim of this thesis was to design, synthesize, and characterize a novel peptide-doxorubicin conjugate, evaluate in vitro stability and cytotoxicity properties of the conjugate and study its mechanism for uptake into the triple-negative breast cancer (TNBC) cells. For the synthesis of the conjugate, first, doxorubicin (Dox) was conjugated to a highly efficient established cross-linker, MCC, to give an intermediate product, MCC-Dox. MCC-Dox was characterized using NMR spectroscopy, mass spectrometry, and RP-HPLC and purified for subsequent reaction. Second, the 11-mer peptide 18-4 (NH₂-CWxEAAYQrFL-CONH₂) with high proteolytic stability and specificity for breast cancer cells was reacted with …

Amphiphilic Cell-Penetrating Hybrid Cyclic-Linear Peptides As A Drug Delivery System, Saghar Mozaffari

Pharmaceutical Sciences (PhD) Dissertations

A number of cyclic peptides containing a positively charged ring composed of arginine residues attached to hydrophobic tail made of tryptophan residues through a lysine linker namely [R₅K]W₅, [R₆K]W₅, [R₅K]W₆, [R₇K]W₅, [R₅K]W₇, [R₆K]W₆, and [R₇K]W₇ were synthesized and evaluated as molecular transporters. The peptides were evaluated for their ability to deliver, fluorescence-labeled cell-impermeable negatively charged phosphopeptide (F′-GpYEEI), and fluorescent labeled anti-HIV drugs (F′-FTC and F′-d4T). The results indicated that the presence of positively …