Pharmaceutics and Drug Design Commons^™

Cysteine And Arginine-Rich Peptides As Molecular Carriers, Amir Nasrolahi Shirazi, Naglaa Salem El-Sayed, Dindayal Mandal, Rakesh Tiwari, Kathy Tavakoli, Matthew Eteshem, Keykavous Parang

Pharmacy Faculty Articles and Research

A number of linear and cyclic peptides containing alternative arginine and cysteine residues, namely linear (CR)₃, linear (CR)₄, linear (CR)_5, cyclic [CR]₄, and cyclic [CR]₅, were synthesized. The peptides were evaluated for their ability to deliver two molecular cargos, fluorescence-labeled cell-impermeable negatively charged phosphopeptide (F′-GpYEEI) and fluorescence-labeled lamivudine (F′-3TC), intracellularly in human leukemia cancer (CCRF-CEM) cells. We investigated the role of cyclization and the number of amino acids in improving the transporting ability of the peptides. The flow cytometry studies suggested that the synthesized peptides were able to work efficiently as …

Application Of Ichip To Grow “Uncultivable” Microorganisms And Its Impact On Antibiotic Discovery, Rinzhin T. Sherpa, Caretta J. Reese, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

Purpose. Antibiotics have revolutionized modern medicine, allowing significant progress in healthcare and improvement in life expectancy. Development of antibiotic resistance by pathogenic bacteria is a natural phenomenon; however, the rate of antibiotic resistance emergence is increasing at an alarming rate, due to indiscriminate use of antibiotics in healthcare, agriculture and even everyday products. Traditionally, antibiotic discovery has been conducted by screening extracts of microorganisms for antimicrobial activity. However, this conventional source has been over-used to such an extent that it poses the risk of “running out” of new antibiotics. Aiming to increase access to a greater diversity of microorganisms, …

Molecular Overlap In The Regulation Of Sk Channels By Small Molecules And Phosphoinositides, Miao Zhang, Xuan-Yu Meng, Ji-Fang Zhang, Meng Cui, Diomedes E. Logothetis

Pharmacy Faculty Articles and Research

Phosphatidylinositol 4,5-bisphosphate (PIP2) directly interacts with the small-conductance Ca2+-activated K+ 2-a (SK2-a) channel/calmodulin complex, serving as a critical element in the regulation of channel activity. We report that changes of protein conformation in close proximity to the PIP2 binding site induced by a small-molecule SK channel modulator, NS309, can effectively enhance the interaction between the protein and PIP2 to potentiate channel activity. This novel modulation of PIP2 sensitivity by small-molecule drugs is likely not to be limited in its application to SK channels, representing an intriguing strategy to develop drugs controlling the activity of the large number of PIP2-dependent proteins.

Cationic Cell-Penetrating Peptides Are Potent Furin Inhibitors, Bruno Ramos-Molina, Adam N. Lick, Amir Nasrolahi Shirazi, Donghoon Oh, Rakesh Tiwari, Naglaa Salem El-Sayed, Keykavous Parang, Iris Lindberg

Pharmacy Faculty Articles and Research

Cationic cell-penetrating peptides have been widely used to enhance the intracellular delivery of various types of cargoes, such as drugs and proteins. These reagents are chemically similar to the multi-basic peptides that are known to be potent proprotein convertase inhibitors. Here, we report that both HIV-1 TAT47-57 peptide and the Chariot reagent are micromolar inhibitors of furin activity in vitro. In agreement, HIV-1 TAT47-57 reduced HT1080 cell migration, thought to be mediated by proprotein convertases, by 25%. In addition, cyclic polyarginine peptides containing hydrophobic moieties which have been previously used as transfection reagents also exhibited potent furin inhibition in vitro …

2014 Brings New Drugs, Rodney Richmond

Faculty Research ​and Publications

No abstract provided.

Analysis Of Humira, Electro-Acupuncture, And Pulsatile Dry Cupping On Reducing Joint Inflammation In Patients With Rheumatoid Arthritis, Natalie Noll

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

Humira, an anti-TNF drug aimed at decreasing inflammation in Rheumatoid Arthritis patients, can cause skin diseases from rashes to skin cancer. Humira works by blocking the chemical receptor RANKL which inhibits the production of osteoclasts. Osteoclasts are cells that attack and eat bone and cartilage therefore an inhibitory mechanism would cause inflammation.. By analyzing Humira’s effect on the human body, Humira can be compared to other treatments such as electro-acupuncture and pulsatile dry cupping to determine the viability of these alternative treatment methods in regards to their abilities to decrease inflammation in Rheumatoid Arthritis patients through blocking RANKL. An analysis …

Target-Directed Biosynthetic Evolution: Redirecting Plant Evolution To Genomically Optimize A Plant’S Pharmacological Profile, Dustin Paul Brown

Theses and Dissertations--Neuroscience

The dissertation describes a novel method for plant drug discovery based on mutation and selection of plant cells. Despite the industry focus on chemical synthesis, plants remain a source of potent and complex bioactive metabolites. Many of these have evolved as defensive compounds targeted on key proteins in the CNS of herbivorous insects, for example the insect dopamine transporter (DAT). Because of homology with the human DAT protein some of these metabolites have high abuse potential, but others may be valuable in treating drug dependence. This dissertation redirects the evolution of a native Lobelia species toward metabolites with greater activity …

Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen

Theses and Dissertations--Pharmacy

Natural products provide some of the most potent anticancer agents and offer a template for new drug design or improvement with the advantage of an enormous chemical space. The overall goal of this thesis research is to enhance the chemical space of two natural products in order to generate novel drugs with better in vivo bioactivities than the original natural products.

Polycarcin V (PV) is a gilvocarcin-type antitumor agent with similar structure and comparable bioactivity with the principle compound of this group, gilvocarcin V (GV). Modest modifications of the polyketide-derived tetracyclic core of GV had been accomplished, but the most …

Nucleoside Reverse Transcriptase Inhibitors Possess Intrinsic Anti-Inflammatory Activity, Benjamin J. Fowler, Bradley D. Gelfand, Younghee Kim, Nagaraj Kerur, Valeria Tarallo, Yoshio Hirano, Shoba Amarnath, Daniel H. Fowler, Marta Radwan, Mark T. Young, Keir Pittman, Paul Kubes, Hitesh Agarwal, Keykavous Parang, David R. Hinton, Ana Bastos-Carvalho, Shengjian Li, Testuhiro Yasuma, Takeshi Mizutani, Reo Yasuma, Charles Wright, Jayakrishna Ambati

Pharmacy Faculty Articles and Research

Nucleoside reverse transcriptase inhibitors (NRTIs) are mainstay therapeutics for HIV that block retrovirus replication. Alu (an endogenous retroelement that also requires reverse transcriptase for its life cycle)–derived RNAs activate P2X7 and the NLRP3 inflammasome to cause cell death of the retinal pigment epithelium in geographic atrophy, a type of age-related macular degeneration. We found that NRTIs inhibit P2X7-mediated NLRP3 inflammasome activation independent of reverse transcriptase inhibition. Multiple approved and clinically relevant NRTIs prevented caspase-1 activation, the effector of the NLRP3 inflammasome, induced by Alu RNA. NRTIs were efficacious in mouse models of geographic atrophy, choroidal neovascularization, graft-versus-host disease, and sterile …

Design, Synthesis And Biological Evaluation Of Novel Compounds With Cns-Activity Targeting Cannabinoid And Biogenic Amine Receptors, Alexander M. Sherwood

LSU New Orleans Theses and Dissertations

This work seeks to contribute to the discipline of neuropharmacology by way of structure activity relationship from the standpoint of an organic chemist. More specifically, we sought to develop robust synthetic methodology able to efficiently produce an array of compounds for the purpose of systematic evaluation of their interaction with specific sights within the central nervous system (CNS) in order to better understand the mind and to develop drugs that may have beneficial effects on neurological function.

The focus of these studies has been toward the development of novel molecules, using a structure-activity relationship approach, that exhibit binding affinity at …

Facile, Regio-And Diastereoselective Synthesis Of Spiro-Pyrrolidine And Pyrrolizine Derivatives And Evaluation Of Their Antiproliferative Activities, Abdulrahman I. Almansour, Raju Suresh Kumar, Farzana Beevi, Amir Nasrolahi Shirazi, Hasnah Osman, Rusli Ismail, Tan Soo Chen, Brian Sullivan, Kellen Mccaffrey, Alaa Nahhas, Keykavous Parang, Mohamed Ashraf Ali

Pharmacy Faculty Articles and Research

A number of novel spiro-pyrrolidines/pyrrolizines derivatives were synthesized through [3+2]-cycloaddition of azomethine ylides with 3,5-bis[(E)-arylmethylidene] tetrahydro-4(1H)-pyridinones 2a-n. Azomethine ylides were generated in situ from the reaction of 1H-indole-2,3-dione (isatin, 3) with N-methylglycine (sarcosine), phenylglycine, or proline. All compounds (50 M) were evaluated for their antiproliferative activity against human breast carcinoma (MDA-MB-231), leukemia lymphoblastic (CCRF-CEM), and ovarian carcinoma (SK-OV-3) cells. N-alpha-Phenyl substituted spiro-pyrrolidine derivatives (5a-n) showed higher antiproliferative activity in MDA-MB-231 than other cancer cell lines. Among spiro-pyrrolizines 6a-n, a number of derivatives including 6a-c and 6i-m showed a comparable activity with doxorubicin in all three cell lines. Among all compounds …

Effects Of Hepatic Ischemia-Reperfusion Injury On The P-Glycoprotein Activity At The Liver Canalicular Membrane And Blood-Brain Barrier Determined By In Vivo Administration Of Rhodamine 123 In Rats, M. K. Miah, Imam H. Shaik, Ulrich Bickel, Reza Mehvar

Pharmacy Faculty Articles and Research

Purpose To investigate the effects of normothermic hepatic ischemia-reperfusion (IR) injury on the activity of P-glycoprotein (P-gp) in the liver and at the blood-brain barrier (BBB) of rats using rhodamine 123 (RH-123) as an in vivo marker.

Methods Rats were subjected to 90 min of partial ischemia or sham surgery, followed by 12 or 24 h of reperfusion. Following intravenous injection, the concentrations of RH-123 in blood, bile, brain, and liver were used for pharmacokinetic calculations. The protein levels of P-gp and some other transporters in the liver and brain were also determined by Western blot analysis.

Results P-gp protein …

Quantification Of Factors Governing Drug Release Kinetics From Nanoparticles: A Combined Experimental And Mechanistic Modeling Approach, Kyle Daniel Fugit

Theses and Dissertations--Pharmacy

Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies.

A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release …

Effects Of Short-Term Portacaval Anastomosis On The Peripheral And Brain Disposition Of The Blood-Brain Barrier Permeability Marker Sodium Fluorescein In Rats, Imam H. Shaik, M. K. Miah, Ulrich Bickel, Reza Mehvar

Pharmacy Faculty Articles and Research

Contradictory results have been reported with regard to the effects of various models of hepatic encephalopathy on the blood-brain barrier (BBB) permeability, which may be due partly to the use of brain concentrations of BBB markers without attention to their peripheral pharmacokinetics. The purpose of the current study was to investigate the effects of short-term portacaval anastomosis (PCA), a type B model of hepatic encephalopathy, on the peripheral pharmacokinetics and brain distribution of sodium fluorescein (FL), which is a small molecule marker of BBB passive permeability. A single 25 mg/kg dose of FL was administered intravenously to 10-day PCA and …

Rescuing Acetylcholinesterase From Nerve Agent Inhibition: Protein Dynamics Driven Drug Discovery, Aiyana M. Emigh, Brian Bennion

STAR Program Research Presentations

Severe morbidity and mortality consequences result from irreversible inhibition of human acetylcholinesterase by organophosphates (OPs). Oxime-based reactivators are currently the only available treatments but lack efficacy in the central nervous system (CNS) where the most damage occurs. Computational docking and molecular dynamics (MD) simulations reveal complex structural barriers that may reduce oxime efficacy. These results may guide future drug designs of more effective countermeasures.

Novel Therapy For Nicotine Addiction In Alcohol Dependent Rats, Bethany Ann Stennett

UNF Graduate Theses and Dissertations

The co-dependence of nicotine and alcohol addiction occurs at high rates, complicates treatment, and is often associated with significant morbidity and mortality. Treatment options of alcohol and tobacco co-dependence are limited. Currently, there are drugs available for nicotine dependence or alcohol dependence. However, there are no therapeutic drugs available on the market for the co-dependence of nicotine and alcohol. Therefore, and important opportunity of new therapeutic options and drug development has presented itself. NT69L, a non-selective neurotensin (NT) agonist, provides a potential novel therapy for nicotine addiction in alcoholics by interacting with the common neurotransmitter circuits supporting the rewarding process …

Discovery Of Dihydroartemisinin And Dasatinib Drug Combination To Cure Pooroutcome Bcr-Abl+ Acute Lymphoblastic Leukemia, Harpreet Singh

Theses and Dissertations (ETD)

Oncogenic signaling by the Philadelphia chromosome-encoded BCR-ABL fusion kinase initiates and drives both Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Food and Drug Administration (FDA)- approved BCR-ABL-specific kinase inhibitors (BCR-ABL–KIs) imatinib, dasatinib and nilotinib induce prolonged remissions in CML but poor leukemia-reduction and relapse-control in Ph+ ALL. The relative primary BCR-ABL–KI-resistance in Ph+ ALL patients carrying predominantly BCR-ABLWT disease cannot be attributed to drug-resistant BCR-ABL mutations (BCR-ABLMUTANTS), and remains poorly understood.

We established a cell-based platform to evaluate the modulation of anti-Ph+ ALL activity of drugs by both tumor-extrinsic cytokines normally present in the leukemia …

Pharmacokinetic/Pharmacodynamic (Pk/Pd) Modeling Of Anti-Neoplastic Agents, Daniel Lexcen, Ahmed H. Salem, Walid F. Elkhatib, Virginia Haynes, Ayman Noreddin

Pharmacy Faculty Books and Book Chapters

"Development of tumor resistance to chemotherapeutics is related to inherent tumor variations regarding sensitivity to chemotherapeutics and to sub-optimal dosing regimens, including variation in patient pharmacokinetics that result in suboptimal exposure of tumor cells to anti-neoplastic drugs [1, 2]. The rate and extent of drug efficacy depends on the extent of drug exposure at the tumor site and the time above the effective concentration [3]. In vitro models that incorporate these pharmacokinetic and pharmacodynamic (PK/PD) principles to optimize therapeutic response may be considered the method of choice for optimizing dosing schedules before translating data from static assays to animals and …

Application Of Pharmacokinetics/Pharmacodynamics (Pk/Pd) In Designing Effective Antibiotic Treatment Regimens, Ghada F. Ahmed, Ayman Noreddin

Pharmacy Faculty Books and Book Chapters

"Designing antibiotic dosing regimens is often not optimal and the dose-response relationship for most antibiotics is not well-known1. Both Pharmacokinetics (PK) and Pharmacodynamics (PD) are characteristics of antimicrobial agents that should be considered in the development of effective antibiotic therapy. By linking the concentration time profile at the site of action to the drug effect (PK/PD), the effect of varying dosage regimens against pathogens could be simulated enabling the identification of effective dosage strategies. It is known that inadequate antibiotic dosing could not only lead to a therapeutic failure, but also to the development of bacterial resistance. Importantly, the evolution …

Inhibition Of Adhesion And Invasion Of Pseudomonas Aeruginosa To Lung Epithelial Cells: A Model Of Cystic Fibrosis Infection, Ayman Noreddin, Ghada Sawy, Walid Elkhatib, Ehab Noreddin, Atef Shibl

Pharmacy Faculty Books and Book Chapters

"Over their life time, CF patients experience multiple infections by various pneumoniacausing bacteria [6]. With more patients surviving to adulthood, chronic infections with Pseudomonas aeruginosa are coming to the forefront as a leading cause of death [7]. Problems presented by infected CF lung are multi-dimensional; the electrolyte balance and pH of the fluids are abnormal. The mucus is thick and of an alternative composition compared to normal lung and may contribute to colonization with Pseudomonas aeruginosa [2, 3, 5]. As such, research is multi-pronged and includes gene therapy to correct the defective protein, amelioration of inflammatory response and thinning of …

N-Myristoylglutamic Acid Derivative Of 3′-Fluoro-3′- Deoxythymidine As An Organogel, Bhupender S. Chhikara, Rakesh Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

Designing microbicidal gels of anti-HIV drugs for local application to prevent HIV infection is a subject of major interest. 3′-Fluoro-3′-deoxythymidine (FLT), a nucleoside reverse transcriptase inhibitor (NRTI), was conjugated with a N-myristoylglutamate scaffold. The conjugate showed gelation at 1% (w/w) in different organic solvents, such as toluene, dichloromethane, and chloroform. The gels were opaque and stable at room temperature. The results indicate that myristoyl glutamate derivative of FLT can form an organogel. The gel could have potential application as a topical anti-HIV microbicidal agent.

Bsa Nanoparticles For Sirna Delivery: Coating Effects On Nanoparticle Properties, Plasma Protein Adsorption, And In Vitro Sirna Delivery, Haran Yogasundaram, Markian Stephan Bahniuk, Harsh-Deep Singh, Hamidreza Montazeri Aliabadi, Hasan Uludag, Larry David Unsworth

Pharmacy Faculty Articles and Research

Developing vehicles for the delivery of therapeutic molecules, like siRNA, is an area of active research. Nanoparticles composed of bovine serum albumin, stabilized via the adsorption of poly-L-lysine (PLL), have been shown to be potentially inert drug-delivery vehicles. With the primary goal of reducing nonspecific protein adsorption, the effect of using comb-type structures of poly(ethylene glycol) (1 kDa, PEG) units conjugated to PLL (4.2 and 24 kDa) on BSA-NP properties, apparent siRNA release rate, cell viability, and cell uptake were evaluated. PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral. Incubation with platelet-poor plasma showed the composition of …

Hepatic Immunosuppressive Effects Of Systemically- Administered Novel Dextran-Methylprednisolone Prodrugs With Peptide Linkers In Rats, Imam H. Shaik, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar

Pharmacy Faculty Articles and Research

The hepatic immunosuppressive activities of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP1) or five (DMP5) amino acids as linkers were studied in rats. At various times (02 weeks) after intravenous administration of single 5 mg/kg (MP equivalent) doses of each prodrug or MP succinate (MPS), livers were isolated and immunologically stimulated ex vivo with lipopolysaccharide. The concentrations of tumor necrosis factor (TNF)-a in the outlet perfusate were then quantitated to assess immune response. Additionally, the concentrations of DMP1, DMP5, and/or MP were measured in the liver. MPS, DMP5, or DMP1 injections caused a maximum of 48.9%, 63.5%, …

Confounding Issues In Estimation Of Patient-Specific Pharmacokinetic Parameters And Dosage Individualization Of Aminoglycosides, Reza Mehvar

Pharmacy Faculty Articles and Research

Aminoglycoside antibiotics are usually administered by multiple short intravenous infusions at fixed intervals. Today, equations reported 35 years ago by Sawchuk and Zaske are still the cornerstone of methods used for determination of patient-specific pharmacokinetic parameters of aminoglycosides and individualization of drug dosage regimens in many clinical settings. Additionally, these methods are included in many clinical pharmacology curricula in pharmacy and other related fields. However, there are a few issues with regard to the application and/or modification of this method in clinical settings, which may result in some confusion among novice clinicians. For example, serum samples collected from different intervals …

Simulating Molecular Mechanisms Of The Mdm2-Mediated Regulatory Interactions: A Conformational Selection Model Of The Mdm2 Lid Dynamics, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Diversity and complexity of MDM2 mechanisms govern its principal function as the cellular antagonist of the p53 tumor suppressor. Structural and biophysical studies have demonstrated that MDM2 binding could be regulated by the dynamics of a pseudo-substrate lid motif. However, these experiments and subsequent computational studies have produced conflicting mechanistic models of MDM2 function and dynamics. We propose a unifying conformational selection model that can reconcile experimental findings and reveal a fundamental role of the lid as a dynamic regulator of MDM2-mediated binding. In this work, structure, dynamics and energetics of apo-MDM2 are studied as a function of posttranslational modifications …

Compound 49b: A Novel Beta-Adrenergic Receptor Agonist In The Treatment Of Diabetic Retinopathy, Kimberly Williams-Guy

Theses and Dissertations (ETD)

Diabetic retinopathy is the leading cause of blindness in working Americans. While there are therapeutic regimens for the disease, more effective methods are needed. We have previously shown that a non-specific beta-adrenergic receptor agonist, isoproterenol, was effective in preventing functional and morphological changes associated with diabetic retinopathy in the rat. Isoproterenol also produced left ventricle remodeling suggesting it entered the systemic circulation. We therefore synthesized various novel beta-adrenergic receptor compounds and screened these compounds in vitro for their ability to reduce markers of inflammation and apoptosis. Of the various compounds tested, Compound 49b was able to reduce both inflammation and …

The Design And Synthesis Of Autotaxin Inhibitors And Analogs Of Lysophosphatidic Acid, Renuka Niranjan Gupte

Theses and Dissertations (ETD)

Lysophosphatidic acid (LPA) is a naturally occurring bioactive phospholipid. It has a wide array of biological effects like cell proliferation, survival, migration, apoptosis invasion, wound healing and angiogenesis. Autotaxin (ATX) was identified as an autocrine tumor cell motility factor from A2058 melanoma conditioned medium. ATX has lysophospholipase D enzyme activity and is responsible for the cleavage of lysophophatidylcholine (LPC) leading to the generation of LPA. Antagonists of Autotaxin would have a potential therapeutic application in cancer research. Chapter 1 is an introduction of LPA and autotaxin. It provides the background and significance of the research. Chapter 2 explores the synthesis …

Antispasmodic And Ca++ Antagonist Potential Of Marrubiin, A Labdane Type Diterpene From Phlomis Bracteosa, Javid Hussain, Riaz Ullah, Arif-Ullah Khan, Fazal Mabood, Mohammad Raza Shah, Ahmed Al-Harrasi, Anwar Gilani

Department of Biological & Biomedical Sciences

A tricyclic labdane type diterpene was isolated for the first time from ethyl acetate soluble part of Phlomis bracteosa. Its structure was confirmed by x-ray which was found to be marrubiin. When studied in isolated rabbit jejunum, marrubiin caused concentration-dependent relaxation of spontaneous and high K+ (80 mM)-induced contractions, like that caused by verapamil, indicating that marrubiin exhibits spasmolytic activity, possibly mediated through Ca++ channel blocking action.

Discovery Of Quinic Acid Derivatives As Oral Anti-Inflammatory Agents, Kui Zeng

Theses and Dissertations (ETD)

Quinic acid (QA) esters found in hot water extracts of Uncaria tomentosa (a.k.a. Cat’s claw) exert anti-inflammatory activity through mechanisms involving inhibition of the pro-inflammatory transcription factor nuclear factor kappa B (NF-κB). Herein, we described the synthesis and biological testing of novel QA derivatives. Inhibition of NF-κB was assessed using A549 (Type II alveolar epithelial-like) cells that stably express a secreted alkaline phosphatase (SEAP) reporter driven by an NF-κB response element. A549- NF-κB cells were stimulated with TNF-α (10 ng/mL) in the presence or absence of QA derivative for 18 hours followed by measurement of SEAP activity. Amide substitution at …

Pk/Pd Modelling Of Comb-Shaped Pegylated Salmon Calcitonin Conjugates Of Differing Molecular Weights, Sinead Ryan, Jesus Maria Frias, David H. Haddleton, David J. Brayden

Articles

Salmon calcitonin (sCT) was conjugated via cysteine-1 to novel combed-shaped end-functionalised poly(PEG) methyl ether methacrylate) (sCT-P) comb-shaped polymers, to yield conjugates of total molecular weights (MW) inclusive of sCT: 6.5, 9.5, 23 and 40 kDa. The conjugates were characterised by HPLC and their in vitro and in vivo bioactivity was measured by cAMP assay on human T47D cells and following intravenous (i.v.) injection to rats, respectively. Stability against endopeptidases, rat serum and liver homogenates was assessed. There were linear and exponential relationships between conjugate MW with potency and efficacy respectively, however the largest MW conjugate still retained 70% of E …