Biology subjects

Dogan, A. B.

Publications and source records attributed to Dogan, A. B..

6 recordsLinked to original sources

bioRxiv2025

Orally Delivered Milk-Derived Nanovesicles Loaded with Connexin 43 Peptides forTargeted Cardiac Ischemia-Reperfusion Therapy

Extracellular vesicles have emerged as promising nanocarriers for targeted drug delivery, but their therapeutic potential is limited by challenges related to administration route, loading, targeted delivery and production at scale. Here, we report an innovative approach for targeted delivery of therapeutic peptides to injured tissues using milk-derived small extracellular vesicles (mEVs) as an abundant, safe, orally administrable nanoplatform. We demonstrate that a sub-population of mEVs naturally contain Connexin 43 (Cx43) and its Carboxyl-Terminal (CT) polypeptides, which have been shown to play crucial roles in wound healing and tissue repair. Leveraging this intrinsic property, we developed an esterification method to efficiently and uniformly load mEVs with enhanced levels of an exogenous Cx43 CT peptide (CT11 - RPRPDDLEI), as assessed by flow cytometry-based vesicle quantification and mass spectrometry. These engineered mEVs exhibited remarkable injury targeting capabilities, with > 30-fold increases in uptake by injured cells compared to non-wounded cells in vitro and preferential accumulation in wounded tissues in vivo. Notably, CT11-loaded mEVs orally administered after myocardial infarction reduced infarct size by >60% and preserved heart function in a mouse model of ischemia-reperfusion injury. This study represents a significant advance in nanomedicine, demonstrating the utilization of naturally occurring milk-derived extracellular vesicles as an oral delivery system for therapeutic peptides, achieving unprecedented targeting efficiency and efficacy in the treatment of myocardial ischemia-reperfusion injury.

bioengineering↗

bioRxiv2022

Conventional polymers may unintentionally refill in vivo with unassociated drugs

Polymers used as drug delivery devices are ultimately limited by how much drug they can hold; with the device failing if the drug is depleted before the disease is cured. Our lab discovered a means to use thermodynamic driving forces to refill certain classes of polymer after implantation, for additional drug delivery windows. These same, refillable polymers can be used as additives, to provide refilling capacity to classical, non-refillable polymers such as poly(methyl methacrylate) (PMMA). In this paper, we investigated the refilling capacity of another conventional polymer: poly(lactic-co-glycolic acid) or PLGA. We explored both unmodified PLGA implants as well as implants supplemented with polymerized cyclodextrin (pCD) in microparticle form, previously shown to add refillability to poly(methyl methacrylate) (PMMA) implants which were otherwise not refillable. Assessments of in situ forming PLGA implants with and without pCD additives were made, including drug loading capacity in a liquid medium, drug refilling through a tissue-mimicking gel medium, and refilling in ex vivo and in vivo conditions. Implant cross-sections were imaged via fluorescence microscopy. Drug release from refilled implants, polymer swelling, degradation, phase inversion characteristics were assessed, and drug/monomer computational simulation studies were performed. While generally, the incorporation of cyclodextrin into implants led to significant increases in the amount of refilled drug; unexpectedly, PLGA implants with no incorporated pCD also showed refilling capability. Moreover, in two out of three in vivo conditions in rats, PLGA alone showed the potential to refill with comparable, if not greater, amounts of drug than PLGA with pCD incorporated. This contrasts predictions, since PLGA has no specifically designed affinity structure, like pCD does. We theorize that the mechanism for PLGAs refilling depends on nano-patterning of hydrophilic and hydrophobic molecular domains, giving rise to its affinity-like behavior. The fact that PLGA implants can be refilled with unassociated drugs, gives rise to concerns about the fate of all implants made of poly alpha-hydroxy esters, and likely other polymers as well, and will likely lead to new directions of study such as of unintended polymer / drug interactions.

bioengineering↗

bioRxiv2021

Polymer microparticles prolong delivery of the 15-PGDH inhibitor SW033291

As the prevalence of age-related fibrotic diseases continues to increase, novel antifibrotic therapies are emerging to address clinical needs. However, many novel therapeutics for managing chronic fibrosis are small-molecule drugs that require frequent dosing to attain effective concentrations. While bolus parenteral administrations have become standard clinical practice, an extended delivery platform would achieve steady state concentrations over a longer time period with fewer administrations. This study lays the foundation for the development of a sustained release platform for the delivery of (+)SW033291, a potent, small-molecule inhibitor of the 15-hydroxyprostaglandin dehydrogenase (15-PGDH) enzyme, which has previously demonstrated efficacy in a murine model of pulmonary fibrosis. Herein, we leverage fine-tuned cyclodextrin microparticles - specifically {beta}-CD microparticles ({beta}-CD MPs) - to extend the delivery of 15-PGDH inhibitor, (+)SW033291, to over one week. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/456403v1_ufig1.gif" ALT="Figure 1"> View larger version (14K): org.highwire.dtl.DTLVardef@13aed1dorg.highwire.dtl.DTLVardef@1a541eaorg.highwire.dtl.DTLVardef@8a9fd5org.highwire.dtl.DTLVardef@1038a77_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2021

Polymer additives to personal protective equipment can inactivate pathogens

Face masks have been proven to be medicines best public health tool for preventing transmission of airborne pathogens. However, in situations with continuous exposure, lower quality and "do-it-yourself" face masks cannot provide adequate protection against pathogens, especially when mishandled. In addition, the use of multiple face masks each day places a strain on personal protective equipment (PPE) supply and is not environmentally sustainable. Therefore, there is a significant clinical and commercial need for a reusable, pathogen-inactivating face mask. Herein, we propose adding quaternary poly(dimethylaminohexadecyl methacrylate), q(PDMAHDM), abbreviated to q(PDM), to existing fabric networks to generate "contact-killing" face masks - effectively turning cotton, polypropylene, and polyester into pathogen resistant materials. It was found that q(PDM)-integrated face masks were able to inactivate both Gram-positive and Gram-negative bacteria in liquid culture and aerosolized droplets. Furthermore, q(PDM) was electrospun into homogeneous polymer fibers, which makes the polymer practical for low-cost, scaled-up production. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/438151v2_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@c07ab2org.highwire.dtl.DTLVardef@b73e8dorg.highwire.dtl.DTLVardef@6bd8e5org.highwire.dtl.DTLVardef@6cc681_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2020

Leveraging Affinity Interactions to Prolong Drug Delivery of Protein Therapeutics

While peptide and protein therapeutics have made tremendous advances in clinical treatments over the past few decades, they have been largely hindered by their ability to be effectively delivered to patients. While bolus parenteral injections have become standard clinical practice, they are insufficient to treat diseases that require sustained, local release of therapeutics. Cyclodextrin-based polymers (pCD) have been utilized as a platform to extend the local delivery of small-molecule hydrophobic drugs by leveraging hydrophobic-driven thermodynamic interactions between pCD and payload to extend its release, which has seen success both in vitro and in vivo. Herein, we proposed the novel synthesis of protein-polymer conjugates that are capped with a "high affinity" adamantane. Using bovine serum albumin as a model protein, and anti-interleukin 10 monoclonal antibodies as a functional example, we outline the synthesis of novel protein-polymer conjugates that, when coupled with cyclodextrin delivery platforms, can maintain a sustained release of up to 65 days without largely sacrificing protein structure/function which has significant clinical applications in local antibody-based treatments for immune diseases, cancers, and diabetes. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/410621v1_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@25ad06org.highwire.dtl.DTLVardef@1827b8eorg.highwire.dtl.DTLVardef@17dd798org.highwire.dtl.DTLVardef@d54d55_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2020

Engineering Selective Molecular Tethers to Enhance Suboptimal Drug Properties

Small-molecule drugs are utilized in a wide variety of clinical applications, however, many of these drugs suffer from one or more suboptimal property that can hinder its delivery or cellular action in vivo, or even shelf an otherwise biologically tolerable drug. While high-throughput screening provides a method to discover drugs with altered chemical properties, directly engineering small-molecule bioconjugates provides an opportunity to specifically modulate drug properties rather than sifting through large drug libraries with seemingly random drug properties. Herein, we propose that selectively "tethering" a drug molecule to an additional group with favorable properties will improve the drug conjugates overall properties, such as solubility. Specifically, we outlined the site-specific chemical conjugation of rapamycin (RAP) to an additional "high-affinity" group to increase the overall affinity the drug has for cyclodextrin-based polymers (pCD). By doing so, we found that RAPs affinity for pCD and RAPs window of delivery from pCD microparticles was tripled without sacrificing RAPs cellular action. This synthesis method was applied to the concept of "affinity" for pCD, but other prosthetic groups can be used in a similar manner to modify other drug properties. This study displays potential for increasing drug delivery windows of small-molecule drugs in pCD systems for chronic drug therapies and introduces the idea of altering drug properties to tune polymer-drug interactions.

bioengineering↗