Topical drug delivery by Sepineo P600 emulgel: Relationship between rheology, physical stability, and formulation performance.

The objective of this present work was to develop and optimize oil-in-water (O/W) emulsion-based gels, namely emulgels that allow maximum topical drug delivery while having desired microstructure and acceptable physical stability. Emulgels containing 2.0 wt% lidocaine were prepared using various concentrations (0.75-5.0 wt%) of Sepineo P600. Their droplet size distribution, physical stability, rheological behaviors, in vitro drug release, and skin permeation profiles were evaluated. Results show that the concentration of Sepineo P600 significantly influenced the microstructure, rheology, and physical stability of the emulgel formulations. The physico-chemical properties also reveals that at least 1.0 wt% Sepineo P600 was needed to produce stable emulgel formulations. All formulations exhibited non-Newtonian shear-thinning properties which are desirable for topical applications. Both the release and permeation rates decreased with increasing viscosity and rigidity of the formulation. The lower the complex modulus of the emulgels, the higher the steady-state flux of the drug through the skin. Adding Sepineo P600 to emulgel systems resulted in increased rheological properties, which in turn slowed the diffusion of the drug for in vitro release. Although as expected skin permeation was rate limiting since in vitro release was 3 to 4 log-fold faster than skin flux. However, an interesting finding was that the derived skin/vehicle partition coefficient suggested the ionic interaction between lidocaine and Sepineo polymer reducing the free drug, i.e., thermodynamic activity and hence the flux with increasing Sepineo P600 concentration. Overall, this study has provided us with valuable insights into understanding the relationship between the microstructure (rheology), physical stability and skin drug delivery properties which will help to design and optimize topical emulgel formulations.

Cell selective BCL-2 inhibition enabled by lipid nanoparticles alleviates lung fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with a high mortality rate due to limited treatment options. Current therapies cannot effectively reverse the damage caused by IPF. Research suggests that promoting programmed cell death (apoptosis) in myofibroblasts, the key cells driving fibrosis, could be a promising strategy. However, inducing apoptosis in healthy cells like epithelial and endothelial cells can cause unwanted side effects. This project addresses this challenge by developing a targeted approach to induce apoptosis specifically in myofibroblasts. We designed liposomes (LPS) decorated with peptides that recognize VCAM-1, a protein highly expressed on myofibroblasts in fibrotic lungs. These VCAM1-targeted LPS encapsulate Venetoclax (VNT), a small molecule drug that inhibits BCL-2, an anti-apoptotic protein. By delivering VNT directly to myofibroblasts, we hypothesize that VCAM1-VNT-LPS can selectively induce apoptosis in these cells, leading to reduced fibrosis and improved lung function. We successfully characterized VCAM1-VNT-LPS for size, surface charge, and drug loading efficiency. Additionally, we evaluated their stability over three months at different temperatures. In vitro and in vivo studies using a bleomycin-induced mouse model of lung fibrosis demonstrated the therapeutic potential of VCAM1-VNT-LPS. These studies showed a reduction in fibrosis-associated proteins (collagen, α-SMA, VCAM1) and BCL-2, while simultaneously increasing apoptosis in myofibroblasts. These findings suggest that VCAM1-targeted delivery of BCL-2 inhibitors using liposomes presents a promising and potentially selective therapeutic approach for IPF.

Targeted Biodegradable Near-Infrared Fluorescent Nanoparticles for Colorectal Cancer Imaging.

Colorectal cancer (CRC) is the third leading cause of cancer death in the U.S., and early detection and diagnosis are essential for effective treatment. Current methods are inadequate for rapid detection of early disease, revealing flat lesions, and delineating tumor margins with accuracy and molecular specificity. Fluorescence endoscopy can generate wide field-of-view images enabling detection of CRC lesions and margins; increased signal intensity and improved signal-to-noise ratios can increase both speed and sensitivity of cancer detection. For this purpose, we developed targeted near-infrared (NIR) fluorescent silica nanoparticles (FSNs). We tuned their size to 50-200 nm and conjugated their surface with an antibody to carcinoembryonic antigen (CEA) to prepare CEA-FSNs. The physicochemical properties and biodegradable profiles of CEA-FSN were characterized, and molecular targeting was verified in culture using HT29 (CEA positive) and HCT116 (CEA negative) cells. CEA-FSNs bound to the HT29 cells to a greater extent than to the HCT116 cells, and smaller CEA-FSNs were internalized into HT29 cells more efficiently than larger CEA-FSNs. After intravenous administration of CEA-FSNs, a significantly greater signal was observed from the CEA-positive HT29 than the CEA-negative HCT116 tumors in xenografted mice. In F344-PIRC rats, polyps in the intestine were detected by white-light endoscopy, and NIR fluorescent signals were found in the excised intestinal tissue after topical application of CEA-FSNs. Immunofluorescence imaging of excised tissue sections demonstrated that the particle signals coregistered with signals for both CRC and CEA. These results indicate that CEA-FSNs have potential as a molecular imaging marker for early diagnosis of CRC.

Cadherin-11 targeted cell-specific liposomes enabled skin fibrosis treatment by inducing apoptosis.

Continuous and aberrant activation of myofibroblasts is the hallmark of pathological fibrosis (e.g., abnormal wound healing). The deposition of excessive extracellular matrix (ECM) components alters or increases the stiffness of tissue and primarily accounts for multiple organ dysfunctions. Among various proteins, Cadherin-11 (CDH11) has been reported to be overexpressed on myofibroblasts in fibrotic tissues. Anti-apoptotic proteins such as (B cell lymphoma-2) (BCL-2) are also upregulated on myofibroblasts. Therefore, we hypothesize that CDH11 could be a targeted domain for cell-specific drug delivery and targeted inhibition of BCL-2 to ameliorate the development of fibrosis in the skin. To prove our hypothesis, we have developed liposomes (LPS) conjugated with CDH11 neutralizing antibody (antiCDH11) to target cell surface CDH11 and loaded these LPS with a BCL-2 inhibitor, Navitoclax (NAVI), to induce apoptosis of CDH11 expressing fibroblasts. The developed LPS were evaluated for physicochemical characterization, stability, in vitro therapeutic efficacy using dermal fibroblasts, and in vivo therapeutic efficacy in bleomycin-induced skin fibrosis model in mice. The findings from in vitro and in vivo studies confirmed that selectivity of LPS was improved towards CDH11 expressing myofibroblasts, thereby improving therapeutic efficacy with no indication of adverse effects. Hence, this novel research work represents a versatile LPS strategy that exhibits promising potential for treating skin fibrosis.

Sustainable Alternatives to Petroleum-Derived Excipients in Pharmaceutical Oil-in-Water Creams.

Recently, vast efforts towards sustainability have been made in the pharmaceutical industry. In conventional oil-in-water (O/W) cream formulations, various petroleum-based excipients, namely mineral oil and petrolatum, are commonly used. Natural or synthetic excipients, derived from vegetable sources, were explored as alternatives to petroleum-based excipients in prototype topical creams, with 1% (w/w) lidocaine. A conventional cream comprised of petroleum-derived excipients was compared to creams containing sustainable excipients in terms of key quality and performance attributes, physicochemical properties, and formulation performance. The petrolatum-based control formulation had the highest viscosity of 248.0 Pa·s, a melting point of 42.7°C, a low separation index at 25°C of 0.031, and an IVRT flux of 52.9 µg/cm2/h. Formulation SUS-4 was the least viscous formulation at 86.9 Pa·s, had the lowest melting point of 33.6°C, the highest separation index of 0.120, and the highest IVRT flux of 139.4 µg/cm2/h. Alternatively, SUS-5 had a higher viscosity of 131.3 Pa·s, a melting point of 43.6°C, a low separation index of 0.046, and the lowest IVRT flux of 25.2 µg/cm2/h. The cumulative drug permeation after 12 h from SUS-4, SUS-5, and the control were 126.2 µg/cm2, 113.8 µg/cm2, and 108.1 µg/cm2, respectively. The composition of the oil-in-water creams had influence on physicochemical properties and drug release; however, skin permeation was not impacted. Sustainable natural or synthetic excipients in topical cream formulations were found to be suitable alternatives to petroleum-based excipients with comparable key quality attributes and performance attributes and should be considered during formulation development.

Liver fibrosis pathologies and potentials of RNA based therapeutics modalities.

Liver fibrosis (LF) occurs when the liver tissue responds to injury or inflammation by producing excessive amounts of scar tissue, known as the extracellular matrix. This buildup stiffens the liver tissue, hinders blood flow, and ultimately impairs liver function. Various factors can trigger this process, including bloodborne pathogens, genetic predisposition, alcohol abuse, non-steroidal anti-inflammatory drugs, non-alcoholic steatohepatitis, and non-alcoholic fatty liver disease. While some existing small-molecule therapies offer limited benefits, there is a pressing need for more effective treatments that can truly cure LF. RNA therapeutics have emerged as a promising approach, as they can potentially downregulate cytokine levels in cells responsible for liver fibrosis. Researchers are actively exploring various RNA-based therapeutics, such as mRNA, siRNA, miRNA, lncRNA, and oligonucleotides, to assess their efficacy in animal models. Furthermore, targeted drug delivery systems hold immense potential in this field. By utilizing lipid nanoparticles, exosomes, nanocomplexes, micelles, and polymeric nanoparticles, researchers aim to deliver therapeutic agents directly to specific biomarkers or cytokines within the fibrotic liver, increasing their effectiveness and reducing side effects. In conclusion, this review highlights the complex nature of liver fibrosis, its underlying causes, and the promising potential of RNA-based therapeutics and targeted delivery systems. Continued research in these areas could lead to the development of more effective and personalized treatment options for LF patients.

Emerging delivery approaches for targeted pulmonary fibrosis treatment.

Pulmonary fibrosis (PF) is a progressive, and life-threatening interstitial lung disease which causes scarring in the lung parenchyma and thereby affects architecture and functioning of lung. It is an irreversible damage to lung functioning which is related to epithelial cell injury, immense accumulation of immune cells and inflammatory cytokines, and irregular recruitment of extracellular matrix. The inflammatory cytokines trigger the differentiation of fibroblasts into activated fibroblasts, also known as myofibroblasts, which further increase the production and deposition of collagen at the injury sites in the lung. Despite the significant morbidity and mortality associated with PF, there is no available treatment that efficiently and effectively treats the disease by reversing their underlying pathologies. In recent years, many therapeutic regimens, for instance, rho kinase inhibitors, Smad signaling pathway inhibitors, p38, BCL-xL/ BCL-2 and JNK pathway inhibitors, have been found to be potent and effective in treating PF, in preclinical stages. However, due to non-selectivity and non-specificity, the therapeutic molecules also result in toxicity mediated severe side effects. Hence, this review demonstrates recent advances on PF pathology, mechanism and targets related to PF, development of various drug delivery systems based on small molecules, RNAs, oligonucleotides, peptides, antibodies, exosomes, and stem cells for the treatment of PF and the progress of various therapeutic treatments in clinical trials to advance PF treatment.

Mucoadhesive Carrier-Mediated Oral Co-delivery of Bcl2 Inhibitors Improves Gastric Cancer Treatment.

Gastric cancer treatment is challenging due to the lack of early-stage diagnostic technology and targeted delivery systems. Currently, the available treatments for gastric cancer are surgery, chemotherapy, immunotherapy, and radiation. These strategies are either invasive or require systemic delivery, exerting toxicities within healthy tissues. By creation of a targeted delivery system to the stomach, gastric cancer can be treated in the early stages. Such an approach reduces the negative effects on the rest of the body by minimizing systemic absorbance and random localization. With this in mind, we developed a mucoadhesive vehicle composed of ß-Glucan And Docosahexaenoic Acid (GADA) for controlled drug/gene delivery. In the current study, we investigated the therapeutic effect of codelivery Bcl2 inhibitors navitoclax (NAVI) and siRNA (Bcl2) via oral using GADA. The therapeutic efficacy of the GADA-mediated oral NAVI/siRNA was investigated in a gastric cancer mouse model. Higher Bcl2 inhibition efficacy was observed in Western blotting and TUNEL assay in mice treated with GADA/NAVI/siRNA compared to free NAVI, siRNA, and NAVI/siRNA. Histology (H&E) and immunohistochemistry (Ki67, TUNEL, and BCl2) analyses confirmed a significant reduction of the tumor region. Interaction between GADA and mucus resulted in retention for over 6 h and thereby sustained local payload release. The developed oral carrier GADA is an emerging vehicle that has promising potential in oral delivery of both small and large molecules, and their mucoadhesive property results in improved therapeutic efficacy with minimal side effects compared to conventional treatment. This study opens a new window for the effective delivery of oral medicine for the treatment of gastric cancer and other gastrointestinal diseases.

Potentials of ionic liquids to overcome physical and biological barriers.

Over the last decades, ionic liquids (IL) have shown great potential in non-invasive delivery starting from synthetic small molecules to biological large molecules. ILs are emerging as a particular class of drug delivery systems due to their unique physiochemical properties, simple surface modification, and functionalization. These features of IL help achieve specific design principles that are essential for a non-invasive drug delivery system. In this review, we have discussed IL and their applications in non-invasive drug delivery systems. We evaluated state-of-the-art development and advances of IL aiming to mitigate the biological and physical barriers to improve transdermal and oral delivery, summarized in this review. We also provided an overview of the various factors determining the systemic transportation of IL-based formulation. Additionally, we have emphasized how the ILs facilitate the transportation of therapeutic molecules by overcoming biological barriers.

Progress and prospect of nanotechnology for cardiac fibrosis treatment.

Cardiac fibrosis is the excessive accumulation of extracellular matrix components in the heart, leading to reduced cardiac functionality and heart failure. This review provides an overview of the therapeutic applications of nanotechnology for the treatment of cardiac fibrosis. We first delve into the fundamental pathophysiology of cardiac fibrosis, highlighting the key molecular players, including Matrix Metalloproteinases, Transforming Growth Factor-beta, and several growth factors, cytokines, and signaling molecules. Each target presents a unique opportunity to develop targeted nano-therapies. We then focus on recent advancements in nanotechnology and how nanoparticles can be engineered to deliver drugs or therapeutic genes. These advanced delivery approaches have shown significant potential to inhibit fibrosis-promoting factors, thereby mitigating the fibrotic response and potentially reversing disease progression. In addition, we discuss the challenges associated with developing and translating nanotechnology-based drug delivery systems, including ensuring biocompatibility, safety, and regulatory compliance. This review highlights how nanotechnology can bridge the gap between lab research and clinical practice for treating cardiac fibrosis.

Bioinspired Approaches for Central Nervous System Targeted Gene Delivery.

Disorders of the central nervous system (CNS) which include a wide range of neurodegenerative and neurological conditions have become a serious global issue. The presence of CNS barriers poses a significant challenge to the progress of designing effective therapeutic delivery systems, limiting the effectiveness of drugs, genes, and other therapeutic agents. Natural nanocarriers present in biological systems have inspired researchers to design unique delivery systems through biomimicry. As natural resource derived delivery systems are more biocompatible, current research has been focused on the development of delivery systems inspired by bacteria, viruses, fungi, and mammalian cells. Despite their structural potential and extensive physiological function, making them an excellent choice for biomaterial engineering, the delivery of nucleic acids remains challenging due to their instability in biological systems. Similarly, the efficient delivery of genetic material within the tissues of interest remains a hurdle due to a lack of selectivity and targeting ability. Considering that gene therapies are the holy grail for intervention in diseases, including neurodegenerative disorders such as Alzheimer's disease, Parkinson's Disease, and Huntington's disease, this review centers around recent advances in bioinspired approaches to gene delivery for the prevention of CNS disorders.

Carbon Coated Iron-Cobalt Nanoparticles for Magnetic Particle Imaging.

Magnetic particle imaging (MPI) is an emerging imaging modality that provides direct and quantitative mapping of iron oxide tracers. To achieve high sensitivity and good spatial resolution images, a magnetic nanoparticle with a higher contrast intensity needs to be developed. Currently, a majority of MPIs being developed for potential clinical application are composed of iron oxide nanoparticles with a spherical shape. In this project, we intend to report development of high-performance carbon (C) coated iron-cobalt (FeCo) nanoparticles (FeCo/C) and investigate their feasibility as a MPI agent. We have synthesized FeCo/C through a facile and simple method at mild temperature that is safe, easy, and up-scalable. We studied the structural and functional relationships and biocompatibility of this MPI agent in vitro. However, to enhance the aqueous solubility and biocompatibility, the surface of FeCo/C was modified with polyethylene glycol (PEG). We found that variation in the ratio of Fe and Co plays a vital role in their physical properties and functionality. In vitro imaging confirms that the Fe3Co1/C nanoparticle has highly competitive MPI intensity compared to VivoTrax, a commercially available MPI agent. Confocal laser scanning microscopy imaging with Rhodamine B labeled FeCo/C displays cellular internalization by the A375 cancer cells. The in vitro toxicity analysis concludes that there is no significant toxicity of FeCo/C nanoparticles. Therefore, the newly developed MPI agent holds strong promise for biomedical imaging and could be further validated in vivo in small animals.

A photothermal driven chemotherapy for the treatment of metastatic melanoma.

Solid tumors are abnormal mass of tissue, which affects the organs based on its malignancy and leads to the dysfunction of the affected organs. The major problem associated with treatment of solid tumors is delivering anticancer therapeutics to the deepest layers/core of the solid tumor. Deposition of excessive extracellular matrix (ECM) hinders the therapeutics to travel towards the core of the tumor. Therefore, conventional anticancer therapeutics can only reduce the tumor size and that also for a limited duration, and tumor recurrence occurs once the therapy is discontinued. Additionally, by the time the cancer is diagnosed, the cancer cells already started affecting the major organs of the body such as lung, liver, spleen, kidney, and brain, due to their ability to metastasize and lung is the primary site for them to be infiltrated. To facilitate the anticancer therapeutics to penetrate the deeper layers of tumor, and to provide concurrent treatment of both the solid tumor and metastasis, we have designed and developed a Bimodal Light Assisted Skin Tumor and Metastasis Treatment (BLAST), which is a combination of photothermal and chemotherapeutic moieties. The BLAST is composed of 2D boron nitride (BN) nanosheet with adsorbed molecules of BCL-2 inhibitor, Navitoclax (NAVI) on its surface, that can breakdown excessive ECM network and thereby facilitate dissociation of the solid tumor. The developed BLAST was evaluated for its ability to penetrate solid tumors using 3D spheroids for the uptake, cytotoxicity, growth inhibition, reactive oxygen species (ROS) detection, penetration, and downregulation of proteins upon laser irradiation. The in vivo therapeutic studies on a skin cancer mice model revealed that the BLAST with and without laser were able to penetrate the solid tumor, reduce tumor volume in mice, dissociate the protein network, and prevent lung metastasis as confirmed by immunohistochemistry and western blot analysis. Post analysis of serum and blood components revealed the safety and efficacy of BLAST in mice. Hence, the developed BLAST holds strong promise in solid tumor treatment and metastasis prevention simultaneously.

RGD Peptide-Functionalized Polyether Ether Ketone Surface Improves Biocompatibility and Cell Response.

Polyether ether ketone (PEEK) is a biocompatible polymer used in maxillofacial and orthopedic applications because of its mechanical properties and chemical stability. However, this biomaterial is inert and requires surface modification to make it bioactive, enhancing implant-tissue integration and giving the material the ability to interact with the surrounding microenvironment. In this paper, surface of PEEK was activated by oxygen plasma treatment and this resulted in increasing reactivity and surface hydrophilicity. Then, a polydopamine (PDA) coating was deposited over the surface followed by biofunctionalization with an RGD peptide. The plasma effect was studied by contact angle measurements and scanning electron microscopy. X-ray photoelectron spectroscopy confirmed the presence of PDA coating and RGD peptide. Crystallinity and phase identification were carried out through X-ray diffraction. Quantification of the immobilized peptide over the PEEK surface was reached through UV-vis spectroscopy. In addition, in vitro tests with fibroblast cell line (NIH/3T3) determined the viability, attachment, spreading, and proliferation of these cells over the modified PEEK surfaces. According to the results, PEEK surfaces functionalized with peptides demonstrated an increased cellular response with each successive surface modification.

Theranostic applications of multifunctional carbon nanomaterials.

Nanobiotechnology is one of the leading research areas in biomedical science, developing rapidly worldwide. Among various types of nanoparticles, carbon nanomaterials (CNMs) have attracted a great deal of attention from the scientific community, especially with respect to their prospective application in the field of disease diagnosis and therapy. The unique features of these nanomaterials, including favorable size, high surface area, and electrical, structural, optical, and chemical properties, have provided an excellent opportunity for their utilization in theranostic systems. Carbon nanotubes, carbon quantum dots, graphene, and fullerene are the most employed CNMs in biomedical fields. They have been considered safe and efficient for non-invasive diagnostic techniques such as fluorescence imaging, magnetic resonance imaging, and biosensors. Various functionalized CNMs exhibit a great capacity to improve cell targeting of anti-cancer drugs. Due to their thermal properties, they have been extensively used in cancer photothermal and photodynamic therapy assisted by laser irradiation and CNMs. CNMs also can cross the blood-brain barrier and have the potential to treat various brain disorders, for instance, neurodegenerative diseases, by removing amyloid fibrils. This review has summarized and emphasized on biomedical application of CNMs and their recent advances in diagnosis and therapy.

ß-Glucan-Mediated Oral Codelivery of 5FU and Bcl2 siRNA Attenuates Stomach Cancer.

Based on cancer-related deaths, stomach cancer is ranked fifth, and first among Hispanics. Lack of technologies for early diagnosis and unavailability of target-specific therapeutics are largely the causes of the poor therapeutic outcomes from existing chemotherapeutics. Currently available therapeutic modalities are invasive and require systemic delivery, although the cancer is localized in the stomach at its early stage. Therefore, we hypothesize that an oral local delivery approach can extend the retention duration of the therapeutics modalities within the stomach and thereby enhance therapeutic efficacy. To accomplish this, we have developed a ß-glucan (BG)-based oral delivery vehicle that can adhere to the mucus lining of the stomach for an extended period while controlling the release of Bcl2 siRNA and 5-fluorouracil (5FU) payload for over 6 h. We found that Bcl2 siRNA selectively knocked down the Bcl2 gene in a C57BL/6 stomach cancer mouse model followed by upregulation of apoptosis and remission of cancer. BG was found to be very effective in maintaining the stability of siRNA for at least 6 h, when submerged in simulated gastric juice tested in vitro. To investigate the potential therapeutic effects in vivo, we used a stomach cancer mouse model, where C57BL/6 mice were treated with 5FU, BG/5FU, siRNA, BG/siRNA, and BG/5FU/siRNA. Higher inhibition of Bcl2 and therapeutic efficacy were observed in mice treated with BG/5FU/siRNA confirmed with Western blotting and a TUNEL assay. Significant reduction in the tumor region was observed with histology (H&E) and immunohistochemistry (Ki67, TUNEL, and Bcl2) analyses. Overall, the oral formulation shows improved efficacy with nonsignificant side effects compared to the conventional treatment tested in the gastric cancer mouse model.

Topical Administration of an Apoptosis Inducer Mitigates Bleomycin-Induced Skin Fibrosis.

Pathological fibrosis is distinguished from physiological wound healing by persistent myofibroblast activation, suggesting that therapies that induce myofibroblast apoptosis selectively could prevent progression and potentially reverse the established fibrosis, such as for scleroderma (a heterogeneous autoimmune disease characterized by multiorgan fibrosis). Navitoclax (NAVI) is a BCL-2/BCL-xL inhibitor with antifibrotic properties and has been investigated as a potential therapeutic for fibrosis. NAVI makes myofibroblasts particularly vulnerable to apoptosis. However, despite NAVI's significant potency, clinical translation of BCL-2 inhibitors, NAVI in this case, is hindered due to the risk of thrombocytopenia. Therefore, in this work, we utilized a newly developed ionic liquid formulation of NAVI for direct topical application to the skin, thereby avoiding systemic circulation and off-target-mediated side effects. The ionic liquid composed of choline and octanoic acid (COA) at a 1:2 molar ionic ratio increases skin diffusion and transportation of NAVI and maintains their retention within the dermis for a prolonged duration. Topical administration of NAVI-mediated BCL-xL and BCL-2 inhibition results in the transition of myofibroblast to fibroblast and ameliorates pre-existing fibrosis, as demonstrated in a scleroderma mouse model. We have observed a significant reduction of α-SMA and collagen, which are known as fibrosis marker proteins, as a result of the inhibition of anti-apoptotic proteins BCL-2/BCL-xL. Overall, our findings show that COA-assisted topical delivery of NAVI upregulates apoptosis specific to myofibroblasts, with minimal presence of the drug in the systemic circulation, resulting in an accelerated therapeutic effect with no discernible drug-associated toxicity.

ß-Glucan and Fatty Acid Based Mucoadhesive Carrier for Gastrointestinal Tract Specific Local and Sustained Drug Delivery.

The oral route is considered the most convenient route of drug administration for both systemic and local delivery. Besides stability and transportation, another unmet but important issue regarding oral medication is retention duration within the specific region of the gastrointestinal (GI) tract. We hypothesize that an oral vehicle that can adhere and maintain retention within the stomach for a longer duration can be more effective to treat stomach-related diseases. Therefore, in this project, we developed a carrier that is highly specific to the stomach and maintains its retention for a longer duration. We developed a vehicle composed of ß-Glucan And Docosahexaenoic Acid (GADA) to observe its affinity and specificity to the stomach. GADA forms a spherical-shaped particle with negative zeta potential values that vary based on the feed ratio of docosahexaenoic acid. Docosahexaenoic acid is an omega-3 fatty acid that has transporters and receptors throughout the GI tract, such as CD36, plasma membrane-associated fatty acid-binding protein (FABP (pm)), and a family of fatty acid transport proteins (FATP1-6). The in vitro studies and characterization data showed that GADA has the capability to carry a payload of hydrophobic molecules and specifically deliver the payload to the GI tract, exert its therapeutic effects, and help to maintain stability for more than 12 h in the gastric and intestinal fluid. The particle size and surface plasmon resonance (SPR) data showed that GADA has a strong binding affinity with mucin in the presence of simulated gastric fluids. We observed a comparatively higher drug release of lidocaine in gastric juice than that in intestinal fluids, demonstrating the influence of the pH values of the media on drug-release kinetics. In vivo and ex vivo imaging of mice demonstrated that GADA maintains its retention within the stomach for at least 4 hr. This stomach-specific oral vehicle holds strong promise to translate various injectable therapeutic drugs to oral form upon further optimizations.