Drug Delivery Vectors Research Articles

Folic acid conjugated sodium alginate based redox responsive smart functional microgels as a potential targeted anticancer drug carrier

In this study, we have fabricated a sodium alginate-based redox-responsive, and cancer cell-targeted specific microgel using a water in oil (w/o) mini emulsion process and characterized it accordingly. Initially, we synthesized folic acid (FA)-grafted sodium alginate (SA), a biocompatible polysaccharide, followed by the preparation of a semi-interpenetrating polymer network (semi-IPN) microgel by crosslinking polyacrylamide (PAAm) with a disulfide crosslinker. The presence of disulfide linkages in the microgel formulation accelerated the release of the anti-cancer drug Doxorubicin (DOX) in the reducing domain of cancer cells (in vitro) (cumulative drug release amount 11 ± 3 %). Folic acid was incorporated into the microgels to enhance its targeting towards cancer cells due to the presence of the folate receptor on cancer cells. MTT (3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay showed an IC50 of ∼30 μg/mL of the DOX-loaded microgels towards breast cancer cells (MDA-MB-231) and a nontoxic behaviour towards normal mouse fibroblast cells (L929). FACS (Fluorescence-Activated Cell Sorting) and cell uptake studies showed significant cell apoptosis upon application of the drug-loaded microgels. In our opinion, this type of microgel can be a potential drug delivery vector for cancer treatment.

Exosome Cargo in Neurodegenerative Diseases: Leveraging Their Intercellular Communication Capabilities for Biomarker Discovery and Therapeutic Delivery

The inexorable progression of neurodegenerative diseases (NDs), including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and multiple sclerosis, is closely related to irreversible brain decline. Accurately characterizing pathophysiological features and identifying reliable biomarkers for early diagnosis and optimized treatment are critical. Hindered by the blood–brain barrier (BBB), obtaining sensitive monitoring indicators for disease progression and achieving efficient drug delivery remain significant challenges. Exosomes, endogenous nanoscale vesicles that carry key bioactive substances, reflect the intracellular environment and play an important role in cell signaling. They have shown promise in traversing the BBB, serving dual roles as potential biomarkers for NDs and vehicles for targeted drug delivery. However, the specific mechanisms by which exosome influence NDs are not fully understood, necessitating further investigation into their attributes and functionalities in the context of NDs. This review explores how exosomes mediate multifaceted interactions, particularly in exacerbating pathogenic processes such as oxidative stress, neuronal dysfunction, and apoptosis integral to NDs. It provides a comprehensive analysis of the profound impact of exosomes under stress and disease states, assessing their prospective utility as biomarkers and drug delivery vectors, offering new perspectives for tackling these challenging diseases.

The role of exosomes in liver cancer: comprehensive insights from biological function to therapeutic applications.

In recent years, cancer, especially primary liver cancer (including hepatocellular carcinoma and intrahepatic cholangiocarcinoma), has posed a serious threat to human health. In the field of liver cancer, exosomes play an important role in liver cancer initiation, metastasis and interaction with the tumor microenvironment. Exosomes are a class of nanoscale extracellular vesicles (EVs)secreted by most cells and rich in bioactive molecules, including RNA, proteins and lipids, that mediate intercellular communication during physiological and pathological processes. This review reviews the multiple roles of exosomes in liver cancer, including the initiation, progression, and metastasis of liver cancer, as well as their effects on angiogenesis, epithelial-mesenchymal transformation (EMT), immune evasion, and drug resistance. Exosomes have great potential as biomarkers for liver cancer diagnosis and prognosis because they carry specific molecular markers that facilitate early detection and evaluation of treatment outcomes. In addition, exosomes, as a new type of drug delivery vector, have unique advantages in the targeted therapy of liver cancer and provide a new strategy for the treatment of liver cancer. The challenges and prospects of exosome-based immunotherapy in the treatment of liver cancer were also discussed. However, challenges such as the standardization of isolation techniques and the scalability of therapeutic applications remain significant hurdles.

C-di-GMP@ZIF-8 nanocomposite injectable hydrogel based on modified chitosan and hyaluronic acid for infected wound healing by activating STING signaling

The treatment of infected wounds relies on antibiotics; however, increasing drug resistance has made therapeutic processes more difficult. Activating self-innate immune abilities may provide a promising alternative to treat wounds with bacterial infections. In this work, we constructed an immunogenic injectable hydrogel crosslinked by the Schiff base reaction of carboxymethyl chitosan (NOCC) and aldehyde hyaluronic acid (AHA) and encapsulated with stimulator of interferon genes (STING) agonist c-di-GMP loaded ZIF-8 nanoparticles (c-di-GMP@ZIF-8). Nanocubic ZIF-8 was screened as the most efficient intracellular drug delivery vector from five differently-shaped morphologies. The NOCC/AHA hydrogel released c-di-GMP@ZIF-8 more quickly (43 %) in acidic environment (pH = 5.5) of infected wounds compared with 34 % in non-infected wound environment (pH = 7.4) at 96 h due to pH-responsive degradation performance. The released c-di-GMP@ZIF-8 was found to activate the STING signaling of macrophages and enhance the secretion of IFN-β, CCL2, and CXCL12 5.8–7.6 times compared with phosphate buffer saline control, which effectively inhibited S. aureus growth and promoted fibroblast migration. In rat models with infected wounds, the c-di-GMP@ZIF-8 nanocomposite hydrogels improved infected wound healing by promoting granulation tissue regeneration, alleviating S. aureus-induced inflammation, and improving angiogenesis. Altogether, this study demonstrated a feasible strategy using STING-targeted and pH-responsive hydrogels for infected wound management.

The cardiac toxicity of PAMAM dendrimer drug delivery systems can be attenuated with the adjunct use of cardioprotective agents.

Polyamidoamine (PAMAM) dendrimer nanoparticles are efficient drug delivery vectors with potential clinical applications in nanomedicine. However, PAMAMs can compromise heart function, and strategies to mitigate cardiotoxicity would be beneficial. In this study, we investigated whether the adjunct use of three key cardioprotective agents could prevent the cardiac injury induced by a seventh-generation cationic PAMAM dendrimer (G7). Isolated rat hearts were subjected to ischemia and reperfusion (I/R) injury in the presence or absence of G7 or the cardioprotective agents Losartan, Epidermal Growth Factor (EGF), or S-nitroso-N-acetylpenicillamine (SNAP). I/R injury significantly compromised cardiac function, in terms of left ventricular hemodynamics, contractility, and vascular dynamics, which were markedly improved (p<0.05) by the administration of Losartan, EGF, or SNAP alone, confirming their cardioprotective effects. The administration of G7 significantly worsened cardiac function recovery following I/R(p<0.05). G7-induced impairments in cardiac and vascular dynamics were significantly improved by co-administration of Losartan, EGF, or SNAP. Treatment with G7 also significantly increased cardiac enzyme levels and infarct size, both of which were markedly reduced upon co-infusion of Losartan, EGF, or SNAP (p<0.05). Thus, G7 deteriorates the recovery of cardiac function in isolated hearts subjected to I/R injury, which can be rescued by co-administration of Losartan, EGF, or SNAP. These findings enhance our understanding of the nanotoxicology of PAMAM dendrimers in the mammalian heart and suggest that the adjunct use of cardioprotective agents is an effective strategy for mitigating the cardiotoxicity of these dendrimers and potentially other drug delivery systems.

Relief of pain in mice by an antibody with high affinity for cell adhesion molecule 1 on nerves

AimsCell adhesion molecule 1 (CADM1) is a member of the immunoglobulin superfamily and is abundantly expressed on nerve fibers. Recently, the anti-CADM1 ectodomain antibody 3E1 has proven useful as a drug delivery vector for CADM1-expressing cells in vitro. When injected subcutaneously into mice, whether 3E1 accumulates on nerve fibers and serves as an analgesic was examined. Main methodsInjected 3E1 was detected by immunohistochemistry and double immunofluorescence. Analgesic effects were verified by a formalin-induced chemical-inflammatory pain test and video-recorded behavior analysis that were performed 6, 12, and 24 h after antibody injection. Primary cultures of mouse dorsal root ganglion (DRG) cells were incubated with 3E1 and expressions of CADM1 and its key downstream molecules were examined by Western blot analyses and live cell imaging. DRG cells were loaded with a Ca2+ fluorescent indicator Fluo-8 and a femtosecond laser pulse was irradiated near the cell body to mechanically stimulate the nerves. Key findingsSubcutaneously injected 3E1 was widely localized almost exclusively on peripheral nerve fibers in the dermis. In formalin tests, 3E1-injected mice exhibited less pain-related behavior than control mice. When 3E1 was added to DRG cell cultures, it localized to neurites and resulted in decreased expression of CADM1, increased phosphorylation of Src and Akt, and CADM1-3E1 complex formation. Femtosecond laser-induced stimulation transmission along neurites was clearly visualized by Fluo-8 fluorescence in control cells, whereas it was markedly suppressed in 3E1-treated cells. Significance3E1 was suggested to be a potential long-acting analgesic based on its high affinity for CADM1.

Structural regression modelling of peptide based drug delivery vectors for targeted anti-cancer therapy.

Drug resistance in cancer poses a serious challenge in finding an effective remedy for cancer patients, because of the multitude of contributing factors influencing this complex phenomenon. One way to counter this problem is using a more targeted and dose-limiting approach for drug delivery, rather than relying on conventional therapies that exhibit multiple pernicious side-effects. Stability and specificity have traditionally been the core issues of peptide-based delivery vectors. In this study, we employed a structural regression modelling approach in the design, synthesis and characterization of a series of peptides that belong to approximately same topological cluster, yet with different electrostatic signatures encoded as a result of their differential positioning of amino acids in a given sequence. The peptides tagged with the fluorophore 5(6)-carboxyfluorescein, showed higher uptake in cancer cells with some of them colocalizing in the lysosomes. The peptides tagged with the anti-cancer drug methotrexate have displayed enhanced cytotoxicity and inducing apoptosis in triple-negative breast cancer cells. They also showed comparable uptake in side-population cells of lung cancer with stem-cell like properties. The most-optimized peptide showed accumulation in the tumor resulting in significant reduction of tumor size, compared to the untreated mice in in-vivo studies. Our results point to the following directives; (i) peptides can be design engineered for targeted delivery (ii) stereochemical engineering of peptide main chain can resist proteolytic enzymes and (iii) cellular penetration of peptides into cancer cells can be modulated by varying their electrostatic signatures.

Peptide ligands for the universal purification of exosomes by affinity chromatography.

Exosomes are gaining prominence as vectors for drug delivery, vaccination, and regenerative medicine. Owing to their surface biochemistry, which reflects the parent cell membrane, these nanoscale biologics feature low immunogenicity, tunable tissue tropism, and the ability to carry a variety of payloads across biological barriers. The heterogeneity of exosomes' size and composition, however, makes their purification challenging. Traditional techniques, like ultracentrifugation and filtration, afford low product yield and purity, and jeopardizes particle integrity. Affinity chromatography represents an excellent avenue for exosome purification. Yet, current affinity media rely on antibody ligands whose selectivity grants high product purity, but mandates the customization of adsorbents for exosomes with different surface biochemistry while their binding strength imposes elution conditions that may harm product's activity. Addressing these issues, this study introduces the first peptide affinity ligands for the universal purification of exosomes from recombinant feedstocks. The peptides were designed to (1) possess promiscuous biorecognition of exosome markers, without binding process-related contaminants and (2) elute the product under conditions that safeguard product stability. Selected ligands SNGFKKHI and TAHFKKKH demonstrated the ability to capture of exosomes secreted by 14 cell sources and purified exosomes derived from HEK293, PC3, MM1, U87, and COLO1 cells with yields of up to 80% and up-to 50-fold reduction of host cell proteins (HCPs) upon eluting with pH gradient from 7.4 to 10.5, recommended for exosome stability. SNGFKKHI-Toyopearl resin was finally employed in a two-step purification process to isolate exosomes from HEK293 cell fluids, affording a yield of 68% and reducing the titer of HCPs to 68 ng/mL. The biomolecular and morphological features of the isolated exosomes were confirmed by analytical chromatography, Western blot analysis, transmission electron microscopy, nanoparticle tracking analysis.

Scalable isolation of surface-engineered extracellular vesicles and separation of free proteins via tangential flow filtration and size exclusion chromatography (TFF-SEC)

BackgroundExtracellular vesicles (EVs) represent small lipid bilayer structures pivotal in mediating intercellular communication via biomolecular transfer. Their inherent characteristics, including packaging, non-immunogenicity, and biofluid stability, position EVs as promising drug delivery vectors. However, developing clinical quality EVs requires multifaceted technological advancement.MethodsIn this study, a method is introduced for engineering extracellular vesicles (eEVs) from cultured cells and their subsequent isolation using lab-scale tangential flow filtration (TFF). This is the first study to evaluate DNA loading efficacy into EVs isolated by TFF, marking a significant milestone in the field of targeted drug delivery. Initially, cells are transfected with EV-display constructs to facilitate the secretion of eEVs bearing the desired coding molecules. Following brief centrifugation, the cell culture media undergoes filtration using hollow fiber filters. TFF, by applying a constant flow, effectively segregates molecules based on designated molecular weight cut-off (MWCO), enriching particles between 50 and 650 nm.ResultsCompared to conventional methods like ultracentrifugation, TFF demonstrates higher efficiency in removing undesired molecules/aggregates while exerting less stress on EVs. Characterization of eEVs through various assays confirms TFF’s superiority in isolating pure EV populations. Additionally, the necessity of size-exclusion chromatography (SEC) after tangential flow filtration (TFF) becomes evident for effectively removing unbound protein contaminants.ConclusionIn conclusion, TFF-SEC emerges as a scalable and superior approach for eEV isolation, promising significant advancements in clinical applications.

Mechanism of Cationic Lipid Induced DNA Condensation: Lipid-DNA Coordination and Divalent Cation Charge Fluctuations.

The condensation of nucleic acids by lipids is a widespread phenomenon in biology with crucial implications for drug delivery. However, the mechanisms of DNA assembly in lipid bilayers remain insufficiently understood due to challenges in measuring and assessing each component's contribution in the lipid-DNA-cation system. This study uses all-atom molecular dynamics simulations to investigate DNA condensation in cationic lipid bilayers. Our exhaustive exploration of the thermodynamic factors reveals unique roles for phospholipid head groups and cations. We observed that bridging cations between lipid and DNA drastically reduce charges, while mobile magnesium cations "ping-ponging" between double strands create charge fluctuations. While the first factor stabilizes the DNA-lipid complex, the latter creates attractive forces to induce the spontaneous condensation of DNAs. This novel mechanism not only sheds light on the current data regarding cationic lipid-induced DNA condensation but also provides potential design strategies for creating efficient gene delivery vectors for drug delivery.

Long circulating liposomal platform utilizing hydrophilic polymer-based surface modification: preparation, characterisation, and biological evaluation

Liposomes are one of the most important drug delivery vectors, nowadays used in clinics. In general, polyethylene glycol (PEG) is used to ensure the stealth properties of the liposomes. Here, we have employed hydrophilic, biocompatible and highly non-fouling N-(2-hydroxypropyl) methacrylamide (HPMA)-based copolymers containing hydrophobic cholesterol anchors for the surface modification of liposomes, which were prepared by the method of lipid film hydration and extrusion through 100 nm polycarbonate filters. Efficient surface modification of liposomes was confirmed by transmission electron microscopy, atomic force microscopy, and gradient ultracentrifugation. The ability of long-term circulation in the vascular bed was demonstrated in rabbits after i.v. application of fluorescently labelled liposomes. Compared to PEGylated liposomes, HPMA-based copolymer-modified liposomes did not induce specific antibody formation and did not activate murine and human complement. Compared with PEGylated liposomes, HPMA-based copolymer-modified liposomes showed a better long-circulating effect after repeated administration. HPMA-based copolymer-modified liposomes thus represent suitable new candidates for a generation of safer and improved liposomal drug delivery platforms.

Fabrication and Characterization of Microneedle Patches for Loading and Delivery of Exosomes.

Exosomes, as emerging "next-generation" biotherapeutics and drug delivery vectors, hold immense potential in diverse biomedical fields, ranging from drug delivery and regenerative medicine to disease diagnosis and tumor immunotherapy. However, the rapid clearance by traditional bolus injection and poor stability of exosomes restrict their clinical application. Microneedles serve as a solution that prolongs the residence time of exosomes at the administration site, thereby maintaining the drug concentration and facilitating sustained therapeutic effects. In addition, microneedles also possess the ability to maintain the stability of bioactive substances. Therefore, we introduce a microneedle patch for loading and delivering exosomes and share the methods, including isolation of exosomes, fabrication, and characterization of exosome-loaded microneedle patches. The microneedle patches were fabricated using trehalose and hyaluronic acid as the tip materials and polyvinylpyrrolidone as the backing material through a two-step casting method. The microneedles demonstrated robust mechanical strength, with tips able to withstand 2 N. Pig skin was used to simulate human skin, and the tips of microneedles completely melted within 60 s after skin puncture. The exosomes released from the microneedles exhibited morphology, particle size, marker proteins, and biological functions comparable to those of fresh exosomes, enabling dendritic cells uptake and promoting their maturation.

TPGS nanoparticles co-loaded with ABT-737 and R848 for breast cancer therapy

The development of new effective drugs to treat breast cancer remains a huge challenge. ABT-737 can inhibit Bcl-2 proteins to promote apoptosis. Resiquimod (R848) is a TLR7/8 agonist that is effective in modulating the immunosuppressive microenvironment. In this study, a codelivery system (TPGS/ABT+R848 NPs) based on D-α-tocopheryl poly (ethylene glycol) 1000 succinate as a potential drug delivery vector to codelivery ABT-737 and R848 was investigated. The size of TPGS/ABT+R848 NPs was 102.5 nm, the drug loading of ABT-737 and R848 was 30.6 % and 12.5 %, and the entrapment efficiency was 84.2 % and 23.7 %, respectively. The nanoparticles showed no significant change in particle size over 14 days. R848 and ABT-737 were released in co-loaded nanoparticles in sequential order. In vitro anti-tumor experiments, the IC50 value of TPGS/ABT+R848 NPs was 0.30 μg·mL−1, 34 times lower than that of free ABT-737. Animal experiments also verified that TPGS/ABT+R848 NPs could enhance the anti-tumor activity, and the tumor weight inhibition rate was 75.3 %. This study demonstrated that TPGS NPs loaded with ABT-737 and R848 have superior combination tumor therapeutic effects, and the co-loaded preparation is conducive to anti-tumor efficacy. The TPGS/ABT+R848 NPs could be a promising platform against breast cancer.

Chitosan-based crosslinking for controlled topical drug release in rhinosinusitis.

Chitosan is a promising drug delivery vector for therapeutics owing to its biocompatibility. Once crosslinked with chitosan, prolonged drug release was noted regardless of hydrophilicity. Hydrophilic drugs may require different strategies to obtain a sustained release profile.

Cell membrane-penetrating capacity of hPP10-Cu, Zn-SOD fusion protein and its antioxidant and anti-inflammatory activity

To investigate the cell membrane-penetrating capacity of human cell-penetrating peptide hPP10 carrying human antioxidant protein Cu-Zn superoxide dismutase (Cu, Zn-SOD) and assess the antioxidant and anti-inflammatory activity of these fusion proteins. The fusion protein hPP10-Cu, Zn-SOD was obtained by genetic engineering and identified by Western blotting. The membrane-penetrating ability of the fusion protein was evaluated by immunofluorescence assay, fluorescence colocalization assay and Western blotting, its SOD enzyme activity was detected using a commercial kit, and its effect on cell viability was assessed with MTT assay. In a HEK293 cell model of H2O2-induced oxidative stress, the effect of hPP10-Cu, Zn-SOD on cell apoptosis was analyzed with flow cytometry and RT-qPCR, and its antioxidant effect was assessed using reactive oxygen species (ROS) assay; its anti-inflammatory effect was evaluated in mouse model of TPA-induced ear inflammation by detecting expression of the inflammatory factors using RT-qPCR, Western blotting and immunohistochemistry. The fusion protein hPP10-Cu, Zn-SOD was successfully obtained. Immunofluorescence assay confirmed obvious membrane penetration of this fusion protein in HEK293 cells, localized both in the cell membrane and the cell nuclei after cell entry. hPP10-Cu, Zn-SOD at the concentration of 5 μmol/L exhibited strong antioxidant activity with minimal impact on cell viability at the concentration up to 10 μmol/L. The fusion protein obviously inhibited apoptosis and decreased intracellular ROS level in the oxidative stress cell model and significantly reduced mRNA and protein expression of the inflammatory factors in the mouse model of ear inflammation. The fusion protein hPP10-Cu, Zn-SOD capable of penetrating the cell membrane possesses strong antioxidant and anti-inflammatory activities with only minimal cytotoxicity, demonstrating the value of hPP10 as an efficient drug delivery vector and the potential of hPP10-Cu, Zn-SOD in the development of skincare products.

#1322 VEGF therapy improves cardio-renal pathophysiology in a novel model of CKD-HFpEF

Abstract Background and Aims Patients with chronic kidney disease (CKD) have a higher risk of developing heart failure with preserved ejection fraction (HFpEF). We developed a model of CKD-HFpEF and showed that renal-cardio pathophysiology is associated with decreased expression and availability of vascular endothelial growth factor in both organs. We showed that renal VEGF therapy improved renal function in our model. We hypothesize that cardiac VEGF therapy will improve cardiac function and will investigate whether cardiac protection in CKD also carries recovery of renal function. Method CKD and normal pigs (n = 4 each, 2 males/2 females) were studied for 14 weeks. In addition, CKD-HFpEF (n = 4, 2 males/2 females) were treated after 6 weeks of disease with a single intracoronary (IC) administration of VEGF attached to a drug-delivery vector (ELP-VEGF) that increases cardiac targeting, and effects quantified 8 weeks later. Renal (multi-detector CT) and cardiac (echocardiography, PV loops) morphology and function were quantified in vivo, microvascular (MV) density (3D micro-CT) ex vivo, and cardiac expression of VEGF was quantified by qPCR. Results Cardiac function, VEGF expression, and MV density were improved after IC ELP-VEGF therapy compared to placebo. Notably, renal hemodynamics (expressed as % change) were significantly improved compared to pre-treatment values and to time-matched untreated CKD-HFpEF pigs (Figure). Conclusion Our study suggests strong crosstalk between the heart and the kidney in a pre-clinical model of CKD-HFpEF. Renal and cardiac hemodynamics were significantly improved after cardiac VEGF therapy, conceptually supporting a cardio-renal axis in CKD and showing the extent of beneficial effects of a novel targeted intervention in a translational fashion.

Prospects of Targeted Gene/Drug Delivery Vectors and their Potential Use in Cancer Therapy

Abstract:: Targeted gene and drug delivery vector developments have completely changed the therapeutic intervention by providing previously unheard-of levels of accuracy and efficacy in treating various illnesses. Cancer is one such fatal disease plaguing people across the globe. This review article highlights the potential uses of targeted delivery systems in the field of cancer treatment while providing a thorough examination of the state of the art. Chemotherapy and radiation therapy are being used to cure cancer, yet they can be frequently ineffective and have serious adverse effects. Novel techniques for therapy have to be designed. Existing chemotherapy is being superseded by particular gene therapy used for genetic diseases. Therefore, to deliver the therapeutic agent to the targeted place, a carrier or vector is needed. The current review is focused on targeted gene/drug delivery vectors concerning i) cationic lipids that target single receptors ii) ligand-peptide conjugated cationic lipids iii) modalities for targeting dual ligands for cancer therapy iv) passive versus active targeting v) properties of nano-formulations for gene and drug delivery. The most recent developments in lipid customization for certain receptors overexpressed in cancer cells are covered to reduce side effects and improve treatment results. By delving into the above areas, this review presents a broad overview of the changing field of cationic lipids in cancer therapy, giving scientists and medical professionals insightful knowledge about the many strategies for ensuring precise and efficient drug delivery in the battle against cancer.

Genetic Mechanisms Driving Uterine Leiomyoma Pathobiology, Epidemiology, and Treatment.

Uterine leiomyomas (ULs) are the most common benign tumor of the uterus. They can be associated with symptoms including abnormal uterine bleeding, pelvic pain, urinary frequency, and pregnancy complications. Despite the high prevalence of UL, its underlying pathophysiology mechanisms have historically been poorly understood. Several mechanisms of pathogenesis have been suggested, implicating various genes, growth factors, cytokines, chemokines, and microRNA aberrations. The purpose of this study is to summarize the current research on the relationship of genetics with UL. Specifically, we performed a literature review of published studies to identify how genetic aberrations drive pathophysiology, epidemiology, and therapeutic approaches of UL. With regards to pathophysiology, research has identified MED12 mutations, HMGA2 overexpression, fumarate hydratase deficiency, and cytogenetic abnormalities as contributors to the development of UL. Additionally, epigenetic modifications, such as histone acetylation and DNA methylation, have been identified as contributing to UL tumorigenesis. Specifically, UL stem cells have been found to contain a unique DNA methylation pattern compared to more differentiated UL cells, suggesting that DNA methylation has a role in tumorigenesis. On a population level, genome-wide association studies (GWASs) and epidemiologic analyses have identified 23 genetic loci associated with younger age at menarche and UL growth. Additionally, various GWASs have investigated genetic loci as potential drivers of racial disparities in UL incidence. For example, decreased expression of Cytohesin 4 in African Americans has been associated with increased UL risk. Recent studies have investigated various therapeutic options, including ten-eleven translocation proteins mediating DNA methylation, adenovirus vectors for drug delivery, and "suicide gene therapy" to induce apoptosis. Overall, improved understanding of the genetic and epigenetic drivers of UL on an individual and population level can propel the discovery of novel therapeutic options.

Matrix metalloproteinase-sensitive size-shrinkable liposomes targeting activated macrophages for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by inflammation, swelling, pain, and cartilage and bone destruction. Exploiting the pathophysiological characteristics of matrix metalloproteinases (MMPs), which are enzymes overexpressed at the inflammation site in RA, has resulted in the development of inflammation-responsive drug delivery vectors. We here prepared a multifunctional microenvironment-responsive liposome with MMP-responsive and particle-size-shrinking properties to target macrophages at inflammation sites. In this liposome, triptolide (TP) was encapsulated in a biofilm-like bilayer with mannose-conjugated DSPE-PEG2000 as the targeting molecule and the enzyme-sensitive peptide PVGLIG as the linker arm connecting DSPE-PEG5000, which formed a hydrated membrane envelope on the liposome surface, prolonging liposome circulation while preventing the active targeting molecule from binding to normal macrophages throughout the body and reducing drug accumulation in normal tissues, thereby alleviating efficacy and reducing toxic side effects. In the joint inflammation microenvironment, PVGLIG was cleaved by overexpressed MMPs, the hydration layer of PEG5000 detached, and the target ligand Man was exposed, thereby leading to Man uptake by activated macrophages and exerting an anti-RA effect. Through in vivo and in vitro evaluations, liposomes were found to effectively target inflammation sites and enrich activated macrophages. They also inhibited osteoclastogenesis and the release of inflammatory cytokines, reactive oxygen species, and MMPs. This offers a promising new strategy in which anti-inflammatory and osteoprotective effects are combined for comprehensive RA treatment.

Abstract 3185: Glatiramer acetate enhances tumor retention and mitigates systemic toxicity of toll-like receptor 9 agonists as intratumoral immunotherapy

Abstract Pathogen-associated molecular patterns (PAMP) are conserved molecular structures produced by microorganisms that are recognized as foreign by receptors of the innate immune system. Unmethylated cytosine-guanine oligodeoxynucleotides (CpG ODNs) are a storied drug class from the PAMP family that ligates Toll-like receptor 9 (TLR9). CpG ODNs have shown promising antitumor effects in preclinical studies by inducing potent pro-inflammatory immune responses. However, there are still practical challenges that have hindered clinical success, including inefficient in vivo delivery and severe immune-related toxicities caused by systemic exposure to CpG. We previously identified that glatiramer acetate (GA), an FDA-approved, lysine-rich polypeptide, could be applied as a cationic drug delivery vector for CpG delivery proximal to the injection site while mitigating systemic release of pro-inflammatory cytokines. To dive into the mechanism and evaluate pharmacological efficacy in more pathological models that simulate colorectal carcinoma, we validated the biodistribution of GA-CpG complexes (or R4B) and explored their safety and antitumor immunity in multiple mouse colorectal carcinoma models. In the CT26 single tumor model, intratumoral R4B treatment displayed comparable antitumoral efficacy as CpG treatment. Genome-wide transcriptome analysis showed that R4B treatment elicited much more prominent immune system response pathways in both lesions and spleens. The biodistribution study proved that R4B localized and gradually released CpG around the injection site while ‘naked’ CpG diffused away from the injection site quickly. In the CT26 dual tumor-bearing model, intratumoral administration of R4B generated systemic immune efficacy that led to an abscopal effect on distant untreated cancers, comparable to treatment with CpG alone. Notably, R4B treatment accomplished these effects with greatly mitigated systemic pro-inflammatory cytokines compared to CpG alone. These data help further elucidate the noncanonical role of glatiramer acetate to serve as a nucleic acid delivery scaffold that potentiates the safety of CpG adjuvant for cancer immunotherapy. Citation Format: Huan Gong, Daniel J. Griffin, Chad E. Groer, Xiaoqing Wu, Moustafa M. Abdelaziz, Sa Wu, Liang Xu, Laird M. Forrest, Cory J. Berkland. Glatiramer acetate enhances tumor retention and mitigates systemic toxicity of toll-like receptor 9 agonists as intratumoral immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3185.