Circulation Half-life Research Articles

DMPC/Chol liposomal copper CX5461 is therapeutically superior to a DSPC/Chol formulation

CX5461, a compound initially identified as an RNA polymerase inhibitor and more recently as a G-quadruplex binder, binds copper to form a complex. Our previous publication showed that the complexation reaction can be leveraged to formulate copper-CX5461 inside liposomes, improving the apparent solubility of CX5461 by over 500-fold and reducing the elimination of CX5461 from the plasma compartment following intravenous administration. In mouse models of acute myeloid leukemia, the resulting formulation was more effective than the free drug solution of CX5461 (pH 3.5) currently used in clinical trials. However, the gains observed with the liposomal formulation were minimal, despite significant increases in circulation half-life. Since the formulation technology used relied on liposomes and the fate of most compounds associated with liposomes is dependent on liposomal lipid composition, the studies described here were designed to evaluate how simple changes in lipid composition could affect therapeutic activity. The previously reported formulation method was simplified to ensure an easy scale-up process. In the modified method, pre-measured solid CX5461 was added to copper-containing liposomes prior to an incubation at 60 °C, which enabled copper-CX5461 complexation inside DSPC/Chol or DMPC/Chol liposomes. Efficacy was determined in BRCA-normal (BxPC3) and BRCA-deficient (Capan-1) models of pancreatic cancer. Both liposomal formulations enhanced the circulation lifetime of CX5461 compared to the free drug solution (pH 3.5). Unlike most compounds that are loaded using a transmembrane pH-gradient, the dissociation of CX5461 from liposomes prepared using the copper complexation method were comparable for DSPC/Chol and DMPC/Chol liposomes, in vitro and in vivo. Nonetheless, copper CX5461 prepared using DMPC/Chol liposomes exhibited superior efficacy. The reason for the improved activity of DMPC/Chol copper-CX5461 was not readily explained by the release data and may be due to the fact that DMPC/Chol liposomes are less stable following localization in the tumor. The results indicate that the therapeutic effects of copper-CX5461 will be dependent on liposomal lipid composition and that liposomal CX5461 should exhibit superior benefits when used to treat BRCA-deficient cancers.

Self-oxygenation mesoporous MnO2 nanoparticles with ultra-high drug loading capacity for targeted arteriosclerosis therapy

Atherosclerosis (AS) is a leading cause of vascular diseases that severely threats the human health due to the lack of efficient therapeutic methods. During the development and progress of AS, macrophages play critical roles, which are polarized into pro-inflammatory M1 phenotype to excrete abundant cytokines and overproduce reactive oxygen species (ROS), and take up excess amount of lipid to form foam cells. In this work, we developed a MnO2-based nanomedicine to re-educate macrophages for targeting AS therapy. The MnO2 was one-pot synthesized under mild condition, showing intrinsic catalase-mimic activity for self-oxygenation by using endogenous H2O2 as substrate. Moreover, the mesoporous structure as well as the abundant metal coordination sites in MnO2 structure facilitated the loading of an anti-AS drug of curcumin (Cur), achieving extraordinarily high drug loading capacity of 54%. Cur displayed a broad spectrum of anti-oxidant and anti-inflammatory capabilities to repolarize M1 macrophages into M2 phenotype, and the catalytic MnO2 recovered the function of lipid efflux transporter to remove lipid from cells by suppressing HIF-1α. Collectively, the nanocarrier and the payload drug functioned as an all-active nanoplatform to synergistically alleviate the syndromes of AS. In ApoE−/− mice model, the nanosystem could significantly prolong the circulation half-life of Cur by sixfold, and enhance drug accumulation in atherosclerotic lesion by 3.5-fold after intravenous injection by virtue of surface hyaluronic acid (HA) modification. As a result, a robust anti-AS efficacy was achieved as evidenced by the decrease of atherosclerotic lesion, plaque area, lipid level.Graphical

Targeting delivery of synergistic dual drugs with elastic PEG-modified multi-functional nanoparticles for hepatocellular carcinoma therapy

Integration of multiple advantages in one system has been leveraged to overcome multiple biological barriers in anti-tumor therapeutic strategies. In this study, multi-functional nanoparticles (MFNPs) are constructed by layer-by-layer method. MFNPs are modified with pH-responsive elastic PEG-GPC3MAb (glypican-3 monoclonal antibody), which draws back into PEG layer in blood and normal tissues; and stretches out of MFNPs surface in the acidic tumor microenvironment. It is proved that blank MFNPs have good biocompatibility by MTT and acute toxicity assays. Elastic PEG chains are able to respond sensitively in different pH environments (6.8 and 7.4), which is demonstrated by transmission electron microscope (TEM) and 1H nuclear magnetic resonance (1H NMR). In vitro experiments show that MFNPs have better specificity to Hepa 1–6 cells, can escape from lysosomes, and are able to increase the nuclear delivery of dual drugs for synergistic therapy, which are proved by flow cytometry, MTT, confocal laser scanning microscopy, and western blot studies. In vivo experiments indicate that MFNPs show extending circulation half-life in blood, promoting localization into tumor tissues, improving the therapeutic efficacy of BAL b/c nude mice with subcutaneous tumors. Overall, the results indicate that FMNPs are a potential candidate for hepatocellular carcinoma therapy.

Albumin Biomolecular Drug Designs Stabilized through Improved Thiol Conjugation and a Modular Locked Nucleic Acid Functionalized Assembly.

Albumin-nucleic acid biomolecular drug designs offer modular multifunctionalization and extended circulatory half-life. However, stability issues associated with conventional DNA nucleotides and maleimide bioconjugation chemistries limit the clinical potential. This work aims to improve the stability of this thiol conjugation and nucleic acid assembly by employing a fast-hydrolyzing monobromomaleimide (MBM) linker and nuclease-resistant nucleotide analogues, respectively. The biomolecular constructs were formed by site-selective conjugation of a 12-mer oligonucleotide to cysteine 34 (Cys34) of recombinant human albumin (rHA), followed by annealing of functionalized complementary strands bearing either a fluorophore or the cytotoxic drug monomethyl auristatin E (MMAE). Formation of conjugates and assemblies was confirmed by gel shift analysis and mass spectrometry, followed by investigation of serum stability, neonatal Fc receptor (FcRn)-mediated cellular recycling, and cancer cell killing. The MBM linker afforded rapid conjugation to rHA and remained stable during hydrolysis. The albumin-nucleic acid biomolecular assembly composed of stabilized oligonucleotides exhibited high serum stability and retained FcRn engagement mediating FcRn-mediated cellular recycling. The MMAE-containing assembly exhibited cytotoxicity in the human MIA PaCa-2 pancreatic cancer cell line with an IC50 of 342 nM, triggered by drug release from breakdown of an acid-labile linker. In summary, this work presents rHA-nucleic acid module-based assemblies with improved stability and retained module functionality that further promotes the drug delivery potential of this biomolecular platform.

Treatment of bladder cancer by geoinspired synthetic chrysotile nanocarrier-delivered circPRMT5 siRNA

BackgroundCircular RNAs (circRNAs) have important functions in many fields of cancer biology. In particular, we previously reported that the oncogenic circRNA, circPRMT5, has a major role in bladder cancer progression. Therapy based on circRNAs have good prospects as anticancer strategies. While anti-circRNAs are emerging as therapeutics, the specific in vivo delivery of anti-circRNAs into cancer cells has not been reported and remains challenging.MethodsSynthesized chrysotile nanotubes (SCNTs) with a relatively uniform length (~ 200 nm) have been designed to deliver an siRNA against the oncogenic circPRMT5 (si-circPRMT5) inhibit circPRMT5. In addition, the antitumor effects and safety evaluation of SCNTs/si-circPRMT5 was assessed with a series of in vitro and in vivo assays.ResultsThe results showed that SCNTs/si-circPRMT5 nanomaterials prolong si-circPRMT5’s half-life in circulation, enhance its specific uptake by tumor cells, and maximize the silencing efficiency of circPRMT5. In vitro, SCNTs encapsulating si-circPRMT5 could inhibit bladder cancer cell growth and progression. In vivo, SCNTs/si-circPRMT5 inhibited growth and metastasis in three bladder tumor models (a subcutaneous model, a tail vein injection lung metastatic model, and an in situ model) without obvious toxicities. Mechanistic study showed that SCNTs/si-circPRMT5 regulated the miR-30c/SNAIL1/E-cadherin axis, inhibiting bladder cancer growth and progression.ConclusionThe results highlight the potential therapeutic utility of SCNTs/si-circPRMT5 to deliver si-circPRMT5 to treat bladder cancer.

Albumin-Binding Aptamer Chimeras for Improved siRNA Bioavailability.

Short interfering RNAs (siRNAs) are potent nucleic acid-based drugs designed to target disease driving genes that may otherwise be undruggable with small molecules. However, therapeutic potential of siRNA in vivo is limited by poor pharmacokinetic properties, including rapid renal clearance and nuclease degradation. Backpacking on natural carriers such as albumin, which is present at high concentration and has a long half-life in serum, is an effective way to modify pharmacokinetics of biologic drugs that otherwise have poor bioavailability. In this work, we sought to develop albumin-binding aptamer-siRNA chimeras to improve the bioavailability of siRNA. A Systematic Evolution of Ligands through Exponential Enrichment (SELEX) approach was used to obtain modified RNA-binding aptamers, which were then fused directly to siRNA via in vitro transcription. Molecular and pharmacokinetic properties of the aptamer-siRNA chimeras were subsequently measured in vitro and in vivo. In vitro assays show that albumin-binding aptamers are stable in serum while maintaining potent gene knockdown capabilities in the chimera format. In vivo, the absolute circulation half-life of the best-performing aptamer-siRNA chimera (Clone 1) was 1.6-fold higher than a scrambled aptamer chimera control. Aptamer-siRNA chimeras exhibit improved bioavailability without compromising biological activity. Hence, this albumin-binding aptamer-siRNA chimera approach may be a promising strategy for drug delivery applications. The online version contains supplementary material available at 10.1007/s12195-022-00718-y.

Fe(III)-Doped Polyaminopyrrole Nanoparticle for Imaging-Guided Photothermal Therapy of Bladder Cancer.

Clinically, the surgical treatment of bladder cancer often faces the problem of tumor recurrence, and the surgical treatment combined with postoperative chemotherapy to inhibit tumor recurrence also faces high toxicity and side effects. Therefore, the need for innovative bladder cancer treatments is urgent. For the past few years, with the development of nano science and technology, imaging-guided therapy using nanomaterials with both imaging and therapy functions has shown great advantages and can not only identify the locations of the tumors but also exhibit biodistributions of nanomaterials in the tumors, significantly improving the accuracy and efficacy of treatment. In this work, we synthesized Fe(III)-doped polyaminopyrrole nanoparticles (FePPy-NH2 NPs). With low cytotoxicity and a blood circulation half-life of 7.59 h, high levels of FePPy-NH2 NPs accumulated in bladder tumors, with an accumulation rate of up to 5.07%ID/g. The coordination of Fe(III) and the amino group in the structure can be used for magnetic resonance imaging (MRI), whereas absorption in the near-infrared region can be applied to photoacoustic imaging (PAI) and photothermal therapy (PTT). MRI and PAI accurately identified the location of the tumor, and based on the imaging data, laser irradiation was employed accurately. With a high photothermal conversion efficiency of 44.3%, the bladder tumor was completely resected without recurrence. Hematological analysis and histopathological analysis jointly confirmed the high level of safety of the experiment.

Overcoming the limitations of cytokines to improve cancer therapy.

Cytokines are pleiotropic soluble proteins used by immune cells to orchestrate a coordinated response against pathogens and malignancies. In cancer immunotherapy, cytokine-based drugs can be developed potentiating pro-inflammatory cytokines or blocking immunosuppressive cytokines. However, the complexity of the mechanisms of action of cytokines requires the use of biotechnological strategies to minimize systemic toxicity, while potentiating the antitumor response. Sequence mutagenesis, fusion proteins and gene therapy strategies are employed to enhance the half-life in circulation, target the desired bioactivity to the tumor microenvironment, and to optimize the therapeutic window of cytokines. In this review, we provide an overview of the different strategies currently being pursued in pre-clinical and clinical studies to make the most of cytokines for cancer immunotherapy.

Nano-Liposomal Encapsulation-Delivered Apelin-13 Attenuates Ev71 Infection-Induced Neurodegeneration by Modulating Il-6 and Tlr7

Background: Enterovirus 71 (EV71) infection serves as a leading cause of hand-foot-and-mouth disease, and induces neural disorders. Apelin-13, as a neuropeptide, presents potential neuroprotective activities, but its short half-life in circulation has limited its clinical use. Objective: To explore the role of nano-liposomal encapsulation-delivered apelin-13 in the development of EV71 infection-induced neurodegeneration. Method: The liposome encapsulating apelin-13 (lipoPEG-A13) was successfully constructed and characterized in the study. The neurodegeneration measurement in an intracranially EV71-infected mouse model was performed in vivo. MTT assays, lactate dehydrogenase release assays, immunohistochemistry, and immunofluorescence staining qPCR assays, and Western blot analysis were respectively performed. Results: EV71 notably replicated and promoted apoptosis in the cerebral cortex from the EV71-infected mice but exhibited comparatively low replication and slightly regulated apoptosis in the cerebellum. Remarkably, lipoPEG-A13 was able to inhibit EV71-induced neurological injury in the murine cerebral cortex in vivo. Meanwhile, LipoPEG-A13 could attenuate EV71-caused apoptosis of the neural cell in the brain. LipoPEG-A13 decreased the Toll-like receptor 7 (TLR7) and interleukin-6 (IL-6) production in the mice. Apelin-13 inhibited the expression of TLR7 and IL-6 in the human astroglioma U251 cells. Apelin-13 could reduce the apoptosis of astrocytic cells infected with EV71. Conclusion: Nano-liposomal encapsulation-delivered apelin-13 attenuated EV71 infection-induced neurodegeneration via modulating IL-6 and TLR7 production. The finding provides new insights into how Nano-liposomal encapsulation-delivered apelin-13 modulates EV71 infection-induced neurological disorders. The Nano-liposomal encapsulation-delivered apelin-13 presents the application potential in the clinical context.

Membrane-wrapped nanoparticles for nucleic acid delivery.

There is an unmet need for carriers that can deliver nucleic acids (NAs) to cancer cells and tumors to perpetuate gene regulation and manage disease progression. Membrane-wrapped nanoparticles (NPs) can be loaded with exogenously designed nucleic acid cargoes, such as plasmid deoxyribonucleic acid (pDNA), messenger ribonucleic acid (mRNA), small interfering RNA (siRNA), microRNA (miRNA), and immunostimulatory CpG oligodeoxynucleotides (CpG ODNs), to mitigate challenges presented by NAs' undesirable negative charge, hydrophilicity, and relatively large size. By conjugating or encapsulating NAs within membrane-wrapped NPs, various physiological barriers can be overcome so that NAs experience increased blood circulation half-lives and enhanced accumulation in intended sites. This review discusses the status of membrane-wrapped NPs as NA delivery vehicles and their advancement in gene regulation for cancer management in vitro and in vivo. With continued development, membrane-wrapped NPs have great potential as future clinical tools to treat cancer and other diseases with a known genetic basis.

“Proof of Concept” Rabbit Experiments Demonstrating GHR106 (hIgG4) as GnRH Antagonist

“Proof of Concept” (P-o-C) experiments in rabbits were conducted to demonstrate reversible suppressions of serum reproductive hormones (LH, testosterone or E2) upon a single injection of a humanized monoclonal antibody against human GnRH receptor, GHR106 (hIgG4). In the case of a male rabbit, a single subcutaneous injection of either 1 mg/kg or 3 mg/kg of the antibody was shown to reduce concurrently the serum LH and testosterone concentrations by 60 to 80% for a period of one week or longer. The reproductive hormone levels returned to the normal range after next two weeks. Similarly, the suppressions of LH and estradiol (E2) were also observed within two days upon a single injection of GHR106 (hIgG4) in the female. The E2 levels can decrease to 30-60% of the normal over a period of one week followed by full recovery of both hormones during the next 5-10 days. P-o-C experiments were expanded to a scale of more than 30 rabbits with identical protocols to those of a single rabbit, in addition to the comparisons with those of the negative control. Reversible suppressions of reproductive hormones were observed consistently with all rabbits in the antibody injection groups, and were shown to be statistically significant. The circulation half-life of GHR106 (hIgG4) in rabbits was estimated to be 4 ± 1 day. Therefore, the results of this study revealed that GHR106(hIgG4) can be used as antibody-based long- acting GnRH antagonist with similar biological actions to those of decapeptide GnRH antagonist such as Cetrorelix or Antide. The relatively long half-life of the antibody-based GnRH antagonist, however, may be more beneficial to the treatment of gynecological and fertility-related diseases which may be caused by modulations of human GnRH receptor in humans, and also in other animal species for fertility controls.

Targeted Theranostic 111In/Lu-Nanotexaphyrin for SPECT Imaging and Photodynamic Therapy.

Theranostic nanoparticles aim to integrate diagnostic imaging and therapy to facilitate image-guided treatment protocols. Herein, we present a theranostic nanotexaphyrin for prostate-specific membrane antigen (PSMA)-targeted radionuclide imaging and focal photodynamic therapy (PDT) accomplished through the chelation of metal isotopes (In, Lu). To realize nanotexaphyrin's theranostic properties, we developed a rapid and robust 111In/Lu-nanotexaphyrin radiolabeling method using a microfluidic system that achieved a high radiochemical yield (>90%). The optimized metalated nanotexaphyrin displayed excellent chemical, photo, and colloidal stabilities, potent singlet oxygen generation, and favorable plasma circulation half-life in vivo (t1/2 = 6.6 h). Biodistribution, including tumor accumulation, was characterized by NIR fluorescence, SPECT/CT imaging, and γ counting. Inclusion of the PSMA-targeting ligand enabled the preferential accumulation of 111In/Lu-nanotexaphyrin in PSMA-positive (PSMA+) prostate tumors (3.0 ± 0.3%ID/g) at 48 h with tumor vs prostate in a 2.7:1 ratio. In combination with light irradiation, the PSMA-targeting nanotexaphyrin showed a potent PDT effect and successfully inhibited PSMA+ tumor growth in a subcutaneous xenograft model. To the best of our knowledge, this study is the first demonstration of the inherent metal chelation-driven theranostic capabilities of texaphyrin nanoparticles, which, in combination with PSMA targeting, enabled prostate cancer imaging and therapy.

Paclitaxel-based supramolecular hydrogel loaded with mifepristone for the inhibition of breast cancer metastasis.

Breast cancer is the leading cause of cancer death among women and almost all of the breast cancer‐caused mortality is related to metastasis. It has been reported that glucocorticoid facilitates the metastasis of breast cancer in mice, and mifepristone can antagonize the effect of glucocorticoid. Paclitaxel is one of the important drugs in the treatment of breast cancer. Mifepristone combined with paclitaxel could be an effective strategy for inhibiting breast cancer metastasis. However, their inherent defects, in terms of short blood circulation half‐life and lack of tumor targeting, not only limit their effectiveness but also cause adverse reactions. Therefore, our aim is to explore a novel protocol against breast cancer metastasis, further optimize its therapeutic efficacy by a nanodelivery system, and explore its mechanism. Herein, a paclitaxel‐conjugated and mifepristone‐loaded hydrogel (PM‐nano) was prepared by self‐assembly. Its characterizations were studied. The antimetastatic effect was evaluated in vitro and in vivo and its mechanism was also explored by western blot assay. The resultant PM‐nano was developed with favorable water solubility and good biocompatibility. Moreover, PM‐nano displayed increased cell uptake properties and stimulated drug release in the tumor micro‐acidic environment. The PM‐nano was more effective in inhibiting the proliferation and metastasis of breast cancer than other groups in vitro and in vivo. The PM‐nano might inhibit metastasis through glucocorticoid receptor/receptor tyrosine kinase‐like orphan receptor 1 and MMPs. Taken together, PM‐nano showed superior antimetastatic effects against breast cancer and excellent biocompatibility in vitro and in vivo, providing a new option for limiting metastasis.

Aptamer-based factor IXa inhibition preserves hemostasis and prevents thrombosis in a piglet model of ECMO

Extracorporeal membrane oxygenation (ECMO) requires anticoagulation to prevent clotting when the patient’s blood contacts the circuit. Unfractionated heparin (UFH) usually prevents clotting but can cause life-threatening bleeding. An anticoagulant that selectively inhibits the contact activation (intrinsic) pathway while sparing the tissue factor (extrinsic) pathway of coagulation might prevent clotting triggered by the circuit while permitting physiologic coagulation at surgical sites. DTRI-178 is an RNA anticoagulant aptamer conjugated to polyethylene glycol that increases its half-life in circulation. This aptamer is based on a previously described molecule (9.3t) that inhibits intrinsic tenase activity by binding to factor IXa on an exosite. Using a piglet model of pediatric venoarterial (VA) ECMO, we compared thromboprevention and blood loss using a single dose of DTRI-178 versus UFH. In each of five experiments, we subjected two litter-matched piglets, one anticoagulated with DTRI-178 and the other with UFH, to simultaneous 12-h periods of VA ECMO. Both anticoagulants achieved satisfactory and comparable thromboprotection. However, UFH piglets had increased surgical site bleeding and required significantly greater blood transfusion volumes than piglets anticoagulated with DTRI-178. Our results indicate that DTRI-178, an aptamer against factor IXa, may be feasible, safer, and result in fewer transfusions and clinical bleeding events in ECMO.

ZRC3308 Monoclonal Antibody Cocktail Shows Protective Efficacy in Syrian Hamsters against SARS-CoV-2 Infection.

We have developed a monoclonal antibody (mAb) cocktail (ZRC-3308) comprising of ZRC3308-A7 and ZRC3308-B10 in the ratio 1:1 for COVID-19 treatment. The mAbs were designed to have reduced immune effector functions and increased circulation half-life. mAbs showed good binding affinities to non-competing epitopes on RBD of SARS-CoV-2 spike protein and were found neutralizing SARS-CoV-2 variants B.1, B.1.1.7, B.1.351, B.1.617.2, and B.1.617.2 AY.1 in vitro. The mAb cocktail demonstrated effective prophylactic and therapeutic activity against SARS-CoV-2 infection in Syrian hamsters. The antibody cocktail appears to be a promising candidate for prophylactic use and for therapy in early COVID-19 cases that have not progressed to severe disease.

Delivering more for less: nanosized, minimal-carrier and pharmacoactive drug delivery systems.

Traditional nanoparticle carriers such as liposomes, micelles, and polymeric vehicles improve drug delivery by protecting, stabilizing, and increasing the circulatory half-life of the encapsulated drugs. However, traditional drug delivery systems frequently suffer from poor drug loading and require an excess of carrier materials. This carrier material excess poses an additional systemic burden through accumulation, if not degradable the need for metabolism, and potential toxicity. To address these shortcomings, minimal-carrier nanoparticle systems and pharmacoactive carrier materials have been developed. Both solutions provide drug delivery systems in which the majority of the nanoparticle is pharmacologically active. While minimal-carrier and pharmacoactive drug delivery systems can improve drug loading, they can also suffer from poor stability. Here, we review minimal-carrier and pharmacoactive delivery systems, discuss ongoing challenges and outline opportunities to translate minimal-carrier and pharmacoactive drug delivery systems into the clinic.

Transgene expression in mice of the Opa1 mitochondrial transmembrane protein through bicontinuous cubic lipoplexes containing gemini imidazolium surfactants

BackgroundLipoplexes are non-viral vectors based on cationic lipids used to deliver DNA into cells, also known as lipofection. The positively charge of the hydrophilic head-group provides the cationic lipids the ability to condensate the negatively charged DNA into structured complexes. The polar head can carry a large variety of chemical groups including amines as well as guanidino or imidazole groups. In particular, gemini cationic lipids consist of two positive polar heads linked by a spacer with different length. As for the hydrophobic aliphatic chains, they can be unsaturated or saturated and are connected to the polar head-groups. Many other chemical components can be included in the formulation of lipoplexes to improve their transfection efficiency, which often relies on their structural features. Varying these components can drastically change the arrangement of DNA molecules within the lamellar, hexagonal or cubic phases that are provided by the lipid matrix. Lipofection is widely used to deliver genetic material in cell culture experiments but the simpler formulations exhibit major drawbacks related to low transfection, low specificity, low circulation half-life and toxicity when scaled up to in vivo experiments.ResultsSo far, we have explored in cell cultures the transfection ability of lipoplexes based on gemini cationic lipids that consist of two C16 alkyl chains and two imidazolium polar head-groups linked with a polyoxyethylene spacer, (C16Im)2(C4O). Here, PEGylated lipids have been introduced to the lipoplex formulation and the transgene expression of the Opa1 mitochondrial transmembrane protein in mice was assessed. The addition of PEG on the surface of the lipid mixed resulted in the formation of Ia3d bicontinuous cubic phases as determined by small angle X-ray scattering. After a single intramuscular administration, the cubic lipoplexes were accumulated in tissues with tight endothelial barriers such as brain, heart, and lungs for at least 48 h. The transgene expression of Opa1 in those organs was identified by western blotting or RNA expression analysis through quantitative polymerase chain reaction.ConclusionsThe expression reported here is sufficient in magnitude, duration and toxicity to consolidate the bicontinuous cubic structures formed by (C16Im)2(C4O)-based lipoplexes as valuable therapeutic agents in the field of gene delivery.Graphical

Effects and mechanisms of dietary bioactive compounds on breast cancer prevention

Breast cancer (BC) is the most often diagnosed cancer among females globally and has become an increasing global health issue over the last decades. Despite the substantial improvement in screening methods for initial diagnosis, effective therapy remains lacking. Still, there has been high recurrence and disease progression after treatment of surgery, endocrine therapy, chemotherapy, and radiotherapy. Considering this view, there is a crucial requirement to develop safe, freely accessible, and effective anticancer therapy for BC. The dietary bioactive compounds as auspicious anticancer agents have been recognized to be active and their implications in the treatment of BC with negligible side effects. Hence, this review focused on various dietary bioactive compounds as potential therapeutic agents in the prevention and treatment of BC with the mechanisms of action. Bioactive compounds have chemo-preventive properties as they inhibit the proliferation of cancer cells, downregulate the expression of estrogen receptors, and cell cycle arrest by inducing apoptotic settings in tumor cells. Therapeutic drugs or natural compounds generally incorporate engineered nanoparticles with ideal sizes, shapes, and enhance their solubility, circulatory half-life, and biodistribution. All data of in vitro, in vivo, and clinical studies of dietary bioactive compounds and their impact on BC were collected from Science Direct, PubMed, and Google Scholar. The data of chemopreventive and anticancer activity of dietary bioactive compounds were collected and orchestrated in a suitable place in the review. These shreds of data will be extremely beneficial to recognize a series of additional diet-derived bioactive compounds to treat BC with the lowest side effects.

Abstract PO-105: Overcoming stromal barriers in PDA with a novel polymeric Toll-like receptor agonist

Abstract The complex tumor microenvironment (TME) of PDA creates a uniquely immune- and drug-privileged sanctuary that contributes to disease pathogenesis and treatment resistance. The profoundly immunosuppressive microenvironment of PDA includes abundant MDSC, Treg, M2-like TAM and a dearth of cytotoxic T-cells. Recent discoveries of highly expressed Toll-like receptors 7 and 8 (TLR7/8) in the desmoplastic stroma of PDA suggest that TLR7/8 agonists may be an effective immune-targeted therapy. TLR7/8 agonists may inhibit tumor growth by any of several mechanisms including myeloid cell reeducation, depletion of MDSC, and/or depletion of Treg, thereby activating cytotoxic CD8+ T cells. However, the circulatory half-life of most TLR7/8 agonists is relatively short, and elevated systemic levels and prolonged treatment can also cause severe adverse reactions that can limit their use and effectiveness. To address these concerns, we have developed a novel polymeric form of a TLR7/8 agonist that exploits a breakthrough synthetic technology to directly polymerize drugs into nanocarriers with defined architectures. These agents are designed to minimize adverse effects and increase efficacy through more favorable pharmacokinetics and enhanced delivery to desmoplastic tumors with release profiles tailorable over the range of days to weeks. This agent is in development in our murine preclinical trials program (MCTP) which is modeled on human clinical trials and involves randomized, blinded, placebo-controlled studies against the current standard-of-care using the KrasLSL-G12D/+;Trp53LSL-R172H/+;p48Cre/+ (KPC) model as our primary platform of the autochthonous disease. Exploratory experiments were performed to determine optimal dose and treatment schedule. KPC mice with ultrasound-imaging documented disease meeting enrollment criteria were subsequently randomized into one of two arms in 28-day pilot studies: control vehicle-treated and polymeric TLR7/8 (n=5-8 animals per arm). Daily health and behavior checks, serial body weight measurements, and complete blood count (CBC) profiles over the course of the study revealed no adverse health effects or overt toxicities. Mice were euthanized at study completion and all organs harvested for histological analyses; single cell suspensions from blood, spleen, peri-pancreatic lymph nodes and primary tumor were analyzed by FACS and/or CyTOF Helios cytometry (incorporating 30+ specific markers and with a particular focus on identifying specific states and subtypes of CD8+ T cells as well as markers of checkpoint activation to assess innate and adaptive immunity in treated versus untreated and tumor versus normal tissues). Preliminary analyses reveal response associated with increases in T cell activation markers and concomitant changes in inhibitory markers. M1 and M2 macrophage populations also appeared to be profoundly affected, suggesting targeting of specific immune cell types and distinct activation states. Citation Format: Christopher C. DuFort, Ciana L. Lopez, Martin C. Whittle, Vladimir Vlaskin, Aditi Vadodkar, Selvi Srinivasan, Patrick S. Stayton, Sunil R. Hingorani. Overcoming stromal barriers in PDA with a novel polymeric Toll-like receptor agonist [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-105.

EXTH-26. LAYER-BY-LAYER NANOPARTICLES DESIGNED FOR DUAL BLOOD-BRAIN BARRIER AND GLIOMA TARGETING

Abstract BACKGROUND While biologically diverse, high grade gliomas (HGGs) have a dismal prognosis in both adults and children. Promising therapeutics have been identified for HGGs based on common genomic alterations and aberrant signaling pathways, but achieving effective drug exposure at the tumor site remains a challenge largely due to the blood-brain barrier (BBB). HYPOTHESIS: A tunable nanocarrier platform can improve nanoparticle delivery across the (BBB) and into glioma cells. METHODS We synthesized layer-by-layer nanoparticles by coating anionic, fluorescent liposomes with nanometers-thick layers of oppositely charged polyelectrolytes, creating a library of organic, nontoxic drug carriers with varied surface chemistries. We characterized the library using dynamic light scattering and quantified interactions with a range of pediatric and adult glioma cell lines using flow cytometry. We used intravital two-photon microscopy to quantify nanoparticle trafficking across the intact BBB through a cranial window in anesthetized mice. RESULTS Nanoparticle surface chemistry strongly influences cellular trafficking in vitro, with two polymers identified as particularly high-performing across brain tumors lines: poly-L-aspartic acid (semi-synthetic) and hyaluronic acid (natural polysaccharide). The addition of the angiopep-2 targeting moiety onto these polymers improved nanoparticle uptake into brain microvascular endothelial cells in vitro without abrogating tumor affinity. We developed a new algorithm to quantify permeability of fluorescent compounds across the BBB in vivo and validated our method by measuring dextran permeability at varied molecular weights. In our initial study in non-tumor-bearing mice (n=12), we successfully quantified nanoparticle permeability across the BBB. In this study, surface functionalization did not increase BBB permeability above the control nanoparticle, though it did improve nanoparticle half-life in circulation and may still impart a therapeutic benefit when loaded with drug. Additional investigations in orthotopic tumor-bearing mice are ongoing. In summary, we report the development of layer-by-layer nanocarriers as a modular drug delivery platform with therapeutic potential for gliomas.