Showing papers on "In vivo published in 2018"

Dependence of Nanoparticle Toxicity on Their Physical and Chemical Properties.

Abstract: Studies on the methods of nanoparticle (NP) synthesis, analysis of their characteristics, and exploration of new fields of their applications are at the forefront of modern nanotechnology. The possibility of engineering water-soluble NPs has paved the way to their use in various basic and applied biomedical researches. At present, NPs are used in diagnosis for imaging of numerous molecular markers of genetic and autoimmune diseases, malignant tumors, and many other disorders. NPs are also used for targeted delivery of drugs to tissues and organs, with controllable parameters of drug release and accumulation. In addition, there are examples of the use of NPs as active components, e.g., photosensitizers in photodynamic therapy and in hyperthermic tumor destruction through NP incorporation and heating. However, a high toxicity of NPs for living organisms is a strong limiting factor that hinders their use in vivo. Current studies on toxic effects of NPs aimed at identifying the targets and mechanisms of their harmful effects are carried out in cell culture models; studies on the patterns of NP transport, accumulation, degradation, and elimination, in animal models. This review systematizes and summarizes available data on how the mechanisms of NP toxicity for living systems are related to their physical and chemical properties.

Development of Quinoline-Based Theranostic Ligands for the Targeting of Fibroblast Activation Protein

Abstract: Fibroblast activation protein (FAP) is overexpressed in cancer-associated fibroblasts and is involved in a variety of tumor-promoting activities such as matrix remodeling, angiogenesis, chemotherapy resistance, and immunosuppression. Because FAP shows low expression in most normal organs, it presents an interesting target for imaging and endoradiotherapy. In this investigation, FAP inhibitors (FAPIs) were modified and optimized for use as theranostic tracers. Methods: FAPIs based on a quinoline structure were synthesized and characterized with respect to binding, internalization, and efflux in cells expressing human and murine FAP as well as CD26. Preclinical pharmacokinetics were determined in tumor-bearing animals with biodistribution experiments and small-animal PET. Finally, a proof-of-concept approach toward imaging and therapy was chosen for 2 patients with metastasized breast cancer. Results: Of 15 synthesized FAPIs, FAPI-04 was identified as the most promising tracer for clinical application. Compared with the previously published ligand, FAPI-02, FAPI-04 showed excellent stability in human serum, higher affinity for FAP as opposed to CD26, and slower excretion in vitro. In vivo, a higher SUV was reached in tumor-bearing animals, leading to larger areas under the curve as calculated from biodistribution experiments. Finally, PET/CT scans with 68Ga-FAPI-04 in 2 patients with metastasized breast cancer revealed high tracer uptake in metastases and a reduction in pain symptoms after therapy with a considerably low dose of 90Y-FAPI-04. Conclusion: FAPI-04 represents a promising tracer for both diagnostic imaging and, possibly, targeted therapy of malignant tumors with a high content of activated fibroblasts, such as breast cancer.

A Tumor-Imaging Method Targeting Cancer-Associated Fibroblasts.

Abstract: The tumor stroma, which accounts for a large part of the tumor mass, represents an attractive target for the delivery of diagnostic and therapeutic compounds. Here, the focus is notably on a subpopulation of stromal cells, known as cancer-associated fibroblasts, which are present in more than 90% of epithelial carcinomas, including pancreatic, colon, and breast cancer. Cancer-associated fibroblasts feature high expression of fibroblast activation protein (FAP), which is not detectable in adult normal tissue but is associated with a poor prognosis in cancer patients. Methods: We developed an iodinated and a DOTA-coupled radiotracer based on a FAP-specific enzyme inhibitor (FAPI) and evaluated them in vitro using uptake, competition, and efflux studies as well as confocal microscopy of a fluorescence-labeled variant. Furthermore, we performed imaging and biodistribution studies on tumor-bearing animals. Finally, proof of concept was realized by imaging patients with 68Ga-labeled FAPI. Results: Both FAPIs showed high specificity, affinity, and rapid internalization into FAP-expressing cells in vitro and in vivo. Biodistribution studies on tumor-bearing mice and on the first cancer patients demonstrated high intratumoral uptake of the tracer and fast body clearance, resulting in high-contrast images and negligible exposure of healthy tissue to radiation. A comparison with the commonly used radiotracer 18F-FDG in a patient with locally advanced lung adenocarcinoma revealed that the new FAP ligand was clearly superior. Conclusion: Radiolabeled FAPIs allow fast imaging with very high contrast in tumors having a high stromal content and may therefore serve as pantumor agents. Coupling of these molecules to DOTA or other chelators allows labeling not only with 68Ga but also with therapeutic isotopes such as 177Lu or 90Y.

Enhancing CAR T cell persistence through ICOS and 4-1BB costimulation.

Abstract: Successful tumor eradication by chimeric antigen receptor-expressing (CAR-expressing) T lymphocytes depends on CAR T cell persistence and effector function. We hypothesized that CD4+ and CD8+ T cells may exhibit distinct persistence and effector phenotypes, depending on the identity of specific intracellular signaling domains (ICDs) used to generate the CAR. First, we demonstrate that the ICOS ICD dramatically enhanced the in vivo persistence of CAR-expressing CD4+ T cells that, in turn, increased the persistence of CD8+ T cells expressing either CD28- or 4-1BB-based CARs. These data indicate that persistence of CD8+ T cells was highly dependent on a helper effect provided by the ICD used to redirect CD4+ T cells. Second, we discovered that combining ICOS and 4-1BB ICDs in a third-generation CAR displayed superior antitumor effects and increased persistence in vivo. Interestingly, we found that the membrane-proximal ICD displayed a dominant effect over the distal domain in third-generation CARs. The optimal antitumor and persistence benefits observed in third-generation ICOSBBz CAR T cells required the ICOS ICD to be positioned proximal to the cell membrane and linked to the ICOS transmembrane domain. Thus, CARs with ICOS and 4-1BB ICD demonstrate increased efficacy in solid tumor models over our current 4-1BB-based CAR and are promising therapeutics for clinical testing.

Oxidized phospholipids are proinflammatory and proatherogenic in hypercholesterolaemic mice

Abstract: Oxidized phospholipids (OxPL) are ubiquitous, are formed in many inflammatory tissues, including atherosclerotic lesions, and frequently mediate proinflammatory changes 1 . Because OxPL are mostly the products of non-enzymatic lipid peroxidation, mechanisms to specifically neutralize them are unavailable and their roles in vivo are largely unknown. We previously cloned the IgM natural antibody E06, which binds to the phosphocholine headgroup of OxPL, and blocks the uptake of oxidized low-density lipoprotein (OxLDL) by macrophages and inhibits the proinflammatory properties of OxPL2-4. Here, to determine the role of OxPL in vivo in the context of atherogenesis, we generated transgenic mice in the Ldlr-/- background that expressed a single-chain variable fragment of E06 (E06-scFv) using the Apoe promoter. E06-scFv was secreted into the plasma from the liver and macrophages, and achieved sufficient plasma levels to inhibit in vivo macrophage uptake of OxLDL and to prevent OxPL-induced inflammatory signalling. Compared to Ldlr-/- mice, Ldlr -/- E06-scFv mice had 57-28% less atherosclerosis after 4, 7 and even 12 months of 1% high-cholesterol diet. Echocardiographic and histologic evaluation of the aortic valves demonstrated that E06-scFv ameliorated the development of aortic valve gradients and decreased aortic valve calcification. Both cholesterol accumulation and in vivo uptake of OxLDL were decreased in peritoneal macrophages, and both peritoneal and aortic macrophages had a decreased inflammatory phenotype. Serum amyloid A was decreased by 32%, indicating decreased systemic inflammation, and hepatic steatosis and inflammation were also decreased. Finally, the E06-scFv prolonged life as measured over 15 months. Because the E06-scFv lacks the functional effects of an intact antibody other than the ability to bind OxPL and inhibit OxLDL uptake in macrophages, these data support a major proatherogenic role of OxLDL and demonstrate that OxPL are proinflammatory and proatherogenic, which E06 counteracts in vivo. These studies suggest that therapies inactivating OxPL may be beneficial for reducing generalized inflammation, including the progression of atherosclerosis, aortic stenosis and hepatic steatosis.

Water-dispersible PEG-curcumin/amine-functionalized covalent organic framework nanocomposites as smart carriers for in vivo drug delivery.

Abstract: Covalent organic frameworks (COFs) as drug-delivery carriers have been mostly evaluated in vitro due to the lack of COFs nanocarriers that are suitable for in vivo studies. Here we develop a series of water-dispersible polymer-COF nanocomposites through the assembly of polyethylene-glycol-modified monofunctional curcumin derivatives (PEG-CCM) and amine-functionalized COFs (APTES-COF-1) for in vitro and in vivo drug delivery. The real-time fluorescence response shows efficient tracking of the COF-based materials upon cellular uptake and anticancer drug (doxorubicin (DOX)) release. Notably, in vitro and in vivo studies demonstrate that PEG-CCM@APTES-COF-1 is a smart carrier for drug delivery with superior stability, intrinsic biodegradability, high DOX loading capacity, strong and stable fluorescence, prolonged circulation time and improved drug accumulation in tumors. More intriguingly, PEG350-CCM@APTES-COF-1 presents an effective targeting strategy for brain research. We envisage that PEG-CCM@APTES-COF-1 nanocomposites represent a great promise toward the development of a multifunctional platform for cancer-targeted in vivo drug delivery.

Biomaterial-assisted targeted modulation of immune cells in cancer treatment

Abstract: The past decade has witnessed the accelerating development of immunotherapies for cancer treatment. Immune checkpoint blockade therapies and chimeric antigen receptor (CAR)-T cell therapies have demonstrated clinical efficacy against a variety of cancers. However, issues including life-threatening off-target side effects, long processing times, limited patient responses and high cost still limit the clinical utility of cancer immunotherapies. Biomaterial carriers of these therapies, though, enable one to troubleshoot the delivery issues, amplify immunomodulatory effects, integrate the synergistic effect of different molecules and, more importantly, home and manipulate immune cells in vivo. In this Review, we will analyse thus-far developed immunomaterials for targeted modulation of dendritic cells, T cells, tumour-associated macrophages, myeloid-derived suppressor cells, B cells and natural killer cells, and summarize the promises and challenges of cell-targeted immunomodulation for cancer treatment.

Thermo-triggered Release of CRISPR-Cas9 System by Lipid-Encapsulated Gold Nanoparticles for Tumor Therapy

Abstract: CRISPR/Cas9 system is a powerful toolbox for gene editing. However, the low delivery efficiency is still a big hurdle impeding its applications. Herein, we report a strategy to deliver Cas9-sgPlk-1 plasmids (CP) by a multifunctional vehicle for tumor therapy. We condensed CPs on TAT peptide-modified Au nanoparticles (AuNPs/CP, ACP) via electrostatic interactions, and coated lipids (DOTAP, DOPE, cholesterol, PEG2000-DSPE) on the ACP to form lipid-encapsulated, AuNPs-condensed CP (LACP). LACP can enter tumor cells and release CP into the cytosol by laser-triggered thermo-effects of the AuNPs; the CP can enter nuclei by TAT guidance, enabling effective knock-outs of target gene (Plk-1) of tumor (melanoma) and inhibition of the tumor both in vitro and in vivo. This AuNPs-condensed, lipid-encapsulated, and laser-controlled delivery system provides a versatile method for high efficiency CRISPR/Cas9 delivery and targeted gene editing for treatment of a wide spectrum of diseases.

In vivo CRISPR editing with no detectable genome-wide off-target mutations

Abstract: CRISPR–Cas genome-editing nucleases hold substantial promise for developing human therapeutic applications1–6 but identifying unwanted off-target mutations is important for clinical translation7. A well-validated method that can reliably identify off-targets in vivo has not been described to date, which means it is currently unclear whether and how frequently these mutations occur. Here we describe ‘verification of in vivo off-targets’ (VIVO), a highly sensitive strategy that can robustly identify the genome-wide off-target effects of CRISPR–Cas nucleases in vivo. We use VIVO and a guide RNA deliberately designed to be promiscuous to show that CRISPR–Cas nucleases can induce substantial off-target mutations in mouse livers in vivo. More importantly, we also use VIVO to show that appropriately designed guide RNAs can direct efficient in vivo editing in mouse livers with no detectable off-target mutations. VIVO provides a general strategy for defining and quantifying the off-target effects of gene-editing nucleases in whole organisms, thereby providing a blueprint to foster the development of therapeutic strategies that use in vivo gene editing. A strategy developed to define off-target effects of gene-editing nucleases in whole organisms is validated and leveraged to show that CRISPR–Cas9 nucleases can be used effectively in vivo without inducing detectable off-target mutations.

Ionic liquids for oral insulin delivery.

Abstract: With the rise in diabetes mellitus cases worldwide and lack of patient adherence to glycemia management using injectable insulin, there is an urgent need for the development of efficient oral insulin formulations. However, the gastrointestinal tract presents a formidable barrier to oral delivery of biologics. Here we report the development of a highly effective oral insulin formulation using choline and geranate (CAGE) ionic liquid. CAGE significantly enhanced paracellular transport of insulin, while protecting it from enzymatic degradation and by interacting with the mucus layer resulting in its thinning. In vivo, insulin-CAGE demonstrated exceptional pharmacokinetic and pharmacodynamic outcome after jejunal administration in rats. Low insulin doses (3–10 U/kg) brought about a significant decrease in blood glucose levels, which were sustained for longer periods (up to 12 hours), unlike s.c. injected insulin. When 10 U/kg insulin-CAGE was orally delivered in enterically coated capsules using an oral gavage, a sustained decrease in blood glucose of up to 45% was observed. The formulation exhibited high biocompatibility and was stable for 2 months at room temperature and for at least 4 months under refrigeration. Taken together, the results indicate that CAGE is a promising oral delivery vehicle and should be further explored for oral delivery of insulin and other biologics that are currently marketed as injectables.

A macromolecular approach to eradicate multidrug resistant bacterial infections while mitigating drug resistance onset

Abstract: Polymyxins remain the last line treatment for multidrug-resistant (MDR) infections. As polymyxins resistance emerges, there is an urgent need to develop effective antimicrobial agents capable of mitigating MDR. Here, we report biodegradable guanidinium-functionalized polycarbonates with a distinctive mechanism that does not induce drug resistance. Unlike conventional antibiotics, repeated use of the polymers does not lead to drug resistance. Transcriptomic analysis of bacteria further supports development of resistance to antibiotics but not to the macromolecules after 30 treatments. Importantly, high in vivo treatment efficacy of the macromolecules is achieved in MDR A. baumannii-, E. coli-, K. pneumoniae-, methicillin-resistant S. aureus-, cecal ligation and puncture-induced polymicrobial peritonitis, and P. aeruginosa lung infection mouse models while remaining non-toxic (e.g., therapeutic index-ED50/LD50: 1473 for A. baumannii infection). These biodegradable synthetic macromolecules have been demonstrated to have broad spectrum in vivo antimicrobial activity, and have excellent potential as systemic antimicrobials against MDR infections.

Antibiotic-loaded nanoparticles targeted to the site of infection enhance antibacterial efficacy.

Abstract: Bacterial resistance to antibiotics has made it necessary to resort to using antibacterial drugs that have considerable toxicities. Here, we show that conjugation of vancomycin-loaded nanoparticles with the cyclic 9-amino-acid peptide CARGGLKSC (CARG), identified via phage display on Staphylococcus aureus (S. aureus) bacteria and through in vivo screening in mice with S. aureus-induced lung infections, increases the antibacterial activity of the nanoparticles in S. aureus-infected tissues and reduces the systemic dose needed, minimizing side effects. CARG binds specifically to S. aureus bacteria but not Pseudomonas bacteria in vitro, selectively accumulates in S. aureus-infected lungs and skin of mice but not in non-infected tissue and Pseudomonas-infected tissue, and significantly enhances the accumulation of intravenously injected vancomycin-loaded porous silicon nanoparticles bearing CARG in S. aureus-infected mouse lung tissue. The targeted nanoparticles more effectively suppress staphylococcal infections in vivo relative to equivalent doses of untargeted vancomycin nanoparticles or of free vancomycin. The therapeutic delivery of antibiotic-carrying nanoparticles bearing peptides targeting infected tissues may help combat difficult-to-treat infections. Nanoparticles carrying an antibiotic and conjugated with a peptide identified via phage display that binds specifically to Staphylococcus aureus effectively suppress staphylococcal infections in vivo.

Preconditioning influences mesenchymal stem cell properties in vitro and in vivo

Abstract: Various diseases and toxic factors easily impair cellular and organic functions in mammals. Organ transplantation is used to rescue organ function, but is limited by scarce resources. Mesenchymal stem cell (MSC)-based therapy carries promising potential in regenerative medicine because of the self-renewal and multilineage potency of MSCs; however, MSCs may lose biological functions after isolation and cultivation for a long time in vitro. Moreover, after they are injected in vivo and migrate into the damaged tissues or organs, they encounter a harsh environment coupled with death signals due to the inadequate tensegrity structure between the cells and matrix. Preconditioning, genetic modification and optimization of MSC culture conditions are key strategies to improve MSC functions in vitro and in vivo, and all of these procedures will contribute to improving MSC transplantation efficacy in tissue engineering and regenerative medicine. Preconditioning with various physical, chemical and biological factors is possible to preserve the stemness of MSCs for further application in studies and clinical tests. In this review, we mainly focus on preconditioning and the corresponding mechanisms for improving MSC activities in vitro and in vivo; we provide a glimpse into the promotion of MSC-based cell therapy development for regenerative medicine. As a promising consequence, MSC transplantation can be applied for the treatment of some terminal diseases and can prolong the survival time of patients in the near future.

Neutrophil-Based Drug Delivery Systems

Abstract: White blood cells (WBCs) are a major component of immunity in response to pathogen invasion. Neutrophils are the most abundant WBCs in humans, playing a central role in acute inflammation induced by pathogens. Adhesion to vasculature and tissue infiltration of neutrophils are key processes in acute inflammation. Many inflammatory/autoimmune disorders and cancer therapies have been found to be involved in activation and tissue infiltration of neutrophils. A promising strategy to develop novel targeted drug delivery systems is the targeting and exploitation of activated neutrophils. Herein, a new drug delivery platform based on neutrophils is reviewed. There are two types of drug delivery systems: neutrophils as carriers and neutrophil-membrane-derived nanovesicles. It is discussed how nanoparticles hijack neutrophils in vivo to deliver therapeutics across blood vessel barriers and how neutrophil-membrane-derived nanovesicles target inflamed vasculature. Finally, the potential applications of neutrophil-based drug delivery systems in treating inflammation and cancers are presented.

In vivo simultaneous transcriptional activation of multiple genes in the brain using CRISPR-dCas9-activator transgenic mice

Abstract: Despite rapid progresses in the genome-editing field, in vivo simultaneous overexpression of multiple genes remains challenging. We generated a transgenic mouse using an improved dCas9 system that enables simultaneous and precise in vivo transcriptional activation of multiple genes and long noncoding RNAs in the nervous system. As proof of concept, we were able to use targeted activation of endogenous neurogenic genes in these transgenic mice to directly and efficiently convert astrocytes into functional neurons in vivo. This system provides a flexible and rapid screening platform for studying complex gene networks and gain-of-function phenotypes in the mammalian brain.

In vitro and in vivo characterization of the JAK1 selectivity of upadacitinib (ABT-494)

Abstract: Anti-cytokine therapies such as adalimumab, tocilizumab, and the small molecule JAK inhibitor tofacitinib have proven that cytokines and their subsequent downstream signaling processes are important in the pathogenesis of rheumatoid arthritis. Tofacitinib, a pan-JAK inhibitor, is the first approved JAK inhibitor for the treatment of RA and has been shown to be effective in managing disease. However, in phase 2 dose-ranging studies tofacitinib was associated with dose-limiting tolerability and safety issues such as anemia. Upadacitinib (ABT-494) is a selective JAK1 inhibitor that was engineered to address the hypothesis that greater JAK1 selectivity over other JAK family members will translate into a more favorable benefit:risk profile. Upadacitinib selectively targets JAK1 dependent disease drivers such as IL-6 and IFNγ, while reducing effects on reticulocytes and natural killer (NK) cells, which potentially contributed to the tolerability issues of tofacitinib. Structure-based hypotheses were used to design the JAK1 selective inhibitor upadacitinib. JAK family selectivity was defined with in vitro assays including biochemical assessments, engineered cell lines, and cytokine stimulation. In vivo selectivity was defined by the efficacy of upadacitinib and tofacitinib in a rat adjuvant induced arthritis model, activity on reticulocyte deployment, and effect on circulating NK cells. The translation of the preclinical JAK1 selectivity was assessed in healthy volunteers using ex vivo stimulation with JAK-dependent cytokines. Here, we show the structural basis for the JAK1 selectivity of upadacitinib, along with the in vitro JAK family selectivity profile and subsequent in vivo physiological consequences. Upadacitinib is ~ 60 fold selective for JAK1 over JAK2, and > 100 fold selective over JAK3 in cellular assays. While both upadacitinib and tofacitinib demonstrated efficacy in a rat model of arthritis, the increased selectivity of upadacitinib for JAK1 resulted in a reduced effect on reticulocyte deployment and NK cell depletion relative to efficacy. Ex vivo pharmacodynamic data obtained from Phase I healthy volunteers confirmed the JAK1 selectivity of upadactinib in a clinical setting. The data presented here highlight the JAK1 selectivity of upadacinitinib and supports its use as an effective therapy for the treatment of RA with the potential for an improved benefit:risk profile.

Advances in siRNA delivery in cancer therapy.

Abstract: RNA interference (RNAi)-based therapeutic approaches are under vibrant scrutinisation to seek cancer cure. siRNA suppress expression of the carcinogenic genes by targeting the mRNA expression. However, in vivo systemic siRNA therapy is hampered by the barriers such as poor cellular uptake, instability under physiological conditions, off-target effects and possible immunogenicity. To overcome these challenges, systemic siRNA therapy warrants the development of clinically suitable, safe, and effective drug delivery systems. Herein, we review the barriers, potential siRNA drug delivery systems, and application of siRNA in clinical trials for cancer therapy. Further research is required to harness the full potential of siRNA as a cancer therapeutic.

Restoration of tumour-growth suppression in vivo via systemic nanoparticle-mediated delivery of PTEN mRNA.

Abstract: Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a well-characterized tumour-suppressor gene that is lost or mutated in about half of metastatic castration-resistant prostate cancers and in many other human cancers The restoration of functional PTEN as a treatment for prostate cancer has, however, proven difficult Here, we show that PTEN messenger RNA (mRNA) can be reintroduced into PTEN-null prostate cancer cells in vitro and in vivo via its encapsulation in polymer-lipid hybrid nanoparticles coated with a polyethylene glycol shell The nanoparticles are stable in serum, elicit low toxicity and enable high PTEN mRNA transfection in prostate cancer cells Moreover, significant inhibition of tumour growth is achieved when delivered systemically in multiple mouse models of prostate cancer We also show that the restoration of PTEN function in PTEN-null prostate cancer cells inhibits the phosphatidylinositol 3-kinase (PI3K)-AKT pathway and enhances apoptosis Our findings provide proof-of-principle evidence of the restoration of mRNA-based tumour suppression in vivo

Enrichment-triggered prodrug activation demonstrated through mitochondria-targeted delivery of doxorubicin and carbon monoxide

Abstract: Controlled activation is a critical component in prodrug development. Here we report a concentration-sensitive platform approach for bioorthogonal prodrug activation by taking advantage of reaction kinetics. Using two ‘click and release’ systems, we demonstrate enrichment and prodrug activation specifically in mitochondria to demonstrate the principle of the approach. In both cases, the payload (doxorubicin or carbon monoxide) was released inside the mitochondrial matrix following the enrichment-initiated click reaction. Furthermore, mitochondria-targeted delivery yielded substantial augmentation of functional biological and therapeutic effects in vitro and in vivo when compared to controls, which did not result in enrichment. This method is thus a platform for targeted drug delivery that is amenable to conjugation with a variety of molecules and is not limited to cell-surface delivery. Taken together, these two 'click and release' pairs clearly demonstrate the concept of enrichment-triggered drug release and the critical feasibility of treating clinically relevant diseases such as acute liver injury and cancer.

Low-Dose X-ray Activation of W(VI)-Doped Persistent Luminescence Nanoparticles for Deep-Tissue Photodynamic Therapy

Abstract: Although photodynamic therapy (PDT) has served as an important strategy for treatment of various diseases, it still experiences many challenges, such as shallow penetration of light, high-dose light irradiation, and low therapy efficiency in deep tissue. Here, a low-dose X-ray-activated persistent luminescence nanoparticle (PLNP)-mediated PDT nanoplatform for depth-independent and repeatable cancer treatment has been reported. In order to improve therapeutic efficiency, this study first synthesizes W(VI)-doped ZnGa2O4:Cr PLNPs with stronger persistent luminescence intensity and longer persistent luminescence time than traditional ZnGa2O4:Cr PLNPs. The proposed PLNPs can serve as a persistent excitation light source for PDT, even after X-ray irradiation has been removed. Both in vitro and in vivo experiments demonstrate that low-dose (0.18 Gy) X-ray irradiation is sufficient to activate the PDT nanoplatform and causes significant inhibitory effect on tumor progression. Therefore, such PDT nanoplatform will provide a promising depth-independent treatment mode for clinical cancer therapy in the future.

A New Approach for Loading Anticancer Drugs Into Mesenchymal Stem Cell-Derived Exosome Mimetics for Cancer Therapy.

Abstract: Exosomes derived from mesenchymal stem cells (MSCs) have been evaluated for their potential to be used as drug delivery vehicles. Synthetically personalized exosome mimetics (EMs) could be the alternative vesicles for drug delivery. In this study, we aimed to isolate EMs from human MSCs. Cells were mixed with paclitaxel (PTX) and PTX-loaded EMs (PTX-MSC-EMs) were isolated and evaluated for their anticancer effects against breast cancer. EMs were isolated from human bone marrow-derived MSCs. MSCs (4 × 106 cells/mL) were mixed with or without PTX at different concentrations in phosphate-buffered saline (PBS) and serially extruded through 10-, 5-, and 1-μm polycarbonate membrane filters using a mini-extruder. MSCs were centrifuged to remove debris and the supernatant was filtered through a 0.22-μm filter, followed by ultracentrifugation to isolate EMs and drug-loaded EMs. EMs without encapsulated drug (MSC-EMs) and those with encapsulated PTX (PTX-MSC-EMs) were characterized by western blotting, nanoparticle tracking analysis (NTA), and transmission electron microscopy (TEM). The anticancer effects of MSC-EMs and PTX-MSC-EMs were assessed with breast cancer (MDA-MB-231) cells both in vitro and in vivo using optical imaging. EMs were isolated by the extrusion method and ultracentrifugation. The isolated vesicles were positive for membrane markers (ALIX and CD63) and negative for golgi (GM130) and endoplasmic (calnexin) marker proteins. NTA revealed the size of MSC-EM to be around 149 nm, while TEM confirmed its morphology. PTX-MSC-EMs significantly (p < 0.05) decreased the viability of MDA-MB-231 cells in vitro at increasing concentrations of EM. The in vivo tumor growth was significantly inhibited by PTX-MSC-EMs as compared to control and/or MSC-EMs. Thus, MSC-EMs were successfully isolated using simple procedures and drug-loaded MSC-EMs were shown to be therapeutically efficient for the treatment of breast cancer both in vitro and in vivo. MSC-EMs may be used as drug delivery vehicles for breast cancers.

Cooperative targeting of melanoma heterogeneity with an AXL antibody-drug conjugate and BRAF/MEK inhibitors.

Abstract: Intratumor heterogeneity is a key factor contributing to therapeutic failure and, hence, cancer lethality. Heterogeneous tumors show partial therapy responses, allowing for the emergence of drug-resistant clones that often express high levels of the receptor tyrosine kinase AXL. In melanoma, AXL-high cells are resistant to MAPK pathway inhibitors, whereas AXL-low cells are sensitive to these inhibitors, rationalizing a differential therapeutic approach. We developed an antibody-drug conjugate, AXL-107-MMAE, comprising a human AXL antibody linked to the microtubule-disrupting agent monomethyl auristatin E. We found that AXL-107-MMAE, as a single agent, displayed potent in vivo anti-tumor activity in patient-derived xenografts, including melanoma, lung, pancreas and cervical cancer. By eliminating distinct populations in heterogeneous melanoma cell pools, AXL-107-MMAE and MAPK pathway inhibitors cooperatively inhibited tumor growth. Furthermore, by inducing AXL transcription, BRAF/MEK inhibitors potentiated the efficacy of AXL-107-MMAE. These findings provide proof of concept for the premise that rationalized combinatorial targeting of distinct populations in heterogeneous tumors may improve therapeutic effect, and merit clinical validation of AXL-107-MMAE in both treatment-naive and drug-resistant cancers in mono- or combination therapy.

Constitutive and TNFα-inducible expression of chondroitin sulfate proteoglycan 4 in glioblastoma and neurospheres: Implications for CAR-T cell therapy

Abstract: The heterogeneous expression of tumor-associated antigens limits the efficacy of chimeric antigen receptor (CAR)-redirected T cells (CAR-Ts) for the treatment of glioblastoma (GBM). We have found that chondroitin sulfate proteoglycan 4 (CSPG4) is highly expressed in 67% of the GBM specimens with limited heterogeneity. CSPG4 is also expressed on primary GBM-derived cells, grown in vitro as neurospheres (GBM-NS), which recapitulate the histopathology and molecular characteristics of primary GBM. CSPG4.CAR-Ts efficiently controlled the growth of GBM-NS in vitro and in vivo upon intracranial tumor inoculation. Moreover, CSPG4.CAR-Ts were also effective against GBM-NS with moderate to low expression of CSPG4. This effect was mediated by the in vivo up-regulation of CSPG4 on tumor cells, induced by tumor necrosis factor-α (TNFα) released by the microglia surrounding the tumor. Overall, the constitutive and TNFα-inducible expression of CSPG4 in GBM may greatly reduce the risk of tumor cell escape observed when targeted antigens are heterogeneously expressed on tumor cells.

Biodegradable, Hydrogen Peroxide, and Glutathione Dual Responsive Nanoparticles for Potential Programmable Paclitaxel Release

Abstract: Reactive oxygen species (ROS) and glutathione (GSH) dual responsive nanoparticulate drug delivery systems (nano-DDSs) hold great promise to improve the therapeutic efficacy and alleviate the side effects of chemo drugs in cancer theranosis. Herein, hydrogen peroxide (H2O2) and GSH dual responsive thioketal nanoparticle (TKN) was rationally designed for paclitaxel (PTX) delivery. Compared to other stimuli-sensitive nano-DDSs, this dual responsive DDS is not only sensitive to biologically relevant H2O2 and GSH for on-demand drug release but also biodegradable into biocompatible byproducts after fulfilling its delivering task. Considering the heterogeneous redox potential gradient, the PTX loaded TKNs (PTX-TKNs) might first respond to the extracellular ROS and then to the intracellular GSH, achieving a programmable release of PTX at the tumor site. The selective toxicity of PTX-TKNs to tumor cells with high levels of ROS and GSH was verified both in vitro and in vivo.

Exosome-mediated delivery of functionally active miRNA-142-3p inhibitor reduces tumorigenicity of breast cancer in vitro and in vivo.

Abstract: Background Exosomes, widely recognized natural nanovesicles, represent one of the recently discovered modes of intercellular communication due to their ability to transmit crucial cellular information that can be engineered to have robust delivery and targeting capacity. MiR-142-3p, one of the upregulated microRNAs (miRNAs) in many types of breast cancer, activates the canonical Wnt signaling pathway and transactivates the miR-150 expression, and results in the hyperproliferation of cancer cells in vitro and mammary glands in vivo. Materials and methods In this study, we exploited the exosomes isolated from bone marrow-derived mesenchymal stem cells (MSCs-Exo) to deliver LNA (locked nucleic acid)-modified anti-miR-142-3p oligonucleotides to suppress the expression level of miR-142-3p and miR-150 in 4T1 and TUBO breast cancer cell lines. Results The in vitro results showed that the MSCs-Exo can efficiently deliver anti-miR-142-3p to reduce the miR-142-3p and miR-150 levels and increase the transcription of the regulatory target genes, APC and P2X7R. We also evaluated in vivo distribution of the MSCs-Exo in tumor-bearing mice. The in vivo result indicated that MSCs-Exo can penetrate the tumor site and are suitable nanovehicles to deliver the inhibitory oligonucleotides into the tumor tissues to downregulate the expression levels of miR-142-3p and miR-150. Conclusion We showed that MSCs-derived exosomes could be used as a feasible nanovehicle to deliver drug molecules like LNA-anti-miR-142-3p in both in vitro and in vivo studies.