Experiments In Tumor-bearing Mice Research Articles

Polydopamine-activated celastrol carbon dots for synergistic chemotherapy-photothermal therapy of tumors

Synergistic chemotherapy and photothermal therapy (PTT) holds the promise of addressing the weakness of individualized chemotherapy and PTT. In this study, we synthesized a chemotherapeutic agent, PDA-Ce-CDs, which combines the photothermal conversion ability and the generation of hydroxyl radicals (•OH), enabling synergistic enhancement of antitumor effects. Furthermore, the localized heating effect of NIR radiation promoted the uptake of the PDA-Ce-CDs and enhances the sensitivity of intracellular reactive oxygen species (ROS). Finally, the antitumor activity of the PDA-Ce-CDs was evaluated through cell experiments and tumor-bearing mice experiments, confirming its excellent antitumor efficacy in vivo and in vitro. Our work presents a new strategy in cancer treatment by utilizing carbon dots in combination with photothermal agents for synergistic chemotherapy-photothermal therapy. This innovative approach offers a new therapeutic avenue for synergistic tumor treatment by harnessing the combined effects of photothermal therapy and chemotherapy.

Synthesis, 123I-Radiolabeling Optimization, and Initial Preclinical Evaluation of Novel Urea-Based PSMA Inhibitors with a Tributylstannyl Prosthetic Group in Their Structures.

Prostate-specific membrane antigen (PSMA) has been identified as a target for the development of theranostic agents. In our current work, we describe the design and synthesis of novel N-[N-[(S)-1,3-dicarboxypropyl]carbamoyl]-(S)-L-lysine (DCL) urea-based PSMA inhibitors with a chlorine-substituted aromatic fragment at the lysine ε-nitrogen atom, a dipeptide including two phenylalanine residues in the L-configuration as the peptide fragment of the linker, and 3- or 4-(tributylstannyl)benzoic acid as a prosthetic group in their structures for radiolabeling. The standard compounds [127I]PSMA-m-IB and [127I]PSMA-p-IB for comparative and characterization studies were first synthesized using two alternative synthetic approaches. An important advantage of the alternative synthetic approach, in which the prosthetic group (NHS-activated esters of compounds) is first conjugated with the polypeptide sequence followed by replacement of the Sn(Bu)3 group with radioiodine, is that the radionuclide is introduced in the final step of synthesis, thereby minimizing operating time with iodine-123 during the radiolabeling process. The obtained DCL urea-based PSMA inhibitors were radiolabeled with iodine-123. The radiolabeling optimization results showed that the radiochemical yield of [123I]PSMA-p-IB was higher than that of [123I]PSMA-m-IB, which were 74.9 ± 1.0% and 49.4 ± 1.2%, respectively. The radiochemical purity of [123I]PSMA-p-IB after purification was greater than 99.50%. The initial preclinical evaluation of [123I]PSMA-p-IB demonstrated a considerable affinity and specific binding to PC-3 PIP (PSMA-expressing cells) in vitro. The in vivo biodistribution of this new radioligand [123I]PSMA-p-IB showed less accumulation than [177Lu]Lu-PSMA-617 in several normal organs (liver, kidney, and bone). These results warrant further preclinical development, including toxicology evaluation and experiments in tumor-bearing mice.

Astatine-211-labeled aza-vesamicol derivatives as sigma receptor ligands for targeted alpha therapy

IntroductionAs sigma receptors are abundantly expressed on different types of cancer cells, several radiolabeled sigma receptor ligands have been developed for cancer imaging and therapy. Previously, we synthesized and evaluated radioiodinated aza-vesamicol derivatives, [125I]pIC3NV, [125I]mIC2N5V, and [125I]mIC3N5V. They accumulated in tumors, and [125I]mIC2N5V and [125I]mIC3N5V showed higher tumor to non-target tissue ratios than [125I]pIC3NV. Therefore, we synthesized and evaluated the corresponding 211At-labeled compounds, [211At]mAtC2N5V and [211At]mAtC3N5V, for targeted alpha therapy (TAT). Methods[211At]mAtC2N5V and [211At]mAtC3N5V were prepared by the standard method of electrophilic astatodestannylation of the corresponding trimethylstannyl precursors. Cellular uptake experiments, and biodistribution experiments and therapeutic experiments in tumor-bearing mice were performed. ResultsThe radiochemical yields of [211At]mAtC2N5V and [211At]mAtC3N5V were 45.5 ± 14.4% and 56.9 ± 13.8%, respectively. After HPLC purification, their radiochemical purities were over 95%.[211At]mAtC2N5V and [211At]mAtC3N5V showed high uptake in DU-145 cells. They demonstrated high accumulation in tumors (6.9 ± 1.4%injected dose/g and 5.1 ± 1.4%injected dose/g at 1 h, respectively) and similar biodistribution tendencies compared with the corresponding 125I-labeled compounds. A single injection of [211At]mAtC2N5V (0.48 MBq) or [211At]mAtC3N5V (0.48 MBq) significantly inhibited tumor growth. ConclusionThese results indicated that [211At]mAtC2N5V and [211At]mAtC3N5V could be potential candidates for TAT.

Abstract 1272: Aberrantly exposed phosphatidylserine as a drug delivery target in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDA) has risen to become the 3rd leading cause of cancer related deaths in the United States with a 5-year survival rate of 11% and a median survival of just 4-6 months. PDA is notoriously chemo-resistant and has shown little to no sensitivity to the current immune checkpoint blockade therapy. A novel marker for the tumor microenvironment is phosphatidylserine, first characterized as a selective marker of tumor vasculature. Phosphatidylserine (PS) is a phospholipid exposed on the outer leaflet of the plasma membrane of tumor associated endothelial cells, apoptotic tumor cells, and some viable tumor cells, where it functions to suppress the immune response. Exposed PS drives immunosuppression by binding to PS receptors expressed on tumor-infiltrating macrophages and dendritic cells. To this point, PS has been targeted with antibodies, such as Bavituximab, that have shown excellent specificity for tumor vasculature and an immune stimulatory environment evidence by polarization of macrophages to a pro-inflammatory M1-like phenotype, a reduction in myeloid-derived suppressor cells, enhanced maturation of dendritic cells and increased primed T cell activity. We have advanced this concept by developing the next generation of PS targeting agent, a fusion protein (betabody) that exploits the PS-binding domain of β2-glycoprotein 1 (β2GP1), an abundant serum protein that binds PS. Betabodies were constructed by fusing domain V of β2GP1 to the Fc of an IgG2a. Betabodies are smaller than full length antibodies (~85 kDa vs 150 kDa), have good affinity for PS (~1 nM) and bind directly to PS. We have demonstrated that betabodies bind specifically to externalized PS through ELISA, ICC and flow cytometry. We established that betabodies localize robustly and specifically to the tumor microenvironment through in vivo localization experiments in tumor-bearing mice. Further studies will exploit the specificity of betabodies to deliver novel microtubule-disrupting agents to exposed PS in the microenvironment of PDA. Because betabodies are internalized inefficiently, therapeutic payloads will be linked to betabodies via enzyme cleavable linkers. This first-in-class tumor targeting therapeutic has potential to provide efficacy in therapy-resistant pancreatic tumors. In addition, similarly to PS targeting antibodies, preliminary data in vitro has shown that treatment of both bone marrow derived macrophages and Raw 264.7 with the unconjugated betabodies repolarize M2 macrophages to a M1 phenotype. The mechanism of action has not yet been fully elucidated; however, it may involve the interaction between the β2GP1 domains and endogenous LPS. This first-in-class tumor targeting therapeutic has potential to provide efficacy in therapy-resistant pancreatic tumors via targeted drug delivery as well as modulation of the immuno-microenvironment like its PS targeting predecessors. Citation Format: Natalie Zara Phinney, Xianming Huang, Mary Lynn Trawick, Kevin Pinney, Rolf Brekken. Aberrantly exposed phosphatidylserine as a drug delivery target in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1272.

RGD Peptide-Conjugated Dodecaborate with the Ga-DOTA Complex: A Preliminary Study for the Development of Theranostic Agents for Boron Neutron Capture Therapy and Its Companion Diagnostics.

A boron neutron capture therapy (BNCT) system, using boron-10-introduced agents coupled with companion diagnostics, is anticipated as a promising cancer theranostic. Thus, this study aimed to synthesize and evaluate a probe closo-dodecaborate-(Ga-DOTA)-c(RGDfK) (16) [Ga = gallium, DOTA =1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, and c(RGDfK) = cyclo(arginine-glycine-aspartate-d-phenylalanine-lysine] containing closo-dodecaborate ([B12H12]2-) as a boron cluster, a [67Ga]Ga-DOTA derivative for nuclear medicine imaging, and an RGD peptide for tumor targeting. Moreover, we prepared a radioiodinated probe [125I]17 in which I-125 is introduced into a closo-dodecaborate moiety of 16. [67Ga]16 and [125I]17 showed high stability and high uptake in cancer cells in vitro. Biodistribution experiments in tumor-bearing mice revealed similar biodistribution patterns between [67Ga]16 and [125I]17, such as a high uptake in the tumor and a low uptake in other non-target tissues. Meanwhile, [125I]17 exhibited higher accumulation in most tissues, including the tumor, than [67Ga]16, probably because of higher albumin binding. The higher the [125I]17 accumulation in the tumor, the more desirable it is for BNCT, with the possibility that the iodo-closo-dodecaborate site may work as an albumin binder.

Octenyl-succinylated inulins for the delivery of hydrophobic drug

The efficacy of hydrophobic anticancer drugs is limited by their poor solubility in water, inefficient target delivery, and toxic side effects. In this work, doxorubicin (DOX) was solubilized using OSA-inulins which created micellar aggregates in aqueous solution above a critical concentration. In vitro delivery of OSA-inulin-DOX micelles resulted in strong inhibition of the growth of MCF-7 breast cancer cells as compared to free DOX. They also displayed a faster cellular uptake rate, indicating that the micelles were promptly internalized into the cells through CD44 receptor-mediated endocytosis. During in vivo tumor suppression experiments in tumor-bearing mice, the OSA-inulin-DOX micelles strongly hindered tumor growth and showed substantially lower systemic toxicity compared with free DOX. Our achievements demonstrate that OSA-inulin has great potential for the encapsulating, dissolving, and targeted delivery of hydrophobic drugs, especially antitumor drugs, for nutraceutical, medical, and pharmaceutical applications.

FSCN1 Promotes Esophageal Carcinoma Progression Through Downregulating PTK6 via its RNA-Binding Protein Effect.

Objective: Esophageal squamous cell carcinoma (ESCC) causes many deaths worldwide every year. Fascin actin-bundling protein 1(FSCN1) has been reported to be a promoter of ESCC via its actin-binding function, however, its new role as an RNA-binding protein (RBP) has not been investigated. Here, we explored the RBP role of FSCN1 in the development of ESCC. Methods: Whole-genome expression sequencing was performed to screen for altered genes after FSCN1 knockdown. RNA immunoprecipitation was performed to determine the target mRNA of FSCN1 as an RBP. In vitro experiments with ECA-109 and KYSE-150 and ex vivo experiments in tumor-bearing mice were performed to investigate the effects of FSCN1 and Protein Tyrosine Kinase 6 (PTK6) on ESCC progression. Results: FSCN1 could downregulate mRNA and the protein level of PTK6. The binding position of PTK6 (PTK6-T2) pre-mRNA to FSCN1 was determined. PTK6-T2 blocked the binding between FSCN1 and the pre-mRNA of PTK6, and thus reversed the promotion effect of FSCN1 on ESCC tumor progression via the AKT/GSK3β signaling pathway. Conclusion: A novel effect of FSCN1, RBP-binding with the pre-mRNA of PTK6, was confirmed to play an important role in ESCC progression. PTK6-T2, which is a specific inhibitor of FSCN1 binding to the pre-mRNA of PTK6, could impede the development of ESCC.

Anisotropic plasmonic Pd-tipped Au nanorods for near-infrared light-activated photoacoustic imaging guided photothermal-photodynamic cancer therapy.

The integration of photothermal therapy (PTT) and photodynamic therapy (PDT) has become a promising cancer treatment method. Herein, anisotropic metal hetero-nanostructure Pd-tipped Au nanorods (PTA NRs) were fabricated, which exhibit plasmon-enhanced photothermal performance under near-infrared laser irradiation. Due to their anisotropic nanostructure, PTA NRs promote the generation of energetic hot electrons and prolong the separation time of electrons and holes. The hot electrons could generate heat energy through the electron-phonon relaxation process and produce reactive oxygen species through energy and electron transformation processes. Because of their high NIR absorption cross-section, as well as good photostability, PTA NRs can be used for NIR-activated photoacoustic imaging-guided PTT-PDT combination cancer therapy. Experiments in tumor-bearing mice proved that PTA NRs exhibit excellent anti-tumor effects, with little side effects on normal organs, making them promising for NIR cancer phototherapy.

Design, synthesis and evaluation of PD-L1 peptide antagonists as new anticancer agents for immunotherapy

Blocking the interaction of programmed cell death protein 1 (PD-1) and its ligand PD-L1 is known as a promising immunotherapy for treatment of a variety of tumors expressing PD-L1 on their cell surface. In the last decade, several antibodies against the PD-1/PD-L1 interaction have been approved, while there are few reports of small-molecule inhibitors against PD-1/PD-L1 axis. Due to many advantages of cancer treatment with small molecules over antibodies, we developed several peptidic PD-L1 antagonists using computational peptide design methods, and evaluated them both in vitro and in vivo. Importantly, among six peptides with best affinity to PD-L1, four peptides exhibited significant potency to block PD-1/PD-L1 axis at molecular level. Moreover, the PD-L1 expression in nine human colorectal cancer cell lines stimulated with interferon-γ was compared and LoVo cells with the highest expression were selected for further experiments. The peptides could also restore the function of activated Jurkat T cells, which had been suppressed by stimulated LoVo cells. A blockade assay in tumor-bearing mice experiments indicated that peptides HS5 and HS6 consisting of a d-amino acid in their structures, could also effectively reduce tumor growth in vivo, without induction of any observable liver or renal toxicity, tissue damages and loss of body weight. As new designed peptides showed no toxicity against murine colon cancer cells in vitro, the observed anti-tumor results in mice are most probably due to disrupting the PD-1/PD-L1 interaction. Thus, peptides described in this study can be considered as proper low molecular weight candidates for immunotherapy of cancer.

Sortase-Mediated Site-Specific Modification of Interleukin-2 for the Generation of a Tumor-Targeting Acetazolamide-Cytokine Conjugate.

Small ligands specific to tumor-associated antigens can be used as alternatives to antibodies for the delivery of small payloads such as radionuclides, cytotoxic drugs, and fluorophores. Their use as a delivery moiety of bioactive proteins such as cytokines remains largely unexplored. Here, we describe the preparation and in vivo characterization of the first small molecule–cytokine conjugate targeting carbonic anhydrase IX (CAIX), a marker of renal cell carcinoma and hypoxia. Site-specific conjugation between interleukin-2 and acetazolamide was obtained by sortase A-mediated transpeptidation. Binding of the conjugate to the cognate CAIX antigen was confirmed by surface plasmon resonance. The in vivo targeting of structures expressing carbonic anhydrase IX was assessed by biodistribution experiments in tumor-bearing mice. Optimization of manufacturability and tumor-targeting performance of acetazolamide–cytokine products will be required in order to enable industrial applications.

Ag/Pd bimetal nanozyme with enhanced catalytic and photothermal effects for ROS/hyperthermia/chemotherapy triple-modality antitumor therapy

We prepared an Ag/Pd bimetallic nanozyme with the peroxidase-like activity as a nanocarrier to load doxorubicin (DOX). It combines photothermal conversion ability and catalytic production of hydroxyl radicals (HO•) to achieve enhanced antitumor effects. The temperature rise under near-infrared (NIR) laser irradiation was recorded to demonstrate the photothermal conversion ability of the Ag/Pd bimetallic nanoparticles (AgPd NPs). The peroxidase-like activity of the AgPd NPs was visually characterized by a color rendering experiment of TMB. Compared with bare Ag NPs, bimetallic AgPd NPs exhibit better photothermal conversion capability (η = 40.97%) and catalytic ability resulting from alloying with palladium. The antitumor effect was evaluated by cell experiments and tumor-bearing mice experiments, and it was confirmed that AgPd@BSA/DOX has excellent antitumor activity in vitro and in vivo. These results indicate that the AgPd@BSA/DOX can effectively catalyze hydrogen peroxide to generate hydroxyl radicals and induce hyperthermia under the irradiation of the NIR laser while releasing the chemotherapy drug DOX to achieve triple modality treatment. Intrinsic enzymatic activity and photothermal property of AgPd@BSA/DOX can be synergized for efficient antitumor treatment, which provided a novel strategy for cancer therapy.

Carbon dots-embedded epitope imprinted polymer for targeted fluorescence imaging of cervical cancer via recognition of epidermal growth factor receptor.

A carbon dots-embedded epitope imprinted polymer (C-MIP) was fabricated for targeted fluorescence imaging of cervical cancer by specifically recognizing the epidermal growth factor receptor (EGFR). The core-shell C-MIP was prepared by a reverse microemulsion polymerization method. This method used silica nanoparticles embedded with carbon dots as carriers, acrylamide as the main functional monomer, and N-terminal nonapeptides of EGFR modified by palmitic acid as templates. Aseries of characterizations (transmission electron microscope, dynamic light scattering, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, zeta potential,and energy dispersive X-ray spectroscopy) prove the successful synthesis of C-MIP. The fluorescence of C-MIP isquenched by the epitopes of EGFR due to the specific recognition of epitopes of EGFR through their imprinted cavities (analytical excitation/emission wavelengths, 540nm/610nm). The linear range of fluorescence quenching is 2.0 to 15.0μgmL-1 and the determination limit is 0.73μgmL-1. The targeted imaging capabilities of C-MIP are demonstrated through in vitro and in vivo experiments. The laser confocal imaging results indicate that HeLa cells (over-expression EGFR) incubated with C-MIP show stronger fluorescence than that of MCF-7 cells (low-expression EGFR), revealing that C-MIP can target tumor cells overexpressing EGFR. The results of imaging experiments in tumor-bearing mice exhibit that C-MIP has a better imaging effect than C-NIP, which further proves the targeted imaging ability of C-MIP in vivo. Graphical abstract An oriented epitope imprinted polymer embedded with carbon dots was prepared for the determination of the epitopes of epidermal growth factor receptor and targeted fluorescence imaging of cervical cancer.

Antitumor immunity triggered by photothermal therapy and photodynamic therapy of a 2D MoS2 nanosheet-incorporated injectable polypeptide-engineered hydrogel combinated with chemotherapy for 4T1 breast tumor therapy

A multifunctional PC10A/DOX/MoS2 hydrogel was designed and prepared for chemotherapy/photothermal therapy/photodynamic therapy of 4T1 tumor, and the immune responses triggered by photothermal and photodynamic effect of MoS2 nanosheet in the hydrogel were also studied. Positively charged DOX and negatively charged PC10A were loaded on the surface of MoS2 nanosheet through layer-by-layer method to prepare hybrid PC10A/DOX/MoS2 nanoparticles. PC10A/DOX/MoS2 nanoparticles were dispersed in PC10A hydrogel to prepare PC10A/DOX/MoS2 hydrogel. 2D MoS2 nanosheet in the hydrogel was simultaneously utilized as photothermal agent and photodynamic agent for the generation of hyperthermia and reactive oxygen species, respectively. This PC10A/DOX/MoS2 hydrogel was injectable and possessed excellent biocompatibility. The results of in vivo tumor-bearing mice experiments showed that a remarkably enhance tumor inhibition was observed by the combination of chemo-photothermal-photodynamic therapy compared with photothermal therapy, photodynamic therapy, or chemotherapy alone. In addition, the results of in vivo therapy exhibited that the PC10A/DOX/MoS2 hydrogel with laser irradiation could activate antitumor immune effects to suppress the growth of primary 4T1 breast tumors and distal lung metastatic nodules. Therefore, these results demonstrated that the PC10A/DOX/MoS2 hydrogel was promising to be utilized in antitumor immunity therapy triggered by photothermal therapy and photodynamic therapy for malignant tumor.

Responsive functionalized MoSe2 nanosystem for highly efficient synergistic therapy of breast cancer

The photothermal/photodynamic synergistic therapy is a promising tumor treatment, but developing nanosystems that achieve synchronous photothermal/photodynamic functions is still quite challenging. Here, we use a simple method to synthesize molybdenum selenide nanoparticles (MoSe2 NPs) with a photothermal effect as a carrier, and load a photosensitizer ICG to form a nanosystem (MoSe2@ICG-PDA-HA)with dual photothermal/photodynamic functions under near-infrared irradiation. In addition, the surface modification of the nanosystem with acid-responsive release polydopamine (PDA) and tumor-targeted hyaluronic acid (HA) enhanced the stability of the photosensitizer ICG and the accumulation of ICG at tumor sites. The multicellular sphere assay simulated solid tumors and demonstrated that MoSe2@ICG-PDA-HA could significantly inhibit the 4T1 cell growth. The anti-tumor experiments in tumor-bearing mice showed that MoSe2@ICG-PDA-HA not only significantly inhibited the growth of 4T1 subcutaneous tumors, but also inhibited their metastasis. This study presented a nanosystem that could improve the photostability of optical materials and enhance the photothermal/photodynamic synergy effect, providing a new idea for finding a way to effectively treat breast cancer.

A biodegradable CO2-based polymeric antitumor nanodrug via a one-pot surfactant- and solvent-free miniemulsion preparation.

In the present study, low molecular weight poly(propylene carbonate) (PPC, Mn = 3500), a biodegradable liquid polymer easily prepared from carbon dioxide (CO2), was modified into poly(propylene carbonate)diacrylate (PPC-DA) by acylation, and methoxy poly(ethylene glycol) (mPEG) was modified into methoxy poly(ethylene glycol) acrylate (mPEG-A). Using PPC-DA as the dispersant to dissolve hydrophobic doxorubicin (DOX) and the initiator, and with mPEG-A as the co-monomer and polymerisable surfactant, a biodegradable nanodrug with excellent biocompatibility was prepared by shear emulsification polymerization without surfactants or organic solvent residues. The nanodrug can be efficiently endocytosed by tumor cells and can rapidly release doxorubicin triggered by the acidic endosomal pH. As evidenced by experiments in tumor-bearing mice, such a nanodrug is stealthy during blood circulation, and targets tumor sites with high efficiency. Moreover, this nanodrug is more effective and less toxic than free doxorubicin. This study provides a green and versatile approach for preparing biodegradable nanodrugs via a simple and efficient process. Moreover, this study extends the applications of CO2 based polymers in the biomedical field, promoting the development of CO2 polymerization fixation.

NO donor inhibits proliferation and induces apoptosis by targeting PI3K/AKT/mTOR and MEK/ERK pathways in hepatocellular carcinoma cells.

PABA/NO, O2-{2,4-dinitro-5-[4-(N-methylamino) benzoyloxy] phenyl} 1-(N, N-dimethylamino) diazen-1-ium-1,2-diolate, is a diazeniumdiolate-based NO-donor prodrug that releases exogenous nitric oxide at high concentrations to induce apoptosis in many tumor cell lines. This study aimed to determine the effects of PABA/NO on hepatocellular carcinoma proliferation and apoptosis induction both in vitro and in vivo experiments. PABA/NO dramatically inhibited the growth of Bel-7402 hepatocellular carcinoma cells and significantly induced apoptosis in a concentration-dependent manner, accompanied by down-regulation of Bcl-2 and Bcl-xL, up-regulation of Bax and Bad, release of Cyt c and activation of cleaved-caspase-9/3 and cleaved-PARP, which were related to suppressing PI3K/AKT/mTOR and MEK/ERK signaling pathways. LY294002 (a PI3K inhibitor) and U0126 (an ERK inhibitor) prior to PABA/NO were found to synergistically enhance PABA/NO-induced apoptosis. Carboxy-PTIO as a NO scavenger obviously attenuated PABA/NO-induced apoptosis. Additionally, H22 tumor-bearing mice experiments demonstrated that PABA/NO exerted good anti-tumor effects via reducing tumor volume, tumor weight and decreasing the expression of CD34. Furthermore, PABA/NO treatment strongly inhibited the phosphorylation of PI3K/AKT/mTOR and MEK/ERK signaling pathways in H22 hepatocellular carcinoma tissues. PABA/NO induced apoptosis through inhibition of PI3K/Akt/mTOR and MEK/ERK pathway in hepatocellular carcinoma cells.

Hollow gold nanoshells-incorporated injectable genetically engineered hydrogel for sustained chemo-photothermal therapy of tumor

BackgroundCombined therapy has demonstrated to be an effective strategy for cancer therapy. Herein, an injectable hydrogel based on the genetically engineered polypeptide and hollow gold nanoshells (HAuNS) has been developed for chemo-photothermal therapy of HepG2 tumor.MethodsPC10A/DOX/HAuNS nanogel was prepared with layer-by-layer through the adsorption of DOX and PC10A successively. DOX with positive charge and PC10A with negative charge were coated step by step onto the surface of negatively charged HAuNS. The multifunctional hydrogel PC10A/DOX/HAuNS were prepared via dissolving hybrid PC10A/DOX/HAuNS nanogel in polypeptide PC10A. Chemotherapy drug DOX in the PC10A/DOX/HAuNS hydrogel was absorbed on the HAuNS and directly embedded in the PC10A hydrogel, which contributes to sequentially release of the drug. Specifically, DOX adsorbed on the HAuNS could be released slowly for sustainable chemotherapy.ResultsThe PC10A/DOX/HAuNS hydrogel could pass 26-gauge needle without clogging, indicating that it is injectable. In addition, the PC10A/DOX/HAuNS hydrogel possessed outstanding photothermal effect and photothermal stability. In both in vitro cell and in vivo tumor-bearing mice experiments, a remarkably enhance tumor inhibition was observed by the combined therapy of chemo-photothermal therapy compared with photothermal therapy or chemotherapy alone.ConclusionsThe combined chemotherapy and photothermal therapy of PC10A/DOX/HAuNS hydrogels could significantly improve the therapeutic effect. Therefore, the multifunctional hydrogel PC10A/DOX/HAuNS is promising to provide a new strategy for sustained chemo-photothermal therapy.

Enhancing Effects of Theanine Liposomes as Chemotherapeutic Agents for Tumor Therapy.

Chemotherapy is one of the most effective methods of treating tumors in clinical study currently, but drug side effects usually are unbearable to the patient, which also makes it difficult to continue chemotherapy. Enhanced drug efficacy and reduced drug side effects are the main strategies for tumor therapy. Herein, based on biochemical regulation, theanine liposomes were designed to adjuvant doxorubicin (DOX) therapy, which can reduce the adverse reactions and enhance the effect of DOX. Stigmasterol was applied instead of traditional cholesterol for reducing the risk of cardiovascular disease. The as-prepared theanine liposomes by two methods had optimal sizes (154.8 and 169.0 nm), which can effectively accumulate in tumor tissues. In vitro experiments demonstrated that the theanine liposomes had a good effect of sustaining drug release. Cell uptake indicated that the presence of theanine can effectively inhibit glutathione (GSH) levels in cells and increase the uptake of DOX. In tumor bearing mice experiments, the combination of the theanine liposomes and DOX showed a better tumor inhibitory effect with a smaller tumor volume (2.7 fold) compared with that of the free DOX group. Meanwhile, under the mediation of theanine, the amount of doxorubicin was greatly reduced to achieve the same therapeutic effect, and the side effects of the drug were largely inhibited. Therefore, theanine liposomes have great application potential in tumor chemotherapy.

Positive feedback nanoamplifier responded to tumor microenvironments for self-enhanced tumor imaging and therapy

Targeted activation or enhancement is an attractive strategy in the design of nano-theranostics. However, the responsiveness of the nanoagents is restricted by the limited levels of intra-tumor stimuli. Herein, we constructed a positive feedback nanoamplifier by encapsulating glucose oxidase (GOx) in the ferric ions contained metal organic framework (MIL-100), and coating the nanoparticles with polydopamine modified hyaluronic acid (HA-PDA). The mechanism of action of the ensuing nanoamplifiers was three pronged: 1) the high intra-tumor acidity accelerated the release of GOx, which consumed endogenous glucose and “starved” the tumors, in addition to aggravating the local acidity and H2O2 levels; 2) the hydroxyl radicals (·OH) generated from the Fenton-like reaction between MIL-100 with H2O2 contributed to the chemodynamic tumor therapy and augmented the O2 microenvironment, which could be speeded up under acid condition; 3) the oxygen (O2) produced in the Fenton-like reaction relieved the intra-tumor hypoxia and ensured the enzymatic reaction of GOx, along with augmenting the photoacoustic signal of nanoamplifier. Preliminary experiments in tumor bearing mice showed that the nanoamplifier not only boosted the local acidity/H2O2/O2 levels in tumor site to successfully suppress the growth of tumors through the self-enhanced chemodynamic/starving therapy, but also achieved the photoacoustic imaging of tumors. Taken together, this novel nanoamplifier with the abilities of self-enhanced tumor imaging and therapy is a promising entrant in the field of anti-tumor theranostics.

A pH-responsive prodrug delivery system self-assembled from acid-labile doxorubicin-conjugated amphiphilic pH-sensitive block copolymers

The development of intelligent drug delivery system that can efficiently deliver doxorubicin (DOX) to tumor site with controlled drug release performance and enhanced therapeutic efficacy is of great significance for cancer chemotherapy. In this report, a nano-prodrug system was prepared successfully by conjugating DOX to pH-sensitive amphiphilic diblock copolymer poly (ethylene glycol) methyl ether‑b‑poly (β‑amino esters) through acid-labile cis‑aconityl moiety (mPEG-b-PAE-cis-DOX). The resultant complex copolymer-drug was able to self-assemble into polymeric micelles (PMs) in an aqueous solution at low concentration, and the critical micelle concentration (CMC) was 3.6 mg/L which was increased as decrease of pH value. H-nuclear magnetic resonance (1H NMR), Fourier transform infrared (FT-IR), dynamic light scattering (DLS), transition electron microscopy (TEM), and classic acid-base titration were combined to confirm and characterize the chemical structure of the copolymer/drug conjugates and the physicochemical properties of the prodrug system. The DOX loading capacity, drug delivery and therapeutic efficacy of the conjugates were evaluated in vitro and in vivo. Notably, the antitumor experiments in tumor-bearing mice demonstrated that the pH-responsive nano-prodrug system effectively enhanced the therapeutic efficacy in comparison to free drug. All above results suggested that pH-responsive prodrug system has the potential to be effective carrier for the DOX delivery and pH-triggered controlled release.