Intravenous Administration of Scutellarin Nanoparticles Augments the Protective Effect against Cerebral Ischemia-Reperfusion Injury in Rats.

This study investigates the protective effect of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with scutellarin (SCU), a flavone isolated from the traditional Chinese medicineErigeron breviscapus (Vant.) Hand.-Mazz., in reducing cerebral ischemia/reperfusion (I/R) injury in vivo. The focal cerebral I/R injury model was established by occluding the middle cerebral artery for 1 h in male Sprague-Dawley (SD) rats. Our SCU-PLGA NPs exhibited an extended in vitro release profile and prolonged blood circulation in rats with cerebral ischemia. More importantly, when administered intravenously once a day for 3 days, SCU-PLGA NPs increased the SCU level in the ischemic brain, compared to free SCU, resulting in a significant reduction of the cerebral infarct volume after cerebral I/R. Furthermore, SCU-PLGA NPs reversed the histopathological changes caused by cerebral I/R injury, as well as attenuated cell apoptosis in the brain tissue, as confirmed by hematoxylin and eosin, and TUNEL staining. Our findings have revealed that our injectable SCU-PLGA NPs provide promising protective effects against cerebral I/R injury, which could be used in combination with the existing conventional thrombolytic therapies to improve stroke management.

Intracellular Activation of a Prostate Specific Antigen-Cleavable Doxorubicin Prodrug: A Key Feature Toward Prodrug-Nanomedicine Design.

L-377,202 prodrug (Dox-PSA) was in phase I clinical trials for patients with metastatic castration-resistant prostate cancer (mCRPC). It consists of doxorubicin (Dox) conjugated to a prostate specific antigen (PSA)-cleavable peptide that can be selectively activated by secreted PSA at the tumor site. However, despite the initial promising results, further clinical testing with Dox-PSA was halted due to toxicity concerns emerging from non-PSA-specific cleavage, following systemic administration. In the present study, we have reported, for the first time, the intracellular activation of Dox-PSA, where Dox nuclear uptake was specific to C4-2B (PSA-expressing) cells, which agreed with the cytotoxicity studies. This finding was confirmed by encapsulating Dox-PSA prodrug into pH-sensitive liposomes to enable prodrug intracellular release, followed by its enzymatic activation. Interestingly, our results demonstrated that Dox-PSA loaded into pH-responsive nanoparticles exhibited cytotoxicity comparable to free prodrug in C4-2B monolayers, with superior activity in tumor spheroids, due to deeper penetration within tumor spheroids. Our approach could open the doors for novel Dox-PSA nanomedicines with higher safety and efficacy to treat advanced and metastatic prostate cancer.

Fluorinated tranylcypromine analogues as inhibitors of lysine-specific demethylase 1 (LSD1, KDM1A).

We report a series of tranylcypromine analogues containing a fluorine in the cyclopropyl ring. A number of compounds with additional m- or p-substitution of the aryl ring were micromolar inhibitors of the LSD1 enzyme. In cellular assays, the compounds inhibited the proliferation of acute myeloid leukemia cell lines. Increased levels of the biomarkers H3K4me2 and CD86 were consistent with LSD1 target engagement.

Magnetic Drug Targeting: Preclinical in Vivo Studies, Mathematical Modeling, and Extrapolation to Humans.

A sound theoretical rationale for the design of a magnetic nanocarrier capable of magnetic capture in vivo after intravenous administration could help elucidate the parameters necessary for in vivo magnetic tumor targeting. In this work, we utilized our long-circulating polymeric magnetic nanocarriers, encapsulating increasing amounts of superparamagnetic iron oxide nanoparticles (SPIONs) in a biocompatible oil carrier, to study the effects of SPION loading and of applied magnetic field strength on magnetic tumor targeting in CT26 tumor-bearing mice. Under controlled conditions, the in vivo magnetic targeting was quantified and found to be directly proportional to SPION loading and magnetic field strength. Highest SPION loading, however, resulted in a reduced blood circulation time and a plateauing of the magnetic targeting. Mathematical modeling was undertaken to compute the in vivo magnetic, viscoelastic, convective, and diffusive forces acting on the nanocapsules (NCs) in accordance with the Nacev-Shapiro construct, and this was then used to extrapolate to the expected behavior in humans. The model predicted that in the latter case, the NCs and magnetic forces applied here would have been sufficient to achieve successful targeting in humans. Lastly, an in vivo murine tumor growth delay study was performed using docetaxel (DTX)-encapsulated NCs. Magnetic targeting was found to offer enhanced therapeutic efficacy and improve mice survival compared to passive targeting at drug doses of ca. 5-8 mg of DTX/kg. This is, to our knowledge, the first study that truly bridges the gap between preclinical experiments and clinical translation in the field of magnetic drug targeting.

Passively Targeted Curcumin-Loaded PEGylated PLGA Nanocapsules for Colon Cancer Therapy In Vivo.

Clinical applications of curcumin for the treatment of cancer and other chronic diseases have been mainly hindered by its short biological half-life and poor water solubility. Nanotechnology-based drug delivery systems have the potential to enhance the efficacy of poorly soluble drugs for systemic delivery. This study proposes the use of poly(lactic-co-glycolic acid) (PLGA)-based polymeric oil-cored nanocapsules (NCs) for curcumin loading and delivery to colon cancer in mice after systemic injection. Formulations of different oil compositions are prepared and characterized for their curcumin loading, physico-chemical properties, and shelf-life stability. The results indicate that castor oil-cored PLGA-based NC achieves high drug loading efficiency (≈18% w(drug)/w(polymer)%) compared to previously reported NCs. Curcumin-loaded NCs internalize more efficiently in CT26 cells than the free drug, and exert therapeutic activity in vitro, leading to apoptosis and blocking the cell cycle. In addition, the formulated NC exhibits an extended blood circulation profile compared to the non-PEGylated NC, and accumulates in the subcutaneous CT26-tumors in mice, after systemic administration. The results are confirmed by optical and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. In vivo growth delay studies are performed, and significantly smaller tumor volumes are achieved compared to empty NC injected animals. This study shows the great potential of the formulated NC for treating colon cancer.

Design of Cationic Multiwalled Carbon Nanotubes as Efficient siRNA Vectors for Lung Cancer Xenograft Eradication.

Polo-Like Kinase (PLK1) has been identified as a potential target in cancer gene therapy via chemical or genetic inhibitory approaches. The biomedical applications of chemically functionalized carbon nanotubes (f-CNTs) in cancer therapy have been studied due to their ability to efficiently deliver siRNA intracellularly. In this study, we established the capacity of cationic MWNT-NH3(+) to deliver the apoptotic siRNA against PLK1 (siPLK1) in Calu6 tumor xenografts by direct intratumoral injections. A direct comparison with cationic liposomes was made. This study validates the PLK1 gene as a potential target in cancer gene therapy including lung cancer, as demonstrated by the therapeutic efficacy of siPLK1:MWNT-NH3(+) complexes and their ability to significantly improve animal survival. Biological analysis of the siPLK1:MWNT-NH3(+) treated tumors by qRT-PCR and Western blot, in addition to TUNEL staining confirmed the biological functionality of the siRNA intratumorally, suggesting that tumor eradication was due to PLK1 knockdown. Furthermore, by using a fluorescently labeled, noncoding siRNA sequence complexed with MWNT-NH3(+), we established for the first time that the improved therapeutic efficacy observed in f-CNT-based siRNA delivery is directly proportional to the enhanced siRNA retention in the solid tumor and subsequent uptake by tumor cells after local administration in vivo.

Cationic Liposome- Multi-Walled Carbon Nanotubes Hybrids for Dual siPLK1 and Doxorubicin Delivery In Vitro.

PURPOSE: To formulate f-MWNTs-cationic liposome hybrids for the simultaneous delivery of siPLK1 and doxorubicin to cancer cells. METHOD: f-MWNTs-cationic liposome hybrids were prepared by the thin film hydration method where the lipid film was hydrated with 100 µg/ml or 1 mg/ml of ox-MWNTs-NH3 (+) or MWNTs-NH3 (+) in 5% dextrose. siRNA complexation and protection ability was determined by agarose gel electrophoresis. f-MWNTs and liposome interaction was evaluated using Nile Red (NR) fluorescence spectroscopy. Cellular uptake in A549 cells was assessed by flow cytometry. Silencing of target proteins was determined by Luciferase and MTT assays. Sub-G1 analysis was performed to evaluate apoptosis following co-delivery of siPLK1 and Doxorubicin (Dox). RESULTS: Zeta potential and siRNA complexation profile obtained for all hybrids were comparable to those achieved with cationic liposomes. ox-MWNTs-NH3 (+) showed greater extent of interaction with cationic liposomes compared to MWNTs-NH3 (+). ox-MWNTs-NH3 (+) was able to protect siRNA from nuclease-mediated degradation. Enhanced cellular uptake of both the carrier and loaded siRNA in A549 cell, were observed for this hybrid compared to the liposomal carrier. A synergistic pro-apoptotic effect was obtained when siPLK1 silencing was combined with doxorubicin treatment for the hybrid:siRNA complexes compared to the lipoplexes, in A549 cells in vitro. CONCLUSIONS: f-MWNTs-cationic liposome hybrid designed in this study can serve as a potential vehicle for the co-delivery of siRNA and cytotoxic drugs to cancer cells in vitro.

Systemic antiangiogenic activity of cationic poly-L-lysine dendrimer delays tumor growth.

This study describes the previously unreported intrinsic capacity of poly-L-lysine (PLL) sixth generation (G(6)) dendrimer molecules to exhibit systemic antiangiogenic activity that could lead to solid tumor growth arrest. The PLL-dendrimer-inhibited tubule formation of SVEC4-10 murine endothelial cells and neovascularization in the chick embryo chick chorioallantoic membrane (CAM) assay. Intravenous administration of the PLL-dendrimer molecules into C57BL/6 mice inhibited vascularisation in Matrigel plugs implanted subcutaneously. Antiangiogenic activity was further evidenced using intravital microscopy of tumors grown within dorsal skinfold window chambers. Reduced vascularization of P22 rat sarcoma implanted in the dorsal window chamber of SCID mice was observed following tail vein administration (i.v.) of the PLL dendrimers. Also, the in vivo toxicological profile of the PLL-dendrimer molecules was shown to be safe at the dose regime studied. The antiangiogenic activity of the PLL dendrimer was further shown to be associated with significant suppression of B16F10 solid tumor volume and delayed tumor growth. Enhanced apoptosis/necrosis within tumors of PLL-dendrimer-treated animals only and reduction in the number of CD31 positive cells were observed in comparison to protamine treatment. This study suggests that PLL-dendrimer molecules can exhibit a systemic antiangiogenic activity that may be used for therapy of solid tumors, and in combination with their capacity to carry other therapeutic or diagnostic agents may potentially offer capabilities for the design of theranostic systems.

Liposome-gold nanorod hybrids for high-resolution visualization deep in tissues.

The design of liposome-nanoparticle hybrids offers a rich toolbox for the fabrication of multifunctional modalities. A self-assembled liposome-gold nanorod hybrid vesicular system that consists of lipid-bilayer-associated gold nanorods designed to allow deep tissue detection, therapy, and monitoring in living animals using multispectral optoacoustic tomography has been fabricated and characterized in vitro and in vivo.

Liposomes: from a clinically established drug delivery system to a nanoparticle platform for theranostic nanomedicine.

For decades, clinicians have used liposomes, self-assembled lipid vesicles, as nanoscale systems to deliver encapsulated anthracycline molecules for cancer treatment. The more recent proposition to combine liposomes with nanoparticles remains at the preclinical development stages; however, such hybrid constructs present great opportunities to engineer theranostic nanoscale delivery systems, which can combine simultaneous therapeutic and imaging functions. Many novel nanoparticles of varying chemical compositions are being developed in nanotechnology laboratories, but further chemical modification is often required to make these structures compatible with the biological milieu in vitro and in vivo. Such nanoparticles have shown promise as diagnostic and therapeutic tools and generally offer a large surface area that allows covalent and non-covalent surface functionalization with hydrophilic polymers, therapeutic moieties, and targeting ligands. In most cases, such surface manipulation diminishes the theranostic properties of nanoparticles and makes them less stable. From our perspective, liposomes offer structural features that can make nanoparticles biocompatible and present a clinically proven, versatile platform for further enhancement of the pharmacological and diagnostic efficacy of nanoparticles. In this Account, we describe two examples of liposome-nanoparticle hybrids developed as theranostics: liposome-quantum dot hybrids loaded with a cytotoxic drug (doxorubicin) and artificially enveloped adenoviruses. We incorporated quantum dots into lipid bilayers, which rendered them dispersible in physiological conditions. This overall vesicular structure allowed them to be loaded with doxorubicin molecules. These structures exhibited cytotoxic activity and labeled cells both in vitro and in vivo. In an alternative design, lipid bilayers assembled around non-enveloped viral nanoparticles and altered their infection tropism in vitro and in vivo with no chemical or genetic capsid modifications. Overall, we have attempted to illustrate how alternative strategies to incorporate nanoparticles into liposomal nanostructures can overcome some of the shortcomings of nanoparticles. Such hybrid structures could offer diagnostic and therapeutic combinations suitable for biomedical and even clinical applications.

Degree of chemical functionalization of carbon nanotubes determines tissue distribution and excretion profile.

Getting rid of the tubes: An assessment of the retention of functionalized multi-walled carbon nanotubes (MWNTs) in the organs of mice was carried out using single photon emission computed tomography and quantitative scintigraphy (see scheme). Increasing the degree of functionalization on MWNTs enhanced renal clearance, while lower functionalization promoted reticuloendethelial system accumulation.

Mild hyperthermia accelerates doxorubicin clearance from tumour-extravasated temperature-sensitive liposomes.

Mild hyperthermia (HT) (40-43 °C) has been combined with temperature-sensitive liposomes (TSL), offering on-demand drug release for increased drug bioavailability and reduced systemic toxicity. Different HT regimens have been applied to trigger liposome drug release in the blood vessels (intravascular) of heated tumours or following tumour extravasation (interstitial). The present study systematically assessed the in vivo doxorubicin (Dox) release and therapeutic efficacy of Dox-loaded TSL with different release profiles. Low temperature-sensitive liposomes (LTSL-Dox), traditional-temperature-sensitive liposomes (TTSL-Dox), and non-temperature-sensitive liposomes (NTSL-Dox) were combined with a single or two HT in different tumour models (murine melanoma B16F10 tumour and human breast MDA-MB-435). The efficacy of each treatment was assessed by monitor tumour growth and mice survival. The level of Dox in tumour tissues was quantified using 14C-Dox and liquid scintillation while Dox release was assessed using live imaging and confocal laser scanning microscopy. Applying a second HT to release Dox from extravasated TTSL-Dox was not therapeutically superior to single HT application due to Dox clearance from the extravasated TTSL-Dox. Our findings revealed that enhanced blood perfusion in heated tumours during the second water bath HT could be seen as a hurdle for TTSL-Dox's anticancer efficacy, where the systemic toxicity of the redistributed Dox from the tumour tissues could be potentiated.

Encapsulation of doxorubicin prodrug in heat-triggered liposomes overcomes off-target activation for advanced prostate cancer therapy.

L-377,202 prodrug consists of doxorubicin (Dox) conjugated to a prostate-specific antigen (PSA) peptide substrate that can be cleaved by enzymatically active PSA at the tumor site. Despite the initial promise in phase I trial, further testing of L-377,202 (herein called Dox-PSA) was ceased due to some degree of non-specific activation and toxicity concerns. To improve safety of Dox-PSA, we encapsulated it into low temperature-sensitive liposomes (LTSL) to bypass systemic activation, while maintaining its biological activity upon controlled release in response to mild hyperthermia (HT). A time-dependent accumulation of activated prodrug in the nuclei of PSA-expressing cells exposed to mild HT was observed, showing that Dox-PSA was efficiently released from the LTSL, cleaved by PSA and entering the cell nucleus as free Dox. Furthermore, we have shown that Dox-PSA loading in LTSL can block its biological activity at 37°C, while the combination with mild HT resulted in augmented cytotoxicity in both 2D and 3D PC models compared to the free Dox-PSA. More importantly, Dox-PSA encapsulation in LTSL prolonged its blood circulation and reduced Dox accumulation in the heart of C4-2B tumor-bearing mice over the free Dox-PSA, thus significantly improving Dox-PSA therapeutic window. Finally, Dox-PSA-loaded LTSL combined with HT significantly delayed tumor growth at a similar rate as mice treated with free Dox-PSA in both solid and metastatic PC tumor models. This indicates this strategy could block the systemic cleavage of Dox-PSA without reducing its efficacy in vivo, which could represent a safer option to treat patients with locally advanced PC. STATEMENT OF SIGNIFICANCE: This study investigates a new tactic to tackle non-specific cleavage of doxorubicin PSA-activatable prodrug (L-377,202) to treat advanced prostate cancer. In the present study, we report a nanoparticle-based approach to overcome the non-specific activation of L-377,202 in the systemic circulation. This includes encapsulating Dox-PSA in low temperature-sensitive liposomes to prevent its premature hydrolysis and non-specific cleavage. This class of liposomes offers payload protection against degradation in plasma, improved pharmacokinetics and tumor targeting, and an efficient and controlled drug release triggered by mild hyperthermia (HT) (∼42°C). We believe that this strategy holds great promise in bypassing any systemic toxicity concerns that could arise from the premature activation of the prodrug whilst simultaneously being able to control the spatiotemporal context of Dox-PSA cleavage and metabolism.

Enhanced cellular internalization and gene silencing with a series of cationic dendron-multiwalled carbon nanotube:siRNA complexes.

One of the major obstacles to the clinical development of gene silencing by small interfering RNA (siRNA) is its effective cytoplasmic delivery. Carbon nanotubes have been proposed as novel nanomaterials that can offer significant advantages for the intracellular delivery of nucleic acids, such as siRNA. We recently demonstrated in a proof-of-principle study that amino-functionalized multiwalled carbon nanotubes (f-MWNT) can effectively deliver in vivo an siRNA sequence, triggering cell apoptosis that results in human lung xenograft eradication and prolonged survival. In the present study, we demonstrate how a newly synthesized series of polycationic dendron-MWNT constructs with a precisely tailored number of amino functions (dendron generations) can complex and effectively deliver double-stranded siRNA to achieve gene silencing in vitro. A systematic comparison between the f-MWNT series in terms of cellular uptake, cytotoxicity, and siRNA complexation is offered. Significant improvement in siRNA delivery with the dendron-MWNT conjugates is shown, and gene silencing was obtained in 2 human cell lines using 2 different siRNA sequences. The study reveals that through f-MWNT structure-biological function analysis novel nanotube-based siRNA transfer vectors can be designed with minimal cytotoxicity and effective delivery and gene-silencing capabilities.

Nanoprecipitation preparation of low temperature-sensitive magnetoliposomes.

Lysolipid-containing thermosensitive liposomes (LTSL) have gained attention for triggered release of chemotherapeutics. Superparamagnetic iron oxide nanoparticles (SPION) offers multimodal imaging and hyperthermia therapy opportunities as a promising theranostic agent. Combining LTSL with SPION may further enhance their performance and functionality of LTSL. However, a major challenge in clinical translation of nanomedicine is the poor scalability and complexity of their preparation process. Exploiting the nature of self-assembly, nanoprecipitation is a simple and scalable technique for preparing liposomes. Herein, we developed a novel SPION-incorporated lysolipid-containing thermosensitive liposome (mLTSL10) formulation using nanoprecipitation. The formulation and processing parameters were carefully designed to ensure high reproducibility and stability of mLTSL10. The effect of solvent, aqueous-to-organic volume ratio, SPION concentration on the mLTSL10 size and dispersity was investigated. mLTSL10 were successfully prepared with a small size (∼100 nm), phase transition temperature at around 42 °C, and high doxorubicin encapsulation efficiency. Indifferent from blank LTSL, we demonstrated that mLTSL10 combining the functionality of both LTSL and SPION can be successfully prepared using a scalable nanoprecipitation approach.

Genetically-engineered anti-PSMA exosome mimetics targeting advanced prostate cancer in vitro and in vivo.

The present work describes the engineering of anti-PSMA peptide-decorated exosome mimetics (EMs) targeting advanced prostate cancer (PC). The targeted EMs were produced from anti-PSMA peptide, WQPDTAHHWATL, expressing U937 monoblastic cells, followed by successive extrusion cycles. The engineered EMs were nanosized, produced at a high yield, and displayed the anti-PSMA peptide, exosomal markers and monocytes proteins on their surface. As anticipated, PSMA-EMs showed increased cellular internalization in PSMA positive PC cell lines (LNCaP and C4-2B), compared to unmodified EMs. Most importantly, higher tumour targeting was observed in solid C4-2B tumours, following intravenous administration, confirming their targeting ability in vivo. Overall, our study indicates that the engineered anti-PSMA peptide-targeted EMs can be a promising drug delivery system for advanced PC.

Dually targeted bioinspired nanovesicle delays advanced prostate cancer tumour growth in vivo.

Prostate cancer (PC) is second-leading cancer in men, with limited treatment options available for men with advanced and metastatic PC. Prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) have been exploited as therapeutic targets in PC due to their upregulation in the advanced stages of the disease. To date, several PSA- and PSMA-activatable prodrugs have been developed to reduce the systemic toxicity of existing chemotherapeutics. Bioinspired nanovesicles have been exploited in drug delivery, offering prolonged drug blood circulation and higher tumour accumulation. For the first time, this study describes the engineering of dually targeted PSA/PSMA nanovesicles for advanced PC. PSMA-targeted bioinspired hybrids were prepared by hydrating a lipid film with anti-PSMA-U937 cell membranes and DOX-PSA prodrug, followed by extrusion. The bioinspired hybrids were characterised using dynamic light scattering, transmission electron microscopy, Dot blot, flow cytometry and Western blot. Cellular binding and toxicity studies in PC cancer cell lines were carried out using flow cytometry, confocal microscopy, and resazurin assay. Finally, tumour targeting and therapeutic efficacy studies were performed in solid and metastatic C4-2B-tumor-bearing mice. Interestingly, our PSMA-targeted hybrids demonstrated high cell uptake in PSMA-expressing cells with significant accumulation in solid and metastatic C4-2B tumour tissues following intravenous administration. More promisingly, our dually targeted PSA/PSMA hybrid significantly slowed down the C4-2B tumour growth in vivo, compared to free DOX-PSA and non-targeted PSA-hybrid. Our PSA/PSMA bioinspired hybrid could offer a highly selective treatment for advanced PC with lower side effects. STATEMENT OF SIGNIFICANCE: This study investigates a new approach to treat prostate cancer using dually targeted bioinspired nanovesicle . Our bioinspired vesicles are made mainly of a human blood cell membrane with a ligand recognising a specific marker (PSMA) on the surface of the prostate cancer cells. The present work describes the successful loading of a doxorubicin prodrug linked to a PSA- activatable peptide into these targeted bioinspired nanovesicle , where the active PSA enzyme presents in these cells converts the drug to its active form. Our dually targeted PSA/PSMA hybrid vesicles has successfully improved site-specific prodrug delivery to tackle advanced prostate cancer, offering a novel and effective prostate cancer treatment.

Hypoxia-targeted cupric-tirapazamine liposomes potentiate radiotherapy in prostate cancer spheroids.

In this study, novel cupric-tirapazamine [Cu(TPZ)2]-liposomes were developed as an effective hypoxia-targeted therapeutic, which potentiated radiotherapy in a three dimensional (3D) prostate cancer (PCa) model. To overcome the low water solubility of the Cu(TPZ)2, a remote loading method was developed to efficiently load the lipophilic complex into different liposomal formulations. The effect of pH, temperature, PEGylation, lipid composition, liposome size, lipid: complex ratio on the liposome properties, and drug loading was evaluated. The highest loading efficiency was obtained at neutral pH, which was independent of lipid composition and incubation time. In addition, enhanced drug loading was achieved upon decreasing the lipid:complex molar ratio with minimal effects on liposomes' morphology. Interestingly, the in vitro potency of the developed liposomes was easily manipulated by changing the lipid composition. The hydrophilic nature of our liposomal formulations improved the complex's solubility, leading to enhanced cellular uptake and toxicity, both in PCa monolayers and tumour spheroids. Moreover, Cu(TPZ)2-loaded liposomes combined with radiation, showed a significant reduction in PCa spheroids growth rate, compared to the free complex or radiation alone, which could potentiate radiotherapy in patients with localised advanced PCa.

PD1 blockade potentiates the therapeutic efficacy of photothermally-activated and MRI-guided low temperature-sensitive magnetoliposomes.

This study investigates the effect of PD1 blockade on the therapeutic efficacy of novel doxorubicin-loaded temperature-sensitive liposomes. Herein, we report photothermally-activated, low temperature-sensitive magnetoliposomes (mLTSL) for efficient drug delivery and magnetic resonance imaging (MRI). The mLTSL were prepared by embedding small nitrodopamine palmitate (NDPM)-coated iron oxide nanoparticles (IO NPs) in the lipid bilayer of low temperature-sensitive liposomes (LTSL), using lipid film hydration and extrusion. Doxorubicin (DOX)-loaded mLTSL were characterized using dynamic light scattering, differential scanning calorimetry, electron microscopy, spectrofluorimetry, and atomic absorption spectroscopy. Photothermal experiments using 808 nm laser irradiation were conducted. In vitro photothermal DOX release studies and cytotoxicity was assessed using flow cytometry and resazurin viability assay, respectively. In vivo DOX release and tumor accumulation of mLTSL(DOX) were assessed using fluorescence and MR imaging, respectively. Finally, the therapeutic efficacy of PD1 blockade in combination with photothermally-activated mLTSL(DOX) in CT26-tumor model was evaluated by monitoring tumor growth, cytokine release and immune cell infiltration in the tumor tissue. Interestingly, efficient photothermal heating was obtained by varying the IO NPs content and the laser power, where on-demand burst DOX release was achievable in vitro and in vivo. Moreover, our mLTSL exhibited promising MR imaging properties with high transverse r2 relaxivity (333 mM-1 s-1), resulting in superior MR imaging in vivo. Furthermore, mLTSL(DOX) therapeutic efficacy was potentiated in combination with anti-PD1 mAb, resulting in a significant reduction in CT26 tumor growth via immune cell activation. Our study highlights the potential of combining PD1 blockade with mLTSL(DOX), where the latter could facilitate chemo/photothermal therapy and MRI-guided drug delivery.