The effect of thermosensitive liposomal formulations on loading and release of high molecular weight biomolecules

Brain-Derived Neurotrophic Factor-Loaded Low-Temperature-Sensitive liposomes as a drug delivery system for repairing podocyte damage

Podocytes, cells of the glomerular filtration barrier, play a crucial role in kidney diseases and are gaining attention as potential targets for new therapies. Brain-Derived Neurotrophic Factor (BDNF) has shown promising results in repairing podocyte damage, but its efficacy via parenteral administration is limited by a short half-life. Low temperature sensitive liposomes (LTSL) are a promising tool for targeted BDNF delivery, preserving its activity after encapsulation. This study aimed to improve LTSL design for efficient BDNF encapsulation and targeted release to podocytes, while maintaining stability and biological activity, and exploiting the conjugation of targeting peptides. While cyclic RGD (cRGD) was used for targeting endothelial cells in vitro, a homing peptide (HITSLLS) was conjugated for more specific uptake by glomerular endothelial cells in vivo. BDNF-loaded LTSL successfully repaired cytoskeleton damage in podocytes and reduced albumin permeability in a glomerular co-culture model. cRGD conjugation enhanced endothelial cell targeting and uptake, highlighting an improved therapeutic effect when BDNF release was induced by thermoresponsive liposomal degradation. In vivo, targeted LTSL showed evidence of accumulation in the kidneys, and their BDNF delivery decreased proteinuria and ameliorated kidney histology. These findings highlight the potential of BDNF-LTSL formulations in restoring podocyte function and treating glomerular diseases.

Engineered therapeutic proteins for sustained-release drug delivery systems

Proteins play a vital role in diverse biological processes in the human body, and protein therapeutics have been applied to treat different diseases such as cancers, genetic disorders, autoimmunity, and inflammation. Protein therapeutics have demonstrated their advantages, such as specific pharmaceutical effects, low toxicity, and strong solubility. However, several disadvantages arise in clinical applications, including short half-life, immunogenicity, and low permeation, leading to reduced drug effectiveness. The structure of protein therapeutics can be modified to increase molecular size, leading to prolonged stability and increased plasma half-life. Notably, the controlled-release delivery systems for the sustained release of protein drugs and preserving the stability of cargo proteins are envisioned as a potential approach to overcome these challenges. In this review, we summarize recent research progress related to structural modifications (PEGylation, glycosylation, poly amino acid modification, and molecular biology-based strategies) and promising long-term delivery systems, such as polymer-based systems (injectable gel/implants, microparticles, nanoparticles, micro/nanogels, functional polymers), lipid-based systems (liposomes, solid lipid nanoparticles, nanostructured lipid carriers), and inorganic nanoparticles exploited for protein therapeutics. STATEMENT OF SIGNIFICANCE: In this review, we highlight recent advances concerning modifying proteins directly to enhance their stability and functionality and discuss state-of-the-art methods for the delivery and controlled long-term release of active protein therapeutics to their target site. In terms of drug modifications, four widely used strategies, including PEGylation, poly amino acid modification, glycosylation, and genetic, are discussed. As for drug delivery systems, we emphasize recent progress relating to polymer-based systems, lipid-based systems developed, and inorganic nanoparticles for protein sustained-release delivery. This review points out the areas requiring focused research attention before the full potential of protein therapeutics for human health and disease can be realized.

Recent Advances of Ocular Drug Delivery Systems: Prominence of Ocular Implants for Chronic Eye Diseases

Chronic ocular diseases can seriously impact the eyes and could potentially result in blindness or serious vision loss. According to the most recent data from the WHO, there are more than 2 billion visually impaired people in the world. Therefore, it is pivotal to develop more sophisticated, long-acting drug delivery systems/devices to treat chronic eye conditions. This review covers several drug delivery nanocarriers that can control chronic eye disorders non-invasively. However, most of the developed nanocarriers are still in preclinical or clinical stages. Long-acting drug delivery systems, such as inserts and implants, constitute the majority of the clinically used methods for the treatment of chronic eye diseases due to their steady state release, persistent therapeutic activity, and ability to bypass most ocular barriers. However, implants are considered invasive drug delivery technologies, especially those that are nonbiodegradable. Furthermore, in vitro characterization approaches, although useful, are limited in mimicking or truly representing the in vivo environment. This review focuses on long-acting drug delivery systems (LADDS), particularly implantable drug delivery systems (IDDS), their formulation, methods of characterization, and clinical application for the treatment of eye diseases.

Cisplatin-Loaded Thermosensitive Liposomes Functionalized with Hyaluronic Acid: Cytotoxicity and In Vivo Acute Toxicity Evaluation

Cisplatin (CDDP) is a potent antitumor drug used in first-line chemotherapy against several solid tumors, including breast cancer. However, toxicities and drug resistance limit its clinical application. Thermosensitive liposome (TSL) functionalized with hyaluronic acid (HA) containing cisplatin (TSL-CDDP-HA) was developed by our research group aiming to promote the release of CDDP in the tumor region under hyperthermia conditions, as well as to decrease toxicity. Thus, this study aimed to evaluate this new formulation (HA-coated TSL-CDDP) concerning in vitro behavior and in vivo toxicity compared to non-coated TSL-CDDP and free CDDP. Cytotoxicity assays and nuclear morphology were carried out against triple-negative breast cancer cells (MDA-MB-231), while an in vivo toxicity study was performed using healthy Swiss mice. The results showed an increase (around 3-fold) in cytotoxicity of the cationic formulation (non-coated TSL-CDDP) compared to free CDDP. On the other hand, TSL-CDDP treatment induced the appearance of 2.5-fold more senescent cells with alteration of nuclear morphology than the free drug after hyperthermia condition. Furthermore, the association of liposomal formulations treatment with hyperthermia increased the percentage of apoptotic cells compared to those without heating. The percentage of apoptotic cells was 1.7-fold higher for TSL-CDDP-HA than for TSL-CDDP. For the in vivo toxicity data, the TSL-CDDP treatment was also toxic to healthy cells, inducing nephrotoxicity with a significant increase in urea levels compared to the saline control group (73.1 ± 2.4 vs. 49.2 ± 2.8 mg/mL). On the other hand, the HA-coated TSL-CDDP eliminated the damages related to the use of CDDP since the animals did not show changes in hematological and biochemical examinations and histological analyses. Thus, data suggest that this new formulation is a potential candidate for the intravenous therapy of solid tumors.

Curcumin- and resveratrol-co-loaded nanoparticles in synergistic treatment of hepatocellular carcinoma

BACKGROUND

Currently, systemic therapies for patients with advanced-stage hepatocellular carcinoma (HCC) rely mainly on systemic drugs. However, traditional systemic drugs have a high rate of serious adverse events, and the curative effects of some potential anticancer drugs, such as curcumin (CUR) and resveratrol (RSV), are less apparent due to their poor bioavailability. Therefore, it is urgent to develop a highly effective therapy to improve patient prognosis. Herein, an injectable HCC-targeted nanoparticle (NP) was designed to deliver CUR and RSV to hepatoma cells.

RESULTS

The molecular self-assembled NPs showed higher tumour retention through the enhanced permeability and retention (EPR) effect of the NPs and surface modification with the HCC-specific peptide moiety SP94 to effectively treat HCC. These HCC-targeted NPs led to a significant reduction in the drug dosage, delayed the rate of drug release and improved the bioavailability of the encapsulated drugs. The drug concentrations in the vicinity of the tumour increased, and a good therapeutic effect was observed without obvious side effects.

CONCLUSIONS

These SP94-mediated NPs allowed large amounts of antitumor drugs to accumulate in tumours, providing a novel strategy for innovative HCC therapy. This nanoplatform also offers an idea for exploring other potential chemotherapeutics.

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.

Mild Hyperthermia Responsive Liposomes for Enhanced In Vitro and In Vivo Anticancer Efficacy of Doxorubicin against Hepatocellular Carcinoma

The current study is aimed to fabricate doxorubicin (Dox) loaded mild temperature responsive liposomes (MTLs) by thin film hydration technique for enhanced in vitro and in vivo anticancer efficacy against hepatocellular carcinoma. The aforementioned Dox loaded MTLs were developed and optimized with extrusion and drug loading techniques. The optimized MTLs were in optimum size range (118.20 ± 2.81–187.13 ± 4.15 nm), colloidal stability (−13.27 ± 0.04 to −32.34 ± 0.15 mV), and enhanced entrapment of Dox (28.71 ± 2.01–79.24 ± 2.16). Furthermore, the optimized formulation (MTL1-E_(AL)) embodied improved physicochemical stability deducted by Fourier transform infra-red (FTIR) spectroscopy and mild hyperthermia-based phase transition demonstrated from differential scanning calorimetry (DSC). An in vitro drug release study revealed mild hyperthermia assisted rapid in vitro Dox release from MTLs-E_(AL) (T_100% ≈ 1 h) by Korsmeyer–Peppas model based Fickian diffusion (n < 0.45). Likewise, an in vitro cytotoxicity study and lower IC₅₀ values also symbolized mild hyperthermia (40.2 °C) based quick and improved cytotoxicity of MTL1-E_(AL) in HepG2 and MCF-7 cells than Dox. The fluorescence microscopy also represented enhanced cellular internalization of MTL1-E_(AL) at mild hyperthermia compared to the normothermia (37.2 °C). In addition, an in vivo animal study portrayed the safety, improved anticancer efficacy and healing of hepatocellular carcinoma (HCC) through MTL1-E_(AL). In brief, the Dox loaded MTLs could be utilized as safe and effective therapeutic strategy against HCC.

Near-infrared light-responsive liposomes for protein delivery: Towards bleeding-free photothermally-assisted thrombolysis

Smart drug delivery systems represent state-of-the-art approaches for targeted therapy of life-threatening diseases such as cancer and cardiovascular diseases. Stimuli-responsive on-demand release of therapeutic agents at the diseased site can significantly limit serious adverse effects. In this study, we engineered a near-infrared (NIR) light-responsive liposomal gold nanorod-containing platform for on-demand delivery of proteins using a hybrid formulation of ultrasmall gold nanorods (AuNRs), thermosensitive phospholipid (DPPC) and non-ionic surfactant (Brij58). In light-triggered release optimization studies, 55.6% (± 4.8) of a FITC-labelled model protein, ovalbumin (MW 45 kDa) was released in 15 min upon NIR irradiation (785 nm, 1.35 W/cm² for 5 min). This platform was then utilized to test on-demand delivery of urokinase-plasminogen activator (uPA) for bleeding-free photothermally-assisted thrombolysis, where the photothermal effect of AuNRs would synergize with the released uPA in clot lysis. Urokinase light-responsive liposomes showed 80.7% (± 4.5) lysis of an in vitro halo-clot model in 30 min following NIR irradiation (785 nm, 1.35 W/cm² for 5 min) compared to 36.3% (± 4.4) and 15.5% (± 5.5) clot lysis from equivalent free uPA and non-irradiated liposomes respectively. These results show the potential of low-dose, site-specific thrombolysis via the combination of light-triggered delivery/release of uPA from liposomes combined with photothermal thrombolytic effects from gold nanorods. In conclusion, newly engineered, gold nanorod-based, NIR light-responsive liposomes represent a promising drug delivery system for site-directed, photothermally-stimulated therapeutic protein release.

Nerve growth factor loaded macrophage-derived nanovesicles for inhibiting neuronal apoptosis after spinal cord injury

Spinal cord injury (SCI) is an extremely destructive central nervous system lesion. Studies have shown that NGF can promote nerve regeneration after SCI. However, it cannot produce the desired effect due to its stability in the body and is difficulty in passing through the blood-brain barrier. In this study, we prepared nanovesicles derived from macrophage membrane encapsulating NGF (NGF-NVs) as a drug carrier for the treatment of SCI. Cell experiments showed that NGF-NVs were effectively taken up by PC12 cells and inhibited neuronal apoptosis. In vivo imaging experiments, a large quantity of NGF was delivered to the injured site with the aid of the good targeting of NVs. In animal experiments, NGF-NVs improved the survival of neurons by significantly activating the PI3K/AKT signaling pathway and had good behavioral and histological recovery effects after SCI. Therefore, NVs are a potential drug delivery vector for SCI therapy.

Near-Infrared Light-Triggered Thermosensitive Liposomes Modified with Membrane Peptides for the Local Chemo/Photothermal Therapy of Melanoma

Purpose

A near-infrared (NIR)-triggered trans-activating transcriptional activator (TAT)-based targeted drug delivery system for the combined chemo/photothermal therapy of melanoma, namely, TAT-TSL-TMZ (temozolomide)/IR820, was developed for the first time.

Methods

TAT-TSL-TMZ/IR820 liposomes were synthesized via thin-film dispersion and sonication. IR820 and TMZ were encased in the inner layer and lipid bilayer of the liposomes, respectively.

Results

Dynamic light scattering results showed that the liposomes had an average hydrodynamic size of 166.9 nm and a zeta potential of -2.55 mV. The encapsulation rates of TMZ and IR820 were 35.4% and 28.6%, respectively. The heating curve obtained under near-infrared (NIR) laser irradiation showed that TAT-TSL-TMZ/IR820 liposomes had good photothermal conversion efficiency. The in vitro drug release curve revealed that NIR laser irradiation could accelerate drug release from TAT-TSL-TMZ/IR820 liposomes. The results of inverted fluorescence microscopy and flow cytometry proved that the uptake of TAT-TSL-TMZ/IR820 liposomes by human melanoma cells (MV3 cells) was concentration-dependent and that the liposomes modified with membrane peptides were more likely to be ingested by cells than unmodified liposomes. Confocal laser scanning microscopy indicated that TAT-TSL-TMZ/IR820 liposomes entered MV3 cells via endocytosis and was stored in lysosomes. In addition, TAT-TSL-TMZ/IR820 liposomes exposed to NIR laser showed 89.73% reduction in cell viability.

Conclusion

This study investigated the photothermal conversion, cell uptake, colocation and chemo/photothermal effect of TAT-TSL-TMZ/IR820 liposomes.

Nanosized Delivery Systems for Therapeutic Proteins: Clinically Validated Technologies and Advanced Development Strategies

The impact of protein therapeutics in healthcare is steadily increasing, due to advancements in the field of biotechnology and a deeper understanding of several pathologies. However, their safety and efficacy are often limited by instability, short half-life and immunogenicity. Nanodelivery systems are currently being investigated for overcoming these limitations and include covalent attachment of biocompatible polymers (PEG and other synthetic or naturally derived macromolecules) as well as protein nanoencapsulation in colloidal systems (liposomes and other lipid or polymeric nanocarriers). Such strategies have the potential to develop next-generation protein therapeutics. Herein, we review recent research progresses on these nanodelivery approaches, as well as future directions and challenges.

Ultrasound-Sensitive Liposomes for Triggered Macromolecular Drug Delivery: Formulation and In Vitro Characterization

Mistletoe lectin-1 (ML1) is a nature-derived macromolecular cytotoxin that potently induces apoptosis in target cells. Non-specific cytotoxicity to normal cells is one of the major risks in its clinical application, and we therefore propose to encapsulate ML1 in a nanocarrier that can specifically release its cargo intratumorally, thus improving the efficacy to toxicity ratio of the cytotoxin. We investigated the encapsulation of ML1 in ultrasound-sensitive liposomes (USL) and studied its release by high-intensity focused ultrasound (HAccessedIFU). USL were prepared by entrapment of perfluorocarbon nanodroplets in pegylated liposomes. The liposomes were prepared with different DPPC/cholesterol/DSPE-PEG2000 lipid molar ratios (60/20/20 for USL20; 60/30/10 for USL10; 65/30/5 for USL5) before combination with perfluorocarbon (PFC) nanoemulsions (composed of DPPC and perfluoropentane). When triggered with HIFU (peak negative pressure, 2-24 MPa; frequency, 1.3 MHz), PFC nanodroplets can undergo phase transition from liquid to gas thus rupturing the lipid bilayer of usl. Small unilamellar liposomes were obtained with appropriate polydispersity and stability. ML1 and the model protein horseradish peroxidase (HRP) were co-encapsulated with the PFC nanodroplets in USL, with 3% and 7% encapsulation efficiency for USL20 and USL10/USL5, respectively. Acoustic characterization experiments indicated that release is induced by cavitation. HIFU-triggered release of HRP from USL was investigated for optimization of liposomal composition and resulted in 80% triggered release for USL with USL10 (60/30/10) lipid composition. ML1 release from the final USL10 composition was also 80%. Given its high stability, suitable release, and ultrasound sensitivity, USL10 encapsulating ML1 was further used to study released ML1 bioactivity against murine CT26 colon carcinoma cells. Confocal live-cell imaging demonstrated its functional activity regarding the interaction with the target cells. We furthermore demonstrated the cytotoxicity of the released ML1 (I.E., After USL were treated with HIFU). The potent cytotoxicity (IC₅₀ 400 ng/ml; free ML1 IC₅₀ 345 ng/ml) was compared to non-triggered USL loaded with ML1. Our study shows that USL in combination with HIFU hold promise as trigger-sensitive nanomedicines for local delivery of macromolecular cytotoxins.

Targeting delivery of partial VAR2CSA peptide guided N-2-Hydroxypropyl trimethyl ammonium chloride chitosan nanoparticles for multiple cancer types

To developing a multiple cancer types targeting drug delivery carrier system, a 28 amino acids from the VAR2CSA was synthesized as the placental CSA-binding peptide (plCSA-BP). Its specific binding ability to cancer cells was tested on cancer tissue array, and the results showed that plCSA-BP could bind to multiple cancer types. Then, the plCSA-BP was used as a guiding peptide to coat nanoparticles synthesized from N-2-HACC (CSA/HACC-NPs) which were loaded with prodigiosin (CSA/HACC-PNPs) or indocyanine green (CSA/HACC-INPs). The cancer cells specific targeting and efficacy of the CSA/HACC-PNPs were tested by different cancer cells in vitro and various cancer xenograft model in vivo. A scramble peptide (SCR) was used as control and synthesized SCR/HACC-PNPs and SCR/HACC-INPs. The results showed that the CSA/HACC-INPs could specifically uptake by JEG-3, PC3 and A594 cells, and the CSA/HACC-PNPs exhibited better anti-cancer activity and lower toxic effect in subcutaneous choriocarcinoma and prostatic tumor models compared with the free prodigiosin, HACC-PNPs and SCR/HACC-PNPs. So, the CSA/HACC-NPs could be used as a specific delivery carrier for multiple cancer types, and provided an alternate treatment option of various cancers with a single recipe.

Current developments in drug delivery with thermosensitive liposomes

Thermosensitive liposomes (TSLs) have been an important research area in the field of tumor targeted chemotherapy. Since the first TSLs appeared that using 1,2-dipalmitoyl-sn-glyce-ro-3-phosphocholine (DPPC) as the primary liposomal lipid, many studies have been done using this type of liposome from basic and practical aspects. While TSLs composed of DPPC enhance the cargo release near the phase transition temperature, it has been shown that many factors affect their temperature sensitivity. Thus numerous attempts have been undertaken to develop new TSLs for improving their thermal response performance. The main objective of this review is to introduce the development and recent update of innovative TSLs formulations, including combination of radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFU), magnetic resonance imaging (MRI) and alternating magnetic field (AMF). In addition, various factors affecting the design of TSLs, such as lipid composition, surfactant, size and serum components are also discussed.

Understanding the Nano-bio Interfaces: Lipid-Coatings for Inorganic Nanoparticles as Promising Strategy for Biomedical Applications

Inorganic nanoparticles (NPs) exhibit relevant physical properties for application in biomedicine and specifically for both the diagnosis and therapy (i.e. theranostic) of severe pathologies, such as cancer. The inorganic NP core is often not stable in aqueous suspension and can induce cytotoxic effects. For this reason, over the years, several coating strategies were suggested to improve the NP stability in aqueous solutions as well as the NP biocompatibility. Among the various components which can be used for NP coatings, lipids, and in particular phospholipids emerged as versatile molecular building blocks for the production of NP coatings suitable for biomedical application. The recent synthetic efforts in NP lipid coatings allows today to introduce on the NP surface a large variety of lipid molecules eventually in mixture with amphiphilic or hydrophobic drugs or active molecules for cell targeting. In this review, the most relevant examples of NP lipid-coatings are presented and grouped in two main categories: supported lipid bilayers (SLB) and hybrid lipid bilayers (HLB). The discussed scientific cases take into account the most commonly used inorganic NP for biomedical applications in cancer therapy and diagnosis.

Adapting liposomes for oral drug delivery

Liposomes mimic natural cell membranes and have long been investigated as drug carriers due to excellent entrapment capacity, biocompatibility and safety. Despite the success of parenteral liposomes, oral delivery of liposomes is impeded by various barriers such as instability in the gastrointestinal tract, difficulties in crossing biomembranes, and mass production problems. By modulating the compositions of the lipid bilayers and adding polymers or ligands, both the stability and permeability of liposomes can be greatly improved for oral drug delivery. This review provides an overview of the challenges and current approaches toward the oral delivery of liposomes.

Targeting therapeutics to endothelium: are we there yet?

Vascular endothelial cells represent an important therapeutic target in many pathologies, including inflammation, oxidative stress, and thrombosis; however, delivery of drugs to this site is often limited by the lack of specific affinity of therapeutics for these cells. Selective delivery of both small molecule drugs and therapeutic proteins to the endothelium has been achieved through the use of targeting ligands, such as monoclonal antibodies, directed against endothelial cell surface markers, particularly cell adhesion molecules (CAMs). Careful selection of target molecules and targeting agents allows for precise delivery to sites of inflammation, thereby maximizing therapeutic drug concentrations at the site of injury. A good understanding of the physiological and pathological determinants of drug and drug carrier pharmacokinetics and biodistribution may allow for a priori identification of optimal properties of drug carrier and targeting agent. Targeted delivery of therapeutics such as antioxidants and antithrombotic agents to the injured endothelium has shown efficacy in preclinical models, suggesting the potential for translation into clinical practice. As with all therapeutics, demonstration of both efficacy and safety are required for successful clinical implementation, which must be considered not only for the individual components (drug, targeting agent, etc.) but also for the sum of the parts (e.g., the drug delivery system), as unexpected toxicities may arise with complex delivery systems. While the use of endothelial targeting has not been translated into the clinic to date, the preclinical results summarized here suggest that there is hope for successful implementation of these agents in the years to come.

Thermosensitive liposomes for triggered release of cytotoxic proteins

Lysolipid-containing thermosensitive liposomes (LTSL) are clinically-relevant drug nanocarriers which have been used to deliver small molecule cytostatics to tumors in combination with local hyperthermia (42 °C) to trigger local drug release. The objective of this study was to investigate the feasibility of LTSL for encapsulation and triggered release of macromolecular drugs such as plant-derived cytotoxins. As therapeutic protein we used Mistletoe lectin-1 (ML1) - a ribosome-inactivating protein with potent cytotoxic activity in tumor cells. Model macromolecules (dextrans, albumin) and ML1 were encapsulated in small unilamellar LTSL with varying lipid compositions by the thin film hydration method and extrusion. LTSLs showed molecular weight dependent heat-triggered release of the loaded cargo. The most promising composition, ML1 formulated in LTSL composed of 86:10:4 %mol DPPC:MSPC:DSPE-PEG₂₀₀₀, was further studied for bioactivity against murine CT26 colon carcinoma cells. Confocal live-cell imaging showed uptake of released ML1 after mild hyperthermia at 42 °C, subsequently leading to potent cytotoxicity by LTSL-ML1. Our study shows that LTSL in combination with localized hyperthermia hold promise as local tumor delivery strategy for macromolecular cytotoxins.