Thermosensitive Liposomes Research Articles

Influence of Phase Transitions on Diffusive Molecular Transport Across Biological Membranes

AbstractPhase transitions of lipid bilayer membranes should affect passive transport of molecules. While this hypothesis has been used to design drug‐releasing thermosensitive liposomes, the effect has yet to be quantified. Herein, we use time‐resolved second harmonic light scattering to measure transport of a molecular cation across membranes of unilamellar liposomes composed of the total lipid extract of E. coli from 9 °C to 36 °C, in which two distinct phase transitions (gel to liquid‐disordered phase) have been identified. While the transport rate slowly increases with temperature as a diffusion process, dramatic jumps are observed at 14.7 °C and 27.6 °C, the known phase transitions. The transport rate constant measured as (7.3±0.8)×10−3 s−1 in the liquid‐disordered phase at 36 °C is 35‐times faster than (2.1±0.2)×10−4 s−1 of the gel phase at 9 °C. For the mixed‐phase between these two phases, the measured rates are consistent with a structure of gel domains among a liquid‐disordered bulk.

Influence of Phase Transitions on Diffusive Molecular Transport Across Biological Membranes.

Phase transitions of lipid bilayer membranes should affect passive transport of molecules. While this hypothesis has been used to design drug-releasing thermosensitive liposomes, the effect has yet to be quantified. Herein, we use time-resolved second harmonic light scattering to measure transport of a molecular cation across membranes of unilamellar liposomes composed of the total lipid extract of E. coli from 9 °C to 36 °C, in which two distinct phase transitions (gel to liquid-disordered phase) have been identified. While the transport rate slowly increases with temperature as a diffusion process, dramatic jumps are observed at 14.7 °C and 27.6 °C, the known phase transitions. The transport rate constant measured as (7.3±0.8)×10-3 s-1 in the liquid-disordered phase at 36 °C is 35-times faster than (2.1±0.2)×10-4 s-1 of the gel phase at 9 °C. For the mixed-phase between these two phases, the measured rates are consistent with a structure of gel domains among a liquid-disordered bulk.

Aptamer-functionalized quercetin thermosensitive liposomes for targeting drug delivery and antitumor therapy

Chemo-thermotherapy, as a promising cancer combination therapy strategy, has attracted widespread attention. In this study, a novel aptamer functionalized thermosensitive liposome encapsulating hydrophobic drug quercetin was fabricated as an efficient drug delivery system. This aptamer-functionalized quercetin thermosensitive liposomes (AQTSL) combined the merits of high-loading yield, sustained drug release, long-term circulation in the body of PEGylated liposomes, passive targeting provided by 100–200 nm nanoparticles, active targeting and improved internalization effects offered by AS1411 aptamer, and temperature-responsive of quercetin release. In addition, AQTSL tail vein injection combined with 42 °C water bath heating on tumor site (AQTSL + 42 °C)treatment inhibited the tumor growth significantly compared with the normal saline administration (p < 0.01), and the inhibition rate reached 75%. Furthermore, AQTSL + 42 °C treatment also slowed down the tumor growth significantly compared with QTSL combined with 42 °C administration (p < 0.05), confirming that AS1411 decoration on QTSL increased the active targeting and internalization effects of the drug delivery system, and AS1411 aptamer itself might also contribute to the tumor inhibition. These data indicate that AQTSL is a potential carrier candidate for different hydrophobic drugs and tumor targeting delivery, and this kind of targeted drug delivery system combined with temperature responsive drug release mode is expected to achieve an ideal tumor therapy effect.

Two-Wave Variable Nanotheranostic Agents for Dual-Mode Imaging-Guided Photo-Induced Triple-Therapy for Cancer.

Photothermal therapy (PTT) is a promising strategy for cancer treatment, but its clinical application relies heavily on accurate tumor positioning and effective combination. Nanotheranostics has shown superior application in precise tumor positioning and treatment, bringing potential opportunities for developing novel PTT‐based therapies. Here, a nanotheranostic agent is proposed to enhance magnetic resonance imaging (MRI)/ near‐infrared fluorescence imaging (NIRFI) imaging‐guided photo‐induced triple‐therapy for cancer. Thermosensitive liposomes co‐loaded with SPIONs/IR780 and Abemaciclib (SIA‐TSLs), peptide ACKFRGD, and click group 2‐cyano‐6‐amino‐benzothiazole (CABT) are co‐modified on the surface of SIA‐TSLs to form SIA‐αTSLs. ACKFRGD can be hydrolyzed to expose the 1, 2‐thiolamino groups in the presence of cathepsin B in tumors, which click cycloaddition with the cyano group on CABT, resulting in the formation of SIA‐αTSLs aggregates. The aggregation of SIA‐αTSLs in tumors enhances the MRI/NIRFI imaging capability and enables precise PTT. Photo‐induced triple‐therapy enhances precision cancer therapy. First, PTT ablates specific tumors and induces ICD via localized photothermal. Second, local tumor heating promotes the rupture of SIA‐αTSLs, which release Abemaciclib to block the tumor cell cycle and inhibit Tregs proliferation. Third, injecting GM‐CSF into tumor tissue leads to recruitment of dendritic cells and initiation of antitumor immunity. Collectively, these results present a promising nanotheranostic strategy for future cancer therapy.

Selecting ideal drugs for encapsulation in thermosensitive liposomes and other triggered nanoparticles

Objective Thermosensitive liposomes (TSL) and other triggered drug delivery systems (DDS) are promising therapeutic strategies for targeted drug delivery. However, successful designs with candidate drugs depend on many variables, including nanoparticle formulation, drug properties, and cancer cell properties. We developed a computational model based on experimental data to predict the potential efficacies of drugs when used with triggered DDS, such as TSL. Methods A computer model based on the Krogh cylinder was developed to predict uptake and cell survival with four anthracyclines when delivered by intravascular triggered DDS (e.g., TSL): doxorubicin (DOX), idarubicin (IDA), pirarubicin (PIR), and aclarubicin (ACLA). We simulated three tumor types derived from SVR angiosarcoma, LLC lung cancer, or SCC-1 oral carcinoma cells. In vitro cellular drug uptake and cytotoxicity data were obtained experimentally and incorporated into the model. Results For all three cell lines, ACLA and IDA had the fastest cell uptake, with slower uptake for DOX and PIR. Cytotoxicity was highest for IDA and lowest for ACLA. The computer model predicted the highest tumor drug uptake for ACLA and IDA, resulting from their rapid cell uptake. Overall, IDA was most effective and produced the lowest tumor survival fraction, with DOX being the second best. Perivascular drug penetration was reduced for drugs with rapid cell uptake, potentially limiting delivery to cancer cells distant from the vasculature. Conclusion Combining simple in vitro experiments with a computer model could provide a powerful screening tool to evaluate the potential efficacy of candidate investigative drugs preceding TSL encapsulation and in vivo studies.

Thermoresponsive Liposomes for Photo-Triggered Release of Hypericin Cyclodextrin Inclusion Complex for Efficient Antimicrobial Photodynamic Therapy.

Antimicrobial strategies with high efficacy against bacterial infections are urgently needed. The development of effective therapies to control bacterial infections is still a challenge. Herein, near-infrared (NIR)-activated thermosensitive liposomes (TSL) were loaded with the NIR-dye 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide (DiR) and the water-soluble hypericin (Hyp) β-cyclodextrin inclusion complex (Hyp-βCD). DiR and Hyp-βCD loaded thermosensitive liposomes (DHβCD-TSL) are functionalized for photothermal triggered release and synergistic photodynamic therapy to eliminate the gram-positive Staphylococcus saprophyticus. The dually active liposomes allow the production of heat and singlet oxygen species with the help of DiR and Hyp, respectively. The elevated temperature, generated by the NIR irradiation, irreversibly damages the bacterial membrane, increases the permeation, and melts the liposomes via a phase-transition mechanism, which allows the release of the Hyp-βCD complex. The photodynamic effect of Hyp-βCD eradicates the bacterial cells owing to its toxic oxygen species production. DHβCD-TSL measured the size of 130 nm with an adequate encapsulation efficiency of 81.3% of Hyp-βCD. They exhibited a phase transition temperature of 42.3 °C, while they remained stable at 37 °C, and 44% of Hyp-βCD was released after NIR irradiation (T > 47 °C). The bacterial viability dropped significantly after the synergistic treatment (>4 log10), indicating that the NIR-activated TSL have immense therapeutic potential to enhance the antibacterial efficacy. The liposomes showed good biocompatibility, which was confirmed by the cellular viability of mouse fibroblasts (L929).

Sequential Dual Delivery System Based on siCOX-2-Loaded Gold Nanostar and Thermal-Sensitive Liposomes Overcome Hypoxia-Mediated Multidrug Resistance in Tumors.

Reversing hypoxia-mediated multidrug resistance (MDR) presents a unique challenge in clinical chemotherapy. Here, a sequential dual delivery system composited with Cyclooxygenase-2 siRNA (siCOX-2) in poly-d-arginine (9R)/2-deoxyglucose (DG)-loaded gold nanostar (GNS) (siCOX-2@RDG) and paclitaxel (PTX)-loaded thermosensitive liposome (PTSL) was proposed to conquer the hypoxia-mediated MDR in tumors. As a result, the prepared siCOX-2@RDG exhibited a starlike morphology with a uniform particle size of 194.36 ± 1.44 nm and a ζ-potential of -11.83 ± 2.01 mV. In vitro, PTSL displayed expected thermal-responsive release properties. As expected, siCOX-2@RDG displayed exceptional DG-mediated hypoxia-targeting capability both in vitro and in vivo and downregulated the expression of COX-2 successfully. Meanwhile, GNS-triggered hyperthermia elevated the cellular uptake of PTSL in PTX-resistant HepG2(HepG2/PTX) cells in vitro and enhanced the permeability of tumor tissues, thus elevating the valid retention of PTX into solid tumors. Finally, we demonstrated that the sequential dual systems composed of siCOX-2@RDG and PTSL could reverse hypoxia-mediated MDR and exhibit excellent synergistic antitumor effects both in vitro and in vivo, prolonging the survival of tumor-bearing mice. The devised sequential dual systems, composed of two independent nanosystems, have a promising potential to overcome hypoxia-mediated MDR in clinical practice.

Iron oxide nanoflowers encapsulated in thermosensitive fluorescent liposomes for hyperthermia treatment of lung adenocarcinoma

Magnetic hyperthermia (MHT) is in the spotlight of nanomedical research for the treatment of cancer employing magnetic iron oxide nanoparticles and their intrinsic capability for heat dissipation under an alternating magnetic field (AMF). Herein we focus on the synthesis of iron oxide nanoflowers (Nfs) of different sizes (15 and 35 nm) and coatings (bare, citrate, and Rhodamine B) while comparing their physicochemical and magnetothermal properties. We encapsulated colloidally stable citrate coated Nfs, of both sizes, in thermosensitive liposomes via extrusion, and RhB was loaded in the lipid bilayer. All formulations proved hemocompatible and cytocompatible. We found that 35 nm Nfs, at lower concentrations than 15 nm Nfs, served better as nanoheaters for magnetic hyperthermia applications. In vitro, magnetic hyperthermia results showed promising therapeutic and imaging potential for RhB loaded magnetoliposomes containing 35 nm Nfs against LLC and CULA cell lines of lung adenocarcinoma.

A biomimetic and bioactive scaffold with intelligently pulsatile teriparatide delivery for local and systemic osteoporosis regeneration.

Osteoporosis is one of the most disabling consequences of aging, osteoporotic fractures and higher risk of the subsequent fractures leading to substantial disability and deaths, indicating both local fractures healing and the early anti-osteoporosis therapy are of great significance. Teriparatide is strong bone formation promoter effective in treating osteoporosis, while side effects limit clinical applications. Traditional drug delivery is lack of sensitive and short-term release, finding a new non-invasive and easily controllable drug delivery to not only repair the local fractures but also improve total bone mass has remained a great challenge. Thus, bioinspired by the natural bone components, we develop appropriate interactions between inorganic biological scaffolds and organic drug molecules, achieving both loaded with the teriparatide in the scaffold and capable of releasing on demand. Herein, biomimetic bone microstructure of mesoporous bioglass, a near-infrared ray triggered switch, thermosensitive liposomes based on a valve, and polydopamine coated as a heater is developed rationally for osteoporotic bone regeneration. Teriparatide is pulsatile released from intelligent delivery, not only rejuvenating osteoporotic bone defect, but also presenting strong systemic anti-osteoporosis therapy. This biomimetic bone carrying novel drug delivery platform is well worth expecting to be a new promising strategy and clinically commercialized to help patients survive from the osteoporotic fracture.

In vitro and in vivo activity of thermosensitive liposomes loaded with doxorubicin and cisplatin

Thermosensitive liposomes loaded with cisplatin and doxorubicin composed of DPPC, DSPC, and DPPE-PEG5000 with different ratios were prepared by thin film hydration method. The Differential Scanning Calorimetry (DSC) curves showed that the liposomes composed of DPPC-DSPC-DPPE-PEG5000 with phospholipid ratio 95:5:0.05 w/w were a suitable formulation as thermosensitive liposomes with a DSC peak at 42.1 °C. The effect of doxorubicin and cisplatin encapsulated non-thermosensitive and thermosensitive liposomes on cellular proliferation and IC50 in SKBR3 & MDA-MB-231 breast cancer and PC-3 & LNcaP prostate cancer cell lines was investigated. The results showed that doxorubicin loaded into thermosensitive liposomes showed 20-fold decrease in the IC50 at 42 °C while comparing it with the same at 37 °C. Also, the results showed a more than 35-fold and 12-fold decrease in the IC50 of cisplatin thermosensitive liposomes at 42 °C, while compared with free cisplatin and cisplatin thermosensitive liposomes at any temperature. The in vivo results showed that the effect of doxorubicin encapsulated thermosensitive liposomes at hyperthermic conditions during the treatment as the tumor growth inhibition was measured 1.5-fold higher than any of the liposomal formulations of doxorubicin. It was also noticed that the tumor volume reduced to 150 mm3 in doxorubicin thermosensitive liposomes (G8) after 3 weeks during the treatment, but increased to 196 mm3 after 4 weeks. The Kaplan-Meir curve showed the 100% survival of the animals from G8 (thermosensitive liposomes containing doxorubicin plus hyperthermia) after 12 weeks. The flow cytometry data revealed more than 25% apoptotic cells and 6.25% necrotic cells in the tumor cells from the tissues of the G8 group of the animals. The results clearly indicate the superior efficacy of doxorubicin and cisplatin containing thermosensitive liposomes treatment during hyperthermia.

Analysis of Magneto-Hyperthermia Duration in Nano-sized Drug Delivery System to Solid Tumors Using Intravascular-Triggered Thermosensitive-Liposome.

Computational models have been developed as a potential platform to identify bio-interactions that cannot be properly understood by experimental models. In the present study, a mathematical model has been employed to investigate the therapeutic response of drug-loaded thermosensitive liposome (TSL) following intravascular release paradigm. Thermal field created by an alternating magnetic field is utilized to release the drug within microvessels. Determining the time required for the application of magneto-hyperthermia is the main purpose of this study. Results show that applying a long-term continuous or pulsed hyperthermia can affect the concentration level of drugs in the extracellular space. The peak value of free and bound drug concentrations in the extracellular space is equal for all hyperthermia programs. Additionally, the concentrations of free and bound drugs are retained at a higher level in pulsed mode compared to the continuous mode (i.e., area under curve (AUC) of pulsed case is slightly higher than continuous case). However, there is no significant difference in bioavailability time. Hence, onset time of tumor growth is similar for different conditions. This study shows that the appropriate time to apply hyperthermia is post-bolus injection until reaching the peak concentration profile in extracellular space. Therefore, in clinical applications similar to the present study's circumstances, continuous hyperthermia for 30min can be a better choice. This study can be a useful guideline for experimental studies to reduce the number of in vivo tests as well as for clinical trials to make the right decision to provide optimal medication programs.

Pharmaceutical Development and Design of Thermosensitive Liposomes Based on the QbD Approach.

This study aimed to produce thermosensitive liposomes (TSL) by applying the quality by design (QbD) concept. In this paper, our research group collected and studied the parameters that significantly impact the quality of the liposomal product. Thermosensitive liposomes are vesicles used as drug delivery systems that release the active pharmaceutical ingredient in a targeted way at ~40–42 °C, i.e., in local hyperthermia. This study aimed to manufacture thermosensitive liposomes with a diameter of approximately 100 nm. The first TSLs were made from DPPC (1,2-dipalmitoyl-sn-glycerol-3-phosphocholine) and DSPC (1,2-dioctadecanoyl-sn-glycero-3-phosphocholine) phospholipids. Studies showed that the application of different types and ratios of lipids influences the thermal properties of liposomes. In this research, we made thermosensitive liposomes using a PEGylated lipid besides the previously mentioned phospholipids with the thin-film hydration method.

Synergic fabrication of multifunctional liposomes nanocomposites for improved radiofrequency ablation combination for liver metastasis cancer therapy

The field of biomedical research has recently been interested in nanoplatforms with various functionalities, such as cancer drug carriers and MRI and optical imaging, as well as thermal treatment, among other things. As a result of the present investigation, a unique multifunctional liposome (MFL) was established in this investigation. Using radiofrequency-induced imaging and drug release based on magnetic field impact, a dual drug delivery targeted with tumor multi-mechanism treatment was made more effective. The C60 (fullerene) surface was coated with iron nanocomposites to establish the proposed nanosystems, and PEGylation was used (Fe3O4-C60-PEG2000). For fullerene radiofrequency-triggered drug release, thermosensitive DPPC liposomes with folate-DSPE-PEG2000 enveloped the binary nanosystems and doxorubicin (DOX). The in vitro cytotoxicity of the nanocomposites was confirmed by the liver metastasis in HT-29 colon cancer cells using radiofrequency. The flow cytometry analysis confirmed the apoptosis cell death mechanism. The thermal treatment combined chemotherapeutic MFL nano framework transformed radiofrequency radiation from thermoresponsive liposomes, which was noticed both in vivo and in vitro. Due to their superior active tumor targeting and magnetic targeting characteristics, the MFL could also selectively destroy cancerous liver cells in highly co-localized targets.

Hyperthermia-induced doxorubicin delivery from thermosensitive liposomes via MR-HIFU in a pig model

PurposeEncapsulation of cytotoxic drugs for a localized release is an effective way to increase the therapeutic window of such agents. In this article we present the localized release of doxorubicin (DOX) from phosphatidyldiglycerol (DPPG2) based thermosensitive liposomes using MR-HIFU mediated hyperthermia in a swine model. Materials and methodsGerman landrace pigs of weights between 37.5 and 53.5 kg received a 30-min infusion of DOX containing thermosensitive liposomes (50 mg DOX/m2). The pigs' biceps femoris was treated locally in two separate target areas with mild hyperthermia using magnetic resonance guided high intensity focused ultrasound, starting 10 min and 60 min after initiation of the infusion, respectively. The pharmacokinetics and biodistribution of DOX were determined and an analysis of the treatment parameters' influence was performed. ResultsCompared to untreated tissue, we found a 15-fold and a 7-fold increase in DOX concentration in the muscle volumes that had undergone hyperthermia starting 10 min and 60 min after the beginning of the infusion, respectively. The pharmacokinetic analysis showed a prolonged circulation time of DOX and a correlation between the AUC of extra-liposomal DOX in the bloodstream and the amount of DOX accumulated in the target tissue. ConclusionsWe have demonstrated a workflow for MR-HIFU hyperthermia drug delivery that can be adapted to a clinical setting, showing that HIFU-hyperthermia is a suitable method for local drug release of DOX using DPPG2 based thermosensitive liposomes in stationary targets. Using the developed pharmacokinetic model, an optimization of the drug quantity deposited in the target via the timing of infusion and hyperthermia should be possible.

Thermosensitive liposomes containing cisplatin functionalized by hyaluronic acid: preparation and physicochemical characterization

Thermosensitive liposomes containing cisplatin functionalized by hyaluronic acid: preparation and physicochemical characterization

Stepwise photothermal therapy and chemotherapy by composite scaffolds of gold nanoparticles, BP nanosheets and gelatin immobilized with doxorubicin-loaded thermosensitive liposomes.

In recent years, the synergistic effect of photothermal therapy (PTT) and chemotherapy has been recognized as an effective strategy for cancer treatment. Controlling the PTT temperature and drug release profile is desirable for minimizing the unexpected damage to normal cells. In this study, a smart platform of stepwise PTT and chemotherapy has been developed by using composite porous scaffolds of biodegradable black phosphorus (BP) nanosheets, gold nanorods(AuNRs), doxorubicin (Dox)-encapsulated thermosensitive liposomes and biodegradable polymers. Under near-infrared (NIR) laser irradiation, the composite scaffolds could attain high and low local temperatures before and after BP degradation, respectively. Dox release from the composite scaffolds could be controlled by the temperature change. In vitro cell culture and in vivo animal experiments indicated that a strong synergistic effect of PTT and chemotherapy could be achieved at an early stage of treatment before BP degradation, and a mild hyperthermia effect was shown for chemotherapy in the late stage after BP degradation. Moreover, the composite scaffolds after the complete release of Dox could support the proliferation of mesenchymal stem cells. The composite scaffolds showed a synergistic effect of stepwise PTT and chemotherapy for breast cancer elimination and promoted stem cell activities after killing cancer cells.

Doxorubicin-encapsulated thermosensitive liposome-functionalized photothermal composite scaffolds for synergistic photothermal therapy and chemotherapy.

Synergistic therapy, especially the combination of photothermal therapy and chemotherapy, has been proposed as an effective therapeutic approach for breast cancer treatment. In this study, a smart platform for synergistic photothermal therapy and chemotherapy was developed by hybridizing doxorubicin-encapsulated thermosensitive liposomes and gold nanorods into porous scaffolds of gelatin and polyglutamic acid (Dox-lipo/AuNR/Gel/PGA). The Dox-lipo/AuNR/Gel/PGA composite scaffolds had good photothermal conversion and temperature-dependent doxorubicin release properties. Under near-infrared laser irradiation, the composite scaffolds increased the local temperature to not only kill the breast cancer cells in the scaffolds but also accelerate the release of doxorubicin to eliminate the breast cancer cells surrounding the scaffolds. In vitro cell culture and in vivo mouse experiments demonstrated that the synergistic effects of photothermal ablation combined with doxorubicin-induced inhibition of the breast cancer cells in and surrounding the composite scaffolds under near-infrared laser irradiation. Moreover, after drug release was complete, the composite scaffolds fostered human bone marrow-derived mesenchymal stem cell proliferation. These results suggested that the composite scaffolds provided synergistic photothermal therapy and chemotherapy for breast cancer cell elimination at the early stage and promoted stem cell activities at the late stage. Therefore, this composite scaffold holds great potential as a synergistic therapy platform for breast cancer treatment.

Near-infrared-II light excitation thermosensitive liposomes for photoacoustic imaging-guided enhanced photothermal-chemo synergistic tumor therapy

Despite the great success of photothermal therapy (PTT), it still suffers from many obstacles, such as the limited penetration depth of light, thermoresistance of tumors, and limitations of mono-therapeutic modalities. Herein, second near-infrared (NIR-II, 1064 nm) light excitation thermosensitive liposomes (DG@TLs) were fabricated for photoacoustic imaging (PAI) guided enhanced PTT-chemotherapy. DG@TLs were constructed by encapsulating NIR-II light excitation semiconducting polymers into liposomes composed of phase change materials (PCMs), along with gambogic acid (GA) with chemotherapeutic and heat shock protein inhibition effects. Under 1064 nm laser irradiation, DG@TLs exhibited superior NIR-II PAI and PTT performances with deep tissue penetration while triggering the thermoresponsive release of GA based on the phase transition of PCMs from solid to liquid. The released GA could enhance the NIR-II PTT efficacy by inhibiting the activity of HSP90, reducing the thermoresistance of tumors, exhibiting significant chemotherapeutic effects, and achieving synergistic anti-tumor efficiency. This work provides a new strategy for achieving on-demand drug release and effective theranostics in deep-seated tumor regions.

Computational Modeling of Combination of Magnetic Hyperthermia and Temperature-Sensitive Liposome for Controlled Drug Release in Solid Tumor.

Combination therapy, a treatment modality that combines two or more therapeutic methods, provides a novel pathway for cancer treatment, as it targets the region of interest (ROI) in a characteristically synergistic or additive manner. To date, liposomes are the only nano-drug delivery platforms that have been used in clinical trials. Here, we speculated that it could be promising to improve treatment efficacy and reduce side effects by intravenous administration of thermo-sensitive liposomes loaded with doxorubicin (TSL-Dox) during magnetic hyperthermia (MHT). A multi-scale computational model using the finite element method was developed to simulate both MHT and temperature-sensitive liposome (TSL) delivery to a solid tumor to obtain spatial drug concentration maps and temperature profiles. The results showed that the killing rate of MHT alone was about 15%, which increased to 50% using the suggested combination therapy. The results also revealed that this combination treatment increased the fraction of killed cells (FKCs) inside the tumor compared to conventional chemotherapy by 15% in addition to reducing side effects. Furthermore, the impacts of vessel wall pore size, the time interval between TSL delivery and MHT, and the initial dose of TSLs were also investigated. A considerable reduction in drug accumulation was observed in the tumor by decreasing the vessel wall pore size of the tumor. The results also revealed that the treatment procedure plays an essential role in the therapeutic potential of anti-cancer drugs. The results suggest that the administration of MHT can be beneficial in the TSL delivery system and that it can be employed as a guideline for upcoming preclinical studies.

Macrophage membrane- and cRGD-functionalized thermosensitive liposomes combined with CPP to realize precise siRNA delivery into tumor cells

Despite the success of small interfering RNAs (siRNAs) in clinical settings, their fast clearance and poor delivery efficiency to target cells still hinder their therapeutic effect. Herein, a new treatment system was constructed by combining thermosensitive liposomes with the macrophage membrane, tumor-targeting cyclic Arg-Gly-Asp peptide, a cell-penetrating peptide, and thermotherapy. The constructed system was found to be thermosensitive and stable; the proteins were inherited from the macrophage membrane. This new system combined with thermotherapy displayed the least uptake by macrophages, the greatest uptake by HepG2 cells, the most obvious HepG2 cell apoptosis, and the strongest inhibition of Bcl-2 mRNA and Bcl-2 protein in HepG2 cells. Moreover, 24 h after system administration in tumor-bearing mice, the most prominent distribution of siRNA was observed in tumors, while almost no siRNA was found in other organs. The strongest inhibition of Bcl-2 mRNA, Bcl-2 protein, and tumors was found in mice that had received the proposed system. In summary, when using the constructed system both in vitro and in mice, less uptake by the reticuloendothelial system, greater accumulation in tumor cells, and improved therapeutic efficacy were observed. Therefore, this new system can deliver siRNA selectively and efficiently, and it is a promising therapeutic candidate for precise tumor-targeted therapy.