Liposomal Doxorubicin Research Articles

What are the harms and benefits of using pegylated liposomal doxorubicin in women with recurrent epithelial ovarian cancer, alone or in combination with other drugs? (Russian translation of the Plain Language Summary (PLS) of the Cochrane Systematic Review)

This publication is the Russian translation of the Plain Language Summary (PLS) of the Cochrane Systematic Review: Newhouse R, Nelissen E, El-Shakankery KH, Rogozińska E, Bain E, Veiga S, Morrison J. Pegylated liposomal doxorubicin for relapsed epithelial ovarian cancer. Cochrane Database of Systematic Reviews 2023, Issue 7. Art. No.: CD006910. DOI: 10.1002/14651858.CD006910.pub3.

CTNI-08. DOSE ADJUSTED TEDDI-R FOR PRIMARY CNS DIFFUSE LARGE B-CELL LYMPHOMA

Abstract We report our initial experience treating 4 patients with the dose adjusted TEDDI-R protocol as reported by Dunleavy et al in 2015. The median age was 63 years, 2 patients were male, median KPS 60. Two patients were newly diagnosed: one of these had inadequate renal function for methotrexate; and the other had experienced acute methotrexate leukoencephalopathy. Two patients were treated for their first recurrence, having progressed during therapy with the MT-R protocol; one of these received salvage WBRT prior to starting. The protocol consisted of temozolomide 90 mg/sq m IV, cycles 1-6, days 2-5; etoposide 45 mg/sq m/day IV cycles 1-6, Days 2-5; liposomal doxorubicin 40 mg/sq m IV, cycles 1-6, day 2; dexamethasone 10 mg PO bid, cycles 1-6, days 1-5; ibrutinib 560 mg qd starting 3 days before cycle 1, day 1, then 560 mg qd, cycles 1-6, days 1-10; rituximab 375 mg/sq m IV cycles 1-6, days 1-2; and cytarabine 70 mg via Ommaya reservoir, cycles 2-6, days,1 and 5. Aspergillosis prophylaxis with isavuconazonium 372 mg mg PO bid was used. Overall, only 1 patient completed all 6 planned cycles; the median number of cycles completed was 4.5. Both newly diagnosed patients died during therapy; one died after 1 cycle from CMV colitis, and the other after 5 cycles from tumor recurrence, pneumonia, and septic shock. One patient with recurrent disease achieved a complete response and went on to high dose chemotherapy and autologous bone marrow transplantation; the other had a partial response after 4 cycles but died from pulmonary embolism. Median PFS for the newly diagnosed patients was 177 days, and for the recurrent patients, 221 days. Median OS for the cohort was 242 days. These preliminary data suggest that the TEDDI-R protocol was relatively toxic, especially for patients with poor neurological function, but can be an effective salvage therapy after progression on methotrexate-based therapy.

Real-world comparative Analysis of Liposomal Doxorubicin versus Paclitaxel as First-Line Therapy for Kaposi Sarcoma.

Real-world comparative Analysis of Liposomal Doxorubicin versus Paclitaxel as First-Line Therapy for Kaposi Sarcoma.

Pegylated liposomal doxorubicin in partially platinum-sensitive, platinum-resistant, or platinum-refractory ovarian cancer: a prospective study.

This study aimed to evaluate the efficacy and safety of pegylated liposomal doxorubicin (PLD) for patients with partially platinum-sensitive, platinum-resistant, or platinum-refractory ovarian cancer. Patients with partially platinum-sensitive, platinum-resistant, or platinum-refractory ovarian cancer were recruited in this prospective, open-label, single-arm, multicenter study. Eligible patients were given 4-6 cycles of PLD (40mg/m2 on day 1, every 4 weeks). The primary endpoint was progression-free survival (PFS). Secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), quality of life, and safety. Exploratory endpoints included the change trend of CA125 and platinum-free interval. Between June 2017 and November 2020, 167 eligible patients were included in the full analysis set. The median PFS and OS were 6.8 months (95% CI, 4.4-9.3 months) and 19.1 months (95% CI, 15.0-23.3 months), respectively. The ORR and DCR were 32.3% and 60.5%, respectively. The ORR (62.3 vs 22.5%) and DCR (84.9 vs 60.7%) of patients with a CA125 decrease after the first cycle were significantly higher than those without a CA125 decrease (all P < .05). Grade ≥ 3 and serious adverse events were reported in 9.9% and 3.9% of patients, respectively. No treatment-related death was observed. PLD showed promising efficacy and manageable tolerability in patients with partially platinum-sensitive, platinum-resistant, or platinum-refractory ovarian cancer.ClinicalTrials.gov Identifier: Chinese Clinical Trial Registry, ChiCTR1900022962.

Intratumoral lactic acid neutralization strategy for boosting chemoimmunotherapy using liposomal sodium bicarbonate

Glycolysis-related lactic acid overproduction creates an “ion-trapping” barrier and immunosuppressive tumor microenvironment that compromise effective intratumoral drug delivery and therapy. Therefore, normalization of tumor microenvironment via lactic acid neutralization can be a promising avenue for overcoming this therapeutic hurdle. In this study, the flexible liposomes loaded with sodium bicarbonate (NaHCO3@Flip) were used as a nano-adjuvant to boost chemoimmunotherapy. Their effects on assisting DOXIL and anti-PD-1 therapy were investigated. NaHCO3@Flip achieved deep tumor penetration, with the ability to neutralize lactic acid and normalize the acidic tumor microenvironment. NaHCO3@Flip is biosafe and can enhance cellular uptake efficiency of doxorubicin (DOX) by overcoming the ion-trapping barrier and amplify immunogenic cell death induced by DOX. The combination therapy of liposomal DOX and NaHCO3@Flip demonstrated enhanced inhibition of tumor growth. NaHCO3@Flip can also synergize with PD-1 antibody therapy. NaHCO3@Flip has the potential to serve as a therapeutic adjuvant for boosting chemoimmunotherapy by overcoming the ion-trapping effect and normalizing the tumor microenvironment.

Nanoparticle-Binding Immunoglobulins Predict Variable Complement Responses in Healthy and Diseased Cohorts.

Systemic administration of nanomedicines results in the activation of the complement cascade, promoting phagocytic uptake and triggering proinflammatory responses. Identifying the biomarkers that can predict the "risk" of abnormally high complement responders can improve the safety and efficacy of nanomedicines. Polyethylene glycol (PEG) and dextran are two types of clinically approved polymer coatings that trigger complement activation. We performed a multifaceted analysis of the factors affecting the complement activation by PEGylated liposomal doxorubicin (PLD) and dextran-coated superparamagnetic iron oxide nanoworms (SPIO NWs) in plasma from patients with different inflammatory disease conditions and healthy donors. The complement activation (measured as deposition of the complement protein C3) varied greatly, with 29-fold and 26-fold differences for PLD and SPIO NWs, respectively. Chronic inflammation, acute infection, use of steroids, and sex had minor effects on the variable complement activation, whereas age inversely correlated with the complement activation. C-reactive protein level was not predictive of high (top 20th percentile) complement responses. Plasma concentrations of the main complement factors, as well as total IgG and IgM, showed no correlation with the activation by either nanoparticle. On the other hand, plasma concentrations of anti-PEG IgG and IgM showed a strong positive correlation with the activation by PLD. Particularly, titers of anti-PEG IgM showed the best predictive value for the "risk" of high complement activation by PLD. Titers of antidextran IgG and IgM showed a lower correlation with the activation by SPIO NWs and poor predictive value of the top 20% complement responses. Nanoparticle-bound immunoglobulins showed the best correlation with complement activation and a strong predictive value, supporting the critical role of immunoglobulins in inciting complement. The opsonization of PLD with C3 in plasma with high anti-PEG antibodies was predominantly via the alternative pathway. Characterizing the nature of nanoparticle-binding antibodies has important implications in mitigating and stratifying nanomedicine safety.

Cediranib and Olaparib Combination Compared With Cediranib or Olaparib Alone, or Chemotherapy in Platinum-Resistant or Primary Platinum-Refractory Ovarian Cancer: NRG-GY005.

We assessed the efficacy of cediranib, olaparib, and cediranib/olaparib compared with standard-of-care chemotherapy (SOC) in platinum-resistant or platinum-refractory epithelial ovarian cancer (PROC). NRG-GY005 is an open-label, four-arm, phase II/III superiority trial enrolling patients with high-grade serous/endometrioid PROC and one to three previous therapies. Key exclusion criteria included previous receipt of poly(ADP-ribose) polymerase inhibitor or receipt of antiangiogenic therapy in the recurrent setting. Treatment arms (SOC [once weekly paclitaxel, topotecan, or pegylated liposomal doxorubicin], cediranib, olaparib, or cediranib/olaparib) were equally randomized. A preplanned interim futility analysis on the basis of progression-free survival (PFS) selected treatment arms to advance to phase III. PFS and overall survival (OS) were phase III coprimary end points, with hierarchical testing of PFS followed by OS to preserve type 1 error control, designed to have 90% power for a 0.625 PFS hazard ratio (HR). OS was tested after PFS in the multiple hierarchical testing procedure. Secondary end points included objective response rate (ORR) and patient-reported outcomes. Five hundred sixty-two eligible patients were enrolled for phase II/III. Three arms met PFS criteria to carry forward to phase III (SOC, cediranib/olaparib, and cediranib). Median PFS was 3.4, 5.2, and 4 months with SOC, cediranib/olaparib, and cediranib, respectively, with a median follow-up duration of 42.2 months. PFS HR estimates for cediranib/olaparib and cediranib (v SOC) were 0.796 (98.3% CI, 0.597 to 1.060) and 0.972 (98.3% CI, 0.726 to 1.300), respectively. Median OS was 13.6, 12.8, and 10.5 months, and of 443 patients with measurable disease, ORR was 8.6%, 24.7%, and 13.1% for SOC, cediranib/olaparib, and cediranib, respectively. No new safety signals were identified. In patients receiving cediranib/olaparib, no statistically significant difference was observed on the NFOSI-DRS-P subscale compared with SOC (98.3% CI, -1.3 to 1.5, P = .8725). The cediranib-containing arms demonstrated clinical activity on the basis of PFS but were not superior compared with SOC.

Developing a delivery strategy for combined drug treatment with multi-targeting immunoliposomes

With the use of targeting delivery systems, drugs can be specifically administered to tumor cells based on the abundant expression of cell surface markers with minimal expression in normal cells. However, development of treatments using this highly specific approach requires empirical optimization of the tumor cell type, cell surface markers and cytotoxic cargo. In this study, we developed a combined targeting drug delivery strategy for lung cancer that utilizes two liposome-encapsulated topoisomerase inhibitors, liposomal doxorubicin (LD) and liposomal irinotecan (LI). First, we evaluated different combination conditions for the drugs and found that co-administration or administration of LD followed by LI produced similar tumor inhibition trends. In contrast, treatment of with LI followed by LD was less effective at inhibiting tumor growth. Next, we targeted the liposomes against two ligands that are overexpressed in lung cancers: PD-L1 and GRP-78. To do so, we fabricated immunoliposomes conjugated with PD-L1 Fab or GRP-78 antibody. In animal models, combinations of GRP-78-targeted LI and PD-L1-targeted LD showed 92% tumor inhibition which is higher than other combination treatments or each drug alone. Our findings, therefore, indicate that combining different targeting moieties with LI and LD may enhance drug delivery and reduce tumor burden.

Comparative Cellular and In Vivo Anti-cancer studies of Doxorubicin Liposomes Prepared with Different Types of Phospholipids

The selection of lipid components of membrane bilayer determines the rigidity of liposomes affecting drug efficacy, especially for cancer drug delivery. The present study evaluated liposomes with different rigidity for delivering doxorubicin (DOX). In this work, liposomes composed of rigid lipid, hydrogenated soybean phosphatidylcholine (HSPC), were totally or partially substituted with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE). The liposomes are composed of phosphatidylcholine (HSPC, POPC), with and without combination with DOPE, cholesterol, and DSPE-mPEG2000 with a molar ratio of 57: 38: 5, respectively. Liposomes were prepared using a thin layer hydration method. Then, in vitro cytotoxicity and in vivo antitumor activity of these liposomes were evaluated. Substitution of HSPC with POPC resulted in similar cytotoxicities profiles similar to the DOX solution on C26 colon cancer cells and LLC cells. The DOPE addition to DOX liposomes reduced the antitumor activity. In conclusion, the lipid substitution of HSPC with POPC or DOPE reduced liposome rigidity; however, it lowered the in vivo antitumor activity.

Enhancing the potency of anti-P32-active targeted PEGylated liposomal doxorubicin using various spacers: In silico, in vitro and in vivo studies

Even though nanoliposomal drug delivery systems are superior to conventional drug delivery methods, studies indicate that they may deliver small quantities of drugs through passive targeting. Specific peptides are used to decorate the surface of the liposomes for active targeting of tumors. Among these, CGKRK is the tumor homing peptide to target p32 protein on the surface of endothelial and tumor cells. In the present study, serine-glycine (SG) and glycine-glycine-glycine (GGG) spacer were added to CGKRK, an anti-P32 peptide and in silico molecular docking studies were conducted. PEGylated liposomal doxorubicin (PLD) was then surface modified with these peptides. All liposomal formulations had the sizes between 96 and 110 nm, negative zeta potentials and there were spherical in shape. The release of the doxorubicin (Dox) followed the same pattern for all formulations during 24 h. The cytotoxic effects of the formulations during 1, 3 and 6 h of the incubation, indicated the time-dependent cytotoxicity of formulations, while the PLD-CGGGKRK was the most potent. Apoptosis and antiangiogenic assays were also demonstrated the ability of PLD-CGGGKRK in inducing apoptosis and decreasing vessels densities. The in vivo anti-tumor study demonstrated the efficacy of CGGGKRK surface-modified PLDs in delaying tumor growth and increasing the median survival. Our findings indicated that the GGG spacer could improve the efficacy of anti-P32 peptide, CGKRK, in targeting breast cancer tumor models in mice and merit further investigation.

Impact of formulation parameters and circulation time on PEGylated liposomal doxorubicin related hand-foot syndrome

PEGylated liposomal doxorubicin (PLD) has effectively reduced the cardiac toxicity of free doxorubicin (DOX) due to its unique nanoscale properties. However, an unexpected accumulation of PLD in the skin has led to hand-foot syndrome (HFS), negatively impacting quality of life and psychological well-being. In this study, self-limiting HFS rat models were created to mimic human symptoms through varying dosing schedules and intensities of PLD. The effects of PLD formulation parameters on HFS were also investigated. The results demonstrated that replacing ammonium sulfate with citric buffer, increasing liposome size, or reducing DSPE-mPEG2000 modification density alleviated HFS. Additionally, liposomes without DSPE-mPEG2000 modification completely avoided HFS, suggesting that PEGylated phospholipid was the key formulation parameter contributing to PLD-induced HFS. Furthermore, the correlation between liposome pharmacokinetics and HFS indicated that PEGylation, rather than the extended circulation time of liposomes, may mediated PLD-related HFS. Better understanding of the formulation parameters that trigger HFS can guide reformulation strategies to mitigate or prevent this syndrome.

Rapid Desensitization to Antitumoral Agents. Result from a Retrospective Study, DESARCh

Antitumoral drugs (ADs) can induce drug hypersensitivity reactions (DHRs). Rapid drug desensitization (RDD) protocols represent an important option to mitigate recurrent DHRs thus allowing the safe administration of ADs at therapeutic doses. The aim of this retrospective study was to assess the effectiveness of the RDD protocols performed at our institution. The “DESARCh” study was a retrospective, observational study that included consecutive patients who underwent RDD protocols from January 2011 to December 2022 at IRCCS Ospedale Sacro Cuore Don Calabria in Negrar di Valpolicella, Verona, Italy. The RDD protocol consisted of a 5-step protocol with 5 different concentrations of the drugs at 1:1, 1:10, 1:100, 1:1,000 and 1:10,000 dilution given intravenously over a 1-hour infusion each, with concentrations increasing from the most diluted to the most concentrated form, preceded by a 30-min premedication regimen. A total of 66 RDD protocols were administered to 25 female patients with ovarian (64%; n = 16/25), breast (12%; n = 3/25), endometrium (8%; n = 2/25), cervix (8%; n = 2/25), uterine (4%; n = 1/25) and fallopian tubes (4%; n = 1/25) cancers. A known history of atopy/allergy was reported by 36% (n = 9/25) of patients. Patients received RDD protocols because of DHRs to carboplatin (n = 23/66, 34.85%), paclitaxel (n = 18/66, 27.27%), pegylated liposomal doxorubicin (n = 3/66, 4.55%), and trastuzumab (n = 22/66, 33.33%). DHRs were mild-moderate, severe and life-threatening in 60.72%, 28.57% and 10.71% of cases, respectively. The success rate of RDD protocols, defined as the rate of complete administration of full target dose with no breakthrough reactions, was 81.82% (n = 54/66). Success rate was lower for carboplatin compared to other drugs (65.22% vs 90.7%; P = .017678). The RDD protocol used in our institution was found to be safe, with a meaningful success rate. However, further research is needed to better understand the underlying mechanisms of DHRs and to enhance effectiveness, particularly for patients experiencing DHRs to platinum compounds. This study was approved by the ethics committee of Verona and Rovigo (Italy) with approval number 15476 on 10/03/2023 and it was registered with the Register of Observational Studies of the Italian Medicines Agency (AIFA) (available since 31 January 2023), with ID n. 109, on 28/02/2023 ( https://www.aifa.gov.it/en/registro-studi-osservazionali ).

Investigation of Dual-Loaded Doxorubicin and Sorafenib Liposomes Co-Modified with Glycyrrhetinic Acid and Cell-Penetrating Peptide TAT.

Combining Doxorubicin (DOX) with sorafenib (SF) is a promising strategy for treating Hepatocellular Carcinoma (HCC). However, strict dosage control is required for both drugs, and there is a lack of target selectivity. This study aims to develop a novel nano-drug delivery system for the combined use of DOX and SF, aiming to reduce their respective dosages, enhance therapeutic efficacy, and improve target selectivity. DOX/SF co-loaded liposomes (LPs) were prepared using the thin-film hydration method. The liposomes were modified with 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine (DSPE)- polyethylene glycol (PEG2000), DSPE-PEG1000-cell penetrating peptide TAT, and Glycyrrhetinic Acid (GA). The basic properties of the liposomes were characterized. CCK-8 cell viability assays were conducted using HepG2, MHCC97-H, and PLC cell models, and apoptosis experiments were performed using HepG2 cells to determine if this delivery system could reduce the respective dosages of DOX and SF and enhance HCC cytotoxicity. Liposome uptake experiments were performed using HepG2 cells to validate the target selectivity of this delivery system. A GA/TAT-DOX/SF-LP liposomal nano drug delivery system was successfully constructed, with a particle size of 150 nm, a zeta potential of -7.9 mV, a DOX encapsulation efficiency of 92%, and an SF encapsulation efficiency of 88.7%. Cellular experiments demonstrated that this delivery system reduced the required dosages of DOX and SF, exhibited stronger cytotoxicity against liver cancer cells, and showed better target selectivity. A simple and referenceable liposomal nano drug delivery system has been developed for the combined application of DOX and SF in hepatocellular carcinoma treatment.

Development and validation of an LC-MS/MS method for the quantification of free and total doxorubicin in human plasma and its clinical application for a novel doxorubicin hydrochloride liposome injection in Chinese patients with breast cancer

AbstractA novel doxorubicin hydrochloride liposome injection was prepared to reduce toxicity and side effects, as well as extend plasma half-life in the treatment of breast cancer. In this study, a rapid and sensitive bioanalytical method was developed and validated to characterize the pharmacokinetic profile of total and free doxorubicin in plasma of 3 Chinese patients after intravenous infusion of this injection. Plasma samples were prepared by protein precipitation for the determination of total doxorubicin, while solid phase extraction was used to determine free doxorubicin. After plasma sample pre-treatment, total and free concentrations were quantified individually using a validated LC-MS/MS method. The calibration curves were found to be linear in the range of 0.20–500.0 ng mL−1 for total doxorubicin and in the range of 1.00–1,000 ng mL−1 for free doxorubicin. The free concentrations in plasma were only one sixth to one quarter of the total levels. Liposomal doxorubicin had a longer apparent half-life (&gt;50 h) than the non-targeted drug (&lt;10 h) reported in the reference. and a lower volume of distribution. This novel injectable formulation steadily released free doxorubicin from liposomes over a long period of time to reduce cardiac toxicity and side effects, while ensuring a clinical curative effect.

Taohong Siwu decoction enhances the chemotherapeutic efficacy of doxorubicin by promoting tumor vascular normalization

BackgroundInstead of completely suppressing blood vessels inside tumors, vascular normalization therapy is proposed to normalize and prune the abnormal vasculature in tumor microenvironment (TME) to acquire a normal and stable blood flow and perfusion. The theoretical basis for the use of “blood-activating and stasis-resolving” formulas in Traditional Chinese Medicine to treat cancer is highly consistent with the principle of vascular normalization therapy, suggesting the potential application of these traditional formulas in vascular normalization therapy. PurposeTo study the underlying mechanisms of a classical “blood-activating and stasis-resolving” formula, Taohong Siwu decoction (TSD), in enhancing the efficacy of chemotherapy for breast cancer treatment. Study designHUVECs and transgenic zebrafish embryos were used as the major model in vitro. A 4T1 mouse breast cancer model was applied to study tumor vasculature normalization of TSD and the combination effects with DOX. ResultsOur data showed that TSD exhibited anti-angiogenic potential in HUVECs and transgenic zebrafish embryos. After 20 days treatment, TSD significantly normalized the tumor vasculature by remodeling vessel structure, reducing intratumoral hypoxia and vessel leakage, and promoting vessel maturation and blood perfusion in 4T1 breast tumor-bearing mice. Moreover, the anti-tumor efficacy of doxorubicin liposome in 4T1 breast tumors was significantly improved by TSD, including the suppression of tumor cell proliferation, angiogenesis, hypoxia, and the increase of cell apoptosis, which is likely through the vascular normalization induced by TSD. TSD also shifted the macrophage polarization from M2 to M1 phenotype in TME during the combination therapy, as evidenced by the reduced number of CD206+ macrophages and increased number of CD86+ macrophages. Additionally, TSD treatment protected against doxorubicin-induced cardiotoxicity in animals, as evidenced by the reduced cardiomyocytes apoptosis and improved heart function. ConclusionThis study demonstrated for the first time that TSD as a classical Chinese formula can enhance the drug efficacy and reduce the side effects of doxorubicin. These findings can support that TSD could be used as an adjuvant therapy in combination with conventional chemotherapy for the future breast cancer treatment.

Preparation of double-loaded bitter ginseng derivative B21–DOX liposomes co-modified with SP94 and BR2 ligand and its in vitro anti-hepatocarcinogenic effect

Aim To construct a novel liposomal drug delivery system co-modified with SP94 and BR2 ligands, encapsulating both the bitter ginseng derivative B21 and doxorubicin (DOX), to achieve superior anti-tumour efficacy and reduced toxic side effects. Methods Liposomes were prepared using an organic phase reaction method, with B21 encapsulated in the lipid phase and DOX in the aqueous phase. The liposomes were further modified with SP94 and BR2 peptides. The characterisations, cytotoxicity, and in vitro targeting effects were assessed through various methods including ultraviolet spectrophotometry, high-performance liquid chromatography, nano-size analysis, ultrafiltration centrifugation, dialysis, transmission electron microscopy, flow cytometry, Methylthiazolyldiphenyl-tetrazolium bromide assay, confocal laser scanning microscopy, transwell assay, and tumorsphere assay. Results SP94/BR2-B21/DOX-LP liposomes were spherical with an average diameter of 120.87 ± 1.00 nm, a polydispersity index (PDI) of 0.223 ± 0.006, and a surface charge of −23.1 ± 1.27 mV. The encapsulation efficiencies for B21 and DOX were greater than 85% and 97% (mg/mg), respectively. The results indicated that SP94/BR2-B21/DOX-LP exhibited enhanced targeting and cytotoxicity compared to single-ligand modified and unmodified liposomes, with the combined encapsulation of B21 and DOX showing synergistic anti-hepatocarcinogenic effects. Conclusion SP94/BR2-B21/DOX-LP liposomes represent a promising targeted drug delivery system for hepatocellular carcinoma, offering improved membrane penetration, enhanced therapeutic efficacy, and reduced systemic toxicity.

Liposomes with Low Levels of Grafted Poly(ethylene glycol) Remain Susceptible to Destabilization by Anti-Poly(ethylene glycol) Antibodies.

Binding of anti-PEG antibodies to poly(ethylene glycol) (PEG) on the surface of PEGylated liposomal doxorubicin (PLD) in vitro and in rats can activate complement and cause the rapid release of doxorubicin from the liposome interior. Here, we find that irinotecan liposomes (IL) and L-PLD, which have 16-fold lower levels of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)-PEG2000 in their liposome membrane as compared to PLD, generate less complement activation but remain sensitive to destabilization and drug release by anti-PEG antibodies. Complement activation and liposome destabilization correlated with the theoretically estimated number of antibody molecules bound per liposome. Drug release from liposomes proceeded through the alternative complement pathway but was accelerated by the classical complement pathway. In contrast to PLD destabilization by anti-PEG immunoglobulin G (IgG), which proceeded by the insertion of membrane attack complexes in the lipid bilayer of otherwise intact PLD, anti-PEG IgG promoted the fusion of L-PLD, and IL to form unilamellar and oligo-vesicular liposomes. Anti-PEG immunoglobulin M (IgM) induced drug release from all liposomes (PLD, L-PLD, and IL) via the formation of unilamellar and oligo-vesicular liposomes. Anti-PEG IgG destabilized both PLD and L-PLD in rats, indicating that the reduction of PEG levels on liposomes is not an effective approach to prevent liposome destabilization by anti-PEG antibodies.

PBPK model of pegylated liposomal doxorubicin to simultaneously predict the concentration-time profile of encapsulated and free doxorubicin in tissues.

The objective of this study was to develop a physiologically based pharmacokinetic (PBPK) model to predict the concentrations of encapsulated and free doxorubicin in plasma and tissues in mice after intravenous injection of PEGylated liposomes (Doxil®). The PBPK model used in this study contains liposomes and free doxorubicin disposition components. The free doxorubicin disposition component was used to simulate the disposition of free doxorubicin produced by mononuclear phagocyte system (MPS)-degrading liposomes. The liver, spleen, kidneys, and lungs contain an additional MPS subcompartment. These compartments are interconnected through blood and lymphatic circulation. The model was validated strictly by four doses of external observed plasma and tissue concentration-time profiles. The fold error (FE) values were almost all within threefold. The sensitivity analysis revealed that the MPS-related parameters greatly influenced the model. The predicted in vivo distribution characteristics of the doxorubicin liposomes and doxorubicin solution were consistent with the observed values. The PBPK model was established based on the physiological mechanism and parameters of practical significance that can be measured in vitro. Thus, it can be used to study the pharmacokinetic properties of liposomes. This study also provides a reference for the establishment of liposome PBPK model.

Pegylated liposomal doxorubicin combined with trabectedin as a treatment option in uterine sarcomas: a single-institution retrospective analysis

ObjectiveThe use of conventional doxorubicin in combination with trabectedin leads to a considerable prolongation of progression-free survival in the treatment of uterine sarcomas but is associated with dose-limiting toxicities. Significant...

Intravenous injection of nattokinase-heparin electrostatic complex improves the therapeutic effect of advanced tumors by dissolving cancer-related thrombosis

AimsCancer-related thrombosis (CAT) is a common complication in cancer patients, significantly impacting their quality of life and survival prospects. Nattokinase (NK) has potent thrombolytic properties, however, its efficacy is limited by low oral bioavailability and the risk of severe allergic reactions with intravenous use. Heparin (HP) is a widely used anticoagulant in clinical settings. This study aimed to overcome the intravenous toxicity of NK and explore its effect on CAT in advanced tumors. Main methodsIn this study, NK-HP electrostatic complexes were constructed, and their safety and thrombolytic efficacy were verified through guinea pig allergy tests, mouse tail vein tests, and both in vivo and in vitro thrombolysis experiments. Additionally, an S180 advanced tumor model was developed and combined with sialic acid-modified doxorubicin liposomes (DOX-SAL) to investigate the impact of NK-HP on CAT and its antitumor effects in advanced tumors. Key findingsWe observed that NK-HP can eliminate the intravenous injection toxicity of NK, has strong thrombolytic performance, and can prevent thrombosis formation. Intravenous injection of NK-HP can enhance the antitumor effect of DOX-SAL by reducing the fibrin content in advanced tumors and increasing the levels of the cross-linked protein degradation product D-dimer. SignificanceThis study developed a method to eliminate the intravenous injection toxicity of NK, proposing a promising therapeutic strategy for CAT treatment, particularly for CAT in advanced tumors, and improving the efficacy of nano-formulations in anti-tumor therapy.