PEGylated liposomes of anastrozole for long-term treatment of breast cancer: in vitro and in vivo evaluation

A Concise Review on Effect of PEGylation on the Properties of Lipid-Based Nanoparticles

Nanoparticle-based drug delivery systems have emerged as promising platforms for enhancing therapeutic efficacy while minimizing off-target effects. Among various strategies employed to optimize these systems, polyethylene glycol (PEG) modification, known as PEGylation-the covalent attachment of PEG to nanoparticles, has gained considerable attention for its ability to impart stealth properties to nanoparticles while also extending circulation time and improving biocompatibility. PEGylation extends to different drug delivery systems, in specific, nanoparticles for targeting cancer cells, where the concentration of drug in the cancer cells is improved by virtue of PEGylation. The primary challenge linked to PEGylation lies in its confirmation. Numerous research findings provide comprehensive insights into selecting PEG for various PEGylation methods. In this review, we have endeavored to consolidate the outcomes concerning the choice of PEG and diverse PEGylation techniques.

Challenges and emerging strategies for next generation liposomal based drug delivery: An account of the breast cancer conundrum

The global cancer burden is witnessing an upsurge with breast cancer surpassing other cancers worldwide. Furthermore, an escalation in the breast cancer caseload is also expected in the coming years. The conventional therapeutic regimens practiced routinely are associated with many drawbacks to which nanotechnological interventions offer a great advantage. But how eminent could liposomes and their advantages be in superseding these existing therapeutic modalities? A solution is reflected in this review that draws attention to a decade-long journey embarked upon by researchers in this wake. This text is a comprehensive discussion of liposomes, the front runners of the drug delivery systems, and their active and passive targeting approaches for breast cancer management. Active targeting has been studied over the decade by many receptors overexpressed on the breast cancer cells and passive targeting with many drug combinations. The results converge on the fact that the actively targeted formulations exhibit a superior efficacy over their non-targeted counterparts and the all liposomal formulations are efficacious over the free drugs. This undoubtedly underlines the dominion of liposomal formulations over conventional chemotherapy. These investigations have led to the development of different liposomal formulations with active and passive targeting capacities that could be explored in depth. Acknowledging and getting a deeper insight into the liposomal evolution through time also unveiled many imperfections and unchartered territories that can be explored to deliver dexterous liposomal formulations against breast cancer and more in the clinical trial pipeline.

Preparation, characterization, pharmacokinetics and anticancer effects of PEGylated β-elemene liposomes

Objective: This study aimed to develop a new polyethylene glycol (PEG)ylated β-elemene liposome (PEG-Lipo-β-E) and evaluate its characterization, pharmacokinetics, antitumor effects and safety in vitro and in vivo.

Methods: The liposomes were prepared by ethanol injection and high-pressure micro-jet homogenization. Characterization of the liposomes was conducted, and drug content, entrapment efficiency (EE), in vitro release and stability were studied by ultra-fast liquid chromatography (UFLC) and a liquid surface method. Blood was drawn from rats to establish the pharmacokinetic parameters. The anticancer effect was evaluated in a KU-19-19 bladder cancer xenograft model. Histological analyses were performed to evaluate safety.

Results: The PEG-Lipo-β-E showed good stability and was characterized as 83.31 ± 0.181 nm in size, 0.279 ± 0.004 in polydispersity index (PDI), −21.4 ± 1.06 mV in zeta potential, 6.65 ± 0.02 in pH, 5.024 ± 0.107 mg/mL in β-elemene (β-E) content, and 95.53 ± 1.712% in average EE. The Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) indicated the formation of PEG-Lipo-β-E. Compared to elemene injection, PEG-Lipo-β-E demonstrated a 1.75-fold decrease in clearance, a 1.62-fold increase in half-life, and a 1.76-fold increase in area under the concentration-time curves (AUCs) from 0 hour to 1.5 hours (P < 0.05). PEG-Lipo-β-E also showed an enhanced anticancer effect in vivo. Histological analyses showed that there was no evidence of toxicity to the heart, kidney, liver, lung or spleen.

Conclusions: The present study demonstrates PEG-Lipo-β-E as a new formulation with ease of preparation, high EE, good stability, improved bioavailability and antitumor effects.

The Enhanced Permeability and Retention (EPR) Effect: The Significance of the Concept and Methods to Enhance Its Application

Chemotherapy for human solid tumors in clinical practice is far from satisfactory. Despite the discovery and synthesis of hundreds of thousands of anticancer compounds targeting various crucial units in cancer cell proliferation and metabolism, the fundamental problem is the lack of targeting delivery of these compounds selectively into solid tumor tissue to maintain an effective concentration level for a certain length of time for drug-tumor interaction to execute anticancer activities. The enhanced permeability and retention effect (EPR effect) describes a universal pathophysiological phenomenon and mechanism in which macromolecular compounds such as albumin and other polymer-conjugated drugs beyond certain sizes (above 40 kDa) can progressively accumulate in the tumor vascularized area and thus achieve targeting delivery and retention of anticancer compounds into solid tumor tissue. Targeting therapy via the EPR effect in clinical practice is not always successful since the strength of the EPR effect varies depending on the type and location of tumors, status of blood perfusion in tumors, and the physical-chemical properties of macromolecular anticancer agents. This review highlights the significance of the concept and mechanism of the EPR effect and discusses methods for better utilizing the EPR effect in developing smarter macromolecular nanomedicine to achieve a satisfactory outcome in clinical applications.

Combined treatment with ultrasound-targeted microbubble destruction technique and NM-aFGF-loaded PEG-nanoliposomes protects against diabetic cardiomyopathy-induced oxidative stress by activating the AKT/GSK-3β1/Nrf-2 pathway

The present study sought to investigate the effect of non-mitogenic acidic fibroblast growth factor (NM-aFGF) loaded PEGylated nanoliposomes (NM-aFGF-PEG-lips) combined with the ultrasound-targeted microbubble destruction (UTMD) technique on modulating diabetic cardiomyopathy (DCM)and the mechanism involved. Animal studies showed that the diabetes mellitus (DM) group exhibited typical myocardial structural and functional changes of DCM. The indexes from the transthoracic echocardiography showed that the left ventricular function in the NM-aFGF-PEG-lips + UTMD group was significantly improved compared with the DM group. Histopathological observation further confirmed that the cardiomyocyte structural abnormalities and mitochondria ultrastructural changes were also significantly improved in the NM-aFGF-PEG-lips + UTMD group compared with DM group. The cardiac volume fraction (CVF) and apoptosis index in the NM-aFGF-PEG-lips + UTMD group decreased to 10.31 ± 0.76% and 2.16 ± 0.34, respectively, compared with those in the DM group (CVF = 21.4 ± 2.32, apoptosis index = 11.51 ± 1.24%). Moreover, we also found significantly increased superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity as well as clearly decreased lipid hydroperoxide levels and malondialdehyde (MDA) activity in the NM-aFGF-PEG-lips + UTMD group compared with those in the DM group (p < .05). Western blot analysis further revealed the highest level of NM-aFGF, p-AKT, p-GSK-3β1, Nrf-2, SOD2 and NQO1 in the NM-aFGF-PEG-lips + UTMD group. This study confirmed using PEGylated nanoliposomes combined with the UTMD technique can effectively deliver NM-aFGF to the cardiac tissue of diabetic rats. The NM-aFGF can then inhibit myocardial oxidative stress damage due to DM by activating the AKT/GSK/Nrf-2 signaling pathway, which ultimately improved the myocardial structural and functional lesions in diabetic rats.

Combination Therapy and Nanoparticulate Systems: Smart Approaches for the Effective Treatment of Breast Cancer

Breast cancer has become one of the biggest concerns for oncologists in the past few decades because of its unpredictable etiopathology and nonavailability of personalized translational medicine. The number of women getting affected by breast cancer has increased dramatically, owing to lifestyle and environmental changes. Besides, the development of multidrug resistance has become a challenge in the therapeutic management of breast cancer. Studies reveal that the use of monotherapy is not effective in the management of breast cancer due to high toxicity and the development of resistance. Combination therapies, such as radiation therapy with adjuvant therapy, endocrine therapy with chemotherapy, and targeted therapy with immunotherapy, are found to be effective. Thus, multimodal and combination treatments, along with nanomedicine, have emerged as a promising strategy with minimum side effects and drug resistance. In this review, we emphasize the multimodal approaches and recent advancements in breast cancer treatment modalities, giving importance to the current data on clinical trials. The novel treatment approach by targeted therapy, according to type, such as luminal, HER2 positive, and triple-negative breast cancer, are discussed. Further, passive and active targeting technologies, including nanoparticles, bioconjugate systems, stimuli-responsive, and nucleic acid delivery systems, including siRNA and aptamer, are explained. The recent research exploring the role of nanomedicine in combination therapy and the possible use of artificial intelligence in breast cancer therapy is also discussed herein. The complexity and dynamism of disease changes require the constant upgrading of knowledge, and innovation is essential for future drug development for treating breast cancer.

Antitumor activity of gemcitabine hydrochloride loaded lipid polymer hybrid nanoparticles (LPHNs): In vitro and in vivo

The present study demonstrated the application of gemcitabine hydrochloride (GEM) loaded lipid polymer hybrid nanoparticles (LPHNs) for the enhancement the chemotherapeutic response. GEM, which is an anti-tumor drug, is frequently utilized for the treatment of non-small cell lung cancer, breast cancer and pancreatic cancer. GEM loaded LPHNs were formed and examined for pharmacokinetic profile and in vivo anticancer activity. Modified double emulsion solvent evaporation method was employed in the preparation of the LPHNs. Cytotoxicities of the GEM loaded LPHNs formulation were evaluated on MCF-7 and MDA-MB-231 cells by MTT assays. Pharmacokinetics and in vivo anticancer efficacy studies were conducted following intraperitoneal administration in female Sprague-Dawley rats. In vivo pharmacokinetic studies in rats exhibited the advantage of the GEM loaded LPHNs over commercial product Gemko® and the GEM loaded LPHNs had longer circulation time. The half-life of GEM in LPHNs formulation was notable advanced (4.2 folds) comparing to commercial product of GEM (native). These findings indicated that GEM loaded LPHNs can be used for enhancing antitumor efficacy for breast cancer treatment.

Herbal ethosomal gel containing luliconazole for productive relevance in the field of biomedicine

This study includes development, characterization, and optimization of herbal ethosomal formulation. The aim of the present study is to develop drug loaded ethosomes capped with Azadirachta indica (neem) which, was further incorporated in Carbopol 934 K thereby, resulting in the formation of ethosomal gel. The formulation is aimed to express effective treatment against fungal infection. The build was formulated using drug (Luliconazole), soyalecithin, ethanolic neem extract and propylene glycol. In total nine ethosomal, formulations of distinct concentrations of ingredients were processed, to determine out the optimized formulation among the all. Further the prepared drug loaded ethosomes were subjected to various evaluation parameters like particle size, zeta potential, polydispersity index (PDI) and % entrapment efficiency. For the evaluation of its surface morphology, transmission electron microscopy was executed whereas, atomic force microscopy was carried out which contributes in detail and depth information of surface morphology. For the analysis of thermal behavior Thermal gravimetric analysis graph was obtained for luliconazole, soyalecithin, neem extract, physical mixture and optimized formulation (LF5). Attenuated total internal reflection Fourier transforms infra-red spectroscopy was performed for luliconazole, soyalecithin, neem extract, physical mixture, and optimized formulation (LF5) to examine the interaction between the drug and the excipients. Viscosity, pH, spreadability and extrudability of the ethosomal gel were calculated to determine the suitability of the formulation for topical application. In vitro drug permeation study and antifungal activity was executed out with the aid of Wistar albino rat skin model and tube dilution assay respectively. The complete study wrap up, that this herbal ethosomal approach provides advanced sustained and targeted delivery of luliconazole. On analyzing the results, ethosomal formulation LF5 was found to be optimized one, due to its optimum concentration of soyalecithin (300 mg) and ethanol (35%). Hence it has maximum entrapment efficiency of 86.56 ± 0.74%. Optimum vesicle size, zeta potential, and PDI were found to be 155.30 ± 1.2 nm, - 42.20 ± 0.3 mV, and 0.186 ± 0.07 respectively. In vitro drug permeation study expresses release of 83.45 ± 2.51 in 24 h whereas; the in vivo activity proved that LF5 is more active and effective against Candida parapsilosis in comparison to Aspergillus niger. In the end, it was estimated that ethosomal suspension and lyophilized ethosomal suspension was utmost stable at 4 °C/60 ± 5 RH. The complete study clearly indicates that the buildup of ethosomal formulation with luliconazole and neem extract show synergistic effect thereby, expressing excellent result against the treatment of fungal infection.

A pre-formulation strategy for the liposome encapsulation of new thioctic acid conjugates for enhanced chemical stability and use as an efficient drug carrier for MPO-mediated atherosclerotic CVD treatment

Lipoyl-apocynin and lipoyl-sesamol are bio-active conjugates of thioctic acid, synthesized using a benign chemical approachviathe combination of thioctic acid and the powerful bio-phytonutrients, apocynin and sesamol, respectively.

Wheat germ agglutinin liposomes with surface grafted cyclodextrins as bioadhesive dual-drug delivery nanocarriers to treat oral cells

Topical management of oral infection requires combined use of multiple classes of drugs and frequent dosing due to low drug retention rates. The sustained, co-delivery of drugs with different solubilities to cells using nanoparticle drug delivery systems remains a challenge. Here, we developed wheat germ agglutinin (WGA) conjugated liposomes with surface grafted cyclodextrin (WGA-liposome-CD) as bioadhesive dual-drug nanocarriers. We effectively encapsulated two physiochemically different drugs (ciprofloxacin and betamethasone) and demonstrated sustained co-drug release in saliva over a 24 h period in vitro. As proof of therapeutic utility in oral cells, we infected oral keratinocytes with Aggregatibacter actinomycetemcomitans, a bacterial pathogen responsible for chronic periodontal disease. Drug release, resulting from nanocarrier cell binding, produced a significant increase in oral cell survival and synergistically reduced inflammation. These results suggest that WGA-liposome-CD nanocarriers are novel cyto-adhesive candidates for delivering multiple drugs with sustained therapeutic activity for localized drug delivery to oral cells.

Flurbiprofen-loaded ethanolic liposome particles for biomedical applications

Present study deals with the preparation, characterization and in-vivo evaluation of flurbiprofen loaded ethanolic liposome which provides predetermined and controlled release of drug through a transdermal drug delivery system. Ethanolic liposomes were prepared by using flurbiprofen, phospholipon 90-G, and ethanol in varied concentration ratio. The prepared ethanolic liposomes were optimized and characterized for particle size, zeta potential, polydispersive index and % entrapment efficiency. FTIR study was performed to analyze the interaction between drug and excipient. To study the thermal behavior of the formulation DSC and TGA were carried out. The surface morphology of ethanolic liposome was performed with the help of SEM, TEM, and AFM. In-vitro drug permeation study of the optimized formulation was carried out using the albino rat skin model and peripheral nociceptive activity was evaluated by writhing assay. In addition, formulations were also inspected for stability study for three months at a different temperature. The optimized formulation EF5 exhibited a particle size of 167.2 ± 3.7 nm with a zeta potential of -51.6 ± 0.2 mV and PDI of 0.209. The optimized formulation showed an ideal surface morphology with a maximum % entrapment efficiency i.e. 93.51 ± 2.1. In-vitro permeation study shows a release of 70.23% in 24 h and transdermal flux was found as 238.2 μg/cm²/h. Writhing assay demonstrate that the optimized formulation decreases the number of writhes and thus shows the peripheral analgesic activity. In stability study, optimized formulation showed maximum stability at 4 °C. These results suggest that transdermal system mediated application of flurbiprofen loaded ethanolic liposome can be considered as an effective way to afford consistent and predictable release of flurbiprofen which could provide beneficial effects in the management of various inflammatory diseases.

Preparation and in vivo safety evaluations of antileukemic homoharringtonine-loaded PEGylated liposomes

In order to improve the in vivo safety and specific delivery efficiency of the antileukemic homoharringtonine (HHT) at the targets, the long-circulating PEGylated liposomes loaded with HHT (LCLipo-HHT) were prepared. Their physical characteristics, in vitro drug release, in vivo pharmacokinetic properties and elementary toxicity were evaluated. The mean diameter of the prepared LCLipo-HHT is 75.6 ± 3.2 nm and the zeta potential is -16.9 ± 2.5 mV. The entrapment efficiency of HHT in the liposomes is 69.5 ± 1.7%. In pharmacokinetic experiments, an increased plasma concentration as well as blood circulation time was obtained when distearoyl phosphoethanolamine-PEG 2000 lipid was added in the formulation, which results in enhancing drug delivery efficiency. Hemolysis test, vascular irritation test and acute toxicity test were used to demonstrate toxicity of LCLipo-HHT. Compared with clinical HHT injection dosage, LCLipo-HHT indicated no vascular irritation, good hemocompatibility, as well as much better safety. Therefore, the prepared LCLipo-HHT can be used as a promising anticancer formulation for antileukemic therapy in the future.

PEGylated long-circulating liposomes deliver homoharringtonine to suppress multiple myeloma cancer stem cells

The goal of this investigation was to evaluate the inhibiting effect of high proportion polyethyleneglycol of long-circulating homoharringtonine liposomes on RPMI8226 multiple myeloma cancer stem cells. The CD138^-CD34^- multiple myeloma cancer stem cells isolated from RPMI8226 cell line using magnetic activated cell sorting system were, respectively, incubated with the optimized formulation of polyethyleneglycol of long-circulating homoharringtonine liposomes and the homoharringtonine in vitro, and the multiple myeloma cancer stem cell proliferation, colony formation, and cell cycle were analyzed. The inhibition of the multiple myeloma CD138^-CD34^- cancer stem cell growth was investigated in non-obese-diabetic/severe-combined-immunodeficiency mice that were implanted with multiple myeloma RPMI 8226 cancer stem cells and treated with the LCL-HHT-H-PEG. The results showed that the polyethyleneglycol of long-circulating homoharringtonine liposomes significantly inhibited MM cancer stem cell proliferation, colony formation, and induced cancer stem cell apoptosis in vitro as well as MM cancer stem cell growth in non-obese-diabetic/severe-combined-immunodeficiency mice compared with the homoharringtonine. In addition, the mouse bone mineral density and the red blood cell count were significantly increased in polyethyleneglycol of long-circulating homoharringtonine liposomes group. In conclusion, the data demonstrated that the developed polyethyleneglycol of long-circulating homoharringtonine liposomes formulation may serve as an efficient therapeutic drug for suppressing CD138^-CD34^- multiple myeloma cancer stem cell growth by inducing cancer stem cell apoptosis in non-obese-diabetic/severe-combined-immunodeficiency mouse model. Impact statement Multiple myeloma (MM) remains largely incurable until now. One of the main reasons is that there are cancer stem cells (CSCs) in MM, which are responsible for MM's drug resistance and relapse. In this study, we wanted to extend our previous investigation²² that whether we developed the LCL-HHT-H-PEG formulation have an inhibitory effect on MM CD138^-CD34^-CSCs in MM CSC engrafted NOD/SCID mouse model. Our data from the present study have demonstrated the therapeutic effect of LCL-HHT-H-PEG on MM-bearing mouse model. The study represents the first attempt to demonstrate that the LCL-HHT-H-PEG formulation is available for treatment MM patients in clinic. Therefore, this finding is important and deserves publication in Experimental Biology and Medicine.