Improving anti-tumour efficacy of PEGylated liposomal doxorubicin by dual targeting of tumour cells and tumour endothelial cells using anti-p32 CGKRK peptide

Precision-engineered PEGylated liposome for dual payload delivery: enhancing efficacy of Doxorubicin hydrochloride and miR-145 mimics in breast cancer cells

Micro-145 down-regulation is frequently found in breast cancers, indicating its potential as a therapeutic target. The introduction of exogenous miR-145 directly to the tumor sites has been a hurdle due to limited delivery, low bioavailability, and hence lower therapeutic efficacy. Thus, this study aims to synthesize and characterize PEGylated liposome co-loaded with Dox-HCl and miR-145 mimics to investigate its in-vitro anti-proliferative activity against MDA-MB-231 cells. The formulations were developed using a composite central design to optimize nanoparticle size and encapsulation efficiency (EE%) of Dox-HCl and miR-145 mimics. The optimized formulation exhibited the highest desirability function (D = 0.814) and displayed excellent stability over 60 days at 4 °C, maintaining a stable nanoparticle size and zeta potential, with relative EE% of Dox-HCl and miR-145 mimics on the final incubation day 94.97 ± 0.53% and 51.96 ± 2.67%, respectively. The system displayed a higher rate of drug release within 4 h of incubation at an acidic condition. Additionally, the optimized formulation demonstrated a higher toxicity (IC50 = 0.58 μM) against MDA-MB-231 cells than the free Dox- HCl and miR-145 regimen (IC50 = 1.00 μM). Our findings suggest that PEGylated liposome is tunable for effective concurrent delivery of anticancer drugs and therapeutic miRNAs into tumor cells, necessitating further investigation.

The impact of phospholipids with high transition temperature to enhance redox-sensitive liposomal doxorubicin efficacy in colon carcinoma model

In this study, we have developed a redox-sensitive (RS) liposomal doxorubicin formulation by incorporating 10,10'-diselanediylbis decanoic acid (DDA) organoselenium compound as the RS moiety. Hence, several RS liposomal formulations were prepared by using DOPE, HSPC, DDA, mPEG2000-DSPE, and cholesterol. In situ drug loading using a pH gradient and citrate complex yielded high drug to lipid ratio and encapsulation efficiency (100%) for RS liposomes. Liposomal formulations were characterized in terms of size, surface charge and morphology, drug loading, release properties, cell uptake and cytotoxicity, as well as therapeutic efficacy in BALB/c mice bearing C26 tumor cells. The formulations showed an average particle size of 200 nm with narrow size distributions (PDI < 0.3), and negative surface charges varying from -6 mV to -18.6 mV. Our study confirms that the presence of the DDA compound in liposomes is highly sensitive to hydrogen peroxide at 0.1% w/v, resulting in a significant burst release of up to 40%. The in vivo therapeutic efficacy study in BALB/c mice bearing C26 colon carcinoma confirmed the promising function of RS liposomes in the tumor microenvironment which led to a prolonged median survival time (MST). The addition of hydrogenated soy phosphatidylcholine (HSPC) with a high transition temperature (Tm: 52-53.5°C) extended the MST of our 3-component formulation of F14 (DOPE/HSPC/DDA) to 60 days in comparison to Caelyx (PEGylated liposomal Dox), which is not RS-sensitive (39 days). Overall, HSPC liposomes bearing RS-sensitive moiety enhanced therapeutic efficacy against colon cancer in vitro and in vivo. This achievement unequivocally underscores the criticality of high-TM phospholipids, particularly HSPC, in significantly enhancing liposome stability within the bloodstream. In addition, RS liposomes enable the on-demand release of drugs, leveraging the redox environment of tumor cells, thereby augmenting the efficacy of the formulation.

Surface-modified cationic liposomes with a matrix metalloproteinase-degradable polyethylene glycol derivative improved doxorubicin delivery in murine colon cancer

PEGylation is a commonly used approach to prolong the blood circulation time of cationic liposomes. However, PEGylation is associated with the "PEG dilemma", which hinders binding and uptake into tumor cells. The cleavable PEG products are a possible solution to this problem. In the current research, doxorubicin-loaded cationic liposomes (Dox-CLs) surface-conjugated with a matrix metalloproteinase-2 (MMP-2)-sensitive octapeptide linker-PEG derivative were prepared and compared to non-PEGylated and PEGylated CLs in terms of size, surface charge, drug encapsulation and release, uptake, in vivo pharmacokinetics, and anticancer efficacy. It was postulated that PEG deshielding in response to the overexpressed MMP-2 in the tumor microenvironment increases the interaction of protected CLs with cellular membranes and improves their uptake by tumor cells/vasculature. MMP2-responsive Dox-CLs had particle sizes of ∼115-140 nm, surface charges of ∼+25 mV, and encapsulation efficiencies of ∼85-95%. In vitro cytotoxicity assessments showed significantly enhanced uptake and cytotoxicity of PEG-cleavable CLs compared to their non-cleavable PEG-coated counterparts or Caelyx®. Also, the chick chorioallantoic membrane assay showed great antiangiogenesis ability of Dox-CLs leading to target and prevent tumor neovascularization. Besides, in vivo studies showed an effective therapeutic efficacy of PEG-cleavable Dox-CLs in murine colorectal cancer with negligible hematological and histopathological toxicity. Altogether, our results showed that MMP2-responsive Dox-CLs could be served as a promising approach to improve tumor drug delivery and uptake.

Study of the anti-cancer activity of a mesoporous silica nanoparticle surface coated with polydopamine loaded with umbelliprenin

A mesoporous silica nanoparticle (MSN) coated with polydopamine (PDA) and loaded with umbelliprenin (UMB) was prepared and evaluated for its anti-cancer properties in this study. Then UMB-MSN-PDA was characterized by dynamic light scattering (DLS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and FTIR methods. UV-visible spectrometry was employed to study the percentage of encapsulation efficiency (EE%). UMB-MSN-PDA mediated cell cytotoxicity and their ability to induce programmed cell death were evaluated by MTT, real-time qPCR, flow cytometry, and AO/PI double staining methods. The size of UMB-MSN-PDA was 196.7 with a size distribution of 0.21 and a surface charge of -41.07 mV. The EE% was 91.92%. FESEM and TEM showed the spherical morphology of the UMB-MSN-PDA. FTIR also indicated the successful interaction of the UMB and MSN and PDA coating. The release study showed an initial 20% release during the first 24 h of the study and less than 40% during 168 h. The lower cytotoxicity of the UMB-MSN-PDA against HFF normal cells compared to MCF-7 carcinoma cells suggested the safety of formulation on normal cells and tissues. The induction of apoptosis in MCF-7 cells was indicated by the upregulation of P53, caspase 8, and caspase 9 genes, enhanced Sub-G1 phase cells, and the AO/PI fluorescent staining. As a result of these studies, it may be feasible to conduct preclinical studies shortly to evaluate the formulation for its potential use in cancer treatment.

Preparation of the Myricetin-Loaded PEGylated Niosomes and Evaluation of their in vitro Anti-Cancer Potentials

Several edible plants contain flavonoids, including myricetin (Myr), which perform a wide range of biological activities. Myr has antitumor properties against various tumor cells. In this study Myr-loaded PEGylated niosomes (Myr-PN) were prepared and their anti-cancer activities were evaluated in vitro. Myr-PNs were prepared as a tool for drug delivery to the tumor site. Myr-PN was characterized in terms of size, zeta potential, and functional groups using dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (SEM). The Myr-PN size was 241 nm with a polydispersity index (PDI) of 0.20, and zeta potential -32.7±6.6 mV. Apoptotic properties of Myr-PN against normal and cancer cell lines were determined by flow cytometry and real-time quantitative PCR. Cancer cells showed higher cytotoxicity when treated with Myr-PN compared with normal cells, indicating that the synthesized nanoparticles pose no adverse effects. Apoptosis was induced in cells treated with 250 μg/mL of Myr-PN, in which 45.2 % of cells were arrested in subG1, suggesting that Myr-PN can induce apoptosis. In vitro, the synthesized Myr-PN demonstrated potent anticancer properties. Furthermore, more research should be conducted in vitro and in vivo to study the more details of Myr-PN anti-cancer effects.

Novel formulation of parthenolide-loaded liposome coated with chitosan and evaluation of its potential anticancer effects in vitro

BACKGROUND

In this study the formulation of parthenolide (PN), an anticancer agent extracted from a natural product, into a liposome (PN-liposome), was examined. The surface of the PN-liposome was modified using chitosan (PN-chitosome). By using real-time quantitative PCR and flow cytometry, we examined the release of PN-chitosomes, cytotoxicity, and ability to induce apoptosis in vitro.

METHODS AND RESULTS

According to the present study, PN-chitosomes had a size of 251 nm which is acceptable for efficient enhanced permeation and retention (EPR) performance. PN-chitosomes were confirmed to be spherical in shape and size through FESEM analysis. In terms of encapsulation efficiency, 94.5% was achieved. PN-chitosome possessed a zeta potential of 34.72 mV, which was suitable for its stability. According to the FTIR spectra of PN and PN-chitosome, PN was chemically stable due to the intermolecular interaction between the liposome and the drug. After 48 h, only 10% of the PN was released from the PN-chitosome in PBS (pH 7.4), and less than 20% was released after 144 h.

CONCLUSION

In a dose-dependent manner, PN-chitosome exhibited anticancer properties that were more cytotoxic against cancer cells than normal cells. Moreover, the formulation activated both the apoptosis pathway and cytotoxic genes in real-time qPCR experiments. According to the cytotoxicity and activating apoptosis of the prepared modified particle, PN-chitosome may be helpful in the treatment of cancer.

In vitro and in vivo study on the anticancer effects of anethole-loaded bovine serum albumin nanoparticles surface decorated with chitosan and folic acid

Anethole (Ant) is a herbal compound with unique properties, which is limited in its clinical use due to its low solubility in aqueous solutions. Therefore, in this study, albumin nanocarrier modified with chitosan-folate was used to transfer Ant to cancer cells and its anticancer effects were evaluated. First, Ant was loaded on albumin nanoparticles by desolvation method and then the surface of nanoparticles was covered with chitosan bound to folate. After characterization, the amount of Ant loading in nanoparticles was measured by the absorption method and then its toxicity effects on breast cancer cell lines, colon, and normal cells were evaluated by the MTT method. The real-time QPCR method was used to investigate the expression changes of apoptosis-related genes in the treated cells compared to the control cells, and finally, the antitumor effects of nanoparticles were evaluated in the mouse model carrying breast cancer. The results of this investigation showed the presence of nanoparticles with dimensions of 252 nm, a dispersion index of 0.28 mV, and a surface charge of 27.14 mV, which are trapped in about 88% of ATL. The toxicity effect of nanoparticles was shown on breast, colon, and normal cancer cells, respectively. In addition, the examination of the gene profile under investigation showed an increase in the expression of BAX and caspase-3 and -9 along with a decrease in the expression of the Bcl-2 gene, which confirms the activation of the internal pathway of apoptosis. The decrease in the volume of tumors and the presence of apoptotic areas in the tissue sections confirmed the antitumor effects of nanoparticles in the in vivo model. The inhibition percentage of free Ant and nanoparticles with a concentration of 25 and 50 mg/kg/tumor volume was reported as 36.9%, 56.6%, and 64.9%, respectively, during 15 days of treatment. These results showed the effectiveness of the formulation in inhibiting cancer cells both in vitro and in vivo.

Preparation and characterization of the myricetin-loaded solid lipid nanoparticles decorated with folic acid-bound chitosan and evaluation of its antitumor and anti-angiogenic activities in vitro and in vivo in mice bearing tumor models

Myricetin is a flavonoid with anticancer properties. This study aimed to formulate myricetin in the form of solid lipid nanoparticles (SLN), decorated with chitosan (CS) and active-targeted with folic acid (FA). After characterization, the in vitro release, cytotoxicity, antioxidant, and ability of the formulation to induce apoptosis using flow cytometry, fluorescent microscopy, and real-time qPCR were examined. Then in vivo anti-angiogenesis on chick chorioallantoic membrane (CAM) and antitumor activities on mice bearing tumor models were investigated. The present study showed that the size of 310 nm and zeta potential of + 30 mV were acceptable for oral administration. The Michaelis–Menten model fitted the drug release pattern with lag during 144 h of the study. The cytotoxicity assay showed that myricetin-SLN-CS-FA significantly killed cancer cells at the concentrations of 6.25, 12.5, 25, 50 and 100 µg/mL (*p < 0.05, **p < 0.01, and ***p < 0.001). The highest level of apoptosis was shown at the concentration of 45 µg/ml in flow cytometry, and fluorescent studies. These results showed the anticancer properties of myricetin-SLN-CS-FA in a dose-dependent manner. The real-time results also indicated that the formulation exerted its cytotoxic effect by activating apoptosis genes. The DPPH, ABTS, and FRAP studies also demonstrated the significant antioxidant properties of the myricetin-SLN-CS-FA (*p < 0.05, **p < 0.01, and ***p < 0.001). The anti-angiogenic activities of the formulations depicted in the CAM assay significantly decrease the number and length of the vessels (*p < 0.05, **p < 0.01, and ***p < 0.001), and also affect VEGF and VEGFR, genes involved in angiogenesis (**p < 0.01, and ***p < 0.001). The antitumor studies indicated the statistically significant effects of myricetin-SLN-CS-FA on reducing tumor volume (*p < 0.05 and ***p < 0.001). The H&E staining of the liver and monitoring of the animal weights also indicated the safety of the formulation. The analysis of mRNA expression in liver and tumor demonstrated that myricetin-SLN-CS-FA exerts its antitumor activities by modulating the inflammatory and oxidative responses in the tissues.

Recent Preclinical and Clinical Progress in Liposomal Doxorubicin

Doxorubicin (DOX) is a potent anti-cancer agent that has garnered great interest in research due to its high efficacy despite dose-limiting toxicities. Several strategies have been exploited to enhance the efficacy and safety profile of DOX. Liposomes are the most established approach. Despite the improvement in safety properties of liposomal encapsulated DOX (in Doxil and Myocet), the efficacy is not superior to conventional DOX. Functionalized (targeted) liposomes present a more effective system to deliver DOX to the tumor. Moreover, encapsulation of DOX in pH-sensitive liposomes (PSLs) or thermo-sensitive liposomes (TSLs) combined with local heating has improved DOX accumulation in the tumor. Lyso-thermosensitive liposomal DOX (LTLD), MM-302, and C225-immunoliposomal(IL)-DOX have reached clinical trials. Further functionalized PEGylated liposomal DOX (PLD), TSLs, and PSLs have been developed and evaluated in preclinical models. Most of these formulations improved the anti-tumor activity compared to the currently available liposomal DOX. However, the fast clearance, the optimization of ligand density, stability, and release rate need more investigations. Therefore, we reviewed the latest approaches applied to deliver DOX more efficiently to the tumor, preserving the benefits obtained from FDA-approved liposomes.

Doxorubicin-loaded liposomes surface engineered with the matrix metalloproteinase-2 cleavable polyethylene glycol conjugate for cancer therapy

Background

Colorectal cancer is one of the prominent leading causes of fatality worldwide. Despite recent advancements within the field of cancer therapy, the cure rates and long-term survivals of patients suffering from colorectal cancer have changed little. The application of conventional chemotherapeutic agents like doxorubicin is limited by some drawbacks such as cardiotoxicity and hematotoxicity. Therefore, nanotechnology has been exploited as a promising solution to address these problems. In this study, we synthesized and compared the anticancer efficacy of doxorubicin-loaded liposomes that were surface engineered with the 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-matrix metalloproteinase-2 (MMP-2) cleavable peptide-polyethylene glycol (PEG) conjugate. The peptide linker was used to cleave in response to the upregulated MMP-2 in the tumor microenvironment, thus exposing a positive charge via PEG-deshielding and enhancing liposomal uptake by tumor cells/vasculature. Liposomal formulations were characterized in terms of size, surface charge and morphology, drug loading, release properties, cell binding and uptake, and cytotoxicity.

Results

The formulations had particle sizes of ~ 100-170 nm, narrow distribution (PDI ˂ 0.2), and various surface charges (- 10.2 mV to + 17.6 mV). MMP-2 overexpression was shown in several cancer cell lines (C26, 4T1, and B16F10) as compared to the normal NIH-3T3 fibroblast cells by gelatin zymography and qRT-PCR. In vitro results demonstrated enhanced antitumor efficacy of the PEG-cleavable cationic liposomes (CLs) as compared to the commercial Caelyx^® (up to fivefold) and the chick chorioallantoic membrane assay showed their great antiangiogenesis potential to target and suppress tumor neovascularization. The pharmacokinetics and efficacy studies also indicated higher tumor accumulation and extended survival rates in C26 tumor-bearing mice treated with the MMP-2 cleavable CLs as compared to the non-cleavable CLs with no remarkable sign of toxicity in healthy tissues.

Conclusion

Altogether, the MMP-2-cleavable CLs have great potency to improve tumor-targeted drug delivery and cellular/tumor-vasculature uptake which merits further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12645-023-00169-8.

Study of FA12 peptide-modified PEGylated liposomal doxorubicin (PLD) as an effective ligand to target Muc1 in mice bearing C26 colon carcinoma: in silico, in vitro, and in vivo study

OBJECTIVES

This study tried to achieve active targeting of Muc1 in cancer; the surface of PEGylated liposomal doxorubicin (PLD/Doxil®) was decorated with FA12 peptide.

METHODS

According to docking results, FA12 was selected for this study, among four different peptides. MD simulation was also conducted as an additional confirmation of the binding interaction between FA12 and Muc1. Liposomal formulations were prepared; ¹HNMR and HPLC techniques were used to verify peptide conjugation to DSPE-PEG2000-COOH. Afterward, DSPE-PEG2000-FA12 was post-inserted into the PLD at 50, 100, 200, and 400 peptides per liposome. The size, zeta potential, release profile, cytotoxicity (IC₅₀), and cell uptake (using fluorescence microscopy and flow cytometry) were evaluated. In vivo biodistribution and antitumor activities were studied on mice bearing C-26 colon carcinoma.

RESULTS

Cell uptake and cytotoxicity results revealed that PLD-100 (targeted PLD with 100 FA12 per liposome) could significantly enhance cellular binding. Furthermore, PLD-100 demonstrated higher antitumor efficacy, indicating more remarkable survival compared to PLD and other targeted PLDs. PLD-100 exhibited higher doxorubicin tumor accumulation compared to PLD.

CONCLUSIONS

FA12 peptide is a promising targeting ligand for PLD to treat cancers with a high level of Muc1 expression and merits further investigations.

Circulating galectin-3 promotes tumor-endothelium-adhesion by upregulating ICAM-1 in endothelium-derived extracellular vesicles

The adhesion of tumor cells to vascular endothelial cells is an important process of tumor metastasis. Studies have shown that tumor could educate vascular endothelial cells to promote tumor metastasis through many ways. However, the effect of tumor cells on the functions of vascular endothelial cells-derived extracellular vesicles (H-EVs) and the mechanisms underlying their effects in tumor-endothelium adhesion in metastasis remain mysterious. In this study, we found that H-EVs promoted the adhesion of triple negative breast cancer cell to endothelial cells and cirGal-3 enhanced the adhesion-promoting effects of H-EVs. The underlying mechanism was related to the upregulation of glycolysis in endothelial cells induced by cirGal-3 which led to the increase of the ICAM-1 expression and its transmission to MDA-MB-231 cells by H-EVs. Targeting of cirGal-3 or glycolysis of vascular endothelium in breast cancer therefore represents a promising therapeutic strategy to reduce metastasis.

A novel and easy to prepare azo-based bioreductive linker and its application in hypoxia-sensitive cationic liposomal doxorubicin: Synthesis, characterization, in vitro and in vivo studies in mice bearing C26 tumor

This study designed and synthesized a cost-effective azo-based hypoxia-sensitive linker (AHSL) using commercially accessible, inexpensive raw materials and simple methods to apply in cationic nanoliposomes. Then, AHSL was post-inserted into the cationic liposome (Cat-lip), and PEG-Azo-Cat-lip was prepared and characterized using DLS. The decrease in the zeta-potential of formulation from + 18.4 mV for Cat-lip to + 6.1 mV and the increase in the size of the PEG-Azo-Cat-lip indicated the successful post insertion of AHSL into the liposomes. The Doxorubicin (Dox) release study showed that PEGylation results in a more stable PEG-Azo-Cat-lip than the Cat-lip. The increased cytotoxicity of the PEG-Azo-Cat-lip in the hypoxic condition also indicated the cleavage of the AHSL in the hypoxic environment. In vivo biodistribution using animal imaging has shown higher tumor accumulation of the MPEG-Azo-Cat-lip than Cat-lip during the 120 h of the study. The results of anti-tumor activities and biosafety of the formulations also showed the higher efficiency of the MPEG-Azo-Cat-lip compared with the Cat-lip. The results of this study indicated the antitumor efficacy of this hypoxia-sensitive which merits further investigation.

Redox-sensitive doxorubicin liposome: a formulation approach for targeted tumor therapy

In this study redox-sensitive (RS) liposomes manufactured using 10,10′-diselanediylbis decanoic acid (DDA), an organoselenium RS compound, to enhance the therapeutic performance of doxorubicin (Dox). The DDA structure was confirmed by 1H NMR and LC–MS/MS. Various liposomal formulations (33 formulations) were prepared using DOPE, Egg PC, and DOPC with Tm ˂ 0 and DDA. Some formulations had mPEG₂₀₀₀-DSPE and cholesterol. After extrusion, the external phase was exchanged with sodium bicarbonate to create a pH gradient. Then, Dox was remotely loaded into liposomes. The optimum formulations indicated a burst release of 30% in the presence of 0.1% hydrogen peroxide at pH 6.5, thanks to the redox-sensitive role of DDA moieties; conversely, Caelyx (PEGylated liposomal Dox) showed negligible release at this condition. RS liposomes consisting of DOPE/Egg PC/DDA at 37.5 /60/2.5% molar ratio, efficiently inhibited C26 tumors among other formulations. The release of Dox from RS liposomes in the TME through the DDA link fracture triggered by ROS or glutathione is seemingly the prerequisite for the formulations to exert their therapeutic action. These findings suggest the potential application of such intelligent formulations in the treatment of various malignancies where the TME redox feature could be exploited to achieve an improved therapeutic response.

Nanoparticles as Physically- and Biochemically-Tuned Drug Formulations for Cancers Therapy

Simple Summary

Conventional antitumor drugs have limitations, including poor water solubility and lack of targeting capability, with consequent non-specific distribution, systemic toxicity, and low therapeutic index. Nanotechnology promises to overcome these drawbacks by exploiting the physical properties of diverse nanocarriers that can be linked to moieties with binding selectivity for cancer cells. The use of nanoparticles as therapeutic formulations allows a targeted delivery and a slow, controlled release of the drug(s), making them tunable modules for applications in precision medicine. In addition, nanoparticles are also being developed as cancer vaccines, offering an opportunity to increase both cellular and humoral immunity, thus providing a new weapon to beat cancer.

Abstract

Malignant tumors originate from a combination of genetic alterations, which induce activation of oncogenes and inactivation of oncosuppressor genes, ultimately resulting in uncontrolled growth and neoplastic transformation. Chemotherapy prevents the abnormal proliferation of cancer cells, but it also affects the entire cellular network in the human body with heavy side effects. For this reason, the ultimate aim of cancer therapy remains to selectively kill cancer cells while sparing their normal counterparts. Nanoparticle formulations have the potential to achieve this aim by providing optimized drug delivery to a pathological site with minimal accumulation in healthy tissues. In this review, we will first describe the characteristics of recently developed nanoparticles and how their physical properties and targeting functionalization are exploited depending on their therapeutic payload, route of delivery, and tumor type. Second, we will analyze how nanoparticles can overcome multidrug resistance based on their ability to combine different therapies and targeting moieties within a single formulation. Finally, we will discuss how the implementation of these strategies has led to the generation of nanoparticle-based cancer vaccines as cutting-edge instruments for cancer immunotherapy.

Pegylated liposomal encapsulation improves the antitumor efficacy of combretastatin A4 in murine 4T1 triple-negative breast cancer model

Combretastatin A4 (CA4), a vascular disrupting agent has been recently proposed as an anticancer agent. However, its low water solubility and low bioavailability limited its clinical efficacy. Overcomingthis issue requires developing new delivery strategies to enhance its anticancer effects. Here, we prepared various PEGylated liposomal formulations containing CA4 composed of different molar ratios of HSPC/DSPE-mPEG₂₀₀₀/Cholesterol/CA4 (F1: 80:5:10:5; F2: 75:5:15:5; F3: 70:5:20:5; F4: 60:5:30:5 and F5: 50:5:40:5) by the thin-film hydration method plus sonication and extrusion. All formulations had a particle diameter of 100-150 nm, a monomodal distribution with low polydispersity index and a negative zeta potential. Among the formulations only F1, F2, and F3 showed a high CA4 encapsulation efficiency; so their anticancer effects on triple-negative breast cancer (TNBC) were investigated in vitro and in vivo. The release study showed that F3 liposomes had significantly lower CA4 release compared to the F1 and F2 liposomes in different pH of 5.5, 6.5, and 7.4. We found that, CA4-loaded liposomes effectively inhibited both proliferation and migration of 4T1 and MDA-MB-231 TNBC cell lines by inducing cell cycle arrest at the G2/M phase and decreasing MMP-2 and MMP-9 expression and activity. In vivo studies revealed that F3 liposomes were highly accumulated at the tumor site and more effectively delayed tumor growth andprolonged the overall survival than other groups in 4T1 breast tumor-bearing mice. Taken together, encapsulation of CA4 in PEGylated F3 liposomes enhances its anti-tumor activity and may be serve as a promising approach for TNBC treatment and merits further investigation.

Synthesis, characterization, and cytotoxicity evaluation of dextran-myristoyl-ECGKRK peptide conjugate

CGKRK is a well-known tumor homing peptide with significant specificity for many types of cancer tissues. Herein, we describe the synthesis of a novel drug delivery system based on dextran decorated with myristoyl-ECGKRK peptide. The myristoylated peptide was synthesized and conjugated to dextran via an ester bond followed by purification. FT-IR and NMR confirmed the success of the conjugation reaction, while the surface morphology examination revealed that the conjugate has a characteristic porous network-like structure. Dynamic-light scattering measurements indicated the ability of the conjugate to self-assemble into nanoparticles with an average size of 248 ± 6.33 nm, and zeta potential of 10.7 mV. The cytotoxicity profiles for the peptide, dextran (Dex0), and dextran-peptide conjugate (Dex1) were evaluated against triple-negative breast cancer cells (MDA-MB-231), breast cancer cells (MCF-7), and human embryonic normal kidney cells (HEK-293). The results revealed that myristoyl-ECGKRK was noncytotoxic on the two different breast cancer cell lines up to 50 μM, but the cell viability was minimally reduced to 85% at 50 μm in HEK-293 cells. Similarly, Dex0 showed a neglected cytotoxicity profile at all tested concentrations. The Dex1 was not toxic to the cells up to a concentration of 8.3 mg/mL.

Antennapedia-derived positively-charged peptide faces multiple problems upon their usage as targeting ligand for liposomal doxorubicin

The positively-charged peptide antp derived from Antennapedia transcription protein is demonstrated to mediate the liposome translocation across the cell membrane. In the current investigation, we prepared a stable liposomal doxorubicin (Dox) formulation and targeted it with the antp peptide from 0 to 200 ligand/liposome. These antp-containing liposomes were investigated in terms of physical stability on storage in the refrigerator and upon incubation in blood. Also, other features like cell binding, uptake, biodistribution, and treatment efficiency were evaluated in C26 colon carcinoma BALB/c mice. The Antp in liposomes resulted in enhanced particle growth with the development of the enormously large liposomes from 2000 to 6000 nm. Upon incubation in blood, these large liposomes were removed. The antp also enhanced the cell binding affinity and cell uptake rate of the liposomes and resulted in the restriction of the cancer cell proliferation, but it failed to improve the chemotherapeutic property of the Dox-liposome. The i.v. injection of antp-liposomes (15 mg Dox/kg) caused severe body weight loss and early death incidence due to probably increased toxicity. The antp targeting offered no advantage to the Dox-liposome in the delivery of Dox to the tumor, and failed to enhance the treatment efficiency of the liposomes.

A novel self-targeting theranostic nanoplatform for photoacoustic imaging-monitored and enhanced chemo-sonodynamic therapy

Sonodynamic therapy has attracted wide attention as a noninvasive therapy due to deep tissue penetration. However, majority sonosensitizers often suffer from poor physiological stability, rapid blood clearance and nonspecific targeting, which seriously hinders their further practical applications. Inspired by the concept of active targeting drug delivery, both dual-functional chemo-drug pemetrexed (PEM, emerges an innate affinity toward the folate receptor) and amphiphilic d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were selected to be covalently linked by an esterase-responsive ester linkage. The synthesized self-targeting TPGS-PEM prodrug and indocyanine green (ICG) as functional motifs can be self-assembled into a TPGS-PEM-ICG nanoplatform within an aqueous medium. The TPGS-PEM-ICG nanoplatform with outstanding structural and physiological stability not only protects the sonosensitizer from reticular endothelial system clearance but also achieves active targeting drug delivery and efficient tumor enrichment. Moreover, TPGS-PEM-ICG nanoplatform can selectively recognize tumor cells and then realize on-demand drug burst release by multiple stimuli of internal lysosomal acidity, esterase and external ultrasound, which guarantee low side effects toward normal tissues and organs. It is also worth noting that our nanoplatform exhibits protruding tumor enrichment under the precise guidance of photoacoustic/fluorescence imaging. Further in vitro and in vivo experimental results well confirmed that the TPGS-PEM-ICG nanoplatform possesses enhanced chemo-sonodynamic effects. Interestingly, the highly toxic reactive oxygen species can remarkably reduce the blood oxygen saturation signal of the tumor microenvironment via precise, multifunctional and high-resolution photoacoustic imaging. Taken together, the TPGS-PEM-ICG nanoplatform can be expected to hold enormous potential for diagnosis, prognosis and targeted therapy for tumor.