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 200nm with narrow size distributions (PDI < 0.3), and negative surface charges varying from -6 mV to -18.6mV. 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.

Novel liposomal glatiramer acetate: Preparation and immunomodulatory evaluation in murine model of multiple sclerosis.

The frequent administration rate required for Glatiramer acetate (GA), a first-line therapy for Multiple sclerosis (MS), poses patient compliance issues. Only a small portion of the subcutaneously administered GA is available for phagocytosis by macrophages, as most of it is hydrolyzed at its administration site or excreted renally. To unravel these hurdles, we have prepared liposomal formulations of GA through thin film-hydration method plus extrusion. The clinical and histopathological efficacy of GA-loaded liposomes were assessed in prophylactic and therapeutic manners on murine model of MS (experimental autoimmune encephalomyelitis (EAE)). The selected GA liposomal formulation showed favorable size (275 nm on average), high loading efficiency, and high macrophage localization. Moreover, administration of GA-liposomes in mice robustly suppressed the inflammatory responses and decreased the inflammatory and demyelinated lesion regions in CNS compared to the free GA with subsequent reduction of the EAE clinical score. Our study indicated that liposomal GA could be served as a reliable nanomedicine-based platform to hopefully curb MS-related aberrant autoreactive immune responses with higher efficacy, longer duration of action, fewer administration frequencies, and higher delivery rate to macrophages. This platform has the potential to be introduced as a vaccine for MS after clinical translation and merits further investigations.

Preparation and characterization of vaginal suppository of semisynthetic derivatives of ergot alkaloids cabergoline.

Background: There is evidence that vaginal cabergoline can help to prevent ovarian hyperstimulation syndrome. Therefore, the vaginal suppository may be a good choice because it can be administered directly into the vagina and has no adverse effects on the stomach. In this regard we developed a cabergoline suppository as an alternative to cabergoline tablets. Design-Expert was used to determine the most suitable concentrations of PEG 6000/400, and Tween 80 to obtain a stable suppository. Specific ratios of PEG6000/400 and Tween 80 were entered as factors, and release, melting time, and hardness were evaluated as responses. In addition, the final formulation was evaluated for weight changes, pH, drug content, degradation time, deformation time, in vitro drug release, DSC analysis, infrared spectroscopy, and stability properties. Results: The suppositories were all smooth and white. They all had a weight that averaged less than 5 %. The formulations showed a pH between 6 and 6.5. The active ingredient content ranged between 79.666 ± 8.54 % and 99.67 ± 6.55 %. Suppository stiffness was between 2.74 ± 0.04 and 4.20 ± 0.03. The decomposition time of the suppositories varied between 11.25 ± 0.15 to 20.19 ± 0.08 min. The deformation time was between 26.11 ± 0.06 to 38.59 ± 0.47 min. Cabergoline content was released over 45 min from formulations of F10 (∼46 %), F2 (∼64 %), F6 (∼69 %), F4 (∼79 %), F1 (∼88 %), and F7 (∼93 %). However, other formulations released more than 95 % within 45 min. Conclusions: All variables except melting time significantly affected our responses. In vitro studies have indicated that the optimized cabergoline formula could be an excellent alternative to cabergoline oral formulations.

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.

Plant Gel-Mediated Synthesis of Gold-Coated Nanoceria Using Ferula gummosa: Characterization and Estimation of Its Cellular Toxicity toward Breast Cancer Cell Lines.

In this study, a novel method using Ferula gummosa gums as a capping agent was used to synthesize the nanoceria for the first time. The method was economical and performed at room temperature. Furthermore, it was coated with gold (Au/nanoceria) and fully characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential (ζ potential). The crystallite size obtained from the results was 28.09 nm for Au/nanoceria. The energy-dispersive X-ray spectroscopy (EDX) analysis of Au/nanoceria revealed the compositional constituents of the product, which display the purity of the Au/nanoceria. The cell toxicity properties of the non-doped and Au-coated nanoceria were identified by a MTT analysis on a breast cancer cell line (MCF7). Additionally, human foreskin fibroblast cells (HFF) were used as a normal cell line. The cytotoxicity results indicated that the toxicological effect of Au/nanoceria on cancer cells was significant while having little toxic effect on normal cells. The toxicity effect of nanoceria clearly shows the dependence on dose and time, so, with increasing the dose of Au/nanoceria, the death of cancer cells also increases.

Nanoliposomal VEGF-R2 peptide vaccine acts as an effective therapeutic vaccine in a murine B16F10 model of melanoma.

Background: The vascular endothelial growth factor receptor-2 (VEGFR-2) plays an important role in melanoma development and progression. Peptide vaccines have shown great potential in cancer immunotherapy by targeting VEGFR-2 as a tumor-associated antigen and boosting the immune response against both tumor cells and tumor endothelial cells. Despite this, the low efficiency of peptide vaccines has resulted in moderate therapeutic results in the majority of studies. Enhancing the delivery of peptide vaccines using nanoliposomes is an important strategy for improving the efficacy of peptide vaccines. In this regard, we designed VEGFR-2-derived peptides restricted to both mouse MHC I and human HLA-A*02:01 using immunoinformatic tools and selected three peptides representing the highest binding affinities. The peptides were encapsulated in nanoliposomal formulations using the film method plus bath sonication and characterized for their colloidal properties. Results: The mean diameter of peptide-encapsulated liposomes was around 135 nm, zeta potential of - 17 mV, and encapsulation efficiency of approximately 70%. Then, vaccine formulations were injected subcutaneously in mice bearing B16F10-established melanoma tumors and their efficiency in triggering immunological, and anti-tumor responses was evaluated. Our results represented that one of our designed VEGFR-2 peptide nanoliposomal formulations (Lip-V1) substantially activated CD4+ (p < 0.0001) and CD8+ (P < 0.001) T cell responses and significantly boosted the production of IFN-γ (P < 0.0001) and IL-4 (P < 0.0001). Furthermore, this formulation led to a significant decrease in tumor volume (P < 0.0001) and enhanced survival (P < 0.05) in mice. Conclusion: Our findings suggest that the nanoliposomal formulation containing VEGFR-2 peptides could be a promising therapeutic vaccination approach capable of eliciting strong antigen-specific immunologic and anti-tumor responses. Supplementary Information: The online version contains supplementary material available at 10.1186/s12645-023-00213-7.

Characterization of stability, safety and immunogenicity of the mRNA lipid nanoparticle vaccine Iribovax® against COVID-19 in nonhuman primates.

mRNA-lipid nanoparticle (mRNA-LNP) vaccines have proved their efficacy, versatility and unprecedented manufacturing speed during the COVID-19 pandemic. Here we report on the physicochemical properties, thermostability, immunogenicity, and protective efficacy of the nucleoside-modified mRNA-LNP vaccine candidate Iribovax® (also called SNEG2c). Injection of BALB/c mice, rabbits and nonhuman primates with two doses of SNEG2c induced production of high-titers of SARS-CoV-2 spike-specific and receptor-binding domain (RBD)-neutralizing antibodies in immunized animals. In addition to the strong humoral response, SNEG2c elicited substantial Th1-biased T-cell response. Sera from rhesus macaques immunized with a low dose of the vaccine showed robust spike-specific antibody titers 3-24× as high as those in convalescent sera from a panel of COVID-19 patients and 50% virus neutralization geometric mean titer of 1024 against SARS-CoV-2. Strikingly, immunization with SNEG2c completely cleared infectious SARS-CoV-2 from the upper and lower respiratory tracts of challenged macaques and protected them from viral-induced lung and trachea lesions. In contrast, the non-vaccinated macaques developed moderate to severe pulmonary pathology after the viral challenge. We present the results of repeat-dose and local tolerance toxicity and thermostability studies showing how the physicochemical properties of the mRNA-LNPs change over time and demonstrating that SNEG2 is safe, well tolerated and stable for long-term. These results support the planned human trials of SNEG2c.

The protective effect of N-acetylcysteine against liposome and chitosan-induced cytotoxicity.

AIM: N-acetylcysteine (NAC) is an antioxidant used to moderate liposome and chitosan-induced cell cytotoxicity at their high concentrations. METHODS: Liposome and chitosan were prepared and characterised. The cytotoxicity effect of liposome with NAC-loaded liposome (liposome-NAC) and chitosan solution with chitosan solution containing NAC (chitosan-NAC) on the A549 cell line was compared. RESULTS: Particle size, zeta potential, and NAC drug release for liposome were 125.9 ± 8 nm, -34.7 ± 2.1 mV, and 51.1% ± 3%, respectively. Scanning electron microscope (SEM) and transmission electron microscope (TEM) indicated spherical shape of liposome. Encapsulation efficiency of liposome-NAC was 12% ± 0.98%. Particle size and zeta potential for chitosan solution were 361 ± 11.3 nm and 10.8 ± 1.52 mV. Stability storage study indicated good stability of chitosan and liposome. Cell viability of liposome-NAC and chitosan-NAC significantly was higher than liposome and chitosan at all four concentrations. CONCLUSIONS: NAC has a protective effect against liposome and chitosan-induced cell toxicity.

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.

Icariin: A Promising Natural Product in Biomedicine and Tissue Engineering.

Among scaffolds used in tissue engineering, natural biomaterials such as plant-based materials show a crucial role in cellular function due to their biocompatibility and chemical indicators. Because of environmentally friendly behavior and safety, green methods are so important in designing scaffolds. A key bioactive flavonoid of the Epimedium plant, Icariin (ICRN), has a broad range of applications in improving scaffolds as a constant and non-immunogenic material, and in stimulating the cell growth, differentiation of chondrocytes as well as differentiation of embryonic stem cells towards cardiomyocytes. Moreover, fusion of ICRN into the hydrogel scaffolds or chemical crosslinking can enhance the secretion of the collagen matrix and proteoglycan in bone and cartilage tissue engineering. To scrutinize, in various types of cancer cells, ICRN plays a decisive role through increasing cytochrome c secretion, Bax/Bcl2 ratio, poly (ADP-ribose) polymerase as well as caspase stimulations. Surprisingly, ICRN can induce apoptosis, reduce viability and inhibit proliferation of cancer cells, and repress tumorigenesis as well as metastasis. Moreover, cancer cells no longer grow by halting the cell cycle at two checkpoints, G0/G1 and G2/M, through the inhibition of NF-κB by ICRN. Besides, improving nephrotoxicity occurring due to cisplatin and inhibiting multidrug resistance are the other applications of this biomaterial.

The comparison of biodistribution of glutathione PEGylated nanoliposomal doxorubicin formulations prepared by pre-insertion and post-insertion methods for brain delivery in normal mice.

Several obstacles limit the efficacy of brain tumour treatment, most notably the blood-brain barrier (BBB), which prevents the brain uptake of the majority of accessible medicines due to tight junctions. The presence of glutathione (GSH) receptors on the BBB surface has been demonstrated in numerous papers; consequently, products containing glutathione as a targeting ligand coupled with nanoliposomes are used to enhance drug delivery across the BBB. Here, the 5% pre-inserted PEG2000-GSH PEGylated liposomal doxorubicin was conducted according to 2B3-101 being tested in clinical trials. In addition, PEGylated nanoliposomal doxorubicin connected to the spacer-GSH targeting ligand (GSGGCE) and the PEG3400 was conducted using post-insertion method. Next, in vivo biodistribution of the produced formulations was tested on healthy mice to see if GSGGCE, as the targeted ligand, could cross the BBB compared to 5% pre-inserted PEG2000-GSH and Caelyx® . Compared to the pre-inserted formulation and Caelyx® , the post-inserted formulations' concentration was lower in the heart and higher in brain tissues, resulting in boosting the brain concentration of accumulated doxorubicin with fewer possible side effects, including cardiotoxicity. In comparison to the pre-insertion procedure, the post-insertion method is easier, faster, and more cost-effective. Moreover, employing PEG3400 and the post-insertion approach in the PEG3400-GSGGCE liposomal formulations was found to be effective in crossing the BBB.

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.

In this work, we used an antimicrobial peptide, FA12, to target Muc1 glycoprotein on the surface of colon cancer cells. The interaction between the peptide and Muc1 as a receptor was verified by molecular dynamics simulation. FA12 peptide was affixed to the surface of the liposomal form of doxorubicin (PLD) specifically to facilitate drug delivery transfer to the tumor site. The main benefits of this novel formulation were improvement of therapeutic efficacy and enhancement of survival time in mice bearing colon cancer.[Figure: see text].

The role of size in PEGylated liposomal doxorubicin biodistribution and anti-tumour activity.

The size of nanoliposome-encapsulated drugs significantly affects their therapeutic efficacy, biodistribution, targeting ability, and toxicity profile for the cancer treatment. In the present study, the biodistribution and anti-tumoral activity of PEGylated liposomal Doxorubicin (PLD) formulations with different sizes were investigated. First, 100, 200, and 400 nm PLDs were prepared by remote loading procedure and characterised for their size, zeta potential, encapsulation efficacy, and release properties. Then, in vitro cellular uptake and cytotoxicity were studied by flow cytometry and MTT assay, and compared with commercially available PLD Caelyx® . In vivo studies were applied on BALB/c mice bearing C26 colon carcinoma. The cytotoxicity and cellular uptake tests did not demonstrate any statistically significant differences between PLDs. The biodistribution results showed that Caelyx® and 100 nm liposomal formulations had the most doxorubicin (Dox) accumulation in the tumour tissue and, as a result, considerably suppressed tumour growth compared with 200 and 400 nm PLDs. In contrast, larger nanoparticles (200 and 400 nm formulations) had more accumulation in the liver and spleen. This study revealed that 90 nm Caelyx® biodistribution profile led to the stronger anti-tumour activity of the drug and hence significant survival extension, and showed the importance of vesicle size in the targeting of nanoparticles to the tumour microenvironment for the treatment of cancer.

Resveratrol-Mediated Gold-Nanoceria Synthesis as Green Nanomedicine for Phytotherapy of Hepatocellular Carcinoma.

BACKGROUND: In the present study, resveratrol was used to prepare complexes of cerium and nanoceria, also coated with gold (CeO2@Au core-shells) to improve the surface interactions in physiological conditions. METHODS: The CeO2@Au core-shells were characterized using powder X-ray diffraction (PXRD), Fourier transforms infrared spectroscopy (FTIR), transmission electron microscope (TEM) analysis, dynamic light scattering (DLS) and ζ potential. RESULTS: The experiment was led to the successful synthesis of nanosized CeO2@Au core-shells, although agglomeration of particles caused the distribution of the larger particles. The TEM analysis demonstrated the particles sizes ranged from 20 nm to 170 nm. Moreover, the PXRD analysis showed that both nanoceria and gold with the same crystal systems and space groups. To investigate the anticancer activity of the CeO2@Au core-shells, the cytotoxicity of the nanoparticles was investigated against liver cancerous cell lines (HepG2). CONCLUSIONS: The results indicated biosynthesized NCs have significant cellular toxicity properties against HepG2 and could be utilized in hepatocarcinoma therapy. Further in vivo investigations is proposed to be designed to assess anti-cancer and safety effects of fabricated nanocomposites.

Docetaxel in combination with metformin enhances antitumour efficacy in metastatic breast carcinoma models: a promising cancer targeting based on PEGylated liposomes.

OBJECTIVES: Metformin has been shown to kill cancer stem-like cells in genetically various types of breast carcinoma. With the aim to simultaneously eradicate the bulk population of tumour cells and the rare population of cancer stem-like cells in breast cancer tissues, we used the combination chemotherapy of docetaxel (DTX) with metformin (MET). Furthermore, we introduce an active loading method based on ammonium sulphate 250 mM (SA) for encapsulating docetaxel into liposomes. METHODS: Docetaxel and metformin encapsulated into PEGylated liposomes with two different methods based on remote or passive loading methods, respectively. The size and surface charge of the liposomes were characterized. DTX content in the nanoliposomes was measured by the high-performance liquid chromatography method. The drug release profiles were evaluated in phosphate-buffered dextrose 5% with the pH of 6.5 and 7.4. We examined the antitumour activity of Taxotere (TAX), and liposomal formulation of DTX and MET as a monotherapy or combination therapy. The biodistribution of liposomes was also investigated using 99mTc hexamethyl propylene amine oxime method in BALB/c mice bearing 4T1 breast carcinoma tumours. KEY FINDINGS: The final formulations were prepared according to the best physicochemical characteristics which were HSPC/mPEG2000-DSPE/Chol (DTX liposomes) and HSPC/DPPG/mPEG2000-DSPE/Chol (MET liposomes), at molar ratios of 85/5/10 and (55/5/5/35), respectively. In vivo experiments showed that when free or liposomal metformin used in combination with liposomal docetaxel, they prolonged median survival time (MST) from 31 in the control group to 46 days, which demonstrates their promising effects on the survival of the 4T1 breast carcinoma mice models. Moreover, combination therapies could significantly increase life span in comparison with phosphate-buffered saline (PBS) and Taxotere groups at the same dose. Furthermore, in the combination therapy study, treatment with DTX liposomes prepared by ammonium sulphate 250 mM buffer alone resulted in similar therapeutic efficacy to combination therapy. The biodistribution study exhibited significant accumulation of DTX liposomes in the tumours due to the Enhanced Permeability and Retention effect. CONCLUSIONS: This study also showed that metformin-based combinatorial chemotherapies have superior efficacy versus their corresponding monotherapy counterparts at same doses. The findings confirm that liposomes based on ammonium sulphate 250 mM could be as a promising formulation for efficient DTX delivering and cancer targeting and therefore merit further investigations.

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 Ë‚ 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.

Preparation, characterization, and biodistribution of glutathione PEGylated nanoliposomal doxorubicin for brain drug delivery with a post-insertion approach.

Objectives: Brain cancer treatments have mainly failed due to their inability to cross the blood-brain barrier. Several studies have confirmed the presence of glutathione (GSH) receptors on BBB's surface, as a result, products like 2B3-101, which contain over 5% pre-inserted GSH PEGylated liposomal doxorubicin, are being tested in clinical trials. Here we conducted the PEGylated nanoliposomal doxorubicin particles that are covalently attached to the glutathione using the post-insertion technique. Compared with the pre-insertion approach, the post-insertion method is notably simpler, faster, and more cost-effective, making it ideal for large-scale pharmaceutical manufacturing. Materials and Methods: The ligands of the DSPE PEG(2000) Maleimide-GSH were introduced in the amounts of 25, 50, 100, 200, and 400 on the available Caelyx. Following physicochemical evaluations, animal experiments such as biodistribution, fluorescence microscopy, and pharmacokinetics were done. Results: In comparison with Caelyx, the 200L and 400L treatment arms were the most promising formulations. We showed that nanocarriers containing 40 times fewer GSH micelles than 2B3-101 significantly increased blood-brain barrier penetrance. Due to the expressed GSH receptors on tissues as an endogenous antioxidant, doxorubicin will likely concentrate in the liver, spleen, heart, and lung in comparison with Caelyx, according to other tissue analyses. Conclusion: The post-insertion technique was found a successful approach with more pharmaceutical aspects for large-scale production. Moreover, further investigations are highly recommended to determine the efficacy of 5% post-inserted GSH targeted nanoliposomes versus 2B3-101 as a similar formulation with a different preparation method.

Nanocarriers Call the Last Shot in the Treatment of Brain Cancers.

Our brain is protected by physio-biological barriers. The blood-brain barrier (BBB) main mechanism of protection relates to the abundance of tight junctions (TJs) and efflux pumps. Although BBB is crucial for healthy brain protection against toxins, it also leads to failure in a devastating disease like brain cancer. Recently, nanocarriers have been shown to pass through the BBB and improve patients' survival rates, thus becoming promising treatment strategies. Among nanocarriers, inorganic nanocarriers, solid lipid nanoparticles, liposomes, polymers, micelles, and dendrimers have reached clinical trials after delivering promising results in preclinical investigations. The size of these nanocarriers is between 10 and 1000 nm and is modified by surface attachment of proteins, peptides, antibodies, or surfactants. Multiple research groups have reported transcellular entrance as the main mechanism allowing for these nanocarriers to cross BBB. Transport proteins and transcellular lipophilic pathways exist in BBB for small and lipophilic molecules. Nanocarriers cannot enter via the paracellular route, which is limited to water-soluble agents due to the TJs and their small pore size. There are currently several nanocarriers in clinical trials for the treatment of brain cancer. This article reviews challenges as well as fitting attributes of nanocarriers for brain tumor treatment in preclinical and clinical studies.

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.