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.

Development of nano-liposomal human growth hormone as a topical formulation for preventing uvb-induced skin damage

Due to its involvement in skin maintenance and repair, topical administration of recombinant human growth hormone (rhGH) is an interesting strategy for therapeutic purposes. We have formulated and characterized a topical rhGH-loaded liposomal formulation (rhGH-Lip) and evaluated its safety, biological activity, and preventive role against UVB-induced skin damage. The rhGH-Lip had an average size and zeta potential of 63 nm and -33 mV, respectively, with 70 % encapsulation efficiency. The formulation was stable at 4 °C for at least one year. The SDS-PAGE and circular dichroism results showed no structural alterations in rhGH upon encapsulation. In vitro, studies in HaCaT, HFFF-2, and Ba/F3-rhGHR cell lines confirmed the safety and biological activity of rhGH-Lip. Franz diffusion cell study showed increased rhGH skin permeation compared to free rhGH. Animal studies in nude mice showed that liposomal rhGH prevented UVB-induced epidermal hyperplasia, angiogenesis, wrinkle formation, and collagen loss, as well as improving skin moisture. The results of this study show that rhGH-Lip is a stable, safe, and effective skin delivery system and has potential as an anti-wrinkle formulation for topical application. This study also provides a new method for the topical delivery of proteins and merits further investigation.

Retraction notice to "The therapeutic potential of human adipose-derived mesenchymal stem cells producing CXCL10 in a mouse melanoma lung metastasis model" [Cancer Lett. 419 (2018) 30-39]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor. After publication, the Editors were contacted by a concerned reader regarding alleged image duplication. These allegations are in regard to Fig. 3a being duplicated from a previously published paper in the journal Stem Cells (Stem Cells. 2008 Sep;26 (9):2332-8. doi: 10.1634/stemcells.2008-0084) and Fig. 8a being duplicated from a previously published paper in the journal Molecular Cancer (Mol Cancer 13, 255 (2014). https://doi.org/10.1186/1476-4598-13-255). After a thorough investigation by the editorial team, the Editors determined that there are multiple identical details between Fig. 5A (Cancer Letters) and Fig. 3A (Stem Cells) and the authors did not produce satisfactory evidence that the published images in Cancer Letters were original. Due to this, the Editor does not have confidence in the results and conclusions presented and has made the decision to retract.

Harnessing CRISPR technology for viral therapeutics and vaccines: from preclinical studies to clinical applications

The CRISPR/Cas system, identified as a type of bacterial adaptive immune system, have attracted significant attention due to its remarkable ability to precisely detect and eliminate foreign genetic material and nucleic acids. Expanding upon these inherent capabilities, recent investigations have unveiled the potential of reprogrammed CRISPR/Cas 9, 12, and 13 systems for treating viral infections associated with human diseases, specifically targeting DNA and RNA viruses, respectively. Of particular interest is the RNA virus responsible for the recent global outbreak of coronavirus disease 2019 (COVID-19), which presents a substantial public health risk, coupled with limited efficacy of current prophylactic and therapeutic techniques. In this regard, the utilization of CRISPR/Cas technology offers a promising gene editing approach to overcome the limitations of conventional methods in managing viral infections. This comprehensive review provides an overview of the latest CRISPR/Cas-based therapeutic and vaccine strategies employed to combat human viral infections. Additionally, we discuss significant challenges and offer insights into the future prospects of this cutting-edge gene editing technology.

Microfluidic-assisted preparation of PLGA nanoparticles loaded with insulin: a comparison with double emulsion solvent evaporation method

Poly lactic-co-glycolic acid (PLGA) is an ideal polymer for the delivery of small and macromolecule drugs. Conventional preparation methods of PLGA nanoparticles (NPs) result in poor control over NPs properties. In this research, a microfluidic mixer was designed to produce insulin-loaded PLGA NPs with tuned properties. Importantly; aggregation of the NPs through the mixer was diminished due to the coaxial mixing of the precursors. The micromixer allowed for the production of NPs with small size and narrow size distribution compared to the double emulsion solvent evaporation (DESE) method. Furthermore, encapsulation efficiency and loading capacity indicated a significant increase in optimized NPs produced through the microfluidic method in comparison to DESE method. NPs prepared by the microfluidic method were able to achieve a more reduction of trans-epithelial electrical resistance values in the Caco-2 cells compared to those developed by the DESE technique that leads to greater paracellular permeation. Compatibility and interaction between components were evaluated by differential scanning calorimetry and fourier transform infrared analysis. Also, the effect of NPs on cell toxicity was investigated using MTT test. Numerical simulations were conducted to analyze the effect of mixing patterns on the properties of the NPs. It was revealed that by decreasing flow rate ratio, i.e. flow rate of the organic phase to the flow rate of the aqueous phase, mixing of the two streams increases. As an alternative to the DESE method, high flexibility in modulating hydrodynamic conditions of the microfluidic mixer allowed for nanoassembly of NPs with superior insulin encapsulation at smaller particle sizes.

Evaluation of the efficiency of nanomicellar formulation of fat-soluble vitamins in patients with cystic fibrosis: the study protocol for a randomized controlled trial

BACKGROUND

Cystic fibrosis is an inherited disease, which is caused by the CFTR protein defects due to mutations in the CFTR gene. Along with CFTR dysfunction, exocrine pancreatic insufficiency plays a key role in persistent fat malabsorption in CF patients; therefore, deficiency of fat-soluble vitamins (A, D, E, and K) is still a therapeutic challenge. Even with efficient pancreatic enzyme medication and CF-specific vitamins, many patients with CF have fat-soluble vitamins deficiency. The present study aims to evaluate the efficiency of nanomicelle formulation of fat-soluble vitamins in children with CF in order to achieve the appropriate serum levels of these vitamins.

METHODS

This prospective, single-blind control trial will be conducted at the Akbar Children's Hospital in Mashhad, Iran. Patients with CF will be enrolled based on the eligibility criteria. The control group will receive the standard formulation of fat-soluble vitamins similar to the routine CF treatment, and for the intervention group, the nanomicelle formulation of fat-soluble vitamins will be administered for 3 months. The primary outcome of this study is the measurement of serum levels of fat-soluble vitamins. The secondary outcomes are clinical assessment by the Shwachman-Kulczycki score, anthropometrics, and quality of life. Outcomes will be assessed before and after 3 months.

DISCUSSION

Due to persistent fat-soluble vitamin deficiency in CF disease, the nanomicelle formulation could be proposed as a new delivery method of fat-soluble vitamins in the treatment of cystic fibrosis.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20220415054541N1. Registered on July 23, 2022.

Liposomal factor VIII as an efficient pharmaceutical system for the treatment of hemophilia

Objectives

Currently, the most important treatment approach for hemophilia type A is recombinant Factor VIII. However, due to its low retention time in the blood, the patients usually need successive injections. In addition, neutralization of injected proteins by antibodies complicates treatment. We examined the prolongation of the persistence time of injectable FVIII in the blood and the potential effects on survival using promising PEGylated liposomes (PEGLip) utilizing hydrogenated soy phosphatidylcholine (HSPC, Tm= 54.5 ºC) and 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC, Tm= - 2 ºC).

Materials and Methods

Nanoliposomes with different percentages of PEG (3% and 5%) were obtained via the thin film hydration procedure and extrusion. Liposomal FVIII formulation was prepared and characterization was done.

Results

The results revealed that the formulations are in the 80-120 nm range with uniform dispersion, which was confirmed using transmission electron microscopy (TEM) imaging. The phase transition temperature (Tm) of the liposomes was obtained by differential scanning calorimetry (DSC). With an attachment efficacy of approximately 87%, proteins bind non-covalently yet with a strong affinity to the exterior of PEGLip. The final formulations underwent additional examination. No significant change was observed in size, charge, and PDI between the FVIII-conjugated liposomal formulations and their liposomal nanoparticles. The selected formulations were injected into BALB/c mice. The circulation time and potential clotting effectiveness of PEGLip-FVIII are vastly improved over free protein, in non-hemophilic mice.

Conclusion

The obtained results showed that using phospholipids with high Tm (HSPC) can improve the hemostatic efficiency of liposomes more than phospholipids with low Tm (POPC).

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 solid lipid nanoparticles encapsulated noscapine and evaluation of its protective effects against imiquimod-induced psoriasis-like skin lesions

Psoriasis is a chronic inflammatory skin disease characterized by thickening the epidermis with erythema, scaling, and proliferation. Noscapine (NOS) has several anti-inflammatory, anti-angiogenic, and anti-fibrotic effects, but its low solubility and large size results in its lower efficacy in the clinic. In this regard, solid lipid nanoparticles (SLN) encapsulated NOS (SLN-NOS) were fabricated using the well-known response surface method based on the central composite design and modified high-shear homogenization and ultrasound method. As a result, Precirol® was selected as the best lipid base for the SLN formulation based on Hildebrand-Hansen solubility parameters, in which SLN-NOS 1 % had the best zeta potential (-35.74 ± 2.59 mV), average particle size (245.66 ± 17 nm), polydispersity index (PDI, 0.226 ± 0.09), high entrapment efficiency (89.77 %), and ICH-based stability results. After 72 h, the SLN-NOS 1 % released 83.23 % and 58.49 % of the NOS at pH 5.8 and 7.4, respectively. Moreover, Franz diffusion cell's results indicated that the skin levels of NOS for SLN and cream formulations were 46.88 % and 13.5 % of the total amount, respectively. Our pharmacological assessments revealed that treatment with SLN-NOS 1 % significantly attenuated clinical parameters, namely ear thickness, length, and psoriasis area and severity index, compared to the IMQ group. Interestingly, SLN-NOS 1 % reduced the levels of interleukin (IL)-17, tumor necrosis factor-α, and transforming growth factor-β, while elevating IL-10, compared to the IMQ group. Histology studies also showed that topical application of SLN-NOS 1 % significantly decreased parakeratosis, hyperkeratosis, acanthosis, and inflammation compared to the IMQ group. Taken together, SLN-NOS 1 % showed a high potential to attenuate skin inflammation.

Aptamer-modified chitosan-capped mesoporous silica nanoparticles for co-delivery of cytarabine and daunorubicin in leukemia

In this study, surface modified mesoporous silica nanoparticles (MSNs) were prepared for the targeted delivery of the anticancer agents, daunorubicin (DNR) and cytarabine (CTR), against K562 leukemia cancer cell lines. The MSNs were surface-modified with pH-sensitive chitosan (CS) to prevent the burst release of anticancer agents at the physiological pH of 7.4 and to enable a higher drug release at lower pH and higher concentration of glutathione. Finally, the MSNs were surface modified with KK1B10 aptamer (Apt) to enhance their uptake by K562 cells through ligand-receptor interactions. The MSNs were characterized using different methods and both in vitro and in vivo experiments were utilized to demonstrate their suitability as targeted anticancer agents. The resultant MSNs exhibited an average particle size of 295 nm, a surface area of 39.06 m2/g, and a cumulative pore volume of 0.09 cm3/g. Surface modification of MSNs with chitosan (CS) resulted in a more regulated and acceptable continuous release rate of DNR. The drug release rate was significantly higher at pH 5 media enriched with glutathione, compared to pH 7.4. Furthermore, MSNs coated with CS and conjugated with aptamer (MSN-DNR + CTR@CS-Apt) exhibited a lower IC50 value of 2.34 µg/ml, compared to MSNs without aptamer conjugation, which displayed an IC50 value of 12.27 µg/ml. The results of the cell cycle analysis indicated that the administration of MSN-DNR + CTR@CS-Apt led to a significant increase in the population of apoptotic cells in the sub-G1 phase. Additionally, the treatment arrested the remaining cells in various other phases of the cell cycle. Furthermore, the interactions between Apt-receptors were found to enhance the uptake of MSNs by cancer cells. The results of in vivo studies demonstrated that the administration of MSN-DNR + CTR@CS-Apt led to a significant reduction in the expression levels of CD71 and CD235a markers, as compared to MSN-DNR + CTR@CS (p < 0.001). In conclusion, the surface modified MSNs prepared in this study showed lower IC50 against cancer cell lines and higher anticancer activity in animal models.

Optimizing nanoliposomal formulations: Assessing factors affecting entrapment efficiency of curcumin-loaded liposomes using machine learning

BACKGROUND

Curcumin faces challenges in clinical applications due to its low bioavailability and poor water solubility. Liposomes have emerged as a promising delivery system for curcumin. This study aims to apply ensemble learning, a machine learning technique, to determine the most effective experimental conditions for formulating stable curcumin-loaded liposomes with a high entrapment efficiency (EE).

METHODS

Two liposomal formulations composed of HSPC:DPPG:Chol:DSPE-mPEG2000 and HSPC:Chol:DSPE-mPEG2000 at 55:5:35:5 and 55:40:5 M ratios, respectively, were prepared using the remote loading method, and their particle size and polydispersity index (PDI) were determined using Dynamic Light Scattering. To model the impact of five factors (molar ratios, particle size, sonication time, pH, and PDI) on EE%, the Least-squares boosting (LSBoost) ensemble learning algorithm was employed due to its capability to effectively handle nonlinear and non-stationary problems. The implementation and optimization of LSBoost were performed using MATLAB R2020a. The dataset was randomly split into training and testing sets, with 70% allocated for training. The mean absolute error (MAE) was used as the cost function to evaluate model performance. Additionally, a novel approach was employed to visualize the results using 3D plots, facilitating practical interpretation.

RESULTS

The optimal model exhibited an MAE of 3.61, indicating its robust predictive capability. The study identified several optimal conditions for achieving the highest EE value of 100%. However, to ensure both the highest EE value and a suitable particle size, it is recommended to set the following conditions: a molar ratio of 55:5:35:5, a PDI within the range of 0.09-0.13, a particle size of approximately 130 nm, a sonication time of 30 min, and a pH within the range of 7.2-8. It is worth mentioning that adjusting the molar ratio to 55:40:5 resulted in a maximum EE of 88.38%.

CONCLUSION

These findings underscore the high performance of ensemble learning in accurately predicting and optimizing the EE of the curcumin-loaded liposomes. The application of this technique provides valuable insights and holds promise for the development of efficient drug delivery systems.

Application of ensemble machine learning approach to assess the factors affecting size and polydispersity index of liposomal nanoparticles

Liposome nanoparticles have emerged as promising drug delivery systems due to their unique properties. Assessing particle size and polydispersity index (PDI) is critical for evaluating the quality of these liposomal nanoparticles. However, optimizing these parameters in a laboratory setting is both costly and time-consuming. This study aimed to apply a machine learning technique to assess the impact of specific factors, including sonication time, extrusion temperature, and compositions, on the size and PDI of liposomal nanoparticles. Liposomal solutions were prepared and subjected to sonication with varying values for these parameters. Two compositions: (A) HSPC:DPPG:Chol:DSPE-mPEG2000 at 55:5:35:5 molar ratio and (B) HSPC:Chol:DSPE-mPEG2000 at 55:40:5 molar ratio, were made using remote loading method. Ensemble learning (EL), a machine learning technique, was employed using the Least-squares boosting (LSBoost) algorithm to accurately model the data. The dataset was randomly split into training and testing sets, with 70% allocated for training. The LSBoost algorithm achieved mean absolute errors of 1.652 and 0.0105 for modeling the size and PDI, respectively. Under conditions where the temperature was set at approximately 60 °C, our EL model predicted a minimum particle size of 116.53 nm for composition (A) with a sonication time of approximately 30 min. Similarly, for composition (B), the model predicted a minimum particle size of 129.97 nm with sonication times of approximately 30 or 55 min. In most instances, a PDI of less than 0.2 was achieved. These results highlight the significant impact of optimizing independent factors on the characteristics of liposomal nanoparticles and demonstrate the potential of EL as a decision support system for identifying the best liposomal formulation. We recommend further studies to explore the effects of other independent factors, such as lipid composition and surfactants, on liposomal nanoparticle characteristics.

Alleviation of acetaminophen-induced liver failure using silibinin nanoliposomes: An in vivo study

BACKGROUND

Acetaminophen (Act) overdose is a known inducer of liver failure in both children and adults. Cell annihilation ensues following acetaminophen overdose and its toxic metabolites by depleting cellular GSH storage and increasing ROS levels. Silymarin extract and its major compound silibinin (SLB) possess robust antioxidant properties by inducing ROS elimination; however, low bioavailability and rapid metabolism limit their applications. Herein, we aimed at using SLB liposomes to combat acetaminophen-induced acute liver toxicity.

METHODS

We have developed a SLB-lipid complex to improve SLB loading efficiency within nanoliposome by using the lipid film method. Liposomes were characterized by using DLS and TEM analysis, and the release pattern, and toxicity profile on the normal cells as well as histopathological and serum analysis were investigated to reveal relevant enzyme activities in an animal model.

RESULTS

Data demonstrated that negatively-charged SLB liposomes of 115 nm had homogeneous spherical morphology, and entrapped a considerable quantity of SLB of almost 40%. Liposomes shows a favorable release pattern and were not toxic against NIH3T3 mouse fibroblast cells. The animal study revealed that treatment of mice with SLB nanoliposomes could significantly preserve liver function as revealed by the reduced levels of ALT and AST hepatic enzymes as well as ALP in the serum. Our data indicated that intraperitoneal administration of SLB Lip could significantly reduce ALT enzyme levels (p < 0.05) compared to N-acetylcysteine, while i.v administration resulted in no significant difference compared to control animals with no treatment.

CONCLUSION

The results of this study support the significant hepatoprotective effect of SLB nanoliposomes against acetaminophen-induced toxicity depending on the route of administration.

Improving the efficacy of peptide vaccines in cancer immunotherapy

Peptide vaccines have shown great potential in cancer immunotherapy by targeting tumor antigens and activating the patient's immune system to mount a specific response against cancer cells. However, the efficacy of peptide vaccines in inducing a sustained immune response and achieving clinical benefit remains a major challenge. In this review, we discuss the current status of peptide vaccines in cancer immunotherapy and strategies to improve their efficacy. We summarize the recent advancements in the development of peptide vaccines in pre-clinical and clinical settings, including the use of novel adjuvants, neoantigens, nano-delivery systems, and combination therapies. We also highlight the importance of personalized cancer vaccines, which consider the unique genetic and immunological profiles of individual patients. We also discuss the strategies to enhance the immunogenicity of peptide vaccines such as multivalent peptides, conjugated peptides, fusion proteins, and self-assembled peptides. Although, peptide vaccines alone are weak immunogens, combining peptide vaccines with other immunotherapeutic approaches and developing novel approaches such as personalized vaccines can be promising methods to significantly enhance their efficacy and improve the clinical outcomes for cancer patients.

Poly-γ-glutamic acid nanoparticles as adjuvant and antigen carrier system for cancer vaccination

Vaccination is an innovative strategy for cancer treatment by leveraging various components of the patients' immunity to boost an anti-tumor immune response. Rationally designed nanoparticles are well suited to maximize cancer vaccination by the inclusion of immune stimulatory adjuvants. Also, nanoparticles might control the pharmacokinetics and destination of the immune potentiating compounds. Poly-γ-glutamic acid (γ-PGA) based nanoparticles (NPs), which have a natural origin, can be easily taken up by dendritic cells (DCs), which leads to the secretion of cytokines which ameliorates the stimulation capacity of T cells. The intrinsic adjuvant properties and antigen carrier properties of γ-PGA NPs have been the focus of recent investigations as they can modulate the tumor microenvironment, can contribute to systemic anti-tumor immunity and subsequently inhibit tumor growth. This review provides a comprehensive overview on the potential of γ-PGA NPs as antigen carriers and/or adjuvants for anti-cancer vaccination.

The effect of m2 peptide targeted nanoliposomes containing crocin on induction of phenotypic change in tumor macrophages to M1 state

AIMS

Crocin has immunomodulatory and anticancer effects. In this study, crocin was used to induce the M1 phenotype in mouse tumor macrophages.

MAIN METHODS

A targeted liposomal formulation with m2 peptide was prepared and characterized to deliver crocin to the M2 macrophages present in the tumor environment. RT-qPCR and IHC were performed for in vitro and in vivo (in C26 colon carcinoma mouse model at a dose of 50 mg/kg) assessment of M1 induction, respectively.

KEY FINDINGS

In vitro results indicated that liposome modified with m2 peptide was non-toxic to macrophages and had an improved uptake by macrophages compared to the non-targeted formulation and induced M1 phenotype through an IL6-independent pathway. M2 peptide- modified liposome showed considerable tumor accumulation and anti-tumor effects and significantly shifted the phenotype of tumor macrophages towards an anti-tumor M1 phenotype.

SIGNIFICANCE

Probably the remarkable anti-tumor responses observed in this study with m2 peptide-targeted liposomal formulations containing crocin were due to the enhanced delivery of crocin to the tumor macrophage and the subsequent initiation of anti-tumor immune responses.

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.

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 crossroad of nanovesicles and oral delivery of insulin

INTRODUCTION

Diabetes mellitus is one of the challenging health problems worldwide. Multiple daily subcutaneous injection of insulin causes poor compliance in patients. Development of efficient oral formulations to improve the quality of life of such patients has been an important goal in pharmaceutical industry. However, due to serious issues such as low bioavailability and instability, it has not been achieved yet.

AREAS COVERED

Due to functional properties of the vesicles and the fact that hepatic-directed vesicles of insulin could reach the clinical phases, we focused on three main vesicular delivery systems for oral delivery of insulin: liposomes, niosomes, and polymersomes. Recent papers were thoroughly discussed to provide a broad overview of such oral delivery systems.

EXPERT OPINION

Although conventional liposomes are unstable in the presence of bile salts, their further modifications such as surface coating could increase their stability in the GI tract. Bilosomes showed good flexibility and stability in GI fluids. Also, niosomes were stable, but they could not induce significant hypoglycemia in animal studies. Although polymersomes were effective, they are expensive and there are some issues about their safety and industrial scale-up. Also, we believe that other modifications such as addition of a targeting agent or surface coating of the vesicles could significantly increase the bioavailability of insulin-loaded vesicles.

Targeting fibroblast activation protein (FAP): advances in CAR-T cell, antibody, and vaccine in cancer immunotherapy

Fibroblast activation protein (FAP) is a serine protease with dual enzymatic activities overexpressed in cancer-associated fibroblasts (CAFs) in several tumor types, while its expression in healthy adult tissues is scarce. FAP overexpression on CAFs is associated with poor prognosis and plays an important role in tumor development, progression, and invasion. Therefore, FAP is considered a robust therapeutic target for cancer therapy. Here, we try to review and highlight the recent advances in immunotherapies for FAP targeting including the anti-FAP antibodies and immunoconjugates, FAP chimeric antigen receptor (CAR)-T cell, and various FAP vaccines in a preclinical and clinical setting. Subsequently, a discussion on the challenges and prospects associated with the development and translation of effective and safe therapies for targeting and depletion of FAP is provided. We proposed that new CAR-T cell engineering strategies and nanotechnology-based systems as well as advanced functional biomaterials can be used to improve the efficiency and safety of CAR-T cells and vaccines against FAP for more personalized immunotherapy. This review emphasizes the immune targeting of FAP as an emerging stromal candidate and one of the crucial elements in immunotherapy and shows the potential for improvement of current cancer therapy. A summary of different immunotherapy approaches to target fibroblast activation protein (FAP) for cancer therapy.

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.

Application of VEGF/VEGFR peptide vaccines in cancer: a systematic review of clinical trials

Peptide vaccines that target vascular endothelial growth factor (VEGF) pathway have shown promising results in inducing strong anti-tumor immune responses with minimal toxicity in various clinical studies. This systematic review was conducted to provide a comprehensive evaluation of the therapeutic efficacy, immune response, survival rate, and side effects of VEGF/VEGF receptor-based peptide vaccines. VEGF/VEGFR2 peptide vaccines were found to be safe and effective in inducing anti-tumor immune responses, while induced moderate clinical benefit. In this regard, further clinical trials are necessary to fully evaluate their clinical effects and the exact correlation between induction of immune response and clinical outcomes.

The Protective Effect of N-acetylcysteine against Liposome and Chitosan-Induced Cytotoxicity

AIM

N-acetylcysteine (NAC) as an antioxidant used to moderate liposome and chitosan-Induced cell cytotoxicity at their high concentrations.

METHODS

liposome and chitosan were prepared and characterized. 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. SEM (Scanning electron microscope) and TEM (Transmission electron microscope) 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.

CONCLUSION

NAC has a protective effect against liposome and chitosan-induced cell toxicity.

Retraction Note: Therapeutic effect of nanoliposomal PCSK9 vaccine in a mouse model of atherosclerosis

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12916-019-1457-8.

Targeting the tumor microenvironment by liposomal Epacadostat in combination with liposomal gp100 vaccine

Indoleamine-2,3-dioxygenase (IDO1) pathway has vital role in cancer immune escape and its upregulation leads to immunosuppressive environment which is associated with poor prognosis and progression in various cancers like melanoma. Previously, we showed the antitumoral efficacy of nanoliposomal form of Epacadostat (Lip-EPA), as an IDO1 inhibitor. Herein, we used Lip-EPA as a combination approach with liposomal gp100 (Lip-gp100) anti-cancer vaccine in melanoma model. Here, we showed that B16F10 tumor express IDO1 so using Lip-EPA will enhance the efficacy of vaccine therapy. The biodistribution of ICG-labelled liposomal form of EPA showed the remarkable accumulation of drug at tumor site. In an in vivo study, Lip-EPA enhanced the antitumor efficacy of Lip-gp100 in which the IDO mRNA expression was decreased (~ fourfold) in tumor samples. Also, we identified a significant increase in the number of infiltrated T lymphocytes (p < 0.0001) with enhanced in interferon gamma (IFN-γ) production (p < 0.0001). Additionally, Lip-EPA + Lip-gp100 significantly modulated intratumoral regulatory T cells which altogether resulted in the highest delay in tumor growth (TGD = 56.54%) and increased life span (ILS > 47.36%) in treated mice. Our study demonstrated that novel combination of Lip-EPA and Lip-gp100 was effective treatment with capability of being used in further clinical studies.

Gold cluster encapsulated liposomes: theranostic agent with stimulus triggered release capability

Cancer is a major cause of death worldwide. Cancer-resistant to chemo or radiotherapy treatment is a challenge that could be overcome by a nanotechnology approach. Providing a theranostic nano-platform for different cancer treatment strategies could be revolutionary. Here we introduce a multifunctional theranostic nanostructure which has the capacity for improving cancer diagnosis and treatment through better chemo and radiotherapy and current x-ray imaging systems through co-encapsulation of a small gold cluster and anticancer drug doxorubicin. 2 nm gold clusters represent good heating under radio frequency electric field (RF-EF) exposure and have been used for in vitro hyperthermia treatment of cancerous cells. Liposomal doxorubicin (169 ± 19.8 nm) with gold clusters encapsulation efficiency of 13.2 ± 3.0% and doxorubicin encapsulation efficiency of 64.7 ± 0.7% were prepared and studied as a theranostic agent with a high potential in different cancer treatment modalities. Exposure to a radiofrequency electric field on prepared formulation caused 20.2 ± 2.1% drug release and twice decreasing of IC50 on colorectal carcinoma cells. X-ray attenuation efficiency of the liposomal gold cluster was better than commercial iohexol and free gold clusters in different concentrations. Finally, treatment of gold clusters on cancerous cells results in a significant decrease in the viability of irradiated cells to cobalt-60 beam. Based on these experiments, we concluded that the conventional liposomal formulation of doxorubicin that has been co-encapsulated with small gold clusters could be a suitable theranostic nanostructure for cancer treatment and merits further investigation.

AR13 peptide-conjugated liposomes improve the antitumor efficacy of doxorubicin in mice bearing C26 colon carcinoma; in silico, in vitro, and in vivo study

Currently, liposomes have emerged as efficient and safer nano-carriers for targeted therapy in different cancers. This work aimed to employ PEGylated liposomal doxorubicin (Doxil®/PLD), modified with AR13 peptide, to target Muc1 on the surface of colon cancerous cells. We performed molecular docking and simulation studies (using Gromacs package) of AR13 peptide against Muc1 to analyze and visualize the peptide-Muc1 binding combination. For in vitro analysis, the AR13 peptide was post-inserted into Doxil® and verified by TLC, ¹H NMR, and HPLC techniques. The zeta potential, TEM, release, cell uptake, competition assay, and cytotoxicity studies were performed. In vivo antitumor activities and survival analysis on mice bearing C26 colon carcinoma were studied. Results showed that after 100 ns simulation, a stable complex between AR13 and Muc1 formed, and molecular dynamics analysis confirmed this interaction. In vitro analysis demonstrated significant enhancement of cellular binding and cell uptake. The results of in vivo study on BALB/c mice bearing C26 colon carcinoma, revealed an extended survival time to 44 days and higher tumor growth inhibition compared to Doxil®. Thus, the AR13 peptide could be explored as a potent ligand for Muc1, improving therapeutic antitumor efficiency in colon cancer cells.

Liposomal celecoxib combined with dendritic cell therapy enhances antitumor efficacy in melanoma

Cancer vaccine efficacy is limited by the immunosuppressive nature of the tumor microenvironment created by inflammation, immune inhibitory factors, and regulatory T cells (Tregs). Inspired by the role of cyclooxygenase-2 (COX-2) in inflammation in the tumor site, we proposed that normalization of the tumor microenvironment by celecoxib as a COX-2 inhibitor might improve the efficacy of Dendritic Cell (DC) therapy in a melanoma model. In the present study, liposomal celecoxib (Lip-CLX) was combined with ex vivo generated DC vaccines pulsed with gp100 peptide (in liposomal and non-liposomal forms) for prophylactic and therapeutic evaluation in the B16F10 melanoma model. Tumor site analysis by flow cytometry demonstrated that intravenous administration of Lip-CLX at a dose of 1 mg/kg in four doses effectively normalized the tumor microenvironment by reducing Tregs and IL-10 production. Furthermore, in combination with DC vaccination (DC + Lip-peptide+Lip-CLX), it significantly increased tumor-infiltrating CD4⁺ and CD8⁺ T cells and secretion of IFN-γ. This combinatorial strategy produced an effective prophylactic and therapeutic antitumor response, which reduced tumor growth and prolonged the overall survival. In conclusion, our findings suggest that the liposomal celecoxib targets the inhibitory mechanisms of the tumor microenvironment and broadens the impact of DC therapy to improve the outcome of immunotherapy in solid tumors.

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.

Three months of combination therapy with nano-curcumin reduces the inflammation and lipoprotein (a) in type 2 diabetic patients with mild to moderate coronary artery disease: Evidence of a randomized, double-blinded, placebo-controlled clinical trial

Diabetes is one of the most common chronic diseases worldwide. Systemic inflammation (high-sensitivity C-reactive protein (hs-CRP)) and lipid metabolism disruption (lipoprotein A, LipoPr (a)) play a critical role in developing and progressing atherosclerosis and acute coronary syndrome in diabetic patients. The anti-oxidant and anti-inflammatory effects of curcumin have been emphasized previously. Therefore, we aimed to evaluate the impact of nano-curcumin on cardiovascular risk factors in type 2 diabetic patients with mild to moderate coronary artery disease (CAD). We performed a randomized, double-blinded, placebo-controlled clinical trial with type 2 diabetic patients (n = 64), and mild to moderate CAD (<70% stenosis in angiography). The patients received nano-curcumin (80 mg/day) or placebo along with optimal medications for 90 days. The biofactors, including hs-CRP and LipoPr (a), and lipid profile, were measured at the admission of patients and end of the study. Nano-curcumin significantly mitigated the hs-CRP and LipoPr (a) levels following 90 days of treatment (P < 0.001 and P = 0.043, respectively). In addition, the mean percentage of change (%Δ) in the hs-CRP and LipoPr (a) levels were meaningfully reduced in the nano-curcumin group compared to the placebo group (P < 0.001 and P = 0.007, respectively). Surprisingly, nano-curcumin notably propagated the number of patients with mild (34.35%) and moderate (62.5%) hs-CRP level category and strikingly diminished the number of patients with severe hs-CRP level category (3.125%) compared to the placebo group (P = 0.016). Nano-curcumin (80 mg/day) might prevent atherosclerosis progression and, in terms of attenuating hs-CRP levels as an inflammation index, succedent cardiovascular events in diabetic heart patients.

Role of exosomes in tumour growth, chemoresistance and immunity: state-of-the-art

Cancer is one of the most lethal diseases, and limited available treatment options contribute to its high mortality rate. Exosomes are considered membrane-bound nanovesicles that include different molecules such as lipids, proteins, and nucleic acids. Virtually most cells could release exosomes via exocytosis in physiological and pathological conditions. Tumour-derived exosomes (TDEs) play essential roles in tumorigenesis, proliferation, progression, metastasis, immune escape, and chemoresistance by transferring functional biological cargos, triggering different autocrine, and paracrine signalling cascades. Due to their antigen-presenting properties, exosomes are widely used as biomarkers and drug carriers and have a prominent role in cancer immunotherapy. They offer various advantages in carrier systems (e.g. in chemotherapy, siRNA, and miRNA), delivery of diagnostic agents owing to their stability, loading of hydrophobic and hydrophilic agents, and drug targeting. Novel exosomes-based carriers can be generated as intelligent systems using various sources and crosslinking chemistry extracellular vesicles (EVs). Exosomes studded with targeting ligands, including peptides, can impart in targeted delivery of cargos to tumour cells. In this review, we comprehensively summarised the important role of tumour-derived exosomes in dictating cancer pathogenesis and resistance to therapy. We have therefore, investigated in further detail the pivotal role of tumour-derived exosomes in targeting various cancer cells and their applications, and prospects in cancer therapy and diagnosis. Additionally, we have implicated the potential utility and significance of tumour exosomes-based nanoparticles as an efficient and novel therapeutic carrier and their applications in treating advanced cancers.

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.

The immunogenic potential of PCSK9 peptide vaccine in mice

Background

Proprotein convertase subtilisin/Kexin 9 (PCSK9) is a serum protein expressed by liver cells that regulates plasma low-density lipoprotein cholesterol (LDL-C) levels by modulating LDL receptors (LDLR). Recent studies of our group indicated the efficient immunogenicity of the nanoliposomal PCSK9 peptide vaccine in different animal models.

Purpose

Herein, we sought to evaluate the immunogenic potential of the non-liposomal form of the vaccine due to its simplicity of processing and lower production cost.

Methods

PCSK9 immunogenic peptide was prepared by linking a short PCSK9 peptide to a tetanus peptide as B and T cell epitopes, respectively. The immunogenic peptide and 0.4% alum adjuvant, in a 1:1 ratio, were mixed thoroughly and homogeneously prior to administration as vaccine formulation. In order to assess the humoral immune response, mice were inoculated subcutaneously four times at bi-week intervals. Immunized animals' blood was sampled two weeks after the last injection. The titers of the anti-PCSK9 antibodies in the serum of vaccinated mice were evaluated using the ELISA method. ELISA was also used to investigate the effects of anti-PCSK9 vaccination on PCSK9 serum concentrations and its interaction with LDL receptor (LDLR).

Results

ELISA analysis showed significant induction of IgG antibody titers by PCSK9 peptide vaccine in vaccinated mice compared to the control group (586±12000 and 642±11566 in male and female vaccinated mice, respectively, p&lt;0.001). No significant difference was found between the male and female vaccine groups (p&gt;0.05). Mechanistic analyses showed that vaccine-induced antibodies decreased serum PCSK9 concentration in vaccine groups compared to the control group (in male mice by 26±5 ng/mL, p&lt;0.01 and female mice by 29±5 ng/mL, p&lt;0.01). Serum concentrations of PCSK9 in control and vaccine groups were found to be 131±8.6 ng/mL and 102±8.1 ng/ml in male mice, and 124±6 ng/ml and 98±10 ng/ml in female mice, respectively. Moreover, vaccine-induced antibodies inhibited the PCSK9/LDLR interaction in the presence of serum from vaccinated mice compared to control mice serum (in male and female groups by 34% and 26%, respectively). The PCSK9 peptide vaccine significantly reduced LDL-C in immunized mice in both male (16.93±2.5 mg/dL, p=0.001) and female groups (22±2.7 mg/dL, p=0.001) compared with the control group.

Conclusions

According to our results, the PCSK9 peptide vaccine stimulates the humoral immune response in albino mice to produce active antibodies that inhibit plasma PCSK9 resulting in plasma LDL-C reduction.

Funding Acknowledgement

Type of funding sources: None.

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.

A review of PD-1/PD-L1 siRNA delivery systems in immune T cells and cancer cells

OBJECTIVES

Programmed cell death 1 (PD-1) is a member of the CD28/CTLA-4 family of inhibitory immunological checkpoint receptors that's also widely produced by exhausted T lymphocytes in an immunosuppressive tumor microenvironment. PD-1 binds to programmed death ligand (PD-L1) and suppresses anti-cancer activity of T lymphocytes. We examined the current literature on how siRNA delivery systems can be used to target PD-1 and PD-L1, as well as the anti-cancer mechanisms and challenges associated with siRNA molecules. We look at studies that use program death 1 siRNA or program death 1 ligand siRNA to treat cancer. Several databases have been used for this purpose, including NCBI, Scopus, and Google Scholar.

KEY FINDINGS

This study looked at several methods for delivering siRNA to immune cells and cancer cells. According to these findings, suppressing PD-1 in T cells increases T lymphocyte activity. PD-L1 suppression in DCs improves antigen presentation and co-stimulatory signals on their surface, resulting in T cell activation. Chemotherapy resistance and cancer cell suppression of T cells are reduced when PD-L1/2 is suppressed in cancer cells.

CONCLUSION

The findings of this study indicated that several strategies for siRNA transfection to immune and cancer cells have been evaluated in recent decades, some of which effectively transfect siRNA to target cells, and defined PD-1 siRNA as a promising strategy for cancer treatment.

Evaluation of the efficacy of oral nano-silymarin formulation in hospitalized patients with COVID-19: A double-blind placebo-controlled clinical trial

Considering the outbreak pandemic of Coronavirus Disease 2019 (COVID-19), the lack of effective therapeutic strategies for the management of this viral disease, and the increasing evidence on the antiviral potential of silymarin, this study aimed to investigate the effectiveness of silymarin nanomicelles on the symptom's resolution time, laboratory parameters, and liver enzymes in patients with COVID-19. The participants were assigned to the nano-silymarin (n = 25) (receiving SinaLive soft gel, containing 70 mg silymarin as nanomicelles) or placebo groups (n = 25) three times daily for two weeks. Patients' symptoms and laboratory findings were assessed at baseline and during the follow-up period (one week and one month after the beginning of the treatment). No significant differences were observed between the two groups in terms of symptoms resolution time, laboratory parameters, and hospitalization duration (p > 0.05). However, the alanine aminotransferase level decreased significantly in the treatment group, compared to the placebo group (p < 0.001). Concomitant use of dexamethasone and remdesivir with silymarin might make the effects of silymarin on the improvement of patients' condition unclear. Further clinical trials are recommended with diverse dosages and larger sample sizes.

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.

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.

Anti-tumor effects of PEGylated-nanoliposomes containing ginger extract in colorectal cancer-bearing mice

OBJECTIVES

This study aimed to develop a nanoliposomal formulation containing ginger ethanolic extract with a higher therapeutic effect for cancer treatment.

MATERIALS AND METHODS

The present study aimed to prepare PEGylated nanoliposomal ginger through the thin film hydration method plus extrusion. Physicochemical characteristics were evaluated, and the toxicity of the prepared liposomes was assessed using the MTT assay. In addition, tumor size was monitored in colorectal cancer-bearing mice. Also, the anticancer effects of liposomal ginger were evaluated by gene expression assay of Bax and Bcl-2 and cytokines including TNF-α, TGF-β, and IFN-γ by Real-time PCR. Also, cytotoxic T lymphocytes (CTLs) and regulatory T lymphocytes (Treg cells) were counted in spleen and tumor tissue by flow cytometry assay.

RESULTS

The nanoliposomes' particle size and polydispersity index (PDI) were 94.95 nm and 0.246 nm, respectively. High encapsulation capacity (80 %) confirmed the technique's efficiency, and the release rate of the extract was 85% at pH 6.5. In addition, this study showed that liposomal ginger at 100 mg/kg/day enhanced the expression of Bax (P<0.05) and IFN-γ (P<0.01) compared with ginger extract in the mouse model. Also, the number of tumor-infiltrating lymphocytes (TILs) and CTLs cell count in tumor tissue showed a significant increase in the LipGin group compared with the Gin group (P<0.05).

CONCLUSION

Results indicated that the liposomal ginger enhanced the antitumor activity; therefore, the prepared liposomal ginger can be used in future clinical trials.

CD73 downregulation by EGFR-targeted liposomal CD73 siRNA potentiates antitumor effect of liposomal doxorubicin in 4T1 tumor-bearing mice

Blocking CD73 ectonucleotidase has been proposed as a potential therapeutic approach for cancer treatment. The present study aimed to investigate the antitumor effect of a novel EGFR-Targeted liposomal CD73 siRNA formulation in combination therapy with liposomal doxorubicin in the 4T1 mouse model. CD73 siRNA was encapsulated into nanoliposomes by the ethanol injection method. After preparation, characterization, morphology, and stability evaluation of formulations, the toxicity was measured by MTT assay. Uptake assay and efficiency of the liposomal formulations were investigated on the 4T1 cell line. The liposomal formulation containing CD73 siRNA was targeted with GE11 peptide for in vivo evaluations. Following biodistribution analysis, the antitumor activity of prepared formulations in combination with liposomal doxorubicin was studied in mice bearing 4T1 metastatic breast cancer cells. Finally, the induction of immune response of formulations in concomitant treatment with liposomal doxorubicin was evaluated in the tumor microenvironment of a mouse model of breast cancer. The size of prepared liposomal formulations at N/P = 16 for the liposomal CD73 siRNA and GE11-liposomal CD73 siRNA groups were 89 nm ± 4.4 and 95 nm ± 6.6, respectively. The nanoparticle's PDI was less than 0.3 and their surface charge was below 10 mV. The results demonstrated that N/P = 16 yielded the best encapsulation efficiency which was 94% ± 3.3. AFM results showed that the liposomes were spherical in shape and were less than 100 nm in size. The results of the MTT assay showed significant toxicity of the liposomes containing CD73 siRNA during the 48-h cell culture. Real-time PCR and flow cytometry results showed that liposomes containing CD73 siRNA could effectively downregulate CD73 expression. Liposomal formulations were able to significantly downregulate CD73 gene expression, in vivo. However, CD73 downregulation efficiency was significantly higher for the targeted form compared to the non-targeted formulation (P value < 0.01). The combination showed maximum tumor growth delay with remarkable survival improvement compared to the control group. Studying the immune responses in the treatment groups which received doxorubicin, showed decreased number of lymphocytes in the tumor environment. However, this decrease was lower in the combination therapy group. Finally, our results clearly showed that CD73 downregulation increases the activity of CD8⁺ lymphocytes (IFN-ℽ production) and also significantly decreases the Foxp3 in the CD25⁺ lymphocytes compared to the control group. GE11-Lipo CD73 siRNA formulation can efficiently knockdown CD73 ectonucleotidase. Also, the efficacy of liposomal doxorubicin is significantly enhanced via the downregulation of CD73 ectonucleotidase.

Enhanced antitumor immune response in melanoma tumor model by anti-PD-1 small interference RNA encapsulated in nanoliposomes

Programmed cell death protein-1 (PD-1), as an immune checkpoint molecule, attenuates T-cell activity and induces T-cell exhaustion. Although siRNA has a great potential in cancer immunotherapy, its delivery to target cells is the main limitation of using siRNA. This study aimed to prepare a liposomal formulation as a siRNA carrier to silence PD-1 expression in T cells and investigate it's in vivo antitumor efficacy. The liposomal siRNA was prepared and characterized by size, zeta potential, and biodistribution. Following that, the uptake assay and mRNA silencing were evaluated in vitro at mRNA and protein levels. siRNA-PD-1 (siPD-1)-loaded liposome nanoparticles were injected into B16F0 tumor-bearing mice to evaluate tumor growth, tumor-infiltrating lymphocytes, and survival rate. Liposomal siPD-1 efficiently silenced PD-1 mRNA expression in T cells (P < 0.0001), and siPD-1-loaded liposomal nanoparticles enhanced the infiltration of T-helper 1 (Th 1) and cytotoxic T lymphocytes into the tumor tissue (P < 0.0001). Liposome-PD-1 siRNA monotherapy and PD-1 siRNA-Doxil (liposomal doxorubicin) combination therapy improved the survival significantly, compared to the control treatment (P < 0.001). Overall, these findings suggest that immunotherapy with siPD-1-loaded liposomes by enhancing T-cell-mediated antitumor immune responses could be considered as a promising strategy for the treatment of melanoma cancer.

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.

Increased Targeting Area in Tumors by Dual-Ligand Modification of Liposomes with RGD and TAT Peptides

Modification with polyethylene glycol (PEGylation) and the use of rigid phospholipids drastically improve the pharmacokinetics of chemotherapeutics and result in more manageable or reduced side-effects. A major drawback is retarded cellular delivery of content, which, along with tumor heterogeneity, are the two main obstacles against tumor targeting. To enhance cellular delivery and reach a bigger area of a tumor, we designed liposomes decorated with two ligands: one for targeting tumor vasculature via a cyclic-pentapeptide containing arginine-glycine-aspartic acid (RGD), which impacts tumor independent of passive accumulation inside tumors, and one for extravascular targeting of tumor cells via a cell-penetrating peptide derived from human immunodeficiency virus type 1 transactivator of transcription (TAT). Liposomes with different ligand combinations were prepared and compared with respect to performance in targeting. Intravital imaging illustrates the heterogeneous behavior of RGD-liposomes in both intravascular and extravascular distribution, whereas TAT-liposomes exhibit a predictable extravascular localization but no intravascular targeting. Dual-ligand modification results in enhanced vascular targeting and a predictable extravascular behavior that improves the therapeutic efficacy of doxorubicin-loaded liposomes but also an augmented clearance rate of liposomes. However, the dual-modified liposome could be a great candidate for targeted delivery of non-toxic payloads or contrast agents for therapeutic or diagnostic purposes. Here we show that the combination of vascular-specific and tumor cell-specific ligands in a liposomal system is beneficial in bypassing the heterogeneous expression of tumor-specific markers.

Lipid-based nanoparticulate delivery systems for HER2-positive breast cancer immunotherapy

Lipid-based nanoparticulate delivery platforms such as liposomes help overcome cell and tissue barriers and allow prolonged therapeutic plasma drug concentrations, simultaneous targeting of tumor tissue, and increased bioavailability of numerous drugs used for treatment of cancer. The human epidermal growth factor receptor, HER2, is an important player in the pathogenesis of breast cancer and is considered a potential cancer biomarker for the design of immunotherapeutics. HER2-positive breast cancer is found in up to 30% of breast cancer patients. Currently, a variety of lipid nanoparticulate systems are being evaluated in preclinical settings and in clinical trials for targeting HER2-positive breast cancer. Advances in functionalized anti-HER2 lipid nanoparticulates have demonstrated promise and may lead to the development of new nano-immunotherapy protocols against HER2 positive breast cancer. Here we present a review of the most up-to-date literature, including our own research, on the use of lipid nanoparticulate carriers in immunotherapy of HER2-positive breast cancer.