Anti-epithelial cell adhesion molecule RNA aptamer-conjugated liposomal doxorubicin as an efficient targeted therapy in mice bearing colon carcinoma tumor model

Functionalized liposomes as a potential drug delivery systems for colon cancer treatment: A systematic review

Colon cancer is one of the lethal diseases in the world with approximately 700,000 fatalities annually. Nowadays, due to the side effects of existing methods in the treatment of colon cancer such as radiotherapy and chemotherapy, the use of targeted nanocarriers in cancer treatment has received wide attention, and among them, especially liposomes have been studied a lot. Based on this, anti-tumor drugs hidden in targeted active liposomes can selectively act on cancer cells. In this systematic review, the use of various ligands such as folic acid, transferrin, aptamer, hyaluronic acid and cRGD for active targeting of liposomes to achieve improved drug delivery to colon cancer cells has been reviewed. The original articles published in English in the databases of Science Direct, PubMed and Google scholar from 2012 to 2022 were reviewed. From the total of 26,256 published articles, 19 studies met the inclusion criteria. The results of in vitro and in vivo studies have revealed that targeted liposomes lead to increasing the efficacy of anti-cancer agents on colon cancer cells with reducing side effects compared to free drugs and non-targeted liposomes. To the best of our knowledge, this is the first systematic review showing promising results for improvement treatment of colon cancer using targeted liposomes.

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

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

Study the Anticancer Properties of Thymol-Loaded PEGylated Bovine Serum Albumin Nanoparticles Conjugated with Folic Acid

Phenolic compounds such as Thymol have an effective role in suppressing cancer, however, their low solubility in aqueous solution has limited their use. This study aimed to prepare Thymol (TY)-loaded bovine serum albumin (BSA) nanoparticles surface-modified with polyethylene glycol (PEG) conjugated with folic acid (FA) and evaluate their inhibitory activity on cancer cells. The TY-BSA-PEG-FA was characterized using DLS, FESEM, and FTIR. The encapsulation efficiency (EE) was evaluated indirectly by using UV absorption. The antioxidant property of nanoparticles was evaluated by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing ability of plasm (FRAP) methods. The effects of nanoparticles against cancer cells were investigated by MTT, AO/PI, flow cytometry, and real-time qPCR methods. The results showed the spherical morphology of TY-BSA-PEG-FA with an average size of 70.0 nm, a PDI of 0.32, a zeta potential of -11.3 mV, and an EE of 89.0±2.3 %. The cytotoxicity effects of nanoparticles against all cell lines were in a concentration-dependent manner. AGS gastric cancer cells were reported to be the most vulnerable to treatment, while pancreatic cancer cells (PANC-1) and normal skin cells (HFF) would be the most resistant. The SubG1 phase arrest of about 66 % occurred at 85 μg/mL. An increase in apoptotic cells in fluorescent staining, along with decreased expression of Bcl-2 and increased expression of the BAX gene demonstrated the induction of apoptosis in treated cells. The powerful inhibitory effect of nanoparticles in inhibiting ABTS free radicals (IC50 =82 μg/mL) and DPPH free radicals (IC50 =844 μg/mL) and the ability to reduce iron ions indicated the antioxidant effects of TY-BSA-PEG-FA. Based on these results, the synthesized nanoparticles may be suitable for further investigation in the treatment of cancer, notably gastric cancer.

Recent Preclinical and Clinical Progress in Liposomal Doxorubicin

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

Aptamers in cancer therapy: problems and new breakthroughs

Aptamers, a class of oligonucleotides that can bind with molecular targets with high affinity and specificity, have been widely applied in research fields including biosensing, imaging, diagnosing, and therapy of diseases. However, compared with the rapid development in the research fields, the clinical application of aptamers is progressing at a much slower speed, especially in the therapy of cancer. Obstructions including nuclease degradation, renal clearance, a complex selection process, and potential side effects have inhibited the clinical transformation of aptamer-conjugated drugs. To overcome these problems, taking certain measures to improve the biocompatibility and stability of aptamer-conjugated drugs in vivo is necessary. In this review, the obstructions mentioned above are thoroughly discussed and the methods to overcome these problems are introduced in detail. Furthermore, landmark research works and the most recent studies on aptamer-conjugated drugs for cancer therapy are also listed as examples, and the future directions of research for aptamer clinical transformation are discussed.

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.

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.

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

Simple Summary

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

Abstract

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

A GD2-aptamer-mediated, self-assembling nanomedicine for targeted multiple treatments in neuroblastoma theranostics

Because current mainstream anti-glycolipid GD2 therapeutics for neuroblastoma (NB) have limitations, such as severe adverse effects, improved therapeutics are needed. In this study, we developed a GD2 aptamer (DB99) and constructed a GD2-aptamer-mediated multifunctional nanomedicine (ANM) with effective, precise, and biocompatible properties, which functioned both as chemotherapy and as gene therapy for NB. DB99 can bind to GD2⁺ NB tumor cells but has minimal cross-reactivity to GD2⁻ cells. Furthermore, ANM is formulated by self-assembly of synthetic aptamers DB99 and NB-specific MYCN small interfering RNA (siRNA), followed by self-loading of the chemotherapeutic agent doxorubicin (Dox). ANM is capable of specifically recognizing, binding, and internalizing GD2⁺, but not GD2⁻, NB tumor cells in vitro. Intracellular delivery of ANM activates Dox release for chemotherapy and MYCN-siRNA-induced MYCN silencing. ANM specifically targets, and selectively accumulates in, the GD2⁺ tumor site in vivo and further induces growth inhibition of GD2⁺ tumors in vivo; in addition, ANM generates fewer or no side effects in healthy tissues, resulting in markedly longer survival with fewer adverse effects. These results suggest that the GD2-aptamer-mediated, targeted drug delivery system may have potential applications for precise treatment of NB.

Aptamer-mediated doxorubicin delivery reduces HCC burden in 3D organoids model

Epithelial cell adhesion molecule (EpCAM) is a surface marker which is frequently overexpressed in hepatocellular carcinoma (HCC) but minimally expressed on mature hepatocytes. We developed a specific aptamer against EpCAM (EpCAM-apt) and tested its potential as a drug delivery agent for HCC. The targeting ability of EpCAM-apt was confirmed in vitro and in vivo after which the complex was conjugated with doxorubicin (Dox) to form EpCAM-apt-Dox. The targeting efficacy of the drug-loaded complex against liver cancer stem-like cells (LCSCs) and therapeutic effects in HCC were evaluated. EpCAM-expressing (EpCAM⁺) HCC cells showed characteristics of stem like cells including greater proliferative capacity and tumour sphere formation. EpCAM-apt-Dox selectively delivered Dox to EpCAM⁺ HCC cells with high drug retention and accumulation versus control. EpCAM-apt-Dox reduced the self-renewal capacity and stem-like cell frequency in vitro. Elimination of cancer stem-like cells (CSCs) with EpCAM-apt-Dox significantly inhibited the growth of HCC cells and patient-derived HCC organoids but exerted minimal cytotoxicity to normal liver organoids. Moreover, EpCAM-apt-Dox suppressed the growth of xenograft tumours derived from HCC organoids in vivo and prolonged mouse survival without inducing adverse effects to major organs. Thus, aptamer-based drug delivery to the stem-like cell population is a promising strategy for HCC treatment.