Biotin and glucose co-modified multi-targeting liposomes for efficient delivery of chemotherapeutics for the treatment of glioma

Status Quo in the Liposome-Based Therapeutic Strategies Against Glioblastoma: "Targeting the Tumor and Tumor Microenvironment"

Glioblastoma is the most aggressive and fatal brain cancer, characterized by a high growth rate, invasiveness, and treatment resistance. The presence of the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) poses a challenging task for chemotherapeutics, resulting in low efficacy, bioavailability, and increased dose-associated side effects. Despite the rigorous treatment strategies, including surgical resection, radiotherapy, and adjuvant chemotherapy with temozolomide, overall survival remains poor. The failure of current chemotherapeutics and other treatment regimens in glioblastoma necessitates the development of new drug delivery methodologies to precisely and efficiently target glioblastoma. Nanoparticle-based drug delivery systems offer a better therapeutic option in glioblastoma, considering their small size, ease of diffusion, and ability to cross the BBB. Liposomes are a specific category of nanoparticles made up of fatty acids. Furthermore, liposomes can be surface-modified to target a particular receptor and are nontoxic. This review discusses various methods of liposome modification for active/directed targeting and various liposome-based therapeutic approaches in the delivery of current chemotherapeutic drugs and nucleic acids in targeting the glioblastoma and tumor microenvironment.

Hybrid nanopotentiators with dual cascade amplification for glioma combined interventional therapy

Glioma is an aggressive malignant brain tumor with a very poor prognosis for survival. The poor tumor targeting efficiency and tumor microenvironment penetration barrier also as troubles inhibited the effective glioma chemotherapy. Here, we design a core-shell structure cascade amplified hybrid catalytic nanopotentiators CFpAD with DM1 encapsulated to overcome the glioma therapeutic obstacles. NIR laser-based BBB penetrating enhances the tumor accumulation of CFpAD. When CFpAD, as the cascade amplified drug, is treated on the cancer cells, the bomb-like CFpAD releases gold nanoparticles as glucose oxidase (GOx) and ferric oxide nanoparticles (FNPs) as peroxides (POx) after blasting, producing ROS via a cascade amplification for tumor cell apoptosis. Gold nanoparticles can rest CAFs and reduce ECM secretion, achieving deep penetration of CFpAD. Moreover, CFpAD also cuts off the nutritional supply of the tumor, reduces the pH value, and releases free radicals to destroy the cancer. The glioma cell viability was significantly decreased through DNA damage and ROS aggregation due to the DM1-based chemotherapy synergistically combined with interventional photothermal therapy (IPTT) and radiotherapy (RT). This domino cascade amplified loop, combined with starvation therapy with IPTT and RT, has good tumor penetration and outstanding antitumor efficacy, and is a promising glioma treatment system.

Functionalized liposomes: an enticing nanocarrier for management of glioma

Glioma is one of the most severe central nervous systems (CNS)-specific tumors, with rapidly growing malignant glial cells accounting for roughly half of all brain tumors and having a poor survival rate ranging from 12 to 15 months. Despite being the most often used technique for glioma therapy, conventional chemotherapy suffers from low permeability of the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) to anticancer drugs. When it comes to nanocarriers, liposomes are thought of as one of the most promising nanocarrier systems for glioma treatment. However, owing to BBB tight junctions, non-targeted liposomes, which passively accumulate in most cancer cells primarily via the increased permeability and retention effect (EPR), would not be suitable for glioma treatment. The surface modification of liposomes with various active targeting ligands has shown encouraging outcomes in the recent times by allowing various chemotherapy drugs to pass across the BBB and BBTB and enter glioma cells. This review article introduces by briefly outlining the landscape of glioma, its classification, and some of the pathogenic causes. Further, it discusses major barriers for delivering drugs to glioma such as the BBB, BBTB, and tumor microenvironment. It further discusses modified liposomes such as long-acting circulating liposomes, actively targeted liposomes, stimuli responsive liposomes. Finally, it highlighted the limitations of liposomes in the treatment of glioma and the various actively targeted liposomes undergoing clinical trials for the treatment of glioma.

In vivo C6 glioma models: an update and a guide toward a more effective preclinical evaluation of potential anti-glioblastoma drugs

Glioblastoma multiform (GBM) is the most common primary brain tumor with a poor prognosis and few therapeutic choices. In vivo, tumor models are useful for enhancing knowledge of underlying GBM pathology and developing more effective therapies/agents at the preclinical level, as they recapitulate human brain tumors. The C6 glioma cell line has been one of the most widely used cell lines in neuro-oncology research as they produce tumors that share the most similarities with human GBM regarding genetic, invasion, and expansion profiles and characteristics. This review provides an overview of the distinctive features and the different animal models produced by the C6 cell line. We also highlight specific applications of various C6 in vivo models according to the purpose of the study and offer some technical notes for more convenient/repeatable modeling. This work also includes novel findings discovered in our laboratory, which would further enhance the feasibility of the model in preclinical GBM investigations.

Drug Permeability: From the Blood-Brain Barrier to the Peripheral Nerve Barriers

Drug delivery into the peripheral nerves and nerve roots has important implications for effective local anesthesia and treatment of peripheral neuropathies and chronic neuropathic pain. Similar to drugs that need to cross the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) to gain access to the central nervous system (CNS), drugs must cross the peripheral nerve barriers (PNB), formed by the perineurium and blood-nerve barrier (BNB) to modulate peripheral axons. Despite significant progress made to develop effective strategies to enhance BBB permeability in therapeutic drug design, efforts to enhance drug permeability and retention in peripheral nerves and nerve roots are relatively understudied. Guided by knowledge describing structural, molecular and functional similarities between restrictive neural barriers in the CNS and peripheral nervous system (PNS), we hypothesize that certain CNS drug delivery strategies are adaptable for peripheral nerve drug delivery. In this review, we describe the molecular, structural and functional similarities and differences between the BBB and PNB, summarize and compare existing CNS and peripheral nerve drug delivery strategies, and discuss the potential application of selected CNS delivery strategies to improve efficacious drug entry for peripheral nerve disorders.

Dietary B vitamins and glioma: A case-control study based on Chinese population

Background

Dietary antioxidants have long been thought to be likely to prevent the development of gliomas. Previous studies have reported vitamin A, C, and E protective effects against gliomas. B vitamins, one of the main vitamins in the diet, are closely related to human health, but the association with gliomas has rarely been reported.

Objective

This study aimed to evaluate the relationship between five B vitamins and glioma.

Methods

In this Chinese population-based case-control study, 506 glioma cases and 506 matched (age and sex) controls were included. The dietary intake of study participants was assessed using a valid 111-item food frequency questionnaire. The intake of five B vitamins was calculated based on participants' dietary information from the food frequency questionnaire. The logistic regression model was used to examine the association between B vitamins and glioma, and the restriction cubic spline evaluated the dose-response relationship between the two.

Results

After adjusting for confounding factors, thiamine (OR = 0.09, 95%CI: 0.05-0.20), riboflavin (OR = 0.12, 95%CI: 0.06-0.25), nicotinic acid (OR = 0.24, 95%CI: 0.12-0.47), folate (OR = 0.07, 95%CI: 0.03-0.15) and biotin (OR = 0.14, 95%CI: 0.07-0.30) in the highest tertile were associated with a significantly decreased risk of glioma compared with the lowest tertile. The results of thiamine and biotin in glioma with different pathological types and grades were different. The restricted cubic spline function showed significant dose-response relationships between the intake of five B vitamins and the risk of glioma. When B vitamins exceeded a specific intake, the risk of glioma did not change.

Conclusion

Our study suggests that higher dietary intake of thiamine, riboflavin, nicotinic acid, and folate are associated with a decreased risk of glioma, but the results of biotin are not consistent among different populations. In the future, prospective studies should be conducted better to validate the effects of B vitamins on gliomas.

Overcoming the blood-brain barrier for the therapy of malignant brain tumor: current status and prospects of drug delivery approaches

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood-brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors.

Establishment and evaluation of glucose-modified nanocomposite liposomes for the treatment of cerebral malaria

Cerebral malaria (CM) is a life-threatening neurological complication caused by Plasmodium falciparum. About 627,000 patients died of malaria in 2020. Currently, artemisinin and its derivatives are the front-line drugs used for the treatment of cerebral malaria. However, they cannot target the brain, which decreases their effectiveness. Therefore, increasing their ability to target the brain by the nano-delivery system with brain-targeted materials is of great significance for enhancing the effects of antimalarials and reducing CM mortality. This study used glucose transporter 1 (GLUT1) on the blood-brain barrier as a target for a synthesized cholesterol-undecanoic acid-glucose conjugate. The molecular dynamics simulation found that the structural fragment of glucose in the conjugate faced the outside the phospholipid bilayers, which was conducive to the recognition of brain-targeted liposomes by GLUT1. The fluorescence intensity of the brain-targeted liposomes (na-ATS/TMP@lipoBX) in the mouse brain was significantly higher than that of the non-targeted liposomes (na-ATS/TMP@lipo) in vivo (P < 0.001) after intranasal administration. The infection and recurrence rate of the mice receiving na-ATS/TMP@lipoBX treatment were significantly decreased, which had more advantages than those of other administration groups. The analysis of pharmacokinetic data showed that na-ATS/TMP@lipoBX could enter the brain in both systemic circulation and nasal-brain pathway to treat malaria. Taken together, these results in this study provide a new approach to the treatment of cerebral malaria.

Berberine and folic acid co-modified pH-sensitive cascade-targeted PTX-liposomes coated with Tween 80 for treating glioma

Chemotherapy is a conventional treatment for glioma, but its efficacy is greatly limited due to low blood-brain barrier (BBB) permeability and lack of specificity. Herein, intelligent and tumor microenvironment (TME)-responsive folic acid (FA) derivatives and mitochondria-targeting berberine (BBR) derivatives co-modified liposome coated with Tween 80 loading paclitaxel (PTX-Tween 80-BBR + FA-Lip) was constructed. Specifically speaking, liposomes modified by FA can be effectively target ed to glioma cells. BBR, due to its delocalized positive electricity and lipophilicity, can be attracted by mitochondrial membrane potential and concentrate on mitochondria to achieve mitochondrial targeting and induce cell apoptosis. By simultaneously modifying the liposome with FA and BBR to deliver drugs, leads to a good therapeutic effect of glioma through FA-based glioma targeting and BBR-based mitochondrial targeting. In addition, the surface of the liposome was coated with Tween 80 to further improve BBB penetration. All results exhibited that PTX-Tween 80-BBR + FA-Lip can observably improve the chemotherapy therapeutic efficacy through the highly specific tumor targeting and mitochondrial targeting, which can provide new ideas and methods for the targeted therapy of glioma.

Triple branched RGD modification on liposomes: A prospective strategy to enhance the glioma targeting efficiency

Glioma, as one of the most common primary intracranial tumors, is in an urgent need for specific targeting agents. Multi-branched RGD ligand is a promising alternative for liposome functionalization which combines the benefits of high affinity with α_vβ₃ receptors and proper branching structure in response to the receptor clustering. Herein, we designed and synthesized single branched, double branched and triple branched RGD ligand (1RGD-Chol, 2RGD-Chol and 3RGD-Chol) respectively, which were then modified on the liposomes to prepare six different kinds of liposomes (including 1RGD-Lip, 2RGD-Lip, 3RGD-Lip, 2 × 1RGD-Lip, 3 × 1RGD-Lip and unmodified Lip). Subsequently, a series of assays were conducted. The results exhibited that the liposome decorated with 3RGD-Chol ligand possessed superior cellular internalization ability in C6 cells and bEnd.3 cells, suggesting the strongest ability of 3RGD-Lip to target the blood-brain barrier (BBB) and glioma cells. Besides, both the cytotoxicity and pro-apoptotic assays revealed that PTX-3RGD-Lip had the strongest ability to inhibit the survival of C6 cells. Moreover, the enrichment of liposomes at tumor site was 3RGD-Lip > 3 × 1RGD-Lip ≈ 2RGD-Lip ≈ 2 × 1RGD-Lip > 1RGD-Lip > Lip according to the in vivo imaging of C6-bearing mice, which was consistent with the result of in vitro targeting experiments. To sum up, the targeting efficiency of liposomes can be strongly promoted by improving the amount of targeting molecules, whereas the branching structure and spatial distance of RGD residues also accounted for the affinity between liposomes and α_vβ₃ receptors. Collectively, PTX-3RGD-Lip would be a prospective strategy in glioma treatment.

Inhibiting the Growth of 3D Brain Cancer Models with Bio-Coronated Liposomal Temozolomide

Nanoparticles (NPs) have emerged as an effective means to deliver anticancer drugs into the brain. Among various forms of NPs, liposomal temozolomide (TMZ) is the drug-of-choice for the treatment and management of brain tumours, but its therapeutic benefit is suboptimal. Although many possible reasons may account for the compromised therapeutic efficacy, the inefficient tumour penetration of liposomal TMZ can be a vital obstacle. Recently, the protein corona, i.e., the layer of plasma proteins that surround NPs after exposure to human plasma, has emerged as an endogenous trigger that mostly controls their anticancer efficacy. Exposition of particular biomolecules from the corona referred to as protein corona fingerprints (PCFs) may facilitate interactions with specific receptors of target cells, thus, promoting efficient internalization. In this work, we have synthesized a set of four TMZ-encapsulating nanomedicines made of four cationic liposome (CL) formulations with systematic changes in lipid composition and physical−chemical properties. We have demonstrated that precoating liposomal TMZ with a protein corona made of human plasma proteins can increase drug penetration in a 3D brain cancer model derived from U87 human glioblastoma multiforme cell line leading to marked inhibition of tumour growth. On the other side, by fine-tuning corona composition we have also provided experimental evidence of a non-unique effect of the corona on the tumour growth for all the complexes investigated, thus, clarifying that certain PCFs (i.e., APO-B and APO-E) enable favoured interactions with specific receptors of brain cancer cells. Reported results open new perspectives into the development of corona-coated liposomal drugs with enhanced tumour penetration and antitumour efficacy.