Transferrin-functionalised microemulsion co-delivery of β-elemene and celastrol for enhanced anti-lung cancer treatment and reduced systemic toxicity

The β-glucan nanotube carrier achieves detoxification and efficacy enhancement of celastrol in intrahepatic cholangiocarcinoma therapy by increasing targeted controlled release and macrophage polarization

Celastrol (Cel) is a monomer from a famous traditional Chinese medicine named Tripterygium wilfordii Hook. f. Cel has shown great potential in treating intrahepatic cholangiocarcinoma (ICC) but still faces problems, including poor water solubility, high toxicity, and lack of targeting ability. Thus, the present work constructed a drug-delivery system using black fungus polysaccharide self-assembled -nanotubes (BFP). Cel-loaded nanotubes (BFP-Cel) were confirmed to have a high loading content of Cel (38 %), liver targeting, and enzyme-controlled release abilities. Moreover, BFP carriers could significantly increase the uptake efficiency of Cel by tumor cells. In vivo experiments showed that BFP-Cel could effectively inhibit tumor growth and reduce the physiological toxicity of Cel. Furthermore, BFP, as a carrier, could regulate the immune microenvironment in the liver through the activation of macrophages and play an immunomodulatory role. In summary, the BFP nanotube carrier could achieve detoxification and efficacy enhancement of Cel in treating ICC by increasing the targetability, controlled release ability, cell-uptake effect, and regulation of the immune microenvironment.

Celastrol-loaded polymeric mixed micelles shows improved antitumor efficacy in 4 T1 bearing xenograft mouse model through spatial targeting

In this study, we have proposed a novel approach that combines hyaluronic acid (HA), folic acid (FA), and celastrol (CLS) within a polymeric micelle system (CLS-HF/MLs), offering a dual-action strategy against breast cancer. Polymeric mixed micelles were prepared through the thin-film hydration method, and comprehensive quality control parameters were established, encompassing particle size, polydispersity index, zeta potential, surface morphology, encapsulation efficiency, drug content, in vitro drug release, and storage stability assessment. The average particle size of CLS-HF/MLs micelles was found to be 120 nm and their drug loading and encapsulation efficiencies were 15.9 % and 89.52 %, respectively. The in vitro release data showed that the CLS-HF/MLs targeted mixed micelles displayed a prolonged release profile compared to the free drug. Additionally, the stability of the developed polymeric mixed micelles was maintained for up to 8 weeks of storage in terms of particle size and drug content. Furthermore, both flow cytometry and confocal laser scanning microscopy studies indicated a significant enhancement in the cellular uptake efficiency and cytotoxicity of CLS-HF/MLs mixed micelles against MCF-7 cell line. In terms of pharmacokinetic analysis, the half-life and AUC values of CLS-HF/MLs mixed micelles were found to be approximately 4.71- and 7.36-folds higher than the values of free drug (CLS), respectively. The CLS-HF/MLs micelles exhibited remarkable antitumor efficacy (almost complete ablation of the 4 T1-cell bearing tumor xenografts mouse model) due to the dual receptor (CD44 and folate) targeting effects with minimal side effects. When considering the cumulative findings of our present research, it becomes evident that mixed micelles designed for chemotherapy offer a promising and potentially effective therapeutic avenue for the treatment of breast cancer.

Better together: nanoscale co-delivery systems of therapeutic agents for high-performance cancer therapy

Combination therapies can enhance the sensitivity of cancer to drugs, lower drug doses, and reduce side effects in cancer treatment. However, differences in the physicochemical properties and pharmacokinetics of different therapeutic agents limit their application. To avoid the above dilemma and achieve accurate control of the synergetic ratio, a nanoscale co-delivery system (NCDS) has emerged as a prospective tool for combined therapy in cancer treatment, which is increasingly being used to co-load different therapeutic agents. In this study, we have summarized the mechanisms of therapeutic agents in combination for cancer therapy, nanoscale carriers for co-delivery, drug-loading strategies, and controlled/targeted co-delivery systems, aiming to give a general picture of these powerful approaches for future NCDS research studies.

Pathophysiological aspects of transferrin-A potential nano-based drug delivery signaling molecule in therapeutic target for varied diseases

Transferrin (Tf), widely known for its role as an iron-binding protein, exemplifies multitasking in biological processes. The role of Tf in iron metabolism involves both the uptake of iron from Tf by various cells, as well as the endocytosis mediated by the complex of Tf and the transferrin receptor (TfR). The direct conjugation of the therapeutic compound and immunotoxin studies using Tf peptide or anti-Tf receptor antibodies as targeting moieties aims to prolong drug circulation time and augment efficient cellular drug uptake, diminish systemic toxicity, traverse the blood-brain barrier, restrict systemic exposure, overcome multidrug resistance, and enhance therapeutic efficacy with disease specificity. This review primarily discusses the various biological actions of Tf, as well as the development of Tf-targeted nano-based drug delivery systems. The goal is to establish the use of Tf as a disease-targeting component, accentuating the potential therapeutic applications of this protein.

Nanoencapsulation of Ruthenium Complex Ru(ThySMet): A Strategy to Improve Selective Cytotoxicity against Breast Tumor Cells in 2D and 3D Culture Models

BACKGROUND

Ruthenium complexes have shown promise in treating many cancers, including breast cancer. Previous studies of our group have demonstrated the potential of the trans- [Ru(PPh3)2(N,N-dimethylN'-thiophenylthioureato-k2O,S)(bipy)]PF6 complex, the Ru(ThySMet), in the treatment of breast tumor cancers, both in 2D and 3D culture systems. Additionally, this complex presented low toxicity when tested in vivo.

AIMS

Improve the Ru(ThySMet) activity by incorporating the complex into a microemulsion (ME) and testing its in vitro effects.

METHODS

The ME-incorporated Ru(ThySMet) complex, Ru(ThySMet)ME, was tested for its biological effects in two- (2D) and three-dimensional (3D) cultures using different types of breast cells, MDAMB- 231, MCF-10A, 4T1.13ch5T1, HMT-3522 and Balb/C 3T3 fibroblasts.

RESULTS

An increased selective cytotoxicity of the Ru(ThySMet)ME for tumor cells was found in 2D cell culture, compared with the original complex. This novel compound also changed the shape of tumor cells and inhibited cell migration with more specificity. Additional 3D cell culture tests using the non-neoplastic S1 and the triple-negative invasive T4-2 breast cells have shown that Ru(ThySMet)ME presented increased selective cytotoxicity for tumor cells compared with the 2D results. The morphology assay performed in 3D also revealed its ability to reduce the size of the 3D structures and increase the circularity in T4-2 cells.

CONCLUSION

These results demonstrate that the Ru(ThySMet)ME is a promising strategy to increase its solubility, delivery, and bioaccumulation in target breast tumors.

The complementary and alternative roles of elemene injection in cancer: An umbrella review

BACKGROUND

In the past, many meta-analyses (MAs) suggested that elemene injection (EI) played a complementary and alternative role in cancer treatment. However, some results were contradictory and a lot of evidences weren't classified. Thus, their clinical guidance effect was very limited.

METHODS

Two reviewers independently retrieved 8 databases from their origin to May 19, 2023 and appropriate MAs were taken into consideration. A pooled analysis was conducted to merge results extracted from trials of included MAs. The methodological quality of MAs and the evidence certainty of pooled results were assessed.

RESULTS

31 MAs were taken into analysis with poor methodological quality. The main weaknesses were in the areas of heterogeneity analysis, bias risk, and literature selection. According to the present evidence, on the one hand, compared with conventional treatment (CT) alone, EI combined with CT may significantly enhance short-term or long-term efficacy and reduce adverse reactions caused by CT in multiple cancers. On the other hand, using EI alone also can improve ORR in the malignant (pleural) effusion and lessen the recurrence rate in bladder cancer obviously with fewer adverse reactions compared with CT alone. However, this evidence was rated as moderate to very low certainty mainly due to the risk of bias in clinical trials.

CONCLUSION

EI may be a viable medication for the treatment of cancer although more convincing trials are still required to demonstrate its alternative and complementary benefits. Besides, it seems to have a broad potential for further development in immunotherapy, drug delivery technique, and predictive factor.

Recent Advances in Nanotechnology-Based Targeted Delivery Systems of Active Constituents in Natural Medicines for Cancer Treatment

Owing to high efficacy and safety, natural medicines have found their way into the field of cancer therapy over the past few decades. However, the effective ingredients of natural medicines have shortcomings of poor solubility and low bioavailability. Nanoparticles can not only solve the problems above but also have outstanding targeting ability. Targeting preparations can be classified into three levels, which are target tissues, cells, and organelles. On the premise of clarifying the therapeutic purpose of drugs, one or more targeting methods can be selected to achieve more accurate drug delivery and consequently to improve the anti-tumor effects of drugs and reduce toxicity and side effects. The aim of this review is to summarize the research status of natural medicines' nano-preparations in tumor-targeting therapies to provide some references for further accurate and effective cancer treatments.

Targeted drug delivery systems for elemene in cancer therapy: The story thus far

Elemene (ELE) is a group of broad-spectrum anticancer active ingredients with low toxicity extracted from traditional Chinese medicines (TCMs), such as Curcumae Rhizoma and Curcuma Radix, which can exert antitumour activities by regulating various signal pathways and targets. However, the strong hydrophobicity, short half-life, low bioavailability and weak in vivo targeting ability of ELE restrict its use. Targeted drug delivery systems based on nanomaterials are among the most viable methods to overcome these shortcomings. In this review, we first summarize recent studies on the clinical uses of ELE as an adjunct antitumour drug. ELE-based combination strategies have great promise for enhancing efficacy, reducing adverse reactions, and improving patients' quality of life and immune function. Second, we summarize recent studies on the antitumour mechanisms of ELE and ELE-based combination strategies. The potential mechanisms include inducing pyroptosis and ferroptosis, promoting senescence, regulating METTL3-mediated m6A modification, suppressing the Warburg effect, and inducing apoptosis and cell cycle arrest. Most importantly, we comprehensively summarize studies on the combination of targeted drug delivery systems with ELE, including passively and actively targeted drug delivery systems, stimuli-responsive drug delivery systems, and codelivery systems for ELE combined with other therapies, which have great promise in improving drug bioavailability, increasing drug targeting ability, controlling drug release, enhancing drug efficacy, reducing drug adverse effects and reversing MDR. Our summary will provide a reference for the combination of TCMs such as ELE with advanced targeted drug delivery systems in the future.

Nano- and Microemulsions in Biomedicine: From Theory to Practice

Nano- and microemulsions are colloidal systems that are widely used in various fields of biomedicine, including wound and burn healing, cosmetology, the development of antibacterial and antiviral drugs, oncology, etc. The stability of these systems is governed by the balance of molecular interactions between nanodomains. Microemulsions as a colloidal form play a special important role in stability. The microemulsion is the thermodynamically stable phase from oil, water, surfactant and co-surfactant which forms the surface of drops with very small surface energy. The last phenomena determines the shortage time of all fluid dispersions including nanoemulsions and emulgels. This review examines the theory and main methods of obtaining nano- and microemulsions, particularly focusing on the structure of microemulsions and methods for emulsion analysis. Additionally, we have analyzed the main preclinical and clinical studies in the field of wound healing and the use of emulsions in cancer therapy, emphasizing the prospects for further developments in this area.

Potential roles and molecular mechanisms of bioactive ingredients in Curcumae Rhizoma against breast cancer

BACKGROUND

Breast cancer is the most prevalent cancer worldwide, with high morbidity and mortality. Despite great advances in the therapeutic strategies, the survival rate in the past decades of patients with breast cancer remains unsatisfactory. Growing evidence has demonstrated that Curcumae Rhizoma, called Ezhu in Chinese, showed various pharmacological properties, including anti-bacterial, anti-oxidant, anti-inflammatory and anti-tumor activities. It has been widely used in Chinese medicine to treat many types of human cancer.

PURPOSE

To comprehensively summarize and analyze the effects of active substances in Curcumae Rhizoma on breast cancer malignant phenotypes and the underlying mechanisms, as well as discuss its medicinal value and future perspectives.

METHOD

We used "Curcumae Rhizoma" or the name of crude extracts and bioactive components in Curcumae Rhizoma in combination with "breast cancer" as key words. Studies focusing on their anti-breast cancer activities and mechanisms of action were extracted from Pubmed, Web of Science and CNKI databases up to October 2022. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guideline was followed.

RESULTS

Crude extracts and 7 main bioactive phytochemicals (curcumol, β-elemene, furanodiene, furanodienone, germacrone, curdione and curcumin) isolated from Curcumae Rhizoma have shown many anti-breast cancer pharmacological properties, including inhibiting cell proliferation, migration, invasion and stemness, reversing chemoresistance, and inducing cell apoptosis, cycle arrest and ferroptosis. The mechanisms of action were involved in regulating MAPK, PI3K/AKT and NF-κB signaling pathways. In vivo and clinical studies demonstrated that these compounds exhibited high anti-tumor efficacy and safety against breast cancer.

CONCLUSION

These findings provide strong evidence that Curcumae Rhizoma acts as a rich source of phytochemicals and has robust anti-breast cancer properties.

Recent advances of CREKA peptide-based nanoplatforms in biomedical applications

Nanomedicine technology is a rapidly developing field of research and application that uses nanoparticles as a platform to facilitate the diagnosis and treatment of diseases. Nanoparticles loaded with drugs and imaging contrast agents have already been used in clinically, but they are essentially passive delivery carriers. To make nanoparticles smarter, an important function is the ability to actively locate target tissues. It enables nanoparticles to accumulate in target tissues at higher concentrations, thereby improving therapeutic efficacy and reducing side effects. Among the different ligands, the CREKA peptide (Cys-Arg-Glu-Lys-Ala) is a desirable targeting ligand and has a good targeting ability for overexpressed fibrin in different models, such as cancers, myocardial ischemia-reperfusion, and atherosclerosis. In this review, the characteristic of the CREKA peptide and the latest reports regarding the application of CREKA-based nanoplatforms in different biological tissues are described. In addition, the existing problems and future application perspectives of CREKA-based nanoplatforms are also addressed.

Hepatoma-targeting and reactive oxygen species-responsive chitosan-based polymeric micelles for delivery of celastrol

A glycyrrhetinic acid-modified carboxymethyl chitosan-thioketal-rhein (GCTR) conjugate was designed and synthesized for the in vivo delivery of celastrol (Cela). Cela was encapsulated into polymeric micelles (PMs) formed by GCTR conjugates self-assembly in water to form Cela/GCTR PMs with high drug loading capacity and small particle size. Cela/GCTR PMs had a sustained-release characteristic in the blood environment and a rapid-release feature in the tumor microenvironment. Cela/GCTR PMs had a significant proliferation inhibitory effect on HepG2 and BEL-7402 cells, but a negligible impact on L-02 cells at low concentrations. Cela/GCTR PMs possessed reactive oxygen species (ROS)-responsive properties in vitro and in cells, could improve the bioavailability of Cela, and exert remarkable hepatoma-targeting properties. Cela/GCTR PMs could also effectively inhibit tumor growth with no apparent damage to different organs. In summary, GCTR PMs with good ROS-responsive and hepatoma-targeting properties are expected to be possible delivery carriers for hydrophobic antineoplastic drugs for hepatocellular carcinoma therapy.

Nano-Traditional Chinese Medicine: a promising strategy and its recent advances

Traditional Chinese medicine(TCM) has been applied to the prevention and treatment of numerous diseases and has an irreplaceable role of rehabilitation and health care. However, the application of TCM is...

Recent progress in nanotechnology-based drug carriers for celastrol delivery

Celastrol (CLT) is an active ingredient that was initially discovered and extracted from the root of Tripterygium wilfordii. The potential pharmacological activities of CLT in cancer, obesity, and inflammatory, auto-immune, and neurodegenerative diseases have been demonstrated in recent years. However, CLT's clinical application is extremely restricted by its low solubility/permeability, poor bioavailability, and potential off-target toxicity. The advent of nanotechnology provides a solution to improve the oral bioavailability, therapeutic effects or tissue-targeting ability of CLT. This review focuses on the most recent advances, improvements, inventions, and updated literature of various nanocarrier systems for CLT.

Transferrin-Decorated Protein-Lipid Hybrid Nanoparticle Efficiently Delivers Cisplatin and Docetaxel for Targeted Lung Cancer Treatment

PURPOSE

Non-small cell lung cancer (NSCLC) therapy faces the barriers including drug resistance. A transferrin-functionalized protein-lipid hybrid nanoparticle (PLHN) was designed loading both cisplatin (CIS) and docetaxel (DTX) for the lung cancer treatment.

METHODS

CIS and DTX were loaded into the hybrid nanoparticle and then decorated with transferrin (Tf). The Tf-functionalized protein-lipid hybrid nanoparticle (Tf-CIS/DTX-PLHN) was investigated by determining the release behavior, cytotoxicity in vitro, and anticancer efficiency in vivo.

RESULTS

Tf-CIS/DTX-PLHN showed a nano-size of 189.5 ± 5.9 nm, and a surface tested to be -16.9 ± 2.1 mV. Tf-CIS/DTX-PLHN exhibited obviously better antitumor ability in vitro and in vivo compared with the non Tf contained CIS and DTX co-loaded lipid nanoparticles (CIS/DTX-LN), single drug loaded nanoparticles, and free drugs.

CONCLUSION

Since remarkable enhanced efficiency of Tf and synergistic effect of the drugs, it could inhibit the lung tumor growth and help with the lung cancer treatment.

Nanotechnology-Based Celastrol Formulations and Their Therapeutic Applications

Celastrol (also called tripterine) is a quinone methide triterpene isolated from the root extract of Tripterygium wilfordii (thunder god vine in traditional Chinese medicine). Over the past two decades, celastrol has gained wide attention as a potent anti-inflammatory, anti-autoimmune, anti-cancer, anti-oxidant, and neuroprotective agent. However, its clinical translation is very challenging due to its lower aqueous solubility, poor oral bioavailability, and high organ toxicity. To deal with these issues, various formulation strategies have been investigated to augment the overall celastrol efficacy in vivo by attempting to increase the bioavailability and/or reduce the toxicity. Among these, nanotechnology-based celastrol formulations are most widely explored by pharmaceutical scientists worldwide. Based on the survey of literature over the past 15 years, this mini-review is aimed at summarizing a multitude of celastrol nanoformulations that have been developed and tested for various therapeutic applications. In addition, the review highlights the unmet need in the clinical translation of celastrol nanoformulations and the path forward.

Terpenoids from Curcumae Rhizoma: Their anticancer effects and clinical uses on combination and versus drug therapies

Cancer is a fatal disease with high mortality and low survival rate worldwide. At present, there is still no known cure for most cancers. Traditional Chinese medicine (TCM) represents a noteworthy reservoir for anticancer agents in drug discovery and development. Curcumae Rhizoma (called Ezhu in Chinese) is widely prescribed in TCM for anticancer therapy owing to its broad-spectrum antineoplastic activities. Especially, the terpenoids isolated from the essential oil of Curcumae Rhizoma form an integral part of cancer research and are well established as a potential anticancer agent. For example, β-elemene has been developed into a new drug for the treatment of solid tumors in China, and is currently undergoing clinical trials in the United States. The review aims to systematically summarize the recent advances on the anticancer effects and related molecular mechanisms of Curcumae Rhizoma, and its terpenoids (β-elemene, Furanodiene, Furanodienone, Germacrone, Curcumol, Curdione). In addition, we evaluated and compared the anticancer efficacy and clinical use of the terpenoids with combination therapies and traditional therapies. Therefore, this review provides sufficient evidence for the anticancer therapeutic potential of Curcumae Rhizoma and its terpenoids, and will contribute to the development of potential anticancer drugs.

Celastrol: A Review of Useful Strategies Overcoming its Limitation in Anticancer Application

Celastrol, a natural bioactive ingredient derived from Tripterygium wilfordii Hook F, exhibits significant broad-spectrum anticancer activities for the treatment of a variety of cancers including liver cancer, breast cancer, prostate tumor, multiple myeloma, glioma, etc. However, the poor water stability, low bioavailability, narrow therapeutic window, and undesired side effects greatly limit its clinical application. To address this issue, some strategies were employed to improve the anticancer efficacy and reduce the side-effects of celastrol. The present review comprehensively focuses on the various challenges associated with the anticancer efficiency and drug delivery of celastrol, and the useful approaches including combination therapy, structural derivatives and nano/micro-systems development. The specific advantages for the use of celastrol mediated by these strategies are presented. Moreover, the challenges and future research directions are also discussed. Based on this review, it would provide a reference to develop a natural anticancer compound for cancer treatment.

Microemulsion systems: from the design and architecture to the building of a new delivery system for multiple-route drug delivery

Poorly soluble active pharmaceutical ingredients (APIs) create major problems in drug dosage form formulation resulting in significant delays in drug pharmaceutical screening, impairing the drug dosage form production. Aiming to minimize the use of excipients for increasing drug apparent solubility and, as a result, its bioavailability, exploration of innovative approaches is an earnest need. Microemulsion is an alternative drug delivery system that emerged as a valuable tool to achieve safe formulations for insoluble compounds and to improve their biopharmaceutical properties and pharmacokinetics. This review aims to present the state of the art of microemulsion systems, bringing an overview about their origin and how they can be properly produced and thoroughly characterized by different approaches. Furthermore, comments on regulatory issues regarding stability assessment and toxicity evaluation are discussed. The review concludes with a current opinion on microemulsion systems. The overall objective of this work was to describe all the potentialities of microemulsion systems as a drug carrier for therapeutic purposes, highlighting the unique features of this nanotechnological platform. Display Image.

Combinative treatment of β-elemene and cetuximab is sensitive to KRAS mutant colorectal cancer cells by inducing ferroptosis and inhibiting epithelial-mesenchymal transformation

Background and Purpose: RAS mutations limit the effectiveness of anti-epidermal growth factor receptor (EGFR) monoclonal antibodies in combination with chemotherapy for metastatic colorectal cancer (mCRC) patients. Therefore, new cell death forms have focused on identifying indirect targets to inhibit Ras-induced oncogenesis. Recently, emerging evidence has shown the potential of triggering ferroptosis for cancer therapy, particularly for eradicating aggressive malignancies that are resistant to traditional therapies.

Methods: KRAS mutant CRC cell HCT116 and Lovo were treated with cetuximab and β-elemene, a bioactive compound isolated from Chinese herb Curcumae Rhizoma. Ferroptosis and epithelial-mesenchymal transformation (EMT) were detected in vitro and in vivo. Orthotopic CRC animal model were established and the tumor growth was monitored by IVIS bioluminescence imaging. Tumor tissues were collected to determine ferroptosis effect and the expression of EMT markers after the treatment.

Results: CCK-8 assay showed that synergetic effect was obtained when 125 µg/ml β-elemene was combined with 25 µg/ml cetuximab in KRAS mutant CRC cells. AV/PI staining suggested a non-apoptotic mode of cell death after the treatment with β-elemene and cetuximab. In vitro, β-elemene in combination with cetuximab was shown to induce iron-dependent reactive oxygen species (ROS) accumulation, glutathione (GSH) depletion, lipid peroxidation, upregulation of HO-1 and transferrin, and downregulation of negative regulatory proteins for ferroptosis (GPX4, SLC7A11, FTH1, glutaminase, and SLC40A1) in KRAS mutant CRC cells. Meanwhile, combinative treatment of β-elemene and cetuximab inhibited cell migration and decreased the expression of mesenchymal markers (Vimentin, N-cadherin, Slug, Snail and MMP-9), but promoted the expression of epithelial marker E-cadherin. Moreover, ferroptosis inhibitors but not other cell death suppressors abrogated the effect of β-elemene in combination with cetuximab on KRAS mutant CRC cells. In vivo, co-treatment with β-elemene and cetuximab inhibited KRAS mutant tumor growth and lymph nodes metastases.

Conclusions: Our data for the first time suggest that the natural product β-elemene is a new ferroptosis inducer and combinative treatment of β-elemene and cetuximab is sensitive to KRAS mutant CRC cells by inducing ferroptosis and inhibiting EMT, which will hopefully provide a prospective strategy for CRC patients with RAS mutations.

Celastrol Suppresses Glioma Vasculogenic Mimicry Formation and Angiogenesis by Blocking the PI3K/Akt/mTOR Signaling Pathway

Angiogenesis and vasculogenic mimicry (VM) are thought to be the predominant processes ensuring tumor blood supply during the growth and metastasis of glioblastoma (GBM). Celastrol has potential anti-glioma effects, however the mechanisms underlying these effects remain unclarified. Recent studies have shown that the PI3K/Akt/mTOR signaling pathway is closely related to angiogenesis and VM formation. In the present study, we have demonstrated, for the first time, that celastrol eliminated VM formation by blocking this signaling pathway in glioma cells. By the treatment of celastrol, tumor growth was suppressed, tight junction and basal lamina structures in tumor microvasculature were disarranged in U87 glioma orthotopic xenografts in nude mice. Periodic acid Schiff (PAS)-CD31 staining revealed that celastrol inhibited both VM and angiogenesis in tumor tissues. Additionally, celastrol reduced the expression levels of the angiogenesis-related proteins CD31, vascular endothelial growth factor receptor (VEGFR) 2, angiopoietin (Ang) 2 and VEGFA, VM-related proteins ephrin type-A receptor (EphA) 2, and vascular endothelial (VE)-cadherin. Hypoxia inducible factor (HIF)-1α, phosphorylated PI3K, Akt, and mTOR were also downregulated by treatment with celastrol. In vitro, we further demonstrated that celastrol inhibited the growth, migration, and invasion of U87 and U251 cells, disrupted VM formation, and blocked the activity of PI3K, Akt, and mTOR. Collectively, our data suggest that celastrol inhibits VM formation and angiogenesis likely by regulating the PI3K/Akt/mTOR signaling pathway.

SYL3C aptamer-anchored microemulsion co-loading β-elemene and PTX enhances the treatment of colorectal cancer

The aim of this study is to construct a SYL3C aptamer-anchored microemulsion based on β-elemene and PTX (SYL3C/EP-MEs) for enhancement on colorectal cancer therapy. Such microemulsion is consist of encapsulated drugs (β-elemene and PTX), tumor targeting ligand (3’-end thiolated SYL3C aptamer), thiol conjugated site (maleimide-modified PEGylated 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, mal-DOPE-PEG), pH-sensitive component (DOPE) and other necessary excipients. SYL3C/EP-MEs showed a spherical particle with an average particle size around 30 nm and a high encapsulation efficiency (>80%) for both drugs. β-elemene and PTX could be released controllably from SYL3C/EP-MEs as pH values changed. SYL3C/EP-MEs displayed a selective affinity to HT-29 cells, leading to an obvious increase in cellular uptake, cell apoptosis and cytotoxicity. In the HT-29 tumor xenograft-bearing nude mice model studies, SYL3C/EP-MEs showed an overwhelming tumor growth inhibition, the longest survival time and the lowest systemic toxicity among all the treatments. The potential mechanism of enhanced anti-cancer ability was probably associated with the induction of M1 macrophage polarization, the downregulation of mutant p53 protein and the reduction of bcl-2 protein expression. Collectively, the microemulsion codelivery of β-elemene and PTX using functionalization with SYL3C aptamer provides a novel approach for combinational colorectal cancer-targeted treatment.

Targeted delivery of celastrol to renal interstitial myofibroblasts using fibronectin-binding liposomes attenuates renal fibrosis and reduces systemic toxicity

Renal fibrosis often occurs in chronic kidney disease, and effective treatment is needed. Celastrol (CEL) may attenuate renal fibrosis, but it distributes throughout the body, leading to severe systemic toxicities. Here we designed a system to deliver CEL specifically to interstitial myofibroblasts, which is a key driver of renal fibrogenesis. Fibronectin is highly expressed in fibrotic kidney. The pentapeptide CREKA, which specifically binds fibronectin, was conjugated to PEGylated liposomes (CREKA-Lip). CREKA-coupled liposomes significantly increased the uptake of unmodified liposomes by activated NRK-49F renal fibroblasts. Systemic administration of CREKA-Lip to mice led to their accumulation in fibrotic kidney, where they were specifically internalized by interstitial myofibroblasts. Loading CEL into CREKA-Lip effectively inhibited the activation and proliferation of NRK-49F cells in vitro, and they markedly alleviated renal fibrosis, injury and inflammation induced by unilateral ureteral obstruction in mice. Besides, CEL-loaded CREKA-Lip was associated with significantly lower toxicity to major organs than free CEL. These results suggest that encapsulating CEL in CREKA-Lip can increase its therapeutic efficacy and reduce its systemic toxicity as a potential treatment for renal fibrosis.

Advances in phytochemical delivery systems for improved anticancer activity

Natural compounds have significant anticancer pharmacological activities, but often suffer from low bioavailability and selectivity that limit therapeutic use. The present work critically analyzes the latest advances on drug delivery systems designed to enhance pharmacokinetics, targeting, cellular uptake and efficacy of anticancer phytoconstituents. Various phytochemicals, including flavonoids, resveratrol, celastrol, curcumin, berberine and camptothecins, carried by liposomes, nanoparticles, nanoemulsions and films showed promising results. Strategies to avoid drug metabolism, overcome physiological barriers and achieve higher concentration at cancer sites through skin, buccal, nasal, vaginal, pulmonary and colon targeted delivery are presented. Current limitations, challenges and future research directions are also discussed.