Synthesis, characterization and in vitro/in vivo evaluation of novel reduction-sensitive hybrid nano-echinus-like nanomedicine

Liver-targeted delivery based on prodrug: passive and active approaches

BACKGROUND

The liver, a central organ in human metabolism, is often the primary target for drugs. However, conditions such as viral hepatitis, cirrhosis, non-alcoholic fatty liver disease (NAFLD), and hepatocellular carcinoma (HCC) present substantial health challenges worldwide. Existing treatments, which suffer from the non-specific distribution of drugs, frequently fail to achieve desired efficacy and safety, risking unnecessary liver harm and systemic side effects.

PURPOSE

The aim of this review is to synthesise the latest progress in the design of liver-targeted prodrugs, with a focus on passive and active targeting strategies, providing new insights into the development of liver-targeted therapeutic approaches.

METHODS

This study conducted an extensive literature search through databases like Google Scholar, PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI), systematically collecting and selecting recent research on liver-targeted prodrugs. The focus was on targeting mechanisms, including the Enhanced Permeability and Retention (EPR) effect, the unique microenvironment of liver cancer, and active targeting through specific transporters and receptors.

RESULTS

Active targeting strategies achieve precise drug delivery by binding specific ligands to liver surface receptors. Passive targeting takes advantage of the EPR effect and tumour characteristics to enrich drugs in liver tumours. The review details successful cases of using small molecule ligands, peptides, antibodies and nanoparticles as drug carriers.

CONCLUSION

Liver-targeted prodrug strategies show great potential in enhancing the efficacy of drug treatment and reducing side effects for liver diseases. Future research should balance the advantages and limitations of both targeting strategies, focusing on optimising drug design and targeting efficiency, especially for clinical application. In-depth research on liver-specific receptors and the development of innovative targeting molecules are crucial for advancing the field of liver-targeted prodrugs.

Research progress in nano-drug delivery systems based on the characteristics of the liver cancer microenvironment

The liver cancer has microenvironmental features such as low pH, M2 tumor-associated macrophage enrichment, low oxygen, rich blood supply and susceptibility to hematotropic metastasis, high chemokine expression, enzyme overexpression, high redox level, and strong immunosuppression, which not only promotes the progression of the disease, but also seriously affects the clinical effectiveness of traditional therapeutic approaches. However, nanotechnology, due to its unique advantages of size effect and functionalized modifiability, can be utilized to develop various responsive nano-drug delivery system (NDDS) by using these characteristic signals of the liver cancer microenvironment as a source of stimulation, which in turn can realize the intelligent release of the drug under the specific microenvironment, and significantly increase the concentration of the drug at the target site. Therefore, researchers have designed a series of stimuli-responsive NDDS based on the characteristics of the liver cancer microenvironment, such as hypoxia, weak acidity, and abnormal expression of proteases, and they have been widely investigated for improving anti-tumor therapeutic efficacy and reducing the related side effects. This paper provides a review of the current application and progress of NDDS developed based on the response and regulation of the microenvironment in the treatment of liver cancer, compares the effects of the microenvironment and the NDDS, and provides a reference for building more advanced NDDS.

Self-assembled glycyrrhetinic acid derivatives for functional applications: a review

Glycyrrhetinic acid (GA), a famous natural product, has been attracting more attention recently because of its remarkable biological activity, natural sweetness, and good biocompatibility. In the past few years, a considerable amount of literature has grown up around the theme of GA-based chemical modification to broaden its functional applications. Promising structures including gels, micelles, nanoparticles, liposomes, and so forth have been constantly reported. On the one hand, the assembly mechanisms of various materials based on GA derivatives have been elucidated via modern analytical techniques. On the other hand, their potential application prospects in edible additives, intelligent drug delivery, and other fields have been investigated fully due to availability, biocompatibility, and controllable degradability. Inspired by these findings, a systematic summary and classification of the materials formed by GA derivatives seems necessary and meaningful. This review sums up the new functional applications of GA derivatives for the first time and provides better prospects for their application and development.

Mechanochemical preparation of triptolide-loaded self-micelle solid dispersion with enhanced oral bioavailability and improved anti-tumor activity

Triptolide (TP), a compound isolated from a Chinese medicinal herb, possesses potent anti-tumor, immunosuppressive, and anti-inflammatory properties, but was clinically limited due to its poor solubility, bioavailability, and toxicity. Considering the environment-friendly, low-cost mechanochemical techniques and potential dissolution enhancement ability of Na₂GA, an amorphous solid dispersion (Na₂GA&TP-BM) consisting of TP and Na₂GA were well-prepared to address these issues. The performance of Na₂GA&TP-BM was improved through ball milling, such as from crystalline state to an amorphous solid dispersion, suitable nano micelle size and surface potential, and increased solubility. This change had a significant improvement of pharmacokinetic behavior in mice and could be able to extend the blood circulation time of the antitumor drug. Moreover, in vitro and in vivo anti-tumor study showed that Na₂GA&TP-BM displayed more potent cytotoxicity to tumor cells. The work illustrated an environment-friendly and safe preparation of the TP formulation, which was promising to enhance the oral bioavailability and antitumor ability of TP, might be considered for efficient anticancer therapy.

One-pot synthesis of Eu-MOFs for bioimaging and drug delivery

OBJECTIVE

The use of metal-organic framework (MOF) platforms has been a topic of growing interest in the fields of drug delivery and bioimaging. This study was designed to develop and evaluate a novel MOF-based drug and radiation delivery nanosystem.

METHODS

Eu-MOFs were characterized in vitro via X-ray diffraction, scanning electronic microscopy, and FT-IR spectrometry. Nanocarrier uptake and associated cell viability were assessed using a CCK-8 assay and using a high content screening system. Biodistribution studies were conducted with a Luminal II IVIS imaging system to assess nanocarrier distribution in different organs. As such, paclitaxel was selected as a model drug in the present study to evaluate Eu-MOF drug loading and release characteristics in vitro via HPLC.

RESULTS

A straightforward one-step approach was used to successfully fabricate sea urchin-shaped Eu-MOFs that were self-assembled from Eu³⁺ and 1,3,5-pyromellitic acid. These MOFs exhibited robust red fluorescence owing to the antenna effect. Owing to their fluorescent properties, these Eu-MOFs were able to facilitate in vivo imaging with a high quantum yield and low background signal. Importantly, our Eu-MOFs exhibited good biocompatibility, low cytotoxicity, and high imaging efficiency. As they exhibited slow-release kinetics and targeted biodistribution profiles, these Eu-MOFs additionally hold great promise as potential anti-cancer agents in clinical settings.

CONCLUSION

Herein, we designed a novel Eu-MOF active targeted drug delivery nanocarrier platform and found that it represents a promising therapeutic tool for cancer treatment.

Novel nano-pomegranates based on astragalus polysaccharides for targeting ERα-positive breast cancer and multidrug resistance

Chemotherapy is an important method for treating breast cancer. However, multidrug resistance is one of the major challenges in breast cancer chemotherapy. There is an urgent need to develop novel, effective antitumor strategies that will perfect existing therapeutic regimens. In this study, the double-targeted nanocarrier, Quercetin-3'3-dithiodipropionic acid-Astragalus polysaccharides-Folic acid (QDAF), was successfully synthesized and self-assembled into a neoteric nano-targeted delivery strategy, named nano-pomegranates, and which were utilized to effectively inhibit multidrug resistance in estrogen receptor α (ERα)-positive breast tumor. The outstanding abilities of nano-pomegranates to release the drug in a reducing environment was determined by in vitro release assay. The cellular studies in MCF-7 cells were examined that nano-pomegranates have remarkable efficiencies of enhancing cellular uptake, inhibition and necrosis and apoptosis. In vivo antitumor experiments showed that nano-pomegranates have better anti-tumor effects and lower systemic toxicity than free Cur. In conclusion, nano-pomegranates have great potential in anti-breast cancer treatment.

Novel Chinese Angelica Polysaccharide Biomimetic Nanomedicine to Curcumin Delivery for Hepatocellular Carcinoma Treatment and Immunomodulatory Effect

BACKGROUND

Using natural polysaccharides from Traditional Chinese Medicine as nanodrug delivery systems have considerable potential for tumor diagnostics and therapeutics.

PURPOSE

On the basis of targeted therapy and combining the advantages of natural polysaccharides (angelica polysaccharide, APS) and natural Chinese medicine (curcumin, Cur) to design functionalized nanoparticles to improve the therapeutic through cell membrane encapsulation and immunotherapy.

STUDY DESIGN AND METHODS

Cur-loaded, glycyrrhetic acid (GA)-APS-disulfide bond (DTA)-Cur nanomicelle (GACS-Cur), which were prepared by the dialysis method. GACS-Cur was encapsulated with the membranes from red blood cells (RBCm) termed GACS-Cur@RBCm, which were prepared by the principle of extrusion using a miniature extruder. The developed formulations were subjected to various in vitro and in vivo evaluation tests.

RESULTS

The resulting APS nanocarriers supported a favorable drug-loading capacity, biocompatibility, and enhanced synergistic anti-hepatoma effects both in vitro and in vivo. After administration in mice, in vivo imaging results showed that the GACS-Cur and RBCm-coated groups had an obvious stronger tumor tissue targeting ability than the control treatment groups. Additionally, the immunomodulatory effect increased IL-12, TNF-α and IFN-γ expression and CD8+ T cell infiltration (1.9-fold) than that of the saline group. Notably, in comparison with hyaluronic acid (HA) nanocarriers, APS nanocarriers possess higher anti-hepatoma efficiency and targeting capabilities and, thus, should be further studied for a wide range of anti-cancer applications.

CONCLUSION

Our data demonstrated that APS nanocarriers encapsulated with erythrocyte membrane mighty be a promising clinical method in the development of efficacy, safety and targeting of liver cancer therapy.

Recent advances in the redox-responsive drug delivery nanoplatforms: A chemical structure and physical property perspective

Poor water solubility, off-target toxicity, and small therapeutic window are among major obstacles for the development of drug products. Redox-responsive drug delivery nanoplatforms not only overcome the delivery and pharmacokinetic pitfalls observed in conventional drug delivery, but also leverage the site-specific delivery properties. Cleavable diselenide and disulfide bonds in the presence of elevated reactive oxygen species (ROS) and glutathione concentration are among widely used stimuli-responsive bonds to design nanocarriers. This review covers a wide range of redox-responsive chemical structures and their properties for designing nanoparticles aiming controlled loading, delivery, and release of hydrophobic anticancer drugs at tumor site.

Smart Responsive Nanoformulation for Targeted Delivery of Active Compounds From Traditional Chinese Medicine

Traditional Chinese medicine (TCM) has been used to treat disorders in China for ~1,000 years. Growing evidence has shown that the active ingredients from TCM have antibacterial, antiproliferative, antioxidant, and apoptosis-inducing features. However, poor solubility and low bioavailability limit clinical application of active compounds from TCM. “Nanoformulations” (NFs) are novel and advanced drug-delivery systems. They show promise for improving the solubility and bioavailability of drugs. In particular, “smart responsive NFs” can respond to the special external and internal stimuli in targeted sites to release loaded drugs, which enables them to control the release of drug within target tissues. Recent studies have demonstrated that smart responsive NFs can achieve targeted release of active compounds from TCM at disease sites to increase their concentrations in diseased tissues and reduce the number of adverse effects. Here, we review “internal stimulus–responsive NFs” (based on pH and redox status) and “external stimulus–responsive NFs” (based on light and magnetic fields) and focus on their application for active compounds from TCM against tumors and infectious diseases, to further boost the development of TCM in modern medicine.

Synergistic Combination Chemotherapy of Lung Cancer: Cisplatin and Doxorubicin Conjugated Prodrug Loaded, Glutathione and pH Sensitive Nanocarriers

Purpose

Prodrug technology-based combination drug therapy has been exploited as a promising treatment strategy to achieve synergistic lung cancer therapy, reduce drug dose, and decrease side effects. In the present study, we synthesized a pH and glutathione (GSH) sensitive prodrug, cisplatin (CIS) and doxorubicin (DOX) conjugates (CIS-DOXp). CIS-DOXp was loaded by nanocarriers and delivered into the tumor site.

Methods

pH and GSH sensitive CIS-DOX prodrug (CIS-DOXp) was synthesized by conjugating GSH responsive CIS prodrug with pH sensitive DOX prodrug. CIS-DOXp-loaded nanocarriers (CIS-DOXp NC) were prepared using emulsification and solvent evaporation method. The morphology, particle size, polydispersity index (PDI) and zeta potential of nanocarriers were measured. In vitro cytotoxicity of nanocarriers and the corresponding free drugs was examined using the MTT assay. In vivo anti-tumor efficiency and biodistribution behaviors were evaluated on lung cancer mice models.

Results

The size, PDI, zeta potential, CIS loading efficiency, and DOX loading efficiency of CIS-DOXp NC were 128.6 ± 3.2 nm, 0.196 ± 0.021, 15.7 ± 1.7 mV, 92.1 ± 2.1%, and 90.4 ± 1.8%, respectively. The best cell killing ability (the lowest combination index of 0.57) was found at the combination ratio of 1:3 (CIS:DOX, w/w) in the drugs co-loaded formulations, indicating the strongest synergism effect. CIS-DOXp NC showed the best tumor inhibition efficiency (79.9%) in mice with negligible body weight lost.

Conclusion

CIS-DOXp NC could be applied as a promising system for the synergistic chemotherapy of lung cancer.

Development of dual-targeted nano-dandelion based on an oligomeric hyaluronic acid polymer targeting tumor-associated macrophages for combination therapy of non-small cell lung cancer

In this study, the novel carrier materials were screened to structure targeting nano-micelles (named ‘nano-dandelion’) for synchronous delivery of curcumin (Cur) and baicalin (Bai), which could effectively overcome the tumor resistance. Mannose (Man) was found to bind better to CD206 receptors on the surface of tumor-associated macrophages (TAMs), thereby increasing the number of nano-dandelion engulfed by TAMs. Furthermore, oligomeric hyaluronic acid (oHA) was able to target CD44 receptors, resulting in recruitment of a higher number of nano-dandelion to locate and engulf tumor cells. The disulfide bond (S–S) in 3,3′-dithiodipropionic acid (DA) could be broken by the high concentration of glutathione (GSH) in the tumor microenvironment (TME). Based on this, we selected DA to connect hydrophobic fragments (quercetin, Que) and oHA. A reduction-sensitive amphiphilic carrier material, quercetin–dithiodipropionic acid–oligomeric hyaluronic acid–mannose–ferulic acid (Que–S–S–oHA–Man–FA; QHMF) was fabricated and synthesized by ¹H NMR. Next, QHMF self-assembled into nano-dandelion, i.e. encapsulated Cur and Bai in water. Critical experimental conditions in the preparation process of nano-dandelion that could affect its final properties were explored. Nano-dandelion with a small particle size (121.0 ± 15 nm) and good normal distribution (PI = 0.129) could easily enter tumor tissue through vascular barrier. In addition, nano-dandelion with a suitable surface potential (–20.33 ± 4.02 mV) could remain stable for a long duration. Furthermore, good cellular penetration and tumor cytotoxicity of nano-dandelion were demonstrated through in vitro cellular studies. Finally, effective antitumor activity and reduced side effects were confirmed through in vivo antitumor experiments in A549 tumor-bearing nude mice.

Novel multifunctional triple folic acid, biotin and CD44 targeting pH-sensitive nano-actiniaes for breast cancer combinational therapy

In this study, novel multifunctional folic acid, biotin, and CD44 receptors targeted and pH-sensitive “nano-actiniaes” were fabricated with icariin (ICA) and curcumin (Cur) as loaded model drugs for breast cancer therapy. The newly synthesized polymer oligomeric hyaluronic acid-hydrazone bond-folic acid-biotin (Bio-oHA-Hyd-FA) was characterized by ¹H NMR spectrogram (proton nuclear magnetic resonance). The obtained drug carrier Bio-oHA-Hyd-FA self-assembled into nanomicelles, named as “nano-actiniaes”, in aqueous media with hydrodynamic diameter of 162.7 ± 5 nm. The size, surface zeta potential, and morphology of the “nano-actiniaes” were observed via TEM. The in vitro release experiment indicated that much more encapsulated icariin (ICA) and curcumin (Cur) were released from the Bio-oHA-Hyd-FA micelles (nano-actiniaes) in the acidic environment. Additionally, the cytotoxicity research demonstrated that the Bio-oHA-Hyd-FA carrier material was completely nontoxic, and the ICA&Cur “nano-actiniaes” had greater cytotoxicity compared with other control groups. In addition, the “nano-actiniaes” were found to significantly inhibit cancer cell invasion by Transwell assay. Moreover, in vivo evaluation of anti-tumor effect illustrated that the ICA and Cur “nano-actiniaes” possessed inhibitory effect on tumors. Consequently, the multi-targeted pH-sensitive “nano-actiniaes” can realize significant tumor targeting and effectively inhibit tumor growth.

Novel dual ROS-sensitive and CD44 receptor targeting nanomicelles based on oligomeric hyaluronic acid for the efficient therapy of atherosclerosis

Although the clinical usage of drugs administration was raising, the application of nanoparticles encapsulating the hydrophobic drugs with plummy efficiency was very scarce for atherosclerosis (AS) treatment. In this work, a novel dual ROS-sensitive and CD44 receptors targeting amphiphilic carrier material, oligomeric hyaluronic acid-2'-[propane-2,2-diyllbls (thio)] diacetic acl-hydroxymethylferrocene (oHA-TKL-Fc), named HASF, was synthesized and characterized by ¹H-NMR spectra. Then, we combined curcumin (Cur) with HASF into nano-micelles (HASF@Cur micelles) by self-assembling method. The resulting HASF@Cur micelles had the average size of 150.8 nm and zeta potential of -35.04 mV to maintain the will-defined spheroidal structure and stability. Importantly, the HASF@Cur micelles had ultrahigh entrapment efficiency (about 51.41 %). Moreover, in vitro release study, Cur release from HASF@Cur micelles was effective in the reactive oxygen species (ROS) condition, and the release rate was interrelated with the concentration of hydrogen peroxide (H₂O₂). Further, fluorescence imaging showed that the HASF@Cur micelles could more selective access to Raw 264.7 cells than free Cur via oHA-receptor mediated endocytosis. The MTT assay attested the safety of amphiphilic carrier material HASF. Additionally, the results of in vivo Oil red O lipid staining studies showed that the lesion area of the aorta was reduced to 47.3±3.4 % with HASF@Cur micelles, compared with the lesion area of Cur group (63.2±2.7 %), HASF@Cur micelles had the more remarkable effect in reducing lesion area (*P < 0.05). Consequently, the novel dual ROS-sensitive and CD44 receptors targeting drug delivery system would become a promising strategy for atherosclerosis.

Glycyrrhetinic acid modified and pH-sensitive mixed micelles improve the anticancer effect of curcumin in hepatoma carcinoma cells

Curcumin (CUR), a natural polyphenolic compound existing in plants, exhibits anticancer potential in inhibiting the growth of various types of human cancer. However, the poor aqueous solubility and low bioavailability limit its clinical applications. pH-sensitive macromolecule F68-acetal-PCL (FAP) and active targeting macromolecule F68-glycyrrhetinic acid (FGA) were designed to fabricate mixed micelles for efficient delivery of CUR. The thin film hydration method was used to prepare CUR loaded mixed (MIX/CUR) micelles. The drug loading rate (DL) of MIX/CUR micelles was 6.31 ± 0.92%, which remained stable for 15 days at 4 °C. The particle size and zeta potential of the MIX/CUR micelles were 91.06 ± 1.37 nm and -9.79 ± 0.47 mV, respectively. The MIX/CUR micelles exhibited pH sensitivity in a weak acid environment, and showed rapid particle size variation and drug release. In addition, in vitro tests demonstrated that MIX/CUR micelles induced higher cytotoxicity and apoptosis than free CUR, non-pH-sensitive F68-PCL (FBP)/CUR micelles and pH-sensitive FAP/CUR micelles in SMMC7721 and Hepa1-6 cells. Besides, mixed micelles were more effective than FBP and FAP micelles in a cell uptake experiment, which was medicated by a GA receptor. All in all, these results indicated that MIX/CUR micelles could be regarded as an ideal drug administration strategy against hepatoma carcinoma cells.