L-EGCG-Mn nanoparticles as a pH-sensitive MRI contrast agent

Epigallocatechin-3-gallate at the nanoscale: a new strategy for cancer treatment

CONTEXT

Epigallocatechin-3-gallate (EGCG), the predominant catechin in green tea, has shown the potential to combat various types of cancer cells through its ability to modulate multiple signaling pathways. However, its low bioavailability and rapid degradation hinder its clinical application.

OBJECTIVE

This review explores the potential of nanoencapsulation to enhance the stability, bioavailability, and therapeutic efficacy of EGCG in cancer treatment.

METHODS

We searched the PubMed database from 2019 to the present, using 'epigallocatechin gallate', 'EGCG', and 'nanoparticles' as search terms to identify pertinent literature. This review examines recent nano-engineering technology advancements that encapsulate EGCG within various nanocarriers. The focus was on evaluating the types of nanoparticles used, their synthesis methods, and the technologies applied to optimize drug delivery, diagnostic capabilities, and therapeutic outcomes.

RESULTS

Nanoparticles improve the physicochemical stability and pharmacokinetics of EGCG, leading to enhanced therapeutic outcomes in cancer treatment. Nanoencapsulation allows for targeted drug delivery, controlled release, enhanced cellular uptake, and reduced premature degradation of EGCG. The studies highlighted include those where EGCG-loaded nanoparticles significantly inhibited tumor growth in various models, demonstrating enhanced penetration and efficacy through active targeting mechanisms.

CONCLUSIONS

Nanoencapsulation of EGCG represents a promising approach in oncology, offering multiple therapeutic benefits over its unencapsulated form. Although the results so far are promising, further research is necessary to fully optimize the design of these nanosystems to ensure their safety, efficacy, and clinical viability.

Biosynthesis of metal nanoparticles: Bioreduction and biomineralization

The biosynthesis of metal nanoparticles by plants, bacteria, and cells has been receiving considerable attention in recent years. The traditional synthesis of metal nanoparticles always needed high temperatures, high pressure, and toxic agents. However, the biosynthesis process (including bioreduction and biomineralization) is simpler, safe, economical, and green. The process of biosynthesis can insulate toxic agents, streamline flux, increase the transition efficiency of interactants, and improve the product yield. The biosynthesized metal nanoparticles share similar characteristics with traditional ones, serving as photosensors to achieve light-to-heat/energy transduction, or a drug delivery system. The biosynthetic metal nanoparticles thus could be widely applied in the medical field for disease diagnosis and treatment. It contributed a novel modality for the facile and green synthesis of metal nanoparticles. Increasing studies have been exploring the mechanism for the biosynthesis of metal nanoparticles, devoted to a controllable biosynthesis process. Combined with our previous studies on the biosynthesis of gold nanoparticles with green tea, tumor cells, and cell components, we reviewed the green methods of bioreduction and biomineralization of metal nanoparticles including the internal mechanism, aimed to make a comprehensive introduction to the biosynthesis of metal nanoparticles and relevant biomedical applications, and inspired further research.

All-in-one approaches for triple-negative breast cancer therapy: metal-phenolic nanoplatform for MR imaging-guided combinational therapy

BACKGROUND

Conventional chemotherapy has poor efficacy in triple-negative breast cancer (TNBC) which is highly heterogeneous and aggressive. Imaging-guided therapy is usually combined with diverse treatment modalities, could realize the integration of diagnosis and treatments. Therefore, the primary challenge for combinational therapy is designing proper delivery systems to accomplish multiple synergistic effects.

RESULTS

Herein, a facile nanoplatform was manufactured to fulfill the all-in-one approaches for TNBC combinational therapy. Fe³⁺-based metal-phenolic networks (MPNs) with bovine serum albumin (BSA) modification served as drug delivery carriers to encapsulate bleomycin (BLM), forming BFE@BSA NPs. The self-assembly mechanism, pH-responsive drug release behavior, and other physicochemical properties of this system were characterized. The potential of BFE@BSA NPs as photothermal transduction agents and magnetic resonance imaging (MRI) contrast agents was explored. The synergistic anti-tumor effects consisting of BLM-induced chemotherapy, Fenton reactions-mediated chemodynamic therapy, and photothermal therapy-induced apoptosis were studied both in vitro and in vivo. Once internalized into tumor cells, released BLM could cause DNA damage, while Fenton reactions were initiated to produce highly toxic •OH. Upon laser irradiation, BFE@BSA NPs could convert light into heat to achieve synergistic effects. After intravenous administration, BFE@BSA NPs exhibited great therapeutic effects in 4T1 tumor xenograft model. Moreover, as T₁-weighted MRI contrast agents, BFE@BSA NPs could provide diagnosis and treatment monitoring for individualized precise therapy.

CONCLUSIONS

A nano-system that integrated imaging and combinational therapy (chemotherapy, chemodynamic therapy and photothermal therapy) were developed to kill the tumor and monitor therapeutic efficacy. This strategy provided an all-in-one theranostic nanoplatform for MRI-guided combinational therapy against TNBC.

A magnetic resonance nanoprobe with STING activation character collaborates with platinum-based drug for enhanced tumor immunochemotherapy

BACKGROUND

Immunochemotherapy is a potent anti-tumor strategy, however, how to select therapeutic drugs to enhance the combined therapeutic effect still needs to be explored. METHODS AND RESULTS: Herein, a magnetic resonance nanoprobe (MnP@Lip) with STING (Stimulator of INterferon Genes) activation character was synthesized and co-administered with platinum-based chemotherapeutics for enhanced immunochemotherapy. MnP@Lip nanoparticles was prepared by simple fabrication process with good reproducibility, pH-sensitive drug release behavior and biocompatibility. In vitro experiments elucidated that Mn²⁺ can promote the polarization of M0 and/or M2 macrophages to M1 phenotype, and promote the maturation of BMDC cells. Upon Mn²⁺ treatment, the STING pathway was activated in tumor cells, mouse lung epithelial cells, and immune cells. More importantly, anti-tumor experiments in vivo proved that MnP@Lip combined with platinum-based chemotherapeutics increased T cells infiltration in the tumor microenvironment, and inhibited tumor growth in the orthotopic therapeutic and postoperative tumor models.

CONCLUSIONS

This kind of therapeutic strategy that combined MnP@Lip nanoparticles with platinum-based chemotherapeutics may provide a novel insight for immunochemotherapy.