Tannic acid/Fe3+ complex coated mesoporous silica nanoparticles for controlled drug release and combined chemo-photothermal therapy

Carrier-free chemo-phototherapeutic nanomedicines with endo/lysosomal escape function enhance the therapeutic effect of drug molecules in tumors

Carrier-free nanomedicines offer advantages of extremely high drug loading capacity (>80%), minimal non-drug constituent burden, and facile preparation processes. Numerous studies have proved that multimodal cancer therapy can enhance chemotherapy efficiency and mitigate multi-drug resistance (MDR) through synergistic therapeutic effects. Upon penetration into the tumor matrix, nanoparticles (NPs) are anticipated to be uptaken by cancer cells, primarily through clathrin-meditated endocytosis pathways, leading to their accumulation in endosomes/lysosomes within cells. However, endo/lysosomes exhibit a highly degradative environment for organic NPs and drug molecules, often resulting in treatment failure. Hence, this study designed a lysosomal escape mechanism with carrier-free nanomedicine, combining the chemotherapeutic drug, curcumin (Cur), and the photothermal/photodynamic therapeutic drug, indocyanine green (ICG), for synergistic cancer treatment (ICG-Cur NPs) via a facile preparation process. To facilitate endo/lysosomal escape, ICG-Cur NPs were modified with metal-phenolic networks (MPNs) of different thickness. The results indicate that a thick MPN coating promotes rapid endo/lysosomal escape of ICG-Cur NPs within 4 h and enhances the photothermal conversion efficiency of ICG-Cur NPs by 55.8%, significantly improving anticancer efficacy in both chemo- and photo-therapies within 3D solid tumor models. This finding underscores the critical role of endo/lysosomal escape capacity in carrier-free drug NPs for therapeutic outcomes and offers a facile solution to achieve it.

Development of a tannic acid- and silicate ion-functionalized PVA-starch composite hydrogel for in situ skeletal muscle repairing

The repair capacity of skeletal muscle is severely diminished in massive skeletal muscle injuries accompanied by inflammation, resulting in muscle function loss and scar tissue formation. In the current work, we developed a tannic acid (TA)- and silicate ion-functionalized tissue adhesive poly(vinyl alcohol) (PVA)-starch composite hydrogel, referred to as PSTS (PVA-starch-TA-SiO32-). It was formed based on the hydrogen bonding of TA to organic polymers, as well as silicate-TA ligand interaction. PSTS could be gelatinized in minutes at room temperature with crosslinked network formation, making it applicable for injection. Further investigations revealed that PSTS had skeletal muscle-comparable conductivity and modulus to act as a temporary platform for muscle repairing. Moreover, PSTS could release TA and silicate ions in situ to inhibit bacterial growth, induce vascularization, and reduce oxidation, paving the way to the possibility of creating a favorable microenvironment for skeletal muscle regeneration and tissue fibrosis control. The in vivo model confirmed that PSTS could enhance muscle fiber regeneration and myotube formation, as well as reduce infection and inflammation risk. These findings thereby implied the great potential of PSTS in the treatment of formidable skeletal muscle injuries.

Folate-Mediated Targeting and Controlled Release: PLGA-Encapsulated Mesoporous Silica Nanoparticles Delivering Capecitabine to Pancreatic Tumor

The discovery of specifically tailored therapeutic delivery systems has sparked the interest of pharmaceutical researchers considering improved therapeutic effectiveness and fewer adverse effects. The current study concentrates on the design and characterization of PLGA (polylactic-co-glycolic acid) capped mesoporous silica nanoparticles (MSN)-based systems for drug delivery for pH-sensitive controlled drug release in order to achieve a targeted drug release inside the acidic tumor microenvironment. The physicochemical properties of the nanoformulations were analyzed using TEM, zeta potential, AFM, TGA, FTIR, and BET analyses in addition to DLS size. The final formed PLGA-FoA-MSN-CAP and pure MSN had sizes within the therapeutic ranges of 164.5 ± 1.8 and 110.7 ± 2.2, respectively. Morphological characterization (TEM and AFM) and elemental analysis (FTIR and XPS) confirmed the proper capping and tagging of PLGA and folic acid (FoA). The PLGA-coated FoA-MSN exhibited a pH-dependent controlled release of the CAP (capecitabine) drug, showing efficient release at pH 6.8. Furthermore, the in vitro MTT test on PANC1 and MIAPaCa-2 resulted in an IC50 value of 146.37 μg/ml and 105.90 μg/ml, respectively. Mitochondrial-mediated apoptosis was confirmed from the caspase-3 and annexin V/PI flow cytometry assay, which displayed a cell cycle arrest at the G1 phase. Overall, the results predicted that the designed nanoformulation is a potential therapeutic agent in treating pancreatic cancer.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

Recent progress in tannic acid based approaches as a natural polyphenolic biomaterial for cancer therapy: A review

Significant advancements have been noticed in cancer therapy for decades. Despite this, there are still many critical challenges ahead, including multidrug resistance, drug instability, and side effects. To overcome obstacles of these problems, various types of materials in biomedical research have been explored. Chief among them, the applications of natural compounds have grown rapidly due to their superb biological activities. Natural compounds, especially polyphenolic compounds, play a positive and great role in cancer therapy. Tannic acid (TA), one of the most famous polyphenols, has attracted widespread attention in the field of cancer treatment with unique structural, physicochemical, pharmaceutical, anticancer, antiviral, antioxidant and other strong biological features. This review concentrated on the basic structure along with the important role of TA in tuning oncological signal pathways firstly, and then focused on the use of TA in chemotherapy and preparation of delivery systems including nanoparticles and hydrogels for cancer therapy. Besides, the application of TA/Fe3+ complex coating in photothermal therapy, chemodynamic therapy, combined therapy and theranostics is discussed.

Design and fabrication of intracellular therapeutic cargo delivery systems based on nanomaterials: current status and future perspectives

Intracellular cargo delivery, the introduction of small molecules, proteins, and nucleic acids into a specific targeted site in a biological system, is an important strategy for deciphering cell function, directing cell fate, and reprogramming cell behavior. With the advancement of nanotechnology, many researchers use nanoparticles (NPs) to break through biological barriers to achieving efficient targeted delivery in biological systems, bringing a new way to realize efficient targeted drug delivery in biological systems. With a similar size to many biomolecules, NPs possess excellent physical and chemical properties and a certain targeting ability after functional modification on the surface of NPs. Currently, intracellular cargo delivery based on NPs has emerged as an important strategy for genome editing regimens and cell therapy. Although researchers can successfully deliver NPs into biological systems, many of them are delivered very inefficiently and are not specifically targeted. Hence, the development of efficient, target-capable, and safe nanoscale drug delivery systems to deliver therapeutic substances to cells or organs is a major challenge today. In this review, on the basis of describing the research overview and classification of NPs, we focused on the current research status of intracellular cargo delivery based on NPs in biological systems, and discuss the current problems and challenges in the delivery process of NPs in biological systems.

Challenges and opportunities for improving the druggability of natural product: Why need drug delivery system?

Bioactive natural products (BNPs) are the marrow of medicinal plants, which are the secondary metabolites of organisms and have been the most famous drug discovery database. Bioactive natural products are famous for their enormous number and great safety in medical applications. However, BNPs are troubled by their poor druggability compared with synthesis drugs and are challenged as medicine (only a few BNPs are applied in clinical settings). In order to find a reasonable solution to improving the druggability of BNPs, this review summarizes their bioactive nature based on the enormous pharmacological research and tries to explain the reasons for the poor druggability of BNPs. And then focused on the boosting research on BNPs loaded drug delivery systems, this review further concludes the advantages of drug delivery systems on the druggability improvement of BNPs from the perspective of their bioactive nature, discusses why BNPs need drug delivery systems, and predicts the next direction.

Endogenous NO-release multi-responsive hollow mesoporous silica nanoparticles for drug encapsulation and delivery

Novel multi-responsive drug delivery vehicles (CDs/PNVCL@HMSNs) were prepared by grafting amino-terminated poly (N-vinyl caprolactam) (PNVCL-NH₂) and amino-rich carbon dots (CDs) on the surface of aldehyde-functionalized HMSNs (HMSNs-CHO) via Schiff base reaction. The CDs were prepared from L-arginine and their surfaces were rich in guanidine. Doxorubicin (DOX) was loaded into the nanoparticles to form drug loaded vehicles (CDs/PNVCL@HMSNs-DOX) and the drug loading efficiency was 58.38%. The drug release behaviors of CDs/PNVCL@HMSNs-DOX showed temperature and pH responsiveness due to the poly (N-vinyl caprolactam) (PNVCL) and Schiff base bond. The high concentration of NO released in high concentration H₂O₂ of tumor site could induce tumor cells apoptosis. The multi-responsive CDs/PNVCL@HMSNs are intriguing drug carriers, which combine drug delivery and NO release in one.

A timescale-guided microfluidic synthesis of tannic acid-FeIII network nanocapsules of hydrophobic drugs

Many drugs are poorly water-soluble and suffer from low bioavailability. Metal-phenolic network (MPN), a hydrophilic thin layer such as tannic acid (TA)-FeIII network, has been recently used to encapsulate hydrophobic drugs to improve their bioavailability. However, it remains challenging to synthesize nanocapsules of a wide variety of hydrophobic drugs and to scale up the production in a continuous manner. Here, we present a microfluidic synthesis method to continuously produce TA-FeIII network nanocapsules of hydrophobic drugs. We hypothesize that nanocapsules can continuously be formed only when the microfluidic mixing timescale is shorter than the drug's nucleation timescale. The hypothesis was tested on three hydrophobic drugs - paclitaxel, curcumin, and vitamin D with varying solubility and nucleation timescale. The proposed mechanism was validated by successfully predicting the synthesis outcomes. The microfluidically-synthesized nanocapsules had well-controlled sizes of 100-200 nm, high drug loadings of 40-70%, and a throughput of up to 70 mg hr-1 per channel. The release kinetics, cellular uptake, and cytotoxicity were further evaluated. The effect of coating constituents on nanocapsule properties were characterized. Fe content of nanocapsules was reported. The stability of nanocapsules at different temperatures and pHs were also tested. The results suggest that the present method can provide a quantitative guideline to predictively design a continuous synthesis scheme for hydrophobic drug encapsulation via MPN nanocapsules with scaled-up capability.

Mesoporous Silica Nanoparticles as a Potential Nanoplatform: Therapeutic Applications and Considerations

With advances in nanotechnology, nanoparticles have come to be regarded as carriers of therapeutic agents and have been widely studied to overcome various diseases in the biomedical field. Among these particles, mesoporous silica nanoparticles (MSNs) have been investigated as potential nanocarriers to deliver drug molecules to various target sites in the body. This review introduces the physicochemical properties of MSNs and synthesis procedures of MSN-based nanoplatforms. Moreover, we focus on updating biomedical applications of MSNs as a carrier of therapeutic or diagnostic cargo and review clinical trials using silica-nanoparticle-based systems. Herein, on the one hand, we pay attention to the pharmaceutical advantages of MSNs, including nanometer particle size, high surface area, and porous structures, thus enabling efficient delivery of high drug-loading content. On the other hand, we look through biosafety and toxicity issues associated with MSN-based platforms. Based on many reports so far, MSNs have been widely applied to construct tissue engineering platforms as well as treat various diseases, including cancer, by surface functionalization or incorporation of stimuli-responsive components. However, even with the advantageous aspects that MSNs possess, there are still considerations, such as optimizing physicochemical properties or dosage regimens, regarding use of MSNs in clinics. Progress in synthesis procedures and scale-up production as well as a thorough investigation into the biosafety of MSNs would enable design of innovative and safe MSN-based platforms in biomedical fields.

Enhanced Immunogenic Cell Death by Apoptosis/Ferroptosis Hybrid Pathway Potentiates PD-L1 Blockade Cancer Immunotherapy

Even though chemotherapy regimens for treating cancer by inducing apoptosis are extensively utilized, their therapeutic effect is hindered by multiple limitations. Thus, a combination of other types of anticancer modalities is urgently needed. Herein, a tannic acid (TA)-Fe³⁺-coated doxorubicin (DOX)-encapsulated 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (ammonium salt) (DSPE-PEG) micelle (TFDD) for apoptosis/ferroptosis-mediated immunogenic cell death (ICD) is reported. By coating TA-Fe³⁺ on the surface of DOX-loaded micelles, an apoptotic agent and a ferroptotic agent are simultaneously delivered into the cancer cells and induce cell death. Furthermore, the intracellular oxidative environment generated by the apoptosis/ferroptosis hybrid pathway stimulates the endoplasmic reticulum (ER) and leads to ICD induction. The in vivo results show that the combination treatment of TFDD and anti-programmed death-ligand 1 antibodies (anti-PD-L1) considerably inhibits tumor growth and improves antitumor immunity by activating CD4⁺ and CD8⁺ T cells and decreasing the ratio of regulatory T cells (Treg) to CD4⁺ T cells. This study suggests that the apoptosis/ferroptosis-mediated ICD inducer may offer a potent strategy for enhanced cancer immunotherapy.

Organic single molecule based nano-platform for NIR-II imaging and chemo-photothermal synergistic treatment of tumor

Integrating multiple functionalities of near-infrared second window fluorescence imaging (NIR-Ⅱ FLI), chemotherapy, and photothermal treatment (PTT) into a single molecule is desirable but still a highly challenging task. Herein, inspired by the results that hyperthermia can enhance the cytotoxicity of some alkylating agents, we designed and synthesized the novel compound NM. By introducing nitrogen mustard's active moiety bis(2-chlorethyl)amino into Donor-Acceptor-Donor (D-A-D) electronic structure, the unimolecular system not only behaviored as a chemotherapeutic agent but also exhibited good PTT and NIR-Ⅱ FLI abilities. The hydrophobic agent NM was encapsulated by DSPE-PEG2000 to generate the nano-platform NM-NPs. The current study on in vitro and in vivo experiments indicated that NM-NPs make vessels visualize clearly in the NIR-II zone and achieve complete tumor elimination through chemo-photothermal synergistic treatment. Overall, this study provides a new innovative strategy for developing superior, versatile phototheranostics for cancer theranostics.

Rod-like hybrid nanomaterial with tumor targeting and pH-responsive for cancer chemo/photothermal synergistic therapy

The development of chemo/photothermal nanotherapeutic systems with excellent photothermal performance, stable drug loading, tumor targeting and strong membrane penetration still remains a challenge. To address this problem, herein a rod-like nanocomposite system (AuNR@FA-PR/PEG) forming from folic acid (FA) terminated carboxylated cyclodextrin (CD) pseudopolyrotaxane (FA-PR) and polyethylene glycol (PEG) modifying gold nanorods (AuNR) was reported. Cisplatin (CDDP) was loaded in AuNR@FA-PR/PEG via coordination bonds to prepare a rod-like pH-responsive nanosystem (AuNR@FA-PR/PEG/CDDP) with chemotherapy/photothermal therapy. The rod-like morphology of AuNR@FA-PR/PEG was characterized by transmission electron microscope. In vitro drug release experiments showed the pH-responsive of AuNR@FA-PR/PEG/CDDP. In vivo real-time imaging assays proved AuNR@FA-PR/PEG/CDDP could rapidly enrich in the tumor area and stay for a long time because of folate targeting and their rod-like morphology. In vivo photothermal imaging assays showed AuNR@FA-PR/PEG/CDDP excellent photothermal performance, the average temperature of tumor region could reach 63.5 °C after 10 min irradiation. In vitro and in vivo experiments also demonstrated that the combined therapy of chemotherapy and photothermal therapy had an outstandingly synergistic effect and improved the therapeutic efficacy comparing with chemotherapy and photothermal therapy alone. Therefore, the prepared rod-like AuNR@FA-PR/PEG/CDDP will provide a new strategy for the effective treatment of cancer.

Recent advances in nanoparticle-based photothermal therapy for breast cancer

Breast cancer is one of the most common cancers among women that is associated with high mortality. Conventional treatments including surgery, radiotherapy, and chemotherapy, which are not effective enough and have disadvantages such as toxicity and damage to healthy cells. Photothermal therapy (PTT) of cancer cells has been took great attention by researchers in recent years due to the use of light radiation and heat generation at the tumor site, which thermal ablation is considered a minimally invasive method for the treatment of breast cancer. Nanotechnology has opened up a new perspective in the treatment of breast cancer using PTT method. Through NIR light absorption, researchers applied various nanostructures because of their specific nature of penetrating and targeting tumor tissue, increasing the effectiveness of PTT, and combining it with other treatments. If PTT is used with common cancer treatments, it can dramatically increase the effectiveness of treatment and reduce the side effects of other methods. PTT performance can also be improved by hybridizing at least two different nanomaterials. Nanoparticles that intensely absorb light and increase the efficiency of converting light into heat can specifically kill tumors through hyperthermia of cancer cells. One of the main reasons that have increased the efficiency of nanoparticles in PTT is their permeability and durability effect and they can accumulate in tumor tissue. Targeted PTT can be provided by incorporating specific ligands to target receptors expressed on the surface of cancer cells on nanoparticles. These nanoparticles can specifically target cancer cells by maintaining the surface area and increasing penetration. In this study, we briefly introduce the performance of light therapy, application of metal nanoparticles, polymer nanoparticles, carbon nanoparticles, and hybrid nanoparticles for use in PTT of breast cancer.

Tannic acid: a crosslinker leading to versatile functional polymeric networks: a review

With the thriving of mussel-inspired polyphenol chemistry as well as the demand for low-cost analogues to polydopamine in adhesive design, tannic acid has gradually become a research focus because of its wide availability, health benefits and special chemical properties. As a natural building block, tannic acid could be used as a crosslinker either supramolecularly or chemically, ensuring versatile functional polymeric networks for various applications. Up to now, a systematic summary on tannic-acid-based networks has still been waiting for an update and outlook. In this review, the common features of tannic acid are summarized in detail, followed by the introduction of covalent and non-covalent crosslinking methods leading to various tannic-acid-based materials. Moreover, recent progress in the application of tannic acid composites is also summarized, including bone regeneration, skin adhesives, wound dressings, drug loading and photothermal conversion. Above all, we also provide further prospects concerning tannic-acid-crosslinked materials.