Gas-generating mesoporous silica nanoparticles with rapid localized drug release for enhanced chemophotothermal tumor therapy

Ultrasound-responsive nanoparticles for nitric oxide release to inhibit the growth of breast cancer

Gas therapy represents a promising strategy for cancer treatment, with nitric oxide (NO) therapy showing particular potential in tumor therapy. However, ensuring sufficient production of NO remains a significant challenge. Leveraging ultrasound-responsive nanoparticles to promote the release of NO is an emerging way to solve this challenge. In this study, we successfully constructed ultrasound-responsive nanoparticles, which consisted of poly (D, L-lactide-co-glycolic acid) (PLGA) nanoparticles, natural L-arginine (LA), and superparamagnetic iron oxide nanoparticles (SPIO, Fe3O4 NPs), denote as Fe3O4-LA-PLGA NPs. The Fe3O4-LA-PLGA NPs exhibited effective therapeutic effects both in vitro and in vivo, particularly in NO-assisted antitumor gas therapy and photoacoustic (PA) imaging properties. Upon exposure to ultrasound irradiation, LA and Fe3O4 NPs were rapidly released from the PLGA NPs. It was demonstrated that LA could spontaneously react with hydrogen peroxide (H2O2) present in the tumor microenvironment to generate NO for gas therapy. Concurrently, Fe3O4 NPs could rapidly react with H2O2 to produce a substantial quantity of reactive oxygen species (ROS), which can oxidize LA to further facilitate the release of NO. In conclusion, the proposed ultrasound-responsive NO delivery platform exhibits significant potential in effectively inhibiting the growth of breast cancer.

Ultrasound-Responsive Lipid Nanoplatform with Nitric Oxide and Carbon Monoxide Release for Cancer Sono-Gaso-Therapy

Local gas therapy is emerging as a potential cancer treatment approach due to its specificity as gas-containing molecules can be packed into a nanodelivery system to release the corresponding gaseous molecules around the tumor site upon a suitable stimulus. Single-gas therapy has been reported, while synergistic dual-gas therapy has rarely been reported. Herein, we report a dual-gas-containing nanoplatform for synergistic cancer gasotherapy upon ultrasound irradiation. First, a robust ultrasound-responsive lipid-coated nanosystem was prepared with suitable particle size and characteristics. A low-intensity ultrasound (1.25 W/cm2) was found to simultaneously modulate carbon monoxide (CO) and nitric oxide (NO) release from the nanosystem in media and CT26 colon cancer cells for efficient therapeutic effect. The intracellular release promoted the overgeneration of reactive oxygen species (ROS) and triggered cancer cell apoptosis synergistically. The in vivo test demonstrated that the optimal dual-gas-containing formulation efficiently inhibited tumor growth (by ∼87%) at relatively low doses upon ultrasound irradiation (1.25 W/cm2, 5 min). This therapeutic efficacy shows that the current responsive lipid-coated delivery system has potential for ultrasound-triggered dual-gas therapy of both superficially and deeply seated cancers.

Functionalization of and through Melanin: Strategies and Bio-Applications

A unique feature of nanoparticles for bio-application is the ease of achieving multi-functionality through covalent and non-covalent functionalization. In this way, multiple therapeutic actions, including chemical, photothermal and photodynamic activity, can be combined with different bio-imaging modalities, such as magnetic resonance, photoacoustic, and fluorescence imaging, in a theragnostic approach. In this context, melanin-related nanomaterials possess unique features since they are intrinsically biocompatible and, due to their optical and electronic properties, are themselves very efficient photothermal agents, efficient antioxidants, and photoacoustic contrast agents. Moreover, these materials present a unique versatility of functionalization, which makes them ideal for the design of multifunctional platforms for nanomedicine integrating new functions such as drug delivery and controlled release, gene therapy, or contrast ability in magnetic resonance and fluorescence imaging. In this review, the most relevant and recent examples of melanin-based multi-functionalized nanosystems are discussed, highlighting the different methods of functionalization and, in particular, distinguishing pre-functionalization and post-functionalization. In the meantime, the properties of melanin coatings employable for the functionalization of a variety of material substrates are also briefly introduced, especially in order to explain the origin of the versatility of melanin functionalization. In the final part, the most relevant critical issues related to melanin functionalization that may arise during the design of multifunctional melanin-like nanoplatforms for nanomedicine and bio-application are listed and discussed.

pH-Dependent Behavior of Novel 5-FU Delivery System in Environmental Conditions Comparable to the Gastro-Intestinal Tract

A biogenic carrier for 5-fluorouracil (5-FU) loading and subsequent tableting as a new drug formulation for slow release has been proposed using the biomineral from blue crab carapace. Due to its highly ordered 3D porous nanoarchitecture, the biogenic carbonate carrier could achieve increased effectiveness in colorectal cancer cure provided that the formulation would successfully pass through the gastric acid conditions. Following the recently proven viability of the concept by demonstrating the slow release of the drug from the carrier using the highly sensitive SERS technique, here we investigated the 5-FU release from the composite tablet drug in pH conditions replicating the gastric environment. The released drug from the tablet was studied in solutions with three relevant pH values, pH 2, pH 3, and pH 4. The 5-FU SERS spectral signature for each pH value was used to build calibration curves for quantitative SERS analysis. The results suggested a similarly slow-releasing pattern in acid pH environments to that in neutral conditions. Although biogenic calcite dissolution was expected in acid conditions, the X-ray diffraction and Raman spectroscopy showed preservation of calcite mineral along with the monohydrocalcite during acid solution exposure for two hours. The total released amount in a time course of seven hours, however, was lower in acidic pH solutions, with a maximum fraction of ~40% of the total amount of loaded drug, for pH 2, as opposed to ~80% for neutral values. Nonetheless, these results clearly prove that the novel composite drug retains its slow-releasing character in environmental conditions compatible with the gastrointestinal pH and that it is a viable and biocompatible alternative for oral delivery of anticancer drug to reach the lower gastro-intestinal tract.

Organic and inorganic nanomedicine for combination cancer therapies

In many cases, a single mode of cancer therapy shows limited efficacy in treating complex and heterogeneous tumors. To improve cancer treatment, combining chemo-, photodynamic-, photothermal-, radio-, and immunotherapy is clinically recognized. When different therapeutic treatments are combined, they often show synergetic effects that further improve therapeutic outcomes. In this review, we introduce nanoparticle (NP)-based combination cancer therapies that use organic and inorganic NPs. Liposomes, polymers, and exosomes can be prepared with amphiphilic properties, high physical stability, and low immune response to treat cancers in a multimodal way. Inorganic NPs, including upconversion, plasmonic, and mesoporous silica NPs, have emerged as a new technology for photodynamic-, photothermal-, and immunotherapy. These NPs can simultaneously carry multiple drug molecules and deliver them efficiently to tumor tissue, as demonstrated in many studies. In addition to reviewing recent advances in organic and inorganic NPs used in combination therapy for cancers, we also discuss their rational design and the outlook for future nanomedicine development.

Nanomedicine-based multimodal therapies: Recent progress and perspectives in colon cancer

Colon cancer has attracted much attention due to its annually increasing incidence. Conventional chemotherapeutic drugs are unsatisfactory in clinical application because of their lack of targeting and severe toxic side effects. In the past decade, nanomedicines with multimodal therapeutic strategies have shown potential for colon cancer because of their enhanced permeability and retention, high accumulation at tumor sites, co-loading with different drugs, and comb-ination of various therapies. This review summarizes the advances in research on various nanomedicine-based therapeutic strategies including chemotherapy, radiotherapy, phototherapy (photothermal therapy and photodynamic therapy), chemodynamic therapy, gas therapy, and immunotherapy. Additionally, the therapeutic mechanisms, limitations, improvements, and future of the above therapies are discussed.

Recent advances in mesoporous silica nanoparticle-based targeted drug-delivery systems for cancer therapy

Targeted drug-delivery systems are a growing research topic in tumor treatment. In recent years, mesoporous silica nanoparticles (MSNs) have been extensively studied and applied in noninvasive and biocompatible drug-delivery systems for tumor therapy due to their outstanding advantages, which include high surface area, large pore volume, tunable pore size, easy surface modification and stable framework. The advances in the application of MSNs for anticancer drug targeting are covered and highlighted in this review, and the challenges and prospects of MSN-based targeted drug-delivery systems are discussed. This review provides new insights for researchers interested in targeted drug-delivery systems against cancer.

Recent developments in mesoporous polydopamine-derived nanoplatforms for cancer theranostics

Polydopamine (PDA), which is derived from marine mussels, has excellent potential in early diagnosis of diseases and targeted drug delivery owing to its good biocompatibility, biodegradability, and photothermal conversion. However, when used as a solid nanoparticle, the application of traditional PDA is restricted because of the low drug-loading and encapsulation efficiencies of hydrophobic drugs. Nevertheless, the emergence of mesoporous materials broaden our horizon. Mesoporous polydopamine (MPDA) has the characteristics of a porous structure, simple preparation process, low cost, high specific surface area, high light-to-heat conversion efficiency, and excellent biocompatibility, and therefore has gained considerable interest. This review provides an overview of the preparation methods and the latest applications of MPDA-based nanodrug delivery systems (chemotherapy combined with radiotherapy, photothermal therapy combined with chemotherapy, photothermal therapy combined with immunotherapy, photothermal therapy combined with photodynamic/chemodynamic therapy, and cancer theranostics). This review is expected to shed light on the multi-strategy antitumor therapy applications of MPDA-based nanodrug delivery systems.

An Update on Mesoporous Silica Nanoparticle Applications in Nanomedicine

The efficient and safe delivery of therapeutic drugs, proteins, and nucleic acids are essential for meaningful therapeutic benefits. The field of nanomedicine shows promising implications in the development of therapeutics by delivering diagnostic and therapeutic compounds. Nanomedicine development has led to significant advances in the design and engineering of nanocarrier systems with supra-molecular structures. Smart mesoporous silica nanoparticles (MSNs), with excellent biocompatibility, tunable physicochemical properties, and site-specific functionalization, offer efficient and high loading capacity as well as robust and targeted delivery of a variety of payloads in a controlled fashion. Such unique nanocarriers should have great potential for challenging biomedical applications, such as tissue engineering, bioimaging techniques, stem cell research, and cancer therapies. However, in vivo applications of these nanocarriers should be further validated before clinical translation. To this end, this review begins with a brief introduction of MSNs properties, targeted drug delivery, and controlled release with a particular emphasis on their most recent diagnostic and therapeutic applications.