Long-lived enhanced magnetization-A practical metabolic MRI contrast material

Noninvasive tracking of biochemical processes in the body is paramount in diagnostic medicine. Among the leading techniques is spectroscopic magnetic resonance imaging (MRI), which tracks metabolites with an amplified (hyperpolarized) magnetization signal injected into the subject just before scanning. Traditionally, the brief enhanced magnetization period of these agents limited clinical imaging. We propose a solution based on amalgamating two materials-one having diagnostic-metabolic activity and the other characterized by robust magnetization retention. This combination slows the magnetization decay in the diagnostic metabolic probe, which receives continuously replenished magnetization from the companion material. Thus, it extends the magnetization lifetime in some of our measurements to beyond 4 min, with net magnetization enhanced by more than four orders of magnitude. This could allow the metabolic probes to remain magnetized from injection until they reach the targeted organ, improving tissue signatures in clinical imaging. Upon validation, this metabolic MRI technique promises wide-ranging clinical applications, including diagnostic imaging, therapeutic monitoring, and posttreatment surveillance.

Encapsulation of a small-molecule drug based on substituted 2-aminothiophenes in calcium carbonate carriers for therapy of melanoma

Although small molecule drugs are widely used in chemotherapy, their low bioavailability, low-concentrated dose in the tumor zone, systemic toxicity, and chemoresistance can significantly limit the therapeutic outcome. These drawbacks can be overcome by two main strategies: (i) development of novel therapeutic molecules with more significant antitumor activity than currently available drugs and (ii) loading chemotherapeutic agents into drug delivery systems. In this study, we aimed to encapsulate a highly prospective small molecule drug based on substituted 2-aminothiophene (2-AT) into calcium carbonate (CaCO3) microparticles (MPs) for the treatment of melanoma tumors. In particular, we have optimized the encapsulation of 2-AT into MPs (2-AT@MPs), studied drug release efficiency, investigated cellular uptake, and evaluated in vivo biodistribution and tumor inhibition efficiency. In vitro results revealed that 2-AT@MPs were able to penetrate into tumor spheroids, leading to prolonged release of 2-AT. By performing intratumoral injection of 2-AT@MPs we observed significant melanoma suppressions in murine models: ∼0.084 cm3 for 2-AT@MPs at a dose of 0.4 g kg-1versus ∼1.370 cm3 for untreated mice. In addition, the 2-AT@MPs showed negligible in vivo toxicity towards major organs such as heart, lung, liver, kidney, and spleen. Thus, this work provided an efficient strategy for the improved chemotherapy of solid tumors by using an encapsulated form of small molecule drugs.

Surface Modification of Mesoporous Silica Nanoparticles for Application in Targeted Delivery Systems of Antitumour Drugs

The problem of tumour therapy has attracted the attention of many researchers for many decades. One of the promising strategies for the development of new dosage forms to improve oncology treatment efficacy and minimise side effects is the development of nanoparticle-based targeted transport systems for anticancer drugs. Among inorganic nanoparticles, mesoporous silica deserves special attention due to its outstanding surface properties and drug-loading capability. This review analyses the various factors affecting the cytotoxicity, cellular uptake, and biocompatibility of mesoporous silica nanoparticles (MSNs), constituting a key aspect in the development of safe and effective drug delivery systems. Special attention is paid to technological approaches to chemically modifying MSNs to alter their surface properties. The stimuli that regulate drug release from nanoparticles are also discussed, contributing to the effective control of the delivery process in the body. The findings emphasise the importance of modifying MSNs with different surface functional groups, bio-recognisable molecules, and polymers for their potential use in anticancer drug delivery systems.

Cytokine Therapy Combined with Nanomaterials Participates in Cancer Immunotherapy

Immunotherapy has gradually become an emerging treatment modality for tumors after surgery, radiotherapy, and chemotherapy. Cytokine therapy is a promising treatment for cancer immunotherapy. Currently, there are many preclinical theoretical bases to support this treatment strategy and a variety of cytokines in clinical trials. When cytokines were applied to tumor immunotherapy, it was found that the efficacy was not satisfactory. As research on tumor immunity has deepened, the role of cytokines in the tumor microenvironment has been further explored. Meanwhile, the study of nanomaterials in drug delivery has been fully developed in the past 20 years. Researchers have begun to think about the possibility of combining cytokine therapy with nanomaterials. Herein, we briefly review various nano-delivery systems that can directly deliver cytokines or regulate the expression of cytokines in tumor cells for cancer immunotherapy. We further discussed the feasibility of the combination of various therapies. We looked forward to the main challenges, opportunities, and prospects of tumor immunotherapy with multiple cytokines and a nano-delivery system.

Preparation and characterization of sodium alginate/phosphate-stabilized amorphous calcium carbonate nanocarriers and their application in the release of curcumin

Phosphate-stabilized amorphous calcium carbonate (ACCP) has excellent biocompatibility, bioactivity, and biodegradability, and can be easily synthesized and stored. However, unmodified ACCP, as a controlled drug release carrier, decomposes rapidly in an acidic environment and highly depends on the system's pH value, which can not meet the need for long-term release of active substances, thus limiting its application scope. To realize the specific pH responsiveness of ACCP nanoparticles, we designed and synthesized monodisperse sodium alginate/ACCP (Alginate/ACCP) composite nanoparticles in this paper. After ultrasonic treatment, nanoparticles with an average particle size less than 200 nm could form stable water dispersion that could be dispersed for up to 10 d. Based on the specific pH sensitivity of sodium alginate, the drug-controlled release performance of composite nanoparticles and the therapeutic effect of drug-loaded nanoparticles on A549 cancer cells were studied. The results indicated that under the same pH condition, the curcumin (Cur) release rate of composite nanoparticles gradually decreased with sodium alginate addition. When the dosage of sodium alginate was 1.0 mg ml^-1, the cumulative drug release rate of nanoparticles in 40 h was only about 35%. Besides, the drug-loaded nanoparticles showed the excellent killing ability of cancer cells, and the survival rate of cancer cells decreased in a concentration-dependent manner. Therefore, through reasonable optimization design, we can synthesize composite nanoparticles with excellent sustained-release properties to provide a new strategy for cancer cells' long-term treatment.

A comprehensive review on alginate-based delivery systems for the delivery of chemotherapeutic agent: Doxorubicin

Doxorubicin (DOX), an anthracycline drug, is widely used for the treatment of several cancers like osteosarcoma, cervical carcinoma, breast cancer, etc. DOX lacks target specificity; thereby it also affects normal cells thus resulting in several side-effects. A drug delivery system (DDS) can be used to deliver the drug in a controlled and sustained manner at a targeted site within the body. Various DDS like nanoemulsions, polymeric nanoparticles, and liposomes are used for loading DOX. Alginate, a polysaccharide is widely used for fabricating DDS due to its biodegradable and bio-compatible properties. Alginates, in combination with other biomaterials, have been extensively used as a novel drug delivery carrier for DOX. Alginate provides a platform for drug delivery in different forms like hydrogels, nanogels, nanoparticles, microparticles, graphene oxide systems, magnetic systems, etc. Herein, we briefly describe alginate in combination with other materials as a nanocarrier for targeted delivery of DOX for anti-cancer treatment.

Immune-adjuvant activity of lentinan-modified calcium carbonate microparticles on a H5N1 vaccine

In recent years, the high prevalence of avian influenza viruses especially H₅N₁ subtype isolated from poultry and human has become a major public health concern. Vaccination is still a major strategy for preventing H₅N₁ infections. Lentinan (LNT), a β-1,3-glucohexaose with β-1,6-branches, is extracted from Lentinus edodes and has been extensively studied for its immunoenhancement effects. In this study, we synthesized and characterized calcium carbonate (CaCO₃) microparticles which modified with LNT as an adjuvant for H₅N₁ vaccine and investigated their ability to enhance immune responses. We prepared spherical and uniform CaCO₃-LNT microparticles with a mean hydrodynamic size was around 2 μm. The H₅N₁ antigen-loaded CaCO₃-LNT particles were injected into mice to evaluate their effectiveness as an adjuvant for H₅N₁ vaccines. The results demonstrated that CaCO₃-LNT/H₅N₁ significantly enhanced the expression of MHC-II and CD86 in lymph node dendritic cells, and increased the ratio of CD4⁺ to CD8⁺ T cells in lymphocytes. Moreover, CaCO₃-LNT/H₅N₁ surprisingly increased the HI titers and induced the secretion of IgG subtypes (IgG1 and IgG2b) and Th-associated cytokines (TNF-α, IFN-γ and IL-4) in immunized mice. Therefore, by combining with the immunostimulatory activity of LNT and the drug/antigen delivery capabilities of CaCO₃, the CaCO₃-LNT/H₅N₁ could induce a stronger cellular and humoral immune response and could be a potential adjuvant for the H₅N₁ vaccine.

Preparation of lentinan-calcium carbonate microspheres and their application as vaccine adjuvants

Adjuvants improve vaccine potency by enhancing immunogenicity and sustaining long-term immune responses. Lentinan (LNT), a β-1,3-glucohexaose with β-1,6-branches, is extracted from the mushroom Lentinus edodes and functions as an effective immunostimulatory drug. Previous studies have demonstrated the adjuvant activity of calcium carbonate (CaCO₃) microspheres as well as their use as antigen delivery systems. In this study, we successfully loaded CaCO₃ microspheres with LNT and evaluated their physicochemical characteristics prior to the adsorption of ovalbumin. Our experimental results demonstrated that LNT-CaCO₃ significantly enhanced lymphocyte proliferation, and boosted the frequency of CD69 + B cells and the ratio of CD4+ to CD8 + T cells in spleen lymphocytes. Moreover, LNT-CaCO₃ unexpectedly induced the secretion of IgG and Th-associated cytokines (IL-2, IL-4, IFN-γ, and TNF-α) in immunized mice. Therefore, LNT-CaCO₃ microspheres induce robust cellular and humoral immune responses and have potential utility as vaccine delivery systems.

Polysaccharide-based nanoparticles for co-loading mitoxantrone and verapamil to overcome multidrug resistance in breast tumor

The aim of this study was to evaluate the potential of polyelectrolyte complex nanoparticles (PENPs) based on hyaluronic acid/chitosan hydrochloride (HA/HCS) for co-loading mitoxantrone (MTO) and verapamil (VRP) to overcome multidrug resistance in breast tumors. PENPs co-loaded with MTO and VRP (MTO-VRP-PENPs) were affected by the method of preparation, molecular weight of HA, mass ratios and initial concentrations of HA/HCS, pH, and drug quantities. Optimized MTO-VRP-PENPs were ~209 nm in size with a zeta potential of approximately -24 mV. Encapsulation efficiencies (%) of MTO and VRP were 98.33%±0.27% and 44.21%±8.62%, respectively. MTO and VRP were successfully encapsulated in PENPs in a molecular or amorphous state. MTO-VRP-PENPs showed significant cytotoxicity in MCF-7/ADR cells in contrast to MTO-loaded PENPs (MTO-PENPs). The reversal index of MTO-VRP-PENPs was 13.25 and 10.33 times greater than that of the free MTO and MTO-PENPs, respectively. In conclusion, MTO-VRP-PENPs may serve as a promising carrier to overcome tumor drug resistance.

Facile fabrication of varisized calcium carbonate microspheres as vaccine adjuvants

HBsAg loaded CaCO₃ microspheres with various diameters were fabricated via different mixing strategies and 1 μm particles has the strongest immune responses as vaccine adjuvant.

Cryo scanning probe nanotomography study of the structure of alginate microcarriers

Nanostructure of microparticles of decellularized rat liver ECM on spherical alginate hydrogel microcarriers is analyzed by cryo scanning probe nanotomography.