Bovine Serum Albumin-Templated Synthesis of Manganese-Doped Copper Selenide Nanoparticles for Boosting Targeted Delivery and Synergistic Photothermal and Photodynamic Therapy

Rationalized landscape on protein-based cancer nanomedicine: Recent progress and challenges

The clinical advancement of protein-based nanomedicine has revolutionized medical professionals' perspectives on cancer therapy. Protein-based nanoparticles have been exploited as attractive vehicles for cancer nanomedicine due to their unique properties derived from naturally biomacromolecules with superior biocompatibility and pharmaceutical features. Furthermore, the successful translation of Abraxane™ (paclitaxel-based albumin nanoparticles) into clinical application opened a new avenue for protein-based cancer nanomedicine. In this mini-review article, we demonstrate the rational design and recent progress of protein-based nanoparticles along with their applications in cancer diagnosis and therapy from recent literature. The current challenges and hurdles that hinder clinical application of protein-based nanoparticles are highlighted. Finally, future perspectives for translating protein-based nanoparticles into clinic are identified.

Expanding Mn2+ loading capacity of BSA via mild non-thermal denaturing and cross-linking as a tool to maximize the relaxivity of water protons

Development of nanoparticles (NPs) serving as contrast enhancing agents in MRI requires a combination of high contrasting effect with the biosafety and hemocompatibility. This work demonstrates that bovine serum albumin (BSA) molecules bound to paramagnetic Mn2+ ions are promising building blocks of such NPs. The desolvation-induced denaturation of BSA bound with Mn2+ ions followed by the glutaraldehyde-facilitated cross-linking provides the uniform in size 102.0 ± 0.7 nm BSA-based nanoparticles (BSA-NPs) loaded with Mn2+ ions, which are manifested in aqueous solutions as negatively charged spheres with high colloid stability. The optimal loading of Mn2+ ions into BSA-NPs provides maximum values of longitudinal and transverse relaxivity at 98.9 and 133.6 mM-1 s-1, respectively, which are among the best known from the literature. The spin trap EPR method indicates that Mn2+ ions bound to BSA-NPs exhibit poor catalytic activity in the Fenton-like reaction. On the contrary, the presence of BSA-NPs has an antioxidant effect by preventing the accumulation of hydroxyl radicals produced by H2O2. The NPs exhibit remarkably low hemolytic activity and hemagglutination can be avoided at concentrations lower than 110 μM. Thus, BSA-NPs bound with Mn2+ ions are promising candidates for combining high contrast effect with biosafety and hemocompatibility.

Aqueous Solution Enhanced Room Temperature Phosphorescence through Coordination-Induced Structural Rigidity

Achieving aqueous solution enhanced room temperature phosphorescence (RTP) is critical for the applications of RTP materials in solution phase, but which faces a great challenge. Herein, for the first time, a strategy of coordination-induced structural rigidity is proposed to achieve enhanced quantum efficiency of aluminum/scandium-doped phosphorescent microcubes (Al/Sc-PMCs) in aqueous solution. The Al/Sc-PMCs in a dry state exhibit a nearly invisible blue RTP. However, they emit a strong RTP emission in aqueous solution with a RTP intensity increase of up to 22.16-times, which is opposite to common solution-quenched RTP. The RTP enhancement mechanism is attributed to the abundant metal sites (Al3+ and Sc3+ ions) on the Al/Sc-PMCs surface that can tightly combine with water molecules through the strong coordination. Subsequently, these coordinated water molecules as the bridging agent can bind with surface groups by hydrogen bonding interaction, thereby rigidifying chemical groups and inhibiting their motions, resulting in the transition from the nonradiative decay to the radiative decay, which greatly enhances the RTP efficiency of the Al/Sc-PMCs. This work not only develops a coordination rigidity strategy to enhance RTP intensity in aqueous solution, but also constructs a phosphorescent probe to achieve reliable and accurate determination of analyte in complex biological matrices.

A pH-responsive supramolecular hydrogel encapsulating a CuMnS nanoenzyme catalyst for synergistic photothermal-photodynamic-chemodynamic therapy of tumours

Traditional cancer therapies no longer meet the current demand for cancer precision therapy and personalized treatment and it's essential to develop new therapeutic modalities as well as to investigate new combination anti-tumor mechanisms. Therefore, amphiphilic prodrug polymer chains linking methoxy poly(ethylene glycol) (mPEG) and cinnamaldehyde (CA) with adipic acid dihydrazide (ADH) as the pH-responsive center were designed and synthesized, which could self-assemble into PAC micelles in aqueous solution. A supramolecular hydrogel was formed based on the host-guest interaction between α-cyclodextrin (α-CD) and PAC micelles. Polyetherimide (PEI) modified copper manganese sulfide nanoenzyme catalysts (PCMS NPs) were prepared by a solvothermal method, which could be uniformly dispersed in the hydrogel to form a composite supramolecular hydrogel (PCMS@PAC/α-CD Gel). Under an acidic tumor environment, pH-responsive hydrazone bonds were broken, resulting in the slow release of CA and the amplification of hydrogen peroxide (H2O2) levels. PCMS NPs exerted peroxidase (POD)-like activity and catalase (CAT)-like activity, which could convert H2O2 into hydroxyl radicals (˙OH) and oxygen (O2) to alleviate intra-tumor hypoxia and induce apoptosis, while exerting glutathione oxidase (GPX)-like activity to consume glutathione (GSH) to further enhance the effect of chemodynamic therapy (CDT). Under near-infrared light (NIR) irradiation, PCMS NPs exhibited an excellent photothermal conversion performance, which could rapidly increase the temperature of tumor cells to above 42 °C for photothermal therapy (PTT) and convert O2 to a superoxide anion (˙O2-) by exerting oxidase (OXD)-like activity for photodynamic therapy (PDT). It was demonstrated by in vitro and in vivo experiments that the PCMS@PAC/α-CD Gel was highly cytotoxic to cancer cells and could effectively inhibit tumor growth, indicating the potential for applications in the fields of biomedicine and smart materials.

Metal selenide nanomaterials for biomedical applications

Metal selenide nanomaterials have received enormous attention as they possess diverse compositions, microstructures, and properties. The combination of selenium with various metallic elements gives the metal selenide nanomaterials distinctive optoelectronic and magnetic properties, such as strong near-infrared absorption, excellent imaging properties, good stability, and long in vivo circulation. This makes metal selenide nanomaterials advantageous and promising for biomedical applications. This paper summarizes the research progress in the last five years in the controlled synthesis of metal selenide nanomaterials in different dimensions and with different compositions and structures. Then we discuss how surface modification and functionalization strategies are well-suited for biomedical fields, including tumor therapy, biosensing, and antibacterial biological applications. The future trends and issues of metal selenide nanomaterials in the biomedical field are also discussed.

Flexible human serum albumin nanocapsules to enhance drug delivery and cellular uptake for photodynamic/chemo cancer therapy

As a non-invasive cancer treatment, photodynamic therapy (PDT) has great applications in superficial tumors because of its high selectivity and low cumulative toxicity. However, the poor tumor-targeting ability and short blood circulation time of conventional photosensitizers (PSs) limit the efficacy of PDT to some extent. In this study, we synthesized flexible hollow human serum albumin (HHSA) and loaded photosensitizer Chlorin e6 (Ce6) and the chemotherapeutic drug Doxorubicin (DOX) for synergistic cancer therapy. HHSA can enhance drug delivery and cellular uptake through targeting gp60 and SPARC receptors and unique flexible hollow structures. The TEM images show that HHSA possesses distinct flexible hollow structures, as well as good monodispersity and deformability. After loading Ce6 and DOX, HHSA@Ce6-DOX displays better therapeutic effects than HHSA@DOX on the growth of 4T1 breast cancers without irradiation. Remarkably, it has a significantly higher therapeutic effect (relative cell activity: 45% vs. 74%) than HHSA@Ce6 under 660 nm irradiation. Furthermore, the excellent biocompatibility of HHSA@Ce6-DOX has been proved both in vitro and in vivo, indicating that it has a promising future in synergistic tumor treatments.

Flexible Hollow Human Serum Albumin-Catalase Nanocapsules with High Accumulation and Uptake Ability for Enhanced Photodynamic Therapy

Introduction

Photodynamic therapy (PDT) has attracted increasing attention for tumor treatment because of its minimal invasiveness and specific spatiotemporal selectivity. However, insufficient tumor accumulation and low cellular uptake of photosensitizers limit its therapeutic efficacy.

Methods

In this study, flexible hollow human serum albumin/catalase nanocapsules (HSA/CATs) were created using a core-assisted protein-coating method and combined with the photosensitizer chlorin e6 (HSA/CAT@Ce6) for PDT.

Results and Discussion

Transmission electron microscopy (TEM) images demonstrate that HSA/CAT nanocapsules are flexible, with a uniform diameter (310 nm) and a well-defined hollow structure. Thanks to their flexibility, HSA/CAT@Ce6 nanocapsules show a higher cellular uptake than rigid nanoparticles. The nanocapsules effectively generate reactive oxygen species (ROS) in 4T1 cells because of their high cellular uptake and catalytic capacity, remarkably enhancing their in vitro PDT efficacy. In addition, the in vivo tumor accumulation of HSA/CAT@Ce6 nanocapsules is significantly larger than that of rigid nanoparticles and Ce6, meaning they are highly effective in tumor cell ablation. This demonstrates that our flexible nanoplatform holds great promise for enhancing PDT of tumor.

Protein-Caged Nanoparticles: A Promising Nanomedicine Against Cancer

Cancer is a severe threat to human wellness. A broad range of nanoparticles (NPs) have been developed to treat cancer. Given their safety profile, natural biomolecules such as protein-based NPs (PNPs) are promising substitutes for synthetic NPs that are currently used in drug delivery systems. In particular, PNPs have diverse characteristics and are monodisperse, chemically and genetically changeable, biodegradable, and biocompatible. To promote their application in clinical settings, PNPs must be precisely fabricated to fully exploit their advantages. This review highlights the different types of proteins that can be used to produce PNPs. Additionally, the recent applications of these nanomedicines and their therapeutic benefits against cancer are explored. Several future research directions that can facilitate the clinical application of PNPs are suggested.

Protein corona: challenges and opportunities for targeted delivery of nanomedicines

INTRODUCTION

Targeted drug delivery has been widely explored as a promising way to improve the performance of nanomedicines. However, protein corona formed on the nano-surface represents a major issue that has great impacts on the in vivo fate of targeting nanomedicines, which has been overlooked in the past. With the increasing understanding of protein corona in the recent decade, many efforts have been made to improve targeting efficacy.

AREAS COVERED

In this review, we briefly summarize insights of targeted delivery systems inspired by protein corona, and discuss the promising strategies to regulate protein corona for better targeting.

EXPERT OPINION

The interaction between nanomedicines and endogenous proteins brings great uncertainty and challenges, but it also provides great opportunities for the development of targeting nanomedicines at the same time. With increasing understanding of protein corona, the strategies to regulate protein corona pave new avenues for the development of targeting nanomedicines.

Multifunctional MnCuInSe/ZnS quantum dots for bioimaging and photodynamic therapy

In this work, manganese (Mn)-doped CuInSe quantum dots (QDs) with a ZnS passivation layer (MnCuInSe/ZnS) have been synthesized via a one-pot microwave-assisted hydrothermal reaction using glutathione (GSH) as a stabilizer. The MnCuInSe/ZnS core-shell QDs combine magnetic resonance imaging (MRI), excitation-dependent red emission, and reactive oxygen radical generation functions, in which regulation of Mn2+ incorporation leads to synergistic imaging and therapeutic modalities. The MnCuInSe/ZnS QDs exhibit high colloidal and photochemical stability in simulated media and at different pH values. An r2/r1 ratio of 9.99 was calculated from MRI studies suggesting their potential application as dual-modal imaging agents. Based on in vitro tests on Hela, B16, and HepG2 cell lines, it is apparent that MnCuInSe/ZnS QDs impose no significant cytotoxicity in the dark, while they can efficiently generate singlet oxygen radicals for photodynamic therapy of cancers, killing more than 80% of B16 cells within 5 min of laser irradiation (671 nm, 1 W cm−2). Furthermore, in vitro fluorescence imaging and cellular internalization of QDs are examined to visualize cellular uptake and in situ ROS generation. Therefore, this research exemplifies a new set of multifunctional chalcogenide QDs for theranostic applications.

Green Synthesis of Mn + Cu Bimetallic Nanoparticles Using Vinca rosea Extract and Their Antioxidant, Antibacterial, and Catalytic Activities

This article outlines the preparation of manganese-doped copper nanoparticles (Mn + Cu NPs) using Vinca rosea (L.) leaf extract as a convenient and environmentally friendly substance. UV–vis, FT–IR, XRD, SEM–EDAX, and DLS instrumental techniques were employed to describe the physical and chemical properties of synthesized V. rosea extract-mediated Vr-Mn + Cu NPs. The synthesized Vr-Mn + Cu NPs were observed to be monodispersed and spherical, with an average size of 412 nm. The plant extract includes a variety of phytochemical components. The Vr-Mn + Cu NPs also have potential antioxidant and antibacterial properties against selected pathogens. The green synthesized Vr-Mn + Cu NPs showed a maximum inhibition zone of 16.33 ± 0.57 mm against E. coli. For dye degradation, MR, EBT, and MO showed the highest degradation percentage capabilities with Vr-Mn + Cu NP-based adsorbents, which were determined to be 78.54 ± 0.16, 87.67 ± 0.06, and 69.79 ± 0.36. The results clearly show that biosynthesized Vr-Mn + Cu NPs may be employed as an antioxidant, antibacterial, photocatalytic dye degradation, and catalytic agent, as well as being ecologically benign.

Wide visible-range activatable fluorescence ZnSe:Eu3+/Mn2+@ZnS quantum dots: local atomic structure order and application as a nanoprobe for bioimaging

The development of QDs-based fluorescent bionanoprobe for cellular imaging fundamentally relies upon the precise knowledge of particle-cell interaction, optical properties of QDs inside and outside of the cell, movement of a particle in and out of the cell, and the fate of particle. We reported engineering and physicochemical characterization of water-dispersible Eu³⁺/Mn²⁺ co-doped ZnSe@ZnS core/shell QDs and studied their potential as a bionanoprobe for biomedical applications, evaluating their biocompatibility, fluorescence behaviour by CytoViva dual mode fluorescence imaging, time-dependent uptake, endocytosis and exocytosis in RAW 264.7 macrophages. The oxidation state and local atomic structure of the Eu dopant studied by X-ray absorption fine structure (XAFS) analysis manifested that the Eu³⁺ ions occupied sites in both ZnSe and ZnS lattices for the core/shell QDs. A novel approach was developed to relieve the excitation constraint of wide bandgap ZnSe by co-incorporation of Eu³⁺/Mn²⁺ codopants, enabling the QDs to be excited at a wide UV-visible range. The QDs displayed tunable emission colors by a gradual increase in Eu³⁺ concentration at a fixed amount of Mn²⁺, systematically enhancing the Mn²⁺ emission intensity via energy transfer from the Eu³⁺ to Mn²⁺ ion. The ZnSe:Eu³⁺/Mn²⁺@ZnS QDs presented high cell viability above 85% and induced no cell activation. The detailed analyses of QDs-treated cells by dual mode fluorescence CytoViva microscopy confirmed the systematic color-tunable fluorescence and its intensity enhances as a function of incubation time. The QDs were internalized by the cells predominantly via macropinocytosis and other lipid raft-mediated endocytic pathways, retaining an efficient amount for 24 h. The unique color tunability and consistent high intensity emission make these QDs useful for developing a multiplex fluorescent bionanoprobe, activatable in wide-visible region.

Modulating the Delivery of 5-Fluorouracil to Human Colon Cancer Cells Using Multifunctional Arginine-Coated Manganese Oxide Nanocuboids with MRI Properties

5-Fluorouracil (5-FU) is one of the most prescribed drugs and the major component of chemotherapy for the treatment of colorectal cancer. In this study, we have designed arginine-functionalized manganese oxide nanocuboids (Arg@MNCs) for the effective delivery of 5-FU to colon cancer cells. Arginine was used as multifunctional agent to provide stability to MNCs, achieve high drug loading, control the release of loaded drug, and improve delivery to cancer cells. The synthesized Arg@MNCs were characterized by DLS, TEM, XRD, FTIR, XPS, TGA, and VSM analysis. The structural and morphological analysis by TEM showed cuboid-shaped MNCs with average particle size ∼15 nm. Biodegradation studies indicated that the Arg@MNCs were degraded at endolyosomal pH in 24 h while remaining stable at physiological pH. Hemolytic toxicity studies revealed the safety and nontoxic nature of the prepared MNCs. 5-FU-loaded Arg@MNCs showed significant control over the release of 5-FU, decrease in the hemolytic toxicity of loaded 5-FU but higher in vitro anticancer activity against HCT 116 and SW480 human colon cancer cells. Importantly, both the bare MNCs and Arg@MNCs showed excellent T1 and T2MR relaxivity under 3.0 T MRI scanner. Thus, the nanostructures developed in this study, i.e., 5-FU-Arg@MNCs could overcome the issues of both MNCs (stability) and 5-FU (low drug loading and nonspecificity) and may be used as a multifunctional theranostic nanocarrier for colon cancer treatment.