A Drug-Free Tumor Therapy Strategy: Cancer-Cell-Targeting Calcification

Metabolic heterogeneity in tumor microenvironment - A novel landmark for immunotherapy

The surrounding non-cancer cells and tumor cells that make up the tumor microenvironment (TME) have various metabolic rhythms. TME metabolic heterogeneity is influenced by the intricate network of metabolic control within and between cells. DNA, protein, transport, and microbial levels are important regulators of TME metabolic homeostasis. The effectiveness of immunotherapy is also closely correlated with alterations in TME metabolism. The response of a tumor patient to immunotherapy is influenced by a variety of variables, including intracellular metabolic reprogramming, metabolic interaction between cells, ecological changes within and between tumors, and general dietary preferences. Although immunotherapy and targeted therapy have made great strides, their use in the accurate identification and treatment of tumors still has several limitations. The function of TME metabolic heterogeneity in tumor immunotherapy is summarized in this article. It focuses on how metabolic heterogeneity develops and is regulated as a tumor progresses, the precise molecular mechanisms and potential clinical significance of imbalances in intracellular metabolic homeostasis and intercellular metabolic coupling and interaction, as well as the benefits and drawbacks of targeted metabolism used in conjunction with immunotherapy. This offers insightful knowledge and important implications for individualized tumor patient diagnosis and treatment plans in the future.

Modulation of Metal Homeostasis for Cancer Therapy

Metal ions such as iron, zinc, copper, manganese, and calcium are essential for normal cellular processes, including DNA synthesis, enzyme activity, cellular signaling, and oxidative stress regulation. When the balance of metal homeostasis is disrupted, it can lead to various pathological conditions, including cancer. Thus, understanding the role of metal homeostasis in cancer has led to the development of anti-tumor strategies that specifically target the metal imbalance. Up to now, diverse small molecule-based chelators, ionophores, metal complexes, and metal-based nanomaterials have been developed to restore the normal balance of metals or exploit the dysregulation for therapeutic purposes. They hold great promise in inhibiting tumor growth, preventing metastasis, and enhancing the effectiveness of existing cancer therapies. In this review, we aim to provide a comprehensive summary of the strategies employed to modulate the homeostasis of iron, zinc, copper, manganese, and calcium for cancer therapy. Their modulation mechanisms for metal homeostasis are succinctly described, and their recent applications in the field of cancer therapy are discussed. At the end, the limitations of these approaches are addressed, and potential avenues for future developments are explored.

In Situ Mitochondrial Biomineralization for Drug-Free Cancer Therapy

The common clinical chemotherapy often brings serious side effects to patients, mainly due to the off-target and leakage of toxic drugs. However, this is fatal for some specific clinical tumors, such as brain tumors and neuroma. This study performs a drug-free approach by encapsulating black phosphorus (BP) and calcium peroxide (CaO2) in liposomes with surface-modified triphenylphosphonium (BCLT) to develop mitochondria targeting calcification for cancer therapy without damaging normal cells. BCLT preferentially accumulates inside tumor mitochondria and then is activated by near-infrared (NIR) laser irradiation to produce abundant PO4 3- and Ca2+ to accelerate in situ mitochondrial mineralization, leading to mitochondrial dysfunction and cancer cell death. More importantly, both PO4 3- and Ca2+ are essential components of metabolism in the body, and random gradient diffusion or premature leakage does not cause damage to adjacent normal cells. This achievement promises to be an alternative to conventional chemotherapy in clinical practice for many specific tumor types.

Cell Membrane as A Promising Therapeutic Target: From Materials Design to Biomedical Applications

The cell membrane is a crucial component of cells, protecting their integrity and stability while facilitating signal transduction and information exchange. Therefore, disrupting its structure or impairing its functions can potentially cause irreversible cell damage. Presently, the tumor cell membrane is recognized as a promising therapeutic target for various treatment methods. Given the extensive research focused on cell membranes, it is both necessary and timely to discuss these developments, from materials design to specific biomedical applications. This review covers treatments based on functional materials targeting the cell membrane, ranging from well-known membrane-anchoring photodynamic therapy to recent lysosome-targeting chimaeras for protein degradation. The diverse therapeutic mechanisms are introduced in the following sections: membrane-anchoring phototherapy, self-assembly on the membrane, in situ biosynthesis on the membrane, and degradation of cell membrane proteins by chimeras. In each section, we outline the conceptual design or general structure derived from numerous studies, emphasizing representative examples to understand advancements and draw inspiration. Finally, we discuss some challenges and future directions in membrane-targeted therapy from our perspective. This review aims to engage multidisciplinary readers and encourage researchers in related fields to advance the fundamental theories and practical applications of membrane-targeting therapeutic agents.

Organismal Function Enhancement through Biomaterial Intervention

Living organisms in nature, such as magnetotactic bacteria and eggs, generate various organic-inorganic hybrid materials, providing unique functionalities. Inspired by such natural hybrid materials, researchers can reasonably integrate biomaterials with living organisms either internally or externally to enhance their inherent capabilities and generate new functionalities. Currently, the approaches to enhancing organismal function through biomaterial intervention have undergone rapid development, progressing from the cellular level to the subcellular or multicellular level. In this review, we will concentrate on three key strategies related to biomaterial-guided bioenhancement, including biointerface engineering, artificial organelles, and 3D multicellular immune niches. For biointerface engineering, excess of amino acid residues on the surfaces of cells or viruses enables the assembly of materials to form versatile artificial shells, facilitating vaccine engineering and biological camouflage. Artificial organelles refer to artificial subcellular reactors made of biomaterials that persist in the cytoplasm, which imparts cells with on-demand regulatory ability. Moreover, macroscale biomaterials with spatiotemporal regulation characters enable the local recruitment and aggregation of cells, denoting multicellular niche to enhance crosstalk between cells and antigens. Collectively, harnessing the programmable chemical and biological attributes of biomaterials for organismal function enhancement shows significant potential in forthcoming biomedical applications.

Calcium-based biomaterials: Unveiling features and expanding applications in osteosarcoma treatment

Calcium, an indispensable element in bone tissues, plays a crucial role in various cellular processes involved in cancer progression. Its ubiquitous yet spatially distinct distribution in the body presents an opportunity to target calcium homeostasis as a novel strategies for cancer treatment, with specific advantages in osteosarcoma therapy. In this comprehensive review, we retrospect the calcium biology intersected with cancer progression, highlight the unveiling features of calcium-based biomaterials in regulating both bone homeostasis and cancer development. We also provide an overview of recent breakthroughs in cancer therapy that leverage calcium biomaterials, showcasing their potential to serve as versatile, customizable platforms for osteosarcoma treatment and as reservoirs for supporting bone reconstruction.

Design and synthesis of bioinspired nanomaterials for biomedical application

Natural materials and bioprocesses provide abundant inspirations for the design and synthesis of high-performance nanomaterials. In the past several decades, bioinspired nanomaterials have shown great potential in the application of biomedical fields, such as tissue engineering, drug delivery, and cancer therapy, and so on. In this review, three types of bioinspired strategies for biomedical nanomaterials, that is, inspired by the natural structures, biomolecules, and bioprocesses, are mainly introduced. We summarize and discuss the design concepts and synthesis approaches of various bioinspired nanomaterials along with their specific roles in biomedical applications. Additionally, we discuss the challenges for the development of bioinspired biomedical nanomaterials, such as mechanical failure in wet environment, limitation in scale-up fabrication, and lack of deep understanding of biological properties. It is expected that the development and clinical translation of bioinspired biomedical nanomaterials will be further promoted under the cooperation of interdisciplinary subjects in future. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Research progress of biomineralization for the diagnosis and treatment of malignant tumors

Malignant tumors have long been a prominent subject of research in order to foster innovation and advancement in diagnostic and therapeutic modalities. However, the current clinical treatment of malignant tumors faces significant limitations. In light of recent advancements, the World Health Organization (WHO) officially designated malignant tumors as a chronic disease in 2006. Accordingly, maintaining the tumor in a stable state and minimizing its detrimental impact on the body emerges as a potentially advantageous approach to oncological treatment. One emerging strategy that has garnered substantial attention from the academic community is the construction of a biomineralized layer surrounding solid tumors for tumor blockade therapy. This innovative approach is regarded as safe, effective, and long-lasting. This review aims to provide a comprehensive summary of the advancements made in the utilization of biomineralization for the diagnosis and treatment of malignant tumors.

10-hydroxycamptothecin-loaded starch-based microcapsules with the stepwise responsive release strategy for targeted controlled release

Controlled and accurate drug release at the target site have been the focus of research. Especially in cancer therapy, economical, convenient and accurate delivery strategies could help to reduce the toxic effects of drugs on normal tissues and improve drug availability. In the study, glutathione (GSH)-responsive microcapsules (FA-RSMCs) were prepared by sonochemical method based on thiolated modified starch. 10-Hydroxycamptothecin (HCPT) was designed as a reactive oxygen species (ROS)-responsive polyprodrug (polyHCPT), which was loaded into the core of the microcapsules to obtain stepwise released drug delivery carriers. In the tumor microenvironment, FA-RSMCs first triggered GSH-responsive cleavage to release polyHCPT, followed by ROS-responsive cleavage of polyHCPT to release intact HCPT drug molecules. The results of experiments in simulated tumor microenvironment showed that FA-RSMCs exhibited good cascade-response release properties in vitro. It exhibited good anti-tumor ability and protection of normal cells in cytotoxicity in vitro. This strategy enhanced the accuracy and safety of targeted delivery of HCPT via microcapsules, which has potential for clinical application.

Bio-Inspired Nanomaterials for Micro/Nanodevices: A New Era in Biomedical Applications

Exploring bio-inspired nanomaterials (BINMs) and incorporating them into micro/nanodevices represent a significant development in biomedical applications. Nanomaterials, engineered to imitate biological structures and processes, exhibit distinctive attributes such as exceptional biocompatibility, multifunctionality, and unparalleled versatility. The utilization of BINMs demonstrates significant potential in diverse domains of biomedical micro/nanodevices, encompassing biosensors, targeted drug delivery systems, and advanced tissue engineering constructs. This article thoroughly examines the development and distinctive attributes of various BINMs, including those originating from proteins, DNA, and biomimetic polymers. Significant attention is directed toward incorporating these entities into micro/nanodevices and the subsequent biomedical ramifications that arise. This review explores biomimicry's structure-function correlations. Synthesis mosaics include bioprocesses, biomolecules, and natural structures. These nanomaterials' interfaces use biomimetic functionalization and geometric adaptations, transforming drug delivery, nanobiosensing, bio-inspired organ-on-chip systems, cancer-on-chip models, wound healing dressing mats, and antimicrobial surfaces. It provides an in-depth analysis of the existing challenges and proposes prospective strategies to improve the efficiency, performance, and reliability of these devices. Furthermore, this study offers a forward-thinking viewpoint highlighting potential avenues for future exploration and advancement. The objective is to effectively utilize and maximize the application of BINMs in the progression of biomedical micro/nanodevices, thereby propelling this rapidly developing field toward its promising future.

Calcium Phosphate-Based Nanomaterials: Preparation, Multifunction, and Application for Bone Tissue Engineering

Calcium phosphate is the main inorganic component of bone. Calcium phosphate-based biomaterials have demonstrated great potential in bone tissue engineering due to their superior biocompatibility, pH-responsive degradability, excellent osteoinductivity, and similar components to bone. Calcium phosphate nanomaterials have gained more and more attention for their enhanced bioactivity and better integration with host tissues. Additionally, they can also be easily functionalized with metal ions, bioactive molecules/proteins, as well as therapeutic drugs; thus, calcium phosphate-based biomaterials have been widely used in many other fields, such as drug delivery, cancer therapy, and as nanoprobes in bioimaging. Thus, the preparation methods of calcium phosphate nanomaterials were systematically reviewed, and the multifunction strategies of calcium phosphate-based biomaterials have also been comprehensively summarized. Finally, the applications and perspectives of functionalized calcium phosphate biomaterials in bone tissue engineering, including bone defect repair, bone regeneration, and drug delivery, were illustrated and discussed by presenting typical examples.

Bioinspired Tumor-Targeting and Biomarker-Activatable Cell-Material Interfacing System Enhances Osteosarcoma Treatment via Biomineralization

Osteosarcoma is an aggressive malignant tumor that primarily develops in children and adolescents. The conventional treatments for osteosarcoma often exert negative effects on normal cells, and chemotherapeutic drugs, such as platinum, can lead to multidrug resistance in tumor cells. Herein, this work reports a new bioinspired tumor-targeting and enzyme-activatable cell-material interface system based on DDDEEK-pY-phenylboronic acid (SAP-pY-PBA) conjugates. Using this tandem-activation system, this work selectively regulates the alkaline phosphatase (ALP) triggered anchoring and aggregation of SAP-pY-PBA conjugates on the cancer cell surface and the subsequent formation of the supramolecular hydrogel. This hydrogel layer can efficiently kill osteosarcoma cells by enriching calcium ions from tumor cells and forming a dense hydroxyapatite layer. Owing to the novel antitumor mechanism, this strategy neither hurts normal cells nor causes multidrug resistance in tumor cells, thereby showing an enhanced tumor treatment effect than the classical antitumor drug, doxorubicin (DOX). The outcome of this research demonstrates a new antitumor strategy based on a bioinspired enzyme-responsive biointerface combining supramolecular hydrogels with biomineralization.

Acidity-Triggered Transformable Polypeptide Self-Assembly to Initiate Tumor-Specific Biomineralization

Biomineralization is a normal physiological process that includes nucleation, crystal growth, phase transformation, and orientation evolution. Notably, artificially induced biomineralization in the tumor tissue has emerged as an unconventional yet promising modality for malignancy therapy. However, the modest ion-chelating capabilities of carboxyl-containing biomineralization initiators lead to a deficient blockade, thus compromising antitumor efficacy. Herein, a biomineralization-inducing nanoparticle (BINP) is developed for blockade therapy of osteosarcoma. BINP is composed of dodecylamine-poly((γ-dodecyl-l-glutamate)-co-(l-histidine))-block-poly(l-glutamate-graft-alendronate) and combines a cytomembrane-insertion moiety, a tumor-microenvironment (TME)-responsive component, and an ion-chelating motif. After intravenous injection into osteosarcoma-bearing mice, BINP responds to the acidic TME to expose the dodecyl group on the surface of the expanded nanoparticles, facilitating their cytomembrane insertion. Subsequently, the protruding bisphosphonic acid group triggers continuous ion deposition to construct a mineralized barrier around the tumor, which blocks substance exchange between the tumor and surrounding normal tissues. The BINP-mediated blockade therapy displays tumor inhibition rates of 59.3% and 52.1% for subcutaneous and orthotopic osteosarcomas, respectively, compared with the Control group. In addition, the suppression of osteoclasts by the alendronate moiety alleviates bone dissolution and further inhibits pulmonary metastases. Hence, the BINP-initiated selective biomineralization provides a promising alternative for clinical osteosarcoma therapy.

Organized mineralized cellulose nanostructures for biomedical applications

Cellulose is the most abundant naturally-occurring polymer, and possesses a one-dimensional (1D) anisotropic crystalline nanostructure with outstanding mechanical robustness, biocompatibility, renewability and rich surface chemistry in the form of nanocellulose in nature. Such features make cellulose an ideal bio-template for directing the bio-inspired mineralization of inorganic components into hierarchical nanostructures that are promising in biomedical applications. In this review, we will summarize the chemistry and nanostructure characteristics of cellulose and discuss how these favorable characteristics regulate the bio-inspired mineralization process for manufacturing the desired nanostructured bio-composites. We will focus on uncovering the design and manipulation principles of local chemical compositions/constituents and structural arrangement, distribution, dimensions, nanoconfinement and alignment of bio-inspired mineralization over multiple length-scales. In the end, we will underline how these cellulose biomineralized composites benefit biomedical applications. It is expected that this deep understanding of design and fabrication principles will enable construction of outstanding structural and functional cellulose/inorganic composites for more challenging biomedical applications.

Thermosensitive Liposomal Nanoplatform Based on Metal-Free Phthalocyanine with Copper(II)-Regulated Photoactivities

This work reports the development of a multifunctional thermosensitive liposomal nanoplatform (PcS4 @Lip-FA) based on a metal-free phthalocyanine modified with tetra-sulfonates (PcPS4 ), which exhibited photodynamic and photothermal activities simultaneously. Upon irradiation with a near infrared laser, thermosensitive PcS4 @Lip-FA could release PcS4 as a result of the local hyperthermia of PcS4 . Interestingly, PcS4 could easily chelate with Cu2+ , leading to the enhancement of photothermal activity and decrease of photodynamic activity. In addition, in vivo fluorescence imaging revealed that PcS4 @Lip-FA could selectively accumulate in tumor tissue of H22 tumor-bearing mice after tail vein injection, and exhibited a significant anticancer phototherapeutic effect, with a tumor inhibition rate of 83.5 %. Therefore, PcPS4 @Lip-FA has realized fluorescence imaging-guided combined cancer treatment, providing a promising multifunctional nanoplatform for cancer diagnostics and therapy.

Advances in single-cell nanoencapsulation and applications in diseases

Single-cell nanoencapsulation is a method of coating the surface of single cell with nanomaterials. In the early 20th century, with the introduction of various types of organic or inorganic nano-polymer materials, the selection of cell types, and the functional modification of the outer coating, this technology has gradually matured. Typical preparation methods include interfacial polycondensation, complex condensation, spray drying, microdroplet ejection, and layer-by-layer (LbL) self-assembly. The LbL assembly technology utilises nanomaterials with opposite charges deposited on cells by strong interaction (electrostatic interaction) or weak interaction (hydrogen bonding, hydrophobic interaction), which drives compounds to spontaneously form films with complete structure, stable performance and unique functions on cells. According to the needs of the disease, choosing appropriate cell types and biocompatible and biodegradable nanomaterials could achieve the purpose of promoting cell proliferation, immune isolation, reducing phagocytosis of the reticuloendothelial system, prolonging the circulation time in vivo, and avoiding repeated administration. Therefore, encapsulated cells could be utilised in various biomedical fields, such as cell catalysis, biotherapy, vaccine manufacturing and antitumor therapy. This article reviews cell nanoencapsulation therapies for diseases, including the various cell sources used, nanoencapsulation technology and the latest advances in preclinical and clinical research.

Controlling dielectric loss of biodegradable black phosphorus nanosheets by iron-ion-modification for imaging-guided microwave thermoacoustic therapy

Microwave-induced thermoacoustic (TA) technology transforms microwave into acoustic waves useable for imaging or therapy, based on the power density of the pulsed microwaves. Exploiting nanoparticles with high biocompatibility, safe metabolism, and high microwave-acoustic conversion is the key to the clinical translational application of TA therapy. In this paper, we proposed a biodegradable and high microwave absorption nanoparticle for TA therapy. The proposed nanoparticle uses iron ions to regulate the atomic defects of biodegradable black phosphorus (BP) nanosheets to augment the dielectric loss. The iron ions adsorb with the lone pair electrons indicated of BP through the conjugated π bond to increase the permanent electric dipoles. With pulsed microwave irradiation, a large number of electric dipoles are repeatedly polarized, causing instantaneous temperature rise and then generating significant TA shockwave via TA cavitation effect. TA shockwave can disrupt cell membranes in situ to trigger programmed apoptosis and produce precise anti-tumor effects. Additionally, the nanoparticle-mediated TA process generates images that deliver valuable data, such as the size, shape, and location of the tumor for treatment planning and monitoring. This hypothesis has been tested in vitro and in vivo with animal models of glioblastoma tumors. The experimental results demonstrate the high theragnostic efficiency for tumor inhibition and TA imaging, exhibiting low systemic cytotoxicity and good biocompatibility after systemic administration. The established BP-based nanoparticle with both safe metabolism and high microwave-acoustic conversion is a promising candidate for precision theranostics without obvious side effects.

Connecting Calcium-Based Nanomaterials and Cancer: From Diagnosis to Therapy

As the indispensable second cellular messenger, calcium signaling is involved in the regulation of almost all physiological processes by activating specific target proteins. The importance of calcium ions (Ca²⁺) makes its "Janus nature" strictly regulated by its concentration. Abnormal regulation of calcium signals may cause some diseases; however, artificial regulation of calcium homeostasis in local lesions may also play a therapeutic role. "Calcium overload," for example, is characterized by excessive enrichment of intracellular Ca²⁺, which irreversibly switches calcium signaling from "positive regulation" to "reverse destruction," leading to cell death. However, this undesirable death could be defined as "calcicoptosis" to offer a novel approach for cancer treatment. Indeed, Ca²⁺ is involved in various cancer diagnostic and therapeutic events, including calcium overload-induced calcium homeostasis disorder, calcium channels dysregulation, mitochondrial dysfunction, calcium-associated immunoregulation, cell/vascular/tumor calcification, and calcification-mediated CT imaging. In parallel, the development of multifunctional calcium-based nanomaterials (e.g., calcium phosphate, calcium carbonate, calcium peroxide, and hydroxyapatite) is becoming abundantly available. This review will highlight the latest insights of the calcium-based nanomaterials, explain their application, and provide novel perspective. Identifying and characterizing new patterns of calcium-dependent signaling and exploiting the disease element linkage offer additional translational opportunities for cancer theranostics.

Prospecting Cellular Gold Nanoparticle Biomineralization as a Viable Alternative to Prefabricated Gold Nanoparticles

Gold nanoparticles (GNPs) have shown considerable potential in a vast number of biomedical applications. However, currently there are no clinically approved injectable GNP formulations. Conversely, gold salts have been used in the clinic for nearly a century. Further, there is evidence of GNP formation in patients treated with gold salts (i.e., chrysiasis). Recent reports evaluating this phenomenon in human cells and in murine models indicate that the use of gold ions for in situ formation of theranostic GNPs could greatly improve the delivery within dense biological tissues, increase efficiency of intracellular gold uptake, and specificity of GNP formation within cancer cells. These attributes in combination with safe clinical application of gold salts make this process a viable strategy for clinical translation. Here, the first summary of the current knowledge related to GNP biomineralization in mammalian cells is provided along with critical assessment of potential biomedical applications of this newly emergent field.

Shielding Ferritin with a Biomineralized Shell Enables Efficient Modulation of Tumor Microenvironment and Targeted Delivery of Diverse Therapeutic Agents

Ferritin (Fn) is considered a promising carrier for targeted delivery to tumors, but the successful application in vivo has not been fully achieved yet. Herein, strong evidence is provided that the Fn receptor is expressed in liver tissues, resulting in an intercept effect in regards to tumor delivery. Building on these observations, a biomineralization technology is rationally designed to shield Fn using a calcium phosphate (CaP) shell, which can improve the delivery performance by reducing Fn interception in the liver while re-exposing it in acidic tumors. Moreover, the selective dissolution of the CaP shell not only neutralizes the acidic microenvironment but also induces the intratumoral immunomodulation and calcification. Upon multiple cell line and patient-derived xenografts, it is demonstrated that the elaboration of the highly flexible Fn@CaP chassis by loading a chemotherapeutic drug into the Fn cavity confers potent antitumor effects, and additionally encapsulating a photosensitizer into the outer shell enables a combined chemo-photothermal therapy for complete suppression of advanced tumors. Altogether, these results support Fn@CaP as a new nanoplatform for efficient modulation of the tumor microenvironment and targeted delivery of diverse therapeutic agents.

Multifunctional Nanosystems with Enhanced Cellular Uptake for Tumor Therapy

Rapid development of nanotechnology provides promising strategies in biomedicine, especially in tumor therapy. In particular, the cellular uptake of nanosystems is not only a basic premise to realize various biomedical applications, but also a fatal factor for determining the final therapeutic effect. Thus, a systematic and comprehensive summary is necessary to overview the recent research progress on the improvement of nanosystem cellular uptake for cancer treatment. According to the process of nanosystems entering the body, they can be classified into three categories. The first segment is to enhance the accumulation and permeation of nanosystems to tumor cells through extracellular microenvironment stimulation. The second segment is to improve cellular internalization from extracellular to intracellular via active targeting. The third segment is to enhance the intracellular retention of therapeutics by subcellular localization. The major factors in the delivery can be utilized to develop multifunctional nanosystems for strengthening the tumor therapy. Ultimately, the key challenges and prospective in the emerging research frontier are thoroughly outlined. This review is expected to provide inspiring ideas, promising strategies and potential pathways for developing advanced anticancer nanosystems in clinical practice.

Biomineralized Prussian Blue Nanotherapeutic for Enhanced Cancer Photothermal Therapy

Photothermal therapy is a promising tumor ablation technique that converts light into heat energy to kill cancer cells. Prussian blue (PB), a biocompatible photothermal reagent, has been widely explored for...

Prussian Blue/Calcium Peroxide Nanocomposites-Mediated Tumor Cell Iron Mineralization for Treatment of Experimental Lung Adenocarcinoma

Current lung cancer diagnosis methods encounter delayed visual confirmation of tumor foci and low-resolution metrics in imaging findings, which delays the early treatment of tumors. Here, we developed a potent lung cancer imaging and treatment strategy centered around a nanotransformational concept of tumor iron mineralization in situ, which employs Prussian blue/calcium peroxide nanocomposites as a precursor. The resultant iron mineralization in tumor cells greatly facilitates the early and differential diagnosis of lung carcinoma from benign nodules via medical imaging, meanwhile introducing oxidative stress to activate the cellular apoptosis and ferroptosis pathways, resulting in inhibition of the malignant behavior of tumor cells. Tumor-microenvironment-triggered iron mineralization enables integration of the detection and prevention of tumor metastasis at its early stages with no assistance of toxic drugs, which offers a potential solution for the precise management of lung cancer with ideal outcomes.

Engineered osteoclasts as living treatment materials for heterotopic ossification therapy

Osteoclasts (OCs), the only cells capable of remodeling bone, can demineralize calcium minerals biologically. Naive OCs have limitations for the removal of ectopic calcification, such as in heterotopic ossification (HO), due to their restricted activity, migration and poor adhesion to sites of ectopic calcification. HO is the formation of pathological mature bone within extraskeletal soft tissues, and there are currently no reliable methods for removing these unexpected calcified plaques. In the present study, we develop a chemical approach to modify OCs with tetracycline (TC) to produce engineered OCs (TC-OCs) with an enhanced capacity for targeting and adhering to ectopic calcified tissue due to a broad affinity for calcium minerals. Unlike naive OCs, TC-OCs are able to effectively remove HO both in vitro and in vivo. This achievement indicates that HO can be reversed using modified OCs and holds promise for engineering cells as "living treatment agents" for cell therapy.

Calcium-Based Biomineralization: A Smart Approach for the Design of Novel Multifunctional Hybrid Materials

Biomineralization consists of a complex cascade of phenomena generating hybrid nano-structured materials based on organic (e.g., polymer) and inorganic (e.g., hydroxyapatite) components. Biomineralization is a biomimetic process useful to produce highly biomimetic and biocompatible materials resembling natural hard tissues such as bones and teeth. In detail, biomimetic materials, composed of hydroxyapatite nanoparticles (HA) nucleated on an organic matrix, show extremely versatile chemical compositions and physical properties, which can be controlled to address specific challenges. Indeed, different parameters, including (i) the partial substitution of mimetic doping ions within the HA lattice, (ii) the use of different organic matrices, and (iii) the choice of cross-linking processes, can be finely tuned. In the present review, we mainly focused on calcium biomineralization. Besides regenerative medicine, these multifunctional materials have been largely exploited for other applications including 3D printable materials and in vitro three-dimensional (3D) models for cancer studies and for drug testing. Additionally, biomineralized multifunctional nano-particles can be involved in applications ranging from nanomedicine as fully bioresorbable drug delivery systems to the development of innovative and eco-sustainable UV physical filters for skin protection from solar radiations.

Calcium Peroxide-Based Nanosystem with Cancer Microenvironment-Activated Capabilities for Imaging Guided Combination Therapy via Mitochondrial Ca2+ Overload and Chemotherapy

Mitochondria are the "power plant" of the cell, providing a constant source of energy, and are involved in a variety of intracellular signaling pathways. Among these pathways, Ca²⁺ homeostasis is closely related to the normal function of mitochondria. By destroying the Ca²⁺ steady state of mitochondria and disrupting their multiple cellular activities, tumor cell killing can be achieved. In addition, the presence of an intracellular oxidative stress state triggers the closure of cellular calcium channels, which leads to intracellular Ca²⁺ retention and enrichment. We designed a targeted and tumor microenvironment (TME)-responsive CaO₂-based nanosystem that can selectively target cancer cells for pH-controlled degradation and drug release, alter cellular physiological mechanisms by disrupting Ca²⁺ homeostasis in an artificial manner, and introduce mitochondrial Ca²⁺ excess-mediated apoptosis. Meanwhile, the production of Ca(OH)₂ will raise the pH of the microenvironment and subsequently promote the oxidation process of glutathione by H₂O₂ released from CaO₂ degradation, achieving the goal of remodeling TME. Moreover, calcium overload of tumor cells and calcification of tissues can both inhibit tumor growth and act as a contrast agent for computed tomography imaging.

Calcification-Based Cancer Diagnosis and Therapy

In nature, calcium deposition is a common biological process in mammals that shapes mechanical structures and creates the functions of bones and teeth, and causes calculi formation. Spontaneous tumor calcification and regional lymph node calcification in colorectal cancer, lung cancer, and glioblastoma have been proven to be benign prognostic factors in the clinic. In line with this concept, we introduce the idea and lead the compound development of artificially inducing bionic calcification around the surface of cancer cells. This process is shown to have excellent effects in the inhibition of growth and metastases of cervical, breast, and lung tumors, as well as superb performance in early-stage diagnosis. Therefore, we predict that this concept may open the door for cancer targeting calcification therapy and diagnosis and provide an outlook for a new avenue in anticancer drug development.

A Decade of Advances in Single-Cell Nanocoating for Mammalian Cells

Strategic advances in the single-cell nanocoating of mammalian cells have noticeably been made during the last decade, and many potential applications have been demonstrated. Various cell-coating strategies have been proposed via adaptation of reported methods in the surface sciences and/or materials identification that ensure the sustainability of labile mammalian cells during chemical manipulation. Here an overview of the methodological development and potential applications to the healthcare sector in the nanocoating of mammalian cells made during the last decade is provided. The materials used for the nanocoating are categorized into polymers, hydrogels, polyphenolic compounds, nanoparticles, and minerals, and the corresponding strategies are described under the given set of materials. It also suggests, as a future direction, the creation of the cytospace system that is hierarchically composed of the physically separated but mutually interacting cellular hybrids.

Inorganic material based macrophage regulation for cancer therapy: basic concepts and recent advances

Macrophages with the M1 phenotype are a type of immune cell with exciting prospects for cancer therapy; however, when these macrophages infiltrate into tumours, many of them are induced by the tumour microenvironment to transform into the M2 type, which can enable tumour defence against external therapeutic strategies, assisting in tumour development. Macrophages have strong plasticity and functional heterogeneity, and their phenotypic transformation is complex and still poorly understood in relation to cancer therapy. Recent material advances in inorganic nanomaterials, especially inorganic elements in vivo, have accelerated the development of macrophage regulation-based cancer treatments. This review summarizes the basics of recent research on macrophage phenotype transformation and discusses the current challenges in macrophage type regulation. Then, the current achievements involving inorganic material-based macrophage regulation and the related anticancer effects of induced macrophages and their extracellular secretions are reviewed systematically. Importantly, inorganic nanomaterial-based macrophage phenotype regulation is flexible and can be adapted for different types of cancer therapies, presenting a possible novel approach for the generation of immune materials for cancer therapy.

Polymer-Based Drug-Free Therapeutics for Anticancer, Anti-Inflammatory, and Antibacterial Treatment

This paper summarizes the area of biomedicinal polymers, which serve as nanomedicines even though they do not contain any anticancer or antiinflammatory drugs. These polymer nanomedicines with unique design are in the literature highlighted as a novel class of therapeutics called "drug-free macromolecular therapeutics." Their therapeutic efficacy is based on the tailored multiple presentations of biologically active vectors, i.e., peptides, oligopeptides, or oligosaccharides. Thus, they enable, for example, to directly induce the apoptosis of malignant cells by the crosslinking of surface slowly internalizing receptors, or to deplete the efficacy of tumor-associated proteins. The precise biorecognition of natural binding motifs by multiple vectors on the polymer construct remains the crucial part in the designing of these drug-free nanomedicines. Here, the rationales, designs, synthetic approaches, and therapeutic potential of drug-free macromolecular therapeutics consisting of various active vectors are described in detail. Recent developments and achievements for namely B-cell lymphoma treatment, Gal-3-positive tumors, inflammative liver injury, and bacterial treatment are reviewed and highlighted. Finally, a possible future prospect within this highly exciting new field of nanomedicine research is presented.

Photocatalysis-mediated drug-free sustainable cancer therapy using nanocatalyst

Drug therapy unavoidably brings toxic side effects and drug content-limited therapeutic efficacy although many nanocarriers have been developed to improve them to a certain extent. In this work, a concept of drug-free therapeutics is proposed and defined as a therapeutic methodology without the use of traditional toxic drugs, without the consumption of therapeutic agents during treatment but with the inexhaustible therapeutic capability to maximize the benefit of treatment, and a Z-scheme SnS1.68-WO2.41 nanocatalyst is developed to achieve near infrared (NIR)-photocatalytic generation of oxidative holes and hydrogen molecules for realizing combined hole/hydrogen therapy by the drug-free therapeutic strategy. Without the need of any drug and other therapeutic agent assistance, the nanocatalyst oxidizes/consumes intratumoral over-expressed glutathione (GSH) by holes and simultaneously generates hydrogen molecules in a lasting and controllable way under NIR irradiation. Mechanistically, generated hydrogen molecules and GSH consumption inhibit cancer cell energy and destroy intratumoral redox balance, respectively, to synergistically damage DNA and induce tumor cell apoptosis. High efficacy and biosafety of combined hole/hydrogen therapy of tumors are achieved by the nanocatalyst. The proposed catalysis-based drug-free therapeutic strategy breaks a pathway to realize high efficacy and low toxicity of cancer treatment.

Novel nanomaterial-organism hybrids with biomedical potential

Instinctive hierarchically biomineralized structures of various organisms, such as eggs, algae, and magnetotactic bacteria, afford extra protection and distinct performance, which endow fragile organisms with a tenacious ability to adapt and survive. However, spontaneous formation of hybrid materials is difficult for most organisms in nature. Rapid development of chemistry and materials science successfully obtained the combinations of organisms with nanomaterials by biomimetic mineralization thus demonstrating the reproduction of the structures and functions and generation of novel functions that organisms do not possess. The rational design of biomaterial-organism hybridization can control biological recognition, interactions, and metabolism of the organisms. Thus, nanomaterial-organism hybrids represent a next generation of organism engineering with great potential biomedical applications. This review summarizes recent advances in material-directed organism engineering and is mainly focused on biomimetic mineralization technologies and their outstanding biomedical applications. Three representative types of biomimetic mineralization are systematically introduced, including external mineralization, internal mineralization, and genetic engineering mineralization. The methods involving hybridization of nanomaterials and organisms based on biomimetic mineralization strategies are described. These strategies resulted in applications of various nanomaterial-organism hybrids with multiplex functions in cell engineering, cancer treatment, and vaccine improvement. Unlike classical biological approaches, this material-based bioregulation is universal, effective, and inexpensive. In particular, instead of traditional medical solutions, the integration of nanomaterials and organisms may exploit novel strategies to solve current biomedical problems. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

A Macromolecular Drug for Cancer Therapy via Extracellular Calcification

Cancer chemotherapy typically relies on drug endocytosis and inhibits tumor cell proliferation via intracellular pathways; however, severe side effects may arise. In this study, we performed a first attempt to develop macromolecular-induced extracellular chemotherapy involving biomineralization by absorbing calcium from the blood through a new type of drug, polysialic acid conjugated with folate (folate-polySia), which selectively induces biogenic mineral formation on tumor cells and results in the pathological calcification of tumors. The macromolecule-initiated extracellular calcification causes cancer cell death mainly by intervening with the glycolysis process in cancer cells. Systemic administration of folate-polySia inhibited cervical and breast tumor growth and dramatically improved survival rates in mice. This study provides an extracellular therapeutic approach for malignant tumor diseases via calcification that is ready for clinical trials and offers new insights into macromolecular anticancer drug discovery.

Fine Customization of Calcium Phosphate Nanostructures with Site-Specific Modification by DNA Templated Mineralization

Calcium phosphate (Ca-P) is the most abundant biomineral in hard tissues with diverse microstructures, which in nature ensure a broad range of functionalities with virtually similar and simple chemical compositions. Artificial fabrication of rationally designed Ca-P materials with arbitrary microstructures is a long-standing challenge for inorganic chemists. Although DNA nanotechnology has been elegantly used to modulate the nanofabrication of inorganic materials because of its programmability, encoding customized Ca-P mineralization with high structural precision remains unachievable because of fast affinity-driven crystal growth. Herein, this long-standing ambition has been skillfully fulfilled by taking advantage of crystallization via a particle attachment (CPA) process. The derived hybrid materials not only well inherited the structural details encoded by the DNA template but also exhibited significantly enhanced mechanical strength, even after heating. Moreover, this method preserved preinstalled synthetic functionalities on the DNA surface, allowing for downstream site-specific modification.

Improvement of organisms by biomimetic mineralization: A material incorporation strategy for biological modification

Biomineralization, a bio-organism controlled mineral formation process, plays an important role in linking biological organisms and mineral materials in nature. Inspired by biomineralization, biomimetic mineralization is used as a bridge tool to integrate biological organisms and functional materials together, which can be beneficial for the development of diversified functional organism-material hybrids. In this review, recent progresses on the techniques of biomimetic mineralization for organism-material combinations are summarized and discussed. Based upon these techniques, the preparations and applications of virus-, prokaryotes-, and eukaryotes-material hybrids have been presented and they demonstrate the great potentials in the fields of vaccine improvement, cell protection, energy production, environmental and biomedical treatments, etc. We suggest that more researches about functional organism and material combination with more biocompatible techniques should be developed to improve the design and applications of specific organism-material hybrids. These rationally designed organism-material hybrids will shed light on the production of "live materials" with more advanced functions in future. STATEMENT OF SIGNIFICANCE: This review summaries the recent attempts on improving biological organisms by their integrations with functional materials, which can be achieved by biomimetic mineralization as the combination tool. The integrated materials, as the artificial shells or organelles, confer diversified functions on the enclosed organisms. The successful constructions of various virus-, prokaryotes-, and eukaryotes-material hybrids have demonstrated the great potentials of the material incorporation strategy in vaccine development, cancer treatment, biological photosynthesis and environment protection etc. The suggested challenges and perspectives indicate more inspirations for the future development of organism-material hybrids.

Biomineralized Bacterial Outer Membrane Vesicles Potentiate Safe and Efficient Tumor Microenvironment Reprogramming for Anticancer Therapy

The highly immunosuppressive tumor microenvironment (TME) in solid tumors often dampens the efficacy of immunotherapy. In this study, bacterial outer membrane vesicles (OMVs) are demonstrated as powerful immunostimulants for TME reprogramming. To overcome the obstacles of antibody-dependent clearance and high toxicity induced by OMVs upon intravenous injection (a classic clinically relevant delivery mode), calcium phosphate (CaP) shells are employed to cover the surface of OMVs, which enables potent OMV-based TME reprograming without side effects. Meanwhile, the pH-sensitive CaP shells facilitate the neutralization of acidic TME, leading to highly beneficial M2-to-M1 polarization of macrophages for improved antitumor effect. Moreover, the outer shells can be integrated with functional components like folic acid or photosensitizer agents, which facilitates the use of the OMV-based platform in combination therapies for a synergic therapeutic effect.

Biomineralization: An Opportunity and Challenge of Nanoparticle Drug Delivery Systems for Cancer Therapy

Biomineralization is a common process in organisms to produce hard biomaterials by combining inorganic ions with biomacromolecules. Multifunctional nanoplatforms are developed based on the mechanism of biomineralization in many biomedical applications. In the past few years, biomineralization-based nanoparticle drug delivery systems for the cancer treatment have gained a lot of research attention due to the advantages including simple preparation, good biocompatibility, degradability, easy modification, versatility, and targeting. In this review, the research trends of biomineralization-based nanoparticle drug delivery systems and their applications in cancer therapy are summarized. This work aims to promote future researches on cancer therapy based on biomineralization. Rational design of nanoparticle drug delivery systems can overcome the bottleneck in the clinical transformation of nanomaterials. At the same time, biomineralization has also provided new research ideas for cancer treatment, i.e., targeted therapy, which has significantly better performance.

Single-Cell Nanoencapsulation: From Passive to Active Shells

Single-cell nanoencapsulation is an emerging field in cell-surface engineering, emphasizing the protection of living cells against external harmful stresses in vitro and in vivo. Inspired by the cryptobiotic state found in nature, cell-in-shell structures are formed, which are called artificial spores and which show suppression or retardation in cell growth and division and enhanced cell survival under harsh conditions. The property requirements of the shells suggested for realization of artificial spores, such as durability, permselectivity, degradability, and functionalizability, are demonstrated with various cytocompatible materials and processes. The first-generation shells in single-cell nanoencapsulation are passive in the operation mode, and do not biochemically regulate the cellular metabolism or activities. Recent advances indicate that the field has shifted further toward the formation of active shells. Such shells are intimately involved in the regulation and manipulation of biological processes. Not only endowing the cells with new properties that they do not possess in their native forms, active shells also regulate cellular metabolism and/or rewire biological pathways. Recent developments in shell formation for microbial and mammalian cells are discussed and an outlook on the field is given.

Inhibiting Cell Viability and Motility by Layer-by-Layer Assembly and Biomineralization

Herein, we proposed a drug-free strategy named cell surface shellization to inhibit the motility of SKOV-3 and HeLa cells. We alternately deposited two- or three-layer cationic polyelectrolyte (PE) and anionic PE films on the surface of SKOV-3 and HeLa cells. Then, a mineral shell (calcium carbonate, CaCO₃) was formed on the surface of polymer shells via electrostatic force and biomineralization. The CCK-8 assay results and live/dead staining showed that the surface shells strongly aggravated the cytotoxicity. The monolayer scratch wound migration assay results and immunofluorescence staining results showed that the shells, especially the mineral shells, could efficiently inhibit the migration of SKOV-3 and HeLa cells without any anticancer drugs. The immunofluorescence results of the three small G proteins of the cells showed that the immunofluorescence intensity in SKOV-3 did not change. Preliminary results from our laboratory showed an increase in MMP-9 secreted by cancer cells after coating with films or mineral shells. It suggests that mechanisms that inhibit cell migration are related to the MMP signaling pathway. All the results indicated that shellization (films or nanomineral shells) but not limited to calcification can be used as one of the tools to change the function of cells.

Boosting two-photon photodynamic therapy with mitochondria-targeting ruthenium-glucose conjugates

Herein, we present a series of dual-targeted ruthenium-glucose conjugates that can function as two-photon absorption (TPA) PDT agents to effectively destroy tumors by preferentially targeting both tumor cells and mitochondria. The in vivo experiments revealed an excellent tumor inhibitory efficiency of the dual-targeted TPA PSs.

Protein@Inorganic Nanodumpling System for High-Loading Protein Delivery with Activatable Fluorescence and Magnetic Resonance Bimodal Imaging Capabilities

Efficient protein delivery into the target cell is highly desirable for protein therapeutics. Current approaches for protein delivery commonly suffer from low-loading protein capacity, poor specificity for target cells, and invisible protein release. Herein, we report a protein@inorganic nanodumpling (ND) system as an intracellular protein delivery platform. Similar to a traditional Chinese food, the dumpling, ND consists of a protein complex "filling" formed by metal-ion-directed self-assembly of protein cargos fused to histidine-rich green fluorescent proteins (H₃₉GFPs), which are further encapsulated by an external surface "wrapper" of manganese dioxide (MnO₂) via in situ biomineralization. This ND structure allows for a high loading capacity (>63 wt %) for protein cargos with enhanced stability. NDs can be targeted and internalized into cancer cells specifically through folic acid receptors by surface-tailored folic acid. The protein cargo release is in a bistimuli-responsive manner, triggered by an either reductive or acidic intracellular microenvironment. Moreover, the MnO₂ nanowrapper is an efficient fluorescence quencher for inner fused GFPs and also a "switch-on" magnetic resonance imaging (MRI) agent via triggered release of Mn²⁺ ions, which enables activatable fluorescence/MRI bimodal imaging of protein release. Finally, the ND is highly potent and specific to deliver functional protein ribonuclease A (RNase A) into cultured target cells and the tumor site in a xenografted mouse model, eliminating the tumor cells with high therapeutic efficacy. Our approach provides a promising alternative to advance protein-based cancer therapeutics.