Potent-By-Design: Amino Acids Mimicking Porous Nanotherapeutics with Intrinsic Anticancer Targeting Properties

Nano-hydroxyapatite promotes cell apoptosis by co-activating endoplasmic reticulum stress and mitochondria damage to inhibit glioma growth

Despite a growing body of studies demonstrating the specific anti-tumor effect of nano-hydroxyapatite (n-HA), the underlying mechanism remained unclear. Endoplasmic reticulum (ER) and mitochondria are two key players in intracellular Ca2+ homeostasis and both require Ca2+ to participate. Moreover, the ER-mitochondria interplay coordinates the maintenance of cellular Ca2+ homeostasis to prevent any negative consequences from excess of Ca2+, hence there needs in-depth study of n-HA effect on them. In this study, we fabricated needle-like n-HA to investigate the anti-tumor effectiveness as well as the underlying mechanisms from cellular and molecular perspectives. Data from in vitro experiments indicated that the growth and invasion of glioma cells were obviously reduced with the aid of n-HA. It is interesting to note that the expression of ER stress biomarkers (GRP78, p-IRE1, p-PERK, PERK, and ATF6) were all upregulated after n-HA treatment, along with the activation of the pro-apoptotic transcription factor CHOP, showing that ER stress produced by n-HA triggered cell apoptosis. Moreover, the increased expression level of intracellular reactive oxygen species and the mitochondrial membrane depolarization, as well as the downstream cell apoptotic signaling activation, further demonstrated the pro-apoptotic roles of n-HA induced Ca2+ overload through inducing mitochondria damage. The in vivo data provided additional evidence that n-HA caused ER stress and mitochondria damage in cells and effectively restrain the growth of glioma tumors. Collectively, the work showed that n-HA co-activated intracellular ER stress and mitochondria damage are critical triggers for cancer cells apoptosis, offering fresh perspectives on ER-mitochondria targeted anti-tumor therapy.

Attenuating Epithelial-to-Mesenchymal Transition in Cancer through Angiopoietin-Like 4 Inhibition in a 3D Tumor Microenvironment Model

Epithelial-to-mesenchymal transition (EMT) plays a crucial role in metastatic cancer progression, and current research, which relies heavily on 2D monolayer cultures, falls short in recapitulating the complexity of a 3D tumor microenvironment. To address this limitation, a transcriptomic meta-analysis is conducted on diverse cancer types undergoing EMT in 2D and 3D cultures. It is found that mechanotransduction is elevated in 3D cultures and is further intensified during EMT, but not during 2D EMT. This analysis reveals a distinct 3D EMT gene signature, characterized by extracellular matrix remodeling coordinated by angiopoietin-like 4 (Angptl4) along with other canonical EMT regulators. Utilizing hydrogel-based 3D matrices with adjustable mechanical forces, 3D cancer cultures are established at varying physiological stiffness levels. A YAP:EGR-1 mediated up-regulation of Angptl4 expression is observed, accompanied by an upregulation of mesenchymal markers, at higher stiffness during cancer EMT. Suppression of Angptl4 using antisense oligonucleotides or anti-cAngptl4 antibodies leads to a dose-dependent abolishment of EMT-mediated chemoresistance and tumor self-organization in 3D, ultimately resulting in diminished metastatic potential and stunted growth of tumor xenografts. This unique programmable 3D cancer cultures simulate stiffness levels in the tumor microenvironment and unveil Angptl4 as a promising therapeutic target to inhibit EMT and impede cancer progression.

In situ injectable thermoresponsive nanocomposite hydrogel based on hydroxypropyl chitosan for precise synergistic calcium-overload, photodynamic and photothermal tumor therapy

Traditional therapies have poor accuracy and significant toxic side effects in the process of tumor treatment. The non-traditional treatment methods with high accuracy and efficacy are worth exploring and investigating. Herein, a strategy that enables precise and synergistic therapies of calcium-overload, photodynamic, and photothermal through facile near infrared (NIR) irradiation was carried out base on the injectable and self-healable hydrogel encapsulating indocyanine green (ICG)-loaded and bovine serum albumin (BSA)-modified calcium peroxide (CaO2) nanoparticles (ICG@CaO2-BSA NPs) and bismuth sulfide (Bi2S3) nanorods. The hydrogel fabricated through the dynamic Schiff-base bonds between hydroxypropyl chitosan (HPCS) and aldehyde-modified Pluronic F127 (F127-CHO) as the delivery substrate for functional substances could adhere and grip tumor tissues due to the adhesion of hydroxyl groups in HPCS and the hydrophobic aggregation caused by thermoresponsiveness of F127-CHO. CaO2 in ICG@CaO2-BSA NPs decomposed in the tumor micro-acidic environment to produce calcium ions (Ca2+) and hydrogen peroxide (H2O2), while ICG generated reactive oxygen species (ROS) under NIR irradiation, the photothermal effect of Bi2S3 nanorods and ICG under NIR irradiation could increase the temperature of tumor tissues and ultimately achieve precise tumor cell destruction. Therefore, this strategy will provide promising prospects for precise and efficient treatment of tumors.

Engineered Nano-Bio Interfaces for Stem Cell Therapy

Engineered nanomaterials (ENMs) with different topographies provide effective nano-bio interfaces for controlling the differentiation of stem cells. The interaction of stem cells with nanoscale topographies and chemical cues in their microenvironment at the nano-bio interface can guide their fate. The use of nanotopographical cues, in particular nanorods, nanopillars, nanogrooves, nanofibers, and nanopits, as well as biochemical forces mediated factors, including growth factors, cytokines, and extracellular matrix proteins, can significantly impact stem cell differentiation. These factors were seen as very effective in determining the proliferation and spreading of stem cells. The specific outgrowth of stem cells can be decided with size variation of topographic nanomaterial along with variation in matrix stiffness and surface structure like a special arrangement. The precision chemistry enabled controlled design, synthesis, and chemical composition of ENMs can regulate stem cell behaviors. The parameters of size such as aspect ratio, diameter, and pore size of nanotopographic structures are the main factors for specific termination of stem cells. Protein corona nanoparticles (NPs) have shown a powerful facet in stem cell therapy, where combining specific proteins could facilitate a certain stem cell differentiation and cellular proliferation. Nano-bio reactions implicate the interaction between biological entities and nanoparticles, which can be used to tailor the stem cells' culmination. The ion release can also be a parameter to enhance cellular proliferation and to commit the early differentiation of stem cells. Further research is needed to fully understand the mechanisms underlying the interactions between engineered nano-bio interfaces and stem cells and to develop optimized regenerative medicine and tissue engineering designs.

Self-Therapeutic Nanomaterials: Applications in Biology and Medicine

Over past decades, nanotechnology has contributed to the biomedical field in areas including detection, diagnosis, and drug delivery via opto-electronic properties or enhancement of biological effects. Though generally considered inert delivery vehicles, a plethora of past and present evidence demonstrates that nanomaterials also exude unique intrinsic biological activity based on composition, shape, and surface functionalization. These intrinsic biological activities, termed self-therapeutic properties, take several forms, including mediation of cell-cell interactions, modulation of interactions between biomolecules, catalytic amplification of biochemical reactions, and alteration of biological signal transduction events. Moreover, study of biomolecule-nanomaterial interactions offers a promising avenue for uncovering the molecular mechanisms of biology and the evolution of disease. In this review, we observe the historical development, synthesis, and characterization of self-therapeutic nanomaterials. Next, we discuss nanomaterial interactions with biological systems, starting with administration and concluding with elimination. Finally, we apply this materials perspective to advances in intrinsic nanotherapies across the biomedical field, from cancer therapy to treatment of microbial infections and tissue regeneration. We conclude with a description of self-therapeutic nanomaterials in clinical trials and share our perspective on the direction of the field in upcoming years.

Nanoparticle-induced chemoresistance: the emerging modulatory effects of engineered nanomaterials on human intestinal cancer cell redox metabolic adaptation

The widespread use of engineered nanomaterials (ENMs) in food products necessitates the understanding of their impact on the gastrointestinal tract (GIT). Herein, we screened several representative food-borne comparator ENMs (i.e. ZnO, SiO₂ and TiO₂ nanoparticles (NPs)) and report that human colon cancer cells can insidiously exploit ZnO NP-induced adaptive response to acquire resistance against several chemotherapeutic drugs. By employing a conditioning and challenge treatment regime, we demonstrate that repeated exposure to a non-toxic dose of ZnO NPs (20 μM) could dampen the efficacy of cisplatin, paclitaxel and doxorubicin by 10-50% in monolayer culture and 3D spheroids of human colon adenocarcinoma cells. Structure-activity relationship studies revealed a complex interplay between nanoparticle surface chemistry and cell type in determining the chemoresistance-inducing effect, with silica coated ZnO NPs having a negligible influence on the anticancer treatment. Mechanistically, we showed that the pro-survival paracrine signaling was potentiated and propagated by a subset of ZnO NP "stressed" (Zn²⁺+/ROS+) cells to the surrounding "bystander" (Zn²⁺+/ROS-) cells. Transcriptome profiling, bioinformatics analysis and siRNA gene knockdown experiments revealed the nuclear factor erythroid 2-related factor 2 (Nrf2) as the key modulator of the ZnO NP-induced drug resistance. Our findings suggest that a ROS-inducing ENM can emerge as a nano-stressor, capable of regulating the chemosensitivity of colon cancer cells.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Tuning the drug multimodal release through a co-assembly strategy based on magnetic gels

Self-assembled short peptide-based gels are highly promising drug delivery systems. However, implementing a stimulus often requires screening different structures to obtain gels with suitable properties, and drugs might not be well encapsulated and/or cause undesirable effects on the gel's properties. To overcome this challenge, a new design approach is presented to modulate the release of doxorubicin as a model chemotherapeutic drug through the interplay of (di)phenylalanine-coated magnetic nanoparticles, PEGylated liposomes and doxorubicin co-assembly in dehydropeptide-based gels. The composites enable an enhancement of the gelation kinetics in a concentration-dependent manner, mainly through the use of PEGylated liposomes. The effect of the co-assembly of phenylalanine-coated nanoparticles with the hydrogel displays a concentration and size dependence. Finally, the integration of liposomes as doxorubicin storage units and of nanoparticles as composites that co-assemble with the gel matrix enables the tuneability of both passive and active doxorubicin release through a thermal, and a low-frequency alternating magnetic field-based trigger. In addition to the modulation of the gel properties, the functionalization with (di)phenylalanine improves the cytocompatibility of the nanoparticles. Hereby, this work paves a way for the development of peptide-based supramolecular systems for on-demand and controlled release of drugs.

Cascade-responsive nanobomb with domino effect for anti-tumor synergistic therapies

The development of reactive oxygen species (ROS) generation agents that can selectively produce sufficient ROS at the tumor site without external energy stimulation is of great significance for the further clinical application of ROS-based therapies. Herein, we designed a cascade-responsive ROS nanobomb (ZnO₂@Ce6/CaP@CPPO/BSA, designated as Z@Ce6/CaP@CB) with domino effect and without external stimulation for the specific generation of multiple powerful ROS storms at the tumor site. The calcium phosphate shell and ZnO₂ core gradually degrade and release Ca²⁺, Zn²⁺ and hydrogen peroxide (H₂O₂) under acid stimulation. On the one hand, Zn²⁺ can enhance the generation of endogenous superoxide anions (·O₂^–) and H₂O₂ through the inhibition of the mitochondrial electron transport chain. On the other hand, the generation of large amounts of exogenous H₂O₂ can cause oxidative damage to tumor cells and further activate bis[2,4,5-trichloro-6-(pentyloxycarbonyl)phenyl] oxalate (CPPO)-mediated chemiexcited photodynamic therapy. In addition, the oxidative stress caused by the generated ROS can lead to the uncontrolled accumulation of Ca²⁺ in cells and further result in Ca²⁺ overload-induced cell death. Therefore, the introduction of Z@Ce6/CaP@CB nanobombs triggered the ‘domino effect’ that caused multiple heavy ROS storms and Ca²⁺ overload in tumors and effectively activated anti-tumor immune response.

Pharmacologic approaches to amino acid depletion for cancer therapy

Cancer cells undergo metabolic reprogramming to support increased demands in bioenergetics and biosynthesis and to maintain reactive oxygen species at optimum levels. As metabolic alterations are broadly observed across many cancer types, metabolic reprogramming is considered a hallmark of cancer. A metabolic alteration commonly seen in cancer cells is an increased demand for certain amino acids. Amino acids are involved in a wide range of cellular functions, including proliferation, redox balance, bioenergetic and biosynthesis support, and homeostatic functions. Thus, targeting amino acid dependency in cancer is an attractive strategy for a number of cancers. In particular, pharmacologically mediated amino acid depletion has been evaluated as a cancer treatment option for several cancers. Amino acids that have been investigated for the feasibility of drug-induced depletion in preclinical and clinical studies for cancer treatment include arginine, asparagine, cysteine, glutamine, lysine, and methionine. In this review, we will summarize the status of current research on pharmacologically mediated amino acid depletion as a strategy for cancer treatment and potential chemotherapeutic combinations that synergize with amino acid depletion to further inhibit tumor growth and progression.

[Drug Discovery Targeting an Amino Acid Transporter for Diagnosis and Therapy]

Nutrients are essential for all living organisms. Because growing cancer cells have strong metabolic demands, nutrient transporters are constitutively increased to facilitate the nutrient uptake. Among these nutrient transporters, L-type amino acid transporter 1 (LAT1), which transports large neutral amino acids including essential amino acids, is critical for cancer growth. Therefore, LAT1 has been considered as an attractive target for diagnosis and therapy of cancers. We have developed several lines of compounds for cancer diagnosis and therapy. To diagnose cancer by using positron emission tomography (PET) probes, we have created amino acid derivatives which are selectively transported by LAT1 and accumulated in cancer cells. In addition to amino acid derivatives as the LAT1 inhibitors, we also have made non-amino acid small compounds as anti-cancer drugs which inhibit LAT1 function and suppress tumor growth. The LAT1 targeting anti-cancer drug showed low toxicity but strong effects on various types of cancer cells in animal models. The novel PET probe is approved for clinical research and the new anti-cancer drug has been under clinical trial. Small compounds targeting the amino acid transporter bring us new tools for cancer diagnosis and therapy.

Mesoporous Silica Nanoparticles and Mesoporous Bioactive Glasses for Wound Management: From Skin Regeneration to Cancer Therapy

Exploring new therapies for managing skin wounds is under progress and, in this regard, mesoporous silica nanoparticles (MSNs) and mesoporous bioactive glasses (MBGs) offer great opportunities in treating acute, chronic, and malignant wounds. In general, therapeutic effectiveness of both MSNs and MBGs in different formulations (fine powder, fibers, composites etc.) has been proved over all the four stages of normal wound healing including hemostasis, inflammation, proliferation, and remodeling. The main merits of these porous substances can be summarized as their excellent biocompatibility and the ability of loading and delivering a wide range of both hydrophobic and hydrophilic bioactive molecules and chemicals. In addition, doping with inorganic elements (e.g., Cu, Ga, and Ta) into MSNs and MBGs structure is a feasible and practical approach to prepare customized materials for improved skin regeneration. Nowadays, MSNs and MBGs could be utilized in the concept of targeted therapy of skin malignancies (e.g., melanoma) by grafting of specific ligands. Since potential effects of various parameters including the chemical composition, particle size/morphology, textural properties, and surface chemistry should be comprehensively determined via cellular in vitro and in vivo assays, it seems still too early to draw a conclusion on ultimate efficacy of MSNs and MBGs in skin regeneration. In this regard, there are some concerns over the final fate of MSNs and MBGs in the wound site plus optimal dosages for achieving the best outcomes that deserve careful investigation in the future.

Life after Cell Death-Survival and Survivorship Following Chemotherapy

Simple Summary

Treatment of aggressive cancers often relies on chemotherapy. This treatment has improved survival rates, but while effective at killing cancer cells, inevitably it also kills or alters the function of others. While many of the known effects are transient and resolve after treatment, as survival rates increase, so does our understanding of the long-term health costs that accompany cancer survivors. Here we provide an overview of common long-term morbidities known to be caused by conventional chemotherapy, including the risk of relapse, but more importantly, the cost of quality of life experienced, especially by those who have cancer in early life. We aim to highlight the importance of the development of targeted therapies to replace the use of conventional chemotherapy, but also that of treating the patients along with the disease to enable not only longer but also healthier life after cancer.

Abstract

To prevent cancer cells replacing and outnumbering their functional somatic counterparts, the most effective solution is their removal. Classical treatments rely on surgical excision, chemical or physical damage to the cancer cells by conventional interventions such as chemo- and radiotherapy, to eliminate or reduce tumour burden. Cancer treatment has in the last two decades seen the advent of increasingly sophisticated therapeutic regimens aimed at selectively targeting cancer cells whilst sparing the remaining cells from severe loss of viability or function. These include small molecule inhibitors, monoclonal antibodies and a myriad of compounds that affect metabolism, angiogenesis or immunotherapy. Our increased knowledge of specific cancer types, stratified diagnoses, genetic and molecular profiling, and more refined treatment practices have improved overall survival in a significant number of patients. Increased survival, however, has also increased the incidence of associated challenges of chemotherapy-induced morbidity, with some pathologies developing several years after termination of treatment. Long-term care of cancer survivors must therefore become a focus in itself, such that along with prolonging life expectancy, treatments allow for improved quality of life.

Direct and Label-Free Cell Status Monitoring of Spheroids and Microcarriers Using Microfluidic Impedance Cytometry

3D cellular spheroids/microcarriers (100 µm-1 mm) are widely used in biomanufacturing, and non-invasive biosensors are useful to monitor cell quality in bioprocesses. In this work, a novel microfluidic approach for label-free and continuous-flow monitoring of single spheroid/microcarrier (hydrogel and Cytodex) based on electrical impedance spectroscopy using co-planar Field's metal electrodes is reported. Through numerical simulation and experimental validation, two unique impedance signatures (|Z_LF | (60 kHz), |Z_HF | (1 MHz)) which are optimal for spheroid growth and viability monitoring are identified. Using a closed-loop recirculation system, it is demonstrated that |Z_LF | increases with breast cancer (MCF-7) spheroid biomass, while higher opacity (impedance ratio |Z_HF |/|Z_LF |) indicates cell death due to compromised cell membrane. Anti-cancer drug (paclitaxel)-treated spheroids also exhibit lower |Z_LF | with increased cell dissociation. Interestingly, impedance characterization of adipose-derived mesenchymal stem cell differentiation on Cytodex microcarriers reveals that adipogenic cells (higher intracellular lipid content) exhibit higher impedance than osteogenic cells (more conductive due to calcium ions) for both microcarriers and single cell level. Taken together, the developed platform offers great versatility for multi-parametric analysis of spheroids/microcarriers at high throughput (≈1 particle/s), and can be readily integrated into bioreactors for long-term and remote monitoring of biomass and cell quality.

Improved anti-cancer effect of epidermal growth factor-gold nanoparticle conjugates by protein orientation through site-specific mutagenesis

Epidermal growth factor (EGF)-nanoparticle conjugates have the potential for cancer therapeutics due to the unique cytotoxic activity in cancer cells with EGF receptor (EGFR) overexpression. To gain its maximum activity, the EGF molecule should be immobilized on the nanoparticle surface in a defined orientation so as the bulky nanoparticle will not interfere EGF-EGFR interaction. Herein, we demonstrate successful enhancement of the anti-cancer activity of EGF-gold nanoparticle conjugates (EGF-GNPs) by controlling the EGF orientation on the surface of the nanoparticle through site-specific mutagenesis. Three lysine-free EGF variants (RR, RS, and SR) were designed, where two endogenous lysine residues were replaced with either arginine (R) or serine (S). The EGF mutants can be conjugated to the GNPs in a controlled orientation through the single amino group at the N-terminus. The ability of the mutants to induce extracellular signal-regulated kinase (ERK) phosphorylation was no different from wild type EGF (WT) in soluble form, rather lowered for one mutant (RR). However, after conjugated to GNPs, the SR mutants exhibited an enhanced biological activity than WT, in terms of ERK phosphorylation and growth inhibition of cancer cells. Further analysis of the binding constant of each mutant indicated the emergent enhanced activity of the GNP conjugates of the SR mutant was not solely contributed to the orientation, but to its higher binding activity to EGFR. These results validate the present genetic recombination strategy to improve the anticancer efficiency of EGF-GNPs.