Triple Hit with Drug Carriers: pH- and Temperature-Responsive Theranostics for Multimodal Chemo- and Photothermal Therapy and Diagnostic Applications

Spatiotemporally Controllable Electrical Stimulator via Independent Photobending and Upconversion Photoluminescence Using Two Different Wavelengths of Near-Infrared/Visible Light as Dual Stimuli

Multistimuli responsive materials are advantageous in that they can enhance the desired response or bypass unwanted reactions. Light is one of the most attractive stimuli since it allows remote spatiotemporal control and multiplexing of properties (e.g., wavelength, intensity, irradiation time, pulsed/continuous wave) for application on multiphotoresponsive materials. However, the operating wavelength for such photoresponsive systems often includes an ultraviolet (UV) range that limits its use in the biomedical field. Herein, we investigate near-infrared (NIR)/visible (Vis) light-responsive nanocomposite films composed of rare earth element (i.e., Yb, Er)-doped NaYF4 nanoparticles (NPs) embedded in azobenzene-incorporated poly(dimethylsiloxane) (AzoPDMS), silk fibroin, and silver nanowire (AgNW) layers. Photobending (PB) of the nanocomposite film is induced by a Vis light of 400-700 nm, while upconversion photoluminescence (UCPL) of embedded NPs is activated by an NIR light of 980 nm. The excitation wavelength of photoluminescence (PL) is shifted to the NIR (λ = 980 nm) range via photon upconversion in rare earth element-doped NPs. Independent operation of PB and UCPL enables both on-demand electrical switching and real-time location monitoring for spatiotemporally controlled electrical pulse stimulation. As a result, the dual-photoresponsive nanocomposite film can be utilized as a remotely controllable electrical stimulator and location indicator via different wavelengths of light.

Nanomaterials based on thermosensitive polymer in biomedical field

The progress of nanotechnology enables us to make use of the special properties of materials on the nanoscale and open up many new fields of biomedical research. Among them, thermosensitive nanomaterials stand out in many biomedical fields because of their “intelligent” behavior in response to temperature changes. However, this article mainly reviews the research progress of thermosensitive nanomaterials, which are popular in biomedical applications in recent years. Here, we simply classify the thermally responsive nanomaterials according to the types of polymers, focusing on the mechanisms of action and their advantages and potential. Finally, we deeply investigate the applications of thermosensitive nanomaterials in drug delivery, tissue engineering, sensing analysis, cell culture, 3D printing, and other fields and probe the current challenges and future development prospects of thermosensitive nanomaterials.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

Liposome-Loaded Targeted Theranostic Fluorescent Nano-Probes for Diagnosis and Treatment of Cervix Carcinoma

Near-infrared fluorescence imaging, with its high sensitivity, non-invasiveness, and superior real-time feedback properties, has become a powerful skill for accurate diagnosis in the clinic. Nanoparticle-assisted chemotherapy is an effective cure for cancer. Specifically, the combination of near-infrared fluorescence imaging with chemotherapy represents a promising method for precise diagnosis and treatment of cervical cancer. To realize this approach, it is necessary to design and synthesize therapeutic nano-probes with detection abilities. In this work, an organic NIRF emissive heptamethine cyanine dye, IR783, was utilized and encapsulated in biocompatible drug-carrier liposomes). Then, the anticancer drug doxorubicin was loaded, to form LP-IR783-DOX nanoparticles. The LP-IR783-DOX nanoparticles had spherical shapes and were smoothly dispersed in aqueous solutions. Favorable absorption (a peak of 800 nm) and fluorescence (a peak of 896 nm) features were obtained from LP-IR783-DOX nanoparticles in the near-infrared region. Moreover, the specific detection abilities of nanoparticles were confirmed in different cell lines, and nanoparticles exhibited strong detection abilities in human cervix carcinoma cells in particular. To analyze the chemotherapeutic properties of LP-IR783-DOX nanoparticles, live HeLa cells were studied in detail, and the application of these NPs resulted in a chemotherapeutic efficiency of 56.75% based on fluorescein isothiocyanate staining and flow cytometry. The results indicate that nanoparticles have great potential for theranostic application of fluorescence imaging and chemotherapy in cases of cervical cancer.

Near-infrared emissive polymer-coated IR-820 nanoparticles assisted photothermal therapy for cervical cancer cells

Photothermal therapy (PTT) has attracted wide attention due to its noninvasiveness and its thermal ablation ability. As photothermal agents are crucial factor in PTT, those with the characteristics of biocompatibility, non-toxicity and high photothermal stability have attracted great interest. In this work, new indocyanine green (IR-820) was utilized as a photothermal agent and near-infrared (NIR) fluorescence imaging nanoprobe. To improve the biocompatibility, poly(styrene-co-maleic anhydride) (PSMA) was utilized to encapsulate the IR-820 molecules to form novel IR-820@PSMA nanoparticles (NPs). Then, the optical and thermal properties of IR-820@PSMA NPs were studied in detail. The IR-820@PSMA NPs showed excellent photothermal stability and biocompatibility. The cellular uptaking ability of the IR-820@PSMA NPs was further confirmed in HeLa cells by the NIR fluorescent confocal microscopic imaging technique. The IR-820@PSMA NPs assisted PTT of living HeLa cells was conducted under 793 nm laser excitation, and a high PTT efficiency of 73.3% was obtained.

Challenges and opportunities of pharmaceutical cocrystals: a focused review on non-steroidal anti-inflammatory drugs

The focus of the review is to discuss the relevant and essential aspects of pharmaceutical cocrystals in both academia and industry with an emphasis on non-steroidal anti-inflammatory drugs (NSAIDs). Although cocrystals have been prepared for a plethora of drugs, NSAID cocrystals are focused due to their humongous application in different fields of medication such as antipyretic, anti-inflammatory, analgesic, antiplatelet, antitumor, and anti-carcinogenic drugs. The highlights of the review are (a) background of cocrystals and other solid forms of an active pharmaceutical ingredient (API) based on the principles of crystal engineering, (b) why cocrystals are an excellent opportunity in the pharma industry, (c) common methods of preparation of cocrystals from the lab scale to bulk quantity, (d) some latest case studies of NSAIDs which have shown better physicochemical properties for example; mechanical properties (tabletability), hydration, solubility, bioavailability, and permeability, and (e) latest guidelines of the US FDA and EMA opening new opportunities and challenges.

Multifunctional polymeric micellar nanomedicine in the diagnosis and treatment of cancer

Polymeric micelles are a prevalent topic of research for the past decade, especially concerning their fitting ability to deliver drug and diagnostic agents. This delivery system offers outstanding advantages, such as biocompatibility, high loading efficiency, water-solubility, and good stability in biological fluids, to name a few. The multifunctional polymeric micellar architect offers the added capability to adapt its surface to meet the looked-for clinical needs. This review cross-talks the recent reports, proof-of-concept studies, patents, and clinical trials that utilize polymeric micellar family architectures concerning cancer targeted delivery of anticancer drugs, gene therapeutics, and diagnostic agents. The manuscript also expounds on the underlying opportunities, allied challenges, and ways to resolve their bench-to-bedside translation for allied clinical applications.

Anti-Tumor Metastasis via Platelet Inhibitor Combined with Photothermal Therapy under Activatable Fluorescence/Magnetic Resonance Bimodal Imaging Guidance

Photothermal therapy (PTT) is a promising tumor therapy strategy; however, heterogeneous heat distribution over the tumor often exists, resulting in insufficient photothermal ablation and potential risk of cancer metastasis, which has been demonstrated to be associate with platelets. Herein, a near-infrared (NIR) photothermal agent of IR780 was conjugated with MRI agent of Gd-DOTA via a disulfide linkage (ICD-Gd), which was coassembly with lipid connecting tumor-homing pentapeptide CREKA (Cys-Arg-Glu-Lys-Ala) (DSPE-PEG-CREKA) to encapsulate a platelet inhibitor of ticagrelor (Tic), affording a multistimuli-responsive nanosystem (DPC@ICD-Gd-Tic). The nanosystem with completely quenching fluorescence could specifically target the tumor-associated platelets and showed pH/reduction/NIR light-responsive drug release, which simultaneously resulting in dis-assembly of nanoparticle and fluorescence recovery, enabling the drug delivery visualization in tumor in situ via activatable NIR fluorescence/MR bimodal imaging. Finally, DPC@ICD-Gd-Tic further integrated the photoinduced hyperthermia and platelet function inhibitor to achieve synergistic anticancer therapy, leading to ablation of primary tumor cells and effectively suppressed their distant metastasis. The number of lung metastases in 4T1 tumor bearing mice was reduced by about 90%, and the size of tumor was reduced by about 70%, while half of the mouse was completely cured by this smart nanosystem.

Target-Induced Core-Satellite Nanostructure Assembly Strategy for Dual-Signal-On Fluorescence Imaging and Raman Quantification of Intracellular MicroRNA Guided Photothermal Therapy

Integrating biological detection and treatment into one system is a smart therapeutic maneuver for efficient cancer treatment. Herein, a target-activated core-satellite nanostructure (CS nanostructure) assembly built on gold nanobipyramids motor (AuNBPs motor)/gold nanoparticle probe (AuNP probe) exhibiting simultaneous dual signal-on imaging, quantification of intracellular microRNA-21 (miR-21), and photothermal therapy (PTT) for cancer is designed. Of note, when the AuNBPs motor/AuNP probe enters into cells, miR-21 triggers the reaction between AuNBPs motor and AuNP probe, resulting in the formation of CS nanostructure assembly. The process of assembling the CS nanostructure is accompanied with strong fluorescent signals from TAMRA and surface-enhanced Raman scattering (SERS) signals from adenine. The fluorescent signal is leveraged to image the intracellular miR-21 level, whereas the SERS signal is utilized for absolute quantification of intracellular miR-21, and the CS nanostructure acts as the photosensitizer for PTT. This strategy can successfully image and quantify miR-21 in a single cell, and also distinguish normal cells from tumor cells. Moreover, under the guidance of fluorescence signal, the assembly kills tumor cells and inhibits tumor growth via PTT. In vitro and in vivo results prove that the proposed strategy possesses enormous potential for application in the diagnosis and treatment of cancer.

Mesoporous Silica Nanoparticles in Bioimaging

A biomedical contrast agent serves to enhance the visualisation of a specific (potentially targeted) physiological region. In recent years, mesoporous silica nanoparticles (MSNs) have developed as a flexible imaging platform of tuneable size/morphology, abundant surface chemistry, biocompatibility and otherwise useful physiochemical properties. This review discusses MSN structural types and synthetic strategies, as well as methods for surface functionalisation. Recent applications in biomedical imaging are then discussed, with a specific emphasis on magnetic resonance and optical modes together with utility in multimodal imaging.

Multifunctional Gold Nanoparticles: A Novel Nanomaterial for Various Medical Applications and Biological Activities

Nanotechnology has become a trending area in science and has made great advances with the development of functional, engineered nanoparticles. Various metal nanoparticles have been widely exploited for a wide range of medical applications. Among them, gold nanoparticles (AuNPs) are widely reported to guide an impressive resurgence and are highly remarkable. AuNPs, with their multiple, unique functional properties, and easy of synthesis, have attracted extensive attention. Their intrinsic features (optics, electronics, and physicochemical characteristics) can be altered by changing the characterization of the nanoparticles, such as shape, size and aspect ratio. They can be applied to a wide range of medical applications, including drug and gene delivery, photothermal therapy (PTT), photodynamic therapy (PDT) and radiation therapy (RT), diagnosis, X-ray imaging, computed tomography (CT) and other biological activities. However, to the best of our knowledge, there is no comprehensive review that summarized the applications of AuNPs in the medical field. Therefore, in this article we systematically review the methods of synthesis, the modification and characterization techniques of AuNPs, medical applications, and some biological activities of AuNPs, to provide a reference for future studies.

Fabrication of PNIPAM-chitosan/decatungstoeuropate/silica nanocomposite for thermo/pH dual-stimuli-responsive and luminescent drug delivery system

A luminescent and dual-stimuli-responsive nanocomposite based on mesoporous silica, poly (N-isopropylacrylamide)-chitosan and decatungstoeuropate was prepared. To fabricate the nanocomposite, the mesoporous silica nanoparticles were coated with thermo/pH dual-responsive poly (N-isopropylacrylamide)-chitosan and the luminescent decatungstoeuropate particles were grafted onto copolymers. The designed nanocarrier could show exhibit good red luminescence as well as obvious thermo/pH stimuli-responsive properties, which could be employed as a drug storage reservoir for the loading and release of anticancer drug doxorubicin (DOX). The research indicated that the releases of DOX were thermo/pH dependent and high temperatures/acidic conditions were favorable for the fast release of drug. In vitro cytotoxicity tests revealed that the drug delivery carrier displayed excellent biocompatible and the composites loaded with DOX showed significant suppression effect on HeLa cells. Luminescence spectra showed that the composite containing decatungstoeuropate displayed fine red luminescence at various temperatures and pH values, which could be utilized as a potential labeling material in field of medicine.

Smart Gold Nanostructures for Light Mediated Cancer Theranostics: Combining Optical Diagnostics with Photothermal Therapy

Nanotheranostics, which combines optical multiplexed disease detection with therapeutic monitoring in a single modality, has the potential to propel the field of nanomedicine toward genuine personalized medicine. Currently employed mainstream modalities using gold nanoparticles (AuNPs) in diagnosis and treatment are limited by a lack of specificity and potential issues associated with systemic toxicity. Light-mediated nanotheranostics offers a relatively non-invasive alternative for cancer diagnosis and treatment by using AuNPs of specific shapes and sizes that absorb near infrared (NIR) light, inducing plasmon resonance for enhanced tumor detection and generating localized heat for tumor ablation. Over the last decade, significant progress has been made in the field of nanotheranostics, however the main biological and translational barriers to nanotheranostics leading to a new paradigm in anti-cancer nanomedicine stem from the molecular complexities of cancer and an incomplete mechanistic understanding of utilization of Au-NPs in living systems. This work provides a comprehensive overview on the biological, physical and translational barriers facing the development of nanotheranostics. It will also summarise the recent advances in engineering specific AuNPs, their unique characteristics and, importantly, tunability to achieve the desired optical/photothermal properties.

Coating biopolymer nanofibers with carbon nanotubes accelerates tissue healing and bone regeneration through orchestrated cell- and tissue-regulatory responses

Tailoring the surface of biomaterial scaffolds has been a key strategy to modulate the cellular interactions that are helpful for tissue healing process. In particular, nanotopological surfaces have been demonstrated to regulate diverse behaviors of stem cells, such as initial adhesion, spreading and lineage specification. Here, we tailor the surface of biopolymer nanofibers with carbon nanotubes (CNTs) to create a unique bi-modal nanoscale topography (500 nm nanofiber with 25 nm nanotubes) and report the performance in modulating diverse in vivo responses including inflammation, angiogenesis, and bone regeneration. When administered to a rat subcutaneous site, the CNT-coated nanofiber exhibited significantly reduced inflammatory signs (down-regulated pro-inflammatory cytokines and macrophages gathering). Moreover, the CNT-coated nanofibers showed substantially promoted angiogenic responses, with enhanced neoblood vessel formation and angiogenic marker expression. Such stimulated tissue healing events by the CNT interfacing were evidenced in a calvarium bone defect model. The in vivo bone regeneration of the CNT- coated nanofibers was significantly accelerated, with higher bone mineral density and up-regulated osteogenic signs (OPN, OCN, BMP2) of in vivo bone forming cells. The in vitro studies using MSCs could demonstrate accelerated adhesion and osteogenic differentiation and mineralization, supporting the osteo-promoting mechanism behind the in vivo bone forming event. These findings highlight that the CNTs interfacing of biopolymer nanofibers is highly effective in reducing inflammation, promoting angiogenesis, and driving adhesion and osteogenesis of MSCs, which eventually orchestrate to accelerate tissue healing and bone regeneration process. STATEMENT OF SIGNIFICANCE: Here we demonstrate that the interfacing of biopolymer nanofibers with carbon nanotubes (CNTs) could modulate multiple interactions of cells and tissues that are ultimately helpful for the tissue healing and bone regeneration process. The CNT-coated scaffolds significantly reduced the pro-inflammatory signals while stimulating the angiogenic marker expressions. Furthermore, the CNT-coated scaffolds increased the bone matrix production of bone forming cells in vivo as well as accelerated the adhesion and osteogenic differentiation of MSCs in vitro. These collective findings highlight that the CNTs coated on the biopolymer nanofibers allow the creation of a promising platform for nanoscale engineering of biomaterial surface that can favor tissue healing and bone regeneration process, through a series of orchestrated events in anti-inflammation, pro-angiogenesis, and stem cell stimulation.

Gold Nanoparticles Synthesis Using Stainless Steel as Solid Reductant: A Critical Overview

Gold nanoparticles (AuNPs) were produced using stainless steel as a solid reductant to assist the synthesis of metal NPs, using HAuCl₄ as a precursor. This method is very easy, quick, and cost-effective, allowing the synthesis of highly stable NPs without additional capping agents. However, the reaction mechanism is still under debate. In order to contribute to the investigation of the synthesis of AuNPs using stainless steel, different experimental conditions were tested. Cl⁻ concentration, pH of the precursor solution, as well as stainless steel composition were systematically changed. The syntheses were performed recording the open circuit potential to potentiometrically explore the electrochemical properties of the system, under operando conditions. Spectroscopic and morphological characterizations were carried out along with potentiometric monitoring, aiming at correlating the synthesis parameters with the AuNPs characteristics. As a result, an overview of the process features, and of its most reasonable mechanism were obtained.

Host-guest fabrication of dual-responsive hyaluronic acid/mesoporous silica nanoparticle based drug delivery system for targeted cancer therapy

In this paper, a targeting hyaluronic acid (HA)/mesoporous silica nanoparticle (MSN) based drug delivery system (DDS) with dual-responsiveness was prepared for cancer therapy. To avoid the side reaction between the anti-cancer drug doxorubicin hydrochloride (DOX) and HA, host-guest interaction was applied to fabricate the DDS named DOX@MSN-SS-N=C-HA. The "nanocontainer" MSN was modified with benzene ring via both pH-sensitive benzoic imine bond and redox-sensitive disulfide linkage. When DOX was loaded in the pores of MSN, the channels were then capped by the "gatekeeper" β-CD grafted HA (HA-g-CD) through host-guest interaction between β-CD and benzene. HA endowed the drug carriers with the targeting capability in CD44 over-expressed cancer cells. After cellular uptake, the carriers could rapidly release DOX for cell apoptosis due to both the hydrolysis of benzoic imine bond at low pH and the cleavage of disulfide bond at a high concentration of glutathione (GSH) intracellular. In vitro drug release studies and in vitro cytotoxicity studies were taken to investigate the dual-responsiveness of the carriers. And the CD44-receptor mediated cancer cell targeting capability was investigated as well. In conclusion, the targeted dual-responsive complex DDS fabricated through host-guest interaction has promising potential in cancer therapy.

Overview of the application of inorganic nanomaterials in cancer photothermal therapy

Cancer photothermal therapy (PTT) has captured the attention of researchers worldwide due to its localized and trigger-activated therapeutic effect.

Nanoengineering of Gold Nanoparticles: Green Synthesis, Characterization, and Applications

The fundamental aspects of the manufacturing of gold nanoparticles (AuNPs) are discussed in this review. In particular, attention is devoted to the development of a simple and versatile method for the preparation of these nanoparticles. Eco-friendly synthetic routes, such as wet chemistry and biosynthesis with the aid of polymers, are of particular interest. Polymers can act as reducing and/or capping agents, or as soft templates leading to hybrid nanomaterials. This methodology allows control of the synthesis and stability of nanomaterials with novel properties. Thus, this review focus on a fundamental study of AuNPs properties and different techniques to characterize them, e.g., Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), UV-Visible spectroscopy, Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy, Small-angle X-Ray Scattering (SAXS), and rheology. Recently, AuNPs obtained by “green” synthesis have been applied in catalysis, in medicine, and as antibacterials, sensors, among others.

Single NIR Laser-Activated Multifunctional Nanoparticles for Cascaded Photothermal and Oxygen-Independent Photodynamic Therapy

Inconvenient dual-laser irradiation and tumor hypoxic environment as well as limited judgment of treating region have impeded the development of combined photothermal and photodynamic therapies (PTT and PDT). Herein, Bi₂Se₃@AIPH nanoparticles (NPs) are facilely developed to overcome these problems. Through a one-step method, free radical generator (AIPH) and phase transition material (lauric acid, LA, 44-46 °C) are encapsulated in hollow bismuth selenide nanoparticles (Bi₂Se₃ NPs). Under a single 808-nm laser irradiation at the tumor area, hyperthermia produced by Bi₂Se₃ not only directly leads to cell death, but also promotes AIPH release by melting LA and triggers free radical generation, which could further eradicate tumor cells in hypoxic environments. Moreover, Bi₂Se₃ with high X-ray attenuation coefficient endows the NPs with high computed tomography (CT) imaging capability, which is important for treating area determination. The results exhibit that Bi₂Se₃@AIPH NPs possesses 31.2% photothermal conversion efficiency for enhanced PTT, ideal free radical generation for oxygen-independent PDT, and 37.77 HU mL mg^-1 X-ray attenuation coefficient for CT imaging with high quality. Most importantly, the tumor growth inhibition rate by synergistic PTT, PDT, and following immunotherapy is 99.6%, and even one tumor disappears completely, which demonstrates excellent cascaded synergistic effect of Bi₂Se₃@AIPH NPs for the tumor therapy.

Bioactive factors for cartilage repair and regeneration: Improving delivery, retention, and activity

Articular cartilage is a remarkable tissue whose sophisticated composition and architecture allow it to withstand complex stresses within the joint. Once injured, cartilage lacks the capacity to self-repair, and injuries often progress to joint wide osteoarthritis (OA) resulting in debilitating pain and loss of mobility. Current palliative and surgical management provides short-term symptom relief, but almost always progresses to further deterioration in the long term. A number of bioactive factors, including drugs, corticosteroids, and growth factors, have been utilized in the clinic, in clinical trials, or in emerging research studies to alleviate the inflamed joint environment or to promote new cartilage tissue formation. However, these therapies remain limited in their duration and effectiveness. For this reason, current efforts are focused on improving the localization, retention, and activity of these bioactive factors. The purpose of this review is to highlight recent advances in drug delivery for the treatment of damaged or degenerated cartilage. First, we summarize material and modification techniques to improve the delivery of these factors to damaged tissue and enhance their retention and action within the joint environment. Second, we discuss recent studies using novel methods to promote new cartilage formation via biofactor delivery, that have potential for improving future long-term clinical outcomes. Lastly, we review the emerging field of orthobiologics, using delivered and endogenous cells as drug-delivering "factories" to preserve and restore joint health. Enhancing drug delivery systems can improve both restorative and regenerative treatments for damaged cartilage. STATEMENT OF SIGNIFICANCE: Articular cartilage is a remarkable and sophisticated tissue that tolerates complex stresses within the joint. When injured, cartilage cannot self-repair, and these injuries often progress to joint-wide osteoarthritis, causing patients debilitating pain and loss of mobility. Current palliative and surgical treatments only provide short-term symptomatic relief and are limited with regards to efficiency and efficacy. Bioactive factors, such as drugs and growth factors, can improve outcomes to either stabilize the degenerated environment or regenerate replacement tissue. This review highlights recent advances and novel techniques to enhance the delivery, localization, retention, and activity of these factors, providing an overview of the cartilage drug delivery field that can guide future research in restorative and regenerative treatments for damaged cartilage.

The appliances and prospects of aurum nanomaterials in biodiagnostics, imaging, drug delivery and combination therapy

Aurum nanomaterials (ANM), combining the features of nanotechnology and metal elements, have demonstrated enormous potential and aroused great attention on biomedical applications over the past few decades. Particularly, their advantages, such as controllable particle size, flexible surface modification, higher drug loading, good stability and biocompatibility, especially unique optical properties, promote the development of ANM in biomedical field. In this review, we will discuss the advanced preparation process of ANM and summarize their recent applications as well as their prospects in diagnosis and therapy. Besides, multi-functional ANM-based theranostic nanosystems will be introduced in details, including radiotherapy (RT), photothermal therapy (PTT), photodynamic therapy (PDT), immunotherapy (IT), and so on.

Gold nanoparticles in chemo-, immuno-, and combined therapy: review [Invited]

Functionalized gold nanoparticles (GNPs) with controlled geometrical and optical properties have been the subject of intense research and biomedical applications. This review summarizes recent data and topical problems in nanomedicine that are related to the use of variously sized, shaped, and structured GNPs. We focus on three topical fields in current nanomedicine: (1) use of GNP-based nanoplatforms for the targeted delivery of anticancer and antimicrobial drugs and of genes; (2) GNP-based cancer immunotherapy; and (3) combined chemo-, immuno-, and phototherapy. We present a summary of the available literature data and a short discussion of future work.

New insights towards mesoporous silica nanoparticles as a technological platform for chemotherapeutic drugs delivery

Mesoporous silica nanoparticles (MSNs) displays interesting properties for biomedical applications such as high chemical stability, large surface area and tunable pores diameters and volumes, allowing the incorporation of large amounts of drugs, protecting them from deactivation and degradation processes acting as an excellent nanoplatform for drug delivery. However, the functional MSNs do not present the ability to transport the therapeutics without any leakage until reach the targeted cells causing side effects. On the other hand, the hydroxyls groups available on MSNs surface allows the conjugation of specific molecules which can binds to the overexpressed Enhanced Growth Factor Receptor (EGFR) in many tumors, representing a potential strategy for the cancer treatment. Beyond that, the targeting molecules conjugate onto mesoporous surface increase its cell internalization and act as gatekeepers blocking the mesopores controlling the drug release. In this context, multifunctional MSNs emerge as stimuli-responsive controlled drug delivery systems (CDDS) to overcome drawbacks as low internalization, premature release before to reach the region of interest, several side effects and low effectiveness of the current treatments. This review presents an overview of MSNs fabrication methods and its properties that affects drug delivery as well as stimuli-responsive CDDS for cancer treatment.

DNA-Templated Silver Nanocluster/Porphyrin/MnO2 Platform for Label-Free Intracellular Zn2+ Imaging and Fluorescence-/Magnetic Resonance Imaging-Guided Photodynamic Therapy

Developing a theranostic platform that integrates diagnosis and treatment in one single nanostructure is necessary for efficient tumor treatment. Here, we presented a novel theranostic nanoprobe for nonlabeled fluorescence imaging of Zn²⁺ and 635 nm red light-triggered photodynamic therapy (PDT) by a multifunctional DNA-templated silver nanocluster/porphyrin/MnO₂ nanoplatform. MnO₂ nanosheets adsorbed hairpin DNA-silver nanoclusters (AgNCs) and porphyrin (P) by facile physisorption, which accelerate the transfection of nanoprobes and P into tumor cells. After entering the cells, the biodegradation of MnO₂ nanosheets by glutathione and acidic hydrogen peroxide released AgNCs for label-free Zn²⁺ fluorescence imaging by the hairpin DNA-fueled dynamic self-assembly of three-way DNA junction architectures, and the released Mn²⁺ could act as an effective magnetic resonance imaging (MRI) contrast agent. In addition, MnO₂ was decomposed in the acidic H₂O₂-ample environment and produced O₂ to overbear hypoxia-related PDT resistance, highly efficient PDT was obtained by excess singlet oxygen (¹O₂) release of P-AgNCs-MnO₂ nanoprobes under light irradiation compared with free P. In vitro and in vivo studies confirmed that P-AgNCs-MnO₂ exhibited high fluorescence specificity, excellent PDT effect, and good biocompatibility and could be used as a contrast agent for MRI. This theranostic platform provided a new avenue for the fluorescence and MRI diagnosis of tumors and efficient tumor treatment.

Carbon nanotube incorporation in PMMA to prevent microbial adhesion

Although PMMA-based biomaterials are widely used in clinics, a major hurdle, namely, their poor antimicrobial (i.e., adhesion) properties, remains and can accelerate infections. In this study, carboxylated multiwalled carbon nanotubes (CNTs) were incorporated into poly(methyl methacrylate) (PMMA) to achieve drug-free antimicrobial adhesion properties. After characterizing the mechanical/surface properties, the anti-adhesive effects against 3 different oral microbial species (Staphylococcus aureus, Streptococcus mutans, and Candida albicans) were determined for roughened and highly polished surfaces using metabolic activity assays and staining for recognizing adherent cells. Carboxylated multiwalled CNTs were fabricated and incorporated into PMMA. Total fracture work was enhanced for composites containing 1 and 2% CNTs, while other mechanical properties were gradually compromised with the increase in the amount of CNTs incorporated. However, the surface roughness and water contact angle increased with increasing CNT incorporation. Significant anti-adhesive effects (35~95%) against 3 different oral microbial species without cytotoxicity to oral keratinocytes were observed for the 1% CNT group compared to the PMMA control group, which was confirmed by microorganism staining. The anti-adhesive mechanism was revealed as a disconnection of sequential microbe chains. The drug-free antimicrobial adhesion properties observed in the CNT-PMMA composite suggest the potential utility of CNT composites as future antimicrobial biomaterials for preventing microbial-induced complications in clinical settings (i.e., Candidiasis).

High Biocompatible ZIF-8 Coated by ZrO2 for Chemo-microwave Thermal Tumor Synergistic Therapy

The zeolitic imidazolate framework-8 (ZIF-8) is a specifically promising drug carrier due to its excellent intrinsic properties. However, the high toxicity of ZIF-8 nanoparticles severely limits their further research and clinical application. In this work, the biocompatibility of ZIF-8 nanoparticles is greatly improved by coating ZrO₂ onto the surface. The survival rate of cells and mice in the ZIF-8@ZrO₂ nanocomposite group is significantly increased compared with the undecorated ZIF-8 nanoparticle group. Doxorubicin (DOX) as a chemotherapeutic drug is deposited during the ZIF-8 growth by a facile one-pot method. Ionic liquid (IL) is loaded into the pore of the ZIF-8/DOX@ZrO₂ nanocomposites for enhancing microwave thermal therapy. The tumor inhibition rate of ZIF-8/DOX@ZrO₂@IL nanocomposites with synergistic microwave thermal therapy and chemotherapy is obviously higher than in other groups. In addition, the ZIF-8/DOX@ZrO₂@IL nanocomposites are used for real-time monitoring of the therapeutic outcomes due to the excellent computed tomography contrast agent, ZrO₂. Therefore, such a ZrO₂ coating strategy shows great promise for overcoming high toxicity of ZIF-8 nanoparticles, which offers a new platform for tumor synergistic microwave thermal therapy and chemotherapy using the ZIF-8/DOX@ZrO₂@IL nanocomposite as a theranostic nanocarrier.

NIR-Light-Triggered Anticancer Strategy for Dual-Modality Imaging-Guided Combination Therapy via a Bioinspired Hybrid PLGA Nanoplatform

A promising approach toward cancer therapy is expected to integrate imaging and therapeutic agents into a versatile nanocarrier for achieving improved antitumor efficacy and reducing the side effects of conventional chemotherapy. Herein, we designed a poly(d,l-lactic- co-glycolic acid) (PLGA)-based theranostic nanoplatform using the double emulsion solvent evaporation method (W/O/W), which is associated with bovine serum albumin (BSA) modifications, to codeliver indocyanine green (ICG), a widely used near-infrared (NIR) dye, and doxorubicin (Dox), a chemotherapeutic drug, for dual-modality imaging-guided chemo-photothermal combination cancer therapy. The resultant ICG/Dox co-loaded hybrid PLGA nanoparticles (denoted as IDPNs) had a diameter of around 200 nm and exhibited excellent monodispersity, fluorescence/size stability, and biocompatibility. It was confirmed that IDPNs displayed a photothermal effect and that the heat induced faster release of Dox, which led to enhanced drug accumulation in cells and was followed by their efficient escape from the lysosomes into the cytoplasm and drug diffusion into the nucleus, resulting in a chemo-photothermal combinatorial therapeutic effect in vitro. Moreover, the IDPNs exhibited a high ability to accumulate in tumor tissue, owing to the enhanced permeability and retention (EPR) effect, and could realize real-time fluorescence/photoacoustic imaging of solid tumors with a high spatial resolution. In addition, the exposure of tumor regions to NIR irradiation could enhance the tumor penetration ability of IDPNs, almost eradicating subcutaneous tumors. In addition, the inhibition rate of IDPNs used in combination with laser irradiation against EMT-6 tumors in tumor-bearing nude mice (chemo-photothermal therapy) was approximately 95.6%, which was much higher than that for chemo- or photothermal treatment alone. Our study validated the fact that the use of well-defined IDPNs with NIR laser treatment could be a promising strategy for the early diagnosis and passive tumor-targeted chemo-photothermal therapy for cancer.

Combinatory Cancer Therapeutics with Nanoceria-Capped Mesoporous Silica Nanocarriers through pH-triggered Drug Release and Redox Activity

In the field of nanomedicine, drug-loaded nanocarriers that integrate nanotechnology and chemotherapeutics are widely used to achieve synergistic therapeutic effects. Here, we prepared mesoporous silica nanoparticles capped with cerium oxide nanoparticles (COP@MSN) wherein a pH trigger-responsive mechanism was used to control drug release and intracellular drug delivery. We blocked the mesopores of the carboxyl-functionalized MSN with aminated COP. These pores could be opened in acidic conditions to release the loaded drug, thus establishing a pH-responsive drug release system. We loaded doxorubicin (DOX) as anticancer biomolecule into the pores of MSN and capped with COP. The COP@DOX-MSN system showed a typical drug release profile in an acidic medium, which, however, was not observed in a neutral medium. In vitro studies using cancer cell line (HeLa) proved that the COP@DOX-MSN entered efficiently into HeLa cells and released DOX to the level sufficient for cytotoxicity. The cytotoxic effect of COP in cancer cells was facilitated by the pro-oxidant property of COPs, which considerably raised the reactive oxygen species (ROS) level, thereby leading to cellular apoptosis. The combination of DOX with COP (COP@DOX-MSN) showed even higher ROS level, demonstrating a cytotoxic synergism of drug and nanoparticle in terms of ROS generation. Collectively, the COP@DOX-MSN is considered useful for cancer treatment with the combined capacity of pH-controlled drug delivery, chemotherapeutics, and redox activity.

Highly stable near-infrared dye conjugated cerasomes for fluorescence imaging-guided synergistic chemo-photothermal therapy of colorectal cancer

Dye-conjugated cerasome loaded with DOX exhibited high stability and controllable drug release, holding great promise in colorectal cancer photothermal chemotherapy.

Advances in nanoparticle development for improved therapeutics delivery: nanoscale topographical aspect

Nanoparticle-based therapeutics delivery holds great promise for the treatment of intractable diseases. The high loading of drug molecules and their precise delivery to target sites are needed to gain optimal therapeutic functions of the nanoparticle delivery system. In this communication, we highlight, among other properties of nanoparticles (e.g. size, shape, surface chemistry, and degradation), the nanoscale topography, which has recently been shown to be an important parameter, ultimately determining drug loading, cell penetration, and body clearance. This nanotopographical aspect is considered to offer a new effective strategy to the development of nanoparticles for drug and gene delivery with enhanced therapeutic outcome.

Photothermally controlled drug release system with high dose loading for synergistic chemo-photothermal therapy of multidrug resistance cancer

Chemotherapy is an important first-line strategy for tumor therapy in cancer treatment, but multidrug resistance (MDR) is a major problem that reduces the efficacy of chemotherapeutics. Herein, we report a novel photothermally controlled intelligent drug release system (AuNP@mSiO₂-DOX-FA) with a large amount of drugs loading for synergistic chemo-photothermal therapy of MDR in breast cancer. The nanoplatform utilized gold nanoparticles as a hyperthermia core, and large-mesoporous silica as a shell for doxorubicin (DOX) loading. Benefiting from the thick layer and large pore size, the encapsulation and loading efficiency were as high as 97.7% and 8.84%, respectively. Furthermore, under the trigger of 808 nm near infrared (NIR) light, the released DOX increased significantly at pH 5.0 and reached to 39.0% in 20 min, achieving a facile intelligent control of chemotherapy additional to the photothermal therapy. The viability of MCF-7/ADR cells could be efficiently reduced to 16.9%, demonstrating the proposed photothermally controlled system with synergistic chemo-photothermal therapy has great potential capability to overcome MDR in breast cancer.

Fabrication of Photothermo-Responsive Drug-Loaded Nanogel for Synergetic Cancer Therapy

Temperature stimulus, easy modulation in comparison to other environmental stimuli, makes thermo-responsive nanocarriers popular in the applications of controlled drug release for cancer therapy. In this study, photosensitive sodium copper chlorophyllin (SCC) was incorporated into thermo-responsive polymeric nanogels consisted of N-isopropylacrylamide and N-(hydroxymethyl)acrylamide. Significant heat was generated from the SCC-containing nanogels under the exposure to 532-nm green laser, and resulted in cell mortality. The thermo-responsive nanogel loaded with 5-FU, an anti-cancer drug, released the drug explosively when exposed to green laser. The combination of hyperthermia and temperature-induced drug release via green laser irradiation greatly enhanced cell mortality to a maximal extent. Such photothermo-responsive nanogel possesses a great potential in anti-cancer treatment.

Silica-based organic-inorganic hybrid nanoparticles and nanoconjugates for improved anticancer drug delivery

After the introduction of first generation MSNs for drug delivery with some challenges such as large particle sizes, irregular morphologies and aggregations, second generation provided uniform spherical morphologies, tunable pore/particle sizes and compositions. Henceforth, organic-inorganic hybrid mesoporous silica nanosystems have grown rapidly and utilized for active and passive targeting of tumorigenic cells especially conjugated with organic polymers followed by third generation counterparts with improved functionalities for cancer therapy. The aim of this review article is to focus on the advancements in mesoporous silica based organic-inorganic hybrid nanoparticles developed as drug carriers targeting cancer cells. Brief introduction to the state-of-the-art in passive and active targeting methods is presented. Specifically, therapeutic, diagnostic and theranostic applications are discussed with emphases on triggered and ligand conjugated organic-inorganic hybrid mesoporous silica nanomaterials. Although mesoporous silica nanoparticles perform well in preclinical tests, clinical translation progresses slowly as appropriate doses needs to be evaluated for human use along with biocompatibility and efficiency depending on surface modifications.

Cyclodextrin–PEG conjugate-wrapped magnetic ferrite nanoparticles for enhanced drug loading and release

Magnetic nanoparticles are envisaged to overcome the impediments in the methods of targeted drug delivery and hence cure cancer effectively. We report herein, manganese ferrite nanoparticles, coated with β-cyclodextrin-modified polyethylene glycol as a carrier for the drug, camptothecin. The particles are of the size of ~ 100 nm and they show superparamagnetic behaviour. The saturation magnetization does not get diminished on polymer coverage of the nanoparticles. The β-cyclodextrin–polyethylene glycol conjugates are characterized using NMR and mass spectrometric techniques. By coating the magnetic nanoparticles with the cyclodextrin–tethered polymer, the drug-loading capacity is enhanced and the observed release of the drug is slow and sustained. The cell viability of HEK293 and HCT15 cells is evaluated and the cytotoxicity is enhanced when the drug is loaded in the polymer-coated magnetic nanoparticles. The noncovalent-binding based and enhanced drug loading on the nanoparticles and the sustained release make the nanocarrier a promising agent for carrying the payload to the target.

Bacteria-like mesoporous silica-coated gold nanorods for positron emission tomography and photoacoustic imaging-guided chemo-photothermal combined therapy

Mesoporous silica nanoshell (MSN) coating has been demonstrated as a versatile surface modification strategy for various kinds of inorganic functional nanoparticles, such as gold nanorods (GNRs), to achieve not only improved nanoparticle stability but also concomitant drug loading capability. However, limited drug loading capacity and low tumor accumulation rate in vivo are two major challenges for the biomedical applications of MSN-coated GNRs (GNR@MSN). In this study, by coating uniformly sized GNRs with MSN in an oil-water biphase reaction system, we have successfully synthesized a new bacteria-like GNR@MSN (i.e., bGNR@MSN) with a significantly enlarged pore size (4-8 nm) and surface area (470 m²/g). After PEGylation and highly efficient loading of doxorubicin (DOX, 40.9%, w/w), bGNR@MSN were used for positron emission tomography (PET, via facile and chelator-free ⁸⁹Zr-labeling) and photoacoustic imaging-guided chemo-photothermal cancer therapy in vivo. PET imaging showed that ⁸⁹Zr-labeled bGNR@MSN(DOX)-PEG can passively target to the 4T1 murine breast cancer-bearing mice with high efficiency (∼10 %ID/g), based on enhanced permeability and retention effect. Significantly enhanced chemo-photothermal combination therapy was also achieved due to excellent photothermal effect and near-infrared-light-triggered drug release by bGNR@MSN(DOX)-PEG at the tumor site. The promising results indicate great potential of bGNR@MSN-PEG nanoplatforms for future cancer diagnosis and therapy.

Mesoporous silica nanoparticles functionalized with hyaluronic acid. Effect of the biopolymer chain length on cell internalization

Mesoporous silica nanoparticles (MSNs) were functionalized with amino groups (MSN-NH₂) and then with hyaluronic acid, a biocompatible biopolymer which can be recognized by CD44 receptors in tumor cells, to obtain a targeting drug delivery system. To this purpose, three hyaluronic acid samples differing for the molecular weight, namely HA_S (8-15 kDa), HA_M (30-50 kDa) and HA_L (90-130 kDa), were used. The MSN-HA_S, MSN-HA_M, and MSN-HA_L materials were characterized through zeta potential and dynamic light scattering measurements at pH = 7.4 and T = 37 °C to simulate physiological conditions. While zeta potential showed an increasing negative value with the increase of the HA chain length, an anomalous value of the hydrodynamic diameter was observed for MSN-HA_L, which was smaller than that of MSN-HA_S and MSN-HA_M samples. The cellular uptake of MSN-HA samples on HeLa cells at 37 °C was studied by optical and electron microscopy. HA chain length affected significantly the cellular uptake that occurred at a higher extent for MSN-NH₂ and MSN-HA_S than for MSN-HA_M and MSN-HA_L samples. Cellular uptake experiments carried out at 4 °C showed that the internalization process was inhibited for MSN-HA samples but not for MSN-NH₂. This suggests the occurrence of two different mechanisms of internalization. For MSN-NH₂ the uptake is mainly driven by the attractive electrostatic interaction with membrane phospholipids, while MSN-HA internalization involves CD44 receptors overexpressed in HeLa cells.

DNA Damage and Apoptosis Induction in Cancer Cells by Chemically Engineered Thiolated Riboflavin Gold Nanoassembly

Herein we have engineered a smart nuclear targeting thiol-modified riboflavin-gold nano assembly, RfS@AuNPs, which accumulates selectively in the nucleus without any nuclear-targeting peptides (NLS/RGD) and shows photophysically in vitro DNA intercalation. A theoretical model using Molecular Dynamics has been developed to probe the mechanism of formation and stability as well as dynamics of the RfS@AuNPs in aqueous solution and within the DNA microenvironment. The RfS@AuNPs facilitate the binucleated cell formation that is reflected in the significant increase of DNA damage marker, γ-H2AX as well as the arrest of most of the HeLa cells at the pre-G1 phase indicating cell death. Moreover, a significant upregulation of apoptotic markers confirms that the cell death occurs through the apoptotic pathway. Analyses of the microarray gene expression of RfS@AuNPs treated HeLa cells show significant alterations in vital biological processes necessary for cell survival. Taken together, our study reports a unique nuclear targeting mechanism through targeting the riboflavin receptors, which are upregulated in cancer cells and induce apoptosis in the targeted cells.

Cancer-Associated, Stimuli-Driven, Turn on Theranostics for Multimodality Imaging and Therapy

Advances in bioinformatics, genomics, proteomics, and metabolomics have facilitated the development of novel anticancer agents that have decreased side effects and increased safety. Theranostics, systems that have combined therapeutic effects and diagnostic capabilities, have garnered increasing attention recently because of their potential use in personalized medicine, including cancer-targeting treatments for patients. One interesting approach to achieving this potential involves the development of cancer-associated, stimuli-driven, turn on theranostics. Multicomponent constructs of this type would have the capability of selectively delivering therapeutic reagents into cancer cells or tumor tissues while simultaneously generating unique signals that can be readily monitored under both in vitro and in vivo conditions. Specifically, their combined anticancer activities and selective visual signal respond to cancer-associated stimuli, would make these theranostic agents more highly efficient and specific for cancer treatment and diagnosis. This article focuses on the progress of stimuli-responsive turn on theranostics that activate diagnostic signals and release therapeutic reagents in response to the cancer-associated stimuli. The present article not only provides the fundamental backgrounds of diagnostic and therapeutic tools that have been widely utilized for developing theranostic agents, but also discusses the current approaches for developing stimuli-responsive turn on theranostics.

A metal-organic framework based nanocomposite with co-encapsulation of Pd@Au nanoparticles and doxorubicin for pH- and NIR-triggered synergistic chemo-photothermal treatment of cancer cells

Here, we report a novel metal-organic framework-based nanocomposite with encapsulated Pd@Au nanoparticles and doxorubicin (DOX) for pH- and NIR-triggered synergistic chemo-photothermal treatment of cancer cells. In this work, Pd nanoparticles, which have uniform size and dispersibility, were first synthesized and used as a template to direct the covering of Au nanosheets. The obtained Au coated Pd (Pd@Au) nanoparticles have excellent dispersibility and photothermal conversion ability, which makes them a good photothermal nanomaterial. Subsequently, an acid-degradable metal-organic framework of ZIF-8 was employed to synchronously encapsulate Pd@Au nanoparticles and DOX to get a metal-organic framework-based nanocomposite (DOX/Pd@Au@ZIF-8). Under acid conditions (e.g. pH ∼5.0 in a lysosome), the ZIF-8 framework of the DOX/Pd@Au@ZIF-8 nanocomposite could be degraded, resulting in the release of encapsulated DOX. Moreover, the present Pd@Au nanoparticles can effectively convert NIR laser light (780 nm, 2.1 W cm^-2) into heat, not only further promoting the release of DOX, but also realizing the synergistic chemo-photothermal treatment of cancer cells. The in vitro experiments showed that this nanocomposite system has an excellent synergistic treatment effect on SMMC-7721 cells, even at low concentrations (e.g. 20 μg mL^-1). With the properties of synergistic chemo-photothermal treatment, we hope that such a nanocomposite system of DOX/Pd@Au@ZIF-8 could open the door to designing a significant multifunctional system for diverse applications in cancer treatment.