Photothermal and biodegradable polyaniline/porous silicon hybrid nanocomposites as drug carriers for combined chemo-photothermal therapy of cancer

Enhancing Phototoxicity in Human Colorectal Tumor Cells Through Nanoarchitectonics for Synergistic Photothermal and Photodynamic Therapies

Phototherapies are promising for noninvasive treatment of aggressive tumors, especially when combining heat induction and oxidative processes. Herein, we show enhanced phototoxicity of gold shell-isolated nanorods conjugated with toluidine blue-O (AuSHINRs@TBO) against human colorectal tumor cells (Caco-2) with synergic effects of photothermal (PTT) and photodynamic therapies (PDT). Mitochondrial metabolic activity tests (MTT) performed on Caco-2 cell cultures indicated a photothermal effect from AuSHINRs owing to enhanced light absorption from the localized surface plasmon resonance (LSPR). The phototoxicity against Caco-2 cells was further increased with AuSHINRs@TBO where oxidative processes, such as hydroperoxidation, were also present, leading to a cell viability reduction from 85.5 to 39.0%. The molecular-level mechanisms responsible for these effects were investigated on bioinspired tumor membranes using Langmuir monolayers of Caco-2 lipid extract. Polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) revealed that the AuSHINRs@TBO incorporation is due to attractive electrostatic interactions with negatively charged groups of the Caco-2 lipid extract, resulting in the expansion of surface pressure isotherms. Upon irradiation, Caco-2 lipid extract monolayers containing AuSHINRs@TBO (1:1 v/v) exhibited ca. 1.0% increase in surface area. This is attributed to the generation of reactive oxygen species (ROS) and their interaction with Caco-2 lipid extract monolayers, leading to hydroperoxide formation. The oxidative effects are facilitated by AuSHINRs@TBO penetration into the polar groups of the extract, allowing oxidative reactions with carbon chain unsaturations. These mechanisms are consistent with findings from confocal fluorescence microscopy, where the Caco-2 plasma membrane was the primary site of the cell death induction process.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

Engineering of copper sulfide mediated by phototherapy performance

Copper sulfide based phototherapy, including photothermal therapy and photodynamic therapy, is an emerging minimally invasive treatment of tumor, which the light was converted to heat or reactive oxygen to kill the tumor cells. Compared with conventional chemotherapy and radiation therapy, Cu2-x S based phototherapy is more efficient and has fewer side effects. However, considering the dose-dependent toxicity of Cu2-x S, the performance of Cu2-x S based phototherapy still cannot meet the requirement of the clinical application to now. To overcome this limitation, engineering of Cu2-x S to improve the phototherapy performance by increasing light absorption has attracted extensive attention. For better guidance of Cu2-x S engineering, we outline the currently engineering method being explored, including (1) structural engineering, (2) compositional engineering, (3) functional engineering, and (4) performance engineering. Also, the relationship between the engineering method and phototherapy performance was discussed in this review. In addition, the further development of Cu2-x S based phototherapy is prospected, including smart materials based phototherapy, phototherapy induced immune microenvironment modulation et al. This review will provide new ideas and opportunities for engineering of Cu2-x S with better phototherapy performance. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Four Ounces Can Move a Thousand Pounds: The Enormous Value of Nanomaterials in Tumor Immunotherapy

The application of nanomaterials in healthcare has emerged as a promising strategy due to their unique structural diversity, surface properties, and compositional diversity. In particular, nanomaterials have found a significant role in improving drug delivery and inhibiting the growth and metastasis of tumor cells. Moreover, recent studies have highlighted their potential in modulating the tumor microenvironment (TME) and enhancing the activity of immune cells to improve tumor therapy efficacy. Various types of nanomaterials are currently utilized as drug carriers, immunosuppressants, immune activators, immunoassay reagents, and more for tumor immunotherapy. Necessarily, nanomaterials used for tumor immunotherapy can be grouped into two categories: organic and inorganic nanomaterials. Though both have shown the ability to achieve the purpose of tumor immunotherapy, their composition and structural properties result in differences in their mechanisms and modes of action. Organic nanomaterials can be further divided into organic polymers, cell membranes, nanoemulsion-modified, and hydrogel forms. At the same time, inorganic nanomaterials can be broadly classified as nonmetallic and metallic nanomaterials. The current work aims to explore the mechanisms of action of these different types of nanomaterials and their prospects for promoting tumor immunotherapy.

Nanomaterials for photothermal cancer therapy

Cancer has emerged as a pressing global public health issue, and improving the effectiveness of cancer treatment remains one of the foremost challenges of modern medicine. The primary clinical methods of treating cancer, including surgery, chemotherapy and radiotherapy, inevitably result in some adverse effects on the body. However, the advent of photothermal therapy offers an alternative route for cancer treatment. Photothermal therapy relies on photothermal agents with photothermal conversion capability to eliminate tumors at high temperatures, which offers advantages of high precision and low toxicity. As nanomaterials increasingly play a pivotal role in tumor prevention and treatment, nanomaterial-based photothermal therapy has gained significant attention owing to its superior photothermal properties and tumor-killing abilities. In this review, we briefly summarize and introduce the applications of common organic photothermal conversion materials (e.g., cyanine-based nanomaterials, porphyrin-based nanomaterials, polymer-based nanomaterials, etc.) and inorganic photothermal conversion materials (e.g., noble metal nanomaterials, carbon-based nanomaterials, etc.) in tumor photothermal therapy in recent years. Finally, the problems of photothermal nanomaterials in antitumour therapy applications are discussed. It is believed that nanomaterial-based photothermal therapy will have good application prospects in tumor treatment in the future.

Neoadjuvant Gold Nanoshell-Based Photothermal Therapy Combined with Liposomal Doxorubicin in a Mouse Model of Colorectal Cancer

Introduction

Traditional cancer treatments, such as chemotherapy, are often incapable of achieving complete responses as standalone therapies. Hence, current treatment strategies typically rely on a combination of several approaches. Nanoparticle-based photothermal therapy (PTT) is a technique used to kill cancer cells through localized, severe hyperthermia that has shown promise as an add-on treatment to multiple cancer therapies. Here, we evaluated whether the combination of gold nanoshell (NS)-based PTT and liposomal doxorubicin could improve outcome in a mouse model of colorectal cancer.

Methods

First, NS-based PTT was performed on tumor-bearing mice. Radiolabeled liposomes were then injected at different timepoints to follow their accumulation in the tumor and determine the ideal injection time after PTT. In addition, fluorescent liposomes were used to observe the liposomal distribution in the tumor after PTT. Finally, we combined PTT and doxorubicin-loaded liposomes and studied the effect of the treatment strategy on the mice by following tumor growth and survival.

Results

PTT significantly improved liposomal accumulation in the tumor, but only when the liposomes were injected immediately after the therapy. The liposomes accumulated mostly in regions adjacent to the ablated areas. When PTT was combined with liposomal doxorubicin, the mice experienced a slowdown in tumor growth and an improvement in survival.

Conclusion

According to our preclinical study, NS-based PTT seems promising as an add-on treatment for liposomal chemotherapy and potentially other systemic therapies, and could be relevant for future application in a clinical setting.

Biomolecule-mimetic nanomaterials for photothermal and photodynamic therapy of cancers: Bridging nanobiotechnology and biomedicine

Nanomaterial-based phototherapy has become an important research direction for cancer therapy, but it still to face some obstacles, such as the toxic side effects and low target specificity. The biomimetic synthesis of nanomaterials using biomolecules is a potential strategy to improve photothermal therapy (PTT) and photodynamic therapy (PDT) techniques due to their endowed biocompatibility, degradability, low toxicity, and specific targeting. This review presents recent advances in the biomolecule-mimetic synthesis of functional nanomaterials for PTT and PDT of cancers. First, we introduce four biomimetic synthesis methods via some case studies and discuss the advantages of each method. Then, we introduce the synthesis of nanomaterials using some biomolecules such as DNA, RNA, protein, peptide, polydopamine, and others, and discuss in detail how to regulate the structure and functions of the obtained biomimetic nanomaterials. Finally, potential applications of biomimetic nanomaterials for both PTT and PDT of cancers are demonstrated and discussed. We believe that this work is valuable for readers to understand the mechanisms of biomimetic synthesis and nanomaterial-based phototherapy techniques, and will contribute to bridging nanotechnology and biomedicine to realize novel highly effective cancer therapies.

Electrically Conductive Hydrogels for Articular Cartilage Tissue Engineering

Articular cartilage is a highly specialized tissue found in diarthrodial joints, which is crucial for healthy articular motion. Despite its importance, articular cartilage has limited regenerative capacities, and the degeneration of this tissue is a leading cause of disability worldwide, with hundreds of millions of people affected. As current treatment options for cartilage degeneration remain ineffective, tissue engineering has emerged as an exciting approach to create cartilage substitutes. In particular, hydrogels seem to be suitable candidates for this purpose due to their biocompatibility and high customizability, being able to be tailored to fit the biophysical properties of native cartilage. Furthermore, these hydrogel matrices can be combined with conductive materials in order to simulate the natural electrochemical properties of articular cartilage. In this review, we highlight the most common conductive materials combined with hydrogels and their diverse applications, and then present the current state of research on the development of electrically conductive hydrogels for cartilage tissue engineering. Finally, the main challenges and future perspectives for the application of electrically conductive hydrogels on articular cartilage repair strategies are also discussed.

Porous biomaterials for tissue engineering: a review

The field of biomaterials has grown rapidly over the past decades. Within this field, porous biomaterials have played a remarkable role in: (i) enabling the manufacture of complex three-dimensional structures; (ii) recreating mechanical properties close to those of the host tissues; (iii) facilitating interconnected structures for the transport of macromolecules and cells; and (iv) behaving as biocompatible inserts, tailored to either interact or not with the host body. This review outlines a brief history of the development of biomaterials, before discussing current materials proposed for use as porous biomaterials and exploring the state-of-the-art in their manufacture. The wide clinical applications of these materials are extensively discussed, drawing on specific examples of how the porous features of such biomaterials impact their behaviours, as well as the advantages and challenges faced, for each class of the materials.

New Degradable Semiconducting Polymers for Photoacoustic Imaging of λ-Carrageenan-Induced Arthritis Mouse Model

Semiconducting polymer has a high extinction coefficient and a long band absorption and can be used as a photoacoustic imaging contrast agent. However, nonbiodegradable semiconducting polymers may cause biosafety issues due to being retained in the body. Therefore, developing degradable semiconducting polymers is necessary for in vivo imaging. Herein, we developed three degradable semiconducting polymers with unique optical properties. We adjusted the optical properties of semiconducting polymers by designing the molecular structure of semiconducting polymers. Polymers with a donor-π-acceptor structure could easily improve the optical properties through adjusting the donor or acceptor units. Through adjusting the electron-donor and -acceptor units, three diketopyrrolopyrrole derivative polymers (DPPTz, DPPQu, and DPPWu) were synthesized and converted into nanosize particles. By introducing the degradable chemical groups in the main chain structure of semiconducting polymers, diketopyrrolopyrrole polymers could be degraded by ClO^-. Among these nanosize particles, DPPTz NPs and DPPQu NPs were used to achieve the in vivo photoacoustic imaging of λ-carrageenan-induced arthritis mouse model. This work provides a novel design idea for the designing of red-shifted semiconducting polymer with degradable properties.

Nanoarchitectonics of Indocyanine Green/Doxorubicin-Loaded Hydroxyl Boron Nitride Nanosheets for Chemophotothermal Therapy

Biocompatible hydroxylated boron nitride nanosheets were effectively loaded with indocyanine green and doxorubicin using successive assembly. The indocyanine green/doxorubicin-loaded hydroxyl boron nitride nanosheets (ICG/DOX@OH-BNNS) integrated photothermal therapy and chemotherapy into a single nano vehicle. It had been confirmed that ICG/DOX@OH-BNNS could produce reactive oxygen species and exhibit excellent photothermal effects and light-triggered faster DOX release with NIR laser irradiation. On the other hand, the fluorescence of DOX in ICG/DOX@OH-BNNS was also used for visualizing subcellular location. Compared with individual chemotherapy and photothermal therapy, the combined treatment of ICG/DOX@OH-BNNS could synergistically induce the apoptosis and death of A549 cells and suppress S180 tumor growth in vivo.

Progress of Nanomaterials-Based Photothermal Therapy for Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the top 15 most prevalent cancers worldwide. However, the current treatment models for OSCC (e.g., surgery, chemotherapy, radiotherapy, and combination therapy) present several limitations: damage to adjacent healthy tissue, possible recurrence, low efficiency, and severe side effects. In this context, nanomaterial-based photothermal therapy (PTT) has attracted extensive research attention. This paper reviews the latest progress in the application of biological nanomaterials for PTT in OSCC. We divide photothermal nanomaterials into four categories (noble metal nanomaterials, carbon-based nanomaterials, metal compounds, and organic nanomaterials) and introduce each category in detail. We also mention in detail the drug delivery systems for PTT of OSCC and briefly summarize the applications of hydrogels, liposomes, and micelles. Finally, we note the challenges faced by the clinical application of PTT nanomaterials and the possibility of further improvement, providing direction for the future research of PTT in OSCC treatment.

Dual Stimuli-Responsive Multifunctional Silicon Nanocarriers for Specifically Targeting Mitochondria in Human Cancer Cells

Specific targeting, selective stimuli-responsiveness, and controlled release of anticancer agents are requested for high therapeutic efficiency with a minimal adverse effect. Herein, we report the sophisticated synthesis and functionalization of fluorescent mesoporous silicon (FMPSi) nanoparticles decorated with graphene oxide (GO) nanosheets. GO-wrapped FMPSi (FMPSi@GO) was loaded with a cisplatin (Cis) anticancer agent, and Cis-loaded FMPSi@GO (FMPSi-Cis@GO) exhibited the dual stimuli (pH and NIR)-responsiveness of controlled drug release, i.e., the drug release rate was distinctly enhanced at acidic pH 5.5 than at neutral pH 7.0 and further enhanced under NIR irradiation at acidic pH condition. Notably, dequalinium-conjugated FMPSi-Cis@GO (FMPSi-Cis@GO@DQA) demonstrated an excellent specificity for mitochondrial targeting in cancer cells without noticeable toxicity to normal human cells. Our novel silicon nanocarriers demonstrated not only stimuli (pH and NIR)-responsive controlled drug release, but also selective accumulation in the mitochondria of cancer cells and destroying them.

Chemo-photothermal immunotherapy for eradication of orthotopic tumors and inhibition of metastasis by intratumoral injection of polydopamine versatile hydrogels

Cancer remains one of the leading causes of death globally and metastasis always leads to treatment failure. Here, we develop a versatile hydrogel loading photothermal agents, chemotherapeutics, and immune-adjuvants to eradicate orthotopic tumors and inhibit metastasis by combinational therapy. Hydrogel networks were synthesized via the thiol-Michael addition of polydopamine (PDA) with thiolated hyaluronic acid. PDA acted as a cross-linking agent and endowed the hydrogel with excellent photothermal property. Meanwhile, a chemotherapeutic agent, doxorubicin (DOX), was loaded in the hydrogel via π‒π stacking with PDA and an immune-adjuvant, CpG-ODN, was loaded via electrostatic interaction. The release of DOX from the hydrogel was initially slow but accelerated due to near infrared light irradiation. The hydrogels showed remarkably synergistic effect against 4T1 cancer cells and stimulated plenty of cytokines secreting from RAW264.7 cells. Moreover, the hydrogels eradicated orthotopic murine breast cancer xenografts and strongly inhibited metastasis after intratumoral injection and light irradiation. The high anticancer efficiency of this chemo-photothermal immunotherapy resulted from the strong synergistic effect of the versatile hydrogels, including the evoked host immune response. The combinational strategy of chemo-photothermal immunotherapy is promising for highly effective treatment of breast cancer.

Towards the translation of electroconductive organic materials for regeneration of neural tissues

Carbon-based conductive and electroactive materials (e.g., derivatives of graphene, fullerenes, polypyrrole, polythiophene, polyaniline) have been studied since the 1970s for use in a broad range of applications. These materials have electrical properties comparable to those of commonly used metals, while providing other benefits such as flexibility in processing and modification with biologics (e.g., cells, biomolecules), to yield electroactive materials with biomimetic mechanical and chemical properties. In this review, we focus on the uses of these electroconductive materials in the context of the central and peripheral nervous system, specifically recent studies in the peripheral nerve, spinal cord, brain, eye, and ear. We also highlight in vivo studies and clinical trials, as well as a snapshot of emerging classes of electroconductive materials (e.g., biodegradable materials). We believe such specialized electrically conductive biomaterials will clinically impact the field of tissue regeneration in the foreseeable future. STATEMENT OF SIGNIFICANCE: This review addresses the use of conductive and electroactive materials for neural tissue regeneration, which is of significant interest to a broad readership, and of particular relevance to the growing community of scientists, engineers and clinicians in academia and industry who develop novel medical devices for tissue engineering and regenerative medicine. The review covers the materials that may be employed (primarily focusing on derivatives of fullerenes, graphene and conjugated polymers) and techniques used to analyze materials composed thereof, followed by sections on the application of these materials to nervous tissues (i.e., peripheral nerve, spinal cord, brain, optical, and auditory tissues) throughout the body.

Conjugated Organic Photothermal Films for Spatiotemporal Thermal Engineering

With the growth of photoenergy harvesting and thermal engineering, photothermal materials (PTMs) have attracted substantial interest due to their unique functions such as localized heat generation, spatiotemporal thermal controllability, invisibility, and light harvesting capabilities. In particular, π-conjugated organic PTMs show advantages over inorganic or metallic PTMs in thin film applications due to their large light absorptivity, ease of synthesis and tunability of molecular structures for realizing high NIR absorption, flexibility, and solution processability. This review is intended to provide an overview of organic PTMs, including both molecular and polymeric PTMs. A description of the photothermal (PT) effect and conversion efficiency (ηPT ) for organic films is provided. After that, the chemical structure and optical properties of organic PTMs are discussed. Finally, emerging applications of organic PT films from the perspective of spatiotemporal thermal engineering principles are illustrated.

Inorganic nanomaterials with rapid clearance for biomedical applications

Inorganic nanomaterials that have inherently exceptional physicochemical properties (e.g., catalytic, optical, thermal, electrical, or magnetic performance) that can provide desirable functionality (e.g., drug delivery, diagnostics, imaging, or therapy) have considerable potential for application in the field of biomedicine. However, toxicity can be caused by the long-term, non-specific accumulation of these inorganic nanomaterials in healthy tissues, preventing their large-scale clinical utilization. Over the past several decades, the emergence of biodegradable and clearable inorganic nanomaterials has offered the potential to prevent such long-term toxicity. In addition, a comprehensive understanding of the design of such nanomaterials and their metabolic pathways within the body is essential for enabling the expansion of theranostic applications for various diseases and advancing clinical trials. Thus, it is of critical importance to develop biodegradable and clearable inorganic nanomaterials for biomedical applications. This review systematically summarizes the recent progress of biodegradable and clearable inorganic nanomaterials, particularly for application in cancer theranostics and other disease therapies. The future prospects and opportunities in this rapidly growing biomedical field are also discussed. We believe that this timely and comprehensive review will stimulate and guide additional in-depth studies in the area of inorganic nanomedicine, as rapid in vivo clearance and degradation is likely to be a prerequisite for the future clinical translation of inorganic nanomaterials with unique properties and functionality.

Near-infrared light and magnetic field dual-responsive porous silicon-based nanocarriers to overcome multidrug resistance in breast cancer cells with enhanced efficiency

The development of drug delivery systems based on external stimuli-responsive nanocarriers is important to overcome multidrug resistance in breast cancer cells. Herein, iron oxide/gold (Fe3O4/Au) nanoparticles were first fabricated via a simple hydrothermal reaction, and subsequently loaded into porous silicon nanoparticles (PSiNPs) via electrostatic interactions to construct PSiNPs@(Fe3O4/Au) nanocomposites. The as-prepared PSiNPs@(Fe3O4/Au) nanocomposites exhibited excellent super-paramagnetism, photothermal effect, and T2-weight magnetic resonance imaging capability. In particular, with the help of a magnetic field, the cellular uptake of PSiNPs@(Fe3O4/Au) nanocomposites was significantly enhanced in drug-resistant breast cancer cells. Moreover, PSiNPs@(Fe3O4/Au) nanocomposites as carriers showed a high loading and NIR light-triggered release of anticancer drugs. Based on the synergistic effect of magnetic field-enhanced cellular uptake and NIR light-triggered intracellular release, the amount of anticancer drug carried by PSiNPs@(Fe3O4/Au) nanocarriers into the nuclei of drug-resistant breast cancer cells sharply increased, accompanied by improved chemo-photothermal therapeutic efficacy. Finally, PSiNPs@(Fe3O4/Au) nanocomposites under the combined conditions of magnetic field attraction and NIR light irradiation also showed improved anticancer drug penetration and accumulation in three-dimensional multicellular spheroids composed of drug-resistant breast cancer cells, leading to a better growth inhibition effect. Overall, the fabricated PSiNPs@(Fe3O4/Au) nanocomposites demonstrated great potential for the therapy of multidrug-resistant breast cancer in future.

Tiny 2D silicon quantum sheets: a brain photonic nanoagent for orthotopic glioma theranostics

We report that atomically thin two-dimensional silicon quantum sheets (2D Si QSs), prepared by a scalable approach coupling chemical delithiation and cryo-assisted exfoliation, can serve as a high-performance brain photonic nanoagent for orthotopic glioma theranostics. With the lateral size of approximately 14.0 nm and thickness of about 1.6 nm, tiny Si QSs possess high mass extinction coefficient of 27.5 L g^-1 cm^-1 and photothermal conversion efficiency of 47.2% at 808 nm, respectively, concurrently contributing to the best photothermal performance among the reported 2D mono-elemental materials (Xenes). More importantly, Si QSs with low toxicity maintain the trade-off between stability and degradability, paving the way for practical clinical translation in consideration of both storage and action of nanoagents. In vitro Transwell filter experiment reveals that Si QSs could effectively go across the bEnd.3 cells monolayer. Upon the intravenous injection of Si QSs, orthotopic brain tumors are effectively inhibited under the precise guidance of photoacoustic imaging, and the survival lifetime of brain tumor-bearing mice is increased by two fold. Atomically thin Si QSs with strong light-harvesting capability are expected to provide an effective and robust 2D photonic nanoplatform for the management of brain diseases.

Recent Advances of Polyaniline-Based Biomaterials for Phototherapeutic Treatments of Tumors and Bacterial Infections

Conventional treatments fail to completely eradicate tumor or bacterial infections due to their inherent shortcomings. In recent years, photothermal therapy (PTT) has emerged as an attractive treatment modality that relies on the absorption of photothermal agents (PTAs) at a specific wavelength, thereby transforming the excitation light energy into heat. The advantages of PTT are its high efficacy, specificity, and minimal damage to normal tissues. To this end, various inorganic nanomaterials such as gold nanostructures, carbon nanostructures, and transition metal dichalcogenides have been extensively explored for PTT applications. Subsequently, the focus has shifted to the development of polymeric PTAs, owing to their unique properties such as biodegradability, biocompatibility, non-immunogenicity, and low toxicity when compared to inorganic PTAs. Among various organic PTAs, polyaniline (PANI) is one of the best-known and earliest-reported organic PTAs. Hence, in this review, we cover the recent advances and progress of PANI-based biomaterials for PTT application in tumors and bacterial infections. The future prospects in this exciting area are also addressed.

Facile synthesis of hollow mesoporous nickel sulfide nanoparticles for highly efficient combinatorial photothermal-chemotherapy of cancer

Traditional techniques for the synthesis of nickel sulfide (NiS) nanoparticles (NPs) always present drawbacks of morphological irregularity, non-porous structure and poor long-term stability, which are extremely unfavorable for establishing effective therapeutic agents. Here, a category of hollow mesoporous NiS (hm-NiS) NPs with uniform spherical structure and good aqueous dispersity were innovatively developed based on a modified solvothermal reaction technique. Upon the successful synthesis of hm-NiS NPs, dopamine was seeded and in situ polymerized into polydopamine (PDA) on the NP surface, followed by functionalization with thiol-polyethylene glycol (SH-PEG) and encapsulation of the chemotherapeutic drug, doxorubicin (DOX), to form hm-NiS@PDA/PEG/DOX (NiPPD) NPs. The resultant NiPPD NPs exhibited a decent photothermal response and stability, attributed to the optical absorption of the hm-NiS nanocore and PDA layer in the near-infrared (NIR) region. Furthermore, stimulus-responsive drug release was achieved under both acidic pH conditions and NIR laser irradiation, owing to the protonation of -NH₂ groups in the DOX molecules and local thermal shock, respectively. Lastly, a strong combinatorial photothermal-chemotherapeutic effect was demonstrated for tumor suppression with minimal systemic toxicity in vivo. Collectively, this state-of-the-art paradigm may provide useful insights to deepen the application of hm-NiS NPs for disease management and precision medicine.

Porous silicon nanomaterials: recent advances in surface engineering for controlled drug-delivery applications

Porous silicon (pSi) nanomaterials are increasingly attractive for biomedical applications due to their promising properties such as simple and feasible fabrication procedures, tunable morphology, versatile surface modification routes, biocompatibility and biodegradability. This review focuses on recent advances in surface modification of pSi for controlled drug delivery applications. A range of functionalization strategies and fabrication methods for pSi-polymer hybrids are summarized. Surface engineering solutions such as stimuli-responsive polymer grafting, stealth coatings and active targeting modifications are highlighted as examples to demonstrate what can be achieved. Finally, the current status of engineered pSi nanomaterials for in vivo applications is reviewed and future prospects and challenges in drug-delivery applications are discussed.

Optical properties of photodynamic therapy drugs in different environments: the paradigmatic case of temoporfin

Computational tools have been used to study the photophysical and photochemical features of photosensitizers in photodynamic therapy (PDT) - a minimally invasive, less aggressive alternative for cancer treatment. PDT is mainly based on the activation of molecular oxygen through the action of a photoexcited sensitizer (photosensitizer). Temoporfin, widely known as mTHPC, is a second-generation photosensitizer, which produces the cytotoxic singlet oxygen when irradiated with visible light and hence destroys tumor cells. However, the bioavailability of the mostly hydrophobic photosensitizer, and hence its incorporation into cells, is fundamental to achieve the desired effect on malignant tissues via PDT. In this study, we focus on the optical properties of the temoporfin chromophore in different environments -in vacuo, in solution, encapsulated in drug delivery agents, namely cyclodextrin, and interacting with a lipid bilayer.

Inorganic Porous Nanoparticles for Drug Delivery in Antitumoral Therapy

The use of nanoparticles in oncology to deliver chemotherapeutic agents has received considerable attention in the last decades due to their tendency to be passively accumulated in solid tumors. Besides this remarkable property, the surface of these nanocarriers can be decorated with targeting moieties capable to recognize malignant cells which lead to selective nanoparticle uptake mainly in the diseased cells, without affecting the healthy ones. Among the different nanocarriers which have been developed with this purpose, inorganic porous nanomaterials constitute some of the most interesting due to their unique properties such as excellent cargo capacity, high biocompatibility and chemical, thermal and mechanical robustness, among others. Additionally, these materials can be engineered to present an exquisite control in the drug release behavior placing stimuli-responsive pore-blockers or sensitive hybrid coats on their surface. Herein, the recent advances developed in the use of porous inorganic nanomedicines will be described in order to provide an overview of their huge potential in the look out of an efficient and safe therapy against this complex disease. Porous inorganic nanoparticles have been designed to be accumulated in tumoral tissues; once there to recognize the target cell and finally, to release their payload in a controlled manner.

Surface Engineering of Metal-Organic Framework as pH-/NIR-Responsive Nanocarrier for Imaging-Guided Chemo-Photothermal Therapy

BACKGROUND

Metal-organic frameworks (MOFs) have attracted intensive research interest in the biomedical field because of their unique properties. However, in order to realize the high loading capacity and therapeutic efficacy, it is still urgent to develop a multifunctional MOFs-based nanoplatform.

MATERIALS AND METHODS

Herein, a pH/near-infrared (NIR) dual-responsive drug delivery system based on zeolitic imidazolate framework-8 (ZIF-8) is constructed for synergistic chemo-photothermal therapy and dual-modal magnetic resonance (MR)/photoacoustic (PA) imaging. The doxorubicin hydrochloride (DOX) is embedded into ZIF-8 through one-pot method, and the resultant ZIF-8/DOX is then successively modified with polydopamine, Mn ions and poly(ethylene glycol). The obtained ZIF-8/DMPP is systematically characterized, and both its in vitro and in vivo biological effects are evaluated in detail.

RESULTS

The ZIF-8/DMPP possesses a high drug-loading content of 18.9% and displays appropriate size and morphology. The pH-dependent degradation and drug release behavior of prepared ZIF-8/DMPP are confirmed. Importantly, the results demonstrate that the photothermal effect of ZIF-8/DMPP under NIR laser irradiation can significantly accelerate its drug releasing rate, further improving the intracellular drug concentrations. Thereafter, the augmented chemotherapeutic efficiency by photothermal effect against cancer cells is verified both in vitro and in vivo. Besides, the favorable MR and PA imaging capacity of ZIF-8/DMPP is also evidenced on the tumor model.

CONCLUSION

Taken together, the surface engineering of ZIF-8-based nanocarrier in this work offers a promising strategy for the multifunctional MOFs-based drug delivery system.

Updates on mechanistic insights and targeting of tumour metastasis

Malignant tumours are one of the major diseases that seriously endanger human health. The characteristics of their invasion and metastasis are one of the main causes of death in cancer patients, and these features cannot be separated from the participation of various molecules-related cells living in the tumour microenvironment and specific structures. Tumour invasion can approximately be divided into several specific steps according to the movement of tumour cells. In each step, there are different actions in the tumour microenvironment that mediate the interactions among substances. Researchers are attempting to clarify every mechanism of the tumour dissemination. However, there is still a long way to the final determination. Here, we review these interactions in tumour invasion and metastasis at the structural, molecular and cellular levels. We also discuss the ongoing studies and the promise of targeting metastasis in tumour therapy.

Progress in Conductive Polyaniline-Based Nanocomposites for Biomedical Applications: A Review

Inherently conducting polymers (ICPs) are a specific category of synthetic polymers with distinctive electro-optic properties, which involve conjugated chains with alternating single and double bonds. Polyaniline (PANI), as one of the most well-known ICPs, has outstanding potential applications in biomedicine because of its high electrical conductivity and biocompatibility caused by its hydrophilic nature, low-toxicity, good environmental stability, and nanostructured morphology. Some of the limitations in the use of PANI, such as its low processability and degradability, can be overcome by the preparation of its blends and nanocomposites with various (bio)polymers and nanomaterials, respectively. This review describes the state-of-the-art of biological activities and applications of conductive PANI-based nanocomposites in the biomedical fields, such as antimicrobial therapy, drug delivery, biosensors, nerve regeneration, and tissue engineering. The latest progresses in the biomedical applications of PANI-based nanocomposites are reviewed to provide a background for future research.

Nanotransducers for Near-Infrared Photoregulation in Biomedicine

Photoregulation, which utilizes light to remotely control biological events, provides a precise way to decipher biology and innovate in medicine; however, its potential is limited by the shallow tissue penetration and/or phototoxicity of ultraviolet (UV)/visible light that are required to match the optical responses of endogenous photosensitive substances. Thereby, biologically friendly near-infrared (NIR) light with improved tissue penetration is desired for photoregulation. Since there are a few endogenous biomolecules absorbing or emitting light in the NIR region, the development of molecular transducers is essential to convert NIR light into the cues for regulation of biological events. In this regard, optical nanomaterials able to convert NIR light into UV/visible light, heat, or free radicals are suitable for this task. Here, the recent developments of optical nanotransducers for NIR-light-mediated photoregulation in medicine are summarized. The emerging applications, including photoregulation of neural activity, gene expression, and visual systems, as well as photochemical tissue bonding, are highlighted, along with the design principles of nanotransducers. Moreover, the current challenges and perspectives in this field are discussed.

Multifunctional PEG-b-polypeptide-decorated gold nanorod for targeted combined chemo-photothermal therapy of breast cancer

The combination of chemotherapy and photothermal therapy is acknowledged as one of the most promising approaches in cancer treatment. Targeted delivery and controlled drug release are two important factors for combined chemo-photothermal therapy. In this study, a multifunctional nanoplatform based on gold nanorod (GNR) decorated with folate-conjugated poly(ethylene glycol)-b-poly(L-γ-glutamylhydrazine) (FEGGH) containing disulfide linker and dihydroxyphenyl groups was developed for targeted combined chemo-photothermal therapy of breast cancer. FEGGH was synthesized by ring-opening polymerization of γ-benzyl-l-glutamate-N-carboxyanhydride using folate/cystamine-heterobifunctionalized poly(ethylene glycol) as an initiator, following by hydrazinolysis and carbodiimide reactions. FEGGH was decorated onto GNR through Au-catechol bonds. Chemotherapeutic drug doxorubicin (DOX) was loaded onto the nanoplatform through pH-sensitive hydrazone linkage, obtaining final product FEGGH^DOX-GNR. The DOX-loaded nanoplatform displayed excellent photostability and reduction/pH dual-responsive drug release behavior. Cytological studies demonstrated the effective internalization of FEGGH^DOX-GNR into MCF-7 cells via folate-mediated endocytosis and additive therapeutic effect of combined photothermal-chemotherapy. These results indicate that our nanoplatform may be a promising strategy for targeted combined chemo-photothermal therapy of breast cancer.

Mild thermotherapy and hyperbaric oxygen enhance sensitivity of TMZ/PSi nanoparticles via decreasing the stemness in glioma

Background

Glioma is a common brain tumor with a high mortality rate. A small population of cells expressing stem-like cell markers in glioma contributes to drug resistance and tumor recurrence.

Methods

Porous silicon nanoparticles (PSi NPs) as photothermal therapy (PTT) agents loaded with TMZ (TMZ/PSi NPs), was combined with hyperbaric oxygen (HBO) therapy in vitro and in vivo. To further investigate underlying mechanism, we detected the expression of stem-like cell markers and hypoxia related molecules in vitro and in vivo after treatment of TMZ/PSi NPs in combination with PTT and HBO.

Results

NCH-421K and C6 cells were more sensitive to the combination treatment. Moreover, the expression of stem-like cell markers and hypoxia related molecules were decreased after combination treatment. The in vivo results were in line with in vitro. The combination treatment presents significant antitumor effects in mice bearing C6 tumor compared with the treatment of TMZ, PTT or TMZ/PSi NPs only.

Conclusion

These results suggested the TMZ/PSi NPs combined with HBO and PTT could be a potential therapeutic strategy for glioma.

Electronic supplementary material

The online version of this article (10.1186/s12951-019-0483-1) contains supplementary material, which is available to authorized users.

A biomolecule-assisted one-pot synthesis of zinc oxide nanoparticles and its bioconjugate with curcumin for potential multifaceted therapeutic applications

Biodegradable ZnO nanoparticles with excellent biocompatibility prepared via a biogenic process have great potential as therapeutic agent-cum-drug carriers for cancer treatment.

Photoluminescent and biodegradable porous silicon nanoparticles for biomedical imaging

A set of unique properties including biodegradability, intrinsic photoluminescence, and mesoporous structure allows porous silicon nanoparticles to address current challenges of translational nanomedicine, especially in biomedical imaging.

Gold Nanorods/Polypyrrole/m-SiO2 Core/Shell Hybrids as Drug Nanocarriers for Efficient Chemo-Photothermal Therapy

Combination therapy as a novel strategy with the combination of photothermal therapy and chemotherapy (photothermal-chemotherapy) has aroused the tremendously increasing interest owing to the synergistic therapeutic effect on destroying cancer cells because the hyperthermia generated from photothermal therapy can promote drug delivery into tumors, which would highly increase therapeutic efficacy as compared to those sole treatments. Herein, we fabricated a novel nanomaterial-based carrier composed of gold nanorods (GNRs), polypyrrole (PPy), and mesoporous silica to form GNRs/PPy/m-SiO₂ core/shell hybrids. After loading the anticancer drug of doxorubicin (DOX), the photothermal effect and the drug-release behavior of GNRs/PPy@m-SiO₂-DOX hybrids were investigated. The in vitro and in vivo near-infrared (NIR) photothermal-chemotherapy were also revealed. The results indicated that the NIR-induced photothermal effect was beneficial to promote the release of the drug. In addition, combination therapy demonstrated the enhanced synergistic efficacy and excellent treatment efficacy for cancer therapy.

Synthetic routes to nanomaterials containing anthracyclines: noncovalent systems

Chemotherapy still constitutes a basic treatment for various types of cancer. Anthracyclines are effective antineoplastic drugs that are widely used in clinical practice. Unfortunately, they are characterized by high systemic toxicity and lack of tumour selectivity. A promising way to enhance treatment effectiveness and reduce toxicity is the synthesis of systems containing anthracyclines either in the form of complexes for the encapsulation of active drugs or their covalent conjugates with inert carriers. In this respect nanotechnology offers an extensive spectrum of possible solutions. In this review, we discuss recent advances in the development of anthracycline prodrugs based on nanocarriers such as copolymers, lipids, DNA, and inorganic systems. The review focuses on the chemical architecture of the noncovalent nanocarrier-drug systems.

Light-responsive Drug Delivery Systems

Materials that interact with light and subsequently change their physicochemical properties are of great interest for drug delivery. The human body is semitransparent to light of the near-infrared (NIR) region, which makes it possible to use light as an external stimulus to trigger drug release. In this chapter, we review light-triggered drug release systems of both photochemical and photothermal mechanisms. We explore recent literature on a variety of light-responsive materials for drug delivery, including organic, inorganic, and hybrid systems, which collectively embody the strategies for synergizing light responsiveness for controlled drug release/activation with other drug delivery techniques.