Temperature responsive porous silicon nanoparticles for cancer therapy - spatiotemporal triggering through infrared and radiofrequency electromagnetic heating

Recent insights and applications of nanocarriers-based drug delivery systems for colonic drug delivery and cancer therapy: An updated review

Colorectal cancer (CRC) is the third most prevalent malignant tumor globally and is associated with high morbidity and mortality rates. The advancement of novel nanocarrier-based drug delivery systems has revolutionized therapeutic strategies for colonic drug delivery and cancer treatment. This review provides updated insights into various nanocarrier technologies, including quantum dots (QDs), polymeric nanoparticles (PNPs), magnetic and metallic nanoparticles, solid lipid nanoparticles (SLNs), and self-microemulsifying and self-nanoemulsifying drug delivery systems (SMEDDS/SNEDDS). These nanocarriers offer enhanced drug stability, controlled release, and targeted delivery, particularly for CRC treatment, resulting in up to 70 % improved therapeutic efficacy and a significant reduction in systemic toxicity as reported in preclinical studies. The review comprehensively discusses the structural composition, mechanisms of action, therapeutic potential, and imaging capabilities of these systems, with a focus on their applications in theranostics and targeted CRC therapy. For instance, polymeric nanoparticles have demonstrated a 50 % increase in bioavailability compared to conventional formulations, while QDs have enabled real-time imaging with high precision for tumor localization. Additionally, the toxicity profiles and challenges associated with these nanocarriers are critically evaluated. Despite significant progress in preclinical and clinical studies, the review highlights the need for optimizing biocompatibility, scalability, and regulatory standards to facilitate the clinical translation of these promising technologies. Emerging formulations such as graphene quantum dots and PEGylated nanoparticles have shown potential for achieving dual therapeutic and diagnostic applications with fewer adverse effects. Overall, nanocarrier-based systems hold great potential for personalized and more effective treatments in colon-targeted therapies.

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.

Nanoparticle-Mediated Hyperthermia and Cytotoxicity Mechanisms in Cancer

Hyperthermia has the potential to damage cancerous tissue by increasing the body temperature. However, targeting cancer cells whilst protecting the surrounding tissues is often challenging, especially when implemented in clinical practice. In this direction, there are data showing that the combination of nanotechnology and hyperthermia offers more successful penetration of nanoparticles in the tumor environment, thus allowing targeted hyperthermia in the region of interest. At the same time, unlike radiotherapy, the use of non-ionizing radiation makes hyperthermia an attractive therapeutic option. This review summarizes the existing literature regarding the use of hyperthermia and nanoparticles in cancer, with a focus on nanoparticle-induced cytotoxicity mechanisms.

Multifunctional mesoporous silica nanoparticles for biomedical applications

Mesoporous silica nanoparticles (MSNs) are recognized as a prime example of nanotechnology applied in the biomedical field, due to their easily tunable structure and composition, diverse surface functionalization properties, and excellent biocompatibility. Over the past two decades, researchers have developed a wide variety of MSNs-based nanoplatforms through careful design and controlled preparation techniques, demonstrating their adaptability to various biomedical application scenarios. With the continuous breakthroughs of MSNs in the fields of biosensing, disease diagnosis and treatment, tissue engineering, etc., MSNs are gradually moving from basic research to clinical trials. In this review, we provide a detailed summary of MSNs in the biomedical field, beginning with a comprehensive overview of their development history. We then discuss the types of MSNs-based nanostructured architectures, as well as the classification of MSNs-based nanocomposites according to the elements existed in various inorganic functional components. Subsequently, we summarize the primary purposes of surface-functionalized modifications of MSNs. In the following, we discuss the biomedical applications of MSNs, and highlight the MSNs-based targeted therapeutic modalities currently developed. Given the importance of clinical translation, we also summarize the progress of MSNs in clinical trials. Finally, we take a perspective on the future direction and remaining challenges of MSNs in the biomedical field.

Reaching new lights: a review on photo-controlled nanomedicines and their in vivo evaluation

The selective and efficient delivery of bioactive molecules to sites of interest remains a formidable challenge in medicine. In recent years, it has been shown that stimuli-responsive drug delivery systems display several advantages over traditional drug administration such as an improved pharmacokinetic profile and the desirable ability to gain control over release. Light emerged as one of the most powerful stimuli due to its high biocompatibility, spatio-temporal control, and non-invasiveness. On the road to clinical translation, various chemical systems of high complexity have been reported with the aim to improve efficacy, safety, and versatility of drug delivery under complex biological conditions. For future research on the chemical design of such photo-controlled nanomedicines, it is essential to gain an understanding of their in vivo translation and efficiency. Here, we discuss photo-controlled nanomedicines that have been evaluated in vivo and provide an overview of the state-of-the-art that should guide future research design.

Responsive Nanostructure for Targeted Drug Delivery

Currently, intelligent, responsive biomaterials have been widely explored, considering the fact that responsive biomaterials provide controlled and predictable results in various biomedical systems. Responsive nanostructures undergo reversible or irreversible changes in the presence of a stimulus, and that stimuli can be temperature, a magnetic field, ultrasound, pH, humidity, pressure, light, electric field, etc. Different types of stimuli being used in drug delivery shall be explained here. Recent research progress in the design, development and applications of biomaterials comprising responsive nanostructures is also described here. More emphasis will be given on the various nanostructures explored for the smart stimuli responsive drug delivery at the target site such as wound healing, cancer therapy, inflammation, and pain management in order to achieve the improved efficacy and sustainability with the lowest side effects. However, it is still a big challenge to develop well-defined responsive nanostructures with ordered output; thus, challenges faced during the design and development of these nanostructures shall also be included in this article. Clinical perspectives and applicability of the responsive nanostructures in the targeted drug delivery shall be discussed here.

The emergence of nanoporous materials in lung cancer therapy

Lung cancer is one of the most common cancers, affecting more than 2.1 million people across the globe every year. A very high occurrence and mortality rate of lung cancer have prompted active research in this area with both conventional and novel forms of therapies including the use of nanomaterials based drug delivery agents. Specifically, the unique physico-chemical and biological properties of porous nanomaterials have gained significant momentum as drug delivery agents for delivering a combination of drugs or merging diagnosis with targeted therapy for cancer treatment. This review focuses on the emergence of nano-porous materials for drug delivery in lung cancer. The review analyses the currently used nanoporous materials, including inorganic, organic and hybrid porous materials for delivering drugs for various types of therapies, including chemo, radio and phototherapy. It also analyses the selected research on stimuli-responsive nanoporous materials for drug delivery in lung cancer before summarizing the various findings and projecting the future of emerging trends. This review provides a strong foundation for the current status of the research on nanoporous materials, their limitations and the potential for improving their design to overcome the unique challenges of delivering drugs for the treatment of lung cancer.

Nanomaterials in cancer: Reviewing the combination of hyperthermia and triggered chemotherapy

Nanoparticle mediated hyperthermia has been explored as a method to increase cancer treatment efficacy by heating tumours inside-out. With that purpose, nanoparticles have been designed and their properties tailored to respond to external stimuli and convert the supplied energy into heat, therefore inducing damage to tumour cells. Moreover, the combination of hyperthermia with chemotherapy has been described as a more effective strategy due to the synergy between the high temperature and the drug's effects, also associated with a remote controlled and on-demand drug release. In this review, the methods behind nanoparticle mediated hyperthermia, namely material design, external stimuli response and energy conversion will be discussed and critically analysed. We will address the most relevant studies on hyperthermia and temperature triggered drug release for cancer treatment. Finally, the advantages, difficulties and challenges of this therapeutic strategy will be discussed, while giving insight for future developments.

Intravital Whole-Process Monitoring Thermo-Chemotherapy Via 2D Silicon Nanoplatform: A Macro Guidance and Long-Term Microscopic Precise Imaging Strategy

Tumor angiogenesis is a complex process that is unamenable to intravital whole-process monitoring, especially on microscopic assessment of tumor microvessel and quantifying microvascular hemodynamics before and after the nanotherapeutics, which hinder the understanding of nanotheranostics outcomes in tumor treatment. Herein, a new photoacoustic (PA) imaging-optical coherence tomography angiography (OCTA)-laser speckle (LS) multimodal imaging strategy is first proposed, which is not only able to precisely macro guide the thermo-chemotherapy of tumor by monitoring blood oxygen saturation (SaO2 ) and hemoglobin content (HbT), but also capable of long-term microscopic investigating the microvessel morphology (microvascular density) and hemodynamics changes (relative blood flow) before and after the nanotherapeutics in vivo. Moreover, to realize the tumor thermo-chemotherapy treatment based on this novel multimodal imaging strategy, a 2D 5-fluorouracil silicon nanosheets (5-Fu-Si NSs) therapeutic agent is designed. Furthermore, 2D high-resolution tumor microvascular images in different stage display that tendency of the thermo-chemotherapy effect is closely associated with tumor angiogenesis. Taken together, the investigations establish the fundamental base in theory and technology for further tailoring the novel specific diagnosis and treatment strategy in tumor. More importantly, this technique will be beneficial to evaluate the tumor microvascular response to nanotherapeutics at microscale.

Recent advances in hybrid system of porous silicon nanoparticles and biocompatible polymers for biomedical applications

Hybrid systems of nanoparticles and polymers have emerged as a new material in the biomedical field. To date, various kinds of hybrid systems have been introduced and applied to drug delivery, regenerative medicine, therapeutics, disease diagnosis, and medical implantation. Among them, the hybridization of nanostructured porous silicon nanoparticles (pSiNPs) and biocompatible polymers has been highlighted due to its unique biological and physicochemical properties. This review focuses on the recent advances in the hybrid systems of pSiNPs and biocompatible polymers from an engineering aspect and its biomedical applications. Representative hybrid formulations, (i) Polymer-coated pSiNPs, (ii) pSiNPs-embedded polymeric nanofibers, are outlined along with their preparation methods, biomedical applications, and future perspectives. We believe this review provides insight into a new hybrid system of pSiNPs and biocompatible polymers as a promising nano-platform for further biomedical applications. Recently developed and representative hybrid systems of porous silicon nanoparticles and biocompatible polymers and their biomedical applications are introduced.

Effects of Doxorubicin Delivery by Nitrogen-Doped Graphene Quantum Dots on Cancer Cell Growth: Experimental Study and Mathematical Modeling

With 18 million new cases diagnosed each year worldwide, cancer strongly impacts both science and society. Current models of cancer cell growth and therapeutic efficacy in vitro are time-dependent and often do not consider the E_max value (the maximum reduction in the growth rate), leading to inconsistencies in the obtained IC₅₀ (concentration of the drug at half maximum effect). In this work, we introduce a new dual experimental/modeling approach to model HeLa and MCF-7 cancer cell growth and assess the efficacy of doxorubicin chemotherapeutics, whether alone or delivered by novel nitrogen-doped graphene quantum dots (N-GQDs). These biocompatible/biodegradable nanoparticles were used for the first time in this work for the delivery and fluorescence tracking of doxorubicin, ultimately decreasing its IC₅₀ by over 1.5 and allowing for the use of up to 10 times lower doses of the drug to achieve the same therapeutic effect. Based on the experimental in vitro studies with nanomaterial-delivered chemotherapy, we also developed a method of cancer cell growth modeling that (1) includes an E_max value, which is often not characterized, and (2), most importantly, is measurement time-independent. This will allow for the more consistent assessment of the efficiency of anti-cancer drugs and nanomaterial-delivered formulations, as well as efficacy improvements of nanomaterial delivery.

A Regenerable Biosensing Platform for Bacterial Toxins

Waterborne diarrheal diseases such as travelers' diarrhea and cholera remain a threat to public health in many countries. Rapid diagnosis of an infectious disease is critical in preventing the escalation of a disease outbreak into an epidemic. Many of the diagnostic tools for infectious diseases employed today are time-consuming and require specialized laboratory settings and trained personnel. There is hence a pressing need for fit-for-purpose point-of-care diagnostic tools with emphasis in sensitivity, specificity, portability, and low cost. We report work toward thermally reversible biosensors for detection of the carbohydrate-binding domain of the Escherichia coli heat-labile enterotoxin (LTB), a toxin produced by enterotoxigenic E. coli strains, which causes travelers' diarrhea. The biosensing platform is a hybrid of two materials, combining the optical properties of porous silicon (pSi) interferometric transducers and a thermoresponsive multivalent glycopolymer, to enable recognition of LTB. Analytical performance of our biosensors allows us to detect, using a label-free format, sub-micromolar concentrations of LTB in solution as low as 0.135 μM. Furthermore, our platform shows a temperature-mediated "catch-and-release" behavior, an exciting feature with potential for selective protein capture, multiple readouts, and regeneration of the sensor over consecutive cycles of use.

Tailored Synthesis of PEGylated Bismuth Nanoparticles for X-ray Computed Tomography and Photothermal Therapy: One-Pot, Targeted Pyrolysis, and Self-Promotion

Complex experimental design is a common problem in the preparation of theranostic nanoparticles, resulting in poor reaction control, expensive production cost, and low experiment success rate. The present study aims to develop PEGylated bismuth (PEG-Bi) nanoparticles with a precisely controlled one-pot approach, which contains only methoxy[(poly(ethylene glycol)]trimethoxy-silane (PEG-silane) and bismuth oxide (Bi₂O₃). A targeted pyrolysis of PEG-silane was achieved to realize its roles as both the reduction and PEGylation agents. The unwanted methoxy groups of PEG-silane were selectively pyrolyzed to form reductive agents, while the useful PEG-chain was fully preserved to enhance the biocompatibility of Bi nanoparticles. Moreover, Bi₂O₃ not only acted as the raw material of the Bi source but also presented a self-promotion in the production of Bi nanoparticles via catalyzing the pyrolysis of PEG-silane. The reaction mechanism was systematically validated with different methods such as nuclear magnetic resonance spectroscopy. The PEG-Bi nanoparticles showed better compatibility and photothermal conversion than those prepared by the complex multiple step approaches in literature studies. In addition, the PEG-Bi nanoparticles possessed prominent performance in X-ray computed tomography imaging and photothermal cancer therapy in vivo. The present study highlights the art of precise reaction control in the synthesis of PEGylated nanoparticles for biomedical applications.

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.

Polymer-Encapsulated Cobalt/Gold Bimetallic Nanoclusters as Stimuli-Responsive Chemiluminescent Nanoprobes for Reactive Oxygen Species

A stimuli-responsive chemiluminescent nanocomposite was developed based on bimetallic nanoclusters encapsulated in a reactive oxygen species (ROS)-responsive polymer for a highly sensitive determination of ROS (i.e., H₂O₂) in biological samples. Cobalt/gold bimetallic nanoclusters (GSH@Co-AuNCs) were synthesized using glutathione (GSH) as a reducing-cum-protecting reagent. The GSH-coated nanoclusters were covalently bound to N-(4-aminobutyl)-N-ethylisoluminol (ABEI) to form the GSH@Co-AuNCs-ABEI, which was further encapsulated in polymeric ROS-sensitive boronic ester modified dextran (Oxi-Dex) nanospheres through hydrophobic interactions. The stimulation of H₂O₂, as a model ROS, led to a sustainable structural cleavage of the Co-AuNCs-ABEI@Oxi-Dex nanocomposites and release of internal GSH@Co-AuNCs-ABEI, accompanied by intense chemiluminescence (CL). On this basis, an enzyme-free and reagent-free CL sensor was developed for a highly sensitive and selective determination of H₂O₂ with a detection limit of 35.8 pM in biological samples. It is of great application potential for the determination of ROS related to various diseases.

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.

Nanotechnology as a Platform for the Development of Injectable Parenteral Formulations: A Comprehensive Review of the Know-Hows and State of the Art

Within recent decades, the development of nanotechnology has made a significant contribution to the progress of various fields of study, including the domains of medical and pharmaceutical sciences. A substantially transformed arena within the context of the latter is the development and production of various injectable parenteral formulations. Indeed, recent decades have witnessed a rapid growth of the marketed and pipeline nanotechnology-based injectable products, which is a testimony to the remarkability of the aforementioned contribution. Adjunct to the ability of nanomaterials to deliver the incorporated payloads to many different targets of interest, nanotechnology has substantially assisted to the development of many further facets of the art. Such contributions include the enhancement of the drug solubility, development of long-acting locally and systemically injectable formulations, tuning the onset of the drug’s release through the endowment of sensitivity to various internal or external stimuli, as well as adjuvancy and immune activation, which is a desirable component for injectable vaccines and immunotherapeutic formulations. The current work seeks to provide a comprehensive review of all the abovementioned contributions, along with the most recent advances made within each domain. Furthermore, recent developments within the domains of passive and active targeting will be briefly debated.

Soft and Condensed Nanoparticles and Nanoformulations for Cancer Drug Delivery and Repurpose

Drug repurpose or reposition is recently recognized as a high-performance strategy for developing therapeutic agents for cancer treatment. This approach can significantly reduce the risk of failure, shorten R&D time, and minimize cost and regulatory obstacles. On the other hand, nanotechnology-based delivery systems are extensively investigated in cancer therapy due to their remarkable ability to overcome drug delivery challenges, enhance tumor specific targeting, and reduce toxic side effects. With increasing knowledge accumulated over the past decades, nanoparticle formulation and delivery have opened up a new avenue for repurposing drugs and demonstrated promising results in advanced cancer therapy. In this review, recent developments in nano-delivery and formulation systems based on soft (i.e., DNA nanocages, nanogels, and dendrimers) and condensed (i.e., noble metal nanoparticles and metal-organic frameworks) nanomaterials, as well as their theranostic applications in drug repurpose against cancer are summarized.

Cavitation Induced by Janus-Like Mesoporous Silicon Nanoparticles Enhances Ultrasound Hyperthermia

The presence of nanoparticles lowers the levels of ultrasound (US) intensity needed to achieve the therapeutic effect and improves the contrast between healthy and pathological tissues. Here, we evaluate the role of two main mechanisms that contribute to the US-induced heating of aqueous suspensions of biodegradable nanoparticles (NPs) of mesoporous silicon prepared by electrochemical etching of heavily boron-doped crystalline silicon wafers in a hydrofluoric acid solution. The first mechanism is associated with an increase of the attenuation of US in the presence of NPs due to additional scattering and viscous dissipation, which was numerically simulated and compared to the experimental data. The second mechanism is caused by acoustic cavitation leading to intense bubble collapse and energy release in the vicinity of NPs. This effect is found to be pronounced for as-called Janus NPs produced via a nano-stopper technique, which allow us to prepare mesoporous NPs with hydrophobic inner pore walls and hydrophilic external surface. Such Janus-like NPs trap air inside the pores when dispersed in water. The precise measurement of the heating dynamics in situ enabled us to detect the excessive heat production by Janus-like NPs over their completely hydrophilic counterparts. The excessive heat is attributed to the high intensity cavitation in the suspension of Janus-like NPs. The present work elicits the potential of specifically designed Janus-like mesoporous silicon NPs in the field of nanotheranostics based on ultrasound radiation.

External temperature control of lymphatic drainage of thermo-sensitive nanomaterials

Nano-carrier-facilitated delivery of bioactive molecules into lymph nodes (LNs) has found application in the treatment and diagnosis of numerous immune-related diseases. Much work has focused on optimization of physicochemical properties of the nano-carrier to enhance lymphatic drainage passively, whereas active modulation of the quantity and timing of lymphatic delivery remains a significant challenge. Here, inspired by the success of thermo-modulation of tumor targeting, we have developed a simple external temperature control strategy to regulate the distribution of thermo-sensitive nanomaterials between the injection site and draining LNs. To demonstrate feasibility of this strategy, we injected Rhodamine-B-labeled poly(N-isopropylacrylamide) (RhB-PNIPAm) (2.5 kDa) into the footpad of mice at different initial temperatures - either below or above the lower critical solution temperature (LCST), followed by physical cooling of the injection site. We show that RhB-PNIPAm drained efficiently into the popliteal and inguinal nodes (pLNs, iLNs, respectively) with low levels of accumulation in major internal organs. Within the first two hours post-injection the rate of drainage was primarily dependent on the initial temperature of RhB-PNIPAm. However, over the course of 24 h, temperature gradient due to local cooling affected significantly the draining of the injection site, resulting in differential accumulation of RhB-PNIPAm in the proximal (pLNs) versus the distal (iLNs) nodes. This study provides a new methodology and insights for modulating in vivo lymphatic distribution of thermo-sensitive nanomaterials with implications in immune regulation and immunotherapy.

Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition

PURPOSE

Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy.

MATERIALS AND METHODS

PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release from the nanostructure was studied at various hyperthermia conditions generated by waterbath, magnetic resonance-guided focused ultrasound (MRgFUS), and alternating magnetic field (AMF). The in vitro cytotoxicity and hyperthermia efficacy of the doxorubicin-loaded nanoparticles (DOX-PEG1500-PMNPs) were assessed using human lung adenocarcinoma (A549) cells.

RESULTS

Heat treatment of DOX-PEG1500-PMNPs containing 235 ± 26 mg·g^-1 DOX at 48 °C by waterbath, MRgFUS, and AMF, respectively led to 71 ± 4%, 48 ± 3%, and 74 ± 5% drug release. Hyperthermia treatment of the A549 cells using DOX-PEG1500-PMNPs led to 77% decrease in the cell viability due to the synergistic effects of magnetic hyperthermia and chemotherapy.

CONCLUSION

The large pores generated in the PMNPs structure could provide a sufficient space for encapsulation of the chemotherapeutics as well as fast drug encapsulation and release kinetics, which together with thermosensitive characteristics of the PEG1500 shell, make DOX-PEG1500-PMNPs promising adjuvants to the magnetic hyperthermia modality.

Theranostics Applications of Nanoparticles in Cancer Immunotherapy

With the advancement in the mechanism of immune surveillance and immune evasion in cancer cells, cancer immunotherapy shows promising results for treating cancer with established efficacy and less toxicity. As a result of the off-target effect, the approach for delivering vaccines, adjuvants, or antibodies directly to tumor sites is gaining widespread attention. An effective alternative is to utilize nanoengineered particles, functioning as drug-delivery systems or as antigens themselves. This article reviews the practical implementation of nanotechnology in cancer immunotherapy.

Tailoring Porous Silicon for Biomedical Applications: From Drug Delivery to Cancer Immunotherapy

In the past two decades, porous silicon (PSi) has attracted increasing attention for its potential biomedical applications. With its controllable geometry, tunable nanoporous structure, large pore volume/high specific surface area, and versatile surface chemistry, PSi shows significant advantages over conventional drug carriers. Here, an overview of recent progress in the use of PSi in drug delivery and cancer immunotherapy is presented. First, an overview of the fabrication of PSi with various geometric structures is provided, with particular focus on how the unique geometry of PSi facilitates its biomedical applications, especially for drug delivery. Second, surface chemistry and modification of PSi are discussed in relation to the strengthening of its performance in drug delivery and bioimaging. Emerging technologies for engineering PSi-based composites are then summarized. Emerging PSi advances in the context of cancer immunotherapy are also highlighted. Overall, very promising research results encourage further exploration of PSi for biomedical applications, particularly in drug delivery and cancer immunotherapy, and future translation of PSi into clinical applications.

Electrolytic conductivity-related radiofrequency heating of aqueous suspensions of nanoparticles for biomedicine

The development of suitable contrast agents can significantly enhance the efficiency of modern imaging and treatment techniques, such as thermoacoustic (TA) tomography and radio-frequency (RF) hyperthermia of cancer. Here, we examine the heating of aqueous suspensions of silicon (Si) and gold (Au) nanoparticles (NPs) under RF irradiation in the MHz frequency range. The heating rate of aqueous suspensions of Si NPs exhibited non-monotonic dependency on the electrical conductivity of the suspension. The experimental results were explained by the mathematical model considering oscillating solvated ions as the main source of Joule heating. These ions could be the product of the dissolution of Si NPs or organic coating of Au NPs. Thus, the ions governed the conductivity of the suspensions, which in turn governs both the heating rate and the near-field RF TA response. The model predicted the contrast in different tissues taking into account both Joule heating and dielectric losses.

Mesoporous silica nanoparticles for drug and gene delivery

Mesoporous silica nanoparticles (MSNs) are attracting increasing interest for potential biomedical applications. With tailored mesoporous structure, huge surface area and pore volume, selective surface functionality, as well as morphology control, MSNs exhibit high loading capacity for therapeutic agents and controlled release properties if modified with stimuli-responsive groups, polymers or proteins. In this review article, the applications of MSNs in pharmaceutics to improve drug bioavailability, reduce drug toxicity, and deliver with cellular targetability are summarized. Particularly, the exciting progress in the development of MSNs-based effective delivery systems for poorly soluble drugs, anticancer agents, and therapeutic genes are highlighted.

Free-Blockage Mesoporous Anticancer Nanoparticles Based on ROS-Responsive Wetting Behavior of Nanopores

To achieve an excellent delivery effect of drug, stimuli-responsive nano "gate" with physical blockage units is usually constructed on the surface of the mesoporous silica nanocarriers (MSNs). In nature, the aquaporins in cell membrane can control the transport of water molecules by regulating the channel wettability, which is resulted from the conformational change of amino acids in the channel. Inspired by this phonomenon, herein a new concept of free-blockage controlled release system is proposed, which is achieved by controlling the wettability of the internal surface of nanopores on MSNs. Such a new system is different from the physical-blockage controlled release system, which bypasses the use of nano "gate" and overcomes the limitations of traditional physical blockage system. Moreover, further studies have shown that the system can selectively release the entrapped doxorubicin in human breast adenocarcinoma (MCF-7) cells triggered by intracellular reactive oxygen species (ROS) but not in normalhuman umbilical vein endothelial cells (HUVECs) containing ROS with low levels. The wettability-determined free-blockage controlled release system is simple and effective, and it can also be triggered by intracellular biological stimuli, which provides a new approach for the future practical application of drug delivery and cancer therapy.

Silicon-based nanotheranostics

With the rapid expansion of nanoscience and nanotechnology in interdisciplinary fields, multifunctional nanomaterials have attracted particular attention. Recent advances in nanotherapeutics for cancer applications provided diverse groups of synthetic particles with defined cellular and biological functions. The advance of nanotechnology significantly increased the number of possibilities for the construction of diverse biological tools. Such materials are destined to be of great importance because of the opportunity to combine the biotechnological potential of nanoparticles together with the recognition, sensitivity and modulation of cellular pathways or genes when applied to living organisms. In this mini review three main types of Si-based nanomaterials are highlighted in the area of their application for therapy and imaging: porous silicon nanoparticles (pSiNPs), mesoporous silica nanoparticles (MSNs), focusing on their nanoconstructs containing coordination compounds, and periodic mesoporous silica nanoparticles (PMONPs). Moreover, a critical discussion on the research efforts in the construction of nanotheranostics is presented.

Near-Infrared-Light-Responsive Magnetic DNA Microgels for Photon- and Magneto-Manipulated Cancer Therapy

Functional DNA molecules have been introduced into polymer-based nanocarrier systems to incorporate chemotherapy drugs for cancer therapy. Here is the first report of dual-responsive microgels composed of a core of Au nanorods and a shell of magnetic ionic liquid and DNA moieties in the cross-linking network simultaneously, as effective drug delivery vectors. TEM images indicated a magnetic polymer shell has an analogous "doughnut" shape which loosely surround the AuNRs core. When irradiated with a near-infrared-light (near-IR) laser, Au nanorods are the motors which convert the light to heat, leading to the release of the encapsulated payloads with high controllability. DNA acts not only as a cross-linker agent, but also as a gatekeeper to regulate the release of drugs. The internalization study and MTT assay confirm that these core-shell DNA microgels are excellent candidates which can enhance the cytotoxicity of cancer cells controlled by near-IR laser and shield the high toxicity of chemotherapeutic agents to improve the killing efficacy of chemotherapeutic agents efficiently in due course.

Cytotoxicity control of silicon nanoparticles by biopolymer coating and ultrasound irradiation for cancer theranostic applications

Silicon nanoparticles (SiNPs) prepared by mechanical grinding of luminescent porous silicon were coated with a biopolymer (dextran) and investigated as a potential theranostic agent for bioimaging and sonodynamic therapy. Transmission electron microscopy, photoluminescence and Raman scattering measurements of dextran-coated SiNPs gave evidence of their enhanced stability in water. In vitro experiments confirmed the lower cytotoxicity of the dextran-coated NPs in comparison with uncoated ones, especially for high concentrations of about 2 mg ml^-1. Efficient uptake of the NPs by cancer cells was found using bioimaging in the optical transmittance and photoluminescence modes. Treatment of the cells with uptaken SiNPs by therapeutic ultrasound for 5-20 min resulted in a strong decrease in the number of living cells, while the total number of cells remained nearly unchanged. The obtained data indicate a 'mild' effect of the combined action of ultrasonic irradiation and SiNPs on cancer cells. The observed results reveal new opportunities for controlling the photoluminescent and sonosensitizing properties of silicon-based NPs for applications in the diagnostics and mild therapy of cancer.

Intracellular responsive dual delivery by endosomolytic polyplexes carrying DNA anchored porous silicon nanoparticles

Bioresponsive cytosolic nanobased multidelivery has been emerging as an enormously challenging novel concept due to the intrinsic protective barriers of the cells and hardly controllable performances of nanomaterials. Here, we present a new paradigm to advance nano-in-nano integration technology amenable to create multifunctional nanovehicles showing considerable promise to overcome restrictions of intracellular delivery, solve impediments of endosomal localization and aid effectual tracking of nanoparticles. A redox responsive intercalator chemistry comprised of cystine and 9-aminoacridine is designed as a cross-linker to cap carboxylated porous silicon nanoparticles with DNA. These intelligent nanocarriers are then encapsulated within novel one-pot electrostatically complexed nano-networks made of a zwitterionic amino acid (cysteine), an anionic bioadhesive polymer (poly(methyl vinyl ether-alt-maleic acid)) and a cationic endosomolytic polymer (polyethyleneimine). This combined nanocomposite is successfully tested for the co-delivery of hydrophobic (sorafenib) or hydrophilic (calcein) molecules loaded within the porous core, and an imaging agent covalently integrated into the polyplex shell by click chemistry. High loading capacity, low cyto- and hemo-toxicity, glutathione responsive on-command drug release, and superior cytosolic delivery are shown as achievable key features of the proposed formulation. Overall, formulating drug molecules, DNA and imaging agents, without any interference, in a physico-chemically optimized carrier may open a path towards broad applicability of these cost-effective multivalent nanocomposites for treating different diseases.

Design and pharmaceutical applications of porous particles

Porous particles have been developed as a novel carrier to improve drug delivery, dissolution, tableting, and so on, which can be prepared by many methods.