Temperature-dependent cell death patterns induced by functionalized gold nanoparticle photothermal therapy in melanoma cells

Enhanced biosafety, anticancer and antibacterial photodynamic activities using silver-pyropheophorbide-a nanoconjugates

Aim: A study of the enhancement of photodynamic activities of pyropheophorbide-a using PG-Ag-PPa nanoconjugates. Materials & methods: The nanoconjugates were formulated from silver nanoparticles and PPa via amide linkage, then characterized, and their photodynamic activities were examined. Results: The nanoconjugates displayed a higher rate of reactive oxygen species generation, commendable cellular uptake by Eca-109 cancer cells, higher photocytotoxicity toward the cancer cells and better bio-safety. They revealed strong antibacterial activity against Escherichia coli following internal reactive oxygen species generation and membrane disintegration. The in vivo anticancer studies confirmed higher cytotoxicity of the nanoconjugates toward cancer cells and better safety than PPa. Conclusion: Therefore, PG-Ag-PPa nanoconjugates could be considered potential nano photosensitizers for photodynamic therapy of tumors and bacterial infection with good bio-safety.

Multifunctional scaffolds for bone repair following age-related biological decline: Promising prospects for smart biomaterial-driven technologies

The repair of large bone defects due to trauma, disease, and infection can be exceptionally challenging in the elderly. Despite best clinical practice, bone regeneration within contemporary, surgically implanted synthetic scaffolds is often problematic, inconsistent, and insufficient where additional osteobiological support is required to restore bone. Emergent smart multifunctional biomaterials may drive important and dynamic cellular crosstalk that directly targets, signals, stimulates, and promotes an innate bone repair response following age-related biological decline and when in the presence of disease or infection. However, their role remains largely undetermined. By highlighting their mechanism/s and mode/s of action, this review spotlights smart technologies that favorably align in their conceivable ability to directly target and enhance bone repair and thus are highly promising for future discovery for use in the elderly. The four degrees of interactive scaffold smartness are presented, with a focus on bioactive, bioresponsive, and the yet-to-be-developed autonomous scaffold activity. Further, cell- and biomolecular-assisted approaches were excluded, allowing for contemporary examination of the capabilities, demands, vision, and future requisites of next-generation biomaterial-induced technologies only. Data strongly supports that smart scaffolds hold significant promise in the promotion of bone repair in patients with a reduced osteobiological response. Importantly, many techniques have yet to be tested in preclinical models of aging. Thus, greater clarity on their proficiency to counteract the many unresolved challenges within the scope of aging bone is highly warranted and is arguably the next frontier in the field. This review demonstrates that the use of multifunctional smart synthetic scaffolds with an engineered strategy to circumvent the biological insufficiencies associated with aging bone is a viable route for achieving next-generation therapeutic success in the elderly population.

NIR-Responsive injectable hydrogel cross-linked by homobifunctional PEG for photo-hyperthermia of melanoma, antibacterial wound healing, and preventing post-operative adhesion

Current therapeutic approaches for skin cancer face significant challenges, including wound infection, delayed skin regeneration, and tumor recurrence. To overcome these challenges, an injectable adhesive near-infrared (NIR)-responsive hydrogel with time-dependent enhancement in viscosity is developed for combined melanoma therapy and antibacterial wound healing acceleration. The multifunctional hydrogel is prepared through the chemical crosslinking between poly(methyl vinyl ether-alt-maleic acid) and gelatin, followed by the incorporation of CuO nanosheets and allantoin. The synergistic inherent antibacterial potential of CuO nanosheets, the regenerative and smoothing effect of allantoin, the extracellular matrix-mimicking effect of gelatin, and the desirable swelling behavior of the hydrogel results in fast wound recovery after photothermal ablation of the tumor. Additionally, the hydrogel can serve as an alternative to sutures owing to its tissue adhesiveness ability, which can further render it the merits for accelerated repair of abdominal lesions while acting as a biocompatible barrier to prevent peritoneal adhesion.

Mechanism and potentialities of photothermal and photodynamic therapy of transition metal dichalcogenides (TMDCs) against cancer

The ultimate goal of nanoparticle-based phototherapy is to suppress tumor growth. Photothermal therapy (PTT) and photothermal photodynamic therapy (PDT) are two types of physicochemical therapy that use light radiation with multiple wavelength ranges in the near-infrared to treat cancer. When a laser is pointed at tissue, photons are taken in the intercellular and intracellular regions, converting photon energy to heat. It has attracted much interest and research in recent years. The advent of transition materials dichalcogenides (TMDCs) is a revolutionary step in PDT/PTT-based cancer therapy. The TMDCs is a multilayer 2D nano-composite. TMDCs contain three atomic layers in which two chalcogens squash in the transition metal. The chalcogen atoms are highly reactive, and the surface characteristics of TMDCs help them to target deep cancer cells. They absorb Near Infrared (NIR), which kills deep cancer cells. In this review, we have discussed the history and mechanism of PDT/PTT and the use of TMDCs and nanoparticle-based systems, which have been practiced for theranostics purposes. We have also discussed PDT/PTT combined with immunotherapy, in which the cancer cell apoptosis is done by activating the immune cells, such as CD8+.

Photothermal Ferrotherapy - Induced Immunogenic Cell Death via Iron-Based Ternary Chalcogenide Nanoparticles Against Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is highly malignant and prone to recurrence and metastasis. Patients with TNBC have limited therapeutic options, often resulting in poor prognosis. Some new treatments for TNBC have been considered in the past decade, such as immunotherapy, photothermal therapy (PTT), and ferroptosis therapy, that allow the rapid and minimally invasive ablation of cancer. However, a multifunctional nanodrug system with more potent efficacy for TNBC is still needed. The use of iron-based ternary chalcogenide nanoparticles (NPs), namely AgFeS2, is reported, which synergistically combines photothermal therapy, ferrotherapy, and immunotherapy in one system for the treatment of TNBC. AgFeS2 possesses excellent photothermal conversion performance for tumor near-infrared (NIR) phototherapy. Upon photoirradiation, these NPs generate heat, accelerate the release of iron ions, and effectively catalyze the Fenton reaction, resulting in cell apoptosis and ferroptosis. Additionally, AgFeS2 promotes the release of tumor-specific antigens and triggers an immune response via immunogenic cell death (ICD), thereby providing unique synergistic mechanisms for cancer therapy. The present study demonstrates the great potential of iron-based ternary chalcogenide as a new therapeutic platform for a combination of photothermal therapy, ferrotherapy, and immunotherapy for the suppression of TNBC.

Near-infrared-driven upconversion nanoparticles with photocatalysts through water-splitting towards cancer treatment

Water splitting is promising, especially for energy and environmental applications; however, there are limited studies on the link between water splitting and cancer treatment. Upconversion nanoparticles (UCNPs) can be used to convert near-infrared (NIR) light to ultraviolet (UV) or visible (Vis) light and have great potential for biomedical applications because of their profound penetration ability, theranostic approaches, low self-fluorescence background, reduced damage to biological tissue, and low toxicity. UCNPs with photocatalytic materials can enhance the photocatalytic activities that generate a shorter wavelength to increase the tissue penetration depth in the biological microenvironment under NIR light irradiation. Moreover, UCNPs with a photosensitizer can absorb NIR light and convert it into UV/vis light and emit upconverted photons, which excite the photoinitiator to create H2, O2, and/or OH˙ via water splitting processes when exposed to NIR irradiation. Therefore, combining UCNPs with intensified photocatalytic and photoinitiator materials may be a promising therapeutic approach for cancer treatment. This review provides a novel strategy for explaining the principles and mechanisms of UCNPs and NIR-driven UCNPs with photocatalytic materials through water splitting to achieve therapeutic outcomes for clinical applications. Moreover, the challenges and future perspectives of UCNP-based photocatalytic materials for water splitting for cancer treatment are discussed in this review.

Advancements in Photothermal Therapy Using Near-Infrared Light for Bone Tumors

Bone tumors, particularly osteosarcoma, are prevalent among children and adolescents. This ailment has emerged as the second most frequent cause of cancer-related mortality in adolescents. Conventional treatment methods comprise extensive surgical resection, radiotherapy, and chemotherapy. Consequently, the management of bone tumors and bone regeneration poses significant clinical challenges. Photothermal tumor therapy has attracted considerable attention owing to its minimal invasiveness and high selectivity. However, key challenges have limited its widespread clinical use. Enhancing the tumor specificity of photosensitizers through targeting or localized activation holds potential for better outcomes with fewer adverse effects. Combinations with chemotherapies or immunotherapies also present avenues for improvement. In this review, we provide an overview of the most recent strategies aimed at overcoming the limitations of photothermal therapy (PTT), along with current research directions in the context of bone tumors, including (1) target strategies, (2) photothermal therapy combined with multiple therapies (immunotherapies, chemotherapies, and chemodynamic therapies, magnetic, and photodynamic therapies), and (3) bifunctional scaffolds for photothermal therapy and bone regeneration. We delve into the pros and cons of these combination methods and explore current research focal points. Lastly, we address the challenges and prospects of photothermal combination therapy.

Slow and steady wins the race: Fractionated near-infrared treatment empowered by graphene-enhanced 3D scaffolds for precision oncology

Surgically addressing tumors poses a challenge, requiring a tailored, multidisciplinary approach for each patient based on the unique aspects of their case. Innovative therapeutic regimens combined to reliable reconstructive methods can contribute to an extended patient's life expectancy. This study presents a detailed comparative investigation of near-infrared therapy protocols, examining the impact of non-fractionated and fractionated irradiation regimens on cancer treatment. The therapy is based on the implantation of graphene oxide/poly(lactic-co-glycolic acid) three-dimensional printed scaffolds, exploring their versatile applications in oncology by the examination of pro-inflammatory cytokine secretion, immune response, and in vitro and in vivo tumor therapy. The investigation into cell death patterns (apoptosis vs necrosis) underlines the pivotal role of protocol selection underscores the critical influence of treatment duration on cell fate, establishing a crucial parameter in therapeutic decision-making. In vivo experiments corroborated the profound impact of protocol selection on tumor response. The fractionated regimen emerged as the standout performer, achieving a substantial reduction in tumor size over time, surpassing the efficacy of the non-fractionated approach. Additionally, the fractionated regimen exhibited efficacy also in targeting tumors in proximity but not in direct contact to the scaffolds. Our results address a critical gap in current research, highlighting the absence of a standardized protocol for optimizing the outcome of photodynamic therapy. The findings underscore the importance of personalized treatment strategies in achieving optimal therapeutic efficacy for precision cancer therapy.

A Biodegradable "One-For-All" Nanoparticle for Multimodality Imaging and Enhanced Photothermal Treatment of Breast Cancer

Silver sulfide nanoparticles (Ag2S-NP) hold promise for various optical-based biomedical applications, such as near-infrared fluorescence (NIRF) imaging, photoacoustics (PA), and photothermal therapy (PTT). However, their NIR absorbance is relatively low, and previous formulations are synthesized using toxic precursors under harsh conditions and are not effectively cleared due to their large size. Herein, sub-5 nm Ag2S-NP are synthesized and encapsulated in biodegradable, polymeric nanoparticles (AgPCPP). All syntheses are conducted using biocompatible, aqueous reagents under ambient conditions. The encapsulation of Ag2S-NP in polymeric nanospheres greatly increases their NIR absorbance, resulting in enhanced optical imaging and PTT effects. AgPCPP nanoparticles exhibit potent contrast properties suitable for PA and NIRF imaging, as well as for computed tomography (CT). Furthermore, AgPCPP nanoparticles readily improve the conspicuity of breast tumors in vivo. Under NIR laser irradiation, AgPCPP nanoparticles significantly reduce breast tumor growth, leading to prolonged survival compared to free Ag2S-NP. Over time, AgPCPP retention in tissues gradually decreases, without any signs of acute toxicity, providing strong evidence of their safety and biodegradability. Therefore, AgPCPP may serve as a "one-for-all" theranostic agent that degrades into small components for excretion after fulfilling diagnostic and therapeutic tasks, offering good prospects for clinical translation.

Hydroxyethylcellulose-Directed Synthesis of Gold Microplates with Hydrogen Peroxide in an Aqueous Phase

In this study, we successfully synthesized well-defined polygonal gold microplates for the first time in an aqueous phase using hydroxyethylcellulose (HEC) in the presence of hydrogen peroxide (H2O2). HEC played a pivotal role during the synthesis, acting not only as a biotemplate but also as an in situ reduction site for the nucleation and growth of gold (Au) microplates. H2O2 played a crucial role in accelerating the growth of Au microplates from the Au nucleus. This methodology is ecofriendly and easy to operate and has potential applications in various fields, such as electronics, photonics, and biotechnology.

Recent Trends in Bio-nanomaterials and Non-invasive Combinatorial Approaches of Photothermal Therapy against Cancer

In 2020, approximately 10 million deaths worldwide were attributed to cancer, making it the primary cause of death globally. Photothermal therapy (PTT) is one of the novel ways to treat and abolish cancer. PTT significantly impacts cancer theranostics compared to other therapies like surgery, chemotherapy, and radiotherapy due to its remarkable binding capability to tumor sites and lower invasiveness into normal healthy tissues. PTT relies on photothermal agents (PTAs), which generate heat by absorbing the near-infrared (NIR) light and destroying cancer cells. Several PTT agents remain longer in the reticuloendothelial system (RES) and induce toxicity, restricting their use in the biomedical field. To overcome this problem, the usage of biodegradable nano-photothermal agents is required. This review has discussed the PTT mechanism of action and different types of novel bio-nanomaterials used for PTT. We also focussed on the combinatorial effects of PTT with other cancer therapies and their effect on human health. The role of LED lights and mild hypothermia in PTT has been discussed briefly in this review.

Tumor-targeted nanodrug FSGG/siGal-9 for transdermal photothermal immunotherapy of melanoma

Photothermal therapy (PTT) is a cancer-targeted treatment approach.The occurrence of tumors may be related to microbial infections (Viruses, bacteria, fungi, etc.), which probably provokes anti-tumor immunity. However, T cells in the context of cancer become exhausted and dysfunctional. Galectin-9 (Gal-9) is highly expressed in normal tissues and associates with body immune tolerance, and was firstly evidenced with much higher expression on the primary solid tumors than CD80/86 (B7) and CD274 (PD-L1) here, which suggests that Gal-9 may be a key factor in inhibiting the anti-tumor immunity, and its receptor T cell immunoglobulin and mucin domain 3 (TIM-3) was discovered on the cytotoxic T lymphocytes (CTL) with high expression as well based on the single cell analysis. The immune checkpoint communications showed that the Gal-9/TIM-3 axis played the most vital role on negatively regulating the anti-tumor immunity of CTL for melanoma. Then, we used a novel transdermal photothermal nanosensitizer (FSGG) loading Gal-9 siRNA (FSGG/siGal-9) for knocking the tumor cells down Gal-9 to block the Gal-9/TIM-3 axis and prohibit CTL exhaustion synergizing PTT against melanoma, which evidenced good effects on inhibiting tumor growth and enhancing anti-tumor immunity, named "photothermal immunotherapy". This paper provides a new perspective for tumor prevention and treatment.

Tumor fluorescence and oxygenation monitoring during photodynamic therapy with chlorin e6 photosensitizer

BACKGROUND

The study is aimed at developing a method for monitoring photodynamic therapy (PDT) of a tumor using chlorin-type photosensitizers (PSs). Lack of monitoring of chlorin e6 (Cе6) photobleaching, hemoglobin oxygenation and blood flow during light exposure can limit the PDT effectiveness.

MATERIALS AND METHODS

Phototheranostics includes spectral-fluorescence diagnostics of Ce6 distribution in the NIR range and PDT with simultaneous assessment of hemoglobin oxygenation and tumor blood flow. Fluorescence diagnostics and PDT were performed using the single laser λexc=660 ± 5 nm.

RESULTS

Combined spectroscopic PDT monitoring method allowed simultaneous estimation of Ce6 photobleaching, hemoglobin oxygenation and tumor vascular thrombosis during PDT without interrupting the therapeutic light exposure.

CONCLUSION

The developed method of tumor phototheranostics using chlorin-type PSs may make it possible to personalize the duration of therapeutic light exposure during PDT.

Ex vivo photothermal treatment-induced immunogenic cell death for anticancer vaccine development

Photothermal therapy is an anti-cancer strategy that induce cell death by converting light energy into heat energy. During photothermal therapy, cancer cells were treated with photothermal agents, such as indocyanine green, and irradiated with a laser. Heat stress in cancer cells results in cellular death and inflammatory responses. In the present study, we demonstrated how ex vivo photothermal (PT)-treated cells underwent immunogenic cell death. PT treatment caused significant expression of heat shock protein (HSP) 27, HSP70, and HSP90 in murine tumor cells. To evaluate the immunogenicity of heat-stressed cells, lysate from PT-treated tumor cells or water-based heated cells was pulsed to syngeneic bone-marrow-derived dendritic cells (DCs) to generate a DC-based vaccine. Administration with PT-treated tumor lysates-pulsed DC vaccine resulted in significant inhibition of tumor growth in BALB/c and C57BL/6 syngeneic tumor-bearing mice. The immunogenicity of PT-treated cancer cells was reduced in the presence of HSP inhibitors, J2, VER-155008 or 17-AAG. Our study elucidates how PT techniques have distinct mechanisms from water-based heating and might be a potentially robust and efficient solution to developing an anti-cancer vaccine.

Laser-induced vapor nanobubbles for B16-F10 melanoma cell killing and intracellular delivery of chemotherapeutics

The most lethal form of skin cancer is cutaneous melanoma, a tumor that develops in the melanocytes, which are found in the epidermis. The treatment strategy of melanoma is dependent on the stage of the disease and often requires combined local and systemic treatment. Over the years, systemic treatment of melanoma has been revolutionized and shifted toward immunotherapeutic approaches. Phototherapies like photothermal therapy (PTT) have gained considerable attention in the field, mainly because of their straightforward applicability in melanoma skin cancer, combined with the fact that these strategies are able to induce immunogenic cell death (ICD), linked with a specific antitumor immune response. However, PTT comes with the risk of uncontrolled heating of the surrounding healthy tissue due to heat dissipation. Here, we used pulsed laser irradiation of endogenous melanin-containing melanosomes to induce cell killing of B16-F10 murine melanoma cells in a non-thermal manner. Pulsed laser irradiation of the B16-F10 cells resulted in the formation of water vapor nanobubbles (VNBs) around endogenous melanin-containing melanosomes, causing mechanical cell damage. We demonstrated that laser-induced VNBs are able to kill B16-F10 cells with high spatial resolution. When looking more deeply into the cell death mechanism, we found that a large part of the B16-F10 cells succumbed rapidly after pulsed laser irradiation, reaching maximum cell death already after 4 h. Practically all necrotic cells demonstrated exposure of phosphatidylserine on the plasma membrane and caspase-3/7 activity, indicative of regulated cell death. Furthermore, calreticulin, adenosine triphosphate (ATP) and high-mobility group box 1 (HMGB1), three key damage-associated molecular patterns (DAMPs) in ICD, were found to be exposed from B16-F10 cells upon pulsed laser irradiation to an extent that exceeded or was comparable to the bona fide ICD-inducer, doxorubicin. Finally, we could demonstrate that VNB formation from melanosomes induced plasma membrane permeabilization. This allowed for enhanced intracellular delivery of bleomycin, an ICD-inducing chemotherapeutic, which further boosted cell death with the potential to improve the systemic antitumor immune response.

Plasmonic and Photothermal Properties of Silica-Capped Gold Nanoparticle Aggregates

Owing to their biocompatibility, gold nanoparticles have many applications in healthcare, notably for targeted drug delivery and the photothermal therapy of tumors. The addition of a silica shell to the nanoparticles can help to minimize the aggregation of the nanoparticles upon exposure to harsh environments and protect any Raman reporters adsorbed onto the metal surface. Here, we report the effects of the addition of a silica shell on the photothermal properties of a series of gold nanostructures, including gold nanoparticle aggregates. The presence of a Raman reporter at the surface of the gold nanoparticles also allows the structures to be evaluated by surface-enhanced Raman scattering (SERS). In this work, we explore the relationship between the degree of aggregation and the position and the extinction of the near-infrared plasmon on the observed SERS intensity and in the increase in bulk temperature upon near-infrared excitation. By tailoring the concentration of the silane and the thickness of the silica shell, it is possible to improve the photothermal heating capabilities of the structures without sacrificing the SERS intensity or changing the optical properties of the gold nanoparticle aggregates.

Theoretical and experimental study on the photothermal effect of palladium nanoparticles based on a finite element model

Palladium nanoparticles (Pd NPs) show significant promise as agents for the photothermal treatment of tumors due to their high photothermal conversion efficiency and thermal stability. theoretical calculations were conducted to investigate the electric field and solid heat conduction of Pd NPs with various sizes and particle distances, aiming to achieve the maximum photothermal conversion efficiency during laser irradiation. Subsequently, Pd NPs with optimal size and structure were synthesized. In vitro and in vivo experiments were conducted to evaluate photothermal conversion. The theoretical results indicated that a peak temperature of 90.12 °C is achieved when the side length is 30 nm with a distance of 2 nm. In vitro experiments demonstrated that the photothermal conversion efficiency of Pd NPs can reach up to 61.9%. in vivo experiments revealed that injecting Pd NPs into blood vessels can effectively reduce the number of laser pulses by 22.22%, thereby inducing obvious vasoconstriction.

Analysis of temperature behavior in biological tissue in photothermal therapy according to laser irradiation angle

The type of death of biological tissue varies with temperature and is broadly classified as apoptosis and necrosis. A new treatment called photothermal therapy is being studied on this basis. Photothermal therapy is a treatment technique based on photothermal effects and has the advantage of not requiring incisions and, therefore, no bleeding. In this study, a numerical analysis of photothermal therapy for squamous cell carcinoma was performed. Photothermal agents used were gold nanoparticles, and the photothermal therapy effect was confirmed by changing the angle of the laser irradiating the tumor tissue. The effectiveness of photothermal therapy was quantitatively assessed on the basis of three apoptotic variables. Further, the volume fraction of gold nanoparticles in the tumor tissue and laser intensity with optimal therapeutic effect for different laser irradiation angles were studied. Thus, the findings of this study can aid the practical implementation of photothermal therapy in the future.

Interactions between gold nanoparticles with different morphologies and human serum albumin

Introduction: Three different shapes of gold nanoparticles were synthesized in this experiment. At the same time, studies compared their effects with human serum albumin (HSA). Methods: Gold nanoparticles (AuNPs) with three different morphologies, such as, nanospheres (AuNSs), nanorods (AuNRs), and nanoflowers (AuNFs) were synthesized via a seeding method and their characteristic absorption peaks were detected using ultraviolet-visible (UV-vis) absorption spectroscopy, Telectron microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta potential measurements, circular dichroism (CD), and Fourier transform infrared spectroscopy (FTIR) to study the interactions between them and HSA. By comparing the thermodynamic parameters and quenching mechanism of the three materials, similarities and differences were determined in their interactions with HSA. Results: The results showed that with an increase in the concentration of the AuNPs with the three different morphologies, the UV-vis absorption peak intensity of the mixed solution increased, but its fluorescence intensity was quenched. This indicates that the three types of AuNPs interact with HSA, and that the interactions between them represent a static quenching process, which is consistent with the conclusions derived from three-dimensional fluorescence experiments. Through variable-temperature fluorescence experiments, the binding constants, number of binding sites, and thermodynamic parameters of the interactions between the three types of AuNPs and HSA were determined. The Gibbs free energy changes were <0, indicating that the reactions of the three types of AuNPs with HSA are spontaneous, resulting in associated matter. Binding constant measurements indicated that the strongest binding took place between the AuNFs and HSA. In addition, the results of fluorescence, CD spectroscopy, and FTIR showed that three different shapes of AuNPs can induce conformational changes in HSA and reduce the α-helix content. Among them, AuNFs have the smallest ability to induce conformational changes. Discussion: According to studies, AuNFs interact more favorably with HSA. This can be used as a reference for the administration of drugs containing AuNPs.

Coiled-Coil-Based Biofunctionalization of 100 nm Gold Nanoparticles with the Trastuzumab Antibody for the Detection of HER2-Positive Cancer Cells

We compared different biofunctionalization strategies for immobilizing trastuzumab, an IgG targeting the HER2 biomarker, onto 100 nm spherical gold nanoparticles because of the E/K coiled-coil peptide heterodimer. First, Kcoil peptides were grafted onto the gold surface while their Ecoil partners were genetically encoded at the C-terminus of trastuzumab's Fc region, allowing for a strong and specific interaction between the antibodies and the nanoparticles. Gold nanoparticles with no Kcoil peptides on their surface were also produced to immobilize Ecoil-tagged trastuzumab antibodies via the specific adsorption of their negatively charged Ecoil tags on the positively charged gold surface. Finally, the nonspecific adsorption of wild-type trastuzumab on the gold surface was also assessed, with and without Kcoil peptides grafted on it beforehand. We developed a thorough workflow to systematically compare the immobilization strategies regarding the stability of nanoparticles, antibody coverage, and ability to specifically bind to HER2-positive breast cancer cells. All nanoparticles were highly monodisperse and retained their localized surface plasmon resonance properties after biofunctionalization. A significant increase in the amount of immobilized antibodies was observed with the two oriented coil-based strategies compared to nonspecific adsorption. Finally, all biofunctionalization strategies allowed for the detection of HER2-positive breast cancer cells, but among the investigated approaches, we recommend using the E/K coiled-coil-based strategy for gold nanoparticle biofunctionalization because it allows for the qualitative and quantitative detection of HER2-positive cells with a higher contrast compared to HER2-negative cells.

Effectiveness of Gold Nanorods of Different Sizes in Photothermal Therapy to Eliminate Melanoma and Glioblastoma Cells

Gold nanorods are the most commonly used nanoparticles in photothermal therapy for cancer treatment due to their high efficiency in converting light into heat. This study aimed to investigate the efficacy of gold nanorods of different sizes (large and small) in eliminating two types of cancer cell: melanoma and glioblastoma cells. After establishing the optimal concentration of nanoparticles and determining the appropriate time and power of laser irradiation, photothermal therapy was applied to melanoma and glioblastoma cells, resulting in the highly efficient elimination of both cell types. The efficiency of the PTT was evaluated using several methods, including biochemical analysis, fluorescence microscopy, and flow cytometry. The dehydrogenase activity, as well as calcein-propidium iodide and Annexin V staining, were employed to determine the cell viability and the type of cell death triggered by the PTT. The melanoma cells exhibited greater resistance to photothermal therapy, but this resistance was overcome by irradiating cells at physiological temperatures. Our findings revealed that the predominant cell-death pathway activated by the photothermal therapy mediated by gold nanorods was apoptosis. This is advantageous as the presence of apoptotic cells can stimulate antitumoral immunity in vivo. Considering the high efficacy of these gold nanorods in photothermal therapy, large nanoparticles could be useful for biofunctionalization purposes. Large nanorods offer a greater surface area for attaching biomolecules, thereby promoting high sensitivity and specificity in recognizing target cancer cells. Additionally, large nanoparticles could also be beneficial for theranostic applications, involving both therapy and diagnosis, due to their superior detection sensitivity.

Niche preclinical and clinical applications of photoacoustic imaging with endogenous contrast

In the past decade, photoacoustic (PA) imaging has attracted a great deal of popularity as an emergent diagnostic technology owing to its successful demonstration in both preclinical and clinical arenas by various academic and industrial research groups. Such steady growth of PA imaging can mainly be attributed to its salient features, including being non-ionizing, cost-effective, easily deployable, and having sufficient axial, lateral, and temporal resolutions for resolving various tissue characteristics and assessing the therapeutic efficacy. In addition, PA imaging can easily be integrated with the ultrasound imaging systems, the combination of which confers the ability to co-register and cross-reference various features in the structural, functional, and molecular imaging regimes. PA imaging relies on either an endogenous source of contrast (e.g., hemoglobin) or those of an exogenous nature such as nano-sized tunable optical absorbers or dyes that may boost imaging contrast beyond that provided by the endogenous sources. In this review, we discuss the applications of PA imaging with endogenous contrast as they pertain to clinically relevant niches, including tissue characterization, cancer diagnostics/therapies (termed as theranostics), cardiovascular applications, and surgical applications. We believe that PA imaging's role as a facile indicator of several disease-relevant states will continue to expand and evolve as it is adopted by an increasing number of research laboratories and clinics worldwide.

Tannic-acid-mediated synthesis and characterization of magnetite-gold nanoplatforms for photothermal therapy

Aim: The design of new hybrid nanoplatforms (HNPs) through the innovative and eco-friendly use of tannic acid (TA) for the synthesis and stabilization of the nanoplatforms. Materials & methods: The size, morphology, composition and magnetic and plasmonic properties of HNPs were investigated together with their ability to generate heat under laser irradiation and the hemotoxicity to explore their potential use for biomedical applications. Results & conclusion: The use of TA allowed the synthesis of the HNPs by adopting a simple and green method. The HNPs preserved the peculiar properties of both magnetic and plasmonic nanoparticles and did not show any hemotoxic effect.

Nanoparticle-Based Treatment Approaches for Skin Cancer: A Systematic Review

Nanoparticles have shown marked promise as both antineoplastic agents and drug carriers. Despite strides made in immunomodulation, low success rates and toxicity remain limitations within the clinical oncology setting. In the present review, we assess advances in drug delivery nanoparticles, for systemic and topical use, in skin cancer treatment. A systematic review of controlled trials, meta-analyses, and Cochrane review articles was conducted. Eligibility criteria included: (1) a primary focus on nanoparticle utility for skin cancer; (2) available metrics on prevention and treatment outcomes; (3) detailed subject population; (4) English language; (5) archived as full-text journal articles. A total of 43 articles were selected for review. Qualitative analysis revealed that nanoscale systems demonstrate significant antineoplastic and anti-metastasis properties: increased drug bioavailability, reduced toxicity, enhanced permeability and retention effect, as well as tumor growth inhibition, among others. Nanoformulations for skin cancers have largely lagged behind those tested in other cancers-several of which have commercialized formulae. However, emerging evidence has indicated a powerful role for these carriers in targeting primary and metastatic skin cancers.

Folate targeting self-limiting hyperthermic nanoparticles for controlled photothermal therapy

Photothermal therapy utilizes photothermal agents and the use of nanoparticle agents is deemed advantageous for multiple reasons. Common nano-photothermal agents normally have high conversion efficiencies and heating rates, but bulk temperature measurement methods do not adequately represent the nanoscale temperatures of these nanoheaters. Herein, we report on the fabrication of self-limiting hyperthermic nanoparticles that can simultaneously photoinduce hyperthermia and report back temperature ratiometrically. The synthesized nanoparticles utilize a plasmonic core to achieve the photoinduced hyperthermic property and fluorescent FRET pairs entrapped in a silica shell to impart the ratiometric temperature sensing ability. The studies demonstrate the photoinduced hyperthermia with simultaneous temperature measurement using these particles and show that the particles can achieve a conversion efficiency of 19.5% despite the shell architecture. These folate-functionalized self-limiting photothermal agents are also used to demonstrate targeted photoinduced hyperthermia in a HeLa cell model.

Controlling local thermal gradients at molecular scales with Janus nanoheaters

The generation and control of heat transport with nanoparticles is an essential objective of thermoplasmonics. Janus nanoparticles consisting of dissimilar materials with contrasting interfacial Kapitza conductance provide a route to control heat transport at the nanoscale. Here we use the recently introduced Atomistic Nodal Approach to map the surface temperature and Kapitza conductance of Janus nanoparticles to individual atoms. We show that the transition in the thermal transport properties between the hydrophobic and hydrophilic interfaces is exceptionally abrupt, occurring over length scales below 1 nm. We demonstrate the generality of this result using coarse-grained and all-atom models of gold nanoparticles. Further, we show how this behaviour provides a route to sustain significant temperature differences, on the order of tens of degrees for μW heat rates, between adjacent molecular layers attached to heated gold nanoparticles. Our work provides fundamental insight into nanoscale heat transport and a principle to design heterogeneous Janus nanoparticles for thermal transport applications.

Different Applications of Temperature responsive nanogels as a new drug delivery system mini review

Temperature-sensitive drug delivery systems (TSDDS) are one of the systems that have received more attention in medical science these days due to their advantages. As these systems are sensitive to temperature, drug delivery to the target becomes more specific. Temperature-sensitive nanogels have many applications, including microbial infections, cancer therapy, transdermal use and tissue repair. These systems are characterized by minimal toxicity, improved therapeutic efficacy and reduced exposure to normal cells. This mini-review is prepared with different types of temperature-sensitive nanogel formation, release mechanisms, and their different applications. Various systems reported under these categories for targeted and controlled delivery of different classes of drugs, such as anti-cancer and antibiotic drugs with special emphasis on anti-cancer drugs and tissue healing, are discussed in this mini-review.

Cu-MOFs based photocatalyst triggered antibacterial platform for wound healing: 2D/2D Schottky junction and DFT calculation

Herein, we developed a multimodal antibacterial nanoplatform via synergism effect including knife-effect, photothermal, photocatalytic induced reactive oxygen species (ROS), and Cu²⁺ inherent attribute. Typically, 0.8-TC/Cu-NS possesses higher photothermal property with the higher photothermal conversion efficiency of 24% and the moderate temperature up to 97 °C. Meanwhile, 0.8-TC/Cu-NS exhibits the more active ROS, ¹O₂ and ·O₂^-. Hence, 0.8-TC/Cu-NS possesses best antibacterial properties against S. aureus and E. coli in vitro with efficiency of 99.94%/99.97% under near-infrared (NIR) light, respectively. In the therapeutic practical use for wound healing of Kunming mice, this system exhibits outstanding curing capacity and good biocompatibility. Based on the electron configuration measurement and density functional theory (DFT) simulation, it is confirmed that the electrons on CB of Cu-TCPP flow fleetingly to MXene trough the interface, with redistribution of charge and band upward bending over Cu-TCPP. As a result, the self-assembled 2D/2D interfacial Schottky junction have made great favor to accelerate photogenerated charges mobility, hamper charge recombination, and increases the photothermal/photocatalytic activity. This work gives us a hint to mostly design the multimodal synergistic nanoplatform under NIR light in biological applications without drug resistance.

Photodynamic and Photothermal Therapies: Synergy Opportunities for Nanomedicine

Tumoricidal photodynamic (PDT) and photothermal (PTT) therapies harness light to eliminate cancer cells with spatiotemporal precision by either generating reactive oxygen species or increasing temperature. Great strides have been made in understanding biological effects of PDT and PTT at the cellular, vascular and tumor microenvironmental levels, as well as translating both modalities in the clinic. Emerging evidence suggests that PDT and PTT may synergize due to their different mechanisms of action, and their nonoverlapping toxicity profiles make such combination potentially efficacious. Moreover, PDT/PTT combinations have gained momentum in recent years due to the development of multimodal nanoplatforms that simultaneously incorporate photodynamically- and photothermally active agents. In this review, we discuss how combining PDT and PTT can address the limitations of each modality alone and enhance treatment safety and efficacy. We provide an overview of recent literature featuring dual PDT/PTT nanoparticles and analyze the strengths and limitations of various nanoparticle design strategies. We also detail how treatment sequence and dose may affect cellular states, tumor pathophysiology and drug delivery, ultimately shaping the treatment response. Lastly, we analyze common experimental design pitfalls that complicate preclinical assessment of PDT/PTT combinations and propose rational guidelines to elucidate the mechanisms underlying PDT/PTT interactions.

Recent Advances in Hydrogel-Based Phototherapy for Tumor Treatment

Phototherapeutic agent-based phototherapies activated by light have proven to be safe modalities for the treatment of various malignant tumor indications. The two main modalities of phototherapies include photothermal therapy, which causes localized thermal damage to target lesions, and photodynamic therapy, which causes localized chemical damage by generated reactive oxygen species (ROS). Conventional phototherapies suffer a major shortcoming in their clinical application due to their phototoxicity, which primarily arises from the uncontrolled distribution of phototherapeutic agents in vivo. For successful antitumor phototherapy, it is essential to ensure the generation of heat or ROS specifically occurs at the tumor site. To minimize the reverse side effects of phototherapy while improving its therapeutic performance, extensive research has focused on developing hydrogel-based phototherapy for tumor treatment. The utilization of hydrogels as drug carriers allows for the sustained delivery of phototherapeutic agents to tumor sites, thereby limiting their adverse effects. Herein, we summarize the recent advancements in the design of hydrogels for antitumor phototherapy, offer a comprehensive overview of the latest advances in hydrogel-based phototherapy and its combination with other therapeutic modalities for tumor treatment, and discuss the current clinical status of hydrogel-based antitumor phototherapy.

A 3D-Printed Graphene BioFuse Implant for Postsurgical Adjuvant Therapy of Cancer: Proof of Concept in 2D- and 3D-Spheroid Tumor Models

Three-dimensional printing is an emerging technology that is finding its niche applications in diverse fields owing to its flexibility concerning personalization and design. Surgery followed by adjuvant therapy is the standard treatment plan in most cancers from stage I to stage III. Most of the available adjuvant therapies, like chemotherapy, radiation therapy, immunotherapy, hormonal therapy, etc., are associated with severe side effects that considerably reduce the quality of life of patients. In addition, there is always the chance of tumor recurrence or metastasis development followed by surgery. This investigation reports the development of a 3D-printed, biodegradable, laser-responsive implant with a chemo-combined thermal ablating potential for adjuvant therapy of cancer. The 3D-printable ink was developed using poly(l-lactide) and hydroxypropyl methylcellulose as the base polymer, doxorubicin as the chemotherapeutic agent, and reduced graphene oxide as the photothermal ablating agent. The personalized implant released the drug pH-dependently (p value < 0.0001) for an extended period (93.55 ± 1.80% → 28 days). The 3D-printed implant exhibited acceptable biophysical properties (tensile strength: 3.85 ± 0.15 MPa; modulus: 92.37 ± 11.50 MPa; thickness: 110 μm) with laser-responsive hyperthermia (ΔT: 37 ± 0.9 °C → 48.5 ± 1.07 °C; 5 min; 1.5 W/cm²) and inherent biodegradable property (SEM analysis). The 3D-printed implant was evaluated for its therapeutic potential in 2D- and 3D-spheroid tumor models (MDA-MB 231 and SCC 084 2D cells) employing MTT cytotoxicity assay, apoptosis assay, cell cycle analysis, and gene expression analysis. The biomolecular aspects and biomechanics of the 3D-printed BioFuse implant were also evaluated by determining the effect of treatment on the expression levels of HSP1A, Hsp70, BAX, and PTEN. It is advocated that the knowledge developed in this project will significantly assist and advance the science aiming to develop a clinically translatable postsurgical adjuvant therapy for cancer.

A photoactive injectable antibacterial hydrogel to support chemo-immunotherapeutic effect of antigenic cell membrane and sorafenib by near-infrared light mediated tumor ablation

Intravenously administered nanocarriers suffer from off-target distribution, pre-targeting drug leakage, and rapid clearance, limiting their efficiency in tumor eradication. To bypass these challenges, an injectable hydrogel with time- and temperature-dependent viscosity enhancement behavior and self-healing property are reported to assist in the retention of the hydrogel in the tumor site after injection. The cancer cell membrane (CCM) and sorafenib are embedded into the hydrogel to elicit local tumor-specific immune responses and induce cancer cell apoptosis, respectively. In addition, hyaluronic acid (HA) coated Bi₂S₃ nanorods (BiH) are incorporated within the hydrogel to afford prolonged multi-cycle local photothermal therapy (PTT) due to the reduced diffusion of the nanorods to the surrounding tissues as a result of HA affinity toward cancer cells. The results show the promotion of immunostimulatory responses by both CCM and PTT through the release of inflammatory cytokines from immune cells, which allows localized and complete ablation of the breast tumor in an animal model by a single injection of the hydrogel. Moreover, the BiH renders strong antibacterial activity to the hydrogel, which is crucial for the clinical translation of injectable hydrogels as it minimizes the risk of infection in the post-cancer lesion formed by PTT-mediated cancer therapy.

Silica Coated Bi2Se3 Topological Insulator Nanoparticles: An Alternative Route to Retain Their Optical Properties and Make Them Biocompatible

Localized surface plasmon resonance (LSPR) is the cause of the photo-thermal effect observed in topological insulator (TI) bismuth selenide (Bi₂Se₃) nanoparticles. These plasmonic properties, which are thought to be caused by its particular topological surface state (TSS), make the material interesting for application in the field of medical diagnosis and therapy. However, to be applied, the nanoparticles have to be coated with a protective surface layer, which prevents agglomeration and dissolution in the physiological medium. In this work, we investigated the possibility of using silica as a biocompatible coating for Bi₂Se₃ nanoparticles, instead of the commonly used ethylene-glycol, which, as is presented in this work, is not biocompatible and alters/masks the optical properties of TI. We successfully prepared Bi₂Se₃ nanoparticles coated with different silica layer thicknesses. Such nanoparticles, except those with a thick, ≈200 nm silica layer, retained their optical properties. Compared to ethylene-glycol coated nanoparticles, these silica coated nanoparticles displayed an improved photo-thermal conversion, which increased with the increasing thickness of the silica layer. To reach the desired temperatures, a 10-100 times lower concentration of photo-thermal nanoparticles was needed. In vitro experiments on erythrocytes and HeLa cells showed that, unlike ethylene glycol coated nanoparticles, silica coated nanoparticles are biocompatible.

Automated Approach to In Vitro Image-Guided Photothermal Therapy with Top-Down and Bottom-Up-Synthesized Graphene Quantum Dots

Graphene-based materials have been the subject of interest for photothermal therapy due to their high light-to-heat conversion efficiency. Based on recent studies, graphene quantum dots (GQDs) are expected to possess advantageous photothermal properties and facilitate fluorescence image-tracking in the visible and near-infrared (NIR), while surpassing other graphene-based materials in their biocompatibility. Several GQD structures including reduced graphene quantum dots (RGQDs) derived from reduced graphene oxide via top-down oxidation and hyaluronic acid graphene quantum dots (HGQDs) hydrothermally bottom-up synthesized from molecular hyaluronic acid were employed to test these capabilities in the present work. These GQDs possess substantial NIR absorption and fluorescence throughout the visible and NIR beneficial for in vivo imaging while being biocompatible at up to 1.7 mg/mL concentrations. In aqueous suspensions, RGQDs and HGQDs irradiated with a low power (0.9 W/cm2) 808 nm NIR laser facilitate a temperature increase up to 47.0 °C, which is sufficient for cancer tumor ablation. In vitro photothermal experiments sampling multiple conditions directly in the 96-well plate were performed using an automated simultaneous irradiation/measurement system developed on the basis of a 3D printer. In this study, HGQDs and RGQDs facilitated the heating of HeLa cancer cells up to 54.5 °C, leading to the drastic inhibition of cell viability from over 80% down to 22.9%. GQD's fluorescence in the visible and NIR traces their successful internalization into HeLa cells maximized at 20 h suggesting both extracellular and intracellular photothermal treatment capabilities. The combination of the photothermal and imaging modalities tested in vitro makes the GQDs developed in this work prospective agents for cancer theragnostics.

Polymersome-based protein drug delivery - quo vadis?

Protein-based therapeutics are an attractive alternative to established therapeutic approaches and represent one of the fastest growing families of drugs. While many of these proteins can be delivered using established formulations, the intrinsic sensitivity of proteins to denaturation sometimes calls for a protective carrier to allow administration. Historically, lipid-based self-assembled structures, notably liposomes, have performed this function. After the discovery of polymersome-based targeted drug-delivery systems, which offer manifold advantages over lipid-based structures, the scientific community expected that such systems would take the therapeutic world by storm. However, no polymersome formulations have been commercialised. In this review article, we discuss key obstacles for the sluggish translation of polymersome-based protein nanocarriers into approved pharmaceuticals, which include limitations imparted by the use of non-degradable polymers, the intricacies of polymersome production methods, and the complexity of the in vivo journey of polymersomes across various biological barriers. Considering this complex subject from a polymer chemist's point of view, we highlight key areas that are worthy to explore in order to advance polymersomes to a level at which clinical trials become worthwhile and translation into pharmaceutical and nanomedical applications is realistic.

Liposomal Iron Oxide Nanoparticles Loaded with Doxorubicin for Combined Chemo-Photothermal Cancer Therapy

Iron oxide nanoparticle (IONP) possesses unique advantages over other nanoparticles in the use of cancer imaging and therapy. Specifically, it has drawn great attention in the emerging research field of photothermal cancer therapy. Herein, we developed doxorubicin (DOX)-loaded liposomal IONP (Lipo-IONP/DOX) and evaluated in vitro and in vivo their applicability for combined chemo-photothermal cancer therapy. The Lipo-IONP was synthesized by the thin-film evaporation method. The prepared Lipo-IONP was observed as about a 240 nm-sized agglomerate of globular-shaped nanoparticles. The TEM and FT-IR data evidenced the successful formation of liposomal IONP. The superparamagnetic property of the Lipo-IONP was confirmed by the SQUID analysis. The DSC data showed a transition temperature of about 47-48 °C for the mixed lipids composing the Lipo IONP, and the DOX release studies revealed the feasibility of induced burst release of DOX by laser irradiation. The Lipo-IONP/DOX possessed a plasma half-life of 42 min, which could ensure sufficient circulation time for magnetic tumor targeting. The in vivo magnetic targeting enabled a significant increase (6.3-fold) in the tumor accumulation of Lipo-IONP/DOX, leading to greater photothermal effects. Finally, the preliminary efficacy study evidenced the applicability as well as the safety of the Lipo-IONP/DOX for use in combined chemo-photothermal cancer therapy. Overall, the study results demonstrated that the Lipo-IONP/DOX might serve as an effective and safe agent for combined chemo-photothermal cancer therapy.

Hyaluronic Acid-Modified Cisplatin-Encapsulated Poly(Lactic-co-Glycolic Acid) Magnetic Nanoparticles for Dual-Targeted NIR-Responsive Chemo-Photothermal Combination Cancer Therapy

Combination chemo-photothermal therapy with nanomaterials can reduce the dose of chemotherapeutic drugs required for effective cancer treatment by minimizing toxic side effects while improving survival times. Toward this end, we prepare hyaluronic acid (HA)-modified poly(lactic-co-glycolic acid) (PLGA) magnetic nanoparticles (MNP) for the CD44 receptor-mediated and magnetic field-guided dual-targeted delivery of cisplatin (CDDP). By co-encapsulating the CDDP and oleic acid-coated iron oxide MNP (IOMNP) in PLGA, the PMNPc was first prepared in a single emulsification/solvent evaporation step and successively surface modified with chitosan and HA to prepare the HA/PMNPc. Spherical HA/PMNPc nanoparticles of ~300 nm diameter can be prepared with 18 and 10% (w/w) loading content of CDDP and IOMNP and a pH-sensitive drug release to facilitate the endosomal release of the CDDP after intracellular uptake. This leads to the higher cytotoxicity of the HA/PMNPc toward the U87 glioblastoma cells than free CDDP with reduced IC50, a higher cell apoptosis rate, and the enhanced expression of cell apoptosis marker proteins. Furthermore, the nanoparticles show the hyperthermia effect toward U87 after short-term near-infrared (NIR) light exposure, which can further elevate the cell apoptosis/necrosis rate and upregulate the HSP70 protein expression due to the photothermal effects. The combined cancer therapeutic efficacy was studied in vivo using subcutaneously implanted U87 cells in nude mice. By using dual-targeted chemo-photothermal combination cancer therapy, the intravenously injected HA/PMNPc under magnetic field guidance and followed by NIR laser irradiation was demonstrated to be the most effective treatment modality by inhibiting the tumor growth and prolonging the survival time of the tumor-bearing nude mice.

Role of Tunable Gold Nanostructures in Cancer Nanotheranostics: Implications on Synthesis, Toxicity, Clinical Applications and Their Associated Opportunities and Challenges

The existing diagnosis and treatment modalities have major limitations related to their precision and capability to understand several stages of disease development. A superior therapeutic system consists of a multifunctional approach in early diagnosis of the disease with a simultaneous progressive cure, using a precise medical approach towards complex treatment. These challenges can be addressed via nanotheranostics and explore suitable approaches to improve health care. Nanotechnology in combination with theranostics as an unconventional platform paved the way for developing novel strategies and modalities leading to diagnosis and therapy for complex disease conditions, ranging from acute to chronic levels. Among the metal nanoparticles, gold nanoparticles are being widely used for theranostics due to their inherent non-toxic nature and plasmonic properties. The unique optical and chemical properties of plasmonic metal nanoparticles along with theranostics have led to a promising era of plausible early detection of disease conditions, and they enable real-time monitoring with enhanced non-invasive or minimally invasive imaging of several ailments. This review aims to highlight the improvement and advancement brought to nanotheranostics by gold nanoparticles in the past decade. The clinical use of the metal nanoparticles in nanotheranostics is explained, along with the future perspectives on addressing the key applications related to diagnostics and therapeutics, respectively. The scope of gold nanoparticles and their realistic potential to design a sophisticated theranostic system is discussed in detail, along with their implications in clinical advancements which are the needs of the hour. The review concluded with the challenges, opportunities, and implications on translational potential of using gold nanoparticles in nanotheranostics.

Recent advances and challenges in temperature monitoring and control in microfluidic devices

Temperature is a critical-yet sometimes overlooked-parameter in microfluidics. Microfluidic devices can experience heating inside their channels during operation due to underlying physicochemical phenomena occurring therein. Such heating, whether required or not, must be monitored to ensure adequate device operation. Therefore, different techniques have been developed to measure and control temperature in microfluidic devices. In this contribution, the operating principles and applications of these techniques are reviewed. Temperature-monitoring instruments revised herein include thermocouples, thermistors, and custom-built temperature sensors. Of these, thermocouples exhibit the widest operating range; thermistors feature the highest accuracy; and custom-built temperature sensors demonstrate the best transduction. On the other hand, temperature control methods can be classified as external- or integrated-methods. Within the external methods, microheaters are shown to be the most adequate when working with biological samples, whereas Peltier elements are most useful in applications that require the development of temperature gradients. In contrast, integrated methods are based on chemical and physical properties, structural arrangements, which are characterized by their low fabrication cost and a wide range of applications. The potential integration of these platforms with the Internet of Things technology is discussed as a potential new trend in the field.

Bacterial-mediated synthesis and characterization of copper oxide nanoparticles with antibacterial, antioxidant, and anticancer potentials

The application of novel bacterial strains for effective biosynthesis of nanoparticles minimizes negative environmental impact and eliminates challenges of available approaches. In the present study, cell-free extract of Stenotrophomonas sp. BS95. was used for synthesis of copper oxide nanoparticles (CuONPs). Characterization of crude and calcined CuONPs was carried out by UV-vis spectroscopy, X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, zeta potential, dynamic light scattering, field emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Afterward, biogenic CuONPs were evaluated for antibacterial, antioxidant, and cytotoxic effects using broth micro-dilution method, DPPH assay and alamarBlue assay, respectively. Finally, molecular mechanisms behind anticancer effects of CuONPs was ascertained by real time PCR. UV-vis absorbance spectra registered surface plasmon resonance peaks at 286 nm and 420 nm for crude and calcined CuONPs, respectively. FTIR spectra exhibited bands associated with organic functional groups of bacterial proteins, confirming capping and functionalization of CuONPs. The average crystallite size of crude and calcined CuONPs was determined as 18.24 and 21.3 nm by XRD, respectively. The average zeta potentials of crude and calcined CuONPs were as -28.57 ± 5.13 and -29.47 ± 4.78 mV, respectively, indicating their high stability. Electron microscopy revealed that crude and calcined CuONPs were roughly spherical particles with an average size of 35.24 ± 4.64 and 43.68 ± 2.31 nm, respectively. Biogenic CuONPs induced antibacterial effects with minimal inhibitory concentrations ranging from 62.5 to 1,000 μg/ml against Gram-negative and Gram-positive strains. The antioxidant activity of crude and calcined CuONPs was found to be 83% ± 2.64% and 78% ± 1.73%, respectively. More intriguingly, CuONPs exerted considerable cytotoxic effects on human colon and gastric adenocarcinoma cells, while induced low toxicity on normal cells. Anticancer effects of biogenic CuONPs were confirmed by significant changes induced in the expression of apoptosis-related genes, including P53, BAX, BCL2 and CCND1. Hence, biosynthesized CuONPs could be considered as potential antimicrobial, antioxidant and anticancer agents.

Influence of Cell Type on the Efficacy of Plasmonic Photothermal Therapy

In plasmonic photothermal therapy (PPTT), illuminated gold nanoparticles are locally heated to produce selective damage in cells. While PPTT is expected to strongly depend on the cell line, available data are sparse and critical parameters remain unclear. To elucidate this pivotal aspect, we present a systematic study of diseased and nondiseased cells from different tissues to evaluate cytotoxicity, uptake of gold nanorods (AuNRs), and viability after PPTT. We identified differences in uptake and toxicity between cell types, linking AuNR concentrations to toxicity. Furthermore, the cell death mechanism is shown to depend on the intensity of the irradiated light and hence the temperature increase. Importantly, the data also underline the need to monitor cell death at different time points. Our work contributes to the definition of systematic protocols with appropriate controls to fully comprehend the effects of PPTT and build meaningful and reproducible data sets, key to translate PPTT to clinical settings.

Nanoparticles-based phototherapy systems for cancer treatment: Current status and clinical potential

Remarkable progress in phototherapy has been made in recent decades, due to its non-invasiveness and instant therapeutic efficacy. In addition, with the rapid development of nanoscience and nanotechnology, phototherapy systems based on nanoparticles or nanocomposites also evolved as an emerging hotspot in nanomedicine research, especially in cancer. In this review, first we briefly introduce the history of phototherapy, and the mechanisms of phototherapy in cancer treatment. Then, we summarize the representative development over the past three to five years in nanoparticle-based phototherapy and highlight the design of the innovative nanoparticles thereof. Finally, we discuss the feasibility and the potential of the nanoparticle-based phototherapy systems in clinical anticancer therapeutic applications, aiming to predict future research directions in this field. Our review is a tutorial work, aiming at providing useful insights to researchers in the field of nanotechnology, nanoscience and cancer.

Facile preparation of Au- and BODIPY-grafted lipid nanoparticles for synergized photothermal therapy

Gold nanoparticles with large size exhibit preferable properties for photothermal therapy (PTT). However, the prolonged tissue retention and slow elimination of gold nanoparticles limit their therapeutic applications. Previously, gold nanoclusters carrying lipid nanoparticles (Au-LNPs) have been reported after simply mixing Au³⁺ with preformed diethylenetriaminepentaacetic acid lipid nanoparticles to solve this contradiction. Au-LNPs demonstrated enhanced photothermal effects in comparison to neat gold nanoparticles. To further improve the photothermal activity, we introduced the organic photothermal agent boron dipyrromethene (BODIPY) to Au-LNPs for synergistic PTT. Au- and BODIPY-grafted LNPs (AB-LNPs) were formed by simply mixing Au-LNPs with BODIPY. The BODIPY could be associated stably to Au-LNPs, and the release of BODIPY from AB-LNPs could be accelerated by laser irradiation. AB-LNPs are scalable and showed excellent photothermal effects. AB-LNPs showed enhanced cellular uptake efficiency compared to free BODIPY in 4T1 breast cancer cells. Under laser irradiation, AB-LNPs exhibited synergistic photothermal effects with significantly reduced dosage compared to monotherapy (treatments with Au-LNPs or free BODIPY alone). This study thus provides a facile and adaptive strategy for the development of a scalable and safe high-performance nanoplatform for synergistic PTT in the treatment of cancer and other diseases.

Collagen-induced assembly of adenosine monophosphate-modified gold nanoparticles for photothermal cancer therapy

Background

Photothermal therapy (PTT) has become an attractive approach for cancer treatment due to its merits of minimal invasiveness, location selectivity, and suitability for various cancer types. In PTT, photosensitizers are usually adopted to convert light to heat at tumor site, thereby generating heat-induced necroptosis or apoptosis. Therefore, the performance of photosensitizer (e.g., photothermal conversion efficiency (PCE), surface property, tumor accumulation and retention, etc.) determines the clinical manifestation of PTT. Currently, the poor tumor retention and potential long-term toxicity are two main obstacles for developing efficient photosensitizers. To address these issues, we have developed an in vivo tumor microenvironment stimuli-responsive self-assembled photosensitizer, which consists of a biomolecule, adenosine monophosphate (AMP) modified gold nanoparticles (AAu NPs), to enhance the accumulation and retention within tumor tissue for efficient PTT.

Results

The obtained AAu NPs with a hydrodynamic diameter of 9.12 ± 0.82 nm have excellent colloidal stability in aqueous solution. No sediments can be observed in the AAu NPs aqueous phase even after several months. The temperature of AAu aqueous suspension is elevated to 53.0 ℃ within 8 min at a low particle concentration of 80 μg/mL. A high PCE of 62.8% is obtained for AAu NPs based on the temperature change curves. The near-infrared (NIR) absorption and PCE of AAu NPs are enhanced compared to the surfactant-free Au NPs, enabling excellent photothermal cell-killing in vitro. When the AAu NPs arrive at the tumor tissue, they quickly form large aggregates via a collagen-induced assembly, leading to enhanced NIR absorption and improved tumor accumulation and retention, which enables a high PTT efficacy in vivo at a low photosensitizer dose of 40 μg and a low laser power density of 1.91 W/cm2.

Conclusions

A collagen-induced self-assembled gold photosensitizer for efficient PTT has been synthesized based on a biomolecule, AMP modification method. The synthesized AAu NPs with high PTT efficacy, superior biosafety and fast excretion from the body is an effective therapeutic agent in photothermal cancer therapy.

A Nanomedicine Structure-Activity Framework for Research, Development, and Regulation of Future Cancer Therapies

Despite their clinical success in drug delivery applications, the potential of theranostic nanomedicines is hampered by mechanistic uncertainty and a lack of science-informed regulatory guidance. Both the therapeutic efficacy and the toxicity of nanoformulations are tightly controlled by the complex interplay of the nanoparticle's physicochemical properties and the individual patient/tumor biology; however, it can be difficult to correlate such information with observed outcomes. Additionally, as nanomedicine research attempts to gradually move away from large-scale animal testing, the need for computer-assisted solutions for evaluation will increase. Such models will depend on a clear understanding of structure-activity relationships. This review provides a comprehensive overview of the field of cancer nanomedicine and provides a knowledge framework and foundational interaction maps that can facilitate future research, assessments, and regulation. By forming three complementary maps profiling nanobio interactions and pathways at different levels of biological complexity, a clear picture of a nanoparticle's journey through the body and the therapeutic and adverse consequences of each potential interaction are presented.

Microbial-Inspired Surface Patterning for Selective Bacterial Actions for Enhanced Performance in Microbial Fuel Cells

The performance of any bio-electrochemical system is dependent on the efficiency of electrode-microbial interactions. Surface properties play a focal role in bacterial attachment and biofilm formation on the electrodes. In addition to electrode surface properties, selective bacterial adhesion onto the electrode surface is mandatory to mitigate energy loss due to undesired bacterial interactions on the electrode surface. In the present study, microbial-patterned graphite scaffolds are developed for selective bacterial-electrode interactions. A power density as high as 1105 mW/m² is achieved with mG-E (a graphite electrode patterned with Escherichia coli), which is about 3 times higher than that of the pristine graphite electrode (370 mW/m²). Initial mechanical pre-treatment of the graphite electrode, followed by bacterial patterning, results in the formation of a unique cobblestone topography with a tuned surface area of 127.12 m²/g. This provides suitable morphology with enhanced active sites for selective bacterial intercalation in graphite layers. This cannot be otherwise achieved by any mechanical or other means. A unique methodology of symbolic regression is adopted to validate a genetic algorithm suitable for predicting a perfect correlation between surface characteristics and electrochemical characteristics with a minimum root-mean-square error of 0.08. The bacterial intercalation onto the graphite electrode causes protuberance of the graphite layers that reduces the surface potential and resistance, leading to high electron transfer. The study presents a unique bacterial-inspired surface patterning on the anode, which is critical for the performance of a microbial fuel cell.

Functionalized Silver and Gold Nanomaterials with Diagnostic and Therapeutic Applications

The functionalization of nanomaterials with suitable capping ligands or bioactive agents is an interesting strategy in designing nanosystems with suitable applicability and biocompatibility; the physicochemical and biological properties of these nanomaterials can be highly improved for biomedical applications. In this context, numerous explorations have been conducted in the functionalization of silver (Ag) and gold (Au) nanomaterials using suitable functional groups or agents to design nanosystems with unique physicochemical properties such as excellent biosensing capabilities, biocompatibility, targeting features, and multifunctionality for biomedical purposes. Future studies should be undertaken for designing novel functionalization tactics to improve the properties of Au- and Ag-based nanosystems and reduce their toxicity. The possible release of cytotoxic radicals or ions, the internalization of nanomaterials, the alteration of cellular signaling pathways, the translocation of these nanomaterials across the cell membranes into mitochondria, DNA damages, and the damage of cell membranes are the main causes of their toxicity, which ought to be comprehensively explored. In this study, recent advancements in diagnostic and therapeutic applications of functionalized Au and Ag nanomaterials are deliberated, focusing on important challenges and future directions.