A Microneedle Patch with Self-Oxygenation and Glutathione Depletion for Repeatable Photodynamic Therapy

Designing Microneedle Patch for Prophylaxis of Postoperative Atrial Fibrillation

Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery, which often occurs within 30 postoperative days, especially peaking at 2-3 days. Antiarrhythmic medications such as amiodarone are recommended in clinical practice for the prophylaxis and treatment of POAF. However, conventional oral administration is hindered due to delayed drug action and high risks of systemic toxicity, and emerging localized delivery strategies suffer from a limited release duration (less than 30 days). Herein, we develop a microneedle (MN) patch for localized delivery of amiodarone to the atria in a "First Rapid and Then Sustained" dual-release mode. Specifically, this patch is composed of a needle array integrated with an amiodarone-loaded reservoir for a sustained and steady release for over 30 days; and an amiodarone-containing coating film deposited on the needle surface via the Langmuir-Blodgett technique for a rapid release at the first day. Upon this design, only one MN patch enables a higher drug accumulation in the atrial tissue at the first day than oral administration and simultaneously remains therapeutical levels for over 30 days, despite at a significantly reduced drug dosage (5.08 mg in total versus ∼10 mg per day), thereby achieving ideal preventive effects and safety in a rat model. Our findings indicate that this MN device provides a robust and efficient delivery platform for long-term prophylaxis of POAF.

Microneedle-assisted dual delivery of PUMA gene and celastrol for synergistic therapy of rheumatoid arthritis through restoring synovial homeostasis

Abnormal proliferation of aggressive fibroblast-like synoviocytes (FLS) and perpetuate synovial inflammation can inevitably accelerate the progression of rheumatoid arthritis (RA). Herein, a strategy of simultaneously promoting FLS apoptosis and inhibiting inflammation as mediated by macrophages is proposed to restore synovial homeostasis for effective RA therapy. A hyaluronic acid-based dissolvable microneedle (MN) is fabricated for transdermal delivery of dual human serum albumin (HSA)-contained biomimetic nanocomplexes to regulate RA FLS and macrophages. Upon skin insertion, dual nanocomplexes are released rapidly from the MN and accumulate in RA joint microenvironment through both passive and active targeting as mediated by HSA. Thioketal-crosslinked fluorinated polyethyleneimine 1.8 K (TKPF) was constructed to bind the plasmid encoding pro-apoptotic gene PUMA with HSA coating layer (TKPF/pPUMA@HSA, TPH). TPH nanocomplexes can upregulate PUMA through RA FLS transfection to trigger efficient apoptosis. Also, HSA nanocomplexes encapsulating the classic anti-inflammatory natural product celastrol (Cel@HSA, CH) can inhibit inflammation of macrophages through blocking NF-κB pathway activation. TPH/CH MN can deplete RA FLS and inhibit M1 macrophage activation, suppress synovial hyperplasia as well as reduce bone and cartilage erosion in a collagen-induced arthritis (CIA) mouse model, demonstrating a promising strategy for efficient RA treatment.

Au-Fe3O4 Janus nanoparticles for imaging-guided near infrared-enhanced ferroptosis therapy in triple negative breast cancer

Triple-negative breast cancer (TNBC) is insensitive to conventional therapy due to its highly invasive nature resulting in poor therapeutic outcomes. Recent studies have shown multiple genes associated with ferroptosis in TNBC, suggesting an opportunity for ferroptosis-based treatment of TNBC. However, the efficiency of present ferroptosis agents for cancer is greatly restricted due to lack of specificity and low intracellular levels of H2O2 in cancer cells. Herein, we report a nano-theranostic platform consisting of gold (Au)-iron oxide (Fe3O4) Janus nanoparticles (GION@RGD) that effectively enhances the tumor-specific Fenton reaction through utilization of near-infrared (NIR) lasers, resulting in the generation of substantial quantities of toxic hydroxyl radicals (•OH). Specifically, Au nanoparticles (NPs) converted NIR light energy into thermal energy, inducing generation of abundant intracellular H2O2, thereby enhancing the iron-induced Fenton reaction. The generated •OH not only lead to apoptosis of malignant tumor cells but also induce the accumulation of lipid peroxides, causing ferroptosis of tumor cells. After functionalizing with the activity-targeting ligand RGD (Arg-Gly-Asp), precise synergistic treatment of TNBC was achieved in vivo under the guidance of Fe3O4 enhanced T2-weighted magnetic resonance imaging (MRI). This synergistic treatment strategy of NIR-enhanced ferroptosis holds promise for the treatment of TNBC.

A Versatile Cryomicroneedle Patch for Traceable Photodynamic Therapy

Photodynamic therapy (PDT) continues to encounter multifarious hurdles, stemming from the ineffectual preservation and delivery system of photosensitizers, the dearth of imaging navigation, and the antioxidant/hypoxic tumor microenvironment. Herein, a versatile cryomicroneedle patch (denoted as CMN-CCPH) is developed for traceable PDT. The therapeutic efficacy is further amplified by catalase (CAT)-induced oxygen (O2) generation and Cu2+-mediated glutathione (GSH) depletion. The CMN-CCPH is composed of cryomicroneedle (CMN) as the vehicle and CAT-biomineralized copper phosphate nanoflowers (CCP NFs) loaded with hematoporphyrin monomethyl ether (HMME) as the payload. Importantly, the bioactive function of HMME and CAT can be optimally maintained under the protection of CCPH and CMN for a duration surpassing 60 days, leading to bolstered bioavailability and notable enhancements in PDT efficacy. The in vivo visualization of HMME and oxyhemoglobin saturation (sO2) monitored by fluorescence (FL)/photoacoustic (PA) duplex real-time imaging unveils the noteworthy implications of CMN-delivered CCPH for intratumoral enrichment of HMME and O2 with reduced systemic toxicity. This versatile CMN patch demonstrates distinct effectiveness in neoplasm elimination, underscoring its promising clinical prospects.

Glutathione-Responsive Polymersome with Continuous Glutathione Depletion for Enhanced Photodynamic Therapy and Hypoxia-Activated Chemotherapy

The high glutathione (GSH) level of the tumor microenvironment severely affects the efficacy of photodynamic therapy (PDT). The current GSH depletion strategies have difficulty meeting the dual needs of security and efficiency. In this study, we report a photosensitizer Chlorin e6 (Ce6) and hypoxia-activated prodrug tirapazamine (TPZ) coloaded cross-linked multifunctional polymersome (TPZ/Ce6@SSPS) with GSH-triggered continuous GSH depletion for enhanced photodynamic therapy and hypoxia-activated chemotherapy. At tumor sites, the disulfide bonds of TPZ/Ce6@SSPS react with GSH to realize decross-linking for on-demand drug release. Meanwhile, the generated highly reactive quinone methide (QM) can further deplete GSH. This continuous GSH depletion will amplify tumor oxidative stress, enhancing the PDT effect of Ce6. Aggravated tumor hypoxia induced by PDT activates the prodrug TPZ, resulting in an enhanced combination of PDT and hypoxia-activated chemotherapy. Both in vitro and in vivo results demonstrate the efficient GSH depletion and potent antitumor activities by TPZ/Ce6@SSPS. This work provides a strategy for the design of a continuous GSH depletion platform, which holds great promise for enhanced combination tumor therapy.

Applications and prospects of microneedles in tumor drug delivery

As drug delivery devices, microneedles are used widely in the local administration of various drugs. Such drug-loaded microneedles are minimally invasive, almost painless, and have high drug delivery efficiency. In recent decades, with advancements in microneedle technology, an increasing number of adaptive, engineered, and intelligent microneedles have been designed to meet increasing clinical needs. This article summarizes the types, preparation materials, and preparation methods of microneedles, as well as the latest research progress in the application of microneedles in tumor drug delivery. This article also discusses the current challenges and improvement strategies in the use of microneedles for tumor drug delivery.

Industrializable approach for preparing hydrogel microneedles and their application in melanoma treatment

Microneedles (MNs) technology has been studied in transdermal drug delivery for more than 20 years with hundreds of clinical trials conducted. However, there are currently no commercially available MNs in medicine due to challenges in materials safety, cost-effective fabrication, and large-scale manufacturing. Herein, an approach for rapid and green fabrication of hydrogel microneedles (HMNs) based on infrared irradiation process was proposed for the first time. The optimized formulation consisted of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), which acted as cross-linked materials and pore-forming agents, respectively. The manufacturing method involved placing MNs patches under infrared irradiation at 70 °C for 2 min and annealing to obtain HMNs with excellent swelling behavior, mechanical strength, and biocompatibility. When model drugs azelaic acid (AZA) and matrine (MAT) were loaded into HMNs systems, the chemical stability of MAT was significantly improved. Ex vivo transdermal delivery experiments indicated that HMNs could achieve synchronous release of AZA and MAT, and the 24-hour percutaneous permeability rates of both drugs were 73.09 ± 0.48 % and 71.56 ± 1.23 %, respectively. In-vivo pharmacokinetic studies, HMNs administration presented dose-dependent stable blood drug concentrations for both drugs. Additionally, prominent anti-tumor efficacy and biosecurity were observed in the drug-loaded HMNs group in the pharmacodynamic evaluation. In summary, the efficient, convenient, and low-cost fabrication method based on infrared irradiation offers the possibility of mass production of drug-loaded HMNs, showing potential for industrial manufacturing development.

An Intelligent and Soluble Microneedle Composed of Bi/BiVO4 Schottky Heterojunction for Tumor Ct Imaging and Starvation/Gas Therapy-Promoted Synergistic Cancer Treatment

Phototherapy and sonodynamic therapy (SDT) are widely used for the synergistic treatment of tumors and have received considerable attention. However, an inappropriate tumor microenvironment, including pH, H2O2, oxygen, and glutathione levels, can reduce the therapeutic effects of synergistic phototherapy and SDT. Here, a novel Bi-based soluble microneedle (MN) is designed for the CT imaging of breast tumors and starvation therapy/gas therapy-enhanced phototherapy/SDT. The optimized Bi/BiVO4 Schottky heterojunction serves as the tip of the MN, which not only has excellent photothermal conversion ability and CT contrast properties, but its heterojunction can also avoid the rapid combination of electrons and hole pairs, thereby enhancing the photodynamic/sonodynamic effects. A degradable MN with excellent mechanical properties is fabricated by optimizing the ratios of poly(vinyl alcohol), poly(vinyl pyrrolidone), and sodium hyaluronate. Glucose oxidase (GOx) and diallyl trisulfide are loaded into the MN to achieve tumor starvation and gas therapy, respectively; And the controlled release of GOx and H2S can be achieved under ultrasound or near-infrared laser irradiation. The in vitro and in vivo results demonstrate that this multifunctional MN can achieve high therapeutic efficacy through starvation therapy/gas therapy-enhanced phototherapy/SDT. The designed multifunctional MN provides a prospective approach for synergistic phototherapy and SDT.

Aggregation-induced emission photosensitizer microneedles for enhanced melanoma photodynamic therapy

The incidence and mortality rates of skin melanoma have been increasing annually. Photodynamic therapy (PDT) enables effective destruction of tumor cells while minimizing harm to normal cells. However, traditional photosensitizers (PSs) suffer from photobleaching, photodegradation and the aggregation-caused quenching (ACQ) effect, and it is challenging for light to reach the deep layers of the skin to maximize the efficacy of PSs. Herein, we developed dissolving microneedles (MNs) loaded with PSs of TPE-EPy@CB[7] through supramolecular assembly. The PSs effectively enhanced the type-I reactive oxygen species (ROS) generation capacity, with a concentration of 2 μM possessing nearly half of the tumor cell-killing ability under 10 min white light irradiation. The MNs were successfully pierced into the targeted site for precise drug delivery. Additionally, the conical structure of the MNs, as well as the lens-like structure after dissolution, facilitated the transmission of light in the subcutaneous tissue, achieving significant inhibition of tumor growth with a tumor suppression rate of 97.8% and no systemic toxicity or side effects in melanoma mice. The results demonstrated the potent melanoma inhibition and biosafety of this treatment approach, exhibiting a new and promising strategy to conquer malignant melanoma.

A silyl porphyrin derivative conjugated with 6-deoxy-6-sulfo-α-d-glucopyranose functions as an efficient photosensitizer for photodynamic therapy

We synthesized a new silyl porphyrin derivative conjugated with 6-deoxy-6-sulfo-α-d-glucopyranose (SGlc). Conjugation with SGlc improved A549 cellular uptake without significant changes in the photophysical and photochemical properties and subcellular localization. This improved cellular uptake led to enhanced photodynamic activity. Furthermore, conjugation with SGlc suppressed dark toxicity. These advantages were not observed for a conjugate with a glucose molecule. These results indicated that the conjugation with SGlc is a promising strategy for enhancing photodynamic efficacy.

Mitochondrial Disruption Nanosystem Simultaneously Depressed Programmed Death Ligand-1 and Transforming Growth Factor-β to Overcome Photodynamic Immunotherapy Resistance

Currently, limited photosensitizers possess the capacity to reverse tumor hypoxia and reduce programmed death ligand-1 (PD-L1) and transforming growth factor-β (TGF-β) expression simultaneously, hindering the perfect photodynamic therapy (PDT) effect due to acquired immune resistance and the tumor hypoxic microenvironment. To tackle these challenges, in this research, we demonstrated that mitochondrial energy metabolism depression can be utilized as an innovative and efficient approach for reducing the expression of PD-L1 and TGF-β simultaneously, which may offer a design strategy for a more ideal PDT nanosystem. Through proteomic analysis of 5637 cells, we revealed that tamoxifen (TMX) can incredibly regulate PD-L1 expression in tumor cells. Then, to selectively deliver clinically used mitochondrial energy metabolism depressant TMX to solid tumors as well as design an ideal PDT nanosystem, we synthesized MHI-TMX@ALB by combining a mitochondria-targeted heptamethine cyanine PDT-dye MHI with TMX through self-assembly with albumin (ALB). Interestingly enough, the MHI-TMX@ALB nanoparticle demonstrated effective reversion of tumor hypoxia and inhibition of PD-L1 protein expression at a lower dosage (7.5 times to TMX), which then enhanced the efficacy of photodynamic immunotherapy via enhancing T-cell infiltration. Apart from this, by leveraging the heptamethine dye's targeting capacity toward tumors and TMX's role in suppressing TGF-β, MHI-TMX@ALB also more effectively mitigated 4T1 tumor lung metastasis development. All in all, the MHI-TMX@ALB nanoparticle could be used as a multifunctional economical PD-L1 and TGF-β codepression immune-regulating strategy, broadening the potential clinical applications for a more ideal PDT nanosystem.

Cascade In Situ Self-Assembly and Bioorthogonal Reaction Enable the Enrichment of Photosensitizers and Carbonic Anhydrase Inhibitors for Pretargeted Cancer Theranostics

We report here a tumor-pretargted theranostic approach for multimodality imaging-guided synergistic cancer PDT by cascade alkaline phosphatase (ALP)-mediated in situ self-assembly and bioorthogonal inverse electron demand Diels-Alder (IEDDA) reaction. Using the enzymatic catalysis of ALP that continuously catalyses the dephosphorylation and self-assembly of trans-cyclooctene (TCO)-bearing P-FFGd-TCO, a high density of fluorescent and magnetic TCO-containing nanoparticles (FMNPs-TCO) can be synthesized and retained on the membrane of tumor cells. They can act as 'artificial antigens' amenable to concurrently capture lately administrated tetrazine (Tz)-decorated PS (775NP-Tz) and carbonic anhydrase (CA) inhibitor (SA-Tz) via the fast IEDDA reaction. This two-step pretargeting process can further induce FMNPs-TCO regrowth into microparticles (FMNPs-775/SA) directly on tumor cell membranes, which is analyzed by bio-SEM and fluorescence imaging. Thus, efficient enrichment of both SA-Tz and 775NP-Tz in tumors can be achieved, allowing to alleviate hypoxia by continuously inhibiting CA activity and improving PDT of tumors. Findings show that subcutaneous HeLa tumors could be completely eradicated and no tumor recurred after irradiation with an 808 nm laser (0.33 W cm-2 , 10 min). This pretargeted approach may be applied to enrich other therapeutic agents in tumors to improve targeted therapy.

Advances of Smart Stimulus-Responsive Microneedles in Cancer Treatment

Microneedles (MNs) have emerged as a highly promising technology for delivering drugs via the skin. They provide several benefits, including high drug bioavailability, non-invasiveness, painlessness, and high safety. Traditional strategies for intravenous delivery of anti-tumor drugs have risks of systemic toxicity and easy development of drug resistance, while MN technology facilitates precise delivery and on-demand release of drugs in local tissues. In addition, by further combining with stimulus-responsive materials, the construction of smart stimulus-responsive MNs can be achieved, which can respond to specific physical/chemical stimuli from the internal or external environment, thereby further improving the accuracy of tumor treatment and reducing toxicity to surrounding tissues/cells. This review systematically summarizes the classification, materials, and reaction mechanisms of stimulus-responsive MNs, outlines the benefits and challenges of various types of MNs, and details their application and latest progress in cancer treatment. Finally, the development prospects of smart MNs in tumor treatment are also discussed, bringing inspiration for future precision treatment of tumors.

Recent Advances in the HPPH-Based Third-Generation Photodynamic Agents in Biomedical Applications

Photodynamic therapy has emerged as a recognized anti-tumor treatment involving three fundamental elements: photosensitizers, light, and reactive oxygen species. Enhancing the effectiveness of photosensitizers remains the primary avenue for improving the biological therapeutic outcomes of PDT. Through three generations of development, HPPH is a 2-(1-hexyloxyethyl)-2-devinyl derivative of pyropheophorbide-α, representing a second-generation photosensitizer already undergoing clinical trials for various tumors. The evolution toward third-generation photosensitizers based on HPPH involves structural modifications for multimodal applications and the combination of multifunctional compounds, leading to improved imaging localization and superior anti-tumor effects. While research into third-generation HPPH is beneficial for advancing PDT treatment, equal attention should also be directed toward the other two essential elements and personalized diagnosis and treatment methodologies.

A transdermal drug delivery system based on dissolving microneedles for boron neutron capture therapy of melanoma

Boron neutron capture therapy (BNCT) is a promising therapy for malignant tumors that requires selective and high concentrations of 10B accumulation in tumor cells. Despite ongoing developments in novel boron agents and delivery carriers, the progress and clinical application of BNCT is still restricted by the low 10B accumulation and tumor-to-normal tissue (T/N) ratio. Herein, a dissolving microneedle-based transdermal drug delivery system was specifically designed for BNCT in a mouse model of melanoma. By incorporating fructose-BPA (F-BPA) into PVA microneedle tips, this system successfully delivered sufficient F-BPA into the melanoma site after the application of only two patches. Notably, the T/N ratio achieved through the treatment combining PVA/F-BPA MNs with BNCT (PVA/F-BPA MNs-BNCT) surpassed 93.16, signifying a great improvement. Furthermore, this treatment approach effectively inhibited tumor growth and significantly enhanced the survival rate of the mice. In brief, our study introduces a novel, simple, and efficient administration strategy for BNCT, opening new possibilities for the design of nanomedicine for BNCT.

Hierarchical MOF@AuNP/Hairpin Nanotheranostic for Enhanced Photodynamic Therapy via O2 Self-Supply and Cancer-Related MicroRNA Imaging In Vivo

Developing a nanotheranostic with a high sensing performance and efficient therapy was significant in cancer diagnosis and treatment. Herein, a Au nanoparticle and hairpin-loaded photosensitive metal-organic framework (PMOF@AuNP/hairpin) nanotheranostic was constructed by growing AuNPs on PMOF in situ and then attaching hairpins. On the one hand, the PMOF@AuNP/hairpin nanotheranostic could effectively transfer O2 into ROS, facilitating efficient PDT. Additionally, the nanotheranostic possessed catalase-like activity, which could effectively catalyze H2O2 to generate O2, thus achieving O2-evolving PDT and significantly enhancing the antitumor effect of PDT in vivo. On the other hand, the nanotheranostic showed a high loading efficiency of hairpins and achieved the sensitive and selective detection of miR-21 both in living cells and in vivo. Moreover, the nanotheranostic could dynamically monitor the miR-21 level. Due to the excellent imaging performance, the nanotheranostic could recognize cancer cells and might provide important information on cancer progression for PDT. The developed PMOF@AuNP/hairpin nanotheranostic provided a useful tool for tumor diagnosis and antitumor therapy.

Prolonging Treatment Window of Photodynamic Therapy with Self-Amplified H2 O2 -Activated Photodynamic/Chemo Combination Therapeutic Nanomedicines

Photodynamic therapy (PDT) is a promising approach to cancer therapy. However, the relatively short tumor retention time of photosensitizers (PSs) makes it difficult to catch the optimal treatment time and restricts multiple PDT within a single injection. In this study, a tumor-specific phototheranostic nanomedicine (DPPa NP) is developed for photodynamic/chemo combination therapy with a prolonged PDT treatment window. DPPa NP is prepared via encapsulating a hydrophobic oxidized bovine serum albumin (BSA-SOH)-conjugatable PS DPPa with amphiphilic H2 O2 -activatable chlorambucil (CL) prodrug mPEG-TK-CL. The released CL under H2 O2 treatment can not only kill tumor cells but also upregulate reactive oxygen species levels within tumor cells, leading to the almost full release of cargoes. The released DPPa may conjugate with overexpressed BSA-SOH, which results in the recovery of the fluorescence signal and photodynamic effect. More importantly, such conjugation transfers DPPa from a small molecule PS into a macromolecular PS with a long tumor retention time and treatment window of PDT, which enables multiple PDT. This study thus provides an effective strategy to prolong the treatment window of PDT and enables tumor-specific fluorescence imaging-guided combination therapy.

Integration of Activation by Hypoxia and Inhibition Resistance of Tumor Cells to Apoptosis for Precise and Augmented Photodynamic Therapy

Photodynamic therapy (PDT) uses photosensitizers to convert oxygen (O2 ) to reactive oxygen species (ROS) under irradiation to induce DNA damage and kill cancer cells. However, the effect of PDT is usually alleviated by apoptosis resistance mechanism of tumor living cells. MTH1 enzyme is known to be such an apoptosis-resistance enzyme which is over expressed as a scavenger to repair the damaged DNA. In this work, a hypoxia-activated nanosystem FTPA, which can be degraded to release the encapsulated PDT photosensitizer 4-DCF-MPYM and an inhibitor TH588 is proposed. The inhibitor TH588 can inhibit the DNA repair process by reducing the activity of MTH1 enzyme, and achieve the purpose of amplifying the therapeutic effect of PDT. This work demonstrates that a precise and augmented tumor PDT is achieved by integration of hypoxia-activation and inhibition resistance of tumor cells to apoptosis.

Strategic Design of Conquering Hypoxia in Tumor for Advanced Photodynamic Therapy

Photodynamic therapy (PDT), with its advantages of high targeting, minimally invasive, and low toxicity side effects, has been widely used in the clinical therapy of various tumors, especially superficial tumors. However, the tumor microenvironment (TME) presents hypoxia due to the low oxygen (O2 ) supply caused by abnormal vascularization in neoplastic tissues and high O2 consumption induced by the rapid proliferation of tumor cells. The efficacy of oxygen-consumping PDT can be hampered by a hypoxic TME. To address this problem, researchers have been developing advanced nanoplatforms and strategies to enhance the therapeutic effect of PDT in tumor treatment. This review summarizes recent advanced PDT therapeutic strategies to against the hypoxic TME, thus enhancing PDT efficacy, including increasing O2 content in TME through delivering O2 to the tumors and in situ generations of O2 ; decreasing the O2 consumption during PDT by design of type I photosensitizers. Moreover, recent synergistically combined therapy of PDT and other therapeutic methods such as chemotherapy, photothermal therapy, immunotherapy, and gas therapy is accounted for by addressing the challenging problems of mono PDT in hypoxic environments, including tumor resistance, proliferation, and metastasis. Finally, perspectives of the opportunities and challenges of PDT in future clinical research and translations are provided.

Local Drug Delivery Techniques for Triggering Immunogenic Cell Death

Immunogenic cell death (ICD), a dying state of the cells, encompasses the changes in the conformations of cell surface and the release of damage-associated molecular patterns, which could initiate an adaptive immune response by stimulating the dendritic cells to present antigens to T cells. Advancements in biomaterials, nanomedicine, and micro- and nano-technologies have facilitated the development of effective ICD inducers, but the potential toxicity of these vesicles encountered in drug delivery via intravenous administration hampers their further application. As alternatives, the local drug delivery systems have gained emerging attention due to their ability to prolong the retention of high payloads at the lesions, sequester drugs from harsh environments, overcome biological barriers to exert optimal efficacy, and minimize potential side effects to guarantee bio-safety. Herein, a brief overview of the local drug delivery techniques used for ICD inducers is provided, explaining how these techniques broaden, alter, and enhance the therapeutic capability while circumventing systemic toxicity at the same time. The historical context and prominent examples of the local administration of ICD inducers are introduced. The complexities, potential pitfalls, and opportunities for local drug delivery techniques in cancer immunotherapy are also discussed.

Exploring Nanocarriers as Treatment Modalities for Skin Cancer

Cancer is a progressive disease of multi-factorial origin that has risen worldwide, probably due to changes in lifestyle, food intake, and environmental changes as some of the reasons. Skin cancer can be classified into melanomas from melanocytes and nonmelanoma skin cancer (NMSC) from the epidermally-derived cell. Together it constitutes about 95% of skin cancer. Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (CSCC) are creditworthy of 99% of NMSC due to the limited accessibility of conventional formulations in skin cancer cells of having multiple obstacles in treatment reply to this therapeutic regime. Despite this, it often encounters erratic bioavailability and absorption to the target. Nanoparticles developed through nanotechnology platforms could be the better topical skin cancer therapy option. To improve the topical delivery, the nano-sized delivery system is appropriate as it fuses with the cutaneous layer and fluidized membrane; thus, the deeper penetration of therapeutics could be possible to reach the target spot. This review briefly outlooks the various nanoparticle preparations, i.e., liposomes, niosomes, ethosomes, transferosomes, transethosomes, nanoemulsions, and nanoparticles technologies tested into skin cancer and impede their progress tend to concentrate in the skin layers. Nanocarriers have proved that they can considerably boost medication bioavailability, lowering the frequency of dosage and reducing the toxicity associated with high doses of the medication.

Gas-assisted phototherapy for cancer treatment

Phototherapies, mainly including photodynamic and photothermal therapy, have made considerable strides in the field of cancer treatment. With the aid of phototherapeutic agents, reactive oxygen species (ROS) or heat are generated under light irradiation to selectively damage cancer cells. However, sole-modality phototherapy faces certain drawbacks, such as limited penetration of phototherapeutic agents into tumor tissues, inefficient ROS generation due to hypoxia, treatment-induced inflammation and resistance of tumor to treatment (e.g., high levels of antioxidants, expression of heat shock protein). Gas therapy, an emerging therapy approach that damages cancer cells by improving the level of certain gas at the tumor site, shows potential to overcome the challenges associated with phototherapies. In addition, with the rapid development of nanotechnology, gas-assisted phototherapy based on nanomedicines has emerged as a promising strategy to enhance the treatment efficacy. This review summarizes recent advances in gas-assisted phototherapy and discusses the prospects and challenges of this strategy in cancer phototherapy.

Advances in Natural Polymer-Based Transdermal Drug Delivery Systems for Tumor Therapy

As an alternative to traditional oral and intravenous injections with limited efficacy, transdermal drug delivery (TDD) has shown great promise in tumor treatment. Over the past decade, natural polymers have been designed into various nanocarriers due to their excellent biocompatibility, biodegradability, and easy availability, providing more options for TDD. In addition, surface functionalization modification of the rich functional groups of natural polymers, which in turn are developed into targeted and stimulus-responsive functional materials, allows precise delivery of drugs to tumor sites and release of drugs in response to specific stimuli. It not only improves the treatment efficiency of tumor but also reduces the toxic and side effects to normal tissues. Therefore, the development of natural polymer-based TDD (NPTDD) systems has great potential in tumor therapy. In this review, the mechanism of NPTDD systems such as penetration enhancers, nanoparticles, microneedles, hydrogels and nanofibers prepared from hyaluronic acid, chitosan, sodium alginate, cellulose, heparin and protein, and their applications in tumor therapy are overviewed. This review also outlines the future prospects and current challenges of NPTDD systems for local treatment tumors.

Effervescent cannabidiol solid dispersion-doped dissolving microneedles for boosted melanoma therapy via the "TRPV1-NFATc1-ATF3" pathway and tumor microenvironment engineering

BACKGROUND

Conventional dissolving microneedles (DMNs) face significant challenges in anti-melanoma therapy due to the lack of active thrust to achieve efficient transdermal drug delivery and intra-tumoral penetration.

METHODS

In this study, the effervescent cannabidiol solid dispersion-doped dissolving microneedles (Ef/CBD-SD@DMNs) composed of the combined effervescent components (CaCO₃ & NaHCO₃) and CBD-based solid dispersion (CBD-SD) were facilely fabricated by the "one-step micro-molding" method for boosted transdermal and tumoral delivery of cannabidiol (CBD).

RESULTS

Upon pressing into the skin, Ef/CBD-SD@DMNs rapidly produce CO₂ bubbles through proton elimination, significantly enhancing the skin permeation and tumoral penetration of CBD. Once reaching the tumors, Ef/CBD-SD@DMNs can activate transient receptor potential vanilloid 1 (TRPV1) to increase Ca²⁺ influx and inhibit the downstream NFATc1-ATF3 signal to induce cell apoptosis. Additionally, Ef/CBD-SD@DMNs raise intra-tumoral pH environment to trigger the engineering of the tumor microenvironment (TME), including the M1 polarization of tumor-associated macrophages (TAMs) and increase of T cells infiltration. The introduction of Ca²⁺ can not only amplify the effervescent effect but also provide sufficient Ca²⁺ with CBD to potentiate the anti-melanoma efficacy. Such a "one stone, two birds" strategy combines the advantages of effervescent effects on transdermal delivery and TME regulation, creating favorable therapeutic conditions for CBD to obtain stronger inhibition of melanoma growth in vitro and in vivo.

CONCLUSIONS

This study holds promising potential in the transdermal delivery of CBD for melanoma therapy and offers a facile tool for transdermal therapies of skin tumors.

Flexible Monitoring, Diagnosis, and Therapy by Microneedles with Versatile Materials and Devices toward Multifunction Scope

Microneedles (MNs) have drawn rising attention owing to their merits of convenience, noninvasiveness, flexible applicability, painless microchannels with boosted metabolism, and precisely tailored multifunction control. MNs can be modified to serve as novel transdermal drug delivery, which conventionally confront with the penetration barrier caused by skin stratum corneum. The micrometer-sized needles create channels through stratum corneum, enabling efficient drug delivery to the dermis for gratifying efficacy. Then, incorporating photosensitizer or photothermal agents into MNs can conduct photodynamic or photothermal therapy, respectively. Besides, health monitoring and medical detection by MN sensors can extract information from skin interstitial fluid and other biochemical/electronic signals. Here, this review discloses a novel monitoring, diagnostic, and therapeutic pattern by MNs, with elaborate discussion about the classified formation of MNs together with various applications and inherent mechanism. Hereby, multifunction development and outlook from biomedical/nanotechnology/photoelectric/devices/informatics to multidisciplinary applications are provided. Programmable intelligent MNs enable logic encoding of diverse monitoring and treatment pathways to extract signals, optimize the therapy efficacy, real-time monitoring, remote control, and drug screening, and take instant treatment.