Photodynamic Therapy for Metastatic Melanoma Treatment: A Review

A review on dendrimer-based nanoconjugates and their intracellular trafficking in cancer photodynamic therapy

Nanotechnology-based cancer treatment has received considerable attention, and these treatments generally use drug-loaded nanoparticles (NPs) to target and destroy cancer cells. Nanotechnology combined with photodynamic therapy (PDT) has demonstrated positive outcomes in cancer therapy. Combining nanotechnology and PDT is effective in targeting metastatic cancer cells. Nanotechnology can also increase the effectiveness of PDT by targeting cells at a molecular level. Dendrimer-based nanoconjugates (DBNs) are highly stable and biocompatible, making them suitable for drug delivery applications. Moreover, the hyperbranched structures in DBNs have the capacity to load hydrophobic compounds, such as photosensitizers (PSs) and chemotherapy drugs, and deliver them efficiently to tumour cells. This review primarily focuses on DBNs and their potential applications in cancer treatment. We discuss the chemical design, mechanism of action, and targeting efficiency of DBNs in tumour metastasis, intracellular trafficking in cancer treatment, and DBNs' biocompatibility, biodegradability and clearance properties. Overall, this study will provide the most recent insights into the application of DBNs and PDT in cancer therapy.

Hypocrellin: A Natural Photosensitizer and Nano-Formulation for Enhanced Molecular Targeting of PDT of Melanoma

Nano-formulation has generated attention in the battle against cancer, because of its great flexibility, reduced adverse side effects, and accuracy in delivering drugs to target tissues dependent on the size and surface characteristics of the disease. The field of photodynamic treatment has advanced significantly in the past years. Photodynamic techniques that use nano-formulations have surfaced to further the field of nanotechnology in medicine, especially in cancer treatment. The pharmaceutical industry is seeing a growing trend toward enhanced drug formulation using nano-formulations such as liposomes, polymeric nanoparticles, dendrimers, nano-emulsions, and micelles. Natural extracts have also shown adverse effects when employed as photosensitizers in cancer therapy because they are cytotoxic when activated by light. Still, natural photosensitizers are a big part of cancer treatment. However, some shortcomings can be minimized by combining nano-formulations with these natural photosensitizers. The synergistic improvement in medication delivery that maintains or increases the mechanism of cell death in malignant cells has also been demonstrated by the combination of photodynamic therapy with nano-formulations and natural photosensitizers. Lastly, this review assesses the feasibility and potential of a photodynamic therapy system based on nano-formulations and natural photosensitizers in clinical treatment applications and briefly discusses the removal of toxic compounds associated with nano-formulations within cells.

Advancements in skin cancer treatment: focus on photodynamic therapy: a review

Some of these include basal cell carcinoma (BCCs), squamous cell carcinoma (SCCs), and melanoma; skin cancer is a leading global health problem due to its high prevalence and possibly due to its serious health implications. Conventional and known therapies like surgeries, radiation therapies and chemotherapy although helpful are sometime deleterious and do not specifically attack the cancers. New advancement is half-breed technique has recently been recognized that photodynamic therapy (PDT) can be considered as a potentially effective modality by using photosensitizers which work through the generation of localized ROS on exposure to light. This review analyzes the recent progress in PDT and evaluation of its effectiveness in the cure of skin malignancies: with the emphasis on its applicability to BCCs and SCCs, as well as the limitations concerning the cure of melanomas. This review gives an insight to how PDT works and how it can be combined with other forms of therapy, and the prospects of photosensitizer carriers with special reference to nanotechnology. Also, the optimization of the parameters associated with the use of PDT is explored in an attempt to improve on its safety and efficacy in treatment. As such, the purpose of this systematic review of the literature is to advance the knowledge of PDT usage in contemporary dermatologic oncology and to contribute to the eventual expansion of this therapy into other skin diseases and potential use as a first-line treatment for skin neoplasia.

Combinatorial approach of cannabidiol and active-targeted-mediated photodynamic therapy in malignant melanoma treatment

Malignant melanoma (MM) continues to claim millions of lives around the world due to its limited therapeutic alternatives. Photodynamic therapy (PDT) has gained popularity in cancer treatment due it increased potency and low off-target toxicity. Studies have pointed out that the heterogeneity of MM tumours reduces the efficacy of current therapeutic approaches, including PDT, leading to high chances of recurrences post-treatment. Accumulating evidence suggests that cannabidiol (CBD), a non-psychoactive derivative of cannabis, can synergise with various anticancer agents to increase their efficacy. However, CBD demonstrates low bioavailability, which is attributed to factors relating to poor water compatibility, poor absorption and rapid metabolism. Nanotechnology offers tools that address these issues and enhance the biological efficiency and targeted specificity of anticancer agents. Herein, we highlighted the standard therapeutic modalities of MM and their pitfalls, as well as pointed out the need for further investigation into PDT combination therapy with CBD.

Applications and challenges of photodynamic therapy in the treatment of skin malignancies

Photodynamic Therapy (PDT), as a minimally invasive treatment method, has demonstrated its distinct advantages in the management of skin malignant tumors. This article examines the current application status of PDT, assesses its successful cases and challenges in clinical treatment, and anticipates its future development trends. PDT utilizes photosensitizers to interact with light of specific wavelengths to generate reactive oxygen species that selectively eradicate cancer cells. Despite PDT's exceptional performance in enhancing patients' quality of life and prognosis, the limitation of treatment depth and the side effects of photosensitizers remain unresolved issues. With the advancement of novel photosensitizers and innovative treatment technology, the application prospects of PDT are increasingly expansive. This article delves into the mechanism of PDT, its application in various skin malignancies, its advantages and limitations, and envisions its future development. We believe that through continuous technological enhancements and integration with other treatment technologies, PDT has the potential to assume a more pivotal role in the treatment of skin malignancies.

Expected role of photodynamic therapy to relieve skin damage in nuclear or radiological emergency: Review

Nuclear and radiological accidents can occur due to poor management, in transportation, radiation therapy and nuclear wards in hospitals, leading to extreme radiation exposure and serious consequences for human health. Additionally, in many of previous radiological accidents, skin damage was observed in patients and survivors due to the high radiation exposure. However, as part of a medical countermeasures in a nuclear/radiological emergency, it is critical to plan for the treatment of radiation-induced skin damage. Hence, the new, non-invasive technology of photodynamic therapy (PDT) is projected to be more effectively used for treating skin damage caused by high-dose radiation. PDT plays an important role in treating, repairing skin damage and promoting wound healing as evidenced by research. This review, highlighted and recommended potential impacts of PDT to repair and decrease radiation-induced skin tissue damage. Moreover, we have suggested some photosensitizer (PS) agent as radio-mitigator drugs to decrease radiobiological effects.

Gold nanostructures in melanoma: Advances in treatment, diagnosis, and theranostic applications

Melanoma, a lethal form of skin cancer, poses a significant challenge in oncology due to its aggressive nature and high mortality rates. Gold nanostructures, including gold nanoparticles (GNPs), offer myriad opportunities in melanoma therapy and imaging due to their facile synthesis and functionalization, robust stability, tunable physicochemical and optical properties, and biocompatibility. This review explores the emerging role of gold nanostructures and their composites in revolutionizing melanoma treatment paradigms, bridging the gap between nanotechnology and clinical oncology, and offering insights for researchers, clinicians, and stakeholders. It begins by elucidating the potential of nanotechnology-driven approaches in cancer therapy, highlighting the unique physicochemical properties and versatility of GNPs in biomedical applications. Various therapeutic modalities, including photothermal therapy, photodynamic therapy, targeted drug delivery, gene delivery, and nanovaccines, are discussed in detail, along with insights from ongoing clinical trials. In addition, the utility of GNPs in melanoma imaging and theranostics is explored, showcasing their potential in diagnosis, treatment monitoring, and personalized medicine. Furthermore, safety considerations and potential toxicities associated with GNPs are addressed, underscoring the importance of comprehensive risk assessment in clinical translation. Finally, the review concludes by discussing current challenges and future directions, emphasizing the need for innovative strategies to maximize the clinical impact of GNPs in melanoma therapy.

Unveiling the potential of photodynamic therapy with nanocarriers as a compelling therapeutic approach for skin cancer treatment: current explorations and insights

Skin carcinoma is one of the most prevalent types of carcinomas. Due to high incidence of side effects in conventional therapies (radiotherapy and chemotherapy), photodynamic therapy (PDT) has gained huge attention as an alternate treatment strategy. PDT involves the administration of photosensitizers (PS) to carcinoma cells which produce reactive oxygen species (ROS) on irradiation by specific wavelengths of light that result in cancer cells' death via apoptosis, autophagy, or necrosis. Topical delivery of PS to the skin cancer cells at the required concentration is a challenge due to the compounds' innate physicochemical characteristics. Nanocarriers have been observed to improve skin permeability and enhance the therapeutic efficiency of PDT. Polymeric nanoparticles (NPs), metallic NPs, and lipid nanocarriers have been reported to carry PS successfully with minimal side effects and high effectiveness in both melanoma and non-melanoma skin cancers. Advanced carriers such as quantum dots, microneedles, and cubosomes have also been addressed with reported studies to show their scope of use in PDT-assisted skin cancer treatment. In this review, nanocarrier-aided PDT in skin cancer therapies has been discussed with clinical trials and patents. Additionally, novel nanocarriers that are being investigated in PDT are also covered with their future prospects in skin carcinoma treatment.

The fusion of light and immunity: Advancements in photoimmunotherapy for melanoma

Metastatic melanoma is an aggressive skin cancer with high mortality and recurrence rates. Despite the clinical success of recent immunotherapy approaches, prevailing resistance rates necessitate the continued development of novel therapeutic options. Photoimmunotherapy (PIT) is emerging as a promising immunotherapy strategy that uses photodynamic therapy (PDT) to unleash systemic immune responses against tumor sites while maintaining the superior tumor-specificity and minimally invasive nature of traditional PDT. In this review, we discuss recent advances in PIT and strategies for the management of melanoma using PIT. PIT can strongly induce immunogenic cell death, inviting the concomitant application of immune checkpoint blockade or adoptive cell therapies. PIT can also be leveraged to selectively remove the suppressive immune populations associated with immunotherapy resistance. The modular nature of PIT therapy design combined with the potential for patient-specific antigen selection or drug co-delivery makes PIT an alluring option for future personalized melanoma care.

Light exposure and its applications in human health

Light exposure has been proven to have a significant impact on human health. As a result, researchers are increasingly exploring its potential benefits and drawbacks. With advancements in understanding light and the manufacturing of light sources, modern health lighting has become widely utilized in daily life and plays a critical role in the prevention and treatment of various illnesses. The use of light in healthcare is a global trend, with many countries actively promoting the development and application of relevant scientific research and medical technology. This field has gained worldwide attention and support from scientists and doctors alike. In this review, we examine the application of lighting in human health and recent breakthroughs in light exposure related to pathology, therapeutic strategies, molecular changes, and more. Finally, we also discuss potential future developments and areas of application.

Current State of Melanoma Therapy and Next Steps: Battling Therapeutic Resistance

Melanoma is the most aggressive and deadly form of skin cancer due to its high propensity to metastasize to distant organs. Significant progress has been made in the last few decades in melanoma therapeutics, most notably in targeted therapy and immunotherapy. These approaches have greatly improved treatment response outcomes; however, they remain limited in their abilities to hinder disease progression due, in part, to the onset of acquired resistance. In parallel, intrinsic resistance to therapy remains an issue to be resolved. In this review, we summarize currently available therapeutic options for melanoma treatment and focus on possible mechanisms that drive therapeutic resistance. A better understanding of therapy resistance will provide improved rational strategies to overcome these obstacles.

Mesoporous silica coated spicules for photodynamic therapy of metastatic melanoma

We report on the fabrication of mesoporous silicon dioxide coated Haliclona sp. spicules (mSHS) to enhance the delivery of the insoluble photosensitizer protoporphyrin IX (PpIX) into deep skin layers and mediate photodynamic therapy for metastatic melanoma in mice. The mSHS are dispersed sharp edged and rod-like micro-particles with a length of approximate 143.6 ± 6.4 μm and a specific surface area of 14.9 ± 3.4 m2/g. The mSHS can be topically applied to the skin, adapting to any desired skin area and lesion site. The insoluble PpIX were incorporated into the mesoporous silica coating layers of mSHS (mSHS@PpIX) with the maximum PpIX loading capacity of 120.3 ± 3.8 μg/mg. The mSHS@PpIX significantly enhanced the deposition of PpIX in the viable epidermis (5.1 ± 0.4 μg/cm2) and in the dermis (0.5 ± 0.2 μg/cm2), which was 154 ± 11-fold and 22 ± tenfold higher than those achieved by SHS, respectively. Topical delivery of PpIX using mSHS (mSHS@PpIX) completely eradicated the primary melanoma in mice in 10 days without recurrence or metastasis over 60 days. These results demonstrate that mSHS can be a promising topical drug delivery platform for the treatment of diverse cutaneous diseases, such as metastatic melanoma.

A Comprehensive Review of Various Therapeutic Strategies for the Management of Skin Cancer

Skin cancer (SC) poses a global threat to the healthcare system and is expected to increase significantly over the next two decades if not diagnosed at an early stage. Early diagnosis is crucial for successful treatment, as the disease becomes more challenging to cure as it progresses. However, identifying new drugs, achieving clinical success, and overcoming drug resistance remain significant challenges. To overcome these obstacles and provide effective treatment, it is crucial to understand the causes of skin cancer, how cells grow and divide, factors that affect cell growth, and how drug resistance occurs. In this review, we have explained various therapeutic approaches for SC treatment via ligands, targeted photosensitizers, natural and synthetic drugs for the treatment of SC, an epigenetic approach for management of melanoma, photodynamic therapy, and targeted therapy for BRAF-mutated melanoma. This article also provides a detailed summary of the various natural drugs that are effective in managing melanoma and reducing the occurrence of skin cancer at early stages and focuses on the current status and future prospects of various therapies available for the management of skin cancer.

A Comprehensive Review on Current Treatments and Challenges Involved in the Treatment of Ovarian Cancer

Ovarian cancer (OC) is the second most common gynaecological malignancy. It typically affects females over the age of 50, and since 75% of cases are only discovered at stage III or IV, this is a sign of a poor diagnosis. Despite intraperitoneal chemotherapy's chemosensitivity, most patients relapse and face death. Early detection is difficult, but treatment is also difficult due to the route of administration, resistance to therapy with recurrence, and the need for precise cancer targeting to minimize cytotoxicity and adverse effects. On the other hand, undergoing debulking surgery becomes challenging, and therapy with many chemotherapeutic medications has manifested resistance, a condition known as multidrug resistance (MDR). Although there are other therapeutic options for ovarian cancer, this article solely focuses on co-delivery techniques, which work via diverse pathways to overcome cancer cell resistance. Different pathways contribute to MDR development in ovarian cancer; however, usually, pump and non-pump mechanisms are involved. Striking cancerous cells from several angles is important to defeat MDR. Nanocarriers are known to bypass the drug efflux pump found on cellular membranes to hit the pump mechanism. Nanocarriers aid in the treatment of ovarian cancer by enhancing the delivery of chemotherapeutic drugs to the tumour sites through passive or active targeting, thereby reducing unfavorable side effects on the healthy tissues. Additionally, the enhanced permeability and retention (EPR) mechanism boosts the bioavailability of the tumour site. To address the shortcomings of conventional delivery, the current review attempts to explain the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors developed to treat ovarian cancer. In conclusion, tailored nanocarriers would optimize medication delivery into the intracellular compartment before optimizing intra-tumour distribution. Other novel treatment possibilities for ovarian cancer include tumour vaccines, gene therapy, targeting epigenetic alteration, and biologically targeted compounds. These characteristics might enhance the therapeutic efficacy.

Overcoming challenges in cancer treatment: Nano-enabled photodynamic therapy as a viable solution

Cancer presents a formidable challenge, necessitating innovative therapies that maximize effectiveness while minimizing harm to healthy tissues. Nanotechnology has emerged as a transformative force in cancer treatment, particularly through nano-enabled photodynamic therapy (NE-PDT), which leverages precise and targeted interventions. NE-PDT capitalizes on photosensitizers activated by light to generate reactive oxygen species (ROS) that initiate apoptotic pathways in cancer cells. Nanoparticle enhancements optimize this process, improving drug delivery, selectivity, and ROS production within tumors. This review dissects NE-PDT's mechanistic framework, showcasing its potential to harness apoptosis as a potent tool in cancer therapy. Furthermore, the review explores the synergy between NE-PDT and complementary treatments like chemotherapy, immunotherapy, and targeted therapies, highlighting the potential to amplify apoptotic responses, enhance immune recognition of cancer cells, and inhibit resistance mechanisms. Preclinical and clinical advancements in NE-PDT demonstrate its efficacy across various cancer types. Challenges in translating NE-PDT into clinical practice are also addressed, emphasizing the need for optimizing nanoparticle design, refining dosimetry, and ensuring long-term safety. Ultimately, NE-PDT represents a promising approach in cancer therapy, utilizing the intricate mechanisms of apoptosis to address therapeutic hurdles. The review underscores the importance of understanding the interplay between nanoparticles, ROS generation, and apoptotic pathways, contributing to a deeper comprehension of cancer biology and novel therapeutic strategies. As interdisciplinary collaborations continue to thrive, NE-PDT offers hope for effective and targeted cancer interventions, where apoptosis manipulation becomes central to conquering cancer. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Recent advances in single-cell engineered live biotherapeutic products research for skin repair and disease treatment

The human microbiome has emerged as a key player in maintaining skin health, and dysbiosis has been linked to various skin disorders. Amidst growing concerns regarding the side effects of antibiotic treatments, the potential of live biotherapeutic products (LBPs) in restoring a healthy microbiome has garnered significant attention. This review aims to evaluate the current state of the art of the genetically or metabolically engineered LBPs, termed single-cell engineered LBPs (eLBPs), for skin repair and disease treatment. While some studies demonstrate promising outcomes, the translation of eLBPs into clinical applications remains a significant hurdle. Substantial concerns arise regarding the practical implementation and scalability of eLBPs, despite the evident potential they hold in targeting specific cells and delivering therapeutic agents. This review underscores the need for further research, robust clinical trials, and the exploration of current advances in eLBP-based bioengineered bacterial chassis and new outlooks to substantiate the viability and effectiveness of eLBPs as a transformative approach in skin repair and disease intervention.

5-aminolevulinic acid sonodynamic therapy for cutaneous squamous cell carcinoma

BACKGROUND

The treatment of deep-invasive cutaneous squamous cell carcinoma (cSCC) is difficult. Sonodynamic therapy (SDT) has showed advantages in large penetration depth, small trauma, good repeatability, high targeting selectivity and effective protection for intact structure and function of tissues and organs.

OBJECTIVE

To study the efficacy and safety of 5-aminolevulinic acid SDT (ALA-SDT) in the treatment of cSCC.

METHODS

The absorption and transformation of ALA after co-incubation with cSCC were detected by UV-Vis and fluorescence absorption. The production of reactive oxygen species (ROS) when protoporphyrin IX (PpIX) excited with ultrasound was detected by ROS detection probe. Cytotoxicity of ALA-SDT to cSCC was detected with cytotoxicity indicators. The tumor volume changes and tumor weight of mice after ALA-SDT were detected. The effects of ALA-SDT on the growth of mice were evaluated through the changes in body weight of mice. Biosafety of treatment was further evaluated by histopathology to determine whether the tissues and organs of mice were affected after ALA-SDT.

RESULTS

ALA can be absorbed and converted into PpIX when incubated with cSCC cells and produces ROS with ultrasound irradiation. ALA-SDT showed a significant cytotoxicity on cSCC cells. With one session of ALA-SDT in vivo, tumor growth was slowed but not stopped and would proceed once treatment was ended. ALA-SDT had no significant effect on body weight changes and major tissues and organs of the mice.

CONCLUSION

ALA-SDT could safely and reduce cSCC cells growth both in vitro and in vivo.

Enhanced Delivery of 5-Aminolevulinic Acid by Lecithin Invasomes in 3D Melanoma Cancer Model

Photodynamic therapy (PDT) is a noninvasive therapeutic approach for the treatment of skin cancer and diseases. 5-Aminolevulinic acid is a prodrug clinically approved for PDT. Once internalized by cancer cells, it is rapidly metabolized to the photosensitizer protoporphyrin IX, which under the proper light irradiation, stimulates the deleterious reactive oxygen species (ROS) production and leads to cell death. The high hydrophilicity of 5-aminolevulinic acid limits its capability to cross the epidermis. Lipophilic derivatives of 5-aminolevulinic acid only partly improved skin penetration, thus making its incorporation into nanocarriers necessary. Here we have developed and characterized 5-aminolevulinic acid loaded invasomes made of egg lecithin, either 1,2-dilauroyl-sn-glycero-3-phosphocholine or 1,2-dioleoyl-sn-glycero-3-phosphocholine, and the terpene limonene. The obtained invasomes are highly thermostable and display a spherical morphology with an average size of 150 nm and an encapsulation efficiency of 80%; moreover, the ex vivo epidermis diffusion tests established that nanovesicles containing the terpene led to a much higher skin penetration (up to 80% in 3 h) compared to those without limonene and to the free fluorescent tracer (less than 50%). Finally, in vitro studies with 2D and 3D human cell models of melanoma proved the biocompatibility of invasomes, the enhanced intracellular transport of 5-aminolevulinic acid, its ability to generate ROS upon irradiation, and consequently, its antiproliferative effect. A simplified scaffold-based 3D skin model containing melanoma spheroids was also prepared. Considering the results obtained, we conclude that the lecithin invasomes loaded with 5-aminolevulinic acid have a good therapeutic potential and may represent an efficient tool that can be considered a valid alternative in the topical treatment of melanoma and other skin diseases.

Exosome camouflaged coordination-assembled Iridium(III) photosensitizers for apoptosis-autophagy-ferroptosis induced combination therapy against melanoma

Melanoma represents the most fatal form of skin cancer due to its resistance mechanisms and high capacity for the development of metastases. Among other medicinal techniques, photodynamic therapy is receiving increasing attention. Despite promising results, the application of photodynamic therapy is inherently limited due to interference from melanin, poor tissue penetration of photosensitizers, low loading into drug delivery systems, and a lack of tumor selectivity. To overcome these limitations, herein, the coordination-driven assembly of Ir(III) complex photosensitizers with Fe(III) ions into nanopolymers for combined photodynamic therapy and chemodynamic therapy is reported. While remaining stable under physiological conditions, the nanopolymers dissociated in the tumor microenvironment. Upon exposure to light, the Ir(III) complexes produced singlet oxygen and superoxide anion radicals, inducing cell death by apoptosis and autophagy. The Fe(III) ions were reduced to Fe(II) upon depletion of glutathione and reduction of the GPX4 levels, triggering cell death by ferroptosis. To provide tumor selectivity, the nanopolymers were further camouflaged with exosomes. The generated nanoparticles were found to eradicate a melanoma tumor as well as inhibit the formation of metastases inside a mouse model.

The Development of Nonthermal Plasma and Tirapazamine as a Novel Combination Therapy to Treat Melanoma In Situ

Although melanoma accounts for only 5.3% of skin cancer, it results in >75% of skin-cancer-related deaths. To avoid disfiguring surgeries on the head and neck associated with surgical excision, there is a clear unmet need for other strategies to selectively remove cutaneous melanoma lesions. Mohs surgery is the current treatment for cutaneous melanoma lesions and squamous and basal cell carcinoma. While Mohs surgery is an effective way to remove melanomas in situ, normal tissue is also excised to achieve histologically negative margins. This paper describes a novel combination therapy of nonthermal plasma (NTP) which emits a multitude of reactive oxygen species (ROS) and the injection of a pharmaceutical agent. We have shown that the effects of NTP are augmented by the DNA-damaging prodrug, tirapazamine (TPZ), which becomes a free radical only in conditions of hypoxemia, which is often enhanced in the tumor microenvironment. In this study, we demonstrate the efficacy of the combination therapy through experiments with B16-F10 and 1205 Lu metastatic melanoma cells both in vitro and in vivo. We also show the safety parameters of the therapy with no significant effects of the therapy when applied to porcine skin. We show the need for the intratumor delivery of TPZ in combination with the surface treatment of NTP and present a model of a medical device to deliver this combination therapy. The importance of functional gap junctions is indicated as a mechanism to promote the therapeutic effect. Collectively, the data support a novel therapeutic combination to treat melanoma and the development of a medical device to deliver the treatment in situ.

Photosensitizers-Loaded Nanocarriers for Enhancement of Photodynamic Therapy in Melanoma Treatment

Malignant melanoma poses a significant global health burden. It is the most aggressive and lethal form of skin cancer, attributed to various risk factors such as UV radiation exposure, genetic modifications, chemical carcinogens, immunosuppression, and fair complexion. Photodynamic therapy is a promising minimally invasive treatment that uses light to activate a photosensitizer, resulting in the formation of reactive oxygen species, which ultimately promote cell death. When selecting photosensitizers for melanoma photodynamic therapy, the presence of melanin should be considered. Melanin absorbs visible radiation similar to most photosensitizers and has antioxidant properties, which undermines the reactive species generated in photodynamic therapy processes. These characteristics have led to further research for new photosensitizing platforms to ensure better treatment results. The development of photosensitizers has advanced with the use of nanotechnology, which plays a crucial role in enhancing solubility, optical absorption, and tumour targeting. This paper reviews the current approaches (that use the synergistic effect of different photosensitizers, nanocarriers, chemotherapeutic agents) in the photodynamic therapy of melanoma.

Enhancing Immunogenicity in Metastatic Melanoma: Adjuvant Therapies to Promote the Anti-Tumor Immune Response

Advanced melanoma is an aggressive form of skin cancer characterized by low survival rates. Less than 50% of advanced melanoma patients respond to current therapies, and of those patients that do respond, many present with tumor recurrence due to resistance. The immunosuppressive tumor-immune microenvironment (TIME) remains a major obstacle in melanoma therapy. Adjuvant treatment modalities that enhance anti-tumor immune cell function are associated with improved patient response. One potential mechanism to stimulate the anti-tumor immune response is by inducing immunogenic cell death (ICD) in tumors. ICD leads to the release of damage-associated molecular patterns within the TIME, subsequently promoting antigen presentation and anti-tumor immunity. This review summarizes relevant concepts and mechanisms underlying ICD and introduces the potential of non-ablative low-intensity focused ultrasound (LOFU) as an immune-priming therapy that can be combined with ICD-inducing focal ablative therapies to promote an anti-melanoma immune response.

Collagen Hydrolysate Effects on Photodynamic Efficiency of Gallium (III) Phthalocyanine on Pigmented Melanoma Cells

The conjugation of photosensitizer with collagen seems to be a very promising approach for innovative topical photodynamic therapy (PDT). The study aims to evaluate the effects of bovine collagen hydrolysate (Clg) on the properties of gallium (III) phthalocyanine (GaPc) on pigmented melanoma. The interaction of GaPc with Clg to form a conjugate (GaPc-Clg) showed a reduction of the intensive absorption Q-band (681 nm) with a blue shift of the maximum (678 nm) and a loss of shape of the UV-band (354 nm). The fluorescence of GaPc, with a strong emission peak at 694 nm was blue shifted due to the conjugation which lower intensity owing to reduce quantum yield (0.012 vs. 0.23, GaPc). The photo- and dark cytotoxicity of GaPc, Glg and GaPc-Clg on pigmented melanoma cells (SH-4) and two normal cell lines (BJ and HaCaT) showed a slight decrease of cytotoxicity for a conjugate, with low selectivity index (0.71 vs. 1.49 for GaPc). The present study suggests that the ability of collagen hydrolysate to form gels minimizes the high dark toxicity of GaPc. Collagen used for conjugation of a photosensitizer might be an essential step in advanced topical PDT.

Nanotechnology-based photo-immunotherapy: a new hope for inhibition of melanoma growth and metastasis

Melanoma is the most aggressive form of skin cancer and there is a need for the development of effective anti-melanoma therapies as it shows high metastatic ability and low response rate. In addition, it has been identified that traditional phototherapy could trigger immunogenic cell death (ICD) to activate antitumor immune response, which could not only effectively arrest primary tumor growth, but also exhibit superior effects in terms of anti-metastasis, anti-recurrence for metastatic melanoma treatment However, the limited tumor accumulation of photosensitizers/photothermal agents and immunosuppressive tumor microenvironment severely weaken the immune effects. The application of nanotechnology facilitates a higher accumulation of photosensitizers/photothermal agents at the tumor site, which can thus improve the antitumor effects of photo-immunotherapy (PIT). In this review, we summarize the basic principles of nanotechnology-based PIT and highlight novel nanotechnologies that are expected to enhance the antitumor immune response for improved therapeutic efficacy.

Porphin e6 complex loaded with gold nanorod mesoporous silica enhances photodynamic therapy in ovarian cancer cells in vitro

A growing amount of experimental evidence has proven that the application of gold nanorods (AuNRs) in photodynamic therapy (PDT) can significantly enhance its therapeutic efficacy. The aim of this study was to establish a protocol for investigating the effect of gold nanorods loaded with the photosensitizer chlorin e6 (Ce6) on photodynamic therapy in the OVCAR3 human ovarian cancer cell line in vitro and to determine whether the PDT effect was different from that of Ce6 alone. OVCAR3 cells were randomly divided into three groups: the control group, Ce6-PDT group, and AuNRs@SiO₂@Ce6-PDT group. Cell viability was measured by MTT assay. The generation of reactive oxygen species (ROS) was measured by a fluorescence microplate reader. Cell apoptosis was detected by flow cytometry. The expression of apoptotic proteins was detected by immunofluorescence and western blotting. The results showed that compared with that of the Ce6-PDT group, the cell viability of the AuNRs@SiO₂@Ce6-PDT group was significantly decreased (P < 0.05) in a dose-dependent manner, and ROS production increased significantly (P < 0.05). The flow cytometry results showed that the proportion of apoptotic cells in the AuNRs@SiO₂@Ce6-PDT group was significantly higher than that in the Ce6-PDT group (P < 0.05). Immunofluorescence and western blot results showed that the protein expression levels of cleaved caspase-9, cleaved caspase-3, cleaved PARP, and Bax in the AuNRs@SiO₂@Ce6-PDT-treated-OVCAR3 cells were higher than those in the Ce6-PDT-treated cells (P < 0.05), and the protein expression levels of caspase-3, caspase-9, PARP, and Bcl-2 were slightly lower than those in the Ce6-PDT group (P < 0.05). In summary, our results show that AuNRs@SiO₂@Ce6-PDT has a significantly stronger effect on OVCAR3 cells than the effect of Ce6-PDT alone. The mechanism may be related to the expression of Bcl-2 family and caspase family in the mitochondrial pathway.

Radiosensitising effect of iron oxide-gold nanocomplex for electron beam therapy of melanoma in vivo by magnetic targeting

Melanoma is a dangerous type of skin cancer sometimes treated with radiotherapy. However, it induces damage to the surrounding healthy tissue and possibly further away areas. Therefore, it is necessary to give a lower dose to the patient with targeted therapy. In this study, the radio-sensitising effect of gold-coated iron oxide nanoparticles on electron beam radiotherapy of a melanoma tumour with magnetic targeting in a mouse model was investigated. Gold-coated iron oxide nanoparticles were prepared in a steady procedure. The melanoma tumour model was induced in mice. Animals were divided into five groups: (1) normal; (2) melanoma; (3) gold-coated iron oxide nanoparticles alone; (4) electron beam radiotherapy; (5) electron beam radiotherapy plus gold-coated iron oxide nanoparticles. The magnet was placed on the tumour site for 2 h. The tumours were then exposed to 6 MeV electron beam radiotherapy for a dose of 8 Gy. Inductively coupled plasma optical emission spectrometry test, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay blood test were also performed. Gold-coated iron oxide nanoparticles with magnetic targeting before electron beam radiotherapy reduced the growth of the tumour compared to the control group. Blood tests did not show any significant toxicity. Deposition of nanoparticles was more in the tumour and spleen tissue and to a lesser extent in the liver, kidney, and lung tissues. The synergistic effect of nanoparticles administered by the intraperitoneal route and then concentrated into the tumour area by application of an external permanent magnet, before delivery of the electron beam radiotherapy improved the overall cancer treatment outcome and prevented metal distribution side effects.

More than Just Skin-Deep: A Review of Imaging's Role in Guiding CAR T-Cell Therapy for Advanced Melanoma

Advanced melanoma is one of the deadliest cancers, owing to its invasiveness and its propensity to develop resistance to therapy. Surgery remains the first-line treatment for early-stage tumors but is often not an option for advanced-stage melanoma. Chemotherapy carries a poor prognosis, and despite advances in targeted therapy, the cancer can develop resistance. CAR T-cell therapy has demonstrated great success against hematological cancers, and clinical trials are deploying it against advanced melanoma. Though melanoma remains a challenging disease to treat, radiology will play an increasing role in monitoring both the CAR T-cells and response to therapy. We review the current imaging techniques for advanced melanoma, as well as novel PET tracers and radiomics, in order to guide CAR T-cell therapy and manage potential adverse events.

Efficient Synthesis of Chlorin e6 and Its Potential Photodynamic Immunotherapy in Mouse Melanoma by the Abscopal Effect

Photodynamic therapy (PDT) can eradicate not only cancer cells but also stimulate an antitumor immune response. Herein, we describe two efficient synthetic methodologies for the preparation of Chlorin e6 (Ce6) from Spirulina platensis and address the phototoxic effect of Ce6 in vitro along with antitumor activity in vivo. Melanoma B16F10 cells were seeded and phototoxicity was monitored by the MTT assay. The C57BL/6 mice were subcutaneously inoculated on the left and right flank with B16F10 cells. The mice were intravenously injected with Ce6 of 2.5 mg/kg and then exposed to red light (660 nm) on the left flank tumors 3 h after the injection. The immune response was studied by analyzing Interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and Interleukin-2 (IL-2) of the right flank tumors through qPCR. Our results revealed that the tumor was suppressed not only in the left flank but also in the right flank, where no PDT was given. The upregulated gene and protein expression of IFN-γ, TNF-α, and IL-2 revealed antitumor immunity due to Ce6-PDT. The findings of this study suggest an efficient methodology of Ce6 preparation and the efficacy of Ce6-PDT as a promising antitumor immune response.

Anti-Hypoxia Nanoplatforms for Enhanced Photosensitizer Uptake and Photodynamic Therapy Effects in Cancer Cells

Photodynamic therapy (PDT) holds great promise in cancer eradication due to its target selectivity, non-invasiveness, and low systemic toxicity. However, due to the hypoxic nature of many native tumors, PDT is frequently limited in its therapeutic effect. Additionally, oxygen consumption during PDT may exacerbate the tumor's hypoxic condition, which stimulates tumor proliferation, metastasis, and invasion, resulting in poor treatment outcomes. Therefore, various strategies have been developed to combat hypoxia in PDT, such as oxygen carriers, reactive oxygen supplements, and the modulation of tumor microenvironments. However, most PDT-related studies are still conducted on two-dimensional (2D) cell cultures, which fail to accurately reflect tissue complexity. Thus, three-dimensional (3D) cell cultures are ideal models for drug screening, disease simulation and targeted cancer therapy, since they accurately replicate the tumor tissue architecture and microenvironment. This review summarizes recent advances in the development of strategies to overcome tumor hypoxia for enhanced PDT efficiency, with a particular focus on nanoparticle-based photosensitizer (PS) delivery systems, as well as the advantages of 3D cell cultures.

Multifunctional Photoactive Nanomaterials for Photodynamic Therapy against Tumor: Recent Advancements and Perspectives

Numerous treatments are available for cancer, including chemotherapy, immunotherapy, radiation therapy, hormone therapy, biomarker testing, surgery, photodynamic therapy, etc. Photodynamic therapy (PDT) is an effective, non-invasive, novel, and clinically approved strategy to treat cancer. In PDT, three main agents are utilized, i.e., photosensitizer (PS) drug, oxygen, and light. At first, the photosensitizer is injected into blood circulation or applied topically, where it quickly becomes absorbed or accumulated at the tumor site passively or actively. Afterward, the tumor is irradiated with light which leads to the activation of the photosensitizing molecule. PS produces the reactive oxygen species (ROS), resulting in the death of the tumor cell. However, the effectiveness of PDT for tumor destruction is mainly dependent on the cellular uptake and water solubility of photosensitizer molecules. Therefore, the delivery of photosensitizer molecules to the tumor cell is essential in PDT against cancer. The non-specific distribution of photosensitizer results in unwanted side effects and unsuccessful therapeutic outcomes. Therefore, to improve PDT clinical outcomes, the current research is mostly focused on developing actively targeted photosensitizer molecules, which provide a high cellular uptake and high absorption capacity to the tumor site by overcoming the problem associated with conventional PDT. Therefore, this review aims to provide current knowledge on various types of actively and passively targeted organic and inorganic nanocarriers for different cancers.

Nanotechnological approaches for diagnosis and treatment of ovarian cancer: a review of recent trends

Formulations from nanotechnology platform promote therapeutic drug delivery and offer various advantages such as biocompatibility, non-inflammatory effects, high therapeutic output, biodegradability, non-toxicity, and biocompatibility in comparison with free drug delivery. Due to inherent shortcomings of conventional drug delivery to cancerous tissues, alternative nanotechnological-based approaches have been developed for such ailments. Ovarian cancer is the leading gynecological cancer with higher mortality rates due to its reoccurrence and late diagnosis. In recent years, the field of medical nanotechnology has witnessed significant progress in addressing existing problems and improving the diagnosis and therapy of various diseases including cancer. Nevertheless, the literature and current reviews on nanotechnology are mainly focused on its applications in other cancers or diseases. In this review, we focused on the nanoscale drug delivery systems for ovarian cancer targeted therapy and diagnosis, and different nanocarriers systems including dendrimers, nanoparticles, liposomes, nanocapsules, and nanomicelles for ovarian cancer have been discussed. In comparison to non-functionalized counterparts of nanoformulations, the therapeutic potential and preferential targeting of ovarian cancer through ligand functionalized nanoformulations’ development has been reviewed. Furthermore, numerous biomarkers such as prostatic, mucin 1, CA-125, apoptosis repeat baculoviral inhibitor-5, human epididymis protein-4, and e-cadherin have been identified and elucidated in this review for the assessment of ovarian cancer. Nanomaterial biosensor-based tumor markers and their various types for ovarian cancer diagnosis are explained in this article. In association, different nanocarrier approaches for the ovarian cancer therapy have also been underpinned. To ensure ovarian cancer control and efficient detection, there is an urgent need for faster and less costly medical tools in the arena of oncology.

Melanoma-targeted photodynamic therapy based on hypericin-loaded multifunctional P123-spermine/folate micelles

Multifunctional P123 micelle linked covalently with spermine (SM) and folic acid (FA) was developed as a drug delivery system of hypericin (HYP). The chemical structures of the modified copolymers were confirmed by spectroscopy and spectrophotometric techniques (UV-vis, FTIR, and ¹H NMR). The copolymeric micelles loading HYP were prepared by solid dispersion and characterized by UV-vis, fluorescence, dynamic light scattering (DLS), ζ potential, and transmission electron microscopy (TEM). The results provided a good level of stability for HYP-loaded P123-SM, P123-FA, and P123-SM/P123-FA in the aqueous medium. The morphology analysis showed that all copolymeric micelles are spherical. Well-defined regions of different contrast allow us to infer that SM and FA were localized on the surface of micelles, and the HYP molecules are located in the core region of micelles. The uptake potential of multifunctional P123 micelle was accessed by exposing the micellar systems loading HYP to two cell lines, B16-F10 and HaCaT. HYP-loaded P123 micelles reveal a low selectivity for melanoma cells, showing significant photodamage for HaCat cells. However, the exposition of B16-F10 cells to Hyp-loaded SM- and FA-functionalized P123 micelles under light irradiation revealed the lowest CC₅₀ values. The interpretation of these results suggested that the combination of SM and FA on P123 micelles is the main factor in enhancing the HYP uptake by melanoma cells, consequently leading to its photoinactivation.

In Vitro Photodynamic Treatment Modality for A375 Melanoma Cell Line Using a Sulphonated Aluminum Phthalocyanine Chloride-Photosensitizer-Gold Nanoparticle Conjugate

Metastatic melanoma cancer stem cells are subpopulations that have been identified and linked to tumor progression, immunoevasive behavior, drug resistance, and metastasis, leading to a poor prognosis. Photodynamic therapy (PDT) is an approach to eradicate cancer through a photochemical process which directly generates reactive oxygen species (ROS). This study investigated the impact of PDT using an aluminum phthalocyanine gold nanoparticle (AlPcS₄Cl-AuNP) conjugate for targeting melanoma stem cells. The isolated stem cells were irradiated at 673.2 nm with a radiant exposure of 5 J/cm². Post-irradiation signs of cell death were determined using microscopy and biochemical assays. A possible enhanced effect of ROS in inducing cell death could be seen when AlPcS₄Cl was conjugated to AuNPs. Nanoparticles as carriers promote the efficient cellular uptake of photosensitizers, enhancing organelle accumulation and the targeted therapy of cancerous cells. A biochemical assay revealed significant post-irradiation signs of cell death. The measurement of adenosine triphosphate (ATP) content revealed a decrease in cell proliferation. The study suggested an approach directed at expanding the knowledge on PDT to improve cancer treatment. Understanding the cell death mechanism through which ROS influence cancer stem cells (CSCs) is, therefore, useful for improving PDT efficiency and preventing tumor recurrence and metastasis.

Photodynamic Therapy Efficacy of Novel Zinc Phthalocyanine Tetra Sodium 2-Mercaptoacetate Combined with Cannabidiol on Metastatic Melanoma

This work reports for the first time on the synthesis, characterization, and photodynamic therapy effect of a novel water-soluble zinc (II) 2(3), 9(10), 16(17), 23(24)-tetrakis-(sodium 2-mercaptoacetate) phthalocyanine (ZnPcTS41), on metastatic melanoma cells (A375) combined with cannabidiol (CBD). The ZnPcTS41 structure was confirmed using FTIR, NMR, MS, and elemental analysis while the electronic absorption spectrum was studied using UV-VIS. The study reports further on the dose-dependent effects of ZnPcTS41 (1-8 µM) and CBD alone (0.3-1.1 µM) at 636 nm with 10 J/cm2 on cellular morphology and viability. The IC50 concentrations of ZnPcTS41 and CBD were found to be 5.3 µM and 0.63 µM, respectively. The cytotoxicity effects of the ZnPcTS41 enhanced with CBD on A375 cells were assessed using MTT cell viability assay, ATP cellular proliferation and inverted light microscopy. Cell death induction was also determined via Annexin V-FITC-PI. The combination of CBD- and ZnPcTS41-mediated PDT resulted in a significant reduction in cell viability (15%***) and an increase in the late apoptotic cell population (25%*). These findings suggest that enhancing PDT with anticancer agents such as CBD could possibly obliterate cancer cells and inhibit tumor recurrence.

Target Prediction of 5,10,15,20-Tetrakis(4'-Sulfonatophenyl)-Porphyrin Using Molecular Docking

Photodynamic therapy has the potential to be a new and effective cancer treatment. Even if in vitro and in vivo research show promise, the molecular mechanism remains unclear. In this study, molecular docking simulations predict the binding affinity of the 5,10,15,20-tetrakis(4'-sulfonatophenyl)-porphyrin tetraammonium photosensitizer on several potential targets in photodynamic treatment. Our results indicate that this photosensitizer binds to several receptor targets, including B-cell lymphoma 2 (BCL-2) and other related proteins BCL-xL, MCL-1, or A1. The binding affinity of the porphyrin derivative with human serum albumin was determined using UV-vis absorption spectroscopy and predicted using molecular docking. We conclude that the studied porphyrin photosensitizer binds to human serum albumin and may inhibit the cancer cell line through its interactions with HIS and MET AA residues from BCL-2, MCL-1, and β-catenin receptors or through its low estimated free energy of binding when interacting with A1 and BCL-B receptors.

Advances in the Application of Nanomaterials to the Treatment of Melanoma

Melanoma can be divided into cutaneous melanoma, uveal melanoma, mucosal melanoma, etc. It is a very aggressive tumor that is prone to metastasis. Patients with metastatic melanoma have a poor prognosis and shorter survival. Although current melanoma treatments have been dramatically improved, there are still many problems such as systemic toxicity and the off-target effects of drugs. The use of nanoparticles may overcome some inadequacies of current melanoma treatments. In this review, we summarize the limitations of current therapies for cutaneous melanoma, uveal melanoma, and mucosal melanoma, as well as the adjunct role of nanoparticles in different treatment modalities. We suggest that nanomaterials may have an effective intervention in melanoma treatment in the future.

Extracellular vesicles as a novel photosensitive drug delivery system for enhanced photodynamic therapy

Photodynamic therapy (PDT) is a promising non-invasive therapeutic approach that utilizes photosensitizers (PSs) to generate highly reactive oxygen species (ROS), including singlet oxygen, for removal of targeted cells. PDT has been proven efficacious for the treatment of several diseases, including cancer, cardiovascular disease, inflammatory bowel disease, and diabetic ocular disease. However, the therapeutic efficacy of PDT is limited and often accompanied by side effects, largely due to non-specific delivery of PSs beyond the desired lesion site. Over the past decade, despite various nanoparticular drug delivery systems developed have markedly improved the treatment efficacy while reducing the off-target effects of PSs, concerns over the safety and toxicity of synthetic nanomaterials following intravenous administration are raised. Extracellular vesicles (EVs), a type of nanoparticle released from cells, are emerging as a natural drug delivery system for PSs in light of EV's potentially low immunogenicity and biocompatibility compared with other nanoparticles. This review aims to provide an overview of the research progress in PS delivery systems and propose EVs as an alternative PS delivery system for PDT. Moreover, the challenges and future perspectives of EVs for PS delivery are discussed.

Melanoma spheroid-containing artificial dermis as an alternative approach to in vivo models

Melanoma spheroid-loaded 3D skin models allow for the study of crucial tumor characteristics and factors at a superior level because the neoplastic cells are integrated into essential human skin components, permitting tumor-skin model communication. Herein, we designed a melanoma-containing artificial dermis by inserting multicellular tumor spheroids from the metastatic phase of WM 1617 melanoma cells into an artificial dermis. We cultured multicellular melanoma spheroids by hanging drop method (250 cells per drop) with a size of 420 μm in diameter after incubation for 14 days. These spheroids were integrated into the dermal equivalents that had been previously preparedwith a type-I collagen matrix and healthy fibroblasts. The melanoma spheroid cells invaded and proliferated in the artificial dermis. Spheroids treated with a 1.0 μmol/L aluminum chloride phthalocyanine nanoemulsion in the absence of light showed high cell viability. In contrast, under irradiation with visible red light (660 nm) at 25 J/cm2, melanoma cells were killed and the healthy tissue was preserved, indicating that photodynamic therapy is effective in such a model. Therefore, the 3D skin melanoma model has potential to promote research in full-thickness skin model targeting optimized preclinical assays.

Iron oxide nanoparticles coated with polydopamine as a potential nano-photothermal agent for treatment of melanoma cancer: an in vivo study

Melanoma is a metastatic cancer resistant to a wide range of therapies, including standard chemotherapy and radiation therapy, and cannot be treated with existing treatments owing to its intrinsic drug resistance. In terms of convenience and cheap cost of fabrication, one of the novel treatments is using polydopamine-coated iron oxide nanoparticles (IONs@PDA). Iron oxide nanoparticles (IONs) were synthesized (7.36 nm) and coated with polydopamine (15-20 nm). To examine the effect of photothermal ablation in melanoma cells (B16-F10), a Q-switched ruby laser (λ = 694 nm, spot size = 4 mm, output power = 5 J/s) was used. The prepared nanoprobe was applied to mice, and their survival after treatment was evaluated. Then histopathological studies were done on the livers and skins of the treated mice. The nanoparticles absorb the laser, raising the temperature and initiating photothermal treatment, with significant apoptosis (74%) after the 4th time of treatment. Photothermal therapy (PTT) by using IONs@PDA proved to be effective in the treatment of melanoma cells (tumor size of < 2 mm) without side effects. The lifespan of mice was significantly increased in a group of mice post-administered IONs@PDA and laser ablation. The fabricated nanoprobe (IONs@PDA) enhanced the melanoma cell apoptosis in the mice model, and it has promise for the treatment of melanoma (B16-F10) cells using photothermal therapy.

Targeting Microenvironment of Melanoma and Head and Neck Cancers in Photodynamic Therapy

Background:

Photodynamic therapy (PDT), in comparison to other skin cancers, is still far less effective for melanoma, due to the strong absorbance and the role of melanin in cytoprotection. The tumour microenvironment (TME) has a significant role in tumour progression, and the hypoxic TME is one of the main reasons for melanoma progression to metastasis and its resistance to PDT. Hypoxia is also a feature of solid tumours in the head and neck region that indicates negative prognosis.

Objective:

The aim of this study was to individuate and describe systematically the main strategies in targeting the TME, especially hypoxia, in PDT against melanoma and head and neck cancers (HNC), and assess the current success in their application.

Methods:

PubMed was used for searching, in MEDLINE and other databases, for the most recent publications on PDT against melanoma and HNC in combination with the TME targeting and hypoxia.

Results:

In PDT for melanoma and HNC, it is very important to control hypoxia levels, and amongst the different approaches, oxygen self-supply systems are often applied. Vascular targeting is promising, but to improve it, optimal drug-light interval, and formulation to increase the accumulation of the photosensitiser in the tumour vasculature, have to be established. On the other side, the use of angiogenesis inhibitors, such as those interfering with VEGF signalling, is somewhat less successful than expected and needs to be further investigated.

Conclusion:

The combination of PDT with immunotherapy by using multifunctional nanoparticles continues to develop and seems to be the most promising for achieving a complete and lasting antitumour effect.

Photoinduced free radical-releasing systems and their anticancer properties

Cancer has been a serious threat and impact on the health and life of human. Phototherapy is considered as a promising therapeutic method to replace the traditional treatment in clinic owing to its noninvasive nature and high efficiency. Photoinitiators have long been used in the field of photopolymerization; however, few studies have been carried out on their potential as anticancer agents under light irradiation. In this study, the effect of a photoinitiator, diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO), on breast cancer is investigated and the related mechanism is elucidated. It is found that TPO has low dark toxicity and significant phototoxicity. TPO can inhibit cell growth and development and promote cell apoptosis through a mitochondrial pathway under light irradiation. Further studies show that cell apoptosis is induced by free radicals produced from the photolysis of TPO to activate JNK phosphorylation. Overall, we identify the antitumor effects of TPO in vitro for the first time, and provides a proof of concept for its application as a novel photolatent therapeutic drug.

Surface Engineering of Nanomaterials with Polymers, Biomolecules, and Small Ligands for Nanomedicine

Nanomedicine is a speedily growing area of medical research that is focused on developing nanomaterials for the prevention, diagnosis, and treatment of diseases. Nanomaterials with unique physicochemical properties have recently attracted a lot of attention since they offer a lot of potential in biomedical research. Novel generations of engineered nanostructures, also known as designed and functionalized nanomaterials, have opened up new possibilities in the applications of biomedical approaches such as biological imaging, biomolecular sensing, medical devices, drug delivery, and therapy. Polymers, natural biomolecules, or synthetic ligands can interact physically or chemically with nanomaterials to functionalize them for targeted uses. This paper reviews current research in nanotechnology, with a focus on nanomaterial functionalization for medical applications. Firstly, a brief overview of the different types of nanomaterials and the strategies for their surface functionalization is offered. Secondly, different types of functionalized nanomaterials are reviewed. Then, their potential cytotoxicity and cost-effectiveness are discussed. Finally, their use in diverse fields is examined in detail, including cancer treatment, tissue engineering, drug/gene delivery, and medical implants.

The Current State of Treatment and Future Directions in Cutaneous Malignant Melanoma

Malignant melanoma is the leading cause of death among cutaneous malignancies. While its incidence is increasing, the most recent cancer statistics show a small but clear decrease in mortality rate. This trend reflects the introduction of novel and more effective therapeutic regimens, including the two cornerstones of melanoma therapy: immunotherapies and targeted therapies. Immunotherapies exploit the highly immunogenic nature of melanoma by modulating and priming the patient's own immune system to attack the tumor. Treatments combining immunotherapies with targeted therapies, which disable the carcinogenic products of mutated cancer cells, have further increased treatment efficacy and durability. Toxicity and resistance, however, remain critical challenges to the field. The present review summarizes past treatments and novel therapeutic interventions and discusses current clinical trials and future directions.

Advances in Photodynamic Therapy Based on Nanotechnology and Its Application in Skin Cancer

Comprehensive cancer treatments have been widely studied. Traditional treatment methods (e.g., radiotherapy, chemotherapy), despite ablating tumors, inevitably damage normal cells and cause serious complications. Photodynamic therapy (PDT), with its low rate of trauma, accurate targeting, synergism, repeatability, has displayed great advantages in the treatment of tumors. In recent years, nanotech-based PDT has provided a new modality for cancer treatment. Direct modification of PSs by nanotechnology or the delivery of PSs by nanocarriers can improve their targeting, specificity, and PDT efficacy for tumors. In this review, we strive to provide the reader with a comprehensive overview, on various aspects of the types, characteristics, and research progress of photosensitizers and nanomaterials used in PDT. And the application progress and relative limitations of nanotech-PDT in non-melanoma skin cancer and melanoma are also summarized.

Investigative on the Molecular Mechanism of Licorice Flavonoids Anti-Melanoma by Network Pharmacology, 3D/2D-QSAR, Molecular Docking, and Molecular Dynamics Simulation

Licorice flavonoids (LCFs) are natural flavonoids isolated from Glycyrrhiza which are known to have anti-melanoma activities in vitro. However, the molecular mechanism of LCF anti-melanoma has not been fully understood. In this study, network pharmacology, 3D/2D-QSAR, molecular docking, and molecular dynamics (MD) simulation were used to explore the molecular mechanism of LCF anti-melanoma. First of all, we screened the key active components and targets of LCF anti-melanoma by network pharmacology. Then, the logIC50 values of the top 20 compounds were predicted by the 2D-QSAR pharmacophore model, and seven highly active compounds were screened successfully. An optimal 3D-QSAR pharmacophore model for predicting the activity of LCF compounds was established by the HipHop method. The effectiveness of the 3D-QSAR pharmacophore was verified by a training set of compounds with known activity, and the possible decisive therapeutic effect of the potency group was inferred. Finally, molecular docking and MD simulation were used to verify the effective pharmacophore. In conclusion, this study established the structure–activity relationship of LCF and provided theoretical guidance for the research of LCF anti-melanoma.

BODIPY nanoparticles functionalized with lactose for cancer-targeted and fluorescence imaging-guided photodynamic therapy

A series of four lactose-modified BODIPY photosensitizers (PSs) with different substituents (-I, -H, -OCH₃, and -NO₂) in the para-phenyl moiety attached to the meso-position of the BODIPY core were synthesized; the photophysical properties and photodynamic anticancer activities of these sensitizers were investigated, focusing on the electronic properties of the different substituent groups. Compared to parent BODIPY H, iodine substitution (BODIPY I) enhanced the intersystem crossing (ISC) to produce singlet oxygen (¹O₂) due to the heavy atom effect, and maintained a high fluorescence quantum yield (Φ_F) of 0.45. Substitution with the electron-donating methoxy group (BODIPY OMe) results in a significant perturbation of occupied frontier molecular orbitals and consequently achieves higher ¹O₂ generation capability with a high Φ_F of 0.49, while substitution with the electron-withdrawing nitro group (BODIPY NO2) led a perturbation of unoccupied frontier molecular orbitals and induces a forbidden dark S₁ state, which is negative for both fluorescence and ¹O₂ generation efficiencies. The BODIPY PSs formed water-soluble nanoparticles (NPs) functionalized with lactose as liver cancer-targeting ligands. BODIPY I and OMe NPs showed good fluorescence imaging and PDT activity against various tumor cells (HeLa and Huh-7 cells). Collectively, the BODIPY NPs demonstrated high ¹O₂ generation capability and Φ_F may create a new opportunity to develop useful imaging-guided PDT agents for tumor cells.