Over the past decades, medicine has made enormous progress, revolutionized by modern technologies and innovative therapeutic approaches. One of the most exciting branches of these developments is photodynamic therapy (PDT). Using a combination of light of a specific wavelength and specially designed photosensitizing substances, PDT offers new perspectives in the fight against cancer, bacterial infections, and other diseases that are resistant to traditional treatment methods. In today’s world, where there is a growing problem of drug resistance, the search for alternative therapies is becoming more and more urgent. Imagine that we could destroy cancer cells or bacteria using light, without the need to use strong chemicals or antibiotics. This is what PDT promises. By activating photosensitizers using appropriately adjusted light, this therapy can induce the death of cancer or bacterial cells while minimizing damage to surrounding healthy tissues. In this work, we will explore this fascinating method, discovering its mechanisms of action, clinical applications, and development prospects. We will also analyze the latest research and patient testimonies to understand the potential of PDT for the future of medicine.

Depression is a common, debilitating, and potentially life-threatening mental disorder affecting individuals across all age groups and populations. It represents one of the major challenges of contemporary medicine. It is estimated that more than 300 million people worldwide are affected, and patients with major depressive disorder (MDD) exhibit a significantly increased risk of suicide, underscoring the urgent need for effective and long-lasting therapeutic strategies. Growing evidence indicates that the pathophysiology of depression involves a complex interplay of genetic vulnerability, chronic stress, dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, neuroinflammation, oxidative stress, mitochondrial dysfunction, and impaired synaptic plasticity, collectively contributing to symptom heterogeneity and treatment resistance. In this review, we synthesize data derived from PubMed, Google Scholar, and ClinicalTrials.gov databases concerning pharmacological and non-pharmacological treatment strategies, with particular emphasis on their cellular and molecular mechanisms of action. We present currently used classes of antidepressant drugs, including selective serotonin reuptake inhibitors (SSRIs), serotonin–norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs), discussing their limitations in the context of contemporary pathophysiological models of depression. We then focus on emerging therapies targeting the glutamatergic, GABAergic, and dopaminergic systems, including ketamine, esketamine, (R)-ketamine, the dextromethorphan–bupropion combination (DMX–BUP), neurosteroids (zuranolone, brexanolone), as well as selective serotonin receptor modulators (gepirone ER) and dopaminergic modulators (cariprazine). The review is complemented by a discussion of non-pharmacological neuromodulatory approaches, such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and photobiomodulation. Rather than providing another summary of clinical response indicators, this article integrates the molecular underpinnings of novel antidepressant agents and neuromodulation techniques with current concepts of depression pathophysiology, highlighting their relevance for the development of precise, mechanistically targeted, and multimodal treatment strategies.

Bladder cancer (BC) remains a clinical challenge due to its complex etiology and high incidence, especially in developed populations. This article presents a broad analysis of the latest advances in BC treatment, offering a new perspective on the growing role of innovative therapies that are effectively changing the standards of oncological care. Focusing on targeted therapy, immunotherapy, antibody–drug conjugates, and breakthrough gene therapies, the paper shows how modern approaches can counteract resistance mechanisms and improve treatment efficacy while limiting toxicity for patients. Progress in the field of immune therapies, including checkpoint inhibitors, offers hope for significant improvement in the outcomes of patients with advanced forms of cancer, and the concept of targeted therapy tailored to the molecular characteristics of the tumor indicates the potential of personalized oncology. Gene and photodynamic therapies, in turn, offer new possibilities for precise action on cancer cells, minimizing the side effects of traditional methods. The article presents innovative therapeutic strategies and results of the latest clinical trials, showing the prospects for the development of BC treatment and highlighting the key challenges facing oncology.

Bakuchiol (BAK), a natural meroterpenoid with antioxidant, anti-inflammatory and anticancer properties, has recently gained attention as a potential adjunct in breast cancer therapy. This review contextualizes breast cancer as a major global health challenge and highlights BAK as a bioactive compound capable of modulating pathways relevant to tumor development and progression. A structured literature search identified studies examining its molecular activity, pharmacological profile, and effects on breast cancer cells and stem cells. Results show that BAK influences oxidative stress regulation, mitochondrial function, apoptosis and estrogen receptor signaling while also affecting PI3K/AKT, MAPK, NF-κB, and EMT-related pathways. In breast cancer models, BAK acts as a selective phytoestrogen, induces S-phase arrest, activates the ATM/ATR–Chk1/Chk2 axis, and triggers mitochondrial apoptosis, particularly in ERα-positive cells. It also suppresses breast cancer stem-cell renewal, promotes BNIP3- and DAPK2-mediated apoptosis, reduces metabolic and transcriptional drivers of metastasis, and shows enhanced anticancer activity in derivative forms. These findings suggest that BAK may provide therapeutic benefit across several mechanisms central to breast cancer biology. In this review, the inclusion criteria encompassed publications describing the action of bakuchiol, its chemical and pharmacological properties, as well as its role in the treatment of various conditions, including cancers. Exclusion criteria included works not related to BAK or its therapeutic use in breast cancer, as well as publications that did not meet basic scientific standards, such as lacking methodological rigor or presenting a low level of scientific evidence. However, current evidence is predominantly in vitro, and limitations such as poor bioavailability and lack of clinical validation underscore the need for further in vivo and translational studies before therapeutic application can be established.

Hypoxia is one of the most important factors limiting the effectiveness of modern anticancer therapies, particularly photodynamic therapy (PDT). The hypoxia of the tumor microenvironment results from abnormal angiogenesis and the high metabolic demand of cancer cells, which leads to reduced oxygen availability necessary for generating reactive oxygen species (ROS). Consequently, conventional therapeutic approaches, mainly based on the type II PDT mechanism, show limited effectiveness under hypoxic conditions. In response to these limitations, strategies are being developed to increase oxygen availability within the tumor. Of particular importance are nanocarriers based on perfluorocarbons (PFCs), which, due to their high gas solubility, can effectively transport and release oxygen in the tumor microenvironment. Research indicates that the use of such systems leads to improved PDT efficiency by increasing the production of singlet oxygen and enhancing cancer cell damage. Parallelly, alternative approaches independent of high oxygen concentration, including type I photosensitizers, are being developed. Unlike classical type II mechanisms, they generate free radicals through electron transfer reactions, which allows effective action even under conditions of significant hypoxia. This approach significantly expands the possibilities of using PDT in the treatment of tumors with low oxygen levels. Current research directions focus on integrating various therapeutic strategies to achieve a synergistic effect. Hybrid systems combining oxygen delivery (e.g., using PFCs) with the use of type I photosensitizers and other treatment methods, such as chemotherapy or immunotherapy, show the greatest clinical potential. Such multifunctional approaches simultaneously allow improving tumor oxygenation and increasing the efficiency of ROS generation, which makes them a promising strategy for the future of anticancer therapies.

Background/Objectives: Non-muscle-invasive bladder cancer (NMIBC) accounts for the majority of newly diagnosed bladder cancers and is characterized by a high recurrence rate despite standard treatments. Photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) offers a promising alternative; however, objective methods for monitoring therapeutic response are needed. Quantitative magnetic resonance imaging (MRI), particularly T1 and T2 relaxation mapping, may provide non-invasive biomarkers of tissue response to PDT. Methods: In this ex vivo study, 50 samples obtained during transurethral electro-resection of bladder tumors were analyzed using a 1.5 Tesla MRI scanner. Twenty-five healthy control tissues (n = 25) served as the control group. Twenty-five NMIBC tissues were analyzed twice: before and after 5-ALA-PDT. T1 and T2 relaxation times were measured, and regions of interest (ROIs) were manually segmented to obtain quantitative values. Statistical analyses were performed to assess the significance of differences observed between study groups. Results: T1 relaxation times significantly differed between groups: 1351.7 ± 271.1 ms in healthy tissue, 727.7 ± 145.0 ms in untreated NMIBC, and 368.9 ± 65.2 ms in NMIBC after PDT (p < 0.0001). T2 values were 93.5 ± 20.3 ms (healthy), 78.5 ± 20.4 ms (NMIBC), and 55.7 ± 6.1 ms (NMIBC_PDT), with significant reduction after PDT (p < 0.01). Conclusions: Quantitative T1 and T2 mapping via MRI is a sensitive and non-invasive method for detecting structural and biochemical changes in bladder tissue following 5-ALA-PDT. These relaxation times may serve as reliable biomarkers for therapeutic response, facilitating in real-time monitoring and personalized treatment planning for NMIBC. Further in vivo studies are warranted to validate these findings and integrate them into clinical practice.