Fungal infection remains a significant therapeutic concern owing to the scarcity of drugs, resistance development, and high levels of toxicity of many conventional antifungals. In this regard, chitosan is one such natural polymer whose biocompatibility, biodegradability, and antimicrobial nature have made it the focus of scientific interest. However, the main problem lies in the polymer’s limited aqueous solubility under physiological conditions and its poor efficacy against fungi. Thus, quaternary ammonium functionalization represents a convenient approach to solving the problem by introducing permanent positive charges into the molecular structure of chitosan, thereby improving water solubility, enabling membrane interactions, and conferring broad-spectrum antifungal activity. Such derivatives can exhibit strong interactions with the negatively charged surface of fungal cells, compromising membrane integrity and inhibiting biofilm formation. Apart from their antifungal activity, such compounds are also promising in local delivery systems, which include coatings, nanoparticles, hydrogels, and wound dressings. Considering their unique chemistry, such compounds appear quite promising for the development of novel antifungal biomaterials that can be adapted to different clinical and pharmaceutical needs. Overall, quaternary ammonium-modified chitosan could be considered a promising platform for the development of next-generation antifungal agents. This review offers a comprehensive discussion regarding the synthesis, mode of action, formulation advancements, safety profile, potential applications, and future directions of quaternary ammonium-functionalized chitosan derivatives as an antifungal agent, with an emphasis on artificial intelligence contributions to this area of research.

Pediatric brain tumors continue to be one of the leading causes of death among children due to cancer because of the inadequacies of existing treatments, which include poor tumor selectivity, poor permeability across the blood-brain barrier, resistance to treatment, and high levels of side effects on developing tissue. Recent advances in nanotechnology-based treatments have been identified as potential strategies to counter these problems, with poly(lactic-co-glycolic acid) (PLGA) nanoparticles gaining a lot of traction due to their biodegradability, biocompatibility, and clinical translatability. PLGA nanocarriers present a versatile system that allows for improved treatment efficacy through precise drug release, pharmacokinetic advantages, and tumor-targeted delivery without causing systemic toxicity. The ability of PLGA carriers to incorporate different types of drugs, such as chemotherapy, nucleic acids, and combination therapies, presents an opportunity to circumvent multidrug resistance and increase the efficacy of treatments in pediatric cancers. Surface modification with targeting molecules, peptides, antibodies, and stimuli-sensitive agents also allows for receptor-mediated drug delivery and utilization of specific features of the tumor microenvironment for targeted drug release. This is especially relevant to pediatric brain tumors, which pose additional obstacles due to biological barriers and heterogeneous nature. Several recent studies have shown that PLGA nanoparticles can be used to optimize biodistribution, enable tissue penetration, influence the tumor microenvironment, and increase antitumor efficacy while decreasing side effects. In this review, the potential application of PLGA nanoparticles in the treatment of childhood brain tumors is discussed based on existing knowledge of the physicochemical properties of PLGA and approaches for its use in targeted drug delivery. Recent developments in the field of PLGA nanoparticle-based therapy and its clinical applications in children are highlighted, especially concerning the improvement of therapeutic localization and precision treatment of pediatric brain tumors.

1. Breast cancer is one of the most frequently diagnosed cancers worldwide, and it is a markedly heterogeneous disorder. Heterogeneity in breast cancer is seen at various levels, such as interpatie...

Otitis externa, or swimmer's ear, is an infection of the outer ear canal caused by microorganisms and especially occurs in athletes, swimmers, and children who have frequent exposure to water and live in warm and humid regions. Epidemiologically, it occurs in about 10% of the general population at some point in their life. Swimmer’s ear is a disease caused by various pathogenic organisms. Pseudomonas aeruginosa is the most frequently identified pathogen in acute diffuse otitis externa; chronic cases often present as polymicrobial or fungal infections. Other species implicated include Staphylococcus aureus, Streptococci, Escherichia coli, and Enterobacter aerogenes; however, species such as S. epidermidis and diphtheroids are commonly considered part of the normal ear flora rather than primary pathogens. It is diagnosed clinically when marked by erythema, oedema, and discomfort, along with hallmark signs such as intense otalgia, otorrhea, and significant tenderness of the tragus or pinna. Conventional therapies are often prescribed, like topical corticosteroids, antibiotics, or antifungal drops, but suffer drawbacks like insufficient drug penetration, irritation, and patient non-compliance. To mitigate the abovementioned demerits, researchers have explored novel approaches, including nanogels, hydrogels, microgels, and nanocubosomes. These systems have demonstrated the ability to enhance the drug's bioavailability, ensure controlled release, and improve patient compliance through prolonged retention time at the targeted site. In this review, we systematically explored alternative therapeutic strategies for managing otitis externa following PRISMA-ScR guidelines. A comprehensive search of ClinicalTrials.gov and the WIPO Patentscope database was conducted. While preclinical results are promising, no active human clinical trials or specific patents were identified, indicating that these mucoadhesive systems are currently in preclinical development. These innovations represent a significant shift toward targeted, sustained-release therapies that may improve patient compliance and therapeutic outcomes in the management of outer ear infections.