Optimizing Dacarbazine Therapy: Design of a Laser-Triggered Delivery System Based on β-Cyclodextrin and Plasmonic Gold Nanoparticles

Liposomal nanoformulations of novel copper-based complexes exhibiting antimelanoma activity - In vitro and in vivo validation

Melanoma stands as the most aggressive form of skin cancer. The lack of effective and safe therapies has led to the investigation of innovative strategies. The present work validates the in vitro and in vivo antimelanoma activity of new copper complexes of 8-hydroxyquinoline (8HQ) derivatives in free or liposomal forms. Firstly, the cytotoxic properties of several copper-based complexes were screened towards human (A375) and murine (B16F10) melanoma cell lines and human dermal fibroblasts or keratinocytes (HaCaT) cell lines. All the complexes presented lower IC50 values (<20 μM) than dacarbazine (DTIC) and temozolomide (TMZ), the positive controls (>80 μM). Aiming to solve low specificity against tumor cells and enhance its targetability to affected sites three metal-based complexes were selected, based on their antiproliferative properties, and incorporated in long blood circulating liposomes. One of them, di-2-(((2-morpholinoethyl)imino)methyl)quinolin-8-olCopper(II), designated as LCR35, was selected for further studies due to the highest incorporation parameters and cytotoxic properties observed. The antiproliferative activity of LCR35 was preserved after its association to liposomes. Moreover, in B16F10 cells this effect was potentiated. Furthermore, cell cycle analysis studies in A375 and B16F10 cell lines were performed to elucidate the mechanism of action of copper-based complex formulations. A cell cycle arrest at G2/M and G0/G1 phases in A375 and B16F10 cells, respectively, both in free and liposomal forms were observed. To validate the therapeutic potential of LCR35 two murine melanoma models were carried out: subcutaneous and metastatic. Pre-clinical studies demonstrated the high therapeutic effect of LCR35, especially after incorporation in liposomes, compared to control group or animals that received LCR35 Free and DTIC. Overall, in vitro and in vivo studies highlight the potential antimelanoma properties of the copper-based complex, LCR35.

Gold Nanoparticles: Multifunctional Properties, Synthesis, and Future Prospects

Gold nanoparticles (NPs) are among the most commonly employed metal NPs in biological applications, with distinctive physicochemical features. Their extraordinary optical properties, stemming from strong localized surface plasmon resonance (LSPR), contribute to the development of novel approaches in the areas of bioimaging, biosensing, and cancer research, especially for photothermal and photodynamic therapy. The ease of functionalization with various ligands provides a novel approach to the precise delivery of these molecules to targeted areas. Gold NPs' ability to transfer heat and electricity positions them as valuable materials for advancing thermal management and electronic systems. Moreover, their inherent characteristics, such as inertness, give rise to the synthesis of novel antibacterial and antioxidant agents as they provide a biocompatible and low-toxicity approach. Chemical and physical synthesis methods are utilized to produce gold NPs. The pursuit of more ecologically sustainable and economically viable large-scale technologies, such as environmentally benign biological processes referred to as green/biological synthesis, has garnered increasing interest among global researchers. Green synthesis methods are more favorable than other synthesis techniques as they minimize the necessity for hazardous chemicals in the reduction process due to their simplicity, cost-effectiveness, energy efficiency, and biocompatibility. This article discusses the importance of gold NPs, their optical, conductivity, antibacterial, antioxidant, and anticancer properties, synthesis methods, contemporary uses, and biosafety, emphasizing the need to understand toxicology principles and green commercialization strategies.

Recent Advances in Cyclodextrin-Based Nanoscale Drug Delivery Systems

Cyclodextrins (CDs) belong to a class of cyclic oligosaccharides characterized by their toroidal shape consisting of glucose units linked via α-1,4-glycosidic bonds. This distinctive toroidal shape exhibits a dual nature, comprising a hydrophobic interior and a hydrophilic exterior, making CDs highly versatile in various pharmaceutical products. They serve multiple roles: they act as solubilizers, stabilizers, controlled release promoters, enhancers of drug bioavailability, and effective means of masking undesirable tastes and odors. Taking advantage of these inherent benefits, CDs have been integrated into numerous nanoscale drug delivery systems. The resulting nanomaterials exploit the exceptional properties of CDs, including their ability to solubilize hydrophobic drugs for substantial drug loading, engage in supramolecular complexation for engineered nanomaterials, increase bioavailability for improved therapeutic efficacy, stabilize labile drugs, and exhibit biocompatibility and versatility. This paper compiles recent studies on CD functional nanoscale drug delivery platforms. First, we described the physicochemical and toxicological aspects of CDs, CD/drug inclusion complexation, and their impact on improving drug bioavailability. We then summarized applications for CD-functional nano delivery systems based on polymeric, hybrid, lipid-based nanoparticles, and CD-based nanofibers. Particular interest was in the targeted applications and the function of the CD molecules used. In most applications, CD molecules were used for drug solubilization and loading, while in some studies, CD molecules were employed for supramolecular complexation to construct nanoscale drug delivery systems. Finally, the review concludes with a thoughtful consideration of the current challenges and outlook.

Highly Soluble Dacarbazine Multicomponent Crystals Less Prone to Photodegradation

Dacarbazine (DTIC) is a widely prescribed oncolytic agent to treat advanced malignant melanomas. Nevertheless, the drug is known for exhibiting low and pH-dependent solubility, in addition to being photosensitive. These features imply the formation of the inactive photodegradation product 2-azahypoxanthine (2-AZA) during pharmaceutical manufacturing and even drug administration. We have focused on developing novel DTIC salt/cocrystal forms with enhanced solubility and dissolution behaviors to overcome or minimize this undesirable biopharmaceutical profile. By cocrystallization techniques, two salts, two cocrystals, and one salt-cocrystal have been successfully prepared through reactions with aliphatic carboxylic acids. A detailed structural study of these new multicomponent crystals was conducted using X-ray diffraction (SCXRD, PXRD), spectroscopic (FT-IR and 1H NMR), and thermal (TG and DSC) analyses. Most DTIC crystal forms reported display substantial enhancements in solubility (up to 19-fold), with faster intrinsic dissolution rates (from 1.3 to 22-fold), contributing positively to reducing the photodegradation of DTIC in solution. These findings reinforce the potential of these new solid forms to enhance the limited DTIC biopharmaceutical profile.

Solid-State Formation of a Potential Melphalan Delivery Nanosystem Based on β-Cyclodextrin and Silver Nanoparticles

Melphalan (Mel) is an antineoplastic widely used in cancer and other diseases. Its low solubility, rapid hydrolysis, and non-specificity limit its therapeutic performance. To overcome these disadvantages, Mel was included in β-cyclodextrin (βCD), which is a macromolecule that increases its aqueous solubility and stability, among other properties. Additionally, the βCD-Mel complex has been used as a substrate to deposit silver nanoparticles (AgNPs) through magnetron sputtering, forming the βCD-Mel-AgNPs crystalline system. Different techniques showed that the complex (stoichiometric ratio 1:1) has a loading capacity of 27%, an association constant of 625 M^-1, and a degree of solubilization of 0.034. Added to this, Mel is partially included, exposing the NH₂ and COOH groups that stabilize AgNPs in the solid state, with an average size of 15 ± 3 nm. Its dissolution results in a colloidal solution of AgNPs covered by multiple layers of the βCD-Mel complex, with a hydrodynamic diameter of 116 nm, a PDI of 0.4, and a surface charge of 19 mV. The in vitro permeability assays show that the effective permeability of Mel increased using βCD and AgNPs. This novel nanosystem based on βCD and AgNPs is a promising candidate as a Mel nanocarrier for cancer therapy.