Advances in the use of MOFs for Cancer Diagnosis and Treatment: An Overview.

Nanoparticles as drug delivery systems and diagnostic agents have gained much attention in recent years, especially for cancer treatment. Nanocarriers improve the therapeutic efficiency and bioavailability of antitumor drugs, besides providing preferential accumulation at the target site. Among different types of nanocarriers for drug delivery assays, metal-organic frameworks (MOFs) have attracted increasing interest in the academic community. MOFs are an emerging class of coordination polymers constructed of metal nodes or clusters and organic linkers that show the capacity to combine a porous structure with high drug loading through distinct kinds of interactions, overcoming the limitations of traditional drug carriers explored up to date. Despite the rational design and synthesis of MOFs, structural aspects and some applications of these materials like gas adsorption have already been comprehensively described in recent years; it is time to demonstrate their potential applications in biomedicine. In this context, MOFs can be used as drug delivery systems and theranostic platforms due to their ability to release drugs and accommodate imaging agents. This review describes the intrinsic characteristics of nanocarriers used in cancer therapy and highlights the latest advances in MOFs as anticancer drug delivery systems and diagnostic agents.

Therapeutic Potential of Melaleuca alternifolia Essential Oil in New Drug Delivery Systems.

Medicinal plants produce secondary metabolites with special biological activities, which may be used as new therapeutic alternatives. For instance, tea tree essential oil (TTO) was shown to exert antimicrobial, antifungal, anthelmintic, antiviral, anti-tumor and anti-inflammatory activities. Due to their thermal instability, active principles can be easily degraded by physicochemical processes; therefore, they must be protected to increase their time of action and improve their controlled release. The aim of this review is to discuss formulations incorporating encapsulated TTO as the active ingredient. Micro and nanoencapsulated systems proved to be more thermostable than TTO and to exert better antimicrobial, antifungal, antiparasitic and larvicidal effects. Nanoencapsulation also reduced oil toxicity. Emulsified and hybrid systems developed by various methods showed improved repellent, antibacterial, antifungal and anti-inflammatory activities, thereby proving promising for the pharmaceutical industry. Liposomal formulations produced by hydration of lipid films exhibited constant rate of terpinen-4-ol release. In addition, their incorporation into biomaterials, such as sponges, nanofibers and films, showed great potential for treating infections. Mainly due to the advantages of their incorporation into new drug delivery systems over conventional formulations, there is an interest in the development of systems containing TTO as a pharmaceutical ingredient of plant origin.

Phthalocyanine-loaded nanostructured lipid carriers functionalized with folic acid for photodynamic therapy.

Breast cancer is a serious public health problem that causes thousands of deaths annually. Chemotherapy continues to play a central role in the management of breast cancer but is associated with extreme off-target toxicity. Therefore, treatments that directly target the tumor and display reduced susceptibility to resistance could improve the outcome and quality of life for patients suffering from this disease. Photodynamic therapy is a targeted treatment based on the use of light to activate a photosensitizer (PS) that then interacts with molecular oxygen and other biochemical substrates to generate cytotoxic levels of Reactive Oxygen Species. Currently approved PS also tends to have poor aqueous solubility that can cause problems when delivered intravenously. In order to circumvent this limitation, in this manuscript, we evaluate the potential of a phthalocyanine-loaded nanostructured lipid carrier (NLC) functionalized with folic acid (FA). To prepare the FA labelled NLC, the polymer PF127 was first esterified with FA and emulsified with an oil phase containing polyoxyethylene 40 stearate, capric/caprylic acid triglycerides, ethoxylated hydrogenated castor oil 40 and the PS zinc phthalocyanine. The resulting PS loaded FA-NLC had a hydrodynamic diameter of 180 nm and were stable in suspension for >90 days. Interestingly, the amount of singlet oxygen generated upon light activation for the PS loaded FA-NLC was substantially higher than the free PS, yet at a lower PS concentration. The PS was released from the NLC in a sustained manner with 4.13 ±â€¯0.58% and 27.7 ±â€¯3.16% after 30 min and 7 days, respectively. Finally, cytotoxicity assays showed that NLC in the concentrations of 09.1 µM of PS present non-toxic with >80 ±â€¯6.8% viable and after 90 s of the light-exposed the results show a statistically significant decrease in cell viability (57 ±â€¯4%). The results obtained allow us to conclude that the functionalized NLC incorporated with PS associated with the PDT technique have characteristics that make them potential candidates for the alternative treatment of breast cancer.

Stimuli-responsive Drug Delivery Nanocarriers in the Treatment of Breast Cancer.

Stimuli-responsive drug-delivery nanocarriers (DDNs) have been increasingly reported in the literature as an alternative for breast cancer therapy. Stimuli-responsive DDNs are developed with materials that present a drastic change in response to intrinsic/chemical stimuli (pH, redox and enzyme) and extrinsic/physical stimuli (ultrasound, Near-infrared (NIR) light, magnetic field and electric current). In addition, they can be developed using different strategies, such as functionalization with signaling molecules, leading to several advantages, such as (a) improved pharmaceutical properties of liposoluble drugs, (b) selectivity with the tumor tissue decreasing systemic toxic effects, (c) controlled release upon different stimuli, which are all fundamental to improving the therapeutic effectiveness of breast cancer treatment. Therefore, this review summarizes the use of stimuli-responsive DDNs in the treatment of breast cancer. We have divided the discussions into intrinsic and extrinsic stimuli and have separately detailed them regarding their definitions and applications. Finally, we aim to address the ability of these stimuli-responsive DDNs to control the drug release in vitro and the influence on breast cancer therapy, evaluated in vivo in breast cancer models.