Recent Patents on Nanotechnology - Volume 14, Issue 3, 2020

Background: Current cerebral drug delivery to the brain and Cerebrospinal Fluid (CSF) is limited by the Blood-Brain Barrier (BBB) or the blood-blood Cerebrospinal Fluid (CSF) barrier. The popular, non-invasive, intranasal delivery provides an exciting route for topical and systemic applications. For example, intranasal drug delivery of Central Nervous System (CNS) drugs can be designed to pass the BBB barrier via the nose-to-brain pathways. Recent nanotechnology research and patenting focus mainly on overcoming typical limitations including bioavailability, transport, BBB penetration, targeted delivery, controlled release rate and controlled degradation. Objective: The aim of the present study was to assess the state-of-the-art of nose-to-brain drug delivery systems and the role of nanotechnology in targeted delivery for the treatment of CNS and related therapeutic conditions. Methods: Patent and related searches were made with analytics to explore and organize nanotech work in intranasal drug delivery to the brain. Technical advancements were mapped by API, formulation and performance criteria. Patents and published patent applications were searched with concept tables of keywords, metadata (e.g., assignee) and patent classes (e.g., International Patent Classes and Cooperative Patent Classes). Results: The reviewed patents and published applications show a focus on formulations and therapeutic indications related to the nano-based nose-to-brain drug delivery. The main patented materials were surface modifiers, delivery systems and excipients. Conclusion: Surface modified nanoparticles can greatly improve drug transport and bioavailability of drugs, particularly higher molecular weight drugs. The most commonly used surface modifiers were chitosan, lectin and cyclodextrin-cross-linker complex. Nanoformulations of herbal drugs could increase drug bioavailability and reduce toxicity. Biotechnology-related drug delivery approaches such as monoclonal antibodies and genetically engineered proteins (molecular Trojan horses) deliver large molecule therapeutics.

Background: Hypertension comes under the category of chronic disease, which requires long term treatment. Hypertension is usually treated by oral administration of various therapeutic agents. There are several limitations of the oral route, making pharmaceutical scientists to discover an alternative route for drug delivery. Methods: The transdermal route may be a better alternative as it shows various advantages like lack of first-pass effect and high patient compliance. The skin may act as a primary barrier for the transdermal delivery of anti-hypertensive drugs; therefore, new approaches are required to cross this barrier. Nanocarrier systems come under these new approaches to cross the skin barrier. Various nanocarrier systems explored for transdermal delivery of antihypertensive drugs are liposomes, elastic liposomes, ethosomes, transethosomes, oleic acid vesicles, niosomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions/microemulsions, and carbon nanotubes. Results: This review summarizes the potential of advanced nanocarrier systems for effective management of hypertension following the transdermal route. The entire literature search regarding the utility of nanocarrier systems in transdermal delivery of antihypertensive drugs was done by using Pubmed and Google Scholar. Conclusion: Nanocarrier systems are capable of reducing various drawbacks of conventional formulations of antihypertensive drugs like excessive first-pass effects, high dosing frequency, and toxicity promoting high patient compliance. However, the clinical efficacy determination of such nanocarrier systems is still a challenge and it will govern their presence in the global pharmaceutical market.

Background: The purpose of this study was to formulate, characterize and in-vitro cytotoxicity of 5-Fluorouracil loaded controlled release nanoparticles for the treatment of skin cancer. The patents on nanoparticles (US8414926B1), (US61654404A), (WO2007150075A3) etc. helped in the selection polymers and method for the preparation of nanoparticles. Methods: In the present study nanoparticles were prepared by simple ionic gelation method using various concentrations of chitosan and sodium tripolyphosphate (TPP). Several process and formulation parameters were screened and optimized using 25-2 fractional factorial design. The prepared nanoparticles were evaluated for particle size, shape, charge, entrapment efficiency, crosslinking mechanism and drug release study. Results: The optimized 5-Fluorouracil loaded nanoparticle were found with particle size of of 320±2.1 nm, entrapment efficiency of 85.12%± 1.1% and Zeta potential of 29mv±1mv. Scanning electron microscopy and dynamic light scattering technique revealed spherical particles with uniform size. The invitro release profile showed controlled release up to 24 hr. Further study was carried using A375 basal cell carcinoma cell-line to elucidate the mechanism of its cytotoxicity by MTT assay. Conclusion: These results demonstrate that the possibility of delivering 5-Fluorouracil to skin with enhanced encapsulation efficiency indicating effectiveness of the formulation for treatment of basal cell carcinoma type of skin cancer.

Aims: The purpose of this work was to obtain a hydrophobic sorbent material with potential applications in oil spill remediation. Background: The accidents due to oil spills cause long-term ecological damage, especially in the aquatic environment. The cleaning of oil spills can be carried out by many methods and techniques, being absorbents the most attractive due to the possibility of recovery and complete elimination of the hydrocarbons in situ from the water surface. In recent years, interest in polymeric materials for oil spill remediation has increased due to its low cost, high stability, and recyclability. Objective: The objective of this work was the development of sorbent materials based on polymer wastes, such as Polyethylene Terephthalate (PET), obtained from recycled bottles, and recycled Polyurethane (PU), for its application in the recovery of oil spills. Methods: Sorbent materials were prepared from polymer wastes, using salt molds for the formation of porous materials with a composition of PU of 5, 10 and 15%, which were subsequently hydrophobized using carbon nanotubes or silica nanoparticles by dip-coating technique. Results and Discussion: The obtained hydrophobic sorbent materials were characterized by Scanning Electron Microscopy (SEM) and Infrared Spectroscopy (FTIR). The resulting absorbent has shown capacity to separate oil from water; the best result was obtained by the sponge of PET-PU (10% PU) hydrophobized with a suspension with low multi-wall carbon nanotubes (MWCNTs) concentration, obtaining an absorption capacity of 2.01 g/g. Conclusion: Besides the standard sorption capacity, these cheap sorbent materials had interesting properties like low density, high hydrophobicity and buoyancy, which could be applied in other applications related to solving oil spills.

Background: The ability to form biofilm and produce several virulence factors has caused numerous human pathogens to become tremendously resistant towards traditional antibiotic treatments, thus, new alternative strategies are urgently in demand. One of the strategies that have recently been developed involves the application of metallic Nanoparticles (NPs). Up to the present, promising results in terms of antimicrobial and antibiofilm activities have been observed in a wide range of metal NPs. Methods: The present study has selected three metal oxides such as ZnO, SnO2 and CeO2 NPs to comparatively investigate their antibiofilm and antibacterial properties against two Gram-positive human pathogens, which are Listeria monocytogenes and Staphylococcus aureus. Results: The anti-biofilm activities of ZnO, SnO2 and CeO2 NPs against S. aureus and L. monocytogenes were assayed by crystal violet staining and confirmed by microscopic visualization using SEM. The synthesis of amyloid protein by S. aureus and exopolysaccharide by L. monocytogenes in the presence of ZnO, SnO2 and CeO2 NPs was evaluated by Congo red assay. Discussion: Results have shown that ZnO, SnO2 and CeO2 NPs effectively inhibited biofilm formation of both L. monocytogenes and S. aureus. The microscopic analysis also confirmed the antibiofilm activity of these NPs. It was also found that only ZnO NPs inhibited cell growth as well as the production of amyloid protein in S. aureus. Conclusion: Overall, these results indicated that ZnO, SnO2 and CeO2 NPs can be considered as potential agents for treating the infections caused by L. monocytogenes and S. aureus, especially those associated with biofilm formation. Based on the present study, further studies are required to understand their mechanisms at both phenotypic and molecular levels, as well as their in vivo cytotoxicity, thereby enabling the applications of these metal oxide NPs in biomedical fields and food industry.

Aims: To use an agroindustrial waste (orange peels) as a source of polyphenols as a reducing medium for obtaining silver nanoparticles by greener method. Background: Several techniques have been employed for AgNPs synthesis, nevertheless, most of them involve the use of toxic chemicals in the process. The use of fungi, bacteria, and plant extracts as subtracts for green synthesis is an ecofriendly alternative, although hypothetic, route for AgNPs large scale synthesis. In the case of plant extracts, it is believed that polyphenols are the biomolecules responsible for the reduction and stabilization of the Ag+ ions into AgNPs, being a sustainable and ecological option; polyphenols could be obtained from plant waste and agroindustrial subproducts. Objective: To develop an efficient, greener, and low-cost method of AgNPs production using natural products. Methods: The basic principle of silver nanoparticles synthesis is the interaction in a mixture of silver nitrate (source of Ag+ ions) and the orange peel extract (reducing and stabilizing agent) under certain conditions. Five treatments were carried out, evaluating several parameters during AgNPs synthesis such as pH, orange peel extract-silver nitrate ratio, time and conditions of incubation, irradiation of UV light, irradiation of microwave, and temperature. Result: The synthesis of silver nanoparticles from an agroindustrial waste as the orange peel was successfully carried out and checked by visual evaluation, UV-Vis spectroscopy, and EDS analysis. The particle size was estimated between 42.82 nm to 151.75 nm, having a spherical and ovoid morphology. Discussion: Through the analysis of several synthesis conditions, it has become possible to establish a suitable treatment to increase antibacterial yield and evaluate morphology and size traits in order to acquire the best conditions for a future industrial scale synthesis. Conclusion: The orange peel aqueous extract resulted as a great source of polyphenols, allowing the successful synthesis of silver nanoparticles in mild conditions. Thus, obtained AgNPs revealed an increased antibacterial effect and potential against Gram-positive bacteria such as Staphyloccocus aureus.