Preparation and optimization of rivastigmine-loaded tocopherol succinate-based solid lipid nanoparticles

Biomaterials-based anti-inflammatory treatment strategies for Alzheimer's disease

The current therapeutic drugs for Alzheimer's disease only improve symptoms, they do not delay disease progression. Therefore, there is an urgent need for new effective drugs. The underlying pathogenic factors of Alzheimer's disease are not clear, but neuroinflammation can link various hypotheses of Alzheimer's disease; hence, targeting neuroinflammation may be a new hope for Alzheimer's disease treatment. Inhibiting inflammation can restore neuronal function, promote neuroregeneration, reduce the pathological burden of Alzheimer's disease, and improve or even reverse symptoms of Alzheimer's disease. This review focuses on the relationship between inflammation and various pathological hypotheses of Alzheimer's disease; reports the mechanisms and characteristics of small-molecule drugs (e.g., nonsteroidal anti-inflammatory drugs, neurosteroids, and plant extracts); macromolecule drugs (e.g., peptides, proteins, and gene therapeutics); and nanocarriers (e.g., lipid-based nanoparticles, polymeric nanoparticles, nanoemulsions, and inorganic nanoparticles) in the treatment of Alzheimer's disease. The review also makes recommendations for the prospective development of anti-inflammatory strategies based on nanocarriers for the treatment of Alzheimer's disease.

Passing of Nanocarriers across the Histohematic Barriers: Current Approaches for Tumor Theranostics

Over the past several decades, nanocarriers have demonstrated diagnostic and therapeutic (i.e., theranostic) potencies in translational oncology, and some agents have been further translated into clinical trials. However, the practical application of nanoparticle-based medicine in living organisms is limited by physiological barriers (blood-tissue barriers), which significantly hampers the transport of nanoparticles from the blood into the tumor tissue. This review focuses on several approaches that facilitate the translocation of nanoparticles across blood-tissue barriers (BTBs) to efficiently accumulate in the tumor. To overcome the challenge of BTBs, several methods have been proposed, including the functionalization of particle surfaces with cell-penetrating peptides (e.g., TAT, SynB1, penetratin, R8, RGD, angiopep-2), which increases the passing of particles across tissue barriers. Another promising strategy could be based either on the application of various chemical agents (e.g., efflux pump inhibitors, disruptors of tight junctions, etc.) or physical methods (e.g., magnetic field, electroporation, photoacoustic cavitation, etc.), which have been shown to further increase the permeability of barriers.

Tailoring the multi-functional properties of phospholipids for simple to complex self-assemblies

The unique interfacial properties, huge diversity, and biocompatible nature of phospholipids make them an attractive pharmaceutical excipient. The amphiphilic nature of these molecules offers them the property to self-assemble into distinct structures. The solubility, chemical and structural properties, surface charge, and critical packing parameters of phospholipids play an essential role during formulation design. This review focuses on the relationship between the structural features of a phospholipid molecule and the formation of different lipid-based nanocarrier drug delivery systems. This provides a rationale and guideline for the selection of appropriate phospholipids while designing a drug delivery system. Finally, we refer to relevant recent case studies covering different types of phospholipid-based systems including simple to complex assemblies. Different carriers in the size range of 50 nm to a few microns can be prepared using phospholipids. The carriers can be delivered through oral, intravenous, nasal, dermal, transmucosal, and subcutaneous routes. A wide range of applicability can be achieved by incorporating various hydrophilic and lipophilic additives in the phospholipid bilayer. Advanced research has led to the discovery of phospholipid complexes and cell membrane mimicking lipids. Overall, phospholipids remain a versatile pharmaceutical excipient for drug delivery. They play multiple roles as solubilizer, emulsifier, surfactant, permeation enhancer, coating agent, release modifier, and liposome former.

Liposome based drug delivery as a potential treatment option for Alzheimer's disease

Alzheimer's disease is a neurodegenerative condition leading to atrophy of the brain and robbing nearly 5.8 million individuals in the United States age 65 and older of their cognitive functions. Alzheimer's disease is associated with dementia and a progressive decline in memory, thinking, and social skills, eventually leading to a point that the individual can no longer perform daily activities independently. Currently available drugs on the market temporarily alleviate the symptoms, however, they are not successful in slowing down the progression of Alzheimer's disease. Treatment and cures have been constricted due to the difficulty of drug delivery to the blood-brain barrier. Several studies have led to identification of vesicles to transport the necessary drugs through the blood-brain barrier that would typically not achieve the targeted area through systemic delivered medications. Recently, liposomes have emerged as a viable drug delivery agent to transport drugs that are not able to cross the blood-brain barrier. Liposomes are being used as a component of nanoparticle drug delivery; due to their biocompatible nature; and possessing the capability to carry both lipophilic and hydrophilic therapeutic agents across the blood brain barrier into the brain cells. Studies indicate the importance of liposomal based drug delivery in treatment of neurodegenerative disorders. The idea is to encapsulate the drugs inside the properly engineered liposome to generate a response of treatment. Liposomes are engineered to target specific diseased moieties and also several surface modifications of liposomes are under research to create a clinical path to the management of Alzheimer's disease. This review deals with Alzheimer's disease and emphasize on challenges associated with drug delivery to the brain, and how liposomal drug delivery can play an important role as a drug delivery method for the treatment of Alzheimer's disease. This review also sheds some light on variation of liposomes. Additionally, it emphasizes on the liposomal formulations which are currently researched or used for treatment of Alzheimer's disease and also discusses the future prospect of liposomal based drug delivery in Alzheimer's disease.

Solid lipid nanoparticles as an effective sodium aescinate delivery system: formulation and anti-inflammatory activity

Sodium aescinate-loaded solid lipid nanoparticles were fabricated using a melt-emulsification and ultrasonication method. Based on mean particle size, polydispersity index, and encapsulation efficiency, orthogonal and Box-Behnken designs were applied to optimize solid lipid nanoparticles with single emulsification and double emulsification methods. The characterization of solid lipid nanoparticles was investigated by X-ray diffractometry, differential scanning calorimetry, and scanning electron microscopy. After optimization of sodium aescinate-loaded solid lipid nanoparticles with single emulsification, the particle size was 90.7 nm and encapsulation efficiency was 76.5%. The sodium aescinate-loaded solid lipid nanoparticles with double emulsification were negatively charged spherical particles with the size of 109.4 nm and encapsulation efficiency up to 86.6%. Both solid lipid nanoparticles with single emulsification and double emulsification exhibited sustained release for 12 h without an initial burst release. The results indicated that sodium aescinate-loaded solid lipid nanoparticles by double emulsification showed more drug loading and stability after reconstitution. The sodium aescinate-solid lipid nanoparticles with double emulsification demonstrated stronger anti-inflammatory activity, including paw edema and ear swelling in mice than that of free sodium aescinate. Therefore, solid lipid nanoparticles have great potential as an effective sodium aescinate delivery system for application in medicine.

Preparation, characterization, and in vivo evaluation of Rose damascene extract loaded solid lipid nanoparticles for targeted brain delivery

According to a variety of experiments, Rose damascene may lead to memory enhancement and acetylcholine esterase inhibition. However, Rose damascene cannot pass through the blood-brain barrier due to its hydrophilic contents. Solid lipid nanoparticles (SLNs) are suitable carriers for brain drug delivery. Herein, SLNs were made by micro-emulsion method. Then, lactoferrin was covalently attached to the surface of the nanoparticles by amide bond interaction for targeted delivery. The nanoparticle properties and the amount of attached lactoferrin were calculated. The effect of the selected compounds on scopolamine-induced animals was also measured by Y-maze, passive avoidance test, elevated plus maze, and forced swim test. The results revealed that the size and zeta potential of nanoparticles were 52 nm and - 13 mV before conjugation, and 161 nm and - 16 mV after conjugation, respectively. The percentage of entrapment efficiency and drug loading before conjugation was 98 ,93.6 and, after conjugation, was 11.2, 15.9, respectively. According to Y-maze and passive avoidance test results, Rose damascene can enhance short-term memory and may also reduce anxiety and depression in scopolamine-induced animals.

Potential Role of Nanoparticles in Treating the Accumulation of Amyloid-Beta Peptide in Alzheimer's Patients

The disorder of Alzheimer's is marked by progressive pathophysiological neurodegeneration. The amino acid peptides in the amyloid plaques found in the brains of people with Alzheimer's disease (AD) are known as amyloid-beta (Aβ). Current treatments are not curative, and the effects associated with AD are reduced. Improving treatment results involved the targeting of drugs at optimum therapeutic concentration. Nanotechnology is seen as an unconventional, modern technology that plays a key role in the treatment of Alzheimer's disease. Using nanoparticles, molecular detection, effective drug targeting, and their combination offer high sensitivity. The aim of this review is to shed light on the function and successful role of nanoparticles to resolve Aβ aggregation and thus to help cure Alzheimer's disease. The analysis divides these nanoparticles into three categories: polymer, lipid, and gold nanoparticles. A thorough comparison was then made between the nanoparticles, which are used according to their role, properties, and size in the procedure. The nanoparticles can prevent the accumulation of Aβ during the efficient delivery of the drug to the cells to treat Alzheimer's disease. Furthermore, this comparison demonstrated the ability of these nanoparticles to deal efficiently with Alzheimer's disease. The role of these nanoparticles varied from delivering the drug to brain cells to dealing with the disease-causing peptide.