The third-generation tyrosine kinase inhibitor osimertinib is approved to treat patients with T790M-positive non-small cell lung cancer (NSCLC) who have developed resistance to earlier-generation drugs. Acquired C797S mutation has been reported to mediate osimertinib resistance in some patients. However, the remaining resistance mechanisms are largely unknown. We performed mutation profiling using targeted next-generation sequencing (NGS) for 416 cancer-relevant genes on 93 osimertinib-resistant lung cancer patients' samples, mainly cell-free DNAs (cfDNAs), and matched pretreatment samples of 12 patients. experiments were conducted to functionally study the secondary mutations identified. G796/C797, L792, and L718/G719 mutations were identified in 24.7%, 10.8%, and 9.7% of the cases, respectively, with certain mutations coexisting in one patient with different prevalence. L792 and L718 mutants markedly increased the half inhibitory concentration (IC) of osimertinib , among which the L718Q mutation conferred the greatest resistance to osimertinib, as well as gefitinib resistance when not coexisting with T790M. Further analysis of the 12 matched pretreatment samples confirmed that these mutations were acquired during osimertinib treatment. Alterations in parallel or downstream oncogenes such as , and were also discovered, potentially contributing to the osimertinib-resistance in patients without secondary mutations. We present comprehensive mutation profiles of a large cohort of osimertinib-resistance lung cancer patients using mainly cfDNA. Besides C797 mutations, novel secondary mutations of L718 and L792 residues confer osimertinib resistance, both and , and are of great clinical and pharmaceutical relevance..

Neurodegenerative disorders including Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, and stroke are rapidly increasing as population ages. The field of nanomedicine is rapidly expanding and promises revolutionary advances to the diagnosis and treatment of devastating human diseases. This paper provides an overview of novel nanomaterials that have potential to improve diagnosis and therapy of neurodegenerative disorders. Examples include liposomes, nanoparticles, polymeric micelles, block ionomer complexes, nanogels, and dendrimers that have been tested clinically or in experimental models for delivery of drugs, genes, and imaging agents. More recently discovered nanotubes and nanofibers are evaluated as promising scaffolds for neuroregeneration. Novel experimental neuroprotective strategies also include nanomaterials, such as fullerenes, which have antioxidant properties to eliminate reactive oxygen species in the brain to mitigate oxidative stress. Novel technologies to enable these materials to cross the blood brain barrier will allow efficient systemic delivery of therapeutic and diagnostic agents to the brain. Furthermore, by combining such nanomaterials with cell-based delivery strategies, the outcomes of neurodegenerative disorders can be greatly improved.

A variety of therapeutic proteins have shown potential to treat central nervous system (CNS) disorders. Challenge to deliver these protein molecules to the brain is well known. Proteins administered through parenteral routes are often excluded from the brain because of their poor bioavailability and the existence of the blood-brain barrier (BBB). Barriers also exist to proteins administered through non-parenteral routes that bypass the BBB. Several strategies have shown promise in delivering proteins to the brain. This review, first, describes the physiology and pathology of the BBB that underscore the rationale and needs of each strategy to be applied. Second, major classes of protein therapeutics along with some key factors that affect their delivery outcomes are presented. Third, different routes of protein administration (parenteral, central intracerebroventricular and intraparenchymal, intranasal and intrathecal) are discussed along with key barriers to CNS delivery associated with each route. Finally, current delivery strategies involving chemical modification of proteins and use of particle-based carriers are overviewed using examples from literature and our own work. Whereas most of these studies are in the early stage, some provide proof of mechanism of increased protein delivery to the brain in relevant models of CNS diseases, while in few cases proof of concept had been attained in clinical studies. This review will be useful to broad audience of students, academicians and industry professionals who consider critical issues of protein delivery to the brain and aim developing and studying effective brain delivery systems for protein therapeutics.

Brain-derived neurotrophic factor (BDNF) is identified as a potent neuroprotective and neuroregenerative agent for many neurological diseases. Regrettably, its delivery to the brain is hampered by poor serum stability and rapid brain clearance. Here, a novel nanoformulation is reported composed of a bio-compatible polymer, poly(ethylene glycol)--poly(L-glutamic acid) (PEG-PLE), that hosts the BDNF molecule in a nanoscale complex, termed here Nano-BDNF. Upon simple mixture, Nano-BDNF spontaneously forms uniform spherical particles with a core-shell structure. Molecular dynamics simulations suggest that binding between BDNF and PEG-PLE is mediated through electrostatic coupling as well as transient hydrogen bonding. The formation of Nano-BDNF complex stabilizes BDNF and protects it from nonspecific binding with common proteins in the body fluid, while allowing it to associate with its receptors. Following intranasal administration, the nanoformulation improves BDNF delivery throughout the brain and displays a more preferable regional distribution pattern than the native protein. Furthermore, intranasally delivered Nano-BDNF results in superior neuroprotective effects in the mouse brain with lipopolysaccharides-induced inflammation, indicating promise for further evaluation of this agent for the therapy of neurologic diseases.

Liposome is one of the most commonly used drug delivery systems in the world, due to its excellent biocompatibility, satisfactory ability in controlling drug release, and passive targeting capability. However, some drawbacks limit the application of liposomes in clinical, such as problems in transporting, storing, and difficulties in maintaining the drug concentration in the local area. Scaffolds usually are used as implants to supply certain mechanical supporting to the defective area or utilized as diagnosis and imaging methods. But, in general, unmodified scaffolds show limited abilities in promoting tissue regeneration and treating diseases. Therefore, liposome-scaffold composite systems are designed to take advantages of both liposomes' biocompatibility and scaffolds' strength to provide a novel system that is more suitable for clinical applications. This review introduces and discusses different types of liposomes and scaffolds, and also the application of liposome-scaffold composite systems in different diseases, such as cancer, diabetes, skin-related diseases, infection and human immunodeficiency virus, and in tissue regeneration like bone, teeth, spinal cord and wound healing.Journal Pre-proof Drug-loaded liposomesLiposomes have been widely investigated as drug carriers, from the approved amphotericin B liposome in 1990 to the successful Onivyde™ in 2015. As drug carriers, liposomes have several advantages, for instance, they can carry various types of drugs, specifically, the internal water core can load hydrophilic drugs and the bilayers can carry hydrophobic ones. Additionally, liposomes exhibit the ability in controlling the drug release and decreasing the side effect of drugs. Furthermore, liposomes also show advantages in low toxicity, non-immunogenic and biodegradability. The phospholipid bilayer can be regarded as satisfactory platforms that can be modified with diverse ligands to achieve the goal of targeting delivery. Furthermore, the stability and efficacy of biological products can also be improved by utilizing liposomes as vehicles. Delivering small molecule hydrophilic drugsSeveral methods, such as reverse evaporation, pH gradient, ammonium sulfate gradient and repeated freeze thawing, are usually applied in the process of preparing small hydrophilic drugs-loaded liposomes. For example, Takeuchi et al. [14] fabricated polyborane encapsulated liposomes though pH gradient or reverse-phase evaporation, then they found that for the encapsulation efficiency of the liposome Journal Pre-proof 6 prepared using the pH gradient was twice as high as that prepared, using reverse-phase evaporation. Additionally, they observed that boron concentration of the polyborane encapsulated liposomes prepared using the pH gradient achieved 110-150 μg/g of tumor tissue. Delivering small molecule hydrophobic drugsUsually the film dispersion method is one of the simplest ways to fabricate lipid drug-loaded liposomes. For example, Fu et al.[15] fabricated novel temperature-sensitive liposomes loading paclitaxel (PTX-...