Nanocomposites Inhibit the Formation, Mitigate the Neurotoxicity, and Facilitate the Removal of β-Amyloid Aggregates in Alzheimer's Disease Mice

Microbubbles in combination with focused ultrasound for the delivery of quercetin-modified sulfur nanoparticles through the blood brain barrier into the brain parenchyma and relief of endoplasmic reticulum stress to treat Alzheimer's disease

The delivery of drugs across the blood-brain barrier (BBB) effectively and safely is one of the major challenges in the treatment of neurodegenerative diseases. In this work, we constructed a nano-system using microbubbles to promote the crossing of drugs across the BBB, where microbubbles in combination with focused ultrasound were used to mediate the transient opening of the BBB and delivery of nanomedicines. This system (Qc@SNPs-MB) was formed by embedding quercetin-modified sulfur nanoparticles (Qc@SNPs) in microbubbles (MB). Qc@SNPs-MB was destroyed instantly when exposed to ultrasonic pulses, and it enhanced the permeability of the blood vessels, resulting in the brief opening of the BBB owing to the "sonoporation" effect. Also, Qc@SNPs were released from the outer shell of the microbubbles and entered the brain across the open BBB, accumulating in the brain parenchyma. Due to the rapid accumulation of Qc@SNPs in the brain, it effectively reduced neuronal apoptosis, inflammatory response, calcium homeostasis imbalance, and oxidative stress, which are all mediated by endoplasmic reticulum stress, and protected nerve cells, thus treating Alzheimer's disease (AD) effectively. The Morris water maze experiment showed that the learning ability and memory ability of the AD mice treated with Qc@SNPs were significantly improved, and no obvious side effects were found. Therefore, Qc@SNPs-MB combined with ultrasound can provide an effective and safe drug delivery method for the treatment of neurodegenerative diseases and a promising strategy for endoplasmic reticulum stress therapy.

Nanochaperones Mediated Delivery of Insulin

Insulin would undergo unfolding and fibrillation under stressed conditions, which may cause serious biotechnological and medical problems. Herein, by mimicking the structure and functions of natural chaperones HSP70s, self-assembled polymeric micelles are used as nanochaperones for the delivery of insulin. The confined hydrophobic domains on the surface of nanochaperones adsorb partially unfolded insulin, inhibiting the aggregation and fibrillation and enhancing the stability of insulin. The bioactivity of insulin is well-reserved after incubation with the nanochaperones at 37 °C for 7 d or heating at 70 °C for 1 h. The stealthy poly(ethylene glycol) chains around the confined domains protect the adsorbed insulin from enzymatic degradation and prolong the circulation time. More importantly, the excellent glucose sensitivity of the hydrophobic domains enables the nanochaperones to release and refold insulin in native form in response to hyperglycemia. This kind of nanochaperone may offer a hopeful strategy for the protection and delivery of insulin.

Light-Induced Chiral Iron Copper Selenide Nanoparticles Prevent β-Amyloidopathy In Vivo

The accumulation and deposition of β-amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d-Fe_x Cu_y Se nanoparticles (NPs) were fabricated that interfer with the self-assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near-infrared (NIR) illumination. d-Fe_x Cu_y Se NPs have a much higher affinity for Aβ42 fibrils than l-Fe_x Cu_y Se NPs and chiral Cu_2-x Se NPs. The chiral Fe_x Cu_y Se NPs also generate more reactive oxygen species (ROS) than chiral Cu_2-x Se NPs under NIR-light irradiation. In living MN9D cells, d-NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In-vivo experiments showed that d-Fe_x Cu_y Se NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence.

Dual functionalized brain-targeting nanoinhibitors restrain temozolomide-resistant glioma via attenuating EGFR and MET signaling pathways

Activation of receptor tyrosine kinase (RTK) protein is frequently observed in malignant progression of gliomas. In this study, the crosstalk activation of epidermal growth factor receptor (EGFR) and mesenchymal-epithelial transition factor (MET) signaling pathways is demonstrated to contribute to temozolomide (TMZ) resistance, resulting in an unfavorable prognosis for patients with glioblastoma. To simultaneously mitigate EGFR and MET activation, a dual functionalized brain-targeting nanoinhibitor, BIP-MPC-NP, is developed by conjugating Inherbin3 and cMBP on the surface of NHS-PEG₈-Mal modified MPC-nanoparticles. In the presence of BIP-MPC-NP, DNA damage repair is attenuated and TMZ sensitivity is enhanced via the down-regulation of E2F1 mediated by TTP in TMZ resistant glioma. In vivo magnetic resonance imaging (MRI) shows a significant repression in tumor growth and a prolonged survival of mice after injection of the BIP-MPC-NP and TMZ. These results demonstrate the promise of this nanoinhibitor as a feasible strategy overcoming TMZ resistance in glioma.

Encapsulated DNase improving the killing efficiency of antibiotics in staphylococcal biofilms

n(DNase) exhibited great potential as a novel antibiotic adjuvant that overcomes biofilm-associated infections with the combinational use of antibiotics.

Mimicking Molecular Chaperones to Regulate Protein Folding

Folding and unfolding are essential ways for a protein to regulate its biological activity. The misfolding of proteins usually reduces or completely compromises their biological functions, which eventually causes a wide range of diseases including neurodegeneration diseases, type II diabetes, and cancers. Therefore, materials that can regulate protein folding and maintain proteostasis are of significant biological and medical importance. In living organisms, molecular chaperones are a family of proteins that maintain proteostasis by interacting with, stabilizing, and repairing various non-native proteins. In the past few decades, efforts have been made to create artificial systems to mimic the structure and biological functions of nature chaperonins. Herein, recent progress in the design and construction of materials that mimic different kinds of natural molecular chaperones is summarized. The fabrication methods, construction rules, and working mechanisms of these artificial chaperone systems are described. The application of these materials in enhancing the thermal stability of proteins, assisting de novo folding of proteins, and preventing formation of toxic protein aggregates is also highlighted and explored. Finally, the challenges and potential in the field of chaperone-mimetic materials are discussed.

Nanomedicine Against Aβ Aggregation by β-Sheet Breaker Peptide Delivery: In Vitro Evidence

The accumulation of amyloid β (Aβ) triggers a cascade of toxic events in Alzheimer's disease (AD). The KLVFF peptide can interfere with Aβ aggregation. However, the peptide suffers from poor bioavailability and the inability to cross the blood-brain barrier. In this work, we study the possibility of adopting nanomedicine to overcome KLVFF limits in biodistribution. We produced new engineered polymeric nanoparticles (NPs), and we evaluated the cellular toxicity of these NPs and validated that KVLFF peptides released by NPs show the same promising effects on AD pathology. Our results revealed the successful generation of KVLFF loaded NPs that, without significant effects on cell heath, are even more potent in reversing Aβ-induced pathologies compared to the free peptide. Therefore, NPs will significantly advance KVLFF treatment as a therapeutic option for AD.

In Situ Modification of the Tumor Cell Surface with Immunomodulating Nanoparticles for Effective Suppression of Tumor Growth in Mice

Current cancer immunotherapies including chimeric antigen receptor (CAR)-based therapies and checkpoint immune inhibitors have demonstrated significant clinical success, but always suffer from immunotoxicity and autoimmune disease. Recently, nanomaterial-based immunotherapies are developed to precisely control in vivo immune activation in tumor tissues for reducing immune-related adverse events. However, little consideration has been put on the spatial modulation of interactions between immune cells and cancer cells to optimize the efficacy of cancer immunotherapies. Herein, a rational design of immunomodulating nanoparticles is demonstrated that can in situ modify the tumor cell surface with natural killer cell (NK cell)-activating signals to achieve in situ activation of tumor-infiltrating NK cells, as well as direction of their antitumor immunity toward tumor cells. Using these immunomodulating nanoparticles, the remarkable inhibition of tumor growth is observed in mice without noticeable side effects. This study provides an accurate immunomodulation strategy that achieves safe and effective antitumor immunity through in situ NK cell activation in tumors. Further development by constructing interactions with various immune cells can potentially make this nanotechnology become a general platform for the design of advanced immunotherapies for cancer treatments.

Efficient Delivery of Nerve Growth Factors to the Central Nervous System for Neural Regeneration

The central nervous system (CNS) plays a central role in the control of sensory and motor functions, and the disruption of its barriers can result in severe and debilitating neurological disorders. Neurotrophins are promising therapeutic agents for neural regeneration in the damaged CNS. However, their penetration across the blood-brain barrier remains a formidable challenge, representing a bottleneck for brain and spinal cord therapy. Herein, a nanocapsule-based delivery system is reported that enables intravenously injected nerve growth factor (NGF) to enter the CNS in healthy mice and nonhuman primates. Under pathological conditions, the delivery of NGF enables neural regeneration, tissue remodeling, and functional recovery in mice with spinal cord injury. This technology can be utilized to deliver other neurotrophins and growth factors to the CNS, opening a new avenue for tissue engineering and the treatment of CNS disorders and neurodegenerative diseases.

Efficient Modulation of β-Amyloid Peptide Fibrillation with Polymer Nanoparticles Revealed by Super-Resolution Optical Microscopy

β-Amyloid peptide (Aβ) aggregation is the essential hallmark of neurodegenerative disorders such as Alzheimer's disease. Efficient inhibitors are highly desired for the prevention of Aβ assembly that has been considered as the primary therapeutic strategy for neurodegenerative diseases. Apart from this, visualization of the aggregates and morphology at high spatial resolution is widely considered of crucial significance on biological treatment. In this work, we have developed small-sized (with diameter of ∼4.7 nm) and positively charged fluorescent conjugated polymer nanoparticles (CPNPs) with strong inhibition effect on Aβ_1-40 peptides fibrillation. Interestingly, the CPNPs also possess excellent photophysical properties, including high photon counts, robust blinking, and repetitive fluorescence switching, that are especially suitable for localization-based super-resolution imaging. Spatial resolution of ∼20 nm for these blinking CPNPs is readily achieved. According to the optical microscopic results, it was found that binding of CPNPs to the terminal of seed fibrils can effectively inhibit the fibrillation process. Owing to these attractive biological and unique photophysical properties, the small-sized CPNPs show high potential in a variety of super-resolution based biological applications.

Quercetin-modified gold-palladium nanoparticles as a potential autophagy inducer for the treatment of Alzheimer's disease

At present, autophagic dysfunction has been considered to be involved in the pathogenesis of Alzheimer's disease (AD). Thus, the activation of autophagy provides a potential means of eliminating the intracellular amyloid-β (Aβ) and slows down the neurotoxicity induced by Aβ. Here, we synthesize a Quercetin (Qu) modified polysorbate 80 (P-80)-coated AuPd core-shell structure. Our results indicate that Concave cubic Qu@P-80@AuPd can activate autophagy of SH-SY5Y cells, promote the fusion of autophagosomes and lysosomes, accelerate the clearance of Aβ, and protect SH-SY5Y cells from Aβ-induced cytotoxicity damage. Furthermore, Concave cubic Qu@P-80@AuPd also has good biocompatibility and high blood-brain barrier (BBB) permeability. Therefore, we anticipate that Concave cubic Qu@P-80@AuPd will be used as a potential autophagy inducer to treat AD.