Multidimensional autophagy nano-regulator boosts Alzheimer's disease treatment by improving both extra/intraneuronal homeostasis.

Intraneuronal dysproteostasis and extraneuronal microenvironmental abnormalities in Alzheimer's disease (AD) collectively culminate in neuronal deterioration. In the context of AD, autophagy dysfunction, a multi-link obstacle involving autophagy downregulation and lysosome defects in neurons/microglia is highly implicated in intra/extraneuronal pathological processes. Therefore, multidimensional autophagy regulation strategies co-manipulating "autophagy induction" and "lysosome degradation" in dual targets (neuron and microglia) are more reliable for AD treatment. Accordingly, we designed an RP-1 peptide-modified reactive oxygen species (ROS)-responsive micelles (RT-NM) loading rapamycin or gypenoside XVII. Guided by RP-1 peptide, the ligand of receptor for advanced glycation end products (RAGE), RT-NM efficiently targeted neurons and microglia in AD-affected region. This nano-combination therapy activated the whole autophagy-lysosome pathway by autophagy induction (rapamycin) and lysosome improvement (gypenoside XVII), thus enhancing autophagic degradation of neurotoxic aggregates and inflammasomes, and promoting Aß phagocytosis. Resultantly, it decreased aberrant protein burden, alleviated neuroinflammation, and eventually ameliorated memory defects in 3 × Tg-AD transgenic mice. Our research developed a multidimensional autophagy nano-regulator to boost the efficacy of autophagy-centered AD therapy.

Dual Enzyme Cascade-Activated Popcorn-Like Nanoparticles Efficiently Remodeled Stellate Cells to Alleviate Pancreatic Desmoplasia.

In pancreatic cancer, excessive desmoplastic stroma severely impedes drug access to tumor cells. By reverting activated pancreatic stellate cells (PSCs) to quiescence, all-trans retinoic acid (ATRA) can attenuate their stromal synthesis and remodel the tumor-promoting microenvironment. However, its modulatory effects have been greatly weakened due to its limited delivery to PSCs. Therefore, we constructed a tripeptide RFC-modified gelatin/oleic acid nanoparticle (RNP@ATRA), which delivered ATRA in an enzyme-triggered popcorn-like manner and effectively resolved the delivery challenges. Specifically, surface RFC was cleaved by aminopeptidase N (APN) on the tumor endothelium to liberate l-arginine, generating nitric oxide (NO) for tumor-specific vasodilation. Then, massive nanoparticles were pushed from the vessels into tumors, showing 5.1- and 4.0-fold higher intratumoral accumulation than free ATRA and APN-inert nanoparticles, respectively. Subsequently, in the interstitium, matrix metalloproteinase-2-induced gelatin degradation caused RNP@ATRA to rapidly release ATRA, promoting its interstitial penetration and PSC delivery. Thus, activated PSCs were efficiently reverted to quiescence, and stroma secretion and vascular compression were reduced, thereby enhancing intratumoral delivery of small-molecule or nanosized chemotherapeutics. Ultimately, RNP@ATRA combined with chemotherapeutics markedly suppressed tumor growth and metastasis without causing additional toxicities. Overall, this work provides a potential nanoplatform for the efficient delivery of PSC-modifying agents in pancreatic cancer and other stroma-rich tumors.

Enhancement of Microglia Functions by Developed Nano-Immuno-Synergist to Ameliorate Immunodeficiency for Malignant Glioma Treatment.

Resident microglia are key factors in mediating immunity against brain tumors, but the microglia in malignant glioma are functionally impaired. Little immunotherapy is explored to restore microglial function against glioma. Herein, oleanolic acid (OA) (microglia "restorer") and D PPA-1 peptide (immune checkpoint blockade) are integrated on a nano-immuno-synergist (D PAM@OA) to work coordinately. The self-assembled OA core is coated with macrophage membrane for efficient blood-brain barrier penetration and microglia targeting, on which D PPA-1 peptide is attached via acid-sensitive bonds for specific release in tumor microenvironment. With the enhanced accumulation of the dual drugs in their respective action sites, D PAM@OA effectively promotes the recruitment and activation of effector T cells by inhibiting aberrant activation of Signal transducer and activator of transcription (STAT-3) pathway in microglia, and assists activated effector T cells in killing tumor cells by blocking elevated immune checkpoint proteins in malignant glioma. Eventually, as adjuvant therapy, the rationally designed nano-immuno-synergist hinders malignant glioma progression and recurrence with or without temozolomide. The work demonstrates the feasibility of a nano-formulation for microglia-based immunotherapy, which may provide a new direction for the treatment of brain tumors.

Medium-chain triglyceride-stabilized docetaxel-loaded HSA nanoparticles effectively inhibited metastatic non-small cell lung cancer.

Metastatic non-small cell lung cancer (NSCLC) is refractory with a very poor prognosis. Docetaxel (DTX) injection (Taxotere®) has been approved for the treatment of locally advanced or metastatic NSCLC. However, its clinical application is restricted by severe adverse effects and non-selective tissue distribution. In this study, we successfully developed DTX-loaded human serum albumin (HSA) nanoparticles (DNPs) with modified Nab technology, by introducing medium-chain triglyceride (MCT) as a stabilizer. The optimized formulation had a particle size of approximately 130 nm and a favorable stabilization time of more than 24 h. DNPs dissociated in circulation in a concentration-dependent manner and slowly released DTX. Compared with DTX injection, DNPs were more effectively taken up by NSCLC cells, thus exerting stronger inhibitory effects on their proliferation, adhesion, migration, and invasion. In addition, DNPs showed prolonged blood retention and increased tumor accumulation relative to DTX injection. Ultimately, DNPs produced more potent inhibitory effects on primary or metastatic tumor foci than DTX injections but caused markedly lower organ toxicity and hematotoxicity. Overall, these results support that DNPs hold great potential for the treatment of metastatic NSCLC in clinical.

Brain-neuron targeted nanoparticles for peptide synergy therapy at dual-target of Alzheimer's disease.

Since the complex interactions of multiple mechanisms involved in Alzheimer's disease (AD) preclude the monotherapeutic approaches from clinical application, combination therapy has become an attractive strategy for AD treatment. However, to be emphasized, the realization of the edges of combination therapy greatly depends on the reasonable choice of targets and the rational design of combination scheme. Acknowledgedly, amyloid plaques and hyperphosphorylated tau (p-tau) are two main hallmarks in AD with close pathological correlations, implying the hopeful prospect of combined intervention in them for AD treatment. Herein, we developed the nano-combination system, neuron-targeting PEG-PLA nanoparticles (CT-NP) loading two peptide drugs H102, a ß-sheet breaker acting on Aß, and NAP, a microtubule stabilizer acting on p-tau. Compared with free peptide combination, nano-combination system partly aligned the in vivo behaviors of combined peptides and enhanced peptide accumulation in lesion neurons by the guidance of targeting peptide CGN and Tet1, facilitating the therapeutic performance of peptide combination. Further, to maximize the therapeutic potential of nano-combination system, the combination ratio and mode were screened by the quantitative evaluation with combination index and U test, respectively, in vitro and in vivo. The results showed that the separated-loading CT-NP at the combination molar ratio of 2:1 (H102:NAP), CT-NP/H102 + CT-NP/NAP(2:1), generated the strongest synergistic therapeutic effects on Aß, p-tau and their linkage, and effectually prevented neuroinflammation, reversed the neuronal damage and restored cognitive performance in 3 × Tg-AD transgenic mice. Our studies provide critical data on the effectiveness of nano-combination therapy simultaneously intervening in Aß and p-tau, confirming the promising application of nano-combination strategy in AD treatment.

Cholinergic Neuron Targeting Nanosystem Delivering Hybrid Peptide for Combinatorial Mitochondrial Therapy in Alzheimer's Disease.

Mitochondrial dysfunction in neurons has recently become a promising therapeutic target for Alzheimer's disease (AD). Regulation of dysfunctional mitochondria through multiple pathways rather than antioxidation monotherapy indicates synergistic therapeutic effects. Therefore, we developed a multifunctional hybrid peptide HNSS composed of antioxidant peptide SS31 and neuroprotective peptide S14G-Humanin. However, suitable peptide delivery systems with excellent loading capacity and effective at-site delivery are still absent. Herein, the nanoparticles made of citraconylation-modified poly(ethylene glycol)-poly(trimethylene carbonate) polymer (PEG-PTMC(Cit)) exhibited desirable loading of HNSS peptide through electrostatic interactions. Meanwhile, based on fibroblast growth factor receptor 1(FGFR1) overexpression in both the blood-brain barrier and cholinergic neuron, an FGFR1 ligand-FGL peptide was modified on the nanosystem (FGL-NP(Cit)/HNSS) to achieve 4.8-fold enhanced accumulation in brain with preferred distribution into cholinergic neurons in the diseased region. The acid-sensitive property of the nanosystem facilitated lysosomal escape and intracellular drug release by charge switching, resulting in HNSS enrichment in mitochondria through directing of the SS31 part. FGL-NP(Cit)/HNSS effectively rescued mitochondria dysfunction via the PGC-1α and STAT3 pathways, inhibited Aß deposition and tau hyperphosphorylation, and ameliorated memory defects and cholinergic neuronal damage in 3xTg-AD mice. The work provides a potential platform for targeted cationic peptide delivery, harboring utility for peptide therapy in other neurodegenerative diseases.

[Constructing Brain Aß-Targeting Nanoparticles Loaded with EGCG for Treating Alzheimer's Disease in Mice].

OBJECTIVE: To construct a nanodelivery system surface-modified with RD2 peptide (polypeptide sequence PTLHTHNRRRRR) for brain tissue penetration and ß-amyloid (Aß) binding. Epigallocatechin-3-gallate (EGCG) was selected for encapsulation in the targeted delivery system and its therapeutic potential for Alzheimer's disease (AD) was investigated. METHODS: EGCG-load nanoparticles (NP/EGCG), NP/EGCG with RD2 peptide surface modification (RD2-NP/EGCG), as well as RD2 peptide-modified blank nanoparticles (RD2-NP) were prepared and characterized. Thioflavin T assay was done to assess the ability of RD2-NP to bind with Aß and ex vivo imaging was conducted to evaluate the distribution of RD2-NP in brain lesion sites. The AD mice model was established by injecting oligomeric Aß 42 in the bilateral hippocampi of ICR mice. Then AD mice were administered intravenously through the tail vein with normal saline, EGCG solution, NP/EGCG or RD2-NP/EGCG for 28 d, respectively, and the Morris water maze tests were performed to assess the spatial memory of mice. Subsequently, RT-PCR method was used to determine the mRNA levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in the hippocampus of the mice, and the morphological changes of hippocampal neurons were observed with Nissl staining. Additionally, the pathological changes of heart, liver, spleen, lung, and kidney were characterized by hematoxylin-eosin (HE) staining. RESULTS: The particle diameter of the prepared RD2-NP/EGCG was (204.83±2.80) nm and the zeta potential was -23.88 mV. The encapsulation efficiency and drug loading capacity were 94.39% and 5.90%, respectively. The RD2 peptide modification has no significant effect on the physiochemical properties of the nanoparticles. RD2-NP had good Aß binding ability, and it could be concentrated in hippocampus and cerebral cortex, the most common Aß deposition sites. The four-week RD2-NP/EGCG treatment significantly decreased the expression of the pro-inflammatory cytokine TNF-α and IL-1ß, restored neuronal losses and hippocampal damage, and ameliorated spatial memory impairment in AD model mice. Moreover, treatment with the RD2-NP/EGCG did not present organ toxicity. CONCLUSION: Surface modified RD2 peptide nanodelivery system can efficiently deliver drugs to AD lesions and improve the therapeutic effect of EGCG on AD.

'Adhesion and release' nanoparticle-mediated efficient inhibition of platelet activation disrupts endothelial barriers for enhanced drug delivery in tumors.

Activated platelets can maintain tumor vessel integrity, thereby leading to limited tumor perfusion and suboptimal antitumor efficacy of nanoparticle-based drugs. Herein, to disrupt the tumor vascular endothelial barriers by inhibiting the transformation of resting platelets to activated platelets, a TM33 peptide-modified gelatin/oleic acid nanoparticle loaded with tanshinone IIA (TNA) was constructed (TM33-GON/TNA). TM33-GON/TNA could adhere to activated platelets by specifically binding their superficial P-selectin and release TNA into the extracellular space under matrix metalloproteinase-2 (MMP-2) stimulation, leading to local high TNA exposure. Thus, platelet activation, adhesion, and aggregation, which occur in the local environment around the activated platelets, were efficiently inhibited, leading to leaky tumor endothelial junctions. Accordingly, TM33-GON/TNA treatment resulted in a 3.2-, 4.0-, and 11.2-fold increase in tumor permeation of Evans blue (macromolecule marker), small-sized Nab-PTX (~10 nm), and large-sized DOX-Lip (~100 nm), respectively, without elevating drug delivery to normal tissues. Ultimately, TM33-GON/TNA plus Nab-PTX exhibited superior antitumor efficacy with minimal side effects in a murine pancreatic cancer model. In addition, the TM33-GON/TNA-induced disrupted endothelial junctions were reversibly restored after the treatment because the number of platelets was not reduced, which implies a low risk of the undesirable systemic bleeding. Hence, TM33-GON/TNA represents a clinically translational adjuvant therapy to magnify the antitumor efficacy of existing nanomedicines in pancreatic cancer and other tumors with tight endothelial lining.

Neuronal mitochondria-targeted micelles relieving oxidative stress for delayed progression of Alzheimer's disease.

Mitochondrial dysfunction is an early event of Alzheimer's disease (AD), contributes the onset and progression of AD, and may represent an effective therapeutic target for AD intervention. Since mitochondria in central neurons are more susceptible to oxidative damage than non-neuronal cells, the specific delivery of the antioxidants to the mitochondria of impaired central neurons is crucial for achieving the therapeutic effect on AD. Here, we prepare the neuronal mitochondria-targeted micelles (CT-NM) through co-decoration with neural cell adhesion molecule (NCAM) mimetic peptide C3 for brain neuron specific binding and the triphenylphosphonium (TPP) for mitochondrial targeting. CT-NM significantly increase the encapsulated resveratrol's concentration in the neuronal mitochondria compared to the micelles modified with C3 only or the resveratrol solution. The resveratrol-loaded CT-NM alleviate the oxidative stress in the neuronal cells, resulting in stabilization of the dynamic balance of mitochondrial fission and fusion. The targeted micelles restore the cognitive performance in APP/PS1 transgenic mice to the level of wild-type mice characterized by up-regulation of sirtuin 1 expression, reduction of amyloid deposition and tau hyperphosphorylation, protection of synapses and inhibition of microglia proliferation. The results demonstrate the delay of the progression of AD through reversing neuronal mitochondrial dysfunction by the targeted delivery of antioxidants.

A dual-ligand fusion peptide improves the brain-neuron targeting of nanocarriers in Alzheimer's disease mice.

The presence of blood-brain barrier (BBB) and specificity of neuron targeting remain two challenges in the effective delivery of nanotherapeutics for the treatment of Alzheimers disease (AD). Traditional strategy of nanocarriers for AD treatment involves co-decoration of both BBB-penetrating ligand and neuron-targeting ligand on the surface of the nanoparticles for "dual-stage" targeted delivery. Instead, we design and optimize a fusion peptide TPL comprising a BBB-penetrating peptide TGN and a neuron binding peptide Tet1 through a four-glycine linker. Compared to the mono-ligand Tet1 or CGN which is the retro-inverso isomer of TGN with higher brain targeting than TGN, the dual-ligand fusion peptide TPL has preferable blood stability and enhanced structural flexibility, resulting in higher binding affinity to either GT1b ganglioside receptor or brain capillary endothelial bEnd.3 cells. The TPL-modified nanoparticles (TPL-NP) increased the BBB-penetration and neuron-targeting efficacy than the nanoparticles co-decorated with the two mono-ligands. Encapsulation of a neuroprotective peptide NAP, TPL-NP significantly enhance reactive oxygen species scavenging ability and effectively protect microtubule from Aß25-35-induced neurotoxicity. Meanwhile, TPL-NP inhibit okadaic acid-induced tau aggregation and neuronal apoptosis. Administration of TPL-NP in AD mice also significantly improves the cognitive performance, down-regulates the tau phosphorylation level, promotes axonal transport and attenuates microgliosis. Taken together, this work demonstrates that the rationally designed dual-ligand fusion peptides can greatly improve the delivery of drugs to the AD lesions, thereby markedly enhancing the efficacy of AD treatment.

Small interfering RNA delivery to the neurons near the amyloid plaques for improved treatment of Alzheimer׳s disease.

Gene therapy represents a promising treatment for the Alzheimer׳s disease (AD). However, gene delivery specific to brain lesions through systemic administration remains big challenge. In our previous work, we have developed an siRNA nanocomplex able to be specifically delivered to the amyloid plaques through surface modification with both CGN peptide for the blood-brain barrier (BBB) penetration and QSH peptide for ß-amyloid binding. But, whether the as-designed nanocomplex could indeed improve the gene accumulation in the impaired neuron cells and ameliorate AD-associated symptoms remains further study. Herein, we prepared the nanocomplexes with an siRNA against ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1), the rate-limiting enzyme of Aß production, as the therapeutic siRNA of AD. The nanocomplexes exhibited high distribution in the Aß deposits-enriched hippocampus, especially in the neurons near the amyloid plaques after intravenous administration. In APP/PS1 transgenic mice, the nanocomplexes down-regulated BACE1 in both mRNA and protein levels, as well as Aß and amyloid plaques to the level of wild-type mice. Moreover, the nanocomplexes significantly increased the level of synaptophysin and rescued memory loss of the AD transgenic mice without hematological or histological toxicity. Taken together, this work presented direct evidences that the design of precise gene delivery to the AD lesions markedly improves the therapeutic outcome.